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Sample records for active sewage sludge

  1. Sewage sludge additive

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Mueller, W. A.; Ingham, J. D. (Inventor)

    1980-01-01

    The additive is for a raw sewage treatment process of the type where settling tanks are used for the purpose of permitting the suspended matter in the raw sewage to be settled as well as to permit adsorption of the dissolved contaminants in the water of the sewage. The sludge, which settles down to the bottom of the settling tank is extracted, pyrolyzed and activated to form activated carbon and ash which is mixed with the sewage prior to its introduction into the settling tank. The sludge does not provide all of the activated carbon and ash required for adequate treatment of the raw sewage. It is necessary to add carbon to the process and instead of expensive commercial carbon, coal is used to provide the carbon supplement.

  2. Sewage sludge treatment system

    NASA Technical Reports Server (NTRS)

    Kalvinskas, John J. (Inventor); Mueller, William A. (Inventor)

    1976-01-01

    Raw sewage may be presently treated by mixing screened raw sewage with activated carbon. The mixture is then allowed to stand in a first tank for a period required to settle the suspended matter to the bottom of the tank as a sludge. Thereafter, the remaining liquid is again mixed with activated carbon and the mixture is transferred to a secondary settling tank, where it is permitted to stand for a period required for the remaining floating material to settle as sludge and for adsorption of sewage carbon as well as other impurities to take place. The sludge from the bottom of both tanks is removed and pyrolyzed to form activated carbon and ash, which is mixed with the incoming raw sewage and also mixed with the liquid being transferred from the primary to the secondary settling tank. It has been found that the output obtained by the pyrolysis process contains an excess amount of ash. Removal of this excess amount of ash usually also results in removing an excess amount of carbon thereby requiring adding carbon to maintain the treatment process. By separately pyrolyzing the respective sludges from the first and second settling tanks, and returning the separately obtained pyrolyzed material to the respective first and second tanks from which they came, it has been found that the adverse effects of the excessive ash buildup is minimized, the carbon yield is increased, and the sludge from the secondary tank can be pyrolyzed into activated carbon to be used as indicated many more times than was done before exhaustion occurs.

  3. Aerobic Heterotrophic Bacterial Populations of Sewage and Activated Sludge

    PubMed Central

    Prakasam, T. B. S.; Dondero, N. C.

    1970-01-01

    Two procedures, the confidence interval method and Mountford's index, were tested in analyses of the microbial populations of 11 laboratory activated sludges acclimated to aromatic compounds. The two methods gave somewhat different results but indicated that the populations were quite dissimilar. The activity of seven of the sludges correlated well with the population structure. Some considerations in analysis of microbial population structure are discussed. PMID:5418947

  4. Is anaerobic digestion effective for the removal of organic micropollutants and biological activities from sewage sludge?

    PubMed

    Gonzalez-Gil, L; Papa, M; Feretti, D; Ceretti, E; Mazzoleni, G; Steimberg, N; Pedrazzani, R; Bertanza, G; Lema, J M; Carballa, M

    2016-10-01

    The occurrence of emerging organic micropollutants (OMPs) in sewage sludge has been widely reported; nevertheless, their fate during sludge treatment remains unclear. The objective of this work was to study the fate of OMPs during mesophilic and thermophilic anaerobic digestion (AD), the most common processes used for sludge stabilization, by using raw sewage sludge without spiking OMPs. Moreover, the results of analytical chemistry were complemented with biological assays in order to verify the possible adverse effects (estrogenic and genotoxic) on the environment and human health in view of an agricultural (re)use of digested sludge. Musk fragrances (AHTN, HHCB), ibuprofen (IBP) and triclosan (TCS) were the most abundant compounds detected in sewage sludge. In general, the efficiency of the AD process was not dependent on operational parameters but compound-specific: some OMPs were highly biotransformed (e.g. sulfamethoxazole and naproxen), while others were only slightly affected (e.g. IBP and TCS) or even unaltered (e.g. AHTN and HHCB). The MCF-7 assay evidenced that estrogenicity removal was driven by temperature. The Ames test did not show point mutation in Salmonella typhimurium while the Comet test exhibited a genotoxic effect on human leukocytes attenuated by AD. This study highlights the importance of combining chemical analysis and biological activities in order to establish appropriate operational strategies for a safer disposal of sewage sludge. Actually, it was demonstrated that temperature has an insignificant effect on the disappearance of the parent compounds while it is crucial to decrease estrogenicity.

  5. The potential application of activated carbon from sewage sludge to organic dyes removal.

    PubMed

    Graham, N; Chen, X G; Jayaseelan, S

    2001-01-01

    The objective of this research work was to study the potential application of activated carbon from sewage sludge to organic dye removal. Methylene blue and crystal violet were the two dyes investigated in the present study. Three activated carbons were produced from the exclusive sewage sludge (referred to as DS), the sludge with the additive of coconut husk (DC) and sludge with the additive of peanut shell (DP) respectively. They were characterized by their surface area and porosity and their surface chemistry structure. Adsorption studies were performed by the batch technique to obtain kinetic and equilibrium data. The results show that the three sludge-derived activated carbons had a developed porosity and marked content of surface functional groups. They exhibited a rapid three-stage adsorption process for both methylene blue and crystal violet. Their adsorption capacities for the two dyes were high, the carbon DP performed best in the adsorption whereas the carbon DC performed worst. It is therefore concluded that the activated carbons made from sewage sludge and its mixtures are promising for dye removal from aqueous streams.

  6. Characterization of mesoporous activated carbons prepared by pyrolysis of sewage sludge with pyrolusite.

    PubMed

    Liu, Chen; Tang, Zhengguang; Chen, Yao; Su, Shijun; Jiang, Wenju

    2010-02-01

    Activated carbons were prepared from sewage sludge by chemical activation. Pyrolusite was added as a catalyst during activation and carbonization. The influence of the mineral addition on the properties of the activated carbons produced was evaluated. The results show that activated carbons from pyrolusite-supplemented sewage sludge had up to a 75% higher BET surface area and up to a 66% increase in mesoporosity over ordinary sludge-based activated carbons. Batch adsorption experiments applying the prepared adsorbents to synthetic dye wastewater treatment yielded adsorption data well fitted to the Langmuir isotherm. The adsorbents from pyrolusite-supplemented sludges performed better in dye removal than those without mineral addition, with the carbon from pyrolusite-augmented sludge T2 presenting a significant increase in maximum adsorption capacity of 50mg/g. The properties of the adsorbents were improved during pyrolusite-catalyzed pyrolysis via enhancement of mesopore production, thus the mesopore channels may provide fast mass transfer for large molecules like dyes.

  7. Lipid profiling in sewage sludge.

    PubMed

    Zhu, Fenfen; Wu, Xuemin; Zhao, Luyao; Liu, Xiaohui; Qi, Juanjuan; Wang, Xueying; Wang, Jiawei

    2017-03-20

    High value-added reutilization of sewage sludge from wastewater treatment plants (WWTPs) is essential in sustainable development in WWTPs. However, despite the advantage of high value reutilization, this process must be based on a detailed study of organics in sludge. We used the methods employed in life sciences to determine the profile of lipids (cellular lipids, free fatty acids (FFAs), and wax/gum) in five sludge samples obtained from three typical WWTPs in Beijing; these samples include one sludge sample from a primary sedimentation tank, two activated sludge samples from two Anaerobic-Anoxic-Oxic (A2/O) tanks, and two activated sludge samples from two membrane bioreactor tanks. The percentage of total raw lipids varied from 2.90% to 12.3%. Sludge from the primary sedimentation tank showed the highest concentrations of lipid, FFA, and wax/gum and the second highest concentration of cellular lipids. All activated sludge contained an abundance of cellular lipids (>54%). Cells in sludge can from plants, animals, microbes and so on in wastewater. Approximately 14 species of cellular lipids were identified, including considerable high value-potential ceramide (9567-38774 mg/kg), coenzyme (937-3897 mg/kg), and some phosphatidylcholine (75-548 mg/kg). The presence of those lipid constituents would thus require a wider range of recovery methods for sludge. Both cellular lipids and FFAs contain an abundance of C16-C18 lipids at high saturation level, and they serve as good resources for biodiesel production.

  8. Sewage sludge gasification: First studies

    SciTech Connect

    Garcia-Bacaicoa, P.; Bilbao, R.; Uson, C.

    1995-11-01

    Wastewater treatment installations produce a large quantity of sewage sludge, the disposal and treatment of which causes several problems because of its volume, its toxic organic constituents and the heavy metals that it contains. Certain methods of treatment and disposal do exist, but they are not entirely satisfactory. Moreover, it is important to develop a technology for the adequate treatment of sewage sludge in order to reduce the environmental problem and the costs of treatment. It can be assumed that gasification is a suitable technology because it reduces the waste volume, destroys the toxic organic compounds and fixes the heavy metals in the resultant solid. In order to gain knowledge of the processes occurring in the gasifier, the results obtained in experiments on the thermal decomposition of sewage sludge at different heating rates are shown.

  9. Sewage sludge treatment with lime.

    PubMed

    Herbst, B

    2000-01-01

    The article describes the application of lime as a method for treatment and hygienisation of sewage sludges with lime products such as quicklime, slake lime and dolomitic lime. As a result of the increase in temperature and pH-value during sludge and lime mixing most pathogenic vectors of disease (i.e. bacteria, worms, viruses and parasites) are reduced in concentration and viability to manufacture a safe product for further application on agricultural land.

  10. [Technology of sewage sludge hygienization].

    PubMed

    Keller, U

    1983-09-01

    That the use of modern technology against the laws of Nature must fail, has been clearly demonstrated again some years ago when sewage sludge postpasteurization was rashly introduced. Although many attempts were made to improve this procedure, it had to be abandoned because of unavoidable massive regrowth of pathogens which invaded the germ-free postpasteurized sludge. In contrast of postpasteurization, long-term large-scale tests with the pasteurization of fresh sludge (prepasteurization) have demonstrated that this procedure where methane digestion with its pathogen displacing effect constitutes the final stage, is basically able to function. With respect to the Swiss Sewage Sludge Decree which came into force in May 1981, and which imposes sludge hygienization for most applications throughout the year, various thermal prepasteurization methods have been offered on the market ready for application to meet the legally prescribed requirements. However, some of them still need selective improvements in order to ensure the desired hygienisation effect permanently. For some time now, attention has been focussed on a novel biological 2-stage procedure based on partial aerobic thermophilic fermentation followed by anaerobic sludge digestion which in addition to good hygienisation promises improved sludge thickening, reduced digestion time, more favourable energy consumption and added process stability etc. Although it has already been offered on the market, this interesting process is being thouroughly tested and optimized in parallel pilot tests plant at the WWTP Altenrhein. Finally, reference is made to further sludge treatment processes such as sludge drying and sludge composting which mostly comprise efficent sludge hygienisation although they may not entirely prevent pathogenic regrowth. Moreover, some unconventional and less popular processes such as liquid sludge irradiation and chemical methods are also mentioned.

  11. Development of quantitative methods for the detection of enteroviruses in sewage sludges during activation and following land disposal.

    PubMed Central

    Hurst, C J; Farrah, S R; Gerba, C P; Melnick, J L

    1978-01-01

    The development and evaluation of methods for the quantitative recovery of enteroviruses from sewage sludge are reported. Activated sewage sludge solids were collected by centrifugation, and elution of the solid-associated virus was accomplished by mechanical agitation in glycine buffer at pH 11.0. Eluted viruses were concentrated either onto an aluminum hydroxide floc or by association with a floc which formed de novo upon adjustment of the glycine eluate to pH 3.5. Viruses which remained in the liquid phase after lowering the pH of glycine eluate were concentrated by adsorption to and elution from membrane filters. The method of choice included high pH glycine elution and subsequent low pH concentration; it yielded an efficiency of recovery from activated sludge of 80% for poliovirus type 1, 68% for echovirus type 7, and 75% for coxsackievirus B3. This method was used to study the survival of naturally occurring virus in sludge at a sewage treatment plant and after subsequent land disposal of the solids after aerobic digestion. Reduction of enterovirus titers per gram (dry weight) of solids were modest during sludge activation but increased to a rate of 2 log 10/week after land disposal. PMID:29559

  12. Sewage sludge pretreatment by microwave irradiation combined with activated carbon fibre at alkaline pH for anaerobic digestion.

    PubMed

    Sun, Dedong; Guo, Sixiao; Ma, Nina; Wang, Guowen; Ma, Chun; Hao, Jun; Xue, Mang; Zhang, Xinxin

    2016-01-01

    This research focuses on the effects of microwave-assisted activated carbon fibre (ACF) (MW-ACF) treatment on sewage sludge at alkaline pH. The disintegration and biodegradability of sewage sludge were studied. It was found that the MW-ACF process at alkaline pH provided a rapid and efficient process to disrupt the microbial cells in the sludge. The results suggested that when irradiated at 800 W MW for 110 s with a dose of 1.0 g ACF/g solid concentration (SS) at pH 10.5, the MW-ACF pretreatment achieved 55% SS disintegration, 23% greater than the value of MW alone (32%). The concentration of total nitrogen, total phosphorus, supernatant soluble chemical oxygen demand, protein, and polysaccharide increased by 60%, 144%, 145%, 74%, and 77%, respectively. An increase in biogas production by 63.7% was achieved after 20 days of anaerobic digestion (AD), compared to the control. The results indicated that the MW-ACF pretreatment process at alkaline pH provides novel sludge management options in disintegration of sewage sludge for further AD.

  13. Microwave Supported Treatment of Sewage Sludge

    NASA Astrophysics Data System (ADS)

    Janíček, František; Perný, Milan; Šály, Vladimír; Giemza, Markus; Hofmann, Peter

    2016-07-01

    This work is focused on microwave treatment of sewage sludge. The aim of our experiments was to investigate the impact of microwave radiation upon different sewage sludge parameters such as concentration of nitrates and nitrites, phosphates, COD (Chemical Oxygen Demand), SVI (Sludge Volume Index) and the microscopic structure of sludge. The experiments with microwave irradiation of sewage sludge indicate that moderate microwave power causes visible effects on the chemical, physical and biological properties of the sludge. The calculation of profitability and energy efficiency is also presented.

  14. Vermistabilization of primary sewage sludge.

    PubMed

    Hait, Subrata; Tare, Vinod

    2011-02-01

    An integrated composting-vermicomposting process has been developed for utilization of primary sewage sludge (PSS). Matured vermicompost was used as bulking material and a source of active microbial culture during aerobic activated composting (AAC). AAC resulted in sufficient enrichment of bulking material with organic matter after 20 cycles of recycling and mixing with PSS and produced materials acceptable for vermicomposting. Vermicomposting caused significant reduction in pH, volatile solids (VS), specific oxygen uptake rate (SOUR), total organic carbon (TOC), C/N ratio and pathogens and substantial increase in electrical conductivity (EC), total nitrogen (TN) and total phosphorous (TP) as compared to compost. Environmental conditions and stocking density have profound effects on vermicomposting. Temperature of 20°C with high humidity is favorable environmental condition for vermicomposting employing Eisenia fetida. Favorable stocking density range for vermiculture is 0.5-2.0 kg m(-2) (optimum: 0.5 kg m(-2)) and for vermicomposting is 2.0-4.0 kg m(-2) (optimum: 3.0 kg m(-2)), respectively.

  15. Physical and Chemical Correlates of Microbial Activity and Biomass in Composting Municipal Sewage Sludge

    PubMed Central

    McKinley, Vicky L.; Vestal, J. Robie

    1985-01-01

    Various physical and chemical parameters were monitored to evaluate their influence on the microbial communities present in composting municipal sewage sludge. Temperature, moisture content, depth, pH, protein content, total nitrogen, total carbon, lipid phosphate biomass, and the rates of microbial incorporation of substrates into lipids were measured at several times throughout the 17- to 19-day composting runs. Temperature was found to have the most consistent and dramatic effect on microbial activity and biomass. When temperatures exceeded 55 to 60°C, microbial activity fell dramatically, usually by more than 1 order of magnitude. Microbial activity was generally greatest in samples taken from the 35 to 50°C areas of the composting piles. Changes in the composition of the compost over time included increased pH, increased protein content, and decreased total organic content. The changes in these parameters appeared to reflect the microbial activity and biomass present. The results of this study indicate that the rate of composting may best be optimized by controlling the composting temperatures, provided that the other parameters fall within reasonable limits in the starting material. PMID:16346940

  16. Sewage sludge dewatering using flowing liquid metals

    DOEpatents

    Carlson, Larry W.

    1986-01-01

    A method and apparatus for reducing the moisture content of a moist sewage sludge having a moisture content of about 50% to 80% and formed of small cellular micro-organism bodies having internally confined water is provided. A hot liquid metal is circulated in a circulation loop and the moist sewage sludge is injected in the circulation loop under conditions of temperature and pressure such that the confined water vaporizes and ruptures the cellular bodies. The vapor produced, the dried sludge, and the liquid metal are then separated. Preferably, the moist sewage sludge is injected into the hot liquid metal adjacent the upstream side of a venturi which serves to thoroughly mix the hot liquid metal and the moist sewage sludge. The venturi and the drying zone after the venturi are preferably vertically oriented. The dried sewage sludge recovered is available as a fuel and is preferably used for heating the hot liquid metal.

  17. Relationship between protozoan and metazoan communities and operation and performance parameters in a textile sewage activated sludge system.

    PubMed

    Araújo dos Santos, Liliana; Ferreira, Vânia; Pereira, Maria Olívia; Nicolau, Ana

    2014-08-01

    The present study aims at investigating the possibility of assessing performance and depuration conditions of an activated sludge wastewater treatment plant through an exploration of the microfauna. The plant, receiving textile industrial (70%) and domestic (30%) sewage, consists of a two-step biological depurating plant, with activated sludge followed by a percolating system. A total of 35 samples were analyzed during five months, and 30 taxa of protozoa and small metazoa were found. Epistylis rotans, Vorticella microstoma, Aspidisca cicada and Arcella sp. were the most frequent protozoa identified. Several significant correlations between biological, physical-chemical and operational parameters were determined, but no significant correlations could be established between biological parameters and removal efficiencies. The Sludge Biotic Index (SBI) reflected the overall state of the community but only presented statistically significant correlations with the influent total suspended solids (TSS), total suspended solids in mixed-liquor (MLTSS) and dissolved oxygen (DO). The determination of key groups and taxa along with general community parameters showed to have potential value as indicators of the depuration conditions. Despite the impossibility of correlating biological parameters and the removal efficiencies, the present study attests the value of the microfauna to assess the operation of the activated sludge systems even in the case of non-conventional plants and/or plants receiving industrial sewage.

  18. The impact of sea water flushing on biological nitrification-denitrification activated sludge sewage treatment process.

    PubMed

    Yu, S M; Leung, W Y; Ho, K M; Greenfield, P F; Eckenfelder, W W

    2002-01-01

    The process performance of the two largest activated sludge processes in Hong Kong, the Sha Tin and the Tai Po Sewage Treatment Works (STW), deteriorated in the initial period after the introduction of seawater flushing in 1995 and 1996, respectively. High effluent ammonia nitrogen (NH4-N) and total suspended solids (TSS) in excess of the discharge standards resulted from incomplete nitrification and changes in floc characteristics. A desktop study on the inhibitory effects of salinity, particularly on nitrification, was subsequently conducted using the Tai Po STW operating data. To assist the upgrade of the Sha Tin STW a five-month extensive bench-scale investigation on a simple but flexible modified Ludzack-Ettinger configuration with bio-selector was conducted to quantify the inhibitory effects due to the saline concentration. The Sha Tin STW upgrade consists of restoration of its original design capacity (conventional process) of 205,000 m3/day from its currently much reduced capacity as a Bardenpho process. Only the volume of the existing biological process and clarifier is to be utilized. The saline concentration ranges from 3,500 up to 6,500 mg Cl-/L, both daily and seasonally. High and greatly fluctuating saline concentrations have been known to inhibit nitrification. Design consideration should also be given to the peak daily and seasonal TKN loading of up to three times the average. Although the nitrifiers maximum specific growth rate was significantly reduced to a low 0.25 day(-1), the inhibition was considered to be tolerable with effluent NH4-N and NO3-N consistently at < 1 and < 6 mg/L. The bio-selector was demonstrated to be efficient in control of sludge foaming and bulking with SVI consistently < or = 125 mL/g. Results from the IAWO Model No. 1 and the hydraulic model of the secondary clarifiers allowed overall process capacity maximization. With an anoxic mass fraction of 25-30%, operating sludge age of 9-14 days and SVI < or = 125 mL/g, both the

  19. Radioactivity in municipal sewage and sludge.

    PubMed Central

    Martin, J E; Fenner, F D

    1997-01-01

    OBJECTIVE: To determine the environmental consequences of discharges of radioactivity from a large medical research facility into municipal sewage, specifically 131I activity in sewage sludge, and the radiation exposures to workers and the public when sludges are incinerated. METHODS: The authors measured radioactivity levels in the sludge at the Ann Arbor, Michigan, Waste Water Treatment Plant following radioiodine treatments of two patients at the University of Michigan hospital complex and performed a series of calculations to estimate potential radiation doses due to releases of 131I from incineration of sewage sludge. RESULTS: Approximately 1.1% of the radioactive 131I administered therapeutically to patients was measured in the primary sludge. Radiation doses from incineration of sludge were calculated to be 0.048 millirem (mrem) for a worker during a period in which the incinerator filtration system failed, a condition that could be considered to represent maximum exposure conditions, for two nine-hour days. Calculated results for a more typically exposed worker (with the filtration system in operation and a 22-week period of incineration) yielded a committed effective dose equivalent of 0.066 mrem. If a worker were exposed to both conditions during the period of incineration, the dose was calculated to be 0.11 mrem. For a member of the public, the committed effective dose equivalent was calculated as 0.003 mrem for a 22-week incineration period. Exposures to both workers and the public were a very small fraction of a typical annual dose (about 100 mrem excluding radon, or 300 mrem with radon) due to natural background radiation. Transport time to the treatment plant for radioiodine was found to be much longer than that of a normal sewage, possibly due to absorption of iodine by organic material in the sewer lines. The residence time of radioiodine in the sewer also appears to be longer than expected. CONCLUSION: 131I in land-applied sludge presents few

  20. Sewage sludge pasteurization by gamma radiation: Financial viability case studies

    NASA Astrophysics Data System (ADS)

    Swinwood, Jean F.; Kotler, Jiri

    This paper examines the financial viability of sewage sludge pasteurization by gamma radiation, by examining the following three North American scenarios: 1) Small volume sewage treatment plant experiencing high sludge disposal costs. 2) Large volume sewage treatment plant experiencing low sludge disposal costs. 3) Large volume sewage treatment plant experiencing high sludge disposal costs.

  1. Enhanced dewaterability of sewage sludge in the presence of Fe(II)-activated persulfate oxidation.

    PubMed

    Zhen, Guangyin; Lu, Xueqin; Zhao, Youcai; Chai, Xiaoli; Niu, Dongjie

    2012-07-01

    The potential benefits of Fe(II)-activated persulfate oxidation on sludge dewatering and its mechanisms were investigated in this study. Capillary suction time (CST) was used to evaluate sludge dewaterability. Both extracellular polymeric substances (EPS) and viscosity were determined in an attempt to explain the observed changes in sludge dewaterability. The optimal conditions to give preferable dewaterability characteristics were found to be persulfate (S(2)O(8)(2-)) 1.2 mmol/gVSS, Fe(II) 1.5 mmol/gVSS, and pH 3.0-8.5, which demonstrated a very high CST reduction efficiency (88.8% reduction within 1 min). It was further observed that both soluble EPS and viscosity played relatively negative roles in sludge dewatering, whereas no correlation was established between sludge dewaterability and bound EPS. Three-dimensional excitation-emission matrix (EEM) fluorescence spectra also revealed that soluble EPS of sludge were degraded and sludge flocs were ruptured by persulfate oxidation, which caused the release of water in the intracellular pace and subsequent improvement of its dewaterability.

  2. A Family Physician's Guide to Sewage Sludge

    PubMed Central

    Connop, Peter J.

    1983-01-01

    The potential environmental and personal health effects from the agricultural uses of domestic sewage sludge may increasingly require the guidance of the family physician, especially in farming communities. This article summarizes the potential health hazards and outlines the tripartite risk phenomenon—hazard identification, risk assessment, and social evaluation. For the agricultural use of dewatered sewage sludge, strict adherence to regulated procedures should not increase risk beyond that of agriculture generally. Confirmation by prospective epidemiological studies is recommended. PMID:21283298

  3. Thixotropic behaviour of thickened sewage sludge

    PubMed Central

    2014-01-01

    The aim of the work is a description of the rheological behaviour of thickened sewage sludge. The sample of thickened sludge was collected from the wastewater treatment plant, where pressure flotation unit is used for a process of thickening. The value of dry matter of collected sample was 3.52%. Subsequently the sample was diluted and the rheological properties of individual samples were obtained. Several types of rheological tests were used for the determination of the sample. At first the hysteresis loop test was performed. The next test was focused on the time-dependency, i.e. measurement of dependence of dynamic viscosity on the time at constant shear rate. Further dependence dynamic viscosity on the temperature was performed. Then the activation energy was obtained from measured values. Finally, the hysteresis areas were counted and measured values were evaluated with use of Herschel-Bulkley mathematical model. PMID:24860659

  4. Sewage sludge dewatering using flowing liquid metals

    DOEpatents

    Carlson, L.W.

    1985-08-30

    This invention relates generally to the dewatering of sludge, and more particularly to the dewatering of a sewage sludge having a moisture content of about 50 to 80% in the form of small cellular micro-organism bodies having internally confined water.

  5. Studies on the survival of enterohemorrhagic and environmental Escherichia coli strains in wastewater and in activated sludges from dairy sewage treatment plants.

    PubMed

    Czajkowska, Danuta; Boszczyk-Maleszak, Hanka; Sikorska, I Rena; Sochaj, Agnieszka

    2008-01-01

    Survival of Escherichia coli O157:H7 strain isolated from milk in Poland and an environmental E. coli strain in wastewater from Garwolin and Łowicz dairies and in activated sludges from dairy sewage treatment plants as well as in dairy wastewater with activated sludges was examined. Environmental materials were contaminated with about 10(8) of target bacteria/ml of sample. The experiments were performed under temperature conditions typical of autumn-winter (6 degrees) and spring-summer (24 degrees C) seasons. It was found that the non-pathogenic E. coli strain survived longer in all media than the enterohemorrhagic serotype. E. coli O157:H7 bacteria were not detected (in direct plating method) in activated sludges after 21-28 days; in dairy wastewater as well as in wastewater with activated sludges after 21-25 days. These periods for environmental E. coli strain were 35-42 days (activated sludges), 25-28 days (wastewater with activated sludges). At higher temperature environmental E. coli were not detected in wastewater from Łowicz dairy sewage treatment plant after 25 days, but the bacteria were still present in wastewater from Garwolin dairy sewage tratment plant after 34 days. The obtained results show that the lack of environmental E. coli bacteria (as a indicator bacteria of fecal contamination) in dairy wastewater and in dairy wastewater with activated sludges could indicate the absence of pathogenic E. coli bacteria. Prolonged existence of the enterohemorrhagic serotype in activated sludges shows the need to treat activated sludges prior to the utilization of these materials as fertilizer.

  6. Co-digestion of grease trap sludge and sewage sludge.

    PubMed

    Davidsson, A; Lövstedt, C; Jansen, J la Cour; Gruvberger, C; Aspegren, H

    2008-01-01

    Redirection of organic waste, from landfilling or incineration, to biological treatment such as anaerobic digestion is of current interest in the Malmö-Copenhagen region. One type of waste that is expected to be suitable for anaerobic digestion is sludge from grease traps. Separate anaerobic digestion of this waste type and co-digestion with sewage sludge were evaluated. The methane potential was measured in batch laboratory tests, and the methane yield was determined in continuous pilot-scale digestion. Co-digestion of sludge from grease traps and sewage sludge was successfully performed both in laboratory batch and continuous pilot-scale digestion tests. The addition of grease trap sludge to sewage sludge digesters was seen to increase the methane yield of 9-27% when 10-30% of sludge from grease traps (on VS-basis) was added. It was also seen that the grease trap sludge increases the methane yield without increasing the sludge production. Single-substrate digestion of grease trap sludge gave high methane potentials in batch tests, but could not reach stable methane production in continuous digestion.

  7. Enhanced dewaterability of sewage sludge with zero-valent iron-activated persulfate oxidation system.

    PubMed

    Hu, Lingling; Liao, Yu; He, Chun; Pan, Wenqi; Liu, Shangkun; Yang, Yichang; Li, Shuzhen; Sun, Lianpeng

    2015-01-01

    The potential benefits of zero-valent iron-activated persulfate (Na2S2O8) oxidation in enhanced dewaterability of sludge, along with the associated mechanisms were investigated in this study. The sludge dewaterability was evaluated in terms of specific resistance to filtration (SRF) and water content. Based on these indexes, it was observed that ZVI-S2O8(2) oxidation effectively improved sludge dewaterability. The optimal conditions to give preferable dewaterability were found when the molar ratio of ZVI/S2O8(2-) was 5:1 and pH value was 3.0. The most important mechanism was proposed to be the degradation of extracellular polymeric substances (EPS) incorporated in sludge flocs and rupture of microbial cells. Three-dimensional excitation-emission matrix fluorescence spectra revealed that the powerful SO4- and ·OH generated from ZVI-S2O8(2-) system destroyed the particular functional groups of fluorescing substances (aromatic protein-like and tryptophan protein-like substances), resulting in the release of bound water and the subsequent enhancement of dewaterability. Therefore, ZVI/S2O8(2-) oxidation is an alternative approach showing great potential to be applied in sludge treatment plants.

  8. Effects of sewage sludge fertilizer on heavy metal accumulation and consequent responses of sunflower (Helianthus annuus).

    PubMed

    Belhaj, Dalel; Elloumi, Nada; Jerbi, Bouthaina; Zouari, Mohamed; Abdallah, Ferjani Ben; Ayadi, Habib; Kallel, Monem

    2016-10-01

    Use of sewage sludge, a biological residue produced from sewage treatment processes in agriculture, is an alternative disposal technique of waste. To study the usefulness of sewage sludge amendment for Helianthus annuus, a pot experiment was conducted by mixing sewage sludge at 2.5, 5, and 7.5 % (w/w) amendment ratios to the agricultural soil. Soil pH decreased whereas electrical conductivity, organic matter, total N, available P, and exchangeable Na, K, and Ca increased in soil amended with sewage sludge in comparison to unamended soil. Sewage sludge amendment led to significant increase in Pb, Ni, Cu, Cr, and Zn concentrations of soil. The increased concentration of heavy metals in soil due to sewage sludge amendment led to increases in shoot and root concentrations of Cr, Cu, Ni, and Zn in plant as compared to those grown on unamended soil. Accumulation was more in roots than shoots for most of the heavy metals. Moreover, high metal removal for the harvestable parts of the crops was recorded. Sewage sludge amendment increased root and shoot length, leaves number, biomass, and antioxidant activities of sunflower. Significant increases in the activities of antioxidant enzymes and in the glutathione, proline, and soluble sugar content in response to amendment with sewage sludge may be defense mechanisms induced in response to heavy metal stress. Graphical abstract Origin, fate and behavior of sewage sludge fertilizer.

  9. Adsorption behavior of activated carbon derived from pyrolusite-modified sewage sludge: equilibrium modeling, kinetic and thermodynamic studies.

    PubMed

    Chen, Yao; Jiang, Wenju; Jiang, Li; Ji, Xiujuan

    2011-01-01

    Activated carbon was developed from sewage sludge using pyrolusite as an additive. It was demonstrated that the removal efficiency of two synthetic dyes (Tracid orange GS and Direct fast turquoise blue GL) by the produced adsorbent was up to 97.6%. The activated carbon with pyrolusite addition had 38.2% higher surface area, 43.8% larger micropore and 54.4% larger mesopore production than ordinary sludge-based activated carbons. Equilibrium adsorption isotherms and kinetics were also investigated based on dyes adsorption tests. The experimental data were analyzed by the Langmuir and Freundlich models of adsorption, and the results fitted well to the Langmuir isotherm. The kinetic data have been analyzed using pseudo-first-order, pseudo-second-order and intraparticle diffusion equation. The experimental data fitted very well with pseudo-second-order kinetic model. Activation energies for the adsorption processes ranged between 8.7 and 19.1 kJ mol 1. Thermodynamic parameters such as standard free energy (deltaG0), standard enthalpy (deltaH0) and standard entropy (deltaS0) were evaluated. The adsorption of these two dyes on the activated carbon was found to be a spontaneous and endothermic process in nature.

  10. Influence of sewage sludge-based activated carbon and temperature on the liquefaction of sewage sludge: yield and composition of bio-oil, immobilization and risk assessment of heavy metals.

    PubMed

    Zhai, Yunbo; Chen, Hongmei; Xu, Bibo; Xiang, Bobin; Chen, Zhong; Li, Caiting; Zeng, Guangming

    2014-05-01

    The influence of sewage sludge-based activated carbons (SSAC) on sewage sludge liquefaction has been carried out at 350 and 400°C. SSAC increased the yield and energy density of bio-oil at 350°C. The metallic compounds were the catalytic factor of SSAC obtained at 550°C (SSAC-550), while carbon was the catalytic factor of SSAC obtained at 650°C. Liquefaction with SSAC redistributed the species of heavy metals in solid residue (SR). With the addition of SSAC, the risk of Cu, Zn and Pb decreased at 350°C, while at 400°C the risk of Cd, Cu, and Zn were decreased. Ecological risk index indicated that 400°C was preferable for the toxicity decrement of SR, while risk assessment code indicated that SR obtained at 350°C contained lower risk. Considering the bio-oil yield, liquefaction at 350°C with SSAC-550 was preferable.

  11. Behavior of metals, pathogen parasites, and indicator bacteria in sewage effluents during biological treatment by activated sludge.

    PubMed

    Tonani, K A A; Julião, F C; Trevilato, T M B; Takayanagui, A M M; Bocio, Ana; Domingo, Jose L; Segura-Muñoz, Susana I

    2011-11-01

    The purpose of this study was to evaluate the behavior of metals, pathogen parasites, and indicator bacteria in sewage effluents during biological treatment by activated sludge in a wastewater treatment plant in Ribeirão Preto (WTP-RP), Sao Paulo, Brazil. The evaluation was done during a period of 1 year. Results showed that metal concentrations in treated effluents decreased, reaching concentrations according to those established by national regulations. The activated sludge process at the WTP-RP promoted a partial removal of parasites considered as possible indicators according to the WHO guidelines. Reduction factors varied between 18.2% and 100% for agents such as Endolimax nana, Entamoeba coli, Entamoeba hystolitica, Giardia sp., Ancylostoma sp., Ascaris sp., Fasciola hepatica, and Strongyloides stercoralis. A removal was also observed in total and fecal coliforms quantification. The present study represents an initial evaluation of the chemical and microbiological removal capacity of the WTP-RP. The results should be of interest for the authorities responsible for the environmental health at municipal, regional, national, and international levels.

  12. Preparation of sewage sludge based activated carbon by using Fenton's reagent and their use in 2-naphthol adsorption.

    PubMed

    Gu, Lin; Wang, Yachen; Zhu, Nanwen; Zhang, Daofang; Huang, Shouqiang; Yuan, Haiping; Lou, Ziyang; Wang, Miaolin

    2013-10-01

    In this study, Fenton's reagents (H2O2/Fe(2+)) are used to activate raw sewage sludge for the preparation of the sludge based activated carbon. The effect of the amount of hydrogen peroxide addition on carbon's chemical composition, texture properties, surface chemistry and morphology are investigated. Choosing an appropriate H2O2 dosage (5 v%) (equivalent to 70.7 mM/(g VS)), it is possible to obtain a comparatively highly porous materials with SBET and the total pore volume being 321 m(2)/g and 0.414 cm(3)/g, respectively. Continuously increasing the oxidant ratio resulted in a decreased SBET value. Further adsorption experiments by using 2-naphthol as model pollutant revealed that the adoption followed a pseudo-second-order kinetics better than pseudo-first-order. The calculated adsorption capacity is 111.9 mg/g on the carbon with 5% H2O2 pretreatment while this value is just 51.5mg/g on carbons without any pretreatment.

  13. Management of sewage sludge and ash containing radioactive materials.

    SciTech Connect

    Bachmaier, J. T.; Aiello, K.; Bastian, R. K.; Cheng, J.-J.; Chiu, W. A.; Goodman, J.; Hogan, R.; Jones, A. R.; Kamboj, S.; Lenhart, T.; Ott, W. R.; Rubin, A. B.; Salomon, S. N.; Schmidt, D. W.; Setlow, L. W.; Yu, C.; Wolbarst, A. B.; Environmental Science Division; Middlesex County Utilities Authority; U.S. EPA; N.J. Dept of Environmental Protection; NRC

    2007-01-01

    Approximately 50% of the seven to eight million metric tonnes of municipal sewage sludge produced annually in the US is reused. Beneficial uses of sewage sludge include agricultural land application, land reclamation, forestry, and various commercial applications. Excessive levels of contaminants, however, can limit the potential usefulness of land-applied sewage sludge. A recently completed study by a federal inter-agency committee has identified radioactive contaminants that could interfere with the safe reuse of sewage sludge. The study found that typical levels of radioactive materials in most municipal sewage sludge and incinerator ash do not present a health hazard to sewage treatment plant workers or to the general public. The inter-agency committee has developed recommendations for operators of sewage treatment plants for evaluating measured or estimated levels of radioactive material in sewage sludge and for determining whether actions to reduce potential exposures are appropriate.

  14. Preparation of biochar from sewage sludge

    NASA Astrophysics Data System (ADS)

    Nieto, Aurora; María Méndez, Ana; Gascó, Gabriel

    2013-04-01

    Biomass waste materials appropriate for biochar production include crop residues (both field residues and processing residues such as nut shells, fruit pits, bagasse, etc), as well as yard, food and forestry wastes, and animal manures. Biochar can and should be made from biomass waste materials and must not contain unacceptable levels of toxins such as heavy metals which can be found in sewage sludge and industrial or landfill waste. Making biochar from biomass waste materials should create no competition for land with any other land use option—such as food production or leaving the land in its pristine state. Large amounts of agricultural, municipal and forestry biomass are currently burned or left to decompose and release CO2 and methane back into the atmosphere. They also can pollute local ground and surface waters—a large issue for livestock wastes. Using these materials to make biochar not only removes them from a pollution cycle, but biochar can be obtained as a by-product of producing energy from this biomass. Sewage sludge is a by-product from wastewater treatment plants, and contains significant amounts of heavy metals, organic toxins and pathogenic microorganisms, which are considered to be harmful to the environment and all living organisms. Agricultural use, land filling and incineration are commonly used as disposal methods. It was, however, reported that sewage sludge applications in agriculture gives rise to an accumulation of harmful components (heavy metals and organic compounds) in soil. For this reason, pyrolysis can be considered as a promising technique to treat the sewage sludge including the production of fuels. The objective of this work is to study the advantages of the biochar prepared from sewage sludge.

  15. The Microbiota and Abundance of the Class 1 Integron-Integrase Gene in Tropical Sewage Treatment Plant Influent and Activated Sludge.

    PubMed

    Paiva, Magna C; Ávila, Marcelo P; Reis, Mariana P; Costa, Patrícia S; Nardi, Regina M D; Nascimento, Andréa M A

    2015-01-01

    Bacteria are assumed to efficiently remove organic pollutants from sewage in sewage treatment plants, where antibiotic-resistance genes can move between species via mobile genetic elements known as integrons. Nevertheless, few studies have addressed bacterial diversity and class 1 integron abundance in tropical sewage. Here, we describe the extant microbiota, using V6 tag sequencing, and quantify the class 1 integron-integrase gene (intI1) in raw sewage (RS) and activated sludge (AS). The analysis of 1,174,486 quality-filtered reads obtained from RS and AS samples revealed complex and distinct bacterial diversity in these samples. The RS sample, with 3,074 operational taxonomic units, exhibited the highest alpha-diversity indices. Among the 25 phyla, Proteobacteria, Bacteroidetes and Firmicutes represented 85% (AS) and 92% (RS) of all reads. Increased relative abundance of Micrococcales, Myxococcales, and Sphingobacteriales and reduced pathogen abundance were noted in AS. At the genus level, differences were observed for the dominant genera Simplicispira and Diaphorobacter (AS) as well as for Enhydrobacter (RS). The activated sludge process decreased (55%) the amount of bacteria harboring the intI1 gene in the RS sample. Altogether, our results emphasize the importance of biological treatment for diminishing pathogenic bacteria and those bearing the intI1 gene that arrive at a sewage treatment plant.

  16. The Microbiota and Abundance of the Class 1 Integron-Integrase Gene in Tropical Sewage Treatment Plant Influent and Activated Sludge

    PubMed Central

    Paiva, Magna C.; Ávila, Marcelo P.; Reis, Mariana P.; Costa, Patrícia S.; Nardi, Regina M. D.; Nascimento, Andréa M. A.

    2015-01-01

    Bacteria are assumed to efficiently remove organic pollutants from sewage in sewage treatment plants, where antibiotic-resistance genes can move between species via mobile genetic elements known as integrons. Nevertheless, few studies have addressed bacterial diversity and class 1 integron abundance in tropical sewage. Here, we describe the extant microbiota, using V6 tag sequencing, and quantify the class 1 integron-integrase gene (intI1) in raw sewage (RS) and activated sludge (AS). The analysis of 1,174,486 quality-filtered reads obtained from RS and AS samples revealed complex and distinct bacterial diversity in these samples. The RS sample, with 3,074 operational taxonomic units, exhibited the highest alpha-diversity indices. Among the 25 phyla, Proteobacteria, Bacteroidetes and Firmicutes represented 85% (AS) and 92% (RS) of all reads. Increased relative abundance of Micrococcales, Myxococcales, and Sphingobacteriales and reduced pathogen abundance were noted in AS. At the genus level, differences were observed for the dominant genera Simplicispira and Diaphorobacter (AS) as well as for Enhydrobacter (RS). The activated sludge process decreased (55%) the amount of bacteria harboring the intI1 gene in the RS sample. Altogether, our results emphasize the importance of biological treatment for diminishing pathogenic bacteria and those bearing the intI1 gene that arrive at a sewage treatment plant. PMID:26115093

  17. Heterogeneous catalytic ozonation of biologically pretreated Lurgi coal gasification wastewater using sewage sludge based activated carbon supported manganese and ferric oxides as catalysts.

    PubMed

    Zhuang, Haifeng; Han, Hongjun; Hou, Baolin; Jia, Shengyong; Zhao, Qian

    2014-08-01

    Sewage sludge of biological wastewater treatment plant was converted into sewage sludge based activated carbon (SBAC) with ZnCl₂ as activation agent, which supported manganese and ferric oxides as catalysts (including SBAC) to improve the performance of ozonation of real biologically pretreated Lurgi coal gasification wastewater. The results indicated catalytic ozonation with the prepared catalysts significantly enhanced performance of pollutants removal and the treated wastewater was more biodegradable and less toxic than that in ozonation alone. On the basis of positive effect of higher pH and significant inhibition of radical scavengers in catalytic ozonation, it was deduced that the enhancement of catalytic activity was responsible for generating hydroxyl radicals and the possible reaction pathway was proposed. Moreover, the prepared catalysts showed superior stability and most of toxic and refractory compounds were eliminated at successive catalytic ozonation runs. Thus, the process with economical, efficient and sustainable advantages was beneficial to engineering application.

  18. Genotoxic and mutagenic effects of sewage sludge on higher plants.

    PubMed

    Corrêa Martins, Maria Nilza; de Souza, Victor Ventura; Souza, Tatiana da Silva

    2016-02-01

    Sewage treatment yields sludge, which is often used as a soil amendment in agriculture and crop production. Although the sludge contains elevated concentrations of macro and micronutrients, high levels of inorganic and organic compounds with genotoxic and mutagenic properties are present in sludge. Application of sludge in agriculture is a pathway for direct contact of crops to toxic chemicals. The objective of this study was to compile information related to the genotoxic and mutagenic effects of sewage sludge in different plant species. In addition, data are presented on toxicological effects in animals fed with plants grown in soils supplemented with sewage sludge. Despite the benefits of using sewage sludge as organic fertilizer, the data showcased in this review suggest that this residue can induce genetic damage in plants. This review alerts potential risks to health outcomes after the intake of food cultivated in sewage sludge-amended soils.

  19. Impact of gas injection on the apparent viscosity and viscoelastic property of waste activated sewage sludge.

    PubMed

    Bobade, Veena; Baudez, Jean Christophe; Evans, Geoffery; Eshtiaghi, Nicky

    2017-05-01

    Gas injection is known to play a major role on the particle size of the sludge, the oxygen transfer rate, as well as the mixing efficiency of membrane bioreactors and aeration basins in the waste water treatment plants. The rheological characteristics of sludge are closely related to the particle size of the sludge floc. However, particle size of sludge floc depends partly on the shear induced in the sludge and partly on physico-chemical nature of the sludge. The objective of this work is to determine the impact of gas injection on both the apparent viscosity and viscoelastic property of sludge. The apparent viscosity of sludge was investigated by two methods: in-situ and after sparging. Viscosity curves obtained by in-situ measurement showed that the apparent viscosity decreases significantly from 4000 Pa s to 10 Pa s at low shear rate range (below 10 s(-1)) with an increase in gas flow rate (0.5LPM to 3LPM); however the after sparging flow curve analysis showed that the reduction in apparent viscosity throughout the shear rate range is negligible to be displayed. Torque and displacement data at low shear rate range revealed that the obtained lower apparent viscosity in the in-situ method is not the material characteristics, but the slippage effect due to a preferred location of the bubbles close to the bob, causing an inconsistent decrease of torque and increase of displacement at low shear rate range. In linear viscoelastic regime, the elastic and viscous modulus of sludge was reduced by 33% & 25%, respectively, due to gas injection because of induced shear. The amount of induced shear measured through two different tests (creep and time sweep) were the same. The impact of this induced shear on sludge structure was also verified by microscopic images.

  20. Determination of pesticide residues in sewage sludge: a review.

    PubMed

    Tadeo, José L; Sánchez-Brunete, Consuelo; Albero, Beatriz; García-Valcárcel, Ana I

    2010-01-01

    Pesticides are widely applied to protect plants from diseases, weeds, and insect damage, and they usually come into contact with soil where they may undergo a variety of transformations and provide a complex pattern of metabolites. Spreading sewage sludge on agricultural lands has been actively promoted by national authorities as an economic way of recycling. However, as a byproduct of wastewater treatment, sewage sludge may contain pesticides and other toxic substances that could be incorporated into agricultural products or be distributed in the environment. This article reviews the determination of pesticides in sewage sludge samples. Sample preparation including pretreatment, extraction, and cleanup, as well as the subsequent instrumental determination of pesticide residues, are discussed. Extraction techniques such as Soxhlet extraction, ultrasound-assisted extraction, pressurized liquid extraction, supercritical fluid extraction, and matrix solid-phase dispersion and their most recent applications to the determination of pesticides in sewage sludge samples are reviewed. Determination of pesticides, generally carried out by GC and HPLC coupled with different detectors, especially MS for the identification and quantification of residues, is summarized and discussed.

  1. Plasma chemical gasification of sewage sludge.

    PubMed

    Balgaranova, Janetta

    2003-02-01

    The possibility for plasma gasification of sewage sludge is investigated. Water steam is used as the plasma generating gas and as a chemical reagent. The experiments are carried out at a sludge to water steam ratio of 1 to 1.5 by weight, and at a plasma torch temperature of up to 2600 degrees C. The calculated average temperature in the reactor after mixing with the sludge particles is up to 1700 degrees C. Proximate and ultimate analyses of the sludge are given. The resulting gases are analysed by gas chromatography. High calorific gas containing mainly carbon monoxide (48% volume) and hydrogen (46% volume), as well as glass-like slag, is obtained. No water-soluble substances are detected within it. The amount of carbon dioxide produced is under 4% mass. No hydrocarbons are observed within the gas. The investigated process is environmentally safe, compact and shows a high rate of conversion.

  2. Sewage sludge dewatering using flowing liquid metals

    SciTech Connect

    Carlson, L.W.

    1986-11-04

    A method is described of reducing the moisture content of a moist sewage sludge having a moisture content of about 50-80% and formed of small cellular micro-organism bodies having internally confined water. The method comprises: circulating a hot liquid metal in a loop; forming a mixture of the moist sludge and the hot liquid metal in a portion of the loop under conditions of temperature and pressure such that the confined water vaporizes and ruptures the cellular bodies; separating the liquid metal, dried sludge, and vaporized water in a separation zone of the loop; and drawing off the dried sludge and vaporized water from the loop whereby the liquid metal is left to be recirculated in the loop.

  3. Optimum BET surface areas for activated carbon produced from textile sewage sludges and its application as dye removal.

    PubMed

    Kacan, Erdal

    2016-01-15

    The purpose of this experimental study is to determine optimum preparation conditions for activated carbons obtained from textile sewage sludge (TSS) for removal of dyes from aqueous solutions. The textile sewage sludge activated carbon (TSSAC) was prepared by chemical activation with potassium hydroxide using Response Surface Methodology (RSM). The most influential factor on each experimental design responses was identified via ANNOVA analysis. Based on the central composite design (CCD), quadratic model was developed to correlate the preparation variables for one response which is the Brunauer-Emmelt-Teller (BET) surface area. RSM based on a three-variable CCD was used to determine the effect of pyrolyzed temperature (400-700 °C), carbonization time (45-180 min) and KOH: weight of TSS (wt%) impregnation ratio (0.5:1-1.5:1) on BET surface area. According to the results, pyrolyzed temperature and impregnation ratio were found as the significant factors for maximizing the BET surface area. The major effect which influences the BET surface area was found as pyrolyzed temperature. Both carbonization time and impregnation ratio of KOH had no significant effect. The optimum conditions for preparing TSSAC, based on response surface and contour plots, were found as follows: pyrolyzed temperature 700 °C, carbonization time of 45 min and chemical impregnation ratio of 0.5. The maximum and optimum BET surface area of TSSAC were found as 336 m(2)/g and 310.62 m(2)/g, respectively. Synozol Blue reactive (RSB) and Setapers Yellow-Brown (P2RFL) industrial textile dyes adsorption capacities were investigated. As expected the TSSAC which has the biggest BET surface area (336 m(2)/g) adsorbed dye best. The maximum (RSB) and (P2RFL) uptake capacities were found as 8.5383 mg/g and 5.4 mg/g, respectively. The results of this study indicated the applicability of TSSAC for removing industrial dyes from aqueous solution.

  4. Characteristics of sewage sludge and distribution of heavy metal in plants with amendment of sewage sludge.

    PubMed

    Dai, Jia-yin; Chen, Ling; Zhao, Jian-fu; Ma, Na

    2006-01-01

    In order to better understand land application of sewage sludge, the characterization of heavy metals and organic pollutants were investigated in three different sewage sludges in Shanghai City, China. It was found that the total concentrations of Cd in all of sewage sludge and total concentrations of Zn in Jinshan sewage sludge, as well as those of Zn, Cu, and Ni in Taopu sludge are higher than Chinese regulation limit of pollutants for sludge to be used in agriculture. Leachability of Hg in all of studied samples and that of Cd in Taopu sewage sludge exceed the limit values of waste solid extraction standard in China legislation. Based on the characteristics for three kinds of sewage sludge, a pot experiment was conducted to investigate the effect of soil amended with Quyang sewage sludge on the accumulation of heavy metal by Begonia semperflorens-hybr; Ophiopogon japonicus (L.F.) Ker-Gaw; Loropetalum chindense-var. rubrum; Dendranthema morifolium; Viola tricolor; A ntirrhinum majus; Buxus radicans Sieb; Viburnum macrocephalum; Osmanthus fragrans Lour; Cinnamomum camphora siebold and Ligustrum lucidum ait. Results showed that 8 species of plant survived in the amended soil, and moreover they flourished as well as those cultivated in the control soil. The heavy metal concentration in plants varied with species, As, Pb, Cd and Cr concentration being the highest in the four herbaceous species studied, particularly in the roots of D. morifolium. These plants, however, did not show accumulator of As, Pb, Cd and Cr. The highest concentration of Ni and Hg was found in the roots of D. morifolium, followed by the leaves of B. semperflorens-hybr. Levels of Zn and Cu were much higher in D. morifolium than in the other plant species. D. morifolium accumulated Ni, Hg, Cu and Zn, which may contribute to the decrease of heavy metal contents in the amended soil. Treatment with sewage sludge did not significantly affect the uptake of heavy metals by the L. chindense-var. rubrum

  5. Sewage sludge disposal strategies for sustainable development.

    PubMed

    Kacprzak, Małgorzata; Neczaj, Ewa; Fijałkowski, Krzysztof; Grobelak, Anna; Grosser, Anna; Worwag, Małgorzata; Rorat, Agnieszka; Brattebo, Helge; Almås, Åsgeir; Singh, Bal Ram

    2017-03-14

    The main objective of the present review is to compare the existing sewage sludge management solutions in terms of their environmental sustainability. The most commonly used strategies, that include treatment and disposal has been favored within the present state-of-art, considering existing legislation (at European and national level), characterization, ecotoxicology, waste management and actual routs used currently in particular European countries. Selected decision making tools, namely End-of-waste criteria and Life Cycle Assessment has been proposed in order to appropriately assess the possible environmental, economic and technical evaluation of different systems. Therefore, some basic criteria for the best suitable option selection has been described, in the circular economy "from waste to resources" sense. The importance of sewage sludge as a valuable source of matter and energy has been appreciated, as well as a potential risk related to the application of those strategies.

  6. Assessment of activated sludge, membrane bioreactors and vertical flow wetlands for upgrading sewage treatment works.

    PubMed

    Besançon, A; Le Corre, K S; Dotro, G; Jefferson, B

    2017-01-01

    This paper demonstrates that utilising a vertical flow (VF) wetland after a conventional activated sludge (CAS) delivers equivalent or better effluent quality to a membrane bioreactor (MBR) based on a side-by-side pilot trial. The CAS was operated under the solids retention times (SRT) of 6, 12, and 20 days, with the effluent from each pilot plant fed onto a soil aquifer treatment column to better understand their water reuse application potential. Results showed an upgraded CAS + VF system could deliver effluents with median values of 34 mgO2.L((-1)), 7 mg.L(-1) and 1.9 mg.L(-1) for organics, solids and ammonia nitrogen, respectively, which were statistically similar to those from the MBR. Water reuse standards were achieved by the upgraded system for most parameters, with the exception of total coliform removal. The upgraded system delivered superior metal removal when compared to the CAS. An economic analysis showed upgrading a CAS with a VF wetland was more favourable than investing in an MBR system for example works of 5000 and 50,000 population equivalents if the VF system was operated at hydraulic loading rates of 0.03 m.d(-1) and 0.08 m.d(-1), respectively. This was delivered for a tenth of the carbon footprint of the MBR treatment.

