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Sample records for organic iodine removal

  1. Eliminating iodine deficiency: obstacles and their removal.

    PubMed

    Padilla, Carmencita David; Fagela-Domingo, Carmelita

    2008-12-01

    Iodine deficiency remains a global concern for developing countries and some industrialised countries. Iodine deficiency is the most common cause of preventable mental retardation, posing a threat to the social and economic development of countries. Initiatives were developed and instituted to accelerate progress to achieve the goal of universal salt iodisation (USI). However, these efforts were not successful in eliminating iodine deficiency disorders (IDD) in some countries. Every year, 50 million children are born without the protection that iodine offers to the growing brain and body and about 18 million suffer some significant degree of mental impairment. The World Health Organization (WHO), United Nations Children's Fund (UNICEF) and non-governmental organisations assist to ensure that populations at risk have access to iodised salt. This paper will review the highlights of iodine deficiency and present the experiences in the various countries in Asia, i.e. assessments of the situation, action plans, and obstacles to implementation. PMID:19904447

  2. METHOD OF REMOVING RADIOACTIVE IODINE FROM GASES

    DOEpatents

    Silverman, L.

    1962-01-23

    A method of removing radioactive iodine from a gaseous medium is given in which the gaseous medium is adjusted to a temperature not exceeding 400 deg C and then passed over a copper fibrous pad having a coating of cupric sulfide deposited thereon. An ionic exchange on the pad results in the formation of cupric iodide and the release of sulfur. (AEC)

  3. Method and apparatus for removing iodine from a nuclear reactor coolant

    DOEpatents

    Cooper, Martin H.

    1980-01-01

    A method and apparatus for removing iodine-131 and iodine-125 from a liquid sodium reactor coolant. Non-radioactive iodine is dissolved in hot liquid sodium to increase the total iodine concentration. Subsequent precipitation of the iodine in a cold trap removes both the radioactive iodine isotopes as well as the non-radioactive iodine.

  4. METHOD OF REMOVING IODINE FROM GASES AND FILTER MEDIUM THEREFOR

    DOEpatents

    Silverman, L.

    1961-08-01

    A method for the removal of iodine from large gas volumes is described. The gaseous medium is heated to a temperature not exceeding 400 deg C. Water vapor is then added to the medium in approximate amounts of 1 lb/cu ft of the medium. The medium is then passed through a porous copper fibrous pad having deposited thereon a coating of silver, the silver coating being treated with hydrogen sulfide forming a layer of silver sulfide. (AEC)

  5. Method for gettering organic, inorganic and elemental iodine in aqueous solutions

    DOEpatents

    Beahm, Edward C.; Shockley, William E.

    1990-07-03

    A process for the removal of iodine from aqueous solutions, particularly the trapping of radioactive iodine to mitigate damage resulting from accidents or spills associated with nuclear reactors, by exposing the solution to well dispersed silver carbonate which reacts with the iodine and iodides, thereby gettering iodine and iodine compounds from solution. The iodine is not only removed from solution but also from the contiguous vapor.

  6. Method for gettering organic, inorganic and elemental iodine in aqueous solutions

    DOEpatents

    Beahm, Edward C.; Shockley, William E.

    1990-01-01

    A process for the removal of iodine from aqueous solutions, particularly the trapping of radioactive iodine to mitigate damage resulting from accidents or spills associated with nuclear reactors, by exposing the solution to well dispersed silver carbonate which reacts with the iodine and iodides, thereby gettering iodine and iodine compounds from solution. The iodine is not only removed from solution but also from the contiguous vapor.

  7. Iodine

    MedlinePlus

    ... 6 weeks increases the healing rate. Also, applying povidone-iodine in addition to compression seems help heal ... Catheter-related infection. Some evidence suggests that applying povidone-iodine reduces the risk of blood stream infections ...

  8. Iodine

    MedlinePlus

    ... the amount depends on the iodine in the soil where they grew and in any fertilizer that ... babies. People living in regions with iodine-deficient soils who eat mostly local foods. These soils produce ...

  9. Iodine

    USGS Publications Warehouse

    Krukowski, S.T.

    2006-01-01

    In descending order, Chile, Japan and the United States have the largest iodine reserves. Chile produces iodine from iodate minerals while Japan and the United States produce it from sodium iodide solutions found in underground iodide solutions. Iodine is also produced from subterranean brines in Azerbaijan, Russia, Turkmenista, Indonesia and Uzbekistan. In 2005, iodine prices increased sharply to US$19 to US$23 then leveled off at US$23 to US$25.

  10. Determination of iodide, iodate and organo-iodine in waters with a new total organic iodine measurement approach.

    PubMed

    Gong, Tingting; Zhang, Xiangru

    2013-11-01

    The dissolved iodine species that dominate aquatic systems are iodide, iodate and organo-iodine. These species may undergo transformation to one another and thus affect the formation of iodinated disinfection byproducts during disinfection of drinking waters or wastewater effluents. In this study, a fast, sensitive and accurate method for determining these iodine species in waters was developed by derivatizing iodide and iodate to organic iodine and measuring organic iodine with a total organic iodine (TOI) measurement approach. Within this method, organo-iodine was determined directly by TOI measurement; iodide was oxidized by monochloramine to hypoiodous acid and then hypoiodous acid reacted with phenol to form organic iodine, which was determined by TOI measurement; iodate was reduced by ascorbic acid to iodide and then determined as iodide. The quantitation limit of organo-iodine or sum of organo-iodine and iodide or sum of organo-iodine, iodide and iodate was 5 μg/L as I for a 40 mL water sample (or 2.5 μg/L as I for an 80 mL water sample, or 1.25 μg/L as I for a 160 mL water sample). This method was successfully applied to the determination of iodide, iodate and organo-iodine in a variety of water samples, including tap water, seawater, urine and wastewater. The recoveries of iodide, iodate and organo-iodine were 91-109%, 90-108% and 91-108%, respectively. The concentrations and distributions of iodine species in different water samples were obtained and compared.

  11. Photovoltaic effect in organic polymer-iodine complex

    NASA Technical Reports Server (NTRS)

    Hermann, A. M.; Rembaum, A.

    1967-01-01

    Certain charge transfer complexes formed from organic polymers and iodine generate appreciable voltages at relatively low impedances upon exposure to light. These films show promise in applications requiring chemically and electrically stable films as detectors of optical radiation and as energy converters in photovoltaic cells.

  12. Formation of organic iodine supplied as iodide in a soil-water system in Chiba, Japan.

    PubMed

    Shimamoto, Yoko S; Takahashi, Yoshio; Terada, Yasuko

    2011-03-15

    Speciation of iodine in a soil-water system was investigated to understand the mechanism of iodine mobility in surface environments. Iodine speciation in soil and pore water was determined by K-edge XANES and HPLC-ICP-MS, respectively, for samples collected at a depth of 0-12 cm in the Yoro area, Chiba, Japan. Pore water collected at a 0-6 cm depth contained 50%-60% of organic iodine bound to dissolved organic matter, with the other portion being I(-). At a 9-12 cm depth, 98% of iodine was in the form of dissolved I(-). In contrast, XANES analysis revealed that iodine in soil exists as organic iodine at all depths. Iodine mapping of soil grains was obtained using micro-XRF analysis, which also indicated that iodine is bound to organic matter. The activity of laccase, which has the ability to oxidize I(-) to I(2), was high at the surface of the soil-water layer, suggesting that iodide oxidizing enzymes can promote iodine organification. The distribution coefficient of organic iodine in the soil-water system was more than 10-fold greater than that of iodide. Transformation of inorganic iodine to organic iodine plays an important role in iodine immobilization, especially in a surface soil-water system.

  13. Urinary iodine excretion rates following intrathecal injections of iodinated organic carbonates.

    PubMed

    Staubus, A E; Newton, B N; Klein, L C; Weinrib, A B; Kunz, A L

    1979-11-01

    Oily iodinated organic carbonates were investigated for use as myelographic media. The urinary excretion of total iodine was used to monitor the apparent elimination rate of these compounds from the subarachnoid space. Within the chain length series of C2-C6, the decrease of elimination rates and disposition rate constants with increasing chain length was demonstrated. This observation is consistent with a dissolution rate-limited elimination model. Such a model was derived and successfully NONLIN computer fitted to the observed elimination data. The model-derived parameter of clearance from the cerebrospinal fluid through the lipid "blood-brain barrier" correlated well with the compound's water solubilities and projected octanol-water partition coefficients. Additional compounds need to be tested to evaluate the postulated model system. PMID:583163

  14. Removal of elemental mercury by iodine-modified rice husk ash sorbents.

    PubMed

    Zhao, Pengfei; Guo, Xin; Zheng, Chuguang

    2010-01-01

    Iodine-modified calcium-based rice husk ash sorbents (I2/CaO/RHA) were synthesized and characterized by X-ray diffraction, X-ray fluorescence, and N2 isotherm adsorption/desorption. Adsorption experiments of vapor-phase elemental mercury (Hg0) were performed in a laboratory-scale fixed-bed reactor. I2/CaO/RHA performances on Hg0 adsorption were compared with those of modified Ca-based fly ash sorbents (I2/CaO/FA) and modified fly ash sorbents (I2/FA). Effects of oxidant loading, supports, pore size distribution, iodine impregnation modes, and temperature were investigated as well to understand the mechanism in capturing Hg0. The modified sorbents exhibited reasonable efficiency for Hg0 removal under simulated flue gas. The surface area, pore size distribution, and iodine impregnation modes of the sorbents did not produce a strong effect on Hg0 capture efficiency, while fair correlation was observed between Hg0 uptake capacity and iodine concentration. Therefore, the content of I2 impregnated on the sorbents was identified as the most important factor influencing the capacity of these sorbents for Hg0 uptake. Increasing temperature in the range of 80-140 degrees C caused a rise in Hg0 removal. A reaction mechanism that may explain the experimental results was presumed based on the characterizations and adsorption study. PMID:21235196

  15. Iodination of organic substrates with halide salts and H2O2 using an organotelluride catalyst.

    PubMed

    Higgs, D E; Nelen, M I; Detty, M R

    2001-02-01

    [figure: see text] Organotelluride 1 is a water-soluble catalyst for the oxidation of iodide with hydrogen peroxide in pH 6 phosphate buffer. In two-phase systems, organic substrates are efficiently iodinated using 0.8 mol % of catalyst. Water-soluble substrates are iodinated without an organic cosolvent.

  16. Removal of water and iodine by solid sorbents: adsorption isotherms and kinetics

    SciTech Connect

    Lin, R.; Tavlarides, L.L.

    2013-07-01

    Tritium and iodine-129 are two major radioactive elements that are present in off-gases from spent fuel reprocessing plants. Adsorption by solid sorbents is the state-of-the-art technique for removal of these species from off-gases. Modeling and simulating adsorption processes require accurate adsorption equilibrium and kinetic data to permit reasonable estimates of process parameters. We have developed a continuous flow single-pellet adsorption system to gather accurate adsorption equilibrium and kinetic data for adsorption of water by molecular sieve 3A and for adsorption of iodine by silver exchanged mordenite. In this paper, the design of the water and iodine adsorption experimental systems are briefly described and results of water adsorption experiments are presented and discussed. Water uptake curves are fitted with the linear-driving force (LDF) model and the shrinking-core model to determine kinetic parameters. It is shown that the kinetics of water adsorption on zeolite 3A under current experimental conditions is controlled by both the external film resistance and the macro-pore diffusion and can be predicted by both the LDF model and the shrinking-core model with the former one performing slightly better. Preliminary results from iodine adsorption experiments will be presented in the conference.

  17. Selective Identification of Organic Iodine Compounds Using Liquid Chromatography-High Resolution Mass Spectrometry.

    PubMed

    Yang, Yijun; Peng, Yue'e; Chang, Qing; Dan, Conghui; Guo, Wei; Wang, Yanxin

    2016-01-19

    A method to selectively and sensitively detect organic iodine compounds and identify their structures has been developed using liquid chromatography-high resolution mass spectrometry (LC-HRMS). Using extracted ion chromatograms of product ions (iodine ion) collected on a rapid scanning quadrupole orbitrap mass spectrometer, the retention times of the unknown organic iodine compounds were determined, and the structural information were acquired according to the MS/MS experiments and the matching with reference standards. We have demonstrated the application of this method by identifying unknown organic iodine compounds in seaweed. A total of 28 possible organic iodine peaks were discovered, among them, the accurate mass and element composition of the corresponding precursor ions were identified for 12 peaks, and molecular structures were confirmed for 4 peaks, which were 3-iodo-L-tyrosine, 3,5-diiodo-L-tyrosine, 4-iodophenol, and 2-iodobenzoic acid. This method is expected to lead to the future discovery of new organic iodine compounds via LC-HRMS in different environmental samples, which is crucial for understanding the iodine biogeochemical cycling.

  18. Iodine-124: a promising positron emitter for organic PET chemistry.

    PubMed

    Koehler, Lena; Gagnon, Katherine; McQuarrie, Steve; Wuest, Frank

    2010-04-13

    The use of radiopharmaceuticals for molecular imaging of biochemical and physiological processes in vivo has evolved into an important diagnostic tool in modern nuclear medicine and medical research. Positron emission tomography (PET) is currently the most sophisticated molecular imaging methodology, mainly due to the unrivalled high sensitivity which allows for the studying of biochemistry in vivo on the molecular level. The most frequently used radionuclides for PET have relatively short half-lives (e.g. 11C: 20.4 min; 18F: 109.8 min) which may limit both the synthesis procedures and the time frame of PET studies. Iodine-124 (124I, t1/2 = 4.2 d) is an alternative long-lived PET radionuclide attracting increasing interest for long term clinical and small animal PET studies. The present review gives a survey on the use of 124I as promising PET radionuclide for molecular imaging. The first part describes the production of 124I. The second part covers basic radiochemistry with 124I focused on the synthesis of 124I-labeled compounds for molecular imaging purposes. The review concludes with a summary and an outlook on the future prospective of using the long-lived positron emitter 124I in the field of organic PET chemistry and molecular imaging.

  19. Removal of mercury from solids using the potassium iodide/iodine leaching process

    SciTech Connect

    Klasson, K.T.; Koran, L.J. Jr.; Gates, D.D.; Cameron, P.A.

    1997-12-01

    Potassium iodide (KI) and iodine (I{sub 2}) leaching solutions have been evaluated for use in a process for removing mercury from contaminated mixed waste solids. Most of the experimental work was completed using surrogate waste. During the last quarter of fiscal year 1995, this process was evaluated using an actual mixed waste (storm sewer sediment from the Oak Ridge Y-12 Site). The mercury content of the storm sewer sediment was measured and determined to be approximately 35,000 mg/kg. A solution consisting of 0.2 M I{sub 2} and 0.4 M KI proved to be the most effective leachant used in the experiments when applied for 2 to 4 h at ambient temperature. Over 98% of the mercury was removed from the storm sewer sediment using this solution. Iodine recovery and recycle of the leaching agent were also accomplished successfully. Mathematical model was used to predict the amount of secondary waste in the process. Both surrogate waste and actual waste were used to study the fate of radionuclides (uranium) in the leaching process.

  20. Apparatus Removes Organic Contaminants From Water

    NASA Technical Reports Server (NTRS)

    Akse, James R.; Thompson, John

    1994-01-01

    Catalytic-oxidation apparatus removes low-molecular-weight, polar, nonionizable organic contaminants from wastewater. Wastewater stream, previously treated by multifiltration process, pumped through apparatus for removal of trace organic contaminants. After injection of oxygen, flow preheated and enters catalytic reactor, where organic contaminants broken down into carbon dioxide and water. Carbon dioxide and unused oxygen removed in degasser.

  1. Effectiveness of decanter modifications on organic removal

    SciTech Connect

    Lambert, D.P.

    1992-08-20

    A series of runs were planned in the Precipitate Hydrolysis Experimental Facility (PHEF) at the Savannah River Plant to determine the effectiveness of equipment and process modifications on the PHEF decanter organic removal efficiency. Runs 54-59 were planned to test the effectiveness of spray recirculation, a new decanter, heated organic recirculation and aqueous drawoff on organic removal efficiency in the revised HAN flowsheet. Runs 60-63 were planned to provide a comparison of the original and new decanter designs on organic removal efficiency in the late wash flowsheet without organic recirculation. Operational problems were experienced in both the PHEF and IDMS pilot facilities because of the production of high boiling organics and the low organic removal efficiency of the PHEF decanters. To prevent these problems in the DWPF Salt and Chemical Cells, modifications were proposed to the decanter and flowsheet to maximize the organic removal efficiency and minimize production of high boiling organics.

  2. Influences of impurities on iodine removal efficiency of silver alumina adsorbent

    SciTech Connect

    Fukasawa, Tetsuo; Funabashi, Kiyomi; Kondo, Yoshikazu

    1997-08-01

    Silver impregnated alumina adsorbent (AgA), which was developed for iodine removal from off-gas of nuclear power and reprocessing plants has been tested laying emphasis on investigation of the influences gaseous impurities have on adsorbent chemical stability and iodine removal efficiency. The influences of the major impurities such as nitrogen oxides and water vapor were checked on the chemical state of impregnated silver compound (AgNO{sub 3}) and decontamination factor (DF) value. At 150{degrees}C, a forced air flow with 1.5% nitrogen oxide (NO/NO{sub 2}=1/1) reduced silver nitrate to metallic silver, whereas pure air and air with 1.5% NO{sub 2} had no effect on the chemical state of silver. Metallic silver showed a lower DF value for methyl iodide in pure air (without impurities) than silver nitrate and the lower DF of metallic silver was improved when impurities were added. At 40{degrees}C, a forced air flow with 1.5% nitrogen dioxide (NO{sub 2}) increased the AgA weight by about 20%, which was caused by the adsorption of nitric acid solution on the AgA surface. AgA with l0wt% silver showed higher weight increase than that with 24wt% silver which had lower porosity. Adsorption of acid solution lowered the DF value, which would be due to the hindrance of contact between methyl iodide and silver. The influences of other gaseous impurities were also investigated and AgA showed superior characteristics at high temperatures. 14 refs., 11 figs.

  3. Investigation of ionic liquids for efficient removal and reliable storage of radioactive iodine: a halogen-bonding case.

    PubMed

    Yan, Chuanyu; Mu, Tiancheng

    2014-03-21

    A series of ionic liquids (ILs) were investigated for removal and storage of radioactive iodine (I2) waste released by nuclear power plants. The I2 removal efficiency of ILs was dependent upon the anion species while cation species seemed to have little influence. Particularly, the I2 removal efficiency of [Bmim][Br] was higher than 96% in 5 hours. The nitrogen gas sweeping tests showed that [Bmim][Br] holds I2 tightly, and the leak of I2 from it was negligible under daily life conditions. Spectroscopy studies indicated that high removal efficiencies and storage reliability of ILs were attributed to halogen bonding (XB). PMID:24492960

  4. Removal efficiency of water purifier and adsorbent for iodine, cesium, strontium, barium and zirconium in drinking water.

    PubMed

    Sato, Itaru; Kudo, Hiroaki; Tsuda, Shuji

    2011-01-01

    The severe incident of Fukushima Daiichi Nuclear Power Station has caused radioactive contamination of environment including drinking water. Radioactive iodine, cesium, strontium, barium and zirconium are hazardous fission products because of the high yield and/or relatively long half-life. In the present study, 4 pot-type water purifiers and several adsorbents were examined for the removal effects on these elements from drinking water. Iodide, iodate, cesium and barium were removed by all water purifiers with efficiencies about 85%, 40%, 75-90% and higher than 85%, respectively. These efficiencies lasted for 200 l, which is near the recommended limits for use of filter cartridges, without decay. Strontium was removed with initial efficiencies from 70% to 100%, but the efficiencies were slightly decreased by use. Zirconium was removed by two models, but hardly removed by the other models. Synthetic zeolite A4 efficiently removed cesium, strontium and barium, but had no effect on iodine and zirconium. Natural zeolite, mordenite, removed cesium with an efficiency as high as zeolite A4, but the removal efficiencies for strontium and barium were far less than those of zeolite A4. Activated carbon had little removal effects on these elements. In case of radioactive contamination of tap water, water purifiers may be available for convenient decontamination of drinking water in the home. PMID:22129747

  5. Removal efficiency of water purifier and adsorbent for iodine, cesium, strontium, barium and zirconium in drinking water.

    PubMed

    Sato, Itaru; Kudo, Hiroaki; Tsuda, Shuji

    2011-01-01

    The severe incident of Fukushima Daiichi Nuclear Power Station has caused radioactive contamination of environment including drinking water. Radioactive iodine, cesium, strontium, barium and zirconium are hazardous fission products because of the high yield and/or relatively long half-life. In the present study, 4 pot-type water purifiers and several adsorbents were examined for the removal effects on these elements from drinking water. Iodide, iodate, cesium and barium were removed by all water purifiers with efficiencies about 85%, 40%, 75-90% and higher than 85%, respectively. These efficiencies lasted for 200 l, which is near the recommended limits for use of filter cartridges, without decay. Strontium was removed with initial efficiencies from 70% to 100%, but the efficiencies were slightly decreased by use. Zirconium was removed by two models, but hardly removed by the other models. Synthetic zeolite A4 efficiently removed cesium, strontium and barium, but had no effect on iodine and zirconium. Natural zeolite, mordenite, removed cesium with an efficiency as high as zeolite A4, but the removal efficiencies for strontium and barium were far less than those of zeolite A4. Activated carbon had little removal effects on these elements. In case of radioactive contamination of tap water, water purifiers may be available for convenient decontamination of drinking water in the home.

  6. Estimating organic micro-pollutant removal potential of activated carbons using UV absorption and carbon characteristics.

    PubMed

    Zietzschmann, Frederik; Altmann, Johannes; Ruhl, Aki Sebastian; Dünnbier, Uwe; Dommisch, Ingvild; Sperlich, Alexander; Meinel, Felix; Jekel, Martin

    2014-06-01

    Eight commercially available powdered activated carbons (PAC) were examined regarding organic micro-pollutant (OMP) removal efficiencies in wastewater treatment plant (WWTP) effluent. PAC characteristic numbers such as B.E.T. surface, iodine number and nitrobenzene number were checked for their potential to predict the OMP removal of the PAC products. Furthermore, the PAC-induced removal of UV254 nm absorption (UVA254) in WWTP effluent was determined and also correlated with OMP removal. None of the PAC characteristic numbers can satisfactorily describe OMP removal and accordingly, these characteristics have little informative value on the reduction of OMP concentrations in WWTP effluent. In contrast, UVA254 removal and OMP removal correlate well for carbamazepine, diclofenac, and several iodinated x-ray contrast media. Also, UVA254 removal can roughly describe the average OMP removal of all measured OMP, and can accordingly predict PAC performance in OMP removal. We therefore suggest UVA254 as a handy indicator for the approximation of OMP removal in practical applications where direct OMP concentration quantification is not always available. In continuous operation of large-scale plants, this approach allows for the efficient adjustment of PAC dosing to UVA254, in order to ensure reliable OMP removal whilst minimizing PAC consumption. PMID:24651017

  7. Iodine oxide in the global marine boundary layer: inorganic versus organic sources

    NASA Astrophysics Data System (ADS)

    Prados-Roman, Cristina; Cuevas, Carlos; Mahajan, Anoop; Fernandez, Rafael; Saiz-Lopez, Alfonso

    2014-05-01

    In the last decades iodine has been object of increasing interest in atmospheric chemistry due to its link to the oxidizing capacity of the atmosphere, the NOx and HOx partitioning and the formation of ultra-fine particles. Recently laboratory and numerous fieldwork efforts have been carried out trying to assess the sources and sinks of reactive iodine in the open marine environment. Within the framework of the Malaspina expedition, in 2010-2011 the Spanish research vessel Hesperides circumnavigated the world aiming at investigating the biogeochemistry, physical oceanography and microbiological biodiversity of the oceans from a multidisciplinary approach. During that 7-months campaign throughout the Atlantic, Indian and Pacific oceans, a MAX-DOAS system was deployed, along with a surface ozone instrument, in order to monitor the geographical distribution of relevant reactive iodine compounds such IO. Complementing this extensive dataset with results from previous works in the Eastern Pacific Ocean, we show not only the ubiquity of iodine oxide in the open marine boundary layer (MBL) ranging between 0.3-1 pptv levels, but also provide what is- to our knowledge- the most comprehensive global map of the of IO and O3 distribution in the subpolar MBL. Ultimately, by means of a photochemical model, we will address the contribution of inorganic and organic iodine sources to the measured levels of IO.

  8. Atmospheric iodine levels influenced by sea surface emissions of inorganic iodine

    NASA Astrophysics Data System (ADS)

    Carpenter, Lucy J.; MacDonald, Samantha M.; Shaw, Marvin D.; Kumar, Ravi; Saunders, Russell W.; Parthipan, Rajendran; Wilson, Julie; Plane, John M. C.

    2013-02-01

    Naturally occurring bromine- and iodine-containing compounds substantially reduce regional, and possibly even global, tropospheric ozone levels. As such, these halogen gases reduce the global warming effects of ozone in the troposphere, and its capacity to initiate the chemical removal of hydrocarbons such as methane. The majority of halogen-related surface ozone destruction is attributable to iodine chemistry. So far, organic iodine compounds have been assumed to serve as the main source of oceanic iodine emissions. However, known organic sources of atmospheric iodine cannot account for gas-phase iodine oxide concentrations in the lower troposphere over the tropical oceans. Here, we quantify gaseous emissions of inorganic iodine following the reaction of iodide with ozone in a series of laboratory experiments. We show that the reaction of iodide with ozone leads to the formation of both molecular iodine and hypoiodous acid. Using a kinetic box model of the sea surface layer and a one-dimensional model of the marine boundary layer, we show that the reaction of ozone with iodide on the sea surface could account for around 75% of observed iodine oxide levels over the tropical Atlantic Ocean. According to the sea surface model, hypoiodous acid--not previously considered as an oceanic source of iodine--is emitted at a rate ten-fold higher than that of molecular iodine under ambient conditions.

  9. Porous supramolecular networks constructed of one-dimensional metal-organic chains: carbon dioxide and iodine capture.

    PubMed

    Yu, Fei; Li, Dan-Dan; Cheng, Lin; Yin, Zheng; Zeng, Ming-Hua; Kurmoo, Mohamedally

    2015-02-16

    In search of porous materials for selective sorption and iodine inclusion, we have found two networks made of chains with a kink at the metal nodes held together by supramolecular interactions (H-bond and π···π stacking). The solvent can be removed and replaced reversibly without loss of crystallinity, as demonstrated by single-crystal-to-single-crystal crystallography. In contrast, iodine uptake degrades the crystallinity to amorphous, and it regains its crystalline state after removal of the iodine at 200 °C. Slight differences in behavior of the sorption and inclusion properties between the tetrahedral metal nodes, Zn and Co, are associated with the size of the nodes. An important feature is the extent of iodine that can be included between the chains that is doubled with temperature from 30 to 100 °C and exceeds the weight in mass of the compounds.

  10. Organ distribution of Corynebacterium parvum labeled with iodine-125.

    PubMed

    Dimitrov, N V; Greenberg, C S; Denny, T

    1977-02-01

    Administration of iv, ip, single sc, multiple sc, and footpad injections of [125I]Corynebacterium parvum in mice revealed different patterns of radioactive vaccine distribution in various organs. High deposition and retention were found in the liver, spleen, and gastrointestinal tract and less in the lungs, kidneys, thymus, and bone marrow. Control animals given 125I showed very rapid clearance of the isotope and no retention in the organs. The pattern of distribution of [125I]C. parvum could be useful when protocols for clinical trials are designed.

  11. Microbial removal of hazardous organic compounds

    SciTech Connect

    Kobayashi, H.; Rittman, B.E.

    1982-03-01

    An in-depth evaluation of the potential for microorganisms to remove anthropogenic organic compounds, mainly priority pollutants and related compounds, is presented. The evaluation indicates that use of properly selected populations of microbes, and the maintenance of environmental conditions most conducive to their metabolism, can be an important means of improving biological treatment of organic wastes. One major theme is that microorganisms not normally associated with biological waste treatment have potential advantages when the removal of anthropogenic compounds is the goal. An extensive summary of examples of anthropogenic compounds and microorganisms that can attack them is presented in tabular form. A second table lists the selective uses of microorganisms for removal of different anthropogenic compounds. (KRM)

  12. Electrolytic trapping of iodine from process gas streams

    DOEpatents

    Horner, Donald E.; Mailen, James C.; Posey, Franz A.

    1977-01-25

    A method for removing molecular, inorganic, and organic forms of iodine from process gas streams comprises the electrolytic oxidation of iodine in the presence of cobalt-III ions. The gas stream is passed through the anode compartment of a partitioned electrolytic cell having a nitric acid anolyte containing a catalytic amount of cobalt to cause the oxidation of effluent iodine species to aqueous soluble species.

  13. Impact of removing iodised salt on children's goitre status in areas with excessive iodine in drinking-water.

    PubMed

    Lv, Shengmin; Xu, Dong; Wang, Yuchun; Jun, Zhao; Jia, Lihui; Du, Yonggui

    2015-01-14

    The impact of removing iodised salt on children's goitre status in a high-iodine area (HIA) remains unclear. The aim of the present study was to explore the changes in the prevalence of goitre in children after removing iodised salt from their diet. For this purpose, three towns with the median water iodine content of 150-300 μg/l were selected randomly in Hengshui City, Hebei Province, China. A total of 452 and 459 children were randomly selected from the three towns in order to measure thyroid volume by ultrasound before and after removing iodised salt, respectively. Their goitre status was judged using the criteria of age-specific thyroid volume recommended by the WHO. After removing iodised salt, the overall median urinary iodine content (MUIC) of children decreased from 518 (interquartile range (IQR) 347-735) to 416 (IQR 274-609) μg/l. The MUIC of children across sex and age group decreased significantly except for the age group of 9 years. The overall prevalence of goitre in the three towns significantly decreased from 24·56% (n 111/452) to 5·88% (n 27/459) (P< 0·001). Goitre prevalence in children aged 8-10 years decreased from 33·70% (n 31/92), 23·32% (n 45/193) and 20·96% (n 35/167) to 6·10% (n 10/164), 5·52% (n 9/163) and 6·06% (n 8/132), respectively. Goitre prevalence in boys and girls decreased from 27·05% (n 66/244) and 21·63% (n 45/208) to 6·66% (n 15/226) and 5·15% (n 12/233), respectively. The decreases in the prevalence of goitre in children across sex and age group were all statistically significant. The present study revealed that goitre prevalence in children decreased significantly after removing iodised salt from their diet for about 1·5 years in the HIA in Hebei Province.

  14. Large Scale Solid Phase Synthesis of Peptide Drugs: Use of Commercial Anion Exchange Resin as Quenching Agent for Removal of Iodine during Disulphide Bond Formation

    PubMed Central

    Reddy, K. M. Bhaskara; Kumari, Y. Bharathi; Mallikharjunasarma, Dokka; Bulliraju, Kamana; Sreelatha, Vanjivaka; Ananda, Kuppanna

    2012-01-01

    The S-acetamidomethyl (Acm) or trityl (Trt) protecting groups are widely used in the chemical synthesis of peptides that contain one or more disulfide bonds. Treatment of peptides containing S-Acm protecting group with iodine results in simultaneous removal of the sulfhydryl protecting group and disulfide formation. However, the excess iodine needs to be quenched or adsorbed as quickly as possible after completion of the disulfide bond formation in order to minimize side reactions that are often associated with the iodination step. We report here a simple method for simultaneous quenching and removal of iodine and isolation of disulphide bridge peptides. The use of excess inexpensive anion exchange resin to the oxidized peptide from the aqueous acetic acid/methanol solution affords quantitative removal of iodine and other color impurities. This improves the resin life time of expensive chromatography media that is used in preparative HPLC column during the purification of peptide using preparative HPLC. Further, it is very useful for the conversion of TFA salt to acetate in situ. It was successfully applied commercially, to the large scale synthesis of various peptides including Desmopressin, Oxytocin, and Octreotide. This new approach offers significant advantages such as more simple utility, minimal side reactions, large scale synthesis of peptide drugs, and greater cost effectiveness. PMID:23118772

  15. Natural solar photolysis of total organic chlorine, bromine and iodine in water.

    PubMed

    Abusallout, Ibrahim; Hua, Guanghui

    2016-04-01

    Municipal wastewater has been increasingly used to augment drinking water supplies due to the growing water scarcity. Wastewater-derived disinfection byproducts (DBPs) may negatively affect the aquatic ecosystems and human health of downstream communities during water reuse. The objective of this research was to determine the degradation kinetics of total organic chlorine (TOCl), bromine (TOBr) and iodine (TOI) in water by natural sunlight irradiation. Outdoor solar photolysis experiments were performed to investigate photolytic degradation of the total organic halogen (TOX) formed by fulvic acid and real water and wastewater samples. The results showed that TOX degradation by sunlight irradiation followed the first-order kinetics with half-lives in the range of 2.6-10.7 h for different TOX compounds produced by fulvic acid. The TOX degradation rates were generally in the order of TOI > TOBr ≅ TOCl(NH2Cl) > TOCl(Cl2). High molecular weight TOX was more susceptible to solar photolysis than corresponding low molecular weight halogenated compounds. The nitrate and sulfite induced indirect TOX photolysis rates were less than 50% of the direct photolysis rates under the conditions of this study. Fulvic acid and turbidity in water reduced TOX photodegradation. These results contribute to a better understanding of the fate of chlorinated, brominated and iodinated DBPs in surface waters. PMID:26841230

  16. Natural solar photolysis of total organic chlorine, bromine and iodine in water.

    PubMed

    Abusallout, Ibrahim; Hua, Guanghui

    2016-04-01

    Municipal wastewater has been increasingly used to augment drinking water supplies due to the growing water scarcity. Wastewater-derived disinfection byproducts (DBPs) may negatively affect the aquatic ecosystems and human health of downstream communities during water reuse. The objective of this research was to determine the degradation kinetics of total organic chlorine (TOCl), bromine (TOBr) and iodine (TOI) in water by natural sunlight irradiation. Outdoor solar photolysis experiments were performed to investigate photolytic degradation of the total organic halogen (TOX) formed by fulvic acid and real water and wastewater samples. The results showed that TOX degradation by sunlight irradiation followed the first-order kinetics with half-lives in the range of 2.6-10.7 h for different TOX compounds produced by fulvic acid. The TOX degradation rates were generally in the order of TOI > TOBr ≅ TOCl(NH2Cl) > TOCl(Cl2). High molecular weight TOX was more susceptible to solar photolysis than corresponding low molecular weight halogenated compounds. The nitrate and sulfite induced indirect TOX photolysis rates were less than 50% of the direct photolysis rates under the conditions of this study. Fulvic acid and turbidity in water reduced TOX photodegradation. These results contribute to a better understanding of the fate of chlorinated, brominated and iodinated DBPs in surface waters.

  17. Removal of organic magnesium in coccolithophore calcite

    NASA Astrophysics Data System (ADS)

    Blanco-Ameijeiras, S.; Lebrato, M.; Stoll, H. M.; Iglesias-Rodriguez, M. D.; Méndez-Vicente, A.; Sett, S.; Müller, M. N.; Oschlies, A.; Schulz, K. G.

    2012-07-01

    Coccolithophore calcite refers to the plates of calcium carbonate (CaCO3) produced by the calcifying phytoplankton, coccolithophores. The empirical study of the elemental composition has a great potential in the development of paleoproxies. However, the difficulties to separate coccolithophore carbonates from organic phases hamper the investigation of coccoliths magnesium to calcium ratios (Mg/Ca) in biogeochemical studies. Magnesium (Mg) is found in organic molecules in the cells at concentrations up to 400 times higher than in inorganically precipitated calcite in present-day seawater. The aim of this study was to optimize a reliable procedure for organic Mg removal from coccolithophore samples to ensure reproducibility in measurements of inorganic Mg in calcite. Two baseline methods comprising organic matter oxidations with (1) bleach and (2) hydrogen peroxide (H2O2) were tested on synthetic pellets, prepared by mixing reagent grade CaCO3 with organic matter from the non-calcifying marine algae Chlorella autotrophica and measured with an ICP-AES (inductively coupled plasma-atomic emission spectrometer). Our results show that treatments with a reductive solution [using hydroxylamine-hydrochloride (NH2OH·HCl + NH4OH)] followed by three consecutive oxidations (using H2O2) yielded the best cleaning efficiencies, removing >99% of organic Mg in 24 h. P/Ca and Fe/Ca were used as indicators for organic contamination in the treated material. The optimized protocol was tested in dried coccolithophore pellets from batch cultures of Emiliania huxleyi, Calcidiscus leptoporus and Gephyrocapsa oceanica. Mg/Ca of treated coccolithophores were 0.151 ± 0.018, 0.220 ± 0.040, and 0.064 ± 0.023 mmol/mol, respectively. Comparison with Mg/Ca literature coccolith values, suggests a tight dependence on modern seawater Mg/Ca, which changes as a consequence of different seawater origins (<10%). The reliable determination of Mg/Ca and Sr/Ca, and the low levels of organic contamination

  18. Selective removal of organics for water reclamation

    NASA Technical Reports Server (NTRS)

    Murphy, Oliver J.; Hitchens, G. Duncan; Kaba, Lamine; Verostko, Charles E.

    1990-01-01

    Electrooxidation is a means of removing organic solutes directly from waste waters without the use of chemical expendables. The feasibility of the concept for oxidation of organic impurities common to urine, shower waters and space habitat humidity condensates was demonstrated. Electrooxidation of urine and waste water ersatz was experimentally demonstrated. The electrooxidation principle, reaction kinetics, efficiency, power, size, experimental test results and water reclamation applications are described. Process operating potentials and the use of anodic oxidation potentials that are sufficiently low to avoid oxygen formation and chloride oxidation are also described. The design of a novel electrochemical system that incorporates a proton exchange membrane (PEM) electrolyte is presented based on parametric test data and current fuel cell technology.

  19. Control of radio-iodine at the German reprocessing plant WAK during operation and after shutdown

    SciTech Connect

    Herrmann, F.J.; Herrmann, B.; Kuhn, K.D.

    1997-08-01

    During 20 years of operation 207 metric tons of oxide fuel from nuclear power reactors with 19 kg of iodine-129 had been reprocessed in the WAK plant near Karlsruhe. In January 1991 the WAK Plant was shut down. During operation iodine releases of the plant as well as the iodine distribution over the liquid and gaseous process streams had been determined. Most of the iodine is evolved into the dissolver off-gas in volatile form. The remainder is dispersed over many aqueous, organic and especially gaseous process and waste streams. After shut down of the plant in January 1991, iodine measurements in the off-gas streams have been continued up to now. Whereas the iodine-129 concentration in the dissolver off-gas dropped during six months after shutdown by three orders of magnitude, the iodine concentrations in the vessel ventilation system of the PUREX process and the cell vent system decreased only by a factor of 10 during the same period. Iodine-129 releases of the liquid high active waste storage tanks did not decrease distinctly. The removal efficiencies of the silver impregnated iodine filters in the different off-gas streams of the WAK plant depend on the iodine concentration in the off-gas. The reason of the observed dependence of the DF on the iodine-129 concentration might be due to the presence of organic iodine compounds which are difficult to remove. 13 refs., 3 figs.

  20. Removal efficiency of radioactive cesium and iodine ions by a flow-type apparatus designed for electrochemically reduced water production.

    PubMed

    Hamasaki, Takeki; Nakamichi, Noboru; Teruya, Kiichiro; Shirahata, Sanetaka

    2014-01-01

    The Fukushima Daiichi Nuclear Power Plant accident on March 11, 2011 attracted people's attention, with anxiety over possible radiation hazards. Immediate and long-term concerns are around protection from external and internal exposure by the liberated radionuclides. In particular, residents living in the affected regions are most concerned about ingesting contaminated foodstuffs, including drinking water. Efficient removal of radionuclides from rainwater and drinking water has been reported using several pot-type filtration devices. A currently used flow-type test apparatus is expected to simultaneously provide radionuclide elimination prior to ingestion and protection from internal exposure by accidental ingestion of radionuclides through the use of a micro-carbon carboxymethyl cartridge unit and an electrochemically reduced water production unit, respectively. However, the removability of radionuclides from contaminated tap water has not been tested to date. Thus, the current research was undertaken to assess the capability of the apparatus to remove radionuclides from artificially contaminated tap water. The results presented here demonstrate that the apparatus can reduce radioactivity levels to below the detection limit in applied tap water containing either 300 Bq/kg of 137Cs or 150 Bq/kg of 125I. The apparatus had a removal efficiency of over 90% for all concentration ranges of radio-cesium and -iodine tested. The results showing efficient radionuclide removability, together with previous studies on molecular hydrogen and platinum nanoparticles as reactive oxygen species scavengers, strongly suggest that the test apparatus has the potential to offer maximum safety against radionuclide-contaminated foodstuffs, including drinking water.

  1. Removal Efficiency of Radioactive Cesium and Iodine Ions by a Flow-Type Apparatus Designed for Electrochemically Reduced Water Production

    PubMed Central

    Hamasaki, Takeki; Nakamichi, Noboru; Teruya, Kiichiro; Shirahata, Sanetaka

    2014-01-01

    The Fukushima Daiichi Nuclear Power Plant accident on March 11, 2011 attracted people’s attention, with anxiety over possible radiation hazards. Immediate and long-term concerns are around protection from external and internal exposure by the liberated radionuclides. In particular, residents living in the affected regions are most concerned about ingesting contaminated foodstuffs, including drinking water. Efficient removal of radionuclides from rainwater and drinking water has been reported using several pot-type filtration devices. A currently used flow-type test apparatus is expected to simultaneously provide radionuclide elimination prior to ingestion and protection from internal exposure by accidental ingestion of radionuclides through the use of a micro-carbon carboxymethyl cartridge unit and an electrochemically reduced water production unit, respectively. However, the removability of radionuclides from contaminated tap water has not been tested to date. Thus, the current research was undertaken to assess the capability of the apparatus to remove radionuclides from artificially contaminated tap water. The results presented here demonstrate that the apparatus can reduce radioactivity levels to below the detection limit in applied tap water containing either 300 Bq/kg of 137Cs or 150 Bq/kg of 125I. The apparatus had a removal efficiency of over 90% for all concentration ranges of radio–cesium and –iodine tested. The results showing efficient radionuclide removability, together with previous studies on molecular hydrogen and platinum nanoparticles as reactive oxygen species scavengers, strongly suggest that the test apparatus has the potential to offer maximum safety against radionuclide-contaminated foodstuffs, including drinking water. PMID:25029447

  2. A method to remove intercalates from bromine and iodine intercalated carbon fibers

    NASA Technical Reports Server (NTRS)

    Hung, Ching-Cheh

    1993-01-01

    Upon exposure to room-temperature fluorine, intercalated carbon fibers (containing either bromine alone or iodine and bromine together) become heavier and less stable. For Amoco P-100 graphitized carbon fibers which were intercalated with 18 percent bromine by weight, 1 hr of fluorine exposure results in a large weight increase, but causes only a small decrease in thermal stability. More than l hr of fluorine exposure time results in small additional increases in fiber weight, but significant further decreases in fiber thermal stability. Such phenomena do not occur if the fluorine exposure is at 250 C. These observations suggest the mechanism that at room temperature, fluorine is absorbed quickly by the intercalated fibers and intercalated slowly into the fibers. Most of the original intercalates are replaced by fluorine in the process of fluorine intercalation. Under an inert environment, the bromine intercalated fibers are much more thermally stable. After 800 C vacuum heating for two weeks, the brominated fibers lost about 45 percent of their bromine, and their resistivity increased from 64 omega-cm to a range of 95 to 170 micro omega-cm. This is still much lower than the 300 micro omega-cm value for pristine P-100. For practical purposes, in order to preserve their thermal stability, brominated fibers need to be protected from exposure to fluorine at room temperature, or to any intercalate at a temperature where, upon direct contact to graphite, an intercalation compound can easily be formed.

  3. (Application of selected microorganisms for organic sulfur removal from coal)

    SciTech Connect

    Elmore, B.B.

    1990-06-20

    Research continues on methods for desulfurization of coal using microorganisms. Topics reported on this term include: coal procurement and preparation, microbial removal of pyrite and sulfate, analytical procedures for characterization of total organic sulfur, organic sulfur removal, microbial activity on model coal organosulfur compounds, screening/detection assays, and monitoring of desulfurization activity. (VC)

  4. Laccase-catalyzed oxidation of iodide and formation of organically bound iodine in soils.

    PubMed

    Seki, Miharu; Oikawa, Jun-ichi; Taguchi, Taro; Ohnuki, Toshihiko; Muramatsu, Yasuyuki; Sakamoto, Kazunori; Amachi, Seigo

    2013-01-01

    Laccase oxidizes iodide to molecular iodine or hypoiodous acid, both of which are easily incorporated into natural soil organic matter. In this study, iodide sorption and laccase activity in 2 types of Japanese soil were determined under various experimental conditions to evaluate possible involvement of this enzyme in the sorption of iodide. Batch sorption experiment using radioactive iodide tracer ((125)I(-)) revealed that the sorption was significantly inhibited by autoclaving (121 °C, 40 min), heat treatment (80 and 100 °C, 10 min), γ-irradiation (30 kGy), N(2) gas flushing, and addition of reducing agents and general laccase inhibitors (KCN and NaN(3)). Interestingly, very similar tendency of inhibition was observed in soil laccase activity, which was determined using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) as a substrate. The partition coefficient (K(d): mL g(-1)) for iodide and specific activity of laccase in soils (Unit g(-1)) showed significant positive correlation in both soil samples. Addition of a bacterial laccase with an iodide-oxidizing activity to the soils strongly enhanced the sorption of iodide. Furthermore, the enzyme addition partially restored iodide sorption capacity of the autoclaved soil samples. These results suggest that microbial laccase is involved in iodide sorption on soils through the oxidation of iodide.

  5. Radio-guided occult lesion localisation using iodine 125 Seeds “ROLLIS” to guide surgical removal of an impalpable posterior chest wall melanoma metastasis

    SciTech Connect

    Dissanayake, Shashini; Dissanayake, Deepthi; Taylor, Donna B

    2015-09-15

    Cancer screening and surveillance programmes and the use of sophisticated imaging tools such as positron emission tomography-computed tomography (PET-CT) have increased the detection of impalpable lesions requiring imaging guidance for excision. A new technique involves intra-lesional insertion of a low-activity iodine-125 ({sup 125}I) seed and detection of the radioactive signal in theatre using a hand-held gamma probe to guide surgery. Whilst several studies describe using this method to guide the removal of impalpable breast lesions, only a handful of publications report its use to guide excision of lesions outside the breast. We describe a case in which radio-guided occult lesion localisation using an iodine 125 seed was used to guide excision of an impalpable posterior chest wall metastasis detected on PET-CT.

  6. Comparison of iodinated trihalomethanes formation during aqueous chlor(am)ination of different iodinated X-ray contrast media compounds in the presence of natural organic matter.

    PubMed

    Ye, Tao; Xu, Bin; Wang, Zhen; Zhang, Tian-Yang; Hu, Chen-Yan; Lin, Lin; Xia, Sheng-Ji; Gao, Nai-Yun

    2014-12-01

    Iodinated trihalomethanes (I-THMs) formation during chlorination and chloramination of five iodinated X-ray contrast media (ICM) compounds (iopamidol, iopromide, iodixanol, histodenz, and diatrizoate) in the presence of natural organic matter (NOM) was evaluated and compared. Chlorination and chloramination of ICM in the absence of NOM yielded only a trace amount of I-THMs, while levels of I-THMs were enhanced substantially in raw water samples. With the presence of NOM, the order with respect to the maximum yield of I-THMs observed during chlorination was iopamidol > histodenz > iodixanol > diatrizoate > iopromide. During chloramination, I-THM formation was enhanced for hisodenz, iodixanol, diatrizoate, and iopromide. The order with respect to the maximum yield of I-THMs observed during chloramination was iopamidol > diatrizoate > iodixanol > histodenz > iopromide. With the exception of iopamidol, I-THM formation was favored at relatively low chlorine doses (≤100 μM) during ICM chlorination, and significant suppression was observed with high chlorine doses applied (>100 μM). However, during chloramination, increasing monochloramine dose monotonously increased the yield of I-THMs for the five ICM. During chlorination of iodixanol, histodenz, and diatrizoate, the yields of I-THMs exhibited three distinct trends as the pH increased from 5 to 9, while peak I-THM formation was found at circumneutral pH for chloramination. Increasing bromide concentration not only considerably enhanced the yield of I-THMs but also shifted the I-THMs towards bromine-containing ones and increased the formation of higher bromine-incorporated species (e.g., CHBrClI and CHBr2I), especially in chloramination. These results are of particular interest to understand I-THM formation mechanisms during chlorination and chloramination of waters containing ICM. PMID:25240119

  7. SU-E-I-49: Simulation Study for Removing Scatter Radiation in Cesium-Iodine Based Flat Panel Detector System

    SciTech Connect

    Yoon, Y; Park, M; Kim, H; Kim, K; Kim, J; Morishita, J

    2015-06-15

    Purpose: This study aims to identify the feasibility of a novel cesium-iodine (CsI)-based flat-panel detector (FPD) for removing scatter radiation in diagnostic radiology. Methods: The indirect FPD comprises three layers: a substrate, scintillation, and thin-film-transistor (TFT) layer. The TFT layer has a matrix structure with pixels. There are ineffective dimensions on the TFT layer, such as the voltage and data lines; therefore, we devised a new FPD system having net-like lead in the substrate layer, matching the ineffective area, to block the scatter radiation so that only primary X-rays could reach the effective dimension.To evaluate the performance of this new FPD system, we conducted a Monte Carlo simulation using MCNPX 2.6.0 software. Scatter fractions (SFs) were acquired using no grid, a parallel grid (8:1 grid ratio), and the new system, and the performances were compared.Two systems having different thicknesses of lead in the substrate layer—10 and 20μm—were simulated. Additionally, we examined the effects of different pixel sizes (153×153 and 163×163μm) on the image quality, while keeping the effective area of pixels constant (143×143μm). Results: In case of 10μm lead, the SFs of the new system (∼11%) were lower than those of the other system (∼27% with no grid, ∼16% with parallel grid) at 40kV. However, as the tube voltage increased, the SF of new system (∼19%) was higher than that of parallel grid (∼18%) at 120kV. In the case of 20μm lead, the SFs of the new system were lower than those of the other systems at all ranges of the tube voltage (40–120kV). Conclusion: The novel CsI-based FPD system for removing scatter radiation is feasible for improving the image contrast but must be optimized with respect to the lead thickness, considering the system’s purposes and the ranges of the tube voltage in diagnostic radiology. This study was supported by a grant(K1422651) from Institute of Health Science, Korea University.

  8. Nonoxidative removal of organics in the activated sludge process

    PubMed Central

    Modin, Oskar; Persson, Frank; Wilén, Britt-Marie; Hermansson, Malte

    2016-01-01

    ABSTRACT The activated sludge process is commonly used to treat wastewater by aerobic oxidation of organic pollutants into carbon dioxide and water. However, several nonoxidative mechanisms can also contribute to removal of organics. Sorption onto activated sludge can remove a large fraction of the colloidal and particulate wastewater organics. Intracellular storage of, e.g., polyhydroxyalkanoates (PHA), triacylglycerides (TAG), or wax esters can convert wastewater organics into precursors for high-value products. Recently, several environmental, economic, and technological drivers have stimulated research on nonoxidative removal of organics for wastewater treatment. In this paper, we review these nonoxidative removal mechanisms as well as the existing and emerging process configurations that make use of them for wastewater treatment. Better utilization of nonoxidative processes in activated sludge could reduce the wasteful aerobic oxidation of organic compounds and lead to more resource-efficient wastewater treatment plants. PMID:27453679

  9. REMOVAL OF URANIUM FROM ORGANIC LIQUIDS

    DOEpatents

    Vavalides, S.P.

    1959-08-25

    A process is described for recovering small quantities of uranium from organic liquids such as hydrocarbon oils. halogen-substituted hydrocarbons, and alcohols. The organic liquid is contacted with a comminuted alkaline earth hydroxide, calcium hydroxide particularly, and the resulting uranium-bearing solid is separated from the liquid by filtration. Uranium may then be recovered from the solid by means of dissolution in nitric acid and conventional extraction with an organic solvent such as tributyl phosphate.

  10. Aqueous adsorption and removal of organic contaminants by carbon nanotubes.

    PubMed

    Yu, Jin-Gang; Zhao, Xiu-Hui; Yang, Hua; Chen, Xiao-Hong; Yang, Qiaoqin; Yu, Lin-Yan; Jiang, Jian-Hui; Chen, Xiao-Qing

    2014-06-01

    Organic contaminants have become one of the most serious environmental problems, and the removal of organic contaminants (e.g., dyes, pesticides, and pharmaceuticals/drugs) and common industrial organic wastes (e.g., phenols and aromatic amines) from aqueous solutions is of special concern because they are recalcitrant and persistent in the environment. In recent years, carbon nanotubes (CNTs) have been gradually applied to the removal of organic contaminants from wastewater through adsorption processes. This paper reviews recent progress (145 studies published from 2010 to 2013) in the application of CNTs and their composites for the removal of toxic organic pollutants from contaminated water. The paper discusses removal efficiencies and adsorption mechanisms as well as thermodynamics and reaction kinetics. CNTs are predicted to have considerable prospects for wider application to wastewater treatment in the future. PMID:24657369

  11. Removal of trace organic micropollutants by drinking water biological filters.

    PubMed

    Zearley, Thomas L; Summers, R Scott

    2012-09-01

    The long-term removal of 34 trace organic micropollutants (<1 μg L(-1)) was evaluated and modeled in drinking water biological filters with sand media from a full-scale plant. The micropollutants included pesticides, pharmaceuticals, and personal care products, some of which are endocrine disrupting chemicals, and represent a wide range of uses, chemical structures, adsorbabilities, and biodegradabilities. Micropollutant removal ranged from no measurable removal (<15%) for 13 compounds to removal below the detection limit and followed one of four trends over the one year study period: steady state removal throughout, increasing removal to steady state (acclimation), decreasing removal, or no removal (recalcitrant). Removals for all 19 nonrecalcitrant compounds followed first-order kinetics when at steady state with increased removal at longer empty bed contact times (EBCT). Rate constants were calculated, 0.02-0.37 min(-1), and used in a pseudo-first-order rate model with the EBCT to predict removals in laboratory biofilters at a different EBCT and influent conditions. Drinking water biofiltration has the potential to be an effective process for the control of many trace organic contaminants and a pseudo-first-order model can serve as an appropriate method for approximating performance. PMID:22881485

  12. Mechanism of paint removing by organic solvents

    SciTech Connect

    Del Nero, V.; Siat, C.; Marti, M.J.; Aubry, J.M.; Lallier, J.P.; Dupuy, N.; Huvenne, J.P.

    1996-01-01

    The mechanism of paint removing has been studied by comparing the stripping efficiency of a given solvent with its ability to swell the film. The most effective solvents have a Hildebrand{close_quote}s parameter, {delta}{sub H}, ranging from 10.5 to 12 and a Dimroth parameter, ET{sub (30)}, ranging from 0.25 to 0.4. The synergy observed with the mixtures DMSO/non polar solvent is explained by a dissociation of the DMSO clusters into individual molecules which diffuse more easily. {copyright} {ital 1996 American Institute of Physics.}

  13. Iodine - Its possible role in tropospheric photochemistry

    NASA Technical Reports Server (NTRS)

    Chameides, W. L.; Davis, D. D.

    1980-01-01

    A detailed study of the photochemistry of iodine and its oxides indicates that iodine species may play an important role in the tropospheric photochemical system. Methyl iodide, often observed in the marine troposphere with an average concentration of 5-10 ppt, is photolyzed and thereby produces I atoms. Chemical interactions with O3, HxOy, and NOx cause I to be converted to other inorganic compounds such as IO, HOI, IONO2, and I2. The production of these species and their subsequent recycling back to I can lead to the catalytic removal of tropospheric O3, the enhancement of the NO2/NO ratio, the destruction of HxOy free radicals, and the conversion of HO2 to OH. Ultimately, tropospheric inorganic iodine is removed by heterogeneous processes. Calculations using a numerical model to simulate tropospheric photochemistry indicate that iodine may have a strong impact upon the atmospheric O3-NOx-HxOy system. The magnitude of these effects is dependent upon the value of several uncertain rate constants and the primary source distributions of CH3I and other organic and inorganic iodine compounds.

  14. Organic matter controls on iodine and plutonium in atmospheric depositions, streams, and soils in the Fukushima Prefecture

    NASA Astrophysics Data System (ADS)

    Xu, C.; Zhang, S.; Sugiyama, Y.; Ohte, N.; Ho, Y. F.; Fujitake, N.; Kaplan, D. I.; Yeager, C. M.; Schwehr, K. A.; Santschi, P. H.

    2015-12-01

    In order to assess how environmental factors are controlling the distribution and migration of radioiodine and plutonium that were emitted from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, we quantified iodine and 239,240Pu concentration changes in soil samples with different land uses (urban, paddy, deciduous forest and coniferous forest), as well as iodine speciation in surface water and rainwater. A ranking of the land uses by their stable 127I and by their 239,240Pu concentrations were quite distinct from that of 134,137Cs, indicating 137Cs might not be a good geochemical proxy for radioactive 129I or Pu in the long-term, post-FDNPP accident. Being a proxy for the long-term fate of 129I, soil 127I content was well correlated to soil organic matter (SOM) content, regardless of land use type, suggesting that SOM might be an important factor controlling iodine biogeochemistry. Other soil chemical properties, such as Eh and pH, had strong correlations to soil 127I content, but only within a given land use (e.g., within urban soils). Organic carbon (OC) and Eh were positively, and pH was negatively correlated to 127I concentrations in surface water and rain samples. It is also noticeable that 127I in the bulk deposition was concentrated along the rainwater passage likely due to plant evapotranspiration activity, with all inorganic iodine being completely converted to organo-iodine by plant organic matter. 239,240Pu activities of all soil samples were well within the global fallout range, but the Fukushima-derived 239,240Pu was detectable at a distance ~61 km away, NW of FDNPP. However, it is confined to the litter layer, even three years after the FDNPP accident-derived emissions. 239,240Pu activities were significantly correlated with soil OC and nitrogen contents, indicating Pu may be associated with nitrogen-containing SOM, similar to what has been observed at other locations in the United States, e.g., Savannah River Site (SRS) and Rocky Flats

  15. FISSION PRODUCT REMOVAL FROM ORGANIC SOLUTIONS

    DOEpatents

    Moore, R.H.

    1960-05-10

    The decontamination of organic solvents from fission products and in particular the treatment of solvents that were used for the extraction of uranium and/or plutonium from aqueous acid solutions of neutron-irradiated uranium are treated. The process broadly comprises heating manganese carbonate in air to a temperature of between 300 and 500 deg C whereby manganese dioxide is formed; mixing the manganese dioxide with the fission product-containing organic solvent to be treated whereby the fission products are precipitated on the manganese dioxide; and separating the fission product-containing manganese dioxide from the solvent.

  16. Controlled iodine release from polyurethane sponges for water decontamination.

    PubMed

    Aviv, Oren; Laout, Natalia; Ratner, Stanislav; Harik, Oshrat; Kunduru, Konda Reddy; Domb, Abraham J

    2013-12-28

    Iodinated polyurethane (IPU) sponges were prepared by immersing sponges in aqueous/organic solutions of iodine or exposing sponges to iodine vapors. Iodine was readily adsorbed into the polymers up to 100% (w/w). The adsorption of iodine on the surface was characterized by XPS and SEM analyses. The iodine loaded IPU sponges were coated with ethylene vinyl acetate (EVA), in order to release iodine in a controlled rate for water decontamination combined with active carbon cartridge, which adsorbs the iodine residues after the microbial inactivation. The EVA coated IPU were incorporated in a water purifier and tested for iodine release to water and for microbial inactivation efficiency according to WQA certification program against P231/EPA for 250l, using 25l a day with flow rate of 6-8min/1l. The antimicrobial activity was also studied against Escherichia coli and MS2 phage. Bacterial results exceeded the minimal requirement for bacterial removal of 6log reduction throughout the entire lifespan. At any testing point, no bacteria was detected in the outlet achieving more than 7.1 to more than 8log reduction as calculated upon the inlet concentration. Virus surrogate, MS2, reduction results varied from 4.11log reduction under tap water, and 5.11log reduction under basic water (pH9) to 1.32 for acidic water (pH5). Controlled and stable iodine release was observed with the EVA coated IPU sponges and was effective in deactivating the bacteria and virus present in the contaminated water and thus, these iodinated PU systems could be used in water purification to provide safe drinking water. These sponges may find applications as disinfectants in medicine. PMID:24096017

  17. Controlled iodine release from polyurethane sponges for water decontamination.

    PubMed

    Aviv, Oren; Laout, Natalia; Ratner, Stanislav; Harik, Oshrat; Kunduru, Konda Reddy; Domb, Abraham J

    2013-12-28

    Iodinated polyurethane (IPU) sponges were prepared by immersing sponges in aqueous/organic solutions of iodine or exposing sponges to iodine vapors. Iodine was readily adsorbed into the polymers up to 100% (w/w). The adsorption of iodine on the surface was characterized by XPS and SEM analyses. The iodine loaded IPU sponges were coated with ethylene vinyl acetate (EVA), in order to release iodine in a controlled rate for water decontamination combined with active carbon cartridge, which adsorbs the iodine residues after the microbial inactivation. The EVA coated IPU were incorporated in a water purifier and tested for iodine release to water and for microbial inactivation efficiency according to WQA certification program against P231/EPA for 250l, using 25l a day with flow rate of 6-8min/1l. The antimicrobial activity was also studied against Escherichia coli and MS2 phage. Bacterial results exceeded the minimal requirement for bacterial removal of 6log reduction throughout the entire lifespan. At any testing point, no bacteria was detected in the outlet achieving more than 7.1 to more than 8log reduction as calculated upon the inlet concentration. Virus surrogate, MS2, reduction results varied from 4.11log reduction under tap water, and 5.11log reduction under basic water (pH9) to 1.32 for acidic water (pH5). Controlled and stable iodine release was observed with the EVA coated IPU sponges and was effective in deactivating the bacteria and virus present in the contaminated water and thus, these iodinated PU systems could be used in water purification to provide safe drinking water. These sponges may find applications as disinfectants in medicine.

  18. Deposition velocity of gaseous organic iodine from the atmosphere to rice plants

    SciTech Connect

    Muramatsu, Yasuyuki; Shigeo-Uchida; Sumiya, Misako; Ohmomo, Yoichiro

    1996-11-01

    To obtain parameter values for the assessment of {sup 129}I transfer from the atmosphere to rice, deposition of CH{sub 3}I to rice plants has been studied. The mass normalized deposition velocity (V{sub D}) of CH{sub 3}I for rough (unhulled) rice was 0.00048 cm{sup 3} g{sup {minus}1} s{sup {minus}1}, which is about 1/300 of that of I{sub 2}. Translocation of iodine, deposited as CH{sub 3}I on leaves and stems, to rice grain was negligibly small. Distribution of iodine between hull and inner part of the grain was found to depend also on the chemical forms of atmospheric iodine to be deposited. The ratio of the iodine distribution in a grain exposed to CH{sub 3}I was as follows: rough rice: brown rice (hulled rice):polished rice = 1.0:0.49:0.38. The distribution ratio in polished grains for CH{sub 3}I exposed rice was about 20 times higher than that for I{sub 2}. 22 refs., 1 fig., 6 tabs.

  19. Removal of bromide and natural organic matter by anion exchange.

    PubMed

    Hsu, Susan; Singer, Philip C

    2010-04-01

    Bromide removal by anion exchange was explored for various water qualities, process configurations, and resin characteristics. Simulated natural waters containing different amounts of natural organic matter (NOM), bicarbonate, chloride, and bromide were treated with a polyacrylate-based magnetic ion exchange (MIEX) resin on a batch basis to evaluate the effectiveness of the resin for removal of bromide. While bromide removal was achieved to some degree, alkalinity (bicarbonate), dissolved organic carbon (DOC), and chloride were shown to inhibit bromide removal in waters with bromide concentrations of 100 and 300 microg/L. Water was also treated using a two-stage batch MIEX process. Two-stage treatment resulted in only a slight improvement in bromide removal compared to single-stage treatment, presumably due to competition with the high concentration of chloride which is present along with bromide in natural waters. In view of the relatively poor bromide removal results for the MIEX resin, a limited set of experiments was performed using polystyrene resins. DOC and bromide removal were compared by treating model waters with MIEX and two polystyrene resins, Ionac A-641 and Amberlite IRA910. The two polystyrene resins were seen to be more effective for bromide removal, while the MIEX resin was more effective at removing DOC.

  20. Charcoal bed operation for optimal organic carbon removal

    SciTech Connect

    Merritt, C.M.; Scala, F.R.

    1995-05-01

    Historically, evaporation, reverse osmosis or charcoal-demineralizer systems have been used to remove impurities in liquid radwaste processing systems. At Nine Mile point, we recently replaced our evaporators with charcoal-demineralizer systems to purify floor drain water. A comparison of the evaporator to the charcoal-demineralizer system has shown that the charcoal-demineralizer system is more effective in organic carbon removal. We also show the performance data of the Granulated Activated Charcoal (GAC) vessel as a mechanical filter. Actual data showing that frequent backflushing and controlled flow rates through the GAC vessel dramatically increases Total Organic Carbon (TOC) removal efficiency. GAC vessel dramatically increases Total Organic Carbon (TOC) removal efficiency. Recommendations are provided for operating the GAC vessel to ensure optimal performance.

  1. Removal of trace organics by anaerobic membrane bioreactors.

    PubMed

    Monsalvo, Victor M; McDonald, James A; Khan, Stuart J; Le-Clech, Pierre

    2014-02-01

    The biological removal of 38 trace organics (pharmaceuticals, endocrine disruptors, personal care products and pesticides) was studied in an anaerobic membrane bioreactor (AnMBR). This work presents complete information on the different removal mechanisms involved in the removal of trace organics in this process. In particular, it is focused on advanced characterization of the relative amount of TO accumulated within the fouling layers formed on the membranes. The results show that only 9 out of 38 compounds were removed by more than 90% while 23 compounds were removed by less than 50%. These compounds are therefore removed in an AnMBR biologically and partially adsorbed and retained by flocs and the deposition developed on the membranes, respectively. A total amount of 288 mg of trace organics was retained per m(2) of membrane, which were distributed along the different fouling layers. Among the trace organics analyzed, 17α-ethynylestradiol, estrone, octylphenol and bisphenol A were the most retained by the fouling layers. Among the fouling layers deposited on the membranes, the non-readily detachable layer has been identified as the main barrier for trace organics.

  2. Removal of trace organics by anaerobic membrane bioreactors.

    PubMed

    Monsalvo, Victor M; McDonald, James A; Khan, Stuart J; Le-Clech, Pierre

    2014-02-01

    The biological removal of 38 trace organics (pharmaceuticals, endocrine disruptors, personal care products and pesticides) was studied in an anaerobic membrane bioreactor (AnMBR). This work presents complete information on the different removal mechanisms involved in the removal of trace organics in this process. In particular, it is focused on advanced characterization of the relative amount of TO accumulated within the fouling layers formed on the membranes. The results show that only 9 out of 38 compounds were removed by more than 90% while 23 compounds were removed by less than 50%. These compounds are therefore removed in an AnMBR biologically and partially adsorbed and retained by flocs and the deposition developed on the membranes, respectively. A total amount of 288 mg of trace organics was retained per m(2) of membrane, which were distributed along the different fouling layers. Among the trace organics analyzed, 17α-ethynylestradiol, estrone, octylphenol and bisphenol A were the most retained by the fouling layers. Among the fouling layers deposited on the membranes, the non-readily detachable layer has been identified as the main barrier for trace organics. PMID:24321247

  3. Biocatalytic removal of organic sulfur from coal

    SciTech Connect

    Webster, D.A.; Kilbane, J.J. II

    1994-09-09

    The objective is to characterize more completely the biochemical ability of the bacterium, Rhodococcus rhodochrous IGTS8, to cleave carbon-sulfur bonds with emphasis on data that will allow the development of a practical coal biodesulfurization process. Another approach for increasing the desulfurization activity of the IGTS8 cultures is to produce strains genetically that have higher activity. The goal of this part of research is to achieve strain improvement by introducing a stronger promoter using genetic engineering techniques. The promoter regulates the transcription of the genes for the desulfurization enzymes, and a stronger promoter, would up-regulate the expression of these genes, resulting in cells with higher desulfurization activity. Promoter probe vectors are used to identify and isolate promoters from a DNA library of the experimental organism. The major accomplishments have been to obtain high biodesulfurization activity in nonaqueous, media, especially using freeze-dried cells, and to have isolated strong promoters from R. rhodochrous IGTS8 which will be used to engineer the organism to produce strains with higher biocatalytic activity.

  4. Selective removal of organics for water reclamation

    NASA Technical Reports Server (NTRS)

    Murphy, Oliver J.; Hitchens, G. Duncan

    1989-01-01

    Electrolysis has been investigated as a means of purifying waste water. The feasibility of the direct electrochemical oxidation of urea has been demonstrated. Urea levels were reduced from 1200 ppm to 1 ppm forming the basis for a new approach to urine purification where the only consumable is electrical energy. Preliminary estimates of the energy requirements are 270 W/hr per liter of urine. Urea oxidation rates of around 350 mg urea/hr/m2 were observed. It is anticipated that a 1 m2 geometric area of electrode could treat urine for a crew of several persons. The low levels of organic contaminants resulting from this treatment indicate that the approach may have an impact as a post treatment process. Experiments are planned to investigate this later possibility.

  5. Combined chemical and microbiological removal of organic sulfur from coal

    SciTech Connect

    Raphaelian, L.A.

    1991-01-01

    The objective of this work is to investigate techniques for chemically converting the sulfur containing organic compounds in coal to compounds that can be treated microbiologically to remove the organically bound sulfur. The goal is to achieve an economically feasible mild chemical oxidation of the organic sulfur in a representative Illinois Basin coal by converting the sulfur to sulfoxides and sulfones; the carbon sulfur bond in the sulfoxides and sulfones would then be broken microbiologically and the sulfur removed from the coal as sulfate.

  6. Iodine poisoning

    MedlinePlus

    Iodine is found in: Amiodarone (Cordarone) Chemicals (catalysts) for photography and engraving Dyes and inks Lugol's solution Pima syrup Potassium iodide Radioactive iodine used for certain medical tests or the treatment ...

  7. Influence of iodine on the treatment of spacecraft humidity condensate to produce potable water

    NASA Technical Reports Server (NTRS)

    Symons, James M.; Muckle, Susan V.

    1990-01-01

    Several compounds in the ersatz humidity condensate do react with iodine to form iodine-substituted organic compounds (TOI), most notably phenol, acetaldehyde, ethanol, and sodium formate. Iodination of the ersatz humidity condensate produced 3.0 to 3.5 mg/L of TOI within 24 hours. The TOI that was produced by the passage of the ersatz humidity condensate through the first iodinated resin (IR) in the adsorption system was removed by the granular activated carbon that followed. TOI detected in the final effluent was formed by the reaction of the non-adsorbable condensate compounds with the final IR in the treatment series. The activated carbon bed series in the adsorption system performed poorly in its removal of TOC. The rapid breakthrough of TOC was not surprising, as the ersatz humidity condensate contained several highly soluble organic compounds, alcohols and organic acids.

  8. Integrating organic micropollutant removal into tertiary filtration: Combining PAC adsorption with advanced phosphorus removal.

    PubMed

    Altmann, Johannes; Sperlich, Alexander; Jekel, Martin

    2015-11-01

    Direct addition of powdered activated carbon (PAC) to a deep-bed filter was investigated at pilot-scale as a single advanced treatment stage for simultaneous removal of organic micropollutants (OMPs) and phosphorus from secondary effluent. PAC doses of 10-50 mg/L were assessed with regard to their impacts on filter performance and removal of 15 selected OMPs over a period of 18 months. The PAC was effectively retained by the filter and had no negative effect on filter head loss. Filter runtime until particle breakthrough depended mainly on coagulant dose and did not decrease significantly due to the additional PAC load. Removal of suspended solids and phosphorus by coagulation was effective independent of the PAC dose. A PAC dose of 35 mg/L PAC was suitable to remove well-adsorbing OMPs (e.g. carbamazepine, diclofenac) by >80% and medium adsorbing OMPs (e.g. primidone, sulfamethoxazole) by 50-80%. Median removals were 50-80% for well-adsorbing and 30-50% for medium adsorbing OMPs with 20 mg/L PAC. Abatement of all OMPs was low (<50%) with 10 mg/L PAC, possibly because of the high effluent organic matter content (median dissolved organic carbon (DOC) concentrations of 11.2 mg/L). In addition to adsorptive removal, relevant concentration decreases of certain OMPs (e.g. 4-formylaminoantipyrine) were attributed to biological transformation in the filter. Adsorption onto accumulating PAC in the top layer of the filter bed led to improved OMP adsorption with increasing filter runtime. The comparison of OMP removal in the pilot filter with laboratory adsorption tests demonstrates that batch test results can be applied to estimate adsorptive OMP removal in real applications.

  9. Integrating organic micropollutant removal into tertiary filtration: Combining PAC adsorption with advanced phosphorus removal.

    PubMed

    Altmann, Johannes; Sperlich, Alexander; Jekel, Martin

    2015-11-01

    Direct addition of powdered activated carbon (PAC) to a deep-bed filter was investigated at pilot-scale as a single advanced treatment stage for simultaneous removal of organic micropollutants (OMPs) and phosphorus from secondary effluent. PAC doses of 10-50 mg/L were assessed with regard to their impacts on filter performance and removal of 15 selected OMPs over a period of 18 months. The PAC was effectively retained by the filter and had no negative effect on filter head loss. Filter runtime until particle breakthrough depended mainly on coagulant dose and did not decrease significantly due to the additional PAC load. Removal of suspended solids and phosphorus by coagulation was effective independent of the PAC dose. A PAC dose of 35 mg/L PAC was suitable to remove well-adsorbing OMPs (e.g. carbamazepine, diclofenac) by >80% and medium adsorbing OMPs (e.g. primidone, sulfamethoxazole) by 50-80%. Median removals were 50-80% for well-adsorbing and 30-50% for medium adsorbing OMPs with 20 mg/L PAC. Abatement of all OMPs was low (<50%) with 10 mg/L PAC, possibly because of the high effluent organic matter content (median dissolved organic carbon (DOC) concentrations of 11.2 mg/L). In addition to adsorptive removal, relevant concentration decreases of certain OMPs (e.g. 4-formylaminoantipyrine) were attributed to biological transformation in the filter. Adsorption onto accumulating PAC in the top layer of the filter bed led to improved OMP adsorption with increasing filter runtime. The comparison of OMP removal in the pilot filter with laboratory adsorption tests demonstrates that batch test results can be applied to estimate adsorptive OMP removal in real applications. PMID:26210030

  10. Removal of radioactive iodine and cesium in water purification processes after an explosion at a nuclear power plant due to the Great East Japan Earthquake.

    PubMed

    Kosaka, Koji; Asami, Mari; Kobashigawa, Naoya; Ohkubo, Keiko; Terada, Hiroshi; Kishida, Naohiro; Akiba, Michihiro

    2012-09-15

    The presence of radionuclides at five water purification plants was investigated after an explosion at a nuclear power plant hit by the Great East Japan Earthquake on 11 March 2011. Radioactive iodine (¹³¹I) and cesium (¹³⁴Cs and ¹³⁷Cs) were detected in raw water in Fukushima and neighboring prefectures. ¹³¹I was not removed by coagulation-flocculation-sedimentation. ¹³¹I was removed by granular activated carbon (GAC) and powdered activated carbon (PAC) at a level of about 30%-40%, although ¹³¹I was not removed in some cases. This was also confirmed by laboratory-scale experiments using PAC. The removal percentages of ¹³¹I in river and pond waters by 25 mg dry/L of PAC increased from 36% to 59% and from 41% to 48%, respectively, with chlorine dosing before PAC. ¹³⁴Cs and ¹³⁷Cs were effectively removed by coagulation at both a water purification plant and in laboratory-scale experiments when turbidity was relatively high. In contrast, ¹³⁴Cs and ¹³⁷Cs in pond water with low turbidity were not removed by coagulation. This was because ¹³⁴Cs and ¹³⁷Cs in river water were present mainly in particulate form, while in pond water they were present mainly as cesium ions (¹³⁴Cs+ and ¹³⁷Cs+). However, the removal of ¹³⁴Cs and ¹³⁷Cs in pond water by coagulation increased markedly when ¹³⁴Cs and ¹³⁷Cs were mixed with sediment 24 h before coagulation. PMID:22717151

  11. Removal of radioactive iodine and cesium in water purification processes after an explosion at a nuclear power plant due to the Great East Japan Earthquake.

