Evaluating Microbial Purification during Soil Treatment of Wastewater with Multicomponent Tracer and Surrogate Tests

USGS Publications Warehouse

Van Cuyk, S.; Siegrist, R.L.; Lowe, K.; Harvey, R.W.

2004-01-01

Soil treatment of wastewater has the potential to achieve high purification efficiency, yet the understanding and predictability of purification with respect to removal of viruses and other pathogens is limited. Research has been completed to quantify the removal of virus and bacteria through the use of microbial surrogates and conservative tracers during controlled experiments with three-dimensional pilot-scale soil treatment systems in the laboratory and during the testing of full-scale systems under field conditions. The surrogates and tracers employed included two viruses (MS-2 and PRID-1 bacteriophages), one bacterium (ice-nucleating active Pseudomonas), and one conservative tracer (bromide ion). Efforts have also been made to determine the relationship between viruses and fecal coliform bacteria in soil samples below the wastewater infiltrative surface, and the correlation between Escherichia coil concentrations measured in percolating soil solution as compared with those estimated from analyses of soil solids. The results suggest episodic breakthrough of virus and bacteria during soil treatment of wastewater and a 2 to 3 log (99-99.9%) removal of virus and near complete removal of fecal coliform bacteria during unsaturated flow through 60 to 90 cm of sandy medium. Results also suggest that the fate of fecal coliform bacteria may be indicative of that of viruses in soil media near the infiltrative surface receiving wastewater effluent. Concentrations of fecal coliform in percolating soil solution may be conservatively estimated from analysis of extracted soil solids.

On the Recent Use of Membrane Technology for Olive Mill Wastewater Purification

PubMed Central

Ochando-Pulido, Javier Miguel; Martinez-Ferez, Antonio

2015-01-01

Many reclamation treatments as well as integrated processes for the purification of olive mill wastewaters (OMW) have already been proposed and developed but not led to completely satisfactory results, principally due to complexity or cost-ineffectiveness. The olive oil industry in its current status, composed of little and dispersed factories, cannot stand such high costs. Moreover, these treatments are not able to abate the high concentration of dissolved inorganic matter present in these highly polluted effluents. In the present work, a review on the actual state of the art concerning the treatment and disposal of OMW by membranes is addressed, comprising microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO), as well as membrane bioreactors (MBR) and non-conventional membrane processes such as vacuum distillation (VD), osmotic distillation (OD) and forward osmosis (FO). Membrane processes are becoming extensively used to replace many conventional processes in the purification of water and groundwater as well as in the reclamation of wastewater streams of very diverse sources, such as those generated by agro-industrial activities. Moreover, a brief insight into inhibition and control of fouling by properly-tailored pretreatment processes upstream the membrane operation and the use of the critical and threshold flux theories is provided. PMID:26426062

Reduce oil and grease content in wastewater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Capps, R.W.; Matelli, G.N.; Bradford, M.L.

Poor water quality is often blamed on biological oxidation unit malfunction. However, poorly treated water entering the bio-unit is more often the problem. At the microscopic level, oil/water-separation dynamics are influenced by pH, fluid velocity, temperature, and unit volumes. Oily water's physical and chemical properties affect pretreatment systems such as API separators, corrugated plate interception (CPI) separators, air flotation and equalization systems. A better understanding of pretreatment systems' limits and efficiencies can improve wastewater quality before it upsets the biological oxidation (BIOX). Oil contamination in refinery wastewater originates from desalting, steam stripping, product treating, tank drains, sample drains and equipmentmore » washdown. The largest volumetric contributors are cooling tower blowdowns and contaminated stormwater. The paper describes the BIOX process; oil/water separation; oil/water emulsions and colloidal solutions; air flotation; surfactants; DAF (dissolved air flotation) process; IAF (induced air flotation) process; equalization; load factors; salts; and system design.« less

Removal of pharmaceutical residue in municipal wastewater by DAF (dissolved air flotation)-MBR (membrane bioreactor) and ozone oxidation.

PubMed

Choi, Miyoung; Choi, Dong Whan; Lee, Jung Yeol; Kim, Young Suk; Kim, Bun Su; Lee, Byoung Ho

2012-01-01

Growing attention is given to pharmaceutical residue in the water environment. It is known that pharmaceuticals are able to survive from a series of wastewater treatment processes. Concerns regarding pharmaceutical residues are attributed to the fact that they are being detected in water and sediment environment ubiquitously. Pharmaceutical treatment using a series of wastewater treatment processes of the DAF (dissolved air flotation)-MBR (membrane bioreactor)-ozone oxidation was conducted in the study. DAF, without addition of coagulant, could remove COD(cr) (chemical oxygen demand by Cr) up to over 70%, BOD 73%, SS 83%, T-N 55%, NH₄(+) 23%, and T-P 65% in influent of municipal wastewater. Average removal rates of water quality parameters by the DAF-MBR system were very high, e.g. COD(cr) 95.88%, BOD₅ 99.66%, COD(mn) (chemical oxygen demand by Mn) 93.63%, T-N 69.75%, NH₄-N 98.46%, T-P 78.23%, and SS 99.51%, which satisfy effluent water quality standards. Despite the high removal rate of the wastewater treatment system, pharmaceuticals were eliminated to be about 50-99% by the MBR system, depending on specific pharmaceuticals. Ibuprofen was well removed by MBR system up to over 95%, while removal rate of bezafibrate ranged between 50 and 90%. With over 5 mg/l of ozone oxidation, most pharmaceuticals which survived the DAF-MBR process were removed completely or resulted in very low survival rate within the range of few micrograms per litre. However, some pharmaceuticals such as bezafibrate and naproxen tended to be resistant to ozone oxidation.

Solutions to microplastic pollution - Removal of microplastics from wastewater effluent with advanced wastewater treatment technologies.

PubMed

Talvitie, Julia; Mikola, Anna; Koistinen, Arto; Setälä, Outi

2017-10-15

Conventional wastewater treatment with primary and secondary treatment processes efficiently remove microplastics (MPs) from the wastewater. Despite the efficient removal, final effluents can act as entrance route of MPs, given the large volumes constantly discharged into the aquatic environments. This study investigated the removal of MPs from effluent in four different municipal wastewater treatment plants utilizing different advanced final-stage treatment technologies. The study included membrane bioreactor treating primary effluent and different tertiary treatment technologies (discfilter, rapid sand filtration and dissolved air flotation) treating secondary effluent. The MBR removed 99.9% of MPs during the treatment (from 6.9 to 0.005 MP L -1 ), rapid sand filter 97% (from 0.7 to 0.02 MP L -1 ), dissolved air flotation 95% (from 2.0 to 0.1 MP L -1 ) and discfilter 40-98.5% (from 0.5 - 2.0 to 0.03-0.3 MP L -1 ) of the MPs during the treatment. Our study shows that with advanced final-stage wastewater treatment technologies WWTPs can substantially reduce the MP pollution discharged from wastewater treatment plants into the aquatic environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Case studies on the physical-chemical parameters' variation during three different purification approaches destined to treat wastewaters from food industry.

PubMed

Ghimpusan, Marieta; Nechifor, Gheorghe; Nechifor, Aurelia-Cristina; Dima, Stefan-Ovidiu; Passeri, Piero

2017-12-01

The paper presents a set of three interconnected case studies on the depuration of food processing wastewaters by using aeration & ozonation and two types of hollow-fiber membrane bioreactor (MBR) approaches. A secondary and more extensive objective derived from the first one is to draw a clearer, broader frame on the variation of physical-chemical parameters during the purification of wastewaters from food industry through different operating modes with the aim of improving the management of water purification process. Chemical oxygen demand (COD), pH, mixed liquor suspended solids (MLSS), total nitrogen, specific nitrogen (NH 4 + , NO 2 - , NO 3 - ) total phosphorous, and total surfactants were the measured parameters, and their influence was discussed in order to establish the best operating mode to achieve the purification performances. The integrated air-ozone aeration process applied in the second operating mode lead to a COD decrease by up to 90%, compared to only 75% obtained in a conventional biological activated sludge process. The combined purification process of MBR and ozonation produced an additional COD decrease of 10-15%, and made the Total Surfactants values to comply to the specific legislation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Energy-neutral sustainable nutrient recovery incorporated with the wastewater purification process in an enlarged microbial nutrient recovery cell

NASA Astrophysics Data System (ADS)

Sun, Dongya; Gao, Yifan; Hou, Dianxun; Zuo, Kuichang; Chen, Xi; Liang, Peng; Zhang, Xiaoyuan; Ren, Zhiyong Jason; Huang, Xia

2018-04-01

Recovery of nutrient resources from the wastewater is now an inevitable strategy to maintain the supply of both nutrient and water for our huge population. While the intensive energy consumption in conventional nutrient recovery technologies still remained as the bottleneck towards the sustainable nutrient recycle. This study proposed an enlarged microbial nutrient recovery cell (EMNRC) which was powered by the energy contained in wastewater and achieved multi-cycle nutrient recovery incorporated with in situ wastewater treatment. With the optimal recovery solution of 3 g/L NaCl and the optimal volume ratio of wastewater to recovery solution of 10:1, >89% of phosphorus and >62% of ammonium nitrogen were recovered into struvite. An extremely low water input ratio of <1% was required to obtain the recovered fertilizer and the purified water. It was proved the EMNRC system was a promising technology which could utilize the chemical energy contained in wastewater itself and energy-neutrally recover nutrient during the continuous wastewater purification process.

Purification and detoxification of petroleum refinery wastewater by electrocoagulation process.

PubMed

Gousmi, N; Sahmi, A; Li, H Z; Poncin, S; Djebbar, R; Bensadok, K

2016-09-01

The treatment of synthetic oily wastewater having the characteristics of a typical petroleum refinery wastewater (PRW) by electrocoagulation (EC) using iron and aluminum electrodes was conducted in an electrolytic reactor equipped with fluid recirculation. During the treatment, the emulsion stability was followed by the measurement of Zeta potential and particle sizes. Effects of some operating conditions such as electrodes material, current density and electrolysis time on removal efficiencies of turbidity, and chemical oxygen demand (COD) were investigated in detail. The PRW purification by the EC process was found to be the most effective using aluminum as the anode and cathode, current density of 60 A/m(2) and 30 min of electrolysis time. Under these conditions, the process efficiencies were 83.52% and 99.94%, respectively, for COD and turbidity removals which correspond to final values of 96 mg O2/L and 0.5 NTU. A moderate energy consumption (0.341 kWh) was needed to treat 1 m(3) of PRW. Besides, the ecotoxicity test proved that toxic substances presented in the PRW, and those inhibiting the germination growth of whet, were eliminated by the EC technique.

Pretreatment of bakery wastewater by coagulation-flocculation and dissolved air flotation.

PubMed

Liu, J C; Lien, C S

2001-01-01

The pretreatment of wastewater from a large-scale bakery was studied. In the coagulation-flocculation reaction, it was found that both alum and FeCl3 were effective in the jar tests. When at coagulant dosage of 90 to 100 mg/l, 55% of COD and 95 to 100% of SS could be removed. The optimum pH was at 6.0. In addition, the removal of SS was affected by pH more significantly, while the removal of COD was not affected in the pH range of 6.0 to 8.0. In the DAF experiments, 48.6% of COD and 69.8% of SS were removed in 10 min at a pressure of 4 kg/cm2, recycle ratio of 0.3 l/min, and pH of 6.0. Upon the addition of 100 mg/l of alum, the removal efficiency of COD did not increase while SS removal increased to 82.1%. It was found that 5-min flocculation time did improve the COD removal while it had little effect on SS removal. Flocculation for longer than 5 min did not enhance the flotation performance. Similar phenomena were observed when FeCl3 was used as the coagulant, except that flocculation had an insignificant effect on COD and SS removal. It was also found that FeCl3 was relatively more effective than alum. In summary, both coagulation-flocculation and DAF were efficient for the pretreatment. The advantages and disadvantages were discussed.

Biodiesel production from indigenous microalgae grown in wastewater.

PubMed

Komolafe, Oladapo; Velasquez Orta, Sharon B; Monje-Ramirez, Ignacio; Yáñez Noguez, Isaura; Harvey, Adam P; Orta Ledesma, María T

2014-02-01

This paper describes a process for producing biodiesel sustainably from microalgae grown in wastewater, whilst significantly reducing the wastewater's nutrients and total coliform. Furthermore, ozone-flotation harvesting of the resultant biomass was investigated, shown to be viable, and resulted in FAMEs of greater oxidation stability. Desmodesmus sp. and two mixed cultures were successfully grown on wastewater. Desmodesmus sp. grew rapidly, to a higher maximum biomass concentration of 0.58 g/L. A native mixed culture dominated by Oscillatoria and Arthrospira, reached 0.45 g/L and exhibited the highest lipid and FAME yield. The FAME obtained from ozone-flotation exhibited the greatest oxidative stability, as the degree of saturation was high. In principle ozone could therefore be used as a combined method of harvesting and reducing FAME unsaturation. During microalgae treatment, the total nitrogen in wastewater was reduced by 55.4-83.9%. More importantly, total coliform removal was as high as 99.8%. Copyright © 2013 Elsevier Ltd. All rights reserved.

Influence of important factors in industrial debugging of desilication of diaspore by flotation

NASA Astrophysics Data System (ADS)

Ma, Chiyu; Chen, Chen; Hu, Yuehua; Zhu, Hailing; Deng, Haibo

2018-02-01

The beneficiation of diaspore with a low ratio of A/S can be realized by desilication using gradient flotation. The concentrate water can be reused in the flotation process after treating with BXF flocculant. Industrial tests of six months of continuous operation were conducted, and the results show that the concentrate with Al2O3 recovery of 83.04% is obtained, and the ratio of A/S increases from 4.46% in the raw ore to 9.57% in the concentrate. Moreover, the comprehensive reuse rate of the waste-water is 75%.

Effective self-purification of polynary metal electroplating wastewaters through formation of layered double hydroxides.

PubMed

Zhou, Ji Zhi; Wu, Yue Ying; Liu, Chong; Orpe, Ajay; Liu, Qiang; Xu, Zhi Ping; Qian, Guang Ren; Qiao, Shi Zhang

2010-12-01

Heavy metal ions (Ni(2+), Zn(2+), and Cr(3+)) can be effectively removed from real polynary metal ions-bearing electroplating wastewaters by a carbonation process, with ∼99% of metal ions removed in most cases. The synchronous formation of layered double hydroxide (LDH) precipitates containing these metal ions was responsible for the self-purification of wastewaters. The constituents of formed polynary metals-LDHs mainly depended on the Ni(2+):Zn(2+):Cr(3+) molar ratio in wastewaters. LDH was formed at pH of 6.0-8.0 when the Ni(2+)/Zn(2+) molar ratio ≥ 1 where molar fraction of trivalent metal in the wastewaters was 0.2-0.4, otherwise ZnO, hydrozincite, or amorphous precipitate was observed. In the case of LDH formation, the residual concentration of Ni(2+), Zn(2+), and Cr(3+) in the treated wastewaters was very low, about 2-3, ∼2, and ∼1 mg/L, respectively, at 20-80 °C and pH of 6.0-8.0, indicating the effective incorporation of heavy metal ions into the LDH matrix. Furthermore, the obtained LDH materials were used to adsorb azoic dye GR, with the maximum adsorption amount of 129-134 mg/g. We also found that the obtained LDHs catalyzed more than 65% toluene to decompose at 350 °C under ambient pressure. Thus the current research has not only shown effective recovery of heavy metal ions from the electroplating wastewaters in an environmentally friendly process but also demonstrated the potential utilization of recovered materials.

Separation of polyethylene terephthalate from municipal waste plastics by froth flotation for recycling industry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Chong-Qing; Wang, Hui, E-mail: huiwang1968@163.com; Liu, You-Nian

Highlights: • Factors of NaOH treatment were studied by orthogonal and single factor experiments. • Mechanism of alkaline treatment for facilitating flotation was manifested. • Flotation separation of PET was achieved with high purity and efficiency. • A flow sheet of purification PET from MWP was designed. - Abstract: Recycling is an effective way to manage plastic wastes and receives considerable attention. Since plastic mixtures are difficult to recycle because of their intrinsic characteristics, separation of mixed plastics is the key problem for recycling. Separation of polyethylene terephthalate (PET) from municipal waste plastics (MWP) by froth flotation combined with alkalinemore » pretreatment was investigated for recycling industry. The effect of process variables was estimated by L{sub 9} (3{sup 4}) orthogonal array of experiments and single factor experiments. The optimum conditions of alkaline pretreatment are 10 wt% sodium hydroxide, 20 min and 70 °C. After alkaline pretreatment under optimum conditions, flotation separation PET from acrylonitrile–butadiene–styrene, polystyrene, polycarbonate or polyvinyl chloride was achieved with high purity and efficiency. The purity of PET is up to 98.46% and the recovery is above 92.47%. A flow sheet of separation PET from MWP by a combination of froth flotation and sink float separation was designed. This study facilitates industrial application of plastics flotation and provides technical insights into recycling of waste plastics.« less

The Role of Nanobubbles in the Precipitation and Recovery of Organic-Phosphine-Containing Beneficiation Wastewater.

PubMed

Xiao, Wei; Ke, Shuo; Quan, Nannan; Zhou, Limin; Wang, Jun; Zhang, Lijuan; Dong, Yaming; Qin, Wenqing; Qiu, Guanzhou; Hu, Jun

2018-05-29

Dissolved air flotation (DAF) is broadly applied in wastewater treatment, especially for the recovery of organic pollution with low concentration. However, the mechanism of interaction between nanoscale gas bubbles and nanoparticles in the process of DAF remains unclear. Here, we investigated the role of nanobubbles in the precipitation of styryl phosphoric acid (SPA)-Pb particles and recovering organic phosphine containined in beneficiation wastewater by UV-vis (ultraviolet-visible) spectra, microflotation tests, nanoparticle tracking analysis, dynamic light scattering, and atomic force microscopy measurements. As suggested from the results, nanobubbles can inhibit the crystallization of SPA-Pb precipitation, which makes the sediment flotation recovery below 20%. After the precipitation crystallization is completed, nanobubbles can flocculate precipitated particles, which can promote the flotation recovery of precipitated particles to 90%. On the basis of the results, we proposed a model to explain the different roles of nanobubbles in the process of precipitation and flotation of SPA-Pb particles. This study will be helpful to understand the interaction between nanobubbles and nanoparticles in the application of flotation.

Novel tiO2 nanocatalysts for wastewater purification: tapping energy from the sun.

PubMed

Liu, Y; Li, J; Qiu, X; Burda, C

2006-01-01

Water treatment using TiO2 semiconductor as a durable heterogeneous photocatalyst has been the focus of environmentalists in recent years. Currently, we developed an inexpensive and highly efficient approach for synthesizing nitrogen-doped TiO2 with lower band-gap energy that can respond to visible light. Doping on the molecular scale led to an enhanced nitrogen concentration of up to 21.8%. Reflectance measurements showed the synthesized N-doped TiO2 nanoparticles are catalytically active with the absorbance that extends into the visible region up to 600 nm. The water purification potential of this new class of compound was evaluated by studying the photodegradation of Acid Orange 7 (AO7) and E. coli. Experiments were conducted to compare the photocatalytic activities of N-doped TiO2 nanocatalysts and commercially available Degussa P25 power under identical solar light exposure. N-doped TiO2 demonstrated superior photocatalytic activities in both chemical compound degradation and bactericidal reactions. The result of this study shows the potential of applying new generations of catalyst for wastewater purification and disinfection.

[Biosorptive-flotation and desorption operation of heavy metals from wastewater effluents by Gordona amarae].

PubMed

Zhou, Dong-qin; Wei, De-zhou

2006-05-01

The process of adsorptive-flotation and desorption to remove and recovery heavy metals from aqueous solution was studied using Gordona amarae as sorbent, and the mechanisms of biosorption and flotation were analyzed. Experimental results showed that the selectivity of Gordona amarae for various heavy metal cations was Pb > Hg > Cu, and the restrain oneself of Cu2+ was the highest. the present of NH4+ ion on loaded Pb2+ cells was remarkably improved, however, K+, Na+, Ca2+, Mg2+ of co-existing ions slightly restrained influence. The flotation recoveries respectively of Pb2+ and biomass more than 93% and 96% for with DA dosage of 17.5 mmol/L in the pH of 9.5, and that was almost quantitative remaining around 94% and 97% being desorbed when desorption frequence of Na2CO3 was up to three times. The measure of Zeta potential and infrared spectroscopy analysis showed that the ioselectric point of Gordona amarae in water was 3.50, up to 4.02 when loaded Pb2+, down to 3.02 when DA doseage added in the loaded biomass. Experiments indicated the lead bosorpting process was likely to involving in the group of -NHCOCH3 and COO- on the cell wall, while the biosorptive flotation was concerned cooperatively to be basing on electrostatic attraction, hydrogen bond, ion exchange and chemical complexation. SEM observation showed that Gordona amarae biomass loaded Hg2+ changed into flocculent matter.

Flotation of Mineral and Dyes: A Laboratory Experiment for Separation Method Molecular Hitchhikers

ERIC Educational Resources Information Center

Rappon, Tim; Sylvestre, Jarrett A.; Rappon, Manit

2016-01-01

Flotation as a method of separation is widely researched and is applied in many industries. It has been used to address a wide range of environmental issues including treatment of wastewater, recovery of heavy metals for recycling, extraction of minerals in mining, and so forth. This laboratory attempts to show how such a simple method can be used…

Comparison of concentration methods for rapid detection of hookworm ova in wastewater matrices using quantitative PCR.

PubMed

Gyawali, P; Ahmed, W; Jagals, P; Sidhu, J P S; Toze, S

2015-12-01

Hookworm infection contributes around 700 million infections worldwide especially in developing nations due to increased use of wastewater for crop production. The effective recovery of hookworm ova from wastewater matrices is difficult due to their low concentrations and heterogeneous distribution. In this study, we compared the recovery rates of (i) four rapid hookworm ova concentration methods from municipal wastewater, and (ii) two concentration methods from sludge samples. Ancylostoma caninum ova were used as surrogate for human hookworm (Ancylostoma duodenale and Necator americanus). Known concentration of A. caninum hookworm ova were seeded into wastewater (treated and raw) and sludge samples collected from two wastewater treatment plants (WWTPs) in Brisbane and Perth, Australia. The A. caninum ova were concentrated from treated and raw wastewater samples using centrifugation (Method A), hollow fiber ultrafiltration (HFUF) (Method B), filtration (Method C) and flotation (Method D) methods. For sludge samples, flotation (Method E) and direct DNA extraction (Method F) methods were used. Among the four methods tested, filtration (Method C) method was able to recover higher concentrations of A. caninum ova consistently from treated wastewater (39-50%) and raw wastewater (7.1-12%) samples collected from both WWTPs. The remaining methods (Methods A, B and D) yielded variable recovery rate ranging from 0.2 to 40% for treated and raw wastewater samples. The recovery rates for sludge samples were poor (0.02-4.7), although, Method F (direct DNA extraction) provided 1-2 orders of magnitude higher recovery rate than Method E (flotation). Based on our results it can be concluded that the recovery rates of hookworm ova from wastewater matrices, especially sludge samples, can be poor and highly variable. Therefore, choice of concentration method is vital for the sensitive detection of hookworm ova in wastewater matrices. Crown Copyright © 2015. Published by Elsevier

Purification of heavy metal loaded wastewater from electroplating industry under synthesis of delafossite (ABO2) by "Lt-delafossite process".

PubMed

John, Melanie; Heuss-Aßbichler, Soraya; Ullrich, Aladin; Rettenwander, Daniel

2016-09-01

In this study we present a new, environmental friendly and economic method, called Lt-delafossite process to treat industrial wastewater (initial Cu(2+)-concentrations of 1-15.6 g/l) by subsequent synthesis of nano-crystalline (doped) delafossite (CuFeO2) solely by precipitation and ageing at temperatures between 50 °C and 90 °C. The reached water purification rates are exclusively ≥99.99% for both wastewater models and wastewaters from electroplating industry. We succeeded to synthesize a mixture of 3R and 2H delafossite at 50 °C after 90 h and ≥70 °C after 16 h of ageing directly from industrial wastewater without any additional phases. In all cases green rust (GR), a Fe(II-III) layered double hydroxysulphate, Cu2O (cuprite) and Fe10O14(OH)2 (ferrihydrite) precipitates first. During ageing of the residues the metastable phases transform to delafossite. The residues are characterized by XRD, FTIR, SEM, TEM, VFTB and Mößbauer measurements. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Review on Advanced Treatment of Pharmaceutical Wastewater

NASA Astrophysics Data System (ADS)

Guo, Y.; Qi, P. S.; Liu, Y. Z.

2017-05-01

The composition of pharmaceutical wastewater is complex, which is high concentration of organic matter, microbial toxicity, high salt, and difficult to biodegrade. After secondary treatment, there are still trace amounts of suspended solids and dissolved organic matter. To improve the quality of pharmaceutical wastewater effluent, advanced treatment is essential. In this paper, the classification of the pharmaceutical technology was introduced, and the characteristics of pharmaceutical wastewater effluent quality were summarized. The methods of advanced treatment of pharmaceutical wastewater were reviewed afterwards, which included coagulation and sedimentation, flotation, activated carbon adsorption, membrane separation, advanced oxidation processes, membrane separation and biological treatment. Meanwhile, the characteristics of each process were described.

Enhancement of nutrient removal from swine wastewater digestate coupled to biogas purification by microalgae Scenedesmus spp.

PubMed

Prandini, Jean Michel; da Silva, Márcio Luís Busi; Mezzari, Melissa Paola; Pirolli, Mateus; Michelon, William; Soares, Hugo Moreira

2016-02-01

This work investigated the effects of swine wastewater-derived biogas on microalgae biomass production and nutrient removal rates from piggery wastewater concomitantly with biogas filtration. Photobioreactors with dominant Scenedesmus spp. were prepared using non-sterile digestate and exposed to different photoperiods. In the presence of biogas and autotrophic conditions microalgae yield of 1.1±0.2 g L(-1) (growth rate of 141.8±3.5 mg L(-1) d(-1)) was obtained leading to faster N-NH3 and P-PO4(3-) assimilation rate of 21.2±1.2 and 3.5±2.5 mg L(-1) d(-1), respectively. H2S up to 3000 ppmv was not inhibitory and completely removed. Maximum CO2 assimilation of 219±4.8 mg L(-1) d(-1) was achieved. Biological consumption of CH4 up to 18% v/v was verified. O2 up to 22% v/v was controlled by adding acetate to exacerbate oxygen demand by microorganisms. Microalgae-based wastewater treatment coupled to biogas purification accelerates nutrient removal concomitantly producing valuable biomass and biomethane. Copyright © 2015 Elsevier Ltd. All rights reserved.

Simultaneous stack gas scrubbing wastewater purification

NASA Technical Reports Server (NTRS)

1978-01-01

Variations of a process for removing sulfur dioxide from stack gases and using it to treat municipal waste water are described. The once-through system lowers the pH of the scrubbing water from minor depressions to a pH of about 2.5 under certain conditions. A recycle system uses iron for catalytic oxidation of sulfurous acid to sulfuric acid allowing very large amounts of sulfur dioxide to be absorbed in a small portion of water. The partial recycle system uses municipal wastewater and iron as a scrubbing medium, followed by neutralization of the wastewater with lime to produce an iron hydroxide precipitation which, when removed, produces tertiary quality treated wastewater. The SO2 scrubber is described, test results are analyzed, and a preliminary capital cost estimate for the three processes is included.

The sensitivity of direct faecal examination, direct faecal flotation, modified centrifugal faecal flotation and centrifugal sedimentation/flotation in the diagnosis of canine spirocercosis.

PubMed

Christie, J; Schwan, E V; Bodenstein, L L; Sommerville, J E M; van der Merwe, L L

2011-06-01

Several faecal examination techniques have shown variable sensitivity in demonstrating Spirocerca lupi (S. lupi) eggs. The objective of this study was to determine which faecal examination technique, including a novel modified centrifugal flotation technique, was most sensitive to diagnose spirocercosis. Ten coproscopic examinations were performed on faeces collected from 33 dogs confirmed endoscopically to have spirocercosis. The tests included a direct faecal examination, a faecal sedimentation/flotation test, 4 direct faecal flotations and 4 modified faecal centrifugal flotations. These latter 2 flotation tests utilised 4 different faecal flotation solutions: NaNO3 (SG 1.22), MgSO4 (SG 1.29), ZnSO4 (SG 1.30) and sugar (SG 1.27). The sensitivity of the tests ranged between 42% and 67%, with the NaNO3 solution showing the highest sensitivity in both the direct and modified-centrifugal flotations. The modified NaNO3 centrifugal method ranked 1st with the highest mean egg count (45.24 +/- 83), and was superior (i.e. higher egg count) and significantly different (P < 0.05) compared with the routine saturated sugar, ZnSO4 and MgSO4 flotation methods. The routine NaNO3 flotation method was also superior and significantly different (P < 0.05) compared with the routine ZnSO4 and MgSO4 flotation methods. Fifteen per cent (n = 5) of dogs had neoplastic oesophageal nodules and a further 18% (n = 6) had both neoplastic and non-neoplastic nodules. S. lupi eggs were demonstrated in 40% of dogs with neoplastic nodules only and 72.9% of the dogs with non-neoplastic nodules. The mean egg count in the non-neoplastic group (61) was statistically greater (P = 0.02) than that of the neoplastic group (1). The results show that faecal examination using a NaNO3 solution is the most sensitive in the diagnosis of spirocercosis. The modified centrifugal flotation faecal method using this solution has the highest egg count. The study also found that dogs with neoplastic nodules shed

Flotation as a remediation technique for heavily polluted dredged material. 2. Characterisation of flotated fractions.

PubMed

Cauwenberg, P; Verdonckt, F; Maes, A

1998-01-19

The particle size distribution and the metal speciation of the heavy metals were investigated on dredged sediment and on the fractions obtained by mechanical agitated (Denver) flotation. The transition metal ions (cadmium, copper, lead and zinc) were flotated specifically independent of the particle size. Particle size analysis, EDTA extraction and sequential extracts indicated that during flotation a redistribution of metals occurred due to the oxidation of metal sulphides. This oxidation process was more pronounced when the flotation was performed at higher pH values and resulted in a decrease in flotation specificity.

On Operating a Nanofiltration Membrane for Olive Mill Wastewater Purification at Sub- and Super-Boundary Conditions.

PubMed

Stoller, Marco; Ochando-Pulido, Javier Miguel; Field, Robert

2017-07-14

In the last decades, membrane processes have gained a significant share of the market for wastewater purification. Although the product (i.e., purified water) is not of high added value, these processes are feasible both technically and from an economic point of view, provided the flux is relatively high and that membrane fouling is strongly inhibited. By controlling membrane fouling, the membrane may work for years without service, thus dramatically reducing operating costs and the need for membrane substitution. There is tension between operating at high permeate fluxes, which enhances fouling but reduces capital costs, and operating at lower fluxes which increases capital costs. Operating batch membrane processes leads to increased difficulties, since the feed fed to the membrane changes as a function of the recovery value. This paper is concerned with the operation of such a process. Membrane process designers should therefore avoid membrane fouling by operating membranes away from the permeate flux point where severe fouling is triggered. The design and operation of membrane purification plants is a difficult task, and the precision to properly describe the evolution of the fouling phenomenon as a function of the operating conditions is a key to success. Many reported works have reported on the control of fouling by operating below the boundary flux. On the other hand, only a few works have successfully sought to exploit super-boundary operating conditions; most super-boundary operations are reported to have led to process failures. In this work, both sub- and super-boundary operating conditions for a batch nanofiltration membrane process used for olive mill wastewater treatment were investigated. A model to identify a priori the point of transition from a sub-boundary to a super-boundary operation during a batch operation was developed, and this will provide membrane designers with a helpful tool to carefully avoid process failures.

Waste water biological purification plants of dairy products industry and energy management

NASA Astrophysics Data System (ADS)

Stepanov, Sergey; Solkina, Olga; Stepanov, Alexander; Zhukova, Maria

2017-10-01

The paper presents results of engineering and economical comparison of waste water biological purification plants of dairy products industry. Three methods of purification are compared: traditional biological purification with the use of secondary clarifiers and afterpurification through granular-bed filters, biomembrane technology and physical-and-chemical treatment together with biomembrane technology for new construction conditions. The improvement of the biological purification technology using nitro-denitrification and membrane un-mixing of sludge mixture is a promising trend in this area. In these calculations, an energy management which is widely applied abroad was used. The descriptions of the three methods are illustrated with structural schemes. Costs of equipment and production areas are taken from manufacturers’ data. The research is aimed at an engineering and economical comparison of new constructions of waste water purification of dairy products industry. The experiment demonstrates advantages of biomembrane technology in waste water purification. This technology offers prospects of 122 million rubles cost saving during 25 years of operation when compared with of the technology of preparatory reagent flotation and of 13.7 million rubles cost saving compared to the option of traditional biological purification.

46 CFR 179.240 - Foam flotation material.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Foam flotation material. 179.240 Section 179.240... Requirements § 179.240 Foam flotation material. (a) Foam may only be installed as flotation material on a vessel when approved by the cognizant OCMI. (b) If foam is installed as flotation material on a vessel...

46 CFR 179.240 - Foam flotation material.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Foam flotation material. 179.240 Section 179.240... Requirements § 179.240 Foam flotation material. (a) Foam may only be installed as flotation material on a vessel when approved by the cognizant OCMI. (b) If foam is installed as flotation material on a vessel...

33 CFR 183.322 - Flotation materials.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Flotation materials. 183.322 Section 183.322 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... of 2 Horsepower or Less General § 183.322 Flotation materials. (a) Flotation materials must meet the...

33 CFR 183.322 - Flotation materials.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Flotation materials. 183.322 Section 183.322 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... of 2 Horsepower or Less General § 183.322 Flotation materials. (a) Flotation materials must meet the...

33 CFR 183.322 - Flotation materials.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Flotation materials. 183.322 Section 183.322 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... of 2 Horsepower or Less General § 183.322 Flotation materials. (a) Flotation materials must meet the...

Roles of surfactants in flotation deinking

Treesearch

Yulin Zhao; Yulin Deng; J.Y. Zhu

2004-01-01

Flotation deinking is a common practice for removing ink from wastepaper, and it is becoming a key process in many recycling paper mills. Flotation deinking was successfully introduced to the paper recycling industry in the 1980s, and its applications in wax removal, sticky control, and fiber fractionation have attracted great research interest. A successful flotation...

Construction of the Syngonium podophyllum-Pseudomonas sp. XNN8 Symbiotic Purification System and Investigation of Its Capability of Remediating Uranium Wastewater.

PubMed

Deng, Qin-Wen; Wang, Yong-Dong; Ding, De-Xin; Hu, Nan; Sun, Jing; He, Jia-Dong; Xu, Fei

2017-02-01

The endophyte Pseudomonas sp. XNN8 was separated from Typha orientalis which can secrete indole-3-acetic acid and 1-aminocyclopropane-1-carboxylate deaminase and siderophores and has strong resistance to uranium it was then colonized in the Syngonium podophyllum; and the S. podophyllum-Pseudomonas sp. XNN8 symbiotic purification system (SPPSPS) for uranium-containing wastewater was constructed. Afterwards, the hydroponic experiments to remove uranium from uranium-containing wastewater by the SPPSPS were conducted. After 24 days of treatment, the uranium concentrations of the wastewater samples with uranium concentrations between 0.5 and 5.0 mg/L were lowered to below 0.05 mg/L. Furthermore, the uranium in the plants was assayed using Fourier transform infrared spectroscopy (FTIR) and extended X-ray absorption fine structure (EXAFS) spectroscopy. The Pseudomonas sp. XNN8 was found to generate substantial organic groups in the roots of the Syngonium podophyllum, which could improve the complexing capability of S. podophyllum for uranium. The uranium in the roots of S. podophyllum was found to be the uranyl phosphate (47.4 %) and uranyl acetate (52.6 %).

33 CFR 183.114 - Test of flotation materials.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.114 Test of flotation materials. (a) Vapor test. The flotation material...

33 CFR 183.114 - Test of flotation materials.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.114 Test of flotation materials. (a) Vapor test. The flotation material...

33 CFR 183.114 - Test of flotation materials.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.114 Test of flotation materials. (a) Vapor test. The flotation material...

The use of fortified soil-clay as on-site system for domestic wastewater purification.

PubMed

Oladoja, N A; Ademoroti, C M A

2006-02-01

The quest for simple, low-cost and high-performance decentralized wastewater treatment system for domestic application in developing nations necessitated this study. Clay samples collected from different deposits in Nigeria were characterized by studying the mineralogical and geochemical composition using X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS), respectively. Three major clay minerals of kaolinite, illite and smectite were identified. The geochemical studies showed the abundance of SiO2, Al2O3 and H2O+ in each of the clay samples. Performance efficiency studies were conducted to determine the best combination ratio of pebbles/soil-clay. Soil-clay fortified by pebbles in combination ratios of 1:3 (i.e. pebbles:soil-clay = 1:3 (w/w) showed the optimum water purification, while the combination 3:1 gave the least. The flow rate studies showed that the wastewater had a longer residence time in non-fortified soil-clay than in fortified soil-clay. Two modes of treatment methods were employed-single and double column treatment methods (SCT and DCT). The two methods gave effluents of good quality characteristics, but those from the DCT were of better quality. The quality of effluents also varies from one clay type to another. The quality of effluents from media containing smectite clay mineral was better than those from other columns. Repeated usage of the fortified clay column showed a decrease of pH, TS and DO, and an increase of COD when monitored over a period of 10 days.

Car wash wastewater treatment and water reuse - a case study.

PubMed

Zaneti, R N; Etchepare, R; Rubio, J

2013-01-01

Recent features of a car wash wastewater reclamation system and results from a full-scale car wash wastewater treatment and recycling process are reported. This upcoming technology comprises a new flocculation-column flotation process, sand filtration, and a final chlorination. A water usage and savings audit (22 weeks) showed that almost 70% reclamation was possible, and fewer than 40 L of fresh water per wash were needed. Wastewater and reclaimed water were characterized by monitoring chemical, physicochemical and biological parameters. Results were discussed in terms of aesthetic quality (water clarification and odour), health (pathological) and chemical (corrosion and scaling) risks. A microbiological risk model was applied and the Escherichia coli proposed criterion for car wash reclaimed water is 200 CFU 100 mL(-1). It is believed that the discussions on car wash wastewater reclamation criteria may assist institutions to create laws in Brazil and elsewhere.

Selective flotation of inorganic sulfides from coal

DOEpatents

Miller, Kenneth J.; Wen, Wu-Wey

1989-01-01

Pyritic sulfur is removed from coal or other carbonaceous material through the use of humic acid as a coal flotation depressant. Following the removal of coarse pyrite, the carbonaceous material is blended with humic acid, a pyrite flotation collector and a frothing agent within a flotation cell to selectively float pyritic sulfur leaving clean coal as an underflow.

Physically absorbable reagents-collectors in elementary flotation

DOE Office of Scientific and Technical Information (OSTI.GOV)

S.A. Kondrat'ev; I.G. Bochkarev

2007-09-15

Based on the reviewed researches held at the Institute of Mining, Siberian Branch, Russian Academy of Sciences, the effect of physically absorbable reagents-collectors on formation of a flotation complex and its stability in turbulent pulp flows in flotation machines of basic types is considered. The basic requirements for physically absorbable reagents-collectors at different flotation stages are established.

Plant uptake-assisted round-the-clock photocatalysis for complete purification of aquaculture wastewater using sunlight.

PubMed

Bian, Zhenfeng; Cao, Fenglei; Zhu, Jian; Li, Hexing

2015-02-17

A novel reactor equipped with solar batteries, Bi2O3/TiO2 film photocatalyst, and celery plant was designed and used for purification of aquaculture wastewater. The Bi2O3/TiO2 film photocatalyst started photocatalytic degradation of organonitrogen compounds under irradiation of sunlight. Meanwhile, the solar batteries absorbed and converted excess sunlight into electric energy and then started UV lamps at night, leading to round-the-clock photocatalysis. Subsequently, the inorganic nitrogen species including NH4(+), NO2(-), and NO3(-) resulting from photocatalytic degradation of the organonitrogen compounds could subsequently be uptaken by the celery plant as the fertilizer to reduce the secondary pollution. It was found that, after 24 h circulation, both organonitrogen compounds and NO2(-) species were completely removed, while NH4(+) and NO3(-) contents also decreased by 30% and 50%, respectively. The reactor could be used repetitively, showing a good potential in practical application.

Selective flotation of inorganic sulfides from coal

DOEpatents

Miller, K.J.; Wen, Wu-Wey

1988-05-31

Pyritic sulfur is removed from coal or other carbonaceous material through the use of humic acid as a coal flotation depressant. Following the removal of coarse pyrite, the carbonaceous material is blended with humic acid, a pyrite flotation collector and a frothing agent within a flotation cell to selectively float pyritic sulfur leaving clean coal as an underflow. 1 fig., 2 tabs.

Flotation separation of waste plastics for recycling-A review.

PubMed

Wang, Chong-qing; Wang, Hui; Fu, Jian-gang; Liu, You-nian

2015-07-01

The sharp increase of plastic wastes results in great social and environmental pressures, and recycling, as an effective way currently available to reduce the negative impacts of plastic wastes, represents one of the most dynamic areas in the plastics industry today. Froth flotation is a promising method to solve the key problem of recycling process, namely separation of plastic mixtures. This review surveys recent literature on plastics flotation, focusing on specific features compared to ores flotation, strategies, methods and principles, flotation equipments, and current challenges. In terms of separation methods, plastics flotation is divided into gamma flotation, adsorption of reagents, surface modification and physical regulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effective harvesting of microalgae by coagulation–flotation

PubMed Central

Xia, Ling; Li, Yinta; Huang, Rong

2017-01-01

This study developed a coagulation–flotation process for microalgae Chlorella sp. XJ-445 harvesting, which was composed of algal surface modification by combined use of Al3+ and cetyltrimethylammonium bromide (CTAB) and followed dispersed bubble flotation. Dissolved organic matter (DOM) in the medium was firstly characterized and mainly consisted of hydrophilic low molecular weight molecules. The dosage of collector (CTAB) and coagulant (Al3+) were optimized, and with the pretreatment of 40 mg Al3+ and 60 mg CTAB per 1 g dry biomass without pH adjustment, a maximum flotation recovery efficiency of 98.73% can be achieved with the presence of DOM. Algal cells characterization results showed that the combined use of CTAB and Al3+ largely enhanced the algal floc size, and exhibited higher degree of hydrophobicity, which favoured the flotation, and can be interpreted by DLVO (Derjaguin, Landau, Verwey and Overbeek) modelling. A benefit in fatty acid conversion was further found with the optimized coagulation–flotation process. It was suggested that this coagulation based flotation is a promising strategy for high-efficiency harvesting of microalgae. PMID:29291079

33 CFR 183.112 - Flotation material and air chambers.

Code of Federal Regulations, 2011 CFR

2011-07-01

... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.112 Flotation material and air chambers. (a) Flotation...

33 CFR 183.112 - Flotation material and air chambers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.112 Flotation material and air chambers. (a) Flotation...

33 CFR 183.112 - Flotation material and air chambers.

Code of Federal Regulations, 2014 CFR

2014-07-01

... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.112 Flotation material and air chambers. (a) Flotation...

33 CFR 183.112 - Flotation material and air chambers.

Code of Federal Regulations, 2010 CFR

2010-07-01

... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.112 Flotation material and air chambers. (a) Flotation...

Water Purification Systems

NASA Technical Reports Server (NTRS)

1992-01-01

A water purification/recycling system developed by Photo-Catalytics, Inc. (PCI) for NASA is commercially available. The system cleanses and recycles water, using a "photo-catalysis" process in which light or radiant energy sparks a chemical reaction. Chemically stable semiconductor powders are added to organically polluted water. The powder absorbs ultraviolet light, and pollutants are oxidized and converted to carbon dioxide. Potential markets for the system include research and pharmaceutical manufacturing applications, as well as microchip manufacture and wastewater cleansing.

Intensification of the Reverse Cationic Flotation of Hematite Ores with Optimization of Process and Hydrodynamic Parameters of Flotation Cell

NASA Astrophysics Data System (ADS)

Poperechnikova, O. Yu; Filippov, L. O.; Shumskaya, E. N.; Filippova, I. V.

2017-07-01

The demand of high grade iron ore concentrates is a major issue due to the depletion of rich iron-bearing ores and high competitiveness in the iron ore market. Iron ore production is forced out to upgrade flowsheets to decrease the silica content in the pelettes. Different types of ore have different mineral composition and texture-structural features which require different mineral processing methods and technologies. The paper presents a comparative study of the cationic and anionic flotation routes to process a fine-grain oxidized iron ore. The modified carboxymethyl cellulose was found as the most efficient depressant in reverse cationic flotation. The results of flotation optimization of hematite ores using matrix of second-order center rotatable uniform design allowed to define the collector concentration, impeller rotation speed and air flowrate as the main flotation parameters impacting on the iron ore concentrate quality and iron recovery in a laboratory flotation machine. These parameters have been selected as independent during the experiments.

Improving quality of textile wastewater with organic materials as multi soil layering

NASA Astrophysics Data System (ADS)

Supriyadi; Widijanto, H.; Pranoto; Dewi, AK

2016-02-01

On agricultural land, fresh water is needed especially for irrigation. Alternative ways to fulfill needs of fresh water is by utilizing wastewater from industry. Wastewater that produced in the industry in Surakarta is over flowing especially textile wastewater. Wastewater that produced from industry has many pollutants that affected decreasing fresh water quality for irrigation. Multi Soil Layering (MSL) is one of method that utilize the soil ability as main media by increasing its function of soil structure to purify wastewater, so it does not contaminate the environment and reusable. This research was purposed to know affectivity of organic materials (such as rice straw, baggase, sawdust, coconut fibre, and corncob) and dosage (5%, 10% and 25%) in MSL, also get alternative purification ways with easy and cheaper price as natural adsorbent. This study using field and laboratory experiment. The result shows that MSL can be an alternative method of purification of wastewater. The appropriate composition of organic materials that can be used as adsorbent is MSL with wood sawdust 10% dosage because it can increase pH, decrease the number of Cr, ammonia, and phosphate but less effective to decrease BOD and COD.

Oxidation of aniline aerofloat in flotation wastewater by sodium hypochlorite solution.

PubMed

Lin, Weixiong; Tian, Jing; Ren, Jie; Xu, Pingting; Dai, Yongkang; Sun, Shuiyu; Wu, Chun

2016-01-01

Aniline aerofloat (dianilinodithiophosphoric acid (C6H5NH)2PSSH) is a widely used phosphorodithioic organic flotation collector that contains aniline groups and dithiophosphate groups. In the present study, sodium hypochlorite solution was used to oxidize aniline aerofloat. The effect of operational parameters and optimum oxidation conditions on aniline aerofloat was studied, and the oxidation pathway of aniline aerofloat was proposed by analyzing its main oxidation intermediates. The results showed that NaOCl concentration had a significant influence on aniline aerofloat oxidation and at 100 mg/L aniline aerofloat, 84.54% was removed under the following optimal conditions: NaOCl concentration = 1.25 g/L, pH = 4, and reaction time = 60 min. The main reaction of aniline aerofloat by NaOCl included N-P bond cleavage, aniline group oxidation, aniline group chlorination, and dithiophosphate group oxidation. The initial reaction was the N-P bond cleavage and the anilines and dithiophosphate was further oxidized to other intermediates by five parallel reaction pathways.

The effect of lizardite surface characteristics on pyrite flotation

NASA Astrophysics Data System (ADS)

Feng, Bo; Feng, Qiming; Lu, Yiping

2012-10-01

The effect of lizardite surface characteristics on pyrite flotation has been investigated through flotation tests, adsorption tests, zeta potential measurements, FTIR study, X-ray photoelectron spectroscopy (XPS) and sedimentation tests. The flotation results show that at pH value 9, where flotation of nickel sulfide ores is routinely performed, two kinds of lizardite samples (native lizardite and leached lizardite) have different effects on the flotation of pyrite. The native lizardite adheres to the surface of pyrite and reduces pyrite flotation recovery while the leached lizardite does not interfere with pyrite flotation. Infrared analyses and XPS tests illustrate that acid leaching changed the surface characteristics of lizardite mineral and the leached lizardite has less magnesium on its surface. It has been determined that the electro-kinetic behavior of lizardite aqueous suspensions is mainly a function of the Mg/Si atomic ratio on lizardite surface. So, the low isoelectric point observed in the leached sample has been linked to values of this ratio lower than that of the native lizardite.

21 CFR 890.3175 - Flotation cushion.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion. (a...

21 CFR 890.3175 - Flotation cushion.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion. (a...

21 CFR 890.3175 - Flotation cushion.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion. (a...

21 CFR 890.3175 - Flotation cushion.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion. (a...

21 CFR 890.3175 - Flotation cushion.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion. (a...

Flotation of Metallurgical Grade Silicon and Silicon Metal from Slag by Selective Hydrogen Fluoride-Assisted Flotation

NASA Astrophysics Data System (ADS)

Larsen, E.; Kleiv, R. A.

2017-12-01

Flotation experiments performed on metallurgical grade silicon have demonstrated that silicon (Si) can be floated in diluted solutions of hydrogen fluoride (HF) and a frother. The recovery was found to depend on HF conditioning time, frother type, and the concentration of both HF and frother. Although Brij 58 produced the highest recoveries of the frothers that was tested, good recoveries were also obtained for Flotanol C07. Chemical analyses showed that the flotation products were purer than the corresponding feed materials, and that most impurity elements were concentrated in the tailings. A case study on cleaning of slag containing 36 pct metallurgical silicon showed promising results concerning the recovery of silicon by flotation.

Interfacial interactions between plastic particles in plastics flotation.

PubMed

Wang, Chong-qing; Wang, Hui; Gu, Guo-hua; Fu, Jian-gang; Lin, Qing-quan; Liu, You-nian

2015-12-01

Plastics flotation used for recycling of plastic wastes receives increasing attention for its industrial application. In order to study the mechanism of plastics flotation, the interfacial interactions between plastic particles in flotation system were investigated through calculation of Lifshitz-van der Waals (LW) function, Lewis acid-base (AB) Gibbs function, and the extended Derjaguin-Landau-Verwey-Overbeek potential energy profiles. The results showed that van der Waals force between plastic particles is attraction force in flotation system. The large hydrophobic attraction, caused by the AB Gibbs function, is the dominant interparticle force. Wetting agents present significant effects on the interfacial interactions between plastic particles. It is found that adsorption of wetting agents promotes dispersion of plastic particles and decreases the floatability. Pneumatic flotation may improve the recovery and purity of separated plastics through selective adsorption of wetting agents on plastic surface. The relationships between hydrophobic attraction and surface properties were also examined. It is revealed that there exists a three-order polynomial relationship between the AB Gibbs function and Lewis base component. Our finding provides some insights into mechanism of plastics flotation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dissolved air flotation as a potential treatment process to remove Giardia cysts from anaerobically treated sewage.

PubMed

Santos, Priscila Ribeiro Dos; Daniel, Luiz Antonio

2017-10-01

Controlling Giardia cysts in sewage is an essential barrier for public health protection, reducing possible routes of protozoa transmission. The aim of this study was to evaluate the capability of dissolved air flotation (DAF), on a bench scale, to remove Giardia cysts from anaerobic effluent. Moreover, removals of indicator microorganisms and physical variables were also investigated. Flocculation conditions were studied, associating different flocculation times with different mean velocity gradients. DAF treatment achieved mean log removals in the range of 2.52-2.62 for Giardia cysts, depending on the flocculation condition. No statistical differences were observed among the flocculation conditions in terms of cyst removal. Low levels of turbidity and apparent color obtained from the treated effluent may indicate good treatment conditions for the DAF process in cyst removal. Indicator microorganisms were not able to predict the parasitological quality of the wastewater treated by flotation in terms of cyst concentrations. The DAF process provided an effective barrier to control cysts from sewage, which is an important parasite source.

Forward Osmosis in Wastewater Treatment Processes.

PubMed

Korenak, Jasmina; Basu, Subhankar; Balakrishnan, Malini; Hélix-Nielsen, Claus; Petrinic, Irena

2017-01-01

In recent years, membrane technology has been widely used in wastewater treatment and water purification. Membrane technology is simple to operate and produces very high quality water for human consumption and industrial purposes. One of the promising technologies for water and wastewater treatment is the application of forward osmosis. Essentially, forward osmosis is a process in which water is driven through a semipermeable membrane from a feed solution to a draw solution due to the osmotic pressure gradient across the membrane. The immediate advantage over existing pressure driven membrane technologies is that the forward osmosis process per se eliminates the need for operation with high hydraulic pressure and forward osmosis has low fouling tendency. Hence, it provides an opportunity for saving energy and membrane replacement cost. However, there are many limitations that still need to be addressed. Here we briefly review some of the applications within water purification and new developments in forward osmosis membrane fabrication.

Selective separation of phosphate and fluoride from semiconductor wastewater.

PubMed

Warmadewanthi, B; Liu, J C

2009-01-01

Hydrofluoric acid (HF) and phosphoric acid (H(3)PO(4)) are widely used in semiconductor industry for etching and rinsing purposes. Consequently, significant amount of wastewater containing phosphate and fluoride is generated. Selective separation of phosphate and fluoride from the semiconductor wastewater, containing 936 mg/L of fluoride, 118 mg/L of phosphate, 640 mg/L of sulfate, and 26.7 mg/L of ammonia, was studied. Chemical precipitation and flotation reactions were utilized in the two-stage treatment processes. The first-stage reaction involved the addition of magnesium chloride (MgCl(2)) to induce selective precipitation of magnesium phosphate. The optimal condition was pH 10 and molar ratio, [Mg(2 + )]/[(PO(4) (3-))], of 3:1, and 66.2% of phosphate was removed and recovered as bobierrite (Mg(3)(PO(4))(2).8H(2)O). No reaction was found between MgCl(2) and fluoride. Calcium chloride (CaCl(2)) was used in the second-stage reaction to induce precipitation of calcium fluoride and calcium phosphate. The optimum molar ratio, [Ca(2 + )]/[F(-)], was 0.7 at pH 10, and residual fluoride concentration of 10.7 mg/L and phosphate concentration of lower than 0.5 mg/L was obtained. Thermodynamic equilibrium was modeled with PHREEQC and compared with experimental results. Sodium dodecylsulfate (SDS) was an effective collector for subsequent solid-liquid removal via dispersed air flotation (DiAF). The study demonstrated that phosphate can be selectively recovered from the wastewater. Potential benefits include recovery of phosphate for reuse, lower required dosage of calcium for fluoride removal, and less amount of CaF(2) sludge.

Electroflotation

NASA Astrophysics Data System (ADS)

Chen, Xueming; Chen, Guohua

Electroflotation (EF) is the flotation using electrolytically generated bubbles of hydrogen and oxygen for separating suspended substances from aqueous phases. This process was first proposed by Elmore in 1905 for flotation of valuable minerals from ores. Compared with the conventional dissolved air flotation (DAF), EF has many advantages, including high flotation efficiency, compact units, easy operation, and less maintenance. Therefore, EF is an attractive alternative to DAF. This technique has been proven very effective in treating oily wastewater or oil-water emulsion, mining wastewater, groundwater, food processing wastewater, restaurant wastewater, industrial sewage, heavy metals containing effluent, and many other water and wastewaters.

Air/Water Purification

NASA Technical Reports Server (NTRS)

1992-01-01

After 18 years of research into air/water pollution at Stennis Space Center, Dr. B. C. Wolverton formed his own company, Wolverton Environmental Services, Inc., to provide technology and consultation in air and water treatment. Common houseplants are used to absorb potentially harmful materials from bathrooms and kitchens. The plants are fertilized, air is purified, and wastewater is converted to clean water. More than 100 U.S. communities have adopted Wolverton's earlier water hyacinth and artificial marsh applications. Catfish farmers are currently evaluating the artificial marsh technology as a purification system.

Flotation machine and process for removing impurities from coals

DOEpatents

Szymocha, K.; Ignasiak, B.; Pawlak, W.; Kulik, C.; Lebowitz, H.E.

1995-12-05

The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other mineral particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal. 4 figs.

Flotation machine and process for removing impurities from coals

DOEpatents

Szymocha, Kazimierz; Ignasiak, Boleslaw; Pawlak, Wanda; Kulik, Conrad; Lebowitz, Howard E.

1995-01-01

The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other minerals particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal.

Flotation machine and process for removing impurities from coals

DOEpatents

Szymocha, K.; Ignasiak, B.; Pawlak, W.; Kulik, C.; Lebowitz, H.E.

1997-02-11

The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other minerals particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal. 4 figs.

Flotation machine and process for removing impurities from coals

DOEpatents

Szymocha, Kazimierz; Ignasiak, Boleslaw; Pawlak, Wanda; Kulik, Conrad; Lebowitz, Howard E.

1997-01-01

The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other minerals particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal.

46 CFR 25.25-13 - Personal flotation device lights.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Personal flotation device lights. 25.25-13 Section 25.25... Preservers and Other Lifesaving Equipment § 25.25-13 Personal flotation device lights. (a) This section... device intended to be worn, and each buoyant vest must have a personal flotation device light that is...

46 CFR 25.25-13 - Personal flotation device lights.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Personal flotation device lights. 25.25-13 Section 25.25... Preservers and Other Lifesaving Equipment § 25.25-13 Personal flotation device lights. (a) This section... device intended to be worn, and each buoyant vest must have a personal flotation device light that is...

46 CFR 25.25-13 - Personal flotation device lights.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Personal flotation device lights. 25.25-13 Section 25.25... Preservers and Other Lifesaving Equipment § 25.25-13 Personal flotation device lights. (a) This section... device intended to be worn, and each buoyant vest must have a personal flotation device light that is...

46 CFR 25.25-13 - Personal flotation device lights.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Personal flotation device lights. 25.25-13 Section 25.25... Preservers and Other Lifesaving Equipment § 25.25-13 Personal flotation device lights. (a) This section... device intended to be worn, and each buoyant vest must have a personal flotation device light that is...

46 CFR 25.25-13 - Personal flotation device lights.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Personal flotation device lights. 25.25-13 Section 25.25... Preservers and Other Lifesaving Equipment § 25.25-13 Personal flotation device lights. (a) This section... device intended to be worn, and each buoyant vest must have a personal flotation device light that is...

Oil-water separation property of polymer-contained wastewater from polymer-flooding oilfields in Bohai Bay, China.

PubMed

Chen, Hua-xing; Tang, Hong-ming; Duan, Ming; Liu, Yi-gang; Liu, Min; Zhao, Feng

2015-01-01

In this study, the effects of gravitational settling time, temperature, speed and time of centrifugation, flocculant type and dosage, bubble size and gas amount were investigated. The results show that the simple increase in settling time and temperature is of no use for oil-water separation of the three wastewater samples. As far as oil-water separation efficiency is concerned, increasing centrifugal speed and centrifugal time is highly effective for L sample, and has a certain effect on J sample, but is not valid for S sample. The flocculants are highly effective for S and L samples, and the oil-water separation efficiency increases with an increase in the concentration of inorganic cationic flocculants. There exist critical reagent concentrations for the organic cationic and the nonionic flocculants, wherein a higher or lower concentration of flocculant would cause a decrease in the treatment efficiency. Flotation is an effective approach for oil-water separation of polymer-contained wastewater from the three oilfields. The oil-water separation efficiency can be enhanced by increasing floatation agent concentration, flotation time and gas amount, and by decreasing bubble size.

Flotation: A promising microalgae harvesting and dewatering technology for biofuels production.

PubMed

Ndikubwimana, Theoneste; Chang, Jingyu; Xiao, Zongyuan; Shao, Wenyao; Zeng, Xianhai; Ng, I-Son; Lu, Yinghua

2016-03-01

Microalgal biomass as renewable energy source is believed to be of great potential for reliable and sustainable biofuels production. However, microalgal biomass production is pinned by harvesting and dewatering stage thus hindering the developing and growing microalgae biotechnology industries. Flotation technology applied in mineral industry could be potentially applied in microalgae harvesting and dewatering, however substantial knowledge on different flotation units is essential. This paper presents an overview on different flotation units as promising cost-effective technologies for microalgae harvesting thus bestowing for further research in development and commercialization of microalgae based biofuels. Dispersed air flotation was found to be less energy consuming. Moreover, Jameson cell flotation and dispersed ozone flotation are believed to be energy efficient microalgae flotation approaches. Microalgae harvesting and dewatering by flotation is still at embryonic stage, therefore extended studies with the focus on life cycle assessment, sustainability of the flotation unit, optimization of the operating parameters using different algal species is imperative. Though there are a number of challenges in microalgae harvesting and dewatering, with well designed and developed cultivation, harvesting/dewatering, extraction and conversion technologies, progressively, microalgae technology will be of great potential for biological carbon sequestration, biofuels and biochemicals production. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Application of gas sensor arrays in assessment of wastewater purification effects.