  7. Urban energy mining from sewage sludge.

    PubMed

    Kwon, E E; Yi, H; Kwon, H H

    2013-01-01

    This work showed that sewage sludge could be a strong candidate for biodiesel production. High lipid content (18-20%) with C(16-18)-carbon range was experimentally identified and measured. These lipids from sewage sludge were converted into biodiesel via the transesterification reaction with MgO-CaO/Al(2)O(3) derived from magnesium slag, and biodiesel conversion was ~98%. The experimental work enabled explaining that temperature is the main driving force for the transesterification reaction, which can be enhanced in the presence of CO(2). This also enables combination of esterification of free fatty acids and transesterification of triglycerides into a single process within 1 min in the temperature range of 350-500°C. Sewage sludge residue after extracting lipids was also a good feedstock for recovering energy via thermo-chemical processes. The impact of CO(2) co-feed on the pyrolysis/gasification process of SS residue was also investigated in this work. The CO(2) injected into the thermo-chemical process remarkably increased the generation of CO by a factor of 2. Moreover, the introduction of CO(2) into the pyrolysis/gasification process enabled reducing condensable hydrocarbons (tar) by expediting cracking; thus, utilizing CO(2) as chemical feedstock for the gasification process not only leads to higher thermal efficiency but also has environmental benefits.

  8. Ammonia sanitisation of sewage sludge using urea.

    PubMed

    Fidjeland, Jørgen; Lalander, Cecilia; Jönsson, Håkan; Vinnerås, Björn

    2013-01-01

    The aim of the study was to develop a simple, low-cost treatment for sewage sludge using urea as a sanitising agent. Sewage sludge was spiked with Enterococcus faecalis and Salmonella typhimurium, treated with 0.5, 1, 1.5 and 2% w/w urea at laboratory scale, and the viability was monitored during 4 months of storage at 4, 10 and 22 °C (only 0.5%). A linear relationship was identified between Salmonella spp. inactivation rate and ammonia (NH3) concentration. Temperature had a positive impact on Salmonella spp. inactivation at higher temperatures, but in the range 4-10 °C temperature influenced this inactivation merely by its impact on the ammonia equilibrium. Enterococcus spp. was more persistent and a lag phase of up to 11 weeks was observed. Higher temperature and ammonia concentration reduced the lag phase duration significantly, and also had a clear effect on the inactivation rate for the treatments with 0.5% urea at 22 °C and 2% urea at 4 and 10 °C. Urea sanitisation of sewage sludge can give a 2 log10 reduction of Enterococcus spp. and more than a 5 log10 reduction of Salmonella spp. within 6 weeks with either 0.5% w/w urea at 22 °C or 2% urea at 10 °C.

  9. Complete survey of German sewage sludge ash.

    PubMed

    Krüger, Oliver; Grabner, Angela; Adam, Christian

    2014-10-21

    The amount of sewage sludge produced worldwide is expected to further increase due to rising efforts in wastewater treatment. There is a growing concern against its direct use as fertilizer due to contamination of the sludge with heavy metals and organic pollutants. Incinerating the sludge degrades organic compounds almost completely and concentrates heavy metals and phosphorus. However, the sewage sludge ash (SSA) is almost completely disposed of and with it all resources are removed from the economic cycle. Comprehensive knowledge of the composition of SSA is crucial to assess the resource recovery potentials. We conducted a survey of all SSA emerging in Germany and determined the respective mass fractions of 57 elements over a period of one year. The median content of phosphorus was 7.9%, indicating an important recovery potential. Important trace elements were Zn (2.5 g/kg), Mn (1.3 g/kg), and Cu (0.9 g/kg). Mass fractions of technology metals such as V, Cr, Ga, Nb, and rare earths were comparatively low. Considering the possible use of SSA as secondary raw material for fertilizer production it should be noted that its Cd and U content (2.7 mg/kg and 4.9 mg/kg respectively) is significantly lower than that of rock phosphate based mineral fertilizers.

  10. Metal transfer in vermicomposting of sewage sludge and plant wastes

    SciTech Connect

    Frank, R.; Klauck, C.; Stonefield, K.I.

    1983-12-01

    Sewage sludge is an urban waste that has a potential nutrient value for recycling into food production. A set of guidelines has been developed that prescribes the quality of sludge suitable for utilization on foodlands. A number of sewage sludges do not meet the criteria and are therefore not acceptable for direct foodland application. One of the options available for such sludges is the production of compost and one of these composting processes involves worms (vermicomposting). This study looks at a pilot vermicomposting operation and follows metal concentrations by batch lot from the sewage sludge to the final commercial product.

  11. IRRADIATION EFFECTS ON THE PHYSICAL CHARACTERISTICS OF SEWAGE SLUDGE

    SciTech Connect

    Lee, M-J.; Lee, J-K.; Yoo, D-H.; Ho, K.

    2004-10-05

    The radiation effects on the physical characteristic of the sewage sludge were studied in order to obtain information which will be used for study on the enhancement of the sludge's dewaterability. Water contents, capillary suction time, zeta potential, irradiation dose, sludge acidity, total solid concentration, sludge particle size and microbiology before and after irradiation were investigated. Irradiation gave an effect on physical characteristics sludge. Water content in sludge cake could be reduced by irradiation at the dose of 10kGy.

  12. Utilization and Conversion of Sewage Sludge as Metal Sorbent

    NASA Astrophysics Data System (ADS)

    Gong, Xu Dong; Li, Loretta Y.

    2013-04-01

    Most biosolids are disposed on land. With improvements in wastewater treatment processes and upgrading of treatment plants across Canada, biosolids generation will increase dramatically. These biosolids will need to be dealt with because they contain various contaminants, including heavy metals and several classes of emerging contaminants. A number of researchers have recently focused on preparation of sewage sludge-based adsorbents by carbonation, physical activation and chemical activation for decontamination of air and wastewater. These previous studies have indicated that sludge-based activated carbon can have good adsorption performance for organic substances in dye wastewater. The overall results suggest that activated carbon from sewage sludge can produce a useful adsorbent, while also reducing the amount of sewage sludge to be disposed. However, sludge-derived activated carbon has not been extensively studied, especially for adsorption of heavy metal ions in wastewater and for its capacity to remove emerging contaminants, such as poly-fluorinated compounds (PFCs). Previous research has indicated that commercial activated carbons adsorb organic compounds more efficiently than heavy metal ions. 45 Activated carbon can be modified to enhance its adsorption capacity for special heavy metal ions,46 e.g. by addition of inorganic and organic reagents. The modifications which are successful for commercial activated carbon should also be effective for sludge-derived activated carbon, but this needs to be confirmed. Our research focuses on (a) investigation of techniques for converting sewage sludge (SS) to activated carbon (AC) as sorbents; (b) exploration of possible modification of the activated carbon (MAC) to improve its sorption capacity; (c) examination of the chemical stability of the activated carbon and the leachability of contaminants from activated carbon,; (d) comparison of adsorptivity with that of other sorbents. Based on XRD and FT-IR, we successfully

  13. The occurrence and significance to animal health of salmonellas in sewage and sewage sludges.

    PubMed Central

    Jones, P. W.; Rennison, L. M.; Lewin, V. H.; Redhead, D. L.

    1980-01-01

    A total of 882 samples of settled sewage, sewage sludges and final effluents from eight sewage treatment plants were examined for the presence of salmonellas. Of these samples 68% were positive, isolations being made most frequently from settled sewage (85%), raw sludge (87%) and anaerobically digested sludge (96%). Fewer isolations were made from final effluent (24%) and processed sludges (58%). Samples usually contained less than 200 salmonellas/100 ml and arguments are presented that such concentrations should not lead to disease in animals if suitable grazing restrictions are followed. PMID:6985928

  14. Rapid thermal conditioning of sewage sludge

    NASA Astrophysics Data System (ADS)

    Zheng, Jianhong

    Rapid thermal conditioning (RTC) is a developing technology recently applied to sewage sludge treatment. Sludge is heated rapidly to a reaction temperature (up to about 220sp°C) under sufficient pressure to maintain the liquid phase. Reaction is quenched after 10 to 30 seconds when the mixture of sludge and steam pass through a pressure let-down valve. This process reduces the amount of sludge requiring land disposal, eliminates the need for polymer coagulant, improves dewaterability, increases methane production, and further reduces the concentration of pathogens. The odor problem associated with traditional thermal conditioning processes is largely minimized. Ammonia removal is readily integrated with the process. For this research, a pilot unit was constructed capable of processing 90 liters of sludge per hour. Over 22 runs were made with this unit using sludge from New York City Water Pollution Control Plants (WPCP). Sludges processed in this equipment were tested to determine the effect of RTC operating conditions on sludge dewaterability, biodegradability, and other factors affecting the incorporation of RTC into wastewater treatment plants. Dewaterability of thermally conditioned sludge was assessed for cetrifugeability and filterability. Bench scale centrifugation was used for evaluating centrifugeability, pressure filtration and capillary suction time (CST) for filterability. A mathematical model developed for centrifuge dewatering was used to predict the effect of RTC on full scale centrifuge performance. Particle size distribution and solids density of raw and treated PDS were also analyzed. An observed increase in sludge solids density at least partially explains its improved centrifugeability. An investigation of thermally conditioned amino acids showed that the L-isomer is highly biodegradable while the D-isomers are generally less so. Glucose is highly biodegradable, but rapidly becomes refractory as thermal conditioning time is lengthened. This

  15. Microplastics in Sewage Sludge: Effects of Treatment.

    PubMed

    Mahon, A M; O'Connell, B; Healy, M G; O'Connor, I; Officer, R; Nash, R; Morrison, L

    2017-01-17

    Waste water treatment plants (WWTPs) are receptors for the cumulative loading of microplastics (MPs) derived from industry, landfill, domestic wastewater and stormwater. The partitioning of MPs through the settlement processes of wastewater treatment results in the majority becoming entrained in the sewage sludge. This study characterized MPs in sludge samples from seven WWTPs in Ireland which use anaerobic digestion (AD), thermal drying (TD), or lime stabilization (LS) treatment processes. Abundances ranged from 4196 to 15 385 particles kg(-1) (dry weight). Results of a general linear mixed model (GLMM) showed significantly higher abundances of MPs in smaller size classes in the LS samples, suggesting that the treatment process of LS shears MP particles. In contrast, lower abundances of MPs found in the AD samples suggests that this process may reduce MP abundances. Surface morphologies examined using scanning electron microscopy (SEM) showed characteristics of melting and blistering of TD MPs and shredding and flaking of LS MPs. This study highlights the potential for sewage sludge treatment processes to affect the risk of MP pollution prior to land spreading and may have implications for legislation governing the application of biosolids to agricultural land.

  16. Phosphate fertilizer from sewage sludge ash (SSA).

    PubMed

    Franz, M

    2008-01-01

    Ashes from sewage sludge incineration are rich in phosphorus content, ranging between 4% and 9%. Due to the current methods of disposal used for these ashes, phosphorus, which is a valuable plant nutrient, is removed from biological cycling. This article proposes the possible three-stage processing of SSA, whereby more than 90% of phosphorus can be extracted to make an adequate phosphate fertilizer. SSA from two Swiss sewage sludge incinerators was used for laboratory investigations. In an initial step, SSA was leached with sulfuric acid using a liquid-to-solid ratio of 2. The leaching time and pH required for high phosphorus dissolution were determined. Inevitably, dissolution of heavy metals takes place that would contaminate the fertilizer. Thus in a second step, leach solution has to be purified by having the heavy metals removed. Both ion exchange using chelating resins and sulfide precipitation turned out to be suitable for removing critical Cu, Ni and Cd. Thirdly, phosphates were precipitated as calcium phosphates with lime water. The resulting phosphate sludge was dewatered, dried and ground to get a powdery fertilizer whose efficacy was demonstrated by plant tests in a greenhouse. By measuring the weight of plants after 6 weeks of growth, fertilized in part with conventional phosphate fertilizer, fertilizer made from SSA was proven to be equal in its plant uptake efficiency.

  17. Microwave oxidation treatment of sewage sludge.

    PubMed

    Lo, Kwang V; Srinivasan, Asha; Liao, Ping H; Bailey, Sam

    2015-01-01

    Microwave-oxidation treatment of sewage sludge using various oxidants was studied. Two treatment schemes with a combination of hydrogen peroxide and ozone were examined: hydrogen peroxide and ozone were introduced into the sludge simultaneously, followed by microwave heating. The other involved the ozonation first, and then the resulting solution was subjected to microwave and hydrogen peroxide treatment. The set with ozonation followed by hydrogen peroxide plus microwave heating yielded higher soluble materials than those of the set with hydrogen peroxide plus ozone first and then microwave treatment. No settling was observed for all treatments in the batch operation, except ozone/microwave plus hydrogen peroxide set at 120°C. The pilot-scale continuous-flow 915 MHz microwave study has demonstrated that microwave-oxidation process is feasible for real-time industrial application. It would help in providing key data for the design of a full-scale system for treating sewage sludge and the formulation of operational protocols.

  18. Co-combustion of different sewage sludge and coal: a non-isothermal thermogravimetric kinetic analysis.

    PubMed

    Otero, M; Calvo, L F; Gil, M V; García, A I; Morán, A

    2008-09-01

    The kinetics of the combustion of coal, two different sewage sludge and their blends (containing different dried weight percentages of sewage sludge) was studied by simultaneous thermogravimetric analysis. Once the weight percentage of sludge in the blend was 10%, the effects on the combustion of coal were hardly noticeable in terms of weight loss. The Arrhenius activation energy corresponding to the co-combustion of the blends was evaluated by non-isothermal kinetic analysis. This showed that, though differences between coal and sewage sludge, the combustion of their blends kept kinetically alike to that of the coal. This work illustrates how thermogravimetric analysis may be used as an easy rapid tool to asses, not only mass loss, but also kinetics of the co-combustion of sewage sludge and coal blends.

  19. Cytotoxic, genotoxic and mutagenic effects of sewage sludge on Allium cepa.

    PubMed

    Corrêa Martins, Maria Nilza; de Souza, Victor Ventura; da Silva Souza, Tatiana

    2016-04-01

    The objective of this study was to ascertain the cytotoxic, genotoxic and mutagenic potential of sewage sludge using Allium cepa bioassay. Solubilized and crude sludge from two sewage treatment stations (STSs), herein named JM and M, were tested. In addition, sanitized, crude and solubilized sludge were also analyzed from STS M. The treatments showed positive response to phytotoxicity, cytotoxicity, genotoxicity and/or mutagenicity. Despite negative results for MN F1 (micronuclei counted in F1 root cells, derived from meristematic cells), the monitoring of genotoxic and mutagenic activities of sewage sludge are recommended because in agricultural areas this residue is applied in large scale and continuously. Based on our results we advise caution in the use of sewage sludge in agricultural soils.

  20. Agronomic characterisation of different types of sewage sludge: policy implications.

    PubMed

    Mosquera-Losada, M R; Muñoz-Ferreiro, N; Rigueiro-Rodríguez, A

    2010-03-01

    Spain is one of the main municipal sewage sludge producers of Europe. This paper aims to agronomically characterise different types of sewage sludge stabilised by different methods (anaerobically digested, composted, and pelletised) and deliver policy recommendations from the results of this characterisation. Anaerobic sewage sludge quality is found to be better in plants with a lower volume of water processing. Composted sludge shows the best quality from a heavy metal point of view, but its low available nitrogen content increases the input of heavy metals when spread, as compared to digested or pelletised sludge. Pelletised sludge has higher heavy metal content than anaerobically digested sludge. Despite the good quality of the sludges, future regulations, especially with regard to Cd levels, will limit the use of this waste in agriculture.

  1. Characteristics of rice straw and sewage sludge as composting materials in Valencia (Spain).

    PubMed

    Iranzo, Maria; Cañizares, Jose V; Roca-Perez, Luis; Sainz-Pardo, Isabel; Mormeneo, Salvador; Boluda, Rafael

    2004-10-01

    This work supports the idea that composting can be useful for minimizing the rice straw and sewage sludge environmental impact. Several physical, chemical and microbiological properties of these raw materials were analyzed. The characteristics of the rice straw were complementary to those of the sewage sludge for the application of composting. The C/N ratios suitable for a rapid increased in microbial activity were the lowest (17-24). A temperature of 62 degrees C during 48 h removed pathogenic microorganisms from rice straw and sewage sludge mixture. The results obtained in the present work suggested that these materials could be use in the composting process.

  2. Treatment of high-strength synthetic sewage in a laboratory-scale upflow anaerobic sludge bed (UASB) with aerobic activated sludge (AS) post-treatment.

    PubMed

    Banihani, Qais H; Field, Jim A

    2013-01-01

    Performance of a combined system up-flow anaerobic sludge blanket (UASB) followed by aerobic treatment activated sludge (AS) for removal of carbonaceous and nitrogenous contaminants at an average temperature of 25°C was investigated. The combined system was fed with high strength synthetic sewage having chemical oxygen demand (COD) of 2500 mg L(-1). The organic loading rate (OLR) of the UASB reactor was increased gradually from 1.1 to 3.8 gCOD L(r) (-1) d(-1). At steady state condition, the UASB reactor achieved removal efficiency up to 83.5% of total COD (COD(tot)), 74.0% of volatile fatty acid (VFA) and 94.0% of protein. The combined system performed an excellent organic removal pushing the overall removal efficiency of COD(tot), VFA and protein to 91.0%, 99.9% and 98.2%, respectively. When the OLR of the UASB increased to 4.4 g COD L(r) (-1) d(-1), the UASB was overloaded and; thus, its effluent quality deteriorated. In respect to nitrogen removal, both partial nitrification and complete nitrification took place in aerobic post-treatment. When the dissolved oxygen (DO) concentration was >2.0 mg L(-1), complete nitrification (period B) occurred with an average nitrification efficiency of 96.2%. The partial nitrification occurred due to high OLR to AS during the overloading event (period A) and when DO concentration was <2.0 mg L(-1) (period C). The maximum accumulated nitrite concentration in periods A, B and C were 90.0, 0.9 and 75.8 mg NO(-) (2) -N L(-1), respectively. The nitrogen balance results of periods A and C indicated that there was a discrepancy between the amount of ammonium nitrogen removed and the amount of oxidized nitrogen formed. This suggests the occurrence of simultaneous nitrification/denitrification (SND) in aerobic post-treatment.

  3. The effect of bioleaching on sewage sludge pyrolysis.

    PubMed

    Chen, Zhihua; Hu, Mian; Cui, Baihui; Liu, Shiming; Guo, Dabin; Xiao, Bo

    2016-02-01

    The effects of bioleaching on sewage sludge pyrolysis were studied. Sewage sludge was treated by bioleaching with solid concentrations of 6% (w/v), 8% (w/v), 10% (w/v). Results showed that bioleaching treatment could modify the physicochemical properties of sewage sludge and enhance the metals removal. The optimum removal efficiencies of heavy metals were achieved with solid concentration of 6% (w/v) bioleaching treatment: Cu, 73.08%; Zn, 78.67%; Pb, 24.65%; Cd, 79.46%. The characterization results of thermogravimetric analysis (TGA) showed that the bioleached sewage sludge with a 6% (w/v) solid concentration treatment was the easiest to decompose. Pyrolytic experiments of bioleached sewage sludge were performed in a laboratory-scale fixed bed reactor. Results indicated that bioleaching treatment greatly influenced the product yields and gas composition.

  4. Evaluation of bangkok sewage sludge for possible agricultural use.

    PubMed

    Pasda, Nuanjun; Panichsakpatana, Supamard; Limtong, Pitayakon; Oliver, Robert; Montange, Denis

    2006-04-01

    Bangkok (Thailand) covers more than 1500 km2 and has 10 million inhabitants. The disposal of wastewater is creating huge problems of pollution. The estimated amount of sewage sludge was estimated to be around 108 tonnes dry matter (DM) per day in 2005. In order to find a lasting way of disposal for this sewage sludge, the suitability of the sludge produced from three waste-water treatment plants for use as fertilizing material was investigated. Monthly samplings and analysis of sewage sludge from each plant showed that the composition of sludge varied according to the area of collection and period of sampling, and there was no link to rainfall cycle. Plant nutrient content was high (i.e. total N from 19 to 38 g kg(-1) DM) whereas organic matter content was low. The concentrations of heavy metals varied between sludge samples, and were sometimes higher than the E.U. or U.S. regulations for sewage sludge use in agriculture. Faecal coliforms were present in the sludge from one of the plants, indicating a possible contamination by night soil. In order to decrease this potentially pathogenic population the sewage sludge should be heated by composting. As the C/N ratio of sewage sludge was low (around 6) some organic by-products with high carbon content could be added as structural material to enhance the composting.

  5. Vitrification as an alternative to landfilling of tannery sewage sludge.

    PubMed

    Celary, Piotr; Sobik-Szołtysek, Jolanta

    2014-12-01

    Due to high content of heavy metals such as chromium, tannery sewage sludge is a material which is difficult to be biologically treated as it is in the case of organic waste. Consequently, a common practice in managing tannery sewage sludge is landfilling. This poses a potential threat to both soil and water environments and it additionally generates costs of construction of landfills that meet specific environment protection requirements. Vitrification of this kind of sewage sludge with the addition of mineral wastes can represent an alternative to landfilling. The aim of this study was to investigate the possibility of obtaining an environmentally safe product by means of vitrification of tannery sewage sludge from a flotation wastewater treatment process and chemical precipitation in order to address the upcoming issue of dealing with sewage sludge from the tannery industry which will be prohibited to be landfilled in Poland after 2016. The focus was set on determining mixtures of tannery sewage sludge with additives which would result in the lowest possible heavy metal leaching levels and highest hardness rating of the products obtained from their vitrification. The plasma vitrification process was carried out for mixtures with various amounts of additives depending on the type of sewage sludge used. Only the materials of waste character were used as additives. One finding of the study was an optimum content of mineral additives in vitrified mixture of 30% v/v waste molding sands with 20% v/v carbonate flotation waste from the zinc and lead industry for the formulations with flotation sewage sludge, and 45% v/v and 5% v/v, respectively, for precipitation sewage sludge. These combinations allowed for obtaining products with negligible heavy metal leaching levels and hardness similar to commercial glass, which suggests they could be potentially used as construction aggregate substitutes. Incineration of sewage sludge before the vitrification process lead to

  6. JPL Activated Carbon Treatment System (ACTS) for sewage

    NASA Technical Reports Server (NTRS)

    1976-01-01

    An Activated Carbon Treatment System (ACTS) was developed for sewage treatment and is being applied to a one-million gallon per day sewage treatment pilot plant in Orange County California. Activities reported include pyrolysis and activation of carbon-sewage sludge, and activated carbon treatment of sewage to meet ocean discharge standards. The ACTS Sewage treatment operations include carbon-sewage treatment, primary and secondary clarifiers, gravity (multi-media) filter, filter press dewatering, flash drying of carbon-sewage filter cake, and sludge pyrolysis and activation. Tests were conducted on a laboratory scale, 10,000 gallon per day demonstration plant and pilot test equipment. Preliminary economic studies are favorable to the ACTS process relative to activated sludge treatment for a 175,000,000 gallon per day sewage treatment plant.

  7. The influence of redox chemistry and pH on chemically active forms of arsenic in sewage sludge-amended soil

    SciTech Connect

    Carbonell-Barrachina, A.; Jugsujinda, A.; DeLaune, R.D.; Patrick, W.H. Jr.; Burlo, F.; Sirisukhodom, S.; Anurakpongsatorn, P.

    1999-07-01

    Chemical fractionation procedures were used to quantify the effect of the sediment redox and pH conditions on the adsorption and solubility of arsenic (As) in municipal sewage sludge and sewage sludge-amended soil. Sludge and sludge-amended soil were incubated in microcosms in which Eh-pH conditions were controlled. Samples were sequentially extracted to determine As in various chemical forms (water soluble, exchangeable, bound to carbonates, bound to iron (Fe) and manganese (Mn) oxides, bound to insoluble organics and sulfides) and the chemically inactive fraction (mineral residues). In both sewage sludge and sludge-amended soil, As chemistry was governed by large molecular humic matter and sulfides and Fe and Mn-oxides. Solubility of As remained low and constant under both aerobic and anaerobic conditions in sludge-amended soil. After dissolution of Fe and Mn-oxides, As{sup 5+} was released into sludge solution, reduced to As{sup 3+} and likely precipitated as sulfide. Therefore, an organic amendment rich in sulfur compounds, such as sewage sludge, would drastically reduce the potential risks derived from As pollution under highly anoxic conditions by precipitation of this toxic metalloid as insoluble and immobile sulfides.

  8. Effects of sewage sludge amendment on heavy metal accumulation and consequent responses of Beta vulgaris plants.

    PubMed

    Singh, R P; Agrawal, M

    2007-05-01

    Use of sewage sludge, a biological residue produced from sewage treatment processes in agriculture is an alternative disposal technique of waste. To study the usefulness of sewage sludge amendment for palak (Beta vulgaris var. Allgreen H-1), a leafy vegetable and consequent heavy metal contamination, a pot experiment was conducted by mixing sewage sludge at 20% and 40% (w/w) amendment ratios to the agricultural soil. Soil pH decreased whereas electrical conductance, organic carbon, total N, available P and exchangeable Na, K and Ca increased in soil amended with sewage sludge in comparison to unamended soil. Sewage sludge amendment led to significant increase in Pb, Cr, Cd, Cu, Zn and Ni concentrations of soil. Cd concentration in soil was found above the Indian permissible limit in soil at both the amendment ratios. The increased concentration of heavy metals in soil due to sewage sludge amendment led to increases in heavy metal uptake and shoot and root concentrations of Ni, Cd, Cu, Cr, Pb and Zn in plants as compared to those grown on unamended soil. Accumulation was more in roots than shoots for most of the heavy metals. Concentrations of Cd, Ni and Zn were more than the permissible limits of Indian standard in the edible portion of palak grown on different sewage sludge amendments ratios. Sewage sludge amendment in soil decreased root length, leaf area and root biomass of palak at both the amendment ratios, whereas shoot biomass and yield decreased significantly at 40% sludge amendment. Rate of photosynthesis, stomatal conductance and chlorophyll content decreased whereas lipid peroxidation, peroxidase activity and protein and proline contents, increased in plants grown in sewage sludge-amended soil as compared to those grown in unamended soil. The study clearly shows that increase in heavy metal concentration in foliage of plants grown in sewage sludge-amended soil caused unfavorable changes in physiological and biochemical characteristics of plants leading

  9. Comparison of phosphorus recovery from incinerated sewage sludge ash (ISSA) and pyrolysed sewage sludge char (PSSC).

    PubMed

    Kleemann, Rosanna; Chenoweth, Jonathan; Clift, Roland; Morse, Stephen; Pearce, Pete; Saroj, Devendra

    2017-02-01

    This research compares and contrasts the physical and chemical characteristics of incinerator sewage sludge ash (ISSA) and pyrolysis sewage sludge char (PSSC) for the purposes of recovering phosphorus as a P-rich fertiliser. Interest in P recovery from PSSC is likely to increase as pyrolysis is becoming viewed as a more economical method of sewage sludge thermal treatment compared to incineration. The P contents of ISSA and PSSC are 7.2-7.5% and 5.6%, respectively. Relative to the sludge, P concentrations are increased about 8-fold in ISSA, compared to roughly 3-fold in PSSC. Both PSSC and ISSA contain whitlockite, an unusual form of calcium phosphate, with PSSC containing more whitlockite than ISSA. Acid leaching experiments indicate that a liquid/solid ratio of 10 with 30min contact time is optimal to release PO4-P into leachate for both ISSA and PSSC. The proportion of P extracted from PSSC is higher due to its higher whitlockite content. Heavy metals are less soluble from PSSC because they are more strongly incorporated in the particles. The results suggest there is potential for the development of a process to recover P from PSSC.

  10. Apparatus for processing municipal solid waste and sewage sludge

    SciTech Connect

    Harendza-harinxma, A. J.

    1980-08-12

    Sewage sludge and municipal solid waste are simultaneously processed by first dissolving a catalyst, such as sodium aluminate, in the sludge, then mixing the sludge-aluminate mixture with the municipal waste to form a carbonizing mixture. After dewatering and drying, the mixture is carbonized in a furnace heated by a mixture of city gas and pyrolysis gases given off by the furnace.

  11. Supercritical water pyrolysis of sewage sludge.

    PubMed

    Ma, Wenchao; Du, Guiyue; Li, Jian; Fang, Yuanhao; Hou, Li'an; Chen, Guanyi; Ma, Degang

    2017-01-01

    Municipal sewage sludge (SS) from wastewater treatment plant containing high water content (>85wt.%), lead to the difficulty of co-combustion with MSW or coal due to the high cost of drying. This study explores an alternative method by supercritical water (SCW) pyrolysis of sewage sludge (SS) in a high pressure reaction vessel. The effects of temperature and moisture content of SS on yield and composition of the products (bio-oil, bio char and non-condensable gas) were studied. A temperature of 385°C and moisture content of 85wt.% were found to be the optimum conditions for the maximum bio-oil production of 37.23wt.%, with a higher heating value of 31.08MJ/kg. In the optimum condition, the yields of aliphatic hydrocarbon and phenols were about 29.23wt.% and 12.51wt.%, respectively. The physical and chemical properties of bio-char were analyzed by using XRF and BET. Results of GC analyses of NCG showed that it has the maximum HHV of 13.39MJ/m(3) at 445°C and moisture content of 85wt.%. The reaction path from SS to bio-oil through SCW pyrolysis was given. Moreover, carbon balance was calculated for the optimal condition, and finding out that 64.27wt.% of the carbon content was transferred from SS to bio-oil. Finally, this work demonstrates that the SCW pyrolysis is a promising disposal method for SS.

  12. Activated Sludge.

    ERIC Educational Resources Information Center

    Saunders, F. Michael

    1978-01-01

    Presents the 1978 literature review of wastewater treatment. This review covers: (1) activated sludge process; (2) process control; (3) oxygen uptake and transfer; (4) phosphorus removal; (5) nitrification; (6) industrial wastewater; and (7) aerobic digestion. A list of 136 references is also presented. (HM)

  13. Effects of chemically contaminated sewage sludge on an aphid population

    SciTech Connect

    Culliney, T.W.; Pimentel, D.

    1986-12-01

    Survival and fecundity of green peach aphids, Myzus persicae, were markedly reduced when they were fed on collard plants grown in pots of soil treated with chemically contaminated sewage sludge, as compared to populations on potted plants grown in uncontaminated sludge or on fertilized soil (control). Calculated demographic parameters differed significantly between the contaminated sludge and uncontaminated sludge populations and between the contaminated sludge and control populations. No significant differences were detected between the uncontaminated sludge and control populations. The ecological effects on the aphids suggest that plant uptake and translocation of chemicals from the contaminated sludge affected aphid fitness through direct toxicity and/or reduced nutritional value of the plant. These results indicate that phytophagous insects may be affected by chemical contaminants in sewage sludge used in agriculture.

  14. Addition of biochar to sewage sludge decreases freely dissolved PAHs content and toxicity of sewage sludge-amended soil.

    PubMed

    Stefaniuk, Magdalena; Oleszczuk, Patryk

    2016-11-01

    Due to an increased content of polycyclic aromatic hydrocarbons (PAHs) frequently found in sewage sludges, it is necessary to find solutions that will reduce the environmental hazard associated with their presence. The aim of this study was to determine changes of total and freely dissolved concentration of PAHs in sewage sludge-biochar-amended soil. Two different sewage sludges and biochars with varying properties were tested. Biochars (BC) were produced from biogas residues at 400 °C or 600 °C and from willow at 600 °C. The freely dissolved PAH concentration was determined by means of passive sampling using polyoxymethylene (POM). Total and freely dissolved PAH concentration was monitored at the beginning of the experiment and after 90 days of aging of the sewage sludge with the biochar and soil. Apart from chemical evaluation, the effect of biochar addition on the toxicity of the tested materials on bacteria - Vibrio fischeri (Microtox(®)), plants - Lepidium sativum (Phytotestkit F, Phytotoxkit F), and Collembola - Folsomia candida (Collembolan test) was evaluated. The addition of biochar to the sewage sludges decreased the content of Cfree PAHs. A reduction from 11 to 43% of sewage sludge toxicity or positive effects on plants expressed by root growth stimulation from 6 to 25% to the control was also found. The range of reduction of Cfree PAHs and toxicity was dependent on the type of biochar. After 90 days of incubation of the biochars with the sewage sludge in the soil, Cfree PAHs and toxicity were found to further decrease compared to the soil with sewage sludge alone. The obtained results show that the addition of biochar to sewage sludges may significantly reduce the risk associated with their environmental use both in terms of PAH content and toxicity of the materials tested.

  15. The Different Physiological and Antioxidative Responses of Zucchini and Cucumber to Sewage Sludge Application.

    PubMed

    Wyrwicka, Anna; Urbaniak, Magdalena

    2016-01-01

    The present study investigates the effect of soil amended with sewage sludge on oxidative changes in zucchini and cucumber plants (Cucurbitaceae) and the consequent activation of their antioxidative systems and detoxification mechanisms. The plants were grown in pots containing soil amended with three concentrations of sewage sludge (1.8 g, 5.4 g and 10.8 g per pot), while controls were potted with vegetable soil. The activities of three antioxidative enzymes, ascorbate peroxidase (APx), catalase (CAT) and guaiacol peroxidase (POx), were assessed, as well as of the detoxifying enzyme S-glutathione transferase (GST). Lipid peroxidation was evaluated by measuring the extent of oxidative damage; α-tocopherol content, the main lipophilic antioxidant, was also measured. Visible symptoms of leaf blade damage after sewage sludge application occurred only on the zucchini plants. The zucchini and cucumber plants showed a range of enzymatic antioxidant responses to sewage sludge application. While APx and POx activities increased significantly with increasing sludge concentration in the zucchini plants, they decreased in the cucumber plants. Moreover, although the activity of these enzymes increased gradually with increasing doses of sewage sludge, these levels fell at the highest dose. An inverse relationship between peroxidases activity and CAT activity was observed in both investigated plant species. In contrast, although GST activity increased progressively with sludge concentration in both the zucchini and cucumber leaves, the increase in GST activity was greater in the zucchini plants, being visible at the lowest dose used. The results indicate that signs of sewage sludge toxicity were greater in zucchini than cucumber, and its defense reactions were mainly associated with increases in APx, POx and GST activity.

  16. The Different Physiological and Antioxidative Responses of Zucchini and Cucumber to Sewage Sludge Application

    PubMed Central

    Wyrwicka, Anna; Urbaniak, Magdalena

    2016-01-01

    The present study investigates the effect of soil amended with sewage sludge on oxidative changes in zucchini and cucumber plants (Cucurbitaceae) and the consequent activation of their antioxidative systems and detoxification mechanisms. The plants were grown in pots containing soil amended with three concentrations of sewage sludge (1.8 g, 5.4 g and 10.8 g per pot), while controls were potted with vegetable soil. The activities of three antioxidative enzymes, ascorbate peroxidase (APx), catalase (CAT) and guaiacol peroxidase (POx), were assessed, as well as of the detoxifying enzyme S-glutathione transferase (GST). Lipid peroxidation was evaluated by measuring the extent of oxidative damage; α-tocopherol content, the main lipophilic antioxidant, was also measured. Visible symptoms of leaf blade damage after sewage sludge application occurred only on the zucchini plants. The zucchini and cucumber plants showed a range of enzymatic antioxidant responses to sewage sludge application. While APx and POx activities increased significantly with increasing sludge concentration in the zucchini plants, they decreased in the cucumber plants. Moreover, although the activity of these enzymes increased gradually with increasing doses of sewage sludge, these levels fell at the highest dose. An inverse relationship between peroxidases activity and CAT activity was observed in both investigated plant species. In contrast, although GST activity increased progressively with sludge concentration in both the zucchini and cucumber leaves, the increase in GST activity was greater in the zucchini plants, being visible at the lowest dose used. The results indicate that signs of sewage sludge toxicity were greater in zucchini than cucumber, and its defense reactions were mainly associated with increases in APx, POx and GST activity. PMID:27327659

  17. Ecotoxicity Assessment of Stabilized Sewage Sludge from Municipal Sewage Treatment Plant

    NASA Astrophysics Data System (ADS)

    Włodarczyk, Elżbieta; Próba, Marta; Wolny, Lidia

    2016-09-01

    Aim of this study was to evaluate the ecotoxicity of municipal sewage sludge conditioned with polyelectrolytes, taken from selected sewage treatment plant. Using the bioindication analysis overall toxicity was assessed, which allows to know the total toxicity of all the harmful substances contained in sewage sludge, in many cases acting synergistically. To prepare a sample of sludge for the basic test, all analyses were performed with a ratio of liquid to solid of 10:1 (water extract). Daphnia pulex biological screening test was used. A dilution series of an water extract of sludge were prepared to include within its scope the lowest concentration that causes 100% effect and the highest producing less than 10% of the effect within a specified range of the assay. The results of the test were read after 24 and 48 hours. Based on the research and analysis of test results it proved that the sewage sludge conditioned with polyelectrolytes exhibit the characteristics of eco-toxic.

  18. Novel technology for sewage sludge utilization: preparation of amino acids chelated trace elements (AACTE) fertilizer.

    PubMed

    Liu, Yangsheng; Kong, Sifang; Li, Yaqiong; Zeng, Hui

    2009-11-15

    This study developed a novel technology for sewage sludge utilization. The bacteria proteins in the sewage sludge were extracted to produce the amino acid chelated trace elements (AACTE) fertilizer by virtue of several chemical processes. Firstly, the sewage sludge was hydrolyzed under hot hydrochloric acid solution to obtain protein solution. The effects of hydrolysis temperature, reaction time and pH on the extraction ratio of protein from the sewage sludge were investigated. Secondly, the protein solution was further hydrolyzed into amino acids under hot acid condition. The effects of the HCl dosage, hydrolysis temperature and reaction time on the yields of amino acids were investigated in detail. Thirdly, the raw amino acids solution was purified by activated carbon decolorization and glacial acetic acid dissolution. Finally, the purified amino acids were used to produce the AACTE fertilizer by chelating with trace elements. Results showed that, under optimum hydrolysis conditions, 78.5% of protein was extracted from the sewage sludge and the amino acids yield was 10-13 g per 100g of dry sludge. The AACTE fertilizer produced was in accordance with China Standard for Amino Acids Foliar Fertilizer. This novel technology is more environmentally friendly compared with the conventional sludge treatments.

  19. Vitrification as an alternative to landfilling of tannery sewage sludge

    SciTech Connect

    Celary, Piotr Sobik-Szołtysek, Jolanta

    2014-12-15

    Highlights: • The possibility of vitrification of tannery sewage sludge was investigated. • Glass cullet was substituted with different wastes of mineral character. • Component ratio in the processed mixtures was optimized. • Environmental safety of the acquired vitrificates was verified. • An alternative management approach of usually landfilled waste was presented. - Abstract: Due to high content of heavy metals such as chromium, tannery sewage sludge is a material which is difficult to be biologically treated as it is in the case of organic waste. Consequently, a common practice in managing tannery sewage sludge is landfilling. This poses a potential threat to both soil and water environments and it additionally generates costs of construction of landfills that meet specific environment protection requirements. Vitrification of this kind of sewage sludge with the addition of mineral wastes can represent an alternative to landfilling. The aim of this study was to investigate the possibility of obtaining an environmentally safe product by means of vitrification of tannery sewage sludge from a flotation wastewater treatment process and chemical precipitation in order to address the upcoming issue of dealing with sewage sludge from the tannery industry which will be prohibited to be landfilled in Poland after 2016. The focus was set on determining mixtures of tannery sewage sludge with additives which would result in the lowest possible heavy metal leaching levels and highest hardness rating of the products obtained from their vitrification. The plasma vitrification process was carried out for mixtures with various amounts of additives depending on the type of sewage sludge used. Only the materials of waste character were used as additives. One finding of the study was an optimum content of mineral additives in vitrified mixture of 30% v/v waste molding sands with 20% v/v carbonate flotation waste from the zinc and lead industry for the formulations with

  20. Impact of sewage sludge applications on the biogeochemistry of soils.

    PubMed

    Devaney, D; Godley, A R; Hodson, M E; Purdy, K; Yamulki, S

    2008-01-01

    This report describes an investigation into the bioavailability and fate of trace metals and their subsequent impact on important soil microbiological functions such as nitrification, denitrification and methane oxidation in low and high Cu containing soils in the presence and absence of residual organic matter from sewage sludge additions made 10 years earlier. The soils being studied are part of long term sewage sludge trials and include a low Cu soil (13.3 mg Cu/kg soil, 4.18 LOI %), left un-amended to serve as a control soil, soil amended with a high Cu sewage sludge (278.3 mg Cu/kg soil, 6.52 LOI %) and soil amended with a low Cu sewage sludge (46.3 mg Cu/kg soil, 6.18 LOI %). Soil was also amended with inorganic metal salts (273.4 mg Cu/kg soil, 4.52 LOI %) to further investigate the impact of Cu in the absence of additional organic matter contained in applied sewage sludge. Data from the first two years of a project are presented which has included field-based studies at long term sewage sludge trials based in Watlington, Oxford, UK and laboratory based studies at the Institute of Grassland & Environmental Research, North Wyke, Devon, UK.

  1. ESBL-producing E. coli in Austrian sewage sludge.

    PubMed

    Reinthaler, Franz Ferdinand; Feierl, Gebhard; Galler, Herbert; Haas, Doris; Leitner, Eva; Mascher, Franz; Melkes, Angelika; Posch, Josefa; Winter, Ingrid; Zarfel, Gernot; Marth, Egon

    2010-03-01

    The aim of this study was to investigate the degree of contamination of sewage sludge with ESBL-producing Escherichia coli strains and the effectiveness of different sewage sludge treatment methods. Monthly sewage sludge samples were collected between January and September 2009 in 5 different sewage treatment plants and tested for the presence of ESBL E. coli. In addition, the number of colony forming units (CFU) of E. coli and coliform bacteria before and after the different sludge treatment methods (aerobic/anaerobic digestion, lime stabilization, and thermal treatment) was investigated. Of the 72 sewage sludge samples investigated, ESBL-positive E. coli were found in 44 (61.1%) sewage sludge samples. The classification of beta-lactamase groups was carried out in 15 strains resulting in the detection of 2 different groups (CTX-M and TEM) of bla genes. All 15 of them had a CTX-M gene and 4 of these strains furthermore carried a TEM gene. With regard to the CFU of E. coli and coliform bacteria, thermal treatment and lime stabilization following dehydration sufficiently reduced pathogen concentrations. The plants using merely stabilization and dehydration showed an increase of E. coli and coliform bacteria and thus also an increase in ESBL-producing E. coli.

  2. Co-digestion of pig slaughterhouse waste with sewage sludge.

    PubMed

    Borowski, Sebastian; Kubacki, Przemysław

    2015-06-01

    Slaughterhouse wastes (SHW) are potentially very attractive substrates for biogas production. However, mono-digestion of these wastes creates great technological problems associated with the inhibitory effects of ammonia and fatty acids on methanogens as well as with the foaming in the digesters. In the following study, the co-digestion of slaughterhouse wastes with sewage sludge (SS) was undertaken. Batch and semi-continuous experiments were performed at 35°C with municipal sewage sludge and pig SHW composed of meat tissue, intestines, bristles and post-flotation sludge. In batch assays, meat tissue and intestinal wastes gave the highest methane productions of 976 and 826 dm(3)/kg VS, respectively, whereas the methane yield from the sludge was only 370 dm(3)/kg VS. The co-digestion of sewage sludge with 50% SHW (weight basis) provided the methane yield exceeding 600 dm(3)/kg VS, which was more than twice as high as the methane production from sewage sludge alone. However, when the loading rate exceeded 4 kg VS/m(3) d, a slight inhibition of methanogenesis was observed, without affecting the digester stability. The experiments showed that the co-digestion of sewage sludge with large amount of slaughterhouse wastes is feasible, and the enhanced methane production does not affect the digester stability.

  3. Identification of metal toxicity in sewage sludge leachate.

    PubMed

    Fjällborg, B; Ahlberg, G; Nilsson, E; Dave, G

    2005-01-01

    Sewage sludge is a source of organic matter and nutrients with the potential for being used as a fertilizer. However, metals in sewage sludge might accumulate in soil after repeated sludge applications, and metal concentrations might reach concentrations that are toxic to microorganisms, soil organisms and/or plants. This toxicity might change with time due to kinetic factors or abiotic factors such as freezing, drying or rainfall. The objective of this study was to determine toxicity of sewage sludge leachate from a lysimeter with 50 cm of sludge applied. Attempts were also made to identify the cause of toxicity of the sludge leachate by toxicity identification and evaluation (TIE) techniques. Sludge leachate was collected monthly during 1 experimental year (August 2001 to August 2002). Metal concentrations were analysed, and the toxicity was determined with Daphnia magna (48-h immobility). The effect of EDTA or sodium thiosulphate addition, filtration through a CM-resin or a Millex-resin on toxicity was also tested. The results showed that toxicity of the sludge leachate apparently varied during the year, and that filtration through the CM-resin reduced most of the toxicity followed by the addition of EDTA. None of the other treatments reduced the toxicity of the sludge leachate. This indicated that one or more metals were responsible for the observed toxicity. Further calculations of toxic units (TU) suggested that Zn contributed most to the toxicity. Results also indicated that Ca concentrations in the sludge leachate reduced the toxicity of Zn.

  4. Removal of aqueous oxalic acid by heterogeneous catalytic ozonation with MnOx/sewage sludge-derived activated carbon as catalysts.

    PubMed

    Huang, Yuanxing; Sun, Yaru; Xu, Zhihua; Luo, Mengyu; Zhu, Chunlei; Li, Liang

    2017-01-01

    MnOx/sewage sludge-derived activated carbon (MnOx/SAC) was prepared as catalysts to improve the performance of aqueous oxalic acid degradation by ozonation. The results indicated that MnOx/SAC had excellent catalytic activity in mineralization of oxalic acid during heterogeneous catalytic ozonation process. MnOx/SAC with a manganese load of 30% exhibited the strongest catalytic activity under the condition of solution pH3.5, which enhanced the oxalic acid removal from 10.3% to 92.2% in 60min compared with that treated by ozone alone. Increase of catalyst dosage and aqueous ozone concentration was advantageous for oxalic acid removal from water. On the basis of catalyst characterization analysis and the observation of inhibitory effect induced by higher pH, less catalyst dosage as well as the presence of hydroxyl radical scavenger, it was deduced that the reaction mechanism involved both hydroxyl radicals attack and surface reactions.

  5. Nitrogen and Phosphorus Removal from Combined Sewage Components by Microbial Activity1

    PubMed Central

    Finstein, M. S.

    1966-01-01

    When primary domestic sewage sludge was combined with settled sewage or secondary-treatment plant effluent, synergism resulted. The activity (measured by oxygen uptake, and the removal of Kjeldahl nitrogen and orthophosphate from solution) which resulted from incubating sludge together with settled sewage exceeded the sum of the activities when these components were incubated separately. A similar synergistic effect occurred with sludge and effluent. The sewage sludges were deficient in readily available nitrogen, but no shortage of phosphorus was demonstrated. The addition of ammonium and orthophosphate salts to sludge, in concentrations equivalent to those found in settled sewage and effluent, stimulated sludge oxygen uptake at least 80% as much as settled sewage or effluent. It is suggested that the synergism reflects increased microbial activity resulting from widened carbon-nitrogen and carbon-phosphorus ratios achieved by combining sludge with nutrient-rich settled sewage or effluent. PMID:5927052

  6. [Bacteriological control of various methods of sewage sludge hygienization].

    PubMed

    Breer, C

    1983-09-01

    As a result of extensive parallel investigations in a water treatment plant it was found that the fresh sludge pasteurization or prepasteurization with ensuing sludge digestion gives a product which is unobjectionable from an epidemiological hygienic point of view. The result were confirmed by investigations in a second plant. Similarly satisfactory results were obtained with the composting of previously desiccated sludge, with the aerobic-thermophilic fermentation of liquid sludge or with the drying of sewage sludge. An alternative to these thermal processes is the application of gamma rays or accelerated electrons.

  7. F- and H-Area Sewage Sludge Application Sites groundwater monitoring report, fourth quarter 1991

    SciTech Connect

    Thompson, C.Y.

    1992-03-01

    Eleven sewage sludge application sites at the Savannah River Site (SRS) were originally the subject of a research program, begun in 1980, using domestic sewage sludge to reclaim borrow pits and to enhance forest productivity at SRS. Currently, the F- and H-Area Sewage Sludge Application Sites are the only remaining active sludge application sites. During fourth quarter 1991, samples from the four monitoring wells at the F-Area site (FSS series) and three monitoring wells at the H-Area site (HSS series) were analyzed for specific conductance, pH, and certain pesticides, herbicides, toxic metals, water quality indicators, and radionuclides. This report describes monitoring results that exceeded the US Environmental Protection Agency primary drinking water standards (PDWS) and the SRS flagging criteria.

  8. Spreading lagooned sewage sludge on farm land: A case history

    SciTech Connect

    Robson, C.M.; Sommers, L.E.

    1995-06-01

    This report describes the development of a project involving the application of approximately 265,000 cubic meters of lagooned sewage sludge from a metropolitan area on privately-owned farm land in an adjacent, rural county. The sludge application project was initiated to enable use of the land occupied by the lagoons for expansion of the sewage treatment plant. The procedures developed will be valuable to those proposing to practice land disposal of stabilized sludge as part of the Nation`s resource conservation program.

  9. Potentially toxic element release by fenton oxidation of sewage sludge.

    PubMed

    Andrews, J P; Asaadi, M; Clarke, B; Ouki, S

    2006-01-01

    The presence, in sewage sludge, of excess levels of the potentially toxic elements (PTE) copper, zinc, chromium, cadmium, nickel, lead and mercury, could impact on our ability to recycle these residues in the future. Far stricter limits on the levels of PTEs are likely in proposed legislation. A method involving the dosing of Fenton's reagent, a mixture of ferrous iron and hydrogen peroxide, under acidic conditions was evaluated for its potential to reduce metal levels. The [Fe]:[H2O2] (w/w) ratio was found to give a good indication of the percentage copper and zinc elution obtainable. Sites with no iron dosing as part of wastewater treatment required extra iron to be added in order to initiate the Fenton's reaction. A significant reduction, in excess of 70%, of the copper and zinc was eluted from both raw primary and activated sludge solid fractions. Cadmium and nickel could be reduced to below detection limits but elution of mercury, lead and chromium was less than 40%. The iron catalyst concentration was found to be a crucial parameter. This process has the potential to reduce the heavy metal content of the sludge and allow the recycling of sludge to continue in a sustainable manner.

  10. Strategic environmental assessment of alternative sewage sludge management scenarios.

    PubMed

    Poulsen, Tjalfe G; Hansen, Jens Aa

    2003-02-01

    Strategic environmental assessment (SEA) of sewage sludge management in a Danish municipality (Aalborg), with 160,000 inhabitants using alternative methods for aggregation of environmental impacts was performed. The purpose is to demonstrate the use of SEA in relation to sludge management and to improve SEA methodology. Six different scenarios for management of sewage sludge within the Aalborg municipality involving thermal treatment, composting and landfilling of sludge were evaluated. Environmental impact categories considered were global warming, non-renewable resources (nutrients and fossil fuels) and land use. Impact categories human health, ecotoxicity and soil quality were excluded as methodology for their assessment is not yet fully developed. Thermal sludge treatment with energy utilisation was shown to be a promising option for sewage sludge management in Aalborg. Sensitivity of the relative environmental impacts with respect to calculation methodology and input parameter values were evaluated to identify important parameters and calculation methods. The analysis showed that aggregation procedures, sludge biogas potential and sludge production were very important whereas sludge transport was not.

  11. 40 CFR Appendix A to Part 503 - Procedure To Determine the Annual Whole Sludge Application Rate for a Sewage Sludge

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Whole Sludge Application Rate for a Sewage Sludge A Appendix A to Part 503 Protection of Environment.... 503, App. A Appendix A to Part 503—Procedure To Determine the Annual Whole Sludge Application Rate for a Sewage Sludge Section 503.13(a)(4)(ii) requires that the product of the concentration for...

  12. Toxic effects of sewage sludges on freshwater edible fish Cirrhina mrigala

    SciTech Connect

    Pereira, L.; Coutinho, C.; Rao, C.V.

    1996-03-01

    Municipal sewage sludges have been advocated by several investigators as a suitable dietary supplement in aquaculture because of the protein contained in it. Other researchers discourage their usage for a variety of reasons, the most common being the presence of heavy metals and pesticides that accumulate in various organs, thereby hampering growth in fish. Settled sewage, if palatable however, would prove to be an excellent low-cost nutrient in intensive aquaculture farms. Sludges may be administered in the aqueous or dehydrated condition, and in either case would be suitable for even fry and fingerlings, if consumed soon after application because of the small particle size. The absence of reports on the effect of sewage sludges from the wastewater treatment plant on animals prompted this investigation, though heavy metal analysis revealed the presence of appreciable quantities of Zn, Cu, Pb and moderate amounts of Ni, Cr, Cd in aqueous activate-sludge. In this study the effect of activated sludge (AcS), raw sludge (RS) in acute and chronic bioassays and hydrated digested sludge (DS) and dehydrated (sun-dried) digested sludge (KS) in chronic feeding experiment on survival, behavior and whole body acetylcholinesterase (AchE) activity of Cirrhina mrigala, a freshwater edible fish, were investigated.

  13. CFD simulation of anaerobic digester with variable sewage sludge rheology.

    PubMed

    Craig, K J; Nieuwoudt, M N; Niemand, L J

    2013-09-01

    A computational fluid dynamics (CFD) model that evaluates mechanical mixing in a full-scale anaerobic digester was developed to investigate the influence of sewage sludge rheology on the steady-state digester performance. Mechanical mixing is provided through an impeller located in a draft tube. Use is made of the Multiple Reference Frame model to incorporate the rotating impeller. The non-Newtonian sludge is modeled using the Hershel-Bulkley law because of the yield stress present in the fluid. Water is also used as modeling fluid to illustrate the significant non-Newtonian effects of sewage sludge on mixing patterns. The variation of the sewage sludge rheology as a result of the digestion process is considered to determine its influence on both the required impeller torque and digester mixing patterns. It was found that when modeling the fluid with the Hershel-Bulkley law, the high slope of the sewage stress-strain curve at high shear rates causes significant viscous torque on the impeller surface. Although the overall fluid shear stress property is reduced during digestion, this slope is increased with sludge age, causing an increase in impeller torque for digested sludge due to the high strain rates caused by the pumping impeller. Consideration should be given to using the Bingham law to deal with high strain rates. The overall mixing flow patterns of the digested sludge do however improve slightly.