    PubMed

    Kosaka, Koji; Asami, Mari; Kobashigawa, Naoya; Ohkubo, Keiko; Terada, Hiroshi; Kishida, Naohiro; Akiba, Michihiro

    2012-09-15

    The presence of radionuclides at five water purification plants was investigated after an explosion at a nuclear power plant hit by the Great East Japan Earthquake on 11 March 2011. Radioactive iodine (¹³¹I) and cesium (¹³⁴Cs and ¹³⁷Cs) were detected in raw water in Fukushima and neighboring prefectures. ¹³¹I was not removed by coagulation-flocculation-sedimentation. ¹³¹I was removed by granular activated carbon (GAC) and powdered activated carbon (PAC) at a level of about 30%-40%, although ¹³¹I was not removed in some cases. This was also confirmed by laboratory-scale experiments using PAC. The removal percentages of ¹³¹I in river and pond waters by 25 mg dry/L of PAC increased from 36% to 59% and from 41% to 48%, respectively, with chlorine dosing before PAC. ¹³⁴Cs and ¹³⁷Cs were effectively removed by coagulation at both a water purification plant and in laboratory-scale experiments when turbidity was relatively high. In contrast, ¹³⁴Cs and ¹³⁷Cs in pond water with low turbidity were not removed by coagulation. This was because ¹³⁴Cs and ¹³⁷Cs in river water were present mainly in particulate form, while in pond water they were present mainly as cesium ions (¹³⁴Cs+ and ¹³⁷Cs+). However, the removal of ¹³⁴Cs and ¹³⁷Cs in pond water by coagulation increased markedly when ¹³⁴Cs and ¹³⁷Cs were mixed with sediment 24 h before coagulation.

  12. Method for removing organic liquids from aqueous solutions and mixtures

    DOEpatents

    Hrubesh, Lawrence W.; Coronado, Paul R.; Dow, Jerome P.

    2004-03-23

    A method for removing organic liquids from aqueous solutions and mixtures. The method employs any porous material preferably in granular form and having small pores and a large specific surface area, that is hydrophobic so that liquid water does not readily wet its surface. In this method, organics, especially organic solvents that mix with and are more volatile than water, are separated from aqueous solution by preferentially evaporating across the liquid/solid boundary formed at the surfaces of the hydrophobic porous materials. Also, organic solvents that are immiscible with water, preferentially wet the surfaces of the hydrophobic material and are drawn within the porous materials by capillary action.

  13. Adsorption combined with ultrafiltration to remove organic matter from seawater.

    PubMed

    Tansakul, Chatkaew; Laborie, Stéphanie; Cabassud, Corinne

    2011-12-01

    Organic fouling and biofouling are the major severe types of fouling of reverse osmosis (RO) membranes in seawater (SW) desalination. Low pressure membrane filtration such as ultrafiltration (UF) has been developed as a pre-treatment before reverse osmosis. However, UF alone may not be an effective enough pre-treatment because of the existence of low-molecular weight dissolved organic matter in seawater. Therefore, the objective of the present work is to study a hybrid process, powdered activated carbon (PAC) adsorption/UF, with real seawater and to evaluate its performance in terms of organic matter removal and membrane fouling. The effect of different PAC types and concentrations is evaluated. Stream-activated wood-based PAC addition increased marine organic matter removal by up to 70% in some conditions. Moreover, coupling PAC adsorption with UF decreased UF membrane fouling and the fouling occurring during short-term UF was totally reversible. It can be concluded that the hybrid PAC adsorption/UF process performed in crossflow filtration mode is a relevant pre-treatment process before RO desalination, allowing organic matter removal of 75% and showing no flux decline for short-term experiments. PMID:21996607

  14. Adsorption combined with ultrafiltration to remove organic matter from seawater.

    PubMed

    Tansakul, Chatkaew; Laborie, Stéphanie; Cabassud, Corinne

    2011-12-01

    Organic fouling and biofouling are the major severe types of fouling of reverse osmosis (RO) membranes in seawater (SW) desalination. Low pressure membrane filtration such as ultrafiltration (UF) has been developed as a pre-treatment before reverse osmosis. However, UF alone may not be an effective enough pre-treatment because of the existence of low-molecular weight dissolved organic matter in seawater. Therefore, the objective of the present work is to study a hybrid process, powdered activated carbon (PAC) adsorption/UF, with real seawater and to evaluate its performance in terms of organic matter removal and membrane fouling. The effect of different PAC types and concentrations is evaluated. Stream-activated wood-based PAC addition increased marine organic matter removal by up to 70% in some conditions. Moreover, coupling PAC adsorption with UF decreased UF membrane fouling and the fouling occurring during short-term UF was totally reversible. It can be concluded that the hybrid PAC adsorption/UF process performed in crossflow filtration mode is a relevant pre-treatment process before RO desalination, allowing organic matter removal of 75% and showing no flux decline for short-term experiments.

  15. A human rights approach to human trafficking for organ removal.

    PubMed

    Budiani-Saberi, Debra; Columb, Seán

    2013-11-01

    Human trafficking for organ removal (HTOR) should not be reduced to a problem of supply and demand of organs for transplantation, a problem of organized crime and criminal justice, or a problem of voiceless, abandoned victims. Rather, HTOR is at once an egregious human rights abuse and a form of human trafficking. As such, it demands a human-rights based approach in analysis and response to this problem, placing the victim at the center of initiatives to combat this phenomenon. Such an approach requires us to consider how various measures impact or disregard victims/potential victims of HTOR and gives us tools to better advocate their interests, rights and freedoms.

  16. Removing environmental organic pollutants with bioremediation and phytoremediation.

    PubMed

    Kang, Jun Won

    2014-06-01

    Hazardous organic pollutants represent a threat to human, animal, and environmental health. If left unmanaged, these pollutants could cause concern. Many researchers have stepped up efforts to find more sustainable and cost-effective alternatives to using hazardous chemicals and treatments to remove existing harmful pollutants. Environmental biotechnology, such as bioremediation and phytoremediation, is a promising field that utilizes natural resources including microbes and plants to eliminate toxic organic contaminants. This technology offers an attractive alternative to other conventional remediation processes because of its relatively low cost and environmentally-friendly method. This review discusses current biological technologies for the removal of organic contaminants, including chlorinated hydrocarbons, focusing on their limitation and recent efforts to correct the drawbacks.

  17. [Mechanisms of removing red tide organisms by organo-clays].

    PubMed

    Cao, Xi-Hua; Song, Xiu-Xian; Yu, Zhi-Ming; Wang, Kui

    2006-08-01

    We tested the influence of the preparation conditions of the quaternary ammonium compounds (QACs) modified clays on their capacities to remove red tide organisms, then discussed the mechanisms of the organo-clays removing red tide organisms. Hexadecyltrimethylammonium (HDTMA) improved the capacity of clays to flocculate red tide algae, and the HDTMA in metastable state enhanced the toxicity of the clay complexes to algae. The capacities of the organo-clays correlated with the toxicity and the adsorbed amount of the QACs used in clays modification, but as the incubation time was prolonged the stability of the organo-clays was improved and the algal removal efficiencies of the clay complexes decreased. When the adsorbed HDTMA was arranged in different clays in which the spatial resistance was different, there was more HDTMA in metastable state in the three-layer montmorillonite. Because of the homo-ion effect the bivalent or trivalent metal ions induced more HDTMA in metastable state and the corresponding organo-clays had high capacities to remove red tide organisms. When the reaction temperature was 60 degrees C the adsorbed HDTMA was easily arranged on cation exchange sites, if the temperature rose or fell the metastable HDTMA would increase so that the capacity of the clays was improved.

  18. Device for removing foreign objects from anatomic organs

    NASA Technical Reports Server (NTRS)

    Angulo, Earl D. (Inventor)

    1992-01-01

    A device is disclosed for removing foreign objects from anatomic organs such as the ear canal or throat. It has a housing shaped like a flashlight, an electrical power source such as a battery or AC power from a wall socket, and a tip extending from the housing. The tip has at least one wire loop made from a shape-memory-effect alloy, such as Nitinol, switchably connected to the electrical power source such that when electric current flows through the wire loop the wire loop heats up and returns to a previously programmed shape such as a curet or tweezers so as to facilitate removal of the foreign object.

  19. An individualistic approach to routine cadaver organ removal.

    PubMed

    Peters, D A

    1988-09-01

    Consenting to the taking of one's organs after death is a moral duty--the duty to consent--which derives from a more general moral duty--the duty to attempt an easy rescue of an endangered person. These two duties can be justified within the framework of factual and value beliefs associated with the general intellectual orientation called "individualism," which informs the liberal democratic tradition in the spirit of John Locke. Individualists value personal liberty and would accept these two duties on the ground that personal liberty is likely to be better protected and advanced in a society that abides by them than in a society that does not. The same reasoning justifies a social policy of routine removal of cadaver organs. Individualists would find it prudent to give up their right to be buried whole and adopt a policy of routine removal of cadaver organs, with organs distributed according to some principle of fair allocation. Since they recognize that their own organs will be of no use to them after death, giving up their right to be buried whole will not be viewed as a significant sacrifice of personal liberty. Some people of basic individualistic sympathies may, however, embrace additional special values that favor their being buried whole. To accommodate such persons, two compromises on a policy of routine taking of cadaver organs are possible: Allow these persons to "opt out" of the system by signing a legally binding document prohibiting the taking of their organs after death, or require everyone to state on their driver's licenses a positive or negative decision concerning organ removal.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Polar organic solvent removal in microcosm constructed wetlands.

    PubMed

    Grove, Janet Kowles; Stein, Otto R

    2005-10-01

    Three polar organic solvents, acetone, tetrahydrofuran (THF) and 1-butanol, were added at 100 mg/l each to post-primary municipal wastewater in order to simulate a mixed waste stream. This mixture was applied to an experimental microcosm subsurface constructed wetland system consisting of replicates of Juncus effusus, Carex lurida, Iris pseudacorus, Pondeteria cordata and unplanted controls in a series of 14-day batch incubations over a yearlong period simulating a summer and winter season. 90% removal of 1-butanol typically took less than 3 days. 90% removal of acetone required from 5 to 10 days in summer and 10 to 14 days in winter. 90% removal of THF required at least 10 days and was frequently not achieved during the 14-day incubations. Initial experiments confirmed that the majority of solvent removal was via microbial bioremediation. Solvent removal was typically better in planted replicates, especially Juncus, regardless of season. The removal rate of all solvents was slower in winter, but the seasonal effect was most pronounced in the unplanted control replicates and least in the Carex and Juncus replicates. Plant and seasonal effects are believed to be due, in part, to variation in metabolic pathways induced by plant and seasonal variation in available root-zone oxygen. Variation in transpiration also influenced species and seasonal effects on THF removal, but not the other more biodegradable solvents. A model based on a prediction of plant uptake of nonionic dissolved chemicals suggests that as much as 39% of the THF in solution could have been removed through plant transpiration.

  1. [Removal efficiency of red tide organisms by modified clay and its impacts on cultured organisms].

    PubMed

    Cao, Xi-hua; Song, Xiu-xian; Yu, Zhi-ming

    2004-09-01

    Removal efficiencies of Prorocentrum donghaiense (Prorocentrum dentatum) by Hexadecyltrimethylammonium (HDTMA) bromide and organo-clay modified by HDTMA were identified. Moreover the toxicity of the unbound HDTMA and HDTMA plus clay to aquacultural organisms, Penaeus japonicus, was also tested. The results suggested that (1) The unbound HDTMA had an excellent ability to remove the red tide organisms. However, its strong toxicity to Penaeus japonicus would restrict its practical use in red tide control. (2) The toxicity of HDTMA could be remarkably decreased by addition of clay and the organo-clay complex had a good ability to removal red tide organisms. At the same time the availability of organo-clay to remove the red tide of P. donghaiense and Heterosigma akashiwo in the lab-imitated cultures were studied. The results indicated that the organo-clay complex could remove 100% P. donghaiense at the dosage of 0.03 g/L and effectively control H. akashiwo at 0.09 g/L while the survival rate of Penaeus japonicus larvae, which were cultured in the red tide seawater, is kept 100%. According to the results in laboratory, the mesocosm tests (CEPEX) in East China Sea were conducted in April and May of 2003. The removal efficiencies of original clay, organic clay and inorganic clay were compared during the CEPEX tests. The results revealed that both inorganic clay and organic clay could remove red tide organisms more effectively than the original clay.

  2. 24 CFR 200.195 - Removal of nonprofit organization from Nonprofit Organization Roster.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... prohibits HUD from taking such other action against a nonprofit organization, as provided in 2 CFR part 2424... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Removal of nonprofit organization from Nonprofit Organization Roster. 200.195 Section 200.195 Housing and Urban Development...

  3. Block-copolymer of polyethylene glycol and polylysine as a carrier of organic iodine: design of long-circulating particulate contrast medium for X-ray computed tomography.

    PubMed

    Trubetskoy, V S; Gazelle, G S; Wolf, G L; Torchilin, V P

    1997-01-01

    In order to obtain small, polymer-stabilized particulate carriers for organic iodine to serve as a contrast agent for X-ray computed tomography (CT) an attempt was made to design a carrier based on polymeric micelles. Here we describe the synthesis of an iodine-containing amphiphilic block-copolymer which can micellize in aqueous solutions. The two blocks of the copolymer consisted of methoxypoly(ethyleneglycol) and poly[epsilon,N-(triiodobenzoyl)-L-lysine]. Upon dispersion in water, the block copolymer formed particles with average diameter 80 nm and iodine content up to 44.7%. The particles start to dissociate to the individual polymeric chains in the concentration range of 0.05-0.5 microM in water at 23 degrees C. Upon intravenous injection at 250 mg of iodine/kg (570 mg of the agent/kg) in rabbits the medium demonstrated exceptional 24 hr half-life in the blood substantiating corona/core structure of the particles with PEG chains protecting the iodine-containing core. The possible use of these particulates as contrast medium for X-ray computed tomography is discussed.

  4. REMOVAL OF ORGANIC CHEMICALS FROM WASTEWATER BY SURFACTANT SEPARATION

    SciTech Connect

    Unknown

    2002-01-01

    This research presents a novel hybrid process for removing organic chemicals from contaminated water. The process uses surfactant to carry out two unit operations (1) Extraction; (2) Foam flotation. In the first step, surfactant is used to extract most of the amounts of organic contaminants in the stream. In the second step, foam flotation is used to further reduce organic contaminants and recover surfactant from the stream. The process combines the advantages of extraction and foam flotation, which allows the process not only to handle a wide range of organic contaminants, but also to effectively treat a wide range of the concentration of organic contaminants in the stream and reduce it to a very low level. Surfactant regeneration can be done by conventional methods. This process is simple and low cost. The wastes are recoverable. The objective of this research is to develop an environmentally innocuous process for the wastewater or reclaimed water treatment with the ability to handle a wide range of organic contaminants, also to effectively treat a wide range of the concentration of organic contaminants in contaminated water and reduce it to a very low level, finally, provides simpler, less energy cost and economically-practical process design. Another purpose is to promote the environmental concern in minority students and encourage minority students to become more involved in environmental engineering research.

  5. A human rights approach to human trafficking for organ removal.

    PubMed

    Budiani-Saberi, Debra; Columb, Seán

    2013-11-01

    Human trafficking for organ removal (HTOR) should not be reduced to a problem of supply and demand of organs for transplantation, a problem of organized crime and criminal justice, or a problem of voiceless, abandoned victims. Rather, HTOR is at once an egregious human rights abuse and a form of human trafficking. As such, it demands a human-rights based approach in analysis and response to this problem, placing the victim at the center of initiatives to combat this phenomenon. Such an approach requires us to consider how various measures impact or disregard victims/potential victims of HTOR and gives us tools to better advocate their interests, rights and freedoms. PMID:23743564

  6. Organic pollutants removal in wastewater by heterogeneous photocatalytic ozonation.

    PubMed

    Xiao, Jiadong; Xie, Yongbing; Cao, Hongbin

    2015-02-01

    Heterogeneous photocatalysis and ozonation are robust advanced oxidation processes for eliminating organic contaminants in wastewater. The combination of these two methods is carried out in order to enhance the overall mineralization of refractory organics. An apparent synergism between heterogeneous photocatalysis and ozonation has been demonstrated in many literatures, which gives rise to an improvement of total organic carbon removal. The present overview dissects the heterogeneous catalysts and the influences of different operational parameters, followed by the discussion on the kinetics, mechanism, economic feasibility and future trends of this integrated technology. The enhanced oxidation rate mainly results from a large amount of hydroxyl radicals generated from a synergistically induced decomposition of dissolved ozone, besides superoxide ion radicals and the photo-induced holes. Six reaction pathways possibly exist for the generation of hydroxyl radicals in the reaction mechanism of heterogeneous photocatalytic ozonation.

  7. Removal of Biologically Active Organic Contaminants using Atomic Oxygen

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A. (Inventor); Banks, Michael A. (Inventor); Banks, Eric B. (Inventor)

    2003-01-01

    Biomedical devices that are to come into contact with living tissue, such as prosthetic and other implants for the human body and the containers used to store and transport them, are together cleaned of non-living, but biologically active organic materials, including endotoxins such as lipopolysaccharides, and assembled into a hermetically sealed package without recontamination. This is achieved by cleaning both the device and package components together in an apparatus, which includes a hermetically sealed chamber, in which they are contacted with atomic oxygen which biocleans them, by oxidizing the biologically active organic materials. The apparatus also includes means for manipulating the device and container and hermetically sealing the cleaned device into the cleaned container to form the package. A calibrated witness coupon visually indicates whether or not the device and container have received enough exposure to the atomic oxygen to have removed the organic materials from their surfaces. Gamma radiation is then used to sterilize the device in the sealed container.

  8. Synthetic applications of pseudocyclic hypervalent iodine compounds.

    PubMed

    Yoshimura, Akira; Yusubov, Mekhman S; Zhdankin, Viktor V

    2016-06-01

    Hypervalent iodine compounds have found wide practical application as versatile, efficient, and sustainable reagents for organic synthesis. Pseudocyclic hypervalent iodine derivatives are characterized by the presence of additional intramolecular non-covalent coordination at the iodine center, which leads to significant alteration of their physical and chemical properties. In comparison with common hypervalent iodine reagents, these pseudocyclic compounds have higher thermal stability, better solubility, and improved reactivity. In recent years, pseudocyclic hypervalent iodine reagents are increasingly used in organic synthesis as environmentally friendly selective oxidants and electrophiles. Furthermore, numerous enantioselective reactions mediated by chiral pseudocyclic hypervalent iodine species have been recently developed. In the present review, the preparation and structural features of pseudocyclic iodine(iii) and iodine(v) derivatives are discussed, and recent developments in their synthetic applications are summarized. PMID:27143521

  9. Removal of organic contaminants by RO and NF membranes

    NASA Technical Reports Server (NTRS)

    Yoon, Yeomin; Lueptow, Richard M.

    2005-01-01

    Rejection characteristics of organic and inorganic compounds were examined for six reverse osmosis (RO) membranes and two nanofiltration (NF) membranes that are commercially available. A batch stirred-cell was employed to determine the membrane flux and the solute rejection for solutions at various concentrations and different pH conditions. The results show that for ionic solutes the degree of separation is influenced mainly by electrostatic exclusion, while for organic solutes the removal depends mainly upon the solute radius and molecular structure. In order to provide a better understanding of rejection mechanisms for the RO and NF membranes, the ratio of solute radius (r(i,s)) to effective membrane pore radius (r(p)) was employed to compare rejections. An empirical relation for the dependence of the rejection of organic compounds on the ratio r(i,s)/r(p) is presented. The rejection for organic compounds is over 75% when r(i,s)/r(p) is greater than 0.8. In addition, the rejection of organic compounds is examined using the extended Nernst-Planck equation coupled with a steric hindrance model. The transport of organic solutes is controlled mainly by diffusion for the compounds that have a high r(i,s)/r(p) ratio, while convection is dominant for compounds that have a small r(i,s)/r(p) ratio. c2005 Elsevier B.V. All rights reserved.

  10. Process for removing an organic compound from water

    DOEpatents

    Baker, Richard W.; Kaschemekat, Jurgen; Wijmans, Johannes G.; Kamaruddin, Henky D.

    1993-12-28

    A process for removing organic compounds from water is disclosed. The process involves gas stripping followed by membrane separation treatment of the stripping gas. The stripping step can be carried out using one or multiple gas strippers and using air or any other gas as stripping gas. The membrane separation step can be carried out using a single-stage membrane unit or a multistage unit. Apparatus for carrying out the process is also disclosed. The process is particularly suited for treatment of contaminated groundwater or industrial wastewater.

  11. Iodine Deficiency

    MedlinePlus

    ... enlargement of the thyroid (goiter – see Goiter brochure ), hypothyroidism (see Hypothyroidism brochure ) and to mental retardation in infants and ... when lying down, and difficulty swallowing and breathing. HYPOTHYROIDISM – As the body’s iodine levels fall, hypothyroidism may ...

  12. Molecular environment of stable iodine and radioiodine (129I) in natural organic matter: Evidence inferred from NMR and binding experiments at environmentally relevant concentrations

    NASA Astrophysics Data System (ADS)

    Xu, Chen; Zhong, Junyan; Hatcher, Patrick G.; Zhang, Saijin; Li, Hsiu-Ping; Ho, Yi-Fang; Schwehr, Kathleen A.; Kaplan, Daniel I.; Roberts, Kimberly A.; Brinkmeyer, Robin; Yeager, Chris M.; Santschi, Peter H.

    2012-11-01

    129I is a major by-product of nuclear fission and had become one of the major radiation risk drivers at Department of Energy (DOE) sites. 129I is present at elevated levels in the surface soils of the Savannah River Site (SRS) F-Area and was found to be bound predominantly to soil organic matter (SOM). Naturally bound 127I and 129I to sequentially extracted humic acids (HAs), fulvic acids (FAs) and a water extractable colloid (WEC) were measured in a 129I-contaminated wetland surface soil located on the SRS. WEC is a predominantly colloidal organic fraction obtained from soil re-suspension experiments to mimic the fraction that may be released during groundwater exfiltration, storm water or surface runoff events. For the first time, NMR techniques were applied to infer the molecular environment of naturally occurring stable iodine and radioiodine binding to SOM. Iodine uptake partitioning coefficients (Kd) by these SOM samples at ambient iodine concentrations were also measured and related to quantitative structural analyses by 13C DPMAS NMR and solution state 1H NMR on the eight humic acid fractions. By assessing the molecular environment of iodine, it was found that it was closely associated with the aromatic regions containing esterified products of phenolic and formic acids or other aliphatic carboxylic acids, amide functionalities, quinone-like structures activated by electron-donating groups (e.g., NH2), or a hemicellulose-lignin-like complex with phenyl-glycosidic linkages. However, FAs and WEC contained much greater concentrations of 127I or 129I than HAs. The contrasting radioiodine contents among the three different types of SOM (HAs, FAs and WEC) suggest that the iodine binding environment cannot be explained solely by the difference in the amount of their reactive binding sites. Instead, indirect evidence indicates that the macro-molecular conformation, such as the hydrophobic aliphatic periphery hindering the active aromatic cores and the hydrophilic

  13. Wastewater disinfection and organic matter removal using ferrate (VI) oxidation.

    PubMed

    Bandala, Erick R; Miranda, Jocelyn; Beltran, Margarita; Vaca, Mabel; López, Raymundo; Torres, Luis G

    2009-09-01

    The use of iron in a +6 valence state, (Fe (VI), as FeO4(-2)) was tested as a novel alternative for wastewater disinfection and decontamination. The removal of organic matter (OM) and index microorganisms present in an effluent of a wastewater plant was determined using FeO4(-2) without any pH adjustment. It was observed that concentrations of FeO4(-2) ranging between 5 and 14 mg l(-1) inactivated up to 4-log of the index microorganisms (initial concentration c.a. 10(6) CFU/100 ml) and achieved OM removal up to almost 50%. The performance of FeO4(-2) was compared with OM oxidation and disinfection using hypochlorite. It was observed that hypochlorite was less effective in OM oxidation and coliform inactivation than ferrate. Results of this work suggest that FeO4(-2) could be an interesting oxidant able to deactivate pathogenic microorganisms in water with high OM content and readily oxidize organic matter without jeopardizing its efficiency on microorganism inactivation.

  14. Wastewater disinfection and organic matter removal using ferrate (VI) oxidation.

    PubMed

    Bandala, Erick R; Miranda, Jocelyn; Beltran, Margarita; Vaca, Mabel; López, Raymundo; Torres, Luis G

    2009-09-01

    The use of iron in a +6 valence state, (Fe (VI), as FeO4(-2)) was tested as a novel alternative for wastewater disinfection and decontamination. The removal of organic matter (OM) and index microorganisms present in an effluent of a wastewater plant was determined using FeO4(-2) without any pH adjustment. It was observed that concentrations of FeO4(-2) ranging between 5 and 14 mg l(-1) inactivated up to 4-log of the index microorganisms (initial concentration c.a. 10(6) CFU/100 ml) and achieved OM removal up to almost 50%. The performance of FeO4(-2) was compared with OM oxidation and disinfection using hypochlorite. It was observed that hypochlorite was less effective in OM oxidation and coliform inactivation than ferrate. Results of this work suggest that FeO4(-2) could be an interesting oxidant able to deactivate pathogenic microorganisms in water with high OM content and readily oxidize organic matter without jeopardizing its efficiency on microorganism inactivation. PMID:19491501

  15. Removal of floating organic in Hanford Waste Tank 241-C-103 restart plan

    SciTech Connect

    Wilson, T.R.; Hanson, C.

    1994-10-03

    The decision whether or not to remove the organic layer from Waste Tank 241-C-103 was deferred until May, 1995. The following restart plan was prepared for removal of the organic if the decision is to remove the organic from the waste tank 241-C-103.

  16. Luminescent MOFs comprising mixed tritopic linkers and Cd(II)/Zn(II) nodes for selective detection of organic nitro compounds and iodine capture

    SciTech Connect

    Rachuri, Yadagiri; Bisht, Kamal Kumar; Parmar, Bhavesh; Suresh, Eringathodi

    2015-03-15

    Two CPs ([Cd{sub 3}(BTC){sub 2}(TIB){sub 2}(H{sub 2}O){sub 4}].(H{sub 2}O){sub 2}){sub n} (1) and ([Zn{sub 3}(BTC){sub 2}(TIB){sub 2}].(H{sub 2}O){sub 6}){sub n} (2) composed of tripodal linkers BTC (1,3,5-benzenetricarboxylate) and TIB (1,3,5-tris(imidazol-1-ylmethyl)benzene) were synthesized via solvothermal route and structurally characterized. Single crystal structural analysis reveals 1 possesses a novel 3D framework structure, whereas 2 represents a previously established compound. Owing to the d{sup 10} configuration of metal nodes and robust 3D frameworks, 1 and 2 exhibit excellent fluorescence properties which have been exploited to sense organic nitro compounds in vapor phase. Compound 1 demonstrates selective sensing of nitromethane over structurally similar methanol with ca. 70 and 43% fluorescence quenching in case of former and later. Similarly, 58% fluorescence quenching was observed in case of nitrobenzene over the structurally resembling toluene for which 30% quenching was observed. Compound 2 did not show any preference for nitro compounds and exhibited comparable fluorescence quenching when exposed to the vapors of nitro or other geometrically resembling organic molecules. Furthermore, adsorption experiments revealed that 1 and 2 can uptake 2.74 and 14.14 wt% molecular iodine respectively in vapor phase which can be released in organic solvents such as hexane and acetonitrile. The maximal iodine uptake in case of 1 and 2 corresponds to 0.15 and 0.80 molecules of iodine per formula unit of respective frameworks. Comprehensive structural description, thermal stability and luminescence behavior for both CPs has also been presented. - Graphical abstract: Two 3D luminescent CPs comprising mixed tripodal ligands have been hydrothermally synthesized and structurally characterized. Iodine encapsulation capacity of synthesized CPs is evaluated and their fluorescence quenching in presence of small organic molecules is exploited for sensing of nitro

  17. Changes in the regulation of iodine crystals and chemical mixtures containing over 2.2 percent iodine. Final rule.

    PubMed

    2007-07-01

    This rulemaking changes the regulation of the listed chemical iodine under the chemical regulatory provisions of the Controlled Substances Act (CSA). The Drug Enforcement Administration (DEA) believes that this action is necessary to remove deficiencies in the existing regulatory controls, which have been exploited by drug traffickers who divert iodine (in the form of iodine crystals and iodine tincture) for the illicit production of methamphetamine in clandestine drug laboratories. This rulemaking moves iodine from List II to List I; reduces the iodine threshold from 0.4 kilograms to zero kilograms; adds import and export regulatory controls; and controls chemical mixtures containing greater than 2.2 percent iodine. This rulemaking establishes regulatory controls that will apply to iodine crystals and iodine chemical mixtures that contain greater than 2.2 percent iodine. This regulation therefore controls iodine crystals and strong iodine tinctures/solutions (e.g., 7 percent iodine) that do not have common household uses and instead have limited application in livestock, horses, and for disinfection of equipment. Household products such as 2 percent iodine tincture/solution and household disinfectants containing iodine complexes will not be adversely impacted by this regulation. Additionally, the final rule exempts transactions of up to one-fluid-ounce (30 ml) of Lugol's Solution. Persons handling regulated iodine materials are required to register with DEA, are subject to the import/export notification requirements of the CSA, and are required to maintain records of all regulated transactions involving iodine regardless of size.

  18. Fractionation and removal of dissolved organic carbon in a full-scale granular activated carbon filter used for drinking water production.

    PubMed

    Gibert, Oriol; Lefèvre, Benoît; Fernández, Marc; Bernat, Xavier; Paraira, Miquel; Pons, Marc

    2013-05-15

    The removal of natural organic matter (NOM) and, more particularly, its individual fractions by two different GACs was investigated in full-scale filters in a drinking water treatment plant (DWTP). Fractionation of NOM was performed by high performance size exclusion chromatography (HPSEC) into biopolymers, humic substances, building blocks and low molecular weight organics. The sorption capacity of GAC in terms of iodine number (IN) and apparent surface area (SBET), as well as the filling of narrow- and super-microporosity were monitored over the 1-year operation of the filters. Both GACs demonstrated to be effective at removing NOM over a wide range of fractions, especially the low and intermediate molecular weight fractions. TOC removal initially occurred via adsorption, and smaller (lighter) fractions were more removed as they could enter and diffuse more easily through the pores of the adsorbent. As time progressed, biodegradation also played a role in the TOC removal, and lighter fractions continued to be preferentially removed due to their higher biodegradability. The gained knowledge would assist drinking water utilities in selecting a proper GAC for the removal of NOM from water and, therefore, complying more successfully the latest water regulations.

  19. REMOVAL OF ORGANIC POLLUTANTS FROM SUBCRITICAL WATER WITH ACTIVATED CARBON

    SciTech Connect

    Steven B. Hawthorne; Arnaud J. Lagadec

    1999-08-01

    The Energy & Environmental Research Center (EERC) has demonstrated that controlling the temperature (and to a lesser extent, the pressure) of water can dramatically change its ability to extract organics and inorganics from matrices ranging from soils and sediments to waste sludges and coal. The dielectric constant of water can be changed from about 80 (a very polar solvent) to <5 (similar to a nonpolar organic solvent) by controlling the temperature (from ambient to about 400 C) and pressure (from about 5 to 350 bar). The EERC has shown that hazardous organic pollutants such as pesticides, PACS (polycyclic aromatic hydrocarbons), and PCBs (polychlorinated biphenyls) can be completely removed from soils, sludges, and sediments at temperatures (250 C) and pressures (<50 atm) that are much milder than typically used for supercritical water processes (temperature >374 C, pressure >221 atm). In addition, the process has been demonstrated to be particularly effective for samples containing very high levels of contaminants (e.g., part per thousand). Current projects include demonstrating the subcritical water remediation process at the pilot scale using an 8-liter system constructed under separate funding during 1997. To date, subcritical water has been shown to be an effective extraction fluid for removing a variety of organic pollutants from soils and sludges contaminated with fossil fuel products and waste products, including PACS from soil (e.g., town gas sites), refining catalysts, and petroleum tank bottom sludges; PCBs from soil and sediments; toxic gasoline components (e.g., benzene) from soil and waste sludge; and phenols from petroleum refinery sludges. The obvious need to clean the wastewater from subcritical water processes led to preliminary experiments with activated carbon placed in line after the extractor. Initial experiments were performed before and after cooling the extractant water (e.g., with water at 200 C and with water cooled to 25 C

  20. Performance of rotating drum biofilter for volatile organic compound removal at high organic loading rates.

    PubMed

    Yang, Chunping; Chen, Hong; Zeng, Guangming; Zhu, Xueqing; Suidan, Makram T

    2008-01-01

    Uneven distribution of volatile organic compounds (VOCs) and biomass, and excess biomass accumulation in some biofilters hinder the application of biofiltration technology. An innovative multilayer rotating drum biofilter (RDB) was developed to correct these problems. The RDB was operated at an empty bed contact time (EBCT) of 30 s and a rotational rate of 1.0 r/min. Diethyl ether was chosen as the model VOC. Performance of the RDB was evaluated at organic loading rates of 32.1, 64.2, 128, and 256 g ether/(m3 x h) (16.06 g ether/(m3 x h) approximately 1.0 kg chemical oxygen demand (COD)/(m3 x d)). The EBCT and organic loading rates were recorded on the basis of the medium volume. Results show that the ether removal efficiency decreased with an increased VOC loading rate. Ether removal efficiencies exceeding 99% were achieved without biomass control even at a high VOC loading rate of 128 g ether/(m3 x h). However, when the VOC loading rate was increased to 256 g ether/(m3 x h), the average removal efficiency dropped to 43%. Nutrient limitation possibly contributed to the drop in ether removal efficiency. High biomass accumulation rate was also observed in the medium at the two higher ether loading rates, and removal of the excess biomass in the media was necessary to maintain stable performance. This work showed that the RDB is effective in the removal of diethyl ether from waste gas streams even at high organic loading rates. The results might help establish criteria for designing and operating RDBs. PMID:18595394

  1. Removal of gasoline volatile organic compounds via air biofiltration

    SciTech Connect

    Miller, R.S.; Saberiyan, A.G.; Esler, C.T.; DeSantis, P.; Andrilenas, J.S.

    1995-12-31

    Volatile organic compounds (VOCs) generated by vapor extraction and air-stripping systems can be biologically treated in an air biofiltration unit. An air biofilter consists of one or more beds of packing material inoculated with heterotrophic microorganisms capable of degrading the organic contaminant of concern. Waste gases and oxygen are passed through the inoculated packing material, where the microorganisms will degrade the contaminant and release CO{sub 2} + H{sub 2}O. Based on data obtained from a treatability study, a full-scale unit was designed and constructed to be used for treating gasoline vapors generated by a vapor-extraction and groundwater-treatment system at a site in California. The unit is composed of two cylindrical reactors with a total packing volume of 3 m{sup 3}. Both reactors are packed with sphagnum moss and inoculated with hydrocarbon-degrading microorganisms of Pseudomonas and Arthrobacter spp. The two reactors are connected in series for air-flow passage. Parallel lines are used for injection of water, nutrients, and buffer to each reactor. Data collected during the startup program have demonstrated an air biofiltration unit with high organic-vapor-removal efficiency.

  2. Organic pollution removal from coke plant wastewater using coking coal.

    PubMed

    Gao, Lihui; Li, Shulei; Wang, Yongtian; Sun, Hao

    2015-01-01

    Coke plant wastewater (CPW) is an intractable chemical wastewater, and it contains many toxic pollutants. This article presents the results of research on a semi-industrial adsorption method of coking wastewater treatment. As a sorbent, the coking coal (CC) was a dozen times less expensive than active carbon. The treatment was conducted within two scenarios, as follows: (1) adsorption after biological treatment of CPW with CC at 40 g L(-1); the chemical oxygen demand (COD) removal was 75.66%, and the concentration was reduced from 178.99 to 43.56 mg L(-1); (2) given an adsorption by CC of 250 g L(-1) prior to the biological treatment of CPW, the eliminations of COD and phenol were 58.08% and 67.12%, respectively. The CC that adsorbed organic pollution and was returned to the coking system might have no effect on both coke oven gas and coke.

  3. Organic pollution removal from coke plant wastewater using coking coal.

    PubMed

    Gao, Lihui; Li, Shulei; Wang, Yongtian; Sun, Hao

    2015-01-01

    Coke plant wastewater (CPW) is an intractable chemical wastewater, and it contains many toxic pollutants. This article presents the results of research on a semi-industrial adsorption method of coking wastewater treatment. As a sorbent, the coking coal (CC) was a dozen times less expensive than active carbon. The treatment was conducted within two scenarios, as follows: (1) adsorption after biological treatment of CPW with CC at 40 g L(-1); the chemical oxygen demand (COD) removal was 75.66%, and the concentration was reduced from 178.99 to 43.56 mg L(-1); (2) given an adsorption by CC of 250 g L(-1) prior to the biological treatment of CPW, the eliminations of COD and phenol were 58.08% and 67.12%, respectively. The CC that adsorbed organic pollution and was returned to the coking system might have no effect on both coke oven gas and coke. PMID:26114284

  4. A Robust Organic Dye for Dye Sensitized Solar Cells Based on Iodine/Iodide Electrolytes Combining High Efficiency and Outstanding Stability

    PubMed Central

    Joly, Damien; Pellejà, Laia; Narbey, Stéphanie; Oswald, Frédéric; Chiron, Julien; Clifford, John N.; Palomares, Emilio; Demadrille, Renaud

    2014-01-01

    Among the new photovoltaic technologies, the Dye-Sensitized Solar Cell (DSC) is becoming a realistic approach towards energy markets such as BIPV (Building Integrated PhotoVoltaics). In order to improve the performances of DSCs and to increase their commercial attractiveness, cheap, colourful, stable and highly efficient ruthenium-free dyes must be developed. Here we report the synthesis and complete characterization of a new purely organic sensitizer (RK1) that can be prepared and synthetically upscaled rapidly. Solar cells containing this orange dye show a power conversion efficiency of 10.2% under standard conditions (AM 1.5G, 1000 Wm−2) using iodine/iodide as the electrolyte redox shuttle in the electrolyte, which is among the few examples of DSC using an organic dyes and iodine/iodide red/ox pair to overcome the 10% efficiency barrier. We demonstrate that the combination of this dye with an ionic liquid electrolyte allows the fabrication of solar cells that show power conversion efficiencies of up to 7.36% that are highly stable with no measurable degradation of initial performances after 2200 h of light soaking at 65°C under standard irradiation conditions. RK1 achieves one of the best output power conversion efficiencies for a solar cell based on the iodine/iodide electrolyte, combining high efficiency and outstanding stability. PMID:24504344

  5. A Robust Organic Dye for Dye Sensitized Solar Cells Based on Iodine/Iodide Electrolytes Combining High Efficiency and Outstanding Stability

    NASA Astrophysics Data System (ADS)

    Joly, Damien; Pellejà, Laia; Narbey, Stéphanie; Oswald, Frédéric; Chiron, Julien; Clifford, John N.; Palomares, Emilio; Demadrille, Renaud

    2014-02-01

    Among the new photovoltaic technologies, the Dye-Sensitized Solar Cell (DSC) is becoming a realistic approach towards energy markets such as BIPV (Building Integrated PhotoVoltaics). In order to improve the performances of DSCs and to increase their commercial attractiveness, cheap, colourful, stable and highly efficient ruthenium-free dyes must be developed. Here we report the synthesis and complete characterization of a new purely organic sensitizer (RK1) that can be prepared and synthetically upscaled rapidly. Solar cells containing this orange dye show a power conversion efficiency of 10.2% under standard conditions (AM 1.5G, 1000 Wm-2) using iodine/iodide as the electrolyte redox shuttle in the electrolyte, which is among the few examples of DSC using an organic dyes and iodine/iodide red/ox pair to overcome the 10% efficiency barrier. We demonstrate that the combination of this dye with an ionic liquid electrolyte allows the fabrication of solar cells that show power conversion efficiencies of up to 7.36% that are highly stable with no measurable degradation of initial performances after 2200 h of light soaking at 65°C under standard irradiation conditions. RK1 achieves one of the best output power conversion efficiencies for a solar cell based on the iodine/iodide electrolyte, combining high efficiency and outstanding stability.

  6. A robust organic dye for dye sensitized solar cells based on iodine/iodide electrolytes combining high efficiency and outstanding stability.

    PubMed

    Joly, Damien; Pellejà, Laia; Narbey, Stéphanie; Oswald, Frédéric; Chiron, Julien; Clifford, John N; Palomares, Emilio; Demadrille, Renaud

    2014-02-07

    Among the new photovoltaic technologies, the Dye-Sensitized Solar Cell (DSC) is becoming a realistic approach towards energy markets such as BIPV (Building Integrated PhotoVoltaics). In order to improve the performances of DSCs and to increase their commercial attractiveness, cheap, colourful, stable and highly efficient ruthenium-free dyes must be developed. Here we report the synthesis and complete characterization of a new purely organic sensitizer (RK1) that can be prepared and synthetically upscaled rapidly. Solar cells containing this orange dye show a power conversion efficiency of 10.2% under standard conditions (AM 1.5G, 1000 Wm(-2)) using iodine/iodide as the electrolyte redox shuttle in the electrolyte, which is among the few examples of DSC using an organic dyes and iodine/iodide red/ox pair to overcome the 10% efficiency barrier. We demonstrate that the combination of this dye with an ionic liquid electrolyte allows the fabrication of solar cells that show power conversion efficiencies of up to 7.36% that are highly stable with no measurable degradation of initial performances after 2200 h of light soaking at 65°C under standard irradiation conditions. RK1 achieves one of the best output power conversion efficiencies for a solar cell based on the iodine/iodide electrolyte, combining high efficiency and outstanding stability.

  7. High exposures to organic solvents among graffiti removers.

    PubMed

    Anundi, H; Lind, M L; Friis, L; Itkes, N; Langworth, S; Edling, C

    1993-01-01

    The exposure to organic solvents among 12 graffiti removers was studied. Health effects were also assessed by structured interview and a symptom questionnaire. Blood and urine samples were collected at the end of the day of air sampling. The concentrations of dichloromethane, glycol ethers, trimethylbenzenes and N-methyl-2-pyrrolidinone in the breathing zone of each worker were measured during one working day. The 8-h time-weighted average exposure to dichloromethane ranged from 18 to 1200 mg/m3. The Swedish Permissible Exposure Limit value for dichloromethane is 120 mg/m3. The air concentrations of glycol ethers, trimethylbenzenes and N-methyl-2-pyrrolidinone were low or not detectable. No exposure-related deviations in the serum concentrations of creatinine, aspartate transaminase, alanine transaminase, gamma-glutamyl transpeptidase or hyaluronan or the urine concentrations of alpha 1-microglobulin, beta 2-microglobulin or N-acetyl-beta-glucosaminidase were found. Irritative symptoms of the eyes and upper respiratory tract were more prevalent than in the general population. This study demonstrates that old knowledge about work hazards is not automatically transferred to new professions. Another aspect is that the public is also exposed as the job is performed during daytime in underground stations. At least for short periods, bystanders may be exposed to high concentrations of organic solvent vapours. People with predisposing conditions, e.g. asthmatics, may risk adverse reactions. PMID:8144235

  8. High exposures to organic solvents among graffiti removers.

    PubMed

    Anundi, H; Lind, M L; Friis, L; Itkes, N; Langworth, S; Edling, C

    1993-01-01

    The exposure to organic solvents among 12 graffiti removers was studied. Health effects were also assessed by structured interview and a symptom questionnaire. Blood and urine samples were collected at the end of the day of air sampling. The concentrations of dichloromethane, glycol ethers, trimethylbenzenes and N-methyl-2-pyrrolidinone in the breathing zone of each worker were measured during one working day. The 8-h time-weighted average exposure to dichloromethane ranged from 18 to 1200 mg/m3. The Swedish Permissible Exposure Limit value for dichloromethane is 120 mg/m3. The air concentrations of glycol ethers, trimethylbenzenes and N-methyl-2-pyrrolidinone were low or not detectable. No exposure-related deviations in the serum concentrations of creatinine, aspartate transaminase, alanine transaminase, gamma-glutamyl transpeptidase or hyaluronan or the urine concentrations of alpha 1-microglobulin, beta 2-microglobulin or N-acetyl-beta-glucosaminidase were found. Irritative symptoms of the eyes and upper respiratory tract were more prevalent than in the general population. This study demonstrates that old knowledge about work hazards is not automatically transferred to new professions. Another aspect is that the public is also exposed as the job is performed during daytime in underground stations. At least for short periods, bystanders may be exposed to high concentrations of organic solvent vapours. People with predisposing conditions, e.g. asthmatics, may risk adverse reactions.

  9. Speciation of iodine in high iodine groundwater in china associated with goitre and hypothyroidism.

    PubMed

    Andersen, Stig; Guan, Haixia; Teng, Weiping; Laurberg, Peter

    2009-05-01

    Iodine intake affects the occurrence of disease in a population. Excessive iodine intake may be caused by a high iodine content of drinking water. Tap water in few locations in Europe contains up to 139 microg/L mostly bound to humic substances, probably leaching from marine sediments in the aquifers. Even higher iodine contents have been found in Chinese waters, previously shown to associate with goitre and hypothyroidism. The aims were to elucidate speciation of high iodine groundwater from deep wells in China and to compare with high iodine waters from Europe. Water was sampled from eight wells in five villages along Bohai Bay, China. Macro-molecules and low molecular weight (MW) substances were separated by size exclusion chromatography (high performance liquid chromatography, Superose 12 HR 10/30, buffer 0.1 M Tris, pH 7.0). Organic material was evaluated by A280 and iodine in fractions measured by the Ce/As method after alkaline incineration. Iodine content of well water varied from 135 to 880 microg/L (median 287 microg/L). The amount of organic material in water was low with A280, <1-5 mAU. The chromatographic traces were similar between samples: One peak of iodine eluted around K (AV) 0.65 corresponding to MW 5 kDa (humic substances) and one peak at V (total) (iodide/low MW substances). The fraction of iodine in macro-molecules, suggested to be humic substances, varied from 8% to 70% (median 27%). Iodine and peak absorbance were associated (p = 0.006). In conclusion, iodine in iodine-rich deep well water in northern China may have marine origin and may associate with humic substances, comparable to shallow well iodine-rich water in Europe. High iodine intake from iodine-rich water suggests the cause of endemic goitre and hypothyroidism in some areas in China being iodine.

  10. Geochemical Cycling of Iodine Species in Soils

    SciTech Connect

    Hu, Q; Moran, J E; Blackwood, V

    2007-08-23

    Iodine is an important element in studies of environmental protection and human health, global-scale hydrologic processes and nuclear nonproliferation. Biogeochemical cycling of iodine in soils is complex, because iodine occurs in multiple oxidation states and as inorganic and organic species that may be hydrophilic, atmophilic, and biophilic. In this study, we applied new analytical techniques to study the content and speciation of stable iodine in representative surface soils, and sorption and transport behavior of iodine species (iodide, iodate, and 4-iodoaniline) in sediments collected at numerous nuclear facilities in the United States, where anthropogenic {sup 129}I from prior nuclear fuel processing activities poses an environmental risk. The surface soil samples were chosen for their geographic locations (e.g., near the ocean or nuclear facilities) and for their differing physico-chemical characteristics (organic matter, texture, etc). Extracted solutions were analyzed by IC and ICP-MS methods to determine iodine concentrations and to examine iodine speciation (iodide, iodate, and organic iodine). In natural soils, iodine is mostly (nearly 90% of total iodine) present as organic species, while inorganic iodine becomes important (up to 50%) only in sediments with low organic matter. Results from laboratory column studies, aimed at examining transport of different iodine species, showed much greater retardation of 4-iodoaniline than iodide or iodate. Careful attention must be given to potential interconversion among species when interpreting the biogeochemical behavior of iodine in the environment. In addition to speciation, input concentration and residence time effects will influence the biogeochemical cycling of anthropogenic 129I deposited on surface soils.

  11. Iodine Satellite

    NASA Technical Reports Server (NTRS)

    Kamhawi, Hani; Dankanich, John; Martinez, Andres; Petro, Andrew

    2015-01-01

    The Iodine Satellite (iSat) spacecraft will be the first CubeSat to demonstrate high change in velocity from a primary propulsion system by using Hall thruster technology and iodine as a propellant. The mission will demonstrate CubeSat maneuverability, including plane change, altitude change and change in its closest approach to Earth to ensure atmospheric reentry in less than 90 days. The mission is planned for launch in fall 2017. Hall thruster technology is a type of electric propulsion. Electric propulsion uses electricity, typically from solar panels, to accelerate the propellant. Electric propulsion can accelerate propellant to 10 times higher velocities than traditional chemical propulsion systems, which significantly increases fuel efficiency. To enable the success of the propulsion subsystem, iSat will also demonstrate power management and thermal control capabilities well beyond the current state-of-the-art for spacecraft of its size. This technology is a viable primary propulsion system that can be used on small satellites ranging from about 22 pounds (10 kilograms) to more than 1,000 pounds (450 kilograms). iSat's fuel efficiency is ten times greater and its propulsion per volume is 100 times greater than current cold-gas systems and three times better than the same system operating on xenon. iSat's iodine propulsion system consists of a 200 watt (W) Hall thruster, a cathode, a tank to store solid iodine, a power processing unit (PPU) and the feed system to supply the iodine. This propulsion system is based on a 200 W Hall thruster developed by Busek Co. Inc., which was previously flown using xenon as the propellant. Several improvements have been made to the original system to include a compact PPU, targeting greater than 80 percent reduction in mass and volume of conventional PPU designs. The cathode technology is planned to enable heaterless cathode conditioning, significantly increasing total system efficiency. The feed system has been designed to

  12. UTILITY OF ZEOLITES IN REMOVAL OF INORGANIC AND ORGANIC WATER POLLUTANTS

    EPA Science Inventory

    Zeolites are well known for their ion exchange, adsorption and acid catalysis properties. Different inorganic and organic pollutants have been removed from water at room temperature using various zeolites. Synthetic zeolite Faujasite Y has been used to remove inorganic pollutants...

  13. Iodine confinement into metal-organic frameworks (MOFs)-low temperature sintering glasses to form novel glass composite material (GCM) alternative waste forms.

    SciTech Connect

    Nenoff, Tina Maria; Garino, Terry J.; Sava, Dorina Florentina

    2010-11-01

    The safe handling of reprocessed fuel addresses several scientific goals, especially when considering the capture and long-term storage of volatile radionuclides that are necessary during this process. Despite not being a major component of the off-gas, radioiodine (I{sub 2}) is particularly challenging, because it is a highly mobile gas and {sup 129}I is a long-lived radionuclide (1.57 x 10{sup 7} years). Therefore, its capture and sequestration is of great interest on a societal level. Herein, we explore novel routes toward the effective capture and storage of iodine. In particular, we report on the novel use of a new class of porous solid-state functional materials (metal-organic frameworks, MOFs), as high-capacity adsorbents of molecular iodine. We further describe the formation of novel glass-composite material (GCM) waste forms from the mixing and sintering of the I{sub 2}-containing MOFs with Bi-Zn-O low-temperature sintering glasses and silver metal flakes. Our findings indicate that, upon sintering, a uniform monolith is formed, with no evidence of iodine loss; iodine is sequestered during the heating process by the in situ formation of AgI. Detailed materials characterization analysis is presented for the GCMs. This includes powder X-ray diffraction, scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS), thermal analysis (thermogravimetric analysis (TGA)), and chemical durability tests including aqueous leach studies (product consistency test (PCT)), with X-ray fluorescence (XRF) and inductively coupled plasma-mass spectrometry (ICP-MS) of the PCT leachate.

  14. Atmospheric science: marine aerosols and iodine emissions.

    PubMed

    McFiggans, Gordon

    2005-02-10

    O'Dowd et al. describe the formation of marine aerosols from biogenic iodine and the growth of these aerosols into cloud-condensation nuclei (CCN). Based on chamber and modelling results, the authors suggest that biogenic organic iodine compounds emitted from macroalgae may be responsible for coastal particle bursts and that production of these compounds in the open ocean could increase CCN there too. It has since been shown that coastal particles are more likely to be produced from the photooxidation of molecular iodine. Moreover, I contend that open-ocean particle production and cloud enhancement do not result from emissions of organic iodine at atmospheric levels. For iodine particles to affect cloud properties over the remote ocean, an additional source of iodine is necessary as organic precursors cannot be responsible.

  15. Atmospheric science: marine aerosols and iodine emissions.

    PubMed

    McFiggans, Gordon

    2005-02-10

    O'Dowd et al. describe the formation of marine aerosols from biogenic iodine and the growth of these aerosols into cloud-condensation nuclei (CCN). Based on chamber and modelling results, the authors suggest that biogenic organic iodine compounds emitted from macroalgae may be responsible for coastal particle bursts and that production of these compounds in the open ocean could increase CCN there too. It has since been shown that coastal particles are more likely to be produced from the photooxidation of molecular iodine. Moreover, I contend that open-ocean particle production and cloud enhancement do not result from emissions of organic iodine at atmospheric levels. For iodine particles to affect cloud properties over the remote ocean, an additional source of iodine is necessary as organic precursors cannot be responsible. PMID:15703706

  16. Removal of organic impurities from liquid carbon dioxide

    NASA Astrophysics Data System (ADS)

    Zito, Richard R.

    2002-09-01

    The use of a high velocity stream of carbon dioxide snowflakes to clean large optics is well known, and has gained widespread acceptance in the astronomical community as a telescope maintenance technique. Ultimately, however, the success of carbon dioxide snow cleaning depends on the availability of high purity carbon dioxide. The higher the purity of the carbon dioxide, the longer will be the time interval between required mirror washings. The highest grades of commercially produced liquid carbon dioxide are often not available in the more remote regions of the world - such as where major astronomical observatories are often located. Furthermore, the purity of even the highest grades of carbon dioxide are only nominal, and wide variations are known to occur from tank to tank. Occasionally, visible deposits of organic impurities are left behind during cleaning with carbon dioxide that is believed to be 99.999% pure. A zeolite molecular sieve based filtration system has proven to be very effective in removing these organic impurities. A zeolite is a complex alumino-silicate. One example has an empirical formula of Na2O(Al2O3)(SiO2)2yH2O, where y=0 to 8. The zeolites have an open crystal structure and are capable of trapping impurities like 8-methylheptadecane (an oil) and 2,6-octadine-1-ol,3,7- dimethyl-,(E)- (a fatty acid). In fact, a zeolite can trap 29.5% of its own weight in SAE 20 lubricant at 25 degree(s)C. After filtration of liquid CO2 through zeolites, the concentration of measured impurities was below the detection limit for state-of-the-art gas chromatography systems.

  17. Removal of Separable Organic From Tank 241-C-103 Scoping Study

    SciTech Connect

    KOCH, M.R.

    2000-05-16

    This study is based on previous evaluations/proposals for removing the floating organic layer in C-103. A practical method is described with assumptions, cost and schedule estimates, and risks. Proposed operational steps include bulk organic removal, phase separation, organic washing and offsite disposal, followed by an in-situ polishing process.

  18. Role of natural organic matter on iodine and (239)(,240)Pu distribution and mobility in environmental samples from the northwestern Fukushima Prefecture, Japan.

    PubMed

    Xu, Chen; Zhang, Saijin; Sugiyama, Yuko; Ohte, Nobuhito; Ho, Yi-Fang; Fujitake, Nobuhide; Kaplan, Daniel I; Yeager, Chris M; Schwehr, Kathleen; Santschi, Peter H

    2016-03-01

    In order to assess how environmental factors are affecting the distribution and migration of radioiodine and plutonium that were emitted from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, we quantified iodine and (239,240)Pu concentration changes in soil samples with different land uses (urban, paddy, deciduous forest and coniferous forest), as well as iodine speciation in surface water and rainwater. Sampling locations were 53-63 km northwest of the FDNPP within a 75-km radius, in close proximity of each other. A ranking of the land uses by their surface soil (<4 cm) stable (127)I concentrations was coniferous forest > deciduous forest > urban > paddy, and (239,240)Pu concentrations ranked as deciduous forest > coniferous forest > paddy ≥ urban. Both were quite distinct from that of (134)Cs and (137)Cs: urban > coniferous forest > deciduous forest > paddy, indicating differences in their sources, deposition phases, and biogeochemical behavior in these soil systems. Although stable (127)I might not have fully equilibrated with Fukushima-derived (129)I, it likely still works as a proxy for the long-term fate of (129)I. Surficial soil (127)I content was well correlated to soil organic matter (SOM) content, regardless of land use type, suggesting that SOM might be an important factor affecting iodine biogeochemistry. Other soil chemical properties, such as Eh and pH, had strong correlations to soil (127)I content, but only within a given land use (e.g., within urban soils). Organic carbon (OC) concentrations and Eh were positively, and pH was negatively correlated to (127)I concentrations in surface water and rain samples. It is also noticeable that (127)I in the wet deposition was concentrated in both the deciduous and coniferous forest throughfall and stemfall water, respectively, comparing to the bulk rainwater. Further, both forest throughfall and stemflow water consisted exclusively of organo-iodine, suggesting all inorganic iodine in the

  19. Role of natural organic matter on iodine and (239)(,240)Pu distribution and mobility in environmental samples from the northwestern Fukushima Prefecture, Japan.

    PubMed

    Xu, Chen; Zhang, Saijin; Sugiyama, Yuko; Ohte, Nobuhito; Ho, Yi-Fang; Fujitake, Nobuhide; Kaplan, Daniel I; Yeager, Chris M; Schwehr, Kathleen; Santschi, Peter H

    2016-03-01

    In order to assess how environmental factors are affecting the distribution and migration of radioiodine and plutonium that were emitted from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, we quantified iodine and (239,240)Pu concentration changes in soil samples with different land uses (urban, paddy, deciduous forest and coniferous forest), as well as iodine speciation in surface water and rainwater. Sampling locations were 53-63 km northwest of the FDNPP within a 75-km radius, in close proximity of each other. A ranking of the land uses by their surface soil (<4 cm) stable (127)I concentrations was coniferous forest > deciduous forest > urban > paddy, and (239,240)Pu concentrations ranked as deciduous forest > coniferous forest > paddy ≥ urban. Both were quite distinct from that of (134)Cs and (137)Cs: urban > coniferous forest > deciduous forest > paddy, indicating differences in their sources, deposition phases, and biogeochemical behavior in these soil systems. Although stable (127)I might not have fully equilibrated with Fukushima-derived (129)I, it likely still works as a proxy for the long-term fate of (129)I. Surficial soil (127)I content was well correlated to soil organic matter (SOM) content, regardless of land use type, suggesting that SOM might be an important factor affecting iodine biogeochemistry. Other soil chemical properties, such as Eh and pH, had strong correlations to soil (127)I content, but only within a given land use (e.g., within urban soils). Organic carbon (OC) concentrations and Eh were positively, and pH was negatively correlated to (127)I concentrations in surface water and rain samples. It is also noticeable that (127)I in the wet deposition was concentrated in both the deciduous and coniferous forest throughfall and stemfall water, respectively, comparing to the bulk rainwater. Further, both forest throughfall and stemflow water consisted exclusively of organo-iodine, suggesting all inorganic iodine in the

  20. Impact of biological filtrations for organic micropollutants and polyfluoroalkyl substances removal from secondary effluent.

    PubMed

    Pramanik, Biplob Kumar; Pramanik, Sagor Kumar; Suja, Fatihah

    2016-08-01

    The impact of biological activated carbon (BAC), sand filtration (SF) and biological aerated filter (BAF) for removal of the selected organic micropollutants and polyfluoroalkyl substances (PFASs) from secondary effluent was studied. BAC led to greater removal of dissolved organic carbon (43%) than BAF (30%) which in turn was greater than SF (24%). All biological filtration systems could effectively remove most of the selected organic micropollutants, and there was a greater removal of these micropollutants by BAC (76-98%) than BAF (70-92%) or SF (68-90%). It was found that all treatment was effective for removal of the hydrophobic (log D > 3.2) and readily biodegradable organic micropollutants. The major mechanism for the removal of these molecules was biodegradation by the micro-organism and sorption by the biofilm. Compared to organic micropollutants removal, there was a lower removal of PFASs by all treatments, and BAF and SF had a considerably lower removal than BAC treatment. The better removal for all molecule types by BAC was due to additional adsorption capacity by the activated carbon. This study demonstrated that the BAC process was most effective in removing organic micropollutants present in the secondary effluent. PMID:26695189

  1. Dry method for recycling iodine-loaded silver zeolite

    DOEpatents

    Thomas, Thomas R.; Staples, Bruce A.; Murphy, Llewellyn P.

    1978-05-09

    Fission product iodine is removed from a waste gas stream and stored by passing the gas stream through a bed of silver-exchanged zeolite until the zeolite is loaded with iodine, passing dry hydrogen gas through the bed to remove the iodine and regenerate the bed, and passing the hydrogen stream containing the hydrogen iodide thus formed through a lead-exchanged zeolite which adsorbs the radioactive iodine from the gas stream and permanently storing the lead-exchanged zeolite loaded with radioactive iodine.

  2. Luminescent MOFs comprising mixed tritopic linkers and Cd(II)/Zn(II) nodes for selective detection of organic nitro compounds and iodine capture

    NASA Astrophysics Data System (ADS)

    Rachuri, Yadagiri; Bisht, Kamal Kumar; Parmar, Bhavesh; Suresh, Eringathodi

    2015-03-01

    Two CPs {[Cd3(BTC)2(TIB)2(H2O)4].(H2O)2}n (1) and {[Zn3(BTC)2(TIB)2].(H2O)6}n (2) composed of tripodal linkers BTC (1,3,5-benzenetricarboxylate) and TIB (1,3,5-tris(imidazol-1-ylmethyl)benzene) were synthesized via solvothermal route and structurally characterized. Single crystal structural analysis reveals 1 possesses a novel 3D framework structure, whereas 2 represents a previously established compound. Owing to the d10 configuration of metal nodes and robust 3D frameworks, 1 and 2 exhibit excellent fluorescence properties which have been exploited to sense organic nitro compounds in vapor phase. Compound 1 demonstrates selective sensing of nitromethane over structurally similar methanol with ca. 70 and 43% fluorescence quenching in case of former and later. Similarly, 58% fluorescence quenching was observed in case of nitrobenzene over the structurally resembling toluene for which 30% quenching was observed. Compound 2 did not show any preference for nitro compounds and exhibited comparable fluorescence quenching when exposed to the vapors of nitro or other geometrically resembling organic molecules. Furthermore, adsorption experiments revealed that 1 and 2 can uptake 2.74 and 14.14 wt% molecular iodine respectively in vapor phase which can be released in organic solvents such as hexane and acetonitrile. The maximal iodine uptake in case of 1 and 2 corresponds to 0.15 and 0.80 molecules of iodine per formula unit of respective frameworks. Comprehensive structural description, thermal stability and luminescence behavior for both CPs has also been presented.

  3. Iodine transport analysis in the ESBWR.

    SciTech Connect

    Kalinich, Donald A.; Gauntt, Randall O.; Young, Michael Francis; Longmire, Pamela

    2009-03-01

    A simplified ESBWR MELCOR model was developed to track the transport of iodine released from damaged reactor fuel in a hypothesized core damage accident. To account for the effects of iodine pool chemistry, radiolysis of air and cable insulation, and surface coatings (i.e., paint) the iodine pool model in MELCOR was activated. Modifications were made to MELCOR to add sodium pentaborate as a buffer in the iodine pool chemistry model. An issue of specific interest was whether iodine vapor removed from the drywell vapor space by the PCCS heat exchangers would be sequestered in water pools or if it would be rereleased as vapor back into the drywell. As iodine vapor is not included in the deposition models for diffusiophoresis or thermophoresis in current version of MELCOR, a parametric study was conducted to evaluate the impact of a range of iodine removal coefficients in the PCCS heat exchangers. The study found that higher removal coefficients resulted in a lower mass of iodine vapor in the drywell vapor space.

  4. Removal of dissolved organic matter by anion exchange: Effect of dissolved organic matter properties

    USGS Publications Warehouse

    Boyer, T.H.; Singer, P.C.; Aiken, G.R.

    2008-01-01

    Ten isolates of aquatic dissolved organic matter (DOM) were evaluated to determine the effect that chemical properties of the DOM, such as charge density, aromaticity, and molecular weight, have on DOM removal by anion exchange. The DOM isolates were characterized asterrestrial, microbial, or intermediate humic substances or transphilic acids. All anion exchange experiments were conducted using a magnetic ion exchange (MIEX) resin. The charge density of the DOM isolates, determined by direct potentiometric titration, was fundamental to quantifying the stoichiometry of the anion exchange mechanism. The results clearly show that all DOM isolates were removed by anion exchange; however, differences among the DOM isolates did influence their removal by MIEX resin. In particular, MIEX resin had the greatest affinity for DOM with high charge density and the least affinity for DOM with low charge density and low aromaticity. This work illustrates that the chemical characteristics of DOM and solution conditions must be considered when evaluating anion exchange treatment for the removal of DOM. ?? 2008 American Chemical Society.

  5. Synthesis of magnetic metal-organic framework (MOF) for efficient removal of organic dyes from water.

    PubMed

    Zhao, Xiaoli; Liu, Shuangliu; Tang, Zhi; Niu, Hongyun; Cai, Yaqi; Meng, Wei; Wu, Fengchang; Giesy, John P

    2015-01-01

    A novel, simple and efficient strategy for fabricating a magnetic metal-organic framework (MOF) as sorbent to remove organic compounds from simulated water samples is presented and tested for removal of methylene blue (MB) as an example. The novel adsorbents combine advantages of MOFs and magnetic nanoparticles and possess large capacity, low cost, rapid removal and easy separation of the solid phase, which makes it an excellent sorbent for treatment of wastewaters. The resulting magnetic MOFs composites (also known as MFCs) have large surface areas (79.52 m(2) g(-1)), excellent magnetic response (14.89 emu g(-1)), and large mesopore volume (0.09 cm(3) g(-1)), as well as good chemical inertness and mechanical stability. Adsorption was not drastically affected by pH, suggesting π-π stacking interaction and/or hydrophobic interactions between MB and MFCs. Kinetic parameters followed pseudo-second-order kinetics and adsorption was described by the Freundlich isotherm. Adsorption capacity was 84 mg MB g(-1) at an initial MB concentration of 30 mg L(-1), which increased to 245 mg g(-1) when the initial MB concentration was 300 mg L(-1). This capacity was much greater than most other adsorbents reported in the literature. In addition, MFC adsorbents possess excellent reusability, being effective after at least five consecutive cycles. PMID:26149818

  6. Synthesis of magnetic metal-organic framework (MOF) for efficient removal of organic dyes from water

    PubMed Central

    Zhao, Xiaoli; Liu, Shuangliu; Tang, Zhi; Niu, Hongyun; Cai, Yaqi; Meng, Wei; Wu, Fengchang; Giesy, John P.

    2015-01-01

    A novel, simple and efficient strategy for fabricating a magnetic metal-organic framework (MOF) as sorbent to remove organic compounds from simulated water samples is presented and tested for removal of methylene blue (MB) as an example. The novel adsorbents combine advantages of MOFs and magnetic nanoparticles and possess large capacity, low cost, rapid removal and easy separation of the solid phase, which makes it an excellent sorbent for treatment of wastewaters. The resulting magnetic MOFs composites (also known as MFCs) have large surface areas (79.52 m2 g−1), excellent magnetic response (14.89 emu g−1), and large mesopore volume (0.09 cm3 g−1), as well as good chemical inertness and mechanical stability. Adsorption was not drastically affected by pH, suggesting π–π stacking interaction and/or hydrophobic interactions between MB and MFCs. Kinetic parameters followed pseudo-second-order kinetics and adsorption was described by the Freundlich isotherm. Adsorption capacity was 84 mg MB g−1 at an initial MB concentration of 30 mg L−1, which increased to 245 mg g−1 when the initial MB concentration was 300 mg L−1. This capacity was much greater than most other adsorbents reported in the literature. In addition, MFC adsorbents possess excellent reusability, being effective after at least five consecutive cycles. PMID:26149818

  7. Synthesis of magnetic metal-organic framework (MOF) for efficient removal of organic dyes from water

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaoli; Liu, Shuangliu; Tang, Zhi; Niu, Hongyun; Cai, Yaqi; Meng, Wei; Wu, Fengchang; Giesy, John P.

    2015-07-01

    A novel, simple and efficient strategy for fabricating a magnetic metal-organic framework (MOF) as sorbent to remove organic compounds from simulated water samples is presented and tested for removal of methylene blue (MB) as an example. The novel adsorbents combine advantages of MOFs and magnetic nanoparticles and possess large capacity, low cost, rapid removal and easy separation of the solid phase, which makes it an excellent sorbent for treatment of wastewaters. The resulting magnetic MOFs composites (also known as MFCs) have large surface areas (79.52 m2 g-1), excellent magnetic response (14.89 emu g-1), and large mesopore volume (0.09 cm3 g-1), as well as good chemical inertness and mechanical stability. Adsorption was not drastically affected by pH, suggesting π-π stacking interaction and/or hydrophobic interactions between MB and MFCs. Kinetic parameters followed pseudo-second-order kinetics and adsorption was described by the Freundlich isotherm. Adsorption capacity was 84 mg MB g-1 at an initial MB concentration of 30 mg L-1, which increased to 245 mg g-1 when the initial MB concentration was 300 mg L-1. This capacity was much greater than most other adsorbents reported in the literature. In addition, MFC adsorbents possess excellent reusability, being effective after at least five consecutive cycles.

  8. [Removal effect of organics in Yangtze River raw water by MIEX resin pretreatment].

    PubMed

    Liu, Cheng; Chen, Wei; Li, Lei; Sheng, Yu

    2009-06-15

    Jar-tests were used to study the removal effect of organics by MIEX pre-treatment from Yangtze River raw water, in which molecular weight, fractionation, UV scan, disinfection by-products, DOC and UV254 were used to estimate the removal effect. The results showed that organics in raw water were mainly composed of low-molecular weight and hydrophilic fraction, which accounted for above 50% of total organics. Above 35% DOC was removed by MIEX pretreatment with a dosage of 10 mL/L and contact time of 15 min, which due to the removal of low molecular weight and hydrophilic organics. The results of UV scan showed that organics which had high adsorption between 190 nm and 250 nm were significantly removed by MIEX pretreatment, while the part that had high adsorption on wavelength above 250 nm could be removed similar to coagulation alone.

  9. Removal of Persistent Organic Contaminants by Electrochemically Activated Sulfate.

    PubMed

    Farhat, Ali; Keller, Jurg; Tait, Stephan; Radjenovic, Jelena

    2015-12-15

    Solutions of sulfate have often been used as background electrolytes in the electrochemical degradation of contaminants and have been generally considered inert even when high-oxidation-power anodes such as boron-doped diamond (BDD) were employed. This study examines the role of sulfate by comparing electro-oxidation rates for seven persistent organic contaminants at BDD anodes in sulfate and inert nitrate anolytes. Sulfate yielded electro-oxidation rates 10-15 times higher for all target contaminants compared to the rates of nitrate anolyte. This electrochemical activation of sulfate was also observed at concentrations as low as 1.6 mM, which is relevant for many wastewaters. Electrolysis of diatrizoate in the presence of specific radical quenchers (tert-butanol and methanol) had a similar effect on electro-oxidation rates, illustrating a possible role of the hydroxyl radical ((•)OH) in the anodic formation of sulfate radical (SO4(•-)) species. The addition of 0.55 mM persulfate increased the electro-oxidation rate of diatrizoate in nitrate from 0.94 to 9.97 h(-1), suggesting a nonradical activation of persulfate. Overall findings indicate the formation of strong sulfate-derived oxidant species at BDD anodes when polarized at high potentials. This may have positive implications in the electro-oxidation of wastewaters containing sulfate. For example, the energy required for the 10-fold removal of diatrizoate was decreased from 45.6 to 2.44 kWh m(-3) by switching from nitrate to sulfate anolyte.

  10. Removal of Persistent Organic Contaminants by Electrochemically Activated Sulfate.

    PubMed

    Farhat, Ali; Keller, Jurg; Tait, Stephan; Radjenovic, Jelena

    2015-12-15

    Solutions of sulfate have often been used as background electrolytes in the electrochemical degradation of contaminants and have been generally considered inert even when high-oxidation-power anodes such as boron-doped diamond (BDD) were employed. This study examines the role of sulfate by comparing electro-oxidation rates for seven persistent organic contaminants at BDD anodes in sulfate and inert nitrate anolytes. Sulfate yielded electro-oxidation rates 10-15 times higher for all target contaminants compared to the rates of nitrate anolyte. This electrochemical activation of sulfate was also observed at concentrations as low as 1.6 mM, which is relevant for many wastewaters. Electrolysis of diatrizoate in the presence of specific radical quenchers (tert-butanol and methanol) had a similar effect on electro-oxidation rates, illustrating a possible role of the hydroxyl radical ((•)OH) in the anodic formation of sulfate radical (SO4(•-)) species. The addition of 0.55 mM persulfate increased the electro-oxidation rate of diatrizoate in nitrate from 0.94 to 9.97 h(-1), suggesting a nonradical activation of persulfate. Overall findings indicate the formation of strong sulfate-derived oxidant species at BDD anodes when polarized at high potentials. This may have positive implications in the electro-oxidation of wastewaters containing sulfate. For example, the energy required for the 10-fold removal of diatrizoate was decreased from 45.6 to 2.44 kWh m(-3) by switching from nitrate to sulfate anolyte. PMID:26572594

  11. Immobilization of iodine in soil-water systems and its relation to iodine species

    NASA Astrophysics Data System (ADS)

    Shimamoto, Y.; Takahashi, Y.

    2009-12-01

    Iodine tends to accumulate in thyroid, and radioactive 131I and 129I are threatening to human health both short-term and long-term, respectively. It is thus important to understand iodine behavior in surface environments. Possible iodine species are I-, IO3-, I2, and organo-iodine species. X-ray absorption near-edge structure (XANES) and high performance liquid chromatography (HPLC) connected to ICP-MS were used to determine iodine species in soil and pore water, respectively. Soil and pore water samples were collected at depths of 0 to 12 cm near a tube well in Yoro, Chiba, Japan, where surface soil is flooded with brine containing iodine of 5.8 mg/L. Soil samples were also collected at depths of 0 to 90 cm in Yakushima Island, Kagoshima, Japan. The soil samples were frozen, and iodine K-edge XANES were measured at BL01B1, SPring-8 (Hyogo, Japan). Soil samples were buried into resin and prepared as thin sections, and mapping of iodine in soil grain was obtained using μ-XRF analysis at BL37XU, SPring-8. HPLC-ICP-MS, equipped with anion exchange or size exclusion column, was used to determine iodine species in pore water. Yoro: The depth profile of iodine concentration in soil correlates quite well with that of organic carbon content. XANES spectra are almost identical to that of humic substances at any depth (Fig. 1). Iodine mapping shows that iodine exists in organic matter more than clay minerals and iron rich mineral. Iodine in pore water exists as I- and organic iodine bound to dissolved humic substances at 0-6 cm, and mainly as I- at 9-12 cm, respectively. Thus, iodine tends to be bound to organic materials in soil as organic iodine, where as iodine in pore water exists mainly as I-. Yakushima: Iodine concentration is higher in volcanic ash soil layer (25-55 cm) than surface organic rich soil layer (0-25 cm). XANES spectrum of volcanic ash soil was different from those of reference materials (Fig. 1). Volcanic ash soil in Yakushima contains imogolite and

  12. Wet Removal of Organic and Black Carbon Aerosols

    NASA Astrophysics Data System (ADS)

    Torres, A.; Bond, T. C.; Lehmann, C.