PubMed

Guz, Łukasz; Łagód, Grzegorz; Jaromin-Gleń, Katarzyna; Suchorab, Zbigniew; Sobczuk, Henryk; Bieganowski, Andrzej

2014-12-23

A gas sensor array consisting of eight metal oxide semiconductor (MOS) type gas sensors was evaluated for its ability for assessment of the selected wastewater parameters. Municipal wastewater was collected in a wastewater treatment plant (WWTP) in a primary sedimentation tank and was treated in a laboratory-scale sequential batch reactor (SBR). A comparison of the gas sensor array (electronic nose) response to the standard physical-chemical parameters of treated wastewater was performed. To analyze the measurement results, artificial neural networks were used. E-nose-gas sensors array and artificial neural networks proved to be a suitable method for the monitoring of treated wastewater quality. Neural networks used for data validation showed high correlation between the electronic nose readouts and: (I) chemical oxygen demand (COD) (r = 0.988); (II) total suspended solids (TSS) (r = 0.938); (III) turbidity (r = 0.940); (IV) pH (r = 0.554); (V) nitrogen compounds: N-NO3 (r = 0.958), N-NO2 (r = 0.869) and N-NH3 (r = 0.978); (VI) and volatile organic compounds (VOC) (r = 0.987). Good correlation of the abovementioned parameters are observed under stable treatment conditions in a laboratory batch reactor.

Some physicochemical aspects of water-soluble mineral flotation.

PubMed

Wu, Zhijian; Wang, Xuming; Liu, Haining; Zhang, Huifang; Miller, Jan D

2016-09-01

Some physicochemical aspects of water-soluble mineral flotation including hydration phenomena, associations and interactions between collectors, air bubbles, and water-soluble mineral particles are presented. Flotation carried out in saturated salt solutions, and a wide range of collector concentrations for effective flotation of different salts are two basic aspects of water-soluble mineral flotation. Hydration of salt ions, mineral particle surfaces, collector molecules or ions, and collector aggregates play an important role in water-soluble mineral flotation. The adsorption of collectors onto bubble surfaces is suggested to be the precondition for the association of mineral particles with bubbles. The association of collectors with water-soluble minerals is a complicated process, which may include the adsorption of collector molecules or ions onto such surfaces, and/or the attachment of collector precipitates or crystals onto the mineral surfaces. The interactions between the collectors and the minerals include electrostatic and hydrophobic interactions, hydrogen bonding, and specific interactions, with electrostatic and hydrophobic interactions being the common mechanisms. For the association of ionic collectors with minerals with an opposite charge, electrostatic and hydrophobic interactions could have a synergistic effect, with the hydrophobic interactions between the hydrophobic groups of the previously associated collectors and the hydrophobic groups of oncoming collectors being an important attractive force. Association between solid particles and air bubbles is the key to froth flotation, which is affected by hydrophobicity of the mineral particle surfaces, surface charges of mineral particles and bubbles, mineral particle size and shape, temperature, bubble size, etc. The use of a collector together with a frother and the use of mixed surfactants as collectors are suggested to improve flotation. Copyright © 2016 Elsevier B.V. All rights reserved.

33 CFR 142.45 - Personal flotation devices.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.45 Personal flotation devices. Personnel, when working in a location such that, in the event of a... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Personal flotation devices. 142...

33 CFR 142.45 - Personal flotation devices.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.45 Personal flotation devices. Personnel, when working in a location such that, in the event of a... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Personal flotation devices. 142...

Remediation of metal-contaminated urban soil using flotation technique.

PubMed

Dermont, G; Bergeron, M; Richer-Laflèche, M; Mercier, G

2010-02-01

A soil washing process using froth flotation technique was evaluated for the removal of arsenic, cadmium, copper, lead, and zinc from a highly contaminated urban soil (brownfield) after crushing of the particle-size fractions >250microm. The metal contaminants were in particulate forms and distributed in all the particle-size fractions. The particle-by-particle study with SEM-EDS showed that Zn was mainly present as sphalerite (ZnS), whereas Cu and Pb were mainly speciated as various oxide/carbonate compounds. The influence of surfactant collector type (non-ionic and anionic), collector dosage, pulp pH, a chemical activation step (sulfidization), particle size, and process time on metal removal efficiency and flotation selectivity was studied. Satisfactory results in metal recovery (42-52%), flotation selectivity (concentration factor>2.5), and volume reduction (>80%) were obtained with anionic collector (potassium amyl xanthate). The transportation mechanisms involved in the separation process (i.e., the true flotation and the mechanical entrainment) were evaluated by the pulp chemistry, the metal speciation, the metal distribution in the particle-size fractions, and the separation selectivity indices of Zn/Ca and Zn/Fe. The investigations showed that a great proportion of metal-containing particles were recovered in the froth layer by entrainment mechanism rather than by true flotation process. The non-selective entrainment mechanism of the fine particles (<20 microm) caused a flotation selectivity drop, especially with a long flotation time (>5 min) and when a high collector dose is used. The intermediate particle-size fraction (20-125 microm) showed the best flotation selectivity. Copyright 2009 Elsevier B.V. All rights reserved.

Modelling the global efficiency of dissolved air flotation.

PubMed

Leppinen, D M; Dalziel, S B; Linden, P F

2001-01-01

The purpose of this paper is to examine how the efficiency of dissolved air flotation is affected by the size of bubbles and particles. The rise speed of bubble/particle agglomerates is modelled as a function of bubble and particle size, while the kinematics of the bubble attachment process is modelled using the population balance approach adopted by Matsui, Fukushi and Tambo. It is found that flotation, in general, is enhanced by the use of larger particles and larger bubbles. In particular, it is concluded that for the ultra-high surface loading rates of 25 m/hr or more planned for future flotation tanks, bubble size will have to be increased by a factor of two over the size currently employed in many facilities during dissolved air flotation.

Biochar-based functional materials in the purification of agricultural wastewater: Fabrication, application and future research needs.

PubMed

Wei, Dongning; Li, Bingyu; Huang, Hongli; Luo, Lin; Zhang, Jiachao; Yang, Yuan; Guo, Jiajun; Tang, Lin; Zeng, Guangming; Zhou, Yaoyu

2018-04-01

Nowadays, agricultural contamination is becoming more and more serious due to the rapid growth of agricultural industry, which discharged antibiotics, pesticides or toxic metals into farmlands. A large number of researchers have applied biochar-based functional materials to the treatment of agricultural wastewater contamination. Meanwhile, biochar has also proved to be a very promising and effective technology in water purification field due to its various beneficial properties (e.g., cost effective, high specific surface area, and surface reactive groups). The focus of this review is to highlight the fabrication methods and application of biochar-based functional materials with the removal of different agricultural contaminants, and discuss the underlying mechanisms. However, the application of biochar-based functional materials is currently under its infancy, with the main hindrance is identified as the gap between laboratory scale and field application, immaturity of engineered biochar production technologies, and lack of quality standards. In order to fill these knowledge gaps, more efforts should be made to pay for the relevant research in future studies. Copyright © 2018 Elsevier Ltd. All rights reserved.

Beneficiation of borax by reverse flotation in boron saturated brine.

PubMed

Cafer Cilek, Emin; Uresin, Hasan

2005-10-15

Flotation is one of the plausible methods for recovering borax fines discharged as fine waste to the tailings dam in the Kirka borax processing plant. A literature review dealing with the flotation behavior of boron minerals reveals that clay minerals in the boron ores coat boron minerals and thus deteriorate the quality of boron concentrates produced by direct flotation. The main objective of this study is therefore to recover borax fines from the tailings of the concentrator by reverse flotation. A three-level-factor experimental design was used to determine the main and interaction effects of variables selected on the metallurgical performance of reverse flotation. An analysis of variance for experimental results indicates that interaction effects of the variables for concentrate quality and recovery of B2O3 is nonsignificant and the most important variable for grade of concentrate and recovery is the collector dosage. It is shown that a concentrate assaying 11.25% B2O3 with 89.90% B2O3 recovery could be produced by means of single-stage (rougher) reverse flotation. Additionally, in order to produce a sufficient-quality concentrate, a multistage reverse flotation scheme involving rougher, scavenger, and two cleaners was devised. A final concentrate containing 23.47% B2O3 with 81.78% B2O3 recovery was obtained from these tests. The reverse flotation method can be thus considered as an important option for the beneficiation of borax fines.

Occurrence and removal of Giardia spp. cysts and Cryptosporidium spp. oocysts from a municipal wastewater treatment plant in Brazil.

PubMed

Santos, Priscila Ribeiro Dos; Daniel, Luiz Antonio

2017-05-01

Sewage and sewage sludge have been recognized as potential sources of two important waterborne pathogenic protozoa: Giardia spp. and Cryptosporidium spp. Due to the lack of studies about the occurrence of these pathogens in sewage and sludge in Brazil, an investigation was conducted at various stages of a municipal wastewater treatment plant (WWTP) aiming to assess the occurrence of Giardia spp. cysts and Cryptosporidium spp. oocysts, their removal by the treatment processes, which are upflow anaerobic sludge blanket (UASB) reactor and dissolved air flotation process, and also the correlations between protozoa and indicator microorganisms. Significant quantities of cysts were detected in 100% of the analyzed wastewater samples, while oocysts were detected only in 39.0% of all wastewater samples. The overall removal of Giardia spp. cysts from the WWTP was on average 2.03 log, and the UASB reactor was more efficient than flotation. The sludge samples presented high quantities of (oo)cysts, implying the risks of contamination in the case of sludge reuse or inadequate disposal. Giardiasis prevalence was estimated between 2.21% and 6.7% for the population served by the WWTP, while cryptosporidiosis prevalence was much lower. Significant positive correlation was obtained only between cysts and Clostridium spores in anaerobic effluent.

Molecular design of flotation collectors: A recent progress.

PubMed

Liu, Guangyi; Yang, Xianglin; Zhong, Hong

2017-08-01

The nature of froth flotation is to selectively hydrophobize valuable minerals by collector adsorption so that the hydrophobized mineral particles can attach air bubbles. In recent years, the increasing commercial production of refractory complex ores has been urgent to develop special collectors for enhancing flotation separation efficiency of valuable minerals from these ores. Molecular design methods offer an effective way for understanding the structure-property relationship of flotation collectors and developing new ones. The conditional stability constant (CSC), molecular mechanics (MM), quantitative structure-activity relationship (QSAR), and first-principle theory, especially density functional theory (DFT), have been adopted to build the criteria for designing flotation collectors. Azole-thiones, guanidines, acyl thioureas and thionocarbamates, amide-hydroxamates, and double minerophilic-group surfactants such as Gemini, dithiourea and dithionocarbamate molecules have been recently developed as high-performance collectors. To design hydrophobic groups, the hydrophilic-hydrophobic balance parameters have been extensively used as criteria. The replacement of aryl group with aliphatic group or CC single bond(s) with CC double bond(s), reduction of carbon numbers, introduction of oxygen atom(s) and addition of trisiloxane to the tail terminal have been proved to be useful approaches for adjusting the surface activity of collectors. The role of molecular design of collectors in practical flotation applications was also summarized. Based on the critical review, some comments and prospects for further research on molecular design of flotation collectors were also presented in the paper. Copyright © 2017 Elsevier B.V. All rights reserved.

Biomimetic Multilayer Nanofibrous Membranes with Elaborated Superwettability for Effective Purification of Emulsified Oily Wastewater.

PubMed

Ge, Jianlong; Jin, Qing; Zong, Dingding; Yu, Jianyong; Ding, Bin

2018-05-09

Creating a porous membrane to effectively separate the emulsified oil-in-water emulsions with energy-saving property is highly desired but remains a challenge. Herein, a multilayer nanofibrous membrane was developed with the inspiration of the natural architectures of earth for gravity-driven water purification. As a result, the obtained biomimetic multilayer nanofibrous membranes exhibited three individual layers with designed functions; they were the inorganic nanofibrous layer to block the serious intrusion of oil to prevent the destructive fouling of the polymeric matrix; the submicron porous layer with designed honeycomb-like cavities to catch the smaller oil droplets and ensures a satisfactory water permeability; and the high porous fibrous substrate with larger pore size provided a template support and allows water to pass through quickly. Consequently, with the cooperation of these three functional layers, the resultant composite membrane possessed superior anti-oil-fouling property and robust oil-in-water emulsion separation performance with good separation efficiency and competitive permeation flux solely under the drive of gravity. The permeation flux of the membrane for the emulsion was up to 5163 L m -2 h -1 with a separation efficiency of 99.5%. We anticipate that our strategy could provide a facile route for developing a new generation of specific membranes for oily wastewater remediation.

Innovations in the flotation of fine and coarse particles

NASA Astrophysics Data System (ADS)

Fornasiero, D.; Filippov, L. O.

2017-07-01

Research on the mechanisms of particle-bubble interaction has provided valuable information on how to improve the flotation of fine (<20 µm) and coarse particles (>100 µm) with novel flotation machines which provide higher collision and attachment efficiencies of fine particles with bubbles and lower detachment of the coarse particles. Also, new grinding methods and technologies have reduced energy consumption in mining and produced better mineral liberation and therefore flotation performance.

Desulfurization of coal by microbial column flotation.

PubMed

Ohmura, N; Saiki, H

1994-06-05

Twenty-three strains capable of oxidizing iron were isolated from coal and ore storage sites as well as coal and ore mines, volcanic areas, and hot spring. Four strains were found to have high iron-oxidizing activity. One strain (T-4) was selected for this experiment since the strain showed the fastest leaching rate of iron and sulfate from pyrite among the four strains. The T-4 strain was assigned for Thiobacillus ferrooxidans from its cultural and morphological characteristics.Bacterial treatment was applied to column flotation. An increase of cell density in the microbial column flotation resulted in the increase of pyrite removal from a coal-pyrite mixture (high sulfur imitated coal) with corresponding decrease of coal recovery. The addition of kerosene into the microbial column flotation increased the recovery of the imitated coal from 55% (without kerosene) to 81% (with 50 microL/L kerosene) with the reduction of pyrite sulfur content from 11% (feed coal) to 3.9% (product coal). The kerosene addition could reduce the pyritic sulfur content by collecting the coal in the recovery. However, the addition could not enhance separation of pyrite from the coal-pyrite mixture, since pyrite rejection was not affected by the increase of the kerosene addition. An excellent separation was obtained by the microbial flotation using a long column which had a length-diameter (L/D) ratio of 12.7. The long column flotation reduced the pyritic sulfur content from 11% (feed coal) to 1.8% (product coal) when 80% of the feed coal was recovered without the kerosene addition. The long column flotation not only attained an excellent separation but also reduced the amount of cells for desulfurization to as little as one-tenth of the reported amount.

Modelling Of Flotation Processes By Classical Mathematical Methods - A Review

NASA Astrophysics Data System (ADS)

Jovanović, Ivana; Miljanović, Igor

2015-12-01

Flotation process modelling is not a simple task, mostly because of the process complexity, i.e. the presence of a large number of variables that (to a lesser or a greater extent) affect the final outcome of the mineral particles separation based on the differences in their surface properties. The attempts toward the development of the quantitative predictive model that would fully describe the operation of an industrial flotation plant started in the middle of past century and it lasts to this day. This paper gives a review of published research activities directed toward the development of flotation models based on the classical mathematical rules. The description and systematization of classical flotation models were performed according to the available references, with emphasize exclusively given to the flotation process modelling, regardless of the model application in a certain control system. In accordance with the contemporary considerations, models were classified as the empirical, probabilistic, kinetic and population balance types. Each model type is presented through the aspects of flotation modelling at the macro and micro process levels.

46 CFR 170.245 - Foam flotation material.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Foam flotation material. 170.245 Section 170.245... REQUIREMENTS FOR ALL INSPECTED VESSELS Special Installations § 170.245 Foam flotation material. (a) Installation of foam must be approved by the OCMI. (b) If foam is used to comply with § 171.070(d), § 171.095(c...

46 CFR 170.245 - Foam flotation material.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Foam flotation material. 170.245 Section 170.245... REQUIREMENTS FOR ALL INSPECTED VESSELS Special Installations § 170.245 Foam flotation material. (a) Installation of foam must be approved by the OCMI. (b) If foam is used to comply with § 171.070(d), § 171.095(c...

On fiber rejection loss in flotation deinking

Treesearch

J.Y. Zhu; Freya Tan

2005-04-01

Reducing fiber rejection loss in flotation deinking is very important to conserve natural resources and reduce the cost of secondary fibers in paper recycling. This study examined two aspects of the problem, fiber consistency in the rejection stream and rate of Froth (or wet stream) rejection. Flotation experiments were conducted using both nylon and wood fibers in...

Wastewater Treatment: The Natural Way

NASA Technical Reports Server (NTRS)

1988-01-01

Wolverton Environmental Services, Inc. is widely acclaimed for innovative work in natural water purification which involves use of aquatic plants to remove pollutants from wastewater at a relatively low-cost. Haughton, Louisiana, visited Wolverton's artificial marsh test site and decided to use this method of wastewater treatment. They built an 11 acre sewage lagoon with a 70 by 900 foot artificial marsh called a vascular aquatic plant microbial filter cell. In the cell, microorganisms and rooted aquatic plants combine to absorb and digest wastewater pollutants, thereby converting sewage to relatively clean water. Raw waste water, after a period in the sewage lagoon, flows over a rock bed populated by microbes that digest nutrients and minerals from the sewage thus partially cleaning it. Additional treatment is provided by the aquatic plants growing in the rock bed, which absorb more of the pollutants and help deodorize the sewage.

33 CFR 183.202 - Flotation and certification requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.202 Flotation and certification requirements. Each boat to which this subpart applies must be manufactured, constructed, or assembled to pass...

33 CFR 183.202 - Flotation and certification requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.202 Flotation and certification requirements. Each boat to which this subpart applies must be manufactured, constructed, or assembled to pass...

A review of zinc oxide mineral beneficiation using flotation method.

PubMed

Ejtemaei, Majid; Gharabaghi, Mahdi; Irannajad, Mehdi

2014-04-01

In recent years, extraction of zinc from low-grade mining tailings of oxidized zinc has been a matter of discussion. This is a material which can be processed by flotation and acid-leaching methods. Owing to the similarities in the physicochemical and surface chemistry of the constituent minerals, separation of zinc oxide minerals from their gangues by flotation is an extremely complex process. It appears that selective leaching is a promising method for the beneficiation of this type of ore. However, with the high consumption of leaching acid, the treatment of low-grade oxidized zinc ores by hydrometallurgical methods is expensive and complex. Hence, it is best to pre-concentrate low-grade oxidized zinc by flotation and then to employ hydrometallurgical methods. This paper presents a critical review on the zinc oxide mineral flotation technique. In this paper, the various flotation methods of zinc oxide minerals which have been proposed in the literature have been detailed with the aim of identifying the important factors involved in the flotation process. The various aspects of recovery of zinc from these minerals are also dealt with here. The literature indicates that the collector type, sulfidizing agent, pH regulator, depressants and dispersants types, temperature, solid pulp concentration, and desliming are important parameters in the process. The range and optimum values of these parameters, as also the adsorption mechanism, together with the resultant flotation of the zinc oxide minerals reported in the literature are summarized and highlighted in the paper. This review presents a comprehensive scientific guide to the effectiveness of flotation strategy. Copyright © 2013 Elsevier B.V. All rights reserved.

Extraction of anthocyanins from black bean canning wastewater with macroporous resins.

PubMed

Wang, Xiaoxi; Hansen, Conly; Allen, Karin

2014-02-01

This study investigated purification of anthocyanins from black bean canning wastewater by column chromatography with 5 types of macroporous resins (Diaion Hp20, Sepabeads Sp70, Sepabeads Sp207, Sepabeads Sp700, and Sepabeads Sp710). By-product of canned black beans was partially purified by filtration, in anticipation of higher performance during column chromatography. Equilibrium adsorption isotherms were measured and analyzed using Langmuir and Freundlich isotherm models. Both Langmuir (all R² ≥ 0.98) and Freundlich (all R² ≥ 0.97) models can describe the adsorption process of anthocyanins from black bean canning wastewater using the tested resins. The adsorption and desorption behaviors of anthocyanins were studied using a dynamic method on the 5 types of resins, and Sp700 presented the highest adsorption capacity (39 ± 4 mg/g; P < 0.05) as well as desorption capacity (19 ± 2%; P < 0.05), indicating that of the resins examined, Sp700 is a better candidate for purification of anthocyanins from black bean canning wastewater. © 2014 Institute of Food Technologists®

Applications of nanotechnology in wastewater treatment--a review.

PubMed

Bora, Tanujjal; Dutta, Joydeep

2014-01-01

Water on Earth is a precious and finite resource, which is endlessly recycled in the water cycle. Water, whose physical, chemical, or biological properties have been altered due to the addition of contaminants such as organic/inorganic materials, pathogens, heavy metals or other toxins making it unsafe for the ecosystem, can be termed as wastewater. Various schemes have been adopted by industries across the world to treat wastewater prior to its release to the ecosystem, and several new concepts and technologies are fast replacing the traditional methods. This article briefly reviews the recent advances and application of nanotechnology for wastewater treatment. Nanomaterials typically have high reactivity and a high degree of functionalization, large specific surface area, size-dependent properties etc., which makes them suitable for applications in wastewater treatment and for water purification. In this article, the application of various nanomaterials such as metal nanoparticles, metal oxides, carbon compounds, zeolite, filtration membranes, etc., in the field of wastewater treatment is discussed.

Foam flotation as a separation process

NASA Technical Reports Server (NTRS)

Currin, B. L.

1986-01-01

The basic principles of foam separation techniques are discussed. A review of the research concerning bubble-particle interaction and its role in the kinetics of the flotation process is given. Most of the research in this area deals with the use of theoretical models to predict the effects of bubble and particle sizes, of liquid flow, and of various forces on the aperture and retention of particles by bubbles. A discussion of fluid mechanical aspects of particle flotation is given.

Coal-oil gold agglomeration assisted flotation to recover gold from refractory ore

NASA Astrophysics Data System (ADS)

Otsuki, A.; Yue, C.

2017-07-01

This study aimed to investigate the applicability of coal-oil gold agglomeration (CGA) assisted flotation to recover gold from a refractory ore. The ore with the grade of 2-5 g/t was tested with the CGA-flotation process in six different size fractions from 38 to 300 urn using different collector types and dosages. In addition, the flotation without CGA was performed under the same condition for comparison. The results showed that the higher gold grade and recovery were achieved by applying the CGA-flotation, compared with the flotation without CGA. More than 20-60 times grade increase from the head grade was obtained with CGA-flotation. The elemental analysis of gold and sulphur explained their relationship with gold recovery. The results well indicated the applicability of CGA to upgrade the refractory gold ore.

Technology of surface wastewater purification, including high-rise construction areas

NASA Astrophysics Data System (ADS)

Tsyba, Anna; Skolubovich, Yury

2018-03-01

Despite on the improvements in the quality of high-rise construction areas and industrial wastewater treatment, the pollution of water bodies continues to increase. This is due to the organized and unorganized surface untreated sewage entry into the reservoirs. The qualitative analysis of some cities' surface sewage composition is carried out in the work. Based on the published literature review, the characteristic contamination present in surface wastewater was identified. The paper proposes a new technology for the treatment of surface sewage and presents the results of preliminary studies.

Evaluation of Gas Phase Dispersion in Flotation under Predetermined Hydrodynamic Conditions

NASA Astrophysics Data System (ADS)

Młynarczykowska, Anna; Oleksik, Konrad; Tupek-Murowany, Klaudia

2018-03-01

Results of various investigations shows the relationship between the flotation parameters and gas distribution in a flotation cell. The size of gas bubbles is a random variable with a specific distribution. The analysis of this distribution is useful to make mathematical description of the flotation process. The flotation process depends on many variable factors. These are mainly occurrences like collision of single particle with gas bubble, adhesion of particle to the surface of bubble and detachment process. These factors are characterized by randomness. Because of that it is only possible to talk about the probability of occurence of one of these events which directly affects the speed of the process, thus a constant speed of flotation process. Probability of the bubble-particle collision in the flotation chamber with mechanical pulp agitation depends on the surface tension of the solution, air consumption, degree of pul aeration, energy dissipation and average feed particle size. Appropriate identification and description of the parameters of the dispersion of gas bubbles helps to complete the analysis of the flotation process in a specific physicochemical conditions and hydrodynamic for any raw material. The article presents the results of measurements and analysis of the gas phase dispersion by the size distribution of air bubbles in a flotation chamber under fixed hydrodynamic conditions. The tests were carried out in the Laboratory of Instrumental Methods in Department of Environmental Engineering and Mineral Processing, Faculty of Mining and Geoengineerin, AGH Univeristy of Science and Technology in Krakow.

The use of low-cost adsorbents for wastewater purification in mining industries.

PubMed

Iakovleva, Evgenia; Sillanpää, Mika

2013-11-01

Recently, great attention has been paid to the environmental problems in mining industry. At present there are different ways of mineral processing, as well as various methods of wastewater treatment, most of them are expensive. Work is ongoing to find low-cost treatments. In this article, low-cost adsorbents, potentially useful for wastewater treatment on mining and metallurgical plants, are reviewed; their characteristics, advantages, and disadvantages of their application are compared. Also adsorption of different metals and radioactive compounds from acidic environment similar to composition of mining and metallurgical wastewaters is considered.

Aquatic macrophytes can be used for wastewater polishing but not for purification in constructed wetlands

NASA Astrophysics Data System (ADS)

Tang, Yingying; Harpenslager, Sarah F.; van Kempen, Monique M. L.; Verbaarschot, Evi J. H.; Loeffen, Laury M. J. M.; Roelofs, Jan G. M.; Smolders, Alfons J. P.; Lamers, Leon P. M.

2017-02-01

The sequestration of nutrients from surface waters by aquatic macrophytes and sediments provides an important service to both natural and constructed wetlands. While emergent species take up nutrients from the sediment, submerged and floating macrophytes filter nutrients directly from the surface water, which may be more efficient in constructed wetlands. It remains unclear, however, whether their efficiency is sufficient for wastewater purification and how plant species and nutrient loading affects nutrient distribution over plants, water and sediment. We therefore determined nutrient removal efficiencies of different vegetation (Azolla filiculoides, Ceratophyllum demersum and Myriophyllum spicatum) and sediment types (clay, peaty clay and peat) at three nutrient input rates, in a full factorial, outdoor mesocosm experiment. At low loading (0.43 mg P m-2 d-1), plant uptake was the main pathway (100 %) for phosphorus (P) removal, while sediments showed a net P release. A. filiculoides and M. spicatum showed the highest biomass production and could be harvested regularly for nutrient recycling, whereas C. demersum was outcompeted by spontaneously developing macrophytes and algae. Higher nutrient loading only stimulated A. filiculoides growth. At higher rates ( ≥ 21.4 mg P m-2 d-1), 50-90 % of added P ended up in sediments, with peat sediments becoming more easily saturated. For nitrogen (N), 45-90 % was either taken up by the sediment or lost to the atmosphere at loadings ≥ 62 mg N m-2 d-1. This shows that aquatic macrophytes can indeed function as an efficient nutrient filter but only for low loading rates (polishing) and not for high rates (purification). The outcome of this controlled study not only contributes to our understanding of nutrient dynamics in constructed wetlands but also shows the differential effects of wetland sediment types and plant species. Furthermore, the acquired knowledge may benefit the application of macrophyte harvesting to remove

Egg flotation estimates nest age for Pacific and Red-throated Loons

USGS Publications Warehouse

Rizzolo, Daniel; Schmutz, Joel A.

2007-01-01

We used Pacific Loon (Gavia pacifica) and Red-throated Loon (G. stellata) nests with known ages to gauge the efficacy of egg flotation for determining nest age in coastal Alaska. Egg flotation accurately estimated nest age for both species; the mean ± 1SD difference between known age and age determined with egg flotation was - 0.05 ± 2.00 d and -0.02 ± 1.63 d for Pacific and Red-throated Loons, respectively. Day of nest initiation did not influence the relationship between known nest age and nest age estimated with egg flotation, indicating incubation period was not shortened in nests initiated later in the season. Additionally, we found no difference in the ability of egg flotation to estimate nest age between two widely dispersed study sites for Pacific Loons, and only a small difference between two of three widely dispersed study sites for Red-throated Loons. Thus, our described relationships between egg flotation categories and nest age should be broadly applicable for these holarctic species. We conclude that for Pacific and Red-throated Loons, egg flotation is a useful technique for determining nest age in the field to better monitor nest fate, and to quantify nest age effects on nest daily survival rate.

Effects of flotation-REST on muscle tension pain.

PubMed

Kjellgren, A; Sundequist, U; Norlander, T; Archer, T

2001-01-01

The purpose of the present study was to investigate whether the floating form of the restricted environmental stimulation technique (REST) may be applied within the field of pain relief. Flotation-REST consists of a procedure whereby an individual is immersed in a tank filled with water of an extremely high salt concentration. Thirty-seven patients (14 men and 23 women) suffering from chronic pain consisting of aching muscles in the neck and back area participated in the study. They were randomly assigned to either a control group (17 participants) or an experimental group (20 participants). The experimental group received nine opportunities to use the flotation-REST technique in the water tank over a three-week period. The results indicated that the most severe perceived pain intensity was significantly reduced, whereas low perceived pain intensity was not influenced by the floating technique. Further, the results indicated that circulating levels of the noradrenaline metabolite 3-methoxy-4-hydroxyphenylethyleneglycol were reduced significantly in the experimental group but not in the control group following treatment, whereas endorphin levels were not affected by flotation. Flotation-REST treatment also elevated the participants' optimism and reduced the degree of anxiety or depression; at nighttime, patients who underwent flotation fell asleep more easily. The present findings describe possible changes, for the better, in patients presenting with chronic pain complaints.

FLOCCULATION-FLOTATION AIDS FOR TREATMENT OF COMBINED SEWER OVERFLOWS

EPA Science Inventory

The objectives of this study were to investigate the flocculation/flotation characteristics of combined sewer overflow through laboratory and field testing. The concept involves the introduction of chemicals and buoyant flotation aids into the overflow and the subsequent cofloccu...

Investigation of impact of water type on borate ore flotation.

PubMed

Ozkan, S G; Acar, A

2004-04-01

In this work, the impact of water type on borate ore flotation was investigated, while various physical parameters during flotation were considered in order to compare the results. Two different colemanite samples from Emet deposits of Turkey, named as Emet-A and Emet-B contained 44% B(2)O(3) and 40% B(2)O(3), respectively. The flotation tests were performed at feed particle size range of -210 +20 microm. Optimal consumption values for the reagents were determined as 2000 gt(-1) for AeroPromoter R825 from Cytec Company, a sulphonate type collector, 1500 gt(-1) for Procol CA927 from Allied Colloids Company, a sulphosuccinamate type collector and 100 gt(-1) for AeroFrother 70 from Cytec Company, an alcohol-type frother. In the tests, the impeller speed of the Denver-type flotation machine was set to 1200 rpm and the samples were fed into a litre cell at 25% solid/liquid ratio and at natural pH value of the slurry at room temperature. The flotation results obtained from the tests with use of tap water, demineralised water and the artificial water prepared with Ca(2+) and Mg(2+) cations deliberately added into demineralised water were compared to each other in optimal flotation conditions.

Flotation mechanisms of molybdenite fines by neutral oils

NASA Astrophysics Data System (ADS)

Lin, Qing-quan; Gu, Guo-hua; Wang, Hui; Liu, You-cai; Fu, Jian-gang; Wang, Chong-qing

2018-01-01

The flotation mechanisms of molybdenite fines by neutral oils were investigated through microflotation test, turbidity measurements, infrared spectroscopy, and interfacial interaction calculations. The results of the flotation test show that at pH 2-11, the floatability of molybdenite fines in the presence of transformer oil is markedly better than that in the presence of kerosene and diesel oil. The addition of transformer oil, which enhances the floatability of molybdenite fines, promotes the aggregation of molybdenite particles. Fourier transform infrared measurements illustrate that physical interaction dominates the adsorption mechanism of neutral oil on molybdenite. Interfacial interaction calculations indicate that hydrophobic attraction is the crucial force that acts among the oil collector, water, and molybdenite. Strong hydrophobic attraction between the oily collector and water provides the strong dispersion capability of the collector in water. Furthermore, the dispersion capability of the collector, not the interaction strength between the oily collectors and molybdenite, has a highly significant role in the flotation system of molybdenite fines. Our findings provide insights into the mechanism of molybdenite flotation.

Selective depression behavior of guar gum on talc-type scheelite flotation

NASA Astrophysics Data System (ADS)

Zhang, Yong-zhong; Gu, Guo-hua; Wu, Xiang-bin; Zhao, Kai-le

2017-08-01

The depression behavior and mechanism of guar gum on talc-type scheelite flotation were systematically investigated by flotation experiments, adsorption tests, zeta-potential measurements, and infrared spectroscopic analyses. The flotation results for monominerals, mixed minerals, and actual mineral samples indicated that guar gum exhibited much higher selective depression for talc than for scheelite. Bench-scale closed-circuit tests showed that a tungsten concentrate with a WO3 grade of 51.43% and a WO3 recovery of 76.18% was obtained. Adsorption tests, zeta-potential measurements, and infrared spectral analyses confirmed that guar gum absorbed more strongly onto the talc surface than onto the scheelite surface because of chemisorption between guar gum and talc. This chemisorption is responsible for the guar gum's highly selective depression for talc and small depression for scheelite. The flotation results provide technical support for talc-type scheelite flotation.

Chemical and colloidal aspects of collectorless flotation behavior of sulfide and non-sulfide minerals.

PubMed

Aghazadeh, Sajjad; Mousavinezhad, Seyed Kamal; Gharabaghi, Mahdi

2015-11-01

Flotation has been widely used for separation of valuable minerals from gangues based on their surface characterizations and differences in hydrophobicity on mineral surfaces. As hydrophobicity of minerals widely differs from each other, their separation by flotation will become easier. Collectors are chemical materials which are supposed to make selectively valuable minerals hydrophobic. In addition, there are some minerals which based on their surface and structural features are intrinsically hydrophobic. However, their hydrophobicities are not strong enough to be floatable in the flotation cell without collectors such as sulfide minerals, coal, stibnite, and so forth. To float these minerals in a flotation cell, their hydrophobicity should be increased in specific conditions. Various parameters including pH, Eh, size distribution, mill types, mineral types, ore characterization, and type of reaction in flotation cells affect the hydrophobicity of minerals. Surface analysis results show that when sulfide minerals experience specific flotation conditions, the reactions on the surface of these minerals increase the amount of sulfur on the surface. These phenomenons improve the hydrophobicity of these minerals due to strong hydrophobic feature of sulfurs. Collectorless flotation reduces chemical material consumption amount, increases flotation selectivity (grade increases), and affects the equipment quantities; however, it can also have negative effects. Some minerals with poor surface floatability can be increased by adding some ions to the flotation system. Depressing undesirable minerals in flotation is another application of collectorless flotation.

Emerging usage of electrocoagulation technology for oil removal from wastewater: A review.

PubMed

An, Chunjiang; Huang, Gordon; Yao, Yao; Zhao, Shan

2017-02-01

Electrocoagulation is a simple and efficient treatment method involving the electrodissolution of sacrificial anodes and formation of hydroxo-metal products as coagulants, while the simultaneous production of hydrogen at the cathode facilitates the pollutant removal by flotation. Oil is one of the most important hydrocarbon products in the modern world. It can cause environmental pollution during various stages of production, transportation, refining and use. Electrocoagulation treatment is particularly effective for destabilization of oil-in-water emulsions by neutralizing charges and bonding oil pollutants to generated flocs and hydrogen bubbles. The development of electrocoagulation technologies provided a promising alternative for oil removal from wastewater. This paper presents a review of emerging electrochemical technologies used for treating oil-containing wastewater. It includes a brief description of the oily wastewater origin and characteristics. The treatment processes developed so far for oily wastewater and the electrocoagulation mechanisms are also introduced. This paper summarizes the current applications of electrocoagulation for oil removal from wastewater. The factors that influence the electrocoagulation treatment efficiencies as well as the process optimization and modeling studies are discussed. The state-of-the-art and development trends of electrocoagulation process for oil removal are further introduced. Copyright © 2016 Elsevier B.V. All rights reserved.

Leaching characteristics of copper flotation waste before and after vitrification.

PubMed

Coruh, Semra; Ergun, Osman Nuri

2006-12-01

Copper flotation waste from copper production using a pyrometallurgical process contains toxic metals such as Cu, Zn, Co and Pb. Because of the presence of trace amounts of these highly toxic metals, copper flotation waste contributes to environmental pollution. In this study, the leaching characteristics of copper flotation waste from the Black Sea Copper Works in Samsun, Turkey have been investigated before and after vitrification. Samples obtained from the factory were subjected to toxicity tests such as the extraction procedure toxicity test (EP Tox), the toxicity characteristic leaching procedure (TCLP) and the "method A" extraction procedure of the American Society of Testing and Materials. The leaching tests showed that the content of some elements in the waste before vitrification exceed the regulatory limits and cannot be disposed of in the present form. Therefore, a stabilization or inertization treatment is necessary prior to disposal. Vitrification was found to stabilize heavy metals in the copper flotation waste successfully and leaching of these metals was largely reduced. Therefore, vitrification can be an acceptable method for disposal of copper flotation waste.

A study of bauxite tailing quality improvement by reverse flotation

NASA Astrophysics Data System (ADS)

Wulandari, W.; Purwasasmita, M.; Sanwani, E.; Malatsih, W.; Fadilla, F.

2018-01-01

The pre-treatment of bauxite ore from Tayan, West Kalimantan includes washing and screening fine bauxite particles (-2mm) prior as the feed to the Bayer process for producing alumina. These fine particles are believed to have high content of silica which is detrimental to the process. This washed bauxite tailing still has a significant amount of alumina content. Previous research has indicated that bauxite ore can be upgraded by applying reverse flotation method to reduce its silica content in the ore. Therefore, this study is aimed to utilize reverse flotation method to recover alumina content from washed bauxite tailing. The reverse flotation experiments were carried out at pH of 6 and 8; while the particle sizes were varied at - 140+270 mesh and -270 mesh, using a batch and circuit configuration. The result of this study shows that the batch reverse flotation can recover alumina in the tailing up to 81.4%, however the silica content is still significant. The complexity of silica-alumina minerals in the tailing prevents a complete separation of the ores by only using reverse flotation.

Improved flotation performance of hematite fines using citric acid as a dispersant

NASA Astrophysics Data System (ADS)

Luo, Xi-mei; Yin, Wan-zhong; Sun, Chuan-yao; Wang, Nai-ling; Ma, Ying-qiang; Wang, Yun-fan

2016-10-01

In this study, citric acid was used as a dispersant to improve the flotation performance of hematite fines. The effect and mechanism of citric acid on the reverse flotation of hematite fines were investigated by flotation tests, sedimentation experiments, scanning electron microscopy (SEM), zeta-potential measurements, and X-ray photoelectron spectroscopy (XPS). The results of SEM analysis and flotation tests reveal that a strong heterocoagulation in the form of slime coating or coagulation in hematite fine slurry affects the beneficiation of hematite ores by froth flotation. The addition of a small amount of citric acid (less than 300 g/t) favorably affects the reverse flotation of hematite fines by improving particle dispersion. The results of sedimentation experiments, zeta-potential measurements, and XPS measurements demonstrate that citric acid adsorbs onto hematite and quartz surfaces via hydrogen bonding, thereby reducing the zeta potentials of mineral surfaces, strengthening the electrical double-layer repulsion between mineral particles, and dispersing the pulp particles.

Heavy metal removal from waste waters by ion flotation.

PubMed

Polat, H; Erdogan, D

2007-09-05

Flotation studies were carried out to investigate the removal of heavy metals such as copper (II), zinc (II), chromium (III) and silver (I) from waste waters. Various parameters such as pH, collector and frother concentrations and airflow rate were tested to determine the optimum flotation conditions. Sodium dodecyl sulfate and hexadecyltrimethyl ammonium bromide were used as collectors. Ethanol and methyl isobutyl carbinol (MIBC) were used as frothers. Metal removal reached about 74% under optimum conditions at low pH. At basic pH it became as high as 90%, probably due to the contribution from the flotation of metal precipitates.

Influence of electrical double-layer interaction on coal flotation.

PubMed

Harvey, Paul A; Nguyen, Anh V; Evans, Geoffrey M

2002-06-15

In the early 1930s it was first reported that inorganic electrolytes enhance the floatability of coal and naturally hydrophobic minerals. To date, explanations of coal flotation in electrolytes have not been entirely clear. This research investigated the floatability of coal in NaCl and MgCl2 solutions using a modified Hallimond tube to examine the role of the electrical double-layer interaction between bubbles and particles. Flotation of coal was highly dependent on changes in solution pH, type of electrolyte, and electrolyte concentration. Floatability of coal in electrolyte solutions was seen not to be entirely controlled by the electrical double-layer interaction. Coal flotation in low electrolyte concentration solutions decreases with increase in concentration, not expected from the theory since the electrical double layer is compressed, resulting in diminishing the (electrical double layer) repulsion between the bubble and the coal particles. Unlike in low electrolyte concentration solutions, coal flotation in high electrolyte concentration solutions increases with increase in electrolyte concentration. Again, this behavior of coal flotation in high electrolyte concentration solutions cannot be quantitatively explained using the electrical double-layer interaction. Possible mechanisms are discussed in terms of the bubston (i.e., bubble stabilized by ions) phenomenon, which explains the existence of the submicron gas bubbles on the hydrophobic coal surface.

Anaerobic treatability of high oil and grease rendering wastewater.

PubMed

Nakhla, George; Al-Sabawi, Mustafa; Bassi, Amerjeet; Liu, Victor

2003-08-29

This study evaluated the use of a new biosurfactant, BOD-Balance, derived from cactus for the treatment of oil-and-grease-laden rendering wastewater anaerobically. Batch laboratory experimental results and preliminary full-scale data are presented. The biosurfactant affected a significant increase in the COD degradation rate for the raw wastewater. However, after reduction of the oil and grease (O&G) by dissolved air flotation, the biosurfactant did not exhibit any advantages. Modeling of the data indicated that various COD fractions, i.e. both soluble and particulate as well as total COD at various testing conditions conformed well to both zero-order and first-order models. The biosurfactant affected a 164-238 and 164-247% increase in COD and particulate COD biodegradation rate for the raw wastewater. The reduction of O&G concentration to <800 mg/l increased total and soluble COD degradation rates by 106%. Results from the full-scale mesophilic anaerobic digestion system indicated that the addition of the biosurfactant at doses of 130-200 mg/l decreased O&G concentrations from 66,300 to 10,200 mg/l over a 2-month-period.

Combined electron-beam and coagulation purification of molasses distillery slops. Features of the method, technical and economic evaluation of large-scale facility

NASA Astrophysics Data System (ADS)

Pikaev, A. K.; Ponomarev, A. V.; Bludenko, A. V.; Minin, V. N.; Elizar'eva, L. M.

2001-04-01

The paper summarizes the results obtained from the study on combined electron-beam and coagulation method for purification of molasses distillery slops from distillery produced ethyl alcohol by fermentation of grain, potato, beet and some other plant materials. The method consists in preliminary mixing of industrial wastewater with municipal wastewater, electron-beam treatment of the mixture and subsequent coagulation. Technical and economic evaluation of large-scale facility (output of 7000 m 3 day -1) with two powerful cascade electron accelerators (total maximum beam power of 400 kW) for treatment of the wastewater by the above method was carried out. It was calculated that the cost of purification of the wastes is equal to 0.25 US$ m -3 that is noticeably less than in the case of the existing method.

Education of Technicians for Water Conservation and Wastewater Control.

ERIC Educational Resources Information Center

Brooking, Walter J.

There is a growing need for supportive personnel with technical preparation in water and wastewater purification and water resource conservation. A curriculum and program guide was developed in 1965-66 by Fayetteville Technical Institute for use by institutions interested in establishing a program to educate technicians. Meeting the need for…

Harvesting of Scenedesmus obliquus FSP-3 using dispersed ozone flotation.

PubMed

Cheng, Ya-Ling; Juang, Yu-Chuan; Liao, Guan-Yu; Tsai, Pei-Wen; Ho, Shih-Hsin; Yeh, Kuei-Ling; Chen, Chun-Yen; Chang, Jo-Shu; Liu, Jhy-Chern; Chen, Wen-Ming; Lee, Duu-Jong

2011-01-01

The Scenedesmus obliquus FSP-3, a species with excellent potential for CO(2) capture and lipid production, was harvested using dispersed ozone flotation. While air aeration does not, ozone produces effective solid-liquid separation through flotation. Ozone dose applied for sufficient algal flotation is similar to those used in practical drinking waterworks. The algae removal rate, surface charge, and hydrophobicity of algal cells, and fluorescence characteristics and proteins and polysaccharides contents of algogenic organic matter (AOM) were determined during ozonation. Proteins released from tightly bound AOM are essential to modifying the hydrophobicity of bubble surfaces for easy cell attachment and to forming a top froth layer for collecting floating cells. Humic substances in the suspension scavenge dosed ozone that adversely affects ozone flotation efficiency of algal cells. Copyright © 2010 Elsevier Ltd. All rights reserved.

21 CFR 880.5550 - Alternating pressure air flotation mattress.

Code of Federal Regulations, 2013 CFR

2013-04-01

... body pressure. The device is used to prevent and treat decubitus ulcers (bed sores). (b) Classification... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification...

21 CFR 880.5550 - Alternating pressure air flotation mattress.

Code of Federal Regulations, 2010 CFR

2010-04-01

... body pressure. The device is used to prevent and treat decubitus ulcers (bed sores). (b) Classification... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification...

21 CFR 880.5550 - Alternating pressure air flotation mattress.

Code of Federal Regulations, 2014 CFR

2014-04-01

... body pressure. The device is used to prevent and treat decubitus ulcers (bed sores). (b) Classification... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification...

21 CFR 880.5550 - Alternating pressure air flotation mattress.

Code of Federal Regulations, 2011 CFR

2011-04-01

... body pressure. The device is used to prevent and treat decubitus ulcers (bed sores). (b) Classification... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification...

21 CFR 880.5550 - Alternating pressure air flotation mattress.

Code of Federal Regulations, 2012 CFR

2012-04-01

... body pressure. The device is used to prevent and treat decubitus ulcers (bed sores). (b) Classification... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification...

Removal of arsenic in flotation of galena and sphalerite

NASA Astrophysics Data System (ADS)

Yu, Dae-hwan; Kim, Min-kyu; Han, Oh-hyung; Park, Chul-hyun

2017-04-01

In Korea, Janggun mine that produces the concentrate of galena (PbS) /sphalerite (ZnS) containing arsenic of 1.3% charges a penalty of US 3/ton to LS-Nikko smelter. Hence in this work, flotation tests for removal of arsenopyrite (FeAsS) from sulfide minerals were carried out using lab scale flotation cell, which maintain grade and recovery of PbS and ZnS in comparison to flotation plant. Particularly, this study was focused on investigating the combination of several chemical reagents such as depressant, collector, activator and etc. that affect flotation performance. In the straight differential flotation for PbS, a PbS grade of 67.80% and a recovery of 80.2% could be obtained with FeAsS removal of 84.1% (0.2% As) under the conditions of 20% feed solids concentration, pH 8.5, 50g/t frother (AF65), 50g/t collector (AP242) and 600g/t As depressant (NaHSO3) and 600g/t Zn depressant (ZnSO4). In the ZnS flotation, the maximum separation achievable for ZnS has been shown to be a grade of 50.27% and a recovery of 88.7%. At this time, FeAsS removal of 87.8% (0.16% As) could be successfully accomplished under pH 11, and 1.2kg/t Zn activator (CuSO4), 100g/t frother (AF65), 100g/t collector (AP211) and 400g/t As depressant (NaHSO3). Acknowledgments This work was supported by the Energy and Resources Engineering Program Grant funded by the Ministry of Trade, Industry and Energy, Korea

Poultry slaughterhouse wastewater treatment plant for high quality effluent.

PubMed

Del Nery, V; Damianovic, M H Z; Moura, R B; Pozzi, E; Pires, E C; Foresti, E

2016-01-01

This paper assesses a wastewater treatment plant (WWTP) regarding the technology used, as well as organic matter and nutrient removal efficiencies aiming to optimize the treatment processes involved and wastewater reclamation. The WWTP consists of a dissolved air flotation (DAF) system, an upflow anaerobic sludge blanket (UASB) reactor, an aerated-facultative pond (AFP) and a chemical-DAF system. The removal efficiencies of chemical oxygen demand (COD) (97.9 ± 1.0%), biochemical oxygen demand (BOD) (98.6 ± 1.0%) and oil and grease (O&G) (91.1 ± 5.2%) at the WWTP, the nitrogen concentration of 17 ± 11 mg N-NH3 and phosphorus concentration of 1.34 ± 0.93 mg PO4(-3)/L in the final effluent indicate that the processes used are suitable to comply with discharge standards in water bodies. Nitrification and denitrification tests conducted using biomass collected at three AFP points indicated that nitrification and denitrification could take place in the pond.

Immobilization of copper flotation waste using red mud and clinoptilolite.

PubMed

Coruh, Semra

2008-10-01

The flash smelting process has been used in the copper industry for a number of years and has replaced most of the reverberatory applications, known as conventional copper smelting processes. Copper smelters produce large amounts of copper slag or copper flotation waste and the dumping of these quantities of copper slag causes economic, environmental and space problems. The aim of this study was to perform a laboratory investigation to assess the feasibility of immobilizing the heavy metals contained in copper flotation waste. For this purpose, samples of copper flotation waste were immobilized with relatively small proportions of red mud and large proportions of clinoptilolite. The results of laboratory leaching demonstrate that addition of red mud and clinoptilolite to the copper flotation waste drastically reduced the heavy metal content in the effluent and the red mud performed better than clinoptilolite. This study also compared the leaching behaviour of metals in copper flotation waste by short-time extraction tests such as the toxicity characteristic leaching procedure (TCLP), deionized water (DI) and field leach test (FLT). The results of leach tests showed that the results of the FLT and DI methods were close and generally lower than those of the TCLP methods.

A Study of the Optimal Model of the Flotation Kinetics of Copper Slag from Copper Mine BOR

NASA Astrophysics Data System (ADS)

Stanojlović, Rodoljub D.; Sokolović, Jovica M.

2014-10-01

In this study the effect of mixtures of copper slag and flotation tailings from copper mine Bor, Serbia on the flotation results of copper recovery and flotation kinetics parameters in a batch flotation cell has been investigated. By simultaneous adding old flotation tailings in the ball mill at the rate of 9%, it is possible to increase copper recovery for about 20%. These results are compared with obtained copper recovery of pure copper slag. The results of batch flotation test were fitted by MatLab software for modeling the first-order flotation kinetics in order to determine kinetics parameters and define an optimal model of the flotation kinetics. Six kinetic models are tested on the batch flotation copper recovery against flotation time. All models showed good correlation, however the modified Kelsall model provided the best fit.

Leaching behaviour and mechanical properties of copper flotation waste in stabilized/solidified products.

PubMed

Mesci, Başak; Coruh, Semra; Ergun, Osman Nuri

2009-02-01

This research describes the investigation of a cement-based solidification/stabilization process for the safe disposal of copper flotation waste and the effect on cement properties of the addition of copper flotation waste (CW) and clinoptilolite (C). In addition to the reference mixture, 17 different mixtures were prepared using different proportions of CW and C. Physical properties such as setting time, specific surface area and compressive strength were determined and compared to a reference mixture and Turkish standards (TS). Different mixtures with the copper flotation waste portion ranging from 2.5 to 12.5% by weight of the mixture were tested for copper leachability. The results show that as cement replacement materials especially clinoptilolite had clear effects on the mechanical properties. Substitution of 5% copper flotation waste for Portland cement gave a similar strength performance to the reference mixture. Higher copper flotation waste addition such as 12.5% replacement yielded lower strength values. As a result, copper flotation waste and clinoptilolite can be used as cementitious materials, and copper flotation waste also can be safely stabilized/solidified in a cement-based solidification/stabilization system.

Reduction of Cryptosporidium, Giardia, and Fecal Indicators by Bardenpho Wastewater Treatment.

PubMed

Schmitz, Bradley W; Moriyama, Hitoha; Haramoto, Eiji; Kitajima, Masaaki; Sherchan, Samendra; Gerba, Charles P; Pepper, Ian L

2018-06-19

Increased demand for water reuse and reclamation accentuates the importance for optimal wastewater treatment to limit protozoa in effluents. Two wastewater treatment plants utilizing advanced Bardenpho were investigated over a 12-month period to determine the incidence and reduction of Cryptosporidium, Giardia, Cyclospora, and fecal indicators. Results were compared to facilities that previously operated in the same geographical area. Protozoa (oo)cysts were concentrated using an electronegative filter and subsequently detected by fluorescent microscopy and/or PCR methods. Cryptosporidium and Giardia were frequently detected in raw sewage, but Cyclospora was not detected in any wastewater samples. Facilities with Bardenpho treatment exhibited higher removals of (oo)cysts than facilities utilizing activated sludge or trickling filters. This was likely due to Bardenpho systems having increased solid wasting rates; however, this mechanism cannot be confirmed as sludge samples were not analyzed. Use of dissolved-air-flotation instead of sedimentation tanks did not result in more efficient removal of (oo)cysts. Concentrations of protozoa were compared with each other, Escherichia coli, somatic coliphage, and viruses (pepper mild mottle virus, Aichi virus 1, adenovirus, and polyomaviruses JC and BK). Although significant correlations were rare, somatic coliphage showed the highest potential as an indicator for the abundance of protozoa in wastewaters.

Modified binders on the basis of flotation tailings

NASA Astrophysics Data System (ADS)

Shapovalov, N. A.; Zagorodnyuk, L. Kh; Shchekina, A. Yu; Gorodov, A. I.

2018-03-01

The article proposes compositions of efficient modified composite binders on the basis of portland cement and flotation tailings; the new binders attain the ultimate compressive stress that is twice as high as that of the cement stone. At that, use of annually growing volume of flotation tailings in the production of the composite binder is a rational way for recycling this type of waste and allows saving the planet's natural resources.

Investigation of foam flotation and phase partitioning techniques

NASA Technical Reports Server (NTRS)

Currin, B. L.

1985-01-01

The present status of foam flotation as a separation process is evaluated and limitations for cells and proteins are determined. Possible applications of foam flotation to separations in microgravity are discussed. Application of the fluid mechanical aspects of foam separation techniques is made to phase partitioning in order to investigate the viscous drag forces that may effect the partitioning of cells in a two phase poly(ethylene glycol) and dextran system.

Beneficiation of the gold bearing ore by gravity and flotation

NASA Astrophysics Data System (ADS)

Gül, Alim; Kangal, Olgaç; Sirkeci, Ayhan A.; Önal, Güven

2012-02-01

Gold concentration usually consists of gravity separation, flotation, cyanidation, or the combination of these processes. The choice among these processes depends on the mineralogical characterization and gold content of the ore. Recently, the recovery of gold using gravity methods has gained attention because of low cost and environmentally friendly operations. In this study, gold pre-concentrates were produced by the stepwise gravity separation and flotation techniques. The Knelson concentrator and conventional flotation were employed for the recovery of gold. Gold bearing ore samples were taken from Gümüşhane Region, northern east part of Turkey. As a result of stepwise Knelson concentration experiments, a gold concentrate assaying around 620 g/t is produced with 41.4wt% recovery. On the other hand, a gold concentrate about 82 g/t is obtained with 89.9wt% recovery from a gold ore assaying 6 g/t Au by direct flotation.

Antibiotics with anaerobic ammonium oxidation in urban wastewater treatment

NASA Astrophysics Data System (ADS)

Zhou, Ruipeng; Yang, Yuanming

2017-05-01

Biofilter process is based on biological oxidation process on the introduction of fast water filter design ideas generated by an integrated filtration, adsorption and biological role of aerobic wastewater treatment process various purification processes. By engineering example, we show that the process is an ideal sewage and industrial wastewater treatment process of low concentration. Anaerobic ammonia oxidation process because of its advantage of the high efficiency and low consumption, wastewater biological denitrification field has broad application prospects. The process in practical wastewater treatment at home and abroad has become a hot spot. In this paper, anammox bacteria habitats and species diversity, and anaerobic ammonium oxidation process in the form of diversity, and one and split the process operating conditions are compared, focusing on a review of the anammox process technology various types of wastewater laboratory research and engineering applications, including general water quality and pressure filtrate sludge digestion, landfill leachate, aquaculture wastewater, monosodium glutamate wastewater, wastewater, sewage, fecal sewage, waste water salinity wastewater characteristics, research progress and application of the obstacles. Finally, we summarize the anaerobic ammonium oxidation process potential problems during the processing of the actual waste water, and proposed future research focus on in-depth study of water quality anammox obstacle factor and its regulatory policy, and vigorously develop on this basis, and combined process optimization.

Modelling and calculation of flotation process in one-dimensional formulation

NASA Astrophysics Data System (ADS)

Amanbaev, Tulegen; Tilleuov, Gamidulla; Tulegenova, Bibigul

2016-08-01

In the framework of the assumptions of the mechanics of the multiphase media is constructed a mathematical model of the flotation process in the dispersed mixture of liquid, solid and gas phases, taking into account the degree of mineralization of the surface of the bubbles. Application of the constructed model is demonstrated on the example of one-dimensional stationary flotation and it is shown that the equations describing the process of ascent of the bubbles are singularly perturbed ("rigid"). The effect of size and concentration of bubbles and the volumetric content of dispersed particles on the flotation process are analyzed.

Drones for Provision of Flotation Support in Simulated Drowning.

PubMed

Bäckman, Anders; Hollenberg, Jacob; Svensson, Leif; Ringh, Mattias; Nordberg, Per; Djärv, Therese; Forsberg, Sune; Hernborg, Olof; Claesson, Andreas

The feasibility and potential of using drones for providing flotation devices in cases of drowning have not yet been assessed. We hypothesize that a drone carrying an inflatable life buoy is a faster way to provide flotation compared with traditional methods. The purpose of this study is to explore the feasibility and efficiency of using a drone for delivering and providing flotation support to conscious simulated drowning victims. A simulation study was performed with a simulated drowning victim 100 m from the shore. A drone (DJI Phantom 4; dji, Shenzhen, China) equipped with an inflatable life buoy of 60 N was compared with traditional surf rescue swimming for providing flotation. The primary outcome was delay (minutes:seconds). A total number of 30 rescues were performed with a median time to delivery of the floating device of 30 seconds (interquartile range [IQR] = 24-32 seconds) for the drone compared with 65 seconds (IQR = 60-77 seconds) with traditional rescue swimming (P < .001). The drone had an accuracy of 100% in dropping the inflatable life buoy < 5 m from the victim, with a median of 1 m (IQR = 1-2 m). Using drones to deliver inflatable life buoys is safe and may be a faster method to provide early flotation devices to conscious drowning victims compared with rescue swimming. Copyright © 2018 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.

Flotation performances and surface properties of chalcopyrite with xanthate collector added before and after grinding

NASA Astrophysics Data System (ADS)

Peng, Huiqing; Wu, Di; Abdelmonem, Mohamed

In this study, effects of the collector added before grinding and after grinding on the subsequent flotation and mineral surface properties were investigated. The pH was controlled at 10 during the grinding and flotation processes opened to the atmosphere. With enough amounts of sodium butyl xanthate addition, adding the collector before grinding recovered more chalcopyrite than adding it after grinding in single mineral flotation. The Eh of each ground pulp before and after conditioning were measured and it was found that adding collector before grinding obtained higher and relatively suitable pulp potential for chalcopyrite flotation. Particle size analyses of the flotation products indicate that the different flotation recoveries occurred due to the different flotation losses in fine particles (<20 μm). XPS analyses focused on the fine particles of flotation feedings and found that more carbon and oxygen, and less iron were remained on mineral surfaces when the collector was added before grinding, due to the higher collector adsorption capacity, larger free oxygen adsorbance and less iron oxide/hydroxide species.

Adsorption mechanism of mixed cationic/anionic collectors in feldspar-quartz flotation system.