  14. Interactions of NO2 with sewage sludge based composite adsorbents.

    PubMed

    Pietrzak, Robert; Bandosz, Teresa J

    2008-06-15

    Interactions of NO2 present in most air were analyzed at room temperature on composite sewage sludge-derived adsorbents. They consist of carbonaceous and inorganic phases with the majority of the latter. The adsorption capacity was evaluated using the dynamic breakthrough experiments. The materials before and after NO2 exposure were characterized using adsorption of nitrogen, thermal analysis and FTIR. The results showed differences in the surface activities of sludge-derived materials towards immobilization and reduction of nitric dioxide. Nitrates and nitrite are the main products of surface reactions. This is linked to the presence of active oxides and hydroxides, which are formed when the surface is exposed to water. The highest activity of the sample pyrolyzed at 650 degrees C is owing to the high content of those species formed as a result of decomposition of inorganic salts (likely chlorides, sulfates and phosphates) during thermal treatment. When sludge is pyrolyzed at 950 degrees C those oxides are engaged in stable mineral phases formed in solid-state reactions, which limits the surface activity towards NO2 retention. The reactivity of the high temperature pyrolyzed samples can be linked to the physical adsorption of water. In a water film nitrous and nitric acid can be formed and they can further react with inorganic and carbonaceous phases to the limited extent.

  15. Utilizing waste activated sludge for animal feeding

    SciTech Connect

    Beszedits, S.

    1981-01-01

    Activated sludge has a high protein content and is a good source of B-group vitamins and generally also of minerals (Ca, Mg, Fe and K). Propionibacterium freudenreichii can be readily incorporated into the activated sludge to synthesize vitamin B12, particularly high vitamin yields being obtained with sewage mixed with dairy waste. Numerous examples of successful use of activated sludge in animal feeding are given.

  16. 40 CFR 60.4780 - What sewage sludge incineration units are exempt from this subpart?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... combustion units that incinerate sewage sludge and are not located at a wastewater treatment facility designed to treat domestic sewage sludge. These units may be subject to another subpart of this part...

  17. [Bioconversion of sewage sludge to biopesticide by Bacillus thuringiensis].

    PubMed

    Chang, Ming; Zhou, Shun-gui; Lu, Na; Ni, Jin-ren

    2006-07-01

    Feasibility of bioconversion of sewage sludge to biopesticide by Bacillus thuringiensis was studied using sewage sludge as a raw material. The fermentation was also compared with conventional medium. Results showed that without any pretreatment, the nutrients contained in sewage sludge were almost sufficient for Bacillus thuringiensis growth, even with a rapid multiplicational rate. Higher viable cells and viable spores values were obtained earlier at 24 h, with 9.48 x 10(8) CFU x mL(-1) and 8.51 x 10(8) CFU x mL(-1) respectively, which was 12 hours earlier and nearly 20 percent higher than conventional medium. SEM of 36 h samples gave a clear phenomenon that the metabolizability in sludge was much faster with spores and crystals spreading around. The crystals in sludge seemed rather bigger and more regular. Also a better crystal protein yield of 2.80 mg x mL(-1) was observed in sludge medium compared to conventional medium at the end of fermentation. Sludge fermentation for Bacillus thuringiensis reduces the producing cost, and gives better fermentation capabilities. It's expected to be a new method for sludge disposal.

  18. Recovery of indigenous enteroviruses from raw and digested sewage sludges.

    PubMed Central

    Goddard, M R; Bates, J; Butler, M

    1981-01-01

    We examined different types of raw sewage sludge treatment, including consolidation, anaerobic mesophilic digestion with subsequent consolidation, and aerobic-thermophilic digestion. Of these, the most efficient reduction in infectious virus titer was achieved by mesophilic digestion with subsequent consolidation, although a pilot-scale aerobic-thermophilic digester was extremely time effective, producing sludges with similarly low virus titers in a small fraction of the time. Although none of the treatments examined consistently produced a sludge with undetectable virus levels, mesophilic digestion alone was found to be particularly unreliable in reducing the levels of infectious virus present in the raw sludge. PMID:6274258

  19. Life cycle assessment of sewage sludge co-incineration in a coal-based power station.

    PubMed

    Hong, Jingmin; Xu, Changqing; Hong, Jinglan; Tan, Xianfeng; Chen, Wei

    2013-09-01

    A life cycle assessment was conducted to evaluate the environmental and economic effects of sewage sludge co-incineration in a coal-fired power plant. The general approach employed by a coal-fired power plant was also assessed as control. Sewage sludge co-incineration technology causes greater environmental burden than does coal-based energy production technology because of the additional electricity consumption and wastewater treatment required for the pretreatment of sewage sludge, direct emissions from sludge incineration, and incinerated ash disposal processes. However, sewage sludge co-incineration presents higher economic benefits because of electricity subsidies and the income generating potential of sludge. Environmental assessment results indicate that sewage sludge co-incineration is unsuitable for mitigating the increasing pressure brought on by sewage sludge pollution. Reducing the overall environmental effect of sludge co-incineration power stations necessitates increasing net coal consumption efficiency, incinerated ash reuse rate, dedust system efficiency, and sludge water content rate.

  20. Municipal sewage sludge as fertilizer. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    Not Available

    1994-12-01

    The bibliography contains citations concerning the use of sewage sludge as fertilizer. References study the effects of municipal sewage sludge on vegetation such as maize, beans, roadside plant life, and hardwood trees. Sewage sludge used as fertilizer to reclaim mined land is explored. Public attitudes are also considered. (Contains a minimum of 247 citations and includes a subject term index and title list.)

  1. Municipal sewage sludge as fertilizer. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    Not Available

    1993-08-01

    The bibliography contains citations concerning the use of sewage sludge as fertilizer. References study the effects of municipal sewage sludge on vegetation such as maize, beans, roadside plant life, and hardwood trees. Sewage sludge used as fertilizer to reclaim mined land is explored. Public attitudes are also considered. (Contains a minimum of 226 citations and includes a subject term index and title list.)

  2. Municipal sewage sludge as fertilizer. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    Not Available

    1994-01-01

    The bibliography contains citations concerning the use of sewage sludge as fertilizer. References study the effects of municipal sewage sludge on vegetation such as maize, beans, roadside plant life, and hardwood trees. Sewage sludge used as fertilizer to reclaim mined land is explored. Public attitudes are also considered. (Contains a minimum of 230 citations and includes a subject term index and title list.)

  3. Sewage sludge to landfill: some pertinent engineering properties.

    PubMed

    O'Kelly, Brendan C

    2005-06-01

    More stringent controls on the quality of wastewater discharges have given rise to increasing volumes of sewage sludge for disposal, principally to land, using either land-spreading or sludge-to-landfill operations. Current sludge-to-landfill methods generally involve mixing the concentrated sludge with other solid waste in municipal landfills. However, stricter waste disposal legislation and higher landfill taxes are forcing the water industry to look for more efficient disposal strategies. Landfill operators are also increasingly reluctant to accept sludge material in the slurry state because of construction difficulties and the potential for instability of the landfill slopes. The engineering and drying properties of a municipal sewage sludge are presented and applied, in particular, to the design, construction, and performance of sewage sludge monofills. Sludge handling and landfill construction are most effectively conducted within the water content range of 85% water content, the optimum water content for standard proctor compaction, and 95% water content, the sticky limit of the sludge material. Standard proctor compaction of the sludge within this water content range also achieves the maximum dry density of approximately 0.56 tonne/m3, which maximizes the storage capacity and, hence, the operational life of the landfill site. Undrained shear strength-water content data (pertinent to the stability of the landfill body during construction) and effective stress-strength parameters, which take into account the landfill age and the effects of ongoing sludge digestion, are presented. Landfill subsidence, which occurs principally because of creep and decomposition of the solid organic particles, is significant and continues indefinitely but at progressively slower rates.

  4. Improvement of anaerobic digestion of sewage sludge through microwave pre-treatment.

    PubMed

    Serrano, A; Siles, J A; Martín, M A; Chica, A F; Estévez-Pastor, F S; Toro-Baptista, E

    2016-07-15

    Sewage sludge generated in the activated sludge process is a polluting waste that must be treated adequately to avoid important environmental impacts. Traditional management methods, such as landfill disposal or incineration, are being ruled out due to the high content in heavy metal, pathogens, micropolluting compounds of the sewage sludge and the lack of use of resources. Anaerobic digestion could be an interesting treatment, but must be improved since the biomethanisation of sewage sludge entails low biodegradability and low methane production. A microwave pre-treatment at pilot scale is proposed to increase the organic matter solubilisation of sewage sludge and enhance the biomethanisation yield. The operational variables of microwave pre-treatment (power and specific energy applied) were optimised by analysing the physicochemical characteristics of sewage sludge (both total and soluble fraction) under different pre-treatment conditions. According to the variation in the sCOD and TN concentration, the optimal operation variables of the pre-treatment were fixed at 20,000 J/g TS and 700 W. A subsequent anaerobic digestion test was carried out with raw and pre-treated sewage sludge under different conditions (20,000 J/g TS and 700 W; 20,000 J/g TS and 400 W; and 30,000 J/g TS and 400 W). Although stability was maintained throughout the process, the enhancement in the total methane yield was not high (up to 17%). Nevertheless, very promising improvements were determined for the kinetics of the process, where the rG and the OLR increased by 43% and 39%, respectively, after carrying out a pre-treatment at 20,000 J/g TS and 700 W.

  5. Effects of lime amendment on availability of heavy metals and maturation in sewage sludge composting.

    PubMed

    Fang, M; Wong, J W

    1999-07-01

    A batch composting study was performed to evaluate the feasibility of co-composting sewage sludge with lime, aiming at reducing the availability of heavy metals in the sludge compost. Sewage sludge with sawdust as bulking agent was amended with lime at 0, 0.63, 1.0, and 1.63% w/w, and composted for 100 days in laboratory batch reactors. The changes in temperature, pH, electrical conductivity (EC), and extractable heavy metal contents were measured while compost maturity was determined by C/N(organic) and cress seed germination during the composting period. Liming raised pH of compost effectively at the initial stage of composting and caused a decrease in EC through precipitation of soluble ions. Lime amendment also significantly reduced water-soluble and Diethylene triamine pentracetic acid (DTPA)-extractable metal contents. The maximum reductions were 60 and 40% for Cu, 80 and 40% for Mn, 55 and 10% for Zn, and 20 and 25% for Ni at the end of the composting period for the lime-amended sludge as compared to the control. In spite of the inhibitory effect of lime amendment on the decomposition activity of sewage sludge, all treatments reached maturation after 63 days of composting as indicated by the results of C/N(organic) ratio and cress seed germination test results. A lime amendment of < or =1.0% is recommended to co-compost with sewage sludge.

  6. Submersible microbial fuel cell for electricity production from sewage sludge.

    PubMed

    Zhang, Yifeng; Olias, Lola Gonzalez; Kongjan, Prawit; Angelidaki, Irini

    2011-01-01

    A submersible microbial fuel cell (SMFC) was utilized to treat sewage sludge and simultaneously generate electricity. Stable power generation (145 +/- 5 mW/m2, 470 omega) was produced continuously from raw sewage sludge for 5.5 days. The maximum power density reached 190 +/- 5 mW/m2. The corresponding total chemical oxygen demand (TCOD) removal efficiency was 78.1 +/- 0.2% with initial TCOD of 49.7 g/L. The power generation of SMFC was depended on the sludge concentration, while dilution of the raw sludge resulted in higher power density. The maximum power density was saturated at sludge concentration of 17 g-TCOD/L, where 290 mw/m2 was achieved. When effluents from an anaerobic digester that was fed with raw sludge were used as substrate in the SMFC, a maximum power density of 318 mW/m2, and a final TCOD removal of 71.9 +/- 0.2% were achieved. These results have practical implications for development of an effective system to treat sewage sludge and simultaneously recover energy.

  7. Useful Ingredients Recovery from Sewage Sludge by using Hydrothermal Reaction

    NASA Astrophysics Data System (ADS)

    Suzuki, Koichi; Moriyama, Mika; Yamasaki, Yuki; Takahashi, Yui; Inoue, Chihiro

    2006-05-01

    Hydrothermal treatment of sludge from a sewage treatment plant was conducted to obtain useful ingredients for culture of specific microbes which can reduce polysulfide ion into sulfide ion and/or hydrogen sulfide. Several additives such as acid, base, and oxidizer were added to the hydrothermal reaction of excess sludge to promote the production of useful materials. After hydrothermal treatment, reaction solution and precipitation were qualitatively and quantitatively analyzed and estimated the availability as nutrition in cultural medium. From the results of product analysis, most of organic solid in sewage was basically decomposed by hydrothermal hydrolysis and transformed into oily or water-soluble compounds. Bacterial culture of sulfate-reducing bacteria (SRB) showed the good results in multiplication with medium which was obtained from hydrothermal treatment of sewage sludge with magnesium or calcium hydroxide and hydrogen peroxide.

  8. Impacts on groundwater due to land application of sewage sludge

    SciTech Connect

    Higgins, A.J.

    1984-06-01

    The project was designed to demonstrate the potential benefits of utilizing sewage sludge as a soil conditioner and fertilizer on Sassafras sandy loam soil. Aerobically digested, liquid sewage sludge was applied to the soil at rates of 0, 22.4, and 44.8 Mg of dry solids/ha for three consecutive years between 1978 and 1981. Groundwater, soil, and crop contamination levels were monitored to establish the maximum sewage solids loading rate that could be applied without causing environmental deterioration. The results indicate that application of 22.4 Mg of dry solids/ha of sludge is the upper limit to ensure protection of the groundwater quality on the site studied. Application rates at or slightly below 22.4 Mg of dry solids/ha are sufficient for providing plant nutrients for the dent corn and rye cropping system utilized in the study.

  9. Distribution of Cd, Ni, Cr and Pb in sewage sludge amended soils

    NASA Astrophysics Data System (ADS)

    Sanfeliu, Teófilo

    2010-05-01

    Restoration of degraded soils with organic wastes could be a feasible practice to minimise erosion in the Mediterranean area. Today the use of sewage sludge to improve the nutrient contents of a soil is a common practice. Contamination of soils by potentially toxic elements (e.g. Cd, Ni, Cr, Pb) from amendments of sewage sludge is subject to strict controls within the European Community in relation to total permissible metal concentrations, soil properties and intended use. This study is aimed at ascertaining the chemical partitioning of Cd, Ni, Cr and Pb in agricultural soils repeatedly amended with sludge. Five surface soils (0-15 cm) that were polluted as a result of agricultural activities were used in this experiment. The sewage sludge amended soils were selected for diversity of physicochemical properties, especially pH and carbonate content. The soils are classified as non-calcareous and calcareous soils. The distribution of chemical forms of Cd, Ni, Cr and Pb in five sewage sludge amended soils was studied using a sequential extraction procedure that fractionates the metal into soluble-exchangeable, specifically sorbed-carbonate bound, oxidizable, reducible and residual forms. With regard to the mineralogical composition of the soil clay fraction, the mineralogical association found was: illite, kaolinite and chlorite. This paper provides quantitative evidence regarding the form of the association of metals and indirectly of their bioavailability. It can help to explain the process by which metals are eliminated from sewage sludge and also indicate the impact of the use of sludge on agricultural soils, as amendments. Data obtained showed different metal distribution trend among the fractions in sludge-amended soils. Comparison of distribution pattern of metals in sludge-applied soils shows that there is possible redistribution of metals among the different phases. Detailed knowledge of the soil at the application site, especially pH, CEC, buffering capacity

  10. Evaluation of forest trees growth after sewage sludge application

    NASA Astrophysics Data System (ADS)

    Vaitkutä--, Dovilé; Balträ--Naitä--, Edita; Booth, Colin A.; Fullen, Michael A.; Pereira, Paulo

    2010-05-01

    Sewage sludge is extensively used in forest to improve soil properties. It is expected that sewage sludge rich in phosphorus, nitrogen and organic material enhance the germination of tree seedlings in poor soils. In Lithuania, the deforested soils are highly acid, and have a lack of nutrients, especially in exploited peat areas. Sewage sludge from industry contains beneficial components for the soils (such as organic matter, phosphorus, nitrogen, calcium, magnesium, etc.). However, it is also rich in heavy metals, especially Cd, Pb, Cu and Zn. High heavy metals concentrations in soil can be phytotoxic and cause reduced plant growth or plant death. The main objectives of this research was to determine the influence of industrial sewage sludge in the forestry and to highlight the idea that industrial sewage sludge containing metals does not favour development of birch and pine trees. The study was performed in Taruskos experimental plot in Panevezys region (Lithuania), amended with industrial sewage sludge ten years ago was afforestated with birch and pine seedlings. In order to observe the effects of the amendment in accumulation the mentioned metals and tree growth we collected data from trees in amended plot and control plot. The results showed that soil parameters were improved in the amended plot, in comparing with control site (higher pH, organic matter and cation exchange capacity). However, the growth of investigated trees was slower (e.g. birch roots, shoot, stem and leaves biomass was 40, 7.4, 18.6, 22% smaller than in control site. In pine case: 30, 1.2, 17, 36%, respectively; the stem height of birch was 16% and pine - 12% smaller than in control site). This reduced growth can be related with heavy metals concentration load on soil and accumulation in trees. Cu and Cd concentrations were higher in soil amended with sewage sludge comparing with control site (60 and 36%, respectively). Also, in contaminated trees Cu and Cd concentrations were higher (Cu

  11. Safety use of sewage sludge as soil conditioner.

    PubMed

    El-Naim, M A; El-Housseini, M; Naeem, M H

    2004-01-01

    A series of field and laboratory experiments were conducted during 1994-996 to study the seasonal changes in sewage sludge characteristics and to evaluate the effect of sludge treatment processes and their application to sandy soil on soil-plant heavy metal contents and the numbers of some pathogenic microorganisms in both treated sludge and sludge provided soils. Results of seasonal production of sludge showed wide variation in their chemical and microbiological characteristics. Lime application resulted in an increase in the pH values and temperature degrees. The maximal values of temperature and pH were obtained when sludge treated with 20% lime. No big difference was observed between the sludge treatments received lime at rates of 10, 15, and 20% lime. The 10% limed-sludge treatment was the best for reducing concentrations of heavy metals and numbers of bacterial pathogens in sludge. Stoping addition of sludge to soil for one cropping season after continuous sludge addition for four seasons sharply decreased the soil heavy metal contents and subsequently decreased their accumulation in the edible parts of plants.

  12. Utilization of night-soil, sewage, and sewage sludge in agriculture.

    PubMed

    PETRIK, M

    1954-01-01

    The author reviews the agricultural use of night-soil, sewage, and sewage sludge from two points of view: the purely agricultural and the sanitary.Knowledge of the chemistry and bacteriology of human faecal matter is still rather scant, and much further work has to be done to find practical ways of digesting night-soil in a short time into an end-product of high fertilizing value and free of pathogens, parasites, and weeds.More is known about sewage and sewage sludge, but expert opinion is not unanimous as to the manner or the value of their use in agriculture. The author reviews a number of studies and experiments made in many countries of the world on the content, digestion, composting, agricultural value, and epidemiological importance of sewage and sewage sludge, but draws from these the conclusion that the chemistry, biology, and bacteriology of the various methods of treatment and use of waste matter need further investigation. He also considers that standards of quality might be set up for sludge and effluents used in agriculture and for water conservation.

  13. Utilization of night-soil, sewage, and sewage sludge in agriculture

    PubMed Central

    Petrik, Milivoj

    1954-01-01

    The author reviews the agricultural use of night-soil, sewage, and sewage sludge from two points of view: the purely agricultural and the sanitary. Knowledge of the chemistry and bacteriology of human faecal matter is still rather scant, and much further work has to be done to find practical ways of digesting night-soil in a short time into an end-product of high fertilizing value and free of pathogens, parasites, and weeds. More is known about sewage and sewage sludge, but expert opinion is not unanimous as to the manner or the value of their use in agriculture. The author reviews a number of studies and experiments made in many countries of the world on the content, digestion, composting, agricultural value, and epidemiological importance of sewage and sewage sludge, but draws from these the conclusion that the chemistry, biology, and bacteriology of the various methods of treatment and use of waste matter need further investigation. He also considers that standards of quality might be set up for sludge and effluents used in agriculture and for water conservation. PMID:13160760

  14. Evaluation of Emission of Greenhouse Gases from Soils Amended with Sewage Sludge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increase in concentrations of various greenhouse gases originated by various human activities, including agricultural origin, could contribute to climate change. Anthropogenic activities such as cultivation of flooded rice and application of waste materials, such as sewage sludge which are rich in ...

  15. Relationship between photosynthetic capacity, nitrogen assimilation and nodule metabolism in alfalfa (Medicago sativa) grown with sewage sludge.

    PubMed

    Antolín, M Carmen; Fiasconaro, M Laura; Sánchez-Díaz, Manuel

    2010-10-15

    Sewage sludge has been used as N fertilizer because it contains some of inorganic N, principally as nitrate and ammonium ions. However, sewage sludge addition to legumes could result in impaired nodule metabolism due to the presence of inorganic N from sludge. A greenhouse experiment was conducted to examine the effects of sewage sludge on growth, photosynthesis, nitrogen assimilation and nodule metabolism in alfalfa (Medicago sativa L. cv. Aragón). Plants were grown in pots with a mixture of perlite and vermiculite (2:1, v/v). The experiment included three treatments: (1) plants inoculated with rhizobia and amended with sewage sludge at rate of 10% (w/w) (RS); (2) plants inoculated with rhizobia without any amendment (R); and (3) non-inoculated plants fed with ammonium nitrate (N). N(2)-fixing plants had lower growth and sucrose phosphate synthase activity but higher photosynthesis than nitrate-fed plants because they compensated the carbon cost of the rhizobia. However, sewage sludge-treated plants evidenced a loss of carbon sink strength due to N(2) fixation by means of decreased photosynthetic capacity, leaf chlorophylls and N concentration in comparison to untreated plants. Sewage sludge did no affect nodulation but decreased nodule enzyme activities involved in carbon and N metabolisms that may lead to accumulation of toxic N-compounds.

  16. [Experimental study on stabilization of sewage sludge by MOC].

    PubMed

    Ma, Jian-Li; Zhao, You-Cai; Niu, Dong-Jie; Chai, Xiao-Li

    2009-03-15

    Magnesium oxychloride cement (MOC) was used for the stability agent in the stabilization experiments of sewage sludge. It is found that MgCl2 in MOC is a kind of water-absorbent, water absorption of MgCl2 can be achieved at 1.55 mL/g (per 100 g sludge). Meanwhile, some water in sludge can be combined with MOC in the hydration reaction and sludge moisture content can be reduced efficaciously. The crystal structure of 3 phase and 5 phase, which occurred in the hydration process, makes the sludge compressive strength as high as 85.14 kg/cm2. The best ratio of MOC/sludge is 3/100, and MgO/MgCl2 is 3/1. Mg-Si-Al gel system is formed with Si2+, Al3+, Cu2+ in the sludge under alkaline condition, and it plays an important role in the stabilization of the heavy metals in sludge. Leaching experiments of sludge show that heavy metal concentrations of Cu, Zn, Cd, Cr, As in lixivium from sludge are lower than leachability standard.

  17. Biochar amendment for integrated composting and vermicomposting of sewage sludge - The effect of biochar on the activity of Eisenia fetida and the obtained vermicompost.

    PubMed

    Malińska, Krystyna; Golańska, Małgorzata; Caceres, Rafaela; Rorat, Agnieszka; Weisser, Patryk; Ślęzak, Ewelina

    2017-02-01

    Sewage sludge derived biochar (SSDB) was used as a supplementary material for municipal sewage sludge (SS) and wood chips mixtures (WC) treated by combined composting and vermicomposting. SSDB added to the mixture before composting resulted in significantly higher reproduction rate: on week 4 the number of cocoons increased by 213% when compared to the mixture with no biochar. On week 6 the average number of juveniles increased 11-fold in the mixture with biochar added before composting and 5-fold in the mixtures with biochar added after composting when compared to the mixture with no biochar. Biochar added before composting reduced bioavailability of Cd and Zn to E. fetida. The biochar-added vermicomposts showed good fertilizing properties except for elevated concentrations of Cr. The pH of all vermicomposts was in the range of 5.27-5.61. The obtained vermicomposts can be used as a growing medium for horticultural purposes or as an amendment in calcareous soils.

  18. PATHOGEN RISKS FROM APPLYING SEWAGE SLUDGE TO LAND

    EPA Science Inventory

    Congress banned ocean dumping of municipal wastes in the late 1980s. In its place, EPA developed guidance (40 CFR Part 503) for land application of processed sewage sludge (biosolids), mainly for agricultural purposes (1). Public health and environmental concerns with processed...

  19. Investigation of sewage sludge treatment using air plasma assisted gasification.

    PubMed

    Striūgas, Nerijus; Valinčius, Vitas; Pedišius, Nerijus; Poškas, Robertas; Zakarauskas, Kęstutis

    2017-03-18

    This study presents an experimental investigation of downdraft gasification process coupled with a secondary thermal plasma reactor in order to perform experimental investigations of sewage sludge gasification, and compare process parameters running the system with and without the secondary thermal plasma reactor. The experimental investigation were performed with non-pelletized mixture of dried sewage sludge and wood pellets. To estimate the process performance, the composition of the producer gas, tars, particle matter, producer gas and char yield were measured at the exit of the gasification and plasma reactor. The research revealed the distribution of selected metals and chlorine in the process products and examined a possible formation of hexachlorobenzene. It determined that the plasma assisted processing of gaseous products changes the composition of the tars and the producer gas, mostly by destruction of hydrocarbon species, such as methane, acetylene, ethane or propane. Plasma processing of the producer gas reduces their calorific value but increases the gas yield and the total produced energy amount. The presented technology demonstrated capability both for applying to reduce the accumulation of the sewage sludge and production of substitute gas for drying of sewage sludge and electrical power.

  20. Gaseous fuels production from dried sewage sludge via air gasification.

    PubMed

    Werle, Sebastian; Dudziak, Mariusz

    2014-07-01

    Gasification is a perspective alternative method of dried sewage sludge thermal treatment. For the purpose of experimental investigations, a laboratory fixed-bed gasifier installation was designed and built. Two sewage sludge (SS) feedstocks, taken from two typical Polish wastewater treatment systems, were analysed: SS1, from a mechanical-biological wastewater treatment system with anaerobic stabilization (fermentation) and high temperature drying; and (SS2) from a mechanical-biological-chemical wastewater treatment system with fermentation and low temperature drying. The gasification results show that greater oxygen content in sewage sludge has a strong influence on the properties of the produced gas. Increasing the air flow caused a decrease in the heating value of the produced gas. Higher hydrogen content in the sewage sludge (from SS1) affected the produced gas composition, which was characterized by high concentrations of combustible components. In the case of the SS1 gasification, ash, charcoal, and tar were produced as byproducts. In the case of SS2 gasification, only ash and tar were produced. SS1 and solid byproducts from its gasification (ash and charcoal) were characterized by lower toxicity in comparison to SS2. However, in all analysed cases, tar samples were toxic.

  1. Effect of seeding during thermophilic composting of sewage sludge

    SciTech Connect

    Nakasaki, K.; Sasaki, M.; Shoda, M.; Kubota, H.

    1985-03-01

    The effect of seeding on the thermophilic composting of sewage sludge was examined by measuring the changes in CO/sub 2/ evolution rates and microbial numbers. Although the succession of thermophilic bacteria and thermophilic actinomycetes clearly reflected the effect of seeding, no clear difference was observed in the overall rate of composting or quality of the composted product. 7 references.

  2. FACTORS AFFECTING DISINFECTION AND STABILIZATION OF SEWAGE SLUDGE

    EPA Science Inventory

    Effective disinfection and stabilization of sewage sludge prior to land application is essential to not only protect human health, but also to convince the public of its benefits and safety. A basic understanding of the key factors involved in producing a stable biosolid product ...

  3. Digested sewage sludge solidification by converter slag for landfill cover.

    PubMed

    Kim, Eung-Ho; Cho, Jin-Kyu; Yim, Soobin

    2005-04-01

    A new technology for solidification of digested sewage sludge referred to as converter slag solidification (CSS) has been developed using converter slag as the solidifying agent and quick lime as the solidifying aid. The CSS technology was investigated by analyzing the physicochemical properties of solidified sludge and determining its microstructural characteristics. The feasibility of using solidified sludge as a landfill cover material was considered in the context of the economical recycling of waste. Sludge solidified using the CSS technology exhibited geotechnical properties that are appropriate for replacing currently used cover soil. Microscopic analyses using XRD, SEM and EDS revealed that the main hydrated product of solidification was CSH (CaO . SiO2 . nH2O), which may play an important role in the effective setting process. Negligible leaching of heavy metals from the solidified sludge was observed. The solidification process of the hydrated sludge, slag and quicklime eliminated the coliform bacteria. Recycled sewage sludge solidified using CCS technology could be used as an effective landfill cover.

  4. Evaluation of nitrogen availability in irradiated sewage sludge, sludge compost and manure compost

    SciTech Connect

    Wen, Guang; Bates, T.E.; Voroney, R.P.

    1995-05-01

    A field experiment was conducted during 2 yr to determine plant availability of organic N from organic wastes, and effects of gamma irradiation on organic N availability in sewage sludge. The wastes investigated were: digested, dewatered sewage sludge (DSS), irradiated sewage sludge (DISS), irradiated, composted sewage sludge (DICSS), and composted livestock manure (CLM). The annual application rates were: 10, 20, 30, and 40 Mg solids ha{sup {minus}1}. Fertilizer N was added to the control, to which no waste was applied, as well as to the waste applications to ensure approximately equal amounts of available N (110 kg N ha{sup {minus}1}) for all treatments. Lettuce, petunias, and beans were grown in 1990 and two cuts of lettuce were harvested in 1991. Crop yields and plant N concentrations were measured. Assuming that crop N harvested/available N applied would be approximately equal for the control and the waste treatments, the N from organic fraction of the wastes, which is as available as that in fertilizer, was estimated. With petunia in 1990 and the combination of first and second cut of lettuce in 1991, the percentage ranged from 11.2 to 29.7 in nonirradiated sludge, 10.1 to 14.0 in irradiated sludge, 10.5 to 32.1 in sludge compost and 10.0 to 19.7 in manure compost. Most often, the highest values were obtained with the lowest application rates. Yields of petunia and N concentrations in second cut lettuce in 1991 were lower with irradiated sludge than with nonirradiated sludge suggest that the availability of organic N in digested sludge may have been reduced after irradiation. Irradiation of sludge appears to have released NH{sub 4}{sup +}-N. The availability of organic N, however, appears to have been reduced by irradiation by greater amount than the increase in NH{sub 4}{sup +}-N. 41 refs., 2 figs., 6 tabs.

  5. Toluene in sewage and sludge in wastewater treatment plants.

    PubMed

    Mrowiec, Bozena

    2014-01-01

    Toluene is a compound that often occurs in municipal wastewater ranging from detectable levels up to 237 μg/L. Before the year 2000, the presence of the aromatic hydrocarbons was assigned only to external sources. The Enhanced Biological Nutrients Removal Processes (EBNRP) work according to many different schemes and technologies. For high-efficiency biological denitrification and dephosphatation processes, the presence of volatile fatty acids (VFAs) in sewage is required. VFAs are the main product of organic matter hydrolysis from sewage sludge. However, no attention has been given to other products of the process. It has been found that in parallel to VFA production, toluene formation occurred. The formation of toluene in municipal anaerobic sludge digestion processes was investigated. Experiments were performed on a laboratory scale using sludge from primary and secondary settling tanks of municipal treatment plants. The concentration of toluene in the digested sludge from primary settling tanks was found to be about 42,000 μg/L. The digested sludge supernatant liquor returned to the biological dephosphatation and denitrification processes for sewage enrichment can contain up to 16,500 μg/L of toluene.

  6. Byproducts Utilization Program: Sewage Sludge Irradiation Project. Progress report, July-December 1983

    SciTech Connect

    Not Available

    1984-12-01

    Engineering support for a demonstration-scale irradiator design included assisting the City of Albuquerque in preparing a comprehensive site plan for their proposed sludge handling and treatment facilities. The solar sludge dryer has been delivered to SNLA. A preliminary sludge drying experiment indicated the importance of optimizing stirring and air flow. Installation of instrumentation and mechanical equipment continued. The Sandia Irradiator for Dried Sewage Solids (SIDSS) was used to irradiate 23 tons of dried, digested sewage sludge for the New Mexico State University (NMSU) Department of Crop and Soil Sciences. Gamma Irradiation Facility (GIF) operations included irradiation of ground pork for Toxoplasma gondii inactivation experiments, irradiation of surgical supplies and soil samples. Beneficial Uses Shipping Systems (BUSS) cask activities included near completion of the two full-scale cask bodies. Work continued on the Cask Safety Analysis Report (SAR) including additional analyses to reconfigure the six strontium fluoride capsules and/or reduce the number of capsules accommodated. NMSU has indicated no regrowth of salmonellae occurred in the irradiated sludge stockpile, while salmonellae did regrow in the unirradiated stockpile. Analyses of raw and digested sewage sludge from the Albuquerque Waste Water Treatment Plant showed levels of Yersinia enterocolitica (a human pathogen of emerging significance) to be below detection limits.

  7. Co-pyrolysis of sewage sludge and manure.

    PubMed

    Ruiz-Gómez, Nadia; Quispe, Violeta; Ábrego, Javier; Atienza-Martínez, María; Murillo, María Benita; Gea, Gloria

    2017-01-01

    The management and valorization of residual organic matter, such as sewage sludge and manure, is gaining interest because of the increasing volume of these residues, their localized generation and the related problems. The anaerobic digestion of mixtures of sewage sludge and manure could be performed due to the similarities between both residues. The purpose of this study is to evaluate the feasibility of the co-pyrolysis of sewage sludge (SS) and digested manure (DM) as a potential management technology for these residues. Pyrolysis of a sewage sludge/manure blend (50:50%) was performed at 525°C in a stirred batch reactor under N2 atmosphere. The product yields and some characteristics of the product were analyzed and compared to the results obtained in the pyrolysis of pure residues. Potential synergetic and antagonist effects during the co-pyrolysis process were evaluated. Although sewage sludge and manure seem similar in nature, there are differences in their pyrolysis product properties and distribution due to their distinct ash and organic matter composition. For the co-pyrolysis of SS and DM, the product yields did not show noticeable synergistic effects with the exception of the yields of organic compounds, being slightly higher than the predicted average, and the H2 yield, being lower than expected. Co-pyrolysis of SS and DM could be a feasible management alternative for these residues in locations where both residues are generated, since the benefits and the drawbacks of the co-pyrolysis are similar to those of the pyrolysis of each residue.

  8. Changes in microbial dynamics during vermicomposting of fresh and composted sewage sludge.

    PubMed

    Villar, Iria; Alves, David; Pérez-Díaz, Domingo; Mato, Salustiano

    2016-02-01

    Municipal sewage sludge is a waste with high organic load generated in large quantities that can be treated by biodegradation techniques to reduce its risk to the environment. This research studies vermicomposting and vermicomposting after composting of sewage sludge with the earthworm specie Eisenia andrei. In order to determine the effect that earthworms cause on the microbial dynamics depending on the treatment, the structure and activity of the microbial community was assessed using phospholipid fatty acid analysis and enzyme activities, during 112days of vermicomposting of fresh and composted sewage sludge, with and without earthworms. The presence of earthworms significantly reduced microbial biomass and all microbial groups (Gram+ bacteria, Gram- bacteria and fungi), as well as cellulase and alkaline phosphatase activities. Combined composting-vermicomposting treatment showed a lesser development of earthworms, higher bacterial and fungal biomass than vermicomposting treatment and greater differences, compared with the control without earthworms, in cellulase, β-glucosidase, alkaline and acid phosphatase. Both treatments were suitable for the stabilization of municipal sewage sludge and the combined composting-vermicomposting treatment can be a viable process for maturation of fresh compost.

  9. Polybrominated diphenyl ethers and polybrominated biphenyls in Australian sewage sludge.

    PubMed

    Clarke, Bradley; Porter, Nichola; Symons, Robert; Marriott, Philip; Ades, Peter; Stevenson, Gavin; Blackbeard, Judy

    2008-10-01

    This paper presents a brief review of the international scientific literature of polybrominated diphenyl ethers (PBDEs) and polybrominated biphenyls (PBBs) in sewage sludge and a survey of these compounds in sewage sludge from 16 Australian wastewater treatment plants (WWTPs). The SigmaPBDE mean concentration in the Australian study was 1137microgkg(-1) dry weight (d.w.) (s.d. 1116) and ranged between 5 and 4 230microgkg(-1)d.w. The urban mean of 1308microgkg(-1) (s.d. 1320) and the rural mean of 911microgkg(-1) (s.d. 831) are not statistically different and are similar to levels in European sludges. Principal components analysis was performed on the data set and revealed that 76% of the data variation could be explained by two components that corresponded to overall concentration of the pentaBDE and the decaBDE commercial formulations. An analysis of variance was performed comparing PBDEs levels at three WWTPs over the years 2005 and 2006, finding differences between treatment plants (BDE-47) but no significant difference in PBDE levels in the years 2005 and 2006. Low levels of BB-153 were detected in all samples of this survey (n=16); mean 0.6microgkg(-1)d.w. (s.d. 0.5). This compound has rarely been reported in any other study of sewage sludges undertaken outside Australia. This work highlights the need for a risk assessment of PBDEs in sewage sludge when used for land application, taking into account typical levels found in Australian sludges and soils.

  10. Impact of Mid-Atlantic sewage sludge probed

    NASA Astrophysics Data System (ADS)

    Blue, Charles

    1992-01-01

    Every year since 1986, 8 million tons of raw sewage has been dumped into the ocean at the Mid-Atlantic Bight, an area 100 miles off the coast of New York and New Jersey. Originally, this location was thought to be a safe dump site because of its considerable depth and strong ocean currents, which would prevent sewage from accumulating on the ocean floor. Recently, several scientists tested that assumption and found evidence for significant amounts of sewage accumulation at the dump site.Scientific studies of the dump site, coordinated by NOAA's National Undersea Research Program, will be presented at the 1992 AGU Ocean Science Meeting in New Orleans, January 27-31. The studies reveal the extent of sewage sludge accumulation at the Mid-Atlantic Bight and determine the environmental impact that significant accumulations of this material has on the ocean environment.

  11. PROCESS DESIGN MANUAL: LAND APPLICATION OF SEWAGE SLUDGE AND DOMESTIC SEPTAGE

    EPA Science Inventory

    Land application of sewage sludge generated by domestic sewage treatment is performed in an environmentally safe and cost–effective manner in many communities. Land application involves taking advantage of the fertilizing and soil conditioning properties of sewage sludge by sp...

  12. Isotherm equilibria of Mn²⁺ biosorption in drinking water treatment by locally isolated Bacillus species and sewage activated sludge.

    PubMed

    Hasan, Hassimi Abu; Abdullah, Siti Rozaimah Sheikh; Kofli, Noorhisham Tan; Kamarudin, Siti Kartom

    2012-11-30

    Manganese (Mn(2+)) is one of the inorganic contaminant that causes problem to water treatment and water distribution due to the accumulation on water piping systems. In this study, Bacillus sp. and sewage activated sludge (SAS) were investigated as biosorbents in laboratory-scale experiments. The study showed that Bacillus sp. was a more effective biosorbent than SAS. The experimental data were fitted to the Langmuir (Langmuir-1 & Langmuir-2), Freundlich, Temkin, Dubinin-Radushkevich (D-R) and Redlich-Peterson (R-P) isotherms to obtain the characteristic parameters of each model. Mn(2+) biosorption by Bacillus sp. was found to be significantly better fitted to the Langmuir-1 isotherm than the other isotherms, while the D-R isotherm was the best fit for SAS; i.e., the χ(2) value was smaller than that for the Freundlich, Temkin, and R-P isotherms. According to the evaluation using the Langmuir-1 isotherm, the maximum biosorption capacities of Mn(2+) onto Bacillus sp. and SAS were 43.5 mg Mn(2+)/g biomass and 12.7 mg Mn(2+)/g biomass, respectively. The data fitted using the D-R isotherm showed that the Mn(2+) biosorption processes by both Bacillus sp. and SAS occurred via the chemical ion-exchange mechanism between the functional groups and Mn(2+) ion.

  13. Eliminating methanogenic activity in hydrogen reactor to improve biogas production in a two-stage anaerobic digestion process co-digesting municipal food waste and sewage sludge.

    PubMed

    Zhu, Heguang; Parker, Wayne; Conidi, Daniela; Basnar, Robert; Seto, Peter

    2011-07-01

    Laboratory scale two-stage anaerobic digestion process model was operated for 280 days to investigate the feasibility to produce both hydrogen and methane from a mixture feedstock (1:1 (v/v)) of municipal food waste and sewage sludge. The maximum hydrogen and methane yields obtained in the two stages were 0.93 and 9.5 mL/mL feedstock. To eliminate methanogenic activity and obtain substantial hydrogen production in the hydrogen reactor, both feedstock and mixed liquor required treatment. The heat treatment (100°C, 10 min) for feedstock and a periodical treatment (every 2-5 weeks, either heating, removal of biomass particles or flushing with air) for mixed liquor were effective in different extent. The methane production in the second stage was significantly improved by the hydrogen production in the first stage. The maximum methane production obtained in the period of high hydrogen production was more than 2-fold of that observed in the low hydrogen production period.

  14. Concentrations and specific loads of UV filters in sewage sludge originating from a monitoring network in Switzerland.

    PubMed

    Plagellat, Cécile; Kupper, Thomas; Furrer, Reinhard; de Alencastro, Luiz Felippe; Grandjean, Dominique; Tarradellas, Joseph

    2006-02-01

    Many substances related to human activities end up in wastewater and accumulate in sewage sludge. The present study focuses on the analysis of widely used UV filters 3-(4-methylbenzylidene) camphor (4-MBC), octyl-methoxycinnamate (OMC), octocrylene (OC) and octyl-triazone (OT) in sewage sludge originating from a monitoring network in Switzerland. Mean concentrations in stabilised sludge from 14 wastewater treatment plants were 1780, 110, 4840 and 5510 microg/kg dry matter for 4-MBC, OMC, OC and OT, respectively. Specific loads in sewage sludge show that UV filters originate mainly from private households, but surface runoff and industries may be considered as additional sources. This indicates that besides use for sunscreens and cosmetics UV filters might occur in plastics and other materials and be released to the environment by volatilization or leaching. Differences between the modeled per capita loads of UV filters in sewage sludge and the observed specific loads in sewage sludge are probably due to erroneous figures of production volumes, degradation and sorption during wastewater treatment as well as degradation processes during transport in the sewer or sludge treatment. Thus, further research is needed to elucidate the fate of UV filters after application and release into the environment. Other compounds used as UV filters should be included in future studies.

  15. Advanced sewage treatment process with excess sludge reduction and phosphorus recovery.

    PubMed

    Saktaywin, W; Tsuno, H; Nagare, H; Soyama, T; Weerapakkaroon, J

    2005-03-01

    An advanced sewage treatment process has been developed, in which excess sludge reduction by ozonation and phosphorus recovery by crystallization process are incorporated to a conventional anaerobic/oxic (A/O) phosphorus removal process. The mathematical model was developed to describe the mass balance principal at a steady state of this process. Sludge ozonation experiments were carried out to investigate solubilization characteristics of sludge and change in microbial activity by using sludge cultured with feed of synthetic sewage under A/O process. Phosphorus was solubilized by ozonation as well as organics, and acid-hydrolyzable phosphorus (AHP) was the most part of solubilized phosphorus for phosphorus accumulating organisms (PAOs) containing sludge. At solubilization of 30%, around 70% of sludge was inactivated by ozonation. The results based on these studies indicated that the proposed process configuration has potential to reduce the excess sludge production as well as to recover phosphorus in usable forms. The system performance results show that this system is practical, in which 30% of solubilization degree was achieved by ozonation. In this study, 30% of solubilization was achieved at 30 mgO(3)/gSS of ozone consumption.

  16. Simultaneous determination of 4-nonylphenol and bisphenol A in sewage sludge.

    PubMed

    Meesters, Roland J W; Schröder, Horst Fr

    2002-07-15

    An analytical method has been developed for simultaneous extraction and determination of two estrogenic active agents, 4-nonylphenol (4-NP) and bisphenol A (BPA), in activated sewage sludge and anaerobically stabilized sewage sludge. Both compounds were determined by GC/MS in freeze-dried sewage sludge samples that had been spiked with these compounds in order to indicate different contamination levels. Extractive steam distillation, Soxhlet extraction, supercritical fluid extraction (SFE), and accelerated solvent extraction (ASE) were applied, and the results were compared. ASE under use of ethyl acetate/formic acid and an extraction temperature of 170 degrees C provided the most efficient extraction procedure for simultaneous extraction and the only reliable extraction results. Analyses of the phenolic compounds were performed by capillary column gas chromatography/mass spectrometry (GC/MS), operating in selected ion monitoring (SIM) mode after an aluminum oxide column-cleanup step prior to acetylation. The observed recovery rates under optimized conditions-ASE with ethyl acetate/formic acid-for 4-NP in spiked activated sewage sludge samples (spiking levels: 51, 88, or 554 microg/g on dry weight basis (dwb)) were 90, 107, or 101%. BPA (spiking levels: 50, 87, or 474 microg/g dwb) was found with recovery rates of 70, 105, or 101%, respectively. For anaerobically stabilized sewage sludge, recoveries for 4-NP (spiking levels: 40, 66, or 196 microg/g dwb) were 97, 95, or 101% and 90, 95, or 101% for BPA (spiking levels: 41, 67, or 474 microg/g dwb), respectively.

  17. Effects of ultrasonic disintegration of excess sewage sludge.

    PubMed

    Zielewicz, Ewa

    2016-10-01

    Breaking down sludge floc (sonodyspergation effect) and destruction of the cell membranes of microorganisms forming floc is a direct effect of ultrasonic disintegration of sludge excess. This results in release of organic material by liquid sludge (the sonolysis effect). Desired technological effects of the disintegration are: to shorten the hydrolytic phase of fermentation, to increase the production of biogas (source of renewable energy) and an increased mineralization (stability) of fermented sludge. The presented study demonstrates research covering thickened excess sludge of various physicochemical properties, collected from nine municipal sewage treatment plants. The sludge was subjected to ultrasonic disintegration using three differently constructed disintegrators and different proportions of sonification area. Direct effects of disintegration were monitored and recorded using selected indicators describing changes in the properties of sludge and increase of substance dispersed and dissolved in the supernatant liquid to be filtered. Studies have demonstrated that those (direct) effects of ultrasonic disintegration depend on the physicochemical properties of the sludge (foremost the concentration of dry solids) that determine their variable susceptibility to the disintegration methods. The direct effects also depend on optimal process conditions (which consist of the construction of the ultrasonic disintegrator), the geometric proportions of the sonication area and the operating parameters of disintegration (which could be appropriately matched to the characteristics of sludge). The most preferable results were obtained for ultrasonic disintegration of sludge with a dry matter concentration C 0 < 4.2 %. The highest effect of sonolysis-an almost 30-fold increase in the COD dissolved in the supernatant-was obtained for the sludge of lowest dry matter (C 0 = 2.0 %), which was sonicated in a reactor with a short transducer of the largest radiating surface

  18. Bioleaching of heavy metals from anaerobically digested sewage sludge.

    PubMed

    Pathak, Ashish; Dastidar, M G; Sreekrishnan, T R

    2008-03-01

    The effects of sulfur concentration, initial pH of the sludge and sludge solid content on metal bioleaching were examined using anaerobically digested sewage sludge procured from a typical sewage treatment plant in Delhi, the capital city of India. Experiments on effect of sulfur concentration were carried out using 0-4 g L(-1) of elemental sulfur to optimize the concentration of elemental sulfur for efficient bioleaching. For the type of sludge (20 g L(-1) solid content) used in the present study, 2 g L(-1) of elemental sulfur was found sufficient in metal bioleaching in the following order: Zn 86%, Cu 71.5%, Mn 70%, Ni 58.3% and Cr 43.8%. Changes in pH, sulfate concentration and oxidation-reduction potential (ORP) as a function of time were experimentally monitored. A rapid change in the above parameters took place in 4-6 days followed by a slow change until the 10th day. The change in pH with time was observed to vary at different initial pH values (pH 7 to pH 3) of the sludge; however, there was not much difference in the final pH achieved and final metal solubilization which ranged from: Cu 83.6-94.2%, Ni 27.7-29.8%, Zn 89-94.8%, Mn 67.5-79% and Cr 34.1-44.1% The results of the present studies strongly indicate that using 2 g L(-1) elemental sulfur, indigenous sulfur oxidizing microorganisms can bring down pH to a value needed for significant metal solubilization. Also, bioleaching can be carried out successfully over a wide range of initial pH values of the sludge. Further, at higher sludge solid concentration than 20 g L(-1), lower metal solubilization was achieved due to the buffering capacity of the sludge.

  19. Evaluation of biochemical and redox parameters in rats fed with corn grown in soil amended with urban sewage sludge.

    PubMed

    Grotto, Denise; Carneiro, Maria Fernanda Hornos; Sauer, Elisa; Garcia, Solange Cristina; de Melo, Wanderley José; Barbosa, Fernando

    2013-09-01

    The increased production of urban sewage sludge requires alternative methods for final disposal. A very promising choice is the use of sewage sludge as a fertilizer in agriculture, since it is rich in organic matter, macro and micronutrients. However, urban sewage sludge may contain toxic substances that may cause deleterious effects on the biota, water and soil, and consequently on humans. There is a lack of studies evaluating how safe the consumption of food cultivated in soils containing urban sewage sludge is. Thus, the aim of this paper was to evaluate biochemical and redox parameters in rats fed with corn produced in a soil treated with urban sewage sludge for a long term. For these experiments, maize plants were grown in soil amended with sewage sludge (rates of 5, 10 and 20 t/ha) or not (control). Four different diets were prepared with the corn grains produced in the field experiment, and rats were fed with these diets for 1, 2, 4, 8 and 12 weeks. Biochemical parameters (glucose, total cholesterol and fractions, triglycerides, aspartate aminotransferase and alanine aminotransferase) as well the redox state biomarkers such as reduced glutathione (GSH), malondialdehyde (MDA), catalase, glutathione peroxidase and butyrylcholinesterase (BuChE) were assessed. Our results show no differences in the biomarkers over 1 or 2 weeks. However, at 4 weeks BuChE activity was inhibited in rats fed with corn grown in soil amended with sewage sludge (5, 10 and 20 t/ha), while MDA levels increased. Furthermore, prolonged exposure to corn cultivated in the highest amount per hectare of sewage sludge (8 and 12 weeks) was associated with an increase in MDA levels and a decrease in GSH levels, respectively. Our findings add new evidence of the risks of consuming food grown with urban sewage sludge. However, considering that the amount and type of toxic substances present in urban sewage sludge varies considerably among different sampling areas, further studies are needed to

  20. Effect of vermicomposting on concentration and speciation of heavy metals in sewage sludge with additive materials.

    PubMed

    He, Xin; Zhang, Yaxin; Shen, Maocai; Zeng, Guangming; Zhou, Mucen; Li, Meirong

    2016-10-01

    The aim of this work was to evaluate the total content and speciation of heavy metals (As, Cr, Cd, Cu, Fe, Mn, Ni, Pb and Zn) during vermicomposting of sewage sludge by Eisenia fetida earthworm with different additive materials (soil, straw, fly ash and sawdust). Results showed that the pH, total organic carbon were reduced, while the electric conductivity and germination index increased after a combined composting - vermicomposting process. The addition of bulking agents accelerated the stabilization of sludge and eliminated its toxicity. The total heavy metals after vermicomposting in 10 scenarios were lowered as compared with the initial values and the control without amendment. BCR sequential extraction indicated that vermicomposting significantly decreased the mobility of all heavy metals by increasing the residual fractions. The activity of earthworms and appropriate addition of amendment materials played a positive role in sequestering heavy metals during the treatment of sewage sludge.

  1. Land Application of Treated Sewage Sludge: Community Health and Environmental Justice

    PubMed Central

    McDonald, Mary Anne; Wing, Steve; Muhammad, Naeema

    2013-01-01

    Background: In the United States, most of the treated sewage sludge (biosolids) is applied to farmland as a soil amendment. Critics suggest that rules regulating sewage sludge treatment and land application may be insufficient to protect public health and the environment. Neighbors of land application sites report illness following land application events. Objectives: We used qualitative research methods to evaluate health and quality of life near land application sites. Methods: We conducted in-depth interviews with neighbors of land application sites and used qualitative analytic software and team-based methods to analyze interview transcripts and identify themes. Results: Thirty-four people in North Carolina, South Carolina, and Virginia responded to interviews. Key themes were health impacts, environmental impacts, and environmental justice. Over half of the respondents attributed physical symptoms to application events. Most noted offensive sludge odors that interfere with daily activities and opportunities to socialize with family and friends. Several questioned the fairness of disposing of urban waste in rural neighborhoods. Although a few respondents were satisfied with the responsiveness of public officials regarding sludge, many reported a lack of public notification about land application in their neighborhoods, as well as difficulty reporting concerns to public officials and influencing decisions about how the practice is conducted where they live. Conclusions: Community members are key witnesses of land application events and their potential impacts on health, quality of life, and the environment. Meaningful involvement of community members in decision making about land application of sewage sludge will strengthen environmental health protections. PMID:23562940

  2. Co-digestion of cultivated microalgae and sewage sludge from municipal waste water treatment.

    PubMed

    Olsson, Jesper; Feng, Xin Mei; Ascue, Johnny; Gentili, Francesco G; Shabiimam, M A; Nehrenheim, Emma; Thorin, Eva

    2014-11-01

    In this study two wet microalgae cultures and one dried microalgae culture were co-digested in different proportions with sewage sludge in mesophilic and thermophilic conditions. The aim was to evaluate if the co-digestion could lead to an increased efficiency of methane production compared to digestion of sewage sludge alone. The results showed that co-digestion with both wet and dried microalgae, in certain proportions, increased the biochemical methane potential (BMP) compared with digestion of sewage sludge alone in mesophilic conditions. The BMP was significantly higher than the calculated BMP in many of the mixtures. This synergetic effect was statistically significant in a mixture containing 63% (w/w VS based) undigested sewage sludge and 37% (w/w VS based) wet algae slurry, which produced 23% more methane than observed with undigested sewage sludge alone. The trend was that thermophilic co-digestion of microalgae and undigested sewage sludge did not give the same synergy.