    2012-12-01

    Organic carbon (OC) and black carbon (BC) aerosols derived from the combustion of fossil fuels and biomass are significant atmospheric pollutants that alter the Earth's radiation balance and affect human health. Carbonaceous aerosol lifetime and extent of its effects are mainly controlled by its wet removal, especially by rain. Limited work has been done to measure both BC and OC from rain events even though these aerosols are co-emitted and exist together in the atmosphere. The choices of analytical techniques for measuring OC and BC in water are limited, and researchers often employ the same techniques used for measuring atmospheric carbon particles. There is no agreement in the methods employed for monitoring carbon concentration in precipitation. As part of the method development, the Single Particle Soot Photometer (SP2), Thermal-Optical Analysis (TOA), Ultraviolet/Visible (UV/VIS) Spectrophotometer, and the Total Organic Carbon (TOC) Analyzer were evaluated for measuring BC suspended in water, water insoluble OC (WIOC) and dissolved OC (DOC). The study also monitored the concentration of BC, WIOC, and DOC in rainwater collected at Bondville (Illinois) for 18 months. Results indicated that 34% (±3%) of the BC mass was lost in the SP2 analysis, most probably during the nebulization process. Filtration required for TOA also had large losses (>75%) because quartz fiber filters were ineffective for capturing BC particles from water. Addition of NH4H2PO4 as a coagulant improved (>95%) the capture efficiency of the filters. UV/VIS spectrophotometry had good linearity, but the sensitivity for detecting BC particles (±20 μg/L) suspended in water was inadequate. TOC analysis was a robust technique for measuring both DOC and total carbon (BC + OC). The chosen techniques were TOC analysis for DOC, and TOA with an optimized filtration procedure for BC and WIOC. The mean concentrations in rainwater were 8.72 (±9.84) μg/L of BC, 88.97 (±62.64) μg/L of WIOC, and 1

  13. Iodine in diet

    MedlinePlus

    ... are good sources. Kelp is the most common vegetable-seafood that is a rich source of iodine. ... iodine deficiency is generally not a problem. Iodine poisoning is rare in the U.S. Very high intake ...

  14. The geochemistry of iodine - a review.

    PubMed

    Fuge, R; Johnson, C C

    1986-06-01

    Iodine has long been recognised as an important element environmentally. Despite this there are many gaps in our knowledge of its geochemistry and even where information is available much of this is based on old data which, in the light of recent data, are suspect.Iodine forms few independent minerals and is unlikely to enter most rock-forming minerals. In igneous rocks its concentration is fairly uniform and averages 0.24 mg/kg. Sedimentary rocks tend to have higher concentrations with average iodine contents of:-recent sediments 5-200 mg/kg, carbonates 2.7 mg/kg, shales 2.3 mg/kg and sandstones 0.8 mg/kg. Organic-rich sediments are particularly enriched in iodine.Soils, generally, are much richer in iodine than the parent rocks with the actual level being decided mainly by soil type and locality. Little soil iodine is water-soluble and much iodine is thought to be associated with organic matter, clays and aluminium and iron oxides. Most iodine in soils is derived from the atmosphere where, in turn, it has been derived from the oceans. Seawater has a mean iodine content of 58 μg/L, while non-saline surface waters have lower and very variable levels. Subsurface brines and mineral waters are generally strongly enriched in iodine.Marine plants are frequently enriched in iodine while terrestrial plants have generally low contents. Iodine is essential for all mammals.Consideration of the geochemical cycle of iodine reveals that its transfer from the oceans to the atmosphere is probably the most important process in its geochemistry.

  15. Composites for removing metals and volatile organic compounds and method thereof

    DOEpatents

    Coronado, Paul R.; Coleman, Sabre J.; Reynolds, John G.

    2006-12-12

    Functionalized hydrophobic aerogel/solid support structure composites have been developed to remove metals and organic compounds from aqueous and vapor media. The targeted metals and organics are removed by passing the aqueous or vapor phase through the composite which can be in molded, granular, or powder form. The composites adsorb the metals and the organics leaving a purified aqueous or vapor stream. The species-specific adsorption occurs through specific functionalization of the aerogels tailored towards specific metals and/or organics. After adsorption, the composites can be disposed of or the targeted metals and/or organics can be reclaimed or removed and the composites recycled.

  16. Organic iodine in Antarctic sea ice: A comparison between winter in the Weddell Sea and summer in the Amundsen Sea

    NASA Astrophysics Data System (ADS)

    Granfors, Anna; Ahnoff, Martin; Mills, Matthew M.; Abrahamsson, Katarina

    2014-12-01

    Recent studies have recognized sea ice as a source of reactive iodine to the Antarctic boundary layer. Volatile iodinated compounds (iodocarbons) are released from sea ice, and they have been suggested to contribute to the formation of iodine oxide (IO), which takes part in tropospheric ozone destruction in the polar spring. We measured iodocarbons (CH3I, CH2ClI, CH2BrI, and CH2I2) in sea ice, snow, brine, and air during two expeditions to Antarctica, OSO 10/11 to the Amundsen Sea during austral summer and ANT XXIX/6 to the Weddell Sea in austral winter. These are the first reported measurements of iodocarbons from the Antarctic winter. Iodocarbons were enriched in sea ice in relation to seawater in both summer and winter. During summer, the positive relationship to chlorophyll a biomass indicated a biological origin. We suggest that CH3I is formed biotically in sea ice during both summer and winter. For CH2ClI, CH2BrI, and CH2I2, an additional abiotic source at the snow/ice interface in winter is suggested. Elevated air concentrations of CH3I and CH2ClI during winter indicate that they are enriched in lower troposphere and may take part in the formation of IO at polar sunrise.

  17. Hair Iodine for Human Iodine Status Assessment

    PubMed Central

    Prejac, Juraj; Višnjević, Vjeran; Skalnaya, Margarita G.; Mimica, Ninoslav; Drmić, Stipe; Skalny, Anatoly V.

    2014-01-01

    Background: Today, human iodine deficiency is, after iron, the most common nutritional deficiency in developed European and underdeveloped third world countries. A current biological indicator of iodine status is urinary iodine, which reflects very recent iodine exposure; a long-term indicator of iodine status remains to be identified. Methods: We analyzed hair iodine in a prospective, observational, cross-sectional, and exploratory study involving 870 apparently healthy Croatians (270 men and 600 women). Hair iodine was analyzed with inductively coupled plasma mass spectrometry. Results: The hair iodine median was 0.499 μg/g, and was 0.482 and 0.508 μg/g for men and women respectively, suggesting no sex-related difference. We studied hair iodine uptake by analyzing the logistic sigmoid saturation curve of the median derivatives to assess iodine deficiency, adequacy, and excess. We estimated overt iodine deficiency to occur when hair iodine concentration was below 0.1–0.15 μg/g. Then there was a saturation range interval of about 0.1–2.0 μg/g where the deposition of iodine in the hair was linearly increasing (R2=0.994). Eventually, the sigmoid curve became saturated at about 2.0 μg/g and upward, suggesting excessive iodine exposure. Conclusion: Hair appears to be a valuable and robust biological indicator tissue for assessing long-term iodine status. We propose that an adequate iodine status corresponds with hair iodine uptake saturation of 0.565–0.739 μg/g (55–65%). PMID:24446669

  18. Removal efficiency of silver impregnated filter materials and performance of iodie filters in the off-gas of the Karlsruhe reprocessing plant WAK

    SciTech Connect

    Herrmann, F.J.; Herrmann, B.; Hoeflich, V.

    1997-08-01

    An almost quantitative retention of iodine is required in reprocessing plants. For the iodine removal in the off-gas streams of a reprocessing plant various sorption materials had been tested under realistic conditions in the Karlsruhe reprocessing plant WAK in cooperation with the Karlsruhe research center FZK. The laboratory results achieved with different iodine sorption materials justified long time performance tests in the WAK Plant. Technical iodine filters and sorption materials for measurements of iodine had been tested from 1972 through 1992. This paper gives an overview over the most important results, Extended laboratory, pilot plant, hot cell and plant experiences have been performed concerning the behavior and the distribution of iodine-129 in chemical processing plants. In a conventional reprocessing plant for power reactor fuel, the bulk of iodine-129 and iodine-127 is evolved into the dissolver off-gas. The remainder is dispersed over many aqueous, organic and gaseous process and waste streams of the plant. Iodine filters with silver nitrate impregnated silica were installed in the dissolver off-gas of the Karlsruhe reprocessing plant WAK in 1975 and in two vessel vent systems in 1988. The aim of the Karlsruhe iodine research program was an almost quantitative evolution of the iodine during the dissolution process to remove as much iodine with the solid bed filters as possible. After shut down of the WAK plant in December 1990 the removal efficiency of the iodine filters at low iodine concentrations had been investigated during the following years. 12 refs., 2 figs., 2 tabs.

  19. Hydrothermal treatment and iodine binding provide insights into the organization of glucan chains within the semi-crystalline lamellae of corn starch granules.

    PubMed

    Vamadevan, Varatharajan; Hoover, Ratnajothi; Bertoft, Eric; Seetharaman, Koushik

    2014-08-01

    The importance of glucan chains that pass through both the amorphous and crystalline lamellae (tie chains) in the organization of corn starch granules was studied using heat-moisture treatment (HMT), annealing (ANN), and iodine binding. Molecular structural analysis showed that hylon starches (HV, HVII, and HVIII) contained higher proportion of intermediate glucan chains (HVIII > HVII > HV) than normal corn (CN) starch. Wide angle X-ray scattering revealed that on HMT, the extent of polymorphic transition in hylon starches decreased with increasing proportion of intermediate and long chains. Iodine treated hylon starches exhibited increased order in the V-type polymorphism as evidenced by the intense peak at 20° 2θ and the strong reflection intensity at 7.5° 2θ and the extent of the change depended on the type of hylon starch. DSC results showed that the gelatinization enthalpy of CN and waxy corn starch (CW) remained unchanged after ANN. However, hylon starches showed a significant increase in enthalpy with more distinct endotherms after ANN. It can be concluded that tie chains influence the organization of crystalline lamellae in amylose extender mutant starches.

  20. Novel Ion-Exchange Coagulants Remove More Low Molecular Weight Organics than Traditional Coagulants.

    PubMed

    Zhao, Huazhang; Wang, Lei; Hanigan, David; Westerhoff, Paul; Ni, Jinren

    2016-04-01

    Low molecular weight (MW) charged organic matter is poorly removed by conventional coagulants but contributes to disinfection byproduct formation during chlorination of drinking waters. We hypothesized that CIEX, a new Al-based hybrid coagulant with ion-exchange functional groups, would be new mechanistic approach to remove low MW organic matter during coagulation and would perform better than polyaluminum chloride (PACl) or metal-salt based coagulants. We measured coagulation performance using dissolved organic carbon (DOC) in a high hardness surface water. CIEX achieved excellent turbidity removal and removed 20% to 46% more DOC than FeCl3, Al2(SO4)3, or PACl, depending on dose. The improved DOC removal was attributable to better removal of low MW organic matter (<2 kDa). We further studied removal mechanisms in a model water containing a low MW organic acid (salicylic acid (SA)). CIEX achieved high removal of organic acids (>90% of SA) independent of pH, whereas removal by metal salts was lower (<15%) and was strongly pH dependent. CIEX ion-exchange capability is facilitated by its covalently bound quaternary ammonium group, which conventional coagulants lack. Plus, unlike other cationic polymers that react with chloramines to form N-nitrosodimethylamine (NDMA), CIEX has a low molar yield (9.3 × 10(-7) mol NDMA per mol CIEX-N).

  1. Consuming iodine enriched eggs to solve the iodine deficiency endemic for remote areas in Thailand

    PubMed Central

    2010-01-01

    Background Evidence showed that the occurrence of iodine deficiency endemic areas has been found in every provinces of Thailand. Thus, a new pilot programme for elimination of iodine deficiency endemic areas at the community level was designed in 2008 by integrating the concept of Sufficient Economic life style with the iodine biofortification of nutrients for community consumption. Methods A model of community hen egg farm was selected at an iodine deficiency endemic area in North Eastern part of Thailand. The process for the preparation of high content iodine enriched hen food was demonstrated to the farm owner with technical transfer in order to ensure the sustainability in the long term for the community. The iodine content of the produced iodine enriched hen eggs were determined and the iodine status of volunteers who consumed the iodine enriched hen eggs were monitored by using urine iodine excretion before and after the implement of iodine enrichment in the model farm. Results The content of iodine in eggs from the model farm were 93.57 μg per egg for the weight of 55 - 60 g egg and 97.76 μg for the weight of 60 - 65 g egg. The biological active iodo-organic compounds in eggs were tested by determination of the base-line urine iodine of the volunteer villagers before and after consuming a hard boiled iodine enriched egg per volunteer at breakfast for five days continuous period in 59 volunteers of Ban Kew village, and 65 volunteers of Ban Nong Nok Kean village. The median base-line urine iodine level of the volunteers in these two villages before consuming eggs were 7.00 and 7.04 μg/dL respectively. After consuming iodine enriched eggs, the median urine iodine were raised to the optimal level at 20.76 μg/dL for Ban Kew and 13.95 μg/dL for Ban Nong Nok Kean. Conclusions The strategic programme for iodine enrichment in the food chain with biological iodo-organic compound from animal origins can be an alternative method to fortify iodine in the diet for

  2. Two-dimensional on-line detection of brominated and iodinated volatile organic compounds by ECD and ICP-MS after GC separation.

    PubMed

    Schwarz, A; Heumann, K G

    2002-09-01

    Inductively coupled plasma-mass spectrometry (ICP-MS) was coupled to a gas chromatographic (GC) system with electron capture detector (ECD), which enables relatively easy characterization and quantification of brominated and iodinated (halogenated) volatile organic compounds (HVOCs) in aquatic and air samples. The GC-ECD system is connected in series with an ICP-MS by a directly heated transfer line and an outlet port-hole for elimination of the ECD make-up gas during ignition of the plasma. The hyphenated GC-ECD/ICP-MS system provides high selectivity and sensitivity for monitoring individual HVOCs under fast chromatographic conditions. The ECD is most sensitive for the detection of chlorinated and brominated but the ICP-MS for iodinated compounds. The greatest advantage of the use of an ICP-MS is its element-specific detection, which allows clear identification of compounds in most cases. The absolute detection limits for ICP-MS are 0.5 pg for iodinated, 10 pg for brominated, and 50 pg for chlorinated HVOCs with the additional advantage that calibration is almost independent on different compounds of the same halogen. In contrast to that detection limits for ECD vary for the different halogenated compounds and lie in the range of 0.03-11 pg. The two-dimensional GC-ECD/ICP-MS instrumentation is compared with electron impact mass spectrometry (EI-MS) and microwave induced plasma atomic emission detection (MIP-AED). Even if EI-MS has additional power in identifying unknown peaks by its scan mode, the detection limits are much higher compared with GC-ECD/ICP-MS, whereas the selective ion monitoring mode (SIM) reaches similar detection limits. The MIP-AED detection limits are at the same level as EI-MS in the scan mode.

  3. Enhancement of the natural organic matter removal from drinking water by nanofiltration.

    PubMed

    Matilainen, A; Liikanen, R; Nyström, M; Lindqvist, N; Tuhkanen, T

    2004-03-01

    Finnish surface waters are abundant in natural organic matter. Natural organic matter can be removed from drinking water in a water treatment process by coagulation and filtration. The standard treatment operations are not able to remove the smallest molar mass fraction of organic matter and the intermediate molar mass matter is only partly removed. The removal of residual natural organic matter from drinking water by nanofiltration was evalueted in this study. Three different nanofiltration membranes were compared in filtering six pre-treated surface waters. The total organic carbon content of the feed waters varied from 2.0 to 4.2 mg l(-1). Other water quality parameters measured were conductivity, alkalinity, hardness, UV-absorbance, SUVA, E2/E3 value and molecular size distribution by high-performance size-exclusion chromatography. The natural organic matter removal efficiencies of the membranes were good and varied between 100% and 49%, and between 85% and 47% according to molecular size distribution and total organic carbon measurements, respectively. Removal of different molecular size fractions varied from 100% to 56%, 100% to 54% and 88% to 19%, regarding high molar mass, intermediate molar mass and low molar mass organic matter, respectively. The Desal-5 DL membrane produced the highest natural organic matter removals.

  4. Iodine-129 Dose in LLW Disposal Facility Performance Assessments

    SciTech Connect

    Wilhite, E.L.

    1999-10-15

    Iodine-129 has the lowest Performance Assessment derived inventory limit in SRS disposal facilities. Because iodine is concentrated in the body to one organ, the thyroid, it has been thought that dilution with stable iodine would reduce the dose effects of 129I.Examination of the dose model used to establish the Dose conversion factor for 129I shows that, at the levels considered in performance assessments of low-level waste disposal facilities, the calculated 129I dose already accounts for ingestion of stable iodine. At higher than normal iodine ingestion rates, the uptake of iodine by the thyroid itself decrease, which effectively cancels out the isotopic dilution effect.

  5. Discovery and Early Uses of Iodine

    NASA Astrophysics Data System (ADS)

    Rosenfeld, Louis

    2000-08-01

    The ancient Chinese recognized goiter and the therapeutic effects of burnt sponge and seaweed in reducing its size or causing its disappearance. The modern use of iodine in the prevention of goiter dates from 1830, when it was proposed that goiter is an iodine deficiency disease due to lack of iodine in the water supply. But unfavorable symptoms of iodism were frequent owing to overenthusiastic use and overdose of iodine. Consequently, iodide prophylaxis was discredited and abandoned. The presence of iodine in organic combination as a normal constituent of the thyroid was established in 1896 and the use of iodine in treatment and prevention of goiter was revived. In 1917 the general use of iodized salt in goitrous areas was shown to be effective in preventing simple endemic goiter.

  6. [Fluorine removal efficiency of organic-calcium during coal combustion].

    PubMed

    Liu, Jing; Liu, Jian-Zhong; Zhou, Jun-Hu; Xiao, Hai-Ping; Cen, Ke-Fa

    2006-08-01

    Effectiveness of calcium magnesium acetate (CMA) and calcium acetate(CA) as feasible HF capture were studied by means of fixed bed tube furnaces. The effects of temperature, particle diameter and Ca/S molar ratio on the fluorine removal efficiency were studied. By contract with CaCO3 at the same condition, we find that the HF capture effectiveness of those sorbents is superior to CaCO3, especially at high temperature. At 1 000 - 1 100 degrees C, the efficiency of fluorine removal during coal combustion of CMA is 1.68 - 1.74 times as that of CaCO3; the efficiency of fluorine removal during coal combustion of CA is 1.28 - 1.37 times as that of CaCO3.

  7. A novel membrane distillation-thermophilic bioreactor system: biological stability and trace organic compound removal.

    PubMed

    Wijekoon, Kaushalya C; Hai, Faisal I; Kang, Jinguo; Price, William E; Guo, Wenshan; Ngo, Hao H; Cath, Tzahi Y; Nghiem, Long D

    2014-05-01

    The removal of trace organic compounds (TrOCs) by a novel membrane distillation-thermophilic bioreactor (MDBR) system was examined. Salinity build-up and the thermophilic conditions to some extent adversely impacted the performance of the bioreactor, particularly the removal of total nitrogen and recalcitrant TrOCs. While most TrOCs were well removed by the thermophilic bioreactor, compounds containing electron withdrawing functional groups in their molecular structure were recalcitrant to biological treatment and their removal efficiency by the thermophilic bioreactor was low (0-53%). However, the overall performance of the novel MDBR system with respect to the removal of total organic carbon, total nitrogen, and TrOCs was high and was not significantly affected by the conditions of the bioreactor. All TrOCs investigated here were highly removed (>95%) by the MDBR system. Biodegradation, sludge adsorption, and rejection by MD contribute to the removal of TrOCs by MDBR treatment.

  8. A novel membrane distillation-thermophilic bioreactor system: biological stability and trace organic compound removal.

    PubMed

    Wijekoon, Kaushalya C; Hai, Faisal I; Kang, Jinguo; Price, William E; Guo, Wenshan; Ngo, Hao H; Cath, Tzahi Y; Nghiem, Long D

    2014-05-01

    The removal of trace organic compounds (TrOCs) by a novel membrane distillation-thermophilic bioreactor (MDBR) system was examined. Salinity build-up and the thermophilic conditions to some extent adversely impacted the performance of the bioreactor, particularly the removal of total nitrogen and recalcitrant TrOCs. While most TrOCs were well removed by the thermophilic bioreactor, compounds containing electron withdrawing functional groups in their molecular structure were recalcitrant to biological treatment and their removal efficiency by the thermophilic bioreactor was low (0-53%). However, the overall performance of the novel MDBR system with respect to the removal of total organic carbon, total nitrogen, and TrOCs was high and was not significantly affected by the conditions of the bioreactor. All TrOCs investigated here were highly removed (>95%) by the MDBR system. Biodegradation, sludge adsorption, and rejection by MD contribute to the removal of TrOCs by MDBR treatment. PMID:24658107

  9. Determination of biological removal of recalcitrant organic contaminants in coal gasification waste water.

    PubMed

    Ji, Qinhong; Tabassum, Salma; Yu, Guangxin; Chu, Chunfeng; Zhang, Zhenjia

    2015-01-01

    Coal gasification waste water treatment needed a sustainable and affordable plan to eliminate the organic contaminants in order to lower the potential environmental and human health risk. In this paper, a laboratory-scale anaerobic-aerobic intermittent system carried out 66 operational cycles together for the treatment of coal gasification waste water and the removal capacity of each organic pollutant. Contaminants included phenols, carboxylic acids, long-chain hydrocarbons, and heterocyclic compounds, wherein the relative content of phenol is up to 57.86%. The long-term removal of 77 organic contaminants was evaluated at different hydraulic retention time (anaerobic24 h + aerobic48 h and anaerobic48 h +aerobic48 h). Contaminant removal ranged from no measurable removal to near-complete removal with effluent concentrations below the detection limit. Contaminant removals followed one of four trends: steady-state removal throughout, increasing removal to steady state (acclimation), decreasing removal, and no removal. Organic degradation and transformation in the reaction were analysed by gas chromatography/mass spectrometry technology.

  10. Iodine and Pregnancy

    PubMed Central

    Yarrington, Christina; Pearce, Elizabeth N.

    2011-01-01

    Iodine is a necessary element for the production of thyroid hormone. We will review the impact of dietary iodine status on thyroid function in pregnancy. We will discuss iodine metabolism, homeostasis, and nutritional recommendations for pregnancy. We will also discuss the possible effects of environmental contaminants on iodine utilization in pregnant women. PMID:21765996

  11. Removal of lead by apatite and its stability in the presence of organic acids.

    PubMed

    Katoh, Masahiko; Makimura, Akihiko; Sato, Takeshi

    2016-12-01

    In this study, lead sorption and desorption tests were conducted with apatite and organic acids (i.e. citric, malic, and formic acids) to understand lead removal by apatite in the presence of an organic acid and lead dissolution from the lead- and organic-acid-sorbed apatite by such organic acid exposure. The lead sorption test showed that the amount of lead removed by apatite in the presence of organic acid varied depending on the type of acid used. The molar amounts of calcium dissolved from apatite in the presence and absence of organic acid were exactly the same as those of lead removed even under different pH conditions as well as different organic acid concentrations, indicating that the varying amount of lead removal in the presence of different organic acids resulted from the magnitude of the dissolution of apatite and the precipitation of lead phosphate minerals. The percentages of lead dissolved from the organic-acid-sorbed and non-organic-acid-sorbed apatite by all the organic acid extractions were equal and higher than those by water extraction. In particular, the highest extractions were observed in the non-organic-acid-sorbed apatite by citric and malic acids. These results suggest that to immobilize lead by the use of apatite in the presence of organic acids, much more apatite must be added than in the absence of organic acid, and that measures must be taken to ensure that the immobilized lead is not dissolved.

  12. Iodine neutron capture therapy

    NASA Astrophysics Data System (ADS)

    Ahmed, Kazi Fariduddin

    A new technique, Iodine Neutron Capture Therapy (INCT) is proposed to treat hyperthyroidism in people. Present thyroid therapies, surgical removal and 131I treatment, result in hypothyroidism and, for 131I, involve protracted treatment times and excessive whole-body radiation doses. The new technique involves using a low energy neutron beam to convert a fraction of the natural iodine stored in the thyroid to radioactive 128I, which has a 24-minute half-life and decays by emitting 2.12-MeV beta particles. The beta particles are absorbed in and damage some thyroid tissue cells and consequently reduce the production and release of thyroid hormones to the blood stream. Treatment times and whole-body radiation doses are thus reduced substantially. This dissertation addresses the first of the several steps needed to obtain medical profession acceptance and regulatory approval to implement this therapy. As with other such programs, initial feasibility is established by performing experiments on suitable small mammals. Laboratory rats were used and their thyroids were exposed to the beta particles coming from small encapsulated amounts of 128I. Masses of 89.0 mg reagent-grade elemental iodine crystals have been activated in the ISU AGN-201 reactor to provide 0.033 mBq of 128I. This activity delivers 0.2 Gy to the thyroid gland of 300-g male rats having fresh thyroid tissue masses of ˜20 mg. Larger iodine masses are used to provide greater doses. The activated iodine is encapsulated to form a thin (0.16 cm 2/mg) patch that is then applied directly to the surgically exposed thyroid of an anesthetized rat. Direct neutron irradiation of a rat's thyroid was not possible due to its small size. Direct in-vivo exposure of the thyroid of the rat to the emitted radiation from 128I is allowed to continue for 2.5 hours (6 half-lives). Pre- and post-exposure blood samples are taken to quantify thyroid hormone levels. The serum T4 concentration is measured by radioimmunoassay at

  13. Iodine volatility. [PWR; BWR

    SciTech Connect

    Beahm, E.C.; Shockley, W.E.

    1984-01-01

    The ultimate aim of this program is to couple experimental aqueous iodine volatilities to a fission product release model. Iodine partition coefficients, for inorganic iodine, have been measured during hydrolysis and radiolysis. The hydrolysis experiments have illustrated the importance of reaction time on iodine volatility. However, radiolysis effects can override hydrolysis in determining iodine volatility. In addition, silver metal in radiolysis samples can react to form silver iodide accompanied by a decrease in iodine volatility. Experimental data are now being coupled to an iodine transport and release model that was developed in the Federal Republic of Germany.

  14. Transparent bifacial dye-sensitized solar cells based on organic counter electrodes and iodine-free electrolyte

    NASA Astrophysics Data System (ADS)

    Ku, Zhiliang; Rong, Yaoguang; Han, Hongwei

    2013-10-01

    In this study, a novel bifacially active transparent dye-sensitized solar cell (DSSCs) assembled with a transparent poly(3,4-ethylenedioxythiophene) (PEDOT) counter electrode and a colorless iodine-free polymer gel (IFPG) electrolyte was developed. The IFPG electrolyte was prepared by employing an ionic liquid (1,2-dimethyl-3-propylinmidazolium iodide, DMPII) as the charge transfer intermediate and a polymer composite as the gelator without the addition of iodine, exhibiting high conductivity and non-absorption characters. PEDOT electrodes were prepared via a facile electro-polymerization method. By controlling the amount of polymerization charge capacity, we optimized the PEDOT electrodes with high transparency and a favorable activity for catalyzing the IFPG electrolyte. The bifacial DSSCs device fabricated by this kind of transparent PEDOT electrode and colorless IFPG electrolyte showed a power conversion efficiency (PCE) of 6.35% and 4.98% at 100 mW cm-2 AM1.5 illumination corresponding to front- and rear-side illumination. It is notable that the PCE under rear-side illumination approaches 80% that of front-side illumination. Moreover, the device shows excellent stability as confirmed by aging test. These promising results highlight the enormous potential of this transparent PEDOT CE and colorless IFPG electrolyte in scaling up and commercialization of low cost and effective bifacial DSSCs.

  15. Odor and volatile organic compound removal from wastewater treatment plant headworks ventilation air using a biofilter.

    PubMed

    Converse, B M; Schroeder, E D; Iranpour, R; Cox, H H J; Deshusses, M A

    2003-01-01

    Laboratory-scale experiments and field studies were performed to evaluate the feasibility of biofilters for sequential removal of hydrogen sulfide and volatile organic compounds (VOCs) from wastewater treatment plant waste air. The biofilter was designed for spatially separated removal of pollutants to mitigate the effects of acid production resulting from hydrogen sulfide oxidation. The inlet section of the upflow units was designated for hydrogen sulfide removal and the second section was designated for VOC removal. Complete removal of hydrogen sulfide (H2S) and methyl tert-butyl ether (MTBE) was accomplished at loading rates of 8.3 g H2S/(m3 x h) (15-second empty bed retention time [EBRT]) and 33 g MTBE/(m3 x h) (60-second EBRT), respectively. In field studies performed at the Hyperion Treatment Plant in Los Angeles, California, excellent removal of hydrogen sulfide, moderate removal of nonchlorinated VOCs such as toluene and benzene, and poor removal of chlorinated VOCs were observed in treating the headworks waste air. During spiking experiments on the headworks waste air, the percentage removals were similar to the unspiked removals when nonchlorinated VOCs were spiked; however, feeding high concentrations of chlorinated VOCs reduced the removal percentages for all VOCs. Thus, biofilters offer a distinct advantage over chemical scrubbers currently used at publicly owned treatment works in that they not only remove odor and hydrogen sulfide efficiently at low cost, but also reduce overall toxicity by partially removing VOCs and avoiding the use of hazardous chemicals.

  16. Atomic Oxygen Treatment for Non-Contact Removal of Organic Protective Coatings from Painting Surfaces

    NASA Technical Reports Server (NTRS)

    Rutledge, Sharon K.; Banks, Bruce A.; Cales, Michael

    1994-01-01

    Current techniques for removal of varnish (lacquer) and other organic protective coatings from paintings involve contact with the surface. This contact can remove pigment, or alter the shape and location of paint on the canvas surface. A thermal energy atomic oxygen plasma, developed to simulate the space environment in low Earth orbit, easily removes these organic materials. Uniform removal of organic protective coatings from the surfaces of paintings is accomplished through chemical reaction. Atomic oxygen will not react with oxides so that most paint pigments will not be affected by the reaction. For paintings containing organic pigments, the exposure can be carefully timed so that the removal stops just short of the pigment. Color samples of Alizarin Crimson, Sap Green, and Zinc White coated with Damar lacquer were exposed to atomic oxygen. The lacquer was easily removed from all of the samples. Additionally, no noticeable change in appearance was observed after the lacquer was reapplied. The same observations were made on a painted canvas test sample obtained from the Cleveland Museum of Art. Scanning electron microscope photographs showed a slight microscopic texturing of the vehicle after exposure. However, there was no removal or disturbance of the paint pigment on the surface. It appears that noncontact cleaning using atomic oxygen may provide a viable alternative to other cleaning techniques. It is especially attractive in cases where the organic protective surface cannot be acceptably or safely removed by conventional techniques.

  17. [Iodine and thyroid: what a clinic should know].

    PubMed

    Santana Lopes, Maria; Jácome de Castro, João; Marcelino, Mafalda; Oliveira, Maria João; Carrilho, Francisco; Limbert, Edward

    2012-01-01

    The World Health Organization considers iodine deficiency as a major worldwide cause of mental and development diseases, estimating that about 13% of the world population is affected by diseases caused by iodine deficiency. Iodine is a trace element necessary for the synthesis of thyroid hormones which, since it cannot be formed by the organism, must be taken regularly with food. Fish and shellfish are generally a good source, because the ocean contains a considerable amount of iodine. On the contrary, plants which grow in iodine-deficient soils are poor in this element, as well as meat and other animal products fed in plants low in iodine. Salt is the best way for iodine supplementation. Cooking the food with iodized salt is a desirable practice because it guarantees the presence of this element. There are also other methods to provide iodine to the general population, such as adding iodine to drinking water or taking supplements of iodine. In pregnancy is recommended iodine supplementation, except in patients with known thyroid disorders. Iodine is an essential component of thyroid hormones (T4 and T3). Inadequate iodine intake leads to inadequate thyroid hormone production. The most important consequences of iodine deficiency, in the general population are goiter and hypothyroidism, and in the severe cases, mental retardation, cretinism and increased neo-natal and infant mortality. The International Council for the Control of Iodine Deficiency Disorders (ICCIDD) formed in 1985, with the only aim of achieving optimal iodine nutrition in the world, in cooperation with UNICEF and WHO. In Portugal, recent studies show significant deficiencies in pregnancy and The Portuguese Society of Endocrinology Diabetes and Metabolism, in partnership with General Directorate of Health, proposed an iodine supplementation during pregnancy with 150-200µg/day. PMID:23069238

  18. Applicability of MIEX(®)DOC process for organics removal from NOM laden water.

    PubMed

    Karpinska, Anna M; Boaventura, Rui A R; Vilar, Vítor J P; Bilyk, Andrzej; Molczan, Marek

    2013-06-01

    The aim of this study was to evaluate applicability of ion exchange process for organics removal from Douro River surface water at the intake of Lever water treatment plant using magnetized ion exchange resin MIEX®. Qualitative analysis of the natural organic matter present in the surface water and prediction of its amenability to removal in conventional coagulation process were assessed. Results obtained in MIEX®DOC process kinetic batch experiments allowed determination of ion exchange efficiency in dissolved organic carbon (DOC), UV absorbing organics, and true color removal. The data were compared with the efficiencies of the conventional unit processes for organics removal at Lever WTP. MIEX®DOC process revealed to be more efficient in DOC removal than conventional treatment achieving the efficiencies in the range of 61-91 %, lowering disinfection by-products formation potential of the water. DOC removal efficiency at Lever WTP depends largely on the raw water quality and ranges from 28 % for water of moderated quality to 89 % of significantly deteriorated quality. In this work, MIEX®DOC process was also used as a reference method for the determination of contribution of anionic fraction to dissolved organic matter and selectivity of the unit processes at Lever WTP for its removal.

  19. Removal of hazardous organic pollutants by biomass adsorption

    SciTech Connect

    Bell, J.P.; Tsezos, M.

    1987-04-01

    This study is aimed at understanding adsorption in biological treatment processes and developing models for predicting the fate of hazardous organic pollutants entering biological wastewater treatment plants. Adsorption of organic chemicals onto two types of inactive microbial biomass was examined. Desorption, temperature effects, and the thermodynamics of the adsorption process were also investigated. Adsorption reversibility demonstrated by pesticides indicate their potential for leaching from land disposal sludges. (Refs. 30).

  20. Removal of dissolved organic carbon and nitrogen during simulated soil aquifer treatment.

    PubMed

    Essandoh, H M K; Tizaoui, C; Mohamed, M H A

    2013-07-01

    Soil aquifer treatment was simulated in 1 m laboratory soil columns containing silica sand under saturated and unsaturated soil conditions to examine the effect of travel length through the unsaturated zone on the removal of wastewater organic matter, the effect of soil type on dissolved organic carbon removal and also the type of microorganisms involved in the removal process. Dissolved organic carbon removal and nitrification did enhance when the wastewater travelled a longer length through the unsaturated zone. A similar consortium of microorganisms was found to exist in both saturated and unsaturated columns. Microbial concentrations however were lowest in the soil column containing silt and clay in addition to silica sand. The presence of silt and clay was detrimental to DOC removal efficiency under saturated soil conditions due to their negative effect on the hydraulic performance of the soil column and microbial growth.

  1. The removal characteristics of natural organic matter in the recycling of drinking water treatment sludge: Role of solubilized organics.

    PubMed

    Zhou, Zhiwei; Yang, Yanling; Li, Xing; Ji, Siyang; Zhang, Hao; Wang, Shuai; Zeng, Qingping; Han, Xinghang

    2016-01-01

    To clarify the role of solubilized organics derived from drinking water treatment sludge (DWTS) in the elimination of natural organic matter (NOM) in the DWTS recycling process, a probe sonoreactor at a frequency of 25 kHz was used to solubilize the organics at varied specific energies. The coagulation behavior related to NOM removal in recycling the sonicated DWTS with and without solubilized organics was evaluated, and the effect on organic fractionations in coagulated water was determined. The study results could provide useful implications in designing DWTS recycling processes that avoid the enrichment of organic matter. Our results indicate that DWTS was disrupted through a low release of soluble chemical oxygen demand (SCOD) and proteins, which could deteriorate the coagulated water quality under the specific energy of 37.87-1212.1 kW h/kg TS. The optimal coagulation behavior for NOM removal was achieved by recycling the sonicated DWTS without solubilized organics at 151.5 kW h/kg TS specific energy. Recycling the sonicated DWTS could increase the enrichment potential of weakly hydrophobic acid, hydrophilic matter, and <3 kDa fractions; the enrichment risks could be reduced by discharging the solubilized organics. Fluorescent characteristic analysis indicated that when recycling the sonicated DWTS without solubilized organics, the removal of humic-like substances was limited, whereas removal of protein-like substances was enhanced, lowering the enrichment potential of protein-like substances.

  2. The removal characteristics of natural organic matter in the recycling of drinking water treatment sludge: Role of solubilized organics.

    PubMed

    Zhou, Zhiwei; Yang, Yanling; Li, Xing; Ji, Siyang; Zhang, Hao; Wang, Shuai; Zeng, Qingping; Han, Xinghang

    2016-01-01

    To clarify the role of solubilized organics derived from drinking water treatment sludge (DWTS) in the elimination of natural organic matter (NOM) in the DWTS recycling process, a probe sonoreactor at a frequency of 25 kHz was used to solubilize the organics at varied specific energies. The coagulation behavior related to NOM removal in recycling the sonicated DWTS with and without solubilized organics was evaluated, and the effect on organic fractionations in coagulated water was determined. The study results could provide useful implications in designing DWTS recycling processes that avoid the enrichment of organic matter. Our results indicate that DWTS was disrupted through a low release of soluble chemical oxygen demand (SCOD) and proteins, which could deteriorate the coagulated water quality under the specific energy of 37.87-1212.1 kW h/kg TS. The optimal coagulation behavior for NOM removal was achieved by recycling the sonicated DWTS without solubilized organics at 151.5 kW h/kg TS specific energy. Recycling the sonicated DWTS could increase the enrichment potential of weakly hydrophobic acid, hydrophilic matter, and <3 kDa fractions; the enrichment risks could be reduced by discharging the solubilized organics. Fluorescent characteristic analysis indicated that when recycling the sonicated DWTS without solubilized organics, the removal of humic-like substances was limited, whereas removal of protein-like substances was enhanced, lowering the enrichment potential of protein-like substances. PMID:26384907

  3. Quadratic electro-optic effect in the nonconjugated conductive polymer iodine-doped trans-polyisoprene, an organic nanometallic system

    NASA Astrophysics Data System (ADS)

    Shrivastava, S.; Thakur, M.

    2011-05-01

    Thin films of 1,4-trans-polyisoprene have been prepared on various substrates from toluene solution and characterized using Fourier transform infrared (FTIR) spectroscopy, optical absorption spectroscopy and X-ray diffraction before and after doping with iodine. The optical absorption spectrum at low doping shows two peaks: one at 4.2 eV and the other at 3.2 eV. X-ray diffraction indicates an increase of (111) and (122) peak intensities upon doping. Quadratic electro-optic measurements have been made using field-induced birefringence. The Kerr coefficients as measured (3.5×10 -10 m/V 2 at 633 nm and 2.5×10 -10 m/V 2 at 1.55 μm) are exceptionally large, and they have been attributed to the subnanometer-size metallic domains formed upon doping and charge transfer.

  4. Removal of ion-implanted photoresists on GaAs using two organic solvents in sequence

    NASA Astrophysics Data System (ADS)

    Oh, Eunseok; Na, Jihoon; Lee, Seunghyo; Lim, Sangwoo

    2016-07-01

    Organic solvents can effectively remove photoresists on III-V channels without damage or etching of the channel material during the process. In this study, a two-step sequential photoresist removal process using two different organic solvents was developed to remove implanted ArF and KrF photoresists at room temperature. The effects of organic solvents with either low molar volumes or high affinities for photoresists were evaluated to find a proper combination that can effectively remove high-dose implanted photoresists without damaging GaAs surfaces. The performance of formamide, acetonitrile, nitromethane, and monoethanolamine for the removal of ion-implanted ArF and KrF photoresists were compared using a two-step sequential photoresist removal process followed by treatment in dimethyl sulfoxide (DMSO). Among the various combinations, the acetonitrile + DMSO two-step sequence exhibited the best removal of photoresists that underwent ion implantation at doses of 5 × 1013-5 × 1015 atoms/cm2 on both flat and trench-structured GaAs surfaces. The ability of the two-step process using organic solvents to remove the photoresists can be explained by considering the affinities of solvents for a polymer and its permeability through the photoresist.

  5. Removal of chlorine gas by an amine functionalized metal-organic framework via electrophilic aromatic substitution.

    PubMed

    DeCoste, Jared B; Browe, Matthew A; Wagner, George W; Rossin, Joseph A; Peterson, Gregory W

    2015-08-11

    Here we report the removal of chlorine gas from air via a reaction with an amine functionalized metal-organic framework (MOF). It is found that UiO-66-NH2 has the ability to remove 1.24 g of Cl2 per g of MOF via an electrophilic aromatic substitution reaction producing HCl, which is subsequently neutralized by the MOF.

  6. UTILITY OF SYNTHETIC ZEOLITES IN REMOVAL OF INORGANIC AND ORGANIC WATER POLLUTANTS

    EPA Science Inventory

    Zeolites are well known for their ion exchange and adsorption properties. Different inorganic and organic pollutants have been removed from water at room temperature using various zeolites. Synthetic zeolites like ZSM-5, Ferrierite, Beta and Faujasite Y have been used to remove i...

  7. Granular activated carbon for removal of organic matter and turbidity from secondary wastewater.

    PubMed

    Hatt, J W; Germain, E; Judd, S J

    2013-01-01

    A range of commercial granular activated carbon (GAC) media have been assessed as pretreatment technologies for a downstream microfiltration (MF) process. Media were assessed on the basis of reduction in both organic matter and turbidity, since these are known to cause fouling in MF membranes. Isotherm adsorption analysis through jar testing with supplementary column trials revealed a wide variation between the different adsorbent materials with regard to organics removal and adsorption kinetics. Comparison with previous work using powdered activated carbon (PAC) revealed that for organic removal above 60% the use of GAC media incurs a significantly lower carbon usage rate than PAC. All GACs tested achieved a minimum of 80% turbidity removal. This combination of turbidity and organic removal suggests that GAC would be expected to provide a significant reduction in fouling of a downstream MF process with improved product water quality. PMID:23306264

  8. DESIGNING FIXED-BED ADSORBERS TO REMOVE MIXTURES OF ORGANICS.

    EPA Science Inventory

    A liquid-phase granular activated carbon (GAC) pilot plant and a full-scale GAC adsorber were designed, built, and operated in order to evaluate their performance for treating a groundwater contaminated with several volatile and synthetic organic chemicals. Several empty bed con...

  9. Static and dynamic removal of aquatic natural organic matter by carbon nanotubes.

    PubMed

    Ajmani, Gaurav S; Cho, Hyun-Hee; Abbott Chalew, Talia E; Schwab, Kellogg J; Jacangelo, Joseph G; Huang, Haiou

    2014-08-01

    Carbon nanotubes (CNTs) were investigated for their capability and mechanisms to simultaneously remove colloidal natural organic matter (NOM) and humic substances from natural surface water. Static removal testing was conducted via adsorption experiments while dynamic removal was evaluated by layering CNTs onto substrate membranes and filtering natural water through the CNT-layered membranes. Analyses of treated water samples showed that removal of humic substances occurred via adsorption under both static and dynamic conditions. Removal of colloidal NOM occurred at a moderate level of 36-66% in static conditions, independent of the specific surface area (SSA) of CNTs. Dynamic removal of colloidal NOM increased from approximately 15% with the unmodified membrane to 80-100% with the CNT-modified membranes. Depth filtration played an important role in colloidal NOM removal. A comparison of the static and dynamic removal of humic substances showed that equilibrium static removal was higher than dynamic (p < 0.01), but there was also a significant linear relationship between static and dynamic removal (p < 0.05). Accounting for contact time of CNTs with NOM during filtration, it appeared that CNT mat structure was an important determinant of removal efficiencies for colloidal NOM and humic substances during CNT membrane filtration.

  10. Static and dynamic removal of aquatic natural organic matter by carbon nanotubes.

    PubMed

    Ajmani, Gaurav S; Cho, Hyun-Hee; Abbott Chalew, Talia E; Schwab, Kellogg J; Jacangelo, Joseph G; Huang, Haiou

    2014-08-01

    Carbon nanotubes (CNTs) were investigated for their capability and mechanisms to simultaneously remove colloidal natural organic matter (NOM) and humic substances from natural surface water. Static removal testing was conducted via adsorption experiments while dynamic removal was evaluated by layering CNTs onto substrate membranes and filtering natural water through the CNT-layered membranes. Analyses of treated water samples showed that removal of humic substances occurred via adsorption under both static and dynamic conditions. Removal of colloidal NOM occurred at a moderate level of 36-66% in static conditions, independent of the specific surface area (SSA) of CNTs. Dynamic removal of colloidal NOM increased from approximately 15% with the unmodified membrane to 80-100% with the CNT-modified membranes. Depth filtration played an important role in colloidal NOM removal. A comparison of the static and dynamic removal of humic substances showed that equilibrium static removal was higher than dynamic (p < 0.01), but there was also a significant linear relationship between static and dynamic removal (p < 0.05). Accounting for contact time of CNTs with NOM during filtration, it appeared that CNT mat structure was an important determinant of removal efficiencies for colloidal NOM and humic substances during CNT membrane filtration. PMID:24810742

  11. Designing fixed-bed adsorbers to remove mixtures of organics

    SciTech Connect

    Hand, D.W.; Crittenden, J.C.; Arora, H.; Miller, J.M.; Lykins, B.W.

    1989-01-01

    A liquid-phase granular activated carbon (GAC) pilot plant and a full-scale GAC adsorber were designed, built, and operated in order to evaluate their performance for treating a groundwater contaminated with several volatile and synthetic organic chemicals. Several empty bed contact times (EBCTs) ranging from 1 to 30 min were used during the pilot-plant study, and a simple method for evaluating the GAC use rate as a function of the EBCT was developed and demonstrated for dichloroethene and trichloroethene (TCE). Pilot-plant data were compared with the pore surface diffusion model, which considers external and internal mass transfer mechanisms of pore and surface diffusion. Natural organic matter in the water was found to decrease GAC capacity and kinetics for TCE.

  12. Removal of organic micropollutants in an artificial recharge system

    NASA Astrophysics Data System (ADS)

    Valhondo, C.; Nödler, K.; Köck-Schulmeyer, M.; Hernandez, M.; Licha, T.; Ayora, C.; Carrera, J.

    2012-04-01

    Emerging contaminants including pharmaceutically active compounds (PhACs), personal care products (PCPs) and pesticides are increasingly being identified in the environment. Emerging pollutants and their transformation products show low concentration in the environment (ng/L), but the effects of the mixtures and lifelong exposure to humans are currently unknown. Many of these contaminants are removed under aerobic conditions in water treatment plants. However, several pharmaceuticals and metabolites present in wastewater are not eliminated by conventional treatment processes. Several lab studies, however, show that the behaviour of many of these micropollutants is affected by the dominant redox conditions. However, data from field experiments are limited and sometimes contradictory. Artificial recharge is a widespread technology to increase the groundwater resources. In this study we propose a design to enhance the natural remediation potential of the aquifer with the installation of a reactive layer at the bottom of the infiltration pond. This layer is a mixture of compost, aquifer material, clay and iron oxide. This layer is intended to provide an extra amount of DOC to the recharge water and to promote biodegradation by means of the development of different redox zones along the travel path through the unsaturated zone and within the aquifer. Moreover, compost, clay and iron oxide of the layer are assumed to increase sorption surfaces for neutral, cationic and anionic compounds, respectively. The infiltration system is sited in Sant Vicenç dels Horts (Barcelona, Spain). It consists of a decantation pond, receiving raw water from the Llobregat River (highly affected from treatment plant effluents), and an infiltration pond (5600 m2). The infiltration rate is around 1 m3/m2/day. The system is equipped with a network of piezometers, suction cups and tensiometers. Infiltration periods have been performed before and after the installation of the reactive layer

  13. Effect of organic load on phosphorus and bacteria removal from wastewater using alkaline filter materials.

    PubMed

    Nilsson, Charlotte; Renman, Gunno; Westholm, Lena Johansson; Renman, Agnieszka; Drizo, Aleksandra

    2013-10-15

    The organic matter released from septic tanks can disturb the subsequent step in on-site wastewater treatment such as the innovative filters for phosphorus removal. This study investigated the effect of organic load on phosphorus (P) and bacteria removal by reactive filter materials under real-life treatment conditions. Two long-term column experiments were conducted at very short hydraulic residence times (average ~5.5 h), using wastewater with high (mean ~120 mg L(-1)) and low (mean ~20 mg L(-1)) BOD7 values. Two alkaline filter materials, the calcium-silicate material Polonite and blast furnace slag (BFS), were tested for the removal capacity of total P, total organic carbon (TOC) and Enterococci. Both experiments showed that Polonite removed P significantly (p < 0.01) better than BFS. An increase in P removal efficiency of 29.3% was observed for the Polonite filter at the lower concentration of BOD7 (p < 0.05). Polonite was also better than BFS with regard to removal of TOC, but there were no significant differences between the two filter materials with regard to removal of Enterococci. The reduction in Enterococci was greater in the experiment using wastewater with high BOD7, an effect attributable to the higher concentration of bacteria in that wastewater. Overall, the results demonstrate the importance of extensive pre-treatment of wastewater to achieve good phosphorus removal in reactive bed filters and prolonged filter life. PMID:24001604

  14. Effect of organic load on phosphorus and bacteria removal from wastewater using alkaline filter materials.

    PubMed

    Nilsson, Charlotte; Renman, Gunno; Westholm, Lena Johansson; Renman, Agnieszka; Drizo, Aleksandra

    2013-10-15

    The organic matter released from septic tanks can disturb the subsequent step in on-site wastewater treatment such as the innovative filters for phosphorus removal. This study investigated the effect of organic load on phosphorus (P) and bacteria removal by reactive filter materials under real-life treatment conditions. Two long-term column experiments were conducted at very short hydraulic residence times (average ~5.5 h), using wastewater with high (mean ~120 mg L(-1)) and low (mean ~20 mg L(-1)) BOD7 values. Two alkaline filter materials, the calcium-silicate material Polonite and blast furnace slag (BFS), were tested for the removal capacity of total P, total organic carbon (TOC) and Enterococci. Both experiments showed that Polonite removed P significantly (p < 0.01) better than BFS. An increase in P removal efficiency of 29.3% was observed for the Polonite filter at the lower concentration of BOD7 (p < 0.05). Polonite was also better than BFS with regard to removal of TOC, but there were no significant differences between the two filter materials with regard to removal of Enterococci. The reduction in Enterococci was greater in the experiment using wastewater with high BOD7, an effect attributable to the higher concentration of bacteria in that wastewater. Overall, the results demonstrate the importance of extensive pre-treatment of wastewater to achieve good phosphorus removal in reactive bed filters and prolonged filter life.

  15. An evaluation of organic substance fraction removal during ion exchange with Miex-DOC resin.

    PubMed

    Wolska, Małgorzata

    2015-07-01

    In this study, the usefulness of Miex-DOC resin in eliminating organic substances and their fractions from water sources for drinking water was evaluated. The objects of study were samples from three surface water sources and one infiltration water source taken at water treatment plants before treatment in technical conditions. In particular, the effectiveness of removing biodegradable and non-biodegradable fractions as a function of resin dosages and water-resin contact times was evaluated. The ion exchange process with the Miex-DOC resin achieved a high effectiveness in removing aromatic non-biodegradable organic substances, and therefore a reduction in UV254 absorbance. The biodegradable fraction is much less susceptible to removal yet its removal effectiveness allows for a significant reduction in hazards connected with secondary microorganism development. The results of this study indicate the possibility of using ion exchange with the Miex-DOC resin for effective removal of disinfection by-product precursors.

  16. An evaluation of organic substance fraction removal during ion exchange with Miex-DOC resin.

    PubMed

    Wolska, Małgorzata

    2015-07-01

    In this study, the usefulness of Miex-DOC resin in eliminating organic substances and their fractions from water sources for drinking water was evaluated. The objects of study were samples from three surface water sources and one infiltration water source taken at water treatment plants before treatment in technical conditions. In particular, the effectiveness of removing biodegradable and non-biodegradable fractions as a function of resin dosages and water-resin contact times was evaluated. The ion exchange process with the Miex-DOC resin achieved a high effectiveness in removing aromatic non-biodegradable organic substances, and therefore a reduction in UV254 absorbance. The biodegradable fraction is much less susceptible to removal yet its removal effectiveness allows for a significant reduction in hazards connected with secondary microorganism development. The results of this study indicate the possibility of using ion exchange with the Miex-DOC resin for effective removal of disinfection by-product precursors. PMID:25976333

  17. Effect of influent aeration on removal of organic matter from coffee processing wastewater in constructed wetlands.

    PubMed

    Rossmann, Maike; Matos, Antonio Teixeira; Abreu, Edgar Carneiro; Silva, Fabyano Fonseca; Borges, Alisson Carraro

    2013-10-15

    The aim of the present study was to evaluate the influence of aeration and vegetation on the removal of organic matter in coffee processing wastewater (CPW) treated in 4 constructed wetlands (CWs), characterized as follows: (i) ryegrass (Lolium multiflorum) cultivated system operating with an aerated influent; (ii) non-cultivated system operating with an aerated influent, (iii) ryegrass cultivated system operating with a non-aerated influent; and (iv) non-cultivated system operating with a non-aerated influent. The lowest average chemical oxygen demand (COD), biochemical oxygen demand (BOD) and total suspended solids (TSS) removal efficiencies of 87, 84 and 73%, respectively, were obtained in the ryegrass cultivated system operating with a non-aerated influent. However, ryegrass cultivation did not influence the removal efficiency of organic matter. Artificial aeration of the CPW, prior to its injection in the CW, did not improve the removal efficiencies of organic matter. On other hand it did contribute to increase the instantaneous rate at which the maximum COD removal efficiency was reached. Although aeration did not result in greater organic matter removal efficiencies, it is important to consider the benefits of aeration on the removal of the other compounds.

  18. Selection of magnetic anion exchange resins for the removal of dissolved organic and inorganic matters.

    PubMed

    Wang, Qiongjie; Li, Aimin; Wang, Jinnan; Shuang, Chengdong

    2012-01-01

    Four magnetic anion exchange resins (MAERs) were used as adsorbents to purify drinking water. The effect of water quality (pH, temperature, ionic strength, etc.) on the performance of MAER for the removal of dissolved organic matter (DOM) was also investigated. Among the four studied MAERs, the strong base resin named NDMP-1 with high water content and enhanced exchange capacity exhibited the highest removal rate of dissolved organic carbon (DOC) (48.9% removal rate) and UV-absorbing substances (82.4% removal rate) with a resin dose of 10 mL/L after 30 min of contact time. The MAERs could also effectively remove inorganic matter such as sulfate, nitrate and fluoride. Because of the higher specific UV absorbance (SUVA) value, the DOM in the raw water was found to be removed more effectively than that in the clarified water by NDMP resin. The temperature showed a weak influence on the removal of DOC from 6 to 26 degrees C, while a relatively strong one at 36 degrees C. The removal of DOM by NDMP was also affected to some extent by the pH value. Moreover, increasing the sulfate concentration in the raw water could decrease the removal rates of DOC and UV-absorbing substances.

  19. Neurocognitive outcomes of children secondary to mild iodine deficiency in pregnant women.

    PubMed

    Caron, Philippe

    2015-07-01

    Iodine deficiency is the most important preventable cause of brain damage worldwide. During pregnancy, severe iodine deficiency causes endemic cretinism, whereas mild-to-moderate iodine deficiency impairs neurocognitive function of the offspring. Numerous reports demonstrate the impact of iodine supplementation on prevention of cretinism, and recent studies evaluate the effects of iodine prophylaxis on neurocognitive development in children of women with mild-to-moderate iodine deficiency. Iodine prophylaxis is generally well tolerated without side effects for the pregnant women and the offspring. In France, the iodine status was recently considered as satisfactory in children and adult population, but regional studies conducted during the last two decades have shown that healthy women are mild-to-moderately iodine deficient during pregnancy. According to recent World Heath Organization guidelines, systematic iodine prophylaxis is recommended in women planning a pregnancy, during gestation and lactation in order to prevent maternal, neonatal and infantile consequences of mild-to-moderate iodine deficiency. PMID:25934357

  20. Neurocognitive outcomes of children secondary to mild iodine deficiency in pregnant women.

    PubMed

    Caron, Philippe

    2015-07-01

    Iodine deficiency is the most important preventable cause of brain damage worldwide. During pregnancy, severe iodine deficiency causes endemic cretinism, whereas mild-to-moderate iodine deficiency impairs neurocognitive function of the offspring. Numerous reports demonstrate the impact of iodine supplementation on prevention of cretinism, and recent studies evaluate the effects of iodine prophylaxis on neurocognitive development in children of women with mild-to-moderate iodine deficiency. Iodine prophylaxis is generally well tolerated without side effects for the pregnant women and the offspring. In France, the iodine status was recently considered as satisfactory in children and adult population, but regional studies conducted during the last two decades have shown that healthy women are mild-to-moderately iodine deficient during pregnancy. According to recent World Heath Organization guidelines, systematic iodine prophylaxis is recommended in women planning a pregnancy, during gestation and lactation in order to prevent maternal, neonatal and infantile consequences of mild-to-moderate iodine deficiency.

  1. Organic dyes removal using magnetically modified rye straw

    NASA Astrophysics Data System (ADS)

    Baldikova, Eva; Safarikova, Mirka; Safarik, Ivo

    2015-04-01

    Rye straw, a very low-cost material, was employed as a biosorbent for two organic water-soluble dyes belonging to different dye classes, namely acridine orange (acridine group) and methyl green (triarylmethane group). The adsorption properties were tested for native and citric acid-NaOH modified rye straw, both in nonmagnetic and magnetic versions. The adsorption equilibrium was reached in 2 h and the adsorption isotherms data were analyzed using the Langmuir model. The highest values of maximum adsorption capacities were 208.3 mg/g for acridine orange and 384.6 mg/g for methyl green.

  2. Occurrence and Removal of Organic Micropollutants in Landfill Leachates Treated by Electrochemical Advanced Oxidation Processes.

    PubMed

    Oturan, Nihal; van Hullebusch, Eric D; Zhang, Hui; Mazeas, Laurent; Budzinski, Hélène; Le Menach, Karyn; Oturan, Mehmet A

    2015-10-20

    In recent years, electrochemical advanced oxidation processes have been shown to be an effective alternative for the removal of refractory organic compounds from water. This study is focused on the effective removal of recalcitrant organic matter (micropollutants, humic substances, etc.) present in municipal solid waste landfill leachates. A mixture of eight landfill leachates has been studied by the electro-Fenton process using a Pt or boron-doped diamond (BDD) anode and a carbon felt cathode or by the anodic oxidation process with a BDD anode. These processes exhibit great oxidation ability due to the in situ production of hydroxyl radicals ((•)OH), a highly powerful oxidizing species. Both electrochemical processes were shown to be efficient in the removal of dissolved total organic carbon (TOC) from landfill leachates. Regarding the electro-Fenton process, the replacement of the classical anode Pt by the anode BDD allows better performance in terms of dissolved TOC removal. The occurrence and removal yield of 19 polycyclic aromatic hydrocarbons, 15 volatile organic compounds, 7 alkylphenols, 7 polychlorobiphenyls, 5 organochlorine pesticides, and 2 polybrominated diphenyl ethers in landfill leachate were also investigated. Both electrochemical processes allow one to reach a quasicomplete removal (about 98%) of these organic micropollutants.

  3. Occurrence and Removal of Organic Micropollutants in Landfill Leachates Treated by Electrochemical Advanced Oxidation Processes.

    PubMed

    Oturan, Nihal; van Hullebusch, Eric D; Zhang, Hui; Mazeas, Laurent; Budzinski, Hélène; Le Menach, Karyn; Oturan, Mehmet A

    2015-10-20

    In recent years, electrochemical advanced oxidation processes have been shown to be an effective alternative for the removal of refractory organic compounds from water. This study is focused on the effective removal of recalcitrant organic matter (micropollutants, humic substances, etc.) present in municipal solid waste landfill leachates. A mixture of eight landfill leachates has been studied by the electro-Fenton process using a Pt or boron-doped diamond (BDD) anode and a carbon felt cathode or by the anodic oxidation process with a BDD anode. These processes exhibit great oxidation ability due to the in situ production of hydroxyl radicals ((•)OH), a highly powerful oxidizing species. Both electrochemical processes were shown to be efficient in the removal of dissolved total organic carbon (TOC) from landfill leachates. Regarding the electro-Fenton process, the replacement of the classical anode Pt by the anode BDD allows better performance in terms of dissolved TOC removal. The occurrence and removal yield of 19 polycyclic aromatic hydrocarbons, 15 volatile organic compounds, 7 alkylphenols, 7 polychlorobiphenyls, 5 organochlorine pesticides, and 2 polybrominated diphenyl ethers in landfill leachate were also investigated. Both electrochemical processes allow one to reach a quasicomplete removal (about 98%) of these organic micropollutants. PMID:26378656

  4. Consequences of excess iodine

    PubMed Central

    Leung, Angela M.; Braverman, Lewis E.

    2014-01-01

    Iodine is a micronutrient that is essential for the production of thyroid hormones. The primary source of iodine is the diet via consumption of foods that have been fortified with iodine, including salt, dairy products and bread, or that are naturally abundant in the micronutrient, such as seafood. Recommended daily iodine intake is 150 μg in adults who are not pregnant or lactating. Ingestion of iodine or exposure above this threshold is generally well-tolerated. However, in certain susceptible individuals, including those with pre-existing thyroid disease, the elderly, fetuses and neonates, or patients with other risk factors, the risk of developing iodine-induced thyroid dysfunction might be increased. Hypothyroidism or hyperthyroidism as a result of supraphysiologic iodine exposure might be either subclinical or overt, and the source of the excess iodine might not be readily apparent. PMID:24342882

  5. Consequences of excess iodine.

    PubMed

    Leung, Angela M; Braverman, Lewis E

    2014-03-01

    Iodine is a micronutrient that is essential for the production of thyroid hormones. The primary source of iodine is the diet via consumption of foods that have been fortified with iodine, including salt, dairy products and bread, or that are naturally abundant in the micronutrient, such as seafood. Recommended daily iodine intake is 150 µg in adults who are not pregnant or lactating. Ingestion of iodine or exposure above this threshold is generally well-tolerated. However, in certain susceptible individuals, including those with pre-existing thyroid disease, the elderly, fetuses and neonates, or patients with other risk factors, the risk of developing iodine-induced thyroid dysfunction might be increased. Hypothyroidism or hyperthyroidism as a result of supraphysiologic iodine exposure might be either subclinical or overt, and the source of the excess iodine might not be readily apparent.

  6. Tritium removal from tritiated water by organic functionalized SBA-15

    SciTech Connect

    Taguchi, A.; Kato, Y.; Akai, R.; Torikai, Y.; Matsuyama, M.

    2015-03-15

    The recovery of tritium from tritiated water is important for reducing tritium emissions to the environment and for recycling tritium. Meso-porous silicas (SBA-15) were modified by -COOH, -SO{sub 3}H and -NH{sub 2} groups and their tritium adsorption ability from tritiated water under solid-liquid sorption was investigated. The adsorption abilities and separation factor of organic functionalized SBAs were comparable to those of bare SBA. The desorption of water from bare SBA and -COOH functionalized SBA were studied by Fourier transform infra-red spectroscopy using D{sub 2}O as a probe molecule. An interaction was observed for D{sub 2}O with -COOH group where the hydrogen bonds became weaker than D{sub 2}O with bare SBA. (authors)

  7. Comparing removal of trace organic compounds and assimilable organic carbon (AOC) at advanced and traditional water treatment plants.

    PubMed

    Lou, Jie-Chung; Lin, Chung-Yi; Han, Jia-Yun; Tseng, Wei-Biu; Hsu, Kai-Lin; Chang, Ting-Wei

    2012-06-01

    Stability of drinking water can be indicated by the assimilable organic carbon (AOC). This AOC value represents the regrowth capacity of microorganisms and has large impacts on the quality of drinking water in a distribution system. With respect to the effectiveness of traditional and advanced processing methods in removing trace organic compounds (including TOC, DOC, UV(254), and AOC) from water, experimental results indicate that the removal rate of AOC at the Cheng Ching Lake water treatment plant (which utilizes advanced water treatment processes, and is hereinafter referred to as CCLWTP) is 54%, while the removal rate of AOC at the Gong Yuan water treatment plant (which uses traditional water treatment processes, and is hereinafter referred to as GYWTP) is 36%. In advanced water treatment units, new coagulation-sedimentation processes, rapid filters, and biological activated carbon filters can effectively remove AOC, total organic carbon (TOC), and dissolved organic carbon (DOC). In traditional water treatment units, coagulation-sedimentation processes are most effective in removing AOC. Simulation results and calculations made using the AutoNet method indicate that TOC, TDS, NH(3)-N, and NO(3)-N should be regularly monitored in the CCLWTP, and that TOC, temperature, and NH(3)-N should be regularly monitored in the GYWTP.

  8. Biomass accumulation patterns for removing volatile organic compounds in rotating drum biofilters.

    PubMed

    Yang, C; Suidan, M T; Zhu, X; Kim, B J

    2003-01-01

    A rotating drum biofilter (RDB) with multi-layered foam media was developed for the improvement of current biofiltration technology. The biofilter was used to investigate the effects of organic loadings and influent volatile organic compound (VOC) concentrations on VOC removal efficiency and biomass accumulation. These effects were evaluated using diethyl ether and toluene separately as model VOCs at an empty bed contact time (EBCT) of 30 s. When the toluene loading increased from 2.0 to 4.0 and 8.0 kgCOD m(-3) day(-1), toluene removal efficiency of the biofilter decreased from over 99% to 78% and 74%, respectively. The biomass distribution was found to be more even within the medium when removing toluene than when removing diethyl ether. Higher organic loading also resulted in the more even distribution of the biomass. The ratios of biomass accumulation rates in the medium of the outermost, middle and innermost layers ranged from 1:0.11:0.02 when removing diethyl ether at 2.0 kgCOD m(-3) day(-1) to 1:0.69:0.51 when removing toluene at 8.0 kgCOD m(-3) day(-1). Review of these ratios revealed three biomass accumulation patterns: surface pattern, in-depth pattern and shallow pattern. Different patterns represent different removal mechanisms in the biofiltration process. Improved biofilter design and operation should be based on the biomass accumulation pattern. PMID:14682574

  9. Combination of ion exchange system and biological reactors for simultaneous removal of ammonia and organics.

    PubMed

    Park, Wooshin; Jang, Eunhee; Lee, Myun-Joo; Yu, Seungho; Kim, Tak-Hyun

    2011-04-01

    A novel process for a simultaneous removal of ammonia and organics was developed on the basis of ion exchange and biological reactions. From batch experiments, it was found out that NH(4)(+) could be removed effectively by combining cation exchange and biological nitrification showing 0.98 mg N/m(2) ∙ s of a maximum flux. On the other hand, the removal of NO(3)(-) was 3.5 times faster than NH(4)(+) and the maximum flux was calculated to be 3.4 mg N/m(2) ∙ s. The systems for NH(4)(+) and NO(3)(-) removal were combined for establishing the IEBR process. When the process was operated in a continuous mode, approximately 95.8% of NH(4)(+) was removed showing an average flux of 0.22 mg N/m(2) · s. The removal efficiency of total nitrogen was calculated as 94.5% whereas that of organics was 99.5%. It was concluded that the IEBR process would be effectively used for a simultaneous removal of NH(4)(+) and organics.

  10. Removal of volatile and semivolatile organic contamination from soil by air and steam flushing.

    PubMed

    Sleep, B E; McClure, P D

    2001-07-01

    A soil core, obtained from a contaminated field site, contaminated with a mixture of volatile and semivolatile organic compounds (VOC and SVOC) was subjected to air and steam flushing. Removal rates of volatile and semivolatile organic compounds were monitored during flushing. Air flushing removed a significant portion of the VOC present in the soil, but a significant decline in removal rate occurred due to decreasing VOC concentrations in the soil gas phase. Application of steam flushing after air flushing produced a significant increase in contaminant removal rate for the first 4 to 5 pore volumes of steam condensate. Subsequently, contaminant concentrations decreased slowly with additional pore volumes of steam flushing. The passage of a steam volume corresponding to 11 pore volumes of steam condensate reduced the total VOC concentration in the soil gas (at 20 degrees C) by a factor of 20 to 0.07 mg/l. The corresponding total SVOC concentration in the condensate declined from 11 to 3 mg/l. Declines in contaminant removal rates during both air and steam flushing indicated rate-limited removal consistent with the persistence of a residual organic phase, rate-limited desorption, or channeling. Pressure gradients were much higher for steam flushing than for air flushing. The magnitude of the pressure gradients encountered during steam flushing for this soil indicates that, in addition to rate-limited contaminant removal, the soil permeability (2.1 x 10(-9) cm2) would be a limiting factor in the effectiveness of steam flushing. PMID:11475159

  11. [Simultaneous removal of carbon and nitrogen from organic-rich wastewater with Anammox].

    PubMed

    Chen, Chongjun; Zhu, Weijing; Huang, Xiaoxiao; Wu, Weixiang

    2014-12-01

    In order to simultaneously remove carbon and nitrogen from organic-rich wastewater, we used an up-flow anaerobic sludge bed/blanket (UASB) reactor that was started up with anammox with high concentration of carbon and nitrogen by gradually raising the organic loading of influent. We optimized the removal of nitrogen and carbon when the chemical oxygen demand (COD) concentration varied from 172 to 620 mg/L. During the entire experiment, the ammonium and total nitrogen removal efficiency was higher than 85%, while the average COD removal efficiency was 56.6%. The high concentration of organic matter did not restrain the activity of anammox bacteria. Based on polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and tapping sequencing analyses, the Planctomycete, Proteobacteria, Chloroflexi, Chlorobi bacteria are detected in the UASB reactor, which indicated complex removal pathway of carbon and nitrogen coexisted in the reactor. However, a part of Planctomycete which referred to anammox bacteria could tolerate a high content of organic carbon, and it provided help for high performance of nitrogen removal in UASB reactor.

  12. [Iodine deficiency in infancy - a risk for cognitive development].

    PubMed

    Remer, T; Johner, S A; Gärtner, R; Thamm, M; Kriener, E

    2010-08-01

    Severe iodine deficiency during pregnancy seriously influences fetal brain development and in the worst case induces cretinism. Recent studies have shown that even a mild iodine deficiency during pregnancy and during the first years of life adversely affects brain development. The World Health Organisation (WHO) considers iodine deficiency as the most common preventable cause of early childhood mental deficiency. In this context, the insufficient production of the four iodine atoms containing thyroxine seems to play a causal role, i. e., due to the iodine substrate deficiency the neuronally particularly relevant free-thyroxine level falls. Due to the very limited iodine storage capacity, the infantile thyroid is eminently dependent on an adequate and steady iodine supply. In the first month of life, when milk is the only energy- and nutrient provider, infants fed a commercial formula regularly have a sufficient iodine supply. However, breastfed infants, who depend on maternal iodine status, frequently show an inadequate iodine intake. Furthermore, iodine intake is critical when complementary food (CF) is introduced. Especially homemade CF is poor in iodine, but also commercial CFs are only partly fortified. A simultaneous inadequate iodine supply of the breastfeeding mother and the preferential use of mostly iodine-poor organic milk cannot ensure an adequate iodine supply of the infant. In terms of an improvement of nutrient supply, especially concerning an unhindered brain development, the corresponding German reference value for iodine intake of infants until age 4 month should be raised from currently 40 microg/d to at least 60 microg/d (WHO-reference: 90 microg/d). PMID:20665419

  13. Recent data on iodine intake in Germany and Europe.

    PubMed

    Gärtner, Roland

    2016-09-01

    Iodine is essential for the synthesis of thyroid hormones. These regulate metabolism, promote growth, development and maturation of all organs, especially the brain. Most iodine is found in oceans and most continental soil and ground water is deficient in iodine. Therefore, around 2 billion individuals are estimated to have insufficient iodine intake and are at risk of iodine deficiency disorders. The best carrier for save iodine supplementation is salt, as the daily intake of salt is mainly constant. Due to the collaboration between international and national organisations and the salt industry, many developing and developed countries introduced universal salt iodization (USI) or have mandatory or voluntary fortification programs. In Germany as in most European countries the use of iodized salt is voluntary not only in household but also in the food industry. Two recent epidemiological surveys in Germany revealed that 33% of children and 32% of adults are still suffering from mild to moderate iodine deficiency. The best surrogate parameter for iodine deficiency is goitre. The goitre prevalence is around 30% in children as well as in adults which is in accordance with the documented iodine deficiency. From other European countries epidemiological derived data on iodine intake are only available from Denmark and Poland. Further efforts are under way to reveal the iodine status with proper methods in all European countries. On this background it might be possible to establish adequate iodine fortification programs in all European countries. PMID:27421794

  14. Method and apparatus for the removal or bioconversion of constituents of organic liquids

    DOEpatents

    Scott, T.; Scott, C.D.

    1994-10-25

    A method and apparatus are disclosed for the removal or conversion of constituents from bulk organic liquids. A countercurrent biphasic bioreactor system is utilized to disperse and recoalesce a biocatalyst contained in the aqueous liquid phase into the organic liquid phase containing the constituent. Two transient, high-intensity electrical fields rupture the aqueous drops into a plurality of microdroplets and induce continuous coalescence and redispersion as the microdroplets travel through the organic phase, thus increasing surface area. As the aqueous microdroplets progress through the organic phase, the biocatalyst then reacts with the constituent to produce a product which is then removed from the bioreactor in the aqueous phase or retained in the organic phase. The organic liquid, now free of the original constituents, is ready for immediate use or further processing. 1 fig.

  15. Method and apparatus for the removal of bioconversion of constituents of organic liquids

    DOEpatents

    Scott, Timothy; Scott, Charles D.

    1994-01-01

    A method and apparatus for the removal or conversion of constituents from bulk organic liquids. A countercurrent biphasic bioreactor system is utilized to disperse and recoalesce a biocatalyst contained in the aqueous liquid phase into the organic liquid phase containing the constituent. Two transient, high-intensity electrical fields rupture the aqueous drops into a plurality of microdroplets and induce continuous coalescence and redispersion as the microdroplets travel through the organic phase, thus increasing surface area. As the aqueous microdroplets progress through the organic phase, the biocatalyst then reacts with the constituent to produce a product which is then removed from the bioreactor in the aqueous phase or retained in the organic phase. The organic liquid, now free of the original constituents, is ready for immediate use or further processing.

  16. Tomato fruits: a good target for iodine biofortification

    PubMed Central

    Kiferle, Claudia; Gonzali, Silvia; Holwerda, Harmen T.; Ibaceta, Rodrigo Real; Perata, Pierdomenico

    2013-01-01

    Iodine is a trace element that is fundamental for human health: its deficiency affects about two billion people worldwide. Fruits and vegetables are usually poor sources of iodine; however, plants can accumulate iodine if it is either present or exogenously administered to the soil. The biofortification of crops with iodine has therefore been proposed as a strategy for improving human nutrition. A greenhouse pot experiment was carried out to evaluate the possibility of biofortifying tomato fruits with iodine. Increasing concentrations of iodine supplied as KI or KIO3 were administered to plants as root treatments and the iodine accumulation in fruits was measured. The influences of the soil organic matter content or the nitrate level in the nutritive solution were analyzed. Finally, yield and qualitative properties of the biofortified tomatoes were considered, as well as the possible influence of fruit storage and processing on the iodine content. Results showed that the use of both the iodized salts induced a significant increase in the fruit’s iodine content in doses that did not affect plant growth and development. The final levels ranged from a few mg up to 10 mg iodine kg - 1 fruit fresh weight and are more than adequate for a biofortification program, since 150 μg iodine per day is the recommended dietary allowance for adults. In general, the iodine treatments scarcely affected fruit appearance and quality, even with the highest concentrations applied. In contrast, the use of KI in plants fertilized with low doses of nitrate induced moderate phytotoxicity symptoms. Organic matter-rich soils improved the plant’s health and production, with only mild reductions in iodine stored in the fruits. Finally, a short period of storage at room temperature or a 30-min boiling treatment did not reduce the iodine content in the fruits, if the peel was maintained. All these results suggest that tomato is a particularly suitable crop for iodine biofortification programs

  17. Kinetic modelling of nitrogen and organics removal in vertical and horizontal flow wetlands.

    PubMed

    Saeed, Tanveer; Sun, Guangzhi

    2011-05-01

    This paper provides a comparative evaluation of the kinetic models that were developed to describe the biodegradation of nitrogen and organics removal in wetland systems. Reaction kinetics that were considered in the model development included first order kinetics, Monod and multiple Monod kinetics; these kinetics were combined with continuous-stirred tank reactor (CSTR) or plug flow pattern to produce equations to link inlet and outlet concentrations of each key pollutants across a single wetland. Using three statistical parameters, a critical evaluation of five potential models was made for vertical and horizontal flow wetlands. The results recommended the models that were developed based on Monod models, for predicting the removal of nitrogen and organics in a vertical and horizontal flow wetland system. No clear correlation was observed between influent BOD/COD values and kinetic coefficients of BOD(5) in VF and HF wetlands, illustrating that the removal of biodegradable organics was insensitive to the nature of organic matter. Higher effluent COD/TN values coincided with greater denitrification kinetic coefficients, signifying the dependency of denitrification on the availability of COD in VF wetland systems. In contrast, the trend was opposite in HF wetlands, indicating that availability of NO(3)-N was the main limiting step for nitrogen removal. Overall, the results suggested the possible application of the developed alternative predictive models, for understanding the complex biodegradation routes of nitrogen and organics removal in VF and HF wetland systems.