PubMed

Vidyadhar, A; Hanumantha Rao, K

2007-02-15

The adsorption mechanism of mixed cationic alkyl diamine and anionic sulfonate/oleate collectors at acidic pH values was investigated on microcline and quartz minerals through Hallimond flotation, electrokinetic and diffuse reflectance FTIR studies. In the presence of anionic collectors, neither of the minerals responded to flotation but the diamine flotation of the minerals was observed to be pH and concentration dependent. The presence of sulfonate enhanced the diamine flotation of the minerals by its co-adsorption. The difference in surface charge between the minerals at pH 2 was found to be the basis for preferential feldspar flotation from quartz in mixed diamine/sulfonate collectors. The infrared spectra revealed no adsorption of sulfonate collector when used alone but displayed its co-adsorption as diamine-sulfonate complex when used with diamine. The presence of sulfonate increased the diamine adsorption due to a decrease in the electrostatic head-head repulsion between the adjacent surface ammonium ions and thereby increasing the lateral tail-tail hydrophobic bonds. The mole ratio of diamine/sulfonate was found to be an important factor in the orientation of alkyl chains and thus the flotation response of minerals. The increase in sulfonate concentration beyond diamine concentration leads to the formation of soluble 1:2 diamine-sulfonate complex or precipitate and the adsorption of these species decreased the flotation since the alkyl chains are in chaotical orientation with a conceivable number of head groups directing towards the solution phase.

Treatment of car wash wastewater by UF membranes

NASA Astrophysics Data System (ADS)

Istirokhatun, Titik; Destianti, Puti; Hargianintya, Adenira; Oktiawan, Wiharyanto; Susanto, Heru

2015-12-01

The existence of car wash service facilitates car owners to remove dirt and grime from their vehicles. However, the dirt washed off vehicles as well as the cleaning materials themselves may be harmful to the environment if they are not properly managed and discharged. Many technologies have been proposed to treat car wash wastewater such as coagulation flocculation, tricking filter and flocculation-flotation. Nevertheless, these technologies have low efficiency to eliminate oil and small organic compounds. Ultrafiltration (UF) membranes were used in this study to treat car wash wastewater. This study investigated the performance of UF membranes under various pressures to remove COD, oil and grease, and also turbidity from car wash waste water. The membrane performance was examined by investigation of permeate flux and membrane rejection. The results meet the standard of environmental regulation and it is possible to be reused. The highest rejection was shown by PES10 (polyethersulfone 10 kDa) in 1 bar operation with complete rejection for both turbidity and oil and grace and 95% rejection for COD.

Flotation and survival equipment studies.

DOT National Transportation Integrated Search

1978-01-01

This report is a collection of various studies, conducted over 15 years, of flotation and survival equipment used or proposed for aviation application, including developmental and prototype designs. Results of these studies were presented at scientif...

Zeta potentials in the flotation of oxide and silicate minerals.

PubMed

Fuerstenau, D W; Pradip

2005-06-30

Adsorption of collectors and modifying reagents in the flotation of oxide and silicate minerals is controlled by the electrical double layer at the mineral-water interface. In systems where the collector is physically adsorbed, flotation with anionic or cationic collectors depends on the mineral surface being charged oppositely. Adjusting the pH of the system can enhance or prevent the flotation of a mineral. Thus, the point of zero charge (PZC) of the mineral is the most important property of a mineral in such systems. The length of the hydrocarbon chain of the collector is important because of chain-chain association enhances the adsorption once the surfactant ions aggregate to form hemimicelles at the surface. Strongly chemisorbing collectors are able to induce flotation even when collector and the mineral surface are charged similarly, but raising the pH sufficiently above the PZC can repel chemisorbing collectors from the mineral surface. Zeta potentials can be used to delineate interfacial phenomena in these various systems.

Thermodynamics of ultra-sonic cavitation bubbles in flotation ore processes

NASA Astrophysics Data System (ADS)

Royer, J. J.; Monnin, N.; Pailot-Bonnetat, N.; Filippov, L. O.; Filippova, I. V.; Lyubimova, T.

2017-07-01

Ultra-sonic enhanced flotation ore process is a more efficient technique for ore recovery than classical flotation method. A classical simplified analytical Navier-Stokes model is used to predict the effect of the ultrasonic waves on the cavitations bubble behaviour. Then, a thermodynamics approach estimates the temperature and pressure inside a bubble, and investigates the energy exchanges between flotation liquid and gas bubbles. Several gas models (including ideal gas, Soave-Redlich-Kwong, and Peng-Robinson) assuming polytropic transformations (from isothermal to adiabatic) are used to predict the evolution of the internal pressure and temperature inside the bubble during the ultrasonic treatment, together with the energy and heat exchanges between the gas and the surrounding fluid. Numerical simulation illustrates the suggest theory. If the theory is verified experimentally, it predicts an increase of the temperature and pressure inside the bubbles. Preliminary ultrasonic flotation results performed on a potash ore seem to confirm the theory.

Removal of arsenopyrite from complex sulfide minerals by froth flotation

NASA Astrophysics Data System (ADS)

Choi, Jin-young; Kim, Yang-soo; Kim, Dong-gyu; Han, Oh-hyung; Park, Chul-hyun

2016-04-01

Arsenic (As) is one of hazardous materials and a penalty element in metal concentrates and so metal concentrates containing arsenic of over 0.5% has been currently restricted in import and export trade. It also corrodes a smelting furnace as well as shortens its life cycle. In korea, Janggun mine that produces galena (PbS) /sphalerite (ZnS) concentrate containing arsenic of 1.78% charges a penalty of US 2/ton to LS-Nikko smelter. Hence in this work, flotation tests for removal of arsenopyrite (FeAsS) from sulfide mineral concentrates were carried out using lab scale flotation cell, which maintain grade and recovery of PbS and ZnS in comparison to flotation plant. Particularly, this study was focused on investigating the combination of several chemical reagents (depressant, collector, activator and etc.) that affect flotation performance. In the straight differential flotation for PbS, a PbS grade of 75.80% and a recovery of 90.12% could be obtained with FeAsS removal of 84.1% (0.2% As) under the conditions of 20% feed solids concentration, pH 8.5, 50g/t frother (AF65), 40g/t collector (AP242) and 800g/t As depressant (NaHSO3) and 600g/t Zn depressant (ZnSO4). In the ZnS flotation, the maximum separation achievable for ZnS using froth flotation has been shown to be a grade of 72.57% and a recovery of 95.43%. At this time, FeAsS removal of 87.8% (0.16% As) could be successfully accomplished under pH 11, and 800g/t Zn activator (CuSO4), 75g/t frother (AF65), 60g/t collector (AP211) and 600g/t As depressant (NaHSO3). Acknowledgments This work was supported by the Energy and Resources Engineering Program Grant funded by the Ministry of Trade, Industry and Energy, Korea

Microbially induced flotation and flocculation of pyrite and sphalerite.

PubMed

Patra, Partha; Natarajan, K A

2004-07-15

Cells of Paenibacillus polymyxa and their metabolite products were successfully utilized to achieve selective separation of sphalerite from pyrite, through microbially induced flocculation and flotation. Adsorption studies and electrokinetic investigations were carried out to understand the changes in the surface chemistry of bacterial cells and the minerals after mutual interaction. Possible mechanisms in microbially induced flotation and flocculation are outlined.

Switching and optimizing control for coal flotation process based on a hybrid model

PubMed Central

Dong, Zhiyong; Wang, Ranfeng; Fan, Minqiang; Fu, Xiang

2017-01-01

Flotation is an important part of coal preparation, and the flotation column is widely applied as efficient flotation equipment. This process is complex and affected by many factors, with the froth depth and reagent dosage being two of the most important and frequently manipulated variables. This paper proposes a new method of switching and optimizing control for the coal flotation process. A hybrid model is built and evaluated using industrial data. First, wavelet analysis and principal component analysis (PCA) are applied for signal pre-processing. Second, a control model for optimizing the set point of the froth depth is constructed based on fuzzy control, and a control model is designed to optimize the reagent dosages based on expert system. Finally, the least squares-support vector machine (LS-SVM) is used to identify the operating conditions of the flotation process and to select one of the two models (froth depth or reagent dosage) for subsequent operation according to the condition parameters. The hybrid model is developed and evaluated on an industrial coal flotation column and exhibits satisfactory performance. PMID:29040305

Chelation and flotation in endodontic practice: an update.

PubMed

Stewart, G G

1986-10-01

The removal of broken instruments and silver points, as well as pulp tissue, may be accomplished by careful instrumentation, irrigation, and flotation. Flotation and recapitulation with smaller instruments and irrigation with copious amounts of sodium hypochlorite can clean out microorganisms and the organic matter from the tubular structure which provides a more ideal surface for sealing the root canal system. A sterile environment was obtained by removing the substrate and creating a more ideal environment for better healing.

Ammonia modification for flotation separation of polycarbonate and polystyrene waste plastics.

PubMed

Wang, Chong-Qing; Wang, Hui; Gu, Guo-Hua; Lin, Qing-Quan; Zhang, Ling-Ling; Huang, Luo-Luo; Zhao, Jun-Yao

2016-05-01

A promising method, ammonia modification, was developed for flotation separation of polycarbonate (PC) and polystyrene (PS) waste plastics. Ammonia modification has little effect on flotation behavior of PS, while it changes significantly that of PC. The PC recovery in the floated product drops from 100% to 3.17% when modification time is 13min and then rises to 100% after longer modification. The mechanism of ammonia modification was studied by contact angle, and Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) measurements. Contact angle of PC indicates the decline of PC recovery in the floated product is ascribed to an increase in surface wettability. FT-IR and XPS spectra suggest that ammonia modification causes chemical reactions occurred on PC surface. Flotation behavior of ammonia-modified PC and PS was investigated with respect to flotation time, frother concentration and particle sizes. Flotation separation of PC and PS waste plastics was conducted based on the flotation behavior of single plastic. PC and PS mixtures with different particle sizes are separated efficiently, implying that the technology possesses superior applicability to particle sizes of plastics. The purity of PS and PC is up to 99.53% and 98.21%, respectively, and the recovery of PS and PC is larger than 92.06%. A reliable, cheap and effective process is proposed for separation of PC and PS waste plastics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterization of flotation color by machine vision

NASA Astrophysics Data System (ADS)

Siren, Ari

1999-09-01

Flotation is the most common industrial method by which valuable minerals are separated from waste rock after crushing and grinding the ore. For process control, flotation plants and devices are equipped with conventional and specialized sensors. However, certain variables are left to the visual observation of the operator, such as the color of the froth and the size of the bubbles in the froth. The ChaCo-Project (EU-Project 24931) was launched in November 1997. In this project a measuring station was built at the Pyhasalmi flotation plant. The system includes an RGB camera and a spectral color measuring instrument for the color inspection of the flotation. The RGB camera or visible spectral range is also measured to compare the operators' comments on the color of the froth relating to the sphalerite concentration and the process balance. Different dried mineral (sphalerite) ratios were studied with iron pyrite to find out about the minerals' typical spectral features. The correlation between sphalerite spectral reflectance and sphalerite concentration over various wavelengths are used to select the proper camera system with filters or to compare the results with the color information from the RGB camera. Various machine vision candidate techniques are discussed for this application and the preprocessed information of the dried mineral colors is used and adapted to the online measuring station. Moving froth bubbles produce total reflections, disturbing the color information. Polarization filters are used and the results are reported. Also the reflectance outside the visible light is studied and reported.

Ozone inactivation of infectious prions in rendering plant and municipal wastewaters.

PubMed

Ding, Ning; Neumann, Norman F; Price, Luke M; Braithwaite, Shannon L; Balachandran, Aru; Belosevic, Miodrag; Gamal El-Din, Mohamed

2014-02-01

Disposal of tissues and organs associated with prion accumulation and infectivity in infected animals (designated as Specified Risk Materials [SRM]) is strictly regulated by the Canadian Food Inspection Agency (CFIA); however, the contamination of wastewater from slaughterhouses that handle SRM still poses public concern. In this study, we examined for the first time the partitioning of infectious prions in rendering plant wastewater and found that a large proportion of infectious prions were partitioned into the scum layer formed at the top after gravity separation, while quite a few infectious prions still remained in the wastewater. Subsequently, we assessed the ozone inactivation of infectious prions in the raw, natural gravity-separated and dissolved air flotation (DAF)-treated (i.e., primary-treated) rendering plant wastewater, and in a municipal final effluent (i.e., secondary-treated municipal wastewater). At applied ozone doses of 43.4-44.6 mg/L, ozone was instantaneously depleted in the raw rendering plant wastewater, while a greater than 4-log10 inactivation was achieved at a 5 min exposure in the DAF-treated rendering plant wastewater. Prion inactivation in the municipal final effluent was conducted with two levels of applied ozone doses of 13.4 and 22.5mg/L, and a greater than 4-log10 inactivation was achieved at a 5 min exposure with the higher ozone dose. Efficiency factor Hom (EFH) models were used to model (i.e., fit) the experimental data. The CT (disinfectant concentration multiplied by contact time) values were determined for 2- and 3-log10 inactivation in the municipal final effluent treated with an ozone dose of 13.4 mg/L. Our results indicate that ozone could serve as a final barrier for prion inactivation in primary- and/or secondary-treated wastewaters. © 2013.

Wastewater retreatment and reuse system for agricultural irrigation in rural villages.

PubMed

Kim, Minyoung; Lee, Hyejin; Kim, Minkyeong; Kang, Donghyeon; Kim, Dongeok; Kim, YoungJin; Lee, Sangbong

2014-01-01

Climate changes and continuous population growth increase water demands that will not be met by traditional water resources, like surface and ground water. To handle increased water demand, treated municipal wastewater is offered to farmers for agricultural irrigation. This study aimed to enhance the effluent quality from worn-out sewage treatment facilities in rural villages, retreat effluent to meet water quality criteria for irrigation, and assess any health-related and environmental impacts from using retreated wastewater irrigation on crops and in soil. We developed the compact wastewater retreatment and reuse system (WRRS), equipped with filters, ultraviolet light, and bubble elements. A pilot greenhouse experiment was conducted to evaluate lettuce growth patterns and quantify the heavy metal concentration and pathogenic microorganisms on lettuce and in soil after irrigating with tap water, treated wastewater, and WRRS retreated wastewater. The purification performance of each WRRS component was also assessed. The study findings revealed that existing worn-out sewage treatment facilities in rural villages could meet the water quality criteria for treated effluent and also reuse retreated wastewater for crop growth and other miscellaneous agricultural purposes.

Dormancy and Recovery Testing for Biological Wastewater Processors

NASA Technical Reports Server (NTRS)

Hummerick, Mary F.; Coutts, Janelle L.; Lunn, Griffin M.; Spencer, LaShelle; Khodadad, Christina L.; Birmele, Michele N.; Frances, Someliz; Wheeler, Raymond

2015-01-01

Resource recovery and recycling waste streams to usable water via biological water processors is a plausible component of an integrated water purification system. Biological processing as a pretreatment can reduce the load of organic carbon and nitrogen compounds entering physiochemical systems downstream. Aerated hollow fiber membrane bioreactors, have been proposed and studied for a number of years as an approach for treating wastewater streams for space exploration.

Preparation of polyelectrolytes for wastewater treatment.

PubMed

Radoiu, Marilena T; Martin, Diana I; Calinescu, Ioan; Iovu, Horia

2004-01-02

Liquid-phase polymerisation of acrylamide-acrylic acid to form polyelectrolytes used in wastewater cleaning was examined using accelerated electron beam and microwave irradiation methods. Polymerisation was carried out in aqueous solutions at temperatures approximately 60 degrees C. Monomers total concentration was established at 40% (36% acrylamide and 4% acrylic acid). Only using the features of simultaneous radiation-induction and microwave heating can result in the formation of linear polymer chains with good water solubility and low residual monomer concentration. The flocculation capacity of the obtained polymers was tested using two wastewaters, one sampled from a slaughterhouse and the other from a vegetable oil plant. Quality indicators such as total suspended matters (TSM), chemical oxygen demand (COD), biological oxygen demand (BOD) and fat, oils and grease (FOG) were measured before and after the treatment with polymeric flocculants and compared with the results obtained in classical treatment with Al(2)(SO(4))(3). It was found that the combined treatment with polymers and Al(2)(SO(4))(3) increases the degree of purification of both wastewaters up to 99%.

Removal of methylene blue from its aqueous solution by froth flotation: hydrophobic silica nanoparticle as a collector

NASA Astrophysics Data System (ADS)

Hu, Nan; Liu, Wei; Ding, Linlin; Wu, Zhaoliang; Yin, Hao; Huang, Di; Li, Hongzhen; Jin, Lixue; Zheng, Huijie

2017-02-01

Dye pollution has been a severe problem faced by worldwide environmentalists. The use of nanoparticles as adsorbents has attracted widespread interests for effectively removing dyes, while the separation of them from an aqueous solution is a difficult and important subject. For achieving the simultaneous removal of methylene blue (MB) and nanoadsorbents, this work utilized a commercial hydrophobic silica nanoparticle (SNP) (200.0 ± 10.0 nm in average particle size) as a collector and then developed a novel froth flotation technology without using any surfactants. Under the suitable conditions of anhydrous ethanol dosage of 8 mL, pH of 9.0, SNP concentration of 600 mg/L, and flotation column height of 600 mm, the removal efficiencies of MB and SNPs and the volume ratio reached 91.1 ± 4.6%, 93.9 ± 4.7%, and 10.5 ± 0.5, respectively. Subsequently, the recovered MB-adsorbed SNPs in the foamate were separated by free setting due to their high concentration and massive agglomeration. After free setting, MB could be effectively separated from the recovered MB-adsorbed SNPs by using ethanol at pH 2.0 and repeating five cycles of washing-centrifugation. Additionally, the regenerated SNPs could be reused for removing MB up to five times. Overall, this work had a significant meaning for the treatment of dye-contaminated wastewaters.

Development of dissolved air flotation technology from the first generation to the newest (third) one (DAF in turbulent flow conditions).

PubMed

Kiuru, H J

2001-01-01

This paper gives a brief description of the development of dissolved air flotation DAF (or so-called high pressure flotation) as an unit operation for removal of solids in water and wastewater treatment during the last 80 years up to this time. The first DAF-systems used in the water industry were the ADKA and Sveen-Pedersen ones from the 1920s. Some of these are still in use. The tanks in which the flotation phenomenon takes place in these systems are very shallow and narrow as well as rather long. The flow rate of water is some 2-3 m/h (at most less than 5 m/h only) and there is a very thin micro-bubble blanket below the water surface between the dry sludge blanket on that and the clarified water which flows almost horizontally below the bubble blanket toward the end of the tanks to be taken out there from near the bottom. The second generation of DAF was introduced in the 1960s and these units are widely in use today. Their tanks are almost square ones having usually a little bit more length than breadth. They are rather deep, too. There is an under-flow wall in front of the back wall of the units having a narrow horizontal gap on the bottom of the tanks for letting out the clarified water from the flotation space. The flow rate of water is usually 5-7 m/h or at most less than 10 m/h. The direction of flow is 30-45 degrees below the horizontal. There is a rather thick micro-bubble bed at the beginning of the tank below the dry sludge blanket. This bubble-bed becomes clearly thinner, when going toward the end of the tank. There are also round DAF tanks which are based on the same hydraulic principles as the rectangular ones presented above. A special application of DAF called the flotation filter was invented at the very end of the 1960s. It is a combination of flotation and rapid sand filtration, both of those being placed in the same tank. Flotation takes place in the upper part of the tank and the filter has been placed in the lower part of it. The direction

Kinetic approach to the study of froth flotation applied to a lepidolite ore

NASA Astrophysics Data System (ADS)

Vieceli, Nathália; Durão, Fernando O.; Guimarães, Carlos; Nogueira, Carlos A.; Pereira, Manuel F. C.; Margarido, Fernanda

2016-07-01

The number of published studies related to the optimization of lithium extraction from low-grade ores has increased as the demand for lithium has grown. However, no study related to the kinetics of the concentration stage of lithium-containing minerals by froth flotation has yet been reported. To establish a factorial design of batch flotation experiments, we conducted a set of kinetic tests to determine the most selective alternative collector, define a range of pulp pH values, and estimate a near-optimum flotation time. Both collectors (Aeromine 3000C and Armeen 12D) provided the required flotation selectivity, although this selectivity was lost in the case of pulp pH values outside the range between 2 and 4. Cumulative mineral recovery curves were used to adjust a classical kinetic model that was modified with a non-negative parameter representing a delay time. The computation of the near-optimum flotation time as the maximizer of a separation efficiency (SE) function must be performed with caution. We instead propose to define the near-optimum flotation time as the time interval required to achieve 95%-99% of the maximum value of the SE function.

Effects of High Pressure ORE Grinding on the Efficiency of Flotation Operations

NASA Astrophysics Data System (ADS)

Saramak, Daniel; Krawczykowska, Aldona; Młynarczykowska, Anna

2014-10-01

This article discusses issues related to the impact of the high pressure comminution process on the efficiency of the copper ore flotation operations. HPGR technology improves the efficiency of mineral resource enrichment through a better liberation of useful components from waste rock as well as more efficient comminution of the material. Research programme included the run of a laboratory flotation process for HPGR crushing products at different levels of operating pressures and moisture content. The test results showed that products of the high-pressure grinding rolls achieved better recoveries in flotation processes and showed a higher grade of useful components in the flotation concentrate, in comparison to the ball mill products. Upgrading curves have also been marked in the following arrangement: the content of useful component in concentrate the floatation recovery. All upgrading curves for HPGR products had a more favourable course in comparison to the curves of conventionally grinded ore. The results also indicate that various values of flotation recoveries have been obtained depending on the machine operating parameters (i.e. the operating pressure), and selected feed properties (moisture).

Slime coating of kaolinite on chalcopyrite in saline water flotation

NASA Astrophysics Data System (ADS)

Li, Zhi-li; Rao, Feng; Song, Shao-xian; Li, Yan-mei; Liu, Wen-biao

2018-05-01

In saline water flotation, the salinity can cause a distinguishable slime coating of clay minerals on chalcopyrite particles through its effect on their electrical double layers in aqueous solutions. In this work, kaolinite was used as a representative clay mineral for studying slime coating during chalcopyrite flotation. The flotation of chalcopyrite in the presence and absence of kaolinite in tap water, seawater, and gypsum-saturated water and the stability of chalcopyrite and kaolinite particles in slurries are presented. Zeta-potential distributions and scanning electron microscopy images were used to characterize and explain the different slime coating degrees and the different flotation performances. Kaolinite particles induced slime coating on chalcopyrite surfaces and reduced chalcopyrite floatability to the greatest extent when the pH value was in the alkaline range. At 0.24wt% of kaolinite, the chalcopyrite floatability was depressed by more than 10% at alkaline pH levels in tap water. Salinity in seawater and gypsum-saturated water compressed the electrical double layers and resulted in extensive slime coating.

18 CFR 1304.400 - Flotation devices and material, all floating structures.

Code of Federal Regulations, 2014 CFR

2014-04-01

... material, all floating structures. 1304.400 Section 1304.400 Conservation of Power and Water Resources... STRUCTURES AND OTHER ALTERATIONS Miscellaneous § 1304.400 Flotation devices and material, all floating structures. (a) All flotation for docks, boat mooring buoys, and other water-use structures and facilities...

18 CFR 1304.400 - Flotation devices and material, all floating structures.

Code of Federal Regulations, 2012 CFR

2012-04-01

... material, all floating structures. 1304.400 Section 1304.400 Conservation of Power and Water Resources... STRUCTURES AND OTHER ALTERATIONS Miscellaneous § 1304.400 Flotation devices and material, all floating structures. (a) All flotation for docks, boat mooring buoys, and other water-use structures and facilities...

18 CFR 1304.400 - Flotation devices and material, all floating structures.

Code of Federal Regulations, 2013 CFR

2013-04-01

... material, all floating structures. 1304.400 Section 1304.400 Conservation of Power and Water Resources... STRUCTURES AND OTHER ALTERATIONS Miscellaneous § 1304.400 Flotation devices and material, all floating structures. (a) All flotation for docks, boat mooring buoys, and other water-use structures and facilities...

Nanomaterials and Water Purification: Opportunities and Challenges

NASA Astrophysics Data System (ADS)

Savage, Nora; Diallo, Mamadou S.

2005-10-01

Advances in nanoscale science and engineering suggest that many of the current problems involving water quality could be resolved or greatly ameliorated using nanosorbents, nanocatalysts, bioactive nanoparticles, nanostructured catalytic membranes and nanoparticle enhanced filtration among other products and processes resulting from the development of nanotechnology. Innovations in the development of novel technologies to desalinate water are among the most exciting and promising. Additionally, nanotechnology-derived products that reduce the concentrations of toxic compounds to sub-ppb levels can assist in the attainment of water quality standards and health advisories. This article gives an overview of the use of nanomaterials in water purification. We highlight recent advances on the development of novel nanoscale materials and processes for treatment of surface water, groundwater and industrial wastewater contaminated by toxic metal ions, radionuclides, organic and inorganic solutes, bacteria and viruses. In addition, we discuss some challenges associated with the development of cost effective and environmentally acceptable functional nanomaterials for water purification.

Adsorption of Crystal Violet on Activated Carbon Prepared from Coal Flotation Concentrate

NASA Astrophysics Data System (ADS)

Aydogmus, Ramazan; Depci, Tolga; Sarikaya, Musa; Riza Kul, Ali; Onal, Yunus

2016-10-01

The objective of this study is firstly to investigate the floatability properties of Zilan- Van coal after microwave irradiation and secondly to produce activated carbon from flotation concentrate in order to remove Crystal Violet (CV) from waste water. The flotation experiments showed that microwave heating at 0.9 kW power level for 60 sec exposure time enhanced the hydrophobicity and increased the flotation yield. The activated carbon with remarkable surface area (696 m2/g) was produced from the flotation concentrate and used to adsorb CV from aqueous solution in a batch reactor at different temperature. The adsorption properties of CV onto the activated carbon are discussed in terms of the adsorption isotherms (Langmuir and Freundlich) and found that the experimental results best fitted by the Langmuir model.

Metal biosorption-flotation. Application to cadmium removal.

PubMed

Matis, K A; Zouboulis, A I; Grigoriadou, A A; Lazaridis, N K; Ekateriniadou, L V

1996-05-01

Biosorption using suspended non-living biomass, and flotation (for consequent solid/liquid separation of the metal-loaded biomass) have been studied in the laboratory as a possible combined process, for the removal of toxic metals (i.e., cadmium) from dilute aqueous solutions. The various parameters of the process were investigated in depth, including re-use of biosorbent. A filter aid (contained in the biomass industrial waste used) was found not really to interfere. Zeta-potential measurements of the aforementioned system were also carried out. Promising results were obtained during continuous-flow experiments. A flotation residence time of 4 min was achieved. Metal removal and suspended biomass recovery were generally over 95%.

Rotating Reverse-Osmosis for Water Purification

NASA Technical Reports Server (NTRS)

Lueptow, RIchard M.

2004-01-01

A new design for a water-filtering device combines rotating filtration with reverse osmosis to create a rotating reverse- osmosis system. Rotating filtration has been used for separating plasma from whole blood, while reverse osmosis has been used in purification of water and in some chemical processes. Reverse- osmosis membranes are vulnerable to concentration polarization a type of fouling in which the chemicals meant not to pass through the reverse-osmosis membranes accumulate very near the surfaces of the membranes. The combination of rotating filtration and reverse osmosis is intended to prevent concentration polarization and thereby increase the desired flux of filtered water while decreasing the likelihood of passage of undesired chemical species through the filter. Devices based on this concept could be useful in a variety of commercial applications, including purification and desalination of drinking water, purification of pharmaceutical process water, treatment of household and industrial wastewater, and treatment of industrial process water. A rotating filter consists of a cylindrical porous microfilter rotating within a stationary concentric cylindrical outer shell (see figure). The aqueous suspension enters one end of the annulus between the inner and outer cylinders. Filtrate passes through the rotating cylindrical microfilter and is removed via a hollow shaft. The concentrated suspension is removed at the end of the annulus opposite the end where the suspension entered.

18 CFR 1304.400 - Flotation devices and material, all floating structures.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Flotation devices and material, all floating structures. 1304.400 Section 1304.400 Conservation of Power and Water Resources... structures. (a) All flotation for docks, boat mooring buoys, and other water-use structures and facilities...

18 CFR 1304.400 - Flotation devices and material, all floating structures.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Flotation devices and material, all floating structures. 1304.400 Section 1304.400 Conservation of Power and Water Resources... structures. (a) All flotation for docks, boat mooring buoys, and other water-use structures and facilities...

Effect of three typical sulfide mineral flotation collectors on soil microbial activity.

PubMed

Guo, Zunwei; Yao, Jun; Wang, Fei; Yuan, Zhimin; Bararunyeretse, P; Zhao, Yue

2016-04-01

The sulfide mineral flotation collectors are wildly used in China, whereas their toxic effect on soil microbial activity remains largely unexplored. In this study, isothermal microcalorimetric technique and soil enzyme assay techniques were employed to investigate the toxic effect of typical sulfide mineral flotation collectors on soil microbial activity. Soil samples were treated with different concentrations (0-100 μg•g - 1 soil) of butyl xanthate, butyl dithiophosphate, and sodium diethyldithiocarbamate. Results showed a significant adverse effect of butyl xanthate (p < 0.05), butyl dithiophosphate, and sodium diethyldithiocarbamate (p < 0.01) on soil microbial activity. The growth rate constants k decreased along with the increase of flotation collectors concentration from 20.0 to 100.0 μg•g(-1). However, the adverse effects of these three floatation collectors showed significant difference. The IC 20 of the investigated flotation reagents followed such an order: IC 20 (butyl xanthate) > IC 20 (sodium diethyldithiocarbamate) > IC 20 (butyl dithiophosphate) with their respective inhibitory concentration as 47.03, 38.36, and 33.34 μg•g(-1). Besides, soil enzyme activities revealed that these three flotation collectors had an obvious effect on fluorescein diacetate hydrolysis (FDA) enzyme and catalase (CAT) enzyme. The proposed methods can provide meaningful toxicological information of flotation reagents to soil microbes in the view of metabolism and biochemistry, which are consistent and correlated to each other.

Improvement of ore recovery efficiency in a flotation column cell using ultra-sonic enhanced bubbles

NASA Astrophysics Data System (ADS)

Filippov, L. O.; Royer, J. J.; Filippova, I. V.

2017-07-01

The ore process flotation technique is enhanced by using external ultra-sonic waves. Compared to the classical flotation method, the application of ultrasounds to flotation fluids generates micro-bubbles by hydrodynamic cavitation. Flotation performances increase was modelled as a result of increased probabilities of the particle-bubble attachment and reduced detachment probability under sonication. A simplified analytical Navier-Stokes model is used to predict the effect of ultrasonic waves on bubble behavior. If the theory is verified by experimentation, it predicts that the ultrasonic waves would create cavitation micro-bubbles, smaller than the flotation bubble added by the gas sparger. This effect leads to increasing the number of small bubbles in the liquid which promote particle-bubble attachment through coalescence between bubbles and micro-bubbles. The decrease in the radius of the flotation bubbles under external vibration forces has an additional effect by enhancing the bubble-particle collision. Preliminary results performed on a potash ore seem to confirm the theory.

The Significance of Myriophyllum elatinoides for Swine Wastewater Treatment: Abundance and Community Structure of Ammonia-Oxidizing Microorganisms in Sediments

PubMed Central

Li, Xi; Zhang, Miaomiao; Liu, Feng; Li, Yong; He, Yang; Zhang, Shunan; Wu, Jinshui

2015-01-01

Myriophyllum elatinoides was reported to effectively treat wastewater by removing nitrogen (N) and phosphorus (P). However, little is known about the abundance and community structure of ammonia-oxidizing microorganisms associated with M. elatinoides purification systems. The objective of this research was to characterize the abundance and community structure of ammonia-oxidizing microorganisms in swine wastewater and determine the main nitrogen removal pathways. In this study, five different waters were treated by M. elatinoides in microcosms for one month. The five waters included tap water (Control), swine wastewater (SW), 50% diluted swine wastewater (50% SW), and two synthetic wastewaters: 200 mg NH4 +-N L−1 (200 NH4 +-N) and 400 mg NH4 +-N L−1 (400 NH4 +-N). The most dramatic changes were in NH4 +-N and total N (TN) concentrations, with average removal rates of 84% and 90%, respectively, in the treatments containing swine wastewater. On days 7, 14, and 28, the dissolved oxygen (DO) increased by 81.8%, 210.4% and 136.5%, respectively, compared with on day 0, in the swine wastewater. The results also showed that the bacterial amoA (AOB) copy numbers in the sediments of the treatments were significantly higher than those of archaeal amoA (AOA) copy numbers (p = 0.015). In addition, the high DO concentrations in swine wastewater responded well to the high abundance of AOB. The AOA and AOB community distributions were positively related with NO3 -N and were negatively related with DO in swine wastewater treatments. In summary, our experimental results suggested that the M. elatinoides purification system could improve the activity of ammonia-oxidizing microorganisms and consequently might contribute to the significant N removal from the swine wastewater. PMID:26444015

The Significance of Myriophyllum elatinoides for Swine Wastewater Treatment: Abundance and Community Structure of Ammonia-Oxidizing Microorganisms in Sediments.

PubMed

Li, Xi; Zhang, Miaomiao; Liu, Feng; Li, Yong; He, Yang; Zhang, Shunan; Wu, Jinshui

2015-01-01

Myriophyllum elatinoides was reported to effectively treat wastewater by removing nitrogen (N) and phosphorus (P). However, little is known about the abundance and community structure of ammonia-oxidizing microorganisms associated with M. elatinoides purification systems. The objective of this research was to characterize the abundance and community structure of ammonia-oxidizing microorganisms in swine wastewater and determine the main nitrogen removal pathways. In this study, five different waters were treated by M. elatinoides in microcosms for one month. The five waters included tap water (Control), swine wastewater (SW), 50% diluted swine wastewater (50% SW), and two synthetic wastewaters: 200 mg NH4+-N L(-1) (200 NH4+-N) and 400 mg NH4+-N L(-1) (400 NH4+-N). The most dramatic changes were in NH4+-N and total N (TN) concentrations, with average removal rates of 84% and 90%, respectively, in the treatments containing swine wastewater. On days 7, 14, and 28, the dissolved oxygen (DO) increased by 81.8%, 210.4% and 136.5%, respectively, compared with on day 0, in the swine wastewater. The results also showed that the bacterial amoA (AOB) copy numbers in the sediments of the treatments were significantly higher than those of archaeal amoA (AOA) copy numbers (p = 0.015). In addition, the high DO concentrations in swine wastewater responded well to the high abundance of AOB. The AOA and AOB community distributions were positively related with NO3-N and were negatively related with DO in swine wastewater treatments. In summary, our experimental results suggested that the M. elatinoides purification system could improve the activity of ammonia-oxidizing microorganisms and consequently might contribute to the significant N removal from the swine wastewater.

Automated flotation control at Jim Walter Resources, Mining Division

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burchfield, J.W.

1993-12-31

Jim Walter Resources (JWR), Mining Division, operates in west-central Alabama in Jefferson and Tuscaloosa Counties. Their products are divided into two grades, three to four million tons of high Btu, low sulfur steam coal, and five to six million tons of medium to low volatile metallurgical coal. Predominantly, the Blue Creek seam of coal in the Warrior Basin is mined. This coal is known for its high Btu content, low sulfur, and strong coking qualities, coupled with a very high grindability. This last quality of high grindability has been very challenging for their preparation plants. Normally, after some processing degradation,more » their clean coal product will range from 40--50% minus 28 mesh. One can easily see from these numbers that froth flotation is critical to clean coal recovery and mine cost. Flotation, unlike most processing equipment, keeps most of its activity and a lot of its chemistry under a bed of froth in the cells. there are many operating variables that are constantly changing, and Management, no matter how responsive they are, cannot react quickly enough. Therefore, automated flotation appeared to be the natural course of action for a mining company that produces a minimum of 40% of its marketable product from flotation cells. The two companies that were supply their flotation chemicals came forward with proposals to fill their needs. Nalco, who has for some time had their Opticus system being tested and utilized in the industry, and Stockhausen (formerly Betz Chemical Co.). Stockhausen had no system of their own, but acquired a system from Process Technology, Inc. (PTI). JWR assigned a plant to each vendor for installation of their systems. The paper describes both systems and their performance.« less

Assessment of a New Silicon Carbide Tubular Honeycomb Membrane for Treatment of Olive Mill Wastewaters

PubMed Central

Fraga, Maria C.; Sanches, Sandra; Crespo, João G.; Pereira, Vanessa J.

2017-01-01

Extremely high removals of total suspended solids and oil and grease were obtained when olive mill wastewaters were filtered using new silicon carbide tubular membranes. These new membranes were used at constant permeate flux to treat real olive mill wastewaters at pilot scale. The filtration conditions were evaluated and optimized in terms of the selection of the permeate flux and flux maintenance strategies employed—backpulsing and backwashing—in order to reduce fouling formation. The results obtained reveal that the combination of backpulses and backwashes helps to maintain the permeate flux, avoids transmembrane pressure increase and decreases the cake resistance. Moreover, membrane cleaning procedures were compared and the main agents responsible for fouling formation identified. Results also show that, under total recirculation, despite an increased concentration of pollutants in the feed stream, the quality of the permeate is maintained. Membrane filtration using silicon carbide membranes is an effective alternative to dissolved air flotation and can be applied efficiently to remove total suspended solids and oil and grease from olive mill wastewaters. PMID:28264453

Assessment of a New Silicon Carbide Tubular Honeycomb Membrane for Treatment of Olive Mill Wastewaters.

PubMed

Fraga, Maria C; Sanches, Sandra; Crespo, João G; Pereira, Vanessa J

2017-02-27

Extremely high removals of total suspended solids and oil and grease were obtained when olive mill wastewaters were filtered using new silicon carbide tubular membranes. These new membranes were used at constant permeate flux to treat real olive mill wastewaters at pilot scale. The filtration conditions were evaluated and optimized in terms of the selection of the permeate flux and flux maintenance strategies employed-backpulsing and backwashing-in order to reduce fouling formation. The results obtained reveal that the combination of backpulses and backwashes helps to maintain the permeate flux, avoids transmembrane pressure increase and decreases the cake resistance. Moreover, membrane cleaning procedures were compared and the main agents responsible for fouling formation identified. Results also show that, under total recirculation, despite an increased concentration of pollutants in the feed stream, the quality of the permeate is maintained. Membrane filtration using silicon carbide membranes is an effective alternative to dissolved air flotation and can be applied efficiently to remove total suspended solids and oil and grease from olive mill wastewaters.

A novel process for separation of polycarbonate, polyvinyl chloride and polymethyl methacrylate waste plastics by froth flotation.

PubMed

Wang, Chong-Qing; Wang, Hui; Huang, Luo-Luo

2017-07-01

A novel process was proposed for separation of ternary waste plastics by froth flotation. Pretreatment of plastics with potassium permanganate (KMnO 4 ) solution was conducted to aid flotation separation of polycarbonate (PC), polyvinyl chloride (PVC) and polymethyl methacrylate (PMMA) plastics. The effect of pretreatment parameters including KMnO 4 concentration, treatment time, temperature and stirring rate on flotation recovery were investigated by single factor experiments. Surface treatment with KMnO 4 changes selectively the flotation behavior of PC, PVC and PMMA, enabling separation of the plastics by froth flotation. Mechanism of surface treatment was studied by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray photoelectron spectrum (XPS). Effect of frother concentration and flotation time on flotation behavior of plastic mixtures was further studied for flotation separation. The optimized conditions for separation of PC are KMnO 4 concentration 2mmolL -1 , treatment time 10min, temperature 60°C, stirring rate 300rpm, flotation time 1min and frother concentration 17.5mgL -1 . Under optimum conditions, PVC and PMMA mixtures are also separated efficiently by froth flotation associated with KMnO 4 treatment. The purity of PC, PVC and PMMA is up to 100%, 98.41% and 98.68%, while the recovery reaches 96.82%, 98.71% and 98.38%, respectively. Economic analysis manifests remarkable profits of the developed process. Reusing KMnO 4 solution is feasible, enabling the process greener. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characteristic of flotation deinking using bio and synthetic surfactant at different air flow rate

NASA Astrophysics Data System (ADS)

Trismawati, Wardana, I. N. G.; Hamidi, Nurkholis; Sasongko, Mega Nur

2016-03-01

Flotation deinking has industrially applied but several problems keep unsolved because limitations have to compete with several variables present. Flotation deinking is multi variables process, so studying flotation deinking is still interesting. In this research, the amount of variables was reduced and focused to the performance comparison between flotation deinking of old newspaper (ONP) using biodegradable fatty acid of morinda citrifolia as the raw bio surfactant (RBS) and biodegradable fatty acid of palm oil that had been converted to be commercial surfactant (CS). The flotation was done at laboratory flotation cell equipped with orifice at different diameter (orifice number 20, 40 and 60) with adjustable airflow rate. Brightness and Effective Residual Ink Concentration (ERIC) of the deinked pulp were measured. The best results were achieved on orifice number 40 with the highest brightness of 41.96 °ISO and 40.96 °ISO when using CS and RBS respectively, and lowest ERIC of 896.82 ppm and 1001.72 ppm when using CS and RBS respectively. The percentage delta of deinking power characteristic between CS and RBS was 2.36% and 11.70% for brightness and ERIC, respectively.

Determination of Ammonia Oxidizing Bacteria and Nitrate Oxidizing Bacteria in Wastewater and Bioreactors

NASA Technical Reports Server (NTRS)

Francis, Somilez Asya

2014-01-01

The process of water purification has many different physical, chemical, and biological processes. One part of the biological process is the task of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB). Both play critical roles in the treatment of wastewater by oxidizing toxic compounds. The broad term is nitrification, a naturally occurring process that is carried out by AOB and NOB by using oxidation to convert ammonia to nitrite and nitrite to nitrate. To monitor this biological activity, bacterial staining was performed on wastewater contained in inoculum tanks and biofilm samples from bioreactors. Using microscopy and qPCR, the purpose of this experiment was to determine if the population of AOB and NOB in wastewater and membrane bioreactors changed depending on temperature and hibernation conditions to determine the optimal parameters for AOB/NOB culture to effectively clean wastewater.

Production of brown and black pigments by using flotation waste from copper slag.

PubMed

Ozel, Emel; Turan, Servet; Coruh, Semra; Ergun, Osman Nuri

2006-04-01

One of the major problems in copper-producing countries is the treatment of the large amount of copper slag or copper flotation waste generated from copper slag which contains significant amounts of heavy metals such as Cu, Zn, Pb and Co. Dumping or disposal of such large quantities of flotation waste from copper slag causes environmental and space problems. In this study, the treatment of flotation waste from copper slag by a thermal method and its use as an iron source in the production of inorganic brown and black pigments that are used in the ceramic industry were investigated. The pigments were produced by calcining different amounts of flotation waste and chromite, Cr2O3, ZnO and CoO mixtures. The pigments obtained were added to transparent ceramic glazes and porcelainized tile bodies. Their colours were defined by L*a*b* measurements with a spectrophotometer. The results showed that flotation waste from copper slag could be used as an iron source to produce brown and black pigments in both ceramic body and glazes.

Long-term performance of high-rate anaerobic reactors for the treatment of oily wastewater.

PubMed

Jeganathan, Jeganaesan; Nakhla, George; Bassi, Amarjeet

2006-10-15

Complex oily wastewater from a food industry was treated in three different UASB reactors at different operating conditions. Although all three systems achieved fat, oil, and grease (FOG) and COD removal efficiencies above 80% at an organic loading of 3 kg COD/m3 x d, system performance deteriorated sharply at higher loading rates, and the presence of high FOG caused a severe sludge flotation resulting in failure. Initially, FOG accumulated onto the biomass which led to sludge flotation and washout of biomass. The loss of sludge in the bed increased the FOG loading to the biomass and failure ensued. Contrary to previous findings, accumulation of FOG rather than influent FOG concentrations or volumetric FOG loading rate was the most importantfactor governing the high-rate anaerobic reactor performance. The critical accumulated FOG loading was identified as 1.04 +/- 0.13 g FOG/g VSS for all three reactors. Furthermore, FOG accumulation onto the biomass was identified mainly as palmitic acid (>60%) whereas the feed LCFA contained only 30% of palmitic acid and 50% of oleic acid.

The effect of the natural bentonite to reduce COD in palm oil mill effluent by using a hybrid adsorption-flotation method

NASA Astrophysics Data System (ADS)

Dewi, Ratni; Sari, Ratna; Syafruddin

2017-06-01

Palm oil mill effluent is waste produced from palm oil processing activities. This waste are comingfrom condensate water, process water and hydrocyclone water. The high levels of contaminants in the palm oil mill effluent causes the waste becomes inappropriate to be discharged to water body before processing, one of the most major contaminants in wastewater is fats, oils and COD.This study investigated the effectiveness of chemically activated bentonite that serves as an alternative to reduce the COD in adsorption and floatation based palm oil effluent waste processing. Natural bentonite was activated by using nitrit acid and benzene. In the existing adsorption material to improve COD reduction capability whereas the flotation method was used to further remove residual effluent which is still remain after the adsorption process. An adsorption columns which operated in batch was used in the present study. By varying the circulation time and adsorbent treatment (activated and non-activated), it was shown that percentage of COD reduction reached 75% at the circulation time of 180 minutes for non activated adsorbent. On the other hand the percentof COD reduction in adsorption and flotation process using activated bentonite reached as high as 88% and 93% at the circulation time of 180 minutes.

Integration process of fermentation and liquid biphasic flotation for lipase separation from Burkholderia cepacia.

PubMed

Sankaran, Revathy; Show, Pau Loke; Lee, Sze Ying; Yap, Yee Jiun; Ling, Tau Chuan

2018-02-01

Liquid Biphasic Flotation (LBF) is an advanced recovery method that has been effectively applied for biomolecules extraction. The objective of this investigation is to incorporate the fermentation and extraction process of lipase from Burkholderia cepacia using flotation system. Initial study was conducted to compare the performance of bacteria growth and lipase production using flotation and shaker system. From the results obtained, bacteria shows quicker growth and high lipase yield via flotation system. Integration process for lipase separation was investigated and the result showed high efficiency reaching 92.29% and yield of 95.73%. Upscaling of the flotation system exhibited consistent result with the lab-scale which are 89.53% efficiency and 93.82% yield. The combination of upstream and downstream processes in a single system enables the acceleration of product formation, improves the product yield and facilitates downstream processing. This integration system demonstrated its potential for biomolecules fermentation and separation that possibly open new opportunities for industrial production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Separation of plastics: The importance of kinetics knowledge in the evaluation of froth flotation.

PubMed

Censori, Matteo; La Marca, Floriana; Carvalho, M Teresa

2016-08-01

Froth flotation is a promising technique to separate polymers of similar density. The present paper shows the need for performing kinetic tests to evaluate and optimize the process. In the experimental study, batch flotation tests were performed on samples of ABS and PS. The floated product was collected at increasing flotation time. Two variables were selected for modification: the concentration of the depressor (tannic acid) and airflow rate. The former is associated with the chemistry of the process and the latter with the transport of particles. It was shown that, like mineral flotation, plastics flotation can be adequately assumed as a first order rate process. The results of the kinetic tests showed that the kinetic parameters change with the operating conditions. When the depressing action is weak and the airflow rate is low, the kinetic is fast. Otherwise, the kinetic is slow and a variable percentage of the plastics never floats. Concomitantly, the time at which the maximum difference in the recovery of the plastics in the floated product is attained changes with the operating conditions. The prediction of flotation results, process evaluation and comparisons should be done considering the process kinetics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Solution chemistry of carbonate minerals and its effects on the flotation of hematite with sodium oleate

NASA Astrophysics Data System (ADS)

Li, Dong; Yin, Wan-zhong; Xue, Ji-wei; Yao, Jin; Fu, Ya-feng; Liu, Qi

2017-07-01

The effects of carbonate minerals (dolomite and siderite) on the flotation of hematite using sodium oleate as a collector were investigated through flotation tests, supplemented by dissolution measurements, solution chemistry calculations, zeta-potential measurements, Fourier transform infrared (FTIR) spectroscopic studies, and X-ray photoelectron spectroscopy (XPS) analyses. The results of flotation tests show that the presence of siderite or dolomite reduced the recovery of hematite and that the inhibiting effects of dolomite were stronger. Dissolution measurements, solution chemistry calculations, and flotation tests confirmed that both the cations (Ca2+ and Mg2+) and CO3 2- ions dissolved from dolomite depressed hematite flotation, whereas only the CO3 2- ions dissolved from siderite were responsible for hematite depression. The zeta-potential, FTIR spectroscopic, and XPS analyses indicated that Ca2+, Mg2+, and CO3 2- (HCO3 -) could adsorb onto the hematite surface, thereby hindering the adsorption of sodium oleate, which was the main reason for the inhibiting effects of carbonate minerals on hematite flotation.

Fine particles flotation of the Moatize coal/Mozambique

NASA Astrophysics Data System (ADS)

Castro, Amilton; de Brum, Irineu A. S.

2017-11-01

This study was done from a sample of coal mined at the Vale-Mozambique mine, located in Moatize district, Tete Province. The aim of this work is to analyze the reagent system in the flotation of coal fines belonging to the UCB layer. Among coal processing methods, flotation stands out as one of the most important for the concentration of this material, in particular in the treatment of fine particles. The total feed of the Vale-Mozambique processing plant is 8000 tph of coal, where 10% of this feed corresponds to the fine fraction that feeds the flotation circuit. The material used in this study had a particle size of 96% smaller than 0.25 mm. The reagents used in the flotation tests were Betacol and diesel oil as hydrophobizing agents and MIBC as frother. The range of Betacol concentrations in the first test phase was 200 g / t at 500 g / t, and in the second phase 200 g / t at 500 g / t of diesel oil and MIBC were kept constant at 300 g / t. The immediate analysis followed the Brazilian standards: NBR 8289, NBR 8293, NBR 8290, NBR 8299. The results showed that it is possible, from a feed with the ash content around 22.84%, to obtain products with levels below of 10% ash, with a mass recovery around 50%. The recovery of carbonaceous matter was also evaluated and presented positive results. Complementing this study, the effect of H2O recovery was evaluated and it was observed that for the concentrations of Betacol the recoveries ranged from 6 to 9%, and for diesel oil plus MIBC were 4 to 7%.

Economy of precipitating agent application in municipal wastewater treatment facilities

NASA Technical Reports Server (NTRS)

Neis, U.; Geppert, B.; Hahn, H. H.; Gleisberg, D.

1983-01-01

Purification by precipitation in this study is not considered primarily as a means of phosphate removal but as a method for reduction of suspended solids BOD and COD. A dynamic calculation procedure is used to allow for exact determination of time dependent variation of costs. The results show that costs of wastewater treatment by precipitation may equal those of conventional primary clarification and secondary biological treatment, especially with low-cost iron-II-salts in simultaneous precipitation and in larger plants ( 20,000 PF). Cost advantages may be accrued in smaller plants by using the more expensive trivalent salts in pre-precipitation as compared to conventional low-load biological treatment. This is due mainly to better effluent quality and, consequently, lower wastewater fees (Wastewater Discharge Act). If the precipitant is dosed temporarily only during periods of highest pollution the savings can be about 5 to 10%.

New Insights into the Role of Pb-BHA Complexes in the Flotation of Tungsten Minerals

NASA Astrophysics Data System (ADS)

Yue, Tong; Han, Haisheng; Hu, Yuehua; Sun, Wei; Li, Xiaodong; Liu, Runqing; Gao, Zhiyong; Wang, Li; Chen, Pan; Zhang, Chenyang; Tian, Mengjie

2017-11-01

Lead ions (lead nitrate) were introduced to modify the surface properties of tungsten minerals, effectively improving the floatability, with benzohydroxamic acid (BHA) serving as the collector. Flotation tests indicated that Pb-BHA complexes were the active species responsible for flotation of the tungsten minerals. The developed Pb-BHA complexes and the novel flotation process effectively increased the recovery of scheelite and wolframite, simplified the technological process, and led to reduced costs. Fourier transform infrared spectra data showed the presence of adsorbed Pb-BHA complexes on the surface of the minerals. The characteristic peaks of BHA shifted by a considerable extent, indicating that chemical adsorption plays an important role in the flotation process. Zeta potential results confirmed physical adsorption of the positively charged Pb-BHA complexes on the mineral surfaces. The synergistic effect between chemical and physical adsorption facilitated the maximum flotation recovery of scheelite and wolframite.

Cross flow cyclonic flotation column for coal and minerals beneficiation

DOEpatents

Lai, Ralph W.; Patton, Robert A.

2000-01-01

An apparatus and process for the separation of coal from pyritic impurities using a modified froth flotation system. The froth flotation column incorporates a helical track about the inner wall of the column in a region intermediate between the top and base of the column. A standard impeller located about the central axis of the column is used to generate a centrifugal force thereby increasing the separation efficiency of coal from the pyritic particles and hydrophillic tailings.

Use of centrifugal-gravity concentration for rejection of talc and recovery improvement in base-metal flotation

NASA Astrophysics Data System (ADS)

Klein, Bern; Altun, Naci Emre; Ghaffari, Hassan

2016-08-01

The possibility of using a centrifugal-gravity concentrator to reject Mg-bearing minerals and minimize metal losses in the flotation of base metals was evaluated. Sample characterization, batch scoping tests, pilot-scale tests, and regrind-flotation tests were conducted on a Ni flotation tailings stream. Batch tests revealed that the Mg grade decreased dramatically in the concentrate products. Pilot-scale testing of a continuous centrifugal concentrator (Knelson CVD6) on the flotation tailings revealed that a concentrate with a low mass yield, low Mg content, and high Ni upgrade ratio could be achieved. Under optimum conditions, a concentrate at 6.7% mass yield was obtained with 0.85% Ni grade at 12.9% Ni recovery and with a low Mg distribution (1.7%). Size partition curves demonstrated that the CVD also operated as a size classifier, enhancing the rejection of talc fines. Overall, the CVD was capable of rejecting Mg-bearing minerals. Moreover, an opportunity exists for the novel use of centrifugal-gravity concentration for scavenging flotation tailings and/or after comminution to minimize amount of Mg-bearing minerals reporting to flotation.

Heterocoagulation of chalcopyrite and pyrite minerals in flotation separation.

PubMed

Mitchell, Timothy K; Nguyen, Anh V; Evans, Geoffrey M

2005-06-30

Heterocoagulation between various fine mineral particles contained within a mineral suspension with different structural and surface chemistry can interfere with the ability of the flotation processes to selectively separate the minerals involved. This paper examines the interactions between chalcopyrite (a copper mineral) and pyrite (an iron mineral often bearing gold) as they approach each other in suspensions with added chemicals, and relates the results to the experimental data for the flotation recovery and selectivity. The heterocoagulation was experimentally studied using the electrophoretic light scattering (ELS) technique and was modelled by incorporating colloidal forces, including the van der Waals, electrostatic double layer and hydrophobic forces. The ELS results indicated that pyrite has a positive zeta potential (zeta) up to its isoelectric point (IEP) at approximately pH 2.2, while chalcopyrite has a positive zeta up to its IEP at approximately pH 5.5. This produces heterocoagulation of chalcopyrite with pyrite between pH 2.2 and pH 5.5. The heterocoagulation was confirmed by the ELS spectra measured with a ZetaPlus instrument from Brookhaven and by small-scale flotation experiments.

[Spectral Analysis of Dissolved Organic Matter of Tannery Wastewater in the Treatment Process].

PubMed

Fan, Chun-hui; Zhang, Ying-chao; Du, Bo; Song, Juan; Huai, Cui-qian; Wang, Jia-hong

2015-06-01

Tannery industry is one of the major traditional industries and important wastewater sources in China. The existing research mainly focus on the quality of inlet and outlet water, rather than the purification and transformation behavior of dissolved organic matter (DOM) in the treatment process of tannery wastewater. The UV spectra and fluorescence spectroscopy were used to detect the spectral characteristics of water samples in the treatment process, and it is analyzed that the formation process and the linear relationships between total fluorescence intensity and parameters. The results showed: the UV absorbance of DOM in wastewater increased firstly and then decreased with longer wavelength, and the wave peaks were found around the wavelength of 230 nr. The values of A253 /A203 and SUVA254 increased firstly and then decreased, indicating the complex reaction process related to free substituent and aromatic rings. The fluorescence peaks appeared at the regions of λ(ex/em) = 320-350/440- 460 and λ(ex/em) = 270-300/390-420, referred as visible humic-like and visible fulvic-like fluorescence, respectively. With the treatment process of tannery wastewater, the following fluorescence phenomenon were monitored, such as the blue-shift of humic-like fluorescence peak in the hydrolytic acidification tank, the appearance of tryptophan fluorescence peak in the second biochemical pond (λ(ex/em) = 290/340), the weak fluorescence peak in the fourth biochemical pond (λ(ex/em) = 350/520) and the stabilized fluorescence characteristics in the secondary sedimentation tank and water outlet. The achievements are helpful to investigate the degradation and formation behavior of water components, and significant for the fluorescence variation analysis in the treatment system. The removal rate of total fluorescence intensity of tannery wastewater fit better the removal rate of TOC with coefficient of r 0.835 5. The UV spectra and 3D-EEMs are effective to reveal the purification

Effects of ozone and peroxone on algal separation via dispersed air flotation.

PubMed

Nguyen, Truc Linh; Lee, D J; Chang, J S; Liu, J C

2013-05-01

Effects of pre-oxidation on algal separation by dispersed air flotation were examined. Ozone (O3) and peroxone (O3 and H2O2) could induce cell lysis, release of intracellular organic matter (IOM), and mineralization of organic substances. Separation efficiency of algal cells improved when pre-oxidized. Total of 76.4% algal cells was separated at 40 mg/L of N-cetyl-N-N-N-trimethylammonium bromide (CTAB), while 95% were separated after 30-min ozonation. Pre-oxidation by ozone and peroxone also enhanced flotation separation efficiency of dissolved organic carbon (DOC), polysaccharide, and protein, in which peroxone process exerted more significantly than O3. Two main mechanisms were involved in flotation separation of unoxidized algal suspension, namely hydrophobic cell surface and cell flocculation resulting from CTAB adsorption. However, flocculation by CTAB was hindered for pre-oxidized algal suspensions. It implied that the compositional changes in extracellular organic matter (EOM) by pre-oxidation were more determined for flotation separation of pre-oxidized cells. Copyright © 2012 Elsevier B.V. All rights reserved.

High-rate wastewater treatment combining a moving bed biofilm reactor and enhanced particle separation.

PubMed

Helness, H; Melin, E; Ulgenes, Y; Järvinen, P; Rasmussen, V; Odegaard, H

2005-01-01

Many cities around the world are looking for compact wastewater treatment alternatives since space for treatment plants is becoming scarce. In this paper development of a new compact, high-rate treatment concept with results from experiments in lab-scale and pilot-scale are presented. The idea behind the treatment concept is that coagulation/floc separation may be used to separate suspended and colloidal matter (resulting in > 70% organic matter removal in normal wastewater) while a high-rate biofilm process (based on Moving Bed biofilm reactors) may be used for removing low molecular weight, easily biodegradable, soluble organic matter. By using flotation for floc/biomass separation, the total residence time for a plant according to this concept will normally be < 1 hour. A cationic polymer combined with iron is used as coagulant at low dosages (i.e. 1-2 mg polymer/l, 5-10 mg Fe/l) resulting in low sludge production (compared to conventional chemical treatment) and sufficient P-removal.

Electron beam treatment of textile dyeing wastewater: operation of pilot plant and industrial plant construction.

PubMed

Han, B; Kim, J; Kim, Y; Choi, J S; Makarov, I E; Ponomarev, A V

2005-01-01

A pilot plant for treating 1000 m3/day of dyeing wastewater with e-beam has been constructed and operated since 1998 in Daegu, Korea together with the biological treatment facility. The wastewater from various stages of the existing purification process has been treated with an electron beam in this plant, and it gave rise to elaborating the optimal technology of the electron beam treatment of wastewater with increased reliability for instant changes in the composition of wastewater. Installation of the e-beam pilot plant resulted in decolorizing and destructive oxidation of organic impurities in wastewater, appreciable reduction of chemical reagent consumption, in reduction of the treatment time, and in increase in the flow rate limit of existing facilities by 30-40%. Industrial plant for treating 10,000 m3/day each, based upon the pilot experimental result, is under construction and will be finished by 2005. This project is supported by the International Atomic Energy Agency (IAEA) and Korean Government.

Removal of Hazardous Pollutants from Wastewaters: Applications of TiO 2 -SiO 2 Mixed Oxide Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rasalingam, Shivatharsiny; Peng, Rui; Koodali, Ranjit T.