  3. Treatment of sewage sludge generated in municipal wastewater treatment plants.

    PubMed

    Tavares, Célia R G; Benatti, Cláudia T; Dias Filho, Benedito P

    2002-01-01

    This study was designed to evaluate the performance of a cylindrical anaerobic digester in treating secondary sewage sludge. A series of three independent batch experiments was performed for a total operation time of 60 d. The system of anaerobic digestion showed stability conditions, with no noticeable scum or foaming problems. The chemical oxygen demand reduction reached 29,21, and 45% in sludge and 95,85, and 82% in supernatant for the three experiments, respectively. Total coliform bacteria levels in the digester ranged from 10(4) to 10(5) in influent sludge and from 10(4) to 10(3) in effluent sludge, with an average reduction of 90%. Fecal coliforms of the order of 10(4) were enumerated in influent sludge and those of the order of 10(0) were enumerated in effluent sludge, with an average reduction of 99.9%. The studied system had satisfactory results, showing that both organic matter and indicator bacteria levels substantially decrease when the sludge is submitted to anaerobic digestion.

  4. Hydrothermal liquefaction of sewage sludge under isothermal and fast conditions.

    PubMed

    Qian, Lili; Wang, Shuzhong; Savage, Phillip E

    2017-02-08

    We investigated the effects of water loading, sludge moisture content, recovery solvent, and additives on the product yields and compositions from isothermal (673K, 60min) and fast (773K, 1min) hydrothermal liquefaction (HTL) of sewage sludge. The water loading (which affects pressure within the reactor) plays a small role in product yields. The sludge moisture content had a larger effect with the highest biocrude yields (26.8wt% from isothermal HTL and 27.5wt% from fast HTL) being produced from sludge that was 85wt% moisture. The HTL biocrude from sludge mainly contains long-chain aliphatic hydrocarbon moieties and aliphatic acids. Dichloromethane recovered more biocrude and energy content (∼50%) than did the other solvents tested. Added K2CO3, Na2CO3, HCOOH, CH3COOH, MoO3-CoO/γ-Al2O3 and Ru/C significantly decrease the biocrude yield when their loadings are 50wt% of the dried sludge. The additives, excepting carbonates, enhance gasification of sludge.

  5. Landfarming of municipal sewage sludge at Oak Ridge, Tennessee

    SciTech Connect

    Tischler, M.L.; Pergler, C.; Wilson, M.; Mabry, D.; Stephenson, M.

    1995-12-01

    The City of Oak Ridge, Tennessee, has been applying municipal sanitary sludge to 9 sites comprising 90 ha on the US Department of Energy (DOE) Oak Ridge Reservation (ORR) since 1983. Approximately 13,000,000 L are applied annually by spraying sludge (2 to 3% solids) under pressure from a tanker. Under an ongoing monitoring program, both the sludge and the soil in the application areas are analyzed for organic, inorganic, and radioactive parameters on a regular basis. Organic pollutants are analyzed in sludge on a semiannual basis and in the soil application areas on an annual basis. Inorganic parameters are analyzed daily (e.g., pH, total solids) or monthly (e.g., nitrogen, manganese) in sludge and annually in soil in application areas. Radionuclides (Co-60, Cs-137, I-131, Be-7, K-40, Ra-228, U-235, U-238) are scanned daily during application by the sewage treatment plant and analyzed weekly in composite sludge samples and annually in soil. Additionally, data on radioactive body burden for maximally exposed workers who apply the sludge show no detectable exposures. This monitoring program is comprehensive and is one of the few in the United States that analyzes radionuclides. Results from the monitoring program show heavy metals and radionuclides are not accumulating to levels in the soil application areas.

  6. The evaluation of sewage sludge and compost toxicity to Heterocypris incongruens in relation to inorganic and organic contaminants content.

    PubMed

    Oleszczuk, Patryk

    2007-12-01

    Sewage sludges and the composts were evaluated chemically and ecotoxicologically to determine their suitability as fertilizers for land application. Four municipal sewage sludges with various properties and pollutant contents were composted in aerobic conditions for 76 days. The content of heavy metals (Cd, Cu, Cr, Pb, Ni, Zn) and polycyclic aromatic hydrocarbons (14 from US EPA List) was analyzed in the sewage sludges and composts as well as together with their physico-chemical properties (total organic carbon, total nitrogen, pH, available forms of magnesium, phosphorus and potassium, cations content, cation exchange capacity, total of exchangeable bases). To evaluate the toxicity of the materials, bioassays with crustacean Heterocypris incongruens (Ostracodtoxkit test) were performed. Neither physical-chemical properties nor heavy metal content underwent any significant changes during the composting process. However, composting significantly influenced the range of losses of polycyclic aromatic hydrocarbons. The magnitude and the ranges of changes in the toxicity H. incongruens were found to be dependent on the tested parameter as well as on sewage sludge type and its dose. It was noted that composting could even increase the toxicity of sewage sludges. Sewage sludge toxicity was mainly determined by the presence of heavy metals, although for some sludges the contribution of organic pollutants as well as the synergistic activity of several factors could not be excluded. According to proposed classification (on the basis of Ostracodtoxkit test) only one sewage sludge/compost was suitable for land application. The studies conducted provide interesting information pointing to the necessity to supplement chemical studies with biological assays.

  7. Systems for the treatment of organic material and particularly sewage sludge

    SciTech Connect

    Schimel, K.A.

    1983-08-30

    Anaerobic digestion of organic material, particularly biological sludge, such as sewage sludge, is carried out in a closed system having a first digestion tank and a second concentration and partial digestion tank. The concentrated and partially digested sludge is fed to the first tank where it is maintained under vacuum such that an active zone of organic material undergoing digestion is detained therein for a long period of time. The digested sludge is withdrawn against the vacuum and has approximately 80 to 90% of the organic solids therein mineralized; thus simplifying dewatering and ultimate disposal of the sludge. Pathogens including viruses are also removed from the digested sludge. Denitrification takes place in the vacuum digester tank and gas consisting essentially of nitrogen is removed. Return sludge from the vacuum digester and influent sludge is fed into the second or concentrator tank to facilitate reseeding with anaerobic organisms. Both tanks are provided with passageways which are coterminous near the upper ends of the tanks and provided with baffles which direct the flow to be in opposite directions in the passageways, thus providing for stripping of the gas and solid-liquid separation. Gas consisting essentially of methane and carbon dioxide is produced from the second tank. Supernatant from the second tank may be recirculated to the source of the sludge to facilitate degradation of remaining organic contaminants.

  8. Quantification of viable helminth eggs in samples of sewage sludge.

    PubMed

    Rocha, Maria Carolina Vieira da; Barés, Monica Eboly; Braga, Maria Cristina Borba

    2016-10-15

    For the application of sewage sludge as fertilizer, it is of fundamental importance the absence of pathogenic organisms, such as viable helminth eggs. Thus, the quantification of these organisms has to be carried out by means of the application of reliable and accurate methodologies. Nevertheless, until the present date, there is no consensus with regard to the adoption of a universal methodology for the detection and quantification of viable helminth eggs. It is therefore necessary to instigate a debate on the different protocols currently in use, as well as to assemble relevant information in order to assist in the development of a more comprehensive and accurate method to quantify viable helminth eggs in samples of sewage sludge and its derivatives.

  9. Variations of metal distribution in sewage sludge composting.

    PubMed

    Nomeda, Sabiene; Valdas, Paulauskas; Chen, Shen-Yi; Lin, Jih-Gaw

    2008-01-01

    In the study, the variations of heavy metal distributions (of Cu, Mn, Pb, and Zn) during the sewage sludge composting process were investigated by sequential extraction procedures. The total content of Cu and Zn in the composted mixture increased after the composting process. Mn and Zn were mainly found in mobile fractions (exchangeable fraction (F1), carbonate fraction (F2), and Fe/Mn oxide fraction (F3)). Cu and Pb were strongly associated with the stable fractions (organic matter/sulfides fraction (F4) and residual fraction (F5)). These five metal fractions were used to calculate the metal mobility (bioavailability) in the sewage sludge and composted mixture. The mobility (bioavailability) of Mn, Pb, and Zn (but not Cu) increased during the composting process. The metal mobility in the composted mixture ranked in the following order: Mn>Zn>Pb>Cu.

  10. [Effects of sewage sludge vermicompost on the growth of marigold].

    PubMed

    Ma, Li; Yin, Xiu-qin

    2010-05-01

    The 1:1, 2:1, 3:1, 4:1, 5:1, and 1:0 mixtures of sewage sludge and cattle dung were treated with earthworm Eisenia foetida, and then, mixed with black soil in the proportions of 10%, 20%, and 30% (dry mass) to investigate the effects of the vermicompost on the marigold plant height, stem diameter, leaf number, branch number, aboveground biomass, underground biomass, ratio of root to shoot, flower bud number, flower yield, flower diameter, and flower biomass. An obvious promotion effect of the vermicompost was observed on the growth of marigold. The smaller the ratio of sewage sludge to cattle dung, the better the growth of marigold; while a higher proportion of the vermicompost to soil would inhibit the marigold growth. In this study, a proportion of 20% vermicompost to soil was the best for the growth of marigold.

  11. Joint NRC/EPA Sewage Sludge Radiological Survey: Survey Design & Test Site Results

    EPA Pesticide Factsheets

    This report contains the results of a radiological survey of nine publicly POTWs around the country, which was commissioned by the Sewage Sludge Subcommittee, to determine whether and to what extent radionuclides concentrate in sewage treatment wastes.

  12. Experimental research of sewage sludge with coal and biomass co-combustion, in pellet form.

    PubMed

    Kijo-Kleczkowska, Agnieszka; Środa, Katarzyna; Kosowska-Golachowska, Monika; Musiał, Tomasz; Wolski, Krzysztof

    2016-07-01

    Increased sewage sludge production and disposal, as well as the properties of sewage sludge, are currently affecting the environment, which has resulted in legislation changes in Poland. Based on the Economy Minister Regulation of 16 July 2015 (Regulation of the Economy Minister, 2015) regarding the criteria and procedures for releasing wastes for landfilling, the thermal disposal of sewage sludge is important due to its gross calorific value, which is greater than 6MJ/kg, and the problems that result from its use and application. Consequently, increasingly restrictive legislation that began on 1 January 2016 was introduced for sewage sludge storage in Poland. Sewage sludge thermal utilisation is an attractive option because it minimizes odours, significantly reduces the volume of starting material and thermally destroys the organic and toxic components of the off pads. Additionally, it is possible that the ash produced could be used in different ways. Currently, as many as 11 plants use sewage sludge as fuel in Poland; thus, this technology must be further developed in Poland while considering the benefits of co-combustion with other fuels. This paper presents the results of experimental studies of the mechanisms and kinetics of sewage sludge, coal and biomass combustion and their co-combustion in spherical-pellet form. Compared with biomass, a higher temperature is required to ignite sewage sludge by flame. The properties of biomass and sewage sludge result in the intensification of the combustion process (by fast ignition of volatile matter). In contrast to coal, a combustion of sewage sludge is determined not only burning the char, but also the combustion of volatiles. The addition of sewage sludge to hard coal and lignite shortens combustion times compared with coal, and the addition of sewage sludge to willow Salix viminalis produces an increase in combustion time compared with willow alone.

  13. Utilization of sewage sludge in the manufacture of lightweight aggregate.

    PubMed

    Franus, Małgorzata; Barnat-Hunek, Danuta; Wdowin, Magdalena

    2016-01-01

    This paper presents a comprehensive study on the possibility of sewage sludge management in a sintered ceramic material such as a lightweight aggregate. Made from clay and sludge lightweight aggregates were sintered at two temperatures: 1100 °C (name of sample LWA1) and 1150 °C (name of sample LWA2). Physical and mechanical properties indicate that the resulting expanded clay aggregate containing sludge meets the basic requirements for lightweight aggregates. The presence of sludge supports the swelling of the raw material, thereby causing an increase in the porosity of aggregates. The LWA2 has a lower value of bulk particle density (0.414 g/cm(3)), apparent particle density (0.87 g/cm(3)), and dry particle density (2.59 g/cm(3)) than it is in the case of LWA1 where these parameters were as follows: bulk particle density 0.685 g/cm(3), apparent particle density 1.05 g/cm(3), and dry particle density 2.69 g/cm(3). Water absorption and porosity of LWA1 (WA = 14.4 %, P = 60 %) are lower than the LWA2 (WA = 16.2 % and P = 66 %). This is due to the higher heating temperature of granules which make the waste gases, liberating them from the decomposition of organic sewage sludge. The compressive strength of LWA2 aggregate is 4.64 MPa and for LWA1 is 0.79 MPa. Results of leaching tests of heavy metals from examined aggregates have shown that insoluble metal compounds are placed in silicate and aluminosilicate structure of the starting materials (clays and sludges), whereas soluble substances formed crystalline skeleton of the aggregates. The thermal synthesis of lightweight aggregates from clay and sludge mixture is a waste-free method of their development.

  14. Simulation of substrate degradation in composting of sewage sludge

    SciTech Connect

    Zhang Jun; Gao Ding; Chen Tongbin; Zheng Guodi; Chen Jun; Ma Chuang; Guo Songlin; Du Wei

    2010-10-15

    To simulate the substrate degradation kinetics of the composting process, this paper develops a mathematical model with a first-order reaction assumption and heat/mass balance equations. A pilot-scale composting test with a mixture of sewage sludge and wheat straw was conducted in an insulated reactor. The BVS (biodegradable volatile solids) degradation process, matrix mass, MC (moisture content), DM (dry matter) and VS (volatile solid) were simulated numerically by the model and experimental data. The numerical simulation offered a method for simulating k (the first-order rate constant) and estimating k{sub 20} (the first-order rate constant at 20 {sup o}C). After comparison with experimental values, the relative error of the simulation value of the mass of the compost at maturity was 0.22%, MC 2.9%, DM 4.9% and VS 5.2%, which mean that the simulation is a good fit. The k of sewage sludge was simulated, and k{sub 20}, k{sub 20s} (first-order rate coefficient of slow fraction of BVS at 20 {sup o}C) of the sewage sludge were estimated as 0.082 and 0.015 d{sup -1}, respectively.

  15. Simulation of substrate degradation in composting of sewage sludge.

    PubMed

    Zhang, Jun; Gao, Ding; Chen, Tong-Bin; Zheng, Guo-Di; Chen, Jun; Ma, Chuang; Guo, Song-Lin; Du, Wei

    2010-10-01

    To simulate the substrate degradation kinetics of the composting process, this paper develops a mathematical model with a first-order reaction assumption and heat/mass balance equations. A pilot-scale composting test with a mixture of sewage sludge and wheat straw was conducted in an insulated reactor. The BVS (biodegradable volatile solids) degradation process, matrix mass, MC (moisture content), DM (dry matter) and VS (volatile solid) were simulated numerically by the model and experimental data. The numerical simulation offered a method for simulating k (the first-order rate constant) and estimating k(20) (the first-order rate constant at 20 degrees C). After comparison with experimental values, the relative error of the simulation value of the mass of the compost at maturity was 0.22%, MC 2.9%, DM 4.9% and VS 5.2%, which mean that the simulation is a good fit. The k of sewage sludge was simulated, and k(20), k(20s) (first-order rate coefficient of slow fraction of BVS at 20 degrees C) of the sewage sludge were estimated as 0.082 and 0.015 d(-1), respectively.

  16. Sewage sludge does not induce genotoxicity and carcinogenesis.

    PubMed

    Silva, Paula Regina Pereira; Barbisan, Luis Fernando; Dagli, Maria Lúcia Zaidan; Saldiva, Paulo Hilário Nascimento

    2012-07-01

    Through a series of experiments, the genotoxic/mutagenic and carcinogenic potential of sewage sludge was assessed. Male Wistar rats were randomly assigned to four groups: Group 1 - negative control; Group 2 - liver carcinogenesis initiated by diethylnitrosamine (DEN; 200 mg/kg i.p.); Group 3 and G4-liver carcinogenesis initiated by DEN and fed 10,000 ppm or 50,000 ppm of sewage sludge. The animals were submitted to a 70% partial hepatectomy at the 3(rd) week. Livers were processed for routine histological analysis and immunohistochemistry, in order to detect glutathione S-transferase positive altered hepatocyte foci (GST-P(+) AHF). Peripheral blood samples for the comet assay were obtained from the periorbital plexus immediately prior to sacrificing. Polychromatic erythrocytes (PCEs) were analyzed in femoral bone-marrow smears, and the frequencies of those micronucleated (MNPCEs) registered. There was no sewage-sludge-induced increase in frequency of either DNA damage in peripheral blood leucocytes, or MNPCEs in the femoral bone marrow. Also, there was no increase in the levels of DNA damage, in the frequency of MNPCEs, and in the development of GST-P AHF when compared with the respective control group.

  17. Sewage sludge does not induce genotoxicity and carcinogenesis

    PubMed Central

    Silva, Paula Regina Pereira; Barbisan, Luis Fernando; Dagli, Maria Lúcia Zaidan; Saldiva, Paulo Hilário Nascimento

    2012-01-01

    Through a series of experiments, the genotoxic/mutagenic and carcinogenic potential of sewage sludge was assessed. Male Wistar rats were randomly assigned to four groups: Group 1 - negative control; Group 2 - liver carcinogenesis initiated by diethylnitrosamine (DEN; 200 mg/kg i.p.); Group 3 and G4-liver carcinogenesis initiated by DEN and fed 10,000 ppm or 50,000 ppm of sewage sludge. The animals were submitted to a 70% partial hepatectomy at the 3rd week. Livers were processed for routine histological analysis and immunohistochemistry, in order to detect glutathione S-transferase positive altered hepatocyte foci (GST-P+ AHF). Peripheral blood samples for the comet assay were obtained from the periorbital plexus immediately prior to sacrificing. Polychromatic erythrocytes (PCEs) were analyzed in femoral bone-marrow smears, and the frequencies of those micronucleated (MNPCEs) registered. There was no sewage-sludge-induced increase in frequency of either DNA damage in peripheral blood leucocytes, or MNPCEs in the femoral bone marrow. Also, there was no increase in the levels of DNA damage, in the frequency of MNPCEs, and in the development of GST-P AHF when compared with the respective control group. PMID:23055806

  18. The legacy of sewage sludge disposal in New York bight

    SciTech Connect

    Buchholtz ten Brink, M.; Casso, M.A.; Allison, M.A.; Schleel, J.S.

    1995-12-31

    From 1924 until 1987, New York City disposed of sewage sludge by dumping at the 12-mile dumpsite in 20 m of water off the New York-New Jersey coast. Approximately 125 {times} 10{sup 6} m{sup 3} was deposited, peaking in the early 1980`s. The dumpsite is at the head of the Hudson Shelf Valley, a submerged river channel crossing the continental shelf, in a region of sandy sediments that are regularly reworked by wave action. The introduction of the chemically and texturally distinct `sludge` sediment provides a tracer to study how accumulated anthropogenic deposits are dispersed throughout the region or transferred off the shelf. This work, begun in 1992, focuses on the fate of the material in the valley, ``downstream`` from the dumpsite. Geophysical, chemical, and radiological tools were used to delineate the sedimentary processes, the extent of contaminant dispersal, and the longterm fate of the dump spoils. Sediment derived from the sewage sludge has preferentially deposited on the valley floor relative to the surrounding shelf, resulting in unnaturally high accumulation rates in the upper valley. Dark, sludge-derived sediment is being covered by cleaner deposits from 0 to 26 km downvalley from the dumpsite, but ongoing resuspension and transport of the sediment results in a sewage signal in the uppermost sediments up to 80 km from the dumpsite. Both buried and surface ``sludge`` is subject to biological mixing. The patchy occurrence of the black sediment and interbedded sand layers observed downvalley suggest that resuspension and transport occur episodically, probably during major storm events.

  19. K-Area and Par Pond Sewage Sludge Application Sites groundwater monitoring reports, second quarter 1992

    SciTech Connect

    Not Available

    1992-10-01

    During second quarter 1992, the three wells at the K-Area Sewage Sludge Application Site (KSS wells) and the three wells at the Par Pond Sewage Sludge Application Site (PSS wells) were sampled for analyses required each quarter or annually by South Carolina Department of Health and Environmental Control Construction Permit 13, 173. This report includes the results of those analyses. None of the analyzed constituents exceeded the Primary Drinking Water Standard or the Savannah River Site Flag 2 criteria at either the K-Area Sewage Sludge Application Site or the Par Pond Sewage Sludge Application Site.

  20. Advanced two-phase digestion of sewage sludge

    SciTech Connect

    Ghosh, S.

    1984-01-01

    This paper describes the development and operating results of a novel configuration of the two-phase digestion concept. The two-phase system, comprises two custom-designed upflow digesters, which were operated in tandem to optimize the liquefying-acidification and acetogenesis-methanation reactions. The results are based on system operation for more than one year with a high-metal-content sewage sludge. During the operating period, the system exhibited an increasing methane yield at hydraulic retention times (HRT) of less than 6 days. With continuing culture enrichment and improvements in reactor design, the methane yield increased from 5 to 6.8 SCF/lb VS added, and then to 7.7 SCF/lb VS added. This methane yield was about 80% of the theoretical methane yield achievable with this sewage sludge--and the highest methane yield reported for sludge at this HRT. Operation of the novel process configuration was very stable and superior to that of conventional single-stage digestion in terms of methane yield, gas generation rate, and net energy production. About 75 weight percent of the organic solids was gasified; this could be the maximum attainable feed conversion efficiency for sludge, considering that between 75% and 80% of this feed is normally biodegradable. 3 references, 7 tables.

  1. Factors affecting decay of Salmonella Birkenhead and coliphage MS2 during mesophilic anaerobic digestion and air drying of sewage sludge.

    PubMed

    Mondal, Tania; Rouch, Duncan A; Thurbon, Nerida; Smith, Stephen R; Deighton, Margaret A

    2015-06-01

    Factors affecting the decay of Salmonella Birkenhead and coliphage, as representatives of bacterial and viral pathogens, respectively, during mesophilic anaerobic digestion (MAD) and air drying treatment of anaerobically digested sewage sludge were investigated. Controlled concentrations of S. Birkenhead were inoculated into non-sterile, autoclaved, γ-irradiated and nutrient-supplemented sludge and cultures were incubated at 37 °C (MAD sludge treatment temperature) or 20 °C (summer air drying sludge treatment temperature). Nutrient limitation caused by microbial competition was the principal mechanism responsible for the decay of S. Birkenhead by MAD and during air drying of digested sludge. The effects of protease activity in sludge on MS2 coliphage decay in digested and air dried sludge were also investigated. MS2 coliphage showed a 3.0-3.5 log10 reduction during incubation with sludge-protease extracts at 37 °C for 25 h. Proteases produced by indigenous microbes in sludge potentially increase coliphage inactivation and may therefore have a significant role in the decay of enteric viruses in sewage sludge. The results help to explain the loss of viability of enteric bacteria and viral pathogens with treatment process time and contribute to fundamental understanding of the various biotic inactivation mechanisms operating in sludge treatment processes at mesophilic and ambient temperatures.

  2. Bioleaching of heavy metals from sewage sludge: a review.

    PubMed

    Pathak, Ashish; Dastidar, M G; Sreekrishnan, T R

    2009-06-01

    During the treatment of sewage, a huge volume of sludge is generated, which is disposed of on land as soil fertilizer/conditioner due to the presence of nitrogen, phosphorus, potassium and other nutrients. However, the presence of toxic heavy metals and other toxic compounds in the sludge restricts its use as a fertilizer. Over the years, bioleaching has been developed as an environmentally friendly and cost-effective technology for the removal of heavy metals from the sludge. The present paper gives an overview of the various bioleaching studies carried out in different modes of operation. The various important aspects such as pathogen destruction, odor reduction and metal recovery from acidic leachate also have been discussed. Further, a detailed discussion was made on the various technical problems associated with the bioleaching process, which need to be addressed while developing the process on a larger scale.

  3. Leachate tests with sewage sludge contaminated by radioactive cesium.

    PubMed

    Tsushima, Ikuo; Ogoshi, Masashi; Harada, Ichiro

    2013-01-01

    The sewer systems of eastern Japan have transported radioactive fallout from the Fukushima Dai-ichi nuclear power plant accident to wastewater treatment plants, where the radioisotopes have accumulated. To better understand the potential problems associated with the disposal of contaminated sewage sludge in landfills, leachate tests were conducted with radioactive incinerator ash, cement solidification incinerator ash, and dewatered sludge cake. Radioactivity was undetectable in the eluate from incinerator ash and dewatered sludge cake, but about 30% of the radioactivity initially in cement solidification incinerator ash appeared in the eluate during the leaching experiments. Moreover, modification of test conditions revealed that the presence of Ca(2+) ions and strong alkali in the water that contacted the incinerator ash enhanced leaching of cesium. Lastly, the capacity of pit soil to absorb radioactive cesium was estimated to be at least 3.0 Bq/g (dry).

  4. The effect of sewage sludge application on soil properties and willow (Salix sp.) cultivation.

    PubMed

    Urbaniak, Magdalena; Wyrwicka, Anna; Tołoczko, Wojciech; Serwecińska, Liliana; Zieliński, Marek

    2017-05-15

    The aim of the study was to determine the impact of sewage sludge from three wastewater treatment plants of different sizes (small, medium and large) applied in two doses (3 and 9 tons per hectare) on soil properties, determined as the content of organic carbon and humus fractions, bacterial abundance, phytotoxicity and PCDD/PCDF TEQ concentrations. The study also evaluated the impact of this sewage sludge on the biometric and physiological parameters and detoxification reaction of willow (Salix sp.) as a typical crop used for the remediation of soil following sludge application. The cultivation of willow on soil treated with sludge was found to result in a gradual increase of humus fractions, total organic carbon content and bacterial abundance as well as soil properties measured using Lepidium sativum. However, it also produced an initial increase of soil phytotoxicity, indicated by Sinapis alba and Sorghum sacharatum, and PCDD/PCDF Toxic Equivalent (TEQ) concentrations, which then fell during the course of the experiment, particularly in areas planted by willow. Although the soil phytotoxicity and PCDD/PCDF TEQ content of the sewage sludge-amended soil initially increased, sludge application was found to have a positive influence on willow, probably due to its high nutrient and carbon content. The obtained results reveal increases in willow biomass, average leaf surface area and leaf length as well as chlorophyll a+b content. Moreover, a strong decline was found in the activity of the detoxifying enzyme glutathione S-transferase (GSTs), a multifunctional enzyme involved in the metabolism of xenobiotics in plants, again demonstrating the used sludge had a positive influence on willow performance.

  5. Analysis of sewage sludge using an experimental prompt gamma neutron activation analysis (pgnaa) set-up with an am-be source

    NASA Astrophysics Data System (ADS)

    Idiri, Z.; Redjem, F.; Beloudah, N.

    2016-09-01

    An experimental PGNAA set-up using a 1 Ci Am-Be source has been developed and used for analysis of bulk sewage sludge samples issued from a wastewater treatment plant situated in an industrial area of Algiers. The sample dimensions were optimized using thermal neutron flux calculations carried out with the MCNP5 Monte Carlo Code. A methodology is then proposed to perform quantitative analysis using the absolute method. For this, average thermal neutron flux inside the sludge samples is deduced using average thermal neutron flux in reference water samples and thermal flux measurements with the aid of a 3He neutron detector. The average absolute gamma detection efficiency is determined using the prompt gammas emitted by chlorine dissolved in a water sample. The gamma detection efficiency is normalized for sludge samples using gamma attenuation factors calculated with the MCNP5 code for water and sludge. Wet and dehydrated sludge samples were analyzed. Nutritive elements (Ca, N, P, K) and heavy metals elements like Cr and Mn were determined. For some elements, the PGNAA values were compared to those obtained using Atomic Absorption Spectroscopy (AAS) and Inductively Coupled Plasma (ICP) methods. Good agreement is observed between the different values. Heavy element concentrations are very high compared to normal values; this is related to the fact that the wastewater treatment plant is treating not only domestic but also industrial wastewater that is probably rejected by industries without removal of pollutant elements. The detection limits for almost all elements of interest are sufficiently low for the method to be well suited for such analysis.

  6. Removal of antibiotics from water using sewage sludge- and waste oil sludge-derived adsorbents.

    PubMed

    Ding, Rui; Zhang, Pengfei; Seredych, Mykola; Bandosz, Teresa J

    2012-09-01

    Sewage sludge- and waste oil sludge-derived materials were tested as adsorbents of pharmaceuticals from diluted water solutions. Simultaneous retention of eleven antibiotics plus two anticonvulsants was examined via batch adsorption experiments. Virgin and exhausted adsorbents were examined via thermal and FTIR analyses to elucidate adsorption mechanisms. Maximum adsorption capacities for the 6 materials tested ranged from 80 to 300 mg/g, comparable to the adsorption capacities of antibiotics on various activated carbons (200-400 mg/g) reported in the literature. The performance was linked to surface reactivity, polarity and porosity. A large volume of pores similar in size to the adsorbate molecules with hydrophobic carbon-based origin of pore walls was indicated as an important factor promoting the separation process. Moreover, the polar surface of an inorganic phase in the adsorbents attracted the functional groups of target molecules. The presence of reactive alkali metals promoted reaction with acidic groups, formation of salts and their precipitation in the pore system.

  7. Bioproduction of ferric sulfate used during heavy metals removal from sewage sludge.

    PubMed

    Drogui, Patrick; Mercier, Guy; Blais, Jean-François

    2005-01-01

    Toxic metals removal from wastewater sewage sludge can be achieved through microbial processes involving Acidithiobacillus ferrooxidans. The oxidation of ferrous ions by A. ferrooxidans, cultured in sewage sludge filtrate, was studied in both batch and continuous flow stirred tank reactors. Sewage sludge filtrate containing natural nutrients (phosphorus and nitrogen) was recovered as effluent following the dehydration of a primary and secondary sludge mixture. Batch and continuous flow stirred tank reactor tests demonstrated that A. ferrooxidans were able to grow and completely oxidize ferrous iron in a culture medium containing more than 80% (v v(-1)) sewage sludge filtrate with 10 g Fe(II) L(-1) added. Toxic levels were reached when total organic carbon in the sewage sludge filtrate exceeded 250 mg L(-1). The ferric iron solution produced in the sludge filtrate by A. ferrooxidans was used to solubilize heavy metals in primary and secondary sludge. The solubilization of Cu, Cr, and Zn yielded 71, 49, and 80%, respectively. This is comparable with the yield percentages obtained using a FeCl(3) solution. The cost of treating wastewater sewage sludge by bioproducing a ferric ion solution from sewage sludge is three times less expensive than the conventional method requiring a commercial ferric chloride solution.

  8. Research on the influence of anaerobic stabilization of various dairy sewage sludge on biodegradation of polycyclic aromatic hydrocarbons PAHs with the use of effective microorganisms.

    PubMed

    Boruszko, Dariusz

    2017-05-01

    Sewage sludge was taken from a dairy WWTP belonging to Mlekovita Cooperative in Wysokie Mazowieckie. There were excess sludge, flotation sludge and a mixture of excess and flotation sludge from pre-treatment of dairy sewage. The initial content of 16 PAHs in excess sludge before fermentation was approximately 689µg·kg(-1) in dry mass, whereas in post-flotation sludge (which constituted around 30% of raw sludge) it was approximately 95µg·kg(-1) in dry mass. A mixture of excess and flotation sludge had the content of 497,7µg·kg(-1) in dry mass. Through comparison of particular hydrocarbons content in raw sewage sludge to the total PAHs content, it was shown that tricyclic compounds, which constituted 46,3% of the PAHs sum (excess sludge), and tetracyclic compounds, which constituted 60,0% of the PAHs sum (flotation sludge), were the dominating fractions. In the sludge subjected to fermentation in reactors with mixed sludge and surplus activated sludge, the general trend of the course of changes in concentrations of PAHs was similar. Both in the sludge inoculated with EM and in that not inoculated with EM, a significant increase in the total PAHs contents was observed in the first fermentation phase (acidic fermentation) after 7 days of the process. Addition of EM into the sludge did not prevent the PAHs release, and therefore higher concentrations of PAHs sum were recorded during the hydrolysis stage than in sludge before fermentation. A decrease in the sum of PAHs was observed after 2 weeks of fermentation in relation to the quantity observed after 1 week of fermentation (except from post-flotation sludge). In the following weeks, there was further decrease in the concentration of the 16 PAHs sum in all sludge types. However, in sludge without EM inoculation, it was lower than in sludge with EM inoculation. The loss of the majority of tested hydrocarbons was reported in the final phase of fermentation.

  9. Palygorskite changes heavy metal bioavailability and microbial functional diversity in sewage sludge composting.

    PubMed

    Liu, Siying; Liu, Jia; Zhao, Juanjuan; Xia, Dongsheng; Pan, Fei; Liu, Ci; Kyzas, George Z; Fu, Jie

    2015-01-01

    To investigate the effects of palygorskite on chemical forms of heavy metal and microbial functional diversity in the sewage sludge composting, a compost matrix of sewage sludge, wheat straw and varying contents of palygorskite were inoculated with the compound microbial preparation. The chemical speciation analysis by a Community Bureau of Reference-sequential extraction indicated the contribution of palygorskite to reduce the bioavailability of a model metal, Cu, during the composting process. The Biolog EcoPlate(TM) test revealed that the microbial community showed better capability of utilizing complex macro-molecules (such as miscellaneous and polymers) in the presence of palygorskite. Increasing the palygorskite contents from 1% to 5%, the microbial activity showed an increasing tendency. However, continuously increasing the palygorskite resulted in a decline of the microbial metabolism. Therefore, appropriate content of palygorskite is an ideal additive for composting, not only enhancing the microbial activity, but also reducing the metal toxicity.

  10. Balancing hygienization and anaerobic digestion of raw sewage sludge.

    PubMed

    Astals, S; Venegas, C; Peces, M; Jofre, J; Lucena, F; Mata-Alvarez, J

    2012-12-01

    The anaerobic digestion of raw sewage sludge was evaluated in terms of process efficiency and sludge hygienization. Four different scenarios were analyzed, i.e. mesophilic anaerobic digestion, thermophilic anaerobic digestion and mesophilic anaerobic digestion followed by a 60 °C or by an 80 °C hygienization treatment. Digester performance (organic matter removal, process stability and biogas yield) and the hygienization efficiency (reduction of Escherichia coli, somatic coliphages and F-specific RNA phages) were the main examined factors. Moreover, a preliminary economical feasibility study of each option was carried out throughout an energy balance (heat and electricity). The obtained results showed that both thermophilic anaerobic digestion and mesophilic anaerobic digestion followed by a hygienization step were able to produce an effluent sludge that fulfills the American and the European legislation for land application. However, higher removal efficiencies of indicators were obtained when a hygienization post-treatment was present. Regarding the energy balance, it should be noted that all scenarios have a significant energy surplus. Particularly, positive heat balances will be obtained for the thermophilic anaerobic digestion and for the mesophilic anaerobic digestion followed by 60 °C hygienization post-treatment if an additional fresh-sludge/digested sludge heat exchanger is installed for energy recovery.

  11. Usage of pumice as bulking agent in sewage sludge composting.

    PubMed

    Wu, Chuandong; Li, Weiguang; Wang, Ke; Li, Yunbei

    2015-08-01

    In this study, the impacts of reused and sucrose-decorated pumice as bulking agents on the composting of sewage sludge were evaluated in the lab-scale reactor. The variations of temperature, pH, NH3 and CO2 emission rate, moisture content (MC), volatile solid, dissolved organic carbon, C/N and the water absorption characteristics of pumice were detected during the 25days composting. The MC of pumice achieved 65.23% of the 24h water absorptivity within the first 2h at the mass ratio of 0.6:1 (pumice:sewage sludge). Reused pumice increased 23.68% of CO2 production and reduced 21.25% of NH3 emission. The sucrose-decorated pumice reduced 43.37% of nitrogen loss. These results suggested that adding pumice and sucrose-decorated pumice in sludge composting matrix could not only adjust the MC of materials, but also improve the degradation of organic matters and reduce nitrogen loss.

  12. A study on torrefaction of sewage sludge to enhance solid fuel qualities

    SciTech Connect

    Poudel, Jeeban; Ohm, Tae-In; Lee, Sang-Hoon; Oh, Sea Cheon

    2015-06-15

    Highlights: • The physio chemical variation of sewage sludge during torrefaction was studied. • Compounds with oxygen were emitted at a temperature lower than that for C{sub x}H{sub y}. • Sewage sludge torrefaction range was defined between 300 and 350 °C. - Abstract: Torrefaction is a treatment which serves to improve the properties of biomass in relation to thermochemical processing techniques for energy generation. In this study, the torrefaction of sewage sludge, which is a non-lignocellulosic waste was investigated in a horizontal tubular reactor under nitrogen flow at temperature ranging from 150 to 400 °C, for torrefaction residence time varying from 0 to 50 min. The torrefaction kinetics of sewage sludge was studied to obtain the kinetic parameters. The torrefied sewage sludge products were characterized in terms of their elemental composition, energy yield, ash content and volatile fraction. The energy and mass yields decreased with an increase in the torrefaction temperature. From an elemental analysis, the weight percentage of carbon in the sewage sludge increased with an increase in the torrefaction temperature. On the other hand, the weight percentages of hydrogen and oxygen tended to decrease. The gaseous products from torrefaction of sewage sludge were also analyzed. From this work, it was found that the compounds with oxygen were emitted at a temperature lower than that for hydrocarbon gases and the temperatures of 300–350 °C were the optimum torrefaction temperatures for sewage sludge.

  13. Nitrate content of lettuce (Lactuca sativa L.) after fertilization with sewage sludge and irrigation with treated wastewater.

    PubMed

    Castro, E; Mañas, M P; De Las Heras, J

    2009-02-01

    A romaine-type lettuce (Lactuca sativa L.) was cultivated over three crop seasons (spring 2005, spring 2006 and autumn-winter 2006) in six 36 m(2) plots in Alcázar de San Juan, Spain. A drip irrigation system was used to water all plots: five plots with drinking water and one plot with wastewater from the activated sludge system of a wastewater treatment plant (WWTP). One drinking water-irrigated plot was not fertilized (control). Five different treatments were applied to the soil: three organic mixtures (sewage sludge, sewage sludge mixed with pine bark and municipal solid waste with composted sludge) and a conventional fertilizer were applied to the four plots irrigated with drinking water. The last plot was irrigated with treated wastewater. The treatments were tested for their effect on plant growth and nitrate concentration in vegetable tissue. An increase in fresh weight in the lettuce was linked to the dosage of sewage sludge. The highest nitrate level was observed in the sewage sludge treatment in all crops and seasons, although, in general, all values were below the maximum limits established by the European Commission for nitrate content in fresh romaine lettuce. In the third crop season, a significant increase in nitrate content was observed in lettuce from organic treatments. Nitrate concentration in lettuce from irrigated treated wastewater was higher than control, although significant differences were not found.

  14. Sewage sludge-derived materials as efficient adsorbents for removal of hydrogen sulfide.

    PubMed

    Bagreev, A; Bashkova, S; Locke, D C; Bandosz, T J

    2001-04-01

    Sewage sludge-derived materials were used as adsorbents of hydrogen sulfide from moist air. The adsorbent obtained by carbonization at 950 degrees C has a capacity twice of that of coconut-shell-based activated carbon. The capacity of the sludge-derived materials increases with increasing carbonization temperature. It is likelythatduring carbonization at 950 degrees C a mineral-like phase is formed that consists of such catalytically active metals as iron, zinc, and copper. The results obtained demonstrate that the presence of iron oxide significantly increases the capacity of commercial carbon and activated alumina. The sludge-derived adsorbents are efficient for hydrogen sulfide removal until the pore entrances are blocked with sulfur as the product of oxidation reaction. For materials in which the catalytic effect is predominant, hydrogen sulfide is adsorbed until all pores are filled with sulfur. There is also indication that chemisorption plays a significant role in the removal of hydrogen sulfide from moist air.

  15. Overview of legislation on sewage sludge management in developed countries worldwide.

    PubMed

    Christodoulou, A; Stamatelatou, K

    2016-01-01

    The need to apply innovative technologies for maximizing the efficiency and minimizing the carbon footprint of sewage treatment plants has upgraded sewage sludge management to a highly sophisticated research and development sector. Sewage sludge cannot be regarded solely as 'waste'; it is a renewable resource for energy and material recovery. From this perspective, legislation on sewage sludge management tends to incorporate issues related to environmental protection, public health, climate change impacts and socio-economic benefits. This paper reviews the existing legislative frameworks and policies on sewage sludge management in various countries, highlighting the common ground as well as the different priorities in all cases studied. More specifically, the key features of legislation regarding sludge management in developed countries such as the USA, Japan, Australia, New Zealand and the European Union (EU27) are discussed.

  16. Co-production of activated carbon, fuel-gas, and oil from the pyrolysis of corncob mixtures with wet and dried sewage sludge.

    PubMed

    Shao, Linlin; Jiang, Wenbo; Feng, Li; Zhang, Liqiu

    2014-06-01

    This study explored the amount and composition of pyrolysis gas and oil derived from wet material or dried material during the preparation of sludge-corncob activated carbon, and evaluated the physicochemical and surface properties of the obtained two types of sludge-corncob-activated carbons. For wet material, owing to the presence of water, the yields of sludge-corncob activated carbon and the oil fraction slightly decreased while the yield of gases increased. The main pyrolysis gas compounds were H2 and CO2, and more H2 was released from wet material than dried material, whereas the opposite holds for CO2 Heterocyclics, nitriles, organic acids, and steroids were the major components of pyrolysis oil. Furthermore, the presence of water in wet material reduced the yield of polycyclic aromatic hydrocarbons from 6.76% to 5.43%. The yield of furfural, one of heterocyclics, increased sharply from 3.51% to 21.4%, which could be explained by the enhanced hydrolysis of corncob. In addition, the surface or chemical properties of the two sludge-corncob activated carbons were almost not affected by the moisture content of the raw material, although their mesopore volume and diameter were different. In addition, the adsorption capacities of the two sludge-corncob activated carbons towards Pb and nitrobenzene were nearly identical.

  17. Pathway of radioisotopes from land surface to sewage sludge

    NASA Astrophysics Data System (ADS)

    Fischer, Helmut W.; Yokoo, Yoshiyuki

    2014-05-01

    Radioactive surface contaminations will only partially remain at the original location - a fraction of the inventory will take part in (mainly terrestrial and aquatic) environmental transport processes. The probably best known and most important process comprises the food chain. Besides, the translocation of dissolved and particle-bound radioisotopes with surface waters plays an important role. These processes can have the effect of displacing large radioisotope amounts over considerable distances and of creating new sinks and hot spots, as it is already known for sewage sludge. We are reporting on a combined modeling and experimental project concerning the transport of I-131 and Cs-134/Cs-137 FDNPP 2011 depositions in the Fukushima Prefecture. Well-documented experimental data sets are available for surface deposition and sewage sludge concentrations. The goal is to model the pathway in between, involving surface runoff, transport in the sewer system and processes in the sewage treatment plant. Watershed runoff and sewer transport will be treated with models developed recently by us in other projects. For sewage treatment processes a new model is currently being constructed. For comparison and further validation, historical data from Chernobyl depositions and tracer data from natural and artificial, e.g. medical, isotopes will be used. First results for 2011 data from Fukushima Prefecture will be presented. The benefits of the study are expected to be two-fold: on one hand, the abundant recent and historical data will help to develop and improve environmental transport models; on the other hand, both data and models will help in identifying the most critical points in the envisaged transport pathways in terms of radiation protection and waste management.

  18. Fossil Fuel Biomarkers in Sewage Sludges: Environmental Significance

    NASA Astrophysics Data System (ADS)

    Payet, C.; Bryselbout, C.; Morel, J.-L.; Lichtfouse, E.

    Fossil fuel biomarkers, or "molecular fossils," are specific organic substances found in coals, petroleums, and sedimentary rocks. They are formed during millions of years of sedimentary burial by geochemical alteration of biological molecules, such as cholesterol, under the effect of biodegradation, temperature, pressure, and mineral catalysis, to produce geochemically mature molecules, for example, aromatic steroids (Fig. 1). Since fossil fuel biomarkers have a very specific molecular structure betraying fossil fuel sources, such markers should be useful in assessing the fossil fuel contamination of various modern media such as soils, plants, waters, and modern sediments. Here the identification of fossil fuel biomarkers of high geothermal maturity in sewage sludges provides evidence of the contamination of sludges by petroleum products. The most likely sources of contamination are contaminated vegetal food, road dust, and soil particles carried by rain water.

  19. Single application of sewage sludge--impact on the quality of an alluvial agricultural soil.

    PubMed

    Suhadolc, Metka; Schroll, Reiner; Hagn, Alexandra; Dörfler, Ulrike; Schloter, Michael; Lobnik, Franc

    2010-12-01

    The effects of sewage sludge on soil quality with regard to its nutrient and heavy metal content, microbial community structure and ability to maintain specific soil function (degradation of herbicide glyphosate) were investigated in a three months study using an alluvial soil (Eutric Fluvisol). Dehydrated sewage sludge significantly increased soil organic matter (up to 20.6% of initial content), total and available forms of N (up to 33% and 220% of initial amount, respectively), as well as total and plant available forms of P (up to 11% and 170% of initial amount, respectively) and K (up to 70% and 47% of initial amount, respectively) in the upper 2 cm soil layer. The increase of organic matter was most prominent 3d after the application of sewage sludge, after 3 months it was no longer significant. Contents of nutrients kept to be significantly higher in the sewage sludge treated soil till the end of experiment. Contents of some heavy metals (Zn, Cu, Pb) increased as well. The highest increase was found for Zn (up to 53% of initial amount), however it was strongly bound to soil particles and its total content was kept below the maximum permissible limit for agricultural soil. Based on molecular fingerprinting of bacterial 16S rRNA gene and fungal ITS fragment on 3rd day and 3rd month after sewage sludge amendment, significant short term effects on bacterial and fungal communities were shown due to the sewage sludge. The effects were more pronounced and more long-term for bacterial than fungal communities. The mineralization of (14)C-glyphosate in the sewage sludge soil was 55.6% higher than in the control which can be linked to (i) a higher glyphosate bioavailability in sewage sludge soil, which was triggered by the pre-sorption of phosphate originating from the sewage sludge and/or (ii) beneficial alterations of the sewage sludge to the physical-chemical characteristics of the soil.

  20. Less-costly activated carbon for sewage treatment

    NASA Technical Reports Server (NTRS)

    Ingham, J. D.; Kalvinskas, J. J.; Mueller, W. A.

    1977-01-01

    Lignite-aided sewage treatment is based on absorption of dissolved pollutants by activated carbon. Settling sludge is removed and dried into cakes that are pyrolyzed with lignites to yield activated carbon. Lignite is less expensive than activated carbon previously used to supplement pyrolysis yield.

  1. Sequential extraction of heavy metals during composting of sewage sludge.

    PubMed

    Amir, Soumia; Hafidi, Mohamed; Merlina, Georges; Revel, Jean-Claude

    2005-05-01

    The major limitation of soil application of sewage sludge compost is the total heavy metal contents and their bioavailability to the soil-plant system. This study was conducted to determine the heavy metal speciation and the influence of changing the physico-chemical properties of the medium in the course of composting on the concentrations, bioavailability or chemical forms of Cu, Zn, Pb and Ni in sewage sludge. Principal physical and chemical properties and FTIR spectroscopical characterization of sludge compost during treatment show the stability and maturity of end product. The total metal contents in the final compost were much lower than the limit values of composts to be used as good soil fertilizer. Furthermore, it was observed by using a sequential extraction procedure in sludge compost at different steps of treatment, that a large proportion of the heavy metals were associated to the residual fraction (70-80%) and more resistant fractions to extraction X-NaOH, X-EDTA, X-HNO3 (12-29%). Less than 2% of metals bound to bioavailable fractions X-(KNO3+H2O). Heavy metal distribution and bioavailability show some changes during composting depending on the metal itself and the physico-chemical properties of the medium. Bioavailable fractions of all elements tend to decrease except Ni-H2O. Zn and mainly Cu present more affinity to organic and carbonate fractions. In contrast, Pb is usually preferentially bound to sulfide forms X-HNO3. Nickel shows a significant decrease of organic form. Significant degrees of correlation were found between heavy metal fractions and changes of some selected variables (e.g. pH, ash, organic matter, humic substance) during the course of composting. Mobile fractions of metals are poorly predictable from the total content. The R2 value was significantly increased by the inclusion of other variables such as the amount of organic matter (OM) and pH.

  2. EU policy on sewage sludge utilization and perspectives on new approaches of sludge management.

    PubMed

    Mininni, G; Blanch, A R; Lucena, F; Berselli, S

    2015-05-01

    This paper presents the current sewage sludge legislation in Europe and expected developments regarding the coming directives on the application of the "End-of-waste" criteria and on fertilizers. Discussion on sludge production and processing is also included. The Directive 86/278 has regulated the use in agriculture of residual sludge from domestic and urban wastewater. After 1986, this directive was transposed in the different member state legislation and currently the national limit values on heavy metals, some organic micropollutants and pathogens are placed in a rather wide range. This seems the inevitable consequence of different attitudes towards sludge management practices in the member states. The discussion by the European Joint Research Center (JRC) in Seville regarding application of end-of-waste criteria for compost and digestate has produced a final document (IPTS 2014) where sludge was excluded from the organic wastes admitted for producing an end-of-waste compost. Sludge processing in Europe seems addressed to different goals: sludge minimization, full stabilization and hygienization by thermal hydrolysis processes before anaerobic digestion, and on-site incineration by fluidized bed furnace. Thermophilic anaerobic digestion was applied with success on the Prague WWTP with a preliminary lysimeter centrifugation. Coming techniques, like wet oxidation and pyrolysis, are applied only on very few plants.

  3. Anaerobic co-digestion of sewage sludge and food waste.

    PubMed

    Prabhu, Meghanath S; Mutnuri, Srikanth

    2016-04-01

    Anaerobic co-digestion of organic matter improves digester operating characteristics and its performance. In the present work, food waste was collected from the institute cafeteria. Two types of sludge (before centrifuge and after centrifuge) were collected from the fluidised bed reactor of the institute treating sewage wastewater. Food waste and sludge were studied for their physico-chemical characteristics, such as pH, chemical oxygen demand, total solids, volatile solids, ammoniacal nitrogen, and total nitrogen. A biomethane potential assay was carried out to find out the optimum mixing ratio of food waste and sludge for anaerobic co-digestion. Results indicated that food waste mixed with sludge in the ratio of 1:2 produced the maximum biogas of 823 ml gVS(-1)(21 days) with an average methane content of 60%. Batch studies were conducted in 5 L lab-glass reactors at a mesophilic temperature. The effect of different substrate loading rates on biogas production was investigated. The mixing ratio of food waste and sludge was 1:2. A loading rate of 1 gVS L d(-1)gave the maximum biogas production of 742 ml g(-1)VS L d(-1)with a methane content of 50%, followed by 2 gVS L d(-1)with biogas of 539 ml g(-1)VS L d(-1) Microbial diversity of the reactor during fed batch studies was investigated by terminal restriction fragment length polymorphism. A pilot-scale co-digestion of food waste and sludge (before centrifuge) indicated the process stability of anaerobic digestion.

  4. Behaviour of emerging contaminants in sewage sludge after anaerobic digestion.

    PubMed

    Boix, C; Ibáñez, M; Fabregat-Safont, D; Morales, E; Pastor, L; Sancho, J V; Sánchez-Ramírez, J E; Hernández, F

    2016-11-01

    Nowadays, there is an increasing concern over the presence of contaminants in the aquatic environment, where they can be introduced from wastewater after their incomplete removal in the treatment plants. In this work, degradation of selected emerging pollutants in the aqueous and solid phases of sewage sludge has been investigated after anaerobic digestion using two different digesters: mesophilic and thermophilic. Initially, sludge samples were screened by ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC-QTOF MS) for identification of emerging contaminants in the samples. In a second step, a target quantitative method based on LC coupled to tandem MS was applied for selected pollutants identified in the previous screening. The behaviour of the compounds under anaerobic conditions was studied estimating the degradation efficiency and distribution of compounds between both sludge phases. Irbesartan and benzoylecgonine seemed to be notably degraded in both phases of the sludge. Venlafaxine showed a significant concentration decrease in the aqueous phase in parallel to an increase in the solid phase. The majority of the compounds showed an increase of their concentrations in both phases after the digestion. Concentrations in the solid phase were commonly higher than in the aqueous for most contaminants, indicating that they were preferentially adsorbed onto the solid particles.

  5. Analysis of Combustion Process of Sewage Sludge in Reference to Coals and Biomass

    NASA Astrophysics Data System (ADS)

    Środa, Katarzyna; Kijo-Kleczkowska, Agnieszka

    2016-06-01

    Production of sewage sludge is an inseparable part of the treatment process. The chemical and sanitary composition of sewage sludge flowing into the treatment plant is a very important factor determining the further use of the final product obtained in these plants. The sewage sludge is characterized by heterogeneity and multi-components properties, because they have characteristics of the classical and fertilizer wastes and energetic fuels. The thermal utilization of sewage sludge is necessary due to the unfavorable sanitary characteristics and the addition of the industrial sewage. This method ensures use of sewage sludge energy and return of expenditure incurred for the treatment of these wastes and their disposal. Sewage sludge should be analyzed in relation to conventional fuels (coals and biomass). They must comply with the applicable requirements, for example by an appropriate degree of dehydration, which guarantee the stable and efficient combustion. This paper takes the issue of the combustion process of the different sewage sludge and their comparison of the coal and biomass fuels.

  6. Transformation and availability of nutrients and heavy metals during integrated composting-vermicomposting of sewage sludges.

    PubMed

    Hait, Subrata; Tare, Vinod

    2012-05-01

    Transformation and availability of nutrients and some heavy metals were assessed during the integrated composting-vermicomposting of both primary sewage sludge (PSS) and waste activated sewage sludge (WAS) using matured vermicompost as indigenous bulking material and employing Eisenia fetida as earthworm species. Vermicomposting resulted in significant increase in total N (TN) (PSS: 41.7-64.6%, F=11.6, P<0.05; WAS: 36.4-58.6%, F=6.4, P<0.05), water soluble N (WSN) (PSS: 37.1-50.5%, F=30.1, P<0.05; WAS: 40.1-53.0%, F=27.6, P<0.05), total P (TP) (PSS: 39.9-69.8%, F=27.1, P<0.05; WAS: 32.2-56.6%, F=21.4, P<0.05) and water soluble P (WSP) (PSS: 25.2-34.3%, F=163.9, P<0.05; WAS: 24.1-34.2%, F=144.3, P<0.05) as compared to the initial compost material depending on different experimental conditions. The study demonstrated that the vermicomposting significantly improved the availability of nutrients in sewage sludges. In addition, vermicomposting considerably reduced the availability of heavy metals except Fe and Mn, presumably by forming organic-bound complexes in spite of several fold increase in their total content. The environmental conditions (i.e., temperature and relative humidity), in general, showed significant effect on the transformation and availability of nutrients and heavy metals. There was no effect of earthworm density on the transformation and availability of heavy metals and nutrients except N and P, possibly due to prior exposure during acclimation period in sewage sludge.

  7. Effect of sewage sludge on formation of acidic ground water at a reclaimed coal mine

    USGS Publications Warehouse

    Cravotta, C.A.