  18. Ammonium removal in constructed wetland microcosms as influenced by season and organic carbon load.

    PubMed

    Riley, Kate A; Stein, Otto R; Hook, Paul B

    2005-01-01

    We evaluated ammonium nitrogen removal and nitrogen transformations in three-year-old, batch-operated, subsurface wetland microcosms. Treatments included replicates of Typha latifolia, Carex rostrata, and unplanted controls when influent carbon was excluded, and C. rostrata with an influent containing organic carbon. A series of 10-day batch incubations were conducted over a simulated yearlong cycle of seasons. The presence of plants significantly enhanced ammonium removal during both summer (24 degrees C, active plant growth) and winter (4 degrees C, plant dormancy) conditions, but significant differences between plant species were evident only in summer when C. rostrata outperformed T. latifolia. The effect of organic carbon load was distinctly seasonal, enhancing C. rostrata ammonium removal in winter but having an inhibitory effect in summer. Season did not influence ammonium removal in T. latifolia or unplanted columns. Net production of organic carbon was evident year-round in units without an influent organic carbon source, but was enhanced in summer, especially for C. rostrata, which produced significantly more than T. latifolia and unplanted controls. No differences in production were evident between species in winter. COD values for C. rostrata microcosms with and without influent organic carbon converged within 24 hours in winter and 7 days in summer. Gravel sorption, microbial immobilization and sequential nitrification/denitrification appear to be the major nitrogen removal mechanisms. All evidence suggests differences between season and species are due to differences in seasonal variation of root-zone oxidation.

  19. Investigating an organ-targeting platform based on hydroxyapatite nanoparticles using a novel in situ method of radioactive ¹²⁵Iodine labeling.

    PubMed

    Ignjatović, Nenad; Vranješ Djurić, Sanja; Mitić, Zarko; Janković, Drina; Uskoković, Dragan

    2014-10-01

    In this study, we have investigated the synthesis of nanoparticles of hydroxyapatite (HAp) and hydroxyapatite coated with chitosan (HAp/Ch) and the chitosan-poly-d,l-lactide-co-glycolide polymer blend (HAp/Ch-PLGA) as an organ-targeting system. We have examined and defined the final destination, as well as the dynamics and the pathways of the synthesized particles following intravenous administration in vivo. The XRD, ZP, FT-IR and SEM analyses have confirmed that the hydroxyapatite nanoparticles with d50=72 nm are coated with polymers. Radioactive 125-Iodine ((125)I), a low energy gamma emitter, was used to develop a novel in situ method for the radiolabeling of particles and investigation of their biodistribution. (125)I-labeled particles exhibited high stability in saline and serum over the second day, which justified their use in the following in vivo studies. The biodistribution of (125)I-labeled particles after intravenous injection in rats differed significantly: HAp particles mostly targeted the liver, HAp/Ch the spleen and the liver, while HAp/Ch-PLGA targeted the lungs. Twenty-four hours post injection, HAp particles were excreted completely, while both (125)I-HAp/Ch and (125)I-HAp/Ch-PLGA were retained in the body for a prolonged period of time with more than 20% of radioactivity still found in different organs. PMID:25175234

  20. Removal of dissolved organic matter in water-hyacinth waste-water treatment lagoons

    SciTech Connect

    Victoria-Rueda, C.H.

    1991-01-01

    Secondary treatment of domestic wastewater in water hyacinth lagoons was evaluated under experimental conditions to assess the role of the roots' bacterial biofilm in the removal of dissolved organic matter (DOM). Research was conducted to (1) quantify removal rates by the biofilm as a function of bulk DOM concentration, (2) formulate an analytical model of DOM removal incorporating biofilm activity, and (3) test the model response to variable organic loads in a pilot-scale plant. Removal of DOM by the biofilm was quantified in continuous-flow water hyacinth tanks at ten concentrations ranging from 45 to 330 g COD m {sup {minus}3} . Total DOM removal in the denitrifying, acetate-based experimental system was measured and partitioned into two fractions associated with the activity of biofilm and suspended bacteria. Calculated DOM removal by the biofilm was adjusted for the release of organic compounds by debris decomposition. Values of DOM removal were used to calculate oxygen transfer rates from the water hyacinth roots. A model of DOM removal in water hyacinth lagoons was formulated. The model, composed of four differential equations, was solved at steady-state conditions and the validity of its simulation results was tested in pilot-scale tanks. Hydraulic detection times ranging from 2 to 28 days were evaluated using biofilm density and concentrations of DOM and particulate organics as monitoring parameters of the model response. The observed decrease of suspended bacterial biomass along the tank was correctly simulated by the model, but predictions of effluent concentrations were not always consistent. Predicted values of biofilm bacterial mass were similar to those measured in the tanks, except when large algal populations were present in the film.

  1. Process for Non-Contact Removal of Organic Coatings from the Surface of Paintings

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A. (Inventor); Rutledge, Sharon K. (Inventor)

    1996-01-01

    The present invention discloses a method of removing organic protective coatings from a painting. In the present invention degraded protective coatings such as lacquers, acrylics, natural resins, carbons, soot, and polyurethane are safely removed from the surface of a painting without contact to the surface of the painting. This method can be used for restoration of paintings when they have been damaged, through age, fire, etc.

  2. Process for non-contact removal of organic coatings from the surface of paintings

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A. (Inventor); Rutledge, Sharon K. (Inventor)

    1995-01-01

    The present invention discloses a method of removing organic protective coatings from a painting. In the present invention degraded protective coatings such as lacquers, acrylics, natural resins, carbons, soot, and polyurethane are safely removed from the surface of a painting without contact to the surface of the painting. This method can be used for restoration of paintings when they have been damaged, through age, fire, etc.

  3. Iodine-deficiency disorders.

    PubMed

    Zimmermann, Michael B; Jooste, Pieter L; Pandav, Chandrakant S

    2008-10-01

    2 billion individuals worldwide have insufficient iodine intake, with those in south Asia and sub-Saharan Africa particularly affected. Iodine deficiency has many adverse effects on growth and development. These effects are due to inadequate production of thyroid hormone and are termed iodine-deficiency disorders. Iodine deficiency is the most common cause of preventable mental impairment worldwide. Assessment methods include urinary iodine concentration, goitre, newborn thyroid-stimulating hormone, and blood thyroglobulin. In nearly all countries, the best strategy to control iodine deficiency is iodisation of salt, which is one of the most cost-effective ways to contribute to economic and social development. When iodisation of salt is not possible, iodine supplements can be given to susceptible groups. Introduction of iodised salt to regions of chronic iodine-deficiency disorders might transiently increase the proportion of thyroid disorders, but overall the small risks of iodine excess are far outweighed by the substantial risks of iodine deficiency. International efforts to control iodine-deficiency disorders are slowing, and reaching the third of the worldwide population that remains deficient poses major challenges. PMID:18676011

  4. Removal of Indoor Volatile Organic Compounds via Photocatalytic Oxidation: A Short Review and Prospect.

    PubMed

    Huang, Yu; Ho, Steven Sai Hang; Lu, Yanfeng; Niu, Ruiyuan; Xu, Lifeng; Cao, Junji; Lee, Shuncheng

    2016-01-04

    Volatile organic compounds (VOCs) are ubiquitous in indoor environments. Inhalation of VOCs can cause irritation, difficulty breathing, and nausea, and damage the central nervous system as well as other organs. Formaldehyde is a particularly important VOC as it is even a carcinogen. Removal of VOCs is thus critical to control indoor air quality (IAQ). Photocatalytic oxidation has demonstrated feasibility to remove toxic VOCs and formaldehyde from indoor environments. The technique is highly-chemical stable, inexpensive, non-toxic, and capable of removing a wide variety of organics under light irradiation. In this paper, we review and summarize the traditional air cleaning methods and current photocatalytic oxidation approaches in both of VOCs and formaldehyde degradation in indoor environments. Influencing factors such as temperature, relative humidity, deactivation and reactivations of the photocatalyst are discussed. Aspects of the application of the photocatalytic technique to improve the IAQ are suggested.

  5. [Characteristic of natural organic matter removal by ferric and aluminium coagulation].

    PubMed

    Zhou, Ling-Ling; Zhang, Yong-Ji; Sun, Li-Hua; Li, Gui-Bai

    2008-05-01

    Natural organic matter removal efficiency and characteristic by ferric chloride and aluminium sulphate were studied. Results showed that ferric chloride was effective in natural organic matter removal when coagulant dosage was higher than 15 mg/L, while aluminium was effective at lower dosage. The TOC of water was reduced to 4.19 mg/L and 9 mg/L at a dosage of 10 mg/L for aluminium sulphate and ferric chloride respectively, while TOC was reduced to 2.44 mg/L and 1.69 mg/L at the dosage of 20 mg/L. Ferric chloride decreased pH sharply than aluminium sulphate which made hydrolysate more positive and attachable for natural organic matter. UV254 and SUVA results showed that ferric chloride removed more conjugate structure materials and unsaturated band contents than aluminium. Ferric chloride was more effective in reducing lower molecular weight organic matter and hydrophilic substances than aluminium, when the dosage of coagulant was 20 mg/L, the removal efficiency of relative molecular weight below 10 000 was 16.4% and 6.1% respectively, while aluminum was more effective in high molecular weight matter removal than ferric chloride.

  6. Removing organic matter from sulfate-rich wastewater via sulfidogenic and methanogenic pathways.

    PubMed

    Vilela, Rogerio Silveira; Damianovic, Márcia Helena Rissato Zamariolli; Foresti, Eugenio

    2014-01-01

    The simultaneous organic matter removal and sulfate reduction in synthetic sulfate-rich wastewater was evaluated for various chemical oxygen demand (COD)/sulfate ratios applied in a horizontal-flow anaerobic immobilized sludge (HAIS) reactor. At higher COD/sulfate ratios (12.5 and 7.5), the removal of organic matter was stable, likely due to methanogenesis. A combination of sulfate reduction and methanogenesis was clearly established at COD/sulfate ratios of 3.0 and 1.9. At a COD/sulfate ratio of 1.0, the organic matter removal was likely influenced by methanogenesis inhibition. The quantity of sulfate removed at a COD/sulfate ratio of 1.0 was identical to that obtained at a ratio of 1.9, indicating a lack of available electron donors for sulfidogenesis. The sulfate reduction and organic matter removal were not maximized at the same COD/sulfate ratio; therefore, competitive inhibition must be the predominant mechanism in establishing an electron flow.

  7. Organic and nitrogen removal from landfill leachate in aerobic granular sludge sequencing batch reactors

    SciTech Connect

    Wei Yanjie; Ji Min; Li Ruying; Qin Feifei

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Aerobic granular sludge SBR was used to treat real landfill leachate. Black-Right-Pointing-Pointer COD removal was analyzed kinetically using a modified model. Black-Right-Pointing-Pointer Characteristics of nitrogen removal at different ammonium inputs were explored. Black-Right-Pointing-Pointer DO variations were consistent with the GSBR performances at low ammonium inputs. - Abstract: Granule sequencing batch reactors (GSBR) were established for landfill leachate treatment, and the COD removal was analyzed kinetically using a modified model. Results showed that COD removal rate decreased as influent ammonium concentration increasing. Characteristics of nitrogen removal at different influent ammonium levels were also studied. When the ammonium concentration in the landfill leachate was 366 mg L{sup -1}, the dominant nitrogen removal process in the GSBR was simultaneous nitrification and denitrification (SND). Under the ammonium concentration of 788 mg L{sup -1}, nitrite accumulation occurred and the accumulated nitrite was reduced to nitrogen gas by the shortcut denitrification process. When the influent ammonium increased to a higher level of 1105 mg L{sup -1}, accumulation of nitrite and nitrate lasted in the whole cycle, and the removal efficiencies of total nitrogen and ammonium decreased to only 35.0% and 39.3%, respectively. Results also showed that DO was a useful process controlling parameter for the organics and nitrogen removal at low ammonium input.

  8. Removal of volatile organic compounds from groundwater: A survey of the technologies

    SciTech Connect

    Singh, S.P.; Counce, R.M.

    1989-05-01

    Groundwater contaminated with volatile organic compounds (VOCs) is being encountered with greater frequency. Since the natural degradation of these contaminants is very slow, artificial means of removing the organic compounds from the groundwater are required to prevent further deterioration of the aquifer. The technologies which have been employed for the removal of VOCs from groundwater are air stripping, biological treatment, carbon adsorption, chemical oxidation, and membrane separation. This report provides a review of the status of these technologies with particular emphasis on air stripping with emissions control. 72 refs., 6 figs., 7 tabs.

  9. Indicators to Identify Trafficking in Human Beings for the Purpose of Organ Removal.

    PubMed

    de Jong, Jessica; Ambagtsheer, Frederike

    2016-02-01

    This article presents indicators to support transplant professionals, judicial and law enforcement authorities and victim support workers with the identification of trafficking in persons for the purpose of organ removal. It outlines the legal and illegal service providers that facilitate trafficking in human beings for the purpose of organ removal and guides the reader through the following criminal process: recruitment, transport, entrance, documents, housing, transplant, aftercare, and finance. Identification of illegal transplant activities by transplant professionals can support police and judiciary with the investigation, disruption, and prosecuting of trafficking networks.

  10. Pilot scale test of a produced water-treatment system for initial removal of organic compounds

    SciTech Connect

    Sullivan, Enid J; Kwon, Soondong; Katz, Lynn; Kinney, Kerry

    2008-01-01

    A pilot-scale test to remove polar and non-polar organics from produced water was performed at a disposal facility in Farmington NM. We used surfactant-modified zeolite (SMZ) adsorbent beds and a membrane bioreactor (MBR) in combination to reduce the organic carbon content of produced water prior to reverse osmosis (RO). Reduction of total influent organic carbon (TOC) to 5 mg/L or less is desirable for efficient RO system operation. Most water disposed at the facility is from coal-bed gas production, with oil production waters intermixed. Up to 20 gal/d of produced water was cycled through two SMZ adsorbent units to remove volatile organic compounds (BTEX, acetone) and semivolatile organic compounds (e.g., napthalene). Output water from the SMZ units was sent to the MBR for removal of the organic acid component of TOC. Removal of inorganic (Mn and Fe oxide) particulates by the SMZ system was observed. The SMZ columns removed up to 40% of the influent TOC (600 mg/L). BTEX concentrations were reduced from the initial input of 70 mg/L to 5 mg/L by the SMZ and to an average of 2 mg/L after the MBR. Removal rates of acetate (input 120-170 mg/L) and TOC (input up to 45 mg/L) were up to 100% and 92%, respectively. The water pH rose from 8.5 to 8.8 following organic acid removal in the MBR; this relatively high pH was likely responsible for observed scaling of the MBR internal membrane. Additional laboratory studies showed the scaling can be reduced by metered addition of acid to reduce the pH. Significantly, organic removal in the MBR was accomplished with a very low biomass concentration of 1 g/L throughout the field trial. An earlier engineering evaluation shows produced water treatment by the SMZ/MBR/RO system would cost from $0.13 to $0.20 per bbl at up to 40 gpm. Current estimated disposal costs for produced water are $1.75 to $4.91 per bbl when transportation costs are included, with even higher rates in some regions. Our results suggest that treatment by an SMZ

  11. Indicators to Identify Trafficking in Human Beings for the Purpose of Organ Removal.

    PubMed

    de Jong, Jessica; Ambagtsheer, Frederike

    2016-02-01

    This article presents indicators to support transplant professionals, judicial and law enforcement authorities and victim support workers with the identification of trafficking in persons for the purpose of organ removal. It outlines the legal and illegal service providers that facilitate trafficking in human beings for the purpose of organ removal and guides the reader through the following criminal process: recruitment, transport, entrance, documents, housing, transplant, aftercare, and finance. Identification of illegal transplant activities by transplant professionals can support police and judiciary with the investigation, disruption, and prosecuting of trafficking networks. PMID:27500249

  12. Indicators to Identify Trafficking in Human Beings for the Purpose of Organ Removal

    PubMed Central

    de Jong, Jessica; Ambagtsheer, Frederike

    2016-01-01

    Abstract This article presents indicators to support transplant professionals, judicial and law enforcement authorities and victim support workers with the identification of trafficking in persons for the purpose of organ removal. It outlines the legal and illegal service providers that facilitate trafficking in human beings for the purpose of organ removal and guides the reader through the following criminal process: recruitment, transport, entrance, documents, housing, transplant, aftercare, and finance. Identification of illegal transplant activities by transplant professionals can support police and judiciary with the investigation, disruption, and prosecuting of trafficking networks. PMID:27500249

  13. Influence of chlorothalonil on the removal of organic matter in horizontal subsurface flow constructed wetlands.

    PubMed

    Casas-Zapata, Juan C; Ríos, Karina; Florville-Alejandre, Tomás R; Morató, Jordi; Peñuela, Gustavo

    2013-01-01

    This study investigates the effects of chlorothalonil (CLT) on chemical oxygen demand (COD) and dissolved organic carbon (DOC) in pilot-scale horizontal subsurface flow constructed wetlands (HSSFCW) planted with Phragmites australis. Physicochemical parameters of influent and effluent water samples, microbial population counting methods and statistical analysis were used to evaluate the influence of CLT on organic matter removal efficiency. The experiments were conducted on four planted replicate wetlands (HSSFCW-Pa) and one unplanted control wetland (HSSFCW-NPa). The wetlands exhibited high average organic matter removal efficiencies (HSSFCW-Pa: 80.6% DOC, 98.0% COD; HSSFCW-NPa: 93.2% DOC, 98.4% COD). The addition of CLT did not influence organic removal parameters. In all cases CLT concentrations in the effluent occurred in concentrations lower than the detection limit of the analytical method. Microbial population counts from HSSFCW-Pa showed significant correlations among different microbial groups and with different physicochemical variables. The apparent independence of organic matter removal and CLT inputs, along with the CLT depletion observed in effluent samples demonstrated that HSSFCW are a viable technology for the treatment of agricultural effluents contaminated with organo-chloride pesticides like CLT.

  14. Influence of chlorothalonil on the removal of organic matter in horizontal subsurface flow constructed wetlands.

    PubMed

    Casas-Zapata, Juan C; Ríos, Karina; Florville-Alejandre, Tomás R; Morató, Jordi; Peñuela, Gustavo

    2013-01-01

    This study investigates the effects of chlorothalonil (CLT) on chemical oxygen demand (COD) and dissolved organic carbon (DOC) in pilot-scale horizontal subsurface flow constructed wetlands (HSSFCW) planted with Phragmites australis. Physicochemical parameters of influent and effluent water samples, microbial population counting methods and statistical analysis were used to evaluate the influence of CLT on organic matter removal efficiency. The experiments were conducted on four planted replicate wetlands (HSSFCW-Pa) and one unplanted control wetland (HSSFCW-NPa). The wetlands exhibited high average organic matter removal efficiencies (HSSFCW-Pa: 80.6% DOC, 98.0% COD; HSSFCW-NPa: 93.2% DOC, 98.4% COD). The addition of CLT did not influence organic removal parameters. In all cases CLT concentrations in the effluent occurred in concentrations lower than the detection limit of the analytical method. Microbial population counts from HSSFCW-Pa showed significant correlations among different microbial groups and with different physicochemical variables. The apparent independence of organic matter removal and CLT inputs, along with the CLT depletion observed in effluent samples demonstrated that HSSFCW are a viable technology for the treatment of agricultural effluents contaminated with organo-chloride pesticides like CLT. PMID:23305280

  15. Radioactive seed localisation to guide removal of impalpable lymph nodes (Radioguided Occult Lesion Localisation using Iodine-125 seeds, “ROLLIS”)

    PubMed Central

    Jackson, Lee; Bourke, Anita Geraldine; Abdul Aziz, Farah; Taylor, Donna

    2014-01-01

    Two patients with cancer requiring removal of specific impalpable lymph nodes for full pathological analysis underwent ultrasound-guided lesion localisation and marking with a low-activity I-125 seed. A gamma probe was used in theatre to localise the signal from the seed and guide excision. Successful removal of the lesions was confirmed with the probe and by specimen radiography. Radioguided Occult Lesion Localisation using I-125 Seeds (“ROLLIS”) provides a method of precisely marking impalpable lesions for surgical excision. PMID:24658526

  16. Protection of Human Beings Trafficked for the Purpose of Organ Removal: Recommendations

    PubMed Central

    Pascalev, Assya; Van Assche, Kristof; Sándor, Judit; Codreanu, Natalia; Naqvi, Anwar; Gunnarson, Martin; Frunza, Mihaela; Yankov, Jordan

    2016-01-01

    Abstract This report presents a comprehensive set of recommendations for protection of human beings who are trafficked for the purpose of organ removal or are targeted for such trafficking. Developed by an interdisciplinary group of international experts under the auspices of the project Trafficking in Human Beings for the Purpose of Organ Removal (also known as the HOTT project), these recommendations are grounded in the view that an individual who parts with an organ for money within an illegal scheme is ipso facto a victim and that the crime of trafficking in human beings for the purpose of organ removal (THBOR) intersects with the crime of trafficking in organs. Consequently, the protection of victims should be a priority for all actors involved in antitrafficking activities: those combating organ-related crimes, such as health organizations and survivor support services, and those combating trafficking in human beings, such as the criminal justice sectors. Taking into account the special characteristics of THBOR, the authors identify 5 key stakeholders in the protection of human beings trafficked for organ removal or targeted for such trafficking: states, law enforcement agencies and judiciary, nongovernmental organizations working in the areas of human rights and antitrafficking, transplant centers and health professionals involved in transplant medicine, and oversight bodies. For each stakeholder, the authors identify key areas of concern and concrete measures to identify and protect the victims of THBOR. The aim of the recommendations is to contribute to the development of a nonlegislative response to THBOR, to promote the exchange of knowledge and best practices in the area of victim protection, and to facilitate the development of a policy-driven action plan for the protection of THBOR victims in the European Union and worldwide. PMID:27500252

  17. Protection of Human Beings Trafficked for the Purpose of Organ Removal: Recommendations.

    PubMed

    Pascalev, Assya; Van Assche, Kristof; Sándor, Judit; Codreanu, Natalia; Naqvi, Anwar; Gunnarson, Martin; Frunza, Mihaela; Yankov, Jordan

    2016-02-01

    This report presents a comprehensive set of recommendations for protection of human beings who are trafficked for the purpose of organ removal or are targeted for such trafficking. Developed by an interdisciplinary group of international experts under the auspices of the project Trafficking in Human Beings for the Purpose of Organ Removal (also known as the HOTT project), these recommendations are grounded in the view that an individual who parts with an organ for money within an illegal scheme is ipso facto a victim and that the crime of trafficking in human beings for the purpose of organ removal (THBOR) intersects with the crime of trafficking in organs. Consequently, the protection of victims should be a priority for all actors involved in antitrafficking activities: those combating organ-related crimes, such as health organizations and survivor support services, and those combating trafficking in human beings, such as the criminal justice sectors. Taking into account the special characteristics of THBOR, the authors identify 5 key stakeholders in the protection of human beings trafficked for organ removal or targeted for such trafficking: states, law enforcement agencies and judiciary, nongovernmental organizations working in the areas of human rights and antitrafficking, transplant centers and health professionals involved in transplant medicine, and oversight bodies. For each stakeholder, the authors identify key areas of concern and concrete measures to identify and protect the victims of THBOR. The aim of the recommendations is to contribute to the development of a nonlegislative response to THBOR, to promote the exchange of knowledge and best practices in the area of victim protection, and to facilitate the development of a policy-driven action plan for the protection of THBOR victims in the European Union and worldwide.

  18. Protection of Human Beings Trafficked for the Purpose of Organ Removal: Recommendations.

    PubMed

    Pascalev, Assya; Van Assche, Kristof; Sándor, Judit; Codreanu, Natalia; Naqvi, Anwar; Gunnarson, Martin; Frunza, Mihaela; Yankov, Jordan

    2016-02-01

    This report presents a comprehensive set of recommendations for protection of human beings who are trafficked for the purpose of organ removal or are targeted for such trafficking. Developed by an interdisciplinary group of international experts under the auspices of the project Trafficking in Human Beings for the Purpose of Organ Removal (also known as the HOTT project), these recommendations are grounded in the view that an individual who parts with an organ for money within an illegal scheme is ipso facto a victim and that the crime of trafficking in human beings for the purpose of organ removal (THBOR) intersects with the crime of trafficking in organs. Consequently, the protection of victims should be a priority for all actors involved in antitrafficking activities: those combating organ-related crimes, such as health organizations and survivor support services, and those combating trafficking in human beings, such as the criminal justice sectors. Taking into account the special characteristics of THBOR, the authors identify 5 key stakeholders in the protection of human beings trafficked for organ removal or targeted for such trafficking: states, law enforcement agencies and judiciary, nongovernmental organizations working in the areas of human rights and antitrafficking, transplant centers and health professionals involved in transplant medicine, and oversight bodies. For each stakeholder, the authors identify key areas of concern and concrete measures to identify and protect the victims of THBOR. The aim of the recommendations is to contribute to the development of a nonlegislative response to THBOR, to promote the exchange of knowledge and best practices in the area of victim protection, and to facilitate the development of a policy-driven action plan for the protection of THBOR victims in the European Union and worldwide. PMID:27500252

  19. Radioactive Iodine and Krypton Control for Nuclear Fuel Reprocessing Facilities

    SciTech Connect

    N. R. Soelberg; J. D. Law; T. G. Garn; M. Greenhalgh; R. T. Jubin; P. Thallapally; D. M. Strachan

    2013-08-01

    The removal of volatile radionuclides generated during used nuclear fuel reprocessing in the US is almost certain to be necessary for the licensing of a reprocessing facility in the US. Various control technologies have been developed, tested, or used over the past 50 years for control of volatile radionuclide emissions from used fuel reprocessing plants. The US DOE has sponsored, since 2009, an Off-gas Sigma Team to perform research and development focused on the most pressing volatile radionuclide control and immobilization problems. In this paper, we focus on the control requirements and methodologies for 85Kr and 129I. Numerous candidate technologies have been studied and developed at laboratory and pilot-plant scales in an effort to meet the need for high iodine control efficiency and to advance alternatives to cryogenic separations for krypton control. Several of these show promising results. Iodine decontamination factors as high as 105, iodine loading capacities, and other adsorption parameters including adsorption rates have been demonstrated under some conditions for both silver zeolite (AgZ) and Ag-functionalized aerogel. Sorbents, including an engineered form of AgZ and selected metal organic framework materials (MOFs), have been successfully demonstrated to capture Kr and Xe without the need for separations at cryogenic temperatures.

  20. Long-term migration of iodine in sedimentary rocks based on iodine speciation and 129I/127I ratio

    NASA Astrophysics Data System (ADS)

    Togo, Y.; Takahashi, Y.; Amano, Y.; Matsuzaki, H.; Suzuki, Y.; Muramatsu, Y.; Iwatsuki, T.

    2012-12-01

    [Introduction] 129I is one of the available indexes of long-term migration of groundwater solutes, because of its long half-life (15.7 million years) and low sorption characteristics. The Horonobe underground research center (Japan Atomic Energy Agency), at which are conducted research and development of fundamental techniques on geological disposal of high-level radioactive waste, is an appropriate site for natural analogue studies, because iodine concentration in groundwater is high in this area. To predict iodine behavior in natural systems, speciation of iodine is essential because of different mobility among each species. In this study, we determined iodine speciation and129I/127I isotope ratios of rock and groundwater samples to investigate long term migration of iodine. [Methods] All rock and groundwater samples were collected at Horonobe underground research center. The region is underlain mainly by Neogene to Quaternary marine sedimentary rocks, the Wakkanai Formation (Wk Fm, siliceous mudstones), and the overlying Koetoi Formation (Kt Fm, diatomaceous mudstones). Iodine species in rock samples were determined by iodine K-edge X-ray absorption near edge structure (SPring-8 BL01B1). Thin sections of rock samples were prepared, and iodine mapping were obtained by micro-XRF analysis (SPring-8 BL37XU). Iodine species (IO3-, I-, and organic I) in groundwater were separately detected by high performance liquid chromatography connected to ICP-MS. The 129I/127I ratios in groundwater and rock samples were measured by accelerator mass spectrometry (MALT, Univ. of Tokyo). Iodine in rock samples were separated by pyrohydrolysis and water extraction. [Results and discussion] Concentration of iodine in groundwater varied widely and was much higher than that of seawater showing a high correlation with that of chlorine (R2 = 0.90). Species of iodine in groundwater was mainly I-. Iodine in rock samples decreased near the boundary between Wk and Kt Fms. Iodine K-edge XANES

  1. Precipitate hydrolysis process for the removal of organic compounds from nuclear waste slurries

    DOEpatents

    Doherty, J.P.; Marek, J.C.

    1987-02-25

    A process for removing organic compounds from a nuclear waste slurry comprising reacting a mixture of radioactive waste precipitate slurry and an acid in the presence of a catalytically effective amount of a copper(II) catalyst whereby the organic compounds in the precipitate slurry are hydrolyzed to form volatile organic compounds which are separated from the reacting mixture. The resulting waste slurry, containing less than 10 percent of the original organic compounds, is subsequently blended with high level radioactive sludge land transferred to a vitrification facility for processing into borosilicate glass for long-term storage. 2 figs., 3 tabs.

  2. Precipitate hydrolysis process for the removal of organic compounds from nuclear waste slurries

    DOEpatents

    Doherty, Joseph P.; Marek, James C.

    1989-01-01

    A process for removing organic compounds from a nuclear waste slurry comprising reacting a mixture of radioactive waste precipitate slurry and an acid in the presence of a catalytically effective amount of a copper (II) catalyst whereby the organic compounds in the precipitate slurry are hydrolyzed to form volatile organic compounds which are separated from the reacting mixture. The resulting waste slurry, containing less than 10 percent of the orginal organic compounds, is subsequently blended with high level radioactive sludge and transferred to a virtrification facility for processing into borosilicate glass for long-term storage.

  3. Anammox for ammonia removal from pig manure effluents: effect of organic matter content on process performance.

    PubMed

    Molinuevo, Beatriz; García, María Cruz; Karakashev, Dimitar; Angelidaki, Irini

    2009-04-01

    The anammox process, under different organic loading rates (COD), was evaluated using a semi-continuous UASB reactor at 37 degrees C. Three different substrates were used: initially, synthetic wastewater, and later, two different pig manure effluents (after UASB-post-digestion and after partial oxidation) diluted with synthetic wastewater. High ammonium removal was achieved, up to 92.1+/-4.9% for diluted UASB-post-digested effluent (95 mg COD L(-1)) and up to 98.5+/-0.8% for diluted partially oxidized effluent (121 mg COD L(-1)). Mass balance clearly showed that an increase in organic loading (from 95 mg COD L(-1) to 237 mg COD L(-1) and from 121 mg COD L(-1) to 290 mg COD L(-1) for the UASB-post-digested effluent and the partially oxidized effluent, respectively) negatively affected the anammox process and facilitated heterotrophic denitrification. Partial oxidation as a pre-treatment method improved ammonium removal at high organic matter concentration. Up to threshold organic load concentration of 142 mg COD L(-1) of UASB-post-digested effluent and 242 mg COD L(-1) of partially oxidized effluent, no effect of organic loading on ammonia removal was registered (ammonium removal was above 80%). However, COD concentrations above 237 mg L(-1) (loading rate of 112 mg COD L(-1)day(-1)) for post-digested effluent and above 290 mg L(-1) (loading rate of 136 mg COD L(-1)day(-1)) for partially oxidized effluent resulted in complete cease of ammonium removal. Results obtained showed that, denitrification and anammox process were simultaneously occurring in the reactor. Denitrification became the dominant ammonium removal process when the COD loading was increased.

  4. Speciation and formation of iodinated trihalomethane from microbially derived organic matter during the biological treatment of micro-polluted source water.

    PubMed

    Wei, Yuanyuan; Liu, Yan; Ma, Luming; Wang, Hongwu; Fan, Jinhong; Liu, Xiang; Dai, Rui-Hua

    2013-09-01

    Water sources are micro-polluted by the increasing range of anthropogenic activities around them. Disinfection byproduct (DBP) precursors in water have gradually expanded from humic acid (HA) and fulvic acid to other important sources of potential organic matter. This study aimed to provide further insights into the effects of microbially derived organic matter as precursors on iodinated trihalomethane (I-THM) speciation and formation during the biological treatment of micro-polluted source water. The occurrence of I-THMs in drinking water treated by biological processes was investigated. The results showed for the first time that CHCl2I and CHBrClI are emerging DBPs in China. Biological pre-treatment and biological activated carbon can increase levels of microbes, which could serve as DBP precursors. Chlorination experiments with bovine serum albumin (BSA), starch, HA, deoxyribonucleic acid (DNA), and fish oil, confirmed the close correlation between the I-THM species identified during the treatment processes and those predicted from the model compounds. The effects of iodide and bromide on the I-THM speciation and formation were related to the biochemical composition of microbially derived organic precursors. Lipids produced up to 16.98μgL(-1) of CHCl2I at an initial iodide concentration of 2mgL(-1). HA and starch produced less CHCl2I at 3.88 and 3.54μgL(-1), respectively, followed by BSA (1.50μgL(-1)) and DNA (1.35μgL(-1)). Only fish oil produced I-THMs when iodide and bromide were both present in solution; the four other model compounds formed brominated species.

  5. [Iodine deficiency during pregnancy ].

    PubMed

    de Luis, D A; Aller, R; Izaola, O

    2005-09-01

    Iodine is an essential micronutrient, it would be administered every day with our diet. The main role of this micronutrient is the synthesis of thyroid hormone. Thyroid hormones are related with brain development and metabolic regulation. Iodine deficit is related with goitre, and an important problem "diseases related with iodine deficiency", including high rate of neonatal mortality, decrease of intelligence, delayed of growth, high rate of aborts and congenital abnormalities.A risk group is pregnant women. Some authors have been demonstrated the utility of iodine supplementation during pregnancy. A systematic review of Cochrane group has shown that iodine supplementation during pregnancy decreased neonatal mortality RR 0.71 (0.56-0.9), and decrease the incidence of cretinism in children under 4 years RR 0.27 (0.12-0.6). As final recommendations, a program in pregnant women must be development to treat with iodine such as we make with folic acid. Pills with iron and iodine (1 mg iron and 25 ug iodine) have been demonstrated better results that pills with iodine. Tablets are the main presentation due to the role of the women in our Society and the work time. Programs of iodine enriched salt have been demonstrated a follow up of 50%. PMID:16386080

  6. Optimization of performance assessment and design characteristics in constructed wetlands for the removal of organic matter.

    PubMed

    Hijosa-Valsero, María; Sidrach-Cardona, Ricardo; Martín-Villacorta, Javier; Bécares, Eloy

    2010-10-01

    Some of the most used constructed wetland (CW) configurations [conventional and modified free-water (FW) flow, surface flow, conventional horizontal subsurface flow (SSF) and soilless systems with floating macrophytes (FM)] were assessed in order to compare their efficiencies for the removal of organic pollutants [COD, filtered COD (FCOD), BOD and total suspended solids (TSS)] from urban sewage under the same climatic and wastewater conditions. The removal performance was calculated using three approaches: effluent concentrations, areal removed loads and mass removal. Results were very different depending on the approach, which indicates that the way to present CW efficiency should be considered carefully. All CW-configurations obtained BOD effluent concentrations below 25 mg L(-1) in summer, with a FW-CW with effluent leaving through the bottom of the tank being the only one maintaining low BOD effluent concentrations even in winter and under high organic loading conditions. In this kind of CW, the presence of plants favoured pollutant removal. SSF-CWs were the most efficient for the removal of COD. FM systems can be as efficient as some gravel bed CWs. Typhaangustifolia worked better than Phragmitesaustralis, at least when the systems were at the beginning of their operation period.

  7. Unit Process Wetlands for Removal of Trace Organic Contaminants and Pathogens from Municipal Wastewater Effluents

    PubMed Central

    Jasper, Justin T.; Nguyen, Mi T.; Jones, Zackary L.; Ismail, Niveen S.; Sedlak, David L.; Sharp, Jonathan O.; Luthy, Richard G.; Horne, Alex J.; Nelson, Kara L.

    2013-01-01

    Abstract Treatment wetlands have become an attractive option for the removal of nutrients from municipal wastewater effluents due to their low energy requirements and operational costs, as well as the ancillary benefits they provide, including creating aesthetically appealing spaces and wildlife habitats. Treatment wetlands also hold promise as a means of removing other wastewater-derived contaminants, such as trace organic contaminants and pathogens. However, concerns about variations in treatment efficacy of these pollutants, coupled with an incomplete mechanistic understanding of their removal in wetlands, hinder the widespread adoption of constructed wetlands for these two classes of contaminants. A better understanding is needed so that wetlands as a unit process can be designed for their removal, with individual wetland cells optimized for the removal of specific contaminants, and connected in series or integrated with other engineered or natural treatment processes. In this article, removal mechanisms of trace organic contaminants and pathogens are reviewed, including sorption and sedimentation, biotransformation and predation, photolysis and photoinactivation, and remaining knowledge gaps are identified. In addition, suggestions are provided for how these treatment mechanisms can be enhanced in commonly employed unit process wetland cells or how they might be harnessed in novel unit process cells. It is hoped that application of the unit process concept to a wider range of contaminants will lead to more widespread application of wetland treatment trains as components of urban water infrastructure in the United States and around the globe. PMID:23983451

  8. Unit Process Wetlands for Removal of Trace Organic Contaminants and Pathogens from Municipal Wastewater Effluents.

    PubMed

    Jasper, Justin T; Nguyen, Mi T; Jones, Zackary L; Ismail, Niveen S; Sedlak, David L; Sharp, Jonathan O; Luthy, Richard G; Horne, Alex J; Nelson, Kara L

    2013-08-01

    Treatment wetlands have become an attractive option for the removal of nutrients from municipal wastewater effluents due to their low energy requirements and operational costs, as well as the ancillary benefits they provide, including creating aesthetically appealing spaces and wildlife habitats. Treatment wetlands also hold promise as a means of removing other wastewater-derived contaminants, such as trace organic contaminants and pathogens. However, concerns about variations in treatment efficacy of these pollutants, coupled with an incomplete mechanistic understanding of their removal in wetlands, hinder the widespread adoption of constructed wetlands for these two classes of contaminants. A better understanding is needed so that wetlands as a unit process can be designed for their removal, with individual wetland cells optimized for the removal of specific contaminants, and connected in series or integrated with other engineered or natural treatment processes. In this article, removal mechanisms of trace organic contaminants and pathogens are reviewed, including sorption and sedimentation, biotransformation and predation, photolysis and photoinactivation, and remaining knowledge gaps are identified. In addition, suggestions are provided for how these treatment mechanisms can be enhanced in commonly employed unit process wetland cells or how they might be harnessed in novel unit process cells. It is hoped that application of the unit process concept to a wider range of contaminants will lead to more widespread application of wetland treatment trains as components of urban water infrastructure in the United States and around the globe.

  9. Overcoming an evolutionary conflict: removal of a reproductive organ greatly increases locomotor performance.

    PubMed

    Ramos, Margarita; Irschick, Duncan J; Christenson, Terry E

    2004-04-01

    One potential consequence of sexual size dimorphism is conflict among characters. For example, a structure evolved for reproduction can impair performance during other activities (e.g., locomotion). Here we provide quantitative evidence for an animal overcoming an evolutionary conflict generated by differential scaling and sexual size dimorphism by obligatorily removing an undamaged reproductive organ, and thus dramatically enhancing its locomotor performance. The spider genus Tidarren (Araneae, Theridiidae) is interesting because, within several species presenting extreme sexual size dimorphism (males representing approximately 1% of the total mass of the female), males voluntarily remove one of their two disproportionately large pedipalps (modified copulatory organs; a single one represents approximately 10% of the body mass in an adult) before achieving sexual maturity. Whether the left or right pedipalp is removed appears to be random. Previous researchers have hypothesized that pedipalp removal might enhance locomotor performance, a prediction that has remained untested. We found that, for male Tidarren sisyphoides, maximum speed increased (44%) significantly and endurance increased (63%) significantly after pedipalp removal. Furthermore, spiders with one pedipalp moved approximately 300% greater distances before exhaustion and had a higher survival after exertion than those with two pedipalps. Removal of the pedipalp may have evolved in male Tidarren because of enhanced abilities to search for females (higher endurance and survival after exertion) and to out-compete rival males on the female's web (higher maximum speed). Our data also highlight how the evolution of conflicts can result in the evolution of a novel behavior.

  10. On the biophilic nature of iodine in seawater

    NASA Astrophysics Data System (ADS)

    Elderfield, Henry; Truesdale, Victor W.

    1980-10-01

    Vertical profiles of concentrations of iodate- and total-iodine have been measured at thirty stations in the Pacific, Atlantic and Antarctic Oceans. The salinity-normalised iodine profiles are indicative of both iodine removal and iodate reduction in the euphotic zone. Thus, surface waters appear to be depleted in iodate-iodine (by 0.03-0.22 μM) but less so in total-iodine (by <0.01-0.06 μM) when compared with the near-constant iodine concentrations (˜0.46 μM) at depth. Graphs of specific total-iodine versus specific phosphate fit a linear model well and lie within a narrow envelope for all stations, suggesting a direct coupling of iodine and nutrients during assimilation/regeneration. The I/C atom ratio calculated from these hydrographic data (1.0 × 10 -4) agrees well with contemporary plankton compositions ( I/C= 1.4 (±0.8) × 10 -4). Similar graphs involving specific iodate also fit a linear model well. However, their gradients vary from station to station leading to a variability in I/C interconversion ratio, analogous to the variability of Redfield nutrient ratios for coastal waters. This variation is attributed to changes in both productivity and nitrate availability. Pacific deep waters contain anomalously high total-iodine concentrations which may reflect regional differences of I/P ratio in surface waters or else diffusion of iodine from bottom sediments.

  11. Dynamics of intracellular polymers in enhanced biological phosphorus removal processes under different organic carbon concentrations.

    PubMed

    Xing, Lizhen; Ren, Li; Tang, Bo; Wu, Guangxue; Guan, Yuntao

    2013-01-01

    Enhanced biological phosphorus removal (EBPR) may deteriorate or fail during low organic carbon loading periods. Polyphosphate accumulating organisms (PAOs) in EBPR were acclimated under both high and low organic carbon conditions, and then dynamics of polymers in typical cycles, anaerobic conditions with excess organic carbons, and endogenous respiration conditions were examined. After long-term acclimation, it was found that organic loading rates did not affect the yield of PAOs and the applied low organic carbon concentrations were advantageous for the enrichment of PAOs. A low influent organic carbon concentration induced a high production of extracellular carbohydrate. During both anaerobic and aerobic endogenous respirations, when glycogen decreased to around 80 ± 10 mg C per gram of volatile suspended solids, PAOs began to utilize polyphosphate significantly. Regressed by the first-order reaction model, glycogen possessed the highest degradation rate and then was followed by polyphosphate, while biomass decay had the lowest degradation rate.

  12. Effectiveness of hand sanitizers with and without organic acids for removal of rhinovirus from hands.

    PubMed

    Turner, Ronald B; Fuls, Janice L; Rodgers, Nancy D

    2010-03-01

    These studies evaluated the effectiveness of ethanol hand sanitizers with or without organic acids to remove detectable rhinovirus from the hands and prevent experimental rhinovirus infection. Ethanol hand sanitizers were significantly more effective than hand washing with soap and water. The addition of organic acids to the ethanol provided residual virucidal activity that persisted for at least 4 h. Whether these treatments will reduce rhinovirus infection in the natural setting remains to be determined.

  13. Reverse osmosis for removing synthetic organics from drinking water: a cost and performance evaluation

    SciTech Connect

    Lykins, B.W.; Clark, R.M.; Fronk, C.A.

    1988-06-01

    Reverse osmosis for removing organic compounds from drinking water has considerable promise. Bench and pilot plant studies on actual waters have shown that several organics proposed for regulation can be removed by reverse osmosis. As membrane technology improves, rejection of more difficult to remove compounds is expected to improve. Also, smaller volumes of concentrate are expected to be produced that can be handled more cost-effectively. One major concern with the use of reverse osmosis is concentrate disposal, which may increase the overall cost of treatment and disposal. The cost of reverse osmosis is very sensitive to such factors as recovery, economies of scale, systems configuration, membrane type, and electric power cost. In certain situations, reverse osmosis is a viable treatment option that is not cost-prohibitive.

  14. Graphene/polyester staple composite for the removal of oils and organic solvents

    NASA Astrophysics Data System (ADS)

    Wu, Ruihan; Yu, Baowei; Liu, Xiaoyang; Li, Hongliang; Bai, Yitong; Ming, Zhu; Chen, Lingyun; Yang, Sheng-Tao; Chang, Xue-Ling

    2016-06-01

    Spongy graphene has been widely applied in oil removal. However, spongy graphene is hardly applicable for crude oil removal, because the complexity and high viscosity of crude oil. Herein, we reported that graphene/polyester staple composite (GPSC) could be used for the removal of oils and organic solvents, in particular crude oil. Graphene oxide was in situ reduced in the presence of polyester staple by hydrazine hydrate to form GPSC. GPSC efficiently adsorbed oils and organic solvents with high adsorption capacities. Demonstrations of treating pure oils and those in simulated sea water by GPSC were successfully performed. Due to the loose structure, GPSC adsorbed crude oil quickly with an adsorption capacity of 52 g g‑1. During the regeneration, the adsorption capacity of GPSC retained around 78% of the initial capacity up to 9 cycles. The implication to the applications of GPSC in water remediation is discussed.

  15. Graphene/polyester staple composite for the removal of oils and organic solvents

    NASA Astrophysics Data System (ADS)

    Wu, Ruihan; Yu, Baowei; Liu, Xiaoyang; Li, Hongliang; Bai, Yitong; Ming, Zhu; Chen, Lingyun; Yang, Sheng-Tao; Chang, Xue-Ling

    2016-06-01

    Spongy graphene has been widely applied in oil removal. However, spongy graphene is hardly applicable for crude oil removal, because the complexity and high viscosity of crude oil. Herein, we reported that graphene/polyester staple composite (GPSC) could be used for the removal of oils and organic solvents, in particular crude oil. Graphene oxide was in situ reduced in the presence of polyester staple by hydrazine hydrate to form GPSC. GPSC efficiently adsorbed oils and organic solvents with high adsorption capacities. Demonstrations of treating pure oils and those in simulated sea water by GPSC were successfully performed. Due to the loose structure, GPSC adsorbed crude oil quickly with an adsorption capacity of 52 g g-1. During the regeneration, the adsorption capacity of GPSC retained around 78% of the initial capacity up to 9 cycles. The implication to the applications of GPSC in water remediation is discussed.

  16. Simulated impacts of crop residue removal and tillage on soil organic matter maintenance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cellulosic biofuel production may generate new markets and additional revenue for farmers. However, residue removal may cause other environmental problems such as soil erosion and loss of soil organic matter (SOM). The objective of this study was to determine the amounts of residue necessary for SOM...

  17. [Removal of different species of red tide organisms with an effective clay-complex system].

    PubMed

    Song, Xiuxian; Yu, Zhiming; Gao, Yonghui

    2003-07-01

    An effective clay-complex system was composed on the base of clay by added other two components A and B. Different red tide species, such as Scrippsiella trochoidea, Amphidinium carterae and Heterosigma akashiwo, were coagulated by this clay-complex system, and the optimum conditions for removal red tide organisms were obtained by means of orthogonal test. The results showed that clay was the most important factors in this complex system to coagulate these three organisms. The removal efficiency on three species was in order of Scrippsiella trochoidea > Amphidinium carterae > Heterosigma akashiwo. At the same time, a preliminary study of mortality rate on Penaeus japonicus (length between 1.0 to 1.5 cm) was conducted with this system, and the result of toxic test revealed that the mortality of aquaculture shrimp in control group (nothing added) reached to 80% after 96 h, however, while that of other three groups which added clay and other two components A and B, was below 40%. Thus, it implied that the addition of clay would be harmless to Penaeus japonicas. Furthermore, suitable concentration of components A and B was not harmful for the aquaculture shrimp, but increased the removal efficiency of red tide organisms. The preliminary results showed that this clay-complex system would be available in the removal of red tide organisms in filed.

  18. Monitoring Organic Contaminant Fluxes Following Dam Removal Utilizing Passive Sampler Technology

    EPA Science Inventory

    Restoration of riverine habitats and their associated ecosystems is a growing priority for government agencies (e.g., USEPA, NOAA, USDA), as well as non-profit conservation organizations (e.g., American Rivers). Dam removal is a major component of many restoration projects credi...

  19. Assessing Changes to Organic Contaminant Fluxes from Contaminated Sediments Following Dam Removal in an Urbanized River

    EPA Science Inventory

    Restoration of rivers and their associated ecosystems is a growing priority for government agencies (e.g., NOAA, USDA), as well as conservation organizations. Dam removal is a major component of many restoration projects credited with reintroducing fish species, improving water ...

  20. Selective removal of phosphate for analysis of organic acids in complex samples.

    PubMed

    Deshmukh, Sandeep; Frolov, Andrej; Marcillo, Andrea; Birkemeyer, Claudia

    2015-04-01

    Accurate quantitation of compounds in samples of biological origin is often hampered by matrix interferences one of which occurs in GC-MS analysis from the presence of highly abundant phosphate. Consequently, high concentrations of phosphate need to be removed before sample analysis. Within this context, we screened 17 anion exchange solid-phase extraction (SPE) materials for selective phosphate removal using different protocols to meet the challenge of simultaneous recovery of six common organic acids in aqueous samples prior to derivatization for GC-MS analysis. Up to 75% recovery was achieved for the most organic acids, only the low pKa tartaric and citric acids were badly recovered. Compared to the traditional approach of phosphate removal by precipitation, SPE had a broader compatibility with common detection methods and performed more selectively among the organic acids under investigation. Based on the results of this study, it is recommended that phosphate removal strategies during the analysis of biologically relevant small molecular weight organic acids consider the respective pKa of the anticipated analytes and the detection method of choice.

  1. OPTIMIZATION OF MULTICOMPONENT PERVAPORATION FOR REMOVAL OF VOLATILE ORGANIC COMPOUNDS FROM WATER

    EPA Science Inventory

    Optimal operation of a hollow fiber membrane module for pervaporative removal of multicomponent volatile organic compounds (VOCs) from wastewater was studied. A shell-and-tube heat-exchange type of hollow fiber module was considered for treatment of a wastewater containing toluen...

  2. Influence of feed time and sulfate load on the organic and sulfate removal in an ASBR.

    PubMed

    Mockaitis, Gustavo; Friedl, Gregor F; Rodrigues, José A D; Ratusznei, Suzana M; Zaiat, Marcelo; Foresti, Eugênio

    2010-09-01

    The removal of sulfate and organic matter was assessed in an ASBR, which treated wastewater containing 500 mg CODL(-1) (3 g CODL(-1)d(-1)) in 8h-cycles at 30 degrees C. The wastewater was enriched with sulfate at [COD/SO(4)(2-)] ratios of 1.34, 0.67 and 0.34 (8.8,4.5 and 2.2 gSO(4)(2-)L(-1)d(-1)). For each COD/[SO(4)(2-)] ratio fill times used were: 10 min (batch), 3 and 6h (fed-batch), achieving sulfate reduction of 30%, 72% and 72% (COD/[SO(4)(2-)] of 1.34); 25%, 58% and 55% (COD/[SO(4)(2-)] of 0.67) and 23%, 37% and 27% (COD/[SO(4)(2-)] of 0.34), respectively, and organic matter removal of 87%, 68% and 80% (COD/[SO(4)(2-)] of 1.34); 78%, 75% and 69% (COD/[SO(4)(2-)] of 0.67) and 85%, 84% and 83% (COD/[SO(4)(2-)] of 0.34), respectively. The results showed that fed-batch operation improved sulfate reduction, whereas organic matter removals were similar for batch and fed-batch operation. In addition, increase in sulfate loading in the fed-batch operation improved organic matter removal. PMID:20392632

  3. Influence and efficiency of catalytic stripper in organic carbon removal from laboratory generated soot aerosols

    EPA Science Inventory

    A catalytic stripper (CS) is a device used to remove the semi-volatile, typically organic carbon, fraction by passing raw or diluted exhaust over an oxidation catalyst heated to 300˚C. The oxidation catalyst used in this study is a commercially available diesel oxidation ca...

  4. Role of fly ash in the removal of organic pollutants from wastewater

    SciTech Connect

    M. Ahmaruzzaman

    2009-03-15

    Fly ash, a relatively abundant and inexpensive material, is currently being investigated as an adsorbent for the removal of various organic pollutants from wastewater. The wastewater contains various types of phenolic compounds, such as chloro, nitro, amino, and other substituted compounds. Various types of pesticides, such as lindane, malathion, carbofuran, etc., and dyes, such as, methylene blue, crystal violet, malachite green, etc., are also present in the wastewater. These contaminants pollute the water stream. These organic pollutants, such as phenolic compounds, pesticides, and dyes, etc., can be removed very effectively using fly ash as adsorbent. This article presents a detailed review on the role of fly ash in the removal of organic pollutants from wastewater. Adsorption of various pollutants using fly ash has been reviewed. The adsorption mechanism and other influencing factors, favorable conditions, and competitive ions, etc., on the adsorption process have also been discussed in this paper. It is evident from the review that fly ash has demonstrated good removal capabilities for various organic compounds. 171 refs., 3 figs., 5 tabs.

  5. Metal-organic gel templated synthesis of magnetic porous carbon for highly efficient removal of organic dyes.

    PubMed

    Wang, Luhuan; Ke, Fei; Zhu, Junfa

    2016-03-21

    Magnetic porous carbon composites are promising materials in various applications, such as adsorbents, supercapacitors and catalyst supports, due to their high surface area, thermal and chemical stability, and easy separation. However, despite the increasing number of reports of magnetic porous carbon composites, the preparation of these materials with environmentally friendly procedures still remains a great challenge. Herein, we report a facile method to prepare a magnetic porous carbon composite with high surface area from a Fe-based metal-organic gel (MOG) template, an extended structure of a metal-organic framework (MOF). The obtained magnetic porous carbon composite was applied to remove organic dyes from an aqueous solution by selecting methyl orange (MO) as a model molecule. It exhibits excellent adsorption capacity (182.82 mg g(-1)), fast adsorption kinetics (8.13 × 10(-3) g mg(-1) min(-1)), and a perfect magnetic separation performance for the MO removal. This study demonstrates a new way to achieve clean synthesis of magnetic porous carbon materials, and opens a new door for the application of MOGs in organic dye removal.

  6. Iodine-induced thyroid blockade: role of selenium and iodine in the thyroid and pituitary glands.

    PubMed

    Basalaeva, Nadezdha L

    2013-08-01

    The purpose of this study was to determine the content of iodine and selenium in the thyroid and pituitary glands of rats under iodine-induced blockade of the thyroid gland. Electron probe microanalysis, wavelength-dispersive spectrometry, and point analysis were used in this investigation. We also determined the expression of sodium iodide symporter and caspase 32 in the thyroid and pituitary glands and the expression of thyroid-stimulating hormone in the pituitary. The samples for iodine analysis must be thoroughly dehydrated, and for this purpose, we developed a method that produced samples of constant mass with minimal loss of substrate (human thyroid gland was used for the investigation). Normal levels of iodine and selenium were found in the thyroid, pituitary, ovaries, testes hypothalamus, and pancreas of healthy rats. The levels of iodine and selenium in I- or Se-positive points and the percentage of positive points in most of these organs were similar to those of controls (basal level), except for the level of iodine in the thyroid gland and testes. Blockade of the thyroid gland changed the iodine level in iodine-positive points of the thyroid and the pituitary glands. On the sixth day of blockage, the iodine level in iodine-positive points of the thyroid gradually decreased to the basal level followed by an abrupt increase on the seventh day, implying a rebound effect. The opposite was found in the pituitary, in which the level of iodine in iodine-positive points increased during the first 6 days and then abruptly decreased on the seventh day. Expression of the thyroid-stimulating hormone in the pituitary decreased during the first 5 days but sharply increased on the sixth day, with a minimum level of iodine in the thyroid and maximum in the pituitary, before normalization of the iodine level in both glands preceding the rebound effect. The expression of sodium iodide symporter increased during the first 4 days of blockage and then decreased in both

  7. Volatilization of iodine from nitric acid using peroxide

    DOEpatents

    Cathers, G.I.; Shipman, C.J.

    1975-10-21

    A method for removing radioactive iodine from nitric acid solution by adding hydrogen peroxide to the solution while concurrently holding the solution at the boiling point and distilling hydrogen iodide from the solution is reported.

  8. [Mechanism of natural organic matter removal by potassium permanganate composite enhanced coagulation].

    PubMed

    Zhang, Yong-Ji; Zhou, Ling-Ling; Li, Wei-Ying; Li, Xing; Li, De-Qiang; Li, Gui-Bai

    2009-03-15

    Streaming current technique, fluctuation of transmitted light technique, molecular weight distribution and XAD resin adsorption technique were used to study the mechanism of natural organic matter removal by potassium permanganate composite (PPC) enhanced coagulation. Results showed that natural organic matter removal efficiency increased 13% by 0.75 mg/L potassium permanganate composite enhanced coagulation compared with that of alum coagulation alone. Streaming current indicated that potassium permanganate composite decreased the organic matter stability by reducing the surface negative charge, and the SC value increased from 55.2 to 61.4, 69.6 and 87.0 by addition of 0.50, 0.75 and 1.0 mg/L PPC. Coagulation index R indicated both nascent manganese dioxide and subsidiaries played an important role in potassium permanganate composite enhanced coagulation process. Potassium permanganate composite enhanced coagulation increased the removal efficiency of lower molecular weight and hydrophilic organic matter compared with alum coagulation, and hydrophilic organic matter can be reduced from 1.9 mg/L to 1.32 mg/L by the addition of 0.75 mg/L potassium permanganate composite.

  9. Enhanced coagulation for turbidity and Total Organic Carbon (TOC) removal from river Kansawati water.

    PubMed

    Narayan, Sumit; Goel, Sudha

    2011-01-01

    The objective of this study was to determine optimum coagulant doses for turbidity and Total Organic Carbon (TOC) removal and evaluate the extent to which TOC can be removed by enhanced coagulation. Jar tests were conducted in the laboratory to determine optimum doses of alum for the removal of turbidity and Natural Organic Matter (NOM) from river water. Various other water quality parameters were measured before and after thejar tests and included: UV Absorbance (UVA) at 254 nm, microbial concentrations, TDS, conductivity, hardness, alkalinity, and pH. The optimum alum dose for removal of turbidity and TOC was 20 mg/L for the sample collected in November 2009 and 100 mg/L for the sample collected in March 2010. In both cases, the dose for enhanced coagulation was significantly higher than that for conventional coagulation. The gain in TOC removal was insignificant compared to the increase in coagulant dose required. This is usual for low TOC (< 2 mg/L)--high alkalinity water. Other water samples with higher TOC need to be tested to demonstrate the effectiveness of enhanced coagulation.

  10. Vertical flow constructed wetlands: kinetics of nutrient and organic matter removal.

    PubMed

    Pérez, M M; Hernández, J M; Bossens, J; Jiménez, T; Rosa, E; Tack, F

    2014-01-01

    The kinetics of organic matter and nutrient removal in a pilot vertical subsurface wetland with red ferralitic soil as substrate were evaluated. The wetland (20 m(2)) was planted with Cyperus alternifolius. The domestic wastewater that was treated in the wetland had undergone a primary treatment consisting of a septic moat and a buffer tank. From the sixth week of operation, the performance of the wetland stabilized, and a significant reduction in pollutant concentration of the effluent wastewater was obtained. Also a significant increase of dissolved oxygen (5 mg/l) was obtained. The organic matter removal efficiency was greater than 85% and the nutrient removal efficiency was greater than 75% in the vertical subsurface wetland. Nitrogen and biochemical oxygen demand (BOD) removal could be described by a first-order model. The kinetic constants were 3.64 and 3.27 d(-1) for BOD and for total nitrogen, respectively. Data on the removal of phosphorus were adapted to a second-order model. The kinetic constant was 0.96 (mg/l)(-1) d(-1). The results demonstrated the potential of vertical flow constructed wetlands to clean treated domestic wastewater before discharge into the environment. PMID:25026582

  11. Organic matter removal from saline agricultural drainage wastewater using a moving bed biofilm reactor.

    PubMed

    Ateia, Mohamed; Nasr, Mahmoud; Yoshimura, Chihiro; Fujii, Manabu

    2015-01-01

    We investigated the effect of salinity on the removal of organics and ammonium from agricultural drainage wastewater (ADW) using moving bed biofilm reactors (MBBRs). Under the typical salinity level of ADW (total dissolved solids (TDS) concentration up to 2.5 g·L(-1)), microorganisms were acclimated for 40 days on plastic carriers and a stable slime layer of attached biofilm was formed. Next, six batch mode MBBRs were set up and run under different salinity conditions (0.2-20 g-TDS·L(-1)). The removal efficiency of chemical oxygen demand (COD) and ammonium-nitrogen (NH4-N) in 6 hours decreased from 98 and 68% to 64 and 21% with increasing salt concentrations from 2.5 to 20 g-TDS·L(-1), respectively. In addition, at decreasing salt levels of 0.2 g-TDS·L(-1), both COD removal and nitrification were slightly lowered. Kinetic analysis indicated that the first-order reaction rate constant (k1) and specific substrate utilization rate (U) with respect to the COD removal remained relatively constant (10.9-11.0 d(-1) and 13.1-16.1 g-COD-removed.g-biomass(-1)·d(-1), respectively) at the salinity range of 2.5-5.0 g-TDS·L(-1). In this study, the treated wastewater met the standard criteria of organic concentration for reuse in agricultural purposes, and the system performance remained relatively constant at the salinity range of typical ADW.

  12. Organic matter removal from saline agricultural drainage wastewater using a moving bed biofilm reactor.

    PubMed

    Ateia, Mohamed; Nasr, Mahmoud; Yoshimura, Chihiro; Fujii, Manabu

    2015-01-01

    We investigated the effect of salinity on the removal of organics and ammonium from agricultural drainage wastewater (ADW) using moving bed biofilm reactors (MBBRs). Under the typical salinity level of ADW (total dissolved solids (TDS) concentration up to 2.5 g·L(-1)), microorganisms were acclimated for 40 days on plastic carriers and a stable slime layer of attached biofilm was formed. Next, six batch mode MBBRs were set up and run under different salinity conditions (0.2-20 g-TDS·L(-1)). The removal efficiency of chemical oxygen demand (COD) and ammonium-nitrogen (NH4-N) in 6 hours decreased from 98 and 68% to 64 and 21% with increasing salt concentrations from 2.5 to 20 g-TDS·L(-1), respectively. In addition, at decreasing salt levels of 0.2 g-TDS·L(-1), both COD removal and nitrification were slightly lowered. Kinetic analysis indicated that the first-order reaction rate constant (k1) and specific substrate utilization rate (U) with respect to the COD removal remained relatively constant (10.9-11.0 d(-1) and 13.1-16.1 g-COD-removed.g-biomass(-1)·d(-1), respectively) at the salinity range of 2.5-5.0 g-TDS·L(-1). In this study, the treated wastewater met the standard criteria of organic concentration for reuse in agricultural purposes, and the system performance remained relatively constant at the salinity range of typical ADW. PMID:26465302

  13. Removal of natural organic matter and arsenic from water by electrocoagulation/flotation continuous flow reactor.

    PubMed

    Mohora, Emilijan; Rončević, Srdjan; Dalmacija, Božo; Agbaba, Jasmina; Watson, Malcolm; Karlović, Elvira; Dalmacija, Milena

    2012-10-15

    The performance of the laboratory scale electrocoagulation/flotation (ECF) reactor in removing high concentrations of natural organic matter (NOM) and arsenic from groundwater was analyzed in this study. An ECF reactor with bipolar plate aluminum electrodes was operated in the horizontal continuous flow mode. Electrochemical and flow variables were optimized to examine ECF reactor contaminants removal efficiency. The optimum conditions for the process were identified as groundwater initial pH 5, flow rate=4.3 l/h, inter electrode distance=2.8 cm, current density=5.78 mA/cm(2), A/V ratio=0.248 cm(-1). The NOM removal according to UV(254) absorbance and dissolved organic matter (DOC) reached highest values of 77% and 71% respectively, relative to the raw groundwater. Arsenic removal was 85% (6.2 μg As/l) relative to raw groundwater, satisfying the drinking water standards. The specific reactor electrical energy consumption was 17.5 kWh/kg Al. The specific aluminum electrode consumption was 66 g Al/m(3). According to the obtained results, ECF in horizontal continuous flow mode is an energy efficient process to remove NOM and arsenic from groundwater. PMID:22902131

  14. Typical low cost biosorbents for adsorptive removal of specific organic pollutants from water.

    PubMed

    Tran, Van Son; Ngo, Huu Hao; Guo, Wenshan; Zhang, Jian; Liang, Shuang; Ton-That, Cuong; Zhang, Xinbo

    2015-04-01

    Specific organic pollutants (SOPs) such as phenolic compounds, PAHs, organic pesticides, and organic herbicides cause health and environmental problems due to their excessive toxic properties and poor biodegradability. Low-cost biosorbents are considered as a promising alternative for conventional adsorbents to remove SOPs from water. These materials have several advantages such as high sorption capacities, good modifiability and recoverability, insensitivity to toxic substances, simple operation in the treatment processes. However, previous reports on various types of biosorbents for removing SOPs are still moderately fragmented. Hence, this paper provides a comprehensive review on using typical low-cost biosorbents obtained from lignocellulose and chitin/chitosan for SOPs adsorption. Especially, their characteristics, biosorption mechanism together with utilization for eliminating SOPs are presented and discussed. The paper also gives a critical view regarding future applications of low-cost biosorbents in SOPs-contaminated water treatment.

  15. The role of organic matter in the removal of emerging trace organic chemicals during managed aquifer recharge.

    PubMed

    Rauch-Williams, T; Hoppe-Jones, C; Drewes, J E

    2010-01-01

    This study explored the effect of different bulk organic carbon matrices on the fate of trace organic chemicals (TOrC) during managed aquifer recharge (MAR). Infiltration through porous media was simulated in biologically active column experiments under aerobic and anoxic recharge conditions. Wastewater effluent derived organic carbon types, differing in hydrophobicity and biodegradability (i. e., hydrophobic acids, hydrophilic carbon, organic colloids), were used as feed substrates in the column experiments. These carbon substrates while fed at the same concentration differed in their ability to support soil biomass growth during porous media infiltration. Removal of degradable TOrC (with the exception of diclofenac and propyphenazone) was equal or better under aerobic versus anoxic porous media infiltration conditions. During the initial phase of infiltration, the presence of biodegradable organic carbon (BDOC) enhanced the decay of degradable TOrC by promoting soil biomass growth, suggesting that BDOC served as a co-substrate in a co-metabolic transformation of these contaminants. However, unexpected high removal efficiencies were observed for all degradable TOrC in the presence of low BDOC concentrations under well adopted oligotrophic conditions. It is hypothesized that removal under these conditions is caused by a specialized microbial community growing on refractory carbon substrates such as hydrophobic acids. Findings of this study reveal that the concentration and character of bulk organic carbon present in effluents affect the degradation efficiency for TOrC during recharge operation. Specifically aerobic, oligotrophic microbiological soil environments present favorable conditions for the transformation of TOrC, including rather recalcitrant compounds such as chlorinated flame retardants.

  16. Tracing the limits of organic micropollutant removal in biological wastewater treatment.

    PubMed

    Falås, Per; Wick, Arne; Castronovo, Sandro; Habermacher, Jonathan; Ternes, Thomas A; Joss, Adriano

    2016-05-15

    Removal of organic micropollutants was investigated in 15 diverse biological reactors through short and long-term experiments. Short-term batch experiments were performed with activated sludge from three parallel sequencing batch reactors (25, 40, and 80 d solid retention time, SRT) fed with synthetic wastewater without micropollutants for one year. Despite the minimal micropollutant exposure, the synthetic wastewater sludges were able to degrade several micropollutants present in municipal wastewater. The degradation occurred immediately after spiking (1-5 μg/L), showed no strong or systematic correlation to the sludge age, and proceeded at rates comparable to those of municipal wastewater sludges. Thus, the results from the batch experiments indicate that degradation of organic micropollutants in biological wastewater treatment is quite insensitive to SRT increases from 25 to 80 days, and not necessarily induced by exposure to micropollutants. Long-term experiments with municipal wastewater were performed to assess the potential for extended biological micropollutant removal under different redox conditions and substrate concentrations (carbon and nitrogen). A total of 31 organic micropollutants were monitored through influent-effluent sampling of twelve municipal wastewater reactors. In accordance with the results from the sludges grown on synthetic wastewater, several compounds such as bezafibrate, atenolol and acyclovir were significantly removed in the activated sludge processes fed with municipal wastewater. Complementary removal of two compounds, diuron and diclofenac, was achieved in an oxic biofilm treatment. A few aerobically persistent micropollutants such as venlafaxine, diatrizoate and tramadol were removed under anaerobic conditions, but a large number of micropollutants persisted in all biological treatments. Collectively, these results indicate that certain improvements in biological micropollutant removal can be achieved by combining different

  17. Tracing the limits of organic micropollutant removal in biological wastewater treatment.

    PubMed

    Falås, Per; Wick, Arne; Castronovo, Sandro; Habermacher, Jonathan; Ternes, Thomas A; Joss, Adriano

    2016-05-15

    Removal of organic micropollutants was investigated in 15 diverse biological reactors through short and long-term experiments. Short-term batch experiments were performed with activated sludge from three parallel sequencing batch reactors (25, 40, and 80 d solid retention time, SRT) fed with synthetic wastewater without micropollutants for one year. Despite the minimal micropollutant exposure, the synthetic wastewater sludges were able to degrade several micropollutants present in municipal wastewater. The degradation occurred immediately after spiking (1-5 μg/L), showed no strong or systematic correlation to the sludge age, and proceeded at rates comparable to those of municipal wastewater sludges. Thus, the results from the batch experiments indicate that degradation of organic micropollutants in biological wastewater treatment is quite insensitive to SRT increases from 25 to 80 days, and not necessarily induced by exposure to micropollutants. Long-term experiments with municipal wastewater were performed to assess the potential for extended biological micropollutant removal under different redox conditions and substrate concentrations (carbon and nitrogen). A total of 31 organic micropollutants were monitored through influent-effluent sampling of twelve municipal wastewater reactors. In accordance with the results from the sludges grown on synthetic wastewater, several compounds such as bezafibrate, atenolol and acyclovir were significantly removed in the activated sludge processes fed with municipal wastewater. Complementary removal of two compounds, diuron and diclofenac, was achieved in an oxic biofilm treatment. A few aerobically persistent micropollutants such as venlafaxine, diatrizoate and tramadol were removed under anaerobic conditions, but a large number of micropollutants persisted in all biological treatments. Collectively, these results indicate that certain improvements in biological micropollutant removal can be achieved by combining different

  18. Removal of bromate and assimilable organic carbon from drinking water using granular activated carbon.

    PubMed

    Huang, W J; Peng, H S; Peng, M Y; Chen, L Y

    2004-01-01

    This study investigated the feasibility of using granular activated carbon (GAC) to remove bromate ion (BrO3-) and assimilable organic carbon (AOC) from drinking water through a rapid small-scale column test (RSSCT) method and a pilot-scale study. Results from RSSCT indicated that the GAC capacity for BrO3- removal was dependent on the GAC type, empty bed contact time (EBCT), and source water quality. The GAC with a high number of basic groups and higher pHpzc values showed an increased BrO3- removal capacity. BrO3- removal was improved by increasing EBCT. The high EBCT provides a greater opportunity for BrO3- to be adsorbed and reduced to Br- on the GAC surface. On the other hand, the presence of dissolved organic carbon (DOC) and anions, such as chloride, bromide, and sulfate, resulted in poor BrO3- reduction. In the GAC pilot plant, a GAC column preloaded for 12 months achieved a BrO3- and AOC removal range from 79-96% and 41-75%, respectively. The BrO3- amount removed was found to be proportional to the influent BrO3- concentration. However, the BrO3- removal rate apparently decreased with increasing operation time. In contrast, the AOC apparently increased during the long-term operation period. This may be a result of the contribution due to new GAC being gradually transformed into biological activated carbon (BAC), and the bacterial biomass adsorbed on GAC surface hindering BrO3- reduction by GAC either by blocking pores or adsorbing at the activated sites for BrO3- reduction. PMID:15566189

  19. Simultaneous enhancement of organics and nitrogen removal in drinking water biofilm pretreatment system with reed addition.

    PubMed

    Feng, Li-Juan; Zhu, Liang; Yang, Qi; Yang, Guang-Feng; Xu, Jian; Xu, Xiang-Yang

    2013-02-01

    A novel drinking water biofilm pretreatment process with reed addition was established for enhancement of simultaneously organics and nitrogen removal. Results showed that nitrate removal efficiency was positively related with the influent C/N ratio, reaching to 87.8±2.8% at the C/N ratio of 4.7. However, the predicted trichloromethane (THM) levels based on total organic carbon (TOC) and UV254 were high with the increase of influent C/N ratio. Combined with the pollutants removal performance and microbial community variation, an appropriate C/N ratio via reed addition was determined at 2.2 for the continuous biofilm reactor. With adjustment of hydraulic retention time (HRT), the highest of nitrate removal efficiency (74.2±1.4%) and organics utilization efficiency (0.63 mg NO3--N mg(-1)TOC) were achieved at an optimum HRT of 18 h, with both low effluent NO3--N (0.88±0.03 mg l(-1)) and TOC (2.86±0.67 mg l(-1)).

  20. Preparation of Silica/Reduced Graphene Oxide Nanosheet Composites for Removal of Organic Contaminants from Water.

    PubMed

    Li, Wen; Liu, Wei; Wang, Haifei; Lu, Wensheng

    2016-06-01

    Graphene-based composites open up new opportunities as effective adsorbents for the removal of organic contaminants from water. In this article, we report a novel and facile process to synthesize well-dispersed silica/reduced graphene oxide (SiO2/RGO) nanosheet composites. The SiO2/RGO nanosheet composites are prepared through a modified sol-gel process with in situ hydrolysis of tetraethoxysilane (TEOS) on graphene oxide (GO) nanosheet, followed by reduction of GO to graphene. In comparison with the RGO nanosheets, the as-prepared SiO2/RGO nanosheet composites have a larger surface area and good aqueous disperse ability. In addition, the application of SiO2/RGO nanosheet composites was demonstrated on removing organic dyes from water. The SiO2/RGO nanosheet composites show rapid and stable adsorption performance on removal of Methylene Blue (MB) and thionine (TH) from water. It is indicated that the resulting SiO2/RGO composites can be utilized as efficient adsorbents for the removal of organic contaminants from water.