The direct release of untreated wastewaters from various industries and households results in the release of toxic pollutants to the aquatic environment. Advanced oxidation processes (AOP) have gained wide attention owing to the prospect of complete mineralization of nonbiodegradable organic substances to environmentally innocuous products by chemical oxidation. In particular, heterogeneous photocatalysis has been demonstrated to have tremendous promise in water purification and treatment of several pollutant materials that include naturally occurring toxins, pesticides, and other deleterious contaminants. In this work, we have reviewed the different removal techniques that have been employed for water purification. In particular, the application ofmore » TiO 2 -SiO 2 binary mixed oxide materials for wastewater treatment is explained herein, and it is evident from the literature survey that these mixed oxide materials have enhanced abilities to remove a wide variety of pollutants.« less

Removal of Hazardous Pollutants from Wastewaters: Applications of TiO 2 -SiO 2 Mixed Oxide Materials

DOE PAGES

Rasalingam, Shivatharsiny; Peng, Rui; Koodali, Ranjit T.

2014-01-01

The direct release of untreated wastewaters from various industries and households results in the release of toxic pollutants to the aquatic environment. Advanced oxidation processes (AOP) have gained wide attention owing to the prospect of complete mineralization of nonbiodegradable organic substances to environmentally innocuous products by chemical oxidation. In particular, heterogeneous photocatalysis has been demonstrated to have tremendous promise in water purification and treatment of several pollutant materials that include naturally occurring toxins, pesticides, and other deleterious contaminants. In this work, we have reviewed the different removal techniques that have been employed for water purification. In particular, the application ofmore » TiO 2 -SiO 2 binary mixed oxide materials for wastewater treatment is explained herein, and it is evident from the literature survey that these mixed oxide materials have enhanced abilities to remove a wide variety of pollutants.« less

Flotation separation of polyvinyl chloride and polyethylene terephthalate plastics combined with surface modification for recycling.

PubMed

Wang, Chongqing; Wang, Hui; Fu, Jiangang; Zhang, Lingling; Luo, Chengcheng; Liu, Younian

2015-11-01

Surface modification with potassium permanganate (KMnO4) solution was developed for separation of polyvinyl chloride (PVC) and polyethylene terephthalate (PET) waste plastics. The floatability of PVC decreases with increasing of KMnO4 concentration, treatment time, temperature and stirring rate, while that of PET is unaffected. Fourier transform infrared (FT-IR) analysis confirms that mechanism of surface modification may be due to oxidization reactions occurred on PVC surface. The optimum conditions are KMnO4 concentration 1.25 mM/L, treatment time 50 min, temperature 60°C, stirring rate 300 r/min, frother concentration 17.5 g/L and flotation time 1 min. PVC and PET with different particle sizes were separated efficiently through two-stage flotation. Additionally, after ultrasonic assisted surface modification, separation of PVC and PET with different mass ratios was obtained efficiently through one-stage flotation. The purity and the recovery of the obtained products after flotation separation are up to 99.30% and 99.73%, respectively. A flotation process was designed for flotation separation of PVC and PET plastics combined with surface modification. This study provides technical insights into physical separation of plastic wastes for recycling industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nanoparticle flotation collectors: mechanisms behind a new technology.

PubMed

Yang, Songtao; Pelton, Robert; Raegen, Adam; Montgomery, Miles; Dalnoki-Veress, Kari

2011-09-06

This is the first report describing a new technology where hydrophobic nanoparticles adsorb onto much larger, hydrophilic mineral particle surfaces to facilitate attachment to air bubbles in flotation. The adsorption of 46 nm cationic polystyrene nanoparticles onto 43 μm diameter glass beads, a mineral model, facilitates virtually complete removal of the beads by flotation. As little as 5% coverage of the bead surfaces with nanoparticles promotes high flotation efficiencies. The maximum force required to pull a glass bead from an air bubble interface into the aqueous phase was measured by micromechanics. The pull-off force was 1.9 μN for glass beads coated with nanoparticles, compared to 0.0086 μN for clean beads. The pull-off forces were modeled using Scheludko's classical expression. We propose that the bubble/bead contact area may not be dry (completely dewetted). Instead, for hydrophobic nanoparticles sitting on a hydrophilic surface, it is possible that only the nanoparticles penetrate the air/water interface to form a three-phase contact line. We present a new model for pull-off forces for such a wet contact patch between the bead and the air bubble. Contact angle measurements of both nanoparticle coated glass and smooth films from dissolved nanoparticles were performed to support the modeling. © 2011 American Chemical Society

Copper Recovery from Yulong Complex Copper Oxide Ore by Flotation and Magnetic Separation

NASA Astrophysics Data System (ADS)

Han, Junwei; Xiao, Jun; Qin, Wenqing; Chen, Daixiong; Liu, Wei

2017-09-01

A combined process of flotation and high-gradient magnetic separation was proposed to utilize Yulong complex copper oxide ore. The effects of particle size, activators, Na2S dosage, LA (a mixture of ammonium sulfate and ethylenediamine) dosage, activating time, collectors, COC (a combination collector of modified hydroxyl oxime acid and xanthate) dosage, and magnetic intensity on the copper recovery were investigated. The results showed that 74.08% Cu was recovered by flotation, while the average grade of the copper concentrates was 21.68%. Another 17.34% Cu was further recovered from the flotation tailing by magnetic separation at 0.8 T. The cumulative recovery of copper reached 91.42%. The modifier LA played a positive role in facilitating the sulfidation of copper oxide with Na2S, and the combined collector COC was better than other collectors for the copper flotation. This technology has been successfully applied to industrial production, and the results are consistent with the laboratory data.

Anisotropic surface physicochemical properties of spodumene and albite crystals: Implications for flotation separation

NASA Astrophysics Data System (ADS)

Xu, Longhua; Peng, Tiefeng; Tian, Jia; Lu, Zhongyuan; Hu, Yuehua; Sun, Wei

2017-12-01

Aluminosilicate minerals (e.g., spodumene, albite) have complex crystal structures and similar surface chemistries, but they have poor selectivity compared to traditional fatty acid collectors, making flotation separation difficult. Previous research has mainly considered the mineral crystal structure as a whole. In contrast, the surface characteristics at the atomic level and the effects of different crystal interfaces on the flotation behavior have rarely been investigated. This study focuses on investigating the surface anisotropy quantitatively, including the chemical bond characteristics, surface energies, and broken bond densities, using density functional theory and classical theoretical calculations. In addition, the anisotropy of the surface wettability and adsorption characteristics were examined using contact angle, zeta potential, and Fourier-transform infrared measurements. Finally, these surface anisotropies with different flotation behaviors were investigated and interpreted using molecular dynamics simulations, scanning electron microscopy, and X-ray photoelectron spectroscopy. This systematic research offers new ideas concerning the selective grinding and stage flotation of aluminosilicate minerals based on the crystal characteristics.

Removal of heavy metals from Missouri lead mill tailings by froth flotation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benn, F.W.; Cornell, W.L.

Froth flotation techniques to remove heavy metals (Pb, Cu, and Zn) from southeast Missouri lead mill tailings were investigated. It has been estimated that southeast Missouri contains between 200 and 300 million st of Pb tailings stored above ground. The tailings were classified as two distinct types: (1) pre-1968 tailings from the Old Lead Belt (some more than 100 years old) and (2) post-1968 tailings from the New Lead Belt. The objectives of the investigation were to reduce the Pb remaining in the tailings to < 500 ppm (< 0.05 pct Pb) and to attempt to recover a marketable concentratemore » to offset a portion of the remediation costs. The remaining dolomite-limestone would then be used as mining backfill or agricultural limestone. Bench-scale froth flotation removed, in percent, 95 Pb, 84 Cu, and 54 Zn, leaving 94 pct of the original weight containing, in parts per million, 400 Pb, 40 Cu, and 300 Zn from the Old Lead Belt tailings. Separate flotation tests also removed, in percent, 85 Pb, 84 Cu, and 80 Zn, leaving 75 pct of the original weight containing, in parts per million, 400 Pb, 200 Cu, and 500 Zn from the New Lead Belt tailings. Concentrates recovered from the Old Lead Belt were retreated to produce a final Pb concentrate containing 72 pct Pb with a cleaner flotation recovery of 79 pct. Froth flotation proved to be a viable method to remove the heavy metals.« less

The nature of hematite depression with corn starch in the reverse flotation of iron ore.

PubMed

Shrimali, Kaustubh; Atluri, Venkata; Wang, Yan; Bacchuwar, Sanket; Wang, Xuming; Miller, Jan D

2018-08-15

The function of corn starch and the significance of the order of addition of corn starch and mono ether amine in the reverse flotation of iron ore has been investigated. Understanding hematite depression with starch and the corresponding hydrophilic state involves consideration of adsorption with amine as well as flocculation of fine hematite. Captive bubble contact angle and micro-flotation experiments indicated that amine has an affinity towards both hematite and quartz, and that the role of starch is to hinder the adsorption of amine at the hematite surface so that flotation is inhibited. Micro-flotation results confirmed that quartz does not have affinity towards starch at pH 10.5. In addition to competitive adsorption, flocculation of fine hematite occurs and images from high resolution X-ray computed tomography (HRXCT) and cryo-SEM reveal further detail regarding floc structure. These results provide substantial evidence that the fine hematite particles are flocculated in the presence of corn starch, and flocculation is dependent on the particle size of hematite, with greater flocculation for finer particles. Thus, starch is playing a dual role in the reverse flotation of iron ore, acting as a depressant by hindering amine adsorption at the hematite surface in order to maintain the hydrophilic surface state of hematite, and acting as a flocculant to aggregate fine hematite particles, which if not flocculated, could diminish the flotation separation efficiency by being transported to the froth phase during reverse flotation. Copyright © 2018 Elsevier Inc. All rights reserved.

Characteristics of activated carbon produced from biosludge and its use in wastewater post-treatment.

PubMed

Pikkov, L; Kallas, J; Rüütmann, T; Rikmann, E

2001-02-01

Experimental research into the bench-scale production of activated carbon from waste-activated sludge from water purification, sawdust, peat, and their mixtures, by carbonisation and activation was undertaken. The research work was carried out to determine possible methods of production of cheap activated carbon from local raw materials and to use it in water purification technology. Along with the samples produced, several commercial activated carbons (namely RB-1, F 100, CA (adsorbent from military gas masks), BAY (product of the USSR)) were tested to compare adsorption properties in the adsorption of phenols, xylidines, amines, methylene blue and molasses. It has been found that the activated carbon produced from waste biosludge was of higher quality than that produced from either sawdust or peat, and performed similarly to RB-1 and F100 in adsorption tests. It was also determined that the activated carbon produced from biosludge could possibly be used in the post-treatment of wastewater. Residual sludge from the biological treatment of the wastewater from the purification of oil-shale in the chemical processing industry could cover up to 80% of the need for activated carbon. Some of this activated carbon could be used in the post-treatment of the same water, adsorbing polyalcaline phenols from the initial content of 4 mg l-1 to the demanded level of 1 mg l-1.

Flotation as a remediation technique for heavily polluted dredged material. 1. A feasibility study.

PubMed

Cauwenberg, P; Verdonckt, F; Maes, A

1998-01-19

The flotation behaviour of highly polluted dredged material was investigated at different pH values by mechanical agitated (Denver) flotation. Up to 80% of cadmium, copper, lead and zinc could be concentrated in the froth layer which represented only 30% of the total mass. The maximum specificity for heavy metals, defined as the concentrating factor, was obtained at pH 8-9. The maximum recovery of heavy metals on the other hand was found to be reached at elevated pH values (pH 12). In addition the specificity of the flotation process for the transition metals could be assigned to their presence as metal sulphides in the dredged material. However, the interaction with organic matter is an important factor in determining their flotability. The carbonate fraction was irrelevant for the flotation behaviour of heavy metals.

Surface-modified microbubbles (colloidal gas aphrons) for nanoparticle removal in a continuous bubble generation-flotation separation system.

PubMed

Zhang, Ming; Guiraud, Pascal

2017-12-01

The treatment of nanoparticle (NP) polluted aqueous suspensions by flotation can be problematic due to the low probability of collision between particles and bubbles. To overcome this limitation, the present work focuses on developing an enhanced flotation technique using the surface-functionalized microbubbles - colloidal gas aphrons (CGAs). The CGA generator was adapted to be air flow rate controlled based on the classical Sebba system; thus it could be well adopted in a continuous flotation process. Cetyl trimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) were employed for CGA creation. Positively surface-charged CTAB-CGAs (∼44.1 μm in size) and negatively surface-charged SDS-CGAs (∼42.1 μm in size) were produced at the optimum stirring speed of 8000 rpm. The half-life of CGAs varied from 100 s to 340 s under the tested conditions, which was largely sufficient for transferring CGAs from bubble generator to flotation cell. The air flow led to less stable CTAB-CGAs but apparently enhanced the stability of SDS-CGAs at higher air flow rates. In the presence of air flow, the drainage behavior was not much related to the type of surfactants. The continuous CGA-flotation trials highlighted the effective separation of silica nanoparticles - the removal efficiencies of different types of SiO 2 NPs could reach approximately 90%-99%; however, at equivalent surfactant concentrations, no greater than 58% of NPs were removed when surfactants and bubbles were separately added into the flotation cell. The SiO 2 NPs with small size were removed more efficiently by the CGA-flotation process. For the flotation with CTAB-CGAs, the neutral and basic initial SNP suspension was recommended, whereas the SDS-CGAs remained high flotation efficiency over all investigated pH. The good performance of CGA-flotation might be interpreted: most of the surfactant molecules well covered/coated on the surfaces of stable CGAs and thus fully contacted with NPs, resulting in

Oily wastewater treatment using a novel hybrid PBR-UASB system.

PubMed

Jeganathan, Jeganaesan; Nakhla, George; Bassi, Amarjeet

2007-04-01

In this study, anaerobic treatability of oily wastewater was investigated in a hybrid reactor system consisting of a packed bed reactor (PBR) followed by an upflow anaerobic sludge blanket (UASB) reactor at 35 degrees C. The system was operated using real pet food wastewater at different hydraulic retention times and loading rates for 165 d. The PBR was packed with sol-gel/alginate beads containing immobilized enzyme which hydrolyzed the oil and grease (O&G) into free long chain fatty acids, that were biodegraded by the UASB. The hybrid system was operated up to an oil loading rate of 4.9 kg O&Gm(-3)d(-1) (to the PBR) without any operational problems for a period of 100 d, with COD and O&G removal efficiencies above 90% and no sludge flotation was observed in the UASB. Beads supplement to the PBR was less than 2 g d(-1) and the relative activity was about 70%. Further increment in O&G loading to 18.7 kg O&Gm(-3)d(-1) caused destabilization of the system with 0.35% (v float/v feed) sludge float removed from the UASB.

Evaluation of constructed wetlands by wastewater purification ability and greenhouse gas emissions.

PubMed

Gui, P; Inamori, R; Matsumura, M; Inamori, Y

2007-01-01

Domestic wastewater is a significant source of nitrogen and phosphorus, which cause lake eutrophication. Among the wastewater treatment technologies, constructed wetlands are a promising low-cost means of treating point and diffuse sources of domestic wastewater in rural areas. However, the sustainable operation of constructed wetland treatment systems depends upon a high rate conversion of organic and nitrogenous loading into their metabolic gaseous end products, such as N2O and CH4. In this study, we examined and compared the performance of three typical types of constructed wetlands: Free Water Surface (FWS), Subsurface Flow (SF) and Vertical Flow (VF) wetlands. Pollutant removal efficiency and N2O and CH4 emissions were assessed as measures of performance. We found that the pollutant removal rates and gas emissions measured in the wetlands exhibited clear seasonal changes, and these changes were closely associated with plant growth. VF wetlands exhibited stable removal of organic pollutants and NH3-N throughout the experiment regardless of season and showed great potential for CH4 adsorption. SF wetlands showed preferable T-N removal performance and a lower risk of greenhouse gas emissions than FWS wetlands. Soil oxidation reduction potential (ORP) analysis revealed that water flow structure and plant growth influenced constructed wetland oxygen transfer, and these variations resulted in seasonal changes of ORP distribution inside wetlands that were accompanied by fluctuations in pollutant removal and greenhouse gas emissions.

Evaluation of High Rate Algae Ponds for treatment of anaerobically digested wastewater: Effect of CO2 addition and modification of dilution rate.

PubMed

de Godos, I; Arbib, Z; Lara, E; Rogalla, F

2016-11-01

High Rate Algae Ponds (HRAP) are the simplest way to grow microalgae biomass and an interesting alternative for wastewater treatment. In this work the performance of these systems was evaluated using anaerobically digested wastewater as culture medium. Two variables were studied in long-term mode: the carbon dioxide supply and the modification of the dilution rates. The results showed that CO2 supply increases the productivity but less than expected considering the potential biomass generation calculated based on the ratios of carbon to nitrogen of microalgae and wastewater. The assimilation into biomass only accounted for 57% of the inlet nitrogen under the best conditions because nitrification and volatilization reduced the availability of this element. The operation under short hydraulic retention times presented a more interesting performance with higher biomass productivities. The biomass produced was efficiently harvested with in a Dissolved Air Flotation (DAF) unit. Copyright © 2016 Elsevier Ltd. All rights reserved.

A new microcolumn flotation cell for determining the wettability and floatability of minerals.

PubMed

Ozkan, A; Yekeler, M

2003-05-15

Flotation is one of the most important physicochemical processes for mineral separations and other recovery operations. Flotation machines have been developed since the beginning of the 19th century and are still under intensive research and development. The cell we devised is a combination of the Canadian column flotation cell and the Partridge-Smith cell. The materials used for the construction of the new cell are cheap and use available laboratory accessories and aquarium materials. The cell functions well in terms of its scale, control, and sample requirement. It can be used both in the laboratory for research and in classrooms for demonstrations of experiments. Some of the data obtained by the flotation method using this cell are in good agreement with data measured independently on the same minerals by the contact angles method. The critical values of surface tension of wetting (gamma(c)) for talc, sulfur, and chemically treated surfaces of calcite and barite obtained by the contact angle measurements were 31, 26, 30.5, and 31.2 mN/m, respectively. On the other hand, the gamma(c) values of those minerals, obtained using our new designed flotation cell, were 30, 28, 31.4, and 34.5 mN/m, respectively. The measurements obtained in our experiment are also comparable to those previously published for the same minerals.

Alternative methods for flotation seat cushion use.

DOT National Transportation Integrated Search

1995-05-01

Alternative methods of using flotation seat cushions for water crash survivors were identified at the Civil Aeromedical Institute (CAMI). These methods, tested in the CAMI survival tank and a theme park wave pool, were: 1) two people facing each othe...

Flotation and flocculation chemistry of coal and oxidized coals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Somasundaran, P.

1990-01-01

The objective of this research project is to understand the fundamentals involved in the flotation and flocculation of coal and oxidized coals and elucidate mechanisms by which surface interactions between coal and various reagents enhance coal beneficiation. An understanding of the nature of the heterogeneity of coal surfaces arising from the intrinsic distribution of chemical moieties is fundamental to the elucidation of mechanism of coal surface modification and its role in interfacial processes such as flotation, flocculation and agglomeration. A new approach for determining the distribution in surface properties of coal particles was developed in this study and various techniquesmore » capable of providing such information were identified. Distributions in surface energy, contact angle and wettability were obtained using novel techniques such as centrifugal immersion and film flotation. Changes in these distributions upon oxidation and surface modifications were monitored and discussed. An approach to the modelling of coal surface site distributions based on thermodynamic information obtained from gas adsorption and immersion calorimetry is proposed. Polyacrylamide and dodecane was used to alter the coal surface. Methanol adsorption was also studied. 62 figs.« less

Improved GSO Optimized ESN Soft-Sensor Model of Flotation Process Based on Multisource Heterogeneous Information Fusion

PubMed Central

Wang, Jie-sheng; Han, Shuang; Shen, Na-na

2014-01-01

For predicting the key technology indicators (concentrate grade and tailings recovery rate) of flotation process, an echo state network (ESN) based fusion soft-sensor model optimized by the improved glowworm swarm optimization (GSO) algorithm is proposed. Firstly, the color feature (saturation and brightness) and texture features (angular second moment, sum entropy, inertia moment, etc.) based on grey-level co-occurrence matrix (GLCM) are adopted to describe the visual characteristics of the flotation froth image. Then the kernel principal component analysis (KPCA) method is used to reduce the dimensionality of the high-dimensional input vector composed by the flotation froth image characteristics and process datum and extracts the nonlinear principal components in order to reduce the ESN dimension and network complex. The ESN soft-sensor model of flotation process is optimized by the GSO algorithm with congestion factor. Simulation results show that the model has better generalization and prediction accuracy to meet the online soft-sensor requirements of the real-time control in the flotation process. PMID:24982935

Flotation removal of the microalga Nannochloropsis sp. using Moringa protein-oil emulsion: A novel green approach.

PubMed

Kandasamy, Ganesan; Shaleh, Sitti Raehanah Muhamad

2018-01-01

A new approach to recover microalgae from aqueous medium using a bio-flotation method is reported. The method involves utilizing a Moringa protein extract - oil emulsion (MPOE) for flotation removal of Nannochloropsis sp. The effect of various factors has been assessed using this method, including operating parameters such as pH, MPOE dose, algae concentration and mixing time. A maximum flotation efficiency of 86.5% was achieved without changing the pH condition of algal medium. Moreover, zeta potential analysis showed a marked difference in the zeta potential values when increase the MPOE dose concentration. An optimum condition of MPOE dosage of 50ml/L, pH 8, mixing time 4min, and a flotation efficiency of greater than 86% was accomplished. The morphology of algal flocs produced by protein-oil emulsion flocculant were characterized by microscopy. This flotation method is not only simple, but also an efficient method for harvesting microalgae from culture medium. Copyright © 2017 Elsevier Ltd. All rights reserved.

Statistical Evaluation and Optimization of Factors Affecting the Leaching Performance of Copper Flotation Waste

PubMed Central

Çoruh, Semra; Elevli, Sermin; Geyikçi, Feza

2012-01-01

Copper flotation waste is an industrial by-product material produced from the process of manufacturing copper. The main concern with respect to landfilling of copper flotation waste is the release of elements (e.g., salts and heavy metals) when in contact with water, that is, leaching. Copper flotation waste generally contains a significant amount of Cu together with trace elements of other toxic metals, such as Zn, Co, and Pb. The release of heavy metals into the environment has resulted in a number of environmental problems. The aim of this study is to investigate the leaching characteristics of copper flotation waste by use of the Box-Behnken experimental design approach. In order to obtain the optimized condition of leachability, a second-order model was examined. The best leaching conditions achieved were as follows: pH = 9, stirring time = 5 min, and temperature = 41.5°C. PMID:22629194

Statistical evaluation and optimization of factors affecting the leaching performance of copper flotation waste.

PubMed

Coruh, Semra; Elevli, Sermin; Geyikçi, Feza

2012-01-01

Copper flotation waste is an industrial by-product material produced from the process of manufacturing copper. The main concern with respect to landfilling of copper flotation waste is the release of elements (e.g., salts and heavy metals) when in contact with water, that is, leaching. Copper flotation waste generally contains a significant amount of Cu together with trace elements of other toxic metals, such as Zn, Co, and Pb. The release of heavy metals into the environment has resulted in a number of environmental problems. The aim of this study is to investigate the leaching characteristics of copper flotation waste by use of the Box-Behnken experimental design approach. In order to obtain the optimized condition of leachability, a second-order model was examined. The best leaching conditions achieved were as follows: pH = 9, stirring time = 5 min, and temperature = 41.5 °C.

Flotation of Heterocoagulated Particulates in Ulexite/SDS/Electrolyte System.

PubMed

Celik; Yasar; El-Shall

1998-07-15

Salt-type minerals can be usually floated with either anionic or cationic collectors. In a number of systems, flotation has been reported to remarkably increase above the concentrations where precipitation of the collector salt is initiated. Some studies attribute this phenomenon to heterocoagulation of oppositely charged colloidal precipitate and mineral particles. In this study, ulexite, a semisoluble boron mineral, in the presence of various multivalent ions, i.e. Ba2+, Mg2+, Ca2+, and Al3+, was found to exhibit excellent flotation even when particles, colloidal precipitates, and bubbles acquire a similar charge, which indicates that attractive structural forces exceed the forces of electrostatic repulsion. Copyright 1998 Academic Press.

Nonambulatory cows: Duration of recumbency and quality of nursing care affect outcome of flotation therapy.

PubMed

Stojkov, J; Weary, D M; von Keyserlingk, M A G

2016-03-01

Cows that are unable or unwilling to stand and remain recumbent for ≥ 12 h are defined as nonambulatory. Care and management of nonambulatory cattle is considered a major animal welfare concern facing the livestock industry, particularly the dairy sector. Flotation therapy has gained interest as a means to promote recovery in nonambulatory cows and is based on the concept that by floating the cow in warm water, secondary pressure damage to muscles and nerves will be reduced. The objective of this study was to assess the physiological responses to stress related to the flotation therapy and to evaluate the effect of recumbency duration and nursing care on the outcome of the flotation therapy. The outcomes of 34 nonambulatory Holstein dairy cows were analyzed after they were subjected to flotation therapy. The duration of recumbency and quality of nursing care provided before initiation of the flotation treatment were assessed based on producer responses to survey questions, and from on-site observations by the researchers. A veterinarian examined all cows before flotation therapy began. The treatment was divided into 5 phases: baseline (before filling), manipulation (placing the cow into the tank), filling (the tank was filled with water), flotation (the cow was confined in the filled tank), and draining (water was removed from the tank). Stress responses to the procedure, excluding the manipulation portion, were assessed using heart rate variability. The high-frequency component (HF normalized units) decreased during the filling and draining phases (2.8 ± 0.2 and 3.1 ± 0.4, respectively) compared with the baseline and floating phase (5.1 ± 0.6 and 4.9 ± 0.3, [corrected] respectively). These results indicate that the stress related to the flotation therapy is greatest during the filling and draining phases of the treatment, when cows likely have to exert increased effort to transition to a standing position. The flotation therapy was less likely to be

Synthesis of nanoparticle emulsion collector HNP and its application in microfine chalcopyrite flotation

NASA Astrophysics Data System (ADS)

He, G. C.; Ding, J.; Huang, C. H.; Kang, Q.

2018-01-01

Hydrophobic polystyrene nanoparticles bearing thiazole groups named HNP were used as collectors to improve recovery of microfine chalcopyrite in flotation. HNP adsorbs onto microfine particles selectively, which were modified hydrophobically to induce flotation effectively. Particle size and scanning electron microscope analysis for HNP show that HNP is a spherical nano particles with small size, uniform distribution and good dispersion. Infrared spectrum analysis for HNP proved that functional monomer 2-mercapto styrene acrylic thiazole was bonded chemically onto styrene. Flotation test results indicate that HNP is the right collector of chalcopyrite. Especially, the recovery of chalcopyrite is higher than 95% in neutral and acid media. FTIR results reveal that the flotation selectivity of collector HNP is due to strong chemical absorption onto chalcopyrite surface. Zeta potential analysis shows that the zeta potential of chalcopyrite decreased more quickly after interaction with HNP with the increase of pulp pH value, confirming that collector HNP is an anionic collector. Scanning electron microscope conform that HNP has good selective adsorption on chalcopyrite.

The Significance of Interfacial Water Structure in Soluble Salt Flotation Systems.

PubMed

Hancer, M.; Celik, M. S.; Miller, J. D.

2001-03-01

Flotation of soluble salts with dodecyl amine hydrochloride (DAH) and sodium dodecyl sulfate (SDS) collectors has demonstrated that the interfacial water structure and hydration states of soluble salt surfaces together with the precipitation tendency of the corresponding collector salts are of considerable importance in explaining their flotation behavior. In particular, the high concentration of ions in these soluble salt brines and their hydration appear to modify the bulk and interfacial structure of water as revealed by contact angle measurements and this effect is shown to be an important feature in the flotation chemistry of soluble salt minerals including alkali halide and alkali oxyanion salts. Depending on characteristic chemical features (salt type), the salt can serve either as a structure maker, in which intermolecular hydrogen bonding between water molecules is facilitated, or as a structure breaker, in which intermolecular hydrogen bonding between water molecules is disrupted. For structure making salts the brine completely wets the salt surface and no contact angle can be measured. For structure breaking salts the brine does not completely wet the salt surface and a finite contact angle is measured. In this regard it has been found that soluble salt flotation either with the cationic DAH or anionic SDS collector is possible only if the salt is a structure breaker. Copyright 2001 Academic Press.

A facile method to prepare dual-functional membrane for efficient oil removal and in situ reversible mercury ions adsorption from wastewater

NASA Astrophysics Data System (ADS)

Zhang, Qingdong; Liu, Na; Cao, Yingze; Zhang, Weifeng; Wei, Yen; Feng, Lin; Jiang, Lei

2018-03-01

In this work, a novel thiol covered polyamide (nylon 66) microfiltration membrane was fabricated by combining mussel-inspired chemistry and coupling reaction, which owns excellent dual-function that can simultaneously remove oil from water efficiently and adsorb the mercury ions contained in the wastewater reversibly. Such membrane exhibited high oil/water separation efficiency, outstanding mercury adsorption ability, and good stability. Moreover, it can be regenerated in nitric acid solution, and maintain its good adsorption performance. The as-prepared membrane showed great potentials for water purification to reduce the heavy metal ion pollution and complicated industrial oily wastewater and living wastewater.

Accuracy of egg flotation throughout incubation to determine embryo age and incubation day in waterbird nests

USGS Publications Warehouse

Ackerman, Joshua T.; Eagles-Smith, Collin A.

2010-01-01

Floating bird eggs to estimate their age is a widely used technique, but few studies have examined its accuracy throughout incubation. We assessed egg flotation for estimating hatch date, day of incubation, and the embryo's developmental age in eggs of the American Avocet (Recurvirostra americana), Black-necked Stilt (Himantopus mexicanus), and Forster's Tern (Sterna forsteri). Predicted hatch dates based on egg flotation during our first visit to a nest were highly correlated with actual hatch dates (r = 0.99) and accurate within 2.3 ± 1.7 (SD) days. Age estimates based on flotation were correlated with both day of incubation (r = 0.96) and the embryo's developmental age (r = 0.86) and accurate within 1.3 ± 1.6 days and 1.9 ± 1.6 days, respectively. However, the technique's accuracy varied substantially throughout incubation. Flotation overestimated the embryo's developmental age between 3 and 9 days, underestimated age between 12 and 21 days, and was most accurate between 0 and 3 days and 9 and 12 days. Age estimates based on egg flotation were generally accurate within 3 days until day 15 but later in incubation were biased progressively lower. Egg flotation was inaccurate and overestimated embryo age in abandoned nests (mean error: 7.5 ± 6.0 days). The embryo's developmental age and day of incubation were highly correlated (r = 0.94), differed by 2.1 ± 1.6 days, and resulted in similar assessments of the egg-flotation technique. Floating every egg in the clutch and refloating eggs at subsequent visits to a nest can refine age estimates.

Dynamic Membrane Technology for Printing Wastewater Reuse

NASA Astrophysics Data System (ADS)

Liu, Lin; Lu, Xujie; Chen, Jihua

As environmental regulations become rigid and the cost of freshwater increases, wastewater is considered as a major resource in China. The paper presented a study on the implementation of the advanced treatment process using dynamic membrane (DM) in reusing of printing wastewater. The DM was well formed by circulating 1.5g/L of PAC in 20 minutes, the trans-membrane pressure of 200 kPa and the cross-flow velocity of 0.75m/s. The printing effluents were treated in effluent treatment plants comprising a physicochemical option followed by biological process. The treated effluent contained chemical oxygen demand (COD), color and turbidity in the range of 45-60 mg/L, 0.030-0.045 (absorbance at 420 nm) and 3-5 NTU. The results showed that the COD, color and turbidity removal efficiencies of the DM permeate were 84%, 85% and 80%, respectively. The wastewater treated by DM was reused as process water and the final concentrated retentate could be discharged directly into sewage treatment works with no additional treatments. Cleaning and regeneration of DM were very convenient if necessary. The proper process was that the polluted DM was cleaned with tap water at high cross-flow velocity. When irreversible pollutants accumulate, it would be rinsed with chemicals tested and the membrane flux would be restored up to 95%. The result showed that DM was considered as a promising method for purification aimed at reuse of printing wastewater, resulting in direct environmental and economic benefits.

Reexamining the functions of zinc sulfate as a selective depressant in differential sulfide flotation--the role of coagulation.

PubMed

Cao, Mingli; Liu, Qi

2006-09-15

Zinc sulfate is a well-known selective depressant for zinc sulfide minerals such as sphalerite during the flotation of complex Cu-Pb-Zn sulfide ores. It deactivates sphalerite flotation by substituting the activating metal ions, and depresses sphalerite flotation by forming hydrophilic coatings of zinc hydroxyl species on sphalerite surfaces. However, we recently observed that zinc sulfate could also induce coagulation of fine sphalerite particles and such coagulation significantly reduced the mechanical entrainment of the fine sphalerite. Therefore, it seems that the effectiveness of zinc sulfate as a selective sphalerite depressant is not only due to its ability to make mineral surface hydrophilic, which reduces genuine flotation, but also due to its ability to coagulate the mineral, which reduces mechanical entrainment. Zinc sulfate is a "dual function" selective flotation depressant.

Modified flotation method with the use of Percoll for the detection of Isospora suis oocysts in suckling piglet faeces.

PubMed

Karamon, Jacek; Ziomko, Irena; Cencek, Tomasz; Sroka, Jacek

2008-10-01

The modification of flotation method for the examination of diarrhoeic piglet faeces for the detection of Isospora suis oocysts was elaborated. The method was based on removing fractions of fat from the sample of faeces by centrifugation with a 25% Percoll solution. The investigations were carried out in comparison to the McMaster method. From five variants of the Percoll flotation method, the best results were obtained when 2ml of flotation liquid per 1g of faeces were used. The limit of detection in the Percoll flotation method was 160 oocysts per 1g, and was better than with the McMaster method. The efficacy of the modified method was confirmed by results obtained in the examination of the I. suis infected piglets. From all faecal samples, positive samples in the Percoll flotation method were double the results than that of the routine method. Oocysts were first detected by the Percoll flotation method on day 4 post-invasion, i.e. one-day earlier than with the McMaster method. During the experiment (except for 3 days), the extensity of I. suis invasion in the litter examined by the Percoll flotation method was higher than that with the McMaster method. The obtained results show that the modified flotation method with the use of Percoll could be applied in the diagnostics of suckling piglet isosporosis.

Isolation and characterization of lost copper and molybdenum particles in the flotation tailings of Kennecott copper porphyry ores

NASA Astrophysics Data System (ADS)

Tserendavga, Tsend-Ayush

The importance of flotation separation has long been, and continues to be, an important technology for the mining industry, especially to metallurgical engineers. However, the flotation process is quite complex and expensive, in addition to being influenced by many variables. Understanding the variables affecting flotation efficiency and how valuable minerals are lost to the tailings gives metallurgists an advantage in their attempts to increase efficiency by designing operations to target the areas of greatest potential value. A successful, accurate evaluation of lost minerals in the tailings and appropriate solutions to improve flotation efficiency can save millions of dollars in the effective utilization of our mineral resources. In this dissertation research, an attempt has been made to understand the reasons for the loss of valuable mineral particles in the tailings from Kennecott Utah Copper ores. Possibilities include liberation, particle aggregation (slime coating) and surface chemistry issues associated with the flotation separation. This research generally consisted of three main aspects. The first part involved laboratory flotation experiments and factors, which affect the flotation efficiency. Results of flotation testing are reported that several factors such as mineral exposure/liberation and slime coating and surface oxidation strongly affect the flotation efficiency. The second part of this dissertation research was to develop a rapid scan dual energy (DE) methodology using 2D radiography to identify, isolate, and prepare lost sulfide mineral particles with the advantages of simple sample preparation, short analysis time, statistically reliable accuracy and confident identification. The third part of this dissertation research was concerned with detailed characterization of lost particles including such factors as liberation, slime coating, and surface chemistry characteristics using advanced analytical techniques and instruments. Based on the

[Complex technology for water and wastewater disinfection and its industrial realization in prototype unit].

PubMed

Arakcheev, E N; Brunman, V E; Brunman, M V; Konyashin, A V; Dyachenko, V A; Petkova, A P

Usage of complex automated electrolysis unit for drinking water disinfection and wastewater oxidation and coagulation is scoped, its ecological and energy efficiency is shown. Properties of technological process of anolyte production using membrane electrolysis of brine for water disinfection in municipal pipelines and potassium ferrate production using electrochemical dissolution of iron anode in NaOH solution for usage in purification plants are listed. Construction of modules of industrial prototype for anolyte and ferrate production and applied aspects of automation of complex electrolysis unit are proved. Results of approbation of electrolytic potassium ferrate for drinking water disinfection and wastewater, rain water and environmental water oxidation and coagulation are shown.

Comparison of the egg flotation and egg candling techniques for estimating incubation day of Canada Goose nests

USGS Publications Warehouse

Reiter, M.E.; Andersen, D.E.

2008-01-01

Both egg flotation and egg candling have been used to estimate incubation day (often termed nest age) in nesting birds, but little is known about the relative accuracy of these two techniques. We used both egg flotation and egg candling to estimate incubation day for Canada Geese (Branta canadensis interior) nesting near Cape Churchill, Manitoba, from 2000 to 2007. We modeled variation in the difference between estimates of incubation day using each technique as a function of true incubation day, as well as, variation in error rates with each technique as a function of the true incubation day. We also evaluated the effect of error in the estimated incubation day on estimates of daily survival rate (DSR) and nest success using simulations. The mean difference between concurrent estimates of incubation day based on egg flotation minus egg candling at the same nest was 0.85 ?? 0.06 (SE) days. The positive difference in favor of egg flotation and the magnitude of the difference in estimates of incubation day did not vary as a function of true incubation day. Overall, both egg flotation and egg candling overestimated incubation day early in incubation and underestimated incubation day later in incubation. The average difference between true hatch date and estimated hatch date did not differ from zero (days) for egg flotation, but egg candling overestimated true hatch date by about 1 d (true - estimated; days). Our simulations suggested that error associated with estimating the incubation day of nests and subsequently exposure days using either egg candling or egg flotation would have minimal effects on estimates of DSR and nest success. Although egg flotation was slightly less biased, both methods provided comparable and accurate estimates of incubation day and subsequent estimates of hatch date and nest success throughout the entire incubation period. ?? 2008 Association of Field Ornithologists.

77 FR 19937 - Inflatable Personal Flotation Devices

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-03

... Advancement Act OMB Office of Management and Budget PFD Personal flotation device STP Standards Technical... using existing inflatable PFDs, and would enable marketing of existing inflatable PFDs to youth. The... approved, and thus does not affect the availability, use, or marketing of existing PFDs to or by the youth...

Processing of metallurgical residues by flotation - bench-scale studies on two industrial products.

PubMed

Rao, S R; Finch, J A

2006-01-01

Resource recovery from two metallurgical residues by flotation was investigated applying an electrostatic model to select initial conditions. The first, a sulphation roast/water leach residue, was processed to float lead sulphate, comparing dodecylamine and xanthate collectors. From the second, a neutralization residue, gypsum, was recovered by reverse flotation of ferric hydroxide, comparing oleate and sulphonate collectors. In both cases, further upgrading by acid leaching was considered.

A review of factors that affect contact angle and implications for flotation practice.

PubMed

Chau, T T; Bruckard, W J; Koh, P T L; Nguyen, A V

2009-09-30

Contact angle and the wetting behaviour of solid particles are influenced by many physical and chemical factors such as surface roughness and heterogeneity as well as particle shape and size. A significant amount of effort has been invested in order to probe the correlation between these factors and surface wettability. Some of the key investigations reported in the literature are reviewed here. It is clear from the papers reviewed that, depending on many experimental conditions such as the size of the surface heterogeneities and asperities, surface cleanliness, and the resolution of measuring equipment and data interpretation, obtaining meaningful contact angle values is extremely difficult and such values are reliant on careful experimental control. Surface wetting behaviour depends on not only surface texture (roughness and particle shape), and surface chemistry (heterogeneity) but also on hydrodynamic conditions in the preparation route. The inability to distinguish the effects of each factor may be due to the interplay and/or overlap of two or more factors in each system. From this review, it was concluded that: Surface geometry (and surface roughness of different scales) can be used to tune the contact angle; with increasing surface roughness the apparent contact angle decreases for hydrophilic materials and increases for hydrophobic materials. For non-ideal surfaces, such as mineral surfaces in the flotation process, kinetics plays a more important role than thermodynamics in dictating wettability. Particle size encountered in flotation (10-200 microm) showed no significant effect on contact angle but has a strong effect on flotation rate constant. There is a lack of a rigid quantitative correlation between factors affecting wetting, wetting behaviour and contact angle on minerals; and hence their implication for flotation process. Specifically, universal correlation of contact angle to flotation recovery is still difficult to predict from first principles

Estimated water requirements for the conventional flotation of copper ores

USGS Publications Warehouse

Bleiwas, Donald I.

2012-01-01

This report provides a perspective on the amount of water used by a conventional copper flotation plant. Water is required for many activities at a mine-mill site, including ore production and beneficiation, dust and fire suppression, drinking and sanitation, and minesite reclamation. The water required to operate a flotation plant may outweigh all of the other uses of water at a mine site, [however,] and the need to maintain a water balance is critical for the plant to operate efficiently. Process water may be irretrievably lost or not immediately available for reuse in the beneficiation plant because it has been used in the production of backfill slurry from tailings to provide underground mine support; because it has been entrapped in the tailings stored in the TSF, evaporated from the TSF, or leaked from pipes and (or) the TSF; and because it has been retained as moisture in the concentrate. Water retained in the interstices of the tailings and the evaporation of water from the surface of the TSF are the two most significant contributors to water loss at a conventional flotation circuit facility.

Physical chemistry mechanisms of CDR system in sulphide mineral flotation

NASA Astrophysics Data System (ADS)

Pak, To-Hyon; Sun, Ti-Chang; Kou, Jue; Huang, Chol-Ryong

2012-03-01

The flotation tests, zeta potential measurements, and Fourier transform infrared spectroscopy (FTIR) analysis on galena, sphalerite, and pyrite were studied in a collecting-depressing-reactivating (CDR) system. In this system, sulphide minerals were first collected and activated by the collector, and then depressed strongly by Ca(OH)2 in a strong alkaline solution. Finally, they were reactivated by H2SO4. The flotation tests of pure minerals showed that in the Ca(OH)2 depressing process sulphide minerals had similar flotation characteristics because they had already been influenced by the collector. Hence, the flotability differences between them were reduced. However, in the H2SO4 reactivating process considerable differences in the flotability between galena and sphalerite/pyrite were produced. That is to say, galena was relatively easy to be reactivated by H2SO4, but sphalerite and pyrite were not reactivated at pH > 11. The zeta potentials of sulfide minerals measured by the Zeta Plus presented irreversible characteristics on the change of pH values. The results of the FTIR spectra analysis indicated that the collectors already adsorbed on the mineral surface were removed partially by Ca(OH)2.

Accuracy of egg flotation throughout incubation to determine embryo age and incubation day in water bird nests

USGS Publications Warehouse

Ackerman, Joshua T.; Eagles-Smith, Collin A.

2010-01-01

Floating bird eggs to estimate their age is a widely used technique, but few studies have examined its accuracy throughout incubation. We assessed egg flotation for estimating hatch date, day of incubation, and the embryo's developmental age in eggs of the American Avocet (Recurvirostra americana), Black-necked Stilt (Himantopus mexicanus), and Forster's Tern (Sterna forsteri). Predicted hatch dates based on egg flotation during our first visit to a nest were highly correlated with actual hatch dates (r = 0.99) and accurate within 2.3 ?? 1.7 (SD) days. Age estimates based on flotation were correlated with both day of incubation (r = 0.96) and the embryo's developmental age (r = 0.86) and accurate within 1.3 ?? 1.6 days and 1.9 ?? 1.6 days, respectively. However, the technique's accuracy varied substantially throughout incubation. Flotation overestimated the embryo's developmental age between 3 and 9 days, underestimated age between 12 and 21 days, and was most accurate between 0 and 3 days and 9 and 12 days. Age estimates based on egg flotation were generally accurate within 3 days until day 15 but later in incubation were biased progressively lower. Egg flotation was inaccurate and overestimated embryo age in abandoned nests (mean error: 7.5 ?? 6.0 days). The embryo's developmental age and day of incubation were highly correlated (r = 0.94), differed by 2.1 ?? 1.6 days, and resulted in similar assessments of the egg-flotation technique. Floating every egg in the clutch and refloating eggs at subsequent visits to a nest can refine age estimates. ?? The Cooper Ornithological Society 2010.

Seed flotation and germination of salt marsh plants: The effects of stratification, salinity, and/or inundation regime

USGS Publications Warehouse

Elsey-Quirk, T.; Middleton, B.A.; Proffitt, C.E.

2009-01-01

We examined the effects of cold stratification and salinity on seed flotation of eight salt marsh species. Four of the eight species were tested for germination success under different stratification, salinity, and flooding conditions. Species were separated into two groups, four species received wet stratification and four dry stratification and fresh seeds of all species were tested for flotation and germination. Fresh seeds of seven out of eight species had flotation times independent of salinity, six of which had average flotation times of at least 50 d. Seeds of Spartina alterniflora and Spartina patens had the shortest flotation times, averaging 24 and 26 d, respectively. Following wet stratification, the flotation time of S. alterniflora seeds in higher salinity water (15 and 36 ppt) was reduced by over 75% and germination declined by more than 90%. Wet stratification reduced the flotation time of Distichlis spicata seeds in fresh water but increased seed germination from 2 to 16% in a fluctuating inundation regime. Fresh seeds of Iva frutescens and S. alternflora were capable of germination and therefore are non-dormant during dispersal. Fresh seeds of I. frutescens had similar germination to dry stratified seeds ranging 25-30%. Salinity reduced seed germination for all species except for S. alterniflora. A fluctuating inundation regime was important for seed germination of the low marsh species and for germination following cold stratification. The conditions that resulted in seeds sinking faster were similar to the conditions that resulted in higher germination for two of four species. ?? 2009 Elsevier B.V.

Separation of polyethylene terephthalate from municipal waste plastics by froth flotation for recycling industry.

PubMed

Wang, Chong-Qing; Wang, Hui; Liu, You-Nian

2015-01-01

Recycling is an effective way to manage plastic wastes and receives considerable attention. Since plastic mixtures are difficult to recycle because of their intrinsic characteristics, separation of mixed plastics is the key problem for recycling. Separation of polyethylene terephthalate (PET) from municipal waste plastics (MWP) by froth flotation combined with alkaline pretreatment was investigated for recycling industry. The effect of process variables was estimated by L9 (3(4)) orthogonal array of experiments and single factor experiments. The optimum conditions of alkaline pretreatment are 10 wt% sodium hydroxide, 20 min and 70°C. After alkaline pretreatment under optimum conditions, flotation separation PET from acrylonitrile-butadiene-styrene, polystyrene, polycarbonate or polyvinyl chloride was achieved with high purity and efficiency. The purity of PET is up to 98.46% and the recovery is above 92.47%. A flow sheet of separation PET from MWP by a combination of froth flotation and sink float separation was designed. This study facilitates industrial application of plastics flotation and provides technical insights into recycling of waste plastics. Copyright © 2014 Elsevier Ltd. All rights reserved.

Pilot scale nanofiltration treatment of olive mill wastewater: a technical and economical evaluation.

PubMed

Sanches, S; Fraga, M C; Silva, N A; Nunes, P; Crespo, J G; Pereira, V J

2017-02-01

The treatment of large volumes of olive mill wastewater is presently a challenge. This study reports the technical and economical feasibility of a sequential treatment of olive mill wastewater comprising a dissolved air flotation pre-treatment and nanofiltration. Different pilot nanofiltration assays were conducted in a concentration mode up to different volume reduction factors (29, 45, 58, and 81). Data attained demonstrated that nanofiltration can be operated at considerably high volume reduction factors and still be effective towards the removal of several components. A flux decline of approximately 50% was observed at the highest volume reduction factor, mainly due to increase of the osmotic pressure. Considerably high rejections were obtained across all experiments for total suspended solids (83 to >99%), total organic carbon (64 to 99%), chemical oxygen demand (53 to 77%), and oil and grease (67 to >82%). Treated water was in compliance with European legal limits for discharge regarding total suspended solids and oil and grease. The potential recovery of phenolic compounds was evaluated and found not relevant. It was demonstrated that nanofiltration is economically feasible, involving operation costs of approximately 2.56-3.08 €/m 3 , depending on the working plan schedule and volume reduction factor, and requiring a footprint of approximately 52 m 2 to treat 1000 m 3 of olive mill wastewater.

Flotation of metal-loaded clay anion exchangers. Part II: the case of arsenates.

PubMed

Lazaridis, N K; Hourzemanoglou, A; Matis, K A

2002-04-01

Hydrotalcite-like materials, or otherwise termed layered double hydroxides, are clays with an ability to remove anions. As they usually are in powder form, these sorbents often present appreciable problems in the solid/liquid separation process following the sorption stage. Sorptive flotation of metal-loaded particles was investigated in this paper, as an alternative two-stage process. In the sorption process, satisfactory removals of arsenic(V) were obtained onto synthetic hydrotalcite particles from water. The effect of some parameters, like the solution ionic strength, concentrations, temperature, etc. was examined. During the second stage of the process, hydrotalcite fine particles were removed from the liquid phase by dispersed-air flotation; various surfactants were tested in relation to the ionic strength of the solution. The combined process of sorptive flotation provides promising results for arsenic removal.

Adsorption of bis(2-hydroxy-3-chloropropyl) dodecylamine on quartz surface and its implication on flotation

NASA Astrophysics Data System (ADS)

Liu, Wengang; Liu, Wenbao; Dai, Shujuan; Wang, Benying

2018-06-01

In order to clarify the effect of polar group modification on flotation performance of amine collector, flotation properties of quartz and hematite using bis(2-hydroxy-3-chloropropyl) dodecylamine (N23) as a collector were investigated. And the adsorption mechanism of N23 on quartz surface was established by zeta potential measurements, SEM/EDS measurements, and molecular structure analysis. Single mineral flotation results indicated that N23 showed stronger collecting ability on quartz and hematite than DDA-CH3COOH. However, starch could depress the flotation of hematite. Flotation recovery of 98.10% for quartz could be achieved, when N23 concentration was 43.33 mg/L and starch concentration was 16.67 mg/L at natural slurry pH. Separation of artificially mixed minerals of hematite and quartz was achieved effectively using N23 as the collector. The optimized separation result with 66.29% iron grade and 90.06% iron recovery in concentrate was obtained when slurry pH was 7.34 with 43.33 mg/L N23 and 23.33 mg/L starch. The interaction energies of N23 with mineral surface also showed well consistency with flotation results. SEM/EDS analyses and zeta potential measurements revealed that N23 could absorb on quartz surface in the forms of strong electrostatic and hydrogen bonding interaction. Compared with DDA, N23 had a higher HLB value and better water-solubility, which resulted in better dispersion in water and stronger adsorption on mineral surface.

Suppression of pyritic sulphur during flotation tests using the bacterium Thiobacillus ferrooxidans.

PubMed

Townsley, C C; Atkins, A S; Davis, A J

1987-07-01

Environmental concern about sulphur dioxide emissions has led to the examination of the possibility of removing pyritic sulphur from coal prior to combustion during froth flotation, a routine method for coal cleaning at the pit-head. The bacterium Thiobacillus ferrooxidans was effective in leaching 80% and 63% -53 mum pyrite at 2% and 6% pulp density in shake flasks in 240 and 340 h, respectively.The natural floatability of pyrite was significantly reduced in the Hallimond tube following 2.5 min of conditioning in membrane-filtered bacterial liquor prior to flotation. The suppression effect was greatly enhanced in the presence of Thiobacillus ferrooxidans. A bacterial suspension in pH 2.0 distilled water showed 85% suppression, whereas in spent growth liquor this value was 95%. The optimum bacterial density was 3.25 x 10(10) cells/g pyrite in 230-ml distilled water (2% pulp density) in the Hallimond tube. The degree of suppression by the cells was related to particle size but not to pH or temperature. The sulphur content of a synthetic coal/pyrite mixture was reduced from 10.9 to 2.1% by flotation after bacterial preconditioning. It is postulated that pyrite removal in coals which are cleaned by froth flotation could be significantly reduced using a bacterial preconditioning stage with a short residence time of 2.5 min.

Performance Modeling and Cost Analysis of a Pilot-Scale Reverse Osmosis Process for the Final Purification of Olive Mill Wastewater

PubMed Central

Ochando-Pulido, Javier Miguel; Hodaifa, Gassan; Victor-Ortega, Maria Dolores; Martinez-Ferez, Antonio

2013-01-01

A secondary treatment for olive mill wastewater coming from factories working with the two-phase olive oil production process (OMW-2) has been set-up on an industrial scale in an olive oil mill in the premises of Jaén (Spain). The secondary treatment comprises Fenton-like oxidation followed by flocculation-sedimentation and filtration through olive stones. In this work, performance modelization and preliminary cost analysis of a final reverse osmosis (RO) process was examined on pilot scale for ulterior purification of OMW-2 with the goal of closing the loop of the industrial production process. Reduction of concentration polarization on the RO membrane equal to 26.3% was provided upon increment of the turbulence over the membrane to values of Reynolds number equal to 2.6 × 104. Medium operating pressure (25 bar) should be chosen to achieve significant steady state permeate flux (21.1 L h−1 m−2) and minimize membrane fouling, ensuring less than 14.7% flux drop and up to 90% feed recovery. Under these conditions, irreversible fouling below 0.08 L h−2 m−2 bar−1 helped increase the longevity of the membrane and reduce the costs of the treatment. For 10 m3 day−1 OMW-2 on average, 47.4 m2 required membrane area and 0.87 € m−3 total costs for the RO process were estimated. PMID:24957058

Heterogeneity of the environmental regulation of industrial wastewater: European wineries.

PubMed

Román-Sánchez, Isabel M; Aznar-Sánchez, José A; Belmonte-Ureña, Luis J

2015-01-01

The European legislation of the pollution of industrial wastewater shows a high degree of heterogeneity. This fact implies that there is a market failure with relevant consequences. Within the European Union, each Member State performs a specific transposition of the Water Framework Directive 2000/60. The member states introduce different sanitation fees to correct water pollution. In this paper, the case of the European wine industry is analyzed. It studies the sanitation fees of the five major wine producing countries: France, Italy, Spain, Germany and Portugal. Results show significant differences among the wastewater fees and the study reveals how such heterogeneity leads to relevant market distortions. The research concludes that more homogeneous environmental regulation would promote more sustainable wine production processes with more efficient water management and purification systems, as well as the introduction of cutting edge technologies.

Enhanced sulfidation xanthate flotation of malachite using ammonium ions as activator.

PubMed

Wu, Dandan; Ma, Wenhui; Mao, Yingbo; Deng, Jiushuai; Wen, Shuming

2017-05-18

In this study, ammonium ion was used to enhance the sulfidation flotation of malachite. The effect of ammonium ion on the sulfidation flotation of malachite was investigated using microflotation test, inductively coupled plasma (ICP) analysis, zeta potential measurements, and scanning electron microscope analysis (SEM). The results of microflotation test show that the addition of sodium sulfide and ammonium sulfate resulted in better sulfidation than the addition of sodium sulfide alone. The results of ICP analysis indicate that the dissolution of enhanced sulfurized malachite surface is significantly decreased. Zeta potential measurements indicate that a smaller isoelectric point value and a large number of copper-sulfide films formed on the malachite surface by enhancing sulfidation resulted in a large amount of sodium butyl xanthate absorbed onto the enhanced sulfurized malachite surface. EDS semi-quantitative analysis and XPS analysis show that malachite was easily sulfurized by sodium sulfide with ammonium ion. These results show that the addition of ammonium ion plays a significant role in the sulfidation of malachite and results in improved flotation performance.

Flotability and flotation separation of polymer materials modulated by wetting agents.

PubMed

Wang, Hui; Wang, Chong-qing; Fu, Jian-gang; Gu, Guo-hua

2014-02-01

The surface free energy, surface tension and contact angles were performed to investigate the properties of wetting agents. Adsorption of wetting agents changes wetting behavior of polymer resins. Flotability of polymer materials modulated by wetting agents was studied, and wetting agents change significantly flotability of polymer materials. The flotability decreases with increasing the concentration of wetting agents, and the wetting ability is lignin sulfonate (LS)>tannic acid (TA)>methylcellulose (MC)>triton X-100 (TX-100) (from strong to weak). There is significant difference in the flotability between polymer resins and plastics due to the presence of additives in the plastics. Flotation separation of two-component and multicomponent plastics was conducted based on the flotability modulated by wetting agents. The two-component mixtures can be efficiently separated using proper wetting agent through simple flotation flowsheet. The multicomponent plastic mixtures can be separated efficiently through multi-stage flotation using TA and LS as wetting agents, and the purity of separated component was above 94%, and the recovery was more than 93%. Copyright © 2013 Elsevier Ltd. All rights reserved.

A novel process for separation of hazardous poly(vinyl chloride) from mixed plastic wastes by froth flotation.

PubMed

Wang, Jianchao; Wang, Hui; Wang, Chongqing; Zhang, Lingling; Wang, Tao; Zheng, Long

2017-11-01

A novel method, calcium hypochlorite (CHC) treatment, was proposed for separation of hazardous poly(vinyl chloride) (PVC) plastic from mixed plastic wastes (MPWs) by froth flotation. Flotation behavior of single plastic indicates that PVC can be separated from poly(ethylene terephthalate) (PET), poly(acrylonitrile-co-butadiene-co-styrene) (ABS), polystyrene (PS), polycarbonate (PC) and poly(methyl methacrylate) (PMMA) by froth flotation combined with CHC treatment. Mechanism of CHC treatment was examined by contact angle measurement, scanning electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopy. Under the optimum conditions, separation of PVC from binary plastics with different particle sizes is achieved efficiently. The purity of PC, ABS, PMMA, PS and PET is greater than 96.8%, 98.5%, 98.8%, 97.4% and 96.3%, respectively. Separation of PVC from multi-plastics was further conducted by two-stage flotation. PVC can be separated efficiently from MPWs with residue content of 0.37%. Additionally, reusing CHC solution is practical. This work indicates that separation of hazardous PVC from MPWs is effective by froth flotation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Flotation and Survival Equipment Studies

DTIC Science & Technology

1978-01-01

the hearing of Lhe latter ditching that he saw no reason to have expected any loss of life with the two exceptions that did occur: failure of life...jackets to inflate and loss of six infants. It is the purpose of this paper to examine the requirements of infant and small-child flotation devices and...surface area immersed, one may crudely estimate the heat loss due to Newtonian cooling at 3 kcal per °C. The total basal heat productivity of a 2

Improved Flotation Technique for Microscopy of In Situ Soil and Sediment Microorganisms

PubMed Central

Bone, T. L.; Balkwill, D. L.

1986-01-01

An improved flotation method for microscopy of in situ soil and sediment microorganisms was developed. Microbial cells were released into gellike flotation films that were stripped from soil and sediment aggregates as these aggregates were submerged in 0.5% solutions of polyvinylpyrrolidone. The use of polyvinylpyrrolidone solutions instead of water facilitated the release of films from saturated samples such as aquifer sediments as well as from typical surface soils. In situ microbial morphological characteristics could then be surveyed rapidly by light microscopy of films stained with acridine orange. This method effectively determined the ranges of morphological diversity in a variety of sample types. It also detected microcolonies and other spatial relationships among microbial cells. Only a small fraction (3.4 to 10.1%) of the microflora was released into the flotation films, but plating and direct evaluations by microscopy showed that this fraction was representative of the total population. Images PMID:16347005

The impact of bacteria of circulating water on apatite-nepheline ore flotation.

PubMed

Evdokimova, G A; Gershenkop, A Sh; Fokina, N V

2012-01-01

A new phenomenon has been identified and studied-the impact of bacteria on the benefication process of non-sulphide ores using circulating water supply-a case study of apatite-nepheline ore. It is shown that bacteria deteriorate the floatability of apatite due to their interaction with active centres of calcium-containing minerals and intense flocculation, resulting in a decrease of the flotation process selectivity thus deteriorating the quality of concentrate. Based on the comparative analysis of primary sequences of 16S rRNA genes, there have been identified dominating bacteria species, recovered from the circulating water used at apatite-nepheline concentrating mills, and their phylogenetic position has been determined. All the bacteria were related to γ-Proteobacteria, including the Acinetobacter species, Pseudomonas alcaliphila, Ps. plecoglossicida, Stenotrophomonas rhizophila. A method of non-sulphide ores flotation has been developed with consideration of the bacterial factor. It consists in use of small concentrations of sodium hypochlorite, which inhibits the development of bacteria in the flotation of apatite-nepheline ores.