    1998-01-01

    Data on rock, ground water, vadose water, and vadose gas chemistry were collected for two years after sewage sludge was applied at a reclaimed surface coal mine in Pennsylvania to determine if surface-applied sludge is an effective barrier to oxygen influx, contributes metals and nutrients to ground water, and promotes the acidification of ground water. Acidity, sulfate, and metals concentrations were elevated in the ground water (6- to 21-m depth) from spoil relative to unmined rock because of active oxidation of pyrite and dissolution of aluminosilicate, carbonate, and Mn-Fe-oxide minerals in the spoil. Concentrations of acidity, sulfate, metals (Fe, Mn, Al, Cd, Cu, Cr, Ni, Zn), and nitrate, and abundances of iron-oxidizing bacteria were elevated in the ground water from sludge-treated spoil relative to untreated spoil having a similar mineral composition; however, gaseous and dissolved oxygen concentrations did not differ between the treatments. Abundances of iron-oxidizing bacteria in the ground water samples were positively correlated with concentrations of ammonia, nitrate, acidity, metals, and sulfate. Concentrations of metals in vadose water samples (<5-m depth) from sludge-treated spoil (pH 5.9) were not elevated relative to untreated spoil (pH 4.4). In contrast, concentrations of nitrate were elevated in vadose water samples from sludge-treated spoil, frequently exceeding 10 mg/L. Downgradient decreases in nitrate to less than 3 mg/L and increases in sulfate concentrations in underlying ground water could result from oxidation of pyrite by nitrate. Thus, sewage sludge added to pyritic spoil can increase the growth of iron-oxidizing bacteria, the oxidation of pyrite, and the acidification of ground water. Nevertheless, the overall effects on ground water chemistry from the sludge were small and probably short-lived relative to the effects from mining only.

  8. Sewage sludge drying process integration with a waste-to-energy power plant.

    PubMed

    Bianchini, A; Bonfiglioli, L; Pellegrini, M; Saccani, C

    2015-08-01

    Dewatered sewage sludge from Waste Water Treatment Plants (WWTPs) is encountering increasing problems associated with its disposal. Several solutions have been proposed in the last years regarding energy and materials recovery from sewage sludge. Current technological solutions have relevant limits as dewatered sewage sludge is characterized by a high water content (70-75% by weight), even if mechanically treated. A Refuse Derived Fuel (RDF) with good thermal characteristics in terms of Lower Heating Value (LHV) can be obtained if dewatered sludge is further processed, for example by a thermal drying stage. Sewage sludge thermal drying is not sustainable if the power is fed by primary energy sources, but can be appealing if waste heat, recovered from other processes, is used. A suitable integration can be realized between a WWTP and a waste-to-energy (WTE) power plant through the recovery of WTE waste heat as energy source for sewage sludge drying. In this paper, the properties of sewage sludge from three different WWTPs are studied. On the basis of the results obtained, a facility for the integration of sewage sludge drying within a WTE power plant is developed. Furthermore, energy and mass balances are set up in order to evaluate the benefits brought by the described integration.

  9. The application of sewage sludge as an expanding agent in the production of lightweight expanded clay aggregate mass.

    PubMed

    Latosińska, J; Zygadło, M

    2011-10-01

    Sewage sludge can be used as an expanding agent in the production of lightweight expanded clay aggregate (LECA) mass. The addition of sewage sludge increases the total porosity and decreases the bulk density of a sinter. The addition of sewage sludge to a raw material used in the production of LECA enabled a decrease in the burning temperature for the maintained operational parameters of a lightweight aggregate. The optimum content of sewage sludge added to a raw material used in LECA production was 5% to 15% of dry mass. The addition of sewage sludge in an amount of 5% and 10% caused an increase in closed porosity.

  10. Comparative assessment of municipal sewage sludge incineration, gasification and pyrolysis for a sustainable sludge-to-energy management in Greece.

    PubMed

    Samolada, M C; Zabaniotou, A A

    2014-02-01

    For a sustainable municipal sewage sludge management, not only the available technology, but also other parameters, such as policy regulations and socio-economic issues should be taken in account. In this study, the current status of both European and Greek Legislation on waste management, with a special insight in municipal sewage sludge, is presented. A SWOT analysis was further developed for comparison of pyrolysis with incineration and gasification and results are presented. Pyrolysis seems to be the optimal thermochemical treatment option compared to incineration and gasification. Sewage sludge pyrolysis is favorable for energy savings, material recovery and high added materials production, providing a 'zero waste' solution. Finally, identification of challenges and barriers for sewage sludge pyrolysis deployment in Greece was investigated.

  11. Transformation products and human metabolites of triclocarban and tricllosan in sewage sludge across the United States

    USGS Publications Warehouse

    Pycke, Benny F.G.; Roll, Isaac B.; Brownawell, Bruce J.; Kinney, Chad A.; Furlong, Edward T.; Kolpin, Dana W.; Halden, Rolf U.

    2014-01-01

    Removal of triclocarban (TCC) and triclosan (TCS) from wastewater is a function of adsorption, abiotic degradation, and microbial mineralization or transformation, reactions that are not currently controlled or optimized in the pollution control infrastructure of standard wastewater treatment. Here, we report on the levels of eight transformation products, human metabolites, and manufacturing byproducts of TCC and TCS in raw and treated sewage sludge. Two sample sets were studied: samples collected once from 14 wastewater treatment plants (WWTPs) representing nine states, and multiple samples collected from one WWTP monitored for 12 months. Time-course analysis of significant mass fluxes (α = 0.01) indicate that transformation of TCC (dechlorination) and TCS (methylation) occurred during sewage conveyance and treatment. Strong linear correlations were found between TCC and the human metabolite 2′-hydroxy-TCC (r = 0.84), and between the TCC-dechlorination products dichlorocarbanilide (DCC) and monochlorocarbanilide (r = 0.99). Mass ratios of DCC-to-TCC and of methyl-triclosan (MeTCS)-to-TCS, serving as indicators of transformation activity, revealed that transformation was widespread under different treatment regimes across the WWTPs sampled, though the degree of transformation varied significantly among study sites (α = 0.01). The analysis of sludge sampled before and after different unit operation steps (i.e., anaerobic digestion, sludge heat treatment, and sludge drying) yielded insights into the extent and location of TCC and TCS transformation. Results showed anaerobic digestion to be important for MeTCS transformation (37–74%), whereas its contribution to partial TCC dechlorination was limited (0.4–2.1%). This longitudinal and nationwide survey is the first to report the occurrence of transformation products, human metabolites, and manufacturing byproducts of TCC and TCS in sewage sludge.

  12. Transformation products and human metabolites of triclocarban and triclosan in sewage sludge across the United States.

    PubMed

    Pycke, Benny F G; Roll, Isaac B; Brownawell, Bruce J; Kinney, Chad A; Furlong, Edward T; Kolpin, Dana W; Halden, Rolf U

    2014-07-15

    Removal of triclocarban (TCC) and triclosan (TCS) from wastewater is a function of adsorption, abiotic degradation, and microbial mineralization or transformation, reactions that are not currently controlled or optimized in the pollution control infrastructure of standard wastewater treatment. Here, we report on the levels of eight transformation products, human metabolites, and manufacturing byproducts of TCC and TCS in raw and treated sewage sludge. Two sample sets were studied: samples collected once from 14 wastewater treatment plants (WWTPs) representing nine states, and multiple samples collected from one WWTP monitored for 12 months. Time-course analysis of significant mass fluxes (α=0.01) indicate that transformation of TCC (dechlorination) and TCS (methylation) occurred during sewage conveyance and treatment. Strong linear correlations were found between TCC and the human metabolite 2'-hydroxy-TCC (r=0.84), and between the TCC-dechlorination products dichlorocarbanilide (DCC) and monochlorocarbanilide (r=0.99). Mass ratios of DCC-to-TCC and of methyl-triclosan (MeTCS)-to-TCS, serving as indicators of transformation activity, revealed that transformation was widespread under different treatment regimes across the WWTPs sampled, though the degree of transformation varied significantly among study sites (α=0.01). The analysis of sludge sampled before and after different unit operation steps (i.e., anaerobic digestion, sludge heat treatment, and sludge drying) yielded insights into the extent and location of TCC and TCS transformation. Results showed anaerobic digestion to be important for MeTCS transformation (37-74%), whereas its contribution to partial TCC dechlorination was limited (0.4-2.1%). This longitudinal and nationwide survey is the first to report the occurrence of transformation products, human metabolites, and manufacturing byproducts of TCC and TCS in sewage sludge.

  13. Transformation Products and Human Metabolites of Triclocarban and Triclosan in Sewage Sludge Across the United States

    PubMed Central

    2015-01-01

    Removal of triclocarban (TCC) and triclosan (TCS) from wastewater is a function of adsorption, abiotic degradation, and microbial mineralization or transformation, reactions that are not currently controlled or optimized in the pollution control infrastructure of standard wastewater treatment. Here, we report on the levels of eight transformation products, human metabolites, and manufacturing byproducts of TCC and TCS in raw and treated sewage sludge. Two sample sets were studied: samples collected once from 14 wastewater treatment plants (WWTPs) representing nine states, and multiple samples collected from one WWTP monitored for 12 months. Time-course analysis of significant mass fluxes (α = 0.01) indicate that transformation of TCC (dechlorination) and TCS (methylation) occurred during sewage conveyance and treatment. Strong linear correlations were found between TCC and the human metabolite 2′-hydroxy-TCC (r = 0.84), and between the TCC-dechlorination products dichlorocarbanilide (DCC) and monochlorocarbanilide (r = 0.99). Mass ratios of DCC-to-TCC and of methyl-triclosan (MeTCS)-to-TCS, serving as indicators of transformation activity, revealed that transformation was widespread under different treatment regimes across the WWTPs sampled, though the degree of transformation varied significantly among study sites (α = 0.01). The analysis of sludge sampled before and after different unit operation steps (i.e., anaerobic digestion, sludge heat treatment, and sludge drying) yielded insights into the extent and location of TCC and TCS transformation. Results showed anaerobic digestion to be important for MeTCS transformation (37–74%), whereas its contribution to partial TCC dechlorination was limited (0.4–2.1%). This longitudinal and nationwide survey is the first to report the occurrence of transformation products, human metabolites, and manufacturing byproducts of TCC and TCS in sewage sludge. PMID:24932693

  14. Estrogenic compounds in Tunisian urban sewage treatment plant: occurrence, removal and ecotoxicological impact of sewage discharge and sludge disposal.

    PubMed

    Belhaj, Dalel; Athmouni, Khaled; Jerbi, Bouthaina; Kallel, Monem; Ayadi, Habib; Zhou, John L

    2016-12-01

    The occurrence, fate and ecotoxicological assessment of selected estrogenic compounds were investigated at Tunisian urban sewage treatment plant. The influents, effluents, as well as primary, secondary and dehydrated sludge, were sampled and analyzed for the target estrogens to evaluate their fate. All target compounds were detected in both sewage and sludge with mean concentrations from 0.062 to 0.993 μg L(-1) and from 11.8 to 792.9 μg kg(-1)dry weight, respectively. A wide range of removal efficiencies during the treatment processes were observed, from 6.3 % for estrone to 76.8 % for estriol. Ecotoxicological risk assessment revealed that the highest ecotoxicological risk in sewage effluent and dehydrated sludge was due to 17β-estradiol with a risk quotient (RQ) of 4.6 and 181.9, respectively, and 17α-ethinylestradiol with RQ of 9.8 and 14.85, respectively. Ecotoxicological risk after sewage discharge and sludge disposal was limited to the presence of 17β-estradiol in dehydrated-sludge amended soil with RQ of 1.38. Further control of estrogenic hormones in sewage effluent and sludge is essential before their discharge and application in order to prevent their introduction into the natural environment.

  15. Mineralogy and leachability of gasified sewage sludge solid residues.

    PubMed

    Hernandez, Ana Belén; Ferrasse, Jean-Henry; Chaurand, Perrine; Saveyn, Hans; Borschneck, Daniel; Roche, Nicolas

    2011-07-15

    Gasification of sewage sludge produces combustible gases as well as tar and a solid residue as by-products. This must be taken into account when determining the optimal thermal conditions for the gasification process. In this study, the influence of temperature, heating atmosphere and residence time on the characteristics of the gasified sewage sludge residues is investigated. ICP-AES analyses reveal that the major chemical elements in the char residues are phosphorus, calcium, iron and silicon. Heavy metals such as copper, zinc, chromium, nickel and lead are also present at relatively high levels - from 50 to more than 1000 mg/kg of dry matter. The major mineral phases' identification - before and after heating - as well as their morphology and approximate chemistry (XRD and SEM-EDX) demonstrate that a number of transformations take place during gasification. These are influenced by the reactor's temperature and the oxidative degree of its internal atmosphere. The copper-, zinc- and chromium-bearing phases are studied using chemometric tools, showing that the distribution of those metals among the mineral phases is considerably different. Finally, batch-leaching tests reveal that metals retained in the residue are significantly stabilized after thermal treatment to a higher or lower extent, depending on the thermal conditions applied.

  16. Effect of linear alkylbenzene sulphonates (LAS) on the anaerobic digestion of sewage sludge.

    PubMed

    Garcia, M T; Campos, E; Sánchez-Leal, J; Ribosa, I

    2006-08-01

    Batch anaerobic biodegradation tests with different alkylbenzene sulphonates (LAS) at increasing concentrations were performed in order to investigate the effect of LAS homologues on the anaerobic digestion process of sewage sludge. Addition of LAS homologues to the anaerobic digesters increased the biogas production at surfactant concentrations 5-10 g/kg dry sludge and gave rise to a partial or total inhibition of the methanogenic activity at higher surfactant loads. Therefore, at the usual LAS concentration range in sewage sludge, no adverse effects on the anaerobic digesters functioning of a wastewater treatment plant (WWTP) can be expected. The increase of biogas production at low surfactant concentrations was attributed to an increase of the bioavailability and subsequent biodegradation of organic pollutants associated with the sludge, promoted by the surfactant adsorption at the solid/liquid interface. When the available surfactant fraction in the aqueous phase instead of the nominal surfactant concentration was used to evaluate the toxicity of LAS homologues, a highly significant relationship between toxicity and alkyl chain length was obtained. Taking into account the homologue distribution of commercial LAS in the liquid phase of the anaerobic digesters of a WWTP, an EC(50) value of 14 mg/L can be considered for LAS toxicity on the anaerobic microorganisms.

  17. Separation of metals and phosphorus from incinerated sewage sludge ash.

    PubMed

    Ito, A; Yamada, K; Ishikawa, N; Umita, T

    2013-01-01

    Microbial acidification of incinerated sewage sludge ash and dissolution of metals from the acidified ash were investigated using a semi-batch reactor at different solid retention times (SRTs). The average pH values ranged from 0.91 to 1.2 at SRTs longer than 10 days, whereas the reduction of SRT to 4 days resulted in an increase in the pH value to about 2. The dissolution efficiencies of Al, As, Cd, Cu and Mn were greater than 60% at a SRT of 4 days. Moreover, the effect of pH on precipitation of metals and P (dissolution of 80%) in the filtrate removed from the acidified sewage ash suspension, and the separation of phosphorus and the other metals in the filtrate using ethylenediaminetetraacetic acid (EDTA) or ferric ion, were examined. Although neutralisation of the filtrate to a pH of 5 simultaneously precipitated 100% of Al and 80% of P recovered from the acidified sewage ash, the addition of EDTA decreased their precipitation to 70 and 50%, respectively, at the same pH value, which would promote precipitation of P as calcium phosphate. Furthermore, neutralising to a pH of 2.5 after the addition of ferric ion precipitated P separately from Al and heavy metals.

  18. Evaluation of emission of greenhouse gases from soils amended with sewage sludge.

    PubMed

    Paramasivam, S; Fortenberry, Gamola Z; Julius, Afolabi; Sajwan, Kenneth S; Alva, A K

    2008-02-01

    Increase in concentrations of various greenhouse gases and their possible contributions to the global warming are becoming a serious concern. Anthropogenic activities such as cultivation of flooded rice and application of waste materials, such as sewage sludge which are rich in C and N, as soil amendments could contribute to the increase in emission of greenhouse gases such as methane (CH(4)) and nitrous oxide (N(2)O) into the atmosphere. Therefore, evaluation of flux of various greenhouse gases from soils amended with sewage sludge is essential to quantify their release into the atmosphere. Two soils with contrasting properties (Candler fine sand [CFS] from Florida, and Ogeechee loamy sand [OLS] from Savannah, GA) were amended with varying rates (0, 24.7, 49.4, 98.8, and 148.3 Mg ha(-1)) of 2 types of sewage sludge (industrial [ISS] and domestic [DSS] origin. The amended soil samples were incubated in anaerobic condition at field capacity soil water content in static chamber (Qopak bottles). Gas samples were extracted immediately after amending soils and subsequently on a daily basis to evaluate the emission of CH(4), CO(2) and N(2)O. The results showed that emission rates and cumulative emission of all three gases increased with increasing rates of amendments. Cumulative emission of gases during 25-d incubation of soils amended with different types of sewage sludge decreased in the order: CO(2) > N(2)O > CH(4). The emission of gases was greater from the soils amended with DSS as compared to that with ISS. This may indicate the presence of either low C and N content or possible harmful chemicals in the ISS. The emission of gases was greater from the CFS as compared to that from the OLS. Furthermore, the results clearly depicted the inhibitory effect of acetylene in both soils by producing more N(2)O and CH(4) emission compared to the soils that did not receive acetylene at the rate of 1 mL g(-1) soil. Enumeration of microbial population by fluorescein diacetate

  19. Qualitative and Quantitative Assessment of Sewage Sludge by Gamma Irradiation with Pasteurization as a Tool for Hygienization

    NASA Astrophysics Data System (ADS)

    Priyadarshini, J.; Roy, P. K.; Mazumdar, A.

    2014-01-01

    In this research work, management of sewage sludge disposal on agricultural soils is addressed. The increasing amount of sewage sludge and more legislative regulation of its disposal have stimulated the need for developing new technologies to recycle sewage sludge efficiently. The research was structured along two main avenues, namely, the efficacy of the irradiation process for removing enteric pathogenic microorganisms and the potential of irradiated sludge as a soil amendment. This study investigated how application of irradiation with heat treatment reduced pathogens in sewage sludge. Raw and pasteurised Sewage sludge was treated at different dose treatment of 1.5, 3 and 5 kilogray (kGy) gamma irradiation individually and for 3 kGy sufficiency was achieved. Decrease in irradiation dose from 5 to 3 kGy was observed for pasteurised sludge resulting in saving of radiation energy. The presence of heavy metals in untreated sewage sludge has raised concerns, which decreases after irradiation.

  20. Comparison of PAHs uptake by selected Monocotyledones and Dicotyledones from municipal and industrial sewage sludge.

    PubMed

    Gworek, Barbara; Klimczak, Katarzyna; Kijeńska, Marta; Gozdowski, Dariusz

    2016-10-01

    The study was focused on two goals: (i) the confirmation of the existence of a general relation between the content of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge and in plants growing in it, regardless of the type and content of sewage sludge, and (ii) if so, the answer to the question whether the uptake of PAHs by plants depends on their type. To realize the set aims, the contents of PAHs in four differentiated plant species were measured, two belonging to the Monocotyledones and two belonging to Dicotyledones group, growing in municipal and industrial sewage sludge in two locations. All the investigations were carried out during the period of 3 years. The results clearly demonstrated that the uptake of PAHs by a plant depended on polyaromatic hydrocarbon concentration in the sewage sludge. The relation between accumulation coefficient of PAHs in plant material vs. the content of PAH in sewage sludge was of exponential character. The results indicate that in case of four- and five-ring PAHs, the root uptake mechanism from soil solution occurs, regardless of the type and origin of sewage sludge and the type of plant. For three-ring PAHs, we can assume for Monocotyledones that the root uptake mechanism occurs because we observe a significant correlation between the content of fluorene, phenanthrene, and anthracene in plant material and in the sewage sludge. For Dicotyledones, the correlation is insignificant, and in this case probably two mechanisms occur-the uptake by roots and by leaves.

  1. Nitrous oxide and methane emissions during storage of dewatered digested sewage sludge.

    PubMed

    Willén, Agnes; Rodhe, Lena; Pell, Mikael; Jönsson, Håkan

    2016-12-15

    This study investigated the effect on greenhouse gas emissions during storage of digested sewage sludge by using a cover during storage or applying sanitisation measures such as thermophilic digestion or ammonia addition. In a pilot-scale storage facility, nitrous oxide and methane emissions were measured on average twice monthly for a year, using a closed chamber technique. The thermophilically digested sewage sludge (TC) had the highest cumulative emissions of nitrous oxide (1.30% of initial total N) followed by mesophilically digested sewage sludge stored without a cover (M) (0.34%) and mesophilically digested sewage sludge stored with a cover (MC) (0.19%). The mesophilically digested sewage sludge sanitised with ammonia and stored with a cover (MAC) showed negligible cumulative emissions of nitrous oxide. Emissions of methane were much lower from TC and MAC than from M and MC. These results indicate that sanitisation by ammonia treatment eliminates the production of nitrous oxide and reduces methane emissions from stored sewage sludge, and that thermophilic digestion has the potential to reduce the production of methane during storage compared with mesophilic digestion. The results also indicate a tendency for lower emissions of nitrous oxide and higher emissions of methane from covered sewage sludge compared with non-covered.

  2. Investigating the levels and trends of organochlorine pesticides and polychlorinated biphenyl in sewage sludge.

    PubMed

    Clarke, Bradley O; Porter, Nichola A; Marriott, Philip J; Blackbeard, Judy R

    2010-05-01

    A study was completed to investigate temporal trends of organochlorine pesticides (OCPs; aldrin, chlordane, dieldrin, heptachlor, hexachlorbenzene, and DDT) and polychlorinated biphenyls (PCBs) in sewage sludge. Between 2004 and 2006 the concentration of OCPs and PCBs in Australian sewage sludge (n=829) was consistently <1000mugkg(-1) dry solids DS. Dieldrin, chlordane and DDE were detected in 68%, 27% and 13% at maximum concentrations of 770, 290 and 270 microgkg(-1) DS, respectively. Time series analysis (1995-2006) of OCPs and PCBs sewage sludge concentrations (n=2266) taken from six wastewater treatment plants (WWTPs) of the same geographic region found that lindane, aldrin HCB, heptachlor, DDT, DDD and PCBs were infrequently detected (<8%). A correlation between dieldrin and chlordane levels was found (P<0.05) which provides evidence of similar environmental mechanisms facilitating movement of dieldrin and chlordane through environment compartments. It has taken more than 10years for dieldrin and chlordane to reduce to less than detectable concentrations in freshly generated sewage sludge in Australia following government restrictions. Internationally, reported sewage sludge OCP concentrations were consistently low and often less than detection limits. Therefore, OCPs are not considered to be a contaminant of regulatory concern for countries that phased out OCP use several decades ago. Concentrations of PCBs in sewage sludge were also consistently low and rarely exceeded European contaminant limits and therefore, regulatory limits may warrant review. The authors recommend that Australian authorities revise regulatory requirements for OCP and PCBs contaminant levels in sewage sludge destined for beneficial reuse as biosolids.

  3. Laboratory measurements of radiance and reflectance spectra of dilute secondary-treated sewage sludge

    NASA Technical Reports Server (NTRS)

    Witte, W. G.; Usry, J. W.; Whitlock, C. H.; Gurganus, E. A.

    1977-01-01

    The National Aeronautics and Space Administration (NASA), in cooperation with the Environmental Protection Agency (EPA) and the National Oceanic and Atmospheric Administration (NOAA), conducted a research program to evaluate the feasibility of remotely monitoring ocean dumping of waste products such as acid and sewage sludge. One aspect of the research program involved the measurements of upwelled spectral signatures for sewage-sludge mixtures of different concentrations in an 11600-liter tank. This paper describes the laboratory arrangement and presents radiance and reflectance spectra in the visible and near-infrared ranges for concentrations ranging from 9.7 to 180 ppm of secondary-treated sewage sludge mixed with two types of base water. Results indicate that upwelled radiance varies in a near-linear manner with concentration and that the sludge has a practically flat signal response between 420 and 970 nm. Reflectance spectra were obtained for the sewage-sludge mixtures at all wavelengths and concentrations.

  4. Laboratory measurements of radiance and reflectance spectra of dilute primary-treated sewage sludge

    NASA Technical Reports Server (NTRS)

    Usry, J. W.; Witte, W. G.; Whitlock, C. H.; Gurganus, E. A.

    1977-01-01

    The feasibility of remotely monitoring ocean dumping of waste products such as acid and sewage sludge is evaluated. The laboratory arrangement, solar simulator, and test results from three experiments conducted in the laboratory are described. Radiance and reflectance spectra are presented for primary-treated sewage sludge mixed with two types of base water. Results indicate that upwelled reflectance varies in a near-linear manner with concentration and that the sludge has a practically flat signal response between 420 and 970 nm. Well-defined upwelled reflectance spectra were obtained for the sewage-sludge mixtures at all wavelengths and concentrations. The spectral-reflectance values appeared to be influenced by the type of base water, but this influence was small, especially for the mixtures with low concentrations of sewage sludge.

  5. Biological testing of a digested sewage sludge and derived composts.

    PubMed

    Moreira, R; Sousa, J P; Canhoto, C

    2008-11-01

    Aiming to evaluate a possible loss of soil habitat function after amendment with organic wastes, a digested sewage sludge and derived composts produced with green residues, where biologically tested in the laboratory using soil animals (Eisenia andrei and Folsomia candida) and plants (Brassica rapa and Avena sativa). Each waste was tested mimicking a field application of 6ton/ha or 12ton/ha. Avoidance tests did not reveal any impact of sludge and composts to soil biota. Germination and growth tests showed that application of composts were beneficial for both plants. Composts did not affect earthworm's mass increase or reproduction, but the highest sludge amendment revealed negative effects on both parameters. Only the amendment of composts at the highest dose originated an impairment of springtails reproductive output. We suggest that bioassays using different test species may be an additional tool to evaluate effects of amendment of organic wastes in soil. Biological tests are sensitive to pollutants at low concentrations and to interactions undetected by routine chemical analysis.

  6. Single application of Sewage Sludge to an Alluvial Agricultural Soil - impacts on Soil Quality

    NASA Astrophysics Data System (ADS)

    Suhadolc, M.; Graham, D. B.; Hagn, A.; Doerfler, U.; Schloter, M.; Schroll, R.; Munch, J. C.; Lobnik, F.

    2009-04-01

    Limited information exists on the effects of sewage sludge on soil quality with regard to their ability to maintain soil functions. We studied effects of sewage sludge amendment on soil chemical properties, microbial community structure and microbial degradation of the herbicide glyphosate. Three months soil column leaching experiment has been conducted using alluvial soils (Eutric Fluvisol) with no prior history of sludge application. The soil was loamy with pH 7,4 and organic matter content of 3,5%. Soil material in the upper 2 cm of columns was mixed with dehydrated sewage sludge which was applied in amounts corresponding to the standards governing the use of sewage sludge for agricultural land. Sludge did increase some nutrients (total N, NH4+, available P and K, organic carbon) and some heavy metals contents (Zn, Cu, Pb) in soil. However, upper limits for heavy metals in agricultural soils were not exceeded. Results of heavy metal availability in soil determined by sequential extraction will be also presented. Restriction fragment length polymorphism (RFLP) analyses of 16s/18s rDNA, using universal fungal and bacterial primers, revealed clear shifts in bacterial and fungal community structure in the upper 2 cm of soils after amendment. Fungal fingerprints showed greater short term effects of sewage sludge, whereas sewage sludge seems to have prolonged effects on soil bacteria. Furthermore, sewage sludge amendment significantly increased glyphosate degradation from 21.6±1% to 33.6±1% over a 2 months period. The most probable reasons for shifts in microbial community structure and increased degradation of glyphosate are beneficial alterations to the physical-chemical characteristics of the soil. Negative effects of potentially toxic substances present in the sewage sludge on soil microbial community functioning were not observed with the methods used in our study.

  7. Modeling the Radiological Impact of Tritium in Sewage Sludge Being Used as Fertilizer

    SciTech Connect

    Venter, A.; Smith, G

    2005-07-15

    A study was undertaken to assess the radiological impact on humans via the foodchain resulting from the presence of tritium and C-14 in sewage sludge being used as fertilizer on agricultural land. The key endpoint of the assessment was the annual individual dose to an average member of potential critical groups. As part of the assessment, a model was developed to simulate the distribution of tritium between sewage sludge and effluent in the sewage treatment plant, the release of tritium upon sludge decomposition and subsequent uptake by plants and animals. The modeling assumptions, as well as key parameters and parameter values will be discussed in this paper.

  8. Determination of mercury in sewage sludge by direct slurry sampling graphite furnace atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Baralkiewicz, Danuta; Gramowska, Hanka; Kózka, Małgorzata; Kanecka, Anetta

    2005-03-01

    Ultrasonic slurry sampling electrothermal atomic absorption spectrometry (ETAAS) method was elaborated to the determination of Hg in sewage sludge samples with the use of KMnO 4+Pd modifier. The minimum sample amount required for slurry preparation with respect to sample homogeneity was evaluated by weighting masses between 3 and 30 mg directly into the autosampler cups. Validation of the proposed method was performed with the use of Certified Reference Materials of sewage sludge, CRM 007-040 and CRM 144R. Two sewage sludge samples from Poznañ (Poland) city were analysed using the present direct method and a method with sample digestion, resulting in no difference within statistical error.

  9. Survivorship of meadow voles, Microtus pennsylvanicus, from sewage sludge-treated fields

    SciTech Connect

    Maly, M.S.

    1984-06-01

    A long-term field study was begun in 1977 at Miami University to evaluate the effects of land application of sewage sludge on experimental old-field communities. The effects of sludge application on toxic metal concentrations in meadow vole (Microtus pennsylvanicus) organs during the first two years of the study have been reported. During the first two years of sludge application, no detrimental effects were observed in vole survivorship as a result of sludge treatment.

  10. Occurrence of high-tonnage anionic surfactants in Spanish sewage sludge.

    PubMed

    Cantarero, Samuel; Prieto, Carlos A; López, Ignacio

    2012-03-01

    Agricultural application has become the most widespread method of sewage sludge disposal, being the most economical outlet for sludge and also recycling beneficial plant nutrients and organic matter to soil for crop production. As a matter of fact, the European Sewage Sludge Directive 86/278/EEC seeks to encourage the disposal of sewage sludge in agriculture applications and regulate its use to prevent harmful effects on the soil environment. At the present time, the sewage sludge Directive is under revision and a possible cut-off limit for some organic chemicals may be implemented. Linear alkylbenzene sulphonate (LAS), the main synthetic anionic surfactant, has been included in the draft list of chemicals to be limited. The present research work deals with the monitoring of LAS and soap in Spanish sewage sludge. The average concentration of LAS found in anaerobic sewage sludge samples was 8.06 g/kg, higher than the average values for European sludge. Besides, it has been also found that more than 55% of Spanish anaerobic sludge would not fulfil the limit proposed by the 3rd European Working paper on sludge. As a consequence, the implementation of the limit for LAS would make the disposal of most Spanish biosolids for agricultural applications almost impossible. Regarding the mechanisms why anionic surfactants are found in sludge, two surfactants are compared: LAS and soap, both readily biodegraded in aerobic conditions. Irrespective of the anaerobic biodegradability of soap, its concentration found in sludge is higher than LAS (only anaerobically biodegradable under particular conditions). The relevance of anaerobic biodegradation to assure environmental protection is discussed for this case.

  11. Oxygen-enriched coincineration of MSW and sewage sludge: Final report

    SciTech Connect

    1994-01-01

    Federal regulations banning ocean dumping of sewage sludge coupled with stricter regulations on the disposal of sewage sludge in landfills have forced municipalities, especially those in the northeast United States, to consider alternate methods for disposal of this solid waste. Coincineration of municipal solid waste (MSW) and sludge has proven to be economically attractive for both Europe and Japan, but has not yet proven to be a viable sludge disposal technology in the United States because of a history of operational problems in existing facilities. The most prevalent problem in coincinerating MSW and a dewatered sewage sludge (15 to 25% solids) is incomplete sludge combustion. Incomplete sludge combustion is primarily a function of sludge particle size, occurring when the surface of the sludge particle dries and hardens, while the inner mass is unaffected. This phenomenon is commonly referred to in the industry as the {open_quotes}hamburger effect.{close_quotes} In an effort to promote technology development in this area, Air Products and Chemicals, Inc. teamed with the US Department of Energy (DOE) through the National Renewable Energy Laboratory (NREL) to evaluate a new process being developed for the disposal of a dewatered sewage sludge, {open_quotes}Oxygen-Enriched Coincineration of MSW and Sewage Sludge.{close_quotes} This report provides a comprehensive summary of the pilot demonstration test program for oxygen-enriched coincineration of MSW and sewage sludge. This report describes the pilot test facility, instrumentation, and methods of data collection and data analyses; describes how the tests were executed; and discusses the test results. Recommendations for the future development of this technology in the current marketplace are also provided.

  12. Effects of several applications of digested sewage sludge on soil and plants.

    PubMed

    de las Heras, Jorge; Mañas, Pilar; Labrador, Juana

    2005-01-01

    Sewage sludge production has significantly increased during the last years in European Union (EU) countries, being primarily used for agricultural purposes. In this study, digested sewage sludge was applied to greenhouse soil over a three-year period (2001--2003), with three sludge treatments in the first two years (2, 4, and 6 kg m(-2)) and three more applications using a greater quantity in the last year (6, 8, and 10 kg m(-2)). The effects of sewage sludge application on soil and on a leafy crop (Lactuca sativa L.) were studied. Mineral elements, organic matter, pH, and heavy metals were measured in soil and plant tissues. Pathogen and indicator microorganism dynamics in soil were also determined after each sludge application. Results showed that sewage sludge applications increased organic matter, P, and N Ca content in soil. Furthermore, Zn, Pb, Ni, and Cu content increased in soils, primarily after high doses of sludge. The highest yield value was obtained in the second-year harvest, since the last sludge application did not increase yield. Fecal coliform numbers decreased significantly one month after sludge application. However, total coliforms, Clostridium sulphite-reducers and Salmonella, were present in soils three months after sludge application.

  13. Re-use of water treatment works sludge to enhance particulate pollutant removal from sewage.

    PubMed

    Guan, Xiao-Hong; Chen, Guang-Hao; Shang, Chii

    2005-09-01

    This paper attempted to study the feasibility of reusing water treatment works sludge ("alum sludge") to improve particulate pollutant removal from sewage. The main issues focused upon were: (1) the appropriate dosage of the alum sludge, (2) the appropriate operating conditions, and (3) the possible mechanisms for enhancement by adding alum sludge. Actual alum sludge and sewage were applied to a series of jar tests conducted under various conditions. It has been found that both the SS and COD removal efficiencies could be improved by the addition of the alum sludge, which was mainly attributed to the removal of relatively fine particles with a size of 48-200 microm. The appropriate dosage of the alum sludge was determined to be 18-20 mg of Al/L. Increasing the mixing speed or reducing the floc size of the alum sludge enhanced the SS and COD removal and the dispersed alum sludge could remove particulate contaminants with smaller size than the raw sewage. ToF-SIMS evidence revealed that the aluminum species at the surface of the alum sludge were effectively utilized for improving the SS and COD removal. It was postulated that the sweep flocculation and/or the physical adsorption might play key roles in the enhancement of particulate pollutant removal from sewage.

  14. Assessment of a potential agricultural application of Bangkok-digested sewage sludge and finished compost products.

    PubMed

    Sreesai, Siranee; Peapueng, Panadda; Tippayamongkonkun, Taninporn; Sthiannopkao, Suthipong

    2013-09-01

    A study was conducted to investigate the levels of plant nutrients, heavy metals, parasites and fecal coliform bacteria in Bangkok-produced sewage sludge and finished compost products for potential agricultural application, as well as to compare the quality of compost under different composting conditions. The results indicated that digested sewage sludge had high fertilizing values for organic matter (19.01 ± 0.09%), total nitrogen (2.17 ± 0.07%), total phosphorus (2.06 ± 0.06%) and total potassium (1.16 ± 0.22%), but it was contaminated with human pathogens, including fecal coliform bacteria, viable helminthes egg and active forms of parasite cysts. Thus, fresh sewage sludge should not be disposed on land unless it has undergone pathogen reduction. It is proven that the quality of the sludge mixed with grass clippings at a ratio of 6:1 volume/volume after having passed a windrow composting process for 8 weeks can be classified as class A biosolids as the levels of remaining fecal coliforms were < 3 most probable number g(-1) dry solid and all human parasites were destroyed. Concentrations of organic matter, total nitrogen, total phosphorus and total potassium in the finished compost were 16.53 ± 1.25%, 1.39 ± 0.06%, 0.42 ± 0.10% and 1.53 ± 0.05% respectively. The total copper concentration was rather high (2291.31 ± 121.77 mg kg(-1)), but all heavy metal concentrations were also well below the United States Environmental Protection Agency pollutant limits for land application. The finished compost products can be considered as a soil conditioner as they have relatively low essential plant nutrient concentrations. It is recommended to be initially used for gardening and landscaping to ensure safety utilization.

  15. Agronomic value of sewage sludge and corn cob biochar in an infertile Oxisol

    NASA Astrophysics Data System (ADS)

    Deenik, J. L.; Cooney, M. J.; Antal, M. J., Jr.

    2013-12-01

    Disposal of sewage sludge and other agricultural waste materials has become increasingly difficult in urban environments with limited land space. Carbonization of the hazardous waste produces biochar as a soil amendment with potential to improve soil quality and productivity. A series of greenhouse pot experiments were conducted to assess the agrnomic value of two biochars made from domestic wastewater sludge and corn cob waste. The ash component of the sewage sludge biochar was very high (65.5%) and high for the corn cob (11.4%) biochars. Both biochars contained low concentrations of heavy metals and met EPA land application criteria. The sewage sludge biochar was a better liming material and source of mineral nutrients than the corn cob biochar, but the corn cob biochar showed the greatest increase in soil carbon and total nitrogen. Both biochar materials increased soil pH compared with soils not receiving biochar, but the sewage sludge biochar was a more effective liming material maintaining elevated soil pH throughout the 3 planting cycles. The sewage sludge biochar also showed the greatest increase in extractable soil P and base cations. In the first planting cycle, both biochars in combination with conventional fertilizers produced significantly higher corn seedling growth than the fertilized control. However, the sewage sludge biochar maintained beneficial effects corn seedling growth through the third planting cycle showing 3-fold increases in biomass production compared with the control in the third planting. The high ash content and associated liming properties and mineral nutrient contributions in the sewage sludge biochar explain benefits to plant growth. Conversion of sewage sludge waste into biochar has the potential to effectively address several environmental issues: 1) convert a hazardous waste into a valuable soil amendment, 2) reduce land and water contamination, and 3) improve soil quality and productivity.

  16. Phytoextraction of heavy metals from municipal sewage sludge by Rosa multiflora and Sida hermaphrodita.

    PubMed

    Antonkiewicz, Jacek; Kołodziej, Barbara; Bielińska, Elżbieta Jolanta

    2017-04-03

    The aim of the study was to evaluate the efficacy of the multiflora rose var. "Jatar" (Rosa multiflora Thunb. ex Murray) and the Virginia fanpetals (Sida hermaphrodita Rusby) to phytoextract heavy metals from municipal sewage sludge. The 6-year field experiment involved four levels of fertilization with sewage sludge at doses of 0, 10, 20, 40, and 60 Mg DM (Dry Mass) sludge ha(-1). The increasing doses of sewage sludge were found to significantly increase the yield of multiflora rose and Virginia fanpetals biomass. They also significantly increased the content of heavy metals in these plants. The highest uptake of heavy metals by the multiflora rose and Virginia fanpetals crops was recorded at the fertilization dose of 60 Mg DM ⋅ ha(-1). Our investigations show that the Virginia fanpetals was more efficient in the phytoextraction of Cr, Ni, Cu, Zn, and Cd from the sewage sludge than the multiflora rose, due to the greater yields and higher heavy metal uptake by the former plant. In turn, the multiflora rose phytoextracted greater amounts of Pb from the sewage sludge. The analyses indicate that the Virginia fanpetals can be used for phytoremediation (phytoextraction) of heavy metals contained in sewage sludge.

  17. Pharmaceutical load in sewage sludge and biochar produced by hydrothermal carbonization.

    PubMed

    vom Eyser, C; Palmu, K; Schmidt, T C; Tuerk, J

    2015-12-15

    We investigated the removal of twelve pharmaceuticals in sewage sludge by hydrothermal carbonization (HTC), which has emerged as a technology for improving the quality of organic waste materials producing a valuable biochar material. In this study, the HTC converted sewage sludge samples to a biochar product within 4h at a temperature of 210 °C and a resulting pressure of about 15 bar. Initial pharmaceutical load of the sewage sludge was investigated as well as the residual concentrations in biochar produced from spiked and eight native sewage sludge samples from three waste water treatment plants. Additionally, the solid contents of source material and product were compared, which showed a considerable increase of the solid content after filtration by HTC. All pharmaceuticals except sulfamethoxazole, which remained below the limit of quantification, frequently occurred in the investigated sewage sludges in the μg/kg dry matter (DM) range. Diclofenac, carbamazepine, metoprolol and propranolol were detected in all sludge samples with a maximum concentration of 800 μg/kgDM for metoprolol. HTC was investigated regarding its contaminant removal efficiency using spiked sewage sludge. Pharmaceutical concentrations were reduced for seven compounds by 39% (metoprolol) to≥97% (carbamazepine). In native biochar samples the four compounds phenazone, carbamazepine, metoprolol and propranolol were detected, which confirmed that the HTC process can reduce the load of micropollutants. In contrast to the other investigated compounds phenazone concentration increased, which was further addressed in thermal behaviour studies including three structurally similar potential precursors.

  18. Characterization of sewage sludge organic matter using solid-state carbon-13 nuclear magnetic resonance spectroscopy.

    PubMed

    Smernik, Ronald J; Oliver, Ian W; Merrington, Graham

    2003-01-01

    Six sewage sludges from five sewage treatment plants in Australia were characterized using solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Spectra were acquired both before and after removal of mineral components through treatment with hydrofluoric acid (HF). Carbon mass balance indicated that little organic matter was lost on HF treatment, which significantly improved NMR sensitivity and spectral resolution, and decreased acquisition time and hence cost of NMR analysis. Two NMR techniques were used, the standard cross polarization (CP) technique and Bloch decay (BD). The BD technique had not been applied previously to the analysis of sewage sludge. For each sludge sample, both before and after HF treatment, the BD spectrum contained significantly more alkyl carbon. Spin counting, another technique applied to sewage sludge here for the first time, showed that the BD spectra of the HF-treated sludges were quantitative, while approximately 30% of the CP NMR signal went undetected. The discrepancy between CP and BD spectra was attributed to the presence of alkyl carbon with such high molecular mobility that the efficiency of cross polarization is affected. This study shows that sewage sludge organic matter is significantly different in chemistry to soil organic matter and has implications for the application of sewage sludge to agricultural land.

  19. Effect of pyrolysis temperatures on freely dissolved polycyclic aromatic hydrocarbon (PAH) concentrations in sewage sludge-derived biochars.

    PubMed

    Zielińska, Anna; Oleszczuk, Patryk

    2016-06-01

    The aim of this study was to evaluate the effect of sewage sludge pyrolysis on freely dissolved (Cfree) polycyclic aromatic hydrocarbon (PAH) contents in biochars. Four sewage sludges with varying properties and PAH contents were pyrolysed at temperatures of 500 °C, 600 °C or 700 °C. Cfree PAH contents were determined using polyoxymethylene (POM). The contents of Cfree PAHs in the sludges ranged from 262 to 294 ng L(-1). Sewage sludge-derived biochars have from 2.3- to 3.4-times lower Cfree PAH contents comparing to corresponding sewage sludges. The Cfree PAH contents in the biochars ranged between 81 ng L(-1) and 126 ng L(-1). As regards agricultural use of biochar, the lower contents of Cfree PAHs in the biochars compared to the sewage sludges makes biochar a safer material than sewage sludge in terms of PAH contents.

  20. Accumulation of cadmium associated with sewage sludge by a marine amphipod crustacean.

    PubMed

    Caparis, M E; Rainbow, P S

    1994-12-01

    Cadmium bound to sewage sludge (5% mixture with littoral mud) is available to the deposit-feeding marine amphipod crustacean Corophium volutator (Pallas). The amphipod accumulates labelled cadmium from sludge in proportion to both duration of exposure and cadmium concentration of the sludge. Newly accumulated cadmium is added onto the existing cadmium body load without significant excretion. Thus, cadmium in association with sewage sludge dumped at sea may be absorbed and accumulated by deposit-feeding invertebrates, with the potential of being transferred along marine food chains.

  1. Phosphorus recovery from sewage sludge ash through an electrodialytic process.

    PubMed

    Guedes, Paula; Couto, Nazaré; Ottosen, Lisbeth M; Ribeiro, Alexandra B

    2014-05-01

    The electrodialytic separation process (ED) was applied to sewage sludge ash (SSA) aiming at phosphorus (P) recovery. As the SSA may have high heavy metals contents, their removal was also assessed. Two SSA were sampled, one immediately after incineration (SA) and the other from an open deposit (SB). Both samples were ED treated as stirred suspensions in sulphuric acid for 3, 7 and 14 days. After 14 days, phosphorus was mainly mobilized towards the anode end (approx. 60% in the SA and 70% in the SB), whereas heavy metals mainly electromigrated towards the cathode end. The anolyte presented a composition of 98% of P, mainly as orthophosphate, and 2% of heavy metals. The highest heavy metal removal was achieved for Cu (ca. 80%) and the lowest for Pb and Fe (between 4% and 6%). The ED showed to be a viable method for phosphorus recovery from SSA, as it promotes the separation of P from the heavy metals.

  2. Evaluation of energy consumption during aerobic sewage sludge treatment in dairy wastewater treatment plant.

    PubMed

    Dąbrowski, Wojciech; Żyłka, Radosław; Malinowski, Paweł

    2017-02-01

    The subject of the research conducted in an operating dairy wastewater treatment plant (WWTP) was to examine electric energy consumption during sewage sludge treatment. The excess sewage sludge was aerobically stabilized and dewatered with a screw press. Organic matter varied from 48% to 56% in sludge after stabilization and dewatering. It proves that sludge was properly stabilized and it was possible to apply it as a fertilizer. Measurement factors for electric energy consumption for mechanically dewatered sewage sludge were determined, which ranged between 0.94 and 1.5 kWhm(-3) with the average value at 1.17 kWhm(-3). The shares of devices used for sludge dewatering and aerobic stabilization in the total energy consumption of the plant were also established, which were 3% and 25% respectively. A model of energy consumption during sewage sludge treatment was estimated according to experimental data. Two models were applied: linear regression for dewatering process and segmented linear regression for aerobic stabilization. The segmented linear regression model was also applied to total energy consumption during sewage sludge treatment in the examined dairy WWTP. The research constitutes an introduction for further studies on defining a mathematical model used to optimize electric energy consumption by dairy WWTPs.

  3. Comprehensive utilization of the pyrolysis products from sewage sludge.

    PubMed

    Xu, W Y; Wu, D

    2015-01-01

    Bio-oils were produced from pyrolysis of sewage sludge in a horizontal tubular furnace under the anoxic or anaerobic conditions, by varying operating parameters and moisture content (MC) of the feedstock. Physicochemical properties of the obtained bio-oil (such as density, acid value, kinematical viscosity, high heating value and flash point) were analysed and compared with Chinese fuel standards. Tend, RT and β were found critical to control the yield and physico-chemical properties of bio-oil products. The relative importance of various parameters such as Tend, RT, β and MC was determined and the optimum values for the lowest kinematic viscosity and acid value and the highest yield of the bio-oil were achieved using the orthogonal matrix method. The parameters 550°C, 45 min, 5°C min(-1) and MC of 10% were found effective in producing the bio-oils with most of the desirable physico-chemical properties and yield. Benefit analysis was conducted to further optimize the operating parameters, considering pyrolysis treatment, comprehensive utilization of the pyrolysis products and final disposal of sewage sludge; the results showed the best economy of the pyrolysis parameters 450°C, 75 min, 3°C min(-1) and MC of 10%. The char obtained under this condition may serve as a microporous liquid adsorbent, while the bio-oil may serve as a low grade fuel oil after upgrading it with conventional fuel oil and deacidification. Pyrolysis products may become economically competitive in addition to being environment friendly.

  4. Impact of Fertilisation with Sewage Sludge on the Content of Lead in Salix Viminalis Biomass

    NASA Astrophysics Data System (ADS)

    Sieciechowicz, Aleksandra; Sadecka, Zofia; Myszograj, Sylwia; Suchowska-Kisielewicz, Monika

    2014-06-01

    Sewage sludge is considered to be high quality fertilizer. Therefore, in Poland, it is used to fertilize energy plants. On the one hand, it allows using large amount of sewage sludge on the other hand it contributes to the production of renewable energy. The study was based on monitoring the plantation of energetic willow Salix viminalis fertilized with sewage sludge from wastewater treatment plant in Sulechow. The aim of the investigation was to study changes of the lead content in different parts collected during a year and analyze the differences in the accumulation of lead in the plants planted at different times. The results of the study showed that the amount of lead content in the biomass willow was not influenced by sewage sludge used as a fertilizer.

  5. F- and H-Area Sewage Sludge Application Sites groundwater monitoring report

    SciTech Connect

    Not Available

    1993-07-01

    Samples from the four wells at the F-Area Sewage Sludge Application Site (FSS wells) and the three wells at the H-Area Sewage Sludge Application Site (HSS wells) are analyzed quarterly for constituents as required by South Carolina Department of Health and Environmental Control Construction Permit 12,076 and, as requested, for other constituents as part of the Savannah River Site Groundwater Monitoring Program. Annual analyses for other constituents, primarily metals, also are required by the permit. Historically and currently, no permit-required analytes exceed standards at the F- and H-Area Sewage Sludge Application Sites except iron, lead, and manganese, which occur in elevated concentrations frequently in FSS wells and occasionally in HSS wells. Tritium and aluminum are the primary nonpermit constituents that exceed standards at the F-Area Sewage Sludge Application Site. Other constituents also exceed standards at this site but only sporadically.

  6. F- and H-Area Sewage Sludge Application Sites groundwater monitoring report

    SciTech Connect

    Not Available

    1992-10-01

    During second quarter 1992, the four wells at the F-Area Sewage Sludge Application Site (FSS wells) and the three wells at the H-Area Sewage Sludge Application Site (HSS wells) of Savannah River Plant were sampled and analyzed for constituents required quarterly by South Carolina Department of Health and Environmental Control Construction Permit 12,076. None of these analytes exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) or the Savannah River Site (SRS) Flag 2 criteria at either sewage sludge site. The F-Area Sewage Sludge Application Site wells also were analyzed for a number of other constituents not required by the permit. Of these constituents, tritium exceeded the PDWS in wells FSS 2D and 3D. Lead exceeded the PDWS in well FSS 3D. Iron exceeded the Flag 2 criterion in well FSS 4D, and manganese exceeded the SRS Flag 2 criterion in wells FSS 2D and 3D.

  7. F- and H-Area Sewage Sludge Application Sites groundwater monitoring report. Second quarter 1992

    SciTech Connect

    Not Available

    1992-10-01

    During second quarter 1992, the four wells at the F-Area Sewage Sludge Application Site (FSS wells) and the three wells at the H-Area Sewage Sludge Application Site (HSS wells) of Savannah River Plant were sampled and analyzed for constituents required quarterly by South Carolina Department of Health and Environmental Control Construction Permit 12,076. None of these analytes exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) or the Savannah River Site (SRS) Flag 2 criteria at either sewage sludge site. The F-Area Sewage Sludge Application Site wells also were analyzed for a number of other constituents not required by the permit. Of these constituents, tritium exceeded the PDWS in wells FSS 2D and 3D. Lead exceeded the PDWS in well FSS 3D. Iron exceeded the Flag 2 criterion in well FSS 4D, and manganese exceeded the SRS Flag 2 criterion in wells FSS 2D and 3D.

  8. F- and H-area Sewage Sludge Application Sites: Groundwater monitoring report. Second quarter 1993

    SciTech Connect

    Not Available

    1993-10-01

    Samples from the four wells at the F-Area Sewage Sludge Application Site (FSS wells) and the three wells at the H-Area Sewage Sludge Application Site (HSS wells) are analyzed quarterly for constituents as required by South Carolina Department of Health and Environmental Control Construction Permit 12,076 and, as requested, for other constituents as part of the Savannah River Site Groundwater Monitoring Program. Annual analyses for other constituents, primarily metals, also are required by the permit. Currently, no permit-required analytes exceed standards at the F- and H-Area Sewage Sludge Application Sites. Tritium and aluminum have been the primary nonpermit constituents exceeding standards at the F-Area Sewage Sludge Application Site. These constituents were not analyzed second quarter 1993. Other constituents also have exceeded standards at this site, but only sporadically, and none of those were analyzed second quarter 1993.

  9. Sewage sludge applied to agricultural soil: Ecotoxicological effects on representative soil organisms.

    PubMed

    Carbonell, G; Pro, J; Gómez, N; Babín, M M; Fernández, C; Alonso, E; Tarazona, J V

    2009-05-01

    Application of sewage sludge to agricultural lands is a current practice in EU. European legislation permits its use when concentrations of metals in soil do not increase above the maximum permissible limits. In order to assess the fate and the effects on representative soil organisms of sewage sludge amendments on agricultural lands, a soil microcosm (multi-species soil system-MS3) experiment was performed. The MS3 columns were filled with spiked soil at three different doses: 30, 60 and 120tha(-1) fresh wt. Seed plants (Triticum aestivum, Vicia sativa and Brassica rapa) and earthworms (Eisenia fetida) were introduced into the systems. After a 21-d exposure period, a statistically significant increase for Cd, Cu, Zn and Hg concentrations was found for the soils treated with the highest application rate. Dose-related increase was observed for nickel concentrations in leachates. Plants and earthworm metal body burden offer much more information than metal concentrations and help to understand the potential for metal accumulation. Bioaccumulation factor (BAF(plant-soil)) presented a different behavior among species and large differences for BAF(earthworm-soil), from control or sewage-amended soil, for Cd and Hg were found. B. rapa seed germination was reduced. Statistically significant decrease in fresh biomass was observed for T. aestivum and V. sativa at the highest application rate, whereas B. rapa biomass decreased at any application rate. Enzymatic activities (dehydrogenase and phosphatase) as well as respiration rate on soil microorganisms were enlarged.

  10. Anaerobic codigestion of sewage sludge and glycerol, focusing on process kinetics, microbial dynamics and sludge dewaterability.