  1. Preparation of Silica/Reduced Graphene Oxide Nanosheet Composites for Removal of Organic Contaminants from Water.

    PubMed

    Li, Wen; Liu, Wei; Wang, Haifei; Lu, Wensheng

    2016-06-01

    Graphene-based composites open up new opportunities as effective adsorbents for the removal of organic contaminants from water. In this article, we report a novel and facile process to synthesize well-dispersed silica/reduced graphene oxide (SiO2/RGO) nanosheet composites. The SiO2/RGO nanosheet composites are prepared through a modified sol-gel process with in situ hydrolysis of tetraethoxysilane (TEOS) on graphene oxide (GO) nanosheet, followed by reduction of GO to graphene. In comparison with the RGO nanosheets, the as-prepared SiO2/RGO nanosheet composites have a larger surface area and good aqueous disperse ability. In addition, the application of SiO2/RGO nanosheet composites was demonstrated on removing organic dyes from water. The SiO2/RGO nanosheet composites show rapid and stable adsorption performance on removal of Methylene Blue (MB) and thionine (TH) from water. It is indicated that the resulting SiO2/RGO composites can be utilized as efficient adsorbents for the removal of organic contaminants from water. PMID:27427624

  2. Green Technology for the Removal of Chloro-Organics from Pulp and Paper Mill Wastewater.

    PubMed

    Choudhary, Ashutosh Kumar; Kumar, Satish; Sharma, Chhaya; Kumar, Vivek

    2015-07-01

    This study evaluates the treatment efficiency of a horizontal subsurface-flow constructed wetland (HSSF-CW) for the removal of chloro-organic compounds from pulp and paper mill wastewater. The surface area of the HSSF-CW unit was 5.25 m² and was planted with Colocasia esculenta. The wastewater was characterized for different chloro-organic compounds, that is, adsorbable organic halides (AOX), chlorophenolics, and chlorinated resin and fatty acids (cRFAs). Under a hydraulic retention time of 5.9 days, the average AOX, chlorophenolics, and cRFA removal from wastewater was 87, 87, and 93%, respectively. Some of the chlorophenolics were found to accumulate in the plant biomass and soil material. The mass balance studies show that a significant fraction of chlorophenolics and cRFA was degraded in the constructed wetland system. Modeling studies were carried out to estimate the first-order area-based removal rate constants (k) for chemical oxygen demand removal. The HSSF-CW was found to be an effective treatment technology for the remediation of pulp and paper mill wastewater. PMID:26163503

  3. Post-refining removal of organic nitrogen compounds from diesel fuels to improve environmental quality.

    PubMed

    Mushrush, George W; Quintana, Marian A; Bauserman, Joy W; Willauer, Heather D

    2011-01-01

    The purpose of this investigation was to remove the organic nitrogen compounds from petroleum-derived diesel fuels. These nitrogen compounds can cause environmental problems, as well as fuel instability problems that can degrade fuels and affect engine performance. Fuels were treated with two different filtering media, activated clay and silica tel. The methylene chloride extracts from both the activated clay and silica gel were subjected to GC/MS analysis. Close to 99% of the total organic nitrogen compounds were removed. About 60% of the nitrogen compounds identified consisted of pyridines, quinolines and tetra-hydroquinolines made up 26%, while indoles and carbazoles about 10% of the total nitrogen compounds. Of the nitrogen heterocyclics identified, indoles and carbazoles were linked to fuel instability reactions. The proposed method was tested on diesels fuels from a variety of countries and found to remove between 97.8 and 99.9% of the N-compounds. The results of this study showed that both of these filtering materials were effective in removing the organic nitrogen compounds and resulted in fuels that exhibited excellent storage stability. These simple filtering methods can be independent of the refining process and do result in an environmentally cleaner burning fuel.

  4. Multipass membrane air-stripping (MAS) for removing volatile organic compounds (VOCs) from surfactant micellar solutions.

    PubMed

    Cheng, Hefa; Hu, Yuanan; Luo, Jian; Sabatini, David A

    2009-10-30

    Air-stripping is one of the most effective technologies for removing volatile organic compounds (VOCs) from surfactant solutions, although the presence of surfactant poses some unique challenges. This study evaluated the effect of a mixed surfactant system on the apparent Henry's law constant of tetrachloroethylene (PCE) and the efficiency of PCE removal from surfactant solutions using a lab-scale hollow fiber membrane contactor. Results show that the presence of surfactant significantly reduced the apparent Henry's law constant of PCE, and the reduction was proportional to the total surfactant concentration. PCE removal efficiency by membrane air-stripping (MAS) decreased as the surfactant system transitioned from solubilization to supersolubilization. Besides significantly reducing the apparent volatility of VOCs, the presence of surfactant brings additional mass transfer resistance in air-stripping, which makes it difficult to achieve high levels of contaminant removal, even at very high air/liquid (A/L) ratios. In contrast, multipass/multistage MAS operated at low A/L ratios could achieve near 100% contaminant removal because of less mass transfer limitation during each stripping pass/stage. Experimental results, together with model calculations demonstrate multipass (and multistage) air-stripping as a cost-effective alternative for removing VOCs from surfactant micellar solutions compared to the options of using large air strippers or operating at high A/L ratios.

  5. Non-defendable resources affect peafowl lek organization: a male removal experiment.

    PubMed

    Loyau, Adeline; Jalme, Michel Saint; Sorci, Gabriele

    2007-01-10

    A lekking mating system is typically thought to be non-resource based with male providing nothing to females but genes. However, males are thought to clump their display sites on areas where they are more likely to encounter females, which may depend on non-defendable resource location. We tested this hypothesis on a feral population of peacocks. In agreement, we found that, within the lek, display site proximity to food resources had an effect on female visitation rate and male mating success. The attractiveness of display sites to male intruders was explained by the distance to the feeding place and by the female visitation rate. We randomly removed 29 territorial males from their display sites. Display sites that were more attractive to male intruders before removal remained highly attractive after removal and display sites closer to the feeding area attracted the attention of intruders significantly more after removal. Similarly, display sites that were more visited by females before removal remained more visited after removal, suggesting again that the likelihood of encountering females is determined by the display site location. Overall, these results are in agreement with non-defendable resources affecting lek spatial organization in the peafowl.

  6. Non-defendable resources affect peafowl lek organization: a male removal experiment.

    PubMed

    Loyau, Adeline; Jalme, Michel Saint; Sorci, Gabriele

    2007-01-10

    A lekking mating system is typically thought to be non-resource based with male providing nothing to females but genes. However, males are thought to clump their display sites on areas where they are more likely to encounter females, which may depend on non-defendable resource location. We tested this hypothesis on a feral population of peacocks. In agreement, we found that, within the lek, display site proximity to food resources had an effect on female visitation rate and male mating success. The attractiveness of display sites to male intruders was explained by the distance to the feeding place and by the female visitation rate. We randomly removed 29 territorial males from their display sites. Display sites that were more attractive to male intruders before removal remained highly attractive after removal and display sites closer to the feeding area attracted the attention of intruders significantly more after removal. Similarly, display sites that were more visited by females before removal remained more visited after removal, suggesting again that the likelihood of encountering females is determined by the display site location. Overall, these results are in agreement with non-defendable resources affecting lek spatial organization in the peafowl. PMID:17074448

  7. Biodesulfurization techniques: Application of selected microorganisms for organic sulfur removal from coals. Final report

    SciTech Connect

    Elmore, B.B.

    1993-08-01

    As an alternative to post-combustion desulfurization of coal and pre-combustion desulfurization using physicochemical techniques, the microbial desulfurization of coal may be accomplished through the use of microbial cultures that, in an application of various microbial species, may remove both the pyritic and organic fractions of sulfur found in coal. Organisms have been isolated that readily depyritize coal but often at prohibitively low rates of desulfurization. Microbes have also been isolated that may potentially remove the organic-sulfur fraction present in coal (showing promise when acting on organic sulfur model compounds such as dibenzothiophene). The isolation and study of microorganisms demonstrating a potential for removing organic sulfur from coal has been undertaken in this project. Additionally, the organisms and mechanisms by which coal is microbially depyritized has been investigated. Three cultures were isolated that grew on dibenzothiophene (DBT), a model organic-sulfur compound, as the sole sulfur source. These cultures (UMX3, UMX9, and IGTS8) also grew on coal samples as the sole sulfur source. Numerous techniques for pretreating and ``cotreating`` coal for depyritization were also evaluated for the ability to improve the rate or extent of microbial depyritization. These include prewashing the coal with various solvents and adding surfactants to the culture broth. Using a bituminous coal containing 0.61% (w/w) pyrite washed with organic solvents at low slurry concentrations (2% w/v), the extent of depyritization was increased approximately 25% in two weeks as compared to controls. At slurry concentrations of 20% w/v, a tetrachloroethylene treatment of the coal followed by depyritization with Thiobacillus ferrooxidans increased both the rate and extent of depyritization by approximately 10%.

  8. Removing perchlorate from samples to facilitate organics detection by pyrolitic methods

    NASA Astrophysics Data System (ADS)

    von Kiparski, Guntram R.; Parker, David R.; Tsapin, Alexandre I.

    2013-07-01

    Thermal volatilization or pyrolysis of solid samples followed by gas chromatography-mass spectrometry (TV-GC-MS) or other downstream analyses has proven robustness and has been adopted for the extraction of organic compounds for their detection in planetary lander science missions (e.g., Viking Lander GC-MS, Phoenix TEGA, MSL SAM, and the future ExoMars MOMA). Pyrolysis to extract organic compounds from soil has limitations when oxidants co-occur in the analyzed sample unless the desired end product is CO2. Pyrolysis of such soils may result in oxidation of organics to CO2 during heating, and thus make organics characterization difficult, if not impossible. Analytical investigations seeking to identify organics in martian soils containing oxidants could benefit from the deployment of technologies that remove known and putative oxidants prior to thermal volatilization. We conducted a series of experiments in order to determine if a polymeric anion exchange resin, commonly used for removing the perchlorate anion from contaminated municipal water supplies, could sustain its substantial perchlorate removal capability while keeping organic compounds intact for downstream detection. We demonstrated that this resin can strongly bind perchlorate from aqueous solution while simultaneously leaving amino acids substantially unaltered. The perchlorate-binding resin could be easily adopted as a pre-treatment for martian soil extracts to create analytical systems with improved organics characterization capabilities compatible with existing TV-GC-MS systems. We propose this strategy to aid detection and characterization of putative martian organics co-situated with perchlorate at sampling sites.

  9. Removal of iodide from water by chlorination and subsequent adsorption on powdered activated carbon.

    PubMed

    Ikari, Mariya; Matsui, Yoshihiko; Suzuki, Yuta; Matsushita, Taku; Shirasaki, Nobutaka

    2015-01-01

    Chlorine oxidation followed by treatment with activated carbon was studied as a possible method for removing radioactive iodine from water. Chlorination time, chlorine dose, the presence of natural organic matter (NOM), the presence of bromide ion (Br⁻), and carbon particle size strongly affected iodine removal. Treatment with superfine powdered activated carbon (SPAC) after 10-min oxidation with chlorine (1 mg-Cl₂/L) removed 90% of the iodine in NOM-containing water (dissolved organic carbon concentration, 1.5 mg-C/L). Iodine removal in NOM-containing water increased with increasing chlorine dose up to 0.1 mg-Cl₂/L but decreased at chlorine doses of >1.0 mg-Cl₂/L. At a low chlorine dose, nonadsorbable iodide ion (I⁻) was oxidized to adsorbable hypoiodous acid (HOI). When the chlorine dose was increased, some of the HOI reacted with NOM to form adsorbable organic iodine (organic-I). Increasing the chlorine dose further did not enhance iodine removal, owing to the formation of nonadsorbable iodate ion (IO₃⁻). Co-existing Br⁻ depressed iodine removal, particularly in NOM-free water, because hypobromous acid (HOBr) formed and catalyzed the oxidation of HOI to IO₃⁻. However, the effect of Br⁻ was small in the NOM-containing water because organic-I formed instead of IO₃⁻. SPAC (median particle diameter, 0.62 μm) had a higher equilibrium adsorption capacity for organic-I than did conventional PAC (median diameter, 18.9 μm), but the capacities of PAC and SPAC for HOI were similar. The reason for the higher equilibrium adsorption capacity for organic-I was that organic-I was adsorbed principally on the exterior of the PAC particles and not inside the PAC particles, as indicated by direct visualization of the solid-phase iodine concentration profiles in PAC particles by field emission electron probe microanalysis. In contrast, HOI was adsorbed evenly throughout the entire PAC particle. PMID:25462731

  10. Rapid removal of organic micropollutants from water by a porous β-cyclodextrin polymer.

    PubMed

    Alsbaiee, Alaaeddin; Smith, Brian J; Xiao, Leilei; Ling, Yuhan; Helbling, Damian E; Dichtel, William R

    2016-01-14

    The global occurrence in water resources of organic micropollutants, such as pesticides and pharmaceuticals, has raised concerns about potential negative effects on aquatic ecosystems and human health. Activated carbons are the most widespread adsorbent materials used to remove organic pollutants from water but they have several deficiencies, including slow pollutant uptake (of the order of hours) and poor removal of many relatively hydrophilic micropollutants. Furthermore, regenerating spent activated carbon is energy intensive (requiring heating to 500-900 degrees Celsius) and does not fully restore performance. Insoluble polymers of β-cyclodextrin, an inexpensive, sustainably produced macrocycle of glucose, are likewise of interest for removing micropollutants from water by means of adsorption. β-cyclodextrin is known to encapsulate pollutants to form well-defined host-guest complexes, but until now cross-linked β-cyclodextrin polymers have had low surface areas and poor removal performance compared to conventional activated carbons. Here we crosslink β-cyclodextrin with rigid aromatic groups, providing a high-surface-area, mesoporous polymer of β-cyclodextrin. It rapidly sequesters a variety of organic micropollutants with adsorption rate constants 15 to 200 times greater than those of activated carbons and non-porous β-cyclodextrin adsorbent materials. In addition, the polymer can be regenerated several times using a mild washing procedure with no loss in performance. Finally, the polymer outperformed a leading activated carbon for the rapid removal of a complex mixture of organic micropollutants at environmentally relevant concentrations. These findings demonstrate the promise of porous cyclodextrin-based polymers for rapid, flow-through water treatment. PMID:26689365

  11. Rapid removal of organic micropollutants from water by a porous β-cyclodextrin polymer.

    PubMed

    Alsbaiee, Alaaeddin; Smith, Brian J; Xiao, Leilei; Ling, Yuhan; Helbling, Damian E; Dichtel, William R

    2016-01-14

    The global occurrence in water resources of organic micropollutants, such as pesticides and pharmaceuticals, has raised concerns about potential negative effects on aquatic ecosystems and human health. Activated carbons are the most widespread adsorbent materials used to remove organic pollutants from water but they have several deficiencies, including slow pollutant uptake (of the order of hours) and poor removal of many relatively hydrophilic micropollutants. Furthermore, regenerating spent activated carbon is energy intensive (requiring heating to 500-900 degrees Celsius) and does not fully restore performance. Insoluble polymers of β-cyclodextrin, an inexpensive, sustainably produced macrocycle of glucose, are likewise of interest for removing micropollutants from water by means of adsorption. β-cyclodextrin is known to encapsulate pollutants to form well-defined host-guest complexes, but until now cross-linked β-cyclodextrin polymers have had low surface areas and poor removal performance compared to conventional activated carbons. Here we crosslink β-cyclodextrin with rigid aromatic groups, providing a high-surface-area, mesoporous polymer of β-cyclodextrin. It rapidly sequesters a variety of organic micropollutants with adsorption rate constants 15 to 200 times greater than those of activated carbons and non-porous β-cyclodextrin adsorbent materials. In addition, the polymer can be regenerated several times using a mild washing procedure with no loss in performance. Finally, the polymer outperformed a leading activated carbon for the rapid removal of a complex mixture of organic micropollutants at environmentally relevant concentrations. These findings demonstrate the promise of porous cyclodextrin-based polymers for rapid, flow-through water treatment.

  12. Rapid removal of organic micropollutants from water by a porous β-cyclodextrin polymer

    NASA Astrophysics Data System (ADS)

    Alsbaiee, Alaaeddin; Smith, Brian J.; Xiao, Leilei; Ling, Yuhan; Helbling, Damian E.; Dichtel, William R.

    2016-01-01

    The global occurrence in water resources of organic micropollutants, such as pesticides and pharmaceuticals, has raised concerns about potential negative effects on aquatic ecosystems and human health. Activated carbons are the most widespread adsorbent materials used to remove organic pollutants from water but they have several deficiencies, including slow pollutant uptake (of the order of hours) and poor removal of many relatively hydrophilic micropollutants. Furthermore, regenerating spent activated carbon is energy intensive (requiring heating to 500-900 degrees Celsius) and does not fully restore performance. Insoluble polymers of β-cyclodextrin, an inexpensive, sustainably produced macrocycle of glucose, are likewise of interest for removing micropollutants from water by means of adsorption. β-cyclodextrin is known to encapsulate pollutants to form well-defined host-guest complexes, but until now cross-linked β-cyclodextrin polymers have had low surface areas and poor removal performance compared to conventional activated carbons. Here we crosslink β-cyclodextrin with rigid aromatic groups, providing a high-surface-area, mesoporous polymer of β-cyclodextrin. It rapidly sequesters a variety of organic micropollutants with adsorption rate constants 15 to 200 times greater than those of activated carbons and non-porous β-cyclodextrin adsorbent materials. In addition, the polymer can be regenerated several times using a mild washing procedure with no loss in performance. Finally, the polymer outperformed a leading activated carbon for the rapid removal of a complex mixture of organic micropollutants at environmentally relevant concentrations. These findings demonstrate the promise of porous cyclodextrin-based polymers for rapid, flow-through water treatment.

  13. Laboratory and field evaluation of a pretreatment system for removing organics from produced water.

    PubMed

    Kwon, Soondong; Sullivan, Enid J; Katz, Lynn E; Bowman, Robert S; Kinney, Kerry A

    2011-09-01

    Co-produced water from the oil and gas industry accounts for a significant waste stream in the United States. This "produced water" is characterized by saline water containing a variety of pollutants, including water soluble and immiscible organics and many inorganic species. To reuse produced water, removal of both the inorganic dissolved solids and organic compounds is necessary. In this research, the effectiveness of a pretreatment system consisting of surfactant modified zeolite (SMZ) adsorption followed by a membrane bioreactor (MBR) was evaluated for simultaneous removal of carboxylates and hazardous substances, such as benzene, toluene, ethylbenzene, and xylenes (BTEX) from saline-produced water. A laboratory-scale MBR, operated at a 9.6-hour hydraulic residence time, degraded 92% of the carboxylates present in synthetic produced water. When BTEX was introduced simultaneously to the MBR system with the carboxylates, the system achieved 80 to 95% removal of BTEX via biodegradation. These results suggest that simultaneous biodegradation of both BTEX and carboxylate constituents found in produced water is possible. A field test conducted at a produced water disposal facility in Farmington, New Mexico confirmed the laboratory-scale results for the MBR and demonstrated enhanced removal of BTEX using a treatment train consisting of SMZ columns followed by the MBR. While most of the BTEX constituents of the produced water adsorbed onto the SMZ adsorption system, approximately 95% of the BTEX that penetrated the SMZ and entered the MBR was biodegraded in the MBR. Removal rates of acetate (influent concentrations of 120 to 170 mg/L) ranged from 91 to 100%, and total organic carbon (influent concentrations as high as 580 mg/L) ranged from 74 to 92%, respectively. Organic removal in the MBR was accomplished at a low biomass concentration of 1 g/L throughout the field trial. While the transmembrane pressure during the laboratory-scale tests was well-controlled, it rose

  14. Effect of organic matter on cyanide removal by illuminated titanium dioxide or zinc oxide nanoparticles

    PubMed Central

    2013-01-01

    Effect of different type of organic compounds (humic acid, oxalate, ethylenediaminetetraacetic acid, nitrilotriacetic acid, phenol) on the photocatalytic removal of cyanide with TiO2 or ZnO was studied in this work with variation of the solution pH, contact time, initial cyanide concentration and type of organic compounds. Photocatalytic oxidation efficiency of cyanide with TiO2 was greatly affected by the solution pH. It increased as the solution pH decreased. Also maximum removal of cyanide by ZnO was observed near at neutral pH because of the reduced photocatalytic activity of ZnO at exceedingly low and high pH values originated from either acidic/photochemical corrosion of the catalyst and/or surface passivation with Zn(OH)2. Removal efficiency of cyanide greatly decreased in the presence of humic acid, ethylenediaminetetraacetic acid, nitrilotriacetic acid compared to that without presence of organic compound because of the competitive oxidation as well as surface blocking by relatively large organic compounds. The oxidation pattern of cyanide was better described by first-order kinetic model. Finally photocatalytic reaction with TiO2 or ZnO can be effectively applied to treat synthetic wastewater contaminated with cyanide. PMID:24499704

  15. Economic evaluation of air stripping to remove volatile organic compounds from water. Final report

    SciTech Connect

    Zaghloul, H.H.; Ball, R.O.; Maloney, S.W.

    1987-12-01

    This report documents the results of a study conducted to provide a basis for estimating the costs of installing and using air stripping to remove volatile organic compounds (VOCs) from water. The air-stripping technology was found to be a very economical and efficient method for contaminant removal. The technology is simple, relatively inexpensive to install, and has low labor and maintenance requirements. VOC removal rates range from 90 to 99.99%. Estimated costs, in terms of percentage of total production costs, were found to be 40% for capital costs, 50% for operational costs, and 10% for maintenance costs, according to literature sources. Results of a survey conducted during this study generally agree with these percentages, except that maintenance costs reported on the survey were lower due to the highly automated nature of new installations.

  16. Salt intake and iodine status of women in Samoa.

    PubMed

    Land, Mary-Anne; Webster, Jacqui L; Ma, Gary; Li, Mu; Su'a, Sarah Asi Faletoese; Ieremia, Merina; Viali, Satu; Faeamani, Gavin; Bell, A Colin; Quested, Christine; Neal, Bruce C; Eastman, Creswell J

    2016-01-01

    The objective of this study was to determine iodine nutrition status and whether iodine status differs across salt intake levels among a sample of women aged 18-45 years living in Samoa. A cross-sectional survey was completed and 24-hr urine samples were collected and assessed for iodine (n=152) and salt excretion (n=119). The median urinary iodine concentration (UIC) among the women was 88 μg/L (Interquartile range (IQR)=54-121 μg/L). 62% of the women had a UIC <100 μg/L. The crude estimated mean 24-hr urinary salt excretion was 6.6 (standard deviation 3.2) g/day. More than two-thirds (66%) of the women exceeded the World Health Organization recommended maximum level of 5 g/day. No association was found between median UIC and salt excretion (81 μg/L iodine where urinary salt excretion >=5 g/day versus 76 μg/L where urinary salt excretion <5 g/day; p=0.4). Iodine nutrition appears to be insufficient in this population and may be indicative of iodine deficiency disorders in Samoan women. A collaborative approach in monitoring iodine status and salt intake will strengthen both programs and greatly inform the level of iodine fortification required to ensure optimal iodine intake as population salt reduction programs take effect. PMID:26965773

  17. Salt intake and iodine status of women in Samoa.

    PubMed

    Land, Mary-Anne; Webster, Jacqui L; Ma, Gary; Li, Mu; Su'a, Sarah Asi Faletoese; Ieremia, Merina; Viali, Satu; Faeamani, Gavin; Bell, A Colin; Quested, Christine; Neal, Bruce C; Eastman, Creswell J

    2016-01-01

    The objective of this study was to determine iodine nutrition status and whether iodine status differs across salt intake levels among a sample of women aged 18-45 years living in Samoa. A cross-sectional survey was completed and 24-hr urine samples were collected and assessed for iodine (n=152) and salt excretion (n=119). The median urinary iodine concentration (UIC) among the women was 88 μg/L (Interquartile range (IQR)=54-121 μg/L). 62% of the women had a UIC <100 μg/L. The crude estimated mean 24-hr urinary salt excretion was 6.6 (standard deviation 3.2) g/day. More than two-thirds (66%) of the women exceeded the World Health Organization recommended maximum level of 5 g/day. No association was found between median UIC and salt excretion (81 μg/L iodine where urinary salt excretion >=5 g/day versus 76 μg/L where urinary salt excretion <5 g/day; p=0.4). Iodine nutrition appears to be insufficient in this population and may be indicative of iodine deficiency disorders in Samoan women. A collaborative approach in monitoring iodine status and salt intake will strengthen both programs and greatly inform the level of iodine fortification required to ensure optimal iodine intake as population salt reduction programs take effect.

  18. Recent experiences with iodine water disinfection in Shuttle

    NASA Technical Reports Server (NTRS)

    Gibbons, Randall E.; Flanagan, David T.; Schultz, John R.; Sauer, Richard L.; Slezak, Terry N.

    1990-01-01

    Microbial proliferation in the STS potable water system is prevented by maintaining a 2-5 ppm iodine residual. The iodine is added to fuel cell water by an iodinated ion exchange resin in the Microbial Check Valve (MCV). Crew comments indicated excessive iodine in the potable water. To better define the problem, a method of in-flight iodine analysis was developed. Inflight analysis during STS-30 and STS-28 indicated iodine residuals were generally in the 9-13 ppm range. It was determined that the high iodine residual was caused by MCV influent temperatures in excess of 120 F. This is well above the MCV operating range of 65-90 F. The solution to this problem was to develop a resin suitable for the higher temperatures. Since 8 months were required to formulate a MCV resin suitable for the higher temperatures, a temporary solution was necessary. Two additional MCV's were installed on the chilled and ambient water lines leading into the galley to remove the excess iodine. These reduced the iodine residual to 3-4 ppm during STS-33, STS-34, STS-36 and STS-32. A high-temperature resin was formulated and initially flown on STS-31.

  19. Iodine deficiency disorders.

    PubMed

    Elliott, T C

    1987-01-01

    Iodine deficiency disorder (IDD) affects 800 million people in the world, yet iodine supplementation is one of the most cost-effective nutritional interventions known. Iodine is incorporated into thyroid hormones, necessary for regulating metabolic rate, growth, and development of the brain and nervous system. IDD may appear as goiter in adults, usually not a serious problem, or in cretinism in children, which is marked by severe mental and physical retardation, with irreversible hearing and speech defects and either deaf-mutism, squint and paralysis, or stunting and edema. Children supplemented by age 1 or 2 can sometimes be helped. Foods contain variable amounts of iodine dependent on the soil where they are grown, hence mountainous and some inland regions have high goiter and IDD incidence. There are also goitrogenic foods, typically those of the cabbage family. Diagnosis is clinical or by blood tests for thyroid hormone levels and ratios. Finger-stick methods are available. Prevention of IDD is simple with either iodized salt or flour, iodinated central water supplies, injectable or oral iodine-containing oil. All cost about $.04 per person per year, except injections, which cost about $1 per person, but have the advantage that they could be combined with immunizations. Local problems with supplements are loss of iodine in salt with storage in tropics, and local production of cheaper uniodinated salt. Emphasis should be given to pregnant women and young children. There is no harm in giving pregnant women iodine injections in 2nd or 3rd trimester. PMID:12343033

  20. Removal of hazardous organics from water using metal-organic frameworks (MOFs): plausible mechanisms for selective adsorptions.

    PubMed

    Hasan, Zubair; Jhung, Sung Hwa

    2015-01-01

    Provision of clean water is one of the most important issues worldwide because of continuing economic development and the steady increase in the global population. However, clean water resources are decreasing everyday, because of contamination with various pollutants including organic chemicals. Pharmaceutical and personal care products, herbicides/pesticides, dyes, phenolics, and aromatics (from sources such as spilled oil) are typical organics that should be removed from water. Because of their huge porosities, designable pore structures, and facile modification, metal-organic frameworks (MOFs) are used in various adsorption, separation, storage, and delivery applications. In this review, the adsorptive purifications of contaminated water with MOFs are discussed, in order to understand possible applications of MOFs in clean water provision. More importantly, plausible adsorption or interaction mechanisms and selective adsorptions are summarized. The mechanisms of interactions such as electrostatic interaction, acid-base interaction, hydrogen bonding, π-π stacking/interaction, and hydrophobic interaction are discussed for the selective adsorption of organics over MOFs. The adsorption mechanisms will be very helpful not only for understanding adsorptions but also for applications of adsorptions in selective removal, storage, delivery and so on.

  1. Physical and oxidative removal of organics during Fenton treatment of mature municipal landfill leachate.

    PubMed

    Deng, Yang

    2007-07-19

    Municipal landfill leachate, especially mature leachate, may disrupt the performance of moderately-sized municipal activated sludge wastewater treatment plants, and likewise tend to be recalcitrant to biological pretreatment. Recently, Fenton methods have been investigated for chemical treatment or pre-treatment of mature leachate. In this paper, the results of laboratory tests to determine the roles of oxidation and coagulation in reducing the organic content of mature leachate during Fenton treatment are presented. The efficiencies of chemical oxygen demand (COD) oxidation and coagulation were tested, and the ratio of COD removal by oxidation to that by coagulation was assessed, under various operating conditions. Low initial pH, appropriate relative and absolute Fenton reagent dosages, aeration, and stepwise addition of reagents increased COD removal by oxidation and the importance of oxidation relative to coagulation. Simultaneous aeration and stepwise reagent addition allowed comparable treatment without initial acidification pH, due to the generation of acidic organic intermediates and the continuous input of CO2. On the other hand, high COD oxidation efficiency and low ferrous dosage inhibited COD removal by coagulation. At significantly high oxidation efficiency, overall COD reduction decrease slightly due to low coagulation efficiency. Under the most favorable conditions (initial pH 3, molar ratio [H(2)O(2)]/[Fe2+]=3, [H2O2]=240 mM, and six dosing steps), 61% of the initial COD was removed, and the ratio of COD removal oxidation to coagulation was 0.75. Results highlighted the synergistic roles of oxidation and coagulation in Fenton treatment of mature leachate, and the role of oxidation in controlling the efficiency of removal of COD by coagulation. PMID:17208367

  2. [Application of selected microorganisms for organic sulfur removal from coal]. Quarterly progress report, March 15, 1990--June 15, 1990

    SciTech Connect

    Elmore, B.B.

    1990-06-20

    Research continues on methods for desulfurization of coal using microorganisms. Topics reported on this term include: coal procurement and preparation, microbial removal of pyrite and sulfate, analytical procedures for characterization of total organic sulfur, organic sulfur removal, microbial activity on model coal organosulfur compounds, screening/detection assays, and monitoring of desulfurization activity. (VC)

  3. The role of ozonation and activated carbon filtration in the natural organic matter removal from drinking water.

    PubMed

    Matilainen, A; Iivari, P; Sallanko, J; Heiska, E; Tuhkanen, T

    2006-10-01

    Aquatic natural organic matter is one of the most important problems in the drinking water treatment process design and development. In this study, the removal of the natural organic matter was followed both in the full-scale drinking water treatment process and in the pilot-scale studies. The full-scale process consisted of coagulation, flocculation and flotation, sand filtration, ozonation, activated carbon filtration and disinfection. The aim of the pilot study was to investigate the influence of the dose and contact time of ozonation, and also the impact of activated carbon filtration, on the removal efficiency of organic matter. Several methods, including high-performance size-exclusion chromatography, total organic carbon content and assimilable organic carbon content measurements were used to characterize the behaviour of organic matter and its removal efficiency. On the full-scale process, total organic carbon was removed by over 90 %. According to size-exclusion measurements, chemical coagulation removed the high molar mass organic matter with an efficiency of 98%. The ozonation further removed the smaller molar mass fraction compounds by about 27%, while residual higher molar mass matter remained quite unaltered. Activated carbon filtration removed primarily intermediate and low molar mass organic matter. In the pilot-tests, conducted with sand filtered water from the full-scale process, it was noticed, that the ozonation removed primarily smaller organic compounds. The amount of assimilable organic carbon increased with increasing ozone dose, up to 0.4 mg l(-1) with the highest ozone dose of 4.0 mg 1(-1). The activated carbon filtration removed the assimilable organic carbon. Total organic carbon content was not reduced in ozonation.

  4. Indicator pathogens, organic matter and LAS detergent removal from wastewater by constructed subsurface wetlands

    PubMed Central

    2014-01-01

    Background Constructed wetland is one of the natural methods of municipal and industrial wastewater treatments with low initial costs for construction and operation as well as easy maintenance. The main objective of this study is to determine the values of indicator bacteria removal, organic matter, TSS, ammonia and nitrate affecting the wetland removal efficiency. Results The average concentration of E. coli and total coliform in the input is 1.127 × 1014 and 4.41 × 1014 MPN/100 mL that reached 5.03 × 1012 and 1.13 × 1014 MPN/100 mL by reducing 95.5% and 74.4% in wetland 2. Fecal streptococcus reached from the average 5.88 × 1014 in raw wastewater to 9.69 × 1012 in the output of wetland 2. Wetland 2 could reduce 1.5 logarithmic units of E. coli. The removal efficiency of TSS for the wetlands is 68.87%, 71.4%, 57.3%, and 66% respectively. Conclusions The overall results show that wetlands in which herbs were planted had a high removal efficiency about the indicator pathogens, organic matter, LAS detergent in comparison to a control wetland (without canes) and could improve physicochemical parameters (DO, ammonia, nitrate, electrical conductivity, and pH) of wastewater. PMID:24581277

  5. Removal of terrestrial dissolved organic carbon in aquatic ecosystems of a temperate river network.

    NASA Astrophysics Data System (ADS)

    Wollheim, W. M.; Stewart, R. J.; Aiken, G.; Butler, K. D.; Morse, N.; Salisbury, J.

    2015-12-01

    Surface waters play an important role in the global carbon balance. Dissolved organic carbon (DOC) fluxes are a major transfer of terrestrial carbon to river systems, and the net removal of terrestrial DOC in aquatic systems is poorly constrained. We used a combination of spatially distributed sampling of three DOC fractions, nitrate, and chloride in streams of different size throughout a river network and modeling to quantify the net removal of terrestrial DOC relative to other constituents during a summer base flow period. The approach was applied to the 400 km2 Ipswich River watershed, MA, USA. We found that aquatic reactivity of terrestrial DOC leading to net loss is low, closer to conservative chloride than to reactive nitrogen. Net removal of DOC occurred mainly from the hydrophobic organic acid fraction, while hydrophilic and transphilic acids showed no net change. Model fits were improved using the different DOC fractions than when using bulk DOC, indicating that partitioning of bulk DOC into different fractions is critical for understanding terrestrial DOC removal. These findings suggest that river systems may have only a modest ability to alter the amounts of terrestrial DOC delivered to coastal zones.

  6. Evaluation of barrier materials for removing pollutants from groundwater rich in natural organic matter.

    PubMed

    Kozyatnyk, I; Haglund, P; Lövgren, L; Tysklind, M; Gustafsson, A; Törneman, N

    2014-01-01

    Permeable barriers are used for passive remediation of groundwater and can be constructed from a range of materials. The optimal material depends on the types of contaminants and physico-chemical parameters present at the site, as well as the hydraulic conductivity, environmental safety, availability, cost and long-term stability of the material itself. The aim of the presented study was to test a number of materials for their ability to remove heavy metals and organic pollutants from groundwater with a high (140 mg L(-1)) content of natural organic matter (NOM). The following materials were included in the study: sand, peat, fly ash, iron powder, lignin and combinations thereof. Polluted water was fed into glass columns loaded with each sorbent and the contaminant removal efficiency of the material was evaluated through chemical analysis of the percolate. Materials based on fly ash and zero-valent iron were found to be the most effective for heavy metal removal, while fly ash and peat were the most effective for removing aliphatic compounds. Filtration through lignin and peat led to leaching of NOM. Although the leaching decreased over time, it remained high throughout the experiments. The results indicate that remediation of contaminated land at disused industrial sites is a complex task that often requires the use of mixed materials or a minimum of two sequential barriers.

  7. Membrane air stripping: A process for removal of organics from aqueous solutions

    SciTech Connect

    Mahmud, H.; Kumar, A.; Narbaitz, R.M.; Matsuura, T.

    1998-10-01

    The membrane air-stripping (MAS) process using microporous polypropylene hollow fiber membranes has shown potential for the removal of volatile organics from aqueous streams over conventional treatment processes, particularly in reducing the size of the equipment. This paper reviews the theoretical aspects and experimental investigations on the performance of these membranes in terms of overall mass transfer capabilities in the removal of organics from aqueous solutions. The reported findings of the effect of pH, ozone, chlorine, influence of packing density and possible fouling on the performance of these hollow fibers membranes are presented. The fate of the stripped air is discussed. Other possible applications as well as the future research needs are highlighted, along with critical assessment of the reported work.

  8. Removal of volatile organics from humidified air streams by absorption. Final report, July 1985-March 1987

    SciTech Connect

    Coutant, R.W.; Zwick, T.; Kim, B.C.

    1987-12-01

    The Air Force frequently relies on air-stripping technologies to remove organic chemicals from ground waters contaminated from fuel and solvent spills. Although air stripping is extremely efficient at removing contaminants from the groundwater, these contaminants are only transferred into the air and in several states, air pollution controls are also required. Activated-carbon beds are one potential emissions control under study. The objective of this study was to determine the effects of contaminant concentration, humidity, and chemical competition on the sorption performance of activated carbons. Based on laboratory results, a preliminary cost comparison was made for heated and unheated carbon beds. Volatile organics of interest included benzene, ethyl benzene, toluene, xylenes. trichloroethylene, and 1,1-dichloroethylene.

  9. The removal of nitrogen and organics in vertical flow wetland reactors: predictive models.

    PubMed

    Saeed, Tanveer; Sun, Guangzhi

    2011-01-01

    Three kinetic models, for predicting the removal of nitrogen and organics in vertical flow wetlands, have been developed and evaluated. These models were established by combining first-order, Monod and multiple Monod kinetics with continuous stirred-tank reactor (CSTR) flow pattern. Critical evaluations of these models using three statistical parameters, coefficient of determination, relative root mean square error and model efficiency, indicated that when the Monod/multiple Monod kinetics was combined with CSTR flow pattern it allowed close match between theoretical prediction and experiment data of nitrogen and organics removal. The kinetic coefficients (derived from Monod/multiple Monod kinetics) was found to increase with pollutant loading, indicating that the coefficients may vary based on different factors, such as influent pollutant concentration, hydraulic loading, and water depth. Overall, this study demonstrated the validity of combining Monod and multiple Monod kinetics with CSTR flow pattern for the modelling and design of vertical flow wetland systems.

  10. Occurrence of trace organic contaminants in wastewater sludge and their removals by anaerobic digestion.

    PubMed

    Yang, Shufan; Hai, Faisal I; Price, William E; McDonald, James; Khan, Stuart J; Nghiem, Long D

    2016-06-01

    This study aims to evaluate the occurrence of trace organic contaminants (TrOCs) in wastewater sludge and their removal during anaerobic digestion. The significant occurrence of 18 TrOCs in primary sludge was observed. These TrOCs occurred predominantly in the solid phase. Some of these TrOCs (e.g. paracetamol, caffeine, ibuprofen and triclosan) were also found at high concentrations (>10,000ng/L) in the aqueous phase. The overall removal of TrOCs (from both the aqueous and solid phase) by anaerobic digestion was governed by their molecular structure (e.g. the presence/absence of electron withdrawing/donating functional groups). While an increase in sludge retention time (SRT) of the digester resulted in a small but clearly discernible increase in basic biological performance (e.g. volatile solids removal and biogas production), the impact of SRT on TrOC removal was negligible. The lack of SRT influence on TrOC removal suggests that TrOCs were not the main substrate for anaerobic digestion. PMID:26795886

  11. Multi-chamber microbial desalination cell for improved organic matter and dissolved solids removal from wastewater.

    PubMed

    Pradhan, Harapriya; Ghangrekar, M M

    2014-01-01

    A five-chamber microbial desalination cell (MDC) with anode, cathode, one central desalination chamber and two concentrate chambers separated by ion exchange membranes was operated in batch mode for more than 60 days. The performance of the MDC was evaluated for chemical oxygen demand (COD) removal, total dissolved solids (TDS) removal and energy production. An average COD removal of 81 ± 2.1% was obtained using acetate-fed wastewater as substrate in the anodic chamber inoculated with mixed anaerobic sludge. TDS removals of 58, 70 and 78% were observed with salt concentration of 8, 20 and 30 g/L, respectively, in the middle desalination chamber. The MDC produced a maximum power output of 16.87 mW/m(2) during polarization. The highest Coulombic efficiency of 12 ± 2.4% was observed in this system using mixed anaerobic sludge as inoculum. The system effectively demonstrated capability for simultaneous organic matter removal and desalination along with power generation.

  12. Assessment of volatile organic compound removal by indoor plants--a novel experimental setup.

    PubMed

    Dela Cruz, Majbrit; Müller, Renate; Svensmark, Bo; Pedersen, Jakob Skov; Christensen, Jan H

    2014-01-01

    Indoor plants can remove volatile organic compounds (VOCs) from the air. The majority of knowledge comes from laboratory studies where results cannot directly be transferred to real-life settings. The aim of this study was to develop an experimental test system to assess VOC removal by indoor plants which allows for an improved real-life simulation. Parameters such as relative humidity, air exchange rate and VOC concentration are controlled and can be varied to simulate different real-life settings. For example, toluene diffusion through a needle gave concentrations in the range of 0.10-2.35 μg/L with deviations from theoretical values of 3.2-10.5%. Overall, the system proved to be functional for the assessment of VOC removal by indoor plants with Hedera helix reaching a toluene removal rate of up to 66.5 μg/m(2)/h. The mode of toluene exposure (semi-dynamic or dynamic) had a significant influence on the removal rate obtained by H. helix.

  13. Can ornamental potted plants remove volatile organic compounds from indoor air? A review.

    PubMed

    Dela Cruz, Majbrit; Christensen, Jan H; Thomsen, Jane Dyrhauge; Müller, Renate

    2014-12-01

    Volatile organic compounds (VOCs) are found in indoor air, and many of these can affect human health (e.g. formaldehyde and benzene are carcinogenic). Plants affect the levels of VOCs in indoor environments, thus they represent a potential green solution for improving indoor air quality that at the same time can improve human health. This article reviews scientific studies of plants' ability to remove VOCs from indoor air. The focus of the review is on pathways of VOC removal by the plants and factors affecting the efficiency and rate of VOC removal by plants. Laboratory based studies indicate that plant induced removal of VOCs is a combination of direct (e.g. absorption) and indirect (e.g. biotransformation by microorganisms) mechanisms. They also demonstrate that plants' rate of reducing the level of VOCs is influenced by a number of factors such as plant species, light intensity and VOC concentration. For instance, an increase in light intensity has in some studies been shown to lead to an increase in removal of a pollutant. Studies conducted in real-life settings such as offices and homes are few and show mixed results.

  14. Natural organic matter removal and fouling in a low pressure hybrid membrane systems.

    PubMed

    Uyak, Vedat; Akdagli, Muge; Cakmakci, Mehmet; Koyuncu, Ismail

    2014-01-01

    The objective of this study was to investigate powdered activated carbon (PAC) contribution to natural organic matter (NOM) removal by a submerged MF and UF hybrid systems. It was found that filtration of surface waters by a bare MF and UF membranes removed negligible TOC; by contrast, significant amounts of TOC were removed when daily added PAC particles were predeposited on the membrane surfaces. These results support the assumption that the membranes surface properties and PAC layer structure might have considerably influential factor on NOM removal. Moreover, it was concluded that the dominant removal mechanism of hybrid membrane system is adsorption of NOM within PAC layer rather than size exclusion of NOM by both of membrane pores. Transmembrane pressure (TMP) increases with PAC membrane systems support the view that PAC adsorption pretreatment will not prevent the development of membrane pressure; on the contrary, PAC particles themselves caused membrane fouling by blocking the entrance of pores of MF and UF membranes. Although all three source waters have similar HPI content, it appears that the PAC interaction with the entrance of membrane pores was responsible for offsetting the NOM fractional effects on membrane fouling for these source waters. PMID:24523651

  15. Iodine status in the Nordic countries – past and present

    PubMed Central

    Nyström, Helena Filipsson; Brantsæter, Anne Lise; Erlund, Iris; Gunnarsdottir, Ingibjörg; Hulthén, Lena; Laurberg, Peter; Mattisson, Irene; Rasmussen, Lone Banke; Virtanen, Suvi; Meltzer, Helle Margrete

    2016-01-01

    Background Adequate iodine nutrition is dependent on ground water content, seafood, and, as many countries use iodized cow fodder, dairy products. In most countries, salt fortification programs are needed to assure adequate iodine intake. Objectives The objectives are threefold: 1) to describe the past and present iodine situation in the Nordic countries, 2) to identify important gaps of knowledge, and 3) to highlight differences among the Nordic countries’ iodine biomonitoring and fortification policies. Design Historical data are compared with the current situation. The Nordic countries’ strategies to achieve recommended intake and urine iodine levels and their respective success rates are evaluated. Results In the past, the iodine situation ranged from excellent in Iceland to widespread goiter and cretinism in large areas of Sweden. The situation was less severe in Norway and Finland. According to a 1960 World Health Organization (WHO) report, there were then no observations of iodine deficiency in Denmark. In Sweden and Finland, the fortification of table salt was introduced 50–75 years ago, and in Norway and Finland, the fortification of cow fodder starting in the 1950s helped improve the population's iodine status due to the high intake of milk. In Denmark, iodine has been added to household salt and salt in bread for the past 15 years. The Nordic countries differ with regard to regulations and degree of governmental involvement. There are indications that pregnant and lactating women, the two most vulnerable groups, are mildly deficient in iodine in several of the Nordic countries. Conclusion The Nordic countries employ different strategies to attain adequate iodine nutrition. The situation is not optimal and is in need of re-evaluation. Iodine researchers, Nordic national food administrations, and Nordic governmental institutions would benefit from collaboration to attain a broader approach and guarantee good iodine health for all. PMID:27283870

  16. Iodine generator for reclaimed water purification

    NASA Technical Reports Server (NTRS)

    Wynveen, R. A.; Powell, J. D.; Schubert, F. H. (Inventor)

    1977-01-01

    The system disclosed is for controlling the iodine level in a water supply in a spacecraft. It includes an iodine accumulator which stores crystalline iodine, an electrochemical valve to control the input of iodine to the drinking water and an iodine dispenser. A pump dispenses fluid through the iodine dispenser and an iodine sensor to a potable water tank storage. The iodine sensor electronically detects the iodine level in the water, and through electronic means, produces a correction current control. The correction current control operates the electro-chemical iodine valve to release iodine from the iodine accumulator into the iodine dispenser.

  17. Synthesis of magnetic nanoporous carbon from metal-organic framework for the fast removal of organic dye from aqueous solution

    NASA Astrophysics Data System (ADS)

    Jiao, Caina; Wang, Yanen; Li, Menghua; Wu, Qiuhua; Wang, Chun; Wang, Zhi

    2016-06-01

    In this paper, a magnetic nanoporous carbon (Fe3O4/NPC) was successfully synthesized by using MOF-5 as carbon precursor and Fe salt as magnetic precursor. The texture properties of the as-synthesized nanocomposite were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibration sample magnetometer (VSM), and N2 adsorption-desorption isotherms. The Fe3O4/NPC had a high surface area with strong magnetic strength. Its adsorption behavior was tested by its adsorption capacity for the removal of methylene blue from aqueous solution. The results demonstrated that the Fe3O4/NPC had a high adsorption capacity, rapid adsorption rate, and easy magnetic separabilty. Moreover, the adsorbent could be easily regenerated by washing it with ethanol. The Fe3O4/NPC can be used as a good alternative for the effective removal of organic dyes from wastewater.

  18. Enhancing zero valent iron based natural organic matter removal by mixing with dispersed carbon cathodes.

    PubMed

    Liu, Peng; Keller, Jurg; Gernjak, Wolfgang

    2016-04-15

    Former studies have shown that adding granular activated carbon (GAC) cathodes could enhance the overall performance of the zero valent iron (ZVI) process for organics removal. The present study evaluates for the first time the performance of such an enhanced ZVI process to remove natural organic matter (NOM), an important water quality parameter in drinking water. Lab-scale batch tests were conducted with surface reservoir feed water from a drinking water plant. In the GAC enhanced ZVI process dissolved organic carbon (DOC) and UV254 were reduced by 61±3% and 70±2%, respectively, during 24h treatment corresponding to 1.8min empty bed contact time. The process was superior to ZVI alone, particularly during the earlier stages of the process due to the synergistically increased iron dissolution rate. Besides GAC, graphite and anthracite also prove to be suitable and potentially more cost-effective options as cathode materials for the enhanced ZVI process, whereby electrically conductive graphite clearly outperformed anthracite. The dominant mechanisms in terms of NOM removal from surface water were found to be coagulation following iron dissolution and adsorption in the case of employing GAC. Oxidation was also occurring to a lesser degree, converting some non-biodegradable into biodegradable DOC.

  19. Assessment of plant-driven removal of emerging organic pollutants by duckweed.

    PubMed

    Reinhold, Dawn; Vishwanathan, Saritha; Park, Jung Jae; Oh, David; Michael Saunders, F

    2010-08-01

    Constructed treatment wetlands have the potential to reclaim wastewaters through removal of trace concentrations of emerging organic pollutants, including pharmaceuticals, personal care products, and pesticides. Flask-scale assessments incorporating active and inactivated duckweed were used to screen for plant-associated removal of emerging organic pollutants in aquatic plant systems. Removals of four of eight pollutants, specifically atrazine, meta-N,N-diethyl toluamide (DEET), picloram, and clofibric acid, were negligible in all experimental systems, while duckweed actively increased aqueous depletion of fluoxetine, ibuprofen, 2,4-dichlorophenoxyacetic acid, and triclosan. Active plant processes affecting depletion of experimental pollutants included enhancement of microbial degradation of ibuprofen, uptake of fluoxetine, and uptake of degradation products of triclosan and 2,4-dichlorophenoxyacetic acid. Passive plant processes, particularly sorption, also contributed to aqueous depletion of fluoxetine and triclosan. Overall, studies demonstrated that aquatic plants contribute directly and indirectly to the aqueous depletion of emerging organic pollutants in wetland systems through both active and passive processes.

  20. Enhancing zero valent iron based natural organic matter removal by mixing with dispersed carbon cathodes.

    PubMed

    Liu, Peng; Keller, Jurg; Gernjak, Wolfgang

    2016-04-15

    Former studies have shown that adding granular activated carbon (GAC) cathodes could enhance the overall performance of the zero valent iron (ZVI) process for organics removal. The present study evaluates for the first time the performance of such an enhanced ZVI process to remove natural organic matter (NOM), an important water quality parameter in drinking water. Lab-scale batch tests were conducted with surface reservoir feed water from a drinking water plant. In the GAC enhanced ZVI process dissolved organic carbon (DOC) and UV254 were reduced by 61±3% and 70±2%, respectively, during 24h treatment corresponding to 1.8min empty bed contact time. The process was superior to ZVI alone, particularly during the earlier stages of the process due to the synergistically increased iron dissolution rate. Besides GAC, graphite and anthracite also prove to be suitable and potentially more cost-effective options as cathode materials for the enhanced ZVI process, whereby electrically conductive graphite clearly outperformed anthracite. The dominant mechanisms in terms of NOM removal from surface water were found to be coagulation following iron dissolution and adsorption in the case of employing GAC. Oxidation was also occurring to a lesser degree, converting some non-biodegradable into biodegradable DOC. PMID:26808400

  1. Iodine and thyroid hormones during pregnancy and postpartum.

    PubMed

    Pérez-López, Faustino R

    2007-07-01

    Iodine is a trace element essential for synthesis of the thyroid hormones, triiodothyronine and thyroxine. These hormones play a vital role in the early growth and development stages of most organs, especially the brain. The World Health Organization (WHO) has declared that, after famine, iodine deficiency is the most avoidable cause of cerebral lesions including different degrees of mental retardation and cerebral paralysis. The main function of iodine in vertebrates is to interact with the thyroid hormones. During pregnancy sufficient quantities of iodine are required to prevent the appearance of hypothyroidism, trophoblastic and embryonic or fetal disorders, neonatal and maternal hypothyroidism, and permanent sequelae in infants. Thyroid hormone receptors and iodothyronine deiodinases are present in placenta and central nervous tissue of the fetus. A number of environmental factors influence the epidemiology of thyroid disorders, and even relatively small abnormalities and differences in the level of iodine intake in a population have profound effects on the occurrence of thyroid abnormalities. The prevalence of disorders related to iodine deficit during pregnancy and postpartum has increased. Iodine supplementation is an effective measure in the case of pregnant and lactating women. However, it is not implemented and the problem is still present even in societies with theoretically advanced health systems. During pregnancy and postpartum, the WHO recommends iodine intake be increased to at least 200 microg/day. Side-effects provoked by iodine supplementation are rare during pregnancy at the recommended doses. PMID:17701774

  2. INFLUENCE OF METHOD FOR REMOVAL OF SESTON ON THE DISSOLVED ORGANIC MATTER(1).

    PubMed

    Parker, B C

    1967-12-01

    Comparisons of various methods and method modifications for treating water samples to render them free of seston prior to analysis of dissolved organic matter have corroborated a number of suspected sources of error. Among the more important points arising from this study arc: 1. All cellulose ester filters must be washed to remove elutable carbon. 2. In some instances filtration to dryness may produce artifacts resulting from cell injury. 3. A significant difference in filter retention can result between 0.45 and 0.22 μ membranes. 4. Among the methods most satisfactory are wet filtration through 0.22 μ pre-washed Millipore membranes and continuous-flow centrifugation at ca. 10,000 x g and 100 cc/min flow rate, both of which have their inherent weaknesses and limitations. 5. Regular centrifugation does not remove some planktonic organisms which have considerable buoyancy, or organic substances may somehow be released by cells without producing morphological damage. The newly developed bio dialysis technique for dissolved organic matter collection consistently yielded lower values than continuous-flow centrifugation. In contrast, biodialysis yielded lower values for pond water and higher values for Scenedesmus cultures than the best filtration method. Evidence suggests that biodialysis will be useful as both a supplementary and, in some zuays, more accurate method in studies of dissolved organic matter. PMID:27065026

  3. Iodine Deficiency in Australia: Be Alarmed. Opinions & Perspectives

    ERIC Educational Resources Information Center

    McElduff, Aidan; Beange, Helen

    2004-01-01

    Iodine deficiency, the leading preventable cause of intellectual impairment in the world (World Health Organization, 1999), has reappeared in Australia. Recently, we identified the re-emergence of iodine deficiency in Sydney (Gunton, Hams, Fiegert & McElduff, 1999). This has been confirmed locally (Li, Ma, Boyages & Eastman, 2001) and…

  4. Size fractionation characterisation of removed organics in reverse osmosis concentrates by ferric chloride.

    PubMed

    Bagastyo, A Y; Keller, J; Batstone, D J

    2011-01-01

    Reverse osmosis membrane separation is the leading method for manufacturing potable purified water. It also produces a concentrate stream, namely reverse osmosis concentrates (ROC), with 10-20% of the water, and almost all other compounds. One method for further treating this stream is by coagulation with ferric chloride. This study evaluates removed organics in ROC treated with ferric chloride. Fractionation with ultrafiltration membranes allows separation of organics based on a nominal molecular weight. A stirred cell system was applied for serial fractionation to classify organic compounds into six groups of < 0.5 kDa, 0.5-1 kDa, 1-3 kDa, 3-5 kDa, 5-10 kDa and > 10 kDa. The study found that raw ROC is rich in low molecular weight compounds (< 1 kDa) with almost 50% of the organics. These compounds include soluble microbial products (SMPs) and smaller humic and fulvic acids as indicated by fluorescence scanning. Conversely, colour was mostly contributed by medium to large molecules of humic and fulvic acids (> 0.5 kDa). Organics and colour were reduced in all molecular groups at an optimum treatment dose 1.48 mM FeCl3 and a pH of 5. However, ferric seemed to effectively remove colour in all size ranges while residual nitrogen was found mostly in the < 1 kDa sizes. Further, the fluorescence indicated that larger humic and fulvic acids were removed with considerable SMPs remaining in the < 0.5 kDa.

  5. Assessing the utility of mixed organic materials for removal of metals in mine drainage impacted waters

    NASA Astrophysics Data System (ADS)

    Song, H.; Neculita, C.; Lee, G.; Jeong, J.; Cho, D.; Chang, S.

    2010-12-01

    The use of natural organic materials in bioreactors is one of the most sustainable technologies for treatment of metals in mine-impacted waters. Several natural organic substrates including mushroom compost, cow manure, sawdust, wood chips, and cut rice straw were characterized and used in combination for treating mine drainage with acidic (pH 3) and moderate pH (pH 6). Bench-scale batch experiments were performed for 35-day period to evaluate the performance of organic substrates in removing dissolved metals. Overall results indicated that mixtures of different substrates showed satisfactory performances in removing metals (Al > Fe > Mn) (up to 100%), generating alkalinity, and reducing sulfate at both pH conditions. The mixture of sawdust and cow manure was found as the most effective whereas the mixture containing 40% cut rice straw gave limited efficiency, suggesting organic carbon released from this substrate is not readily available for biodegradation under anaerobic conditions. The mushroom compost based bioreactors released significant amount of sulfate, which may raise a concern upon the start-up of field-scale bioreactors. Collectively, the substrate mixtures had comparable performances to the mushroom compost, the most commonly used material in field bioreactors, in terms of metal removal, pH neutralization, and sulfate reduction, except for the reactors containing rice straw. Especially, the mixture of sawdust and cow manure was the most efficient substrate for treatment of mine-impacted waters. The correlation between the extent of sulfate reduction and dissolved organic carbon/SO42- ratio was weak and this indicates the type of DOC plays more important role in sulfate reduction than the absolute concentration and that the ratio is not sensitive enough to properly describe the relative effectiveness of substrate mixtures.

  6. The removal kinetics of dissolved organic matter and the optical clarity of groundwater

    NASA Astrophysics Data System (ADS)

    Chapelle, Francis H.; Shen, Yuan; Strom, Eric W.; Benner, Ronald

    2016-09-01

    Concentrations of dissolved organic matter (DOM) and ultraviolet/visible light absorbance decrease systematically as groundwater moves through the unsaturated zones overlying aquifers and along flowpaths within aquifers. These changes occur over distances of tens of meters (m) implying rapid removal kinetics of the chromophoric DOM that imparts color to groundwater. A one-compartment input-output model was used to derive a differential equation describing the removal of DOM from the dissolved phase due to the combined effects of biodegradation and sorption. The general solution to the equation was parameterized using a 2-year record of dissolved organic carbon (DOC) concentration changes in groundwater at a long-term observation well. Estimated rates of DOC loss were rapid and ranged from 0.093 to 0.21 micromoles per liter per day (μM d-1), and rate constants for DOC removal ranged from 0.0021 to 0.011 per day (d-1). Applying these removal rate constants to an advective-dispersion model illustrates substantial depletion of DOC over flow-path distances of 200 m or less and in timeframes of 2 years or less. These results explain the low to moderate DOC concentrations (20-75 μM; 0.26-1 mg L-1) and ultraviolet absorption coefficient values ( a 254 < 5 m-1) observed in groundwater produced from 59 wells tapping eight different aquifer systems of the United States. The nearly uniform optical clarity of groundwater, therefore, results from similarly rapid DOM-removal kinetics exhibited by geologically and hydrologically dissimilar aquifers.

  7. The removal kinetics of dissolved organic matter and the optical clarity of groundwater

    NASA Astrophysics Data System (ADS)

    Chapelle, Francis H.; Shen, Yuan; Strom, Eric W.; Benner, Ronald

    2016-04-01

    Concentrations of dissolved organic matter (DOM) and ultraviolet/visible light absorbance decrease systematically as groundwater moves through the unsaturated zones overlying aquifers and along flowpaths within aquifers. These changes occur over distances of tens of meters (m) implying rapid removal kinetics of the chromophoric DOM that imparts color to groundwater. A one-compartment input-output model was used to derive a differential equation describing the removal of DOM from the dissolved phase due to the combined effects of biodegradation and sorption. The general solution to the equation was parameterized using a 2-year record of dissolved organic carbon (DOC) concentration changes in groundwater at a long-term observation well. Estimated rates of DOC loss were rapid and ranged from 0.093 to 0.21 micromoles per liter per day (μM d-1), and rate constants for DOC removal ranged from 0.0021 to 0.011 per day (d-1). Applying these removal rate constants to an advective-dispersion model illustrates substantial depletion of DOC over flow-path distances of 200 m or less and in timeframes of 2 years or less. These results explain the low to moderate DOC concentrations (20-75 μM; 0.26-1 mg L-1) and ultraviolet absorption coefficient values (a 254 < 5 m-1) observed in groundwater produced from 59 wells tapping eight different aquifer systems of the United States. The nearly uniform optical clarity of groundwater, therefore, results from similarly rapid DOM-removal kinetics exhibited by geologically and hydrologically dissimilar aquifers.

  8. Cascade air-stripping system for removal of low and semi-volatile organic contaminants

    SciTech Connect

    Jang, Won.

    1989-01-01

    Many hazardous waste sites have been known to have groundwaters contaminated with low volatile, hazardous compounds such as bromoform 1,1,2,2-tetrachloroethane, 1,2-dibromo-3-chloropropane (DBCP), napthalene, and polychlorinated biphenyls (PCBs). In addition, a large number of public water supplies have been reported to have taste and odor problems in drinking water, which are attributed primarily to naturally occurring compounds, such as 2-methylisoborneol (MIB), geosmin, etc. These classes of compounds have very low Henry's Constant, H{sub c}, in the range of 1 to 50 atm. Air-stripping in countercurrent packed towers is a well accepted treatment process for removing volatile organic chemicals (VOCs) from water. The USEPA has identified packed countercurrent air-stripping as not only the least-cost, but also one of the best available technologies for the removal of VOCs. However, the economic viability of this process is limited to volatile compounds of H{sub c} value greater than SO atm. A novel modification of the conventional countercurrent air-stripping process, introduced as cascade air-stripping was proposed for cost effective removal of these classes of compounds from water and at hazardous waste spill-sites. The main objectives of this study were to demonstrate the concept of cascade air-stripping; to compare cascade air-stripping with conventional air-stripping under identical conditions; and to verify the hypothesis that the cascade system is superior to the conventional system at the pilot and prototype scales. Results of the pilot and prototype study showed that the cascade airstrip ping system was a viable and economical approach to remove low and semi-volatile organic compounds from water. The cascade system consistently showed higher removals than the conventional system for both pilot and prototype scale study.

  9. Efficient generation of perfluoroalkyl radicals from sodium perfluoroalkanesulfinates and a hypervalent iodine(iii) reagent: mild, metal-free synthesis of perfluoroalkylated organic molecules.

    PubMed

    Sakamoto, Ryu; Kashiwagi, Hirotaka; Selvakumar, Sermadurai; Moteki, Shin A; Maruoka, Keiji

    2016-07-01

    This article describes an efficient method for the introduction of perfluoroalkyl groups into N-acrylamides, 2-isocyanides, olefins, and other heterocycles using perfluoroalkyl radicals that were generated from the reaction between sodium perfluoroalkanesulfinates and a hypervalent iodine(iii) reagent. This approach represents a simple, scalable perfluoroalkylation method under mild and metal-free conditions.

  10. Thorough removal of inorganic and organic mercury from aqueous solutions by adsorption on Lemna minor powder.

    PubMed

    Li, Shun-Xing; Zheng, Feng-Ying; Yang, Huang; Ni, Jian-Cong

    2011-02-15

    The adsorption ability of duckweed (Lemna minor) powders for removing inorganic and organic mercury (methyl and ethyl mercury) has been studied using cold vapour atomic absorption spectrometry. The optimal adsorption conditions were: (a) the pH value of the solution 7.0 for inorganic and ethyl mercury, 9.0 for methyl mercury, and (b) equilibrium adsorption time 10, 20, and 40 min for inorganic mercury, methyl mercury, and ethyl mercury, respectively. After adsorption by L. minor powder for 40 min, when the initial concentrations of inorganic and organic mercury were under 12.0 μg L(-1) and 50.0 μg L(-1), respectively, the residual concentrations of mercury could meet the criterion of drinking water (1.0 μg L(-1)) and the permitted discharge limit of wastewater (10.0 μg L(-1)) set by China and USEPA, respectively. Thorough removal of both inorganic and organic mercury from aqueous solutions was reported for the first time. The significant adsorption sites were C-O-P and phosphate groups by the surface electrostatic interactions with aqueous inorganic and organic mercury cations, and then the selective adsorption was resulted from the strong chelating interaction between amine groups and mercury on the surface of L. minor cells.

  11. Substrate removal kinetics and performance assessment of a vermifilter bioreactor under organic shock load conditions.

    PubMed

    Kumar, Tarun; Hari Prasad, K S; Singh, Nitin Kumar

    2016-01-01

    In the present study, the effect of short-term organic shock loads (675, 799, 1,084 and 1,410 mg COD/L) on the treatment performance of a pilot-scale vermifilter (VF), employing an epigeic earthworm Eisenia fetida and treating synthetic domestic wastewater is investigated. The effect of organic shock loads on the performance and stability of vermifiltration reactor was evaluated to identify its feasibility in actual field conditions. Prior to the application of each organic shock load, normal loading conditions were maintained to achieve the pseudo steady state (PSS) conditions. The results showed satisfactory endurance against imposed organic shock loads with negligible reduction in chemical oxygen demand (COD) removals and it was almost similar to PSS condition with removal efficiencies of ∼ 66, 71, 67 and 68%, respectively. The experimental COD data fit well to first-order kinetic model, with a regression value of 0.95. At the end of all shock loads, the nutritional analysis of vermicompost obtained from the top layer of VF, showed increased concentration of total nitrogen (∼31 g/Kg) and total phosphorus (29 g/Kg). Besides, an augmented earthworm biomass, ∼23.2% on weight basis and ∼22% on number basis, was observed at the end of the study. PMID:27642837

  12. In the best interests of the deceased: a possible justification for organ removal without consent?

    PubMed

    den Hartogh, Govert

    2011-08-01

    Opt-out systems of postmortem organ procurement are often supposed to be justifiable by presumed consent, but this justification turns out to depend on a mistaken mental state conception of consent. A promising alternative justification appeals to the analogical situation that occurs when an emergency decision has to be made about medical treatment for a patient who is unable to give or withhold his consent. In such cases, the decision should be made in the best interests of the patient. The analogous suggestion to be considered, then, is, if the potential donor has not registered either his willingness or his refusal to donate, the probabilities that he would or would not have preferred the removal of his organs need to be weighed. And in some actual cases the probability of the first alternative may be greater. This article considers whether the analogy to which this argument appeals is cogent, and concludes that there are important differences between the emergency and the organ removal cases, both as regards the nature of the interests involved and the nature of the right not to be treated without one's consent. Rather, if opt-out systems are to be justified, the needs of patients with organ failure and/or the possibility of tacit consent should be considered. PMID:21594614

  13. New biodegradable organic-soluble chelating agents for simultaneous removal of heavy metals and organic pollutants from contaminated media.

    PubMed

    Ullmann, Amos; Brauner, Neima; Vazana, Shlomi; Katz, Zhanna; Goikhman, Roman; Seemann, Boaz; Marom, Hanit; Gozin, Michael

    2013-09-15

    Advanced biodegradable and non-toxic organic chelators, which are soluble in organic media, were synthesized on the basis of the S,S-ethylenediamine-disuccinate (S,S-EDDS) ligand. The modifications suggested in this work include attachment of a lipophilic hydrocarbon chain ("tail") to one or both nitrogen atoms of the S,S-EDDS. The new ligands were designed and evaluated for application in the Sediments Remediation Phase Transition Extraction (SR-PTE) process. This novel process is being developed for the simultaneous removal of both heavy metals and organic pollutants from contaminated soils, sediments or sludge. The new chelators were designed to bind various target metal ions, to promote extraction of these ions into organic solvents. Several variations of attached tails were synthesized and tested. The results for one of them, N,N'-bis-dodecyl-S,S-EDDS (C24-EDDS), showed that the metal-ligand complexes are concentrated in the organic-rich phase in the Phase Transition Extraction process (more than 80%). Preliminary applications of the SR-PTE process with the C24-EDDS ligand were conducted also on actually contaminated sludge (field samples). The extraction of five toxic metals, namely, Cd, Cu, Ni, Pb and Zn was examined. In general, the extraction performance of the new ligand was not less than that of S,S-EDDS when a sufficient ligand-to-extracted ion ratio (about 4:1 was applied.

  14. Efficiency of conventional drinking-water-treatment processes in removal of pharmaceuticals and other organic compounds.

    PubMed

    Stackelberg, Paul E; Gibs, Jacob; Furlong, Edward T; Meyer, Michael T; Zaugg, Steven D; Lippincott, R Lee

    2007-05-15

    Samples of water and sediment from a conventional drinking-water-treatment (DWT) plant were analyzed for 113 organic compounds (OCs) that included pharmaceuticals, detergent degradates, flame retardants and plasticizers, polycyclic aromatic hydrocarbons (PAHs), fragrances and flavorants, pesticides and an insect repellent, and plant and animal steroids. 45 of these compounds were detected in samples of source water and 34 were detected in samples of settled sludge and (or) filter-backwash sediments. The average percent removal of these compounds was calculated from their average concentration in time-composited water samples collected after clarification, disinfection (chlorination), and granular-activated-carbon (GAC) filtration. In general, GAC filtration accounted for 53% of the removal of these compounds from the aqueous phase; disinfection accounted for 32%, and clarification accounted for 15%. The effectiveness of these treatments varied widely within and among classes of compounds; some hydrophobic compounds were strongly oxidized by free chlorine, and some hydrophilic compounds were partly removed through adsorption processes. The detection of 21 of the compounds in 1 or more samples of finished water, and of 3 to 13 compounds in every finished-water sample, indicates substantial but incomplete degradation or removal of OCs through the conventional DWT process used at this plant.

  15. Efficiency of conventional drinking-water-treatment processes in removal of pharmaceuticals and other organic compounds

    USGS Publications Warehouse

    Stackelberg, P.E.; Gibs, J.; Furlong, E.T.; Meyer, M.T.; Zaugg, S.D.; Lippincott, R.L.

    2007-01-01

    Samples of water and sediment from a conventional drinking-water-treatment (DWT) plant were analyzed for 113 organic compounds (OCs) that included pharmaceuticals, detergent degradates, flame retardants and plasticizers, polycyclic aromatic hydrocarbons (PAHs), fragrances and flavorants, pesticides and an insect repellent, and plant and animal steroids. 45 of these compounds were detected in samples of source water and 34 were detected in samples of settled sludge and (or) filter-backwash sediments. The average percent removal of these compounds was calculated from their average concentration in time-composited water samples collected after clarification, disinfection (chlorination), and granular-activated-carbon (GAC) filtration. In general, GAC filtration accounted for 53% of the removal of these compounds from the aqueous phase; disinfection accounted for 32%, and clarification accounted for 15%. The effectiveness of these treatments varied widely within and among classes of compounds; some hydrophobic compounds were strongly oxidized by free chlorine, and some hydrophilic compounds were partly removed through adsorption processes. The detection of 21 of the compounds in 1 or more samples of finished water, and of 3 to 13 compounds in every finished-water sample, indicates substantial but incomplete degradation or removal of OCs through the conventional DWT process used at this plant. ?? 2007 Elsevier B.V. All rights reserved.

  16. Degradation of algal organic matter using microbial fuel cells and its association with trihalomethane precursor removal.

    PubMed

    Wang, Huan; Liu, Dongmei; Lu, Lu; Zhao, Zhiwei; Xu, Yongpeng; Cui, Fuyi

    2012-07-01

    In order to provide an alternative for removal of algal organic matter (AOM) produced during algal blooms in aquatic environment, microbial fuel cell (MFC) was used to study AOM degradation and its association with THM precursor removal. The chemical oxygen demand (COD) removals in MFCs were 81 ± 6% and 73 ± 3% for AOM from Microcystis aeruginosa (AOM(M)) and Chlorella vulgaris (AOM(C)), respectively. THM precursor was also effectively degraded (AOM(M) 85 ± 2%, AOM(C) 72 ± 4%). The major AOM components (proteins, lipids, and carbohydrates) were obviously removed in MFCs. The contribution of each component to the THM formation potential (THMFP) was obtained based on calculation. The THMFP produced from soluble microbial products was very low. If the energy input during operation process was not considered, MFCs treatment could recover electrical energy of 0.29 ± 0.02 kWh/kg COD (AOM(M)) and 0.35 ± 0.06 kWh/kg COD (AOM(C)).

  17. Development of adsorbent for the simultaneous removal of organic and inorganic contaminants from aqueous solution.

    PubMed

    Choi, J W; Chung, S G; Hong, S W; Kim, D J; Lee, S H

    2011-01-01

    In this study, a modified adsorbent, alginate complex beads, was prepared and applied to the removal of mixed contaminants from wastewater. The alginate complex beads were generated by the immobilization of powdered activated carbon and synthetic zeolites onto alginate gel beads, which were then dried at 110 °C for 20 h until the diameter had been reduced to 1 mm. This dry technique increased the hardness of the adsorbent to assure its durability and application. The adsorption onto the alginate complex beads of organic and inorganic compounds, as target contaminants, was investigated by performing both equilibrium and kinetic batch experiments. From the adsorption isotherms, according to the Langmuir equation, the alginate complex bead was capable of effectively removing benzene, toluene, zinc and cadmium. From kinetic batch experiments, the removal efficiencies of benzene, toluene, zinc and cadmium were found to be 66.5, 92.4, 74.1 and 76.7%, respectively, for initial solution concentrations of 100 mg L(-1). The results indicated that the adsorbent developed in this study has the potential to be a promising material for the removal of mixed pollutants from industrial wastewater or contaminated groundwater. PMID:22020474

  18. Use of adsorption process to remove organic mercury thimerosal from industrial process wastewater.

    PubMed

    Velicu, Magdalena; Fu, Hongxiang; Suri, Rominder P S; Woods, Kevin

    2007-09-30

    Carbon adsorption process is tested for removal of high concentration of organic mercury (thimerosal) from industrial process wastewater, in batch and continuously flow through column systems. The organic mercury concentration in the process wastewater is about 1123 mg/L due to the thimerosal compound. Four commercially available adsorbents are tested for mercury removal and they are: Calgon F-400 granular activated carbon (GAC), CB II GAC, Mersorb GAC and an ion-exchange resin Amberlite GT73. The adsorption capacity of each adsorbent is described by the Freundlich isotherm model at pH 3.0, 9.5 and 11.0 in batch isotherm experiments. Acidic pH was favorable for thimerosal adsorption onto the GACs. Columns-in-series experiments are conducted with 30-180 min empty bed contact times (EBCTs). Mercury breakthrough of 30 mg/L occurred after about 47 h (96 Bed Volume Fed (BVF)) of operation, and 97 h (197 BVF) with 120 min EBCT and 180 min EBCT, respectively. Most of the mercury removal is attributed to the 1st adsorbent column. Increase in contact time by additional adsorbent columns did not lower the effluent mercury concentration below 30 mg/L. However, at a lower influent wastewater pH 3, the mercury effluent concentration decreased to less than 7 mg/L for up to 90 h of column operation (183 BVF). PMID:17459583

  19. Interaction of bisphenol A with dissolved organic matter in extractive and adsorptive removal processes.

    PubMed

    Zhu, Fei-Die; Choo, Kwang-Ho; Chang, Hyun-Shik; Lee, Byunghwan

    2012-05-01

    The fate of endocrine disrupting chemicals (EDCs) in natural and engineered systems is complicated due to their interactions with various water constituents. This study investigated the interaction of bisphenol A (BPA) with dissolved organic matter (DOM) and colloids present in surface water and secondary effluent as well as its adsorptive removal by powdered activated carbons. The solid phase micro-extraction (SPME) method followed by thermal desorption and gas chromatography-mass spectrometry (GC-MS) was utilized for determining the distribution of BPA molecules in water. The BPA removal by SPME decreased with the increased DOM content, where the formation of BPA-DOM complexes in an aqueous matrix was responsible for the reduced extraction of BPA. Colloidal particles in water samples sorbed BPA leading to the marked reduction of liquid phase BPA. BPA-DOM complexes had a negative impact on the adsorptive removal of BPA by powered activated carbons. The complex formation was characterized based on Fourier transform infrared (FTIR) and ultraviolet-visible (UV-Vis) spectroscopy, along with the calculation of molecular interactions between BPA and functional groups in DOM. It was found that the hydrogen bonding between DOM and BPA would be preferred over aromatic interactions. A pseudo-equilibrium molecular coordination model for the complexation between a BPA molecule and a hydroxyl group of the DOM was developed, which enabled estimation of the maximum sorption site and complex formation constant as well as prediction of organic complexes at various DOM levels. PMID:22330311

  20. Formation and removal of dissolved organic nitrogen (DON) in membrane bioreactor and conventional activated sludge processes.

    PubMed

    Han, Xiaomeng; Wang, Zhiwei; Ma, Jinxing; Zheng, Junjian; Wang, Pan; Wu, Zhichao

    2015-08-01

    Dissolved organic nitrogen (DON) has become a growing concern due to its contribution to eutrophication and nitrogenous disinfection byproducts (N-DBPs) formation. However, information of DON in membrane bioreactors (MBRs) is very limited. In this study, occurrence, transformation and fate of DON in an MBR system were systematically investigated. MBR sludge showed a larger hydrolysis rate of particle organic nitrogen (PON) and also a higher transformation rate of DON to nitrate compared to conventional activated sludge (CAS). For long-term experiments, MBR achieved higher DON removal efficiency at low temperature than CAS; however, at high temperature, the effluent DON concentrations were almost the same in both systems. Batch tests on DON biodegradability showed that DON concentration increased and large molecular weight DON accumulated after 3-h aeration at low temperature, while DON concentration continuously decreased with the increase of aeration time at high temperature. The obtained results provide insights in DON removal in MBRs for meeting increasingly stringent regulations in terms of nitrogen removal.