Separation of packaging plastics by froth flotation in a continuous pilot plant.

PubMed

Carvalho, Teresa; Durão, Fernando; Ferreira, Célia

2010-11-01

The objective of the research was to apply froth flotation to separate post-consumer PET (Polyethylene Terephthalate) from other packaging plastics with similar density, in a continuously operated pilot plant. A representative sample composed of 85% PET, 2.5% PVC (Polyvinyl Chloride) and 11.9% PS (Polystyrene) was subjected to a combination of alkaline treatment and surfactant adsorption followed by froth flotation. A mineral processing pilot plant, owned by a Portuguese mining company, was adapted for this purpose. The experimentation showed that it is possible to produce an almost pure concentrate of PET, containing 83% of the PET in feed, in a single bank of mechanical flotation cells. The concentrate grade attained was 97.2% PET, 1.1% PVC and 1.1% PS. By simulation it was shown that the Portuguese recycling industry specifications can be attained if one cleaning and one scavenger stages are added to the circuit. Copyright © 2010 Elsevier Ltd. All rights reserved.

Peracetic acid (PAA) disinfection of primary, secondary and tertiary treated municipal wastewaters.

PubMed

Koivunen, J; Heinonen-Tanski, H

2005-11-01

The efficiency of peracetic acid (PAA) disinfection against enteric bacteria and viruses in municipal wastewaters was studied in pilot-scale. Disinfection pilot-plant was fed with the primary or secondary effluent of Kuopio municipal wastewater treatment plant or tertiary effluent from the pilot-scale dissolved air flotation (DAF) unit. Disinfectant doses ranged from 2 to 7 mg/l PAA in the secondary and tertiary effluents, and from 5 to 15 mg/l PAA in the primary effluents. Disinfection contact times were 4-27 min. Disinfection of secondary and tertiary effluents with 2-7 mg/l PAA and 27 min contact time achieved around 3 log reductions of total coliforms (TC) and enterococci (EC). PAA disinfection also significantly improved the hygienic quality of the primary effluents: 10-15 mg/l PAA achieved 3-4 log reductions of TC and EC, 5 mg/l PAA resulting in below 2 log reductions. F-RNA coliphages were more resistant against the PAA disinfection and around 1 log reductions of these enteric viruses were typically achieved in the disinfection treatments of the primary, secondary and tertiary effluents. Most of the microbial reductions occurred during the first 4-18 min of contact time, depending on the PAA dose and microorganism. The PAA disinfection efficiency remained relatively constant in the secondary and tertiary effluents, despite of small changes of wastewater quality (COD, SS, turbidity, 253.7 nm transmittance) or temperature. The disinfection efficiency clearly decreased in the primary effluents with substantially higher microbial, organic matter and suspended solids concentrations. The results demonstrated that PAA could be a good alternative disinfection method for elimination of enteric microbes from different wastewaters.

Optimized conditions for selective gold flotation by ToF-SIMS and ToF-LIMS

NASA Astrophysics Data System (ADS)

Chryssoulis, S. L.; Dimov, S. S.

2004-06-01

This work describes a comprehensive characterization of the factors controlling the floatability of free gold from flotation test using reagents (collectors) at plant concentration levels. A relationship between the collectors loadings on gold particles and their surface composition has been established. The findings of this study show that silver activates gold flotation and there is a strong correlation between the surface concentration of silver and the loading of certain collectors. The organic surface analysis was done by ToF-SIMS while the inorganic surface analysis was carried out by time-of-flight laser ionization mass spectrometry (ToF-LIMS). The developed testing protocol based on ToF-LIMS and ToF-SIMS complementary surface analysis allows for optimization of the flotation scheme and hence improved gold recovery.

Anglesite and silver recovery from jarosite residues through roasting and sulfidization-flotation in zinc hydrometallurgy.

PubMed

Han, Haisheng; Sun, Wei; Hu, Yuehua; Jia, Baoliang; Tang, Honghu

2014-08-15

Hazardous jarosite residues contain abundant valuable minerals that are difficult to be recovered by traditional flotation process. This study presents a new route, roasting combined with sulfidization-flotation, for the recovery of anglesite and silver from jarosite residues of zinc hydrometallurgy. Surface appearance and elemental distribution of jarosite residues was examined by scanning electron microscopy and energy dispersive X-ray spectrometry analysis, respectively. Decomposition and transformation mechanisms of jarosite residues were illustrated by differential thermal analysis. Results showed that after roasting combined with flotation, the grade and recovery of lead were 43.89% and 66.86%, respectively, and those of silver were 1.3 kg/t and 81.60%, respectively. At 600-700 °C, jarosite was decomposed to release encapsulated valuable minerals such as anglesite (PbSO4) and silver mineral; silver jarosite decomposed into silver sulfate (Ag2SO4); and zinc ferrite (ZnO · Fe2O3) decomposed into zinc sulfate (ZnSO4) and hematite (Fe2O3). Bared anglesite and silver minerals were modified by sodium sulfide and easily collected by flotation collectors. This study demonstrates that the combination of roasting and sulfidization-flotation provides a promising process for the recovery of zinc, lead, and silver from jarosite residues of zinc hydrometallurgy. Copyright © 2014 Elsevier B.V. All rights reserved.

Bacteria Provide Cleanup of Oil Spills, Wastewater

NASA Technical Reports Server (NTRS)

2010-01-01

Through Small Business Innovation Research (SBIR) contracts with Marshall Space Flight Center, Micro-Bac International Inc., of Round Rock, Texas, developed a phototrophic cell for water purification in space. Inside the cell: millions of photosynthetic bacteria. Micro-Bac proceeded to commercialize the bacterial formulation it developed for the SBIR project. The formulation is now used for the remediation of wastewater systems and waste from livestock farms and food manufacturers. Strains of the SBIR-derived bacteria also feature in microbial solutions that treat environmentally damaging oil spills, such as that resulting from the catastrophic 2010 Deepwater Horizon oil rig explosion in the Gulf of Mexico.

Application of cellulose nanofibers to remove water-based flexographic inks from wastewaters.

PubMed

Balea, Ana; Monte, M Concepción; de la Fuente, Elena; Negro, Carlos; Blanco, Ángeles

2017-02-01

Water-based or flexographic inks in paper and plastic industries are more environmentally favourable than organic solvent-based inks. However, their use also creates new challenges because they remain dissolved in water and alter the recycling process. Conventional deinking technologies such as flotation processes do not effectively remove them. Adsorption, coagulation/flocculation, biological and membrane processes are either expensive or have negative health impacts, making the development of alternative methods necessary. Cellulose nanofibers (CNF) are biodegradable, and their structural and mechanical properties are useful for wastewater treatment. TEMPO-oxidised CNF have been evaluated for the decolourisation of wastewaters that contained copper phthalocyanine blue, carbon black and diarlyide yellow pigments. CNF in combination with a cationic polyacrylamide (cPAM) has also been tested. Jar-test methodology was used to evaluate the efficiency of the different treatments and cationic/anionic demand, turbidity and ink concentration in waters were measured. Results show that dual-component system for ink removal has a high potential as an alternative bio-based adsorbent for the removal of water-based inks. In addition, experiments varying CNF and cPAM concentrations were performed to optimise the ink-removal process. Ink concentration reductions of 100%, 87.5% and 83.3% were achieved for copper phthalocyanine blue, carbon black and diarlyide yellow pigments, respectively. Flocculation studies carried out show the decolourisation mechanism during the dual-component treatment of wastewaters containing water-based inks.

Design and function of biomimetic multilayer water purification membranes

PubMed Central

Ling, Shengjie; Qin, Zhao; Huang, Wenwen; Cao, Sufeng; Kaplan, David L.; Buehler, Markus J.

2017-01-01

Multilayer architectures in water purification membranes enable increased water throughput, high filter efficiency, and high molecular loading capacity. However, the preparation of membranes with well-organized multilayer structures, starting from the nanoscale to maximize filtration efficiency, remains a challenge. We report a complete strategy to fully realize a novel biomaterial-based multilayer nanoporous membrane via the integration of computational simulation and experimental fabrication. Our comparative computational simulations, based on coarse-grained models of protein nanofibrils and mineral plates, reveal that the multilayer structure can only form with weak interactions between nanofibrils and mineral plates. We demonstrate experimentally that silk nanofibril (SNF) and hydroxyapatite (HAP) can be used to fabricate highly ordered multilayer membranes with nanoporous features by combining protein self-assembly and in situ biomineralization. The production is optimized to be a simple and highly repeatable process that does not require sophisticated equipment and is suitable for scaled production of low-cost water purification membranes. These membranes not only show ultrafast water penetration but also exhibit broad utility and high efficiency of removal and even reuse (in some cases) of contaminants, including heavy metal ions, dyes, proteins, and other nanoparticles in water. Our biomimetic design and synthesis of these functional SNF/HAP materials have established a paradigm that could lead to the large-scale, low-cost production of multilayer materials with broad spectrum and efficiency for water purification, with applications in wastewater treatment, biomedicine, food industry, and the life sciences. PMID:28435877

Design and function of biomimetic multilayer water purification membranes.

PubMed

Ling, Shengjie; Qin, Zhao; Huang, Wenwen; Cao, Sufeng; Kaplan, David L; Buehler, Markus J

2017-04-01

Multilayer architectures in water purification membranes enable increased water throughput, high filter efficiency, and high molecular loading capacity. However, the preparation of membranes with well-organized multilayer structures, starting from the nanoscale to maximize filtration efficiency, remains a challenge. We report a complete strategy to fully realize a novel biomaterial-based multilayer nanoporous membrane via the integration of computational simulation and experimental fabrication. Our comparative computational simulations, based on coarse-grained models of protein nanofibrils and mineral plates, reveal that the multilayer structure can only form with weak interactions between nanofibrils and mineral plates. We demonstrate experimentally that silk nanofibril (SNF) and hydroxyapatite (HAP) can be used to fabricate highly ordered multilayer membranes with nanoporous features by combining protein self-assembly and in situ biomineralization. The production is optimized to be a simple and highly repeatable process that does not require sophisticated equipment and is suitable for scaled production of low-cost water purification membranes. These membranes not only show ultrafast water penetration but also exhibit broad utility and high efficiency of removal and even reuse (in some cases) of contaminants, including heavy metal ions, dyes, proteins, and other nanoparticles in water. Our biomimetic design and synthesis of these functional SNF/HAP materials have established a paradigm that could lead to the large-scale, low-cost production of multilayer materials with broad spectrum and efficiency for water purification, with applications in wastewater treatment, biomedicine, food industry, and the life sciences.

Polishing Step Purification of High-Strength Wastewaters by Nanofiltration and Reverse Osmosis

PubMed Central

Zhou, Jinxiang; Baker, Brian O.; Grimsley, Charles T.; Husson, Scott M.

2016-01-01

This article reports findings on the use of nanofiltration (NF) and reverse osmosis (RO) for secondary treatment of high-strength rendering facility wastewaters following an ultrafiltration step. These wastewaters present significant challenges to classical treatment technologies. Constant-pressure, direct-flow membrane filtration experiments were done to screen for flux and effluent water permeate quality of ten commercial NF and RO membranes. All membranes tested were effective in reducing total dissolved salts (TDS) and chemical oxygen demand (COD); however, only two membranes (Koch MPF-34 and Toray 70UB) gave sufficiently stable flux values to warrant longer term cross-flow filtration studies. Cross-flow flux measurements, scanning electron microscopy (SEM), X-ray dispersive spectroscopy (EDS), and attenuated total reflectance-Fourier-transform infrared spectroscopy (ATR-FTIR) indicated that both membranes were eventually fouled by organic and inorganic foulants; however, the Toray 70UB RO membrane yielded a capacity of 1600 L/m2 prior to cleaning. A preliminary economic analysis compared the estimated costs of energy and consumables for a dual-stage UF/RO membrane process and dissolved air floatation (DAF) and found membrane process costs could be less than about 40% of the current DAF process. PMID:26978407

Surface chemistry control for selective fossil resin flotation

DOEpatents

Miller, Jan D.; Yi, Ye; Yu, Qiang

1994-01-01

A froth flotation method is disclosed for separating fine particles of fossil resin from by use of frothing reagents which include an aliphatic organic compound having a polar group and containing not more than four carbon atoms. Butanol is an effective frothing reagent in this method.

Surface chemistry control for selective fossil resin flotation

DOEpatents

Miller, J.D.; Yi, Y.; Yu, Q.

1994-06-07

A froth flotation method is disclosed for separating fine particles of fossil resin by use of frothing reagents which include an aliphatic organic compound having a polar group and containing not more than four carbon atoms. Butanol is an effective frothing reagent in this method. 12 figs.

21 CFR 890.5170 - Powered flotation therapy bed.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Powered flotation therapy bed. 890.5170 Section 890.5170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5170...

21 CFR 890.5170 - Powered flotation therapy bed.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Powered flotation therapy bed. 890.5170 Section 890.5170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5170...

21 CFR 890.5170 - Powered flotation therapy bed.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Powered flotation therapy bed. 890.5170 Section 890.5170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5170...

21 CFR 890.5170 - Powered flotation therapy bed.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Powered flotation therapy bed. 890.5170 Section 890.5170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5170...

21 CFR 890.5170 - Powered flotation therapy bed.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered flotation therapy bed. 890.5170 Section 890.5170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5170...

[Study on the determination of trace Cu and Mn in foodstuff preconcentration by precipitate flotation and FAAS].

PubMed

Li, Chun-xiang; Chen, Ting-yu; Yan, Yong-sheng

2007-10-01

In the present paper, the use of 8-hydroxyquinoline(oxine, HQ) complexs in precipitate flotation to separate and preconcentrate Cu and Mn, using SDBS as collector, followed by AAS spectrophotometric determination is proposed. The optimum conditions of precipitate flotation were studied. The effects of several parameters of flotation processes condition on single metal ions precipitation-flotation and multi-metal ions coprecipitation-flotation of Cu and Mn at pH 9 were investigated. The experimental results show that the flotation rate of Cu is supreme with pH 9. Under the condition of pH 9 and changing the ratio of concentration, when Mn/Cu> or =8, the recovery rate of Cu is less than 90%. This method is simple, rapid, accurate, sensitive and precise and avoids using the virulent organic solvent. The linear range of Cu is 0.5-5.0 microg x mL(-1) with the correlative coefficient of 0.9996, detection limit of this method was found to be 1.59 x 10(-3) microg x mL(-1), the linear range of Mn is 0.5-5.0 microg x mL(-1) with the correlative coefficient of 0.9987, and the detection limit of this method was found to be 3.52 x 10(-3) microg x mL(-1). The method was applied to the determination of Cu and Mn in foodstuff, and the recovery is 87.6%-100.7%. The result was satisfactory.

Inclusion flotation-driven channel segregation in solidifying steels

PubMed Central

Li, Dianzhong; Chen, Xing-Qiu; Fu, Paixian; Ma, Xiaoping; Liu, Hongwei; Chen, Yun; Cao, Yanfei; Luan, Yikun; Li, Yiyi

2014-01-01

Channel segregation, which is featured by the strip-like shape with compositional variation in cast materials due to density contrast-induced flow during solidification, frequently causes the severe destruction of homogeneity and some fatal damage. An investigation of its mechanism sheds light on the understanding and control of the channel segregation formation in solidifying metals, such as steels. Until now, it still remains controversial what composes the density contrasts and, to what extent, how it affects channel segregation. Here we discover a new force of inclusion flotation that drives the occurrence of channel segregation. It originates from oxide-based inclusions (Al2O3/MnS) and their sufficient volume fraction-driven flotation becomes stronger than the traditionally recognized inter-dendritic thermosolutal buoyancy, inducing the destabilization of the mushy zone and dominating the formation of channels. This study uncovers the mystery of oxygen in steels, extends the classical macro-segregation theory and highlights a significant technological breakthrough to control macrosegregation. PMID:25422943

Froth conductivity for in situ monitoring of fiber (solid) and wet rejects in flotation deinking

Treesearch

J. Y. Zhu; M. Fleischmann; R. Gleisner

2006-01-01

Reduced fiber rejection in flotation deinking is very important to reduce the cost of secondary fibers in paper recycling and to conserve natural resources. Online monitoring of fiber rejection is a prerequisite to achieving process control for the reduction of fiber rejection in flotation deinking. It also can improve understanding of the effects of various operating...

Study of reverse flotation of calcite from scheelite in acidic media

NASA Astrophysics Data System (ADS)

Deng, Rongdong; Huang, Yuqing; Hu, Yuan; Ku, Jiangang; Zuo, Weiran; Yin, Wanzhong

2018-05-01

A new coated-reactive reverse flotation method based on the generation of CO2 bubbles at a calcite surface in acidic solution was used to separate calcite from scheelite. The dissolution kinetics of coated and uncoated calcite were studied in sulfuric acid. The CO2 bubbles generated on the uncoated calcite particle surface are enough to float the particle. However, most of these bubbles left the surface quickly, preventing calcite from floating. Here, a mixture of polyvinyl alcohol polymer and sodium dodecyl sulfonate was used to coat the mineral particles and form a stable membrane, resulting in the formation of a stable foam layer on the calcite surface. After the calcite is coated, the generated bubbles could be successfully captured on the calcite surface, and calcite particles could float to the air-water interface and remain there for more than one hour. Flotation tests indicated that a high-quality tungsten concentrate with a grade of more than 75% and a recovery of more than 99% could be achieved when the particle size was between 0.3 and 1.5 mm. The present results provide theoretical support for the development of a highly efficient flotation separation for carbonate minerals.

Molecular dynamics simulation of siderite-hematite-quartz flotation with sodium oleate

NASA Astrophysics Data System (ADS)

Li, Lixia; Hao, Haiqing; Yuan, Zhitao; Liu, Jiongtian

2017-10-01

Models of sodium oleate adsorption on siderite, hematite and quartz were investigated by molecular dynamic simulation, respectively. Surface energy was calculated to confirm the cleavage plan of hematite and quartz. Both natural cleavage plane of siderite and calculated plane were used to investigate the flotation of the three minerals. Based on the molecular simulation in solution with water as medium, adsorption quantity and interaction capability of oleate ions on the three minerals indicated that siderite could be collected efficiently by sodium oleate at neutral pH. Results of flotation experiments were further demonstrated by analysis of relative concentration of carbon atoms and oxygen atoms.

Oxidative Pressure Leaching of Silver from Flotation Concentrates with Ammonium Thiocyanate Solution

NASA Astrophysics Data System (ADS)

Yang, Sheng-Hai; Yang, Jian-Guang; Liu, Wei; Chen, Geng-Tao; Tang, Mo-Tang; Qiu, Guan-Zhou

2010-02-01

The thermodynamics and technologies of the selective pressure leaching of silver from flotation concentrates were investigated in an ammonium thiocyanate medium. Thermodynamic analyses, which include silver solubility in NH4SCN solution and Eh-pH diagrams of the Me-MeS-NH4SCN-H2O system at 25 °C, were discussed. The effects of several factors, such as temperature, leaching time, oxidant, pH value, flotation concentrates concentration, surfactant concentration, and so on, on the extraction percentages of silver and zinc were investigated. The following optimal leaching conditions were obtained: NH4SCN concentration 1.5 M, lignin concentration 0.5 g/L, Fe3+ concentration 2 g/L, flotation concentrates addition 200 g/L, and oxygen pressure 1.2 MPa at 130 °C for 3 hours. Under these optimum conditions, the average extraction percentage of silver exceeded 94 pct, whereas the average extraction percentage of zinc was less than 3 pct. Only 7 pct of ammonium thiocyanate was consumed after 4 cycles, which indicated that ammonium thiocyanate hardly was oxidized under these oxidative pressure leaching conditions.

[Concordance between the zinc sulphate flotation and centrifugal sedimentation methods for the diagnosis of intestinal parasites].

PubMed

Inês, Elizabete De Jesus; Pacheco, Flavia Thamiris Figueiredo; Pinto, Milena Carneiro; Mendes, Patrícia Silva de Almeida; Da Costa-Ribeiro, Hugo; Soares, Neci Matos; Teixeira, Márcia Cristina Aquino

2016-12-01

The diagnosis of intestinal parasitic infections depends on the parasite load, the specific gravity density of the parasite eggs, oocysts or cysts, and the density and viscosity of flotation or sedimentation medium where faeces are processed. To evaluate the concordance between zinc sulphate flotation and centrifugal sedimentation in the recovery of parasites in faecal samples of children. Faecal samples of 330 children from day care centers were evaluated by zinc sulphate flotation and centrifugal sedimentation techniques. The frequencies of detection of parasites by each method were determined and the agreement between the diagnostic techniques was evaluated using the kappa index, with 95% confidence intervals. The faecal flotation in zinc sulphate diagnosed significantly more cases of Trichuris trichiura infection when compared to centrifugal sedimentation (39/330; 11.8% vs. 13/330; 3.9%, p<0.001), with low diagnostic concordance between methods (kappa=0.264; 95% CI: 0.102-0.427). Moreover, all positive samples for Enterobius vermicularis eggs (n=5) and Strongyloides stercoralis larvae (n=3) were diagnosed only by zinc sulphate. No statistical differences were observed between methods for protozoa identification. The results showed that centrifugal flotation in zinc sulphate solution was significantly more likely to detect light helminths eggs such as those of T. trichiura and E. vermicularis in faeces than the centrifugal sedimentation process.

The Adsorption Capacity of GONs/CMC/Fe₃O₄ Magnetic Composite Microspheres and Applications for Purifying Dye Wastewater.

PubMed

Lv, Shenghua; Zhu, Linlin; Li, Ying; Jia, Chunmao; Sun, Shiyu

2017-01-11

Graphene oxide nanosheets (GONs)/carboxymethyl chitosan (CMC)/Fe₃O₄ magnetic composite microspheres (MCMs) were prepared by enclosing Fe₃O₄ particles with CMC and GONs in turn. The microstructures of GONs and GONs/CMC/Fe₃O₄ MCMs were characterized by FTIR, XRD, TEM, and SEM. The effects of GON content, pH value, and adsorption time on the adsorption capacity of the MCMs were investigated. The results show that the GONs/CMC/Fe₃O₄ MCMs have a greater specific surface area and a strong adsorption capacity for dye wastewater. Meanwhile, the adsorption mechanism was investigated, and the results accorded with the pseudo-second-order kinetic model and the Freundlich isotherm model. The search results indicate that GONs/CMC/Fe₃O₄ MCMs can be used to purify dye wastewater and has an important potential use in the practical purification of dye wastewater.

Separation of four flavonol glycosides from Solanum rostratum Dunal using aqueous two-phase flotation followed by preparative high-performance liquid chromatography.

PubMed

Chang, Lin; Shao, Qian; Xi, Xingjun; Chu, Qiao; Wei, Yun

2017-02-01

Aqueous two-phase flotation followed by preparative high-performance liquid chromatography was used to separate four flavonol glycosides from Solanum rostratum Dunal. In the aqueous two-phase flotation section, the effects of sublation solvent, solution pH, (NH 4 ) 2 SO 4 concentration in aqueous solution, cosolvent, N 2 flow rate, flotation time, and volumes of the polyethylene glycol phase on the recovery were investigated in detail, and the optimal conditions were selected: 50 wt% polyethylene glycol 1000 ethanol solvent as the flotation solvent, pH 4, 350 g/L of (NH 4 ) 2 SO 4 concentration in aqueous phase, 40 mL/min of N 2 flow rate, 30 min of flotation time, 10.0 mL of flotation solvent volume, and two times. After aqueous two-phase flotation concentration, the flotation products were purified by preparative high-performance liquid chromatography. The purities of the final products A and B were 98.1 and 99.0%. Product B was the mixture of three compounds based on the analysis of high-performance liquid chromatography at the temperature of 10°C, while product A was hyperoside after the identification by nuclear magnetic resonance. Astragalin, 3'-O-methylquercetin 3-O-β-d-galactopyranoside, and 3'-O-methylquercetin 3-O-β-d-glucopyranoside were obtained with the purity of 93.8, 97.1, and 99.2%, respectively, after the further separation of product B using preparative high-performance liquid chromatography. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Flotation of algae for water reuse and biomass production: role of zeta potential and surfactant to separate algal particles.

PubMed

Kwak, Dong-Heui; Kim, Mi-Sug

2015-01-01

The effect of chemical coagulation and biological auto-flocculation relative to zeta potential was examined to compare flotation and sedimentation separation processes for algae harvesting. Experiments revealed that microalgae separation is related to auto-flocculation of Anabaena spp. and requires chemical coagulation for the whole period of microalgae cultivation. In addition, microalgae separation characteristics which are associated with surfactants demonstrated optimal microalgae cultivation time and separation efficiency of dissolved CO2 flotation (DCF) as an alternative to dissolved air flotation (DAF). Microalgae were significantly separated in response to anionic surfactant rather than cationic surfactant as a function of bubble size and zeta potential. DAF and DCF both showed slightly efficient flotation; however, application of anionic surfactant was required when using DCF.

REMOVAL OF HUMICSUBSTANCES AND ALGAE BY DISSOLVED AIR FLOTATION

EPA Science Inventory

Dissolved air flotation (DAF) is used in place of conventional gravity settling as a means to separate low density floc particles from water. The following objectives were: (1) to compare DAF to conventional water treatment of coagulation-flocculation followed by gravity settling...

Sensitivity of double centrifugation sugar fecal flotation for detecting intestinal helminths in coyotes (Canis latrans).

PubMed

Liccioli, Stefano; Catalano, Stefano; Kutz, Susan J; Lejeune, Manigandan; Verocai, Guilherme G; Duignan, Padraig J; Fuentealba, Carmen; Ruckstuhl, Kathreen E; Massolo, Alessandro

2012-07-01

Fecal analysis is commonly used to estimate prevalence and intensity of intestinal helminths in wild carnivores, but few studies have assessed the reliability of fecal flotation compared to analysis of intestinal tracts. We investigated sensitivity of the double centrifugation sugar fecal flotation and kappa agreement between fecal flotation and postmortem examination of intestines for helminths of coyotes (Canis latrans). We analyzed 57 coyote carcasses that were collected between October 2010 and March 2011 in the metropolitan area of Calgary and Edmonton, Alberta, Canada. Before analyses, intestines and feces were frozen at -80 C for 72 hr to inactivate Echinococcus eggs, protecting operators from potential exposure. Five species of helminths were found by postmortem examination, including Toxascaris leonina, Uncinaria stenocephala, Ancylostoma caninum, Taenia sp., and Echinococcus multilocularis. Sensitivity of fecal flotation was high (0.84) for detection of T. leonina but low for Taenia sp. (0.27), E. multilocularis (0.46), and U. stenocephala (0.00). Good kappa agreement between techniques was observed only for T. leonina (0.64), for which we detected also a significant correlation between adult female parasite intensity and fecal egg counts (R(s)=0.53, P=0.01). Differences in sensitivity may be related to parasite characteristics that affect recovery of eggs on flotation. Fecal parasitologic analyses are highly applicable to study the disease ecology of urban carnivores, and they often provide important information on environmental contamination and potential of zoonotic risks. However, fecal-based parasitologic surveys should first assess the sensitivity of the techniques to understand their biases and limitations.

Enzymatic Purification of Microplastics in Environmental Samples.

PubMed

Löder, Martin G J; Imhof, Hannes K; Ladehoff, Maike; Löschel, Lena A; Lorenz, Claudia; Mintenig, Svenja; Piehl, Sarah; Primpke, Sebastian; Schrank, Isabella; Laforsch, Christian; Gerdts, Gunnar

2017-12-19

Micro-Fourier transform infrared (micro-FTIR) spectroscopy and Raman spectroscopy enable the reliable identification and quantification of microplastics (MPs) in the lower micron range. Since concentrations of MPs in the environment are usually low, the large sample volumes required for these techniques lead to an excess of coenriched organic or inorganic materials. While inorganic materials can be separated from MPs using density separation, the organic fraction impedes the ability to conduct reliable analyses. Hence, the purification of MPs from organic materials is crucial prior to conducting an identification via spectroscopic techniques. Strong acidic or alkaline treatments bear the danger of degrading sensitive synthetic polymers. We suggest an alternative method, which uses a series of technical grade enzymes for purifying MPs in environmental samples. A basic enzymatic purification protocol (BEPP) proved to be efficient while reducing 98.3 ± 0.1% of the sample matrix in surface water samples. After showing a high recovery rate (84.5 ± 3.3%), the BEPP was successfully applied to environmental samples from the North Sea where numbers of MPs range from 0.05 to 4.42 items m -3 . Experiences with different environmental sample matrices were considered in an improved and universally applicable version of the BEPP, which is suitable for focal plane array detector (FPA)-based micro-FTIR analyses of water, wastewater, sediment, biota, and food samples.

Towards Plasma-Based Water Purification: Challenges and Prospects for the Future

NASA Astrophysics Data System (ADS)

Foster, John

2016-10-01

Freshwater scarcity derived from climate change, pollution, and over-development has led to serious consideration for water reuse. Advanced water treatment technologies will be required to process wastewater slated for reuse. One new and emerging technology that could potentially address the removal micropollutants in both drinking water as well as wastewater slated for reuse is plasma-based water purification. Plasma in contact with liquid water generates reactive species that attack and ultimately mineralize organic contaminants in solution. This interaction takes place in a boundary layer centered at the plasma-liquid interface. An understanding of the physical processes taking place at this interface, though poorly understood, is key to the optimization of plasma water purifiers. High electric field conditions, large density gradients, plasma-driven chemistries, and fluid dynamic effects prevail in this multiphase region. The region is also the source function for longer-lived reactive species that ultimately treat the water. Here, we review the need for advanced water treatment methods and in the process, make the case for plasma-based methods. Additionally, we survey the basic methods of interacting plasma with liquid water (including a discussion of breakdown processes in water), the current state of understanding of the physical processes taking place at the plasma-liquid interface, and the role that these processes play in water purification. The development of diagnostics usable in this multiphase environment along modeling efforts aimed at elucidating physical processes taking place at the interface are also detailed. Key experiments that demonstrate the capability of plasma-based water treatment are also reviewed. The technical challenges to the implementation of plasma-based water reactors are also discussed. NSF CBET 1336375 and DOE DE-SC0001939.

Separation of plastics by froth flotation. The role of size, shape and density of the particles.

PubMed

Pita, Fernando; Castilho, Ana

2017-02-01

Over the last few years, new methods for plastic separation in mining have been developed. Froth flotation is one of these techniques, which is based on hydrophobicity differences between particles. Unlike minerals, most of the plastics are naturally hydrophobic, thus requiring the addition of chemicals that promote the selective wettability of one of its components, for a flotation separation. The floatability of six granulated post-consumer plastic - Polystyrene (PS), Polymethyl methacrylate (PMMA), Polyethylene Terephthalate (PET-S, PET-D) and Polyvinyl Chloride (PVC-M, PVC-D) - in the presence of tannic acid (wetting agent), and the performance of the flotation separation of five bi-component plastic mixtures - PS/PMMA, PS/PET-S, PS/PET-D, PS/PVC-M and PS/PVC-D - were evaluated. Moreover, the effect of the contact angle, density, size and shape of the particles was also analysed. Results showed that all plastics were naturally hydrophobic, with PS exhibiting the highest floatability. The contact angle and the flotation recovery of six plastics decreased with increasing tannic acid concentration, occurring depression of plastics at very low concentrations. Floatability differed also with the size and shape of plastic particles. For regular-shaped plastics (PS, PMMA and PVC-D) floatability decreased with the increase of particle size, while for lamellar-shaped particles (PET-D) floatability was slightly greater for coarser particles. Thus, plastic particles with small size, lamellar shape and low density present a greater floatability. The quality of separation varied with the mixture type, depending not only on the plastics hydrophobicity, but also on the size, density and shape of the particles, i.e. the particle weight. Flotation separation of plastics can be enhanced by differences in hydrophobicity. In addition, flotation separation improves if the most hydrophobic plastic, that floats, has a lamellar shape and lower density and if the most hydrophilic

Nanoparticle flotation collectors--the influence of particle softness.

PubMed

Yang, Songtao; Razavizadeh, Bi Bi Marzieh; Pelton, Robert; Bruin, Gerard

2013-06-12

The ability of polymeric nanoparticles to promote glass bead and pentlandite (Pn, nickel sulfide mineral) attachment to air bubbles in flotation was measured as a function of the nanoparticle glass transition temperature using six types of nanoparticles based on styrene/N-butylacrylate copolymers. Nanoparticle size, surface charge density, and hydrophobicity were approximately constant over the series. The ability of the nanoparticles to promote air bubble attachment and perform as flotation collectors was significantly greater for softer nanoparticles. We propose that softer nanoparticles were more firmly attached to the glass beads or mineral surface because the softer particles had a greater glass/polymer contact areas and thus stronger overall adhesion. The diameters of the contact areas between polymeric nanoparticles and glass surfaces were estimated with the Young-Laplace equation for soft, liquidlike particles, whereas JKR adhesion theory was applied to the harder polystyrene particles. The diameters of the contact areas were estimated to be more than an order of magnitude greater for the soft particles compared to harder polystyrene particles.

A Plasmonic Colloidal Photocatalyst Composed of a Metal-Organic Framework Core and a Gold/Anatase Shell for Visible-Light-Driven Wastewater Purification from Antibiotics and Hydrogen Evolution.

PubMed

Tilgner, Dominic; Kempe, Rhett

2017-03-02

Porous coordination polymers (PCP) or metal- organic frameworks (MOF) are promising materials for the generation of photocatalytically active composite materials. Here, a novel synthesis concept is reported, which permits the formation of PCP/MOF-core-Au/anatase-shell materials. These materials are photocatalysts for wastewater purification and hydrogen generation from water under visible-light illumination. MIL-101 (Cr) is utilized as the core material, which directs the size of the core-shell compound and ensures the overall stability. In addition, its excellent reversible large molecule sorption behavior allows the materials synthesis. The crystalline anatase shell is generated stepwise under mild conditions using titanium(IV) isopropoxide as a precursor. The high degree of control of the vapor phase deposition process permits the precise anatase shell formation. The generation of plasmonic active gold particles on the TiO 2 shell leads to an efficient material for visible-light-driven photocatalysis with a higher activity than gold-decorated P25 (Degussa). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Clarification of Muscat musts using wheat proteins and the flotation technique.

PubMed

Marchal, Richard; Lallement, Armelle; Jeandet, Philippe; Establet, Gérard

2003-03-26

The bovine spongiform encephalopathy (BSE, mad cow) crisis has led some wine-makers to question gelatin as a fining agent and to reject the use of these animal proteins. The search for a substitute for gelatin was begun by comparing vegetable proteins (particularly gluten) with gelatin fining treatments. Clairette de Die (French-controlled appellation) is a sparkling sweet wine. The alcoholic fermentation begins in a tank, continues in a crown-cap bottle, and stops before the complete consumption of sugar. All particles present in the bottle have to be removed before corking, and it is important to have a must as clear as possible. This study concerned the clarifying of a Muscat must, treated with pectinases, using a very efficient flotation technique. The must is fined with bentonite/silica/protein (fish gelatin, wheat gluten, or lupin isolate) to induce flocculation and then pressurized (6 bar). After depressurization, microbubbles cling to flocculates and climb to the top of the flotation tank (this flotation foam is clarified using a rotary filter). At laboratory scale, gluten (20 g/hL) and gelatin (10 g/hL) (each combined with bentonite and silica gel) gave turbidities of 50 and 35 NTU, respectively (6.5 and 4.1% of that of the nontreated must). The Muscat must was also clarified by static settling. The turbidity decreased by 86% for the gluten/bentonite fining and by 60% for the gelatin/bentonite fining. Visually, gluten flocculation takes longer to occur and flocculates sedimentation is longer than with gelati, but the removal of insoluble particles is more complete and leads to lower turbidities. At an industrial scale, gluten (20 g/hL) and gelatin (10 g/hL) (each combined with bentonite and silica gel) gave turbidities of 60 and 48 NTU, respectively. Turbidities measured in the tanks 14 h after the flotation showed a better efficiency for the wheat gluten (24 NTU) compared to gelatin (28 NTU). This is explained by the static settling that completed the

Dielectric barrier discharge-based investigation and analysis of wastewater treatment and pollutant removal.

PubMed

Ramdani, N; Lousdad, A; Tilmatine, A; Nemmich, S

2016-01-01

Current research reveals that the oxidation by ozone is considered as an effective solution and offers irrefutable advantages in wastewater treatment. It is also well known that ozone is used to treat different types of water due to its effectiveness in water purification and for its oxidation potential. This process of ozonation is becoming progressively an alternative technology and is inscribed in a sustainable development perspective in Algeria. In this regards, the present paper investigates the wastewater treatment process by ozone produced by dielectric barrier discharge (DBD) under high potential. Three (DBD) ozone generators of cylindrical form have been used, at a laboratory scale, for treating collected samples from the wastewater treatment plant (WWTP) of the city of Sidi-Bel-Abbes located in the west of Algeria. Our experimental results reveal the efficiency of this type of treatment on the basis of the physicochemical analysis (pH, turbidity, chemical oxygen demand, biological oxygen demand, heavy metals) and microbial analysis downstream of the WWTP, which showed a high rate of elimination of all the parameters.

Apparatus for the separation of hydrophobic and hydrophilic particles using microbubble column flotation together with a process and apparatus for generation of microbubbles

DOEpatents

Yoon, Roe-Hoan; Adel, Gregory T.; Luttrell, Gerald H.

1995-01-01

An apparatus is disclosed for the microbubble flotation separation of very fine and coarse particles, especially coal, and minerals so as to produce high purity and high recovery efficiency. This is accomplished through the use of a flotation column, microbubbles, recycling of the flotation pulp, and countercurrent wash water to gently wash the froth. Also disclosed are unique processes and apparatus for generating microbubbles for flotation in a highly efficient and inexpensive manner using either a porous tube or in-line static generators.

Cu(I)/Cu(II) mixed-valence surface complexes of S-[(2-hydroxyamino)-2-oxoethyl]-N,N-dibutyldithiocarbamate: Hydrophobic mechanism to malachite flotation.

PubMed

Liu, Sheng; Zhong, Hong; Liu, Guangyi; Xu, Zhenghe

2018-02-15

Hydroxamate and sulfhydryl surfactants are effective collectors for flotation of copper minerals. The combination application of hydroxamate and sulfhydryl collectors has been proved to be an effective approach for improving the flotation recovery of non-sulfide copper minerals. A surfactant owing both hydroxamate and dithiocarbamate groups might exhibit strong affinity to non-sulfide copper minerals through double sites adsorption, rendering an enhanced hydrophobization to non-sulfide copper minerals flotation. The flotation performance of S-[(2-hydroxyamino)-2-oxoethyl]- N,N-dibutyldithiocarbamate (HABTC) to malachite, calcite and quartz were first evaluated through systematic micro-flotation experiments. HABTC's hydrophobic mechanism to malachite was further investigated and analyzed by zeta potential, Fourier transform infrared spectroscopy (FTIR), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS). The micro-flotation results demonstrated HABTC was an excellent collector for malachite flotation and exhibited favorable selectivity for flotation separation of malachite from quartz or calcite under pH 8.5-10.3. Zeta potential and FTIR implied that HABTC might bond with the surface copper atoms of malachite, with releasing the H + ions of its hydroxamate group into pulp. ToF-SIMS provided clear evidences that the Cu-hydroxamate and Cu-dithiocarbamate groups were formed on malachite surfaces after HABTC adsorption. XPS revealed that Cu(I)/Cu(II) mixed-valence surface complexes of HABTC anchored on malachite through formation of Cu(I)S and Cu(II)O bonds, accompanying with reduction of partial surface Cu(II) to Cu(I). The Cu(I)/Cu(II) mixed-valence double chelating character and "chair"-shape N,N-dibutyldithiocarbamate hydrophobic group, resulting in an enhanced affinity and hydrophobization of HABTC to malachite flotation. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluation of an alternative method for wastewater treatment containing pesticides using solar photocatalytic oxidation and constructed wetlands.

PubMed

Berberidou, Chrysanthi; Kitsiou, Vasiliki; Lambropoulou, Dimitra A; Antoniadis, Αpostolos; Ntonou, Eleftheria; Zalidis, George C; Poulios, Ioannis

2017-06-15

The present study proposes an integrated system based on the synergetic action of solar photocatalytic oxidation with surface flow constructed wetlands for the purification of wastewater contaminated with pesticides. Experiments were conducted at pilot scale using simulated wastewater containing the herbicide clopyralid. Three photocatalytic methods under solar light were investigated: the photo-Fenton and the ferrioxalate reagent as well as the combination of photo-Fenton with TiO 2 P25, which all led to similar mineralization rates. The subsequent treatment in constructed wetlands resulted in further decrease of DOC and inorganic ions concentrations, especially of NO 3 - . Clopyralid was absent in the outlet of the wetlands, while the concentration of the detected intermediates was remarkably low. These findings are in good agreement with the results of phytotoxicity of the wastewater, after treatment with the ferrioxalate/wetlands process, which was significantly reduced. Thus, this integrated system based on solar photocatalysis and constructed wetlands has the potential to effectively detoxify wastewater containing pesticides, producing a purified effluent which could be exploited for reuse applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Apparatus for the separation of hydrophobic and hydrophilic particles using microbubble column flotation together with a process and apparatus for generation of microbubbles

DOEpatents

Yoon, R.H.; Adel, G.T.; Luttrell, G.H.

1995-03-14

An apparatus is disclosed for the microbubble flotation separation of very fine and coarse particles, especially coal, and minerals so as to produce high purity and high recovery efficiency. This is accomplished through the use of a flotation column, microbubbles, recycling of the flotation pulp, and countercurrent wash water to gently wash the froth. Also disclosed are unique processes and apparatus for generating microbubbles for flotation in a highly efficient and inexpensive manner using either a porous tube or in-line static generators. 14 figs.

Effect of acidified water glass on the flotation separation of scheelite from calcite using mixed cationic/anionic collectors

NASA Astrophysics Data System (ADS)

Dong, Liuyang; Jiao, Fen; Qin, Wenqing; Zhu, Hailing; Jia, Wenhao

2018-06-01

In this paper, the effect of acidified water glass (AWG) on the flotation separation of scheelite from calcite using mixed collector of dodecylamine (DDA) and sodium oleate (NaOL) was investigated. The flotation results show that AWG could selectively depress the flotation of calcite at pH 7. A series of mechanism experiments confirm that the chemisorption of AWG on calcite surface is more intense than scheelite. Although the chemisorption of NaOL on calcite surface is almost unaffected by the presence of AWG, the chemisorption of AWG hinders the adsorption of DDA on calcite surface.

New influence factor inducing difficulty in selective flotation separation of Cu-Zn mixed sulfide minerals

NASA Astrophysics Data System (ADS)

Deng, Jiu-shuai; Mao, Ying-bo; Wen, Shu-ming; Liu, Jian; Xian, Yong-jun; Feng, Qi-cheng

2015-02-01

Selective flotation separation of Cu-Zn mixed sulfides has been proven to be difficult. Thus far, researchers have found no satisfactory way to separate Cu-Zn mixed sulfides by selective flotation, mainly because of the complex surface and interface interaction mechanisms in the flotation solution. Undesired activation occurs between copper ions and the sphalerite surfaces. In addition to recycled water and mineral dissolution, ancient fluids in the minerals are observed to be a new source of metal ions. In this study, significant amounts of ancient fluids were found to exist in Cu-Zn sulfide and gangue minerals, mostly as gas-liquid fluid inclusions. The concentration of copper ions released from the ancient fluids reached 1.02 × 10-6 mol/L, whereas, in the cases of sphalerite and quartz, this concentration was 0.62 × 10-6 mol/L and 0.44 × 10-6 mol/L, respectively. As a result, the ancient fluid is a significant source of copper ions compared to mineral dissolution under the same experimental conditions, which promotes the unwanted activation of sphalerite. Therefore, the ancient fluid is considered to be a new factor that affects the selective flotation separation of Cu-Zn mixed sulfide ores.

Mechanism of microbial flotation using Thiobacillus ferrooxidans for pyrite suppression.

PubMed

Ohmura, N; Kitamura, K; Saiki, H

1993-03-15

Microbial desulfurization might be developed as a new process for the removal of pyrite sulfur from coal sluries such as coal-water mixture (CWM). An application of iron-oxidizing bacterium Thiobacillus ferrooxidans to flotation would shorten the periods of the microbial removal of pyrite from some weeks by leaching methods to a few minutes. The floatability of pyrite in flotation was mainly reduced by T. ferrooxidans itself rather than by other microbial substances in bacterial culture as additive of flotation liquor. Floatability was suppressed within a few seconds by bacterial contact. The suppression was proportional to increasing the number of cells observed between bacterial adhesion and the suppression of floatability. If 25% of the total pyrite surface area covered with the bacteria, pyrite floatability would be completely depressed. Bacteria that lost their iron-oxidizing activities by sodium cyanide treatment were also able to adhere to pyrite and reduced pyrite floatability as much as normal bacteria did. Thiobacillus ferrooxidans ATCC 23270, T-1, 9, and 11, which had different iron-oxidizing abilities, suppressed floatability to similar-levels. The oxidizing ability of bacteria did not influence the suppressing effect. These results showed the mechanism of the suppression of pyrite floatability by bacteria. Quick bacterial adhesion to pyrite induced floatability suppression by changing the surface property from hydrophobic. The quick adhesion of the bacterium was the novel function which worked to change the surface property of pyrite to remove it from coal. (c) 1993 John Wiley & Sons, Inc.

[Thermoacidophilic micirobial community oxidizing the gold-bearing flotation concentrate of a pyrite-arsenopyrite ore].

PubMed

Paniushkina, A E; Tsaplina, I A; Grigor'eva, N V; Kondrat'eva, T F

2014-01-01

An aboriginal community of thermophilic acidophilic chemolithotrophic microorganisms (ACM) was isolated from a sample of pyrite gold-bearing flotation concentrateat 45-47 degrees C and pH 1.8-2.0. Compared to an experimental thermoacidophilic microbial consortium formed in the course of cultivation in parallel bioreactors, it had lower rates of iron leaching and oxidation, while its rate of sulfur oxidation was higher. A new thermophilic acidophilic microbial community was obtained by mutual enrichment with the micioorganisms from thie experimental and aboriginal communities during oxidation of sulfide ore flotation concentrate at 47 degrees C. The dominant bacteria of this new ACM community were Acidithiobacillus caldus strains (the most active sulfur oxidizers) and Sulfobacillus thermotolerans strains (active oxidizers of both iron and sulfur), while iron-oxidizing archaea of the family Ferroplasmaceae and heterotrophic bacteria Alicyclobacillus tolerans were the minor components. The new ACM community showed promise for leaching/oxidation of sulfides from flotation concentrates at high pulp density (S:L = 1:4).

Dissolved air flotation and centrifugation as methods for oil recovery from ruptured microalgal cells.

PubMed

Ghasemi Naghdi, Forough; Schenk, Peer M

2016-10-01

Solvent-free microalgal lipid recovery is highly desirable for safer, more sustainable and more economical microalgal oil production. Dispersed air flotation and centrifugation were evaluated for the ability to separate oil and debris from a slurry mixture of osmotically fractured Chaetoceros muelleri cells with and without utilizing collectors. Microalgal oil partially phase-separated as a top layer and partially formed an oil-in-water emulsion. Although collectors, such as sodium dodecyl sulphate enhanced selective flotation, by just adjusting the pH and cell concentration of the mixture, up to 78% of the lipids were recovered in the froth. Using centrifugation of fractured microalgal slurry resulted in removal of 60% cell debris and up to 68.5% of microalgal oil was present in the supernatant. Both methods, centrifugation and flotation provided options for separation of microalgal oil from C. muelleri slurry with similar fatty acid recoveries of 57% and 60%, respectively. Copyright © 2016. Published by Elsevier Ltd.

Determination of trace elements in dolomite and gypsum by atomic absorption spectrometry: overcoming the matrix interference by flotation separation

NASA Astrophysics Data System (ADS)

Stafilov, Trajče; Zendelovska, Dragica; Pavlovska, Gorica; Čundeva, Katarina

2002-05-01

The interferences of Ca and Mg as matrix elements in dolomite and gypsum on Ag, Cd, Cr, Mn, Tl and Zn absorbances during their electrothermal atomic absorption spectrometric (ETAAS) determination are investigated. The results reveal that Ca and Mg do not interfere on Zn and Mn, tend to decrease absorbances of Ag, Cd and Cr, while Tl suffers the most significant influence. A flotation separation method is proposed to eliminate matrix interferences. Hydrated iron(III) oxide, Fe 2O 3· xH 2O, and iron(III) hexamethylenedithiocarbamate, Fe(HMDTC) 3, are applied as flotation collectors. The influence of hydrophobic dithiocarbamate anion, HMDTC, on flotation recoveries of each analyte is studied. The most suitable concentrations of dolomite and gypsum solutions for flotation are determined. To avoid flotation suppression due to the reaction of Ca 2+ and Mg 2+ with surfactant ions, a fit foaming agent was selected. The elements present in dolomite and gypsum as traces have been analyzed by ETAAS. Their ETAAS limits of detection following flotation are found to be 0.021 μg·g -1 for Ag, 0.019 μg·g -1 for Cd, 0.014 μg·g -1 for Cr and 0.11 μg·g -1 for Tl. The determination of Mn and Zn can be performed by flame AAS (FAAS). The limit of detection for Mn is 1.5 μg·g -1, while for Zn 0.8 μg·g -1.

Experimental investigation of oily wastewater treatment using combined membrane systems.

PubMed

Salahi, A; Mohammadi, T

2010-01-01

Investigations were carried out for purification of oily wastewater by a combined of ultrafiltration/reverse osmosis (UF/RO) processes. Laboratory-scale UF using polysulfone (PS) and polyacrylonitrile (PAN) membranes were employed with typical oily wastewater collected from API unit of Tehran refinery. The PAN membrane showed higher rejection, more permeation flux and less fouling resistance than the PS membrane. Both membranes produced permeate with oil and grease contents generally less than 5 ppm. Rejection of chemical oxygen demand (COD) and biological oxygen demand (BOD5) were found to be 65% for UF treatment. In this work, Hermia's models were used to investigate the fouling mechanism involved in UF of the oily wastewater. The results showed that the best fit to experimental data corresponds to the cake layer formation model followed by the intermediate blocking model for both the UF membranes. For further treatment of the UF permeates, RO was applied using a thin film composite polyamide membrane. The rejection of COD, BOD5 and total dissolved solid (TDS) after UF/RO treatment increased up to 98%, 98% and 95%, respectively. The results showed that the final permeate has very high quality and even better than that is currently introduced to the cooling towers in Tehran refinery.

Separation of polycarbonate and acrylonitrile-butadiene-styrene waste plastics by froth flotation combined with ammonia pretreatment.

PubMed

Wang, Chong-Qing; Wang, Hui; Liu, Qun; Fu, Jian-Gang; Liu, You-Nian

2014-12-01

The objective of this research is flotation separation of polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) waste plastics combined with ammonia pretreatment. The PC and ABS plastics show similar hydrophobicity, and ammonia treatment changes selectively floatability of PC plastic while ABS is insensitive to ammonia treatment. The contact angle measurement indicates the dropping of flotation recovery of PC is ascribed to a decline of contact angle. X-ray photoelectron spectroscopy demonstrates reactions occur on PC surface, which makes PC surface more hydrophilic. Separation of PC and ABS waste plastics was conducted based on the flotation behavior of single plastic. At different temperatures, PC and ABS mixtures were separated efficiently through froth flotation with ammonia pretreatment for different time (13 min at 23 °C, 18 min at 18 °C and 30 min at 23 °C). For both PC and ABS, the purity and recovery is more than 95.31% and 95.35%, respectively; the purity of PC and ABS is up to 99.72% and 99.23%, respectively. PC and ABS mixtures with different particle sizes were separated effectively, implying that ammonia treatment possesses superior applicability. Copyright © 2014 Elsevier Ltd. All rights reserved.

95. FLOTATION ROOM, LOOKING SOUTHWEST, WITH LEAD ROUGHER CELLS AT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

95. FLOTATION ROOM, LOOKING SOUTHWEST, WITH LEAD ROUGHER CELLS AT RIGHT AND LEAD CLEANER CELLS AT LEFT. NOTE SUNNYSIDE GOLD CORP. "SG" LOGO ON ROUGHER CELL LAUNDER. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

Data book for 12.5-inch diameter SRB thermal model water flotation test; 1.29 psia, series P022

NASA Technical Reports Server (NTRS)

Allums, S. L.

1974-01-01

Data acquired from tests conducted to determine how thermal conditions affect SRB (Space Shuttle Solid Rocket Booster) flotation at a scaled pressure of 1.29 psia are presented. Included are acceleration, pressure, and temperature data recorded from initial water impact to final flotation position using a 12.5-inch diameter thermal model of the SRB. Nineteen valid tests were conducted. These thermal tests indicated the following basic differences relative to the ambient temperature and pressure model tests: (1) more water was taken on board during penetration and (2) model flotation/sinking was temperature sensitive.

Data book for 12.5-inch diameter SRB thermal model water flotation test - 14.7 psia, series P024

NASA Technical Reports Server (NTRS)

Allums, S. L.

1974-01-01

Tests were conducted to determine how thermal conditions affect space shuttle solid rocket booster (SRB) flotation. Acceleration, pressure, and temperature data were recorded from initial water impact to final flotation position using a 12.5-inch diameter thermal model of the SRB at ambient pressure. The model was 136.9 inches long and weighed 117.3 lbm. The tests indicated the following differences from ambient temperature tests: (1) significant negative static pressures can occur during penetration; (2) maximum penetration is increased; and (3) final flotation is in the spar buoy mode.

Photocatalytic wastewater purification with simultaneous hydrogen production using MoS2 QD-decorated hierarchical assembly of ZnIn2S4 on reduced graphene oxide photocatalyst.

PubMed

Zhang, Shuqu; Wang, Longlu; Liu, Chengbin; Luo, Jinming; Crittenden, John; Liu, Xia; Cai, Tao; Yuan, Jili; Pei, Yong; Liu, Yutang

2017-09-15

It is attractive to photocatalytically purify wastewater and simultaneously convert solar energy into clean hydrogen energy. However, it is still a challenge owing to the relatively low photocatalytic efficiency of photocatalysts. In this study, we synthesized a molybdenum disulfide (MoS 2 ) quantum dot-decorated 3D nanoarchitecture (MoS 2 QDs) of indium zinc sulfide (ZnIn 2 S 4 ) and reduced grapheme oxide (MoS 2 QDs@ZnIn 2 S 4 @RGO) photocatalyst using a simple solvothermal method. The RGO promotes the electron transfer, and the highly dispersed MoS 2 QDs provides numerous catalytic sites. The photocatalytic purification of rhodamine B (RhB), eosin Y (EY), fulvic acid (FA), methylene blue (MB) and p-nitrophenol (PNP) in simulated wastewaters were further tested. The degradation efficiencies and TOC removal were 91% and 75% for PNP, 92.2% and 72% for FA, 98.5% and 80% for MB, 98.6% and 84% for EY, and 98.8% and 88% for RhB, respectively (C organics  = 20 mg/L, C catalyst  = 1.25 g/L, t = 12 h, I light  = 3.36 × 10 -5  E L -1  s -1 ). Among these tests, the highest hydrogen production was achieved (45 μmol) during RhB degradation. Both experimental and calculational results prove that lower LUMO (lowest unoccupied molecular orbit) level of organic molecules was available for transferring electrons to catalysts, resulting in more efficient hydrogen production. Significantly, the removal efficiencies of natural organic substances in actual river water reached 76.3-98.4%, and COD reduced from 32 to 16 mg/L with 13.8 μmol H 2 production after 12 h. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biodegradation of phytosanitary products in biological wastewater treatment.

PubMed

Massot, A; Estève, K; Noilet, P; Méoule, C; Poupot, C; Mietton-Peuchot, M

2012-04-15

Agricultural activity generates two types of waste: firstly, biodegradable organic effluents generally treated by biological processes and, secondly, phytosanitary effluents which contain residues of plant protection products. The latter are collected and treated. Current technological solutions are essentially based on concentration or physical-chemical processes. However, recent improvements in the biodegradability of pesticides open the way to the consideration of alternative, biological, treatment using mixed liquor from wastewater plant activated sludge. The feasibility of the biological treatment of viticultural effluents has been evaluated by the application of pesticides to activated sludge. The necessity for selection of a pesticide-resistant biomass has been highlighted. The elimination of the phytosanitary products shows the potential of a resistant biomass in the treatment of pesticides. The aerated biological storage ponds at three wineries, followed by a sand or reed-bed filter, were used for the treatment of the total annual volume of the viticulture effluents and validate the laboratory experiments. The results show that the biological purification of pesticides by activated sludge is possible by allowing approximately 8 days for biomass adaptation. Stability of purification occurs between 20 and 30 days. Copyright © 2012 Elsevier Ltd. All rights reserved.

A neural network controller of a flotation process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Durao, F.; Cortez, L.

1995-12-31

The dynamic control of a froth flotation section is simulated through a neural network feedback controller, trained in order to stabilize the concentrate metal grade and recovery by applying random step changes to the feed metal grade. The results of the application example show that this controller seems to be sufficiently robust and a good alternative to handle a non-linear process.

Vertical flow constructed wetlands for municipal wastewater and septage treatment in French rural area.

PubMed

Paing, J; Voisin, J

2005-01-01

This paper presents the purification performance of 20 wastewater treatment plants with vertical reed bed filters (Macrophyltres), built between 1998 and 2003 by SAS Voisin, for communities of between 150 and 1400 PE. The first stage vertical reed bed (directly fed with raw wastewater by intermittent feeding) achieved high removal of SS, BOD and COD (mean respectively 96%, 98%, 92%). The second stage permitted compliance easily with effluent standards (SS < 15 mg/l, BOD < 15 mg/l, COD < 90 mg/l and mean TKN < 10 mg/l). Performance was not significantly influenced by variations of organic and hydraulic load, nor by seasonal variations. Rigorous operation and maintenance were required to obtain optimal performances. Another application of vertical reed beds is the treatment of septage (sludge from individual septic tanks). The results obtained on two sites operating for 2 and 3 years are presented. The first site achieved complete treatment of septage (solid and liquid fraction), the second permitted a pre-treatment for co-treatment of percolate with wastewater.

Navy frogmen attach flotation collar to Apollo 7 command module

NASA Image and Video Library

1968-10-22

U.S. Navy frogmen attach a flotation collar to the Apollo 7 command module during recovery operations in the Atlantic. The Apollo 7 spacecraft splashed down at 7:11 a.m., October 22, 1968, approximately 200 nautical miles south-southwest of Bermuda.

Conventional and thermophilic aerobic treatability of high strength oily pet food wastewater using membrane-coupled bioreactors.

PubMed

Kurian, R; Acharya, C; Nakhla, G; Bassi, A

2005-11-01

Although thermophilic treatment systems have recently gained considerable interest, limited information exists on the comparative performances of membrane-coupled bioreactors (MBR) at thermophilic and conventional conditions. In this study aerobic MBRs operating at room temperature (20 degrees C) and at lower thermophilic range (45 degrees C) were investigated for the treatment of dissolved air flotation (DAF) pretreated pet food wastewater. The particular wastewater is characterized by oil and grease (O & G) concentrations as high as 6 g/L, COD of 51 g/L, BOD of 16 g/L and volatile fatty acid (VFA) of 8.3 g/L. The performances of the two systems in terms of COD, BOD and O & G removal at varying hydraulic retention time (HRT) are compared. COD removal efficiencies in the thermophilic MBR varied from 75% to 98% and remained constant at 94% in the conventional MBR. The O & G removal efficiencies were 66-86% and 98% in the thermophilic and conventional MBR, respectively. Interestingly, high concentrations of VFA were recorded, equivalent to 50-73% of total COD, in the thermophilic MBR effluent. The observed yield in the thermophilic MBR was 40% of that observed in the conventional MBR.

Process and apparatus for separating fine particles by microbubble flotation together with a process and apparatus for generation of microbubbles

DOEpatents

Yoon, R.H.; Adel, G.T.; Luttrell, G.H.

1991-01-01

A method and apparatus are disclosed for the microbubble flotation separation of very fine particles, especially coal, so as to produce a high purity and large recovery efficiently. This is accomplished through the use of a high aspect ratio flotation column, microbubbles, and a countercurrent use of wash water to gently wash the froth. Also, disclosed are unique processes and apparatus for generating microbubbles for flotation in a high efficient and inexpensive manner using either a porous tube or an in-line static generator. 23 figures.

Headgroup interactions and ion flotation efficiency in mixtures of a chelating surfactant, different foaming agents, and divalent metal ions.