    PubMed

    Jensen, P D; Astals, S; Lu, Y; Devadas, M; Batstone, D J

    2014-12-15

    Anaerobic codigestion (AcoD) is a proven option to significantly boost biogas production while utilizing existing digesters and infrastructure. The aim of the present research was to conduct an exhaustive study regarding anaerobic codigestion of mixed sewage sludge and crude glycerol considering impacts on organic load, hydraulic load, process performance and microbial community. The methane potential of crude glycerol varied from 370 mL CH4·g(-1) VS to 483 mL CH4·g(-1) VS for different samples tested. The half maximal inhibitory concentration of crude glycerol was 1.01 g VS L(-1), and the primary mechanism of inhibition was through overload from rapid fermentation rather than the presence of toxic compounds in the crude glycerol. In continuous operation over 200 days, feeding glycerol at up to 2% v/v, increased organic load by up to 70% and resulted in a 50% increase in methane production. Glycerol dosing resulted in no change in apparent dewaterability, with both codigestion and control reactors returning values of 22%-24%. Members of the phylum Thermotogae emerged as a niche population during AcoD of sewage sludge and glycerol; however there was no gross change in microbial community structure and only minimal changes in diversity. AcoD did not result in synergisms between sewage sludge and crude glycerol. Actually, at dose rate up to 2% v/v glycerol dosing is still an effective strategy to increase the organic loading rate of continuous anaerobic digesters with minimal impact of the hydraulic retention time. Nonetheless, the dose rate must be managed to: (i) prevent process inhibition and (ii) ensure sufficient degradation time to produce a stable biosolids product.

  11. Preparation of the sludge activated carbon with domestic sludge mixed agricultural straw

    NASA Astrophysics Data System (ADS)

    Wang, Laifu; Wang, Yan; Lian, Jingyan

    2017-01-01

    Urban sewage sludge with complicated composition produce largely each year, pollution problem and resource utilization has increasingly become the focus of attention. Sewage sludge is utilized to prepare adsorbent that is a new type method. Agricultural stalks was added to material (urban sewage sludge) and activator (ZnCl2), calcined under the condition of no inert gas, and obtained domestic sludge activated carbon. The properties were measured by iodine adsorption value and BET, discussed influence factors of sludge activated carbon preparation, including activator concentration, solid-liquid ratio, calcific temperature and calcific time. The best process condition of orthogonal experiment had explored that activated time is 10 minutes, calcific temperature is 350°C, the activator concentration ZnCl2 is 3 mol/L and the mixing ratio of raw materials and activator is approximately 1:5. The iodine adsorption value and the optimal BET of as-obtained domestic sludge activated carbon is 445.06 mg/g, 525.31m2/g, respectively.

  12. Speciation Dynamics of Phosphorus during (Hydro)Thermal Treatments of Sewage Sludge.

    PubMed

    Huang, Rixiang; Tang, Yuanzhi

    2015-12-15

    (Hydro)thermal treatments of sewage sludge from wastewater treatment process can significantly reduce waste volume and transform sludge into valuable products such as pyrochar and hydrochar. Given the global concern with phosphorus (P) resource depletion, P recycling/reclamation from or direct soil application of the derived chars can be potential P recycling practices. In order to evaluate P recyclability as well as the selection and optimization of treatment techniques, it is critical to understand the effects of different treatment techniques and conditions on P speciation and distribution. In the present study, we systematically characterized P speciation in chars derived from thermal (i.e., pyrolysis) and hydrothermal treatments of municipal sewage sludge using complementary chemical extraction and nuclear magnetic resonance (NMR) spectroscopy methods. P species in the raw activated sludge was dominated by orthophosphate and long-chain polyphosphates, whereas increased amounts of pyrophosphate and short-chain polyphosphates formed after pyrolysis at 250-600 °C. In contrast, hydrothermal treatments resulted in the production of only inorganic orthophosphate in the hydrochar. In addition to the change of molecular speciation, thermal treatments also altered the physical state and extractability of different P species in the pyrochars from pyrolysis, with both total P and polyphosphate being less extractable with increasing pyrolysis temperature. Results from this study suggest that P speciation and availability in sludge-derived chars are tunable by varying treatment techniques and conditions, and provide fundamental knowledge basis for the design and selection of waste management strategies for better nutrient (re)cycling and reclamation.

  13. Phosphorus recovery from digested sewage sludge as MAP by the help of metal ion separation.

    PubMed

    Güney, Kenan; Weidelener, Alexander; Krampe, Jörg

    2008-11-01

    This study was designed to solve metal ion influence problem on phosphorus recovery from digested sewage sludge as MAP. The experimental steps were proceeded to maximize MAP production and its quality. Used experimental steps were: All digested sewage sludge samples were taken from Stuttgart University sewage treatment plant for research and education (LFKW). Four different forms of LFKW digested sewage sludge were used as feeding sample. These were: original digested sludge, diluted digested sludge, centrifuged digested sludge and incinerated digested sludge. A Donnan membrane unit having a Nafion 117 (DuPont) cation exchange membrane was used to remove metal ions from the samples used. Highest metal ion removal efficiencies, which were 98%, 97%, and 80% for Al, Ca and Fe ions, respectively, were obtained from incinerated digested sludge run. Incinerated digested sludge run was used as preliminary step for MAP production and high quality MAP was produced. Produced MAP fulfils all requirements related with Düngemittelverordnung 2003 and it could be used as a fertilizer in Germany.

  14. K-Area and Par Pond Sewage Sludge Application Sites groundwater monitoring report, Third quarter 1992

    SciTech Connect

    Thompson, C.Y.

    1993-01-01

    During third quarter 1992, the three wells at the K-Area Sewage Sludge Application Site (KSS wells) and the three wells at the Par Pond Sewage Sludge Application Site (PSS wells) were sampled for analyses required each quarter or annually by South Carolina Department of Health and Environmental Control Construction Permit 13,173 and for base-neutral/acid semivolatile constituents. None of the analytical results exceeded standards.

  15. PAHs content of sewage sludge in Europe and its use as soil fertilizer

    SciTech Connect

    Suciu, Nicoleta A. Lamastra, Lucrezia; Trevisan, Marco

    2015-07-15

    Highlights: • Sewage sludge contamination by PAHs may restrict its use as soil fertilizer. • Long term data concerning sewage sludge contamination by PAHs is lacking. • Literature review for EU countries and monitoring data for Italy is presented. • Focus PEARL model was used to simulate B(a)Pyr, the most toxic PAH, fate in soil. • The simulated B(a)Pyr soil concentration was much lower than its LOEC for soil organisms. - Abstract: The European Commission has been planning limits for organic pollutants in sewage sludge for 14 years; however no legislation has been implemented. This is mainly due to lack of data on sewage sludge contamination by organic pollutants, and possible negative effects to the environment. However, waste management has become an acute problem in many countries. Management options require extensive waste characterization, since many of them may contain compounds which could be harmful to the ecosystem, such as heavy metals, organic pollutants. The present study aims to show the true European position, regarding the polycyclic aromatic hydrocarbons (PAHs) content of sewage sludge, by comparing the Italian PAHs content with European Union countries, and at assessing the suitability of sewage sludge as soil fertilizer. The FOCUS Pearl model was used to estimate the concentration of benzo [a] pyrene (B(a)Pyr), the most toxic PAH in soil, and its exposure to organisms was then evaluated. The simulated B(a)Pyr and PAHs, expressed as B(a)Pyr, concentrations in soil were much lower than the B(a)Pyr’s most conservative lowest observable effect concentration (LOEC) for soil organisms. Furthermore, the results obtained indicate that it is more appropriate to apply 5 t ha{sup −1} sewage sludge annually than 15 t ha{sup −1} triennially. Results suggest, the EU maximum recommended limit of 6 mg kg{sup −1} PAHs in sewage sludge, should be conservative enough to avoid groundwater contamination and negative effects on soil organisms.

  16. The use of reed canary grass and giant miscanthus in the phytoremediation of municipal sewage sludge.

    PubMed

    Antonkiewicz, Jacek; Kołodziej, Barbara; Bielińska, Elżbieta Jolanta

    2016-05-01

    The application of municipal sewage sludge on energy crops is an alternative form of recycling nutrients, food materials, and organic matter from waste. Municipal sewage sludge constitutes a potential source of heavy metals in soil, which can be partially removed by the cultivation of energy crops. The aim of the research was to assess the effect of municipal sewage sludge on the uptake of heavy metals by monocotyledonous energy crops. Sewage sludge was applied at doses of 0, 10, 20, 40, and 60 Mg DM · ha(-1) once, before the sowing of plants. In a 6-year field experiment, the effect of four levels of fertilisation with sewage sludge on the uptake of heavy metals by two species of energy crops, reed canary grass (Phalaris arundinacea L.) of 'Bamse' cultivar and giant miscanthus (Miscanthus × giganteus GREEF et DEU), was analysed. It was established that the increasing doses of sewage sludge had a considerable effect on the increase in biomass yield from the tested plants. Due to the increasing doses of sewage sludge, a significant increase in heavy metals content in the energy crops was recorded. The heavy metal uptake with the miscanthus yield was the highest at a dose of 20 Mg DM · ha(-1), and at a dose of 40 Mg DM · ha(-1) in the case of reed canary grass. Research results indicate that on account of higher yields, higher bioaccumulation, and higher heavy metal uptake, miscanthus can be selected for the remediation of sewage sludge.

  17. Biological and abiotic losses of polynuclear aromatic hydrocarbons (PAHs) from soils freshly amended with sewage sludge

    SciTech Connect

    Wild, S.R.; Jones, K.C. )

    1993-01-01

    Sewage sludge containing typical indigenous concentrations of polynuclear aromatic hydrocarbons (PAHs) was applied to several different soils in glass microcosms. Biologically active and sterilized soils were monitored for PAH content over a period of approximately 205 d. Agricultural soils with and without previous exposure to sewage sludge were tested, together with a forest soil and a soil from a major roadside. Loss of PAHs from a soil spike with a PAH standard solution was also investigated. Results indicate the PAH compounds with less than four benzene rings are susceptible to abiotic loss processes. However, losses by these mechanisms were insignificant for compounds with four or more benzene rings. Half-lives for the sludge-applied PAHs were derived and indicated a strong dependence of persistence on chemical structure. Half-lives for phenanthrene and benzo[ghi]perylene were between 83 and 193 d and 282 and 535 d, respectively. Mean half-lives correlate directly with log K[sub ow] and inversely with log water solubility. Behavior of PAHs was different in each soil, probably due to different soil characteristics and history of PAH exposure. The soil spiked with PAHs provided the lowest half-life values for most PAH compounds, suggesting a higher susceptibility of spiked PAHs to both abiotic and biological degradation.

  18. The fate of radionuclides in sewage sludge applied to land

    SciTech Connect

    Boston, H.L.; Van Miegroet, H.; Larsen, I.L.; Walzer, A.E. ); Carlton, J.E. )

    1990-01-01

    Municipal sewage sludge containing up to 12 pCi/g {sup 137}Cs, 20 pCi/g {sup 60}Co, and 300 ppm U was injected in a pasture (43 Mg/ha) and sprayed over a young pine plantation (34 Mg/ha). In the pasture, radionuclides were largely retained in the upper 15 cm of the soil, and only about 15% moved below 15 cm. Sludge rapidly infiltrated the soil on the pine plantation. One year after application, at least 85% of the {sup 137}Cs, {sup 60}Co, and U were found in the upper 7 cm of the pine plantation, with only about 15% moving into the 7- to 15-cm strata. On-site total added radiation dose was 2 to 6 mrem/year. Radionuclides were not detected above background in soil solutions at {approximately}50 cm depth or in shallow down-gradient groundwater wells. Surface runoff from application areas did not have elevated radionuclide concentrations. Concentrations of these radionuclides increased slightly in vegetation on treated sites, and uranium was notably higher in earthworms. 9 refs., 2 tabs.

  19. Production and characterization of glazed tiles containing incinerated sewage sludge.

    PubMed

    Lin, D F; Chang, W C; Yuan, C; Luo, H L

    2008-01-01

    In this article, glaze with different colorants was applied to tile specimens manufactured by incinerated sewage sludge ash (ISSA) and clay. Improvements using different amounts of colorants, and glaze components and concentrations on tile bodies were investigated. Four different proportions of clay (by weight ratio) were replaced by ISSA. Tiles of size 12 cm x 6 cm x 1 cm were made and left in an electric furnace to make biscuit tiles at 800 degrees C. Afterwards, four colorants, Fe2O3 (red), V2O5 (yellow), CoCO3 (blue), and MnO2 (purple), and four different glaze concentrations were applied on biscuit tile specimens. These specimens were later sintered into glazed tiles at 1050 degrees C. The study shows that replacement of clay by sludge ash had adverse effects on properties of tiles. Water absorption increased and bending strength reduced with increased amounts of ash. However, both water absorption and bending strength improved for glazed ash tiles. Abrasion of grazed tiles reduced noticeably from 0.001 to 0.002 g. This implies glaze can enhance abrasion resistance of tiles. Effects like lightfastness and acid-alkali resistance improved as different glazes were applied on tiles. In general, red glazed tiles showed the most stable performance, followed by blue, yellow, and purple.

  20. Thermal decomposition of sewage sludge under N2, CO2 and air: Gas characterization and kinetic analysis.

    PubMed

    Hernández, Ana Belén; Okonta, Felix; Freeman, Ntuli

    2017-03-25

    Thermochemical valorisation processes that allow energy to be recovered from sewage sludge, such as pyrolysis and gasification, have demonstrated great potential as convenient alternatives to conventional sewage sludge disposal technologies. Moreover, these processes may benefit from CO2 recycling. Today, the scaling up of these technologies requires an advanced knowledge of the reactivity of sewage sludge and the characteristics of the products, specific to the thermochemical process. In this study the behaviour of sewage sludge during thermochemical conversion, under different atmospheres (N2, CO2 and air), was studied, using TGA-FTIR, in order to understand the effects of different atmospheric gases on the kinetics of degradation and on the gaseous products. The different steps observed during the solid degradation were related with the production of different gaseous compounds. A higher oxidative degree of the atmosphere surrounding the sample resulted in higher reaction rates and a shift of the degradation mechanisms to lower temperatures, especially for the mechanisms taking place at temperatures above 400 °C. Finally, a multiple first-order reaction model was proposed to compare the kinetic parameters obtained under different atmospheres. Overall, the highest activation energies were obtained for combustion. This work proves that CO2, an intermediate oxidative atmosphere between N2 and air, results in an intermediate behaviour (intermediate peaks in the derivative thermogravimetric curves and intermediate activation energies) during the thermochemical decomposition of sewage sludge. Overall, it can be concluded that the kinetics of these different processes require a different approach for their scaling up and specific consideration of their characteristic reaction temperatures and rates should be evaluated.

  1. Soil Microbial Functional and Fungal Diversity as Influenced by Municipal Sewage Sludge Accumulation

    PubMed Central

    Frąc, Magdalena; Oszust, Karolina; Lipiec, Jerzy; Jezierska-Tys, Stefania; Nwaichi, Eucharia Oluchi

    2014-01-01

    Safe disposal of municipal sewage sludge is a challenging global environmental concern. The aim of this study was to assess the response of soil microbial functional diversity to the accumulation of municipal sewage sludge during landfill storage. Soil samples of a municipal sewage sludge (SS) and from a sewage sludge landfill that was 3 m from a SS landfill (SS3) were analyzed relative to an undisturbed reference soil. Biolog EcoPlatesTM were inoculated with a soil suspension, and the Average Well Color Development (AWCD), Richness (R) and Shannon-Weaver index (H) were calculated to interpret the results. The fungi isolated from the sewage sludge were identified using comparative rDNA sequencing of the LSU D2 region. The MicroSEQ® ID software was used to assess the raw sequence files, perform sequence matching to the MicroSEQ® ID-validated reference database and create Neighbor-Joining trees. Moreover, the genera of fungi isolated from the soil were identified using microscopic methods. Municipal sewage sludge can serve as a habitat for plant pathogens and as a source of pathogen strains for biotechnological applications. PMID:25170681

  2. Effects of sewage sludge biochar on plant metal availability after application to a Mediterranean soil.

    PubMed

    Méndez, A; Gómez, A; Paz-Ferreiro, J; Gascó, G

    2012-11-01

    Pyrolytic conversion of sewage sludge into biochar could be a sustainable management option for Mediterranean agricultural soils. The aim of this work is to evaluate the effects of biochar from sewage sludge pyrolysis on soil properties; heavy metals solubility and bioavailability in a Mediterranean agricultural soil and compared with those of raw sewage sludge. Biochar (B) was prepared by pyrolysis of selected sewage sludge (SL) at 500°C. The pyrolysis process decreased the plant-available of Cu, Ni, Zn and Pb, the mobile forms of Cu, Ni, Zn, Cd and Pb and also the risk of leaching of Cu, Ni, Zn and Cd. A selected Mediterranean soil was amended with SL and B at two different rates in mass: 4% and 8%. The incubation experiment (200 d) was conducted in order to study carbon mineralization and trace metal solubility and bioavailability of these treatments. Both types of amendments increased soil respiration with respect to the control soil. The increase was lower in the case of B than when SL was directly added. Metals mobility was studied in soil after the incubation and it can be established that the risk of leaching of Cu, Ni and Zn were lower in the soil treated with biochar that in sewage sludge treatment. Biochar amended samples also reduced plant availability of Ni, Zn, Cd and Pb when compared to sewage sludge amended samples.

  3. Medium-Chain Chlorinated Paraffins (CPs) Dominate in Australian Sewage Sludge.

    PubMed

    Brandsma, Sicco H; van Mourik, Louise; O'Brien, Jake W; Eaglesham, Geoff; Leonards, Pim E G; de Boer, Jacob; Gallen, Christie; Mueller, Jochen; Gaus, Caroline; Bogdal, Christian

    2017-03-21

    To simultaneously quantify and profile the complex mixture of short-, median-, and long-chain CPs (SCCPs, MCCPs, and LCCPs) in Australian sewage sludge, we applied and further validated a recently developed novel instrumental technique, using quadrupole time-of-flight high resolution mass spectrometry running in the negative atmospheric pressure chemical ionization mode (APCI-qTOF-HRMS). Without using an analytical column the cleaned extracts were directly injected into the qTOF-HRMS followed by quantification of the CPs by a mathematical algorithm. The recoveries of the four SCCP, MCCP and LCCP-spiked sewage sludge samples ranged from 86 to 123%. This APCI-qTOF-HRMS method is a fast and promising technique for routinely measuring SCCPs, MCCPs, and LCCPs in sewage sludge. Australian sewage sludge was dominated by MCCPs with concentrations ranging from 542 to 3645 ng/g dry weight (dw). Lower SCCPs concentrations (<57-1421 ng/g dw) were detected in the Australian sewage sludge, which were comparable with the LCCPs concentrations (116-960 ng/g dw). This is the first time that CPs were reported in Australian sewage sludge. The results of this study gives a first impression on the distribution of the SCCPs, MCCPs, and LCCPs in Australia wastewater treatment plants (WWTPs).

  4. A study on torrefaction of sewage sludge to enhance solid fuel qualities.

    PubMed

    Poudel, Jeeban; Ohm, Tae-In; Lee, Sang-Hoon; Oh, Sea Cheon

    2015-06-01

    Torrefaction is a treatment which serves to improve the properties of biomass in relation to thermochemical processing techniques for energy generation. In this study, the torrefaction of sewage sludge, which is a non-lignocellulosic waste was investigated in a horizontal tubular reactor under nitrogen flow at temperature ranging from 150 to 400°C, for torrefaction residence time varying from 0 to 50 min. The torrefaction kinetics of sewage sludge was studied to obtain the kinetic parameters. The torrefied sewage sludge products were characterized in terms of their elemental composition, energy yield, ash content and volatile fraction. The energy and mass yields decreased with an increase in the torrefaction temperature. From an elemental analysis, the weight percentage of carbon in the sewage sludge increased with an increase in the torrefaction temperature. On the other hand, the weight percentages of hydrogen and oxygen tended to decrease. The gaseous products from torrefaction of sewage sludge were also analyzed. From this work, it was found that the compounds with oxygen were emitted at a temperature lower than that for hydrocarbon gases and the temperatures of 300-350°C were the optimum torrefaction temperatures for sewage sludge.

  5. Medium-Chain Chlorinated Paraffins (CPs) Dominate in Australian Sewage Sludge

    PubMed Central

    2017-01-01

    To simultaneously quantify and profile the complex mixture of short-, median-, and long-chain CPs (SCCPs, MCCPs, and LCCPs) in Australian sewage sludge, we applied and further validated a recently developed novel instrumental technique, using quadrupole time-of-flight high resolution mass spectrometry running in the negative atmospheric pressure chemical ionization mode (APCI-qTOF-HRMS). Without using an analytical column the cleaned extracts were directly injected into the qTOF-HRMS followed by quantification of the CPs by a mathematical algorithm. The recoveries of the four SCCP, MCCP and LCCP-spiked sewage sludge samples ranged from 86 to 123%. This APCI-qTOF-HRMS method is a fast and promising technique for routinely measuring SCCPs, MCCPs, and LCCPs in sewage sludge. Australian sewage sludge was dominated by MCCPs with concentrations ranging from 542 to 3645 ng/g dry weight (dw). Lower SCCPs concentrations (<57–1421 ng/g dw) were detected in the Australian sewage sludge, which were comparable with the LCCPs concentrations (116–960 ng/g dw). This is the first time that CPs were reported in Australian sewage sludge. The results of this study gives a first impression on the distribution of the SCCPs, MCCPs, and LCCPs in Australia wastewater treatment plants (WWTPs). PMID:28218842

  6. PAHs content of sewage sludge in Europe and its use as soil fertilizer.

    PubMed

    Suciu, Nicoleta A; Lamastra, Lucrezia; Trevisan, Marco

    2015-07-01

    The European Commission has been planning limits for organic pollutants in sewage sludge for 14years; however no legislation has been implemented. This is mainly due to lack of data on sewage sludge contamination by organic pollutants, and possible negative effects to the environment. However, waste management has become an acute problem in many countries. Management options require extensive waste characterization, since many of them may contain compounds which could be harmful to the ecosystem, such as heavy metals, organic pollutants. The present study aims to show the true European position, regarding the polycyclic aromatic hydrocarbons (PAHs) content of sewage sludge, by comparing the Italian PAHs content with European Union countries, and at assessing the suitability of sewage sludge as soil fertilizer. The FOCUS Pearl model was used to estimate the concentration of benzo [a] pyrene (B(a)Pyr), the most toxic PAH in soil, and its exposure to organisms was then evaluated. The simulated B(a)Pyr and PAHs, expressed as B(a)Pyr, concentrations in soil were much lower than the B(a)Pyr's most conservative lowest observable effect concentration (LOEC) for soil organisms. Furthermore, the results obtained indicate that it is more appropriate to apply 5tha(-1) sewage sludge annually than 15tha(-1) triennially. Results suggest, the EU maximum recommended limit of 6mgkg(-)(1) PAHs in sewage sludge, should be conservative enough to avoid groundwater contamination and negative effects on soil organisms.

  7. Utilization of municipal sewage sludge as additives for the production of eco-cement.

    PubMed

    Lin, Yiming; Zhou, Shaoqi; Li, Fuzhen; Lin, Yixiao

    2012-04-30

    The effects of using dried sewage sludge as additive on cement property in the process of clinker burning were investigated in this paper. The eco-cement samples were prepared by adding 0.50-15.0% of dried sewage sludge to unit raw meal, and then the mixtures were burned at 1450 °C for 2 h. The results indicated that the major components in the eco-cement clinkers were similar to those in ordinary Portland cement. Although the C(2)S phase formation increased with the increase of sewage sludge content, it was also found that the microstructure of the mixture containing 15.0% sewage sludge in raw meal was significantly different and that a larger amount of pores were distributed in the clinker. Moreover, all the eco-cement pastes had a longer initial setting time and final setting time than those of plain cement paste, which increased as the sewage sludge content in the raw meal increased. All the eco-cement pastes had lower early flexural strengths, which increased as the sewage sludge content increased, while the compressive strengths decreased slightly. However, this had no significant effect on all the strengths at later stages. Furthermore, the leaching concentrations of all the types of eco-cement clinkers met the standard of Chinese current regulatory thresholds.

  8. ISCORS ASSESSMENT OF RADIOACTIVITY IN SEWAGE SLUDGE: MODELING TO ASSESS RADIATION DOSES

    EPA Science Inventory

    The Interagency Steering Committee on Radiation Standards (ISCORS) has recently completed a study of the occurrence within the United States of radioactive materials in sewage sludge and sewage incineration ash. One component of that effort was an examination of the possible tran...

  9. Efficient, high-speed methane fermentation for sewage sludge using subcritical water hydrolysis as pretreatment.

    PubMed

    Yoshida, Hiroyuki; Tokumoto, Hayato; Ishii, Kyoko; Ishii, Ryo

    2009-06-01

    A novel biomass-energy process for the production of methane from sewage sludge using a subcritical water (sub-CW) hydrolysis reaction as pretreatment is proposed. The main substances of sewage sludge hydrolyzed by sub-CW at 513 K for 10 min were acetic acid, formic acid, pyroglutamic acid, alanine, and glycine. Fermentation experiments were conducted in an anaerobic-sludge reactor for two different samples: real sewage sludge and a model solution containing components typically produced by the sub-CW pretreatment of sewage sludge. In the experiment for the sub-CW pretreatment of sewage sludge, methane generation was twice that for non-pretreatment after 3 days of incubation. In the model experiment, the methane conversion was about 40% with the application of mixture of organic acids and amino acids after 5 days of incubation. Furthermore, the methane conversion was about 60% for 2 days when only organic acids, such as acetic acid and formic acid, were applied. Because acetic acid is the key intermediate and main precursor of the methanogenesis step, fermentation experiments were conducted in an anaerobic-sludge reactor with high concentrations of acetic acid (0.01-0.1M). Nearly 100% of acetic acid was converted to methane and carbon dioxide in 1-3 days.

  10. Comparative study of two extraction methods for enteric virus recovery from sewage sludge by molecular methods.

    PubMed

    Schlindwein, A D; Simões, C M O; Barardi, C R M

    2009-07-01

    The aim of this study was to compare two nucleic acid extraction methods for the recovery of enteric viruses from activated sludge. Test samples were inoculated with human adenovirus (AdV), hepatitis A virus (HAV), poliovirus (PV) and rotavirus (RV) and were then processed by an adsorption-elution-precipitation method. Two extraction methods were used: an organic solvent-based method and a silica method. The organic-based method was able to recoup 20% of the AdV, 90% of the RV and 100% of both the PV and HAV from seeded samples. The silica method was able to recoup 1.8% of the AdV and 90% of the RV. These results indicate that the organic-based method is more suitable for detecting viruses in sewage sludge.

  11. Sewage sludge pretreatment and disposal. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1995-06-01

    The bibliography contains citations concerning techniques and equipment used in the pretreatment and disposal of sewage sludges. Citations discuss sludge digestion, dewatering, disinfection, stabilization, chlorination, and desulfurization. Topics include pretreatment programs, land disposal, incineration, and waste utilization. Environmental monitoring and protection, federal regulations, and legal aspects are examined. (Contains 50-250 citations and includes a subject term index and title list.)

  12. Batchwise mesophilic anaerobic co-digestion of secondary sludge from pulp and paper industry and municipal sewage sludge.

    PubMed

    Hagelqvist, Alina

    2013-04-01

    Residues from forest-industry wastewater-treatment systems are treated as waste at many pulp and paper mills. These organic substances have previously been shown to have potential for production of large quantities of biogas. There is concern, however, that the process would require expensive equipment because of the slow degradation of these substances. Pure non-fibrous sludge from forest industry showed lower specific methane production during mesophilic digestion for 19days, 53±26 Nml/g of volatile solids as compared to municipal sewage sludge, 84±24 Nml/g of volatile solids. This paper explores the possibility of using anaerobic co-digestion with municipal sewage sludge to enhance the potential of methane production from secondary sludge from a pulp and paper mill. It was seen in a batch anaerobic-digestion operation of 19 days that the specific methane production remained largely the same for municipal sewage sludge when up to 50% of the volatile solids were replaced with forest-industry secondary sludge. It was also shown that the solid residue from anaerobic digestion of the forest-industry sludge should be of suitable quality to use for improving soil quality on lands that are not used for food production.

  13. Improving material and energy recovery from the sewage sludge and biomass residues

    SciTech Connect

    Kliopova, Irina Makarskienė, Kristina

    2015-02-15

    Highlights: • SRF production from 10–40 mm fraction of pre-composted sludge and biomass residues. • The material and energy balance of compost and SRF production. • Characteristics of raw materials and classification of produced SRF. • Results of the efficiency of energy recovery, comparison analysis with – sawdust. - Abstract: Sewage sludge management is a big problem all over the world because of its large quantities and harmful impact on the environment. Energy conversion through fermentation, compost production from treated sludge for agriculture, especially for growing energetic plants, and treated sludge use for soil remediation are widely used alternatives of sewage sludge management. Recently, in many EU countries the popularity of these methods has decreased due to the sewage sludge content (heavy metals, organic pollutions and other hazards materials). This paper presents research results where the possibility of solid recovered fuel (SRF) production from the separate fraction (10–40 mm) of pre-composted materials – sewage sludge from municipal waste water treatment plant and biomass residues has been evaluated. The remaining fractions of pre-composted materials can be successfully used for compost or fertiliser production, as the concentration of heavy metals in the analysed composition is reduced in comparison with sewage sludge. During the experiment presented in this paper the volume of analysed biodegradable waste was reduced by 96%: about 20% of input biodegradable waste was recovered to SRF in the form of pellets with 14.25 MJ kg{sup −1} of the net calorific value, about 23% were composted, the rest – evaporated and discharged in a wastewater. The methods of material-energy balances and comparison analysis of experiment data have been chosen for the environmental impact assessment of this biodegradable waste management alternative. Results of the efficiency of energy recovery from sewage sludge by SRF production and burning

  14. From agricultural use of sewage sludge to nutrient extraction: A soil science outlook.

    PubMed

    Kirchmann, Holger; Börjesson, Gunnar; Kätterer, Thomas; Cohen, Yariv

    2017-03-01

    The composition of municipal wastewater and sewage sludge reflects the use and proliferation of elements and contaminants within society. In Sweden, official statistics show that concentrations of toxic metals in municipal sewage sludge have steadily decreased, by up to 90 %, since the 1970s, due to environmental programmes and statutory limits on metals in sludge and soil. Results from long-term field experiments show that reduced metal pollution during repeated sewage sludge application has reversed negative trends in soil biology. Despite this Swedish success story, organic waste recycling from Swedish towns and cities to arable land is still limited to only about 20 % of the total amount produced. Resistance among industries and consumers to products grown on land treated with sewage sludge may not always be scientifically grounded; however, there are rational obstacles to application of sewage sludge to land based on its inherent properties rather than its content of pollutants. We argue that application of urban organic wastes to soil is an efficient form of recycling for small municipalities, but that organic waste treatment from large cities requires other solutions. The large volumes of sewage sludge collected in towns and cities are not equitably distributed back to arable land because of the following: (i) The high water and low nutrient content in sewage sludge make long-distance transportation too expensive; and (ii) the low plant availability of nutrients in sewage sludge results in small yield increases even after many years of repeated sludge addition. Therefore, nutrient extraction from urban wastes instead of direct organic waste recycling is a possible way forward. The trend for increased combustion of urban wastes will make ash a key waste type in future. Combustion not only concentrates the nutrients in the ash but also leads to metal enrichment; hence, direct application of the ash to land is most often not possible. However, inorganic

  15. Thc continuous emission monitoring guidance for part 503 sewage sludge incinerators

    SciTech Connect

    Not Available

    1994-06-30

    The Envrionmental Protection Agency's guidance document for monitoring of total hydrocarbons (THCs) at sewage sludge incinerators was finalized in response to comments received from Federal, State and local government agencies. The document contains recommendations for compliance with these requirements. It addresses installation, calibration, operation, and maintenance procedures for sewage sludge incinerators in the following areas: (1) THC continuous emissions monitoring (CEM); (2) oxygen CEM; (3) moisture CEM; (4) quality assurance; and (5) recordkeeping and reporting. The document will provide guidance for both the interim and long-term sludge permitting programs.

  16. Enhanced Lipid and Biodiesel Production from Glucose-Fed Activated Sludge: Kinetics an Microbial Community Analysis

    EPA Science Inventory

    An innovative approach to increase biofuel feedstock lipid yields from municipal sewage sludge via manipulation of carbon:nitrogen (C:N) ratio and glucose loading in activated sludge bioreactors was investigated. Sludge lipid and fatty acid methyl ester (biodiesel) yields (% cel...

  17. Invasion of Tomato Roots and Reproduction of Meloidogyne incognita as Affected by Raw Sewage Sludge

    PubMed Central

    Castagnone-Sereno, Philippe; Kermarrec, Alain

    1991-01-01

    The antagonistic effects of raw sewage sludge on infection of tomato by Meloidogyne incognita were tested in greenhouse pot experiments. Sludge was mixed with the soil or added on its surface before and after inoculation of tomato plants with nematode eggs. Juvenile penetration was determined 1 and 10 days after inoculation, and 6 weeks later root systems were assessed for nematode reproduction. Fewer juveniles penetrated roots in pots with sludge added to the soil than in unamended control pots. In both experiments, roots were severely galled despite a significant reduction in gall ratings in amended relative to unamended soils. Egg production in treated soil was less (P = 0.05) than in control pots, regardless of whether sludge was incorporated or added 1 day before or after inoculation. In treated pots, RF values (final egg number/inoculation egg number) were strongly reduced. The toxic effects observed on the parasite may result from the ammoniacal nitrogen released in the soil within 7 days after treatment, associated with possible poor host suitability of tomatoes grown in amended substrate and short-lasting compound(s) active after root invasion. PMID:19283192

  18. Effect of organic matter on phosphorus recovery from sewage sludge subjected to microwave hybrid pretreatment.

    PubMed

    Wang, Yawei; Xiao, Qingcong; Zhong, Hui; Zheng, Xiang; Wei, Yuansong

    2016-01-01

    Microwave (MW) hybrid processes are able to disrupt the flocculent structure of complex waste activated sludge, and help promote the recovery of phosphorus as struvite. In this study, to optimize struvite yield, (1) the characteristics of matter released in MW-hybrid treatments were compared, including MW, MW-acid, MW-alkali, MW-H2O2, and MW-H2O2-alkali. The results showed that selective release of carbon, nitrogen, phosphorus, Ca(2+), and Mg(2+) achieved by sludge pretreatment using MW-hybrid processes. MW-H2O2 is the recommended sludge pretreatment process for phosphorus recovery in the form of struvite. The ratio of Mg(2+):NH4(+)-N:PO4(3-)-P was 1.2:2.9:1 in the supernatant. (2) To clarify the effects of organic matter on struvite recovery, the composition and molecular weight distribution of organic matters were analyzed. Low molecular weight COD was found to facilitate the removal rate of NH4(+)-N and PO4(3)-P via crystallization, and the amorphous struvite crystals (<1kDa) from the filtered solutions had high purity. Therefore, the present study reveals the necessity of taking into consideration the interference effect of high molecular weight organic matters during struvite crystallization from sewage sludge.

  19. Assessing the usefulness of clostridia spores for evaluating sewage sludge hygienization.

    PubMed

    Martín-Díaz, Julia; Ruiz-Hernando, Maria; Astals, Sergi; Lucena, Francisco

    2017-02-01

    The capability of clostridia spores to act as pathogen indicators in sewage sludge treatment was investigated. Sulfite-reducing clostridia and E. coli levels were monitored during waste activated sludge pre-treatments (alkali and ultrasound) and its subsequent mesophilic anaerobic digestion. E. coli was maintained or reduced depending on treatment type and intensity. However, alkali pre-treatment (35.3gNaOH/kgTS) by itself and alkali (157gNaOH/kgTS) and ultrasound (27,000kJ/kgTS) pre-treatments followed by anaerobic digestion provoked reproducible clostridia increases. Specifically, up to 2.7log10 after 35.3gNaOH/kgTS pre-treatment and up to 1.9 and 1.1log10 after digesting the 157gNaOH/kg TS and 27,000kJ/kgTS pre-treated sludge, respectively. Having rejected the hypotheses of sporulation and floc dissipation, the most plausible explanation for these clostridia increases is re-growth. These results question the suitability of clostridia spores as indicators of sludge treatment and other biological treatments where clostridia may have a role.

  20. Phosphorus recovery from sewage sludge with a hybrid process of low pressure wet oxidation and nanofiltration.

    PubMed

    Blöcher, Christoph; Niewersch, Claudia; Melin, Thomas

    2012-04-15

    Phosphorus recovery from sewage sludge will become increasingly important within the next decades due to depletion of mineral phosphorus resources. In this work a new process concept was investigated, which aims at realising phosphorus recovery in a synergistic way with the overall sewage sludge treatment scheme. This process combines a low pressure wet oxidation for sewage sludge decomposition as well as phosphorus dissolution and a nanofiltration process to separate phosphorus from heavy metals and obtain a clean diluted phosphoric acid, from which phosphorus can be recovered as clean fertiliser. It was shown that this process concept is feasible for sewage sludge for wastewater treatment plants that apply enhanced biological removal or precipitation with alumina salts for phosphorus removal. The critical parameter for phosphorus dissolution in the low pressure wet oxidation process is the iron concentration, while in the nanofiltration multi-valent cations play a predominant role. In total, a phosphorus recovery of 54% was obtained for an exemplary wastewater treatment plant. Costs of the entire process are in the same range as conventional sewage sludge disposal, with the benefit being phosphorus recovery and reduced emission of greenhouse gases due to avoidance of sludge incineration.

  1. Analysis of the combustion and pyrolysis of dried sewage sludge by TGA and MS.

    PubMed

    Magdziarz, Aneta; Werle, Sebastian

    2014-01-01

    In this study, the combustion and pyrolysis processes of three sewage sludge were investigated. The sewage sludge came from three wastewater treatment plants. Proximate and ultimate analyses were performed. The thermal behaviour of studied sewage sludge was investigated by thermogravimetric analysis with mass spectrometry (TGA-MS). The samples were heated from ambient temperature to 800 °C at a constant rate 10 °C/min in air (combustion process) and argon flows (pyrolysis process). The thermal profiles presented in form of TG/DTG curves were comparable for studied sludges. All TG/DTG curves were divided into three stages. The main decomposition of sewage sludge during the combustion process took place in the range 180-580 °C with c.a. 70% mass loss. The pyrolysis process occurred in lower temperature but with less mass loss. The evolved gaseous products (H2, CH4, CO2, H2O) from the decomposition of sewage sludge were identified on-line.

  2. Effective water content reduction in sewage wastewater sludge using magnetic nanoparticles.

    PubMed

    Lakshmanan, Ramnath; Kuttuva Rajarao, Gunaratna

    2014-02-01

    The present work compares the use of three flocculants for sedimentation of sludge and sludge water content from sewage wastewater i.e. magnetic iron oxide nanoparticles (MION), ferrous sulfate (chemical) and Moringa crude extract (protein). Sludge water content, wet/dry weight, turbidity and color were performed for, time kinetics and large-scale experiment. A 30% reduction of the sludge water content was observed when the wastewater was treated with either protein or chemical coagulant. The separation of sludge from wastewater treated with MION was achieved in less than 5min using an external magnet, resulted in 95% reduction of sludge water content. Furthermore, MION formed denser flocs and more than 80% reduction of microbial content was observed in large volume experiments. The results revealed that MION is efficient in rapid separation of sludge with very low water content, and thus could be a suitable alternative for sludge sedimentation and dewatering in wastewater treatment processes.

  3. Particulate and colloidal silver in sewage effluent and sludge discharged from British wastewater treatment plants.

    PubMed

    Johnson, Andrew C; Jürgens, Monika D; Lawlor, Alan J; Cisowska, Iwona; Williams, Richard J

    2014-10-01

    Differential filtration was used to measure silver (>2 nm) entering and leaving nine sewage treatment plants (STPs). The mean concentration of colloidal (2-450 nm) silver, which includes nanosilver, was found to be 12 ng L(-1) in the influent and 6 ng L(-1) in the effluent. For particulate silver (>450 nm) the mean values were 3.3 μg L(-1) for influent and 0.08 μg L(-1) for effluent. Thus, removal was around 50% and 98% for colloidal and particulate silver respectively. There was no significant difference in performance between the different types of STP investigated (three examples each of activated sludge, biological filter and biological filter with tertiary treatment located across England, UK). In addition, treated sewage sludge samples (biosolids) were taken from several STPs to measure the total silver likely to be discharged to soils. Total silver was 3-14 mg kg(-1) DW in the sludge (median 3.6), which if the sludge were added at the recommended rate to soil, would add 11 μg kg(-1) yr(-1) to the top 20 cm soil layer. Predicted concentrations using the LF2000-WQX model for all the rivers of England and Wales for nanosilver were typically in the 0-1 ng L(-1) range but levels up to 4 ng L(-1) are possible in a high discharge and low flow scenario. Predicted concentrations for the total particulate forms were mostly below 50 ng L(-1) except for a high discharge and low flow scenario where concentrations could reach 135 ng L(-1).

  4. Environmental and plant effects of sewage sludge application to forests and pastures

    SciTech Connect

    Van Miegroet, H.; Boston, H.L.; Johnson, D.W.

    1989-01-01

    Digested sewage sludge was applied to pastures and tree plantations at 19 to 44 Mg/ha (dry weight) as part of a municipal sludge disposal program. The sludge had low concentrations of heavy metals and traces of /sup 137/Cs and /sup 60/Co. Monitoring of soils, soil solutions, and runoff indicated that N, P, heavy metals, and radionuclides were largely retained in the upper 15cm of the soil. Soil solutions had elevated NO/sub 3//sup /minus// concentrations often >100 mg/L, but no significant increases in groundwater NO/sub 3//sup /minus// were found during the first year. Runoff from active sites had elevated concentrations of NO/sub 3//sup /minus// (20--30 mg/L), soluble P (1 mg/L), BOD/sub 5/ (5--30 mg/L), and fecal coliform (up to 14,000 colonies per 100 ml), not unlike runoff from pastures with cattle. Enrichment of organic N (2 times), available (inorganic) N (5 to 10 times), and Bray-P in the upper soils persisted for several years following sludge application. Sludge increased vegetation N concentrations from 1.5% to 2.3% and P concentrations from 0.16% to 0.31%. With the exception of Zn, heavy metals did not accumulate substantially in the vegetation. The sludge addition increased the survival and growth of sycamore (Platanus occidentalis L.). For a loblolly pine (Pinus taeda L.) plantation future growth improvements are expected based on elevated foliar N concentrations. 37 refs., 3 figs., 7 tabs.

  5. Comparative assessment of municipal sewage sludge incineration, gasification and pyrolysis for a sustainable sludge-to-energy management in Greece

    SciTech Connect

    Samolada, M.C.; Zabaniotou, A.A.

    2014-02-15

    Highlights: • The high output of MSS highlights the need for alternative routes of valorization. • Evaluation of 3 sludge-to-energy valorisation methods through SWOT analysis. • Pyrolysis is an energy and material recovery process resulting to ‘zero waste’. • Identification of challenges and barriers for MSS pyrolysis in Greece was investigated. • Adopters of pyrolysis systems face the challenge of finding new product markets. - Abstract: For a sustainable municipal sewage sludge management, not only the available technology, but also other parameters, such as policy regulations and socio-economic issues should be taken in account. In this study, the current status of both European and Greek Legislation on waste management, with a special insight in municipal sewage sludge, is presented. A SWOT analysis was further developed for comparison of pyrolysis with incineration and gasification and results are presented. Pyrolysis seems to be the optimal thermochemical treatment option compared to incineration and gasification. Sewage sludge pyrolysis is favorable for energy savings, material recovery and high added materials production, providing a ‘zero waste’ solution. Finally, identification of challenges and barriers for sewage sludge pyrolysis deployment in Greece was investigated.

  6. Sulfur Transformation during Microwave and Conventional Pyrolysis of Sewage Sludge.

    PubMed

    Zhang, Jun; Zuo, Wei; Tian, Yu; Chen, Lin; Yin, Linlin; Zhang, Jie

    2017-01-03

    The sulfur distributions and evolution of sulfur-containing compounds in the char, tar and gas fractions were investigated during the microwave and conventional pyrolysis of sewage sludge. Increased accumulation of sulfur in the char and less production of H2S were obtained from microwave pyrolysis at higher temperatures (500-800 °C). Three similar conversion pathways were identified for the formation of H2S during microwave and conventional pyrolysis. The cracking of unstable mercaptan structure in the sludge contributed to the release of H2S below 300 °C. The decomposition of aliphatic-S compounds in the tars led to the formation of H2S (300-500 °C). The thermal decomposition of aromatic-S compounds in the tars generated H2S from 500 to 800 °C. However, the secondary decomposition of thiophene-S compounds took place only in conventional pyrolysis above 700 °C. Comparing the H2S contributions from microwave and conventional pyrolysis, the significant increase of H2S yields in conventional pyrolysis was mainly attributed to the decomposition of aromatic-S (increasing by 10.4%) and thiophene-S compounds (11.3%). Further investigation on the inhibition mechanism of H2S formation during microwave pyrolysis confirmed that, with the special heating characteristics and relative shorter residence time, microwave pyrolysis promoted the retention of H2S on CaO and inhibited the secondary cracking of thiophene-S compounds at higher temperatures.

  7. Composting of anaerobic sludge: an economically feasible element of a sustainable sewage sludge management.

    PubMed

    Cukjati, N; Zupančič, G D; Roš, M; Grilc, V

    2012-09-15

    An investigation into the feasibility of anaerobic sludge composting, as a sustainable treatment of sewage sludge management, was carried out under actual Slovenian environmental conditions. In order to demonstrate successful composting, five pilot plant experiments were performed during the summer and winter conditions. The first three experiments were performed with pile aeration, while experiments 4 and 5 were carried out by pile turning. Anaerobic sludge to bulking agent ratios were set at 1-6.4:1. The composting was successful and thermophilic temperature being achieved in all cases. In winter conditions, the composting process was prolonged; and low ambient temperatures had a significant impact in pile turning experiments. During winter, a temperature drop of 30 °C during turning of the material doubled the necessary time for an adequate composting process. Five scenarios were considered within an economic feasibility study and in the most favourable scenario, where 60% of compost was commercialised and 40% was used as landfill cover. The payback period in this scenario was 2.9 years. The study of compost quality showed that it can be used in variety of civil engineering applications, especially as a landfill cover and for recultivation of degraded areas.

  8. [Impacts of alkaline thermal treatment on characteristics of sludge from sewage treatment plant].

    PubMed

    Yang, Shi-Dong; Chen, Xia; Liu, Cao; Xiao, Ben-Yi

    2015-02-01

    Alkaline thermal treatment is an important pretreatment method for sewage sludge. In this paper, in order to optimize the alkaline thermal treatment conditions for sludge pretreatment, four pretreatment parameters ( sludge concentration, pH, temperature and treatment time) were investigated through orthogonal experiments to determine their effects on the sludge disintegration, sludge concentration and sludge morphology of sewage sludge. The experimental results showed that the significance of the four factors on sludge characteristics was in the order of pH > temperature > treatment time > sludge concentration. Additionally, the optimal conditions of the four factors for the release of soluble chemical oxygen demand (SCOD) of unit sludge and decrease of sludge concentration were as follows: 36.55 g x L(-1), pH 12.45, 175 degrees C and 60 min. While the optimal conditions for the decrease of particle size and fractal dimension were 36.55 g x L(-1), pH 12.5, 175 degrees C and 45 min.

  9. Improving material and energy recovery from the sewage sludge and biomass residues.

    PubMed

    Kliopova, Irina; Makarskienė, Kristina

    2015-02-01

    Sewage sludge management is a big problem all over the world because of its large quantities and harmful impact on the environment. Energy conversion through fermentation, compost production from treated sludge for agriculture, especially for growing energetic plants, and treated sludge use for soil remediation are widely used alternatives of sewage sludge management. Recently, in many EU countries the popularity of these methods has decreased due to the sewage sludge content (heavy metals, organic pollutions and other hazards materials). This paper presents research results where the possibility of solid recovered fuel (SRF) production from the separate fraction (10-40 mm) of pre-composted materials--sewage sludge from municipal waste water treatment plant and biomass residues has been evaluated. The remaining fractions of pre-composted materials can be successfully used for compost or fertiliser production, as the concentration of heavy metals in the analysed composition is reduced in comparison with sewage sludge. During the experiment presented in this paper the volume of analysed biodegradable waste was reduced by 96%: about 20% of input biodegradable waste was recovered to SRF in the form of pellets with 14.25 MJ kg(-1) of the net calorific value, about 23% were composted, the rest--evaporated and discharged in a wastewater. The methods of material-energy balances and comparison analysis of experiment data have been chosen for the environmental impact assessment of this biodegradable waste management alternative. Results of the efficiency of energy recovery from sewage sludge by SRF production and burning, comparison analysis with widely used bio-fuel-sawdust and conclusions made are presented.

  10. Molybdenum uptake by forage crops grown on sewage sludge -- Amended soils in the field and greenhouse

    SciTech Connect

    McBride, M.B.; Richards, B.K.; Steenhuis, T.; Spiers, G.

    2000-06-01

    Molybdenum (Mo) is a plant-available element in soils that can adversely affect the health of farm animals. There is a need for more information on its uptake into forage crops from waste materials, such as sewage sludge, applied to agricultural land. Field and greenhouse experiments with several crops grown on long-term sewage sludge-amended soils as well as soils recently amended with dewatered (DW) and alkaline-stabilized (ALK) sludges indicated that Mo supplied from sludge is readily taken up by legumes in particular. Excessive uptake into red clover (Trifolium pratense L.) was seen in a soil that had been heavily amended with sewage sludge 20 yr earlier, where the soil contained about 3 mg Mo/kg soil, three times the background soil concentration. The greenhouse and field studies indicated that Mo can have a long residual availability in sludge-amended soils. The effect of sludge application was to decrease Cu to Mo ratios in legume forages, canola (Brassica napus var. napus) and soybeans [Glycine max (L.) Merr.] below the recommended limit of 2:1 for ruminant diets, a consequence of high bioavailability of Mo and low uptake of Cu added in sludge. Molybdenum uptake coefficients (UCs) for ALK sludge were higher than for DW sludge, presumably due to the greater solubility of Mo measured in the more alkaline sludges and soils. Based on these UCs, it is tentatively recommended that cumulative Mo loadings on forages grown on nonacid soils should not exceed 1.0 kg/ha from ALK sludge or 4.0 kg/ha from DW sludge.

  11. Mosquito biolarvicide production by sequential fermentation with dual strains of Bacillus thuringiensis subsp. israelensis and Bacillus sphaericus using sewage sludge.

    PubMed

    Zhuang, Li; Zhou, Shungui; Wang, Yueqiang; Chang, Min

    2011-01-01

    This study demonstrated the bioconversion of sewage sludge into a composite biolarvicide for mosquito control based on sequential fermentation with dual strains of Bacillus thuringiensis subsp. israelensis (Bti) and Bacillus sphaericus (Bs). Results showed that sewage sludge was a suitable fermentation substrate for supporting growth, sporulation and mosquitocidal proteins synthesis by Bti and Bs. Through sequential fermentation with dual strains, a 10-L bench-scale fermentor was capable of producing Bti and Bs at a cell concentration of 2.1×10(9) and 6.8×10(8) CFU/mL, respectively. Such sequential fermentation can save half of raw materials and energy consumption comparing with the sludge fermentation with single strain. The toxic activity and persistence of the composite biolarvicide against mosquito larvae in the polluted waters were enhanced by the increased toxin complexity and synergistic interactions. This study, for the first time, validates the technical feasibility of using sewage sludge to produce a cost-effective composite biolarvicide based on Bti and Bs.

  12. Modeling organic micro pollutant degradation kinetics during sewage sludge composting.

    PubMed

    Sadef, Yumna; Poulsen, Tjalfe Gorm; Bester, Kai

    2014-11-01

    Degradation of 13 different organic micro-pollutants in sewage sludge during aerobic composting at 5 different temperatures over a 52 day period was investigated. Adequacy of two kinetic models: a single first order, and a dual first order expression (using an early (first 7 days) and a late-time (last 45 days) degradation coefficient), for describing micro-pollutant degradation, and kinetic constant dependency on composting temperature were evaluated. The results showed that both models provide relatively good descriptions of the degradation process, with the dual first order model being most accurate. The single first order degradation coefficient was 0.025 d(-1) on average across all compounds and temperatures. At early times, degradation was about three times faster than at later times. Average values of the early and late time degradation coefficients for the dual first order model were 0.066 d(-1) and 0.022 d(-1), respectively. On average 30% of the initial micro-pollutant mass present in the compost was degraded rapidly during the early stages of the composting process. Single first order and late time dual first order kinetic constants were strongly dependent on composting temperature with maximum values at temperatures of 35-65°C. In contrast the early time degradation coefficients were relatively independent of composting temperature.

  13. Transformation of phosphorus during drying and roasting of sewage sludge.

    PubMed

    Li, Rundong; Yin, Jing; Wang, Weiyun; Li, Yanlong; Zhang, Ziheng

    2014-07-01

    Sewage sludge (SS), a by-product of wastewater treatment, consists of highly concentrated organic and inorganic pollutants, including phosphorus (P). In this study, P with different chemical fractions in SS under different drying and roasting temperatures was investigated with the use of appropriate standards, measurements, and testing protocol. The drying and roasting treatment of SS was conducted in a laboratory-scale furnace. Two types of SS samples under different treatment temperatures were analyzed by (31)P NMR spectroscopy. These samples were dried by a vacuum freeze dryer at -50°C and a thermoelectric thermostat drying box at 105°C. Results show that the inorganic P (IP) content increased as the organic P content decreased, and the bio-availability of P increased because IP is a form of phosphorousthat can be directly absorbed by plants. (31)P NMR analysis results indicate the change in P fractions at different temperatures. Non-apatite P was the dominant form of P under low-temperature drying and roasting, whereas apatite P was the major one under high-temperature drying and roasting. Results indicate that temperature affects the transformation of P.

  14. Sewage sludge composting: quality assessment for agricultural application.

    PubMed

    Nafez, Amir Hossein; Nikaeen, Mahnaz; Kadkhodaie, Safora; Hatamzadeh, Maryam; Moghim, Sharareh

    2015-11-01

    In order to use sewage sludge (SS) composts in agriculture, it is extremely important to estimate the quality of compost products. The aim of this study was to investigate the quality of composted SS as a fertilizer and soil amendment especially in semi-arid areas. To determine the quality and agronomic value of the SS compost products, analyses on pH, electrical conductivity, organic matter content, C/N ratio, phytotoxicity, microbial load, and heavy metal content of composted anaerobically digested SS, with different proportions (1:1, 1:2, and 1:3 v/v) of green and dry plant waste, as bulking agents, were performed. The 1:2 and 1:3 mixtures of SS and green/dry plant waste were the most beneficial for composting, with final composts attaining high organic matter degradation and exhibiting low amounts of heavy metals, a relatively high germination index, and significant reduction of pathogens, suggesting the agricultural relevance of composted SS and green/dry plant waste at 1:2 and 1:3 (v/v) proportions. pH and electrical conductivity were also within the permissible limits. With respect to international standards, it appears that composted SS and green/dry plant waste at 1:2 and 1:3 proportions pose no threat to soil or plant quality if used in agriculture or land restoration.