  1. Combined ion exchange treatment for removal of dissolved organic matter and hardness.

    PubMed

    Apell, Jennifer N; Boyer, Treavor H

    2010-04-01

    Dissolved organic matter (DOM) and hardness cations are two common constituents of natural waters that substantially impact water treatment processes. Anion exchange treatment, and in particular magnetic ion exchange (MIEX), has been shown to effectively remove DOM from natural waters. An important advantage of the MIEX process is that it is used as a slurry in a completely mixed flow reactor at the beginning of the treatment train. Hardness ions can be removed with cation exchange resins, although typically using a fixed bed reactor at the end of a treatment train. In this research, the feasibility of combining anion and cation exchange treatment in a single completely mixed reactor for treatment of raw water was investigated. The sequence of anion and cation exchange treatment, the number of regeneration cycles, and the chemistry of the regeneration solution were systematically explored. Simultaneous removal of DOM (70% as dissolved organic carbon) and hardness (>55% as total hardness) was achieved by combined ion exchange treatment. Combined ion exchange is expected to be useful as a pre-treatment for membrane systems because both DOM and divalent cations are major foulants of membranes.

  2. Nutrient and dissolved organic carbon removal from natural waters using industrial by-products.

    PubMed

    Wendling, Laura A; Douglas, Grant B; Coleman, Shandel; Yuan, Zheng

    2013-01-01

    Attenuation of excess nutrients in wastewater and stormwater is required to safeguard aquatic ecosystems. The use of low-cost, mineral-based industrial by-products with high Ca, Mg, Fe or Al content as a solid phase in constructed wetlands potentially offers a cost-effective wastewater treatment option in areas without centralised water treatment facilities. Our objective was to investigate use of water treatment residuals (WTRs), coal fly ash (CFA), and granular activated carbon (GAC) from biomass combustion in in-situ water treatment schemes to manage dissolved organic carbon (DOC) and nutrients. Both CaO- and CaCO(3)-based WTRs effectively attenuated inorganic N species but exhibited little capacity for organic N removal. The CaO-based WTR demonstrated effective attenuation of DOC and P in column trials, and a high capacity for P sorption in batch experiments. Granular activated carbon proved effective for DOC and dissolved organic nitrogen (DON) removal in column trials, but was ineffective for P attenuation. Only CFA demonstrated effective removal of a broad suite of inorganic and organic nutrients and DOC; however, Se concentrations in column effluents exceeded Australian and New Zealand water quality guideline values. Water treated by filtering through the CaO-based WTR exhibited nutrient ratios characteristic of potential P-limitation with no potential N- or Si-limitation respective to growth of aquatic biota, indicating that treatment of nutrient-rich water using the CaO-based WTR may result in conditions less favourable for cyanobacterial growth and more favourable for growth of diatoms. Results show that selected industrial by-products may mitigate eutrophication through targeted use in nutrient intervention schemes.

  3. Combining adsorption with anodic oxidation as an innovative technique for removal and destruction of organics.

    PubMed

    Brown, N W; Roberts, E P L

    2013-01-01

    Coupling of adsorption with electrochemical oxidation is a novel approach to the treatment of aqueous organics that has demonstrated a number of key benefits over the individual application of these processes. This is based on a highly conducting adsorbent material, developed under the trade name Nyex™, that is able to rapidly adsorb the organics and anodically oxidise them within a single treatment unit. Successful scale up of the process (in both continuous and batch operation) has been achieved for the polishing of two separate groundwaters (one containing relatively simple petrol, diesel and their degradation products and the other with a range of more complex organics). Treatment showed that low discharge consents can be achieved, including the removal of more complex and difficult to treat compounds to below the limits of detection. Energy consumption for electrochemical regeneration was relatively low (down to 0.5 kWh/m(3)) suggesting that the process could be a practical alternative approach for effluent polishing.

  4. Preparation of graphene sponge by vapor phase reduction for oil and organic solvent removal

    NASA Astrophysics Data System (ADS)

    Wu, Ruihan; Yu, Baowei; Jin, Xinyan; Liu, Xiaoyang; Bai, Yitong; Chen, Lingyun; Ming, Zhu; Yang, Hua; Yang, Sheng-Tao; Luo, Jianbin

    2016-10-01

    Due to the porous structure and hydrophobicity, graphene sponge has huge adsorption capacity for oils and organic solvents. In this study, we reported that graphene sponge could be prepared by vapor phase reduction (denoted as VPRGS) for oil and organic solvent removal. Graphene oxide was lyophilized and reduced by steamy hydrazine hydrate to produce VPRGS. VPRGS had huge capacity for oils and organic solvents (72–224 g g‑1). In particular, the adsorption capacity for crude oil reached 165 g g‑1, suggesting that VPRGS could be applied in oil leakage remediation. VPRGS could treat pollutants both in pure liquid form and in the simulated sea water, where the hydrophobic nature of VPRGS allowed the floating of VPRGS on simulated sea water. VPRGS could be easily regenerated without obvious capacity loss up to 9 cycles. The implications to the applications of VPRGS in oil/water separation and water remediation are discussed.

  5. Concentration maxima of volatile organic iodine compounds in the bottom layer water and the cold, dense water over the Chukchi Sea in the western Arctic Ocean: a possibility of production related to the degradation of organic matter

    NASA Astrophysics Data System (ADS)

    Ooki, A.; Kawasaki, S.; Kuma, K.; Nishino, S.; Kikuchi, T.

    2016-01-01

    We conducted a shipboard observation over the Chukchi Sea and the Canada Basin in the western Arctic Ocean in September and October 2012 to obtain vertical distributions of four volatile organic iodine compounds (VOIs) in seawater. The VOIs observed in this study were iodomethane (CH3I), iodoethane (C2H5I), diiodomethane (CH2I2), and chloroiodomethane (CH2ClI). Maximum concentrations of the four VOIs were found in the bottom layer water over the Chukchi Sea shelf, in which layer the maximum concentration of ammonium (NH4+) also occurred. A significant correlation was observed between C2H5I and NH4+ (correlation coefficient R = 0.93, P < 0.01, n = 64) and between CH3I and NH4+ (R= 0.77, P < 0.01, n = 64), suggesting that the production of these VOIs increased with the degradation of organic matter. Over the northern Chukchi Sea shelf-slope area, concentration maxima of CHI2, CH2ClI, and CH3I were found in the subsurface cold, dense water (CDW). A large nitrogen deficit (N deficit = NH4++ NO3-+ NO2--16PO43-) occurred simultaneously in this water, suggesting the production of the three VOIs in the sediment or the bottom layer water over the shelf, probably in association with the degradation of organic matter. We conclude that VOI production over the Chukchi Sea shelf can be largely attributed to the degradation of organic matter that is produced in the highly productive shelf water. High concentrations of CH2ClI were also found in the Alaskan Coastal Water (ACW) from the Bering Strait to the surface of the northern Chukchi slope. The VOIs that originated at the Chukchi Sea shelf are expected to be laterally transported to the Arctic Ocean basin through the CDW and the surface ACW.

  6. Concentration maxima of volatile organic iodine compounds in the bottom layer water and the cold, dense water over the Chukchi Sea in the western Arctic Ocean: a possibility of production related to degradation of organic matter

    NASA Astrophysics Data System (ADS)

    Ooki, A.; Kawasaki, S.; Kuma, K.; Nishino, S.; Kikuchi, T.

    2015-07-01

    We conducted a shipboard observation over the Chukchi Sea and the Canada Basin in the western Arctic Ocean in September and October 2012 to obtain vertical distributions of four volatile organic iodine compounds (VOIs) in seawater. VOIs are believed to play a role in ozone destruction in the troposphere and lower stratosphere. The VOIs observed in this study were iodomethane (CH3I), iodoethane (C2H5I), diiodomethane (CH2I2) and chloroiodomethane (CH2ClI). Maximum concentrations of the four VOIs were found in the bottom layer water over the Chukchi Sea shelf, in which layer the maximum concentration of ammonium (NH4+) also occurred. A significant correlation was observed between C2H5I and NH4+ (correlate coefficient R = 0.93) and between CH3I and NH4+ (R = 0.77), suggesting production of these VOIs increased with degradation of organic matter. Over the northern Chukchi Sea shelf-slope area, concentration maxima of CH2I2, CH2ClI, and CH3I were found in the subsurface cold, dense water (CDW). A large nitrogen deficit (N-deficit = NH4+ + NO3- + NO2- - 16PO43-) simultaneously occurred in this water, suggesting production of the three VOIs in the sediment or the bottom layer water over the shelf, probably in association with degradation of organic matter. We conclude that VOI production over the Chukchi Sea shelf can be largely attributed to the degradation of organic matter that is produced in the highly productive shelf water. High concentrations of CH2ClI were also found in the Alaskan Coastal Water (ACW) from the Bering Strait to the surface of the northern Chukchi slope. The VOIs that originated at the Chukchi Sea shelf are expected to be laterally transported to the Arctic Ocean Basin though the subsurface CDW and the surface ACW.

  7. Effects of water washing on removing organic residues in bottom ashes of municipal solid waste incinerators.

    PubMed

    Lin, Yen-Ching; Panchangam, Sri Chandana; Wu, Chung-Hsin; Hong, Pui-Kwan Andy; Lin, Cheng-Fang

    2011-01-01

    Due to their potential toxicity and odourous nature, the residual organics in municipal solid waste incinerators are recently gaining attention as an important issue of resources recovery apart from their complex mixture of organic counterpart. Studies of the organic fractions in municipal solid waste incinerator residues have been limited. In this study, extended solid-phase extraction of the water-washed bottom ash and liquid-phase extraction of the washing water were carried out with regard to bottom ash samples from three mass-burning incinerators in Taipei County (Taiwan) during four consecutive seasons of year 2008-2009. Supercritical fluid extraction and Soxtec extraction techniques along with GC-MS were successfully used to characterize the residual organics in weathered and washed bottom ashes. Supercritical fluid extraction provided the quantification of aliphatics and aromatic compounds such as hexanoic acid and benzaldehyde, respectively. Soxtec extraction was useful for qualitative analysis of aromatic and aliphatic groups in the ashes and many of which were odourous and toxic compounds. By mixing one unit weight (g) bottom ash with two unit volume (mL) water for 15 min, total organic carbon in the bottom ash was greatly reduced (e.g., from 4.1 to 1.8 wt.%). Among the removed were foul odour-causing compounds such as pyridine and quinoline derivatives, while some aromatic compounds such as 4-hydroxybenzaldehyde and low-molecular-weight aliphatics such as hexanoic acid remained. The results here suggest that washing with water can be an effective pre-treatment step for removing odour-causing and environmental concerned organics. PMID:21112610

  8. Removal Rate of Organic Matter Using Natural Cellulose via Adsorption Isotherm and Kinetic Studies.

    PubMed

    Din, Mohd Fadhil Md; Ponraj, Mohanadoss; Low, Wen-Pei; Fulazzaky, Mohamad Ali; Iwao, Kenzo; Songip, Ahmad Rahman; Chelliapan, Shreeshivadasan; Ismail, Zulhilmi; Jamal, Mohamad Hidayat

    2016-02-01

    In this study, the removal of natural organic matter (NOM) using coconut fiber (CF) and palm oil fiber (POF) was investigated. Preliminary analysis was performed using a jar test for the selection of optimal medium before the fabricated column model experiment. The equilibrium studies on isotherms and kinetic models for NOM adsorption were analyzed using linearized correlation coefficient. Results showed that the equilibrium data were fitted to Langmuir isotherm model for both CF and POF. The most suitable adsorption model was the pseudo-first-order kinetic model for POF and pseudo-second-order kinetic model for CF. The adsorption capacities achieved by the CF and POF were 15.67 and 30.8 mg/g respectively. Based on this investigation, it can be concluded that the POF is the most suitable material for the removal of NOM in semi polluted river water.

  9. Removing synthetic organic chemicals from drinking water by granular activated carbon: performance and cost

    SciTech Connect

    Lykins, B.W.; Clark, R.M.; Adams, J.Q.

    1988-03-01

    GAC has been shown to be an effective adsorbent for removing many of the SOCs scheduled for regulation and to be an effective broad-spectrum adsorbent. U.S. EPA data presented in the paper demonstrates by field-scale contactors, pilot-columns, and minicolumns the adsorbability of many SOCs. In DWRD laboratories, isotherm, microcolumn, and pilot column studies are underway on others. The extent of SOC removal depends on several factors such as EBCT, type of GAC used, competition for adsorption sites from other organics, precursor material, etc. Each utility considering GAC for SOC control should evaluate their specific situation. The evaluation should include some method for predicting full-scale operation.

  10. Removal Rate of Organic Matter Using Natural Cellulose via Adsorption Isotherm and Kinetic Studies.

    PubMed

    Din, Mohd Fadhil Md; Ponraj, Mohanadoss; Low, Wen-Pei; Fulazzaky, Mohamad Ali; Iwao, Kenzo; Songip, Ahmad Rahman; Chelliapan, Shreeshivadasan; Ismail, Zulhilmi; Jamal, Mohamad Hidayat

    2016-02-01

    In this study, the removal of natural organic matter (NOM) using coconut fiber (CF) and palm oil fiber (POF) was investigated. Preliminary analysis was performed using a jar test for the selection of optimal medium before the fabricated column model experiment. The equilibrium studies on isotherms and kinetic models for NOM adsorption were analyzed using linearized correlation coefficient. Results showed that the equilibrium data were fitted to Langmuir isotherm model for both CF and POF. The most suitable adsorption model was the pseudo-first-order kinetic model for POF and pseudo-second-order kinetic model for CF. The adsorption capacities achieved by the CF and POF were 15.67 and 30.8 mg/g respectively. Based on this investigation, it can be concluded that the POF is the most suitable material for the removal of NOM in semi polluted river water. PMID:26803100

  11. Petroleum refinery secondary effluent polishing using freezing processes--toxicity and organic contaminant removal.

    PubMed

    Gao, W; Smith, D W; Habib, M

    2008-06-01

    A petroleum refinery secondary effluent was treated using two freezing techniques--spray freezing and unidirectional downward freezing (UDF). The freezing processes were effective to remove toxicity and total organic carbon (TOC)- and chemical oxygen demand (COD)-causing materials in the effluent. Agitation of the liquid during UDF significantly improved the impurity separation efficiency; 85 to 96% removal of TOC and COD was achieved without any pretreatment and freezing only 70% of the feed water. The treatment efficiency of the spray freezing was at the same level as that of UDF without mixing. The spray ice with longer storage time released more contaminants with early meltwater. The initial contaminant concentration of the feed water and the freezing temperatures (-10 degrees C and -25 degrees C) had no significant influence on the treatment efficiency. A small fluctuation in effluent TOC concentration caused a dramatic change in effluent toxicity (Microtox). The effective concentration (EC20) (Microtox) was effective in detecting effluent toxicity. PMID:18686927

  12. Dynamics of organic matter, nitrogen and phosphorus removal and their interactions in a tidal operated constructed wetland.

    PubMed

    Li, Chunyan; Wu, Shubiao; Dong, Renjie

    2015-03-15

    This paper demonstrates the potential of tidal flow operated constructed wetland application for the removal dynamics of organic matter, nitrogen and phosphorus. Near-complete removal of organic matter was achieved with a constant removal efficiency of 95%, irrespective of TOC influent loadings ranged from 10 g/m(2) · d to 700 g/m(2) · d. High NH4(+)-N removal at 95% efficiency under influent loading of 17 g/m(2) · d, was stably obtained and was not negatively influenced by increasing influent organic carbon loading rate. Increased influent TOC loading (350 g/m(2) · d to 700 g/m(2) · d) significantly enhanced denitrification capacity and increased TN removal from 30% to 95%. Under tidal flow operation, a higher carbon supply (C/N = 20) for complete TN removal was demonstrated as comparing to that observed in traditional CWs approaches. In addition, the removal of phosphorus was strongly influenced by organic loadings. However, further investigations are needed to elucidate the detailed mechanism that would explain the role of organic loading in phosphorus removal.

  13. Dynamics of organic matter, nitrogen and phosphorus removal and their interactions in a tidal operated constructed wetland.

    PubMed

    Li, Chunyan; Wu, Shubiao; Dong, Renjie

    2015-03-15

    This paper demonstrates the potential of tidal flow operated constructed wetland application for the removal dynamics of organic matter, nitrogen and phosphorus. Near-complete removal of organic matter was achieved with a constant removal efficiency of 95%, irrespective of TOC influent loadings ranged from 10 g/m(2) · d to 700 g/m(2) · d. High NH4(+)-N removal at 95% efficiency under influent loading of 17 g/m(2) · d, was stably obtained and was not negatively influenced by increasing influent organic carbon loading rate. Increased influent TOC loading (350 g/m(2) · d to 700 g/m(2) · d) significantly enhanced denitrification capacity and increased TN removal from 30% to 95%. Under tidal flow operation, a higher carbon supply (C/N = 20) for complete TN removal was demonstrated as comparing to that observed in traditional CWs approaches. In addition, the removal of phosphorus was strongly influenced by organic loadings. However, further investigations are needed to elucidate the detailed mechanism that would explain the role of organic loading in phosphorus removal. PMID:25585144

  14. Radioactive iodine uptake

    MedlinePlus

    ... much radioactive iodine is taken up by your thyroid gland in a certain time period. A similar test ... over the area of your neck where the thyroid gland is located. The probe detects the location and ...

  15. Iodine Clock Reaction.

    ERIC Educational Resources Information Center

    Mitchell, Richard S.

    1996-01-01

    Describes a combination of solutions that can be used in the study of kinetics using the iodine clock reaction. The combination slows down degradation of the prepared solutions and can be used successfully for several weeks. (JRH)

  16. In-situ identification of iron electrocoagulation speciation and application for natural organic matter (NOM) removal.

    PubMed

    Dubrawski, Kristian L; Mohseni, Madjid

    2013-09-15

    In this work, iron speciation in electrocoagulation (EC) was studied to determine the impact of operating parameters on natural organic matter (NOM) removal from natural water. Two electrochemical EC parameters, current density (i) and charge loading rate (CLR), were investigated. Variation of these parameters led to a near unity current efficiency (φ = 0.957 ± 0.03), at any combination of i in a range of 1-25 mA/cm(2) and CLR in a range of 12-300 C/L/min. Higher i and CLR led to a higher bulk pH and limited the amount of dissolved oxygen (DO) reduced at the cathode surface due to mass transfer limitations. A low i (1 mA/cm(2)) and intermediate CLR (60 C/L/min) resulted in low bulk DO (<2.5 mg/L), where green rust (GR) was identified by in-situ Raman spectroscopy as the primary crystalline electrochemical product. Longer electrolysis times at higher i led to magnetite (Fe3O4) formation. Both higher (300 C/L/min) and lower (12 C/L/min) CLR values led to increased DO and/or increased pH, with lepidocrocite (γ-FeOOH) as the only crystalline species observed. The NOM removal of the three identified species was compared, with conditions leading to GR formation showing the greatest dissolved organic carbon removal, and highest removal of the low apparent molecular weight (<550 Da) chromophoric NOM fraction, determined by high performance size exclusion chromatography.

  17. In-situ identification of iron electrocoagulation speciation and application for natural organic matter (NOM) removal.

    PubMed

    Dubrawski, Kristian L; Mohseni, Madjid

    2013-09-15

    In this work, iron speciation in electrocoagulation (EC) was studied to determine the impact of operating parameters on natural organic matter (NOM) removal from natural water. Two electrochemical EC parameters, current density (i) and charge loading rate (CLR), were investigated. Variation of these parameters led to a near unity current efficiency (φ = 0.957 ± 0.03), at any combination of i in a range of 1-25 mA/cm(2) and CLR in a range of 12-300 C/L/min. Higher i and CLR led to a higher bulk pH and limited the amount of dissolved oxygen (DO) reduced at the cathode surface due to mass transfer limitations. A low i (1 mA/cm(2)) and intermediate CLR (60 C/L/min) resulted in low bulk DO (<2.5 mg/L), where green rust (GR) was identified by in-situ Raman spectroscopy as the primary crystalline electrochemical product. Longer electrolysis times at higher i led to magnetite (Fe3O4) formation. Both higher (300 C/L/min) and lower (12 C/L/min) CLR values led to increased DO and/or increased pH, with lepidocrocite (γ-FeOOH) as the only crystalline species observed. The NOM removal of the three identified species was compared, with conditions leading to GR formation showing the greatest dissolved organic carbon removal, and highest removal of the low apparent molecular weight (<550 Da) chromophoric NOM fraction, determined by high performance size exclusion chromatography. PMID:23871255

  18. Removal of organic pollutants and heavy metals in soils by electrokinetic remediation.

    PubMed

    Ricart, M T; Pazos, M; Gouveia, S; Cameselle, C; Sanroman, M A

    2008-07-01

    In this work, the feasibility of electrokinetic remediation for the restoration of polluted soil with organic and inorganic compounds had been development and evaluated using a model soil sample. The model soil was prepared with kaolinite clay artificially polluted in the laboratory with chromium and an azo dye: Reactive Black 5 (RB5). The electromigration of Cr in a spiked kaolinite sample was studied in alkaline conditions. Despite of the high pH registered in the kaolinite sample (around pH 9.5), Cr migrated towards the cathode and it was accumulated in the cathode chamber forming a white precipitate. The removal was not complete, and 23% of the initial Cr was retained into the kaolinite sample close to the cathode side. The azo dye RB5 could be effectively removed from kaolinite by electrokinetics and the complete cleanup of the kaolinite could be achieved in alkaline environment. In this condition, RB5 formed an anion that migrated towards the anode where it was accumulated and quickly degraded upon the electrode surface. The electrokinetic treatment of a kaolinite sample polluted with both Cr and RB5 yielded very good results. The removal of Cr was improved compared to the experiment where Cr was the only pollutant, and RB5 reached a removal as high as 95%. RB5 was removed by electromigration towards the anode, where the dye was degraded upon the surface of the electrode by electrochemical oxidation. Cr was transported towards the cathode by electromigration and electroosmosis. It is supposed that the interaction among RB5 and Cr into the kaolinite sample prevented premature precipitation and allow Cr to migrate and concentrate in the cathode chamber. PMID:18569297

  19. Removal of persistent organic pollutants from micro-polluted drinking water by triolein embedded absorbent.

    PubMed

    Liu, Huijuan; Ru, Jia; Qu, Jiuhui; Dai, Ruihua; Wang, Zijian; Hu, Chun

    2009-06-01

    A new biomimetic absorbent, cellulose acetate (CA) embedded with triolein (CA-triolein), was prepared and applied for the removal of persistent organic pollutants (POPs) from micro-polluted aqueous solution. The comparison of CA-triolein, CA and granular activated carbon (GAC) for dieldrin removal was investigated. Results showed that CA-triolein absorbent gave a lowest residual concentration after 24 h although GAC had high removal rate in the first 4 h adsorption. Then the removal efficiency of mixed POPs (e.g. aldrin, dieldrin, endrin and heptachlor epoxide), absorption isotherm, absorbent regeneration and initial column experiments of CA-triolein were studied in detail. The linear absorption isotherm and the independent absorption in binary isotherm indicated that the selected POPs are mainly absorbed onto CA-triolein absorbent by a partition mechanism. The absorption constant, K, was closely related to the hydrophobic property of the compound. Thermodynamic calculations showed that the absorption was spontaneous, with a high affinity and the absorption was an endothermic reaction. Rinsing with hexane the CA-triolein absorbent can be regenerated after absorption of POPs. No significant decrease in the dieldrin removal efficiency was observed even when the absorption-regeneration process was repeated for five times. The results of initial column experiments showed that the CA-triolein absorbent did not reach the breakthrough point at a breakthrough empty-bed volume (BV) of 3200 when the influent concentration was 1-1.5 microg/L and the empty-bed contact time (EBCT) was 20 min. PMID:19246190

  20. Iodine Hall Thruster

    NASA Technical Reports Server (NTRS)

    Szabo, James

    2015-01-01

    Iodine enables dramatic mass and cost savings for lunar and Mars cargo missions, including Earth escape and near-Earth space maneuvers. The demonstrated throttling ability of iodine is important for a singular thruster that might be called upon to propel a spacecraft from Earth to Mars or Venus. The ability to throttle efficiently is even more important for missions beyond Mars. In the Phase I project, Busek Company, Inc., tested an existing Hall thruster, the BHT-8000, on iodine propellant. The thruster was fed by a high-flow iodine feed system and supported by an existing Busek hollow cathode flowing xenon gas. The Phase I propellant feed system was evolved from a previously demonstrated laboratory feed system. Throttling of the thruster between 2 and 11 kW at 200 to 600 V was demonstrated. Testing showed that the efficiency of iodine fueled BHT-8000 is the same as with xenon, with iodine delivering a slightly higher thrust-to-power (T/P) ratio. In Phase II, a complete iodine-fueled system was developed, including the thruster, hollow cathode, and iodine propellant feed system. The nominal power of the Phase II system is 8 kW; however, it can be deeply throttled as well as clustered to much higher power levels. The technology also can be scaled to greater than 100 kW per thruster to support megawatt-class missions. The target thruster efficiency for the full-scale system is 65 percent at high specific impulse (Isp) (approximately 3,000 s) and 60 percent at high thrust (Isp approximately 2,000 s).

  1. An Evaluation of Technology to Remove Problematic Organic Compounds from the International Space Station Potable Water

    NASA Technical Reports Server (NTRS)

    Rector, Tony; Metselaar, Carol; Peyton, Barbara; Steele, John; Michalek, William; Bowman, Elizabeth; Wilson, Mark; Gazda, Daniel; Carter, Layne

    2014-01-01

    Since activation of the Water Processor Assembly (WPA) on the International Space Station (ISS) in November of 2008, there have been three events in which the TOC (Total Organic Carbon) in the product water has increased to approximately 3 mg/L and has subsequently recovered. Analysis of the product water in 2010 identified the primary component of the TOC as dimethylsilanediol (DMSD). An investigation into the fate of DMSD in the WPA ultimately determined that replacement of both Multifiltration (MF) Beds is the solution to recovering product water quality. The MF Beds were designed to ensure that ionic breakthrough occurs before organic breakthrough. However, DMSD saturated both MF Beds in the series, requiring removal and replacement of both MF Beds with significant life remaining. Analysis of the MF Beds determined that the adsorbent was not effectively removing DMSD, trimethylsilanol, various polydimethylsiloxanes, or dimethylsulfone. Coupled with the fact that the current adsorbent is now obsolete, the authors evaluated various media to identify a replacement adsorbent as well as media with greater capacity for these problematic organic contaminants. This paper provides the results and recommendations of this collaborative study.

  2. Removal of total organic carbon from sewage wastewater using poly(ethylenimine)-functionalized magnetic nanoparticles.

    PubMed

    Lakshmanan, Ramnath; Sanchez-Dominguez, Margarita; Matutes-Aquino, Jose A; Wennmalm, Stefan; Kuttuva Rajarao, Gunaratna

    2014-02-01

    The increased levels of organic carbon in sewage wastewater during recent years impose a great challenge to the existing wastewater treatment process (WWTP). Technological innovations are therefore sought that can reduce the release of organic carbon into lakes and seas. In the present study, magnetic nanoparticles (NPs) were synthesized, functionalized with poly(ethylenimine) (PEI), and characterized using TEM (transmission electron microscopy), X-ray diffraction (XRD), FTIR (Fourier transform infrared spectroscopy), CCS (confocal correlation spectroscopy), SICS (scattering interference correlation spectroscopy), magnetism studies, and thermogravimetric analysis (TGA). The removal of total organic carbon (TOC) and other contaminants using PEI-coated magnetic nanoparticles (PEI-NPs) was tested in wastewater obtained from the Hammarby Sjöstadsverk sewage plant, Sweden. The synthesized NPs were about 12 nm in diameter and showed a homogeneous particle size distribution in dispersion by TEM and CCS analyses, respectively. The magnetization curve reveals superparamagnetic behavior, and the NPs do not reach saturation because of surface anisotropy effects. A 50% reduction in TOC was obtained in 60 min when using 20 mg/L PEI-NPs in 0.5 L of wastewater. Along with TOC, other contaminants such as turbidity (89%), color (86%), total nitrogen (24%), and microbial content (90%) were also removed without significant changes in the mineral ion composition of wastewater. We conclude that the application of PEI-NPs has the potential to reduce the processing time, complexity, sludge production, and use of additional chemicals in the WWTP.

  3. Upgrading coagulation with hollow-fibre nanofiltration for improved organic matter removal during surface water treatment.

    PubMed

    Köhler, Stephan J; Lavonen, Elin; Keucken, Alexander; Schmitt-Kopplin, Philippe; Spanjer, Tom; Persson, Kenneth

    2016-02-01

    Rising organic matter concentrations in surface waters in many Nordic countries require current drinking water treatment processes to be adapted. Accordingly, the use of a novel nanofiltration (NF) membrane was studied during a nine month period in pilot scale at a large drinking water treatment plant in Stockholm, Sweden. A chemically resistant hollow-fibre NF membrane was fed with full scale process water from a rapid sand filter after aluminum sulfate coagulation. The combined coagulation and NF process removed more than 90% of the incoming lake water dissolved organic carbon (DOC) (8.7 mg C L(-1)), and 96% of the absorbance at 254 nm (A254) (0.28 cm(-1) incoming absorbance). Including granulated active carbon GAC) filter, the complete pilot plant treatment process we observed decreases in DOC concentration (8.7-0.5 mg C L(-1)), SUVA (3.1-1.7 mg(-1) L m(-1)), and the average nominal molecular mass (670-440 Da). Meanwhile, water hardness was practically unaffected (<20% reduction). Humic substances (HS) and biopolymers were almost completely eliminated (6510-140 and 260 to 10 μg C L(-1) respectively) and low molecular weight (LMW) neutrals decreased substantially (880-190 μg C L(-1)). Differential excitation emission matrices (EEMs), which illustrate the removal of fluorescing organic matter (FDOM) over a range of excitation and emission wavelengths, demonstrate that coagulation removed 35 ± 2% of protein-like material and 65 ± 2% of longer emission wavelength, humic-like FDOM. The subsequent NF treatment was somewhat less selective but still preferentially targeted humic-like FDOM (83 ± 1%) to a larger extent than protein-like material (66 ± 3%). The high selectivity of organic matter during coagulation compared to NF separation was confirmed from analyses with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), and liquid chromatography with organic carbon detection (LC-OCD), as coagulation exclusively

  4. Upgrading coagulation with hollow-fibre nanofiltration for improved organic matter removal during surface water treatment.

    PubMed

    Köhler, Stephan J; Lavonen, Elin; Keucken, Alexander; Schmitt-Kopplin, Philippe; Spanjer, Tom; Persson, Kenneth

    2016-02-01

    Rising organic matter concentrations in surface waters in many Nordic countries require current drinking water treatment processes to be adapted. Accordingly, the use of a novel nanofiltration (NF) membrane was studied during a nine month period in pilot scale at a large drinking water treatment plant in Stockholm, Sweden. A chemically resistant hollow-fibre NF membrane was fed with full scale process water from a rapid sand filter after aluminum sulfate coagulation. The combined coagulation and NF process removed more than 90% of the incoming lake water dissolved organic carbon (DOC) (8.7 mg C L(-1)), and 96% of the absorbance at 254 nm (A254) (0.28 cm(-1) incoming absorbance). Including granulated active carbon GAC) filter, the complete pilot plant treatment process we observed decreases in DOC concentration (8.7-0.5 mg C L(-1)), SUVA (3.1-1.7 mg(-1) L m(-1)), and the average nominal molecular mass (670-440 Da). Meanwhile, water hardness was practically unaffected (<20% reduction). Humic substances (HS) and biopolymers were almost completely eliminated (6510-140 and 260 to 10 μg C L(-1) respectively) and low molecular weight (LMW) neutrals decreased substantially (880-190 μg C L(-1)). Differential excitation emission matrices (EEMs), which illustrate the removal of fluorescing organic matter (FDOM) over a range of excitation and emission wavelengths, demonstrate that coagulation removed 35 ± 2% of protein-like material and 65 ± 2% of longer emission wavelength, humic-like FDOM. The subsequent NF treatment was somewhat less selective but still preferentially targeted humic-like FDOM (83 ± 1%) to a larger extent than protein-like material (66 ± 3%). The high selectivity of organic matter during coagulation compared to NF separation was confirmed from analyses with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), and liquid chromatography with organic carbon detection (LC-OCD), as coagulation exclusively

  5. Impact of exogenous organic carbon on the removal of chemicals of concern in the high rate nitrifying trickling filters.

    PubMed

    Mai, Lei; van den Akker, Ben; Du, Jun; Kookana, Rai S; Fallowfield, Howard

    2016-06-01

    The application of fixed bed high rate nitrifying trickling filters (NTFs) for the removal of track organic chemicals of concern (CoC) is less well known than their application to nutrient removal in water treatment. Particularly, the effect of exogenous organic carbon substrate (sucrose) loading on the performance of NTFs is not well understood. A laboratory-scale NTF system was operated in recirculation mode, with the objective of removing ammonia and CoC simultaneously. The efficiency of a high rate NTF for removal both of low concentration of ammonia (5 mg NH4-N L(-1)) and different concentrations of CoC in the presence of an exogenous organic carbon substrate (30 mg total organic carbon (TOC) L(-1)) was investigated. In the presence of exogenous organic carbon, the results demonstrated that the high rate NTF was able to successfully remove most of the CoCs investigated, with the removal ranging from 20.2% to 87.54%. High removal efficiencies were observed for acetaminophen (87.54%), bisphenol A (86.60%), trimethoprim (86.24%) and 17α-ethynylestradiol (80.60%). It was followed by the medium removal efficiency for N, N-diethyl-m-toluamide (61.31%) and atrazine (56.90%). In contrast, the removal of caffeine (28.43%) and benzotriazole (20.20%) was poorer in the presence of exogenous organic carbon. The removal efficiency for CoC was also compared with the results obtained in our previous study in the absence of exogenous organic carbon. The results showed that the addition of exogenous organic carbon was able to improve the removal of some of the CoC. Significant TOC percentage removals (45.68%-84.43%) and ammonia removal rate (mean value of 0.44 mg NH4-N L(-1) h(-1)) were also achieved in this study. The findings from this study provide valuable information for optimising the efficiency of high rate NTF for the removal of ammonia, CoC and TOC.

  6. Impact of exogenous organic carbon on the removal of chemicals of concern in the high rate nitrifying trickling filters.

    PubMed

    Mai, Lei; van den Akker, Ben; Du, Jun; Kookana, Rai S; Fallowfield, Howard

    2016-06-01

    The application of fixed bed high rate nitrifying trickling filters (NTFs) for the removal of track organic chemicals of concern (CoC) is less well known than their application to nutrient removal in water treatment. Particularly, the effect of exogenous organic carbon substrate (sucrose) loading on the performance of NTFs is not well understood. A laboratory-scale NTF system was operated in recirculation mode, with the objective of removing ammonia and CoC simultaneously. The efficiency of a high rate NTF for removal both of low concentration of ammonia (5 mg NH4-N L(-1)) and different concentrations of CoC in the presence of an exogenous organic carbon substrate (30 mg total organic carbon (TOC) L(-1)) was investigated. In the presence of exogenous organic carbon, the results demonstrated that the high rate NTF was able to successfully remove most of the CoCs investigated, with the removal ranging from 20.2% to 87.54%. High removal efficiencies were observed for acetaminophen (87.54%), bisphenol A (86.60%), trimethoprim (86.24%) and 17α-ethynylestradiol (80.60%). It was followed by the medium removal efficiency for N, N-diethyl-m-toluamide (61.31%) and atrazine (56.90%). In contrast, the removal of caffeine (28.43%) and benzotriazole (20.20%) was poorer in the presence of exogenous organic carbon. The removal efficiency for CoC was also compared with the results obtained in our previous study in the absence of exogenous organic carbon. The results showed that the addition of exogenous organic carbon was able to improve the removal of some of the CoC. Significant TOC percentage removals (45.68%-84.43%) and ammonia removal rate (mean value of 0.44 mg NH4-N L(-1) h(-1)) were also achieved in this study. The findings from this study provide valuable information for optimising the efficiency of high rate NTF for the removal of ammonia, CoC and TOC. PMID:26989940

  7. An evaluation of alternative cleaning methods for removing an organic contaminant from a stainless steel part

    SciTech Connect

    Boyd, J.L.

    1996-08-01

    As of December 1995, the manufacture of Freon, along with many other chlorofluorocarbons (CFCs), was prohibited by the Clean Air Act of 1990 (CAA). The ban of CFC solvents has forced manufacturers across the country to search for alternative metal cleaning techniques. The objective of this study was to develop a thorough, scientific based approach for resolving one specific manufacturer`s problem of removing organic contamination from a stainless steel part. This objective was accomplished with an approach that involved: (1) defining the problem, (2) identifying the process constraints, (3) researching alternate cleaning methods, (4) researching applicable government regulations, (5) performing a scientific evaluation and (6) drawing conclusions.

  8. Acrylation of pre-irradiated polypropylene and its application for removal of organic pollutants

    NASA Astrophysics Data System (ADS)

    Said, Hossam M.; Sokker, Hesham H.; El-Hag Ali, Amr

    2010-04-01

    Reactive extrusion of pre-irradiated polypropylene (PP) at different doses of gamma radiation was studied in the presence of different concentrations of acrylic acid monomer (AAc). Preliminary investigations study the feasibility or removal of organic pollutants. The optical properties and surface morphology of the grafted polypropylene were observed by FT-IR, UV/vis and scanning electron microscopy (SEM). The affinity of this membrane to the basic dye was found to be increased with increase in the dose of gamma irradiation and the ratio of acrylic acid monomer (AAc).

  9. Effect of spray aeration on organics and nitrogen removal in vertical subsurface flow constructed wetland.

    PubMed

    Ding, Yi; Wang, Wei; Song, Xin-Shan; Wang, Gang; Wang, Yu-Hui

    2014-12-01

    The objective of present study was to assess the simultaneous removal of organics and nitrogen by four lab-scale vertical subsurface flow constructed wetlands (V-SFCWs). The emergent plants employed were Canna indica. Five-month experiments showed that the planted and aerated system largely reduced the COD by 95%, NH4 by 88% and total inorganic nitrogen (TIN) by 83%. It outperformed the unplanted or simple aerated system and was much better than non-aerated system. The study provided a strong evidence to support widespread research and application of spray aeration as a low-cost and energy-efficient aeration technology in V-SFCWs. PMID:25259785

  10. Effect of spray aeration on organics and nitrogen removal in vertical subsurface flow constructed wetland.

    PubMed

    Ding, Yi; Wang, Wei; Song, Xin-Shan; Wang, Gang; Wang, Yu-Hui

    2014-12-01

    The objective of present study was to assess the simultaneous removal of organics and nitrogen by four lab-scale vertical subsurface flow constructed wetlands (V-SFCWs). The emergent plants employed were Canna indica. Five-month experiments showed that the planted and aerated system largely reduced the COD by 95%, NH4 by 88% and total inorganic nitrogen (TIN) by 83%. It outperformed the unplanted or simple aerated system and was much better than non-aerated system. The study provided a strong evidence to support widespread research and application of spray aeration as a low-cost and energy-efficient aeration technology in V-SFCWs.

  11. Rethinking the global secondary organic aerosol (SOA) budget: stronger production, faster removal, shorter lifetime

    NASA Astrophysics Data System (ADS)

    Hodzic, Alma; Kasibhatla, Prasad S.; Jo, Duseong S.; Cappa, Christopher D.; Jimenez, Jose L.; Madronich, Sasha; Park, Rokjin J.

    2016-06-01

    Recent laboratory studies suggest that secondary organic aerosol (SOA) formation rates are higher than assumed in current models. There is also evidence that SOA removal by dry and wet deposition occurs more efficiently than some current models suggest and that photolysis and heterogeneous oxidation may be important (but currently ignored) SOA sinks. Here, we have updated the global GEOS-Chem model to include this new information on formation (i.e., wall-corrected yields and emissions of semi-volatile and intermediate volatility organic compounds) and on removal processes (photolysis and heterogeneous oxidation). We compare simulated SOA from various model configurations against ground, aircraft and satellite measurements to assess the extent to which these improved representations of SOA formation and removal processes are consistent with observed characteristics of the SOA distribution. The updated model presents a more dynamic picture of the life cycle of atmospheric SOA, with production rates 3.9 times higher and sinks a factor of 3.6 more efficient than in the base model. In particular, the updated model predicts larger SOA concentrations in the boundary layer and lower concentrations in the upper troposphere, leading to better agreement with surface and aircraft measurements of organic aerosol compared to the base model. Our analysis thus suggests that the long-standing discrepancy in model predictions of the vertical SOA distribution can now be resolved, at least in part, by a stronger source and stronger sinks leading to a shorter lifetime. The predicted global SOA burden in the updated model is 0.88 Tg and the corresponding direct radiative effect at top of the atmosphere is -0.33 W m-2, which is comparable to recent model estimates constrained by observations. The updated model predicts a population-weighed global mean surface SOA concentration that is a factor of 2 higher than in the base model, suggesting the need for a reanalysis of the contribution of

  12. The improvement of removal effects on organic pollutants in Wastewater Treatment Plants (WWTP)

    NASA Astrophysics Data System (ADS)

    Marincas, O.; Petrov, P.; Ternes, T.; Avram, V.; Moldovan, Z.

    2009-08-01

    Purpose of this study is to improve the efficiency of removal in wastewater treatment plants of some organic pollutants like pharmaceuticals, antioxidants, pesticides (triazines, phenylurea herbicides), personal care products (PCPs) musk fragrances (galaxolide and tonalide) and estrogens using zeolites with excellent absorption capacity. The zeolite selected for all experiments was Szedimentin-MW. The experiment took place in three stages: no zeolite addition, zeolite added at the end of the bioreactor and zeolite added at the start of the bioreactor. The water samples were pre-concentrated with solid phase extraction (SPE) procedure and analyzed with analytical system Gas Chromatography/Mass Spectrometry (GC/MS).

  13. Biotreatment of produced water for removal of sulfides, organics, and toxicity

    SciTech Connect

    Rajganesh, B.; Selvaraj, P.T.; Manning, F.S.

    1995-12-31

    Water coproduced with petroleum may contain sulfides and organic constituents that give the water an aquatic toxicity preventing surface discharge. A simulated sour produced water and actual field samples of produced water were successfully biotreated with mixed cultures of Thiobacillus denitrificans and floc-forming heterotrophs. Complete removal of benzene, toluene, phenol, acetic acid, sulfides, and Microtox toxicity was achieved. These results indicate that a reactor system as simple in concept as a specialized activated sludge system can be used to treat produced water with these mixed contaminants, allowing surface discharge of the water for reuse.

  14. Modeling the removal of dissolved organic carbon by ion exchange in a completely mixed flow reactor.

    PubMed

    Boyer, Treavor H; Miller, Cass T; Singer, Philip C

    2008-04-01

    A mathematical model was developed to describe removal of dissolved organic carbon (DOC) by a macroporous, strong-base anion exchange resin in a completely mixed flow reactor with resin recycle and partial resin regeneration. The two-scale model consisted of a microscale model describing the uptake of DOC by the resin coupled with a macroscale model describing the continuous-flow process. Equilibrium and kinetic parameters were estimated from batch laboratory experiments. The model was validated using continuous-flow data from two pilot plant studies. Model predictions were found to be in good agreement with the observed pilot plant data.

  15. Metal-Organic Frameworks for Removal of Xe and Kr from Nuclear Fuel Reprocessing Plants

    SciTech Connect

    Liu, Jian; Thallapally, Praveen K.; Strachan, Denis M.

    2012-08-07

    Removal of Xenon (Xe) and Krypton (Kr) from in parts per million (ppm) levels were demonstrated for the first time using two well known metal-organic frameworks (MOFs), HKUST-1 and Ni/DOBDC. Results of an activated carbon were also included for comparison. Ni/DOBDC has higher Xe/Kr selectivities than those of the activated carbon. Moreover, results show that the Ni/DOBDC and HKUST-1 can selectively adsorb Xe and Kr from air even at 1000 ppm concentration. This shows a promising future for MOFs in a radioactive nuclides separation from spent fuel.

  16. Iodine deficiency and thyroid disorders.

    PubMed

    Zimmermann, Michael B; Boelaert, Kristien

    2015-04-01

    Iodine deficiency early in life impairs cognition and growth, but iodine status is also a key determinant of thyroid disorders in adults. Severe iodine deficiency causes goitre and hypothyroidism because, despite an increase in thyroid activity to maximise iodine uptake and recycling in this setting, iodine concentrations are still too low to enable production of thyroid hormone. In mild-to-moderate iodine deficiency, increased thyroid activity can compensate for low iodine intake and maintain euthyroidism in most individuals, but at a price: chronic thyroid stimulation results in an increase in the prevalence of toxic nodular goitre and hyperthyroidism in populations. This high prevalence of nodular autonomy usually results in a further increase in the prevalence of hyperthyroidism if iodine intake is subsequently increased by salt iodisation. However, this increase is transient because iodine sufficiency normalises thyroid activity which, in the long term, reduces nodular autonomy. Increased iodine intake in an iodine-deficient population is associated with a small increase in the prevalence of subclinical hypothyroidism and thyroid autoimmunity; whether these increases are also transient is unclear. Variations in population iodine intake do not affect risk for Graves' disease or thyroid cancer, but correction of iodine deficiency might shift thyroid cancer subtypes toward less malignant forms. Thus, optimisation of population iodine intake is an important component of preventive health care to reduce the prevalence of thyroid disorders.

  17. Iodine deficiency: Physiological, clinical and epidemiological features, and pre-analytical considerations.

    PubMed

    Doggui, Radhouene; El Atia, Jalila

    2015-02-01

    Low dietary intake is associated with severe pathologies (especially goiter and cretinism) that affect life quality. Iodine deficiency disorders are a major public health problem worldwide. In fact, 246 million school-aged children have insufficient iodine intake (data from 2012). Extrapoling this value to general population leads to the estimation that 1.9 billion people have insufficient iodine intake. So, it is crucial to interpret correctly data from iodine status survey. The World Health Organization recommends urinary iodine as the main indicator for the assessment of iodine status in epidemiological surveys. To improve the result, some considerations can be taken into account by the biologist, epidemiologist or public health physician for the realization of epidemiological surveys. After a reminder about the physiological and physiopathological feature of iodine, a description of some useful parameters was made to improve the exploration of iodine status in epidemiological surveys.

  18. SITE EMERGING TECHNOLOGY SUMMARY. BIOSCRUBBER FOR REMOVING HAZARDOUS ORGANIC EMISSIONS FROM SOIL, WATER, AND AIR DECONTAMINATION PROCESSES

    EPA Science Inventory

    An advanced biofiltration system has been developed for the removal of trace organic contaminants in air. This bioscrubber uses activated carbon as a support for biogrowth. An advanced engineering design was incorporated into the bioscrubber to allow biomass removal and nutrient ...

  19. EPA/NSF ETV Equipment Verification Testing Plan for the Removal of Volatile Organic Chemical Contaminants by Adsorptive Media Processes

    EPA Science Inventory

    This document is the Environmental Technology Verification (ETV) Technology Specific Test Plan (TSTP) for evaluation of drinking water treatment equipment utilizing adsorptive media for synthetic organic chemical (SOC) removal. This TSTP is to be used within the structure provid...

  20. Characteristics of arsenate removal from water by metal-organic frameworks (MOFs).

    PubMed

    Li, Jie; Wu, Yi-nan; Li, Zehua; Zhu, Miao; Li, Fengting

    2014-01-01

    Contamination of arsenic in groundwater and surface water occurs frequently across the globe, requiring an effective purification technology. Among the common technologies, the adsorption method is widely used for the merits of low cost and easy operation. Nevertheless, the development of efficient adsorbents remains one of the central challenges in this field. In this article, one kind of typical porous metal-organic framework material (MIL-53(Al)) was explored for the removal of arsenate from water. MIL-53(Al) has a maximum removal capacity of 105.6 mg/g and a conditional capacity of 15.4 mg/g at a low equilibrium concentration (10 μg/L). The optimum initial pH value is 8.0. Except for PO4(3-), other coexisting anions do not show a notable influence on the adsorption capacity of MIL-53(Al). In general, MIL-53(Al) is a promising new material for arsenate removal from water. Investigation of the effects of electrical charges, Fourier transform infrared spectroscopy spectra, and X-ray photoelectron spectroscopy (XPS) spectra revealed that electrostatic attraction and hydrogen bond might be involved in the adsorption process of arsenate onto MIL-53(Al).

  1. One-pot hydrothermal preparation of graphene sponge for the removal of oils and organic solvents

    NASA Astrophysics Data System (ADS)

    Wu, Ruihan; Yu, Baowei; Liu, Xiaoyang; Li, Hongliang; Wang, Weixuan; Chen, Lingyun; Bai, Yitong; Ming, Zhu; Yang, Sheng-Tao

    2016-01-01

    Graphene sponge (GS) has found applications in oil removal due to the hydrophobic nature of graphene sheets. Current hydrothermal preparations of GS use toxic reducing reagents, which might cause environmental pollution. In this study, we reported that graphene oxide (GO) could be hydrothermally reduced by glucose to form GS for the adsorption of oils and various organic solvents. Graphene sheets were reduced by glucose during the hydrothermal treatment and formed 3D porous structure. GS efficiently adsorbed organic solvents and oils with competitive adsorption capacities. GS was able to treat pollutants in pure liquid form and also in the simulated seawater. GS could be easily regenerated by evaporating or burning. After 10 cycles, the adsorption capacity still retained 77% by evaporating and 87% by burning. The implication to the applications of GS in water remediation is discussed.

  2. Removal of volatile organic compounds using amphiphilic cyclodextrin-coated polypropylene.

    PubMed

    Lumholdt, Ludmilla; Fourmentin, Sophie; Nielsen, Thorbjørn T; Larsen, Kim L

    2014-01-01

    Polypropylene nonwovens were functionalised using a self-assembled, amphiphilic cyclodextrin coating and the potential for water purification by removal of pollutants was studied. As benzene is one of the problematic compounds in the Water Framework Directive, six volatile organic compounds (benzene and five benzene-based substances) were chosen as model compounds. The compounds were tested as a mixture in order to provide a more realistic situation since the wastewater will be a complex mixture containing multiple pollutants. The volatile organic compounds are known to form stable inclusion complexes with cyclodextrins. Six different amphiphilic cyclodextrin derivatives were synthesised in order to elucidate whether or not the uptake abilities of the coating depend on the structure of the derivative. Headspace gas chromatography was used for quantification of the uptake exploiting the volatile nature of benzene and its derivatives. The capacity was shown to increase beyond the expected stoichiometries of guest-host complexes with ratios of up to 16:1. PMID:25550739

  3. Removal of volatile organic compounds using amphiphilic cyclodextrin-coated polypropylene.

    PubMed

    Lumholdt, Ludmilla; Fourmentin, Sophie; Nielsen, Thorbjørn T; Larsen, Kim L

    2014-01-01

    Polypropylene nonwovens were functionalised using a self-assembled, amphiphilic cyclodextrin coating and the potential for water purification by removal of pollutants was studied. As benzene is one of the problematic compounds in the Water Framework Directive, six volatile organic compounds (benzene and five benzene-based substances) were chosen as model compounds. The compounds were tested as a mixture in order to provide a more realistic situation since the wastewater will be a complex mixture containing multiple pollutants. The volatile organic compounds are known to form stable inclusion complexes with cyclodextrins. Six different amphiphilic cyclodextrin derivatives were synthesised in order to elucidate whether or not the uptake abilities of the coating depend on the structure of the derivative. Headspace gas chromatography was used for quantification of the uptake exploiting the volatile nature of benzene and its derivatives. The capacity was shown to increase beyond the expected stoichiometries of guest-host complexes with ratios of up to 16:1.

  4. Removal of VUV pre-treated natural organic matter by biologically activated carbon columns.

    PubMed

    Buchanan, W; Roddick, F; Porter, N

    2008-07-01

    A potential alternative water treatment process using VUV (185 nm+254 nm) irradiation followed by a biological treatment is described. The system uses sufficient VUV radiation (16J cm(-2)) to significantly enhance the production of biologically degradable moieties prior to treatment with biologically activated carbon (BAC). Two similar activated carbons were used, one virgin and one taken from a water treatment plant with an established biofilm. The VUV-BAC process decreased the overall dissolved organic carbon (DOC) concentration of a natural water sample by 54% and 44% for the virgin carbon and previously used BAC, respectively. Furthermore, VUV-BAC treatment decreased the trihalomethane (THM) formation potential (THMFP) by 60-70% and the haloacetic acid (HAA) formation potential (HAAFP) by 74%. The BAC systems effectively removed the hydrogen peroxide residual produced by VUV irradiation. Although nitrite formation can result from VUV treatment of natural organic matter (NOM), none was detected before or after BAC treatment.

  5. Iodine supplementation in the newborn.

    PubMed

    Ghirri, Paolo; Lunardi, Sara; Boldrini, Antonio

    2014-01-01

    Iodine deficiency can be defined as the world's greatest single cause of preventable brain damage. Fetal and neonatal hypothyroidism, caused by iodine deficiency can be prevented prior to conception and then during pregnancy and lactation when an adequate iodine supplementation is ensured. Extremely low birth weight preterm babies risk having a negative iodine balance status in the first weeks of life, exacerbating the hypothyroxinaemia of the prematurity. It is important to ensure that these babies are provided with an adequate iodine intake from the first days of life. Mothers and newborns should avoid environmental iodine excess during pregnancy or lactation.

  6. [Effects of understory removal on soil labile organic carbon pool in a Cinnamomum camphora plantation].

    PubMed

    Wu, Ya-Cong; Li, Zheng-Cai; Cheng, Cai-Fang; Liu, Rong-Jie; Wang, Bin; Geri, Le-Tu

    2013-12-01

    Taking a 48-year-old Cinnamomum camphora plantation in the eastern area of our subtropics as test object, this paper studied the labile organic carbon contents and their ratios to the total organic carbon (TOC) in 0-60 cm soil layer under effects of understory removal (UR). As compared with no understory removal (CK), the soil TOC and easily-oxidized carbon (EOC) contents under UR decreased, with a decrement of 4.8% - 34.1% and 27.1% - 36.2%, respectively, and the TOC and EOC contents had a significant difference in 0-10 cm and 0-20 cm layers, respectively. The water-soluble organic carbon (WSOC) (except in 0-10 cm and 10-20 cm layers) and light fraction organic matter (LFOM) under UR increaesd, but the difference was not significant. The ratio of soil WSOC to soil TOC in UR stand was higher than that in CK stand, while the ratio of soil EOC to soil TOC showed an opposite trend. In the two stands, soil WSOC, EOC, and LFOM had significant or extremely significant correlations with soil TOC, and the correlation coefficients of soil EOC and LFOM with soil TOC were higher in UR stand than in CK, but the correlation coefficient between soil WSOC and TOC was in opposite. The soil EOC, LFOM, and TOC in the two stands were significantly or extremely significantly correlated with soil nutrients, but the soil WSOC in UR stand had no significant correlations with soil hydrolyzable N, available P, exchangeable Ca, and exchangeable Mg.

  7. Colour and organic removal of biologically treated coffee curing wastewater by electrochemical oxidation method.

    PubMed

    Bejankiwar, Rajesh S; Lokesh, K S; Gowda, T P Halappa

    2003-05-01

    The treatment of biologically treated wastewater of coffee-curing industry by the electrochemical oxidation using steel anode was investigated. Bench-scale experiments were conducted for activated sludge process on raw wastewater and the treated effluents were further treated by electrochemical oxidation method for its colour and organic content removal. The efficiency of the process was determined in terms of removal percentage of COD, BOD and colour during the course of reaction. Several operating parameters like time, pH and current density were examined to ascertain their effects on the treatment efficiency. Steel anode was found to be effective for the COD and colour removal with anode efficiency of 0.118 kgCOD x h(-1) x A(-1) x m(-2) and energy consumption 20.61 kWh x kg(-1) of COD at pH 9. The decrease in pH from 9 to 3 found to increase the anode efficiency from 0.118 kgCOD x h(-1) x A(-1) x m(-2) to 0.144 kWh x kg(-1) of COD while decrease the energy consumption from 20.61 kWh x kg(-1) of COD to 12.86 kWh x kg(-1) of COD. The pH of 5 was considered an ideal from the present treatment process as it avoids the addition of chemicals for neutralization of treated effluents and also economical with respect to energy consumption. An empirical relation developed for relationship between applied current density and COD removal efficiency showed strong predictive capability with coefficient of determination of 96.5%.

  8. Removal of natural organic matter from drinking water by advanced oxidation processes.

    PubMed

    Matilainen, Anu; Sillanpää, Mika

    2010-06-01

    Over the past 10-20years the amount of the natural organic matter (NOM) has been increased in raw water supplies on several areas. The presence of NOM causes many problems in drinking water treatment processes, including: (i) negative effect on water quality by colour, taste and odor problems, (ii) increased coagulant and disinfectant dose requirements (which in turn results increased sludge and potential harmful disinfection by-product formation), (iii) promoted biological growth in distribution system, and (iv) increased levels of complexed heavy metals and adsorbed organic pollutants. Thus, more efficient methods for the removal of NOM have emerged. Among these are advanced oxidation processes (AOPs). These include O(3)/H(2)O(2), O(3)/UV, UV/H(2)O(2), TiO(2)/UV, H(2)O(2)/catalyst, Fenton and photo-Fenton prosesses as well as ultrasound. In the present work, an overview of the recent research studies dealing with AOP methods for the removal of NOM and related compounds from drinking water is presented.

  9. Calcium effect on the metabolic pathway of phosphorus accumulating organisms in enhanced biological phosphorus removal systems.

    PubMed

    Zhang, Hai-Ling; Sheng, Guo-Ping; Fang, Wei; Wang, Yong-Peng; Fang, Cai-Yun; Shao, Li-Min; Yu, Han-Qing

    2015-11-01

    Phosphorus accumulating organisms (PAOs) have been found to act as glycogen-accumulating organisms (GAOs) under certain conditions, thus, the deterioration in the performance of enhanced biological phosphorus removal systems is not always attributed to the proliferation of GAOs. In this work, the effects of calcium on the metabolic pathway of PAOs were explored. It was found that when the influent Ca(2+) concentration was elevated, the tendency and extent of extracellular calcium phosphate precipitation increased, and the intracellular inert Ca-bound polyphosphate was synthesized, while the microbial population remained almost unchanged. The changes in the ratios of phosphorus released/acetate uptaken, the glycogen degraded/acetate uptaken and the poly-β-hydroxyalkanoates synthesized/acetate uptaken during the anaerobic period confirm that, as the influent Ca(2+) concentration was increased, the polyphosphate-accumulating metabolism was partially shifted to the glycogen-accumulating metabolism. At an influent Ca(2+) around 50 mg/L, in addition to the extracellular calcium phosphate precipitation, the intracellular inert Ca-bound polyphosphate synthesis might also be involved in the metabolic change of PAOs. The results of the present work would be beneficial to better understand the biochemical metabolism of PAOs in enhanced biological phosphorus removal systems. PMID:26233656

  10. Removal of endotoxins from bacteriophage preparations by extraction with organic solvents.

    PubMed

    Szermer-Olearnik, Bożena; Boratyński, Janusz

    2015-01-01

    Lipopolysaccharide (LPS, endotoxin, pyrogen) constitutes a very troubling contaminant of crude phage lysates produced in Gram-negative bacteria. Toxicity of LPS depends on the strong innate immunity response including the cytokines. Therefore, its removal is important for bacteriophage applications. In this paper, we present a procedure for extractive removal of endotoxin from bacteriophage preparations with water immiscible solvents (1-octanol or 1-butanol). During extraction most of the phage lytic activity is retained in the aqueous phase, while endotoxin accumulates in the organic solvent. The levels of endotoxin (expressed as endotoxin units, EU) in the aqueous bacteriophage-containing fraction determined by limulus amebocyte lysate or EndoLISA assay were exceptionally low. While the initial endotoxin levels in the crude phage lysates ranged between 10(3) and 10(5) EU/ml the average level after organic extraction remaining in the aqueous fraction was 5.3 EU/ml. These values when related to phage titers decreased from 10(3)-10(5) EU/10(9) PFU (plaque forming units) down to an average of 2.8 EU/10(9) PFU. The purification procedure is scalable, efficient and applicable to all the bacteriophages tested: T4, HAP1 (E. coli) and F8 (P. aeruginosa).

  11. Determination of dissolved organic matter removal efficiency in wastewater treatment works using fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Carstea, Elfrida M.; Bridgeman, John

    2015-04-01

    Fluorescence spectroscopy was used to investigate the removal efficiency of dissolved organic matter (DOM) in several wastewater treatment works, at different processing stages. The correlation between fluorescence values and biochemical oxygen demand (BOD), chemical oxygen demand (COD) and total organic carbon (TOC) has been examined. Fluorescence was measured for unfiltered and filtered (0.45 and 0.20 μm) samples of crude, settled and secondary treated wastewater (activated sludge), and final effluent. Moreover, the potential of using portable fluorimeters has been explored in a laboratory scale activated sludge process. Good correlations were observed for filtered and unfiltered wastewater samples between protein-like fluorescence intensity (excitation 280 nm, emission 350 nm) and BOD (r = 0.78), COD (r = 0.90) and TOC (r = 0.79). BOD displayed a higher correlation at the 0.20 μm filtered samples compared to COD and TOC. Slightly better relation was seen between fluorescence and conventional parameters at the portable fluorimeters compared to laboratory-based instruments. The results indicated that fluorescence spectroscopy, in particular protein-like fluorescence, could be used for continuous, real-time assessment of DOM removal efficiency in wastewater treatment works.

  12. Kinetics of organic removal in fixed-bed aerobic biological reactor.

    PubMed

    Borghei, S M; Sharbatmaleki, M; Pourrezaie, P; Borghei, G

    2008-03-01

    The process kinetics of a lab-scale upflow aerobic immobilized biomass (UAIB) reactor using simulated sugar-manufacturing wastewater as feed was investigated. The experimental unit consisted of a 22l reactor filled with high porosity pumice stone. The UAIB reactor was tested under different organic loads and different hydraulic retention times (HRT) and the substrate loading removal rate was compared with prediction of Stover-Kincannon model, second-order model and the first order substrate removal model. After obtaining steady-state conditions, organic loading rate was increased from 750 to 4500 g COD/m(3) day to resemble wastewater from sugar production lines, and hydraulic retention time was decreased from 1 to 0.5 days, stepwise. Nine different operational conditions were applied changing these two parameters in a certain program. As a result of the calculations, Stover-Kincannon model and second-order model known as "Grau" model were found to be the most appropriate models for this reactor. Stover-Kincannon model and Grau second-order model gave high correlation coefficients, which were 99.7% and 99.4%, respectively. Therefore, these models could be used in predicting the behavior or design of the UAIB reactors.

  13. Calcium effect on the metabolic pathway of phosphorus accumulating organisms in enhanced biological phosphorus removal systems.

    PubMed

    Zhang, Hai-Ling; Sheng, Guo-Ping; Fang, Wei; Wang, Yong-Peng; Fang, Cai-Yun; Shao, Li-Min; Yu, Han-Qing

    2015-11-01

    Phosphorus accumulating organisms (PAOs) have been found to act as glycogen-accumulating organisms (GAOs) under certain conditions, thus, the deterioration in the performance of enhanced biological phosphorus removal systems is not always attributed to the proliferation of GAOs. In this work, the effects of calcium on the metabolic pathway of PAOs were explored. It was found that when the influent Ca(2+) concentration was elevated, the tendency and extent of extracellular calcium phosphate precipitation increased, and the intracellular inert Ca-bound polyphosphate was synthesized, while the microbial population remained almost unchanged. The changes in the ratios of phosphorus released/acetate uptaken, the glycogen degraded/acetate uptaken and the poly-β-hydroxyalkanoates synthesized/acetate uptaken during the anaerobic period confirm that, as the influent Ca(2+) concentration was increased, the polyphosphate-accumulating metabolism was partially shifted to the glycogen-accumulating metabolism. At an influent Ca(2+) around 50 mg/L, in addition to the extracellular calcium phosphate precipitation, the intracellular inert Ca-bound polyphosphate synthesis might also be involved in the metabolic change of PAOs. The results of the present work would be beneficial to better understand the biochemical metabolism of PAOs in enhanced biological phosphorus removal systems.

  14. Static electricity of polymers reduced by treatment with iodine

    NASA Technical Reports Server (NTRS)

    Hermann, A. M.; Landel, R. F.; Rembaum, A.

    1967-01-01

    Treating organic polymers with iodine improves the electrical conductivity. Diffusion enables products of desired properties to be custom formulated. This eliminates a buildup of static electricity and the need for fillers or bound metal salts.

  15. Successful treatment of Graves disease in pregnancy with Lugol's iodine.

    PubMed

    Jamieson, A; Semple, C G

    2000-02-01

    We report a case of Grave's disease in pregnancy complicated by intolerance of standard antithyroid drug therapy. We describe the success of prolonged use of organic iodine as a primary treatment prior to surgical intervention. PMID:10765530

  16. Iodine-Induced hypothyroidism.

    PubMed

    Markou, K; Georgopoulos, N; Kyriazopoulou, V; Vagenakis, A G

    2001-05-01

    Iodine is an essential element for thyroid hormone synthesis. The thyroid gland has the capacity and holds the machinery to handle the iodine efficiently when the availability of iodine becomes scarce, as well as when iodine is available in excessive quantities. The latter situation is handled by the thyroid by acutely inhibiting the organification of iodine, the so-called acute Wolff-Chaikoff effect, by a mechanism not well understood 52 years after the original description. It is proposed that iodopeptide(s) are formed that temporarily inhibit thyroid peroxidase (TPO) mRNA and protein synthesis and, therefore, thyroglobulin iodinations. The Wolff-Chaikoff effect is an effective means of rejecting the large quantities of iodide and therefore preventing the thyroid from synthesizing large quantities of thyroid hormones. The acute Wolff-Chaikoff effect lasts for few a days and then, through the so-called "escape" phenomenon, the organification of intrathyroidal iodide resumes and the normal synthesis of thyroxine (T4) and triiodothyronine (T3) returns. This is achieved by decreasing the intrathyroidal inorganic iodine concentration by down regulation of the sodium iodine symporter (NIS) and therefore permits the TPO-H202 system to resume normal activity. However, in a few apparently normal individuals, in newborns and fetuses, in some patients with chronic systemic diseases, euthyroid patients with autoimmune thyroiditis, and Graves' disease patients previously treated with radioimmunoassay (RAI), surgery or antithyroid drugs, the escape from the inhibitory effect of large doses of iodides is not achieved and clinical or subclinical hypothyroidism ensues. Iodide-induced hypothyroidism has also been observed in patients with a history of postpartum thyroiditis, in euthyroid patients after a previous episode of subacute thyroiditis, and in patients treated with recombinant interferon-alpha who developed transient thyroid dysfunction during interferon-a treatment. The

  17. Effects of aeration position on organics, nitrogen and phosphorus removal in combined oxidation pond-constructed wetland systems.

    PubMed

    Wang, Xiaoou; Tian, Yimei; Zhao, Xinhua; Peng, Sen; Wu, Qing; Yan, Lijian

    2015-12-01

    Given that few studies investigated the effects of aeration position (AP) on the performance of aerated constructed wetlands, the aim of this study was to evaluate the effects of AP on organics, nitrogen and phosphorus removal in lab-scale combined oxidation pond-constructed wetland (OP-CW) systems. Results showed that middle aeration allowed the CW to possess more uniform oxygen distribution and to achieve greater removals of COD and NH3-N, while the CW under bottom aeration and surface aeration demonstrated more distinct stratification of oxygen distribution and surface aeration brought about better TN removal capacity for the OP-CW system. However, no significant influence of artificial aeration or AP on TP removal was observed. Overall, AP could significantly affect the spatial distribution of dissolved oxygen by influencing the oxygen diffusion paths in aerated CWs, thereby influencing the removal of pollutants, especially organics and nitrogen, which offers a reference for the design of aerated CWs.

  18. Removal of high organic loads from winery wastewater by aquatic plants.

    PubMed

    Zimmels, Y; Kirzhner, F; Schreiber, J

    2008-09-01

    Laboratory- and field-scale purification tests of raw and diluted winery wastewater (WWW) were carried out using aquatic plants at high organic loads. The laboratory tests were performed using artificial light at 1800 to 1900 lux. The objective of the current study was to define the potential of floating and emergent aquatic macrophytes and the microorganisms attached to their roots, to reduce high organic loads that characterize WWW, thereby providing, for these effluents, an effective treatment and management system. These microorganisms are believed to have a major role in the treatment process. In this context, the potential of floating and emergent macrophytes to improve the water quality of raw compared with diluted WWW was evaluated. In raw WWW (chemical oxygen demand [COD] 5.6 g/L),growth inhibition of both water hyacinth (Eichhornia crassipes) and water pennywort (Hydrocotyle umbellata) was observed. A 1:1 dilution of WWW with fresh (tap) water facilitated growth of these plants. At this dilution level, growth of pennywort was limited, while that of water hyacinth was robust. In terms of reductions in biochemical oxygen demand, COD, and total suspended solids, both water hyacinth and pennywort performed better in diluted compared with raw WWW. At 1:1 and 1:3 dilution, 95.9 to 97% of the COD was removed after 23 days, in the presence of Hydrocotyle and Eichhornia plants and aeration. The capacity of new emergent plants to remove high organic loads from WWW, at enhanced kinetics, was demonstrated. This unique property was tested and compared with the role of the gravel media that support growth of the high-capacity emergent plants. In the presence of reed and salt marsh plants, 83 to 99% of the COD was removed within a period of 24 to 29 days, at 1.5:1 dilution. The new emergent plants proved to be effective, even at record high levels of COD. At an initial level of 16,460 mg/L, the COD was brought down to 2870 mg/L after 24 days (82.6% removal), while 12

  19. Simultaneous removal of organic contaminants and heavy metals from kaolin using an upward electrokinetic soil remediation process.

    PubMed

    Wang, Jing-Yuan; Huang, Xiang-Jun; Kao, Jimmy C M; Stabnikova, Olena

    2007-06-01

    Kaolins contaminated with heavy metals, Cu and Pb, and organic compounds, p-xylene and phenanthrene, were treated with an upward electrokinetic soil remediation (UESR) process. The effects of current density, cathode chamber flushing fluid, treatment duration, reactor size, and the type of contaminants under the vertical non-uniform electric field of UESR on the simultaneous removal of the heavy metals and organic contaminants were studied. The removal efficiencies of p-xylene and phenanthrene were higher in the experiments with cells of smaller diameter or larger height, and with distilled water flow in the cathode chamber. The removal efficiency of Cu and Pb were higher in the experiments with smaller diameter or shorter height cells and 0.01M HNO(3) solution as cathode chamber flow. In spite of different conditions for removal of heavy metals and organics, it is possible to use the upward electrokinetic soil remediation process for their simultaneous removal. Thus, in the experiments with duration of 6 days removal efficiencies of phenanthrene, p-xylene, Cu and Pb were 67%, 93%, 62% and 35%, respectively. The experiment demonstrated the feasibility of simultaneous removal of organic contaminants and heavy metals from kaolin using the upward electrokinetic soil remediation process. PMID:17110023

  20. [Iodinated contrast media and iodine allergy: myth or reality?].

    PubMed

    Meunier, B; Joskin, J; Damas, F; Meunier, P

    2013-09-01

    The term "iodine allergy" is an old phrase that refers to a reaction to iodinated contrast media. After a brief review of definitions, pathophysiological mechanisms and risk factors of this clinical entity, management is urged immediate and delayed according to the most recent recommendations from the literature. We underline that iodine allergy, as such, does not really exist.

  1. Removal of Salmonella and indicator micro-organisms in integrated constructed wetlands treating agricultural wastewater.

    PubMed

    McCarthy, Gemma; Lawlor, Peadar G; Gutierrez, Montserrat; Gardiner, Gillian E

    2011-01-01

    The purpose of this study was to investigate the removal of pathogenic and indicator micro-organisms in integrated constructed wetland (ICW) systems treating agricultural wastewater. Nine ICW's treating piggery (3) or dairy (6) wastewaters were sampled and indicator micro-organisms were enumerated in the influent as well as the effluent from the first, mid- and final cells. The presence/absence of Salmonella was also determined and any Salmonella isolates recovered were characterized. Mean counts of coliform, E. coli and Enterococcus across all nine ICW systems were lower in the final effluent than in the effluent from cell 1 (P < 0.001). An antibiotic susceptible isolate of Salmonella Dublin, a bovine-adapted serotype, was isolated from the influent to one dairy ICW but was not detected in any of the ICW cells. An antibiotic sensitive Salmonella Dublin isolate with the same molecular fingerprint was also recovered from the cell 1 effluent of another dairy ICW but was absent from the influent and the mid-cell and final effluents. Salmonella Typhimurium DT104b was detected in the liquid fraction of anaerobically digested pig manure as well as in the effluent from the first cell and mid-cell of an ICW treating this material, but was absent in the final effluent. Molecular fingerprinting by pulsed field gel electrophoresis demonstrated that the recovered isolates were highly related. However, they had different antimicrobial resistance profiles, with some highly resistant isolates recovered. In conclusion, counts of indicator micro-organisms were reduced significantly within ICW, with E. coli and Enterococcus non-detectable in the final effluent. Moreover, Salmonella, when present in the influent, appears to have been removed.

  2. Volatilization of iodine from vegetation

    NASA Astrophysics Data System (ADS)

    Amiro, B. D.; Johnston, F. L.

    Gaseous emissions of iodine were measured from bean plant foliage. A gamma-emitting iodine tracer, Na 125I, was taken up by the plants from a hydroponic growth medium and released to a cuvette atmosphere. The dynamics of the flux were studied using a flow-through gamma detector. The relationship between leaf radioactive tracer activity and growth-medium activity was linear, as was the relationship between the iodine flux and both leaf and growth-medium activity. Iodine flux and leaf conductance to water responded similarly to changes in light levels, suggesting that the stomata may partially control the flux. The flux was inhibited by aeration of the hydroponic growth medium, and we postulate that methylation causes the iodine flux. Iodine emissions from living vegetation probably contribute <0.1 % to the stable iodine concentration in the atmosphere above terrestrial areas. However, this pathway may be a direct route for radioactive iodine transport from contaminated soils to the atmosphere.

  3. Removal of natural organic matter from water using ion-exchange resins and cyclodextrin polyurethanes

    NASA Astrophysics Data System (ADS)

    Nkambule, T. I.; Krause, R. W.; Mamba, B. B.; Haarhoff, J.

    Natural organic matter (NOM) consists of a complex mixture of naturally occurring organic compounds. Although it is not considered toxic by itself, NOM present during water disinfection may result in the formation of disinfection by-products (DBPs), many of which are either carcinogenic or mutagenic. Although it is difficult to completely characterize NOM due to its complex and large structure, a consideration of its structure is necessary for a better understanding of the mechanism of NOM removal from water. In this study, water from the Vaalkop water treatment plant was characterized for its NOM composition by fractionation over ion-exchange resins. Fractionation at different pH with different resins resulted in the isolation of the neutral, basic and acidic fractions of both the hydrophobic and hydrophilic NOM. The hydrophilic basic fraction was found to be the most abundant fraction in the source water. Each of the isolated NOM fractions were percolated through cyclodextrin (CD) polyurethanes, resulting in an adsorption efficiency of between 6% and 33%. The acidic fractions were the most adsorbed fractions by the CD polyurethanes, while the neutral fractions being the least adsorbed. The water samples were then subjected to an ozonation regime at the treatment plant and then fractionated as before. As expected there were decreases of the neutral and basic fractions after ozonation. The application of CD polyurethanes to the fractions after ozonation resulted in a removal efficiency of up to 59%, nearly double that of the non-treated sample. Also, in the case of the ozone pre-treated samples, it was mainly the hydrophilic basic fraction which was removed. All the fractions were subjected to a chlorination test to determine the trihalomethane (THM) formation potential. All six NOM fractions resulted in THM formation, but the hydrophilic basic fraction was found to be the most reactive and formed the highest THM concentration. The effect of the combination of

  4. Pretreatment technique for siderite removal for organic carbon isotope and C:N ratio analysis in geological samples.

    PubMed

    Larson, Toti E; Heikoop, Jeffrey M; Perkins, George; Chipera, Steve J; Hess, Marcey A

    2008-01-01

    A method for the removal of siderite from geological samples to determine organic carbon isotope compositions using elemental analysis isotope ratio mass spectrometry is presented which includes calculations for % organic carbon in samples that contain diagenetic carbonate. The proposed method employs in situ acidification of geological samples with 6 N HCl and silver capsule sample holders and was tested on modern peach leaf samples (NIST 1547) and ancient lacustrine samples from Valles Caldera, New Mexico. The in situ acidification technique eliminates potential errors associated with the removal of soluble organic material using standard acid decanting techniques and allows for removal of the less soluble siderite, which is not efficiently removed using vapor acidification techniques.