PubMed

Svanedal, Ida; Boija, Susanne; Norgren, Magnus; Edlund, Håkan

2014-06-10

The correlation between interaction parameters and ion flotation efficiency in mixtures of chelating surfactant metal complexes and different foaming agents was investigated. We have recently shown that chelating surfactant 2-dodecyldiethylenetriaminepentaacetic acid (4-C12-DTPA) forms strong coordination complexes with divalent metal ions, and this can be utilized in ion flotation. Interaction parameters for mixed micelles and mixed monolayer formation for Mg(2+) and Ni(2+) complexes with the chelating surfactant 4-C12-DTPA and different foaming agents were calculated by Rubingh's regular solution theory. Parameters for the calculations were extracted from surface tension measurements and NMR diffusometry. The effects of metal ion coordination on the interactions between 4-C12-DTPA and the foaming agents could be linked to a previously established difference in coordination chemistry between the examined metal ions. As can be expected from mixtures of amphoteric surfactants, the interactions were strongly pH-dependent. Strong correlation was found between interaction parameter β(σ) for mixed monolayer formation and the phase-transfer efficiency of Ni(2+) complexes with 4-C12-DTPA during flotation in a customized flotation cell. In a mixture of Cu(2+) and Zn(2+), the significant difference in conditional stability constants (log K) between the metal complexes was utilized to selectively recover the metal complex with the highest log K (Cu(2+)) by ion flotation. Flotation experiments in an excess concentration of metal ions confirmed the coordination of more than one metal ion to the headgroup of 4-C12-DTPA.

Plasma-based water purification: Challenges and prospects for the future

NASA Astrophysics Data System (ADS)

Foster, John E.

2017-05-01

Freshwater scarcity derived from seasonal weather variations, climate change, and over-development has led to serious consideration for water reuse. Water reuse involves the direct processing of wastewater for either indirect or directly potable water reuse. In either case, advanced water treatment technologies will be required to process the water to the point that it can be reused in a meaningful way. Additionally, there is growing concern regarding micropollutants, such as pharmaceuticals and personal care products, which have been detected in finished drinking water not removed by conventional means. The health impact of these contaminants in low concentration is not well understood. Pending regulatory action, the removal of these contaminants by water treatment plants will also require advanced technology. One new and emerging technology that could potentially address the removal of micropollutants in both finished drinking water as well as wastewater slated for reuse is plasma-based water purification. Plasma in contact with liquid water generates a host of reactive species that attack and ultimately mineralize contaminants in solution. This interaction takes place in the boundary layer or interaction zone centered at the plasma-liquid water interface. An understanding of the physical processes taking place at the interface, though poorly understood, is key to the optimization of plasma-based water purifiers. High electric field conditions, large density gradients, plasma-driven chemistries, and fluid dynamic effects prevail in this multiphase region. The region is also the source function for longer-lived reactive species that ultimately treat the water. Here, we review the need for advanced water treatment methods and in the process, make the case for plasma-based methods. Additionally, we survey the basic methods of interacting plasma with liquid water (including a discussion of breakdown processes in water), the current state of understanding of the

Surface modification of malachite with ethanediamine and its effect on sulfidization flotation

NASA Astrophysics Data System (ADS)

Feng, Qicheng; Zhao, Wenjuan; Wen, Shuming

2018-04-01

Ethanediamine was used to modify the mineral surface of malachite to improve its sulfidization and flotation behavior. The activation mechanism was investigated by adsorption experiments, X-ray photoelectron spectroscopy (XPS) analysis, and zeta potential measurements. Microflotation experiments showed that the flotation recovery of malachite was enhanced after the pretreatment of the mineral particles with ethanediamine prior to the addition of Na2S. Adsorption tests revealed that numerous sulfide ion species in the pulp solution were transferred onto the mineral surface through the formation of more copper sulfide species. This finding was confirmed by the results of the XPS measurements. Ethanediamine modification not only increased the contents of copper sulfide species on the malachite surface but also enhanced the reactivity of the sulfidization products. During sulfidization, Cu(II) species on the mineral surface were reduced into Cu(I) species, and the percentages of S22- and Sn2- relative to the total S increased after modification, resulting in increased surface hydrophobicity. The results of zeta potential measurements showed that the ethanediamine-modified mineral surface adsorbed with more sulfide ion species was advantageous to the attachment of xanthate species, thereby improving malachite floatability. The proposed ethanediamine modification followed by sulfidization xanthate flotation exhibits potential for industrial application.

Flotation in ethanol affects storability of spruce pine seeds

Treesearch

James P. Barnett

1970-01-01

Flotation in 95-percent ethanol quickly separates full and empty seeds of spruce pine (Pinus glabra Walt.) without reducing viability measured soon after treatment. Results of two studies reported here, however, indicate that soaking in ethanol causes viability of the seeds to decline rapidly in storage. This phenomenon led to the enormous...

Novel Fluorinated Tensioactive Extractant Combined with Flotation for Decontamination of Extractant Residual during Solvent Extraction

NASA Astrophysics Data System (ADS)

Wu, Xue; Chang, Zhidong; Liu, Yao; Choe, Chol Ryong

2017-12-01

Solvent-extraction is widely used in chemical industry. Due to the amphiphilic character, a large amount of extractant remains in water phase, which causes not only loss of reagent, but also secondary contamination in water phase. Novel fluorinated extractants with ultra-low solubility in water were regarded as effective choice to reduce extractant loss in aqueous phase. However, trace amount of extractant still remained in water. Based on the high tensioactive aptitude of fluorinated solvent, flotation was applied to separate fluorinated extractant remaining in raffinate. According to the data of surface tension measurement, the surface tension of solution was obviously decreased with the addition of fluorinated extractant tris(2,2,3,3,4,4,5,5-octafluoropentyl) phosphate (FTAP). After flotation, the FTAP dissolved in water can be removed as much as 70%, which proved the feasibility of this key idea. The effects of operation time, gas velocity, pH and salinity of bulk solution on flotation performance were discussed. The optimum operating parameters were determined as gas velocity of 12ml/min, operating time of 15min, pH of 8.7, and NaCl volume concentration of 1.5%, respectively. Moreover, adsorption process of FTAP on bubble surface was simulated by ANSYS VOF model using SIMPLE algorithm. The dynamic mechanism of flotation was also theoretically investigated, which can be considered as supplement to the experimental results.

Data book for 12.5-inch diameter SRB thermal model water flotation test: 14.7 psia, series P020

NASA Technical Reports Server (NTRS)

Allums, S. L.

1974-01-01

Data acquired from the initial series of tests conducted to determine how thermal conditions affect SRB (Space Shuttle Solid Rocket Booster) flotation are presented. Acceleration, pressure, and temperature data recorded from initial water impact to final flotation position using a 12.5-inch diameter thermal model of the SRB at ambient pressure are included. The model was 136.9 inches long and weighed 117.3 lbm. The tests indicated the following differences from ambient temperature tests: (1) significant negative static pressures can occur during penetration; (2) maximum penetration is increased; and (3) final flotation is in the spar buoy mode.

Evaluation of an improved flotation device for infants and small children.

DOT National Transportation Integrated Search

1971-07-01

A simple, lightweight, life-support infant flotation device incorporating reliable self-righting, thermal protection and automatic self-ventilation is described This design concept utilizes prior data relative to the centers of gravity of infants and...

Treatment of Spacecraft Wastewater Using a Hollow Fiber Membrane Biofilm Redox Control Reactor

NASA Technical Reports Server (NTRS)

Smith, Daniel P.

2003-01-01

The purpose of this project was to develop and evaluate design concepts for biological treatment reactors for the purification of spacecraft wastewater prior to reverse osmosis treatment. The motivating factor is that wastewater recovery represents the greatest single potential reduction in the resupply requirements for crewed space missions. Spacecraft wastewater composition was estimated from the characteristics of the three major component streams: urine/flush water, hygiene water, and atmospheric condensate. The key characteristics of composite spacecraft wastewater are a theoretical oxygen demand of 4519 mg/L, of which 65% is nitrogenous oxygen demand, in a volume of 11.5 liter/crew-day. The organic carbon to nitrogen ratio of composite wastewater is 0.86. Urine represents 93% of nitrogen and 49% of the organic carbon in the composite wastestream. Various bioreaction scenarios were evaluated to project stoichiometric oxygen demands and the ability of wastewater carbon to support denitrification. Ammonia nitrification to the nitrite oxidation state reduced the oxygen requirement and enabled wastewater carbon to provide nearly complete denitrification. A conceptual bioreactor design was established using hollow fiber membranes for bubbleless oxygen transfer in a gravity-free environment, in close spatial juxtaposition to a second interspaced hollow fiber array for supplying molecular hydrogen. Highly versatile redox control and an enhanced ability to engineer syntrophic associations are stated advantages. A prototype reactor was constructed using a microporous hollow fiber membrane module for aeration. Maintaining inlet gas pressure within 0.25 psi of the external water pressure resulted in bubble free operation with no water ingress into hollow fiber lumens. Recommendations include the design and operational testing of hollow fiber bioreactors using: 1) Partial nitrification/nitrite predenitrification; 2) Limited aeration for simultaneous nitrification

Tests on the centrifugal flotation technique and its use in estimating the prevalence of Toxocara in soil samples from urban and suburban areas of Malaysia.

PubMed

Loh, A G; Israf, D A

1998-03-01

The influence of soil texture (silt, sand and laterite) and flotation solutions (saturated NaCl, sucrose, NaNO3, and ZnSO4) upon the recovery of Toxocara ova from seeded soil samples with the centrifugal flotation technique was investigated. Soil samples of different texture were artificially seeded with Toxocara spp. ova and subjected to a centrifugal flotation technique which used various flotation solutions. The results showed significant (P < 0.001) interactions between the soil types and the flotation solutions. The highest percentage of ova recovery was obtained with silty soil (34.9-100.8%) with saturated NaCl as the flotation solution (45.3-100.8%). A combination of washing of soil samples with 0.1% Tween 80, and flotation using saturated NaCl and a 30 min coverslip recovery period was used to study the prevalence of contamination of soil samples. Forty-six soil samples were collected from up to 24 public parks/playgrounds in urban areas of Petaling Jaya and suburban areas of Serdang. The prevalence of Toxocara species in the urban and suburban areas was 54.5% and 45.8% respectively.

Using factorial experimental design to evaluate the separation of plastics by froth flotation.

PubMed

Salerno, Davide; Jordão, Helga; La Marca, Floriana; Carvalho, M Teresa

2018-03-01

This paper proposes the use of factorial experimental design as a standard experimental method in the application of froth flotation to plastic separation instead of the commonly used OVAT method (manipulation of one variable at a time). Furthermore, as is common practice in minerals flotation, the parameters of the kinetic model were used as process responses rather than the recovery of plastics in the separation products. To explain and illustrate the proposed methodology, a set of 32 experimental tests was performed using mixtures of two polymers with approximately the same density, PVC and PS (with mineral charges), with particle size ranging from 2 to 4 mm. The manipulated variables were frother concentration, air flow rate and pH. A three-level full factorial design was conducted. The models establishing the relationships between the manipulated variables and their interactions with the responses (first order kinetic model parameters) were built. The Corrected Akaike Information Criterion was used to select the best fit model and an analysis of variance (ANOVA) was conducted to identify the statistically significant terms of the model. It was shown that froth flotation can be used to efficiently separate PVC from PS with mineral charges by reducing the floatability of PVC, which largely depends on the action of pH. Within the tested interval, this is the factor that most affects the flotation rate constants. The results obtained show that the pure error may be of the same magnitude as the sum of squares of the errors, suggesting that there is significant variability within the same experimental conditions. Thus, special care is needed when evaluating and generalizing the process. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adsorption of modified dextrins on molybdenite: AFM imaging, contact angle, and flotation studies.

PubMed

Beaussart, Audrey; Parkinson, Luke; Mierczynska-Vasilev, Agnieszka; Beattie, David A

2012-02-15

The adsorption of three dextrins (a regular wheat dextrin, Dextrin TY, carboxymethyl (CM) Dextrin, and hydroxypropyl (HP) Dextrin) on molybdenite has been investigated using adsorption isotherms, tapping mode atomic force microscopy (TMAFM), contact angle measurements, and dynamic bubble-surface collisions. In addition, the effect of the polymers on the flotation recovery of molybdenite has been determined. The isotherms revealed the importance of molecular weight in determining the adsorbed amounts of the polymers on molybdenite at plateau coverage. TMAFM revealed the morphology of the three polymers, which consisted of randomly dispersed domains with a higher area fraction of surface coverage for the substituted dextrins. The contact angle of polymer-treated molybdenite indicated that polymer layer coverage and hydration influenced the mineral surface hydrophobicity. Bubble-surface collisions indicated that the polymers affected thin film rupture and dewetting rate differently, correlating with differences in the adsorbed layer morphology. Direct correlations were found between the surface coverage of the adsorbed layers, their impact on thin film rupture time, and their impact on flotation recovery, highlighting the paramount role of the polymer morphology in the bubble/particle attachment process and subsequent flotation. Copyright © 2011 Elsevier Inc. All rights reserved.

Selective depression mechanism of ferric chromium lignin sulfonate for chalcopyrite-galena flotation separation

NASA Astrophysics Data System (ADS)

Yu, Jin-sheng; Liu, Run-qing; Wang, Li; Sun, Wei; Peng, Hong; Hu, Yue-hua

2018-05-01

Selective recovery of chalcopyrite-galena ore by flotation remains a challenging issue. The development of highly efficient, low-cost, and environmentally friendly depressants for this flotation is necessary because most of available reagents (e.g., K2Cr2O4) are expensive and adversely affect the environment. In this study, ferric chromium lignin sulfonate (FCLS), which is a waste-product from the paper and pulp industry, was introduced as a selective depressant for galena with butyl xanthate (BX) as a collector. Results show that the residue recovery of Pb in Cu concentrate was substantially reduced to 4.73% using FCLS compared with 10.71% using the common depressant K2Cr2O4. The underlying mechanisms were revealed using zeta-potential measurements and X-ray photoelectron spectroscopy (XPS). Zeta-potential measurements revealed that FCLS was more efficiently absorbed onto galena than onto chalcopyrite. XPS measurements further suggested that FCLS enhanced the surface oxidation of galena but prevented that of chalcopyrite. Thus, FCLS could be a potential candidate as a depressant for chalcopyrite-galena flotation because of its low cost and its lack of detrimental effects on the environment.

Investigation of the possibility of copper recovery from the flotation tailings by acid leaching.

PubMed

Antonijević, M M; Dimitrijević, M D; Stevanović, Z O; Serbula, S M; Bogdanovic, G D

2008-10-01

The flotation tailings pond of the Bor Copper Mine poses a great ecological problem not only for the town of Bor but also for the surrounding soils and watercourses. Since the old flotation tailings contain about 0.2% of copper on the average, we investigated their leaching with sulphuric acid in the absence and presence of an oxidant. The aim was to determine the leaching kinetics of copper and iron as affected by various factors such as: the pH value of the leach solution, stirring speed, pulp density, particle size, concentration of ferric ions, temperature and time for leaching. The average copper and iron recovery obtained was from 60% to 70% and from 2% to 3%, respectively. These results indicate that the old flotation tailings pond represents an important source of secondary raw material for the extraction of copper and that it should be valorized rather than land reclamation. At the end of the paper, a mechanism of dissolution of copper and iron minerals from the tailings was described.

The application of atomic force microscopy in mineral flotation.

PubMed

Xing, Yaowen; Xu, Mengdi; Gui, Xiahui; Cao, Yijun; Babel, Bent; Rudolph, Martin; Weber, Stefan; Kappl, Michael; Butt, Hans-Jürgen

2018-06-01

During the past years, atomic force microscopy (AFM) has matured to an indispensable tool to characterize nanomaterials in colloid and interface science. For imaging, a sharp probe mounted near to the end of a cantilever scans over the sample surface providing a high resolution three-dimensional topographic image. In addition, the AFM tip can be used as a force sensor to detect local properties like adhesion, stiffness, charge etc. After the invention of the colloidal probe technique it has also become a major method to measure surface forces. In this review, we highlight the advances in the application of AFM in the field of mineral flotation, such as mineral morphology imaging, water at mineral surface, reagent adsorption, inter-particle force, and bubble-particle interaction. In the coming years, the complementary characterization of chemical composition such as using infrared spectroscopy and Raman spectroscopy for AFM topography imaging and the synchronous measurement of the force and distance involving deformable bubble as a force sensor will further assist the fundamental understanding of flotation mechanism. Copyright © 2018 Elsevier B.V. All rights reserved.

Apparatus and process for the separation of hydrophobic and hydrophilic particles using microbubble column flotation together with a process and apparatus for generation of microbubbles

DOEpatents

Yoon, R.H.; Adel, G.T.; Luttrell, G.H.

1992-12-01

A method and apparatus are disclosed for the microbubble flotation separation of very fine and coarse particles, especially coal and minerals, so as to produce high purity and high recovery efficiency. This is accomplished through the use of a flotation column, microbubbles, recycling of the flotation pulp, and countercurrent wash water to gently wash the froth. Also disclosed are unique processes and apparatus for generating microbubbles for flotation in a highly efficient and inexpensive manner using either a porous tube or in-line static generators. 14 figs.

Apparatus and process for the separation of hydrophobic and hydrophilic particles using microbubble column flotation together with a process and apparatus for generation of microbubbles

DOEpatents

Yoon, Roe-Hoan; Adel, Gregory T.; Luttrell, Gerald H.

1992-01-01

A method and apparatus are disclosed for the microbubble flotation separation of very fine and coarse particles, especially coal and minerals, so as to produce high purity and high recovery efficiency. This is accomplished through the use of a flotation column, microbubbles, recycling of the flotation pulp, and countercurrent wash water to gently wash the froth. Also disclosed are unique processes and apparatus for generating microbubbles for flotation in a highly efficient and inexpensive manner using either a porous tube or in-line static generators.

Apparatus and process for the separation of hydrophobic and hydrophilic particles using microbubble column flotation together with a process and apparatus for generation of microbubbles

DOEpatents

Yoon, R.H.; Adel, G.T.; Luttrell, G.H.

1998-09-29

A method and apparatus are disclosed for the microbubble flotation separation of very fine and coarse particles, especially coal and minerals, so as to produce high purity and high recovery efficiency. This is accomplished through the use of a flotation column, microbubbles, recycling of the flotation pulp, and countercurrent wash water to gently wash the froth. Also disclosed are unique processes and apparatus for generating microbubbles for flotation in a highly efficient and inexpensive manner using either a porous tube or in-line static generators. 14 figs.

Apparatus and process for the separation of hydrophobic and hydrophilic particles using microbubble column flotation together with a process and apparatus for generation of microbubbles

DOEpatents

Yoon, Roe-Hoan; Adel, Gregory T.; Luttrell, Gerald H.

1998-01-01

A method and apparatus are disclosed for the microbubble flotation separation of very fine and coarse particles, especially coal and minerals, so as to produce high purity and high recovery efficiency. This is accomplished through the use of a flotation column, microbubbles, recycling of the flotation pulp, and countercurrent wash water to gently wash the froth. Also disclosed are unique processes and apparatus for generating microbubbles for flotation in a highly efficient and inexpensive manner using either a porous tube or in-line static generators.

Flotation of oil-agglomerated coal for ash and pyrite removal -- Simultaneous grinding and agglomeration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, S.; Perkson, A.; Trass, O.

1996-12-31

Oil agglomeration is an excellent technique for the beneficiation of fine coal. For separation of the spherical agglomerates by screening, a high level of oil must be used, however. When the subsequent separation is done by flotation, this disadvantage is eliminated. Better pyrite removal is also possible. In this paper, such a fine coal beneficiation process, also called hydrophobic flocculation-flotation (HFF), is described. It features low non-polar oil consumption, intensive mechanical energy input, and smaller agglomerates or looser flocs. This process can be simplified by grinding the coal in water with small amounts of oil added. The excess grinding energymore » is then used for agglomerating the coal. The Prince coal from Nova Scotia contained 13.3% ash and 3.3% total sulfur, 1.4% pyritic. After four stages of flotation, ash and pyrite removal were 93% and 66% respectively, with 87% combustibles recovery. The parameters affecting the HFF process, such as particle size, dosage of non-polar oil, pH value of the slurry and duration of agitation, were investigated. Simultaneous grinding and agglomeration (SGA) utilizing the Szego Mill was also explored at the very low oil levels used. The intensive agitation/preconditioning step prior to flotation was eliminated. When the other parameters established from the sequential process were used with the SGA process, virtually identical beneficiation results were obtained, but with slightly lower combustibles recovery. While further testing is required to properly optimize the SGA process conditions, significant equipment simplification and energy savings are possible.« less

Flotation selectivity of novel alkyl dicarboxylate reagents for apatite-calcite separation.

PubMed

Karlkvist, Tommy; Patra, Anuttam; Rao, Kota Hanumantha; Bordes, Romain; Holmberg, Krister

2015-05-01

The investigation aims to demonstrate the conceptual thoughts behind developing mineral specific reagents for use in flotation of calcium containing ores. For this purpose, a series of dicarboxylate-based surfactants with varying distance between the carboxylate groups (one, two or three methylene groups) was synthesized. A surfactant with the same alkyl chain length but with only one carboxylate group was also synthesized and evaluated. The adsorption behavior of these new reagents on pure apatite and pure calcite surfaces was studied using Hallimond tube flotation, FTIR and ζ potential measurements. The relation between the adsorption behavior of a given surfactant at a specific mineral surface and its molecular structure over a range of concentrations and pH values, as well as the region of maximum recovery, was established. It was found that one of the reagents, with a specific distance between the carboxylate groups, was much more selective for a particular mineral surface than the other homologues. For example, out of the four compounds synthesized, only the one where the carboxylate groups were separated by a single methylene group floated apatite but not calcite, whereas calcite was efficiently floated with the monocarboxylic reagent, but not with the other reagents synthesized. This selective adsorption of a given surfactant to a particular mineral surface relative to other mineral surfaces as evidenced in the flotation studies was substantiated by ζ potential and infra-red spectroscopy data. Copyright © 2014 Elsevier Inc. All rights reserved.

Cork boiling wastewater treatment and reuse through combination of advanced oxidation technologies.

PubMed

Ponce-Robles, L; Miralles-Cuevas, S; Oller, I; Agüera, A; Trinidad-Lozano, M J; Yuste, F J; Malato, S

2017-03-01

Industrial preparation of cork consists of its immersion for approximately 1 hour in boiling water. The use of herbicides and pesticides in oak tree forests leads to absorption of these compounds by cork; thus, after boiling process, they are present in wastewater. Cork boiling wastewater shows low biodegradability and high acute toxicity involving partial inhibition of their biodegradation when conventional biological treatment is applied. In this work, a treatment line strategy based on the combination of advanced physicochemical technologies is proposed. The final objective is the reuse of wastewater in the cork boiling process; thus, reducing consumption of fresh water in the industrial process itself. Coagulation pre-treatment with 0.5 g/L of FeCl 3 attained the highest turbidity elimination (86 %) and 29 % of DOC elimination. Similar DOC removal was attained when using 1 g/L of ECOTAN BIO (selected for ozonation tests), accompanied of 64 % of turbidity removal. Ozonation treatments showed less efficiency in the complete oxidation of cork boiling wastewater, compared to solar photo-Fenton process, under the studied conditions. Nanofiltration system was successfully employed as a final purification step with the aim of obtaining a high-quality reusable permeate stream. Monitoring of unknown compounds by LC-QTOF-MS allowed the qualitative evaluation of the whole process. Acute and chronic toxicity as well as biodegradability assays were performed throughout the whole proposed treatment line.

A novel mineral flotation process using Thiobacillus ferrooxidans.

PubMed

Nagaoka, T; Ohmura, N; Saiki, H

1999-08-01

Oxidative leaching of metals by Thiobacillus ferrooxidans has proven useful in mineral processing. Here, we report on a new use for T. ferrooxidans, in which bacterial adhesion is used to remove pyrite from mixtures of sulfide minerals during flotation. Under control conditions, the floatabilities of five sulfide minerals tested (pyrite, chalcocite, molybdenite, millerite, and galena) ranged from 90 to 99%. Upon addition of T. ferrooxidans, the floatability of pyrite was significantly suppressed to less than 20%. In contrast, addition of the bacterium had little effect on the floatabilities of the other minerals, even when they were present in relatively large quantities: their floatabilities remained in the range of 81 to 98%. T. ferrooxidans thus appears to selectively suppress pyrite floatability. As a consequence, 77 to 95% of pyrite was removed from mineral mixtures while 72 to 100% of nonpyrite sulfide minerals was recovered. The suppression of pyrite floatability was caused by bacterial adhesion to pyrite surfaces. When normalized to the mineral surface area, the number of cells adhering to pyrite was significantly larger than the number adhering to other minerals. These results suggest that flotation with T. ferrooxidans may provide a novel approach to mineral processing in which the biological functions involved in cell adhesion play a key role in the separation of minerals.

An investigation of the efficacy of biological additives for the suppression of pyritic sulphur during simulated froth flotation of coal.

PubMed

Stainthorpe, A C

1989-02-05

The biological molecule responsible for the suppression of pyritic sulfur in fine coal simulated froth flotation treated with bacteria was identified. Protein was found to be the most effective agent in pyrite suppression of the three cell components (protein, lipid, and carbohydrate) assayed. Coal recovery and ash removal of the flotation process were only slightly reduced by this treatment. Other protein-containing materials were evaluated for their ability to suppress pyrite flotation. Whey was found to be the most cost-effective flotation additive of those assayed. The sulfur content of the whey-treated float was reduced by 84.0% in a synthetically prepared fractionated coal (10.7% sulfur), by a raw whey dosage of 20 microL/g coal. The inorganic sulfur component of a natural high sulfur coal fraction (10.9%) was completely depressed by this whey addition. The effect of particle size and pulp density upon the process were investigated.

A fine coal circuitry study using column flotation and gravity separation. Quarterly report, 1 March 1995--31 May 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

Honaker, R.Q.; Reed, S.

1995-12-31

Column flotation provides excellent recovery of ultrafine coal while producing low ash content concentrates. However, column flotation is not efficient for treating fine coal containing significant amounts of mixed-phase particles. Fortunately, enhanced gravity separation has proved to have the ability to treat the mixed-phased particles more effectively. A disadvantage of gravity separation is that ultrafine clay particles are not easily rejected. Thus, a combination of these two technologies may provide a circuit that maximizes both the ash and sulfur rejection that can be achieved by physical coal cleaning while maintaining a high energy recovery. This project is studying the potentialmore » of using different combinations of gravity separators, i.e., a Floatex hydrosizer and a Falcon Concentrator, and a proven flotation column, which will be selected based on previous studies by the principle investigator. During this reporting period, an extensive separation performance comparison between a pilot-scale Floatex Density Separator (18{times}18-inch) and an existing spiral circuit has been conducted at Kerf-McGee Coal Preparation plan for the treatment of nominally {minus}16 mesh coal. The results indicate that the Floatex is a more efficient separation device (E{sub p}=0.12) than a conventional coal spiral (E{sub p}=0.18) for Illinois seam coals. In addition, the treatment of {minus}100 mesh Illinois No. 5 fine coal from the same plant using Falcon concentrator, column flotation (Packed-Column) and their different combinations was also evaluated. For a single operation, both Falcon concentrator and column flotation can produce a clean coal product with 90% combustible recovery and 5% ash content. In the case of the combined circuit, column flotation followed by the Falcon achieved a higher combustible recovery value (about 75%) than that obtained by the individual units while maintaining an ash content less than 3%.« less

Frogmen on Apollo command module boilerplate flotation collar during recovery

NASA Image and Video Library

1966-02-22

Apollo command module boilerplate floats in the Atlantic Ocean during a practice recovery exercise. Frogmen in a liferaft and on the flotation collar secure the command module boilerplate for hoisting onto a nearby recovery ship. The exercise was conducted in preparation for the forthcoming Apollo-Saturn 201 (AS-201) mission.

Basic studies on the role of components of Bacillus megaterium as flotation biocollectors in sulphide mineral separation.

PubMed

Vasanthakumar, Balasubramanian; Ravishankar, Honnavar; Subramanian, Sankaran

2014-03-01

Studies were carried out to assess the utility of the cellular and extracellular constituents of Bacillus megaterium for the flotation of sphalerite and galena minerals. Based on the flotation results on the individual minerals, it was observed that sphalerite was preferentially floated compared to galena. A maximum selectivity index (SI) value of 11.7 was achieved in the presence of the soluble fraction of the thermolysed cells, which was higher than that obtained with the intact cells (SI of 6.5) and the insoluble fraction of the thermolysed cells (SI of 9.6). The results of the various enzymatic treatment tests revealed that extracellular DNA played a vital role in the selective flotation of sphalerite. A noteworthy finding was that the single-stranded DNA (ssDNA) had a higher biocollector capacity vis-à-vis the double-stranded DNA (dsDNA), leading to better flotation efficiency. About 95 % recovery of sphalerite could be achieved from the mineral mixture by the combined addition of the ssDNA with the non-DNA components of the bacterial cells, resulting in a maximum SI of 19.1. Calcium and phosphate components of the nutrient media were found to be essential for better selectivity of separation of sphalerite. The mechanisms of microbe-mineral interaction are discussed.

Enhancement of Chlorella vulgaris harvesting via the electro-coagulation-flotation (ECF) method.

PubMed

Wong, Y K; Ho, Y H; Leung, H M; Ho, K C; Yau, Y H; Yung, K K L

2017-04-01

This article explores the potential of using an electro-coagulation-flotation (ECF) harvester to allow flotation of microalgae cells for surface harvesting. A response surface methodology (RSM) model was used to optimize ECF harvesting by adjusting electrode plate material, electrode plate number, charge of the electrodes, electrolyte concentration, and pH value of the culture solution. The result revealed that three aluminum electrode plates (one anode and two cathodes), brine solution (8 g/L), and acidity (pH = 4) of culture solution (optimized ECF harvester) The highest flocculant concentration was measured at 2966 mg/L after 60 min and showed a 79.8 % increase of flocculation concentration. Such results can provide a basis for designing a large-scale microalgae harvester for commercial use in the future.

Selective depression of titanaugite in the ilmenite flotation with carboxymethyl starch

NASA Astrophysics Data System (ADS)

Meng, Qingyou; Yuan, Zhitao; Yu, Li; Xu, Yuankai; Du, Yusheng; Zhang, Chen

2018-05-01

In order to intensify the flotation separation of ilmenite from titanaugite, surface modification of mineral particles was carried out using carboxymethyl starch (CMS) by microflotation experiments, zeta potential measurements, Fourier transform infrared (FTIR) and atomic force microscopy (AFM) analysis. Microflotation results showed that CMS was a selective depressant, and it effectively enhanced the floatability difference between ilmenite and titanaugite in the pH range from 6.0 to 10.0. As it was revealed by the zeta potential, FTIR and AFM analysis, the CMS adsorption occurred onto mineral surfaces through chemisorption and hydrogen bonding, while CMS exhibited a stronger interaction with titanaugite than ilmenite. After that, the CMS adsorption impeded the adsorption of sodium oleate collector on titanaugite surfaces, giving rise to a concomitant decrease in the floatability of titanaugite. These findings exhibit great potential for CMS application in the selective flotation of ilmenite.

Raw water clarification by flotation with microbubbles and nanobubbles generated with a multiphase pump.

PubMed

Azevedo, A; Etchepare, R; Rubio, J

2017-05-01

Raw water clarification by flotation was studied by injecting air into a centrifugal multiphase pump to generate microbubbles (MBs) and nanobubbles (NBs). Measurements of gas dispersion parameters were performed and optimal conditions were obtained using a pump pressure of 4 bar. Values showed a bubble Sauter diameter of 75 μm, an air holdup of 1.2%, a bubble surface area flux of 34 s -1 and an NB concentration of 1 × 10 8 NBs mL -1 (measuring 220 nm). Then, a study compared flotation with bubbles formed with the multiphase pump (F-MP) to lamellar settling at the clarification stage of a water treatment plant (WTP), in Brazil. The F-MP showed a higher separation efficiency at high hydraulic loads (9-15 m h -1 ), even without the use of a polymer, reaching 2 NTU (10-25 NTU raw water feed), which was much lower than the technical goal of the WTP (5 NTU). The results and the technical aspects are discussed, and it is concluded that the employment of MBs and NBs with pumps widens new research lines and applications in modern flotation.

The Adsorption Capacity of GONs/CMC/Fe3O4 Magnetic Composite Microspheres and Applications for Purifying Dye Wastewater

PubMed Central

Lv, Shenghua; Zhu, Linlin; Li, Ying; Jia, Chunmao; Sun, Shiyu

2017-01-01

Graphene oxide nanosheets (GONs)/carboxymethyl chitosan (CMC)/Fe3O4 magnetic composite microspheres (MCMs) were prepared by enclosing Fe3O4 particles with CMC and GONs in turn. The microstructures of GONs and GONs/CMC/Fe3O4 MCMs were characterized by FTIR, XRD, TEM, and SEM. The effects of GON content, pH value, and adsorption time on the adsorption capacity of the MCMs were investigated. The results show that the GONs/CMC/Fe3O4 MCMs have a greater specific surface area and a strong adsorption capacity for dye wastewater. Meanwhile, the adsorption mechanism was investigated, and the results accorded with the pseudo-second-order kinetic model and the Freundlich isotherm model. The search results indicate that GONs/CMC/Fe3O4 MCMs can be used to purify dye wastewater and has an important potential use in the practical purification of dye wastewater. PMID:28772419

Understanding the role of ion interactions in soluble salt flotation with alkylammonium and alkylsulfate collectors.

PubMed

Ozdemir, Orhan; Du, Hao; Karakashev, Stoyan I; Nguyen, Anh V; Celik, M S; Miller, Jan D

2011-03-15

There is anecdotal evidence for the significant effects of salt ions on the flotation separation of minerals using process water of high salt content. Examples include flotation of soluble salt minerals such as potash, trona and borax in brine solutions using alkylammonium and alkylsulfate collectors such as dodecylamine hydrochloride and sodium dodecylsulfate. Although some of the effects are expected, some do not seem to be encompassed by classical theories of colloid science. Several experimental and modeling techniques for determining solution viscosity, surface tension, bubble-particle attachment time, contact angle, and molecular dynamics simulation have been used to provide further information on air-solution and solid-solution interfacial phenomena, especially with respect to the interfacial water structure due to the presence of dissolved ions. In addition atomic force microscopy, and sum frequency generation vibrational spectroscopy have been used to provide further information on surface states. These studies indicate that the ion specificity effect is the most significant factor influencing flotation in brine solutions. Copyright © 2011 Elsevier B.V. All rights reserved.

Zeta Potential Measurements on Three Clays from Turkey and Effects of Clays on Coal Flotation

PubMed

Hussain; Dem&idot;rc&idot;; özbayoğlu

1996-12-25

There is a growing trend of characterizing coal and coal wastes in order to study the effect of clays present in them during coal washing. Coarse wastes from the Zonguldak Coal Washery, Turkey, were characterized and found to contain kaolinite, illite, and chlorite. These three clays, obtained in almost pure form from various locations in Turkey, have been subjected to X-ray diffraction (XRD) analysis to assess their purity and zeta potential measurements in order to evaluate their properties in terms of their surface charge and point of zero charge (pzc) values. It was found from XRD data that these clays were almost pure and their electrokinetic potential should therefore be representative of their colloidal behavior. All three clay minerals were negatively charged over the range from pH 2.5 to 11. Chlorite and illite have pzc at pH 3 and pH 2.5, respectively, whereas kaolinite has no pzc. The effect of these clays in Zonguldak coal, wastes, and black waters on coal flotation was studied by floating artificial mixtures of Zonguldak clean coal (4.5% ash) and individual clay. The flotation tests on coal/individual clay revealed that each clay influences coal flotation differently according to its type and amount. Illite had the worst effect on coal floated, followed by chlorite and kaolinite. The loss of yield in coal was found to be 18% for kaolinite, 20% for chlorite, and 28% for illite, indicating the worst effect of illite and least for kaolinite during coal flotation.

Potential dual use of biochar for wastewater treatment and soil amelioration

NASA Astrophysics Data System (ADS)

Marschner, Bernd; Werner, Steffen; Alfes, Karsten; Lübken, Manfred

2013-04-01

Irrigating crops with wastewater from open drainage channels is a common practice in urban agricultural production in many dry regions of Africa, Asia and Latin America. While the wastewater-borne nutrients reduce the need for inputs of mineral fertilizers or manures and thus reduce production costs, wastewater-borne pathogens and contaminants pose a health risk for the producers and consumers of the crops. Furthermore, the input of nutrients with the irrigation water may greatly exceed crop requirements and thus lead to unproductive leaching losses of nutrients. It is generally acknowledged that biochar additions can increase the soil's sorption and retention capacity for nutrients and water. However, positive effects on crop production are generally only observed, if this is combined with mineral fertilizers or manures due to the low nutrient content of biochars. Biochar possibly also has a high potential for use in water purification, replacing the coal-based activated carbon as a sorbent for contaminants and pathogens. It was therefore hypothesized that biochar can be used for pathogen removal from wastewater while at the same time being loaded with nutrients and contaminants. If contaminants are of minor concern the "loaded" biochar can be used as a soil amendment, providing not only long-term sorption capacity but also nutrients. Experiments were conducted with pyrochar from Miscanthus, rice husks and wood chips, which strongly differed in elemental composition, MIR-DRIFT spectra, surface charge properties and sorption potential for DOC and phosphate. When used as top filter layer in a sand column system, the biochars effectively reduced E. coli concentrations from raw wastewater by up to 2 log units. While biochars from rice husks and Miscanthus accumulated N substantially, wood chip biochar showed no N retention. On the other hand, P accumulation was most pronounced for wood chip biochar. Ongoing incubation experiments with the "loaded" and fresh biochar in

Laboratory-and mill-scale study of surfactant spray flotation deinking

Treesearch

Greg Delozier; Yulin Zhao; Yulin Deng; David White; Junyong Zhu; Mark Prein

2005-01-01

As the cost of quality waste paper continues to escalate in response to an increased global demand for this finite resource, loss of saleable fiber within flotation rejects becomes both environmentally and economically unacceptable. The ability of surfactant spray technology to reduce fiber loss without detriment to pulp brightness gains has been demonstrated during...

The utilization of waste by-products for removing silicate from mineral processing wastewater via chemical precipitation.

PubMed

Kang, Jianhua; Sun, Wei; Hu, Yuehua; Gao, Zhiyong; Liu, Runqing; Zhang, Qingpeng; Liu, Hang; Meng, Xiangsong

2017-11-15

This study investigates an environmentally friendly technology that utilizes waste by-products (waste acid and waste alkali liquids) to treat mineral processing wastewater. Chemical precipitation is used to remove silicate from scheelite (CaWO 4 ) cleaning flotation wastewater and the waste by-products are used as a substitute for calcium chloride (CaCl 2 ). A series of laboratory experiments is conducted to explain the removal of silicate and the characterization and formation mechanism of calcium silicate. The results show that silicate removal reaches 90% when the Ca:Si molar ratio exceeds 1.0. The X-ray diffraction (XRD) results confirm the characterization and formation of calcium silicate. The pH is the key factor for silicate removal, and the formation of polysilicic acid with a reduction of pH can effectively improve the silicate removal and reduce the usage of calcium. The economic analysis shows that the treatment costs with waste acid (0.63 $/m 3 ) and waste alkali (1.54 $/m 3 ) are lower than that of calcium chloride (2.38 $/m 3 ). The efficient removal of silicate is confirmed by industrial testing at a plant. The results show that silicate removal reaches 85% in the recycled water from tailings dam. Copyright © 2017 Elsevier Ltd. All rights reserved.

Separation of polycarbonate and acrylonitrile–butadiene–styrene waste plastics by froth flotation combined with ammonia pretreatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Chong-qing; Wang, Hui, E-mail: huiwang1968@163.com; Liu, Qun

Highlights: • Ammonia treatment changes selectively floatability of PC. • The effects of ammonia on PC were investigated through contact angle and XPS. • Reactions between ammonia and PC surface make PC more hydrophilic. • PC and ABS mixtures with different particle sizes were separated effectively. - Abstract: The objective of this research is flotation separation of polycarbonate (PC) and acrylonitrile–butadiene–styrene (ABS) waste plastics combined with ammonia pretreatment. The PC and ABS plastics show similar hydrophobicity, and ammonia treatment changes selectively floatability of PC plastic while ABS is insensitive to ammonia treatment. The contact angle measurement indicates the dropping ofmore » flotation recovery of PC is ascribed to a decline of contact angle. X-ray photoelectron spectroscopy demonstrates reactions occur on PC surface, which makes PC surface more hydrophilic. Separation of PC and ABS waste plastics was conducted based on the flotation behavior of single plastic. At different temperatures, PC and ABS mixtures were separated efficiently through froth flotation with ammonia pretreatment for different time (13 min at 23 °C, 18 min at 18 °C and 30 min at 23 °C). For both PC and ABS, the purity and recovery is more than 95.31% and 95.35%, respectively; the purity of PC and ABS is up to 99.72% and 99.23%, respectively. PC and ABS mixtures with different particle sizes were separated effectively, implying that ammonia treatment possesses superior applicability.« less

46 CFR 28.110 - Life preservers or other personal flotation devices.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Life preservers or other personal flotation devices. 28.110 Section 28.110 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Requirements for All Vessels § 28.110 Life preservers or...

46 CFR 28.110 - Life preservers or other personal flotation devices.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Life preservers or other personal flotation devices. 28.110 Section 28.110 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Requirements for All Vessels § 28.110 Life preservers or...

46 CFR 28.110 - Life preservers or other personal flotation devices.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Life preservers or other personal flotation devices. 28.110 Section 28.110 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Requirements for All Vessels § 28.110 Life preservers or...

46 CFR 28.110 - Life preservers or other personal flotation devices.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Life preservers or other personal flotation devices. 28.110 Section 28.110 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Requirements for All Vessels § 28.110 Life preservers or...

Study on the pre-treatment of oxidized zinc ore prior to flotation

NASA Astrophysics Data System (ADS)

He, Dong-sheng; Chen, Yun; Xiang, Ping; Yu, Zheng-jun; Potgieter, J. H.

2018-02-01

The pre-treatment of zinc oxide bearing ores with high slime content is important to ensure that resources are utilized optimally. This paper reports an improved process using hydrocyclone de-sliming, dispersion reagents, and magnetic removal of iron minerals for the pre-treatment of zinc oxide ore with a high slime and iron content, and the benefits compared to traditional technologies are shown. In addition, this paper investigates the damage related to fine slime and iron during zinc oxide flotation, the necessity of using hydrocyclone de-sliming together with dispersion reagents to alleviate the influence of slime, and interactions among hydrocyclone de-sliming, reagent dispersion, and magnetic iron removal. Results show that under optimized operating conditions the entire beneficiation technology results in a flotation concentrate with a Zn grade of 34.66% and a recovery of 73.41%.

Formation of zinc sulfide species during roasting of ZnO with pyrite and its contribution on flotation.

PubMed

Zheng, Yong-Xing; Lv, Jin-Fang; Wang, Hua; Wen, Shu-Ming; Pang, Jie

2018-05-18

In this paper, formation of zinc sulfide species during roasting of ZnO with FeS 2 was investigated and its contribution on flotation was illustrated. The evolution process, phase and crystal growth were investigated by thermogravimetry (TG), X-Ray diffraction (XRD) along with thermodynamic calculation and scanning electron microscopy-Energy-dispersive X-ray spectroscopy (SEM-EDS), respectively, to interpret the formation mechanism of ZnS species. It was found that ZnS was initially generated at about 450 °C and then the reaction prevailed at about 600 °C. The generated Fe x S would dissolve into ZnS and then form (Zn, Fe)S compound in form of Fe 2 Zn 3 S 5 when temperature increased to about 750 °C. This obviously accelerated ZnS phase formation and growth. In addition, it was known that increasing of ZnO dosage had few effects on the decomposition behavior of FeS 2 . Then, flotation tests of different zinc oxide materials before and after treatment were performed to further confirm that the flotation performances of the treated materials could be obviously improved. Finally, a scheme diagram was proposed to regular its application to mineral processing. It was systematically illustrated that different types of ZnS species needed to be synthetized when sulfidization roasting-flotation process was carried out to treat zinc oxide materials.

Donning times and flotation characteristics of infant life preservers : four representative types.

DOT National Transportation Integrated Search

1991-04-01

Four currently available representative types of infant life preservers were tested to assess the donning times and flotation characteristics for infant subjects(6 months to 2 years old). Two of the four devices tested were fixed-foam recreational de...

Drainage and fractionation of wood fibers in a flotation froth

Treesearch

J.Y. Zhu; Freya Tan

2005-01-01

Understanding fiber fractionation in a froth is very important to the quality of recovered fibers in flotation deinking operations. Fiber length is a very important fiber quality parameter in paper-making. For example, long fibers tend to produce a paper with higher tear strength than short fibers. In this study, fibers in froth collected at different froth drainage...

A Novel Mineral Flotation Process Using Thiobacillus ferrooxidans

PubMed Central

Nagaoka, Toru; Ohmura, Naoya; Saiki, Hiroshi

1999-01-01

Oxidative leaching of metals by Thiobacillus ferrooxidans has proven useful in mineral processing. Here, we report on a new use for T. ferrooxidans, in which bacterial adhesion is used to remove pyrite from mixtures of sulfide minerals during flotation. Under control conditions, the floatabilities of five sulfide minerals tested (pyrite, chalcocite, molybdenite, millerite, and galena) ranged from 90 to 99%. Upon addition of T. ferrooxidans, the floatability of pyrite was significantly suppressed to less than 20%. In contrast, addition of the bacterium had little effect on the floatabilities of the other minerals, even when they were present in relatively large quantities: their floatabilities remained in the range of 81 to 98%. T. ferrooxidans thus appears to selectively suppress pyrite floatability. As a consequence, 77 to 95% of pyrite was removed from mineral mixtures while 72 to 100% of nonpyrite sulfide minerals was recovered. The suppression of pyrite floatability was caused by bacterial adhesion to pyrite surfaces. When normalized to the mineral surface area, the number of cells adhering to pyrite was significantly larger than the number adhering to other minerals. These results suggest that flotation with T. ferrooxidans may provide a novel approach to mineral processing in which the biological functions involved in cell adhesion play a key role in the separation of minerals. PMID:10427053

Method for simultaneous use of a single additive for coal flotation, dewatering, and reconstitution

DOEpatents

Wen, Wu-Wey; Gray, McMahan L.; Champagne, Kenneth J.

1995-01-01

A single dose of additive contributes to three consecutive fine coal unit operations, i.e., flotation, dewatering and reconstitution, whereby the fine coal is first combined with water in a predetermined proportion so as to formulate a slurry. The slurry is then mixed with a heavy hydrocarbon-based emulsion in a second predetermined proportion and at a first predetermined mixing speed and for a predetermined period of time. The conditioned slurry is then cleaned by a froth flotation method to form a clean coal froth and then the froth is dewatered by vacuum filtration or a centrifugation process to form reconstituted products that are dried to dust-less clumps prior to combustion.

Antifouling grafting of ceramic membranes validated in a variety of challenging wastewaters.

PubMed

Mustafa, Ghulam; Wyns, Kenny; Buekenhoudt, Anita; Meynen, Vera

2016-11-01

Compared to traditional separation and purification techniques, membrane filtration is particularly beneficial for the treatment of wastewater streams such as pulp and paper mill effluents (PPME), olive oil wastewater (OOWW) and oil/gas produced water (PW). However, severe membrane fouling can be a major issue. In this work, the use of ceramic membranes and the potential for the broad applicability of a recently developed antifouling grafting was evaluated to tackle this issue. To this end, the fouling behavior of native and grafted membranes was tested in the selected difficult wastewater streams, both in dead-end and in cross-flow mode. In addition, the quality of the produced permeate water was determined to assess the overall performance of the investigated membranes for reuse or recycling of the treated wastewater. The obtained results show that grafting significantly enhances the antifouling tendency of the ceramic membranes. Particularly, the membrane grafted with methyl groups using the Grignard technique (MGR), showed in all cases no or negligible fouling as compared to the native membrane. As a consequence, the process flux or filtration capacity of the MGR membrane in cross-flow is always higher and more stable than the native membrane, even though the grafting lowers the pure water flux. Hence, the inert character of the MGR membrane is repeatedly proven and shown to be broadly applicable and generic for anti-fouling, without loss in permeate quality. Moreover, in case of OOWW, the quality of the MGR permeate is even better than that of the native membrane due to its lower fouling. All results can be explained taking into account the physico-chemical properties of foulants and membranes, as shown in previous work. In conclusion, the use of MGR membranes could provide an optimum economical solution for the treatment of the selected challenging wastewaters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Indirect determination of thiocyanate with ammonium sulfate and ethanol by extraction-flotation of copper.

PubMed

Li, Q; Wei, W; Liu, Q

2000-10-01

A new method for the indirect determination of thiocyanate with ammonium sulfate and ethanol by extraction-flotation of copper in the presence of ascorbic acid is described. A small amount of Cu(II) is reduced to Cu(I) by ascorbic acid, then Cu(I) is precipitated with SCN-. In the course of phase separation of ethanol from water, the precipitated CuSCN stays in the interface of ethanol and water. A good linear relationship is observed between the flotation yield of Cu(II) and the amount of SCN-. Using 1.0 ml of 1 x 10(-3) M ascorbic acid solution, 50 micrograms of Cu(II), 3.5 g of (NH4)2SO4 and 3.0 ml of ethanol with a total volume of 10 ml, the concentration of thiocyanate could then be determined by determining the flotation yield of Cu(II). The detection limit for thiocyanate is 5 x 10(-5) M. Every parameter was optimized and the reaction mechanism was studied. The method is simple and rapid and it was successfully applied to the determination of thiocyanate in urine and saliva of smokers and non-smokers and in venous blood of patients infused with sodium nitroprusside.

Development of Technology for Enrichment of Silver Containing Ores

NASA Astrophysics Data System (ADS)

Shekiladze, Asmati; Kavtelashvili, Otari; Bagnashvili, Mamuka

2016-10-01

The progress of Georgian economics is substantially associated with a development of new deposits of mineral resources. Among them is the David-Gareji deposit where at present the intensive searching geological works are performed. The work goal involves the elaboration of the technology for processing of silver-containing quartz-barite ores. Without its development the mining of more valuable gold-polymetallic ores is impossible. Because of ore complexity silver and barite are considered in a common technological aspect. The investigations were carried out on the representative samples of quartz-barite ores containing 78-88 g/ton of silver and 27-29 % of silver is a nugget in the form of the simple sulphides and chlorides. The ore is characterized by fine coalescence of barite and ore-generating minerals. Non-ferrous metals haven't any industrial value because of their very low content. Therefore, for the processing of the ores under study the direct selective scheme of flotation enrichment was chosen and the formula of optimal reagent regime was elaborated. Potassium xanthogenate is used as a collector for flotation of silver minerals and pine oil- as a foaming agent. The effect of the pulp - pH and medium temperature on silver flotation was studied. It was established that the silver is actively floats in neutral medium. For barite flotation the various collectors were tested: sulfidezid cotton oil-soap stock, soaps of fatty acids and alkyl sulphates of C12 - C16 row, among the “Baritol” is the most efficient one. Depression of the barren rock was carried out by liquid glass in alkaline medium. The effect of pulp pH on barite flotation has been investigated. The best results were obtained at pH=8.5. The increase of the pulp alkalinity has no essential effect on the indexes of the barite enrichment. Conditional concentrate of the barite is obtained by two fold purification of the main flotation concentrate by the addition of the liquid glass to the re-purification

Degradation of organic pollutants and microorganisms from wastewater using different dielectric barrier discharge configurations--a critical review.

PubMed

Mouele, Emile S Massima; Tijani, Jimoh O; Fatoba, Ojo O; Petrik, Leslie F

2015-12-01

The growing global drinking water crisis requires the development of novel advanced, sustainable, and cost-effective water treatment technologies to supplement the existing conventional methods. One such technology is advanced oxidation based on dielectric barrier discharge (DBD). DBD such as single and double planar and single and double cylindrical dielectric barrier configurations have been utilized for efficient degradation of recalcitrant organic pollutants. The overall performance of the different DBD system varies and depends on several factors. Therefore, this review was compiled to give an overview of different DBD configurations vis-a-viz their applications and the in situ mechanism of generation of free reactive species for water and wastewater treatment. Our survey of the literature indicated that application of double cylindrical dielectric barrier configuration represents an ideal and viable route for achieving greater water and wastewater purification efficiency.

Succinonitrile Purification Facility

NASA Technical Reports Server (NTRS)

2003-01-01

The Succinonitrile (SCN) Purification Facility provides succinonitrile and succinonitrile alloys to several NRA selected investigations for flight and ground research at various levels of purity. The purification process employed includes both distillation and zone refining. Once the appropriate purification process is completed, samples are characterized to determine the liquidus and/or solidus temperature, which is then related to sample purity. The lab has various methods for measuring these temperatures with accuracies in the milliKelvin to tenths of milliKelvin range. The ultra-pure SCN produced in our facility is indistinguishable from the standard material provided by NIST to well within the stated +/- 1.5mK of the NIST triple point cells. In addition to delivering material to various investigations, our current activities include process improvement, characterization of impurities and triple point cell design and development. The purification process is being evaluated for each of the four vendors to determine the efficacy of each purification step. We are also collecting samples of the remainder from distillation and zone refining for analysis of the constituent impurities. The large triple point cells developed will contain SCN with a melting point of 58.0642 C +/- 1.5mK for use as a calibration standard for Standard Platinum Resistance Thermometers (SPRTs).

A novel method to harvest Chlorella sp. by co-flocculation/air flotation.

PubMed

Zhang, Haiyang; Lin, Zhe; Tan, Daoyong; Liu, Chunhua; Kuang, Yali; Li, Zhu

2017-01-01

To develop a more effective dissolved air flotation process for harvesting microalgae biomass, a co-flocculation/air flotation (CAF) system was developed that uses an ejector followed by a helix tube flocculation reactor (HTFR) as a co-flocculation device to harvest Chlorella sp. 64.01. The optimal size distribution of micro-bubbles and an air release efficiency of 96 % were obtained when the flow ratio of inlet fluid (raw water) to motive fluid (saturated water) of the ejector was 0.14. With a reaction time of 24 s in the HTFR, microalgae cells and micro-bubbles were well flocculated, and these aerated flocs caused a fast rising velocity (96 m/h) and high harvesting efficiency (94 %). In a CAF process, micro-bubbles can be encapsulated into microalgae flocs, which makes aerated flocs more stable. CAF is an effective approach to harvesting microalgae.

Carboxymethylcellulose adsorption on molybdenite: the effect of electrolyte composition on adsorption, bubble-surface collisions, and flotation.

PubMed

Kor, Mohammad; Korczyk, Piotr M; Addai-Mensah, Jonas; Krasowska, Marta; Beattie, David A

2014-10-14

The adsorption of carboxymethylcellulose polymers on molybdenite was studied using spectroscopic ellipsometry and atomic force microscopy imaging with two polymers of differing degrees of carboxyl group substitution and at three different electrolyte conditions: 1 × 10(-2) M KCl, 2.76 × 10(-2) M KCl, and simulated flotation process water of multicomponent electrolyte content, with an ionic strength close to 2.76 × 10(-2) M. A higher degree of carboxyl substitution in the adsorbing polymer resulted in adsorbed layers that were thinner and with more patchy coverage; increasing the ionic strength of the electrolyte resulted in increased polymer layer thickness and coverage. The use of simulated process water resulted in the largest layer thickness and coverage for both polymers. The effect of the adsorbed polymer layer on bubble-particle attachment was studied with single bubble-surface collision experiments recorded with high-speed video capture and image processing and also with single mineral molybdenite flotation tests. The carboxymethylcellulose polymer with a lower degree of substitution resulted in almost complete prevention of wetting film rupture at the molybdenite surface under all electrolyte conditions. The polymer with a higher degree of substitution prevented rupture only when adsorbed from simulated process water. Molecular kinetic theory was used to quantify the effect of the polymer on the dewetting dynamics for collisions that resulted in wetting film rupture. Flotation experiments confirmed that adsorbed polymer layer properties, through their effect on the dynamics of bubble-particle attachment, are critical to predicting the effectiveness of polymers used to prevent mineral recovery in flotation.

Method for enhancing selectivity and recovery in the fractional flotation of particles in a flotation column

DOEpatents

Klunder, Edgar B [Bethel Park, PA

2011-08-09

The method relates to particle separation from a feed stream. The feed stream is injected directly into the froth zone of a vertical flotation column in the presence of a counter-current reflux stream. A froth breaker generates a reflux stream and a concentrate stream, and the reflux stream is injected into the froth zone to mix with the interstitial liquid between bubbles in the froth zone. Counter-current flow between the plurality of bubbles and the interstitial liquid facilitates the attachment of higher hydrophobicity particles to bubble surfaces as lower hydrophobicity particles detach. The height of the feed stream injection and the reflux ratio may be varied in order to optimize the concentrate or tailing stream recoveries desired based on existing operating conditions.

The role of S(II) and Pb(II) in xanthate flotation of smithsonite: Surface properties and mechanism

NASA Astrophysics Data System (ADS)

Jia, Kai; Feng, Qiming; Zhang, Guofan; Ji, Wanying; Zhang, Wukai; Yang, Bingqian

2018-06-01

Smithsonite is a readily dissolvable carbonate mineral that is naturally hydrophilic, making recovery of this ore by flotation difficult. The flotation results showed that conditioning with only sodium sulfide (Na2S) did not successfully allow the smithsonite samples to float, whereas treatment with a combination of S(II), Pb(II) and xanthate (with Na2S as the sulfurizing reagent, lead ions (Pb(II)) as the activator, and xanthate as the collector) improved the flotation of smithsonite, achieving a mass recovery of 95.8%. A combination of analytical techniques, including X-ray diffraction (XRD), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), in conjunction with depth profiling, was used to investigate the chemical nature of the sulfur and lead species on the smithsonite surface. For S(II)-conditioned smithsonite, a layer of ZnS formed on the smithsonite (ZnCO3) substrates; this newly formed ZnS coating was amorphous or poorly crystallized. For smithsonite samples conditioned with S(II) and Pb(II), the microstructures and the phase constituents, obtained by AFM and XRD analyses, confirmed the formation of the PbS species with a cubic galena structure on the surface. XPS depth profiling showed that the PbS layer was 18-nm thick, which corresponds to 30 PbS molecular layers. This study presents direct evidence that the coating of the activation product, PbS, on the smithsonite surface was similar to a relatively thick galena layer, which led to successful flotation.

Development of copper recovery process from flotation tailings by a combined method of high‒pressure leaching‒solvent extraction.

PubMed

Han, Baisui; Altansukh, Batnasan; Haga, Kazutoshi; Stevanović, Zoran; Jonović, Radojka; Avramović, Ljiljana; Urosević, Daniela; Takasaki, Yasushi; Masuda, Nobuyuki; Ishiyama, Daizo; Shibayama, Atsushi

2018-06-15

Sulfide copper mineral, typically Chalcopyrite (CuFeS 2 ), is one of the most common minerals for producing metallic copper via the pyrometallurgical process. Generally, flotation tailings are produced as a byproduct of flotation and still consist of un‒recovered copper. In addition, it is expected that more tailings will be produced in the coming years due to the increased exploration of low‒grade copper ores. Therefore, this research aims to develop a copper recovery process from flotation tailings using high‒pressure leaching (HPL) followed by solvent extraction. Over 94.4% copper was dissolved from the sample (CuFeS 2 as main copper mineral) by HPL in a H 2 O media in the presence of pyrite, whereas the iron was co‒dissolved with copper according to an equation given as C Cu  = 38.40 × C Fe . To avoid co‒dissolved iron giving a negative effect on the subsequent process of electrowinning, solvent extraction was conducted on the pregnant leach solution for improving copper concentration. The result showed that 91.3% copper was recovered in a stripped solution and 98.6% iron was removed under the optimal extraction conditions. As a result, 86.2% of copper was recovered from the concentrate of flotation tailings by a proposed HPL‒solvent extraction process. Copyright © 2018 Elsevier B.V. All rights reserved.

Investigation of corrosion caused by constituents of refinery wastewater effluent used as circulating cooling water.