  15. Treatment of municipal sewage sludge in supercritical water: A review.

    PubMed

    Qian, Lili; Wang, Shuzhong; Xu, Donghai; Guo, Yang; Tang, Xingying; Wang, Laisheng

    2016-02-01

    With increasing construction of wastewater treatment plants and stricter policies, municipal sewage sludge (MSS) disposal has become a serious problem. Treatment of MSS in supercritical water (SCW) can avoid the pre-drying procedure and secondary pollution of conventional methods. SCW treatment methods can be divided into supercritical water gasification (SCWG), supercritical water partial oxidation (SCWPO) and supercritical water oxidation (SCWO) technologies with increasing amounts of oxidants. Hydrogen-rich gases can be generated from MSS by SCWG or SCWPO technology using oxidants less than stoichiometric ratio while organic compounds can be completely degraded by SCWO technology with using an oxidant excess. For SCWG and SCWPO technologies, this paper reviews the influences of different process variables (MSS properties, moisture content, temperature, oxidant amount and catalysts) on the production of gases. For SCWO technology, this paper reviews research regarding the removal of organics with or without hydrothermal flames and the changes in heavy metal speciation and risk. Finally, typical systems for handling MSS are summarized and research needs and challenges are proposed.

  16. Increased biogas production at wastewater treatment plants through co-digestion of sewage sludge with grease trap sludge from a meat processing plant.

    PubMed

    Luostarinen, S; Luste, S; Sillanpää, M

    2009-01-01

    The feasibility of co-digesting grease trap sludge from a meat-processing plant and sewage sludge was studied in batch and reactor experiments at 35 degrees C. Grease trap sludge had high methane production potential (918 m(3)/tVS(added)), but methane production started slowly. When mixed with sewage sludge, methane production started immediately and the potential increased with increasing grease trap sludge content. Semi-continuous co-digestion of the two materials was found feasible up to grease trap sludge addition of 46% of feed volatile solids (hydraulic retention time 16d; maximum organic loading rate 3.46 kgVS/m(3)d). Methane production was significantly higher and no effect on the characteristics of the digested material was noticed as compared to digesting sewage sludge alone. At higher grease trap sludge additions (55% and 71% of feed volatile solids), degradation was not complete and methane production either remained the same or decreased.

  17. Combustion characteristics of paper and sewage sludge in a pilot-scale fluidized bed.

    PubMed

    Yu, Yong-Ho; Chung, Jinwook

    2015-01-01

    This study characterizes the combustion of paper and sewage sludge in a pilot-scale fluidized bed. The highest temperature during combustion within the system was found at the surface of the fluidized bed. Paper sludge containing roughly 59.8% water was burned without auxiliary fuel, but auxiliary fuel was required to incinerate the sewage sludge, which contained about 79.3% water. The stability of operation was monitored based on the average pressure and the standard deviation of pressure fluctuations. The average pressure at the surface of the fluidized bed decreased as the sludge feed rate increased. However, the standard deviation of pressure fluctuations increased as the sludge feed rate increased. Finally, carbon monoxide (CO) emissions decreased as oxygen content increased in the flue gas, and nitrogen oxide (NOx) emissions were also tied with oxygen content.

  18. Feasibility of bioleaching combined with Fenton oxidation to improve sewage sludge dewaterability.

    PubMed

    Liu, Changgeng; Zhang, Panyue; Zeng, Chenghua; Zeng, Guangming; Xu, Guoyin; Huang, Yi

    2015-02-01

    A novel joint method of bioleaching with Fenton oxidation was applied to condition sewage sludge. The specific resistance to filtration (SRF) and moisture of sludge cake (MSC) were adopted to evaluate the improvement of sludge dewaterability. After 2-day bioleaching, the sludge pH dropped to about 2.5 which satisfied the acidic condition for Fenton oxidation. Meanwhile, the SRF declined from 6.45×10(10) to 2.07×10(10) s2/g, and MSC decreased from 91.42% to 87.66%. The bioleached sludge was further conditioned with Fenton oxidation. From an economical point of view, the optimal dosages of H2O2 and Fe2+ were 0.12 and 0.036 mol/L, respectively, and the optimal reaction time was 60 min. Under optimal conditions, SRF, volatile solids reduction, and MSC were 3.43×10(8) s2/g, 36.93%, and 79.58%, respectively. The stability and settleability of sewage sludge were both improved significantly. Besides, the results indicated that bioleaching-Fenton oxidation was more efficient in dewatering the sewage sludge than traditional Fenton oxidation. The sludge conditioning mechanisms by bioleaching-Fenton oxidation might mainly include the flocculation effects and the releases of extracellular polymeric substances-bound water and intercellular water.

  19. Evaluation for agricultural usage with speciation of heavy metals in a municipal sewage sludge.

    PubMed

    Hanay, Ozge; Hasar, Halil; Kocer, Nilüfer Nacar; Aslan, Sibel

    2008-07-01

    This study was carried out to evaluate the agricultural usage of an anaerobically digested sludge in the contents and fractions of heavy metals. Therefore, a sequential extraction scheme according to the BCR's (Community Bureau of Reference) guidelines and total acid digestion were applied to sewage sludge samples. The results of total heavy metal concentrations in sewage sludge showed that the highest total concentrations were Fe, Zn and Mn. When Turkish, Europe and US EPA directives were compared with each other by depending on the use of sludge for agricultural purposes, all the heavy metals determined for this sludge were below the maximum permitted levels, except for Cd. This sludge should not be applied to land due to its high Cd content. The results of heavy metal fractions indicated that some metals (Cd, Mn, Pb, and Fe) distributed mainly in the residual fraction. All fractions of Zn showed no variation. Cu and Cr were most abundant in the oxidizable phase while Ni was in exchangeable phase. Although total content of Ni in the sludge is lower than the maximum levels allowed by all the directives, it tends to be easily moved and dispersed in the environment. Due to its high mobility, the examined sewage sludge may cause phyto-toxicity after its agricultural application.

  20. Occurrence of hexabromocyclododecane (HBCD) in sewage sludge from Shanghai: implications for source and environmental burden.

    PubMed

    Xiang, Nan; Chen, Ling; Meng, Xiang-Zhou; Dai, Xiaohu

    2015-01-01

    Sewage sludge is regarded as one important sink for hydrophobic pollutants, including hexabromocyclododecane (HBCD), but the current pollution situation of HBCD in sludge from China is unknown, despite that many studies have reported its occurrence in other environmental compartments across China. In this study, we collected 27 sludge samples from Shanghai to investigate the occurrence and distribution, to examine the diastereoisomer profile and sources, and to provide advice for future pollution control. HBCD is ubiquitous in sludge with a mean concentration of 4.7ngg(-1) dry weight (dw) (range: 0.10-37.2ngg(-1) dw), lower than data from European countries and the United States. Sludge from wastewater treatment plants (WWTPs) treating industrial wastewater contained high levels of HBCD. However, no significant relationships were found between HBCD and four parameters (total organic carbon, the percentage of industrial wastewater, capacity and sludge production of WWTPs). α- and γ-HBCD were two main components with the corresponding contributions of 47.9% and 48.0%. Comparing with the annual production of HBCD in China, its storage in sewage sludge is extremely low (less than 0.002%), indicating future release of HBCD from waste polystyrene foam will be significant, and careful considerations should be taken during waste disposal. To our knowledge, this is the first report on HBCD in sewage sludge from China.

  1. Simplified mechanistic model for the two-stage anaerobic degradation of sewage sludge.

    PubMed

    Donoso-Bravo, Andrés; Pérez-Elvira, Sara; Fdz-Polanco, Fernando

    2015-01-01

    Two-phase anaerobic systems are being increasingly implemented for the treatment of both sewage sludge and organic fraction of municipal solid waste. Despite the good amount of mathematical models in anaerobic digestion, few have been applied in two-phase systems. In this study, a three-reaction mechanistic model has been developed, implemented and validated by using experimental data from a long-term anaerobic two-phase (TPAD) digester treating sewage sludge. A sensitivity analysis shows that the most influential parameters of the model are the ones related to the hydrolysis reaction and the activity of methanogens in the thermophilic reactor. The calibration procedure highlights a noticeable growth rate of the thermophilic methanogens throughout the evaluation period. Overall, all the measured variables are properly predicted by the model during both the calibration and the cross-validation periods. The model's representation of the organic matter behaviour is quite good. The most important disagreements are observed for the biogas production especially during the validation period. The whole application procedure underlines the ability of the model to properly predict the behaviour of this bioprocess.

  2. Co-digestion of sewage sludge with glycerol to boost biogas production

    SciTech Connect

    Fountoulakis, M.S.; Petousi, I.; Manios, T.

    2010-10-15

    The feasibility of adding crude glycerol from the biodiesel industry to the anaerobic digesters treating sewage sludge in wastewater treatment plants was studied in both batch and continuous experiments at 35 {sup o}C. Glycerol addition can boost biogas yields, if it does not exceed a limiting 1% (v/v) concentration in the feed. Any further increase of glycerol causes a high imbalance in the anaerobic digestion process. The reactor treating the sewage sludge produced 1106 {+-} 36 ml CH{sub 4}/d before the addition of glycerol and 2353 {+-} 94 ml CH{sub 4}/d after the addition of glycerol (1% v/v in the feed). The extra glycerol-COD added to the feed did not have a negative effect on reactor performance, but seemed to increase the active biomass (volatile solids) concentration in the system. Batch kinetic experiments showed that the maximum specific utilization rate ({mu}{sub max}) and the saturation constant (K{sub S}) of glycerol were 0.149 {+-} 0.015 h{sup -1} and 0.276 {+-} 0.095 g/l, respectively. Comparing the estimated values with the kinetics constants for propionate reported in the literature, it can be concluded that glycerol uptake is not the rate-limiting step during the process.

  3. Co-digestion of sewage sludge with glycerol to boost biogas production.

    PubMed

    Fountoulakis, M S; Petousi, I; Manios, T

    2010-10-01

    The feasibility of adding crude glycerol from the biodiesel industry to the anaerobic digesters treating sewage sludge in wastewater treatment plants was studied in both batch and continuous experiments at 35 degrees C. Glycerol addition can boost biogas yields, if it does not exceed a limiting 1% (v/v) concentration in the feed. Any further increase of glycerol causes a high imbalance in the anaerobic digestion process. The reactor treating the sewage sludge produced 1106+/-36 ml CH(4)/d before the addition of glycerol and 2353+/-94 ml CH(4)/d after the addition of glycerol (1% v/v in the feed). The extra glycerol-COD added to the feed did not have a negative effect on reactor performance, but seemed to increase the active biomass (volatile solids) concentration in the system. Batch kinetic experiments showed that the maximum specific utilization rate (mu(max)) and the saturation constant (K(S)) of glycerol were 0.149+/-0.015 h(-1) and 0.276+/-0.095 g/l, respectively. Comparing the estimated values with the kinetics constants for propionate reported in the literature, it can be concluded that glycerol uptake is not the rate-limiting step during the process.

  4. Combined effects of Fenton peroxidation and CaO conditioning on sewage sludge thermal drying.

    PubMed

    Liu, Huan; Liu, Peng; Hu, Hongyun; Zhang, Qiang; Wu, Zhenyu; Yang, Jiakuan; Yao, Hong

    2014-12-01

    Joint application of Fenton's reagent and CaO can dramatically enhance sludge dewaterability, thus are also likely to affect subsequent thermal drying process. This study investigated the synergistic effects of the two conditioners on the thermal drying behavior of sewage sludge and the emission characteristics of main sulfur-/nitrogen-containing gases. According to the results, Fenton peroxidation combined with CaO conditioning efficiently promoted sludge heat transfer, reduced the amounts of both free and bound water, and created porous structure in solids to provide evaporation channels, thus producing significant positive effects on sludge drying performance. In this case, the required time for drying was shortened to one-third. Additionally, joint usage of Fenton's reagent and CaO did not increase the losses of organic matter during sludge drying process. Meanwhile, they facilitated the formation of sulfate and sulfonic acid/sulfone, leading to sulfur retention in dried sludge. Both of Fenton peroxidation and CaO conditioning promoted the oxidation, decomposition, and/or dissolution of protein and inorganic nitrogen in sludge pre-treatment. As a consequence, the emissions of sulfurous and nitrogenous gases from dewatered sludge drying were greatly suppressed. These indicate that combining Fenton peroxidation with CaO conditioning is a promising strategy to improve drying efficiency of sewage sludge and to control sulfur and nitrogen contaminants during sludge thermal drying process.

  5. Prevalence of Cryptosporidium oocysts and Giardia cysts in raw and treated sewage sludges.

    PubMed

    Amorós, Inmaculada; Moreno, Yolanda; Reyes, Mariela; Moreno-Mesonero, Laura; Alonso, Jose L

    2016-11-01

    Treated sludge from wastewater treatment plants (WWTPs) is commonly used in agriculture as fertilizers and to amend soils. The most significant health hazard for sewage sludge relates to the wide range of pathogenic microorganisms such as protozoa parasites.The objective of this study was to collect quantitative data on Cryptosporidium oocysts and Giardia cysts in the treated sludge in wastewater treatment facilities in Spain. Sludge from five WWTPs with different stabilization processes has been analysed for the presence of Cryptosporidium and Giardia in the raw sludge and after the sludge treatment. A composting plant (CP) has also been assessed. After a sedimentation step, sludge samples were processed and (oo)cysts were isolated by immunomagnetic separation (IMS) and detected by immunofluorescence assay (IFA). Results obtained in this study showed that Cryptosporidium oocysts and Giardia cysts were present in 26 of the 30 samples (86.6%) of raw sludge samples. In treated sludge samples, (oo)cysts have been observed in all WWTP's analysed (25 samples) with different stabilization treatment (83.3%). Only in samples from the CP no (oo)cysts were detected. This study provides evidence that (oo)cysts are present in sewage sludge-end products from wastewater treatment processes with the negative consequences for public health.

  6. The comparison of the migration and transformation behavior of heavy metals during pyrolysis and liquefaction of municipal sewage sludge, paper mill sludge, and slaughterhouse sludge.

    PubMed

    Shao, Jianguang; Yuan, Xingzhong; Leng, Lijian; Huang, Huajun; Jiang, Longbo; Wang, Hou; Chen, Xiaohong; Zeng, Guangming

    2015-12-01

    Municipal sewage sludge, paper mill sludge, and slaughterhouse sludge were pyrolyzed and liquefied for the production of bio-char. The migration and transformation behavior of Cu, Cr, and Zn during pyrolysis and liquefaction of these sludges were studied. Pyrolysis and liquefaction promoted mobile fraction (F1 and F2) to stable fraction (F3 and F4). The results showed that pyrolysis and liquefaction largely affected the redistribution of Cu and Zn in raw materials. The environmental risk assessment results indicated that the environmental risk levels of Cu and Zn were significantly reduced in bio-char, and risk level of Cr was slightly decreased after pyrolysis or liquefaction. Both pyrolysis and liquefaction were promising detoxification technologies for the three sludges in terms of the mitigation of heavy metals toxicity. It was suggested that dewatered sludge could be reduced toxicity/risk before utilization by pyrolysis or liquefaction technology, especially for Cu and Zn in slaughterhouse sludge.

  7. Ecotoxicological evaluation of the bioleaching treatment of sewage sludges contaminated with heavy metals

    SciTech Connect

    Renoux, A.Y.; Tyagi, R.D.; Paquette, L.; Samson, R.

    1995-12-31

    A new decontamination technology of sewage sludge, the bioleaching of heavy metals, was assessed using ecotoxicity bioassays. Sewage sludges, treated or non-treated, were mixed with a non-contaminated soil used as a negative control at a rate of 1 to 100 g per liter of soil. Aqueous elutriates (TCLP) of the sludges were used for the aqueous bioassays. The bioleaching of metals reduced the toxic effects associated with sludge for most of the bioassays, although the sludge after treatment exhibited an inherent level of toxicity at high loading rates. With respect to seed germination, bioleached sludge was less toxic (EC50 barley: 53 g/L; lettuce: 13.6) than the non-treated (72; 16.8 g/L). The treated sludge stimulated the barley growth at > 5 6 g/L. The non-treated causes an inhibition at 100 g/L. Earthworms survived in up to 56 g/L of bioleached sludge, compared to 32 g/L of the non-treated. The Microtox{reg_sign} EC50s were 4.0% and 8.4% for nontreated and treated sludges respectively. No genotoxicity (SOS Chromotest) in the sludge elutriates was detected, and no significant treatment effects were noticeable using the lettuce root elongation bioassay. The Daphnia magna mortality of the elutriate was increased with sludge treatment. However, the lettuce root elongation and D. magna mortality bioassay results were difficult to interpret due to variability in standard deviations. This study demonstrated that the ecotoxicological battery of bioassays, and particularly direct contact bioassays, can be used to assess sewage sludge remediation technologies.

  8. Influence of forced air volume on water evaporation during sewage sludge bio-drying.

    PubMed

    Cai, Lu; Chen, Tong-Bin; Gao, Ding; Zheng, Guo-Di; Liu, Hong-Tao; Pan, Tian-Hao

    2013-09-01

    Mechanical aeration is critical to sewage sludge bio-drying, and the actual water loss caused by aeration can be better understood from investigations of the relationship between aeration and water evaporation from the sewage sludge bio-drying pile based on in situ measurements. This study was conducted to investigate the effects of forced air volume on the evaporation of water from a sewage sludge bio-drying pile. Dewatered sewage sludge was bio-dried using control technology for bio-drying, during which time the temperature, superficial air velocity and water evaporation were measured and calculated. The results indicated that the peak air velocity and water evaporation occurred in the thermophilic phase and second temperature-increasing phase, with the highest values of 0.063 ± 0.027 m s(-1) and 28.9 kg ton(-1) matrix d(-1), respectively, being observed on day 4. Air velocity above the pile during aeration was 43-100% higher than when there was no aeration, and there was a significantly positive correlation between air volume and water evaporation from day 1 to 15. The order of daily means of water evaporation was thermophilic phase > second temperature-increasing phase > temperature-increasing phase > cooling phase. Forced aeration controlled the pile temperature and improved evaporation, making it the key factor influencing water loss during the process of sewage sludge bio-drying.

  9. Bio-oil from thermo-chemical hydro-liquefaction of wet sewage sludge.

    PubMed

    Malins, Kristaps; Kampars, Valdis; Brinks, Janis; Neibolte, Ilze; Murnieks, Raimonds; Kampare, Ruta

    2015-01-01

    The present work demonstrates the influence of experimental conditions such as weight ratio of sewage sludge to water (1/0-1/15), reaction temperature (200-350°C), initial H2 pressure (2.0-11.0MPa), residence time (10-100min) and type of catalysts (Na2CO3, Raney nickel, FeSO4, MoS2) on hydro-liquefaction process of sewage sludge. High amount of water improves the hydro-liquefaction process of sewage sludge by increasing the yield of bio-oil and the total conversion. The highest yield of bio-oil (47.79 wt.%) from sewage sludge was obtained with initial H2 pressure 5.0MPa, reaction temperature 300°C, and residence time 40min. Under these experimental conditions, using weight ratio of sewage sludge to water 1/5, catalyst (FeSO4) - 5 wt.% of dry SS, mixing speed 350rpm the obtained bio-oil had the highest energy recovery (69.84%), total conversion (70.64%) and its calorific value was 35.22MJ/kg.

  10. A spatial multicriteria decision making tool to define the best agricultural areas for sewage sludge amendment.

    PubMed

    Passuello, Ana; Cadiach, Oda; Perez, Yolanda; Schuhmacher, Marta

    2012-01-01

    Sewage sludge amendment on agricultural soils has recently become a practice of heightened interest, as a consequence of sewage sludge production increase. This practice has benefits to soil and crops, however it may also lead to environmental contamination, depending on the characteristics of the fields. In order to define the suitability of the different agricultural fields to receive sewage sludge, a spatial tool is proposed. This tool, elaborated in GIS platform, aggregates different criteria regarding human exposure and environmental contamination. The spatial tool was applied to a case study in the region of Catalonia (NE of Spain). Within the case study, each step of the tool development is detailed. The results show that the studied region has different suitability degrees, being the appropriate areas sufficient for receiving the total amount of sewage sludge produced. The sensitivity analysis showed that "groundwater contamination", "distance to urban areas", "metals concentration in soil" and "crop type" are the most important criteria of the evaluation. The developed tool successfully tackled the problem, providing a comprehensive procedure to evaluate agricultural land suitability to receive sewage sludge as an organic fertilizer. Also, the tool implementation gives insights to decision makers, guiding them to more confident decisions, based on an extensive group of criteria.

  11. Speciation of heavy metals during co-composting of sewage sludge with lime.

    PubMed

    Wong, J W C; Selvam, A

    2006-05-01

    During composting the humification of organic matter will have a significant effect on the physicochemical form of existence of heavy metals. Therefore the present study was conducted to investigate the effect of co-composting sewage sludge with lime on heavy metal speciation and the changes in DTPA extractable metals. Metal speciation was conducted to evaluate the redistribution of Cu, Mn, Ni, Pb and Zn in sewage sludge composted with lime. Sewage sludge was mixed with sawdust in 2:1 (w/w fresh weight) and then composted with lime at 0%, 0.63%, 1% or 1.63% (dry weight) for 100 days. The lime addition did not cause any changes in the different forms of Cu and Mn, but the composting process caused transformations of residual form of Cu and Mn into oxidizable and reducible form, respectively. For Ni, the reducible form was mainly transformed into residual form and lime addition decreased this transformation. Major transformation of different forms of Pb was not found, however the residual form of Pb increased with lime addition. The predominant residual form of Zn was mainly transformed into oxidizable form and the lime addition reduced this transformation. Addition of lime to sewage sludge during composting resulted in lower DTPA extractable metal contents. Therefore, lime is a suitable material to co-compost with sewage sludge to reduce the availability of heavy metals.

  12. Modeling of the reburning process using sewage sludge-derived syngas

    SciTech Connect

    Werle, Sebastian

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Gasification provides an attractive method for sewage sludges treatment. Black-Right-Pointing-Pointer Gasification generates a fuel gas (syngas) which can be used as a reburning fuel. Black-Right-Pointing-Pointer Reburning potential of sewage sludge gasification gases was defined. Black-Right-Pointing-Pointer Numerical simulation of co-combustion of syngases in coal fired boiler has been done. Black-Right-Pointing-Pointer Calculation shows that analysed syngases can provide higher than 80% reduction of NO{sub x}. - Abstract: Gasification of sewage sludge can provide clean and effective reburning fuel for combustion applications. The motivation of this work was to define the reburning potential of the sewage sludge gasification gas (syngas). A numerical simulation of the co-combustion process of syngas in a hard coal-fired boiler was done. All calculations were performed using the Chemkin programme and a plug-flow reactor model was used. The calculations were modelled using the GRI-Mech 2.11 mechanism. The highest conversions for nitric oxide (NO) were obtained at temperatures of approximately 1000-1200 K. The combustion of hard coal with sewage sludge-derived syngas reduces NO emissions. The highest reduction efficiency (>90%) was achieved when the molar flow ratio of the syngas was 15%. Calculations show that the analysed syngas can provide better results than advanced reburning (connected with ammonia injection), which is more complicated process.

  13. [Distribution and removal of anaerobic antibiotic resistant bacteria during mesophilic anaerobic digestion of sewage sludge].

    PubMed

    Tong, Juan; Wang, Yuan-Yue; Wei Yuan, Song

    2014-10-01

    Sewage sludge is one of the major sources that releasing antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARG) into the environment since it contains large amount of ARB, but there is little information about the fate of the anaerobic ARB in the anaerobic digestion of sewage sludge. Therefore, the distribution, removal and seasonal changes of tetracycline and β-lactam antibiotics resistant bacteria in the mesophilic egg-shaped digesters of a municipal wastewater treatment plant were investigated for one year in this study. Results showed that there were higher amounts of ARB and higher resistance rate of β-lactam antibiotics than that of tetracycline antibiotics in the sewage sludge. All ARB could be significantly reduced during the mesophilic anaerobic digestion process by 1.48-1.64 log unit (P < 0.05). Notably, the ampicillin and cephalothin resistance rates were significantly increased after anaerobic digestion by 12.0% and 14.3%, respectively (P < 0.05). The distribution of ARB in the sewage sludge had seasonal change characteristics. Except for chlorotetracycline resistant bacteria, there were more ARB in the sewage sludge in cold season than in warm season (P < 0.05).

  14. Influence of anaerobic co-digestion of sewage and brewery sludges on biogas production and sludge quality.

    PubMed

    Pecharaply, Athapol; Parkpian, Preeda; Annachhatre, Ajit P; Jugsujinda, Aroon

    2007-06-01

    This research investigated operating parameters and treatment efficiency for the digestion of sewage and brewery sludge. The prime objective of this study was to enhance the quality of treated sludge for use as agriculture fertilizer and to enhance biogas production, a by-product that can be used as an energy source. Three bench-scale completely stirred tank reactor (CSTR) anaerobic digesters were operated at mesophilic condition (36+/-0.2 degrees C). A mixture of sewage and brewery sludge were used as substrates at ratios of 100:0, 75:25, 50:50, 25:75 and 0:100, based on wet weight basis (w/w). For each digester, the solids retention times (SRT) were 20 days. The organic loading and volatile solids loading were between 1.3-2.2 kg chemical oxygen demand (COD)/m3/day and 0.9-1.5 kg/m3/day, respectively. The digester fed with brewery sludge as co-substrate yielded higher treatment efficiency than sewage sludge alone. The removal efficiencies measured in terms of soluble chemical oxygen demand (SCOD) and total chemical oxygen demands (TCOD) ranged from 40% to 75% and 22% to 35%, respectively. Higher SCOD and TCOD removal efficiencies were obtained when higher fractions of brewery sludge was added to the substrate mixture. Removal efficiency was lowest for sewage sludge alone. Measured volatile solid (VS) reduction ranged from 15% to 20%. Adding a higher fraction of brewery sludge to the mixture increased the VS reduction percentage. The biogas production and methane yield also increased with increase in brewery sludge addition to the digester mixture. The methane content present in biogas of each digester exceeded 70% indicating the system was functioning as an anaerobic process. Likewise the ratio of brewery sewage influenced not only the treatment efficiency but also improved quality of treated sludge by lowering number of pathogen (less than 2 MPN/g of dried sludge) and maintaining a high nutrient concentration of nitrogen (N) 3.2-4.2%, phosphorus (P) 1.9-3.2% and

  15. Municipal sewage sludge and phosphorus as amendments for minesoils on the Cumberland Plateau

    SciTech Connect

    Walker, C.L.; Ammons, J.T.; Reynolds, J.H.; Dimmick, R.W.

    1996-12-31

    A study was conducted to evaluate the benefit of applying municipal sewage sludge and/or phosphorus on surface mined land on the Cumberland Plateau in Fentress County, Tennessee. The objective of the study was to evaluate minesoil fertility and plant response after treatment. The site was prepared according to surface mine regulations and sampled before and after treatment. The experiment was conducted as a split, split, split block arranged in a randomized complete block design with four replications. Each replication contained a sludge treatment, a phosphorus treatment, a sludge/phosphorus combination treatment and a control. Minesoils amended with sludge alone had the greatest increase in fertility and plant response. Phosphorus alone had a comparable, though slightly lower response of plant growth on the sludge. Legume species responded particularly well on phosphorus. A combination of sludge and phosphorus had a slightly suppressive effect on some plant growth responses compared to sludge alone.

  16. Natural attenuation of toxic metal phytoavailability in 35-year-old sewage sludge-amended soil.

    PubMed

    Tai, Yiping; Li, Zhian; Mcbride, Murray B

    2016-04-01

    Toxic heavy metals persist in agricultural soils and ecosystem for many decades after their application as contaminants in sewage sludge and fertilizer products This study assessed the potential long-term risk of cadmium (Cd), lead (Pb), zinc (Zn), and copper (Cu) in land-applied sewage sludge to food crop contamination. A sewage sludge-amended soil (SAS) aged in the field more than 35 years was used in a greenhouse pot experiment with leafy vegetables (lettuce and amaranth) having strong Cd and Zn accumulation tendencies. Soil media with variable levels of available Cd, Zn, and Cu (measured using 0.01 M CaCl2 extraction) were prepared by diluting SAS with several levels of uncontaminated control soil. Despite long-term aging in the field, the sludge site soil still retains large reserves of heavy metals, residual organic matter, phosphorus, and other nutrients, but its characteristics appear to have stabilized over time. Nevertheless, lettuce and amaranth harvested from the sludge-treated soil had undesirable contents of Cd and Zn. The high plant uptake efficiency for Cd and Zn raises a concern regarding the quality and safety of leafy vegetables in particular, when these crops are grown on soils that have been amended heavily with sewage sludge products at any time in their past.

  17. Remediation of chromite ore processing residue by pyrolysis process with sewage sludge.

    PubMed

    Zhang, Dalei; Kong, Hainan; Wu, Deyi; He, Shengbing; Hu, Zhanbo; Hu, Xiaofang

    2009-06-01

    The present work developed a novel technique to treat chromite ore processing residue (COPR). The process involved mixing the COPR with sewage sludge followed by pyrolysis. The gaseous organic fraction generated during pyrolysis of sludge was beneficial to Cr(VI) reduction. Process variables, such as the amount of sludge added to COPR (sludge-to-COPR (S/C) ratio), heating temperature, reaction time and particle size, were systematically varied, and their influences on the Cr(VI) reduction in COPR were investigated. Cr(VI) content had decreased greatly, from 3384 mg kg(-1) for untreated COPR to less than 30 mg kg(-1) for COPR treated at 600 degrees C.

  18. Getting on with persistent pollutants: Decreasing trends of perfluoroalkyl acids (PFAAs) in sewage sludge.

    PubMed

    Ulrich, Hanna; Freier, Korbinian P; Gierig, Michael

    2016-10-01

    Sewage sludge can be a relevant source of perfluoroalkyl acids (PFAAs) for the environment. In order to reduce emissions from this source, Bavarian authorities enforced in 2008 an analysis of PFAAs from sewage sludge derived from municipal wastewater treatment plants (WWTPs). 4981 sludge samples from 1165 different WWTPs were analyzed between 2008 and 2013 for 11 PFAAs compounds. During this period, 71 WWTPs exceeded the precautionary limit of 125 μg kg(-1) dm of total PFAAs in sludge samples at least once with a decreasing tendency. The yearly exceedances of the investigated WWTPs decreased from 6% in 2008 to 0.8% in 2013. At the same time, the percentage of uncontaminated WWTPs increased from 33% to 65%. Perfluorooctane sulfonic acid (PFOS) was the predominant compound found in 41% of all sludge samples. Perfluorodecanoic acid (PFDA) was detected in 19% and Perfluorooctanoic acid (PFOA) in 7%. Very high PFAAs concentrations (>500 μg kg(-1) dm) in sewage sludge were generally caused by firefighting foams containing PFAAs or emissions from PFAAs-using industries including metal plating, textile, leather or paper industries. Trend analyses of the six year period show that PFAAs contamination in sewage sludge clearly decreased for 47% of the WWTPs. However, for 16% of the WWTPs an increasing trend was detected, even though the concentration levels were below the precautionary limit. During the six years of investigation the load of total PFAAs in sewage sludge was reduced by more than 90%, from 17 t a(-1) in 2008 to 1.5 t a(-1) in 2013.

  19. Sewage sludge, compost and other representative organic wastes as agricultural soil amendments: Benefits versus limiting factors.

    PubMed

    Alvarenga, Paula; Mourinha, Clarisse; Farto, Márcia; Santos, Teresa; Palma, Patrícia; Sengo, Joana; Morais, Marie-Christine; Cunha-Queda, Cristina

    2015-06-01

    Nine different samples of sewage sludges, composts and other representative organic wastes, with potential interest to be used as agricultural soil amendments, were characterized: municipal sewage sludge (SS1 and SS2), agro industrial sludge (AIS), municipal slaughterhouse sludge (MSS), mixed municipal solid waste compost (MMSWC), agricultural wastes compost (AWC), compost produced from agricultural wastes and sewage sludge (AWSSC), pig slurry digestate (PSD) and paper mill wastes (PMW). The characterization was made considering their: (i) physicochemical parameters, (ii) total and bioavailable heavy metals (Cd, Cr, Cu, Ni, Pb, Zn and Hg), (iii) organic contaminants, (iv) pathogenic microorganisms and (v) stability and phytotoxicity indicators. All the sludges, municipal or other, comply with the requirements of the legislation regarding the possibility of their application to agricultural soil (with the exception of SS2, due to its pathogenic microorganisms content), with a content of organic matter and nutrients that make them interesting to be applied to soil. The composts presented, in general, some constraints regarding their application to soil, and their impairment was due to the existence of heavy metal concentrations exceeding the proposed limit of the draft European legislation. As a consequence, with the exception of AWSSC, most compost samples were not able to meet these quality criteria, which are more conservative for compost than for sewage sludge. From the results, the composting of sewage sludge is recommended as a way to turn a less stabilized waste into a material that is no longer classified as a waste and, judging by the results of this work, with lower heavy metal content than the other composted materials, and without sanitation problems.

  20. Valuable compounds from sewage sludge by thermal hydrolysis and wet oxidation. A review.

    PubMed

    Suárez-Iglesias, Octavio; Urrea, José Luis; Oulego, Paula; Collado, Sergio; Díaz, Mario

    2017-04-15

    Sewage sludge is considered a costly waste, whose benefit has received a lot of attention for decades. In this sense, a variety of promising technologies, such as thermal hydrolysis and wet oxidation, are currently employed. Thermal hydrolysis is used as a pretreatment step ahead of anaerobic digestion processes and wet oxidation is intended for the solubilization and partial oxidation of the sludge. Such processes could be utilized for solubilizing polysaccharides, lipids, fragments of them and phosphorus (thermal hydrolysis) or for generating carboxylic acids (wet oxidation). This article compiles the available information on the production of valuable chemicals by these techniques and comments on their main features. Temperature, reaction duration times and sludge characteristics influence the experimental results significantly, but only the first two variables have been thoroughly studied. For thermal hydrolysis, a rise of temperature led to an increase in the solubilized biomolecules, but also to a greater decomposition of proteins and undesirable reactions of carbohydrates with themselves or with proteins. At constant temperature, the amounts of substances that can be recovered tend to become time independent after several minutes. Diluted and activated sludges seem to be more readily hydrolyzable than the thickened and primary ones. For wet oxidation, the dependence of the production of carboxylic acids with temperature and time is not simple: their concentration can increase, decrease or go through a maximum. At high temperatures, acetic acid is the main carboxylic acid obtained. Concentrated, fermented and secondary sludge seem to be more suitable for yielding higher amounts of acid than diluted, undigested and primary ones.

  1. 40 CFR Table 5 to Subpart Llll of... - Summary of Reporting Requirements for New Sewage Sludge Incineration Units a

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... New Sewage Sludge Incineration Units a 5 Table 5 to Subpart LLLL of Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for New Sewage Sludge Incineration Units Pt. 60, Subpt. LLLL, Table...

  2. 40 CFR Table 5 to Subpart Llll of... - Summary of Reporting Requirements for New Sewage Sludge Incineration Units a

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... New Sewage Sludge Incineration Units a 5 Table 5 to Subpart LLLL of Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for New Sewage Sludge Incineration Units Pt. 60, Subpt. LLLL, Table...

  3. 40 CFR Table 4 to Subpart Mmmm of... - Model Rule-Operating Parameters for Existing Sewage Sludge Incineration Units a

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Existing Sewage Sludge Incineration Units a 4 Table 4 to Subpart MMMM of Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Emission Guidelines and Compliance Times for Existing Sewage Sludge Incineration Units Pt....

  4. 40 CFR Table 4 to Subpart Mmmm of... - Model Rule-Operating Parameters for Existing Sewage Sludge Incineration Units a

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Existing Sewage Sludge Incineration Units a 4 Table 4 to Subpart MMMM of Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Emission Guidelines and Compliance Times for Existing Sewage Sludge Incineration Units Pt....

  5. Combined Effects of Soil Biotic and Abiotic Factors, Influenced by Sewage Sludge Incorporation, on the Incidence of Corn Stalk Rot

    PubMed Central

    Fortes, Nara Lúcia Perondi; Navas-Cortés, Juan A; Silva, Carlos Alberto; Bettiol, Wagner

    2016-01-01

    The objectives of this study were to evaluate the combined effects of soil biotic and abiotic factors on the incidence of Fusarium corn stalk rot, during four annual incorporations of two types of sewage sludge into soil in a 5-years field assay under tropical conditions and to predict the effects of these variables on the disease. For each type of sewage sludge, the following treatments were included: control with mineral fertilization recommended for corn; control without fertilization; sewage sludge based on the nitrogen concentration that provided the same amount of nitrogen as in the mineral fertilizer treatment; and sewage sludge that provided two, four and eight times the nitrogen concentration recommended for corn. Increasing dosages of both types of sewage sludge incorporated into soil resulted in increased corn stalk rot incidence, being negatively correlated with corn yield. A global analysis highlighted the effect of the year of the experiment, followed by the sewage sludge dosages. The type of sewage sludge did not affect the disease incidence. A multiple logistic model using a stepwise procedure was fitted based on the selection of a model that included the three explanatory parameters for disease incidence: electrical conductivity, magnesium and Fusarium population. In the selected model, the probability of higher disease incidence increased with an increase of these three explanatory parameters. When the explanatory parameters were compared, electrical conductivity presented a dominant effect and was the main variable to predict the probability distribution curves of Fusarium corn stalk rot, after sewage sludge application into the soil. PMID:27176597

  6. Combined Effects of Soil Biotic and Abiotic Factors, Influenced by Sewage Sludge Incorporation, on the Incidence of Corn Stalk Rot.

    PubMed

    Ghini, Raquel; Fortes, Nara Lúcia Perondi; Navas-Cortés, Juan A; Silva, Carlos Alberto; Bettiol, Wagner

    2016-01-01

    The objectives of this study were to evaluate the combined effects of soil biotic and abiotic factors on the incidence of Fusarium corn stalk rot, during four annual incorporations of two types of sewage sludge into soil in a 5-years field assay under tropical conditions and to predict the effects of these variables on the disease. For each type of sewage sludge, the following treatments were included: control with mineral fertilization recommended for corn; control without fertilization; sewage sludge based on the nitrogen concentration that provided the same amount of nitrogen as in the mineral fertilizer treatment; and sewage sludge that provided two, four and eight times the nitrogen concentration recommended for corn. Increasing dosages of both types of sewage sludge incorporated into soil resulted in increased corn stalk rot incidence, being negatively correlated with corn yield. A global analysis highlighted the effect of the year of the experiment, followed by the sewage sludge dosages. The type of sewage sludge did not affect the disease incidence. A multiple logistic model using a stepwise procedure was fitted based on the selection of a model that included the three explanatory parameters for disease incidence: electrical conductivity, magnesium and Fusarium population. In the selected model, the probability of higher disease incidence increased with an increase of these three explanatory parameters. When the explanatory parameters were compared, electrical conductivity presented a dominant effect and was the main variable to predict the probability distribution curves of Fusarium corn stalk rot, after sewage sludge application into the soil.

  7. Impact of chemically contaminated sewage sludge on the collard arthropod community

    SciTech Connect

    Culliney, T.W.; Pimentel, D.; Lisk, D.J.

    1986-08-01

    Stress effects on a terrestrial arthropod community were evident in a study of collards grown in soil amended with chemically contaminated sewage sludge. Plant growth in the contaminated sludge was significantly reduced compared with growth in plots treated with relatively uncontaminated sludge from two small towns or with mature alone. Population densities of major arthropod taxa tended to be lower in plots of contaminated sludge than they were in uncontaminated sludge and manure plots. Species richness and diversity were also reduced in contaminated-sludge plots compared with those of uncontaminated sludge and manure treatments. In general, few differences were observed in plant growth and arthropod numbers between the uncontaminated-sludge treatment, or uncontaminated sludge treated with cadmium or with the insecticide dieldrin. Because cadmium and dieldrin were applied at dosages of cadmium and polychlorinated biphenyls (PCB's) found in the contaminated sludge, results suggested that these two toxins were not responsible for the effects on plants and arthropods observed in the contaminated-sludge treatment. Results of this study indicated the potential for sludge-borne contaminants to suppress growth in crop plants and reduce abundance of their associated arthropods.

  8. Heavy metals and its chemical speciation in sewage sludge at different stages of processing.

    PubMed

    Tytła, Malwina; Widziewicz, Kamila; Zielewicz, Ewa

    2016-01-01

    The analysis of heavy metal concentrations and forms in sewage sludge constitutes an important issue in terms of both health and environmental hazards the metals pose. The total heavy metals concentration enables only the assessment of its contamination. Hence the knowledge of chemical forms is required to determine their environmental mobility and sludge final disposal. Heavy metals speciation was studied by using four-stage sequential extraction BCR (Community Bureau of Reference). This study was aimed at determining the total concentration of selected heavy metals (Zn, Cu, Ni, Pb, Cd, Cr and Hg) and their chemical forms (except for Hg) in sludge collected at different stages of its processing at two municipal Wastewater Treatment Plants in southern Poland. Metals contents in sludge samples were determined by using flame atomic absorption spectrometry (FAAS) and electrothermal atomic absorption spectrometry (ETAAS). This study shows that Zn and Cu appeared to be the most abundant in sludge, while Cd and Hg were in the lowest concentrations. The sewage sludge revealed the domination of immobile fractions over the mobile ones. The oxidizable and residual forms were dominant for all the heavy metals. There was also a significant difference in metals speciation between sludges of different origin which was probably due to differences in wastewater composition and processes occurring in biological stage of wastewater treatment. The results indicate a negligible capability of metals to migrate from sludge into the environment. Our research revealed a significant impact of thickening, stabilization and hygienization on the distribution of heavy metals in sludge and their mobility.

  9. [Factors of effecting hydrogen production from anaerobic fermentation of excess sewage sludge].

    PubMed

    Cai, Mu-lin; Liu, Jun-xin

    2005-03-01

    Large amounts of sewage sludge is produced from the treatment of wastewater by biological processes, which is usually treated by anaerobic digestion to produce methane gas. Acetogenesis and hydrogen are an intermediate phase during the anaerobic digestion. Batch tests of fermentative hydrogen production under different initial pH (3.0 - 12.5) were compared using the raw sludge and alkaline pretreated sludge. The influences of the characteristics and concentration of sludge were also examined thereafter. Results show that the optimal initial pH for biohydrogen production from sewage sludge was around 11.0. Under this optimal condition, the biohydrogen yield of raw sludge was 8.1 mL/g, and it would reach to 16.9 mL/g when the sludge was pretreated by alkali. Furthermore, there is no methane generation during the biohydrogen fermentation of the alkaline pretreatment sludge in 4 days and the hydrogen consumption is also slowed down. In addition, a low VSS/SS rate will reduce the hydrogen yield, while the concentrations of sludge have no obvious compact on it.

  10. Environmental application for GIS: Assessing Iskandar Malaysia's (IM) sewage sludge for potential biomass resource

    NASA Astrophysics Data System (ADS)

    Salim, M. R.; Shaharuddin, N.; Abdullah Halim, K.

    2014-02-01

    The low carbon scenario could be achieved through the identification of major sectors contributing to the emission of high greenhouse gases (GHG) into the atmosphere. Sewage treatment plant (STP) was ranked as one of the major sectors that emits methane gas (CH4) during treatment processes, including sludge treatment. Sludge treatment is also capital extensive with high operational cost. Thus, sewage sludge has been accepted as a nuisance in STP. However, many has claimed that, sludge produced contain organic matter that has the potential for biomass resource. Thus, it would be such a Žwaste? if sludge are directly disposed of into the landfill without utilizing them at its full potential. In order to do so, it is vital to be able to determine the amount of sludge production. This research was implemented in Iskandar Malaysia regions in the state of Johor. By using GIS tool, the regions that produced the most sewage sludge can be determined, and can be group as critical area. Result shows that Nusajaya produces the most, compared to other regions, which indicated Nusajaya as a densely populated region.

  11. Prediction of full-scale dewatering results of sewage sludges by the physical water distribution.

    PubMed

    Kopp, J; Dichtl, N

    2001-01-01

    The dewaterability of sewage sludge can be described by the total solids concentration of the sludge cake and the polymer-demand for conditioning. The total solids concentration of the sludge cake depends on the physical water distribution. The various types of water in sewage sludge are mainly distinguished by the type and the intensity of their physical bonding to the solids. In a sewage sludge suspension four different types of water can be distinguished. These are the free water, which is not bound to the particles, the interstitial water, which is bound by capillary forces between the sludge flocs, the surface water, which is bound by adhesive forces and intracellular water. Only the share of free water can be separated during mechanical dewatering. It can be shown, that by thermo-gravimeteric measurement of the free water content, an exact prediction of full-scale dewatering results is possible. By separation of all free water during centrifugation the maximum dewatering result is reached. Polymer conditioning increases the velocity of the sludge water release, but the free water content is not influenced by this process. Furthermore it is not possible, to replace the measuring of the water distribution by other individual parameters such as ignition loss.

  12. Phytotoxicity of municipal sewage sludge composts related to physico-chemical properties, PAHs and heavy metals.

    PubMed

    Oleszczuk, Patryk

    2008-03-01

    The aim of the study was to determine the influence of the composting on the phytotoxicity of sewage sludge in relation to their physical-chemical properties, heavy metals and polycyclic aromatic hydrocarbons content. Four municipal sewage sludges were composted for 76 days. A Phytotoxkit Test and pot experiment with Lepidium sativum were used for bioassay. The total PAH content in sludges ranged from 3674.1 to 11236.3 microg kg(-1). Heavy metals content was in the range Cd (1.9-76 mg kg(-1)), Cr (27.6-120 mg kg(-1)), Cu (156-335 mg kg(-1)), Pb (37.5-59.5 mg kg(-1)), Ni (21.7-155 mg kg(-1)) and Zn (1015-1385 mg kg(-1)). The results showed a varied toxicity of sewage sludge in relation to the plant tested. In the case of two sludges a 100% inhibition of seed germination were noted. Sludge composting limited their negative influence on most of the phytotoxicity parameters. Only chlorophyll concentration was often lower than in the plant bred on compost obtained from sludge.

  13. The migration and transformation behaviors of heavy metals during the hydrothermal treatment of sewage sludge.

    PubMed

    Huang, Hua-Jun; Yuan, Xing-Zhong

    2016-01-01

    Various hydrothermal treatment methods, including hydrothermal carbonization, liquefaction and sub/super-critical water gasification, have been applied to the disposal of sewage sludge for producing bio-materials or bio-fuels. It has become a research hotspot whether the heavy metals contained in sewage sludge can be well treated/stabilized after the hydrothermal treatments. This review firstly summarized the methods of assessing heavy metals' contamination level/risk and then discussed the migration and transformation behaviors of heavy metals from the following aspects: the effect of reaction temperature, the effect of additives (catalysts and other biomass), the effect of the type of solvent and the effect of reaction time. This review can provide an important reference for the further study of the migration and transformation behaviors of heavy metals during the hydrothermal treatment of sewage sludge.

  14. Modeling of the reburning process using sewage sludge-derived syngas.

    PubMed

    Werle, Sebastian

    2012-04-01

    Gasification of sewage sludge can provide clean and effective reburning fuel for combustion applications. The motivation of this work was to define the reburning potential of the sewage sludge gasification gas (syngas). A numerical simulation of the co-combustion process of syngas in a hard coal-fired boiler was done. All calculations were performed using the Chemkin programme and a plug-flow reactor model was used. The calculations were modelled using the GRI-Mech 2.11 mechanism. The highest conversions for nitric oxide (NO) were obtained at temperatures of approximately 1000-1200K. The combustion of hard coal with sewage sludge-derived syngas reduces NO emissions. The highest reduction efficiency (>90%) was achieved when the molar flow ratio of the syngas was 15%. Calculations show that the analysed syngas can provide better results than advanced reburning (connected with ammonia injection), which is more complicated process.

  15. Biological and ecophysiological reactions of white wall rocket (Diplotaxis erucoides L.) grown on sewage sludge compost.

    PubMed

    Korboulewsky, Nathalie; Bonin, Gilles; Massiani, Catherine

    2002-01-01

    We studied the effects of sewage sludge compost on white wall rocket (Diplotaxis erucoides L.) compared with mineral fertilization and control (without any fertilizer) in a greenhouse experiment. The plants grown on the compost-amended soil showed a different growth dynamic: a significant delay in flowering and a bigger root system. Both the compost and the fertilization treatments increased biomass and seed yield. Heavy metal (Cu, Cd, Zn, Ni) distribution within the plant was in the following order: roots > leaves > stems, except for zinc which was homogeneously distributed. The balance of mineral nutrition was not affected by treatments. Zinc was the trace element which was most taken up. Unlike many species of Brassicaceae, white wall rocket is not a hyperaccumulator. Although sewage sludge compost improved plant growth, delay in flowering shows that it is necessary to take precautions when spreading sewage sludge in natural areas.

  16. Anaerobic co-digestion of fruit and vegetable wastes and primary sewage sludge.

    PubMed

    Velmurugan, B; Arathy, E C; Hemalatha, R; Philip, Jerry Elsa; Alwar Ramanujam, R

    2010-01-01

    Anaerobic co-digestion of fruit and vegetable wastes (FVW) and primary sewage sludge was carried out in a fed-batch reactor having a volume of 21 under ambient temperature conditions. Three different proportions (25:75, 50:50 and 75:25 in terms ofVS) of fruit and vegetable wastes and primary sewage sludge were studied for an organic loading rate (OLR) of 1.0 g VS/ l.d and with a hydraulic retention time (HRT) of 25 days. The reactor with 75% FVW and 25% sewage sludge (in terms of VS) showed better performance in terms of VS reduction and biogas yield when compared to other two proportions.

  17. Co-digestion of glycerine and sewage sludge to optimise green electricity production.

    PubMed

    Maes, L; Weemaes, M; Hellinck, N; De Gueldre, G; Van De Steene, B

    2013-01-01

    Sewage sludge and crude glycerine were co-digested in the mesophilic digester of Hoogstraten wastewater treatment plant. Additions of up to 1 kg of crude glycerine/(m³ reactor).(day) were done without significant operational problems. At higher dosage, severe digester foaming was observed. Methane production during co-digestion was up to 20% higher than what would be expected based on the digester input. Compared to the period before glycerine dosage, every tonne of added crude glycerine resulted in a surplus methane production of 489 Nm³. The theoretical methane production from the used crude glycerine was 341 Nm³ per tonne. The difference is explained by a higher sewage sludge degradability during co-digestion with glycerine. Glycerine dosage can remedy the lowered specific biogas yield of sewage sludge in Flanders and consequently enhance green electricity production.

  18. Evaluation of the anaerobic co-digestion of sewage sludge and tomato waste at mesophilic temperature.

    PubMed

    Belhadj, Siham; Joute, Yassine; El Bari, Hassan; Serrano, Antonio; Gil, Aida; Siles, José A; Chica, Arturo F; Martín, M Angeles

    2014-04-01

    Sewage sludge is a hazardous waste, which must be managed adequately. Mesophilic anaerobic digestion is a widely employed treatment for sewage sludge involving several disadvantages such as low methane yield, poor biodegradability, and nutrient imbalance. Tomato waste was proposed as an easily biodegradable co-substrate to increase the viability of the process in a centralized system. The mixture proportion of sewage sludge and tomato waste evaluated was 95:5 (wet weight), respectively. The stability was maintained within correct parameters in an organic loading rate from 0.4 to 2.2 kg total volatile solids (VS)/m(3) day. Moreover, the methane yield coefficient was 159 l/kg VS (0 °C, 1 atm), and the studied mixture showed a high anaerobic biodegradability of 95 % (in VS). Although the ammonia concentration increased until 1,864 ± 23 mg/l, no inhibition phenomenon was determined in the stability variables, methane yield, or kinetics parameters studied.

  19. Co-digestion of intermediate landfill leachate and sewage sludge as a method of leachate utilization.

    PubMed

    Montusiewicz, A; Lebiocka, M

    2011-02-01

    This study examines the co-digestion of intermediate landfill leachate and sewage sludge from a municipal wastewater treatment plant. Application of leachate as a co-fermentation component increased the concentrations of soluble organic compounds (expressed as total organic carbon), ammonium nitrogen, and alkalinity in the digester influents. The biogas yield obtained from the co-fermentation of a 20:1 sewage sludge: intermediate leachate mixture was 1.30 m(3) per kg of removed volatile solids (VS), while that from a 10:1 mixture was 1.24 m(3) per kg of removed VS. These values exceeded the biogas yield for the sludge alone by 13% and 8%, respectively. The leachate addition influenced the proportion of methane to a minor extent. Increased methane yields of 16.9% and 6.2% per kg of removed VS were found for the two sewage sluge:intermediate leachate mixtures, respectively.

  20. F- and H-Area Sewage Sludge Application Sites Groundwater Monitoring Report: Third quarter 1993

    SciTech Connect

    Not Available

    1994-01-01

    Samples from the four wells at the F-Area Sewage Sludge Application Site (FSS wells) and the three wells at the H-Area Sewage Sludge Application Site (HSS wells) are analyzed quarterly for constituents as required by South Carolina Department of Health and Environmental Control Construction Permit 12,076 and, as requested, for other constituents as part of the Savannah River Site Groundwater Monitoring Program. Annual analyses for other constituents, primarily metals, also are required by the permit. Currently, iron, lead, and manganese are the only permit-required analytes that exceed standards at the F- and H-Area Sewage Sludge Application Sites. Tritium and aluminum are the nonpermit constituents exceeding standards. Other constituents have exceeded standards at this site previously, but only sporadically.

  1. Moisture variation associated with water input and evaporation during sewage sludge bio-drying.

    PubMed

    Cai, Lu; Gao, Ding; Chen, Tong-Bin; Liu, Hong-Tao; Zheng, Guo-Di; Yang, Qi-Wei

    2012-08-01

    The variation of moisture during sewage sludge bio-drying was investigated. In situ measurements were conducted to monitor the bulk moisture and water vapor, while the moisture content, water generation, water evaporation and aeration water input of the bio-drying bulk were calculated based on the water mass balance. The moisture in the sewage sludge bio-drying material decreased from 66% to 54% in response to control technology for bio-drying. During the temperature increasing and thermophilic phases of sewage sludge bio-drying, the moisture content, water generation and water evaporation of the bulk initially increased and then decreased. The peak water generation and evaporation occurred during the thermophilic phase. During the bio-drying, water evaporation was much greater than water generation, and aeration facilitated the water evaporation.