  5. Reverse osmosis followed by activated carbon filtration for efficient removal of organic micropollutants from river bank filtrate.

    PubMed

    Kegel, F Schoonenberg; Rietman, B M; Verliefde, A R D

    2010-01-01

    Drinking water utilities in Europe are faced with a growing presence of organic micropollutants in their water sources. The aim of this research was to assess the robustness of a drinking water treatment plant equipped with reverse osmosis and subsequent activated carbon filtration for the removal of these pollutants. The total removal efficiency of 47 organic micropollutants was investigated. Results indicated that removal of most organic micropollutants was high for all membranes tested. Some selected micropollutants were less efficiently removed (e.g. the small and polar NDMA and glyphosate, and the more hydrophobic ethylbenzene and napthalene). Very high removal efficiencies for almost all organic micropollutants by the subsequent activated carbon, fed with the permeate stream of the RO element were observed except for the very small and polar NDMA and 1,4-dioxane. RO and subsequent activated carbon filtration are complementary and their combined application results in the removal of a large part of these emerging organic micropollutants. Based on these experiments it can be concluded that the robustness of a proposed treatment scheme for the drinking water treatment plant Engelse Werk is sufficiently guaranteed.

  6. A physiological systems model for iodine for use in radiation protection

    SciTech Connect

    Leggett, Richard Wayne

    2010-01-01

    This paper summarizes the biokinetic database for iodine in the human body and proposes a biokinetic model for use in dose assessments for radioiodine. The model unifies and extends existing physiological systems models describing three subsystems of the iodine cycle in the body: circulating (extrathyroidal) inorganic iodide; thyroidal iodine (trapping and organic binding of iodide, and synthesis, storage, and secretion of thyroid hormones); and extrathyroidal organic iodine. Thyroidal uptake of iodide is described as a function of daily stable iodine intake and requirements for thyroid hormones. Baseline parameter values are developed for adults with typical iodine intakes and hormone requirements. Estimated thyroid doses derived from the baseline parameter values and reference thyroid weights are higher than values predicted by the current model of the International Commission on Radiological Protection (ICRP) for adults for intake of iodine isotopes with half-lives up to a few hours but consistent with ICRP predictions for longer-lived isotopes. For nearly all iodine isotopes, the proposed model yields order-of-magnitude differences from the ICRP s current iodine model for adults for stomach wall, salivary gland, and kidneys. Dose estimates for intravenously injected 131I-labeled thyroid hormones based on the present model differ substantially from current ICRP values for adult patients for some organs, including the thyroid. Subsequent studies will address age-specific biokinetics of iodine, reduction of doses from radioiodine due to thyroid blocking, and effects of dietary iodine levels and thyroid hormone requirements on thyroid doses from radioiodine.

  7. Nutrient and dissolved organic carbon removal from water using mining and metallurgical by-products.

    PubMed

    Wendling, Laura A; Douglas, Grant B; Coleman, Shandel; Yuan, Zheng

    2012-05-15

    Excess nutrient input to water bodies frequently results in algal blooms and development of oxygen deficient conditions. Mining or metallurgical by-products can potentially be utilised as filtration media within water treatment systems such as constructed wetlands, permeable reactive barriers, or drain liners. These materials may offer a cost-effective solution for the removal of nutrients and dissolved organic carbon (DOC) from natural waters. This study investigated steel-making, alumina refining (red mud and red sand) and heavy mineral processing by-products, as well as the low-cost mineral-based material calcined magnesia, in laboratory column trials. Influent water and column effluents were analysed for pH and flow rate, alkalinity, nutrient species and DOC, and a range of major cations and anions. In general, by-products with high Ca or Mg, and to a lesser extent those with high Fe content, were well-suited to nutrient and DOC removal from water. Of the individual materials examined, the heavy mineral processing residue neutralised used acid (NUA) exhibited the highest sorption capacity for P, and removed the greatest proportions of all N species and DOC from influent water. In general, NUA and mixtures containing NUA, particularly those with calcined magnesia or red mud/red sand were the most effective in removing nutrients and DOC from influent water. Post-treatment effluents from columns containing NUA and NUA/steel-making by-product, NUA/red sand and NUA/calcined magnesia mixtures exhibited large reductions in DOC, P and N concentrations and exhibited a shift in nutrient ratios away from potential N- and Si-limitation and towards potential P-limitation. If employed as part of a large-scale water treatment scheme, use of these mining and metallurgical by-products for nutrient removal could result in reduced algal biomass and improved water quality. Identification and effective implementation of mining by-products or blends thereof in constructed wetlands

  8. A laboratory characterisation of inorganic iodine emissions from the sea surface: dependence on oceanic variables and parameterisation for global modelling

    NASA Astrophysics Data System (ADS)

    MacDonald, S. M.; Gómez Martín, J. C.; Chance, R.; Warriner, S.; Saiz-Lopez, A.; Carpenter, L. J.; Plane, J. M. C.

    2014-06-01

    Reactive iodine compounds play a significant role in the atmospheric chemistry of the oceanic boundary layer by influencing the oxidising capacity through catalytically removing O3 and altering the HOx and NOx balance. The sea-to-air flux of iodine over the open ocean is therefore an important quantity in assessing these impacts on a global scale. This paper examines the effect of a number of relevant environmental parameters, including water temperature, salinity and organic compounds, on the magnitude of the HOI and I2 fluxes produced from the uptake of O3 and its reaction with iodide ions in aqueous solution. The results of these laboratory experiments and those reported previously (Carpenter et al., 2013), along with sea surface iodide concentrations measured or inferred from measurements of dissolved total iodine and iodate reported in the literature, were then used to produce parameterised expressions for the HOI and I2 fluxes as a function of wind speed, sea-surface temperature and O3. These expressions were used in the Tropospheric HAlogen chemistry MOdel (THAMO) to compare with MAX-DOAS measurements of iodine monoxide (IO) performed during the HaloCAST-P cruise in the eastern Pacific ocean (Mahajan et al., 2012). The modelled IO agrees reasonably with the field observations, although significant discrepancies are found during a period of low wind speeds (< 3 m s-1), when the model overpredicts IO by up to a factor of 3. The inorganic iodine flux contributions to IO are found to be comparable to, or even greater than, the contribution of organo-iodine compounds and therefore its inclusion in atmospheric models is important to improve predictions of the influence of halogen chemistry in the marine boundary layer.

  9. A laboratory characterisation of inorganic iodine emissions from the sea surface: dependence on oceanic variables and parameterisation for global modelling

    NASA Astrophysics Data System (ADS)

    MacDonald, S. M.; Gómez Martín, J. C.; Chance, R.; Warriner, S.; Saiz-Lopez, A.; Carpenter, L. J.; Plane, J. M. C.

    2013-12-01

    Reactive iodine compounds play a~significant role in the atmospheric chemistry of the oceanic boundary layer by influencing the oxidising capacity through catalytically removing O3 and altering the HOx and NOx balance. The sea-to-air flux of iodine over the open ocean is therefore an important quantity in assessing these impacts on a global scale. This paper examines the effect of a number of relevant environmental parameters, including water temperature, salinity and organic compounds, on the magnitude of the HOI and I2 fluxes produced from the uptake of O3 and its reaction with iodide ions in aqueous solution. The results of these laboratory experiments and those reported previously (Carpenter et al., 2013), along with sea surface iodide concentrations measured or inferred from measurements of dissolved total iodine and iodate reported in the literature, were then used to produce parameterised expressions for the HOI and I2 fluxes as a function of wind speed, sea-surface temperature and O3. These expressions were used in the Tropospheric HAlogen chemistry MOdel (THAMO) to compare with MAX-DOAS measurements of iodine monoxide (IO) performed during the HaloCAST-P cruise in the Eastern Pacific ocean (Mahajan et al., 2012). The modelled IO agrees reasonably with the field observations, although significant discrepancies are found during a period of low wind speeds (<3 m s-1), when the model overpredicts IO by up to a factor of three. The inorganic iodine flux contributions to IO are found to be comparable to, or even greater than, the contribution of organo-iodine compounds and therefore its inclusion in atmospheric models is important to improve predictions of the influence of halogen chemistry in the marine boundary layer.

  10. Low acetate concentrations favor polyphosphate-accumulating organisms over glycogen-accumulating organisms in enhanced biological phosphorus removal from wastewater.

    PubMed

    Tu, Yunjie; Schuler, Andrew J

    2013-04-16

    Glycogen-accumulating organisms (GAOs) are thought to compete with polyphosphate-accumulating organisms (PAOs) in enhanced biological phosphorus removal (EBPR) wastewater treatment systems. A laboratory sequencing batch reactor (SBR) was operated for one year to test the hypothesis that PAOs have a competitive advantage at low acetate concentrations, with a focus on low pH conditions previously shown to favor GAOs. PAOs dominated the system under conventional SBR operation with rapid acetate addition (producing high in-reactor concentrations) and pH values of 7.4-8.4. GAOs dominated when the pH was decreased (6.4-7.0). Decreasing the acetate addition rate led to very low reactor acetate concentrations, and PAOs recovered, supporting the study hypothesis. When the acetate feed rate was increased, EBPR failed again. Dominant PAOs and GAOs were Candidatus Accumulibacter phosphatis and Defluviicoccus Cluster 2, respectively, according to fluorescent in situ hybridization and 454 pyrosequencing. Surprisingly, GAOs were not the immediate causes of PAO failures, based on functional and population measurements. Pyrosequencing results suggested Dechloromonas and Tetrasphaera spp. may have also been PAOs, and additional potential GAOs were also identified. Full-scale systems typically have lower in-reactor acetate concentrations than laboratory SBRs, and so, previous laboratory studies may have overestimated the practical importance of GAOs as causes of EBPR failure. PMID:23477409

  11. Low acetate concentrations favor polyphosphate-accumulating organisms over glycogen-accumulating organisms in enhanced biological phosphorus removal from wastewater.

    PubMed

    Tu, Yunjie; Schuler, Andrew J

    2013-04-16

    Glycogen-accumulating organisms (GAOs) are thought to compete with polyphosphate-accumulating organisms (PAOs) in enhanced biological phosphorus removal (EBPR) wastewater treatment systems. A laboratory sequencing batch reactor (SBR) was operated for one year to test the hypothesis that PAOs have a competitive advantage at low acetate concentrations, with a focus on low pH conditions previously shown to favor GAOs. PAOs dominated the system under conventional SBR operation with rapid acetate addition (producing high in-reactor concentrations) and pH values of 7.4-8.4. GAOs dominated when the pH was decreased (6.4-7.0). Decreasing the acetate addition rate led to very low reactor acetate concentrations, and PAOs recovered, supporting the study hypothesis. When the acetate feed rate was increased, EBPR failed again. Dominant PAOs and GAOs were Candidatus Accumulibacter phosphatis and Defluviicoccus Cluster 2, respectively, according to fluorescent in situ hybridization and 454 pyrosequencing. Surprisingly, GAOs were not the immediate causes of PAO failures, based on functional and population measurements. Pyrosequencing results suggested Dechloromonas and Tetrasphaera spp. may have also been PAOs, and additional potential GAOs were also identified. Full-scale systems typically have lower in-reactor acetate concentrations than laboratory SBRs, and so, previous laboratory studies may have overestimated the practical importance of GAOs as causes of EBPR failure.

  12. Flowfield measurements in a model scramjet combustion using laser-induced iodine fluorescence

    NASA Technical Reports Server (NTRS)

    Mcdaniel, J. C., Jr.

    1984-01-01

    Preliminary designs were completed for an iodine mixing chamber and the optical setup to be used with a modified wind tunnel in obtaining accurate, spatially resolved measurements of variables in the flowfield of a model nonreacting scramjet combustor. Schematics of the iodine-seeded wind tunnel and a sketch of the charcoal filter for removing the iodine are included along with a cutaway section of the laboratory.

  13. Efficiency of bioaugmentation in the removal of organic matter in aquaculture systems.

    PubMed

    Lopes, R B; Olinda, R A; Souza, B A I; Cyrino, J E P; Dias, C T S; Queiroz, J F; Tavares, L H S

    2011-05-01

    Several techniques are currently used to treat effluents. Bioaugmentation is a new bioremediation strategy and has been employed to improve effluent quality by treating the water during the production process. This technology consists basically of the addition of microorganisms able to degrade or remove polluting compounds, especially organic matter and nutrients. The objective of this study was to assess the effects of bioaugmentation on some parameters of organic matter and on the performance of juvenile tilapias in an intensive aquaculture production system. The combination of two bacterial consortiums in a complete randomized design was employed in a factorial analysis with two factors. Statistical differences between treatments were analyzed by the analysis of variance (ANOVA) and Tukey test at the 5% level. One of the treatments, heterotrophic bacterial supplementation, was able to reduce biochemical oxygen demand (BOD) by 23%, dissolved organic carbon (DOC) by 83.7% and phytoplanktonic biomass by 43%. On the other hand, no damage was done to either the physical-chemical indicators of water quality or to the growth performance of juvenile tilapias assessed in this study. PMID:21755158

  14. Variation and removal efficiency of assimilable organic carbon (AOC) in an advanced water treatment system.

    PubMed

    Lou, Jie-Chung; Chen, Bi-Hsiang; Chang, Ting-Wei; Yang, Hung-Wen; Han, Jia-Yun

    2011-07-01

    This study investigates the microorganism growth indicator and determines the assimilable organic carbon (AOC) content at the Cheng-Ching Lake Advanced Water Treatment Plant (CCLAWTP) in Kaohsiung, Taiwan. Notably, AOC is associated with the biological stability within the water distribution network and has garnered considerable attention in the environmental engineering field in recent years. Water samples were collected from the effluent of each unit in CCLAWTP once monthly during December 2008 to November 2009. Items of water quality related to carbon concentration levels, including AOC, total organic carbon, dissolved organic carbon, UV(254), and specific ultraviolent absorbance were analyzed. Analytical results demonstrate that the average AOC concentration in raw water was 83.61 μg/L and reduced in freshwater was controlled at an average of 50 μg/L after an advanced treatment system of roughly 54% of AOC was removed in compliance with treatment plant standards. If AOC concentrations in freshwater can be reduced, study results can provide a direction for improving water treatment capabilities. PMID:20835921

  15. Hyperparathyroidism after radioactive iodine therapy for Graves disease

    SciTech Connect

    Esselstyn, C.B. Jr.; Schumacher, O.P.; Eversman, J.; Sheeler, L.; Levy, W.J.

    1982-11-01

    The association of external ionizing radiation to the head and neck and the subsequent development of hyperfunctioning parathyroid glands has been documented in recent years. This also has been demonstrated experimentally in animals. Despite the numbers of patients with Graves disease who have been treated with radioactive iodine, there are no reports in the literature of parathyroid surgery for hyperparathyroidism secondary to earlier treatment with radioactive iodine for Graves disease. This report describes the operative and pathologic findings in four patients with hyperparathyroidism. These patients had previously been treated with radioactive iodine for Graves disease. The pathologic findings at surgery included in three cases a single enlarged hyperplastic gland consistent with a parathyroid adenoma. One patient had hyperplasia of all four glands. The two largest glands and halves of the two remaining glands were removed. In a long-term follow-up of children and adolescents treated with radioactive iodine for Graves disease, Levy and Schumacher found calcium elevations in 10 of 159 patients. The increased incidence of hyperparathyroidism following radioactive iodine treatment for Graves disease in children and adolescents would seem several times higher than normal. Whether adults who have radioactive iodine treatment for Graves disease have a similar increase incidence is not known. Meanwhile it would seem reasonable to suggest that patients whose hyperthyroidism is treated with radioactive iodine should have their serum calcium levels determined at 5-year intervals.

  16. AGING AND IODINE LOADING OF SILVER-FUNCTIONALIZED AEROGELS

    SciTech Connect

    Bruffey, Stephanie H; Jubin, Robert Thomas; Anderson, Kaara K; Walker Jr, Joseph Franklin

    2013-01-01

    Engineered silver-functionalized silica aerogels are being investigated for their application in off-gas treatment at a used nuclear fuel reprocessing facility. Reprocessing will release several key volatile radionuclides, including iodine-129. To achieve regulatory compliance, iodine-129 must be removed from any off-gas stream prior to environmental discharge. Silver-functionalized aerogels have been demonstrated to have high iodine capture capacity, high porosity and potential for conversion into a waste form. Capture materials used in off-gas treatment may be exposed to a heated, high humidity, acidic gas stream for months. Extended exposure to this stream could affect sorbent performance. It was the aim of this study to evaluate what impacts might be observed when Ag0-functionalized aerogels prepared at Pacific Northwest National Laboratory were contacted with a dry air stream for up to 6 months and then used to adsorb iodine from a synthetic off-gas stream. Results demonstrate that there is some loss of iodine capture capacity caused by aging, but that this loss is not as marked as for aging of more traditional iodine sorbents, such as silver-impregnated mordenite. Specifically, aging silver-functionalized aerogel under a dry air stream for up to 6 months can decrease its iodine capacity from 41wt% to 32wt%.

  17. Aging and iodine loading of silver-functionalized aerogels

    SciTech Connect

    Bruffey, S.H.; Jubin, R.T.; Anderson, K.K.; Walker, J.F.

    2013-07-01

    Engineered silver-functionalized silica aerogels are being investigated for their potential application in off-gas treatment at a used nuclear fuel reprocessing facility. Reprocessing will release several key volatile radionuclides, including iodine-129. To achieve regulatory compliance, iodine-129 must be removed from any off-gas stream prior to environmental discharge. Ag{sup 0}-functionalized aerogels have been demonstrated to have high iodine-capture capacity, high porosity, and potential for conversion into a waste form. Capture materials used in off-gas treatment may be exposed to a heated, high-humidity, acidic gas stream for months. Extended exposure to this stream could affect sorbent performance. It was the aim of this study to evaluate what impacts might be observed when Ag{sup 0}-functionalized aerogels prepared at Pacific Northwest National Laboratory were contacted with a dry air stream for up to 6 months and then used to adsorb iodine from a synthetic off-gas stream. Results demonstrate that there is some loss of iodine-capture capacity caused by aging, but that this loss is not as marked as for aging of more traditional iodine sorbents, such as silver-impregnated mordenite. Specifically, aging silver-functionalized aerogel under a dry air stream for up to 6 months can decrease its iodine capacity from 41 wt% to 32 wt%. (authors)

  18. Effect of dietary iodine on production of iodine enriched eggs

    PubMed Central

    Sumaiya, Shaikh; Nayak, Sunil; Baghel, R. P. S.; Nayak, Anju; Malapure, C. D.; Kumar, Rajesh

    2016-01-01

    Aim: Objective of this study was to investigate the effect of different levels of iodine supplementation on iodine content of eggs in laying hens. Materials and Methods: In the experiment, 135 laying hens (White Leghorn) of 55 weeks age were randomly distributed to 5 dietary treatments; each group contained 27 laying hens distributed in three replicates of 9 birds each. Diet T1 was control basal layer diet without iodine enrichment in which iodine content (I2) was as per NRC recommendation. Basal diets were supplemented with calcium iodate (Ca (IO3)2) at 5, 10, 15 and 20 mg/kg in T2, T3, T4 and T5 groups, respectively. The iodine content in the calcium iodate is 65.21%, therefore, the diets T2, T3, T4 and T5 contained 3.25, 6.50, 9.75 and 13.0 ppm iodine, respectively. The laying hens were fed the respective experimental diets ad libitum during the experimental period of 10-week. The iodine content of egg yolk and albumen was analyzed at the end of 5th and 10th week of the experiment. Economics of feeding for the production of iodine enriched egg was calculated at the end of the experiment. Results: Increasing iodine levels in diet of hens from 0.45 to 13.0 ppm significantly increased egg iodine concentration, the highest concentration of egg iodine was observed in the group fed diet supplemented with 13.0 ppm iodine followed by those fed 9.75, 6.50, 3.25 and 0.45 ppm iodine in diet. There was no significant difference in the iodine levels of unboiled versus boiled eggs. Therefore, the consumers are ensured to receive the optimal levels of iodine from boiled iodine-enriched eggs. Among different diets, minimum and significantly lower feeding cost (Rs. per dozen or per kg eggs) was noticed in hens allotted T3 diet (6.50 ppm I2). However, feeding cost of hens receiving 3.25 and 9.25 ppm I2 was statistically (p<0.05) similar to control group (T1). Further, it was noticed that feeding cost (Rs. per dozen or per kg eggs) was significantly increased due to the inclusion

  19. Efficient Removal and Recovery of Uranium by a Layered Organic-Inorganic Hybrid Thiostannate.

    PubMed

    Feng, Mei-Ling; Sarma, Debajit; Qi, Xing-Hui; Du, Ke-Zhao; Huang, Xiao-Ying; Kanatzidis, Mercouri G

    2016-09-28

    Uranium is important in the nuclear fuel cycle both as an energy source and as radioactive waste. It is of vital importance to recover uranium from nuclear waste solutions for further treatment and disposal. Herein we present the first chalcogenide example, (Me2NH2)1.33(Me3NH)0.67Sn3S7·1.25H2O (FJSM-SnS), in which organic amine cations can be used for selective UO2(2+) ion-exchange. The UO2(2+)-exchange kinetics perfectly conforms to pseudo-second-order reaction, which is observed for the first time in a chalcogenide ion-exchanger. This reveals the chemical adsorption process and its ion-exchange mechanism. FJSM-SnS has excellent pH stability in both strongly acidic and basic environments (pH = 2.1-11), with a maximum uranium-exchange capacity of 338.43 mg/g. It can efficiently capture UO2(2+) ions in the presence of high concentrations of Na(+), Ca(2+), or HCO3(-) (the highest distribution coefficient Kd value reached 4.28 × 10(4) mL/g). The material is also very effective in removing of trace levels of U in the presence of excess Na(+) (the relative amounts of U removed are close to 100%). The UO2(2+)···S(2-) interactions are the basis for the high selectivity. Importantly, the uranyl ion in the exchanged products could be easily eluted with an environmentally friendly method, by treating the UO2(2+)-laden materials with a concentrated KCl solution. These advantages coupled with the very high loading capacity, low cost, environmentally friendly nature, and facile synthesis make FJSM-SnS a new promising remediation material for removal of radioactive U from nuclear waste solutions.

  20. Efficient Removal and Recovery of Uranium by a Layered Organic-Inorganic Hybrid Thiostannate.

    PubMed

    Feng, Mei-Ling; Sarma, Debajit; Qi, Xing-Hui; Du, Ke-Zhao; Huang, Xiao-Ying; Kanatzidis, Mercouri G

    2016-09-28

    Uranium is important in the nuclear fuel cycle both as an energy source and as radioactive waste. It is of vital importance to recover uranium from nuclear waste solutions for further treatment and disposal. Herein we present the first chalcogenide example, (Me2NH2)1.33(Me3NH)0.67Sn3S7·1.25H2O (FJSM-SnS), in which organic amine cations can be used for selective UO2(2+) ion-exchange. The UO2(2+)-exchange kinetics perfectly conforms to pseudo-second-order reaction, which is observed for the first time in a chalcogenide ion-exchanger. This reveals the chemical adsorption process and its ion-exchange mechanism. FJSM-SnS has excellent pH stability in both strongly acidic and basic environments (pH = 2.1-11), with a maximum uranium-exchange capacity of 338.43 mg/g. It can efficiently capture UO2(2+) ions in the presence of high concentrations of Na(+), Ca(2+), or HCO3(-) (the highest distribution coefficient Kd value reached 4.28 × 10(4) mL/g). The material is also very effective in removing of trace levels of U in the presence of excess Na(+) (the relative amounts of U removed are close to 100%). The UO2(2+)···S(2-) interactions are the basis for the high selectivity. Importantly, the uranyl ion in the exchanged products could be easily eluted with an environmentally friendly method, by treating the UO2(2+)-laden materials with a concentrated KCl solution. These advantages coupled with the very high loading capacity, low cost, environmentally friendly nature, and facile synthesis make FJSM-SnS a new promising remediation material for removal of radioactive U from nuclear waste solutions. PMID:27584863

  1. Removal of trace organic chemicals and performance of a novel hybrid ultrafiltration-osmotic membrane bioreactor.

    PubMed

    Holloway, Ryan W; Regnery, Julia; Nghiem, Long D; Cath, Tzahi Y

    2014-09-16

    A hybrid ultrafiltration-osmotic membrane bioreactor (UFO-MBR) was investigated for over 35 days for nutrient and trace organic chemical (TOrC) removal from municipal wastewater. The UFO-MBR system uses both ultrafiltration (UF) and forward osmosis (FO) membranes in parallel to simultaneously extract clean water from an activated sludge reactor for nonpotable (or environmental discharge) and potable reuse, respectively. In the FO stream, water is drawn by osmosis from activated sludge through an FO membrane into a draw solution (DS), which becomes diluted during the process. A reverse osmosis (RO) system is then used to reconcentrate the diluted DS and produce clean water suitable for direct potable reuse. The UF membrane extracts water, dissolved salts, and some nutrients from the system to prevent their accumulation in the activated sludge of the osmotic MBR. The UF permeate can be used for nonpotable reuse purposes (e.g., irrigation and toilet flushing). Results from UFO-MBR investigation illustrated that the chemical oxygen demand, total nitrogen, and total phosphorus removals were greater than 99%, 82%, and 99%, respectively. Twenty TOrCs were detected in the municipal wastewater that was used as feed to the UFO-MBR system. Among these 20 TOrCs, 15 were removed by the hybrid UFO-MBR system to below the detection limit. High FO membrane rejection was observed for all ionic and nonionic hydrophilic TOrCs and lower rejection was observed for nonionic hydrophobic TOrCs. With the exceptions of bisphenol A and DEET, all TOrCs that were detected in the DS were well rejected by the RO membrane. Overall, the UFO-MBR can operate sustainably and has the potential to be utilized for direct potable reuse applications. PMID:25113310

  2. Nitrogen removal from high organic loading wastewater in modified Ludzack-Ettinger configuration MBBR system.

    PubMed

    Torkaman, Mojtaba; Borghei, Seyed Mehdi; Tahmasebian, Sepehr; Andalibi, Mohammad Reza

    2015-01-01

    A moving bed biofilm reactor with pre-denitrification configuration was fed with a synthetic wastewater containing high chemical oxygen demand (COD) and ammonia. By changing different variables including ammonium and COD loading, nitrification rate in the aerobic reactor and denitrification rate in the anoxic reactor were monitored. Changing the influent loading was achieved via adjusting the inlet COD (956-2,096 mg/L), inlet ammonium (183-438 mg/L), and hydraulic retention time of the aerobic reactor (8, 12, and 18 hours). The overall organic loading rate was in the range of 3.60-17.37 gCOD/m2·day, of which 18.5-91% was removed in the anoxic reactor depending on the operational conditions. Considering the complementary role of the aerobic reactor, the overall COD removal was in the range 87.3-98.8%. In addition, nitrification rate increased with influent ammonium loading, the maximum rate reaching 3.05 gNH4/m2·day. One of the most important factors affecting nitrification rate was influent C:N entering the aerobic reactor, by increasing which nitrification rate decreased asymptotically. Nitrate removal efficiency in the anoxic reactor was also controlled by the inlet nitrate level entering the anoxic reactor. Furthermore, by increasing the nitrate loading rate from 0.91 to 3.49 gNO/m3·day, denitrification rate increased from 0.496 to 2.47 gNO/m3·day. PMID:26465296

  3. Wet scrubber analysis of volatile organic compound removal in the rendering industry.

    PubMed

    Kastner, James R; Das, K C

    2002-04-01

    The promulgation of odor control rules, increasing public concerns, and U.S. Environmental Protection Agency (EPA) air regulations in nonattainment zones necessitates the remediation of a wide range of volatile organic compounds (VOCs) generated by the rendering industry. Currently, wet scrubbers with oxidizing chemicals are used to treat VOCs; however, little information is available on scrubber efficiency for many of the VOCs generated within the rendering process. Portable gas chromatography/mass spectrometry (GC/MS) units were used to rapidly identify key VOCs on-site in process streams at two poultry byproduct rendering plants. On-site analysis was found to be important, given the significant reduction in peak areas if samples were held for 24 hr before analysis. Major compounds consistently identified in the emissions from the plant included dimethyl disulfide, methanethiol, octane, hexanal, 2-methylbutanal, and 3-methylbutanal. The two branched aldehydes, 2-methylbutanal and 3-methylbutanal, were by far the most consistent, appearing in every sample and typically the largest fraction of the VOC mixture. A chlorinated hydrocarbon, methanesulfonyl chloride, was identified in the outlet of a high-intensity wet scrubber, and several VOCs and chlorinated compounds were identified in the scrubbing solution, but not on a consistent basis. Total VOC concentrations in noncondensable gas streams ranged from 4 to 91 ppmv. At the two plants, the odor-causing compound methanethiol ranged from 25 to 33% and 9.6% of the total VOCs (v/v). In one plant, wet scrubber analysis using chlorine dioxide (ClO2) as the oxidizing agent indicated that close to 100% of the methanethiol was removed from the gas phase, but removal efficiencies ranged from 20 to 80% for the aldehydes and hydrocarbons and from 23 to 64% for total VOCs. In the second plant, conversion efficiencies were much lower in a packed-bed wet scrubber, with a measurable removal of only dimethyl sulfide (20-100%).

  4. QSAR models for the removal of organic micropollutants in four different river water matrices.

    PubMed

    Sudhakaran, Sairam; Calvin, James; Amy, Gary L

    2012-04-01

    Ozonation is an advanced water treatment process used to remove organic micropollutants (OMPs) such as pharmaceuticals and personal care products (PPCPs). In this study, Quantitative Structure Activity Relationship (QSAR) models, for ozonation and advanced oxidation process (AOP), were developed with percent-removal of OMPs by ozonation as the criterion variable. The models focused on PPCPs and pesticides elimination in bench-scale studies done within natural water matrices: Colorado River, Passaic River, Ohio River and Suwannee synthetic water. The OMPs removal for the different water matrices varied depending on the water quality conditions such as pH, DOC, alkalinity. The molecular descriptors used to define the OMPs physico-chemical properties range from one-dimensional (atom counts) to three-dimensional (quantum-chemical). Based on a statistical modeling approach using more than 40 molecular descriptors as predictors, descriptors influencing ozonation/AOP were chosen for inclusion in the QSAR models. The modeling approach was based on multiple linear regression (MLR). Also, a global model based on neural networks was created, compiling OMPs from all the four river water matrices. The chemically relevant molecular descriptors involved in the QSAR models were: energy difference between lowest unoccupied and highest occupied molecular orbital (E(LUMO)-E(HOMO)), electron-affinity (EA), number of halogen atoms (#X), number of ring atoms (#ring atoms), weakly polar component of the solvent accessible surface area (WPSA) and oxygen to carbon ratio (O/C). All the QSAR models resulted in a goodness-of-fit, R(2), greater than 0.8. Internal and external validations were performed on the models. PMID:22245076

  5. Removal of trace organic chemicals and performance of a novel hybrid ultrafiltration-osmotic membrane bioreactor.

    PubMed

    Holloway, Ryan W; Regnery, Julia; Nghiem, Long D; Cath, Tzahi Y

    2014-09-16

    A hybrid ultrafiltration-osmotic membrane bioreactor (UFO-MBR) was investigated for over 35 days for nutrient and trace organic chemical (TOrC) removal from municipal wastewater. The UFO-MBR system uses both ultrafiltration (UF) and forward osmosis (FO) membranes in parallel to simultaneously extract clean water from an activated sludge reactor for nonpotable (or environmental discharge) and potable reuse, respectively. In the FO stream, water is drawn by osmosis from activated sludge through an FO membrane into a draw solution (DS), which becomes diluted during the process. A reverse osmosis (RO) system is then used to reconcentrate the diluted DS and produce clean water suitable for direct potable reuse. The UF membrane extracts water, dissolved salts, and some nutrients from the system to prevent their accumulation in the activated sludge of the osmotic MBR. The UF permeate can be used for nonpotable reuse purposes (e.g., irrigation and toilet flushing). Results from UFO-MBR investigation illustrated that the chemical oxygen demand, total nitrogen, and total phosphorus removals were greater than 99%, 82%, and 99%, respectively. Twenty TOrCs were detected in the municipal wastewater that was used as feed to the UFO-MBR system. Among these 20 TOrCs, 15 were removed by the hybrid UFO-MBR system to below the detection limit. High FO membrane rejection was observed for all ionic and nonionic hydrophilic TOrCs and lower rejection was observed for nonionic hydrophobic TOrCs. With the exceptions of bisphenol A and DEET, all TOrCs that were detected in the DS were well rejected by the RO membrane. Overall, the UFO-MBR can operate sustainably and has the potential to be utilized for direct potable reuse applications.

  6. Combined chemical and microbiological removal of organic sulfur from coal. Technical report, September 1, 1990--August 31, 1991

    SciTech Connect

    Raphaelian, L.A.

    1991-12-31

    The objective of this work is to investigate techniques for chemically converting the sulfur containing organic compounds in coal to compounds that can be treated microbiologically to remove the organically bound sulfur. The goal is to achieve an economically feasible mild chemical oxidation of the organic sulfur in a representative Illinois Basin coal by converting the sulfur to sulfoxides and sulfones; the carbon sulfur bond in the sulfoxides and sulfones would then be broken microbiologically and the sulfur removed from the coal as sulfate.

  7. Implications of biocrust removal on soil organic carbon losses by water erosion in a badlands area

    NASA Astrophysics Data System (ADS)

    Chamizo, Sonia; Raúl Román, José; Miralles, Isabel; Rodríguez-Caballero, Emilio; Cantón, Yolanda

    2015-04-01

    In arid and semiarid ecosystems, soils are characterized by having low organic carbon (OC) content and low fertility. In these systems, runoff, often generated in interplant soils, plays a crucial role in OC redistribution from source (interplant) areas to sink (vegetation) patches. Far from being bare, interplant soils in most arid and semiarid ecosystems are commonly covered by communities of cyanobacteria, algae, lichens and mosses, known as biocrusts, which may reach up to 80% of soil cover. Biocrusts fix atmospheric C and increase the soil OC pool by several folds respect bare soils. In addition, biocrusts form a film on the surface that strongly protects soils against water erosion and prevents from OC losses. However, the role of BSCs in reducing OC losses associated to runoff and erosion may depend on the type and development of biocrust. On the other hand, loss of BSCs provoked by frequent disturbances in arid and semiarid areas leads to an increase in runoff and erosion, which may have important effects on OC losses and nutrient impoverishment in interplant areas. Despite their recognized role, very few studies have explicitly evaluated OC losses from runoff and erosion in soils covered by different types of biocrusts and, more importantly, the effects of biocrust disturbance on OC losses. The aim of this study was to analyse the influence of two biocrust types (cyanobacteria and lichens) as well as of biocrust removal on dissolved and sediment OC losses, in a badlands site of southeastern Spain. Runoff and erosion after rain were measured in small field plots (1 m2) during one hydrological year and water samples collected for determination of dissolved OC and OC bonded to sediments. Our results showed that total OC losses decreased with biocrust development and that biocrust removal caused a dramatic increase in OC losses. The first rain after biocrust removal contributed the most to OC losses as runoff and, more noticeable, erosion greatly increased

  8. Biotransformation of trace organic compounds by activated sludge from a biological nutrient removal treatment system.

    PubMed

    Inyang, Mandu; Flowers, Riley; McAvoy, Drew; Dickenson, Eric

    2016-09-01

    The removal of trace organic compounds (TOrCs) and their biotransformation rates, kb (LgSS(-)(1)h(-)(1)) was investigated across different redox zones in a biological nutrient removal (BNR) system using an OECD batch test. Biodegradation kinetics of fourteen TOrCs with initial concentration of 1-36μgL(-)(1) in activated sludge were monitored over the course of 24h. Degradation kinetic behavior for the TOrCs fell into four groupings: Group 1 (atenolol) was biotransformed (0.018-0.22LgSS(-)(1)h(-)(1)) under anaerobic, anoxic, and aerobic conditions. Group 2 (meprobamate and trimethoprim) biotransformed (0.01-0.21LgSS(-)(1)h(-)(1)) under anoxic and aerobic conditions, Group 3 (DEET, gemfibrozil and triclosan) only biotransformed (0.034-0.26LgSS(-)(1)h(-)(1)) under aerobic conditions, and Group 4 (carbamazepine, primidone, sucralose and TCEP) exhibited little to no biotransformation (<0.001LgSS(-)(1)h(-)(1)) under any redox conditions. BNR treatment did not provide a barrier against Group 4 compounds. PMID:27309772

  9. Analytical model of dual-media biofilter for removal of organic air pollutants

    SciTech Connect

    Abumaizar, R.J.; Smith, E.H.; Kocher, W.

    1997-06-01

    A steady-state mathematical model is presented to describe the kinetics of volatile organic compound (VOC) removal in biofilters that consist of a mixed compost and granular activated carbon (GAC) medium. The model describes the basic transport of VOCs from the gas phase into the liquid phase of the compost biofilm and into the carbon particles, using the assumptions of diffusion as characterized by Fick`s law. The kinetics of biological degradation of substrate (pollutant) in the compost biofilm are assumed to follow a Monod-like relationship. Experimental data were compared with model predictions under steady-state conditions for treatment of a mixture of benzene, toluene, ethylbenzene, and o-xylene (BTEX) vapors. Best results were obtained when model applications were divided according to first-order biodegradation kinetics for relatively low influent concentrations (< 50 ppm) of pollutants and zero-order reaction for higher (235--440 ppm) influent concentrations. In both instances, the model produced suitable approximation of experimental bed depth versus concentration profiles at steady state for individual compounds in biofilters containing small but varying amounts of GAC. The presence of GAC improved BTEX removal efficiencies over a biofilter containing only compost.

  10. Removal of organic contaminants from aqueous solution by cattle manure compost (CMC) derived activated carbons

    NASA Astrophysics Data System (ADS)

    Qian, Qingrong; Chen, Qinghua; Machida, Motoi; Tatsumoto, Hideki; Mochidzuki, Kazuhiro; Sakoda, Akiyoshi

    2009-04-01

    The activated carbons (ACs) prepared from cattle manure compost (CMC) with various pore structure and surface chemistry were used to remove phenol and methylene blue (MB) from aqueous solutions. The adsorption equilibrium and kinetics of two organic contaminants onto the ACs were investigated and the schematic models for the adsorptive processes were proposed. The result shows that the removal of functional groups from ACs surface leads to decreasing both rate constants for phenol and MB adsorption. It also causes the decrement of MB adsorption capacity. However, the decrease of surface functional groups was found to result in the increase of phenol adsorption capacity. In our schematic model for adsorptive processes, the presence of acidic functional groups on the surface of carbon is assumed to act as channels for diffusion of adsorbate molecules onto small pores, therefore, promotes the adsorption rate of both phenol and MB. In phenol solution, water molecules firstly adsorb on surface oxygen groups by H-bonding and subsequently form water clusters, which cause partial blockage of the micropores, deduce electrons from the π-electron system of the carbon basal planes, hence, impede or prevent phenol adsorption. On the contrary, in MB solution, the oxygen groups prefer to combine with MB + cations than water molecules, which lead to the increase of MB adsorption capacity.

  11. Impacts of natural organic matter on perchlorate removal by an advanced reduction process.

    PubMed

    Duan, Yuhang; Batchelor, Bill

    2014-01-01

    Perchlorate can be destroyed by Advanced Reduction Processes (ARPs) that combine chemical reductants (e.g., sulfite) with activating methods (e.g., UV light) in order to produce highly reactive reducing free radicals that are capable of rapid and effective perchlorate reduction. However, natural organic matter (NOM) exists widely in the environment and has the potential to influence perchlorate reduction by ARPs that use UV light as the activating method. Batch experiments were conducted to obtain data on the impacts of NOM and wavelength of light on destruction of perchlorate by the ARPs that use sulfite activated by UV light produced by low-pressure mercury lamps (UV-L) or by KrCl excimer lamps (UV-KrCl). The results indicate that NOM strongly inhibits perchlorate removal by both ARP, because it competes with sulfite for UV light. Even though the absorbance of sulfite is much higher at 222 nm than that at 254 nm, the results indicate that a smaller amount of perchlorate was removed with the UV-KrCl lamp (222 nm) than with the UV-L lamp (254 nm). The results of this study will help to develop the proper way to apply the ARPs as practical water treatment processes. PMID:24521418

  12. Organic removal activity in biofilm and suspended biomass fractions of MBBR systems.

    PubMed

    Piculell, Maria; Welander, Thomas; Jönsson, Karin

    2014-01-01

    The moving bed biofilm reactor (MBBR) wastewater treatment process is usually designed based on the assumption that all activity in the process occurs in the biofilm on the MBBR carriers, although there is always some active biomass in the bulk liquid due to biofilm sloughing and, sometimes, free-growing bacteria. In this study the removal of organic matter is evaluated in laboratory-scale MBBR reactors under varying load, hydraulic retention time (HRT), oxygen concentration and volumetric filling degree of carriers in order to determine the heterotrophic activity in the different fractions of the MBBR biomass. The results showed that the heterotrophic conversions in an MBBR can show the same type of diffusion limited dependency on oxygen as nitrification, even for easily degradable substrates such as acetate. The contribution to the removal from the suspended biomass is shown to vary depending on HRT, as the amount of suspended solids changes. The developed method in this report is a useful tool for determining heterotrophic activity in the separate fractions of biomass in MBBRs.

  13. A UASB reactor coupled to a hybrid aerobic MBR as innovative plant configuration to enhance the removal of organic micropollutants.

    PubMed

    Alvarino, T; Suárez, S; Garrido, M; Lema, J M; Omil, F

    2016-02-01

    An innovative plant configuration based in an UASB reactor coupled to a hybrid aerobic membrane bioreactor designed for sustainable treatment of municipal wastewater at ambient temperatures and low hydraulic retention time was studied in terms of organic micropollutants (OMPs) removal. OMPs removal mechanisms, as well as the potential influence of biomass activity and physical conformation were assessed. Throughout all periods of operation (150 days) high organic matter removals were maintained (>95%) and, regarding OMPs removal, this innovative system has shown to be more efficient than conventional technologies for those OMPs which are prone to be biotransformed under anaerobic conditions. For instance, sulfamethoxazole and trimethoprim have both shown to be biodegradable under anaerobic conditions with similar efficiencies (removal efficiencies above 84%). OMPs main removal mechanism was found to be biotransformation, except in the case of musk fragrances which showed medium sorption onto sludge. OMPs removal was strongly dependent on the efficiency of the primary metabolism (organic matter degradation and nitrification) and the type of biomass. PMID:26386770

  14. Dissolved organic matter removal using magnetic anion exchange resin treatment on biological effluent of textile dyeing wastewater.

    PubMed

    Fan, Jun; Li, Haibo; Shuang, Chendong; Li, Wentao; Li, Aimin

    2014-08-01

    This study investigated the removal of dissolved organic matter (DOM) from real dyeing bio-treatment effluents (DBEs) with the use of a novel magnetic anion exchange resin (NDMP). DOMs in two typical DBEs were fractionized using DAX-8/XAD-4 resin and ultrafiltration membranes. The hydrophilic fractions and the low molecular weight (MW) (<3kDa) DOM fractions constituted a major portion (>50%) of DOMs for the two effluents. The hydrophilic and low MW fractions of both effluents were the greatest contributors of specific UV254 absorbance (SUVA254), and the SUVA254 of DOM fractions decreased with hydrophobicity and MW. Two DBEs exhibited acute and chronic biotoxicities. Both acute and chronic toxicities of DOM fractions increased linearly with the increase of SUVA254 value. Kinetics of dissolved organic carbon (DOC) removal via NDMP treatment was performed by comparing it with that of particle active carbon (PAC). Results indicated that the removal of DOC from DBEs via NDMP was 60%, whereas DOC removals by PAC were lower than 15%. Acidic organics could be significantly removed with the use of NDMP. DOM with large MW in DBE could be removed significantly by using the same means. Removal efficiency of NDMP for DOM decreased with the decrease of MW. Compared with PAC, NDMP could significantly reduce the acute and chronic bio-toxicities of DBEs. NaCl/NaOH mixture regenerants, with selected concentrations of 10% NaCl (m/m)/1% NaOH (m/m), could improve desorption efficiency. PMID:25108712

  15. Atmospheric Pressure Method and Apparatus for Removal of Organic Matter with Atomic and Ionic Oxygen

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A. (Inventor); Rutledge, Sharon K. (Inventor)

    1996-01-01

    A gas stream containing ionic and atomic oxygen in inert gas is used to remove organic matter from a substrate. The gas stream is formed by flowing a mixture of gaseous oxygen in an inert gas such as helium at atmospheric pressure past a high voltage, current limited, direct current arc which contacts the gas mixture and forms the ionic and atomic oxygen. The arc is curved at the cathode end and the ionic oxygen formed by the arc nearer to the anode end of the arc is accelerated in a direction towards the cathode by virtue of its charge. The relatively high mass to charge ratio of the ionic oxygen enables at least some of it to escape the arc before contacting the cathode and it is directed onto the substrate. This is useful for cleaning delicate substrates such as fine and historically important paintings and delicate equipment and the like.

  16. Atmospheric Pressure Method and Apparatus for Removal of Organic Matter with Atomic and Ionic Oxygen

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A. (Inventor); Rutledge, Sharon K. (Inventor)

    1997-01-01

    A gas stream containing ionic and atomic oxygen in inert gas is used to remove organic matter from a substrate. The gas stream is formed by flowing a mixture of gaseous oxygen in an inert gas such as helium at atmospheric pressure past a high voltage, current limited, direct current arc which contacts the gas mixture and forms the ionic and atomic oxygen. The arc is curved at the cathode end and the ionic oxygen formed by the arc nearer to the anode end of the arc is accelerated in a direction towards the cathode by virtue of its charge. The relatively high mass to charge ratio of the ionic oxygen enables at least some of it to escape the arc before contacting the cathode and it is directed onto the substrate. This is useful for cleaning delicate substrates such as fine and historically important paintings and delicate equipment and the like.

  17. Ultrasonic removal of organic deposits and polymer-induced formation damage

    SciTech Connect

    Roberts, P.M.; Venkitaraman, A.; Sharma, M.M.

    2000-03-01

    Experiments were conducted to investigate ultrasonic energy for reducing near-wellbore formation damage caused by organic deposits and polymers. It is shown that mechanical agitation provided by the acoustic waves re-suspends the paraffin and restores the effective permeability of the core to its undamaged condition. The depth of treatment is approximately 12 to 15 cm. This suggests that an acoustic source with or without solvents may provide an effective method of removing paraffins from the wellbore and the near-wellbore region. Ultrasonics was not as effective at restoring permeability damage caused by polymers. Results demonstrate that ultrasonic cleaning may be a viable method for cleaning the near-wellbore region when paraffin precipitation is a problem. The method would be particularly effective at treating long sections of pay where chemical methods may be too expensive.

  18. Synthesis of organic rectorite with novel Gemini surfactants for copper removal

    NASA Astrophysics Data System (ADS)

    Han, Guocheng; Han, Yang; Wang, Xiaoying; Liu, Shijie; Sun, Runcang

    2014-10-01

    Three novel Gemini surfactants were used to prepare organic rectorite (OREC) under microwave irradiation, in comparison with single-chain surfactant ester quaternary ammonium salt (EQAS) and cetyltrimethyl ammonium bromide (CTAB). The structure and morphology of OREC were characterized by XRD, BET, FT-IR, TEM and TGA. The removal of Cu2+ on OREC from aqueous solution was performed. The results reveal that Gemini surfactants modified REC had larger interlayer distance and higher surface area than single-chain surfactants EQAS and CTAB, and the increasing amount or chain length of Gemini surfactants led to larger layer spacing and higher adsorption capacities. The adsorption behavior of Gemini surfactant modified REC can be better described by Freundlich adsorption isotherm model, with a maximum adsorption capacity of 15.16 mg g-1. The desorption and regeneration experiments indicate good reuse property of Gemini modified REC adsorbent. Therefore, this study may widen the utilization of Gemini surfactants modified layered silicates.

  19. Selective removal of organic contaminants from sediments: A methodology for toxicity identification evaluations (TIEs)

    USGS Publications Warehouse

    Lebo, J.A.; Huckins, J.N.; Petty, J.D.; Ho, K.T.; Stern, E.A.

    2000-01-01

    Aqueous slurries of a test sediment spiked with dibenz[a,h]anthracene, 2,4,5,2',4',5'-hexachlorobiphenyl, p,p'-DDE, or phenanthrene were subjected to decontamination experimentation. The spiked sediments were agitated at elevated temperatures for at least 96 h in the presence of either of the two contaminant-absorbing media: clusters of polyethylene membrane or lipid- containing semipermeable membrane devices (SPMDs). The effects of treatment temperature and surface area of media on the removal of contaminants were explored. This work is part of a larger methodology for whole-sediment toxicity identification evaluation (TIE). A method is being sought that is capable of detoxifying sediments with respect to organic contaminants while leaving toxicity attributable to inorganic contaminants unaffected. (C) 2000 Elsevier Science Ltd.

  20. Age and speciation of iodine in groundwater and mudstones of the Horonobe area, Hokkaido, Japan: Implications for the origin and migration of iodine during basin evolution

    NASA Astrophysics Data System (ADS)

    Togo, Yoko S.; Takahashi, Yoshio; Amano, Yuki; Matsuzaki, Hiroyuki; Suzuki, Yohey; Terada, Yasuko; Muramatsu, Yasuyuki; Ito, Kazumasa; Iwatsuki, Teruki

    2016-10-01

    This paper reports the concentration, speciation and isotope ratio (129I/127I) of iodine from both groundwater and host rocks in the Horonobe area, northern Hokkaido, Japan, to clarify the origin and migration of iodine in sedimentary rocks. Cretaceous to Quaternary sedimentary rocks deposited nearly horizontally in Tenpoku Basin and in the Horonobe area were uplifted above sea level during active tectonics to form folds and faults in the Quaternary. Samples were collected from the Pliocene Koetoi and late Miocene Wakkanai formations (Fms), which include diatomaceous and siliceous mudstones. The iodine concentration in groundwater, up to 270 μmol/L, is significantly higher than that of seawater, with the iodine enrichment factor relative to seawater reaching 800-1500. The iodine concentration in the rocks decreases from the Koetoi to Wakkanai Fms, suggesting that iodine was released into the water from the rocks of deeper formations. The iodine concentration in the rocks is sufficiently high for forming iodine-rich groundwater as found in this area. X-ray absorption near edge structure (XANES) analysis shows that iodine exists as organic iodine and iodide (I-) in host rocks, whereas it exists mainly as I- in groundwater. The isotope ratio is nearly constant for iodine in the groundwater, at [0.11-0.23] × 10-12, and it is higher for iodine in rocks, at [0.29-1.1] × 10-12, giving iodine ages of 42-60 Ma and 7-38 Ma, respectively. Some iodine in groundwater must have originated from Paleogene and even late Cretaceous Fms, which are also considered as possible sources of oil and gas, in view of the old iodine ages of the groundwater. The iodine ages of the rocks are older than the depositional ages, implying that the rocks adsorbed some iodine from groundwater, which was sourced from greater depths. The iodine concentration in groundwater decreases with decreasing chlorine concentration due to mixing of iodine-rich connate water and meteoric water. A likely scenario

  1. Effect of recirculation on organic matter removal in a hybrid constructed wetland system.

    PubMed

    Ayaz, S C; Findik, N; Akça, L; Erdoğan, N; Kinaci, C

    2011-01-01

    This research project aimed to determine the technologically feasible and applicable wastewater treatment systems which will be constructed to solve environmental problems caused by small communities in Turkey. Pilot-scale treatment of a small community's wastewater was performed over a period of more than 2 years in order to show applicability of these systems. The present study involves removal of organic matter and suspended solids in serially operated horizontal (HFCW) and vertical (VFCW) sub-surface flow constructed wetlands. The pilot-scale wetland was constructed downstream of anaerobic reactors at the campus of TUBITAK-MRC. Anaerobically pretreated wastewater was introduced into this hybrid two-stage sub-surface flow wetland system (TSCW). Wastewater was first introduced into the horizontal sub-surface flow system and then the vertical flow system before being discharged. Recirculation of the effluent was tested in the system. When the recirculation ratio was 100%, average removal efficiencies for TSCW were 91 +/- 4% for COD, 83 +/- 10% for BOD and 96 +/- 3% for suspended solids with average effluent concentrations of 9 +/- 5 mg/L COD, 6 +/- 3 mg/L BOD and 1 mg/L for suspended solids. Comparing non-recirculation and recirculation periods, the lowest effluent concentrations were obtained with a 100% recirculation ratio. The effluent concentrations met the Turkish regulations for discharge limits of COD, BOD and TSS in each case. The study showed that a hybrid constructed wetland system with recirculation is a very effective method of obtaining very low effluent organic matter and suspended solids concentrations downstream of anaerobic pretreatment of domestic wastewaters in small communities. PMID:21977661

  2. Use of complementary and alternative medicine before and after organ removal due to urologic cancer

    PubMed Central

    Mani, Jens; Juengel, Eva; Arslan, Ilhan; Bartsch, Georg; Filmann, Natalie; Ackermann, Hanns; Nelson, Karen; Haferkamp, Axel; Engl, Tobias; Blaheta, Roman A

    2015-01-01

    Objective Many patients use complementary and alternative medicine (CAM) as primary treatment or symptom relief for a variety of illnesses. This study was designed to investigate the influence of surgical removal of a tumor-bearing urogenital organ on CAM use. Methods From 2007 to 2011, 350 patients underwent major urological surgery for kidney, prostate, or bladder cancer at the Goethe-University Hospital, Frankfurt, Germany. Data from 172 patients (49%), who returned a questionnaire, were retrospectively evaluated using the hospital information system along with the questionnaire to objectify CAM use 2 years before and after surgery. Results From the 172 patients returning questionnaires, 56 (33%) used CAM before and/or after surgery and 116 (67%) never used CAM. Of the 56 CAM users, 30 (54%) used CAM presurgery and 53 (95%) used CAM postsurgery, indicating a significant change of mind about CAM use. Patients of German nationality used CAM significantly more than patients of other nationalities. Higher educational status (high-school diploma or higher) was a significant factor in favor of CAM use. The most common type of CAM used before/after surgery was an alternative medical system (63/49%), a manipulative and body-based method (50/19%), and a biological-based therapy (37/32%). Information about CAM, either provided by medical professionals or by other sources, was the main reason determining whether patients used CAM or not. Conclusion The number of patients using CAM almost doubled after surgical removal of a cancer-bearing organ. Better awareness and understanding of CAM use by medical professionals could improve patient counseling. PMID:26491269

  3. The Removal of Terrestrial Dissolved Organic Matter in Coastal Regions by Photo-Flocculation Process

    NASA Astrophysics Data System (ADS)

    Abdulla, H. A.; Mopper, K.

    2015-12-01

    The fate of terrestrial dissolved organic matter (tDOM) as it moves to open ocean was the focus of many studies for the last three decades, most of these studies were focused on three major removal processes: 1) Photochemical mineralization of tDOM (conversion to inorganic forms); 2) Microbial oxidation; and 3) Mixing-induced flocculation. Based on recent estimations, the combination of theses removal processes accounts for ~20-35% of the loss of tDOM in estuaries and coastal regions; which is far from closing the gap between the riverine fluxes of tDOM and the amount of tDOM detected in the open ocean. In a preliminary experiment to determine if photo-flocculation indeed occurs at pH values and ionic strengths found in estuaries. A 0.1-μm filtered riverine was diluted 1:1 with artificial seawater and MilliQ water to yield final salinities ranging from 0 - 15; the pH of the saline samples was ranged from 6-8. Photo-flocculation was observed for all salinities, with particles organic carbon (POC) values ranged from 3.2 to 8.5% of the original DOC. Interestingly, the composition of the Photo-flocculated particles in the saline samples was markedly different from the zero salinity samples as shown in their FT-IR spectra. The photo-flocculated particles that formed in the saline samples appear to be rich in carbohydrate and amide functionalities (protein-like), while containing insignificant deprotonated carboxylate. While the flocs that formed in freshwater (salinity zero) are richer in deprotonated carboxyl groups, and relatively depleted in carbohydrate functionality.

  4. Autotrophic and heterotrophic denitrification for simultaneous removal of nitrogen, sulfur and organic matter.

    PubMed

    Guerrero, Lorna; Aguirre, Juan P; Muñoz, Maria A; Barahona, Andrea; Huiliñir, Cesar; Montalvo, Silvio; Borja, Rafael

    2016-07-01

    The aim of this investigation was to assess the startup and operation of a laboratory-scale hybrid UASB-Anaerobic Filter Reactor (UASFB) of 1 L volume, kept at 30°C, in order to carry out a simultaneous autotrophic and heterotrophic denitrification process. First, the heterotrophic and autotrophic populations were separately enriched, with specific cultures and subsequently the UASFB was inoculated with 2 g L(-1) of volatile suspended solids (VSS), with a ratio of 1.5:1 (autotrophs: heterotrophs). The influent or synthetic wastewater used was composed of: Na2S2O3·5H2O, CH3COOK, NaNO3, NaHCO3, K2HPO4, NH4Cl and saline solution. The concentrations varied depending on the organic loading rate (OLR), nitrogen loading rate (NLR) and sulfur loading rate (SLR) applied. In the UASFB reactor, two experimental conditions were tested and assessed: (i) COD/N ratio of 3.6 and SLR of 0.75 kg S m(-3) d(-1); and (ii) COD/N ratio of 5.8 and SLR of 0.25 kg S m(-3) d(-1). The results obtained demonstrated that an inoculum coming from an anaerobic reactor was able to carry out the process, obtaining a maximum nitrate removal of 85.3% in the first stage of operation and 99.5% in the second stage. The recovery of sulfur in form of sulfate in the effluent did not present a tendency to stabilize during the measured time, with a maximum thiosulfate removal of 32.5%, when the SLR was lowered to 0.25 kg S m(-3) d(-1). The maximum organic matter elimination, measured as COD, was 75.8%, which indicates the relatively good performance and behavior of the heterotrophic microorganisms. PMID:27093220

  5. Autotrophic and heterotrophic denitrification for simultaneous removal of nitrogen, sulfur and organic matter.

    PubMed

    Guerrero, Lorna; Aguirre, Juan P; Muñoz, Maria A; Barahona, Andrea; Huiliñir, Cesar; Montalvo, Silvio; Borja, Rafael

    2016-07-01

    The aim of this investigation was to assess the startup and operation of a laboratory-scale hybrid UASB-Anaerobic Filter Reactor (UASFB) of 1 L volume, kept at 30°C, in order to carry out a simultaneous autotrophic and heterotrophic denitrification process. First, the heterotrophic and autotrophic populations were separately enriched, with specific cultures and subsequently the UASFB was inoculated with 2 g L(-1) of volatile suspended solids (VSS), with a ratio of 1.5:1 (autotrophs: heterotrophs). The influent or synthetic wastewater used was composed of: Na2S2O3·5H2O, CH3COOK, NaNO3, NaHCO3, K2HPO4, NH4Cl and saline solution. The concentrations varied depending on the organic loading rate (OLR), nitrogen loading rate (NLR) and sulfur loading rate (SLR) applied. In the UASFB reactor, two experimental conditions were tested and assessed: (i) COD/N ratio of 3.6 and SLR of 0.75 kg S m(-3) d(-1); and (ii) COD/N ratio of 5.8 and SLR of 0.25 kg S m(-3) d(-1). The results obtained demonstrated that an inoculum coming from an anaerobic reactor was able to carry out the process, obtaining a maximum nitrate removal of 85.3% in the first stage of operation and 99.5% in the second stage. The recovery of sulfur in form of sulfate in the effluent did not present a tendency to stabilize during the measured time, with a maximum thiosulfate removal of 32.5%, when the SLR was lowered to 0.25 kg S m(-3) d(-1). The maximum organic matter elimination, measured as COD, was 75.8%, which indicates the relatively good performance and behavior of the heterotrophic microorganisms.

  6. Effects of effluent organic matter characteristics on the removal of bulk organic matter and selected pharmaceutically active compounds during managed aquifer recharge: Column study

    NASA Astrophysics Data System (ADS)

    Maeng, Sung Kyu; Sharma, Saroj K.; Abel, Chol D. T.; Magic-Knezev, Aleksandra; Song, Kyung-Guen; Amy, Gary L.

    2012-10-01

    Soil column experiments were conducted to investigate the effects of effluent organic matter (EfOM) characteristics on the removal of bulk organic matter (OM) and pharmaceutically active compounds (PhACs) during managed aquifer recharge (MAR) treatment processes. The fate of bulk OM and PhACs during an MAR is important to assess post-treatment requirements. Biodegradable OM from EfOM, originating from biological wastewater treatment, was effectively removed during soil passage. Based on a fluorescence excitation-emission matrix (F-EEM) analysis of wastewater effluent-dominated (WWE-dom) surface water (SW), protein-like substances, i.e., biopolymers, were removed more favorably than fluorescent humic-like substances under oxic compared to anoxic conditions. However, there was no preferential removal of biopolymers or humic substances, determined as dissolved organic carbon (DOC) observed via liquid chromatography with online organic carbon detection (LC-OCD) analysis. Most of the selected PhACs exhibited removal efficiencies of greater than 90% in both SW and WWE-dom SW. However, the removal efficiencies of bezafibrate, diclofenac and gemfibrozil were relatively low in WWE-dom SW, which contained more biodegradable OM than did SW (copiotrophic metabolism). Based on this study, low biodegradable fractions such as humic substances in MR may have enhanced the degradation of diclofenac, gemfibrozil and bezafibrate by inducing an oligotrophic microbial community via long term starvation. Both carbamazepine and clofibric acid showed persistent behaviors and were not influenced by EfOM.

  7. [Effects and mechanism on removing organics and reduction of membrane fouling using granular macro-porous anion exchange resin in drinking water treatment].

    PubMed

    He, Huan; Dong, Bing-Zhi; Xu, Guang-Hong; Yan, Zhao-Hui

    2014-05-01

    A granular macro-porous anion exchange resin combined with coagulation was used as pretreatment of microfiltration membrane, and their effects and mechanism on removing organics and reduction of membrane fouling were evaluated. The results showed that resin could be effective in removing organics with medium and small molecular weight ( Mr) but ineffective in removing organics with large Mr, while couagulation could significantly remove organics with large Mr, with a limited removal for organics with medium and small Mr. Using resin alone as pretreatment could be effective in removal of organics but limited in reduction of membrane fouling. With combination of coagulation and resin as pretreatment of microfiltration, not only organics could be removed effectively, but also membrane fouling could be reduced.

  8. Spontaneous electrochemical processing in conventional organic solutions for iron ion removal and metal deposition

    NASA Astrophysics Data System (ADS)

    Sun, Jinghua

    2002-01-01

    In one part of this research, spontaneous electrochemical redox reactions in conventional organic solutions commonly used in solvent extraction were demonstrated. In these reactions, the more noble metal is reduced while the less noble metal dissolves simultaneously. This technique was successfully applied in metal recovery or impurity separation in laboratory tests using synthetic and commercially produced solutions. The second use of the process was in depositing metal seed layers on metallized wafers for use in chip manufacture. The patented process in the first application, called galvanic stripping, has been demonstrated on batch and continuous levels to separate iron from a sulfate medium using DEHPA. The use of zinc and steel scrap as reductants was evaluated. The reductant was found to be one of the most important components in the galvanic stripping process. The effects of other processing variables such as solution chemistry, reductant surface area, ferric ion concentration in the organic phase, agitation, and aqueous pH on iron recovery and efficiency were also evaluated. An experimental design with statistical analysis was utilized to optimize overall iron removal and process efficiency. The continuous test allowed the cycling of the organic and strip aqueous solutions and produced a concentrated iron sulfate strip solution containing ferrous ions in the range of 90 to 130 g/L. Based on the galvanic stripping principle a novel metal deposition technique was successfully applied for depositing seed layers on TiSiN and other metal films on Si wafers for subsequent electroless copper deposition as well as the deposition of gold onto a sputtered copper film. XPS measurements confirmed that the deposited particles or films were a pure metallic metal phase. The effects of various factors including the organic bath composition, reaction time, temperature and agitation on the deposit surface morphologies and the distribution of nuclei were investigated.

  9. Iodine oxide in the global marine boundary layer

    NASA Astrophysics Data System (ADS)

    Prados-Roman, C.; Cuevas, C. A.; Hay, T.; Fernandez, R. P.; Mahajan, A. S.; Royer, S.-J.; Galí, M.; Simó, R.; Dachs, J.; Großmann, K.; Kinnison, D. E.; Lamarque, J.-F.; Saiz-Lopez, A.

    2014-08-01

    Emitted mainly by the oceans, iodine is a halogen compound important for atmospheric chemistry due to its high ozone depletion potential and effect on the oxidizing capacity of the atmosphere. Here we present a comprehensive dataset of iodine oxide (IO) measurements in the open marine boundary layer (MBL) made during the Malaspina 2010 circumnavigation. Results show IO mixing ratios ranging from 0.4 to 1 pmol mol-1 and, complemented with additional field campaigns, this dataset confirms through observations the ubiquitous presence of reactive iodine chemistry in the global marine environment. We use a global model with organic (CH3I, CH2ICl, CH2I2 and CH2IBr) and inorganic (HOI and I2) iodine ocean emissions to investigate the contribution of the different iodine source gases to the budget of IO in the global MBL. In agreement with previous estimates, our results indicate that, globally averaged, the abiotic precursors contribute about 75% to the iodine oxide budget. However, this work reveals a strong geographical pattern in the contribution of organic vs. inorganic precursors to reactive iodine in the global MBL.

  10. Performance of organics and nitrogen removal in subsurface wastewater infiltration systems by intermittent aeration and shunt distributing wastewater.

    PubMed

    Pan, Jing; Yuan, Fang; Yu, Long; Huang, Linli; Fei, Hexin; Cheng, Fan; Zhang, Qi

    2016-07-01

    Organics and nitrogen removal in four subsurface wastewater infiltration systems (SWISs), named SWIS A (without intermittent aeration and shunt distributing wastewater), SWIS B (with intermittent aeration), SWIS C (with shunt distributing wastewater) and SWIS D (with intermittent aeration and shunt distributing wastewater) was investigated. High average removal rates of 92.3% for COD, 90.2% for NH4-N and 88.1% for TN were achieved simultaneously in SWIS D compared with SWIS A, B and C. The excellent TN removal of SWIS D was due to intermittent aeration provided sufficient oxygen for nitrification in upper matrix and the favorable anoxic or anaerobic environment for denitrification in subsequent matrix, and moreover, shunt distributing wastewater provided sufficient carbon source for denitrification process. The results indicated that intermittent artificial aeration combined with shunt distributing wastewater could achieve high organics and nitrogen removal in SWISs.

  11. Iodine: deficiency and therapeutic considerations.

    PubMed

    Patrick, Lyn

    2008-06-01

    Iodine deficiency is generally recognized as the most commonly preventable cause of mental retardation and the most common cause of endocrinopathy (goiter and primary hypothyroidism). Iodine deficiency becomes particularly critical in pregnancy due to the consequences for neurological damage during fetal development as well as during lactation. The safety of therapeutic doses of iodine above the established safe upper limit of 1 mg is evident in the lack of toxicity in the Japanese population that consumes 25 times the median intake of iodine consumption in the United States. Japan's population suffers no demonstrable increased incidence of autoimmune thyroiditis or hypothyroidism. Studies using 3.0- to 6.0-mg doses to effectively treat fibrocystic breast disease may reveal an important role for iodine in maintaining normal breast tissue architecture and function. Iodine may also have important antioxidant functions in breast tissue and other tissues that concentrate iodine via the sodium iodide symporter. PMID:18590348

  12. Adsorption of iodine from COIL waste gas on soaked coal-based activated carbon

    NASA Astrophysics Data System (ADS)

    Zhou, Junbo; Hao, Shan; Gao, Liping

    2014-04-01

    The chemical oxygen-iodine laser (COIL) has wide application prospects in military, industrial and medical treatment fields as a second generation gas chemical laser to follow the first HF/DF chemical laser. However, a COIL releases large amounts of gas, such as helium, oxygen, chlorine and iodine. Chlorides have a serious corrosive effect on the system, especially iodine vapor crystallization, which seriously endangers the normal use of vacuum systems, and radioactive methyl iodide, which is hazardous to operators and pollutes the environment. The use of soaked coal-based activated carbon as an adsorbent for removing methyl iodine is proposed, while it is proposed that coal-based activated carbon is an effective adsorbent for removing stable iodine. The research conducted in this work shows that iodine residues are less than 0.5 μg ml-1 after the adsorption treatment and the decontamination factor of the coal-based activated carbon for removing stable iodine is more than 1000. Using this method can achieve the purpose of removing harmful iodine, satisfy the requirements for engineering applications, and also be applied to other nuclear power plant flue gas treatments.

  13. The effects of organic fouling on the removal of radionuclides by reverse osmosis membranes.

    PubMed

    Ding, Shiyuan; Yang, Yu; Li, Chen; Huang, Haiou; Hou, Li-An

    2016-05-15

    The removals of cesium (Cs) and strontium (Sr), two hazardous and abundant radionuclides in aquatic environment, were assessed with their isotopes in a synthetic water containing Suwannee River natural organic matter (SRNOM), a natural surface water (SW) and a wastewater effluent (WW) by two different types of ultra-low pressure RO membranes (M1 and M2). The rejections of Sr by the membranes M1 and M2 were higher than 97.5% and 96.0%, respectively, and the rejections of Cs exceeded 90.0% and 85.0%, respectively, in the filtration of real water. The membrane M1 exhibited a more significant flux decline in the filtration of the SRNOM solution, while more severe flux declines were observed with the membrane M2 in the filtration of SW and WW. Protein-like materials with relatively high molecular weight were the main contributors to the flux decline, and humic-acid-like compounds had little effect on the flux decline. Donnan exclusion and size exclusion by humic-acid-like compounds improved the rejections by the membrane M2 with weaker hydrophilicity, while the cake-enhanced concentration polarization reduced the rejections of Cs and Sr by the membrane M1 with stronger hydrophilicity. The ionic strength in the real water resulted in the mitigation of membrane fouling. This study provided important insights into foulant characterization and the mechanisms of organic-fouling-enhanced rejections of Cr and Sr by ultra-low pressure RO membranes.

  14. Removal of organic dyes using Cr-containing activated carbon prepared from leather waste.

    PubMed

    Oliveira, Luiz C A; Coura, Camila Van Zanten; Guimarães, Iara R; Gonçalves, Maraisa

    2011-09-15

    In this work, hydrogen peroxide decomposition and oxidation of organics in aqueous medium were studied in the presence of activated carbon prepared from wet blue leather waste. The wet blue leather waste, after controlled pyrolysis under CO(2) flow, was transformed into chromium-containing activated carbons. The carbon with Cr showed high microporous surface area (up to 889 m(2)g(-1)). Moreover, the obtained carbon was impregnated with nanoparticles of chromium oxide from the wet blue leather. The chromium oxide was nanodispersed on the activated carbon, and the particle size increased with the activation time. It is proposed that these chromium species on the carbon can activate H(2)O(2) to generate HO radicals, which can lead to two competitive reactions, i.e. the hydrogen peroxide decomposition or the oxidation of organics in water. In fact, in this work we observed that activated carbon obtained from leather waste presented high removal of methylene blue dye combining the adsorption and oxidation processes.

  15. Effects of vomeronasal organ removal on olfactory sex discrimination and odor preferences of female ferrets.

    PubMed

    Woodley, S K; Cloe, A L; Waters, P; Baum, M J

    2004-10-01

    Previous research suggests that body odorants, including anal scents and urinary odors, contribute to sex discrimination and mate identification in European ferrets of both sexes. We assessed the possible role of the vomeronasal organ (VNO) in these functions by surgically removing the organ bilaterally in sexually experienced female ferrets. Lesioned (VNOx) and sham-operated control (VNOi) females reliably discriminated between male- and female-derived anal scent gland as well as fresh urinary odors in habituation/dishabituation tests. However, VNOi females spent significantly more time than VNOx subjects investigating male urinary odors in these tests. Also, VNOi females, but not VNOx subjects, preferred to investigate day-old male versus female urine spots as well as wooden blocks that had previously been soiled by male versus female ferrets. Both groups of female ferrets preferred to approach volatile odors from a breeding male instead of an estrous female in Y-maze tests and both groups showed similar levels of receptive sexual behavior in response to a male's neck grip. The VNO is apparently not required for olfactory sex discrimination or mate recognition in this carnivore, but instead may play a role in promoting continued contact with nonvolatile body odors previously deposited by opposite-sex conspecifics during territorial scent marking. PMID:15466811

  16. Removal of volatile organic compounds using amphiphilic cyclodextrin-coated polypropylene

    PubMed Central

    Lumholdt, Ludmilla; Fourmentin, Sophie; Nielsen, Thorbjørn T

    2014-01-01

    Summary Polypropylene nonwovens were functionalised using a self-assembled, amphiphilic cyclodextrin coating and the potential for water purification by removal of pollutants was studied. As benzene is one of the problematic compounds in the Water Framework Directive, six volatile organic compounds (benzene and five benzene-based substances) were chosen as model compounds. The compounds were tested as a mixture in order to provide a more realistic situation since the wastewater will be a complex mixture containing multiple pollutants. The volatile organic compounds are known to form stable inclusion complexes with cyclodextrins. Six different amphiphilic cyclodextrin derivatives were synthesised in order to elucidate whether or not the uptake abilities of the coating depend on the structure of the derivative. Headspace gas chromatography was used for quantification of the uptake exploiting the volatile nature of benzene and its derivatives. The capacity was shown to increase beyond the expected stoichiometries of guest–host complexes with ratios of up to 16:1. PMID:25550739

  17. Case report on the successful removal of an organic penetrating object into the orbit.

    PubMed

    Rezae, Leyla; Najafi, Farid; Moradinazar, Mehdi; Ahmadijouybari, Tooraj

    2014-01-01

    The penetration of objects into the orbit can lead to blindness and even to the death of the patient. The penetration of organic objects longer than 7 cm into the eye is a rare phenomenon. In this study, we report a case in which a 6-year-old boy fell on a pencil which penetrated the upper side of his right eye orbit. Because of the agitation of the child and the lack of access, it was not possible to perform a brain or orbital computed tomography (CT) scan, but an X-ray showed that the object had gone directly into the retro-orbital space. As the result of a clinical diagnosis, it was possible to ascertain that the globe was severely hypertonic. Throughout this process the child was extremely agitated. After consultation with the neurosurgery service, the patient was rushed to the operation room. After anesthesia and superanasal peritomy, the pencil was removed slowly from the orbit. Neurology and CT scans after surgery didn't show any ocular or brain symptoms. Once the patient's general condition had improved sufficiently and his visual acuity had returned to 10/10, he was discharged from the hospital. This case shows that even without specialized tests, such as CT scans, an organ can be saved.

  18. Made-to-order metal-organic frameworks for trace carbon dioxide removal and air capture

    PubMed Central

    Shekhah, Osama; Belmabkhout, Youssef; Chen, Zhijie; Guillerm, Vincent; Cairns, Amy; Adil, Karim; Eddaoudi, Mohamed

    2014-01-01

    Direct air capture is regarded as a plausible alternate approach that, if economically practical, can mitigate the increasing carbon dioxide emissions associated with two of the main carbon polluting sources, namely stationary power plants and transportation. Here we show that metal-organic framework crystal chemistry permits the construction of an isostructural metal-organic framework (SIFSIX-3-Cu) based on pyrazine/copper(II) two-dimensional periodic 44 square grids pillared by silicon hexafluoride anions and thus allows further contraction of the pore system to 3.5 versus 3.84 Å for the parent zinc(II) derivative. This enhances the adsorption energetics and subsequently displays carbon dioxide uptake and selectivity at very low partial pressures relevant to air capture and trace carbon dioxide removal. The resultant SIFSIX-3-Cu exhibits uniformly distributed adsorption energetics and offers enhanced carbon dioxide physical adsorption properties, uptake and selectivity in highly diluted gas streams, a performance, to the best of our knowledge, unachievable with other classes of porous materials. PMID:24964404

  19. Graphene nanosheets and graphite oxide as promising adsorbents for removal of organic contaminants from aqueous solution.