PubMed

Zhang, Zhongzhi; Song, Shaofu; Huang, Jie; Ji, Lin; Wu, Fangyun

2003-01-01

The corrosion rate of steel plate using single-factor, multifactor, and complex water systems was investigated via refinery wastewater effluents used as circulating cooling water. The results show that the primary corrosion factors of steel depend on the characteristics of the ions, the formation of the oxidized coating, the diffusion of dissolved oxygen, and other complex factors, although ions such as chloride, calcium, and carbonate play an important role. The corrosion rate of carbon steel exhibits two trends: The corrosion rate is high at low conductivity, increases to a maximum, and then decreases and becomes stable with increasing conductivity, as is the case with chloride, sulfate, nitrate and calcium ions. On the other hand, the corrosion rate is highest at low conductivity and then decreases and becomes stable with increasing conductivity, as is the case with carbonate, silicate, and sodium nitrate ions. Research results indicate that the anticorrosive ability is minimal at low conductivity; but is excellent at high conductivity. Pretreatment of low-conductivity water using air flotation and clarification to decrease the concentrations of chloride, calcium, and carbonate ions to a suitable level to satisfy the anticorrosion requirements is required. However, it is not necessary to significantly reduce the salt concentration or conductivity of the water by osmosis or ion exchange to obtain an anticorrosion effect when reusing wastewater effluents as circulating cooling water.

[FTIR and 13C NMR Analysis of Dissolved Organic Matter (DOM) in the Treatment Process of Tannery Wastewater].

PubMed

Fan, Chun-hui; Zhang, Ying-chao; Tang, Ze-heng; Wang, Jia-hong

2015-05-01

wastewater is significant to understand the purification mechanism of contaminants in tannery wastewater.

Removal of copper (II) from aqueous solutions by flotation using polyaluminum chloride silicate (PAX-XL60 S) as coagulant and carbonate ion as activator.

PubMed

Ghazy, S E; Mahmoud, I A; Ragab, A H

2006-01-01

Flotation is a separation technology for removing toxic heavy metal ions from aqueous solutions. Here a simple and rapid flotation procedure is presented for the removal of copper(II) from aqueous solutions. It is based on the use of polyaluminum chloride silicate (PAX-XL60 S) as coagulant and flocculent, carbonate ion as activator and oleic acid (HOL) as surfactant. Both ion and precipitate flotation are included depending on the solution pH. Ion and precipitate flotation in the aqueous HOL-PAX-XL60 S-Cu2+-CO3(2-) system gave powerful preferential removal of Cu2+ (F -100%) over the HOL-PAX-XL60 S-Cu2+ system containing no CO3(2+) ion (F approximately 86%). The role of CO3(2-) ion is also evident from decreasing the dose of PAX-XL60 S from 700 mg l(-1) to 200 mg l(-1). The other parameters, influencing the flotation process, namely: metal ion, surfactant and PAX-XL60 S concentrations, ionic strength, temperature and foreign ions were examined. Moreover, the procedure was successfully applied to recover Cu2+ ions from different volumes up to 11 and from natural water samples.

The removal of heavy metals from contaminated soil by a combination of sulfidisation and flotation.

PubMed

Vanthuyne, Mathias; Maes, André

2002-05-06

The possibility of removing cadmium, copper, lead and zinc from Belgian loamy soil by a combination of sulfidisation pre-treatment and Denver flotation was investigated. The potentially available--sulfide convertible--metal content of the metal polluted soil was estimated by EDTA (0.1 M, pH 4.65) extraction and BCR sequential extraction. EDTA extraction is better at approximating the metal percentage that is expected to be convertible into a metal sulfide phase, in contrast to the sequential extraction procedure of 'Int. J. Environ. Anal. Chem. 51 (1993) pp. 135-151' in which transition metals present as iron oxide co-precipitates are dissolved by hydroxylammoniumchloride in the second extraction step. To compare the surface characteristics of metal sulfides formed by sulfidisation with those of crystalline metal sulfides, two types of synthetic sediments were prepared and extracted with 0.1 M EDTA (pH 4.65) in anoxic conditions. Separate metal sulfides or co-precipitates with iron sulfide were formed by sulfide conditioning. The Denver flotation of both types of synthetic sediments (kerosene as collector at high background electrolyte concentrations) resulted in similar concentrating factors for freshly formed metal sulfides as for fine-grained crystalline metal sulfides. The selective flotation of metal sulfides after sulfide conditioning of a polluted soil, using kerosene or potassium ethyl xanthate as collectors and MIBC as frother, was studied at high background electrolyte concentrations. The sulfidisations were made in ambient air and inside an anoxic glove box. The concentrating factors corrected by the potentially available metal percentage, determined by 0.1 M EDTA extraction, lie between 2 and 3. The selective flotation of these finely dispersed, amorphous, metal sulfides can possibly be improved by optimising the bubble-particle interaction.

A Simple Flotation De-Linking Experiment for the Recycling of Paper

ERIC Educational Resources Information Center

Venditti, Richard A.

2004-01-01

A laboratory exercise for the flotation de-linking of wastepaper is described, which consists of disintegrating printed wastepaper in a blender and then removing the ink or toner contaminants by pumping air bubbles through suspension using an aquarium pump or other source of air bubbles. The exercise has proven extremely reliable and consistent in…

Potential of using plant extracts for purification of shallow well water in Malawi

NASA Astrophysics Data System (ADS)

Pritchard, M.; Mkandawire, T.; Edmondson, A.; O'Neill, J. G.; Kululanga, G.

There has been very little scientific research work into the use of plant extracts to purify groundwater. Research studies on the purification of groundwater have mainly been carried out in developed countries and have focused on water purification systems using aluminium sulphate (a coagulant) and chlorine (a disinfectant). Such systems are expensive and not viable for rural communities due to abject poverty. Shallow well water, which is commonly available throughout Africa, is often grossly contaminated and usually consumed untreated. As a result, water-related diseases kill more than 5 million people every year worldwide. This research was aimed at examining natural plant extracts in order to develop inexpensive ways for rural communities to purify their groundwater. The study involved creating an inventory of plant extracts that have been used for water and wastewater purification. A prioritisation system was derived to select the most suitable extracts, which took into account criteria such as availability, purification potential, yield and cost of extraction. Laboratory trials were undertaken on the most promising plant extracts, namely: Moringa oleifera, Jatropha curcas and Guar gum. The extracts were added to water samples obtained from five shallow wells in Malawi. The trials consisted of jar tests to assess the coagulation potential and the resulting effect on physico-chemical and microbiological parameters such as temperature, pH, turbidity and coliforms. The results showed that the addition of M. oleifera, J. curcas and Guar gum can considerably improve the quality of shallow well water. Turbidity reduction was higher for more turbid water. A reduction efficiency exceeding 90% was achieved by all three extracts on shallow well water that had a turbidity of 49 NTU. A reduction in coliforms was about 80% for all extracts. The pH of the water samples increased with dosage, but remained within acceptable levels for drinking water for all the extracts

High-performance reagent modes for flotation recovery of platiniferous copper and nickel sulfides from hard-to-beneficiate ores

NASA Astrophysics Data System (ADS)

Matveeva, T. N.; Chanturiya, V. A.

2017-07-01

The paper presents the results of the recent research performed in IPKON Russian Academy of Sciences that deals with development and substantiation of new selective reagents for effective flotation recovery of non-ferrous and noble metals from refractory ores. The choice and development of new selective reagents PTTC, OPDTC, modified butylxanthate (BXm) and modified diethyl-dithiocarbamate (DEDTCm) to float platiniferous copper and nickel sulfide minerals from hard-to-beneficiate ores is substantiated. The mechanism of reagents adsorption and regulation of minerals floatability is discussed. The study of reagent modes indicates that by combining PTTC with the modified xanthate results in 6 - 7 % increase in the recovery of copper, nickel and PGM in the flotation of the low-sulfide platiniferous Cu-Ni ore from the Fedorovo-Panskoye deposit. The substitution of OPDTC for BX makes it possible to increase recovery of Pt by 13 %, Pd by 9 % and 2 - 4 times the noble metal content in the flotation concentrate.

Predicting the efficiencies of 2-mercaptobenzothiazole collectors used as chelating agents in flotation processes: a density-functional study.

PubMed

Yekeler, Hülya; Yekeler, Meftuni

2006-09-01

In recent years, several new chelating reagents have been synthesized and tested for their collecting power in sulfide and non-sulfide minerals flotation. Many researchers have indicated that chelating reagents have the advantage of offering better selectivity and specificity as flotation collectors. Therefore, density functional theory (DFT) calculations at the B3LYP/6-31G(d,p) level were performed to investigate the observed activities of 2-mercaptobenzothiazole, 6-methyl-2-mercaptobenzothiazole and 6-methoxy-2-mercaptobenzothiazole as the most popular flotation collectors. The molecular properties and activity relationships were determined by the HOMO localizations, the HOMO energies, Mulliken charges and the electrostatic potentials at the thioamide functional group, which is the key site in the forming efficiency of the collectors studied. It is concluded that these quantities can be used successfully for understanding the collecting abilities of 2-mercaptobenzothiazoles. The results obtained theoretically are consistent with the experimental data reported in the literature.

Imidazoline conditioner for the flotation of oxidized coal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hefner, R.E. Jr.

1984-05-22

Froth flotation of oxidized coal in the presence of certain imidazoline or imidazolinium salts improves both the selectivity and recovery attained. Imidazolines found particularly efficacious are those bearing a fatty alkyl group in the 2- position and an N-aminoethyl or N-hydroxyethyl group. Preferred imidazolinium salts are those corresponding to the following formula: 1-((-)OOC-CH/sub 2/-),1-(C/sub 11/ to C/sub 17/ alkyl or alkenyl-COO-CH/sub 2/-),2-R-2-imidazoline(+) wherein R is a C/sub 6/ to C/sub 22/ alkyl or alkenyl group.

FROGMEN - MERCURY-ATLAS (MA)-9 - FAITH "7" - FLOTATION COLLAR - RECOVERY - PACIFIC

NASA Image and Video Library

1963-05-16

S63-07707 (16 May 1963) --- A U.S. Navy frogman team attaches a flotation collar to the Mercury-Atlas 9 (MA-9)"Faith 7" spacecraft during recovery operations in the central Pacific near Midway Island. The Mercury-Atlas spacecraft with astronaut L. Gordon Cooper Jr., pilot, still inside, was hoisted aboard the USS Kearnage. Photo credit: NASA

Combination of three-stage sink-float method and selective flotation technique for separation of mixed post-consumer plastic waste.

PubMed

Pongstabodee, Sangobtip; Kunachitpimol, Napatr; Damronglerd, Somsak

2008-01-01

The aim of this research was to separate the different plastics of a mixed post-consumer plastic waste by the combination of a three-stage sink-float method and selective flotation. By using the three-stage sink-float method, six mixed-plastic wastes, belonging to the 0.3-0.5 cm size class and including high density polyethylene (HDPE), polypropylene (PP), polyvinylchloride (PVC), polystyrene (PS), polyethylene terephthalate (PET) and acrylonitrile-butadiene-styrene copolymers (ABS) were separated into two groups, i.e., a low density plastic group (HDPE and PP) and a high density plastic group (PET, PVC, PS and ABS) by tap water. Plastic whose density is less than that of the medium solution floats to the surface, while the one whose density is greater than that of the medium solution sinks to the bottom. The experimental results elucidated that complete separation of HDPE from PP was achieved by the three-stage sink-float method with 50% v/v ethyl alcohol. To succeed in the separation of a PS/ABS mixture from a PET/PVC mixture by the three-stage sink-float method, a 30% w/v calcium chloride solution was employed. To further separate post-consumer PET/PVC and PS/ABS based on plastic type, selective flotation was carried out. In order to succeed in selective flotation separation, it is necessary to render hydrophilic the surface of one or more species while the others are kept in a hydrophobic state. In flotation studies, the effects of wetting agent, frother, pH of solution and electrolyte on separation were determined. The selective flotation results showed that when using 500 mg l(-1) calcium lignosulfonate, 0.01 ppm MIBC, and 0.1 mg l(-1) CaCl2 at pH 11, PET could be separated from PVC. To separate ABS from PS, 200 mg l(-1) calcium lignosulfonate and 0.1 mg l(-1) CaCl2 at pH 7 were used as a flotation solution. Wettability of plastic increases when adding CaCl2 and corresponds to a decrease in its contact angles and to a reduction in the recovery of plastic in

The bubble method of water purification

NASA Astrophysics Data System (ADS)

Smirnov, B. M.; Babaeva, N. Yu.; Naidis, G. V.; Panov, V. A.; Saveliev, A. S.; Son, E. E.; Tereshonok, D. V.

2018-02-01

The processes of water purification from admixture molecules are analyzed. The purification rate is limited due to a low diffusion coefficient of the admixture molecules in water. At non-small concentrations of the admixture molecules, the water purication can proceed through association of molecules in condensed nanoparticles which fall on the bottom of the water volume. The rate of association may be increased in an external electric field, but in reality this cannot change significantly the rate of the purification process. The bubble method of water purification is considered, where air bubbles formed at the bottom of the water volume, transfer admixture molecules to the interface. This method allows one to clean small water volumes fast. This mechanism of water purification is realized experimentally and exhibits the promises of the bubble purification method.

Controlled synthesis of flexible graphene aerogels macroscopic monolith as versatile agents for wastewater treatment

NASA Astrophysics Data System (ADS)

Dong, Shuying; Xia, Longji; Guo, Teng; Zhang, Fangyuan; Cui, Lingfang; Su, Xianfa; Wang, Dong; Guo, Wei; Sun, Jianhui

2018-07-01

Emerging applications for environmental purification require agents that not only possess high decontamination efficiency, but also are capable of withstanding mechanical deformation without secondary pollution and degradation of performance. To this end, we have controlled synthesis of mechanically flexible graphene aerogel (GA) by vacuum freeze-drying of their hydrogel precursors obtained from heating the aqueous mixtures of graphene oxide (GO) and Vitamin C (VC) without stirring. Through the adaptable process conditions, such as the particle size of carbon, GO concentration, dosage of reducing agent and solution pH, the highly porous, ultralight and mechanically flexible GA are synthesized. Owing to the porous, robust and stable structure, the resulting GA show very promising performance in water purification including enrichment of organic liquid solvents (alcohols, oil and alkanes), removal of hexavalent chromium Cr(VI) and purified industrial wastewater, as well as flexible conductors. The successful creation of the GA may provide new insights into the design of carbon-based aerogels for various applications, as the GA can be prepared via a very simple procedure and available in macroscopic diverse morphologies with tunable porosity.

The use of ozone, ozone plus UV radiation, and aerobic microorganisms in the purification of some agro-industrial wastewaters.

PubMed

Benitez, F Javier; Acero, Juan L; Gonzalez, Teresa; Garcia, Juan

2002-08-01

The oxidation of the pollutant organic matter present in wastewaters generated during different stages in the black table-olive industry was investigated by using ozone alone or combined with UV radiation; by using aerobic microorganisms; and finally, by aerobic degradation of the previously ozonated wastewaters. In the ozonation processes, the removal of substrate (COD) and aromatic compounds, the decreases in BOD5 and pH, and the ozone consumed in the reaction were evaluated. A kinetic study was conducted that led to the evaluation of the stoichiometric ratio for the chemical reaction, as well as the rate constants for the substrate reduction and ozone disappearance. In the single aerobic degradation treatment, the evolution of substrate and biomass was monitored during the process, and a kinetic study was performed by applying the Contois model to the experimental data, giving the specific biokinetic constant, the cell yield coefficient, and the rate constant for the microorganism death phase. Finally, a combined process was performed, consisting in the aerobic degradation of pre-ozonated wastewaters, and the effect of such chemical pretreatment on the substrate removal and kinetic parameters of the later biological stage is discussed.

Enhancing the auto-flocculation of photosynthetic bacteria to realize biomass recovery in brewery wastewater treatment.

PubMed

Lu, Haifeng; Dong, Shan; Zhang, Guangming; Han, Ting; Zhang, Yuanhui; Li, Baoming

2018-02-15

Photosynthetic bacteria (PSB) wastewater treatment technology can simultaneously realize wastewater purification and biomass production. The produced biomass contains high value-added products, which can be used in medical and agricultural industry. However, because of the small size and high electronegativity, PSB are hard to be collected from wastewater, which hampers the commercialization of PSB-based industrial processes. Auto-flocculation is a low cost, energy saving, non-toxic biomass collection method for microbiology. In this work, the influence factors with their optimal levels and mechanism for enhancing the auto-flocculation of PSB were investigated in pure cultivation medium. Then PSB auto-flocculation performance in real brewery wastewater was probed. Results showed that Na + concentration, pH and light intensity were three crucial factors except the initial inoculum sizes and temperature. In the pure medium cultivation system, the optimal condition for PSB auto-flocculation was as follows: pH was 9.5, inoculum size was 420 mg l -1 , Na + concentration was 0.067 mol l -1 , light intensity was 5000 lux, temperature was 30°C. Under the optimal condition, the auto-flocculation ratio and biomass recovery reached 85.0% and 1488 mg l -1 , which improved by 1.67-fold and 2.14-fold compared with the PSB enrichment cultivation conditions, respectively. Mechanism analysis showed that the protein/polysaccharides ratio and absolute Zeta potential value had a liner relationship. For the brewery wastewater treatment, under the above optimal condition, the chemical oxygen demand removal reached 94.3% with the auto-flocculation ratio and biomass recovery of 89.6% and 1510 mg l -1 , which increased 2.75-fold and 2.77-fold, respectively.

Small scale recirculating vertical flow constructed wetland (RVFCW) for the treatment and reuse of wastewater.

PubMed

Gross, A; Sklarz, M Y; Yakirevich, A; Soares, M I M

2008-01-01

The quantity of freshwater available worldwide is declining, revealing a pressing need for its more efficient use. Moreover, in many developing countries and lightly populated areas, raw wastewater is discarded into the environment posing serious ecological and health problems. Unfortunately, this situation will persist unless low-cost, effective and simple technologies are brought in. The aim of this study is to present such a treatment method, a novel setup which is termed recirculating vertical flow constructed wetland (RVFCW). The RVFCW is composed of two components: (i) a three-layer bed consisting of planted organic soil over an upper layer of filtering media (i.e. tuff or beads) and a lower layer of limestone pebbles, and (ii) a reservoir located beneath the bed. Wastewater flows directly into the plant root zone and trickles down through the three-layer bed into the reservoir, allowing passive aeration. From the reservoir the water is recirculated back to the bed, several times, until the desired purification is achieved. The results obtained show that the RVFCW is an effective and convenient strategy to treat (domestic, grey and agro) wastewater for re-use in irrigation. The system performance is expected to be further improved once current optimization experiments and mathematical modeling studies are concluded. IWA Publishing 2008.

Solvent extraction of Cu, Mo, V, and U from leach solutions of copper ore and flotation tailings.

PubMed

Smolinski, Tomasz; Wawszczak, Danuta; Deptula, Andrzej; Lada, Wieslawa; Olczak, Tadeusz; Rogowski, Marcin; Pyszynska, Marta; Chmielewski, Andrzej Grzegorz

2017-01-01

Flotation tailings from copper production are deposits of copper and other valuable metals, such as Mo, V and U. New hydrometallurgical technologies are more economical and open up new possibilities for metal recovery. This work presents results of the study on the extraction of copper by mixed extractant consisting p -toluidine dissolved in toluene. The possibility of simultaneous liquid-liquid extraction of molybdenum and vanadium was examined. D2EHPA solutions was used as extractant, and recovery of individual elements compared for the representative samples of ore and copper flotation tailings. Radiometric methods were applied for process optimization.

Microbial Diversity in Soil Treatment Systems for Wastewater

NASA Astrophysics Data System (ADS)

Van Cuyk, S.; Spear, J.; Siegrist, R.; Pace, N.

2002-05-01

There is an increasing awareness and concern over land based wastewater system performance with respect to the removal of bacteria and virus. The goal of this work is to describe and identify the organismal composition of the microbiota in the applied wastewater effluent, the rich biomat that develops at the infiltrative surface, and in the soil percolate in order to aid in the understanding of bacterial and virus purification in soil treatment systems. The traditional reliance on pure culture techniques to describe microbiota is circumvented by the employment of a molecular approach. Microbial community characterization is underway based on cloning and sequencing of 16S rRNA genes for phylogenetic analyses, to determine the nature and quantity of microbiota that constitute these ecosystems. Knowledge of the organisms naturally present can influence the design and treatment capacity of these widely used land based systems. Laboratory, intermediate and field scale systems are currently under study. Since human pathogens are known to exist in sewage effluents, their removal in wastewater infiltration systems and within the underlying soil are in need of a more fundamental understanding. The relationship between design parameters and environmental conditions, including a microbial characterization, is essential for the prevention of contamination in groundwater sources. Preliminary results indicate the presence of uncultured organisms and phylogenetic kinds that had not been detected in these systems using other methods. Acinetobacter johnsonii and Acrobacter cryaerophilus were the two dominant species found in septic tank effluent, comprising 20% and 11% of the library respectively. In soil samples collected from the infiltrative surface of a column dosed with STE, there was no dominant bacterial species present. Percolate samples collected from the outflow of the column showed that a tuber borchii symbiont, a common soil microorganism, dominated the bacterial

Treatment performance and microorganism community structure of integrated vertical-flow constructed wetland plots for domestic wastewater.

PubMed

Wu, Su-qing; Chang, Jun-jun; Dai, Yanran; Wu, Zhen-bin; Liang, Wei

2013-06-01

In order to investigate the treatment performance and microorganism mechanism of IVCW for domestic wastewater in central of China, two parallel pilot-scale IVCW systems were built to evaluate purification efficiencies, microbial community structure and enzyme activities. The results showed that mean removal efficiencies were 81.03 % for COD, 51.66 % for total nitrogen (TN), 42.50 % for NH4 (+)-N, and 68.01 % for TP. Significant positive correlations between nitrate reductase activities and TN and NH4 (+)-N removal efficiencies, along with a significant correlation between substrate enzyme activity and operation time, were observed. Redundancy analysis demonstrated gram-negative bacteria were mainly responsible for urease and phosphatase activities, and also played a major role in dehydrogenase and nitrate reductase activities. Meanwhile, anaerobic bacteria, gram-negative bacteria, and saturated FA groups, gram-positive bacteria exhibited good correlations with the removal of COD (p=0.388), N (p=0.236), and TP (p=0.074), respectively. The IVCW system can be used to treat domestic wastewater effectively.

Removal of chromium(III) from tannery wastewater using activated carbon from sugar industrial waste.

PubMed

Fahim, N F; Barsoum, B N; Eid, A E; Khalil, M S

2006-08-21

Chromium is commonly found in huge quantities in tannery wastewaters. For this reason, the removal and recovery of the chromium content of tannery wastewaters is crucial for environmental protection and economic reasons. Removal and recovery of chromium were carried out by using low-cost potential adsorbents. For this purpose three types of activated carbon; C1, the waste generated from sugar industry as waste products and the others (C2, C3) are commercial granular activated carbon, were used. The adsorption process and extent of adsorption are dependent on the physical and chemical characteristics of the adsorbent, adsorbate and experimental condition. The effect of pH, particle size and different adsorbent on the adsorption isotherm of Cr(III) was studied in batch system. The sorption data fitted well with Langmuir adsorption model. The efficiencies of activated carbon for the removal of Cr(III) were found to be 98.86, 98.6 and 93 % for C1, C2 and C3, respectively. The order of selectivity is C1>C2>C3 for removal of Cr(III) from tannery wastewater. Carbon "C1" of the highest surface area (520.66 m(2)/g) and calcium content (333.3 mg/l) has the highest adsorptive capacity for removal of Cr(III). The results revealed that the trivalent chromium is significantly adsorbed on activated carbon collected from sugar industry as waste products and the method could be used economically as an efficient technique for removal of Cr(III) and purification of tannery wastewaters.

Taguchi optimization: Case study of gold recovery from amalgamation tailing by using froth flotation method

NASA Astrophysics Data System (ADS)

Sudibyo, Aji, B. B.; Sumardi, S.; Mufakir, F. R.; Junaidi, A.; Nurjaman, F.; Karna, Aziza, Aulia

2017-01-01

Gold amalgamation process was widely used to treat gold ore. This process produces the tailing or amalgamation solid waste, which still contains gold at 8-9 ppm. Froth flotation is one of the promising methods to beneficiate gold from this tailing. However, this process requires optimal conditions which depends on the type of raw material. In this study, Taguchi method was used to optimize the optimum conditions of the froth flotation process. The Taguchi optimization shows that the gold recovery was strongly influenced by the particle size which is the best particle size at 150 mesh followed by the Potassium amyl xanthate concentration, pH and pine oil concentration at 1133.98, 4535.92 and 68.04 gr/ton amalgamation tailing, respectively.

New insights into the oleate flotation response of feldspar particles of different sizes: Anisotropic adsorption model.

PubMed

Xu, Longhua; Tian, Jia; Wu, Houqin; Deng, Wei; Yang, Yaohui; Sun, Wei; Gao, Zhiyong; Hu, Yuehua

2017-11-01

The anisotropic adsorption of sodium oleate (NaOL) on feldspar surfaces was investigated to elucidate the different flotation properties of feldspar particles of four different size ranges. Microflotation experiments showed that the feldspar flotation recovery of particles with sizes spanning different ranges decreased in the order 0-19>19-38>45-75>38-45μm. Zeta potential and FTIR measurements showed that NaOL was chemically adsorbed on the Al sites of the feldspar surface. The anisotropic surface energies and broken bond densities estimated by density functional theory calculations showed that, although feldspar mostly exposed (010) and (001) surfaces, only the (001) surfaces contained the Al sites needed for NaOL adsorption. The interaction energies calculated by molecular dynamics simulations confirmed the more favorable NaOL adsorption on (001) than (010) surfaces, which may represent the main cause for the anisotropic NaOL adsorption on feldspar particles of different sizes. SEM measurements showed that the main exposed surfaces on coarse and fine feldspar particles were the side (010) and basal (001) ones, respectively. A higher fraction of Al-rich (001) surfaces is exposed on fine feldspar particles, resulting in better floatability compared with coarse particles. XPS and adsorption measurements confirmed that the Al content on the feldspar surface varied with the particle size, explaining the different NaOL flotation of feldspar particles of different sizes. Therefore, the present results suggest that coarsely ground ore should be used for the separation of feldspar gangue minerals. Further improvements in the flotation separation of feldspar from associated valuable minerals can be achieved through selective comminution or grinding processes favoring the exposure of (010) surfaces. Copyright © 2017 Elsevier Inc. All rights reserved.

Air Stripping Designs and Reactive Water Purification Processes for the Lunar Surface

NASA Technical Reports Server (NTRS)

Boul, Peter J.; Lange, Kevin; Conger, Bruce; Anderson, Molly

2010-01-01

Air stripping designs are considered to reduce the presence of volatile organic compounds in the purified water. Components of the wastewater streams are ranked by Henry's Law Constant and the suitability of air stripping in the purification of wastewater in terms of component removal is evaluated. Distillation processes are modeled in tandem with air stripping to demonstrate the potential effectiveness and utility of these methods in recycling wastewater on the Moon. Scaling factors for distillation and air stripping columns are presented to account for the difference in the lunar gravitation environment. Commercially available distillation and air stripping units which are considered suitable for Exploration Life Support are presented. The advantages to the various designs are summarized with respect to water purity levels, power consumption, and processing rates. An evaluation of reactive distillation and air stripping is presented with regards to the reduction of volatile organic compounds in the contaminated water and air. Among the methods presented, an architecture is presented for the evaluation of the simultaneous oxidation of organics in air and water. These and other designs are presented in light of potential improvements in power consumptions and air and water purities for architectures which include catalytic activity integrated into the water processor. In particular, catalytic oxidation of organics may be useful as a tool to remove contaminants that more traditional distillation and/or air stripping columns may not remove. A review of the current leading edge at the commercial level and at the research frontier in catalytically active materials is presented. Themes and directions from the engineering developments in catalyst design are presented conceptually in light of developments in the nanoscale chemistry of a variety of catalyst materials.

Purification of contaminated paddy fields by clean water irrigation over two decades.

PubMed

Tai, Yiping; Lu, Huanping; Li, Zhian; Zhuang, Ping; Zou, Bi; Xia, Hanping; Wang, Faming; Wang, Gang; Duan, Jun; Zhang, Jianxia

2013-10-01

Paddy fields near a mining site in north part of Guangdong Province, PR China, were severely contaminated by heavy metals as a result of wastewater irrigation from the tailing pond. The following clean water irrigation for 2 decades produced marked rinsing effect, especially on Pb and Zn. Paddy fields continuously irrigated with wastewater ever since mining started (50 years) had 1,050.0 mg kg−1 of Pb and 810.3 mg kg−1 of Zn for upper 20 cm soil, in comparison with 215.9 mg kg−1 of Pb and 525.4 mg kg−1 of Zn, respectively, with clean water irrigation for 20 years. Rinsing effect mainly occurred to a depth of upper 40 cm, of which the soil contained highest metals. Copper and Cd in the farmlands were also reduced due to clean water irrigation. Higher availability of Pb might partly account for more Pb transferred from the tailing pond to the farmland and also more Pb removal from the farmland as a result of clean water irrigation. Neither rice in the paddy field nor dense weeds in the uncultivated field largely took up the metals. However, they might contribute to activate metals differently, leading to a different purification extent. Rotation of rice and weed reduced metal retention in the farmland soil, in comparison with sole rice growth. Harvesting of rice grain (and partially rice stalk) only contributed small fraction of total amount of removed metal. In summary, heavy metal in paddy field resulting from irrigation of mining wastewater could be largely removed by clean water irrigation for sufficient time.

Pharmaceutical grey water footprint: Accounting, influence of wastewater treatment plants and implications of the reuse.

PubMed

Martínez-Alcalá, Isabel; Pellicer-Martínez, Francisco; Fernández-López, Carmen

2018-05-15

Emerging pollutants, including pharmaceutical compounds, are producing water pollution problems around the world. Some pharmaceutical pollutants, which mainly reach ecosystems within wastewater discharges, are persistent in the water cycle and can also reach the food chain. This work addresses this issue, accounting the grey component of the water footprint (GWF P ) for four of the most common pharmaceutical compounds (carbamazepine (CBZ), diclofenac (DCF), ketoprofen (KTP) and naproxen (NPX)). In addition, the GWF C for the main conventional pollutants is also accounted (nitrate, phosphates and organic matter). The case study is the Murcia Region of southeastern Spain, where wastewater treatment plants (WWTPs) purify 99.1% of the wastewater discharges and there is an important direct reuse of the treated wastewater in irrigation. Thus, the influence of WWTPs and reuse on the GWF is analysed. The results reveal that GWF P , only taking into account pharmaceutical pollutants, has a value of 301 m 3 inhabitant -1 year -1 ; considering only conventional pollutants (GWF C ), this value increases to 4718 m 3 inhabitant -1 year -1 . So, the difference between these values is such that in other areas with consumption habits similar to those of the Murcia Region, and without wastewater purification, conventional pollutants may well establish the value of the GWF. On average, the WWTPs reduce the GWF C by 90% and the GWF P by 26%. These different reductions of the pollutant concentrations in the treated effluents show that the GWF is not only due to conventional pollutants, and other contaminants can became critical, such as the pharmaceutical pollutants. The reuse further reduces the value of the GWF for the Murcia Region, by around 43.6%. However, the reuse of treated wastewater is controversial, considering the pharmaceutical contaminants and their possible consequences in the food chain. In these cases, the GWF of pharmaceutical pollutants can be used to provide a

40 CFR 63.133 - Process wastewater provisions-wastewater tanks.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 10 2014-07-01 2014-07-01 false Process wastewater provisions-wastewater tanks. 63.133 Section 63.133 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater...

40 CFR 63.133 - Process wastewater provisions-wastewater tanks.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Process wastewater provisions-wastewater tanks. 63.133 Section 63.133 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater...

40 CFR 63.133 - Process wastewater provisions-wastewater tanks.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Process wastewater provisions-wastewater tanks. 63.133 Section 63.133 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater...

40 CFR 63.133 - Process wastewater provisions-wastewater tanks.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Process wastewater provisions-wastewater tanks. 63.133 Section 63.133 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater...

33 CFR 149.331 - What are the requirements for hybrid personal flotation devices?

Code of Federal Regulations, 2010 CFR

2010-07-01

..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: DESIGN, CONSTRUCTION, AND... commercial hybrid personal flotation devices (PFDs) used as work vests comply with the procedures required... PFDs on the deepwater port must be of the same or similar design and must have the same method of...

Surface treatment with Fenton for separation of acrylonitrile-butadiene-styrene and polyvinylchloride waste plastics by flotation.

PubMed

Wang, Jian-Chao; Wang, Hui; Huang, Luo-Luo; Wang, Chong-Qing

2017-09-01

Surface treatment with Fenton was applied to flotation separation of acrylonitrile-butadienestyrene (ABS) and polyvinylchloride (PVC). After treatment, the floatability of ABS has a dramatic decrease, while the floatability of PVC is not affected. Fourier transform infrared spectroscopy (FT-IR) spectra and X-ray photoelectron spectroscopy (XPS) spectra were recorded to ascertain the mechanism of Fenton treatment. FT-IR and XPS analysis confirms that the introduction of oxygen-containing group occurs on the surface of ABS. The optimum conditions are molar ration (H 2 O 2 :Fe 2+ ) 10000, H 2 O 2 concentration 0.4M/L, pH 5.8, treatment time 2min and temperature 25°C, frother concentration 15mg/L and flotation time 3min. Particle sizes and mixing ratios were also investigated. Plastic mixtures of ABS and PVC with different particle sizes and mixing ratios can be effectively separated. The purity of ABS and PVC are up to 100% and 99.78%, respectively; the recovery of ABS and PVC are up to 99.89% and 100%, respectively. A practical, environmentally friendly and effective reagent, namely Fenton, was originally applied to surface treatment of ABS and PVC waste plastics for flotation separation of their mixtures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Multidimensional Analysis of Copper Ore Flotation in Terms of Applied Hydrophobizing Agents

NASA Astrophysics Data System (ADS)

Pięta, Paulina; Niedoba, Tomasz; Surowiak, Agnieszka

2018-03-01

Flotation is a method of enrichment used to distribute particles, which differ in their surface properties. Hydrophobic solids intrinsically create contact at the solid-liquid-gas interface. However, not all minerals, including copper minerals, can be characterized by this crucial ability. In that case it is necessary to use the collector reagents which guarantees a high efficiency of the enrichment process. The main aim of the paper was to examine the impact of selected collector types and dosages on the results of Polish sandstone copper ore flotation and to find optimal parameter values for products that meet quality and quantity requirements. The laboratory tests were carried out with an application of two types of collectors (Hostaflot, sodium ethyl xanthate aqueous solution) in dosages 100 and 150 g/Mg. Data analysis was based on the use of the taxonomy methods in order to select optimal conditions of collector dosage and type. Based on the indexes, it was found that the best enrichment effects were obtained with a sodium ethyl xanthate aqueous solution 150 g/Mg.

Implementation of reverse flotation method to reduce reactive and non-reactive silica in bauxite ore from West Kalimantan

NASA Astrophysics Data System (ADS)

Wulandari, Winny; Purwasasmita, Mubiar; Sanwani, Edy; Pixelina, Adinda Asri; Maulidan, Agus

2017-01-01

This paper reports a study that implements reverse flotation method to separate silica from West Kalimantan bauxite ores. The study is aimed to find the good process condition to obtain low-silica bauxite as the feed for the Bayer process. The experiments were carried out in a 1 L of flotation cell tank. Dodecylamine was used as the collector, starch as the depressant, and MIBC as the frother. The varied parameters were solid content to solution (15-30% w/w), and pH (6 - 10). The results of XRF of products show that in all reverse flotation experiments, the ratio of alumina to silica (Al/Si) are increased from 7 up to 14. The increase of solid percentage in the flotation gives a good result for Al/Si ratio as well as alumina and silica recovery in concentrate, with 30% w/w solid percentage to solution increases Al/Si ratio to 14.38, with silica recovery of 20%. The good separation with variation of depressants is obtained with depressant concentration of 400 g/ton bauxite, with Al/Si ratio in concentrate 15 and ratio in tailing 7. For the pH variation, the good condition is obtained at pH 8, while for collector concentration, the good condition is obtained at 200 g/ton bauxite. XRD analysis of the feed indicates that bauxite ore consists of gibbsite, diaspore, kaolinite, halloysite, quartz, boehmite, hematite and rutile. It is found that the concentrate has similar minerals, but halloysite became very minor or classified as a trace.

Vitrification of copper flotation waste.

PubMed

Karamanov, Alexander; Aloisi, Mirko; Pelino, Mario

2007-02-09

The vitrification of an hazardous iron-rich waste (W), arising from slag flotation of copper production, was studied. Two glasses, containing 30wt% W were melted for 30min at 1400 degrees C. The first batch, labeled WSZ, was obtained by mixing W, blast furnace slag (S) and zeolite tuff (Z), whereas the second, labeled WG, was prepared by mixing W, glass cullet (G), sand and limestone. The glass frits showed high chemical durability, measured by the TCLP test. The crystallization of the glasses was evaluated by DTA. The crystal phases formed were identified by XRD resulting to be pyroxene and wollastonite solid solutions, magnetite and hematite. The morphology of the glass-ceramics was observed by optical and scanning electron microscopy. WSZ composition showed a high rate of bulk crystallization and resulted to be suitable for producing glass-ceramics by a short crystallization heat-treatment. WG composition showed a low crystallization rate and good sinterability; glass-ceramics were obtained by sinter-crystallization of the glass frit.

Effects of flotation-restricted environmental stimulation technique on stress-related muscle pain: what makes the difference in therapy--attention-placebo or the relaxation response?

PubMed

Bood, Sven A; Sundequist, Ulf; Kjellgren, Anette; Nordstrom, Gun; Norlander, Torsten

2005-01-01

The purpose of the present study was to examine the potential effects of attention-placebo on flotation tank therapy. Flotation-restricted environmental stimulation technique is a method whereby an individual lies in a floating tank and all stimuli are reduced to a minimum. Thirty-two patients were diagnosed as having stress-related muscular pain. In addition, 16 of the participants had received the diagnosis of burnout depression. The patients were treated with flotation-restricted environmental stimulation technique for six weeks. One-half of the patients were also given special attention for 12 weeks (high attention), while the remainder received attention for only six weeks (normal attention). The participants exhibited lowered blood pressure, reduced pain, anxiety, depression, stress and negative affectivity, as well as increased optimism, energy and positive affectivity. The results were largely unaffected by the degree of attention-placebo or diagnosis. It was concluded that flotation therapy is an effective, noninvasive method for treating stress-related pain, and that the method is not more affected by placebo than by other methods currently used in pain treatment. The treatment of both burnout depression and pain related to muscle tension constitutes a major challenge for the patient as well as the care provider, an area in which great gains can be made if the treatment is effective. Flotation therapy may constitute an integral part of such treatment.

Strep-Tagged Protein Purification.

PubMed

Maertens, Barbara; Spriestersbach, Anne; Kubicek, Jan; Schäfer, Frank

2015-01-01

The Strep-tag system can be used to purify recombinant proteins from any expression system. Here, protocols for lysis and affinity purification of Strep-tagged proteins from E. coli, baculovirus-infected insect cells, and transfected mammalian cells are given. Depending on the amount of Strep-tagged protein in the lysate, a protocol for batch binding and subsequent washing and eluting by gravity flow can be used. Agarose-based matrices with the coupled Strep-Tactin ligand are the resins of choice, with a binding capacity of up to 9 mg ml(-1). For purification of lower amounts of Strep-tagged proteins, the use of Strep-Tactin magnetic beads is suitable. In addition, Strep-tagged protein purification can also be automated using prepacked columns for FPLC or other liquid-handling chromatography instrumentation, but automated purification is not discussed in this protocol. The protocols described here can be regarded as an update of the Strep-Tag Protein Handbook (Qiagen, 2009). © 2015 Elsevier Inc. All rights reserved.

Stable thermophilic anaerobic digestion of dissolved air flotation (DAF) sludge by co-digestion with swine manure.

PubMed

Creamer, K S; Chen, Y; Williams, C M; Cheng, J J

2010-05-01

Environmentally sound treatment of by-products in a value-adding process is an ongoing challenge in animal agriculture. The sludge produced as a result of the dissolved air flotation (DAF) wastewater treatment process in swine processing facilities is one such low-value residue. The objective of this study was to determine the fundamental performance parameters for thermophilic anaerobic digestion of DAF sludge. Testing in a semi-continuous stirred tank reactor and in batch reactors was conducted to determine the kinetics of degradation and biogas yield. Stable operation could not be achieved using pure DAF sludge as a substrate, possibly due to inhibition by long-chain fatty acids or to nutrient deficiencies. However, in a 1:1 ratio (w/w, dry basis) with swine manure, operation was both stable and productive. In the semi-continuous stirred reactor at 54.5 degrees Celsius, a hydraulic residence time of 10 days, and an organic loading rate of 4.68 gVS/day/L, the methane production rate was 2.19 L/L/day and the specific methane production rate was 0.47 L/gVS (fed). Maximum specific methanogenic activity (SMA) in batch testing was 0.15 mmoles CH(4) h(-1) gVS(-1) at a substrate concentration of 6.9 gVS L(-1). Higher substrate concentrations cause an initial lag in methane production, possibly due to long-chain fatty acid or nitrogen inhibition. Copyright 2009 Elsevier Ltd. All rights reserved.

Flotation-separation of aluminum from some water samples using powdered marble waste and oleic acid.

PubMed

Ghazy, Shaban el-Sayed; Samra, Salem el-Sayed; Mahdy, Abd el-Fattah Mohammed; el-Morsy, Sherin Mohammed

2003-10-01

Bench-scale experiments were conducted in the laboratory, aiming to remove aluminum from water. They were based on the use of powdered marble wastes (PMW), which are inexpensive and produced in large quantity, and thus potentially cause environmental problems, as an effective inorganic sorbent and oleic acid (HOL) as surfactant. The main parameters (solution pHs, sorbent, surfactant and aluminum concentrations, shaking time, ionic strength and the presence of foreign ions) that influence the sorptive-flotation process were examined. Good results were obtained under the optimum conditions, for which nearly 100% of aluminum at pH 7 and at room temperature (approximately 25 degrees C) was removed. The procedure was successfully applied to the recovery of aluminum spiked to some natural water samples. Moreover, a sorption and flotation mechanism is suggested.

46 CFR 117.72 - Personal flotation devices carried in addition to life jackets.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Personal flotation devices carried in addition to life jackets. 117.72 Section 117.72 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL... approved life jackets required to be worn during drills and emergencies. (b) Wearable marine buoyant...

46 CFR 117.72 - Personal flotation devices carried in addition to life jackets.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Personal flotation devices carried in addition to life jackets. 117.72 Section 117.72 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL... approved life jackets required to be worn during drills and emergencies. (b) Wearable marine buoyant...

Separation and Purification of Mineral Salts from Spacecraft Wastewater Processing via Electrostatic Beneficiation

NASA Technical Reports Server (NTRS)

Miles, John D., II; Lunn, Griffin

2013-01-01

Electrostatic separation is a class of material processing technologies commonly used for the sorting of coarse mixtures by means of electrical forces acting on charged or polarized particles. Most if not all of the existing tribo-electrostatic separators had been initially developed for mineral ores beneficiation. It is a well-known process that has been successfully used to separate coal from minerals. Potash (potassium) enrichment where underground salt mines containing large amounts of sodium is another use of this techno logy. Through modification this technology can be used for spacecraft wastewater brine beneficiation. This will add in closing the gap beeen traveling around Earth's Gravity well and long-term space explorations. Food has been brought on all man missions, which is why plant growth for food crops continues to be of interest to NASA. For long-term mission considerations food productions is one of the top priorities. Nutrient recovery is essential for surviving in or past low earth orbit. In our advance bio-regenerative process instead of nitrogen gas produced; soluble nitrate salts that can be recovered for plant fertilizer would be produced instead. The only part missing is the beneficiation of brine to separate the potassium from the sodium. The use of electrostatic beneficiation in this experiment utilizes the electrical charge differences between aluminum and dried brine by surface contact. The helixes within the aluminum tribocharger allows for more surface contact when being agitated. When two materials are in contact, the material with the highest affinity for electrons becomes negatively charged, while the other becomes positively charged. This contact exchange of charge may cause the particles to agglomerate depending on their residence time within the tribocharger, compromising the efficiency of separation. The aim of this experiment is to further the development in electrostatic beneficiation by optimizing the separation of ersatz and

Adsorption of N-tallow 1,3-propanediamine-dioleate collector on albite and quartz minerals, and selective flotation of albite from greek stefania feldspar ore.

PubMed

Vidyadhar, A; Hanumantha Rao, K; Forssberg, K S E

2002-04-01

The adsorption behavior of tallow 1,3-propanediamine-dioleate (Duomeen TDO) collector on albite and quartz minerals is assessed through Hallimond flotation, zeta potential, and diffuse reflectance FTIR investigations, together with the species distribution of the collector. The collector performance on albite separation from a natural feldspar material is evaluated in bench scale flotation tests. The Hallimond flotation responses of the minerals as a function of pH and collector concentration indicate that albite can be selectively floated from quartz at pH 2 where the doubly positively charged collector species adsorb on albite but not on quartz. However, the zeta potential and infrared spectra reveal that the adsorption behavior of the collector is similar on both minerals. The discrepancy in the flotation and adsorption results is attributed to the coarse and fine particle size fractions, and the shorter and longer equilibration periods employed in these studies respectively. The comparable adsorption on fine particles of albite and quartz at pH 2 is explained by the interaction of ammonium ions on silanol groups by hydrogen bonding as well as electrostatic interactions. The changes in zeta potentials are in good agreement with the formation of ionic species and free molecular forms of the collector. The IR spectra show the coexistence of neutral oleic acid together with charged amine species at low pH values in accordance with the species distribution diagram. Selective flotation of albite is accomplished from a natural feldspar material with tallow diamine-dioleate collector at pH 2 using sulfuric acid, only when the feed is deslimed prior to the bench scale flotation tests. An albite recovery exceeding 85% is achieved from a feed material containing about 50% albite.

78 FR 49412 - Personal Flotation Devices Labeling and Standards

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-14

...The Coast Guard proposes to remove references to type codes in its regulations on the carriage and labeling of Coast Guard-approved personal flotation devices (PFDs). PFD type codes are unique to Coast Guard approval and are not well understood by the public. Removing these type codes from our regulations would facilitate future incorporation by reference of new industry consensus standards for PFD labeling that will more effectively convey safety information, and is a step toward harmonization of our regulations with PFD requirements in Canada and in other countries.

Fe(II)-regulated moderate pre-oxidation of Microcystis aeruginosa and formation of size-controlled algae flocs for efficient flotation of algae cell and organic matter.

PubMed

Qi, Jing; Lan, Huachun; Liu, Ruiping; Liu, Huijuan; Qu, Jiuhui

2018-06-15

The coagulation/flocculation/flotation (C/F/F) process is becoming a popular method for algae-laden water treatment. However, the efficiency of flotation is highly dependent on the ability of the preceding coagulation/flocculation process to form flocculated algae flocs. This study aims to improve the Microcystis aeruginosa flotation efficiency from algae cell and organic matter aspects by applying Fe(II)-regulated pretreatment enhanced Al coagulation process. The ability of the C/F/F process to remove cyanobacterial cells can be enhanced from 8% to 99% at a Fe(II) dose of 30 μM. The Al dose needed can be reduced by more than half while achieving successful flotation. The introduced Fe(II) after KMnO 4 can not only realize moderate pre-oxidation of cyanobacterial cells, but also form in-situ Fe(III). The DOC value can also be decreased significantly due to the formation of in-situ Fe(III), which is more efficient in dissolved organic matter (DOM) removal compared with pre-formed Fe(III). In addition, the gradually hydrolyzed in-situ Fe(III) can facilitate the hydrolysis of Al as a dual-coagulant and promote the clustering and cross-linking of Al hydrolyzates, which can enhance the formation of size-controlled algae flocs. Finally, the size-controlled algae flocs can be effectively floated by the bubbles released in the flotation process due to the efficient collision and attachment between flocs and bubbles. Therefore, the efficient flotation of algae cell and organic matter can be realized by the Fe(II) regulated moderate pre-oxidation of M. aeruginosa and formation of size-controlled algae flocs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Simultaneous photocatalytic and microbial degradation of dye-containing wastewater by a novel g-C3N4-P25/photosynthetic bacteria composite

PubMed Central

Zhang, Xinying; Wu, Yan; Xiao, Gao; Tang, Zhenping; Wang, Meiyin; Liu, Fuchang; Zhu, Xuefeng

2017-01-01

Azo dyes are very resistant to light-induced fading and biodegradation. Existing advanced oxidative pre-treatment methods based on the generation of non-selective radicals cannot efficiently remove these dyes from wastewater streams, and post-treatment oxidative dye removal is problematic because it may leave many byproducts with unknown toxicity profiles in the outgoing water, or cause expensive complete mineralization. These problems could potentially be overcome by combining photocatalysis and biodegradation. A novel visible-light-responsive hybrid dye removal agent featuring both photocatalysts (g-C3N4-P25) and photosynthetic bacteria encapsulated in calcium alginate beads was prepared by self-assembly. This system achieved a removal efficiency of 94% for the dye reactive brilliant red X-3b and also reduced the COD of synthetic wastewater samples by 84.7%, successfully decolorized synthetic dye-contaminated wastewater and reduced its COD, demonstrating the advantages of combining photocatalysis and biocatalysis for wastewater purification. The composite apparently degrades X-3b by initially converting the dye into aniline and phenol derivatives whose aryl moieties are then attacked by free radicals to form alkyl derivatives, preventing the accumulation of aromatic hydrocarbons that might suppress microbial activity. These alkyl intermediates are finally degraded by the photosynthetic bacteria. PMID:28273118

Electrothermal atomic absorption spectrometric determination of cobalt, copper, lead and nickel traces in aragonite following flotation and extraction separation.

PubMed

Zendelovska, D; Pavlovska, G; Cundeva, K; Stafilov, T

2001-03-30

A method of determination of Co, Cu, Pb and Ni in nanogram quantities from aragonite is presented. Flotation and extraction of Co, Cu, Pb and Ni is suggested as methods for elimination matrix interferences of calcium. The method of flotation is performed by iron(III) hexamethylenedithiocarbamate, Fe(HMDTC)(3), as a colloid precipitate collector. The liquid-liquid extraction of Co, Cu, Pb and Ni is carried out by sodium diethyldithiocarbamate, NaDDTC, as complexing reagent into methylisobutyl ketone, MIBK. The electrothermal atomic absorption spectrometry (ETAAS) is used for determination of analytes. The detection limits of ETAAS followed by flotation are: 7.8 ng.g(-1) for Co, 17.1 ng.g(-1) for Cu, 7.2 ng.g(-1) for Pb and 9.0 mug.g(-1) for Ni. The detection limits of ETAAS followed by extraction are found to be: 12.0 ng.g(-1) for Co, 51.0 ng.g(-1) for Cu, 24.0 ng.g(-1) for Pb and 21.0 ng.g(-1) for Ni.

Translations on Environmental Quality, Number 176

DTIC Science & Technology

1978-08-21

impurities, which considerably reduces the production areas occupied by purification installations as a result of the compactness of the flotation ...industrial wastes such as [phosphogin], pyrite gas, ash from thermal electric power stations, slag from nonferrous and ferrous metallurgy and wastes

Use of alkyl sulfates in the dewaterng of a coal flotation concentrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zubkova, Yu.N.; Basenkova, V.L.; Kucher, R.V.

1981-01-01

The possibility has been shown of using anionic SAAs in the dewatering of a coal flotation concentrate. It has been established that the adsorption of alkyl sulfates (ASs) obeys the general laws of the adsorption of organic substances from solutions on coals. The addition of electrolytes intensifies the adsorption of ASs, leading to the hydrophobization of the coal particles. 10 refs.

46 CFR 180.72 - Personal flotation devices carried in addition to life jackets.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Personal flotation devices carried in addition to life jackets. 180.72 Section 180.72 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL... emergencies. (b) Wearable marine buoyant devices that include “ski vests,” “boating vests,” and “fishing vests...

46 CFR 180.72 - Personal flotation devices carried in addition to life jackets.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Personal flotation devices carried in addition to life jackets. 180.72 Section 180.72 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL... emergencies. (b) Wearable marine buoyant devices that include “ski vests,” “boating vests,” and “fishing vests...

Removal of copper(II) from some environmental samples by sorptive-flotation using powdered marble wastes as sorbents and oleic acid as surfactant.

PubMed

Ghazy, S E; Samra, S E; Mahdy, A F M; El-Morsy, S M

2004-11-01

A simple and economic experimental sorptive -flotation procedure is presented for the removal of copper(II) species from aqueous solutions. It is based on using powdered marble wastes (PMW), which are widespread and inexpensive and may represent an environmental problem, as the effective inorganic sorbent and oleic (HOL) as the surfactant. The main parameters (i.e. initial solution pH, sorbent, surfactant and copper concentrations, stirring times, ionic strength, temperature and the presence of foreign ions) influencing the flotation of PMW and /or Cu(II) were examined. Nearly, 100% of PMW and Cu(II) were removed from aqueous solutions at pH7 after stirring for 10 min and at room temperature, (approximately 25 degrees C). The procedure was successfully applied to recover Cu(II) spiked to some natural water samples. A mechanism for sorption and flotation is suggested.

Combining ZnO/microwave treatment for changing wettability of WEEE styrene plastics (ABS and HIPS) and their selective separation by froth flotation

NASA Astrophysics Data System (ADS)

Thanh Truc, Nguyen Thi; Lee, Byeong-Kyu

2017-10-01

This study reports a simple froth flotation method to separate plastic wastes of acrylonitrile-butadiene-styrene (ABS) and high impact polystyrene (HIPS) after initial hydrophilization by coating the plastics with ZnO and microwave treatment. ABS and HIPS are typical styrene-based WEEE plastics having similar density and hydrophobicity, which hinders their separation for recycling. After coating with ZnO, 2-min microwave treatment rearranged the ABS surface and thus changed its molecular mobility and increased its hydrophilicity. The combined ZnO coating/microwave treatment facilitated the selective separation of ABS and HIPS with 100% and 95.2% recovery and 95.4% and 100% purity in froth flotation, respectively. The combination of ZnO coating-microwave treatment and froth flotation can be utilized as a selective ABS/HIPS separation technique for improved recycling of WEEE plastics.

Features Extraction of Flotation Froth Images and BP Neural Network Soft-Sensor Model of Concentrate Grade Optimized by Shuffled Cuckoo Searching Algorithm

PubMed Central

Wang, Jie-sheng; Han, Shuang; Shen, Na-na; Li, Shu-xia

2014-01-01

For meeting the forecasting target of key technology indicators in the flotation process, a BP neural network soft-sensor model based on features extraction of flotation froth images and optimized by shuffled cuckoo search algorithm is proposed. Based on the digital image processing technique, the color features in HSI color space, the visual features based on the gray level cooccurrence matrix, and the shape characteristics based on the geometric theory of flotation froth images are extracted, respectively, as the input variables of the proposed soft-sensor model. Then the isometric mapping method is used to reduce the input dimension, the network size, and learning time of BP neural network. Finally, a shuffled cuckoo search algorithm is adopted to optimize the BP neural network soft-sensor model. Simulation results show that the model has better generalization results and prediction accuracy. PMID:25133210

Extraction of acetanilides in rice using ionic liquid-based matrix solid phase dispersion-solvent flotation.

PubMed

Zhang, Liyuan; Wang, Changyuan; Li, Zuotong; Zhao, Changjiang; Zhang, Hanqi; Zhang, Dongjie

2018-04-15

Ionic liquid-based matrix solid phase dispersion-solvent flotation coupled with high performance liquid chromatography was developed for the determination of the acetanilide herbicides, including metazachlor, propanil, alachlor, propisochlor, pretilachlor, and butachlor in rice samples. Some experimental parameters, including the type of dispersant, the mass ratio of dispersant to sample, pH of sample solution, the type of extraction solvent, the type of ionic liquid, flotation time, and flow rate of N 2 were optimized. The average recoveries of the acetanilide herbicides at spiked concentrations of 50, 125, and 250 µg/kg ranged from 89.4% to 108.7%, and relative standard deviations were equal to or lower than 7.1%, the limits of quantification were in the range of 38.0 to 84.7 µg/kg. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sensory Isolation in Flotation Tanks: Altered States of Consciousness and Effects on Well-Being

ERIC Educational Resources Information Center

Kjellgren, Anette; Lyden, Francisca; Norlander, Torsten

2008-01-01

A qualitative analysis (The Empirical Phenomenological Psychological method) of interviews involving eight patients (depression, burn-out syndrome, and chronic pain) was carried out in order to obtain knowledge regarding the effects of flotation tank therapy. This knowledge might be helpful for both professionals and potential floaters. The…

Industrial wastewater treatment using higher aquatic vegetation in the former mining company of the Far Eastern Federal district

NASA Astrophysics Data System (ADS)

Krupskaya, L. T.; Zvereva, V. P.; Gula, K. E.; Gul', L. P.; Golubev, D. A.; Filatova, M. Yu.

2017-09-01

The article describes the results of studying the problems of industrial wastewater treatment using higher aquatic vegetation (hydrophytes) in the former mining enterprise of the Far Eastern Federal District (FEFD). They are aimed at reducing the negative environment impact of toxic tin ore wastes. The material of research were drainage, mine and slime waters as well as Lemna minor and Common reed grass (Phragmites communis). In the work conventional modern physico-chemical, chemical, biological and mathematical-statistical methods were used, as well as in the process of research the methods of atomic absorption spectrophotometry for AAS and mass spectrometry with inductively coupled plasma on ISP-MS ELASN DRS II PerkinElmer was applied. The data obtained in the course of the experiment (2015-2016), indicate that a degree of wastewater treatment, using Lemna minor, is high. Virtually, all compounds of toxic chemical elements contained in industrial wastewater (zinc, cobalt, nickel, cadmium, iron, manganese, lead, etc.) were fully absorbed by a hydrophyte. Pollutant extraction was almost 95%. The obtained results of the study in laboratory conditions proved the possibility of effective use of the Lemna minor for the purification of drainage and mine waters. A key contribution of this paper is the relationship between possible toxic metals contained in industrial wastewater and a higher degree of absorption by their higher aquatic vegetation. These hydrophytes absorb these possible toxic metals in an aqueous medium and are contaminated with these heavy metals.

Enhanced independence and quality of life through treatment with flotation-Restricted Environmental Stimulation Technique of a patient with both Attention Deficit Hyperactivity Disorder and Aspergers Syndrome: a case report

PubMed Central

Kjellgren, Anette; Bood, Sven-Åke; Norlander, Torsten

2009-01-01

Introduction The objective of this qualitative case report was to describe experiences of flotation-Restricted Environmental Stimulation Technique from the perspective of a woman with Attention Deficit Hyperactivity Disorder, Aspergers syndrome and experiences of depression and distress. Case presentation The respondent is a 36-year-old woman from Sweden, assessed and diagnosed by a neuropsychological multi-professional team in 2006. The 19-session flotation series prolonged during almost one year. Conclusion The positive development of arousal control, activity regulation, sensory integration and interpretation, cognitive functioning and emotional maturity created experiences of personal independence and quality of life. Flotation-restrictive environmental stimulation technique was experienced as a meaningful treatment. Additional studies of treatment for Attention Deficit Hyperactivity Disorder and comorbid disorders in adults using the flotation-restrictive environmental stimulation technique are strongly encouraged. PMID:19829887

Enhanced independence and quality of life through treatment with flotation-Restricted Environmental Stimulation Technique of a patient with both Attention Deficit Hyperactivity Disorder and Aspergers syndrome: a case report.

PubMed

Edebol, Hanna; Kjellgren, Anette; Bood, Sven-Ake; Norlander, Torsten

2009-07-07

The objective of this qualitative case report was to describe experiences of flotation-Restricted Environmental Stimulation Technique from the perspective of a woman with Attention Deficit Hyperactivity Disorder, Aspergers syndrome and experiences of depression and distress. The respondent is a 36-year-old woman from Sweden, assessed and diagnosed by a neuropsychological multi-professional team in 2006. The 19-session flotation series prolonged during almost one year. The positive development of arousal control, activity regulation, sensory integration and interpretation, cognitive functioning and emotional maturity created experiences of personal independence and quality of life. Flotation-restrictive environmental stimulation technique was experienced as a meaningful treatment. Additional studies of treatment for Attention Deficit Hyperactivity Disorder and comorbid disorders in adults using the flotation-restrictive environmental stimulation technique are strongly encouraged.

Utilization of flotation wastes of copper slag as raw material in cement production.