    PubMed

    Ji, Liangliang; Chen, Wei; Xu, Zhaoyi; Zheng, Shourong; Zhu, Dongqiang

    2013-01-01

    Graphenes are an emerging class of carbon nanomaterials whose adsorption properties toward organic compounds have not been well understood. In the present study, graphene nanosheets were prepared by reoxidation and abrupt heating of graphite oxide, which was prepared by sequential chemical oxidation of commercial nonporous graphite powder. Adsorption properties of three aromatic compounds (naphthalene, 2-naphthol, and 1-naphthylamine) and one pharmaceutical compound (tylosin) on graphene nanosheets and graphite oxide were examined to explore the potential of these two adsorbents for the removal of organic contaminants from aqueous solutions. Compared with the literature data of adsorption on carbon nanotubes, adsorption of bulky, flexible tylosin on graphene nanosheets exhibited markedly faster adsorption kinetics, which can be attributed to their opened-up layer structure. Graphene nanosheets and graphite oxide showed similar sequences of adsorption affinity: 1-naphthylamine > 2-naphthol > tylosin > naphthalene (with much larger differences observed on graphite oxide). It was proposed that the strong adsorption of the three aromatic compounds was mainly due to π-π electron donor-acceptor interactions with the graphitic surfaces of adsorbents. Additionally, Lewis acid-base interaction was likely an important factor contributing to the strong adsorption of 1-naphthylamine and tylosin, especially for the O-functionality-abundant graphite oxide. After being normalized on the basis of adsorbent surface area, adsorption affinities of all four tested adsorbates on graphene nanosheets were very close to those on nonporous graphite powder, reflecting complete accessibility of the adsorbent surface area in adsorption.

  20. Removal of fluorescence and ultraviolet absorbance of dissolved organic matter in reclaimed water by solar light.

    PubMed

    Wu, Qianyuan; Li, Chao; Wang, Wenlong; He, Tao; Hu, Hongying; Du, Ye; Wang, Ting

    2016-05-01

    Storing reclaimed water in lakes is a widely used method of accommodating changes in the consumption of reclaimed water during wastewater reclamation and reuse. Solar light serves as an important function in degrading pollutants during storage, and its effect on dissolved organic matter (DOM) was investigated in this study. Solar light significantly decreased the UV254 absorbance and fluorescence (FLU) intensity of reclaimed water. However, its effect on the dissolved organic carbon (DOC) value of reclaimed water was very limited. The decrease in the UV254 absorbance intensity and FLU excitation-emission matrix regional integration volume (FLU volume) of reclaimed water during solar light irradiation was fit with pseudo-first order reaction kinetics. The decrease of UV254 absorbance was much slower than that of the FLU volume. Ultraviolet light in solar light had a key role in decreasing the UV254 absorbance and FLU intensity during solar light irradiation. The light fluence-based removal kinetic constants of the UV254 and FLU intensity were independent of light intensity. The peaks of the UV254 absorbance and FLU intensity with an apparent molecular weight (AMW) of 100Da to 2000Da decreased after solar irradiation, whereas the DOC value of the major peaks did not significantly change.

  1. Removal of fluorescence and ultraviolet absorbance of dissolved organic matter in reclaimed water by solar light.

    PubMed

    Wu, Qianyuan; Li, Chao; Wang, Wenlong; He, Tao; Hu, Hongying; Du, Ye; Wang, Ting

    2016-05-01

    Storing reclaimed water in lakes is a widely used method of accommodating changes in the consumption of reclaimed water during wastewater reclamation and reuse. Solar light serves as an important function in degrading pollutants during storage, and its effect on dissolved organic matter (DOM) was investigated in this study. Solar light significantly decreased the UV254 absorbance and fluorescence (FLU) intensity of reclaimed water. However, its effect on the dissolved organic carbon (DOC) value of reclaimed water was very limited. The decrease in the UV254 absorbance intensity and FLU excitation-emission matrix regional integration volume (FLU volume) of reclaimed water during solar light irradiation was fit with pseudo-first order reaction kinetics. The decrease of UV254 absorbance was much slower than that of the FLU volume. Ultraviolet light in solar light had a key role in decreasing the UV254 absorbance and FLU intensity during solar light irradiation. The light fluence-based removal kinetic constants of the UV254 and FLU intensity were independent of light intensity. The peaks of the UV254 absorbance and FLU intensity with an apparent molecular weight (AMW) of 100Da to 2000Da decreased after solar irradiation, whereas the DOC value of the major peaks did not significantly change. PMID:27155416

  2. The effects of organic fouling on the removal of radionuclides by reverse osmosis membranes.

    PubMed

    Ding, Shiyuan; Yang, Yu; Li, Chen; Huang, Haiou; Hou, Li-An

    2016-05-15

    The removals of cesium (Cs) and strontium (Sr), two hazardous and abundant radionuclides in aquatic environment, were assessed with their isotopes in a synthetic water containing Suwannee River natural organic matter (SRNOM), a natural surface water (SW) and a wastewater effluent (WW) by two different types of ultra-low pressure RO membranes (M1 and M2). The rejections of Sr by the membranes M1 and M2 were higher than 97.5% and 96.0%, respectively, and the rejections of Cs exceeded 90.0% and 85.0%, respectively, in the filtration of real water. The membrane M1 exhibited a more significant flux decline in the filtration of the SRNOM solution, while more severe flux declines were observed with the membrane M2 in the filtration of SW and WW. Protein-like materials with relatively high molecular weight were the main contributors to the flux decline, and humic-acid-like compounds had little effect on the flux decline. Donnan exclusion and size exclusion by humic-acid-like compounds improved the rejections by the membrane M2 with weaker hydrophilicity, while the cake-enhanced concentration polarization reduced the rejections of Cs and Sr by the membrane M1 with stronger hydrophilicity. The ionic strength in the real water resulted in the mitigation of membrane fouling. This study provided important insights into foulant characterization and the mechanisms of organic-fouling-enhanced rejections of Cr and Sr by ultra-low pressure RO membranes. PMID:26994696

  3. Made-to-order metal-organic frameworks for trace carbon dioxide removal and air capture.

    PubMed

    Shekhah, Osama; Belmabkhout, Youssef; Chen, Zhijie; Guillerm, Vincent; Cairns, Amy; Adil, Karim; Eddaoudi, Mohamed

    2014-06-25

    Direct air capture is regarded as a plausible alternate approach that, if economically practical, can mitigate the increasing carbon dioxide emissions associated with two of the main carbon polluting sources, namely stationary power plants and transportation. Here we show that metal-organic framework crystal chemistry permits the construction of an isostructural metal-organic framework (SIFSIX-3-Cu) based on pyrazine/copper(II) two-dimensional periodic 4(4) square grids pillared by silicon hexafluoride anions and thus allows further contraction of the pore system to 3.5 versus 3.84 Å for the parent zinc(II) derivative. This enhances the adsorption energetics and subsequently displays carbon dioxide uptake and selectivity at very low partial pressures relevant to air capture and trace carbon dioxide removal. The resultant SIFSIX-3-Cu exhibits uniformly distributed adsorption energetics and offers enhanced carbon dioxide physical adsorption properties, uptake and selectivity in highly diluted gas streams, a performance, to the best of our knowledge, unachievable with other classes of porous materials.

  4. Measurements and Modelling of Reactive Iodine Oxides in the Coastal MBL

    NASA Astrophysics Data System (ADS)

    Najera, J. J.; Bloss, W. J.

    2012-04-01

    The release of iodine compounds into the marine atmosphere can affect a number of aspects of atmospheric composition: Iodine species can participate in catalytic ozone destruction cycles, which may be augmented by bromine species; reactions of iodine compounds can perturb the OH:HO2 and NO:NO2 ratios, heterogeneous loss of reservoir compounds such as HOI and INO3 can lead to removal of HOx and NOx, and higher iodine oxides can contribute to the formation and/or growth of aerosol particles. In this work, we focus upon understanding the effect of the spatial distribution of iodine emissions upon local HOx and NOx levels in the immediate vicinity of a coastal sites, using new observations to re-evaluate previous field campaign data. We present an analysis of results from a new instruments which measures point inorganic iodine species concentrations. The technique of resonance fluorescence (RF) is employed for the detection of iodine atoms, and the total photolabile iodine content. Measurements made at Mace Head, Ireland during July-August 2007 and May 2011 are presented. A detailed 1-dimensional photochemical box model is employed in a lagrangian sense to simulate the evolving chemical composition of an air column advected across the coastal margin. The model is compared with the observed iodine species, and then used to explore the transient response of the NOx and HOx families at the Mace Head site to heterogeneous iodine emissions: The transit time between the intertidal iodine emission zone and the shoreline site where previous measurements of HOx, NOx etc. have been made is insufficient for steady-state to become established, although this assumption has been used in earlier model studies of such data. Finally, we consider the limitations in our ability to quantify the impacts of iodine chemistry, which arise from uncertainties in the iodine kinetics and photochemistry - for example, what is the atmospheric lifetime of inorganic iodine ? - and explore their

  5. LABORATORY REPORT ON IODINE ({sup 129}I AND {sup 127}I) SPECIATION, TRANSFORMATION AND MOBILITY IN HANFORD GROUNDWATER, SUSPENDED PARTICLES AND SEDIMENTS

    SciTech Connect

    Kaplan, D.; Santschi, P.; Xu, C.; Zhang, S.; Ho, Y.; Li, H.; Schwehr, K.

    2012-09-30

    than iodide K{sub d} values, and the K{sub d} values for both species tended to increase with the amount of organic carbon (OC) present in the sediment. It is especially noteworthy that this trend existed at the very low OC concentrations that naturally exist in the Hanford sediments. Iodine and OC can form essentially irreversible covalent bonds, thereby providing a yet unstudied {sup 129}I retardation reaction at the Hanford Site. In addition to the transformation of iodine species, the sediment collected from the vadose zone also released stable iodide into the aqueous phase. It was found that the three sediments all took up the ambient iodate from the groundwater and slowly transformed it into iodide under the laboratory conditions, likely dependent on the abundance of reducing agents such as organic matter and Fe{sup 2+}. Therefore two competitive iodine processes were identified, the tendency for the sediment to reduce iodate to iodide, and the groundwater chemistry to maintain the iodine as iodate, presumably it is largely the result of natural pH and dissolved O{sub 2}/Eh levels. Suspended carbonate (and silica) particles collected from Hanford groundwater contained elevated amounts of iodine (142 ± 8 μg/g iodine), consisting mainly of iodate (>99%). Iodate was likely incorporated into the carbonate structure during calcite precipitation upon degasing of CO{sub 2} as the groundwater samples were removed from the subsurface. This concentration of groundwater iodate in precipitated carbonate has implication to long-term fate and transport of 129I and on active in-situ {sup 129}I groundwater remediation. This study provides some of the first groundwater radioiodine speciation studies conducted in arid environments and provides much needed mechanistic descriptions to permit making informed decisions about low-cost/high intellectual input remediation options, such as monitored natural attenuation, or long-term stewardship of nuclear waste disposal sites.

  6. Use of poly(ethylene terephtalate) film bag to sample and remove humidity from atmosphere containing volatile organic compounds.

    PubMed

    Beghi, Sandra; Guillot, Jean-Michel

    2008-03-01

    Nalophan bags made from poly(ethylene terephtalate) film are often used to collect odorous gases. In this paper, the sample water removal method, based on humidity diffusion through the sample bag film, was applied using Nalophan bags and Tedlar bags to sample volatile organic compounds (VOCs) at low concentration (10 microg/m(3)). The removal of water with Nalophan bags enabled a reduction in relative humidity (RH) in a 10-L air sample from 80% to 20% in 2h at 20 degrees C. The use of Nalophan bags for the removal of water did not involve significant VOC loss among the 11 compounds studied. PMID:18243220

  7. Comparison of two treatments for the removal of selected organic micropollutants and bulk organic matter: conventional activated sludge followed by ultrafiltration versus membrane bioreactor.

    PubMed

    Sahar, E; Ernst, M; Godehardt, M; Hein, A; Herr, J; Kazner, C; Melin, T; Cikurel, H; Aharoni, A; Messalem, R; Brenner, A; Jekel, M

    2011-01-01

    The potential of membrane bioreactor (MBR) systems to remove organic micropollutants was investigated at different scales, operational conditions, and locations. The effluent quality of the MBR system was compared with that of a plant combining conventional activated sludge (CAS) followed by ultrafiltration (UF). The MBR and CAS-UF systems were operated and tested in parallel. An MBR pilot plant in Israel was operated for over a year at a mixed liquor suspended solids (MLSS) range of 2.8-10.6 g/L. The MBR achieved removal rates comparable to those of a CAS-UF plant at the Tel-Aviv wastewater treatment plant (WWTP) for macrolide antibiotics such as roxythromycin, clarithromycin, and erythromycin and slightly higher removal rates than the CAS-UF for sulfonamides. A laboratory scale MBR unit in Berlin - at an MLSS of 6-9 g/L - showed better removal rates for macrolide antibiotics, trimethoprim, and 5-tolyltriazole compared to the CAS process of the Ruhleben sewage treatment plant (STP) in Berlin when both were fed with identical quality raw wastewater. The Berlin CAS exhibited significantly better benzotriazole removal and slightly better sulfamethoxazole and 4-tolyltriazole removal than its MBR counterpart. Pilot MBR tests (MLSS of 12 g/L) in Aachen, Germany, showed that operating flux significantly affected the resulting membrane fouling rate, but the removal rates of dissolved organic matter and of bisphenol A were not affected. PMID:21330721

  8. A multi-level bioreactor to remove organic matter and metals, together with its associated bacterial diversity.

    PubMed

    Wu, Yonghong; Hu, Zhengyi; Kerr, Philip G; Yang, Linzhang

    2011-01-01

    The purpose of this study was to treat complex wastewater consisting of domestic wastewater, tobacco processing and building materials washings. The proposed multi-level bioreactor consists of a biopond-biofilter, anoxic/aerobic (A/O) fluidized beds and a photoautotrophic system. The results show that when the hydraulic load of the bioreactor was 200 m3/d, it successfully and simultaneously removed the organic matter and metals. When the bioreactor was in a relatively steady-state condition, the overall average organic matter and metals removal efficiencies are as follows, COD (89%), UV245 nm-matter (91%), Cu (78%), Zn (79%) and Fe (84%). The growth conditions of the native bacterial habitat were improved, which resulted from the increase of the in bacterial diversity under the rejuvenated conditions induced by the bioreactor. The results demonstrate that the multi-level bioreactor, without a sludge treatment system, can remove heterogeneous organic matter and metals from wastewater.

  9. Sorption mechanism and predictive models for removal of cationic organic contaminants by cation exchange resins.

    PubMed

    Jadbabaei, Nastaran; Zhang, Huichun

    2014-12-16

    Understanding the sorption mechanism of organic contaminants on cation exchange resins (CXRs) will enable application of these resins for the removal of cationic organic compounds from contaminated water. In this study, sorption of a diverse set of 12 organic cations and 8 neutral aromatic solutes on two polystyrene CXRs, MN500 and Amberlite 200, was examined. MN500 showed higher sorbed concentrations due to its microporous structure. The sorbed concentrations followed the same trend of aromatic cations > aliphatic cations > neutral solutes for both resins. Generally, solute-solvent interactions, nonpolar moiety of the solutes, and resin matrix can affect selectivity of the cations. Sorbed concentrations of the neutral compounds were significantly less than those of the cations, indicating a combined effect of electrostatic and nonelectrostatic interactions. By conducting multiple linear regression between Gibbs free energy of sorption and Abraham descriptors for all 20 compounds, polarity/polarizability (S), H-bond acidity (A), induced dipole (E), and electrostatic (J(+)) interactions were found to be involved in the sorption of the cations by the resins. After converting the aqueous sorption isotherms to sorption from the ideal gas-phase by water-wet resins, a more significant effect of J(+) was observed. Predictive models were then developed based on the linear regressions and validated by accurately estimating the sorption of different test set compounds with a root-mean-square error range of 0.91-1.1 and 0.76-0.85 for MN500 and Amberlite 200, respectively. The models also accurately predicted sorption behavior of aniline and imidazole between pH 3 and 10. PMID:25409479

  10. [Variation characteristics and removal rate of fluorescence organic matter in the petrochemical wastewater treatment process].

    PubMed

    Zhou, Jing-Ling; Xi, Hong-Bo; Zhou, Yue-Xi; Xu, Ji-Xian; Song, Guang-Qing

    2014-03-01

    Petrochemical wastewater is of huge quantity released during the production and complicated contaminants of petrochemical wastewater will have immense negative impact on ecology environment. Three-dimensional excitation-emission matrix fluorescence(3D-EEM) was used to investigate the characteristic fluorescence of influent and effluent from each processing unit of Hydrolysis-acidification +A/O+ Contact-oxidation Process in a typical petrochemical wastewater treatment plant . The results showed that there were 4 fluorescence peaks named Peak A, Peak B, Peak D, Peak E in the spectrum chart of influent, they are around lambda(ex/lambda(em) = 220/300, 225/340, 270/300, 275/340 nm, the primary source of fluorescence organic matter(FOM) is industrial wastewater. The fluorescence intensity of each fluorescence peak was decreased, while location was unchanged in the effluent of Hydrolysis-acidification. Peak C appeared from the effluent of anaerobic tank at lambda(ex)/lambda(em) = 250/425 nm, then the fluorescence intensity of Peak C was enhanced in the effluent of aerobic tank. Peak A disappeared from the effluent of secondary sedimentation tank. The spectrum chart of the wastewater had no obvious variation after secondary sedimentation tank. The removal rate of FOM was expressed with the degradation percentage of the fluorescence intensity, the total FOM was reduced by 92.0% after processing, and the removal rate of the FOM fluoresce around Peak A, Peak B, Peak D, Peak E were 100.0%, 91.2%, 80.3%, 92.0% respectively. A volatile I(Peak B)/I(Peak E) value of influent but a relatively stable value of effluent demonstrated that the wastewater treatment plant operated steadily and the process has higher capacity in resistance to shock loading.

  11. Net removal of dissolved organic carbon in the subsurface Black Sea

    NASA Astrophysics Data System (ADS)

    Margolin, A. R.; Gerringa, L. J.; Hansell, D. A.; Rijkenberg, M. J. A.

    2015-12-01

    Dissolved organic carbon (DOC) concentrations in the deep Black Sea are ~2.5 times higher than found in the global ocean. The two major external sources of DOC are rivers and the Mediterranean, while expansive phytoplankton blooms contribute autochthonous carbon to the Black Sea's ~800 Tg C DOC reservoir. Here, a basin-wide zonal section of DOC is explored using data from the 2013 Dutch GEOTRACES GA04-N "MedBlack" cruise 64PE373. DOC distributions are interpreted with respect to well-described hydrographic and biogeochemical layers of the Black Sea. DOC concentrations were >180 µmol kg-1 at the surface, decreasing to ~125 µmol kg-1 at the base of the oxic layer and reaching a minimum of ~113 µmol kg-1 in the upper anoxic layer between ~150 and 500 m. Maximum anoxic layer concentrations of 122 µmol kg-1 were found in the homogeneous benthic bottom layer (>1775 m). Determined from the relationship of DOC with salinity, we found that ~34-41 µmol kg-1 was removed from the basin's oxic layer in <5 years, and an additional 13 ± 5 µmol kg-1 was removed from the anoxic layer during its ~300-600 years residence time, given steady state. We find no evidence for DOC accumulation in the anoxic Black Sea, and suggest that concentrations are elevated relative to the ocean due to input of terrigenous DOC from rivers. The Black Sea's relatively elevated DOC pool may be analogous to the previously hypothesized anoxic Eocene ocean's elevated reservoir if the Eocene ocean received a substantial amount of terrigenous DOC from rivers.

  12. Color and chlorinated organics removal from pulp mills wastewater using activated petroleum coke.

    PubMed

    Shawwa, A R; Smith, D W; Sego, D C

    2001-03-01

    Delayed petroleum coke, a waste by-product from the oil sand industry, was utilized in the production of activated carbon. The activated carbon was then evaluated for color and chlorinated organics reduction from pulp mill wastewater. The activation of the petroleum coke was evaluated using a fixed bed reactor involving carbonization and activation steps at temperature of 850 degrees C and using steam as the activation medium. The activation results showed that the maximum surface area of the activated coke was achieved at an activation period of 4 h. The maximum surface area occurred at burnoff and water efficiency of 48.5 and 54.3%, respectively. Increasing the activation period to 6 h resulted in a decrease in the surface area. Methylene blue adsorption results indicated that the activation process was successful. Methylene blue adsorbed per 100 g of applied activated coke was 10 times higher than that adsorbed by raw petroleum coke. Adsorption equilibrium results of the bleached wastewater and the activated coke showed that significant color, COD, DOC and AOX removal (> 90%) was achieved when the activated coke dose exceeded 15,000 mg/L. Adsorption isotherms, in terms of COD, DOC, UV and color were developed based on the batch equilibrium data. Based on these isotherms, the amount of activated coke required to achieve certain removal of color and AOX can be predicted. The utilization of the petroleum coke for the production of activated carbon can provide an excellent disposal option for the oil sand industry at the same time would provide a cheap and valuable activated carbon.

  13. [Allergy to iodinated drugs and to foods rich in iodine: Iodine is not the allergenic determinant].

    PubMed

    Dewachter, Pascale; Mouton-Faivre, Claudie

    2015-11-01

    "Iodine allergy" does not exist. The concept of "iodine allergy" should be abandoned since it may result in inappropriate measures such as drug, food or environmental eviction. Immediate or non-immediate allergic hypersensitivity to iodinated contrast media is not infrequent. The corresponding allergens have not been identified. Iodine is not involved. Immediate or non-immediate allergic hypersensitivity to povidone iodine is rare. The corresponding allergen is povidone in case of immediate hypersensitivity while nonoxynol might be involved during non-immediate hypersensitivity. Seafood allergens belong to a group of muscle proteins. Immediate drug hypersensitivity or food hypersensitivity is assessed by immediate-reading skin tests while non-immediate drug hypersensitivity is investigated by delayed-reading skin testing. Combined histamine and tryptase measurement is invaluable during the diagnostic approach of immediate hypersensitivity. Other biological tests are being evaluated. Allergic hypersensitivity to iodinated contrast agents does not contraindicate the use of other iodinated drugs.

  14. [Allergy to iodinated drugs and to foods rich in iodine: Iodine is not the allergenic determinant].

    PubMed

    Dewachter, Pascale; Mouton-Faivre, Claudie

    2015-11-01

    "Iodine allergy" does not exist. The concept of "iodine allergy" should be abandoned since it may result in inappropriate measures such as drug, food or environmental eviction. Immediate or non-immediate allergic hypersensitivity to iodinated contrast media is not infrequent. The corresponding allergens have not been identified. Iodine is not involved. Immediate or non-immediate allergic hypersensitivity to povidone iodine is rare. The corresponding allergen is povidone in case of immediate hypersensitivity while nonoxynol might be involved during non-immediate hypersensitivity. Seafood allergens belong to a group of muscle proteins. Immediate drug hypersensitivity or food hypersensitivity is assessed by immediate-reading skin tests while non-immediate drug hypersensitivity is investigated by delayed-reading skin testing. Combined histamine and tryptase measurement is invaluable during the diagnostic approach of immediate hypersensitivity. Other biological tests are being evaluated. Allergic hypersensitivity to iodinated contrast agents does not contraindicate the use of other iodinated drugs. PMID:26387623

  15. Iodine mobilization in groundwater system at Datong basin, China: evidence from hydrochemistry and fluorescence characteristics.

    PubMed

    Li, Junxia; Wang, Yanxin; Guo, Wei; Xie, Xianjun; Zhang, Liping; Liu, Yaqing; Kong, Shuqiong

    2014-01-15

    Characterizing the speciation of iodine in groundwater is essential for understanding its hydrogeochemical behavior in aquifer systems. To quantify the variations in iodine speciation and assess factors controlling the distribution and transformation of iodine, 82 groundwater samples and 1 rain water were collected from the Datong basin, northern China in this study. Factor analysis (FA) and excitation emission matrix with parallel factor analysis (EEM-PARAFAC) were used to clarify the potential relationships among iodine species and other hydrochemical parameters. The iodine concentrations of groundwater range from 6.23 to 1380 μg L(-1) with 47% of samples exceeding its drinking water level of 150 μg L(-1) as recommended by the Chinese government. 57% of samples have ratios of iodate to total iodine greater than 60%, while iodide as the major species in 22% of the samples. Significant amounts of organic iodine with concentrations higher than 100 μg L(-1) were observed in 9 groundwater samples. Redox conditions of groundwater system strongly affect iodine concentration and speciation of inorganic iodine in groundwater, and extremely reducing condition restricts the iodine release from sediments into groundwater. The results of FA show that iodine mobilization in groundwater is related to the nature of dissolved organic matter. EEM-PARAFAC model demonstrates the dominance of terrestrial DOM sources and the presence of microbial activities in groundwater system of the Datong basin. It is proposed that degradation of organic matter and reductive dissolution of iron oxyhydroxides are major hydrogeochemical processes responsible for the mobilization of iodine release and the genesis of organic iodine. PMID:24064343

  16. Iodine mobilization in groundwater system at Datong basin, China: evidence from hydrochemistry and fluorescence characteristics.

    PubMed

    Li, Junxia; Wang, Yanxin; Guo, Wei; Xie, Xianjun; Zhang, Liping; Liu, Yaqing; Kong, Shuqiong

    2014-01-15

    Characterizing the speciation of iodine in groundwater is essential for understanding its hydrogeochemical behavior in aquifer systems. To quantify the variations in iodine speciation and assess factors controlling the distribution and transformation of iodine, 82 groundwater samples and 1 rain water were collected from the Datong basin, northern China in this study. Factor analysis (FA) and excitation emission matrix with parallel factor analysis (EEM-PARAFAC) were used to clarify the potential relationships among iodine species and other hydrochemical parameters. The iodine concentrations of groundwater range from 6.23 to 1380 μg L(-1) with 47% of samples exceeding its drinking water level of 150 μg L(-1) as recommended by the Chinese government. 57% of samples have ratios of iodate to total iodine greater than 60%, while iodide as the major species in 22% of the samples. Significant amounts of organic iodine with concentrations higher than 100 μg L(-1) were observed in 9 groundwater samples. Redox conditions of groundwater system strongly affect iodine concentration and speciation of inorganic iodine in groundwater, and extremely reducing condition restricts the iodine release from sediments into groundwater. The results of FA show that iodine mobilization in groundwater is related to the nature of dissolved organic matter. EEM-PARAFAC model demonstrates the dominance of terrestrial DOM sources and the presence of microbial activities in groundwater system of the Datong basin. It is proposed that degradation of organic matter and reductive dissolution of iron oxyhydroxides are major hydrogeochemical processes responsible for the mobilization of iodine release and the genesis of organic iodine.

  17. Iodine insufficiency: a global health problem?

    PubMed

    Swanson, Christine A; Pearce, Elizabeth N

    2013-09-01

    As a result of collaborative efforts with international organizations and the salt industry, many developing and developed countries practice universal salt iodization (USI) or have mandatory salt fortification programs. As a consequence, the prevalence of iodine deficiency decreased dramatically. The United States and Canada are among the few developed countries that do not practice USI. Such an undertaking would require evidence of deficiency among vulnerable population groups, including pregnant women, newborns, and developing infants. Government agencies in the United States rely heavily on data from NHANES to assess the iodine status of the general population and pregnant women in particular. NHANES data suggest that pregnant women in the United States remain mildly deficient. This is important, because the developing fetus is dependent on maternal iodine intake for normal brain development throughout pregnancy. Professional societies have recommended that pregnant and lactating women, or those considering pregnancy, consume a supplement providing 150 μg iodine daily. The United States and Canada collaborate on the daily recommended intake and are also confronted with the challenge of identifying the studies needed to determine if USI is likely to be beneficial to vulnerable population groups without exposing them to harm.

  18. Iodine insufficiency: a global health problem?

    PubMed

    Swanson, Christine A; Pearce, Elizabeth N

    2013-01-01

    As a result of collaborative efforts with international organizations and the salt industry, many developing and developed countries practice universal salt iodization (USI) or have mandatory salt fortification programs. As a consequence, the prevalence of iodine deficiency decreased dramatically. The United States and Canada are among the few developed countries that do not practice USI. Such an undertaking would require evidence of deficiency among vulnerable population groups, including pregnant women, newborns, and developing infants. Government agencies in the United States rely heavily on data from NHANES to assess the iodine status of the general population and pregnant women in particular. NHANES data suggest that pregnant women in the United States remain mildly deficient. This is important, because the developing fetus is dependent on maternal iodine intake for normal brain development throughout pregnancy. Professional societies have recommended that pregnant and lactating women, or those considering pregnancy, consume a supplement providing 150 μg iodine daily. The United States and Canada collaborate on the daily recommended intake and are also confronted with the challenge of identifying the studies needed to determine if USI is likely to be beneficial to vulnerable population groups without exposing them to harm. PMID:24038248

  19. Origin of electronic transport of lithium phthalocyanine iodine crystal

    SciTech Connect

    Koike, Noritake; Oda, Masato; Shinozuka, Yuzo

    2013-12-04

    The electronic structures of Lithium Phthalocyanine Iodine are investigated using density functional theory. Comparing the band structures of several model crystals, the metallic conductivity of highly doped LiPcI{sub x} can be explained by the band of doped iodine. These results reveal that there is a new mechanism for electronic transport of doped organic semiconductors that the dopant band plays the main role.

  20. Simultaneous nitrate and phosphate removal from wastewater lacking organic matter through microbial oxidation of pyrrhotite coupled to nitrate reduction.

    PubMed

    Li, Ruihua; Morrison, Liam; Collins, Gavin; Li, Aimin; Zhan, Xinmin

    2016-06-01

    This study investigated the efficiency of a pyrrhotite autotrophic denitrification biofilter (PADB) technology for simultaneous N and P removal from wastewater lacking organic matter. A PADB was constructed with natural pyrrhotite as the biofilter medium and inoculated with autotrophic denitrifies enriched from anaerobic sludge. Over an operating period of 247 days, PADB efficiently removed NO3(-) and PO4(3-) simultaneously from wastewater that lacked organic matter. The hydraulic retention time (HRT), and influent NO3(-) and PO4(3-) concentrations affected the removal of NO3(-) and PO4(3-). A longer HRT led to lower concentrations of NO3(-) and PO4(3-) in the effluent. The PO4(3-) removal was influenced by NO3(-) removed; the more NO3(-) removed, the more PO4(3-) removed. As the synthetic wastewater containing NO3(-)-N of 28 mg L(-1) and PO4(3-)-P of 6 mg L(-1) in the absence of organic matter was treated by PADB at HRT of 24 h, total oxidized nitrogen (TON; NO2(-)-N + NO3(-)-N) and PO4(3-)-P concentrations of effluent were as low as 1.13 and 0.28 mg L(-1), respectively. When treatment of municipal wastewater treatment plant (WWTP) secondary effluent with TON of 21.11 mg L(-1) and PO4(3-)-P of 2.62 mg L(-1) at HRT of 24 h, the effluent TON was 1.89 mg L(-1) and PO4(3-)-P was 0.34 mg L(-1). PO4(3-) was removed through the formation of secondary minerals with Fe and Ca. These secondary minerals contained elevated phosphorus, which presents a potential for P recovery from wastewater. PMID:27017573

  1. Removal of inorganic mercury and methylmercury from surface waters following coagulation of dissolved organic matter with metal-based salts

    USGS Publications Warehouse

    Henneberry, Y.K.; Kraus, T.E.C.; Fleck, J.A.; Krabbenhoft, D.P.; Bachand, P.M.; Horwath, W.R.

    2011-01-01

    The presence of inorganic mercury (IHg) and methylmercury (MeHg) in surface waters is a health concern worldwide. This study assessed the removal potential use of metal-based coagulants as a means to remove both dissolved IHg and MeHg from natural waters and provides information regarding the importance of Hg associations with the dissolved organic matter (DOM) fraction and metal hydroxides. Previous research indicated coagulants were not effective at removing Hg from solution; however these studies used high concentrations of Hg and did not reflect naturally occurring concentrations of Hg. In this study, water collected from an agricultural drain in the Sacramento-San Joaquin Delta was filtered to isolate the dissolved organic matter (DOM) fraction. The DOM was then treated with a range of coagulant doses to determine the efficacy of removing all forms of Hg from solution. Three industrial-grade coagulants were tested: ferric chloride, ferric sulfate, and polyaluminum chloride. Coagulation removed up to 85% of DOM from solution. In the absence of DOM, all three coagulants released IHg into solution, however in the presence of DOM the coagulants removed up to 97% of IHg and 80% of MeHg. Results suggest that the removal of Hg is mediated by DOM-coagulant interactions. There was a preferential association of IHg with the more aromatic, higher molecular weight fraction of DOM but no such relationship was found for MeHg. This study offers new fundamental insights regarding large-scale removal of Hg at environmentally relevant regarding large-scale removal of Hg at environmentally relevant concentrations.

  2. Removal and transformation of recalcitrant organic matter from stabilized saline landfill leachates by coagulation-ozonation coupling processes.

    PubMed

    Monje-Ramirez, I; Orta de Velásquez, M T

    2004-05-01

    The Bordo Poniente sanitary landfill in Mexico City currently receives 11,500 ton/day of solid wastes. The landfill has been in operation since 1985, in what was formerly Texcoco Lake, now a dried-up lakebed. The physico-chemical characteristics of the leachate generated by this particular landfill are altered by the incorporation of freatic saline water present in the area. This paper reports the results from a study evaluating coagulation and ozonation as alternative processes for removing and transforming recalcitrant organic matter from stabilized saline landfill leachate. Coagulation with ferric sulfate was found to remove up to 67% of COD and 96% of leachate color. The remaining 33% COD was removed with ozone. Recalcitrant organic matter removal by ozonation is limited by the reaction kinetic due mainly to ozone's low reactivity with the organic compounds present in the leachates (amines, amides, alcohols, aliphatic compounds, and carboxylic acids). However, ozone contributes greatly to changing the recalcitrant characteristics of organic matter. Leachate biodegradability was found to be significantly enhanced through ozonation: BOD(5) values reach 265%, and the BOD(5)/COD ratio increases from 0.003 to 0.015. Infrared analysis of ozonated leachates shows that the main by-products of recalcitrant organic matter ozonation are an increase in the hydroxyl and carboxylic groups, and the presence of aldehydes groups.

  3. Computational screening of iodine uptake in zeolitic imidazolate frameworks in a water-containing system.

    PubMed

    Yuan, Yue; Dong, Xiuqin; Chen, Yifei; Zhang, Minhua

    2016-08-17

    Iodine capture is of great environmental significance due to the high toxicity and volatility of I2. Here we conduct a systematic computational investigation of iodine adsorption in zeolitic imidazolate frameworks (ZIFs) by adopting the grand canonical Monte Carlo (GCMC) simulation and the density functional theory (DFT) method. The results confirm the vital structural factors for iodine adsorption at 298 K and moderate pressures including metal sites, organic linkers, symmetry, and topology types. The uptake will be enhanced by active metal sites, the simple imidazolate linker and single asymmetric linkers with polar functional groups. The symmetry effect is stronger than the surface properties. Meanwhile low steric hindrance is more beneficial than polar functional groups to iodine adsorption. The specific topology types like mer bringing large surface areas and large diameter cages result in high iodine capacities. Iodine molecules tend to locate in cages with large diameters and aggregates along the sides of cages. In contrast, water prefers small diameter cages. In hydrophilic materials, water has a negative impact on iodine uptake due to its similar adsorption sites to iodine. The selectivity of iodine over water increases with increasing water content due to the large diameter cages of ZIFs. This work proves that ZIFs can be identified as efficient and economical adsorbents with high diversity for iodine in a water-containing system. Furthermore, it provides comprehensive insights into key structural factors for iodine uptake and separation in silver-free porous solids. PMID:27499079

  4. Carbon Dioxide Removal from Flue Gas Using Microporous Metal Organic Frameworks

    SciTech Connect

    Lesch, David A

    2010-06-30

    UOP LLC, a Honeywell Company, in collaboration with Professor Douglas LeVan at Vanderbilt University (VU), Professor Adam Matzger at the University of Michigan (UM), Professor Randall Snurr at Northwestern University (NU), and Professor Stefano Brandani at the University of Edinburgh (UE), supported by Honeywell's Specialty Materials business unit and the Electric Power Research Institute (EPRI), have completed a three-year project to develop novel microporous metal organic frameworks (MOFs) and an associated vacuum-pressure swing adsorption (vPSA) process for the removal of CO{sub 2} from coal-fired power plant flue gas. The project leveraged the team's complementary capabilities: UOP's experience in materials development and manufacturing, adsorption process design and process commercialization; LeVan and Brandani's expertise in high-quality adsorption measurements; Matzger's experience in syntheis of MOFs and the organic components associated with MOFs; Snurr's expertise in molecular and other modeling; Honeywell's expertise in the manufacture of organic chemicals; and, EPRI's knowledge of power-generation technology and markets. The project was successful in that a selective CO{sub 2} adsorbent with good thermal stability and reasonable contaminant tolerance was discovered, and a low cost process for flue gas CO{sub 2} capture process ready to be evaluated further at the pilot scale was proposed. The team made significant progress toward the current DOE post-combustion research targets, as defined in a recent FOA issued by NETL: 90% CO{sub 2} removal with no more than a 35% increase in COE. The team discovered that favorable CO{sub 2} adsorption at more realistic flue gas conditions is dominated by one particular MOF structure type, M/DOBDC, where M designates Zn, Co, Ni, or Mg and DOBDC refers to the form of the organic linker in the resultant MOF structure, dioxybenzenedicarboxylate. The structure of the M/DOBDC MOFs consists of infinite-rod secondary

  5. Removal of organic and inorganic sulfur compounds by ozone and granular activated carbon

    SciTech Connect

    Shepherd, B.; Ball, G.W.

    1996-11-01

    Most groundwater supplies in the western U.S. are relatively low in dissolved organic matter, are generally free of bacteria, and are platable to their consumers. In areas of western Nevada, certain groundwaters are near active geothermal areas, which can produce sulfurous types of tastes and odors (T&Os) in the water. Other water quality characteristics can consist of either relatively low or highly mineralized waters, variations in pH, and temperatures ranging from those slightly above normal groundwaters to pressurized steam. Watersource Consulting Engineers (WCE) and Shepherd Laboratories (SL) conducted an engineering study of a high-capacity well for a local northwestern Nevada utility. WCE`s original task had been to design pumping and storage facilities for the well, in addition to evaluating basic treatment. Originally, WCE anticipated designing facilities to remove hydrogen sulfide (H{sub 2}S) and reduce color, primarily with chlorination and aeration. SL was requested to evaluate existing water quality and eventually conduct bench-scale testing of several treatment processes. As the study proceeded, the original goals were modified when it became evident that water quality conditions required more extensive evaluation. The study was done in several stages, reflecting the information gained during each stage. The final recommended design criteria included treatment for improving water quality relative to T&O, color, total organic carbon (TOC), and, to a limited extent, fluoride. The water quality goals adopted by the utility encompassed primary maximum contaminant levels (MCLs) for regulatory compliance and secondary MCLs for aesthetically pleasing water. The treatment processes evaluated and recommended in this study were designed primarily to improve the aesthetic qualities of color, taste, and odor. Fluoride reduction was evaluated but was not included in the final design requirements, except for the overall reduction provided by the recommended process.

  6. Organic silicon compounds anf hydrogen sulfide removal from biogas by mineral and adsorbent

    NASA Astrophysics Data System (ADS)

    Choi, J.

    2015-12-01

    Biogas utilized for energy production needs to be free from organic silicon compounds and hydrogen sulfide , as their burning has damaging effects on utilities and humans; organic silicon compounds and hydrogen sulfide can be found in biogas produced from biomass wastes, due to their massive industrial use in synthetic product,such as cosmetics, detergents and paints.Siloxanes and hydrogen sulfide removal from biogas can be carried out by various methods (Ajhar et al., 2010); aim of the present work is to find a single practical andeconomic way to drastically and simultaneously reduce both hydrogen sulfide and the siloxanes concentration to less than 1 ppm. Some commercial activated carbons previously selected (Monteleoneet al., 2011) as being effective in hydrogen sulfide up taking have been tested in an adsorption measurement apparatus, by flowing both hydrogen sulphide and volatile siloxane (Decamethycyclopentasiloxane or D5) in a nitrogen stream,typically 25-300 ppm D5 over N2, through an clay minerals, Fe oxides and Silica; the adsorption process was analyzed by varying some experimental parameters (concentration, grain size, bed height). The best silica shows an adsorption capacity of 0.2 g D5 per gram of silica. The next thermo gravimetric analysis (TGA) confirms the capacity data obtained experimentally by the breakthrough curve tests.The capacity results depend on D5 and hydrogen sulphide concentrations. A regenerative silica process is then carried out byheating the silica bed up to 200 ° C and flushing out the adsorbed D5 and hydrogen sulphide samples in a nitrogen stream in athree step heating procedure up to 200 ° C. The adsorption capacity is observed to degrade after cyclingthe samples through several adsorption-desorption cycles.

  7. Effect of temperature on removal of trace organic chemicals in managed aquifer recharge systems.

    PubMed

    Alidina, Mazahirali; Shewchuk, Justin; Drewes, Jörg E

    2015-03-01

    This study was undertaken to investigate whether changes in temperature experienced in MAR systems affect attenuation of trace organic chemicals (TOrCs). A set of laboratory-scale soil columns were placed in a temperature-controlled environmental chamber and operated at five different temperature set-points (30, 20, 10, 8 and 4°C) covering the range of typical groundwater temperatures in cold, moderate and arid climate regions. Removal of bulk organic carbon both in the infiltration zone as well as during deeper infiltration was independent of temperature. Of the 22 TOrCs investigated, only six chemicals exhibited changes in attenuation as a function of temperature. Attenuation of four of the compounds (diclofenac, gemfibrozil, ketoprofen and naproxen) decreased as the temperature was reduced from 30°C to 4°C, likely due to decreased microbial activity at lower temperatures. As the temperature was decreased, however, attenuation of oxybenzone and trimethoprim were noted to increase. This increased attenuation was likely due to more efficient sorption at lower temperatures, though possible changes in the microbial composition as the temperature decreased may also have contributed to this change. Changes in rate constants of attenuation (ka) for the biotransformed TOrCs with temperature suggested the existence of a critical temperature at 10°C for three of the four TOrCs, where significant changes to rates of attenuation occurred. Results from this study indicated that for most TOrCs, changes in temperature do not impact their attenuation. Thus, seasonal changes in temperature are not considered to be a major concern for attenuation of most TOrCs in MAR systems.

  8. Simultaneous nitrification/denitrification and trace organic contaminant (TrOC) removal by an anoxic-aerobic membrane bioreactor (MBR).

    PubMed

    Phan, Hop V; Hai, Faisal I; Kang, Jinguo; Dam, Hoa K; Zhang, Ren; Price, William E; Broeckmann, Andreas; Nghiem, Long D

    2014-08-01

    Simultaneous nitrification/denitrification and trace organic contaminant (TrOC) removal during wastewater treatment by an integrated anoxic-aerobic MBR was examined. A set of 30 compounds was selected to represent TrOCs that occur ubiquitously in domestic wastewater. The system achieved over 95% total organic carbon (TOC) and over 80% total nitrogen (TN) removal. In addition, 21 of the 30 TrOCs investigated here were removed by over 90%. Low oxidation reduction potential (i.e., anoxic/anaerobic) regimes were conducive to moderate to high (50% to 90%) removal of nine TrOCs. These included four pharmaceuticals and personal care products (primidone, metronidazole, triclosan, and amitriptyline), one steroid hormone (17β-estradiol-17-acetate), one industrial chemical (4-tert-octylphenol) and all three selected UV filters (benzophenone, oxybenzone, and octocrylene). Internal recirculation between the anoxic and aerobic bioreactors was essential for anoxic removal of remaining TrOCs. A major role of the aerobic MBR for TOC, TN, and TrOC removal was observed.

  9. Simultaneous removal of organic matter and nitrogen from milking parlor wastewater by a magnetic activated sludge (MAS) process.

    PubMed

    Ying, Chun; Umetsu, Kazutaka; Ihara, Ikko; Sakai, Yasuzo; Yamashiro, Takaki

    2010-06-01

    The magnetic activated sludge (MAS) process is a modification of the conventional activated sludge process to improve the solid-liquid separation characteristics. It was developed to reduce the production of excess sludge and the time required for the conventional activated sludge process. In this study, actual milking parlor wastewater was treated with a MAS process and no sludge was removed. The effectiveness of continuous aeration and intermittent aeration in removing organic matter and nitrogen were compared. Both processes were highly efficient at removing chemical oxygen demand (COD) (averaged 91% removal) and ammonium nitrogen (NH(4)-N) (averaged 99% removal). In marked contrast to the continuous aeration process, the 30-min aeration/90-min non-aeration cycle of the intermittent aeration process rapidly reduced the nitrate nitrogen (NO(3)-N) concentration to near-zero. This result indicates that NO(3)-N was almost completely denitrified via nitrite nitrogen (NO(2)-N) to nitrogen gas. Removal of organic material and nitrogen can be considered to have occurred simultaneously in the single tank of the MAS process.

  10. Evaluation of refractory organic removal in combined biological powdered activated carbon--microfiltration for advanced wastewater treatment.

    PubMed

    Seo, G T; Ohgaki, S

    2001-01-01

    Biological powdered activated carbon (BPAC) was incorporated with a microfiltration (MF, 0.2 micron pore size) system to remove the refractory organic matter contained in secondary sewage effluent. A synthetic secondary sewage effluent was used as influent in this study, containing both non-biodegradable organic substances (such as humic acid, lignin sulfonate, tannic acid and arabic gum powder) and biodegradable ones. These refractory organic materials were possibly degraded in contact with microorganisms for 20-27 days. Although humic acid and arabic gum were weakly adsorbed on the activated carbon, they could be effectively removed in the BPAC reactor. The TOC removal at a powdered activated carbon (PAC) concentration of 20 g/L was higher than at 0.5-2 g PAC/L (83% and 66-68%, respectively). The higher removal efficiency was due to the increased rejection at the membrane module in which most of the PAC was accumulated. More than 90% of non-biodegradable compounds removal (detected as E280, UV absorption at 280 nm) occurred in the BPAC reactor. The biological growth parameter b/Y, used in system design, was estimated to be 0.017 d-1. Relatively high permeate flux of 1.88 m/d could be obtained even at higher PAC concentration of 20 g/L.

  11. Zirconium-Based Metal-Organic Framework for Removal of Perrhenate from Water.

    PubMed

    Banerjee, Debasis; Xu, Wenqian; Nie, Zimin; Johnson, Lewis E V; Coghlan, Campbell; Sushko, Maria L; Kim, Dongsang; Schweiger, Michael J; Kruger, Albert A; Doonan, Christian J; Thallapally, Praveen K

    2016-09-01

    The efficient removal of pertechnetate (TcO4(-)) anions from liquid waste or melter off-gas solution for an alternative treatment is one of the promising options to manage (99)Tc in legacy nuclear waste. Safe immobilization of (99)Tc is of major importance because of its long half-life (t1/2 = 2.13 × 10(5) yrs) and environmental mobility. Different types of inorganic and solid-state ion-exchange materials have been shown to absorb TcO4(-) anions from water. However, both high capacity and selectivity have yet to be achieved in a single material. Herein, we show that a protonated version of an ultrastable zirconium-based metal-organic framework can adsorb perrhenate (ReO4(-)) anions, a nonradioactive surrogate for TcO4(-), from water even in the presence of other common anions. Synchrotron-based powder X-ray diffraction and molecular simulations were used to identify the position of the adsorbed ReO4(-) (surrogate for TcO4(-)) molecule within the framework. PMID:27494264

  12. Superior removal of arsenic from water with zirconium metal-organic framework UiO-66

    PubMed Central

    Wang, Chenghong; Liu, Xinlei; Chen, J. Paul; Li, Kang

    2015-01-01

    In this study, water stable zirconium metal-organic framework (UiO-66) has been synthesized and for the first time applied as an adsorbent to remove aquatic arsenic contamination. The as-synthesized UiO-66 adsorbent functions excellently across a broad pH range of 1 to 10, and achieves a remarkable arsenate uptake capacity of 303 mg/g at the optimal pH, i.e., pH = 2. To the best of our knowledge, this is the highest arsenate As(V) adsorption capacity ever reported, much higher than that of currently available adsorbents (5–280 mg/g, generally less than 100 mg/g). The superior arsenic uptake performance of UiO-66 adsorbent could be attributed to the highly porous crystalline structure containing zirconium oxide clusters, which provides a large contact area and plenty of active sites in unit space. Two binding sites within the adsorbent framework are proposed for arsenic species, i.e., hydroxyl group and benzenedicarboxylate ligand. At equilibrium, seven equivalent arsenic species can be captured by one Zr6 cluster through the formation of Zr-O-As coordination bonds. PMID:26559001

  13. Effective Removal of Tetracycline from Aqueous Solution by Organic Acid-Coated Magnetic Nanoparticles.

    PubMed

    Guo, Liang; Liang, Yuyan; Chen, Xuelan; Xu, Wei; Wu, Kesheng; Wei, Hua; Xiong, Yonghua

    2016-03-01

    Self-assembled iron oxide nanocomposites are good magnetic nano-adsorbents that can be prepared using simple methods. Four types of organic acid-functionalised (oleic acid, undecenoic acid, caprylic acid or hexanoic acid) magnetic nanoparticles (MNPs) were synthesised through a one-pot chemisorption method for the removal of tetracycline (TC) from aqueous solution. The undecenoic acid-coated MNPs (UA-MNPs) exhibited the highest adsorption efficiency and can be easily retrieved with a low-gradient magnetic separator (0.4 Tesla) at pH 5.0 aqueous solution. The TC adsorption process on the UA-MNPs followed the Langmuir isotherm and the maximum adsorption capacities increased from 86.96 mg g(-1) to 222.2 mg g(-1) with the increase in temperature from 288 K to 318 K. The kinetics of adsorption fits pseudo-second-order model perfectly with a rate constant, 5.946 g mg(-1) min(-1) at 298 K. The positive values of the enthalpy (AH) and the negative value of the free energy (AG) indicated an endothermic and spontaneous adsorption process of TC on the UA-MNPs. Moreover, the UA-MNPs possessed excellent ability to adsorb the other three major types of TC antibiotics, including chlortetracycline, oxytetracycline and doxycycline. PMID:27455621

  14. Fate of terrestrial colored dissolved organic matter (CDOM) in the Arctic Ocean: exported or removed?

    NASA Astrophysics Data System (ADS)

    Granskog, M. A.; Stedmon, C. A.; Dodd, P. A.; Amon, R. M. W.; Pavlov, A. K.; de Steur, L.; Hansen, E.

    2012-04-01

    Colored dissolved organic matter (CDOM) was measured with hydrographic parameters (salinity, d18O and inorganic nutrients) across Fram Strait. East Greenland Current (EGC) surface waters showed a pronounced CDOM absorption maximum between 30 and 120 m depth associated with both river and sea ice brine-enriched water, characteristic of polar mixed layer water and upper halocline water. Lowest CDOM was found in the Atlantic inflow within the West Spitsbergen Current (WSC). Although applied elsewhere in the Arctic, we show that the salinity-CDOM relationship not suitable for evaluating the mixing behavior of CDOM (conservative vs. non-conservative) in Fram Strait. The strong correlation between meteoric water and optical properties of CDOM are indicative of the terrigenous origin of CDOM in the EGC and marine origin in WSC. Based on CDOM absorption in Polar Water and comparison with an Arctic river discharge weighted mean, we estimate that a 68% integrated loss of CDOM absorption across 250-600 nm has occurred, with a preferential removal of absorption at longer wavelengths reflecting the loss of high molecular weight material. Budget calculations of CDOM exports through Fram Strait using modeled volume transports indicate that the net southward export of CDOM in Fram Strait equals to 8 to 14% of the total riverine CDOM inputs to the Arctic Ocean, thus physical export is not a major sink of CDOM. We propose that CDOM can aid in discriminating glacial melt waters from Arctic riverine freshwater on the east Greenland shelf.

  15. Superior removal of arsenic from water with zirconium metal-organic framework UiO-66

    NASA Astrophysics Data System (ADS)

    Wang, Chenghong; Liu, Xinlei; Chen, J. Paul; Li, Kang

    2015-11-01

    In this study, water stable zirconium metal-organic framework (UiO-66) has been synthesized and for the first time applied as an adsorbent to remove aquatic arsenic contamination. The as-synthesized UiO-66 adsorbent functions excellently across a broad pH range of 1 to 10, and achieves a remarkable arsenate uptake capacity of 303 mg/g at the optimal pH, i.e., pH = 2. To the best of our knowledge, this is the highest arsenate As(V) adsorption capacity ever reported, much higher than that of currently available adsorbents (5-280 mg/g, generally less than 100 mg/g). The superior arsenic uptake performance of UiO-66 adsorbent could be attributed to the highly porous crystalline structure containing zirconium oxide clusters, which provides a large contact area and plenty of active sites in unit space. Two binding sites within the adsorbent framework are proposed for arsenic species, i.e., hydroxyl group and benzenedicarboxylate ligand. At equilibrium, seven equivalent arsenic species can be captured by one Zr6 cluster through the formation of Zr-O-As coordination bonds.

  16. Species and distribution of inorganic and organic phosphorus in enhanced phosphorus removal aerobic granular sludge.

    PubMed

    Huang, Wenli; Huang, Weiwei; Li, Huifang; Lei, Zhongfang; Zhang, Zhenya; Tay, Joo Hwa; Lee, Duu-Jong

    2015-10-01

    The species and distribution of phosphorus (P) in an enhanced biological phosphorus removal (EBPR)-aerobic granular sludge (AGS) were fractionated and further analyzed. Results showed that microbial cells, extracellular polymeric substances (EPS) and mineral precipitates contributed about 73.7%, 17.6% and 5.3-6.4% to the total P (TP) of EBPR-AGS, respectively. Inorganic P (IP) species were orthophosphate, pyrophosphate and polyphosphate among which polyphosphate was the major P species in the AGS, cells and EPS. Monoester and diester phosphates were identified as the organic P (OP) species in the AGS and cells. Hydroxyapatite (Ca5(PO4)3OH) and calcium phosphate (Ca2(PO4)3) were the dominant P minerals accumulated in the core of the granules. Cells along with polyphosphate were mainly in the outer layer of AGS while EPS were distributed in the whole granules. Based on the above results, the distribution of IP and OP species in AGS has been conceived.

  17. Species and distribution of inorganic and organic phosphorus in enhanced phosphorus removal aerobic granular sludge.

    PubMed

    Huang, Wenli; Huang, Weiwei; Li, Huifang; Lei, Zhongfang; Zhang, Zhenya; Tay, Joo Hwa; Lee, Duu-Jong

    2015-10-01

    The species and distribution of phosphorus (P) in an enhanced biological phosphorus removal (EBPR)-aerobic granular sludge (AGS) were fractionated and further analyzed. Results showed that microbial cells, extracellular polymeric substances (EPS) and mineral precipitates contributed about 73.7%, 17.6% and 5.3-6.4% to the total P (TP) of EBPR-AGS, respectively. Inorganic P (IP) species were orthophosphate, pyrophosphate and polyphosphate among which polyphosphate was the major P species in the AGS, cells and EPS. Monoester and diester phosphates were identified as the organic P (OP) species in the AGS and cells. Hydroxyapatite (Ca5(PO4)3OH) and calcium phosphate (Ca2(PO4)3) were the dominant P minerals accumulated in the core of the granules. Cells along with polyphosphate were mainly in the outer layer of AGS while EPS were distributed in the whole granules. Based on the above results, the distribution of IP and OP species in AGS has been conceived. PMID:26144019

  18. Removal of volatile organic compounds by heterogeneous ozonation on microporous synthetic alumina silicate.

    PubMed

    Brodu, Nicolas; Zaitan, Hicham; Manero, Marie-Hélène; Pic, Jean-Stéphane

    2012-01-01

    A hybrid process combining adsorption and ozonation was examined as an alternative treatment for odorous volatile organic compounds (VOCs). Methyl ethyl ketone (MEK) was chosen to study the influence of operating parameters. Two synthetic aluminosilicates (faujasite-Y and ZSM-5) were tested for adsorption and reactivity with ozone. The adsorption equilibrium measurement on both adsorbents showed that adsorption performance depends on temperature but is not sensitive to relative humidity, due to the hydrophobic properties of the materials. Adsorbed VOCs were oxidized at low temperature when ozonated flow was sent to the reactor. Regeneration of the fixed bed was achieved at the same time, releasing mainly CO(2) and H(2)O. Intermediates of oxidation, such as 2,3-butanedione and acetic acid, were identified, leading to incomplete mineralization. The influence of concentration and humidity are discussed. Four successive cycles were tested: after the first adsorption/ozonation cycle, the adsorption efficiency was not affected during subsequent cycles. These results show that the same sample of adsorbent can be used in the treatment process for a long time. Ozonation regeneration is a promising process for VOC removal.

  19. Model-based design of sequencing batch reactor for removal of biodegradable organics and nitrogen.

    PubMed

    Velmurugan, S; Clarkson, William W; Veenstra, John N

    2010-05-01

    The process design of sequencing batch reactors (SBR) based on mathematical modeling is complex because of the unsteady nature of the process and the large number of kinetic and stoichiometric parameters involved. This paper proposes a model-based design methodology that uses a mathematical model with fewer parameters for removal of organic and nitrogen substrates in the SBR. The resulting mathematical model has been calibrated and validated before its use in model-based design. The data for model calibration and validation were obtained from the operation of a full-scale 836 m3/h (5.3 mgd) SBR system at the City of Tahlequah, Oklahoma. A calibration methodology also was presented to determine unknown kinetic and stoichiometric parameters using an optimization technique called simulated annealing. Model-based design reduced the total volume of the reactor by approximately 11% from the existing design. It also eliminated 0.92 hours of cycle time and 1.07 hours of aeration time per cycle, which would result in a total energy savings of $11,640 per year for the 836 m3/h (5.3 mgd) SBR system.

  20. Metal-organic frameworks for removal of Xe and Kr from nuclear fuel reprocessing plants.

    PubMed

    Liu, Jian; Thallapally, Praveen K; Strachan, Denis

    2012-08-01

    Removal of xenon (Xe) and krypton (Kr) from process off-gases containing 400 ppm Xe, 40 ppm Kr, 78% N(2), 21% O(2), 0.9% Ar, 0.03% CO(2), and so forth using adsorption was demonstrated for the first time. Two well-known metal-organic frameworks (MOFs), HKUST-1 and Ni/DOBDC, which both have unsaturated metal centers but different pore morphologies, were selected as novel adsorbents. Results of an activated carbon were also included for comparison. The Ni/DOBDC has higher Xe/Kr selectivities than those of the activated carbon and the HKUST-1. In addition, results show that the Ni/DOBDC and HKUST-1 can adsorb substantial amounts of Xe and Kr even when they are mixed in air. Moreover, the Ni/DOBDC can successfully separate 400 ppm Xe from 40 ppm Kr and air containing O(2), N(2), and CO(2) with a Xe/Ke selectivity of 7.3 as indicated by our breakthrough results. This shows a promising future for MOFs in radioactive nuclide separations from spent fuels.

  1. Tubular biofilter for toluene removal under various organic loading rates and gas empty bed residence times.

    PubMed

    Chen, Hong; Yang, Chunping; Zeng, Guangming; Luo, Shenglian; Yu, Guanlong

    2012-10-01

    A tubular biofilter (TBF) which consisted of a closed chamber, a polyurethane sponge tube and a nutrient solution distributor was developed and evaluated under organic loading rates (OL) ranging from 18.7 to 149.3 gm(-3)h(-1) and gas empty bed residence times (EBRTs) of 30-5.0 s. Using toluene as model VOC, the startup of the TBF lasted approximately 7 weeks. The removal efficiency decreased from 99% to 52.2% when OL was increased from 18.7 to 149.3g toluene m(-3)h(-1) at 15s, but did not decline significantly when the EBRT was reduced from 30 to 5.0 s at 18.7 gm(-3)h(-1). Biomass concentration did not increase significantly within the sponge tube during the 391 days' operation as observed through the Plexiglas pipe of the TBF. The TBF is suitable for treating waste gases with low toluene concentrations even at high gas flow and over long periods.

  2. Is anaerobic digestion effective for the removal of organic micropollutants and biological activities from sewage sludge?

    PubMed

    Gonzalez-Gil, L; Papa, M; Feretti, D; Ceretti, E; Mazzoleni, G; Steimberg, N; Pedrazzani, R; Bertanza, G; Lema, J M; Carballa, M

    2016-10-01

    The occurrence of emerging organic micropollutants (OMPs) in sewage sludge has been widely reported; nevertheless, their fate during sludge treatment remains unclear. The objective of this work was to study the fate of OMPs during mesophilic and thermophilic anaerobic digestion (AD), the most common processes used for sludge stabilization, by using raw sewage sludge without spiking OMPs. Moreover, the results of analytical chemistry were complemented with biological assays in order to verify the possible adverse effects (estrogenic and genotoxic) on the environment and human health in view of an agricultural (re)use of digested sludge. Musk fragrances (AHTN, HHCB), ibuprofen (IBP) and triclosan (TCS) were the most abundant compounds detected in sewage sludge. In general, the efficiency of the AD process was not dependent on operational parameters but compound-specific: some OMPs were highly biotransformed (e.g. sulfamethoxazole and naproxen), while others were only slightly affected (e.g. IBP and TCS) or even unaltered (e.g. AHTN and HHCB). The MCF-7 assay evidenced that estrogenicity removal was driven by temperature. The Ames test did not show point mutation in Salmonella typhimurium while the Comet test exhibited a genotoxic effect on human leukocytes attenuated by AD. This study highlights the importance of combining chemical analysis and biological activities in order to establish appropriate operational strategies for a safer disposal of sewage sludge. Actually, it was demonstrated that temperature has an insignificant effect on the disappearance of the parent compounds while it is crucial to decrease estrogenicity. PMID:27344252

  3. Superior removal of arsenic from water with zirconium metal-organic framework UiO-66.

    PubMed

    Wang, Chenghong; Liu, Xinlei; Chen, J Paul; Li, Kang

    2015-11-12

    In this study, water stable zirconium metal-organic framework (UiO-66) has been synthesized and for the first time applied as an adsorbent to remove aquatic arsenic contamination. The as-synthesized UiO-66 adsorbent functions excellently across a broad pH range of 1 to 10, and achieves a remarkable arsenate uptake capacity of 303 mg/g at the optimal pH, i.e., pH = 2. To the best of our knowledge, this is the highest arsenate As(V) adsorption capacity ever reported, much higher than that of currently available adsorbents (5-280 mg/g, generally less than 100 mg/g). The superior arsenic uptake performance of UiO-66 adsorbent could be attributed to the highly porous crystalline structure containing zirconium oxide clusters, which provides a large contact area and plenty of active sites in unit space. Two binding sites within the adsorbent framework are proposed for arsenic species, i.e., hydroxyl group and benzenedicarboxylate ligand. At equilibrium, seven equivalent arsenic species can be captured by one Zr6 cluster through the formation of Zr-O-As coordination bonds.

  4. Intraluminal iodination of thyroglobulin

    SciTech Connect

    Ofverholm, T.; Ericson, L.E.

    1984-03-01

    The intraluminal distribution of newly synthesized (injection of (/sup 3/H)leucine) and newly iodinated (injection of Na/sup 125/I) proteins in thyroids of rats given T4 for 2 days was studied with quantitative electron microscopic autoradiography. Three, 4.5, and 6 h after (/sup 3/H)leucine about 90%, 85%, and 65%, respectively, of the luminal label was confined to the microvillus region. This distribution differed from that of newly iodinated protein; already 2 min after injection only about 30% of the grains was located over the microvillus region. The remaining 70% of the grains located outside the microvillus region formed a gradient towards the center of the lumen. The grain distributions 30 min and 2 h after Na/sup 125/I were similar to that present after 2 min. The distribution of grains after pulse labeling with Na/sup 125/I (injected 2 min before propylthiouracil and 2 h before fixation) was also similar to that found in rats injected with Na/sup 125/I alone, indicating that diffusion of labeled proteins in the lumen was very slow in T4-treated rats. A slow diffusion was also suggested by the presence of an unlabeled peripheral ring in follicle lumens of T4-treated rats injected with Na/sup 125/I 48 h before fixation. In normal rats given (/sup 3/H)leucine 3 h before fixation or Na/sup 125/I 1 h or 48 h before fixation the grains were homogeneously distributed in most follicle lumens. Together our findings indicate that (1) administration of T4 has effects on the diffusion properties of the colloid; (2) iodine is incorporated not only into newly synthesized thyroglobulin recently delivered to the follicle lumen but also into molecules already stored in the lumen; (3) a portion of the iodine incorporated into proteins is bound to molecules which are not in direct contact with thyroperoxidase in the apical plasma membrane.

  5. Iodine addition using triiodide solutions

    NASA Technical Reports Server (NTRS)

    Rutz, Jeffrey A.; Muckle, Susan V.; Sauer, Richard L.

    1992-01-01

    The study develops: a triiodide solution for use in preparing ground service equipment (GSE) water for Shuttle support, an iodine dissolution method that is reliable and requires minimal time and effort to prepare, and an iodine dissolution agent with a minimal concentration of sodium salt. Sodium iodide and hydriodic acid were both found to dissolve iodine to attain the desired GSE iodine concentrations of 7.5 +/- 2.5 mg/L and 25 +/- 5 mg/L. The 1.75:1 and 2:1 sodium iodide solutions produced higher iodine recoveries than the 1.2:1 hydriodic acid solution. A two-hour preparation time is required for the three sodium iodide solutions. The 1.2:1 hydriodic acid solution can be prepared in less than 5 min. Two sodium iodide stock solutions (2.5:1 and 2:1) were found to dissolve iodine without undergoing precipitation.

  6. The effects of magnetic field on the removal of organic compounds and metals by coagulation and flocculation

    NASA Astrophysics Data System (ADS)

    Duangduen, C.; Nathaporn, A.; Kitiphatmontree, M.

    2006-09-01

    The effects of magnetic field (MF) were studied using surface water from the Pra Ram IX reservoir. Dissolved organic carbon (DOC) removal was improved by exposure of untreated water to MF for up to 5 hours duration. MF was found to alter the physico-chemical properties of some involved substances. Optimum DOC removal (15-20%) was observed after 30-40 minutes of exposure. Flocculation was also improved in the presence of MF. The removal of DOC, iron, heavy metals (As, Zn) was the best with an optimum ferric chloride dosage of 50 mg/L and exposure to 0.35Tesla magnetic field for 30 min. However, Ca removal was not affected by this treatment.

  7. Trophic complexity in aqueous systems: bacterial species richness and protistan predation regulate dissolved organic carbon and dissolved total nitrogen removal.

    PubMed

    Saleem, Muhammad; Fetzer, Ingo; Harms, Hauke; Chatzinotas, Antonis

    2016-02-24

    Loading of water bodies with dissolved organic carbon (DOC) and dissolved total nitrogen (DTN) affects their integrity and functioning. Microbial interactions mitigate the negative effects of high nutrient loads in these ecosystems. Despite numerous studies on how biodiversity mediates ecosystem functions, whether and how diversity and complexity of microbial food webs (horizontal, vertical) and the underlying ecological mechanisms influence nutrient removal has barely been investigated. Using microbial microcosms accommodating systematic combinations of prey (bacteria) and predator (protists) species, we showed that increasing bacterial richness improved the extent and reliability of DOC and DTN removal. Bacterial diversity drove nutrient removal either due to species foraging physiology or functional redundancy, whereas protistan diversity affected nutrient removal through bacterial prey resource partitioning and changing nutrient balance in the system. Our results demonstrate that prey-predator diversity and trophic interactions interactively determine nutrient contents, thus implying the vital role of microbial trophic complexity as a biological buffer against DOC and DTN.

  8. Trophic complexity in aqueous systems: bacterial species richness and protistan predation regulate dissolved organic carbon and dissolved total nitrogen removal.

    PubMed

    Saleem, Muhammad; Fetzer, Ingo; Harms, Hauke; Chatzinotas, Antonis

    2016-02-24

    Loading of water bodies with dissolved organic carbon (DOC) and dissolved total nitrogen (DTN) affects their integrity and functioning. Microbial interactions mitigate the negative effects of high nutrient loads in these ecosystems. Despite numerous studies on how biodiversity mediates ecosystem functions, whether and how diversity and complexity of microbial food webs (horizontal, vertical) and the underlying ecological mechanisms influence nutrient removal has barely been investigated. Using microbial microcosms accommodating systematic combinations of prey (bacteria) and predator (protists) species, we showed that increasing bacterial richness improved the extent and reliability of DOC and DTN removal. Bacterial diversity drove nutrient removal either due to species foraging physiology or functional redundancy, whereas protistan diversity affected nutrient removal through bacterial prey resource partitioning and changing nutrient balance in the system. Our results demonstrate that prey-predator diversity and trophic interactions interactively determine nutrient contents, thus implying the vital role of microbial trophic complexity as a biological buffer against DOC and DTN. PMID:26888033

  9. Seasonal variations in fate and removal of trace organic chemical contaminants while operating a full-scale membrane bioreactor.

    PubMed

    Trinh, Trang; van den Akker, Ben; Coleman, Heather M; Stuetz, Richard M; Drewes, Jörg E; Le-Clech, Pierre; Khan, Stuart J

    2016-04-15

    Trace organic chemical (TrOC) contaminants are of concern for finished water from water recycling schemes because of their potential adverse environmental and public health effects. Understanding the impacts of seasonal variations on fate and removal of TrOCs is important for proper operation, risk assessment and management of treatment systems for water recycling such as membrane bioreactors (MBRs). Accordingly, this study investigated the fate and removal of a wide range of TrOCs through a full-scale MBR plant during summer and winter seasons. TrOCs included 12 steroidal hormones, 3 xeno-estrogens, 2 pesticides and 23 pharmaceuticals and personal care products. Seasonal differences in the mechanisms responsible for removing some of the TrOCs were evident. In particular the contribution of biotransformation and biomass adsorption to the overall removal of estrone, bisphenol A, 17β-estradiol and triclosan were consistently different between the two seasons. Substantially higher percentage removal via biotransformation was observed during the summer sampling period, which compensated for a reduction in removal attributed to biomass adsorption. The opposite was observed during winter, where the contribution of biotransformation to the overall removal of these TrOCs had decreased, which was offset by an improvement in biomass adsorption. The exact mechanisms responsible for this shift are unknown, however are likely to be temperature related as warmer temperatures can lower sorption efficiency, yet enhance biotransformation of these TrOCs.

  10. Aerobic co-treatment of landfill leachate and domestic wastewater - are slowly biodegradable organics removed or simply diluted?

    PubMed

    Campos, R; Ferraz, F M; Vieira, E M; Povinelli, J

    2014-01-01

    This study investigated the co-treatment of landfill leachate/domestic wastewater in bench-scale activated sludge (AS) reactors to determine whether the slowly biodegradable organic matter (SBOM) was removed rather than diluted. The AS reactors were loaded with mixtures of raw leachate and leachate that was pretreated by air stripping. The tested volumetric ratios were 0%, 0.2%, 2% and 5%. For all of the tested conditions, the reactors performed better when pretreated leachate was used rather than raw leachate, and the best volumetric ratio was 2%. The following removals were obtained: 97% for the biochemical oxygen demand (BOD5,20), 79% for total suspended solids, 77% for dissolved organic carbon and 84% for soluble chemical oxygen demand. Most of the pretreated leachate SBOM (65%) was removed rather than diluted or adsorbed into the sludge, as confirmed by Fourier transform infrared (FTIR) spectroscopy analyses.

  11. Aerobic co-treatment of landfill leachate and domestic wastewater - are slowly biodegradable organics removed or simply diluted?

    PubMed

    Campos, R; Ferraz, F M; Vieira, E M; Povinelli, J

    2014-01-01

    This study investigated the co-treatment of landfill leachate/domestic wastewater in bench-scale activated sludge (AS) reactors to determine whether the slowly biodegradable organic matter (SBOM) was removed rather than diluted. The AS reactors were loaded with mixtures of raw leachate and leachate that was pretreated by air stripping. The tested volumetric ratios were 0%, 0.2%, 2% and 5%. For all of the tested conditions, the reactors performed better when pretreated leachate was used rather than raw leachate, and the best volumetric ratio was 2%. The following removals were obtained: 97% for the biochemical oxygen demand (BOD5,20), 79% for total suspended solids, 77% for dissolved organic carbon and 84% for soluble chemical oxygen demand. Most of the pretreated leachate SBOM (65%) was removed rather than diluted or adsorbed into the sludge, as confirmed by Fourier transform infrared (FTIR) spectroscopy analyses. PMID:25521128

  12. Effect of natural dissolved organic carbon on phosphate removal by ferric chloride and aluminum sulfate treatment of wetland waters

    NASA Astrophysics Data System (ADS)

    Qualls, Robert G.; Sherwood, Lindsay J.; Richardson, Curtis J.

    2009-09-01

    The use of wetlands for the removal of excess N and P has become widespread. Some sensitive P-limited ecosystems, however, may require additional reductions in the concentration of P entering the system. It has been proposed that the treatment of wetlands through addition of ferric chloride or aluminum sulfate can augment the natural P removal mechanisms. However, high concentrations of natural dissolved organic matter may interfere with the removal of P by metal addition. We evaluated the doses of ferric chloride and aluminum sulfate necessary to reduce total P concentrations below 0.32 μM (10 μg/L) in water from the Northern Everglades, and we determined the effect of various concentrations (21, 38, and 60 mg/L) of natural dissolved organic carbon (DOC) on the removal of PO4 and total P. High concentrations of natural DOC inhibited both the short-term removal of PO4 and the longer-term removal of total P from the water column. Similar results were observed using 15 μM citric acid in an experiment to determine whether citric acid could effectively mimic the inhibition of phosphorus removal associated with natural DOC. Stoichiometry of these experiments indicates that the mechanism of natural DOC interference was not complexation of the metal ions by the DOC; we hypothesize that it could be adsorption to the terminal hydroxyl groups on a polynuclear Fe or Al colloid, effectively blocking the adsorption sites from a phosphate molecule. Also, the ability of citric acid to mimic the inhibitory effects also suggests that the results of the study are broadly applicable to wetland and other waters with high natural organic acid concentrations.

  13. [Application of selected microorganisms for organic sulfur removal from coal]. Quarterly progress report, December 15, 1989--March 15, 1990

    SciTech Connect

    Not Available

    1990-03-20

    Research continues on methods to desulfurize coal using microorganisms. Topics reported on this term include: coal procurement and preparation, microbial pyrite and sulfate removal, analytical procedures for characterization of total organic sulfur, microbial activity on model coal organosulfur compounds, screening assays, and plasmid mediation techniques.(VC)

  14. Assessment of Methods to Consolidate Iodine-Loaded Silver-Functionalized Silica Aerogel

    SciTech Connect

    Matyas, Josef; Engler, Robert K.

    2013-09-01

    The U.S. Department of Energy is currently investigating alternative sorbents for the removal and immobilization of radioiodine from the gas streams in a nuclear fuel reprocessing plant. One of these new sorbents, Ag0-functionalized silica aerogels, shows great promise as a potential replacement for Ag-bearing mordenites because of its high selectivity and sorption capacity for iodine. Moreover, a feasible consolidation of iodine-loaded Ag0-functionalized silica aerogels to a durable SiO2-based waste form makes this aerogel an attractive choice for sequestering radioiodine. This report provides a preliminary assessment of the methods that can be used to consolidate iodine-loaded Ag0-functionalized silica aerogels into a final waste form. In particular, it focuses on experimental investigation of densification of as prepared Ag0-functionalized silica aerogels powders, with or without organic moiety and with or without sintering additive (colloidal silica), with three commercially available techniques: 1) hot uniaxial pressing (HUP), 2) hot isostatic pressing (HIP), and 3) spark plasma sintering (SPS). The densified products were evaluated with helium gas pycnometer for apparent density, with the Archimedes method for apparent density and open porosity, and with high-resolution scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS) for the extent of densification and distribution of individual elements. The preliminary investigation of HUP, HIP, and SPS showed that these sintering methods can effectively consolidate powders of Ag0-functionalized silica aerogel into products of near-theoretical density. Also, removal of organic moiety and adding 5.6 mass% of colloidal silica to Ag0-functionalized silica aerogel powders before processing provided denser products. Furthermore, the ram travel