PubMed

Alp, I; Deveci, H; Süngün, H

2008-11-30

Copper slag wastes, even if treated via processes such as flotation for metal recovery, still contain heavy metals with hazardous properties posing environmental risks for disposal. This study reports the potential use of flotation waste of a copper slag (FWCS) as iron source in the production of Portland cement clinker. The FWCS appears a suitable raw material as iron source containing >59% Fe(2)O(3) mainly in the form of fayalite (Fe(2)SiO(4)) and magnetite (Fe(3)O(4)). The clinker products obtained using the FWCS from the industrial scale trial operations over a 4-month period were characterised for the conformity of its chemical composition and the physico-mechanical performance of the resultant cement products was evaluated. The data collected for the clinker products produced using an iron ore, which is currently used as the cement raw material were also included for comparison. The results have shown that the chemical compositions of all the clinker products including those of FWCS are typical of a Portland cement clinker. The mechanical performance of the standard mortars prepared from the FWCS clinkers were found to be similar to those from the iron ore clinkers with the desired specifications for the industrial cements e.g. CEM I type cements. Furthermore, the leachability tests (TCLP and SPLP) have revealed that the mortar samples obtained from the FWCS clinkers present no environmental problems while the FWCS could act as the potential source of heavy metal contamination. These findings suggest that flotation wastes of copper slag (FWCS) can be readily utilised as cement raw material due to its availability in large quantities at low cost with the further significant benefits for waste management/environmental practices of the FWCS and the reduced production and processing costs for cement raw materials.

Enhancing the effectiveness of polyoxyethylene in the filtration of flotation concentrate. [With polyoxyethylene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baichenko, A.A.; Kaminskii, V.S.; Sokolova, V.S.

1977-01-01

Laboratory data are presented on the degradation of polyoxyethylene during storage and under mechanical and chemical action. Provided the physico-chemical properties of the polymer are considered and conditions are adjusted to minimize its degradation during solution preparation, POE can be used as a highly effective flocculant for the commercial filtration of flotation concentrate.

A review of induction and attachment times of wetting thin films between air bubbles and particles and its relevance in the separation of particles by flotation.

PubMed

Albijanic, Boris; Ozdemir, Orhan; Nguyen, Anh V; Bradshaw, Dee

2010-08-11

Bubble-particle attachment in water is critical to the separation of particles by flotation which is widely used in the recovery of valuable minerals, the deinking of wastepaper, the water treatment and the oil recovery from tar sands. It involves the thinning and rupture of wetting thin films, and the expansion and relaxation of the gas-liquid-solid contact lines. The time scale of the first two processes is referred to as the induction time, whereas the time scale of the attachment involving all the processes is called the attachment time. This paper reviews the experimental studies into the induction and attachment times between minerals and air bubbles, and between oil droplets and air bubbles. It also focuses on the experimental investigations and mathematical modelling of elementary processes of the wetting film thinning and rupture, and the three-phase contact line expansion relevant to flotation. It was confirmed that the time parameters, obtained by various authors, are sensitive enough to show changes in both flotation surface chemistry and physical properties of solid surfaces of pure minerals. These findings should be extended to other systems. It is proposed that measurements of the bubble-particle attachment can be used to interpret changes in flotation behaviour or, in conjunction with other factors, such as particle size and gas dispersion, to predict flotation performance. Copyright 2010 Elsevier B.V. All rights reserved.

Purification of silicon for photovoltaic applications

NASA Astrophysics Data System (ADS)

Delannoy, Yves

2012-12-01

Solar grade silicon, as a starting material for crystallization to produce solar cells, is discussed here in terms of impurities whose maximum content is estimated from recent literature and conferences. A review of the production routes for each category of solar-grade silicon (undoped, compensated or heavily compensated) is proposed with emphasis on the metallurgical route. Some recent results are proposed concerning segregation, showing that directional solidification systems can be used for solidification even at high solidification rate (15 cm/h). Results on inductive plasma purification, where boron is evacuated as HBO in a gas phase blown from an inductive plasma torch, are shown to apply as well to arc plasmas and purification by moist gas. Special attention is paid to the history of impurities in the purification processes, showing that impure auxiliary phases (silicon tetrachloride, slag, aluminum, etc.) often need their own purification process to enable their recycling, which has to be considered to evaluate the cost (financial, energetic and environmental) of the purification route.

Grand Forks - East Grand Forks Urban Water Resources Study. Wastewater Management Appendix.

DTIC Science & Technology

1981-07-01

SLUIGES FROM AEROBIC DIGESTION . 2. LOADING RATE OF 20 LB/FT 2/YR APPLICABLE TO BIOLOGICAL SLUDGES FROM ANAEROBIC DIGESTION. 3. EXPECTED PERFORMANCE...plant size as follows: Sludge Handling Facilities Flow Range Biological Sludge Lime Sludge Flow <_ 3 MCD Flotation thickening, Gravity thicken & aerobic ... digestion , & drying beds. drying beds. 3 MGD < Mot; < 10 MGD Flotation thickening, Gravity thicken & anaerobic digestion, & vacuum filter. vacuum

Oxygen Sag and Stream Purification.

ERIC Educational Resources Information Center

Neal, Larry; Herwig, Roy

1978-01-01

Presents a literature review of water quality related to oxygen sag and stream purification, covering publications of 1976-77. This review includes: (1) self-purification models; (2) oxygen demand; and (3) reaeration and oxygen transfer. A list of 60 references is also presented. (HM)

Optimized Production of Coal Fly Ash Derived Synthetic Zeolites for Mercury Removal from Wastewater

NASA Astrophysics Data System (ADS)

Tauanov, Z.; Shah, D.; Itskos, G.; Inglezakis, V.

2017-09-01

Coal fly ash (CFA) derived synthetic zeolites have become popular with recent advances and its ever-expanding range of applications, particularly as an adsorbent for water and gas purification and as a binder or additive in the construction industry and agriculture. Among these applications, perpetual interest has been in utilization of CFA derived synthetic zeolites for removal of heavy metals from wastewater. We herein focus on utilization of locally available CFA for efficient adsorption of mercury from wastewater. To this end, experimental conditions were investigated so that to produce synthetic zeolites from Kazakhstani CFAs with conversion into zeolite up to 78%, which has remarkably high magnetite content. In particular, the effect of synthesis reaction temperature, reaction time, and loading of adsorbent were systematically investigated and optimized. All produced synthetic zeolites and the respective CFAs were characterized using XRD, XRF, PSA and porosimetric instruments to obtain microstructural and mineralogical data. Furthermore, the synthesized zeolites were studied for the removal of mercury from aqueous solutions. A comparison of removal eficiency and its relationship to the physical and chemical properties of the synthetic zeolites were analyzed and interpreted.

Optimization of Cu-Zn Massive Sulphide Flotation by Selective Reagents

NASA Astrophysics Data System (ADS)

Soltani, F.; Koleini, S. M. J.; Abdollahy, M.

2014-10-01

Selective floatation of base metal sulphide minerals can be achieved by using selective reagents. Sequential floatation of chalcopyrite-sphalerite from Taknar (Iran) massive sulphide ore with 3.5 % Zn and 1.26 % Cu was studied. D-optimal design of response surface methodology was used. Four mixed collector types (Aer238 + SIPX, Aero3477 + SIPX, TC1000 + SIPX and X231 + SIPX), two depressant systems (CuCN-ZnSO4 and dextrin-ZnSO4), pH and ZnSO4 dosage were considered as operational factors in the first stage of flotation. Different conditions of pH, CuSO4 dosage and SIPX dosage were studied for sphalerite flotation from first stage tailings. Aero238 + SIPX induced better selectivity for chalcopyrite against pyrite and sphalerite. Dextrin-ZnSO4 was as effective as CuCN-ZnSO4 in sphalerite-pyrite depression. Under optimum conditions, Cu recovery, Zn recovery and pyrite content in Cu concentrate were 88.99, 33.49 and 1.34 % by using Aero238 + SIPX as mixed collector, CuCN-ZnSO4 as depressant system, at ZnSO4 dosage of 200 g/t and pH 10.54. When CuCN was used at the first stage, CuSO4 consumption increased and Zn recovery decreased during the second stage. Maximum Zn recovery was 72.19 % by using 343.66 g/t of CuSO4, 22.22 g/t of SIPX and pH 9.99 at the second stage.

Strategy to identify the causes and to solve a sludge granulation problem in methanogenic reactors: application to a full-scale plant treating cheese wastewater.

PubMed

Macarie, Hervé; Esquivel, Maricela; Laguna, Acela; Baron, Olivier; El Mamouni, Rachid; Guiot, Serge R; Monroy, Oscar

2017-08-26

Granulation of biomass is at the basis of the operation of the most successful anaerobic systems (UASB, EGSB and IC reactors) applied worldwide for wastewater treatment. Despite of decades of studies of the biomass granulation process, it is still not fully understood and controlled. "Degranulation/lack of granulation" is a problem that occurs sometimes in anaerobic systems resulting often in heavy loss of biomass and poor treatment efficiencies or even complete reactor failure. Such a problem occurred in Mexico in two full-scale UASB reactors treating cheese wastewater. A close follow-up of the plant was performed to try to identify the factors responsible for the phenomenon. Basically, the list of possible causes to a granulation problem that were investigated can be classified amongst nutritional, i.e. related to wastewater composition (e.g. deficiency or excess of macronutrients or micronutrients, too high COD proportion due to proteins or volatile fatty acids, high ammonium, sulphate or fat concentrations), operational (excessive loading rate, sub- or over-optimal water upflow velocity) and structural (poor hydraulic design of the plant). Despite of an intensive search, the causes of the granulation problems could not be identified. The present case remains however an example of the strategy that must be followed to identify these causes and could be used as a guide for plant operators or consultants who are confronted with a similar situation independently of the type of wastewater. According to a large literature based on successful experiments at lab scale, an attempt to artificially granulate the industrial reactor biomass through the dosage of a cationic polymer was also tested but equally failed. Instead of promoting granulation, the dosage caused a heavy sludge flotation. This shows that the scaling of such a procedure from lab to real scale cannot be advised right away unless its operability at such a scale can be demonstrated.

Treatment of combined acid mine drainage (AMD)--flotation circuit effluents from copper mine via Fenton's process.

PubMed

Mahiroglu, Ayse; Tarlan-Yel, Esra; Sevimli, Mehmet Faik

2009-07-30

The treatability of a copper mine wastewater, including heavy metals, AMD, as well as flotation chemicals, with Fenton process was investigated. Fenton process seems advantageous for this treatment, because of Fe(2+) content and low pH of AMD. First, optimum Fe(2+) condition under constant H(2)O(2) was determined, and initial Fe(2+) content of AMD was found sufficient (120 mg/L for removal of chemical oxygen demand (COD) of 6125 mg/L). In the second step, without any additional Fe(2+), optimum H(2)O(2) dosage was determined as 40 mg/L. Fe(2+)/H(2)O(2) molar ratio of 1.8 was enough to achieve the best treatment performance. In all trials, initial pH of AMD was 4.8 and pH adjustment was not performed. Utilization of existing pH and Fe(2+), low H(2)O(2) requirements, and up to 98% treatment performances in COD, turbidity, color, Cu(2+), Zn(2+) made the proposed treatment system promising. Since the reaction occurs stepwise, a two-step kinetic model was applied and calculated theoretical maximum removal rate was consistent to experimental one, which validates the applied model. For the optimum molar ratio (1.8), 140 mL/L sludge of high density (1.094 g/mL), high settling velocity (0.16 cm/s) with low specific resistance (3.15 x 10(8)m/kg) was obtained. High reaction rates and easily dewaterable sludge characteristics also made the proposed method advantageous.

Optimization of electrocoagulation (EC) process for the purification of a real industrial wastewater from toxic metals.

PubMed

Gatsios, Evangelos; Hahladakis, John N; Gidarakos, Evangelos

2015-05-01

In the present work, the efficiency evaluation of electrocoagulation (EC) in removing toxic metals from a real industrial wastewater, collected from Aspropyrgos, Athens, Greece was investigated. Manganese (Mn), copper (Cu) and zinc (Zn) at respective concentrations of 5 mg/L, 5 mg/L and 10 mg/L were present in the wastewater (pH=6), originated from the wastes produced by EBO-PYRKAL munitions industry and Hellenic Petroleum Elefsis Refineries. The effect of operational parameters such as electrode combination and distance, applied current, initial pH and initial metal concentration, was studied. The results indicated that Cu and Zn were totally removed in all experiments, while Mn exhibited equally high removal percentages (approximately 90%). Decreasing the initial pH and increasing the distance between electrodes, resulted in a negative effect on the efficiency and energy consumption of the process. On the other hand, increasing the applied current, favored metal removal but resulted in a power consumption increase. Different initial concentrations did not affect metal removal efficiency. The optimal results, regarding both cost and EC efficiency, were obtained with a combination of iron electrodes, at 2 cm distance, at initial current of 0.1 A and pH=6. After 90 min of treatment, maximum removal percentages obtained were 89% for Mn, 100% for Cu and 100% for Zn, at an energy consumption of 2.55 kWh/m(3). Copyright © 2015 Elsevier Ltd. All rights reserved.

Shuttle Wastewater Solution Characterization

NASA Technical Reports Server (NTRS)

Adam, Niklas; Pham, Chau

2011-01-01

During the 31st shuttle mission to the International Space Station, STS-129, there was a clogging event in the shuttle wastewater tank. A routine wastewater dump was performed during the mission and before the dump was completed, degraded flow was observed. In order to complete the wastewater dump, flow had to be rerouted around the dump filter. As a result, a basic chemical and microbial investigation was performed to understand the shuttle wastewater system and perform mitigation tasks to prevent another blockage. Testing continued on the remaining shuttle flights wastewater and wastewater tank cleaning solutions. The results of the analyses and the effect of the mitigation steps are detailed in this paper.

A perspective of stepwise utilisation of Bayer red mud: Step two--Extracting and recovering Ti from Ti-enriched tailing with acid leaching and precipitate flotation.

PubMed

Huang, Yanfang; Chai, Wencui; Han, Guihong; Wang, Wenjuan; Yang, Shuzhen; Liu, Jiongtian

2016-04-15

The extraction and recovery of Ti from Ti-enriched tailing with acid leaching and precipitate flotation, as one of the critical steps, was proposed for the stepwise utilization of red mud. The factors influencing acid leaching and precipitate flotation were examined by factorial design. The leaching thermodynamics, kinetics of Ti(4+), Al(3+) and Fe(3+), and the mechanism of selectively Fe(3+) removal using [Hbet][Tf2N] as precipitating reagent were discussed. The extracting of Ti(4+), Al(3+) and Fe(3+) in concentrated H2SO4 is controlled by diffusion reactions, depending mainly upon leaching time and temperature. The maximum extracting efficiency of Ti(4+) is approximately 92.3%, whereas Al(3+) and Fe(3+) leaching are respectively 75.8% and 84.2%. [Hbet][Tf2N], as a precipitating reagent, operates through a coordination mechanism in flotation. The pH value is the key factor influencing the flotation recovery of Ti(4+), whereas the dosage of precipitating reagent is that for Al(3+) recovery. The maximum flotation recovery of Ti(4+) is 92.7%, whereas the maximum Al(3+) recovery is 93.5%. The total recovery rate for extracting and recovering titanium is 85.5%. The liquor with Ti(4+) of 15.5g/L, Al(3+) of 30.4g/L and Fe(3+) of 0.48g/L was obtained for the following hydrolysis step in the integrated process for red mud utilisation. Copyright © 2016 Elsevier B.V. All rights reserved.

Selective Sulfidation of Lead Smelter Slag with Pyrite and Flotation Behavior of Synthetic ZnS

NASA Astrophysics Data System (ADS)

Han, Junwei; Liu, Wei; Wang, Dawei; Jiao, Fen; Zhang, Tianfu; Qin, Wenqing

2016-08-01

The selective sulfidation of lead smelter slag with pyrite in the presence of carbon and Na salts, and the flotation behavior of synthetic ZnS were studied. The effects of temperature, time, pyrite dosage, Na salts, and carbon additions were investigated based on thermodynamic calculation, and correspondingly, the growth mechanism of ZnS particles was studied at high temperatures. The results indicated that the zinc in lead smelter slag was selectively converted into zinc sulfides by sulfidation roasting. The sulfidation degree of zinc was increased until the temperature, time, pyrite, and carbon dosages reached their optimum values, under which it was more than 95 pct. The growth of ZnS particles largely depended upon roasting temperature, and the ZnS grains were significantly increased above 1373 K (1100 °C) due to the formation of a liquid phase. After the roasting, the zinc sulfides generated had a good floatability, and 88.34 pct of zinc was recovered by conventional flotation.

Investigation of thermal treatment on selective separation of post consumer plastics prior to froth flotation.

PubMed

Guney, Ali; Poyraz, M Ibrahim; Kangal, Olgac; Burat, Firat

2013-09-01

Plastics have become the widely used materials because of their advantages, such as cheapness, endurance, lightness, and hygiene. However, they cause waste and soil pollution and they do not easily decompose. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. Depending on their surface characteristics, these plastics can be separated from each other by flotation method which is useful mineral processing technique with its low cost and simplicity. The main objective of this study is to investigate the flotation characteristics of PET and PVC and determine the effect of plasticizer reagents on efficient plastic separation. For that purpose, various parameters such as pH, plasticizer concentration, plasticizer type, conditioning temperature and thermal conditioning were investigated. As a result, PET particles were floated with 95.1% purity and 65.3% efficiency while PVC particles were obtained with 98.1% purity and 65.3% efficiency. Copyright © 2013 Elsevier Ltd. All rights reserved.

Process for purification of silicon

NASA Technical Reports Server (NTRS)

Rath, H. J.; Sirtl, E.; Pfeiffer, W.

1981-01-01

The purification of metallurgically pure silicon having a silicon content of more than 95% by weight is accomplished by leaching with an acidic solution which substantially does not attack silicon. A mechanical treatment leading to continuous particle size reduction of the granulated silicon to be purified is combined with the chemical purification step.

Some aspects of using ultrasounds to improve sulfurous mineral flotation technology

NASA Technical Reports Server (NTRS)

Mihu, V. P.; Pop, I.

1974-01-01

The results are discussed which were obtained with a new method of desorption of collector reagents connected with improving the selectivity of the flotation of copper and lead concentrate through the action of ultrasounds. Analysis of the results obtained by treating copper and lead concentrate in an ultraacoustic field indicates an increase in the copper content of the copper concentrate, of the lead content in the lead concentrate and, at the same time, a reduction in the lead of the copper concentrate.

Ancylostoma caninum: calibration and comparison of diagnostic accuracy of flotation in tube, McMaster and FLOTAC in faecal samples of dogs.

PubMed

Cringoli, Giuseppe; Rinaldi, Laura; Maurelli, Maria Paola; Morgoglione, Maria Elena; Musella, Vincenzo; Utzinger, Jürg

2011-05-01

We performed a calibration of flotation in tube, McMaster and FLOTAC to determine the optimal flotation solution (FS) and the influence of faecal preservation for the diagnosis of Ancylostoma caninum in dogs, and compared the accuracy of the three copromicroscopic techniques. Among nine different FS, sodium chloride and sodium nitrate performed best for detection and quantification of A. caninum eggs. Faecal samples, either fresh or preserved in formalin 5%, resulted in higher A. caninum egg counts, compared to frozen samples or preserved in formalin 10% or sodium acetate-acetic acid-formalin. FLOTAC consistently resulted in higher A. caninum eggs per gram of faeces (EPG) and lower coefficient of variation (CV) than McMaster and flotation in tube. The best results in terms of mean faecal egg counts (highest value, i.e. 117.0EPG) and CV (lowest value, i.e. 4.8%) were obtained with FLOTAC using sodium chloride and faecal samples preserved in formalin 5%. Our findings suggest that the FLOTAC technique should be considered for the diagnosis of A. caninum in dogs. Copyright © 2011 Elsevier Inc. All rights reserved.

Combining sun-based technologies (microalgae and solar disinfection) for urban wastewater regeneration.

PubMed

Gutiérrez-Alfaro, Sergio; Rueda-Márquez, Juan J; Perales, José A; Manzano, Manuel A

2018-04-01

Solar disinfection (SODIS) of urban wastewater can be a suitable technology for improving the microbiological quality of reclaimed water as a complement to other extensive and environmentally friendly technologies such as microalgae biotreatment. The objective of this work is to evaluate the feasibility of incorporating the SODIS technology at the end of a pilot scale urban wastewater treatment plant (WWTP) where the processes are based on microalgae biotechnology and comprising three Upflow Anaerobic Sludge Blanket (UASB, 20m 3 each one) reactor, six High Rate Algal Ponds (HRAP, 32m 2 each one), and a Dissolved Air Flotation (DAF, 1m 3 ) unit. E. coli concentration was monitored at the effluent of the different units (UASB, HRAP, DAF) of the pilot WWTP. The efficiency of the SODIS process was studied for the inactivation of three of the commonly employed indicator microorganisms (Escherichia coli, Enterococcus spp. and Clostridium perfringens) using a compound parabolic collector (CPC) for five months under various conditions of irradiance and temperature. E. coli and Enterococcus spp. were more effectively disinfected by the SODIS unit (2.9 and 2.5 logarithms of reduction on average, respectively) than by the HRAP (2 and 1.1) or the DAF (0.9 and 0.1). On the contrary, the DAF technology achieved better reduction rates of C. perfringens (1.7) than the SODIS (0.9) and the HRAP (0.1). No regrowth of any microorganisms was detected during dark storage after the SODIS treatment. Incorporating a SODIS unit after the non-conventional WWTP processes substantially increases the possibilities for reuse of the treated water after receiving a cumulative UV radiation dose of 25W·h/m 2 (50min of normalized time of solar illumination). The surface requirement of the SODIS equipment would be 3.5 times smaller than the HRAP's surface. Copyright © 2017 Elsevier B.V. All rights reserved.

Simultaneous separation/enrichment and detection of trace ciprofloxacin and lomefloxacin in food samples using thermosensitive smart polymers aqueous two-phase flotation system combined with HPLC.

PubMed

Lu, Yang; Chen, Bo; Yu, Miao; Han, Juan; Wang, Yun; Tan, Zhenjiang; Yan, Yongsheng

2016-11-01

Smart polymer aqueous two phase flotation system (SPATPF) is a new separation and enrichment technology that integrated the advantages of the three technologies, i.e., aqueous two phase system, smart polymer and flotation sublation. Ethylene oxide and propylene oxide copolymer (EOPO)-(NH4)2SO4 SPATPF is a pretreatment technique, and it is coupled with high-performance liquid chromatography to analyze the trace ciprofloxacin and lomefloxacin in real food samples. The optimized conditions of experiment were determined in the multi-factor experiment by using response surface methodology. The flotation efficiency of lomefloxacin and ciprofloxacin was 94.50% and 98.23% under the optimized conditions. The recycling experimentsshowed that the smart polymer EOPO could use repeatedly, which will reduce the cost in the future application. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessing the feasibility of wastewater recycling and treatment efficiency of wastewater treatment units.

PubMed

Lou, Jie-Chung; Lin, Yung-Chang

2008-02-01

Wastewater reuse can significantly reduce environmental pollution and save the water sources. The study selected Cheng-Ching Lake water treatment plant in southern Taiwan to discuss the feasibility of wastewater recycling and treatment efficiency of wastewater treatment units. The treatment units of this plant include wastewater basin, sedimentation basin, sludge thickener and sludge dewatering facility. In this study, the treatment efficiency of SS and turbidity were 48.35-99.68% and 24.15-99.36%, respectively, showing the significant removal efficiency of the wastewater process. However, the removal efficiencies of NH(3)-N, total organic carbon (TOC) and chemical oxygen demand (COD) are limited by wastewater treatment processes. Because NH(3)-N, TOC and COD of the mixing supernatant and raw water are regulated raw water quality standards, supernatant reuse is feasible and workable during wastewater processes at this plant. Overall, analytical results indicated that supernatant reuse is feasible.

Biocapture of CO₂ by Different Microalgal-Based Technologies for Biogas Upgrading and Simultaneous Biogas Slurry Purification under Various Light Intensities and Photoperiods.

PubMed

Guo, Pengfei; Zhang, Yuejin; Zhao, Yongjun

2018-03-15

Abstract : Co-cultivation of microalgae and microbes for pollutant removal from sewage is considered as an effective wastewater treatment method. The aim of this study is to screen the optimal photoperiod, light intensity and microalgae co-cultivation method for simultaneously removing nutrients in biogas slurry and capturing CO₂ in biogas. The microalgae-fungi pellets are deemed to be a viable option because of their high specific growth rate and nutrient and CO 2 removal efficiency under the photoperiod of 14 h light:10 h dark. The order of both the biogas slurry purification and biogas upgrading is ranked the same, that is Chlorella vulga ris - Ganoderma lucidum > Chlorella vulga ris -activated sludge > Chlorella vulgaris under different light intensities. For all cultivation methods, the moderate light intensity of 450 μmol m -2 s -1 is regarded as the best choice. This research revealed that the control of photoperiod and light intensity can promote the biological treatment process of biogas slurry purification and biogas upgrading using microalgal-based technology.

Entanglement of purification: from spin chains to holography

NASA Astrophysics Data System (ADS)

Nguyen, Phuc; Devakul, Trithep; Halbasch, Matthew G.; Zaletel, Michael P.; Swingle, Brian

2018-01-01

Purification is a powerful technique in quantum physics whereby a mixed quantum state is extended to a pure state on a larger system. This process is not unique, and in systems composed of many degrees of freedom, one natural purification is the one with minimal entanglement. Here we study the entropy of the minimally entangled purification, called the entanglement of purification, in three model systems: an Ising spin chain, conformal field theories holographically dual to Einstein gravity, and random stabilizer tensor networks. We conjecture values for the entanglement of purification in all these models, and we support our conjectures with a variety of numerical and analytical results. We find that such minimally entangled purifications have a number of applications, from enhancing entanglement-based tensor network methods for describing mixed states to elucidating novel aspects of the emergence of geometry from entanglement in the AdS/CFT correspondence.

Psychotherapeutic Treatment in Combination with Relaxation in a Flotation Tank: Effects on "Burn-Out Syndrome"

ERIC Educational Resources Information Center

Kjellgren, Anette; Buhrkall, Hanne; Norlander, Torsten

2010-01-01

The focus of this study was to investigate experiences gained from treatment combining relaxation in flotation tank with psychotherapy for sufferers from "burn-out syndrome". Six people participated in a ten week program. They were all interviewed; the data were analyzed using the Empirical Phenomenological Psychological method. Five…

Wastewater Collection.

ERIC Educational Resources Information Center

Chatterjee, Samar; And Others

1978-01-01

Presents a literature review of wastewater collection systems and components. This review covers: (1) planning, (2) construction; (3) sewer system evaluation; (4) maintenance; (5) rehabilitation; (6) overview prevention; and (7) wastewater pumping. A list of 111 references is also presented. (HM)

Simultaneous separation of copper, cadmium and cobalt from sea-water by co-flotation with octadecylamine and ferric hydroxide as collectors.

PubMed

Cabezon, L M; Caballero, M; Cela, R; Perez-Bustamante, J A

1984-08-01

A method is proposed for the simultaneous quantitative separation of traces ofCu(II), Cd(II) and Co(II) from sea-water samples by means of the co-flotation (adsorbing colloid flotation) technique with ferric hydroxide as co-precipitant and octadecylamine as collector. The experimental parameters have been studied and optimized. The drawbacks arising from the low solubility of octadecylamine and the corresponding sublates in water have been avoided by use of a 6M hydrochloric acid-MIBK-ethanol (1:2:2 v v ) mixture. The results obtained by means of the proposed method have been compared with those given by the usual ammonium pyrrolidine dithiocarbamate/MIBK extraction method.

Wastewater garden--a system to treat wastewater with environmental benefits to community.

PubMed

Nair, Jaya

2008-01-01

Many communities and villages around the world face serious problems with lack of sanitation especially in disposing of the wastewater-black water and grey water from the houses, or wash outs from animal rearing sheds. Across the world diverting wastewater to the surroundings or to the public spaces are not uncommon. This is responsible for contaminating drinking water sources causing health risks and environmental degradation as they become the breeding grounds of mosquitoes and pathogens. Lack of collection and treatment facilities or broken down sewage systems noticed throughout the developing world are associated with this situation. Diverting the wastewater to trees and vegetable gardens was historically a common practice. However the modern world has an array of problems associated with such disposal such as generation of large quantity of wastewater, unavailability of space for onsite disposal or treatment and increase in population. This paper considers the wastewater garden as a means for wastewater treatment and to improve the vegetation and biodiversity of rural areas. This can also be implemented in urban areas in association with parks and open spaces. This also highlights environmental safety in relation to the nutrient, pathogen and heavy metal content of the wastewater. The possibilities of different types of integration and technology that can be adopted for wastewater gardens are also discussed. IWA Publishing 2008.

Biohydrogen production from industrial wastewaters.

PubMed

Moreno-Andrade, Iván; Moreno, Gloria; Kumar, Gopalakrishnan; Buitrón, Germán

2015-01-01

The feasibility of producing hydrogen from various industrial wastes, such as vinasses (sugar and tequila industries), and raw and physicochemical-treated wastewater from the plastic industry and toilet aircraft wastewater, was evaluated. The results showed that the tequila vinasses presented the maximum hydrogen generation potential, followed by the raw plastic industry wastewater, aircraft wastewater, and physicochemical-treated wastewater from the plastic industry and sugar vinasses, respectively. The hydrogen production from the aircraft wastewater was increased by the adaptation of the microorganisms in the anaerobic sequencing batch reactor.

Microbial Community Profiles in Wastewaters from Onsite Wastewater Treatment Systems Technology

PubMed Central

Jałowiecki, Łukasz; Chojniak, Joanna Małgorzata; Dorgeloh, Elmar; Hegedusova, Berta; Ejhed, Helene; Magnér, Jörgen; Płaza, Grażyna Anna

2016-01-01

The aim of the study was to determine the potential of community-level physiological profiles (CLPPs) methodology as an assay for characterization of the metabolic diversity of wastewater samples and to link the metabolic diversity patterns to efficiency of select onsite biological wastewater facilities. Metabolic fingerprints obtained from the selected samples were used to understand functional diversity implied by the carbon substrate shifts. Three different biological facilities of onsite wastewater treatment were evaluated: fixed bed reactor (technology A), trickling filter/biofilter system (technology B), and aerated filter system (the fluidized bed reactor, technology C). High similarities of the microbial community functional structures were found among the samples from the three onsite wastewater treatment plants (WWTPs), as shown by the diversity indices. Principal components analysis (PCA) showed that the diversity and CLPPs of microbial communities depended on the working efficiency of the wastewater treatment technologies. This study provided an overall picture of microbial community functional structures of investigated samples in WWTPs and discerned the linkages between microbial communities and technologies of onsite WWTPs used. The results obtained confirmed that metabolic profiles could be used to monitor treatment processes as valuable biological indicators of onsite wastewater treatment technologies efficiency. This is the first step toward understanding relations of technology types with microbial community patterns in raw and treated wastewaters. PMID:26807728

Municipal wastewater biological nutrient removal driven by the fermentation liquid of dairy wastewater.

PubMed

Liu, Hui; Chen, Yinguang; Wu, Jiang

2017-11-01

Carbon substrate is required by biological nutrient removal (BNR) microorganism, but it is usually insufficient in the influent of many municipal wastewater treatment plants. In this study the use of ethanol-enriched fermentation liquid, which was derived from dairy wastewater, as the preferred carbon substrate of BNR was reported. First, the application of dairy wastewater and food processing wastewater and their fermentation liquid as the carbon substrate of BNR was compared in the short-term tests. The fermented wastewater showed higher BNR performance than the unfermented one, and the fermentation liquid of dairy wastewater (FL-DW), which was obtained under pH 8 and fermentation time of 6 day, exhibited the highest phosphorus (95.5%) and total nitrogen (97.6%) removal efficiencies due to its high ethanol content (57.9%). Then, the long-term performance of FL-DW acting as the carbon substrate of BNR was compared with that of acetate and ethanol, and the FL-DW showed the greatest phosphorus and total nitrogen removal. Further investigation showed that the use of FL-DW caused the highest polyhydroxyalkanoates (PHAs) synthesis in BNR microbial cells, and more PHAs were used for phosphorus uptake and denitrification rather than glycogen synthesis and microbial growth. The FL-DW can be used as a preferred carbon substrate for BNR microbes. AB: aerobic end sludge active biomass; BNR: biological nutrient removal; DW: dairy wastewater; FL-DW: fermentation liquid of dairy wastewater; FPW: food processing wastewater; FL-FPW: fermentation liquid of food processing wastewater; PHAs: polyhydroxyalkanoates; PHB: poly-3-hydroxybutyrate; PHV: poly-3-hydroxyvalerate; PH2MV: poly-3-hydroxy-2- methylvalerate; PAOs: phosphorus accumulating organisms; SBR: sequencing batch reactor; SOP: soluble ortho-phosphorus; TN: total nitrogen; TSS: total suspended solids; VSS: volatile suspended solids; VFAs: volatile fatty acids; WWTPs: wastewater treatment plants.

Photocatalytic materials and technologies for air purification.

PubMed

Ren, Hangjuan; Koshy, Pramod; Chen, Wen-Fan; Qi, Shaohua; Sorrell, Charles Christopher

2017-03-05

Since there is increasing concern for the impact of air quality on human health, the present work surveys the materials and technologies for air purification using photocatalytic materials. The coverage includes (1) current photocatalytic materials for the decomposition of chemical contaminants and disinfection of pathogens present in air and (2) photocatalytic air purification systems that are used currently and under development. The present work focuses on five main themes. First, the mechanisms of photodegradation and photodisinfection are explained. Second, system designs for photocatalytic air purification are surveyed. Third, the photocatalytic materials used for air purification and their characteristics are considered, including both conventional and more recently developed photocatalysts. Fourth, the methods used to fabricate these materials are discussed. Fifth, the most significant coverage is devoted to materials design strategies aimed at improving the performance of photocatalysts for air purification. The review concludes with a brief consideration of promising future directions for materials research in photocatalysis. Copyright © 2016 Elsevier B.V. All rights reserved.

[Flotation and extraction spectrophotometric determination of trace silicate in water].

PubMed

Di, J; Liu, Q; Li, W

2000-12-01

In HCl solution, silicate reacted with molybdate ammonium to produce silicomolibdic, then a yellow compound which was produced from the oxidation of TMB was simultaneously isolated to benzene phase by flotation and then isolated to dimethylsulfoxideformic acid by extraction. The compound gives a high absorption at 458 nm. The apparent molar absorptivity is 1.26 x 10(5) L.mol-1.cm-1. In the range of 0.02-1 mg.L-1 Si obeys Beer's law. The proposed method which combines with enrichment and measurement is simple, rapid, selective and convenient to determine silicate in water with satisfied results.

Removal of airborne microorganisms emitted from a wastewater treatment oxidation ditch by adsorption on activated carbon.

PubMed

Li, Lin; Gao, Min; Liu, Junxin; Guo, Xuesong

2011-01-01

Bioaerosol emissions from wastewater and wastewater treatment processes are a significant subgroup of atmospheric aerosols. Most previous work has focused on the evaluation of their biological risks. In this study, however, the adsorption method was applied to reduce airborne microorganisms generated from a pilot scale wastewater treatment facility with oxidation ditch. Results showed adsorption on granule activated carbon (GAC) was an efficient method for the purification of airborne microorganisms. The GAC itself had a maximum adsorption capacity of 2217 CFU/g for airborne bacteria and 225 CFU/g for fungi with a flow rate of 1.50 m3/hr. Over 85% of airborne bacteria and fungi emitted from the oxidation ditch were adsorbed within 80 hr of continuous operation mode. Most of them had a particle size of 0.65-4.7 microm. Those airborne microorganisms with small particle size were apt to be adsorbed. The SEM/EDAX, BET and Boehm's titration methods were applied to analyse the physicochemical characteristics of the GAC. Relationships between GAC surface characteristics and its adsorption performance demonstrated that porous structure, large surface area, and hydrophobicity rendered GAC an effective absorber of airborne microorganisms. Two regenerate methods, ultraviolet irradiation and high pressure vapor, were compared for the regeneration of used activated carbon. High pressure vapor was an effective technique as it totally destroyed the microorganisms adhered to the activated carbon. Microscopic observation was also carried out to investigate original and used adsorbents.

Biocapture of CO2 by Different Microalgal-Based Technologies for Biogas Upgrading and Simultaneous Biogas Slurry Purification under Various Light Intensities and Photoperiods

PubMed Central

Guo, Pengfei; Zhang, Yuejin; Zhao, Yongjun

2018-01-01

Co-cultivation of microalgae and microbes for pollutant removal from sewage is considered as an effective wastewater treatment method. The aim of this study is to screen the optimal photoperiod, light intensity and microalgae co-cultivation method for simultaneously removing nutrients in biogas slurry and capturing CO2 in biogas. The microalgae–fungi pellets are deemed to be a viable option because of their high specific growth rate and nutrient and CO2 removal efficiency under the photoperiod of 14 h light:10 h dark. The order of both the biogas slurry purification and biogas upgrading is ranked the same, that is Chlorella vulgaris–Ganoderma lucidum > Chlorella vulgaris–activated sludge > Chlorella vulgaris under different light intensities. For all cultivation methods, the moderate light intensity of 450 μmol m−2 s−1 is regarded as the best choice. This research revealed that the control of photoperiod and light intensity can promote the biological treatment process of biogas slurry purification and biogas upgrading using microalgal-based technology. PMID:29543784

Antifouling membranes for sustainable water purification: strategies and mechanisms.

PubMed

Zhang, Runnan; Liu, Yanan; He, Mingrui; Su, Yanlei; Zhao, Xueting; Elimelech, Menachem; Jiang, Zhongyi

2016-10-24

One of the greatest challenges to the sustainability of modern society is an inadequate supply of clean water. Due to its energy-saving and cost-effective features, membrane technology has become an indispensable platform technology for water purification, including seawater and brackish water desalination as well as municipal or industrial wastewater treatment. However, membrane fouling, which arises from the nonspecific interaction between membrane surface and foulants, significantly impedes the efficient application of membrane technology. Preparing antifouling membranes is a fundamental strategy to deal with pervasive fouling problems from a variety of foulants. In recent years, major advancements have been made in membrane preparation techniques and in elucidating the antifouling mechanisms of membrane processes, including ultrafiltration, nanofiltration, reverse osmosis and forward osmosis. This review will first introduce the major foulants and the principal mechanisms of membrane fouling, and then highlight the development, current status and future prospects of antifouling membranes, including antifouling strategies, preparation techniques and practical applications. In particular, the strategies and mechanisms for antifouling membranes, including passive fouling resistance and fouling release, active off-surface and on-surface strategies, will be proposed and discussed extensively.

Wastewater Treatment

MedlinePlus

... cleaned, water can carry disease. Since we live, work and play so close to water, harmful bacteria have to be removed to make water safe. Effects of wastewater pollutants If wastewater is not properly treated, then the environment and human health can be negatively impacted. These ...

Hamiltonian purification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orsucci, Davide; Burgarth, Daniel; Facchi, Paolo

The problem of Hamiltonian purification introduced by Burgarth et al. [Nat. Commun. 5, 5173 (2014)] is formalized and discussed. Specifically, given a set of non-commuting Hamiltonians (h{sub 1}, …, h{sub m}) operating on a d-dimensional quantum system ℋ{sub d}, the problem consists in identifying a set of commuting Hamiltonians (H{sub 1}, …, H{sub m}) operating on a larger d{sub E}-dimensional system ℋ{sub d{sub E}} which embeds ℋ{sub d} as a proper subspace, such that h{sub j} = PH{sub j}P with P being the projection which allows one to recover ℋ{sub d} from ℋ{sub d{sub E}}. The notions of spanning-set purificationmore » and generator purification of an algebra are also introduced and optimal solutions for u(d) are provided.« less

APPLICATION OF HEAVY MEDIA SEPARATION, FLOTATION AND CARBONATE LEACHING TO CONGO ORES. Topical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Breymann, J.B. III

1951-10-31

The possibility of separating the U minerals from the carbonate minerals in magnesitic-dolomitic U ores from Union Miniere du Haute Katanga, Belgian Congo, by heavy media separation or froth flotation was investigated. Tables are included which show conditions and reagents. Results of tests of carbonate leaching of the whole ore and of the carbonate fiotation products are also tabulated. (auth)

Algal removal from cyanobacteria-rich waters by preoxidation-assisted coagulation-flotation: Effect of algogenic organic matter release on algal removal and trihalomethane formation.

PubMed

Lin, Jr-Lin; Hua, Lap-Cuong; Hung, Shih Kai; Huang, Chihpin

2018-01-01

The cyanobacteria-bloom in raw waters frequently causes an unpredictable chemical dosing of preoxidation and coagulation for an effective removal of algal cells in water treatment plants. This study investigated the effects of preoxidation with NaOCl and ClO 2 on the coagulation-flotation effectiveness in the removal of two commonly blooming cyanobacteria species, Microcystis aeruginosa (MA) and Cylindrospermopsis raciborskii (CR), and their corresponding trihalomethane (THM) formation potential. The results showed that dual dosing with NaOCl plus ClO 2 was more effective in enhancing the deformation of cyanobacterial cells compared to single dosing with NaOCl, especially for CR-rich water. Both preoxidation approaches for CR-rich water effectively reduced the CR cell count with less remained dissolved organic carbon (DOC), which benefited subsequent coagulation-flotation. However, preoxidation led to an adverse release of algogenic organic matter (AOM) in the case of MA-rich water. The release of AOM resulted in a poor removal in MA cells and a large amount of THM formation after oxidation-assisted coagulation-flotation process. The reduction in THM formation potential of CR-rich waters is responsible for effective algae and DOC removal by alum coagulation. It is concluded that the species-specific characteristic of cyanobacteria and their AOM released during chlorination significantly influences the performance of coagulation-flotation for AOM removal and corresponding THM formation. Copyright © 2017. Published by Elsevier B.V.

Water purification in Borexino

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giammarchi, M.; Balata, M.; Ioannucci, L.

Astroparticle Physics and Underground experiments searching for rare nuclear events, need high purity materials to act as detectors or detector shielding. Water has the advantage of being cheap, dense and easily available. Most of all, water can be purified to the goal of obatining a high level of radiopurity. Water Purification can be achieved by means of a combination of processes, including filtration, reverse osmosis, deionization and gas stripping. The Water Purification System for the Borexino experiment, will be described together with its main performances.

Affinity chromatography: A versatile technique for antibody purification.

PubMed

Arora, Sushrut; Saxena, Vikas; Ayyar, B Vijayalakshmi

2017-03-01

Antibodies continue to be extremely utilized entities in myriad applications including basic research, imaging, targeted delivery, chromatography, diagnostics, and therapeutics. At production stage, antibodies are generally present in complex matrices and most of their intended applications necessitate purification. Antibody purification has always been a major bottleneck in downstream processing of antibodies, due to the need of high quality products and associated high costs. Over the years, extensive research has focused on finding better purification methodologies to overcome this holdup. Among a plethora of different techniques, affinity chromatography is one of the most selective, rapid and easy method for antibody purification. This review aims to provide a detailed overview on affinity chromatography and the components involved in purification. An array of support matrices along with various classes of affinity ligands detailing their underlying working principles, together with the advantages and limitations of each system in purifying different types of antibodies, accompanying recent developments and important practical methodological considerations to optimize purification procedure are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

Wastewater: A Potential Bioenergy Resource.

PubMed

Prakash, Jyotsana; Sharma, Rakesh; Ray, Subhasree; Koul, Shikha; Kalia, Vipin Chandra

2018-06-01

Wastewaters are a rich source of nutrients for microorganisms. However, if left unattended the biodegradation may lead to severe environmental hazards. The wastewaters can thus be utilized for the production of various value added products including bioenergy (H 2 and CH 4 ). A number of studies have reported utilization of various wastewaters for energy production. Depending on the nature of the wastewater, different reactor configurations, wastewater and inoculum pretreatments, co-substrate utilizations along with other process parameters have been studied for efficient product formation. Only a few studies have reported sequential utilization of wastewaters for H 2 and CH 4 production despite its huge potential for complete waste degradation.

[Purification of eutrophic wastewater by Cyperus alternifolius, Coleus blumei and Jasminum sambac planted in a floating phytoremediation system].

PubMed

Liu, Shizhe; Lin, Dongjiao; Tang, Shujun; Luo, Jian

2004-07-01

In a greenhouse study, Cyperus alternifolius, Coleus blumei and Jasminum sambac were cultured in a floating phytoremediation system with plantation cups inserted into a polyfoam plate that floated in the upper part of a tank filled with 100 L domestic wastewater. The contents of chemical oxygen demand (CODCr), total P (T-P), total N (T-N), soluble P(S-P), ammonia-nitrogen (NH4+ -N) and nitrate-nitrogen (NO3- -N) in the domestic wastewater were tested during the growth of these three plants. The results showed that Cyperus alternifolius and Coleus blumei could grow well in the floating phytoremediation system, their dry weight being 285.8% and 371.4% of the initial weight of planting, respectively, but Jasminum sambac could not grow well, being 125.0% of the initial weight of planting. The removal rate of TN by these 3 plants was 68.0%, 62.0% and 45.0%, and that of NO3- -N, CODCr and TP was 98.0%, 80.0% and 92.0%, 78.0%, 66.0% and 55.0%, and 90.6%, 90.5% and 88.0% respectively. Cyperus alternifolius and Coleus blumei had good effects on the removal of pollutants in the floating phytoremediation system.

Efficacy of brown sugar flotation and hot water methods for detecting Rhagoletis indifferens (Dipt., Tephritidae) larvae

USDA-ARS?s Scientific Manuscript database

The brown sugar flotation and hot water methods are accepted procedures for detecting larval western cherry fruit fly, Rhagoletis indifferens Curran, in sweet cherry [Prunus avium (L.) L.] and could be included in a systems approach for showing the absence of larvae in fruit. The methods require cr...

The role of selected tree species in industrial sewage sludge/flotation tailing management.

PubMed

Mleczek, Mirosław; Rutkowski, Paweł; Niedzielski, Przemysław; Goliński, Piotr; Gąsecka, Monika; Kozubik, Tomisław; Dąbrowski, Jędrzej; Budzyńska, Sylwia; Pakuła, Jarosław

2016-11-01

The aim of the study was to estimate the ability of ten tree and bush species to tolerate and accumulate Cd, Cu, Pb, Zn, and As species [As(III), As(V), and total organic arsenic] in industrial sewage sludge extremely contaminated with arsenic (almost 27.5 g kg(-1)) in a pot experiment. The premise being that it will then be possible to select the most promising tree/bush species, able to grow in the vicinity of dams where sewage sludge/flotation tailings are used as landfill. Six of the ten tested tree species were able to grow on the sludge. The highest content of total As was observed in Betula pendula roots (30.0 ± 1.3 mg kg(-1) DW), where the dominant As species was the toxic As(V). The highest biomass of Quercus Q1 robur (77.3 § 2.6 g) and Acer platanoides (76.0 § 4.9 g) was observed. A proper planting of selected tree species that are able to thrive on sewage sludge/flotation tailings could be an interesting and promising way to protect dams. By utilizing differences in their root systems and water needs, we will be able to reduce the risk of fatal environmental disasters.

Arbuscular mycorrhizal fungi in two vertical-flow wetlands constructed for heavy metal-contaminated wastewater bioremediation.

PubMed

Xu, Zhouying; Wu, Yang; Jiang, Yinghe; Zhang, Xiangling; Li, Junli; Ban, Yihui

2018-05-01

Over the last three decades, the presence of arbuscular mycorrhizal fungi (AMF) in wetland habitats had been proven, and their roles played in wetland ecosystems and potential functions in wastewater bioremediation technical installations are interesting issues. To increase knowledge on the functions of AMF in the plant-based bioremediation of wastewater, we constructed two vertical-flow wetlands planting with Phragmites australis and investigated AMF distribution in plant roots and their roles played in purification of wastewater polluted by heavy metals (HMs), utilizing the Illumina sequencing technique. A total of 17 operational taxonomic units (OTUs) from 33,031 AMF sequences were obtained, with Glomus being the most dominant. P. australis living in the two vertical-flow constructed wetlands (CWs) harbored diverse AMF comparable with the AM fungal communities in upland habitats. The AMF composition profiles of CW1 (vegetated with non-inoculated plants) and CW2 (vegetated with mycorrhizal plants inoculated with Rhizophagus intraradices) were significantly different. CW1 (15 OTUs) harbored more diverse AMF than CW2 (7 OTUs); however, CW2 harbored much more OTU13 than CW1. In addition, a zipf species abundance distribution (SAD), which might due to the heavy overdominance of OTU13, was observed across AM fugal taxa in P. australis roots of the two CWs. CW1 and CW2 showed high (> 70%) removal capacity of HMs. CW2 exhibited significant higher Cd and Zn removal efficiencies than CW1 (CK) (p = 0.005 and p = 0.008, respectively). It was considered that AMF might play a role in HM removal in CWs.

Semiconductor grade, solar silicon purification project

NASA Technical Reports Server (NTRS)

Ingle, W. M.; Rosler, R. R.; Thompson, S. W.; Chaney, R. E.

1979-01-01

Experimental apparatus and procedures used in the development of a 3-step SiF2(x) polymer transport purification process are described. Both S.S.M.S. and E.S. analysis demonstrated that major purification had occured and some samples were indistinguishable from semiconductor grade silicon (except possibly for phosphorus). Recent electrical analysis via crystal growth reveals that the product contains compensated phosphorus and boron. The low projected product cost and short energy payback time suggest that the economics of this process will result in a cost less than the goal of $10/Kg(1975 dollars). The process appears to be readily scalable to a major silicon purification facility.

X-PEEM, XPS and ToF-SIMS characterisation of xanthate induced chalcopyrite flotation: Effect of pulp potential

NASA Astrophysics Data System (ADS)

Kalegowda, Yogesh; Chan, Yuet-Loy; Wei, Der-Hsin; Harmer, Sarah L.

2015-05-01

Synchrotron-based X-ray photoemission electron microscopy (X-PEEM), X-ray photo-electron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and ultraviolet visible spectroscopy were used to characterize the flotation behaviour of chalcopyrite with xanthate at different processing conditions. The flotation recovery of chalcopyrite decreased from 97% under oxidative conditions (Eh ~ 385 mV SHE, pH 4) to 41% at a reductive potential of - 100 mV SHE (at pH 9). X-PEEM images constructed from the metal L3 absorption edges were used to produce near-edge X-ray absorption fine structure (NEXAFS) spectra from regions of interest, allowing the variability in mineral surface chemistry of each mineral particle to be analysed, and the effect of pulp potential (Eh) on the flotation of chalcopyrite to be determined. XPS, ToF-SIMS and NEXAFS analyses of chalcopyrite particles at oxidative conditions show that the surface was mildly oxidised and covered with adsorbed molecular CuEX. The Cu 2p XPS and Cu L2,3 NEXAFS spectra were dominated by CuI species attributed to bulk chalcopyrite and adsorbed CuEX. At a reductive potential of - 100 mV SHE, an increase in concentration of CuI and FeIII oxides and hydroxides was observed. X-PEEM analysis was able to show the presence of a low percentage of CuII oxides (CuO or Cu(OH)2) with predominantly CuI oxide (Cu2O) which is not evident in Cu 2p XPS spectra.

Purification and reuse of non-point source wastewater via Myriophyllum-based integrative biotechnology: A review.

PubMed

Liu, Feng; Zhang, Shunan; Luo, Pei; Zhuang, Xuliang; Chen, Xiang; Wu, Jinshui

2018-01-01

In this review, the applications of Myriophyllum-based integrative biotechnology to remove common non-point source (NPS) pollutants, such as nitrogen, phosphorus, heavy metals, and organic pollutants (e.g., pesticides and antibiotics) are summarized. The removal of these pollutants via various mechanisms, including uptake by plant and microbial communities in macrophyte-based treatment systems are discussed. This review highlights the potential use of Myriophyllum biomass to produce animal feed, fertilizer, and other valuable by-products, which can yield cost-effective returns and attract more attention to the regulation and recycling of NPS pollutants. In addition, it demonstrates that utilization of Myriophyllum species is a promising and reliable strategy for wastewater treatment. The future development of sustainable Myriophyllum-based treatment systems is discussed from various perspectives. Copyright © 2017 Elsevier Ltd. All rights reserved.

21 CFR 876.5665 - Water purification system for hemodialysis.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Water purification system for hemodialysis. 876... SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5665 Water purification system for hemodialysis. (a) Identification. A water purification system for hemodialysis is a...

21 CFR 876.5665 - Water purification system for hemodialysis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Water purification system for hemodialysis. 876... SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5665 Water purification system for hemodialysis. (a) Identification. A water purification system for hemodialysis is a...

21 CFR 876.5665 - Water purification system for hemodialysis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Water purification system for hemodialysis. 876... SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5665 Water purification system for hemodialysis. (a) Identification. A water purification system for hemodialysis is a...

21 CFR 876.5665 - Water purification system for hemodialysis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Water purification system for hemodialysis. 876... SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5665 Water purification system for hemodialysis. (a) Identification. A water purification system for hemodialysis is a...

Nutrient removal of a floating plant system receiving low- pollution wastewater: Effects of plant species and influent concentration

NASA Astrophysics Data System (ADS)

Duan, J. J.; Zhao, J. N.; Xue, L. H.; Yang, L. Z.

2016-08-01

Plant floating bed was adopted in this study to compare the purification effect of four plant species (Oenanthe javanica, Ipomoea aquatica, Hydrocotyle vulgaris, and Iris sibirica) receiving high and low treated domestic sewage. The experiment was conducted for eight months during the low temperature season. The results indicated that the average removal rates of TN and NH4+-N in I. aquatica floating bed were relatively high both under high and low influent concentration during the first stage of the experiment. During the second stage, H. vulgaris showed the best performance for nitrogen treatment, and the average removal rates of TN were 70.7% and 87.7% under high and low influent concentration, while the average removal rates of NH4 +-N were as high as 98.9% and 98.9%, accordingly. Moreover, H. vulgaris contributed most for plant assimilation to nitrogen removal among different plant floating systems. It was also found that the existence of hydrophytes effectively controlled the rise of water pH value and algae growth and reproduction, which helped to improve the aquatic environment. The results provide engineering parameters for the future design of an ecological remediation technology for low-pollution wastewater purification.

Chemical looping integration with a carbon dioxide gas purification unit

DOEpatents

Andrus, Jr., Herbert E.; Jukkola, Glen D.; Thibeault, Paul R.; Liljedahl, Gregory N.

2017-01-24

A chemical looping system that contains an oxidizer and a reducer is in fluid communication with a gas purification unit. The gas purification unit has at least one compressor, at least one dryer; and at least one distillation purification system; where the gas purification unit is operative to separate carbon dioxide from other contaminants present in the flue gas stream; and where the gas purification unit is operative to recycle the contaminants to the chemical looping system in the form of a vent gas that provides lift for reactants in the reducer.

Review of wastewater problems and wastewater-management planning in the San Francisco Bay region, California

USGS Publications Warehouse

Hines, Walter G.

1973-01-01

The San Francisco Bay region has suffered adverse environmental effects related to the discharge of municipal-, industrial-, and agricultural- wastewater and storm-water runoff. Specific pollutional properties of theses discharges are not well understood in all cases although the toxic materials and aquatic-plant nutrients (biostimulants) found in municipal and industrial waterwater are considered to be a major cause of regional water-quality problems. Other water-quality problems in the region are commonly attributed to pesticides found in agricultural wastewater and potentially pathogenic bacteria in municipal-wastewater discharges and in storm-water runoff. The geographical distribution and magnitude of wastewater discharges in the bay region, particularly those from municipalities and industries, is largely a function of population, economic growth, and urban development. As might be expected, the total volume of wastewater has increased in a trend paralleling this growth and development. More significant, perhaps, is the fact that the total volume parameters such as BOD (biochemical oxygen demand), biostimulant concentrations, and toxicity, has increased despite large expenditures on new and improved municipal- and industrial-wastewater-treatment plants. Also, pollutant loadings from other major source, such as agriculture and storm-water runoff, have increased. At the time of writing (1972), many Federal, State, regional, and local agencies are engaged in a comprehensive wastewater-management-planning effort for the entire bay region. Initial objectives of this planning effort are: (1) the consolidation and coordination of loosely integrated wastewater-management facilities and (2) the elimination of wastewater discharges to ecologically sensitive areas, such as fresh-water streams and shallow extremities of San Francisco Bay. There has been some investigation of potential long-range wastewater-management alternatives based upon disposal in deep water in the

Purification of functionalized DNA origami nanostructures.

PubMed

Shaw, Alan; Benson, Erik; Högberg, Björn

2015-05-26

The high programmability of DNA origami has provided tools for precise manipulation of matter at the nanoscale. This manipulation of matter opens up the possibility to arrange functional elements for a diverse range of applications that utilize the nanometer precision provided by these structures. However, the realization of functionalized DNA origami still suffers from imperfect production methods, in particular in the purification step, where excess material is separated from the desired functionalized DNA origami. In this article we demonstrate and optimize two purification methods that have not previously been applied to DNA origami. In addition, we provide a systematic study comparing the purification efficacy of these and five other commonly used purification methods. Three types of functionalized DNA origami were used as model systems in this study. DNA origami was patterned with either small molecules, antibodies, or larger proteins. With the results of our work we aim to provide a guideline in quality fabrication of various types of functionalized DNA origami and to provide a route for scalable production of these promising tools.

Sunlight, iron and radicals to tackle the resistant leftovers of biotreated winery wastewater.

PubMed

Ioannou, Lida; Velegraki, Theodora; Michael, Costas; Mantzavinos, Dionissios; Fatta-Kassinos, Despo

2013-04-01

Winery wastewater is characterized by high organic content consisting of alcohols, acids and recalcitrant high-molecular-weight compounds (e.g. polyphenols, tannins and lignins). So far, biological treatment constitutes the best available technology for such effluents that are characterized by high seasonal variability; however the strict legislation applied on the reclamation and reuse of wastewaters for irrigation purposes introduces the need for further treatment of the bioresistant fraction of winery effluents. In this context, the use of alternative treatment technologies, aiming to mineralize or transform refractory molecules into others which could be further biodegraded, is a matter of great concern. In this study, a winery effluent that had already been treated in a sequencing batch reactor was subjected to further purification by homogeneous and heterogeneous solar Fenton oxidation processes. The effect of various operating variables such as catalyst and oxidant concentration, initial pH, temperature and lamp power on the abatement of chemical oxygen demand (COD), dissolved organic carbon (DOC), color, total phenolics and ecotoxicity has been assessed in the homogeneous solar Fenton process. In addition, a comparative assessment between homogeneous and heterogeneous solar Fenton processes was performed. In the present study the homogeneous solar Fenton process has been demonstrated to be the most effective process, yielding COD, DOC and total phenolics removal of about 69%, 48% and 71% in 120 min of the photocatalytic treatment, respectively.

From wastewater to fertilisers--Technical overview and critical review of European legislation governing phosphorus recycling.

PubMed

Hukari, Sirja; Hermann, Ludwig; Nättorp, Anders

2016-01-15

The present paper is based on an analysis of the EU legislation regulating phosphorus recovery and recycling from wastewater stream, in particular as fertiliser. To recover phosphorus, operators need to deal with market regulations, health and environment protection laws. Often, several permits and lengthy authorisation processes for both installation (e.g. environmental impact assessment) and the recovered phosphorus (e.g. End-of-Waste, REACH) are required. Exemptions to certain registration processes for recoverers are in place but rarely applied. National solutions are often needed. Emerging recovery and recycling sectors are affected by legislation in different ways: Wastewater treatment plants are obliged to remove phosphorus but may also recover it in low quantities for operational reasons. Permit processes allowing recovery and recycling operations next to water purification should thus be rationalised. In contrast, the fertiliser industry relies on legal quality requirements, ensuring their market reputation. For start-ups, raw-material sourcing and related legislation will be the key. Phosphorus recycling is governed by fragmented decision-making in regional administrations. Active regulatory support, such as recycling obligation or subsidies, is lacking. Legislation harmonisation, inclusion of recycled phosphorus in existing fertiliser regulations and support of new operators would speed up market penetration of novel technologies, reduce phosphorus losses and safeguard European quality standards.

Wastewater treatment by nanofiltration membranes

NASA Astrophysics Data System (ADS)

Mulyanti, R.; Susanto, H.

2018-03-01

Lower energy consumption compared to reverse osmosis (RO) and higher rejection compared to ultrafiltration make nanofiltration (NF) membrane get more and more attention for wastewater treatment. NF has become a promising technology not only for treating wastewater but also for reusing water from wastewater. This paper presents various application of NF for wastewater treatments. The factors affecting the performance of NF membranes including operating conditions, feed characteristics and membrane characteristics were discussed. In addition, fouling as a severe problem during NF application is also presented. Further, future prospects and challenges of NF for wastewater treatments are explained.