  2. Supercritical water gasification of sewage sludge: gas production and phosphorus recovery.

    PubMed

    Acelas, Nancy Y; López, Diana P; Brilman, D W F Wim; Kersten, Sascha R A; Kootstra, A Maarten J

    2014-12-01

    In this study, the feasibility of the gasification of dewatered sewage sludge in supercritical water (SCW) for energy recovery combined with P-recovery from the solid residue generated in this process was investigated. SCWG temperature (400°C, 500°C, 600°C) and residence time (15min, 30min, 60min) were varied to investigate their effects on gas production and the P recovery by acid leaching. The results show that the dry gas composition for this uncatalyzed gasification of sewage sludge in SCW mainly comprised of CO2, CO, CH4, H2, and some C2-C3 compounds. Higher temperatures and longer residence times favored the production of H2 and CH4. After SCWG, more than 95% of the P could be recovered from the solid residue by leaching with acids. SCWG combined with acid leaching seems an effective method for both energy recovery and high P recovery from sewage sludge.

  3. Potential of biohydrogen production from effluents of citrus processing industry using anaerobic bacteria from sewage sludge.

    PubMed

    Torquato, Lilian D M; Pachiega, Renan; Crespi, Marisa S; Nespeca, Maurílio Gustavo; de Oliveira, José Eduardo; Maintinguer, Sandra I

    2017-01-01

    Citrus crops are among the most abundant crops in the world, which processing is mainly based on juice extraction, generating large amounts of effluents with properties that turn them into potential pollution sources if they are improperly discarded. This study evaluated the potential for bioconversion of effluents from citrus-processing industry (wastewater and vinasse) into hydrogen through the dark fermentation process, by applying anaerobic sewage sludge as inoculum. The inoculum was previously heat treated to eliminate H2-consumers microorganisms and improve its activity. Anaerobic batch reactors were operated in triplicate with increasing proportions (50, 80 and 100%) of each effluent as substrate at 37°C, pH 5.5. Citrus effluents had different effects on inoculum growth and H2 yields, demonstrated by profiles of acetic acid, butyric acid, propionic acid and ethanol, the main by-products generated. It was verified that there was an increase in the production of biogas with the additions of either wastewater (7.3, 33.4 and 85.3mmolL(-1)) or vinasse (8.8, 12.7 and 13.4mmolL(-1)) in substrate. These effluents demonstrated remarkable energetic reuse perspectives: 24.0MJm(-3) and 4.0MJm(-3), respectively. Besides promoting the integrated management and mitigation of anaerobic sludge and effluents from citrus industry, the biohydrogen production may be an alternative for the local energy supply, reducing the operational costs in their own facilities, while enabling a better utilization of the biological potential contained in sewage sludges.

  4. Barium uptake by maize plants as affected by sewage sludge in a long-term field study.

    PubMed

    Nogueira, Thiago Assis Rodrigues; deMelo, Wanderley José; Fonseca, Ivana Machado; Marques, Marcos Omir; He, Zhenli

    2010-09-15

    A long-term experiment was carried out under field conditions in Jaboticabal, SP, Brazil, with the objective of evaluating the concentration of Ba in soil and in maize plants grown in a soil treated with sewage sludge for nine consecutive years. During 2005/2006, maize was used as test plants and the experimental design was in randomized complete blocks with four treatments and five replicates. Treatments consisted of: 0.0, 45.0, 90.0 and 127.5 t ha(-1) sewage sludge (dry basis). Sewage sludge application increased soil Ba concentration. Barium accumulated in the parts of maize plants were generally affected by the successive applications of sewage sludge to the soil. However, the concentration of Ba in maize grain did not exceed the critical levels of Ba for human consumption. Sewage sludge applied to soil for a long time did not affect dry matter and grain production, nevertheless had the similar effect of mineral fertilization.

  5. [Effect of different sludge retention time (SRT) on municipal sewage sludge bioleaching continuous plug flow reaction system].

    PubMed

    Liu, Fen-Wu; Zhou, Li-Xiang; Zhou, Jun; Jiang, Feng; Wang, Dian-Zhan

    2012-01-01

    A plug-flow bio-reactor of 700 L working volume for sludge bioleaching was used in this study. The reactor was divided into six sections along the direction of the sludge movement. Fourteen days of continuous operation of sludge bioleaching with different sludge retention time (SRT) under the condition of 1.2 m3 x h(-1) aeration amount and 4 g x L(-1) of microbial nutritional substance was conducted. During sludge bioleaching, the dynamic changes of pH, DO, dewaterability (specific resistance to filtration, SRF) of sewage sludge in different sections were investigated in the present study. The results showed that sludge pH were maintained at 5.00, 3.00, 2.90, 2.70, 2.60 and 2.40 from section 1 to section 6 and the SRF of sludge was drastically decreased from initial 0.64 x 10(13) m x kg(-1) to the final 0.33 x 10(13) m x kg(-1) when bioleaching system reached stable at hour 72 with SRT 2.5d. In addition, the sludge pH were maintained at 5.10, 4.10, 3.20, 2.90, 2.70 and 2.60, the DO value were 0.43, 1.47, 3.29, 4.76, 5.75 and 5.88 mg x L(-1) from section 1 to section 6, and the SRF of sludge was drastically decreased from initial 0.56 x 10(13) to the final 0.20 x 10(13) m x kg(-1) when bioleaching system reached stable at hour 120 with SRT 2 d. The pH value was increased to 3.00 at section 6 at hour 48 h with SRT 1.25 d. The bioleaching system imbalanced in this operation conditions because of the utilization efficiency of microbial nutritional substance by Acidibacillus spp. was decreased. The longer sludge retention time, the easier bioleaching system reached stable. 2 d could be used as the optimum sludge retention time in engineering application. The bioleached sludge was collected and dewatered by plate-and-frame filter press to the moisture content of dewatered sludge cake under 60%. This study would provide the necessary data to the engineering application on municipal sewage sludge bioleaching.

  6. Evaluation of the improvement of sonication pre-treatment in the anaerobic digestion of sewage sludge.

    PubMed

    Martín, María Ángeles; González, Inmaculada; Serrano, Antonio; Siles, José Ángel

    2015-01-01

    Sewage sludge is a polluting and hazardous waste generated in wastewater treatment plants with severe management problems. The high content in heavy metal, pathogens and micropolluting compounds limit the implementation of the available management methods. Anaerobic digestion could be an interesting treatment method, but must be improved since the biomethanisation of sewage sludge entails low biodegradability and low methane production. A sonication pre-treatment at lab scale is proposed to increase the organic matter solubilisation of sewage sludge and enhance the biomethanisation yield. Sonication time was optimised by analysing the physicochemical characteristics of sewage sludge (both total and soluble fraction) at different pre-treatment times. The pre-treatment time was fixed at 45 min under the study conditions given that the solubilisation of organic matter did not increase significantly at lower sonication times, whereas the concentration of total nitrogen increased markedly at higher times. The volatile fatty acids generation rate was also evaluated for the pre-treatment conditions. The anaerobic digestion of untreated and pre-treated sewage sludge was subsequently compared and promising results were obtained for loads of 1.0 g VS/L (VS, total volatile solids). The methane yield coefficient increased from 88 to 172 mLSTP/g VS (STP, 0 °C, 1 atm) after the pre-treatment, while biodegradability was found to be around 81% (in VS). Moreover, the allowed organic loading rate and methane production rate observed for the sewage sludge reached values of up to 4.1 kg VS/m(3)·d and 1270 LSTP/m(3)·d, respectively.

  7. Modification to degradation of hexazinone in forest soils amended with sewage sludge.

    PubMed

    Wang, Huili; Wang, Chengjun; Chen, Fan; Ma, Meiping; Lin, Zhenkun; Wang, Wenwei; Xu, Zhengti; Wang, Xuedong

    2012-01-15

    Influences of one sewage sludge on degradation of hexazinone and formation of its major metabolites were investigated in four forest soils (A, B, C and D), collected in Zhejiang Province, China. In non-amended forest soils, the degradation half-life of hexazinone was 21.4, 30.4, 19.4 and 32.8 days in forest soil A, B, C and D, respectively. Degradation could start in soil A and C without lag period because the two soils had been contaminated by this herbicide for a long time, possibly leading to completion of acclimation period of hexazinone-degrading bacteria. In forest soils amended with sewage sludge, the degradation rate constant increased by 17.3% in soil A, 48.2% in soil B, 8.1% in soil C and 51.6% in soil D, respectively. The higher degradation rates (soil A and C) in non-amended soils accord with the lower rate increase in sewage sludge-amended soils. Under non-sterile conditions, biological mechanism accounted for 51.8-62.4% of hexazinone degradation in four soils. Under sterile conditions, the four soils had the similar chemical degradation capacity for hexazinone. In non-amended soil B, only one metabolite (B) was detected, while two metabolites (B and C) were found in sewage sludge-amended soil B. Similarly situated in agricultural soils, N-demethylation at 6-position of triazine ring, hydroxylation at the 4-positon of cyclohexyl group, and removal of the dimethylamino group with formation of a carbonyl group at 6-position of triazine ring appear to be the principal mechanism involved in hexazinone degradation in sewage sludge-amended forest soils. These data will improve understanding of the actual pollution risk as a result of forest soil fertilization with sewage sludge.

  8. A study on removal characteristics of copper from aqueous solution by sewage sludge and pomace ashes.

    PubMed

    Bouzid, J; Elouear, Z; Ksibi, M; Feki, M; Montiel, A

    2008-04-01

    In the present work, the abilities of sewage sludge and pomace ashes to remove copper (Cu(2+)) ions from aqueous solutions are compared. Batch adsorption experiments were performed in order to evaluate the removal efficiency of these materials. Effect of contact time, solution pH, ash concentration and temperature on the removal of Cu(2+) was investigated. The results of batch equilibrium studies showed that the solution pH was the key factor affecting the adsorption characteristics. In general, the amount of Cu removed increased as the solid concentration and pH increased, and then it remained constant over a wide pH region. The adsorption test of applying sewage sludge and pomace ashes into synthetic wastewater revealed that the adsorption data of these materials for copper ions were better fitted to the Langmuir isotherm since the correlation coefficients for the Langmuir isotherm were higher than that for the Freundlich isotherm. The estimated maximum capacities of copper adsorbed by sewage sludge and pomace ashes were 5.71 and 6.98 mg g(-1), respectively. Experimental results indicated that the adsorption was favorable at higher pH and higher temperature. Values of DeltaG degrees ranging from -4.64 to -5.13 kcal mol(-1) for sewage sludge ash and from -4.97 to -5.53 kcal mol(-1) for pomace ash suggest that the adsorption reaction is a physical process enhanced by the electrostatic effect. The values of DeltaH degrees and DeltaS degrees are, respectively, 4.27 kcal mol(-1) and 30.6 cal K(-1)mol(-1) for sewage sludge ash and 4.33 kcal mol(-1) and 31.3 cal K(-1)mol(-1) for pomace ash. The mechanisms of copper removal by these materials included adsorption and precipitation. The sewage sludge and pomace ashes are shown to be effective adsorbents for this metal.

  9. Dry co-digestion of sewage sludge and rice straw under mesophilic and thermophilic anaerobic conditions.

    PubMed

    Chu, Xiangqian; Wu, Guangxue; Wang, Jiaquan; Hu, Zhen-Hu

    2015-12-01

    Dry anaerobic digestion of sewage sludge can recover biogas as energy; however, its low C/N ratio limits it as a single substrate in the anaerobic digestion. Rice straw is an abundant agricultural residue in China, which is rich in carbon and can be used as carbon source. In the present study, the performance of dry co-digestion of sewage sludge and rice straw was investigated under mesophilic (35 °C) and thermophilic (55 °C) conditions. The operational factors impacting dry co-digestion of sewage sludge and rice straw such as C/N ratio, moisture content, and initial pH were explored under mesophilic conditions. The results show that low C/N ratios resulted in a higher biogas production rate, but a lower specific biogas yield; low moisture content of 65 % resulted in the instability of the digestion system and a low specific biogas yield. Initial pH ranging 7.0-9.0 did not affect the performance of the anaerobic digestion. The C/N ratio of 26-29:1, moisture content of 70-80 %, and pH 7.0-9.0 resulted in good performance in the dry mesophilic co-digestion of sewage sludge and rice straw. As compared with mesophilic digestion, thermophilic co-digestion of sewage sludge and rice straw significantly enhanced the degradation efficiency of the substrates and the specific biogas yield (p < 0.05) at the conditions of C/N ratio 26:1, moisture content 80 %, and natural initial pH. Although high concentrations of ammonia-nitrogen (NH4-N, 1500 mg/kg wet weight) were formed during thermophilic digestion, there was no obvious inhibition occurred. The results indicated that rice straw can be used as carbon source for the dry co-digestion of sewage sludge under mesophilic and thermophilic conditions.

  10. Chemical removal and recovery of phosphorus from excess sludge in a sewage treatment plant.

    PubMed

    Kato, K; Murotani, N; Matsufuji, H; Saitoh, M; Tashiro, Y

    2006-05-01

    We describe a process for the recovery of phosphorus from excess sludge in a sewage treatment plant that currently uses polyaluminium chloride for chemical phosphorus removal. Instead, we employed alkaline dissolution of excess sludge with calcium phosphate precipitation to recover phosphorus from sewage. The recovery ratio for phosphorus from sewage using the phosphorus recovery system is approximately 50%. In addition, the amount of excess sludge in the phosphorus recovery system is approximately half that of conventional chemical phosphorus removal. Alkaline dissolution of excess sludge resulted in dissolution of aluminium into the supernatant. Furthermore, since dissolved aluminium can be reused as a coagulant, the phosphorus recovery system could be used to economize coagulant consumption. Operation and maintenance costs of the phosphorus recovery system are 25.9 U.S. cents per 1 m3 of sewage compared to 32.0 U.S. cents per 1 m3 of sewage for conventional chemical phosphorus removal, representing a decrease of 20% in the operation and maintenance costs.

  11. Simple sample digestion of sewage and sludge for multi-element analysis

    SciTech Connect

    Sung, J.F.C.; Nevissi, A.E.; Dewalle, F.B.

    1984-01-01

    A simple digestion method of sewage, sludge, and other materials in sealed ampuls for multi-element determination is reported. The sealed samples are digested in an autoclave at 125/sup 0/C and 1.2 atmosphere pressure for one hour. In a single digestion both volatile and non-volatile elements are recovered. Comparison of this method with conventional hot plate digestion using NBS reference materials, sewage, and sludge, shows equal or better recoveries of the metals in sealed ampuls. The method is not prone to metal contamination and can be used for large numbers of samples.

  12. Monometal and competitive adsorption of heavy metals by sewage sludge-amended soil.

    PubMed

    Antoniadis, Vasileios; Tsadilas, Christos D; Ashworth, Daniel J

    2007-06-01

    Sewage sludge-amended soils may alter their ability to adsorb heavy metals over time, due to the decomposition of sludge-borne organic matter. Thus, we studied Cd, Ni, and Zn adsorption by a sewage sludge-amended soil (Typic Xerofluvent) before and after one-year incubation in both monometal and competitive systems. In the monometal system, the order of decreasing sorption was Zn>Cd>Ni. Competition significantly reduced metal K(d), especially that of Cd which decreased by nearly 50%. Over the course of the incubation there was a 31% reduction of soil organic matter content. At the same time, in competitive systems Cd K(d) significantly decreased, while Zn K(d) significantly increased, and Ni K(d) remained unaffected. This study shows that sewage sludge-amended soils may change in their ability to sorb heavy metals over time at high metal concentrations. The data suggest that Cd is likely to be of most environmental significance in such soils, since it exhibited decreased sorption under competitive conditions and as the organic matter content of the soil was reduced. The potential for long-term release of metals should be considered in the risk assessment associated with sewage sludge addition to soils, particularly in climates where degradation of organic matter is likely to be enhanced.

  13. Sewage sludge fertiliser use: implications for soil and plant copper evolution in forest and agronomic soils.

    PubMed

    Ferreiro-Domínguez, Nuria; Rigueiro-Rodríguez, Antonio; Mosquera-Losada, M Rosa

    2012-05-01

    Fertilisation with sewage sludge may lead to crop toxicity and environmental degradation. This study aims to evaluate the effects of two types of soils (forest and agronomic), two types of vegetation (unsown (coming from soil seed bank) and sown), and two types of fertilisation (sludge fertilisation and mineral fertilisation, with a no fertiliser control) in afforested and treeless swards and in sown and unsown forestlands on the total and available Cu concentration in soil, the leaching of this element and the Cu levels in plant. The experimental design was completely randomised with nine treatments and three replicates. Fertilisation with sewage sludge increased the concentration of Cu in soil and plant, but the soil values never exceeded the maximum set by Spanish regulations. Sewage sludge inputs increased both the total and Mehlich 3 Cu concentrations in agronomic soils and the Cu levels in plant developed in agronomic and forest soils, with this effect pronounced in the unsown swards of forest soils. Therefore, the use of high quality sewage sludge as fertiliser may improve the global productivity of forest, agronomic and silvopastoral systems without creating environmental hazards.

  14. Two step esterification-transesterification process of wet greasy sewage sludge for biodiesel production.

    PubMed

    Urrutia, C; Sangaletti-Gerhard, N; Cea, M; Suazo, A; Aliberti, A; Navia, R

    2016-01-01

    Sewage sludge generated in municipal wastewater treatment plants was used as a feedstock for biodiesel production via esterification/transesterification in a two-step process. In the first esterification step, greasy and secondary sludge were tested using acid and enzymatic catalysts. The results indicate that both catalysts performed the esterification of free fatty acids (FFA) simultaneously with the transesterification of triacylglycerols (TAG). Acid catalyst demonstrated better performance in FFA esterification compared to TAG transesterification, while enzymatic catalyst showed the ability to first hydrolyze TAG in FFA, which were esterified to methyl esters. In addition, FAME concentration using greasy sludge were higher (63.9% and 58.7%), compared with those of secondary sludge (11% and 16%), using acid and enzymatic catalysts, respectively. Therefore, only greasy sludge was used in the second step of alkaline transesterification. The alkaline transesterification of the previously esterified greasy sludge reached a maximum FAME concentration of 65.4% when using acid catalyst.

  15. Use of Municipal Sewage Sludge for Improvement of Forest Sites in the Southeast

    SciTech Connect

    Charles R. Berry

    1987-09-01

    In eight field experiments dried municipal sewage sludge was applied to forest sites before planting of seedlings. In all cases, tree growth was faster on sludge-amended plots than on plots that received fertilizer and lime or no amendment. In all studies, concentrations of total nitrogen in the soil were higher on sludge plots than on control or fertilizer plots, even on good forest sites. In seven of the eight studies, concentrations of phosphorus also were higher on sludge plots than on control or fertilizer plots. Nitrogen and phosphorus tended to be higher in foliage from trees growing on sludge plots. Deep subsoiling was beneficial regardless of soil amendment. Where weeds were plentiful at the outset, they became serious competitors on plots receiving sludge.

  16. Rheological measurements on different types of sewage sludge for pumping design.

    PubMed

    Lotito, Vincenzo; Lotito, Adriana Maria

    2014-05-01

    Sewage sludge pumping could represent an optimal solution to assure adequate treatment of sludge in centralized plants, with a consequent reduction of the environmental impact of sludge disposal (volume, odour, putrescence), because small wastewater treatment plants usually do not provide an adequate treatment due to high costs. An accurate knowledge of rheological parameters is required to compute head loss for pipeline design, but only few data are available. In order to circumvent the problem of the scarcity of sludge rheological data, we have performed tests on different types of sludge, with solids concentration and temperature in the typical range of a conventional wastewater treatment plant. Bingham rheological parameters and sludge thixotropy values have been processed by regression analysis to identify their dependence on solids concentration or temperature. The results of this study allow the definition of guidelines and optimal strategies for designers in order to reduce pumping costs.

  17. Sanitation ability of anaerobic digestion performed at different temperature on sewage sludge.

    PubMed

    Scaglia, Barbara; D'Imporzano, Giuliana; Garuti, Gilberto; Negri, Marco; Adani, Fabrizio

    2014-01-01

    A small amount of ammonia is used in full-scale plants to partially sanitize sewage sludge, thereby allowing successive biological processes to enable the high biological stability of the organic matter. Nevertheless, ammonia and methane are both produced during the anaerobic digestion (AD) of sludge. This paper describes the evaluation of a lab-scale study on the ability of anaerobic process to sanitize sewage sludge and produce biogas, thus avoiding the addition of ammonia to sanitize sludge. According to both previous work and a state of the art full-scale plant, ammonia was added to a mixture of sewage sludge at a rate so that the pH values after stirring were 8.5, 9 and 9.5. This procedure determined an ammonia addition lower than that generally indicated in the literature. The same sludge was also subjected to an AD process for 60 days under psychrophilic, mesophilic and thermophilic conditions. The levels of fecal coliform, Salmonella spp. helmints ova, pH, total N, ammonia fractions and biogas production were measured at different times during each process. The results obtained suggested that sludge sanitation can be achieved using an AD process; however, the addition of a small amount of ammonia was not effective in sludge sanitation because the buffer ability of the sludge reduced the pH and thus caused ammonia toxicity. Mesophilic and thermophilic AD sanitized better than psychrophilic AD did, but the total free ammonia concentration under the thermophilic condition inhibited biogas production. The mesophilic condition, however, allowed for both sludge sanitation and significant biogas production.

  18. Land application of chemically treated sewage sludge. II. Effects on soil and plant heavy metal content

    SciTech Connect

    Soon, Y.K.; Bates, T.E.; Moyer, J.R.

    1980-07-01

    Anaerobically digested sewage sludges resulting from treatment of sewage with Ca(OH)/sub 2/, Al/sub 2/(SO/sub 4/)/sub 3/, or FeCl/sub 3/ for phosphorus precipitation were applied to corn (Zea mays L.) and bromegrass (Bromus inermis Leyess) grown on a soil having an initial pH of 7.3. Rates of sludge supplied 200, 400, 800, and and 1,600 kg N/ha each year for 5 years. Treatments with NH/sub 4/NO/sub 3/ supplying 0, 100, 20, and 400 kg N/ha were included for comparison. Plant tissue was analyzed for Cu, Zn, Mn, Cd, Ni, Cr, and Pb. No toxicity or deficiency symptoms were noted. Soil Zn, Cd, and Ni extracted by NTA (nitrilotriacetic acid) were increased by continued sludge application. The NTA-extractable Zn and Cd were positively correlated with the Zn and Cd concentrations in corn stover. Soil pH was reduced by the Fe-sludge application, slightly affected by the Al-sludge, and increased by the Ca-sludge. Increases in Cu concentrations in bromegrass and corn stover were associated with increases in the N content rather than the source of N, and plant Cu concentrations remained relatively constant across years. Sewage sludge application increased Zn, Cd, and Ni concentrations in bromegrass and corn stover, and Zn and Ni concentrations in corn grain, particularly at the higher metal loadings from sludge application. Zinc and Cd concentrations, especially in corn stover, increased with continued sludge application during the 5-year period. The inclusion of soil pH as a factor, in addition to cummulative amounts of Zn or Cd added as a constituent of sludge, improved the regression equations predicting Zn or Cd uptake.

  19. Effects of the basicity on the comelting conditions of municipal solid waste incinerator fly ash and sewage sludge ash.

    PubMed

    Lin, Kae-Long

    2006-12-01

    In this study, the effects of the basicity on the pouring point of the municipal solid waste incinerator fly ash-sewage sludge ash mixture is investigated. Four kinds of sewage sludge ash, which were collected from several primary and secondary sewage treatment plants and were produced by different processes and sludge conditioning alternatives, were used as modifiers. The results indicate that the pouring point of the mixture increased with increasing basicity, within the range of 0.65-1.90. The pouring point is affected by the contents of the mixtures (CaO, SiO2, Al2O3, and the flux). It is suggested that an increase in the CaO content tends to raise the pouring point, whereas an increase in the SiO2 and/or the Al2O3 contents cause as adverse reaction. The prediction equation, obtained by multilinear regression (significant level is 0.05), is as follows: pouring temperature = 1189.6 + 4.19 CaO - 0.96 SiO2 - 4.33 Al2O3 (R2 = 0.91). In general, the pouring point decreased when the basicity was < 1. The pouring point apparently increased when the basicity was > 1.2. The regression squares for the different basicities were between 0.84 and 0.91. From these relationships, we note that a basicity index of 5 gave the best R2 (0.91). From the results of this study, it can be concluded that the modification of the basicity of the fly ash by the addition of sewage sludge ash to lower the pouring point is feasible and leads to a more energy-efficient melting process. In addition, these synthetic slags have a good pozzolanic reactive activity.

  20. Feedstock and process influence on biodiesel produced from waste sewage sludge.

    PubMed

    Capodaglio, Andrea G; Callegari, Arianna

    2017-04-04

    Disposal of sewage sludge is one of the most important issues in wastewater treatment throughout Europe, as EU sludge production, estimated at 9.5 million tons dry weight in 2005, is expected to approach 13 million tons in 2020. While sludge disposal costs may constitute 30-50% of the total operation costs of wastewater treatment processes, waste sewage sludge still contains resources that may be put to use, like nutrients and energy, that can be recovered through a variety of approaches. Research has shown that waste sewage sludge can be a valuable and very productive feedstock for biodiesel generation, containing lipids (the fats from which biofuels are extracted) in amounts that would require large areas cultivated with typical biodiesel feedstock, to produce, and at a much lower final cost. Several methods have been tested for the production of biodiesel from sewage sludge. To date, among the most efficient such process is pyrolysis, and in particular Microwave-Assisted Pyrolysis (MAP), under which process conditions are more favorable in energetic and economic terms. Sludge characteristics are very variable, depending on the characteristics of the wastewater-generating service area and on the wastewater treatment process itself. Each sludge can be considered a unique case, and as such experimental determination of the optimal biodiesel yields must be conducted on a case-by-case basis. In addition to biodiesel, other pyrolysis products can add to the energetic yield of the process (and not only). This paper discusses how feedstock properties and process characteristics may influence biodiesel (and other products) yield from pyrolytic (and in particular, MAP) processes, and discusses future possible technological developments.

  1. Sewage sludge pasteurization by gamma radiation: A Canadian demonstration project — 1988-91

    NASA Astrophysics Data System (ADS)

    Swinwood, Jean F.; Wilson, Bruce K.

    Nordion International Inc. and a Canadian city, in cooperation with the Federal & Provincial Ministries of the Environment, began a project in 1988 to construct and operate a commercial-scale sewage sludge pasteurization facility using gamma radiation technology. The facility is scheduled to begin operations in 1991. This paper discusses the objectives and scope of the project, the design of the irradiation system, and the plans to market the pasteurized sludge as a high-value, organic soil conditioner and fertilizer.

  2. Assessment of Heavy Metals in Municipal Sewage Sludge: A Case Study of Limpopo Province, South Africa

    PubMed Central

    Shamuyarira, Kudakwashe K.; Gumbo, Jabulani R.

    2014-01-01

    Heavy metals in high concentrations can cause health and environmental damage. Nanosilver is an emerging heavy metal which has a bright future of use in many applications. Here we report on the levels of silver and other heavy metals in municipal sewage sludge. Five towns in Limpopo province of South Africa were selected and the sludge from their wastewater treatment plants (WWTPs) was collected and analysed. The acid digested sewage sludge samples were analysed using Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) methods. The concentrations of silver found were low, but significant, in the range 0.22 to 21.93 mg/kg dry mass. The highest concentration of silver was found in Louis Trichardt town with a concentration of 21.93 ± 0.38 mg/kg dry mass while the lowest was Thohoyandou with a concentration of 6.13 ± 0.12 mg/kg dry mass. A control sludge sample from a pit latrine had trace levels of silver at 0.22 ± 0.01 mg/kg dry mass. The result showed that silver was indeed present in the wastewater sewage sludge and at present there is no DWAF guideline standard. The average Cd concentration was 3.10 mg/kg dry mass for Polokwane municipality. Polokwane and Louis Trichardt municipalities exhibited high levels of Pb, in excess DWAF guidelines, in sludge at 102.83 and 171.87 mg/kg respectfully. In all the WWTPs the zinc and copper concentrations were in excess of DWAF guidelines. The presence of heavy metals in the sewage sludge in excess of DWAF guidelines presents environmental hazards should the sludge be applied as a soil ameliorant. PMID:24595211

  3. Dioxin-like compounds in Australian sewage sludge--review and national survey.

    PubMed

    Clarke, Bradley; Porter, Nichola; Symons, Robert; Blackbeard, Judy; Ades, Peter; Marriott, Philip

    2008-07-01

    An Australian survey of dioxin-like compounds in sewage sludge was conducted in two parts (a) a national survey, and (b) a time-study. All sewage sludge samples analysed as part of these studies had low overall concentrations of dioxin-like compounds. Out of 37 samples, all except one, were within the reported concentration range of soil within the Australian environment. The mean concentration of dioxin-like compounds in the Australian sewage sludge survey of 2006 was found to be 5.6 (s.d. 4.5) ng WHO(05) TEQkg(-1) (n=14) and were within the range of 1.2-15.3 ng WHO(05) TEQ kg(-1). All the Australian sewage sludge samples cited in these studies were below the Victorian EPA "investigation limit" of 50 ng WHO(98) TEQ kg(-1), and well below the European proposed guidelines of 100 ng I-TEQ kg(-1). The burden of dioxin-like compounds in Australian sewage sludge is low and its land application as biosolids is not likely to pose a problem. A general positive relationship was found between population of the town producing the waste and both dioxin-like PCDD/Fs and dioxin-like PCBs. The one exception to this trend was sludge from a town that had a history of smelting and had a relatively high burden of dioxin-like compounds. Sludge from one rural WWTP also had a higher burden of dioxin-like compounds. The treatment plant services a geographically isolated town with a low population and no known emitters of dioxin-like compounds. However, this sample also had a relatively high burden of dioxin-like PCBs, which could be the source of the dioxin-like PCDD/Fs found in this sludge. The time study analyzing sludges from three WWTP from the same city between the years 2002 and 2006 found no apparent difference between WWTPs, but a statistically significant decline of 1.49 ng WHO(05) TEQ kg(-1) per year. Also, a comprehensive review of the scientific literature, presents typical levels and sources of dioxin-like compounds in international sewage sludges.

  4. Methane from partially digested sewage sludge using a steam-injection rapid thermal reactor. Final report

    SciTech Connect

    Leuschner, A.P.; Laquidara, M.J.

    1988-09-01

    Each day, a fleet of barges hauls 300,000 cubic feet of sewage sludge from wastewater treatment facilities in New York City, to an ocean dumping site 106 miles offshore. On January 1, 1992, this ocean dumping site will be officially closed by federal mandate, forcing the city to find alternative disposal methods for its sewage sludge. Researchers at Dynatech and the Thayer School of Engineering at Dartmouth College have explored an innovative method for enhancing the anaerobic digestion sludge treatment system. Results from an extensive series of laboratory tests indicate that using a thermal reactor, an additional 70% of the organic material in the sludge can be converted to biogas by anaerobic digestion. More importantly, 85% of the total organic material is removed from the sludge. The remaining sludge was dewatered and found to be two to four times drier than normally dewatered sludge. Applying these results to NYC, the volume of sludge requiring disposal might be reduced from 300,000 cubic feet per day to about 13,000 cubic feet per day through a three-step process employing thermal reactors, anaerobic digestion and dewatering.

  5. Facile synthesis of sewage sludge-derived in-situ multi-doped nanoporous carbon material for electrocatalytic oxygen reduction

    PubMed Central

    Yuan, Shi-Jie; Dai, Xiao-Hu

    2016-01-01

    Developing efficient, low-cost, and stable carbon-based catalysts for oxygen reduction reaction (ORR) to replace the expensive platinum-based electrocatalysts remains a major challenge that hamper the practical application of fuel cells. Here, we report that N, Fe, and S co-doped nanoporous carbon material, derived via a facile one-step pyrolysis of sewage sludge, the major byproduct of wastewater treatment, can serve as an effective electrocatalyst for ORR. Except for the comparable catalytic activity with commercial 20% Pt/C via a nearly four-electron transfer pathway in both alkaline and acid medium, the as-synthesized co-doped electrocatalyst also exhibits excellent methanol crossover resistance and outstanding long-term operation stability. The organic compounds in sewage sludge act as the carbon source and the in-situ N and S dopant in the fabrication, while the inorganic compounds serve as the in-built template and the in-situ Fe dopant. Our protocol demonstrates a new approach in the economic and eco-friendly benign reuse of sewage sludge, and also provides a straightforward route for synthesizing excellent carbon-based electrocatalysts as promising candidates for ORR directly from a type of waste/pollution. PMID:27273314

  6. Facile synthesis of sewage sludge-derived in-situ multi-doped nanoporous carbon material for electrocatalytic oxygen reduction

    NASA Astrophysics Data System (ADS)

    Yuan, Shi-Jie; Dai, Xiao-Hu

    2016-06-01

    Developing efficient, low-cost, and stable carbon-based catalysts for oxygen reduction reaction (ORR) to replace the expensive platinum-based electrocatalysts remains a major challenge that hamper the practical application of fuel cells. Here, we report that N, Fe, and S co-doped nanoporous carbon material, derived via a facile one-step pyrolysis of sewage sludge, the major byproduct of wastewater treatment, can serve as an effective electrocatalyst for ORR. Except for the comparable catalytic activity with commercial 20% Pt/C via a nearly four-electron transfer pathway in both alkaline and acid medium, the as-synthesized co-doped electrocatalyst also exhibits excellent methanol crossover resistance and outstanding long-term operation stability. The organic compounds in sewage sludge act as the carbon source and the in-situ N and S dopant in the fabrication, while the inorganic compounds serve as the in-built template and the in-situ Fe dopant. Our protocol demonstrates a new approach in the economic and eco-friendly benign reuse of sewage sludge, and also provides a straightforward route for synthesizing excellent carbon-based electrocatalysts as promising candidates for ORR directly from a type of waste/pollution.

  7. Anaerobic digestion of sewage sludge with grease trap sludge and municipal solid waste as co-substrates.

    PubMed

    Grosser, A; Neczaj, E; Singh, B R; Almås, Å R; Brattebø, H; Kacprzak, M

    2017-05-01

    The feasibility of simultaneous treatment of multiple wastes via co-digestion was studied in semi-continuous mode at mesophilic conditions. The obtained results indicated that sewage sludge, organic fraction of municipal waste (OFMSW) and grease trap sludge (GTS) possess complementary properties that can be combined for successful anaerobic digestion. During the co-digestion period, methane yield and VS removal were significantly higher in comparison to digestion of sewage sludge alone. Addition of GTS to digesters treating sewage sludge resulted in increased VS removal and methane yield up to 13% (from 50 to 56.4) and 52% (from 300 to 456,547m(3)/Mg VSadd), respectively. While the use of OFMSW as the next co-substrate in the feedstock, can boost methane yield and VS removal up to 82% (300-547m(3)/Mg VSadd) and approximately 29% (from 50% to 64.7%), respectively. Moreover, the results of the present laboratory study revealed that the addition of co-substrates to the feedstock had a significant influence on biogas composition. During the experiment methane content in biogas ranged from 67% to 69%. While, the concentration of LCFAs was increasing with the gradual increase in the share of co-substrates in the mixtures, wherein only the oleic acid was higher than some inhibition concentrations which have been reported in the literature. However, it did not significantly affect the efficiency of the co-digestion process.

  8. [Sewage sludge conditioning by bioleaching combined with Fenton-like oxidation].

    PubMed

    Liu, Chang-geng; Zhang, Pan-yue; Jiang, Jiao-jiao; Zeng, Cheng-hua; Huang, Yi; Xu, Guo-yin

    2015-01-01

    Bioleaching combined with Fenton-like oxidation was used to condition sewage sludge. The results showed that it took approximately 1 d to decrease pH from 6.9 to 2.5 by bioleaching, with fixed sulfur power and FeSO4 x 7H2O dosages of 3 g x L(-1) and 8 g x L(-1), respectively. After bioleaching, the volatile solids(VS) reduction was 13.4%, and the specific resistance to filtration(SRF) dropped from 3.1 x 10(9)s2 x g(-1) to 1.5 x 10(9)s2 x g(-1) with a reduction of 51.6%, but the bioleached sludge was still difficult to be dewatered. The bioleached sludge was further oxidized by Fenton-like oxidation. The results indicated that the optimal H2O2 dosage and reaction time were 3.3 g x L(-1) and 60 min, respectively. Under the optimal conditions, VS reduction was 30.8%, SRF was declined to 1.9 x 10(8) s2 x g(-1) with a reduction of 93.9%, and the moisture of sludge cake was 76.9%. After treated by bioleaching combined with Fenton-like oxidation, the dewaterability and stability of sewage sludge were significantly improved. Besides, the combined technology was more efficient in conditioning sewage sludge than single Fenton-like oxidation.

  9. Concentrations of trace substances in sewage sludge from 28 wastewater treatment works in the UK.

    PubMed

    Jones, Vera; Gardner, Mike; Ellor, Brian

    2014-09-01

    Concentrations of trace substances in sewage sludge have been measured in a survey of 28 wastewater treatment works (WwTWs) in the UK carried out over a period of 12months. Approximately 250 samples were analysed for more than 40 trace contaminants, including trace metals, pharmaceuticals, polycyclic aromatic hydrocarbons (PAHs), 'emerging' and regulated organic pollutants. All substances investigated were found to be present in at least some of the sludges sampled. Concentrations were relatively homogenous across all the WwTWs, irrespective of the treatment process, influent and effluent concentrations, and the location of the sludge sampling point within each works. Analysis of the results against existing regulatory and proposed thresholds suggested that levels are mostly below the limits set in the Sewage Sludge Directive, and proposed new limits for sludge used in agriculture. Predicted soil concentrations after application of sewage sludge to land were below the predicted no effect concentrations (PNEC) for all determinands. Predicted concentrations of pharmaceuticals in soil were also below thresholds deemed to indicate negligible environmental risk.

  10. Plant uptake of cadmium from acid-extracted anaerobically digested sewage sludge. [Beta vulgaris

    SciTech Connect

    Logan, T.J.; Feltz, R.E.

    1985-01-01

    Approximately 80% of the Cd in an anaerobically digested sewage sludge was removed by acid extraction and dewatering. The acid extracted sludge was treated by (i) neutralization to pH 5.9 with Ca(OH)/sub 2/, (ii) addition of monocalcium phosphate (MCP) followed by Ca(OH)/sub 2/ neutralization to pH 5.9, and, (iii) addition of rock phosphate (RP) followed by Ca(OH)/sub 2/ neutralization to pH 5.9. The three treated sludges and the non acid-extracted sludge were applied to Spinks loamy sand at rates equivalent to 18.7 and 37.4 ..mu..mol Cd kg/sup -1/. Swiss chard (Beta vulgaris) was grown in the greenhouse for 56 d. Cadmium, Fe, Ca, and P were measured in saturation extracts of treated soil after sludge addition. These data indicated that hydroxyapatite was stable throughout the study in the soil receiving MCP treated sludge but not in other soil treatments. Cadmium concentration in saturation extracts of the soil with MCP sludge decreased while Cd concentration in saturation extracts of the other sludge treatments were much higher throughout the study. Chard yields were higher in the control than in any of the sludge treatments, and the difference was attributed to greater N availability in the control. Cadmium concentration in Swiss chard tissue at harvest was significantly lower from the MCP sludge than from the other sludges. Cadmium concentration in chard tissue was also higher from the aerated sludge (11.9 mmol Cd kg/sup -1/) than from the three acid-extracted sludges (2.58-3.29 mmol Cd kg/sup -1/). No significant difference in the Cd concentration of chard was obtained for the 18.7 and 37.4 ..mu..mol Cd kg/sup -1/ rates of the MCP sludge, while Cd concentrations in chard increased linearly with Cd applied by the other sludges.

  11. Recovering metals from sewage sludge, waste incineration residues and similar substances with hyperaccumulative plants

    NASA Astrophysics Data System (ADS)

    Kisser, Johannes; Gattringer, Heinz; Iordanopoulos-Kisser, Monika

    2015-04-01

    Sewage sludges as well as ashes from waste incineration plants are known accumulation sinks of many elements that are either important nutrients for biological organisms (phosphorus, potassium, magnesium, etc.) or valuable metals when considered on their own in pure form (nickel, chrome, zinc, etc.); they are also serious pollutants when they occur in wild mixtures at localized anthropogenic end- of-stream points. Austria and many other countries have to import up to 90% of the material inputs of metals from abroad. These primary resources are becoming more expensive as they become more scarce and remaining deposits more difficult to mine, which is a serious concern for industrialized nations. Basic economic and strategic reasoning demands an increase in recycling activities and waste minimization. Technologies to recover metals in a reasonable and economically relevant manner from very diffuse sources are practically non-existent or require large amounts of energy and chemicals, which pose environmental risks. On the other hand agriculture uses large volumes of mineral fertilizers, which are often sourced from mines as well, and thus are also subject to the same principle of finiteness and potential shortage in supply. These converted biological nutrients are taken up by crops and through the food chain and human consumption end up in sewage systems and in wastewater treatment plants in great quantities. The metabolized nutrients mostly do not return to agriculture, but due to contamination with heavy metals are diverted to be used as construction aggregates or are thermally treated and end up rather uselessly in landfills. The project BIO-ORE aimed to explore new pathways to concentrate metals from diluted sources such as sewage sludge and wastewater by using highly efficient biological absorption and transport mechanisms. These enzymatic systems from plants work with very little energy input. The process is called bioaccumulation and can be most effectively

  12. Anaerobic co-digestion of grease sludge and sewage sludge: the effect of organic loading and grease sludge content.

    PubMed

    Noutsopoulos, C; Mamais, D; Antoniou, K; Avramides, C; Oikonomopoulos, P; Fountoulakis, I

    2013-03-01

    The objective of this study was to assess the feasibility of co-digesting grease sludge (GS) originating from domestic wastewater along with sewage sludge (SS) and to assess the effect of organic loading rate (OLR) and GS content on process performance. Three lab-scale semi-continuous fed mesophilic anaerobic digesters were operated under various OLRs and SS-GS mixtures. According to the results, addition of GS up to 60% of the total VS load of feed resulted in a 55% increase of biogas yield (700 vs. 452m(3)/tVSadded) for an OLR of 3.5kg VS/m(3)/d. A stable and satisfactory operation of anaerobic co-digestion units can be achieved for a GS-OLR up to 2.4kg VSGS/m(3)/d. For such values biogas yield is linearly proportional to the applied GS-OLR, whereas biogas yield is minimal for GS-OLR higher than this limit and acidification of the anaerobic digestion units is taking place.

  13. Compacted sewage sludge as a barrier for tailings: the heavy metal speciation and total organic carbon content in the compacted sludge specimen.

    PubMed

    Zhang, Huyuan; Zhang, Qing; Yang, Bo; Wang, Jinfang

    2014-01-01

    Acid mine drainage (AMD) was the main environmental problem facing the mining industry. For AMD had high heavy metals content and low pH, the compacted sewage sludge might be a barrier for tailings whose oxidation and weathering produced AMD, with its own carbon source, microorganism reduction ability and impermeability. To study the heavy metals environmental risk, under the simulate AMD, the deionized water (DW), and the pH 2.1 sulfuric acid water (SA) seepage conditions, respectively, the changes of the chemical speciation of heavy metals Cd, Cu, Fe, Ni, Zn and total organic carbon (TOC) content in the compacted sewage sludge were assessed in the different periods. The results indicated according to the distribution of heavy metals, the potential mobility was for Cd: 6.08 under AMD, 7.48 under SA, ∞ under DW; for Cu: 0.08 under AMD, 0.17 under SA, 0.59 under DW; for Fe: 0.15 under AMD, 0.22 under SA, 0.22 under DW; for Ni: 2.60 under AMD, 1.69 under SA, 1.67 under DW; and for Zn: 0.15 under AMD, 0.23 under SA and 0.21 under DW at the second checking time. TOC content firstly decreased from 67.62±0% to 66.29±0.35%, then increased to 67.74±0.65% under the AMD seepage while TOC decreased to 63.30±0.53%, then to 61.33±0.37% under the DW seepage, decreased to 63.86±0.41%, then to 63.28±0.49% under SA seepage. That indicated under the AMD seepage, the suitable microorganisms communities in the compacted sewage sludge were activated. And the heavy metals environmental risk of compacted sewage sludge was lower with AMD condition than with other two. So the compacted sewage sludge as a barrier for tailings was feasible as the aspect of environmental risk assessment.

  14. Gaseous emissions from sewage sludge combustion in a moving bed combustor.

    PubMed

    Batistella, Luciane; Silva, Valdemar; Suzin, Renato C; Virmond, Elaine; Althoff, Chrtistine A; Moreira, Regina F P M; José, Humberto J

    2015-12-01

    Substantial increase in sewage sludge generation in recent years requires suitable destination for this residue. This study evaluated the gaseous emissions generated during combustion of an aerobic sewage sludge in a pilot scale moving bed reactor. To utilize the heat generated during combustion, the exhaust gas was applied to the raw sludge drying process. The gaseous emissions were analyzed both after the combustion and drying steps. The results of the sewage sludge characterization showed the energy potential of this residue (LHV equal to 14.5 MJ kg(-1), db) and low concentration of metals, polycyclic aromatic hydrocarbons (PAH), polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF). The concentration of CO, NOx, BTEX (benzene, toluene, ethylbenzene and xylenes) emitted from the sludge combustion process were lower than the legal limits. The overall sludge combustion and drying process showed low emissions of PCDD/PCDF (0.42 ng I-TEQ N m(-3)). BTEX and PAH emissions were not detected. Even with the high nitrogen concentration in the raw feed (5.88% db), the sludge combustion process presented NOx emissions below the legal limit, which results from the combination of appropriate feed rate (A/F ratio), excess air, and mainly the low temperature kept inside the combustion chamber. It was found that the level of CO emissions from the overall sludge process depends on the dryer operating conditions, such as the oxygen content and the drying temperature, which have to be controlled throughout the process in order to achieve low CO levels. The aerobic sewage sludge combustion process generated high SO2 concentration due to the high sulfur content (0.67 wt%, db) and low calcium concentration (22.99 g kg(-1)) found in the sludge. The high concentration of SO2 in the flue gas (4776.77 mg N m(-3)) is the main factor inhibiting PCDD/PCDF formation. Further changes are needed in the pilot plant scheme to reduce SO2 and particulate matter emissions

  15. Characterization and environmental implications of nano- and larger TiO(2) particles in sewage sludge, and soils amended with sewage sludge.

    PubMed

    Kim, Bojeong; Murayama, Mitsuhiro; Colman, Benjamin P; Hochella, Michael F

    2012-04-01

    Titanium dioxide (TiO(2)) is the most extensively used engineered nanoparticle to date, yet its fate in the soil environment has been investigated only rarely and is poorly understood. In the present study, we conducted two field-scale investigations to better describe TiO(2) nano- and larger particles in their most likely route of entry into the environment, i.e., the application of biosolids to soils. We particularly concentrated on the particles in the nano-size regime due to their novel and commercially useful properties. First, we analyzed three sewage sludge products from the US EPA TNSSS sampling inventory for the occurrence, qualitative abundance, and nature of TiO(2) nano- and larger particles by using analytical scanning electron microscopy and analytical (scanning) transmission electron microscopy. Nano- and larger particles of TiO(2) were repeatedly identified across the sewage sludge types tested, providing strong evidence of their likely concentration in sewage sludge products. The TiO(2) particles identified were as small as 40 nm, and as large as 300 nm, having faceted shapes with the rutile crystal structure, and they typically formed small, loosely packed aggregates. Second, we examined surface soils in mesocosms that had been amended with Ag nanoparticle-spiked biosolids for the occurrence of TiO(2) particles. An aggregate of TiO(2) nanoparticles with the rutile structure was again identified, but this time TiO(2) nanoparticles were found to contain Ag on their surfaces. This suggests that TiO(2) nanoparticles from biosolids can interact with toxic trace metals that would then enter the environment as a soil amendment. Therefore, the long-term behavior of TiO(2) nano- and larger particles in sewage sludge materials as well as their impacts in the soil environment need to be carefully considered.

  16. Identification of new bacteria harboring qnrS and aac(6')-Ib/cr and mutations possibly involved in fluoroquinolone resistance in raw sewage and activated sludge samples from a full-scale WWTP.

    PubMed

    Paiva, Magna C; Reis, Mariana P; Costa, Patrícia S; Dias, Marcela F; Bleicher, Lucas; Scholte, Larissa L S; Nardi, Regina M D; Nascimento, Andréa M A

    2017-03-01

    Wastewater treatment plants (WWTPs) harbor bacteria and antimicrobial resistance genes, favoring gene exchange events and resistance dissemination. Here, a culture-based and metagenomic survey of qnrA, qnrB, qnrS, and aac(6')-Ib genes from raw sewage (RS) and activated sludge (AS) of a full-scale municipal WWTP was performed. A total of 96 bacterial isolates were recovered from nalidixic acid-enrichment cultures. Bacteria harboring the aac(6')-Ib gene predominated in RS, whereas qnrS-positive isolates were specific to AS. Novel qnrS- and aac(6')-Ib-cr positive species were identified: Morganella morganii, Providencia rettgeri, and Pseudomonas guangdongensis (qnrS), and Alcaligenes faecalis and P. rettgeri (aac(6')-Ib-cr). Analysis of qnrS and aac(6')-Ib sequences from isolates and clone libraries suggested that the diversity of qnrS is wider than that of aac(6')-Ib. A large number of amino acid mutations were observed in the QnrS and AAC(6')-Ib proteins at previously undetected positions, whose structural implications are not clear. An accumulation of mutations at the C72, Q73, L74, A75 and M76 positions of QnrS, and D181 of AAC(6')-Ib might be important for resistance. These findings add significant information on bacteria harboring qnrS and aac(6')-Ib genes, and the presence of novel mutations that may eventually emerge in clinical isolates.

  17. Effect of wastewater treatment processes on the pyrolysis properties of the pyrolysis tars from sewage sludges

    NASA Astrophysics Data System (ADS)

    Wu, Xia; Xie, Li-Ping; Li, Xin-Yu; Dai, Xiao-Hong; Fei, Xue-Ning; Jiang, Yuan-Guang

    2011-06-01

    The pyrolysis properties of five different pyrolysis tars, which the tars from 1# to 5# are obtained by pyrolyzing the sewage sludges of anaerobic digestion and indigestion from the A2/O wastewater treatment process, those from the activated sludge process and the indigested sludge from the continuous SBR process respectively, were studied by thermal gravimetric analysis at a heating rate of 10 °C/min in the nitrogen atmosphere. The results show that the pyrolysis processes of the pyrolysis tars of 1#, 2#, 3# and 5# all can be divided into four stages: the stages of light organic compounds releasing, heavy polar organic compounds decomposition, heavy organic compounds decomposition and the residual organic compounds decomposition. However, the process of 4# pyrolysis tar is only divided into three stages: the stages of light organic compounds releasing, decomposition of heavy polar organic compounds and the residual heavy organic compounds respectively. Both the sludge anaerobic digestion and the "anaerobic" process in wastewater treatment processes make the content of light organic compounds in tars decrease, but make that of heavy organic compounds with complex structure increase. Besides, both make the pyrolysis properties of the tars become worse. The pyrolysis reaction mechanisms of the five pyrolysis tars have been studied with Coats-Redfern equation. It shows that there are the same mechanism functions in the first stage for the five tars and in the second and third stage for the tars of 1#, 2#, 3# and 5#, which is different with the function in the second stage for 4# tar. The five tars are easy to volatile.

  18. Sewage sludge biochar as an efficient catalyst for oxygen reduction reaction in an microbial fuel cell.

    PubMed

    Yuan, Yong; Yuan, Tian; Wang, Dingmei; Tang, Jiahuan; Zhou, Shungui

    2013-09-01

    Sewage sludge (SS) biochars have been prepared under an inert atmosphere at different temperatures. Morphologic and chemical analyses reveal that the surface of the biochar carbonized at 900°C (SS900) has more abundant micropores, and higher nitrogen and iron contents as compared to those carbonized at 500 (SS500) and 700°C (SS700). The electrochemical analyses display that the prepared biochars are active for catalyzing oxygen reduction reaction (ORR). However, more positive peak potential and larger peak current of ORR are found using the SS900 as compared to the SS500 and SS700. In MFCs, the maximum power density of 500±17 mW m(-2) was obtained from the SS900 cathode, which is comparable to the Pt cathode. The proposed cathode exhibited good stability and great tolerance to methanol. Given these results, it is expected that the SS-derived biochar cathode can find application in fuel cell systems.

  19. Comparing the use of sewage sludge ash and glass powder in cement mortars.

    PubMed

    Chen, Zhen; Poon, Chi Sun

    2016-09-23

    This study explored the suitability of using sewage sludge ash (SSA) and mixed-colored glass powder (MGP) as construction materials in cement mortars. Positive findings from this study may help promote the recycling of waste SSA and MGP in construction works. The results indicated that the SSA decreased while MGP improved the mortar workability. The SSA exhibited very low pozzolanic activity, but the cement mortar prepared with 20% SSA yielded strength values slightly superior to those of the glass mortars due to its water absorption ability. MGP can serve as a pozzolan and when 20% of cement was replaced by MGP, apparent compressive strength gains were found at later curing ages. The SSA could be used to mitigate ASR expansion while the MGP was superior in resisting drying shrinkage.

  20. Efficiency of repeated phytoextraction of cadmium and zinc from an agricultural soil contaminated with sewage sludge.

    PubMed

    Luo, Kai; Ma, Tingting; Liu, Hongyan; Wu, Longhua; Ren, Jing; Nai, Fengjiao; Li, Rui; Chen, Like; Luo, Yongming; Christie, Peter

    2015-01-01

    Long-term application of sewage sludge resulted in soil cadmium (Cd) and zinc (Zn) contamination in a pot experiment conducted to phytoextract Cd/Zn repeatedly using Sedum plumbizincicola and Apium graceolens in monoculture or intercropping mode eight times. Shoot yields and soil physicochemical properties changed markedly with increasing number of remediation crops when the two plant species were intercropped compared with the unplanted control soil and the two monoculture treatments. Changes in soil microbial indices such as average well colour development, soil enzyme activity and soil microbial counts were also significantly affected by the growth of the remediation plants, especially intercropping with S. plumbizincicola and A. graveolens. The higher yields and amounts of Cd taken up indicated that intercropping of the hyperaccumulator and the vegetable species may be suitable for simultaneous agricultural production and soil remediation, with larger crop yields and higher phytoremediation efficiencies than under monoculture conditions.

  1. A detailed kinetic model for the hydrothermal decomposition process of sewage sludge.

    PubMed

    Yin, Fengjun; Chen, Hongzhen; Xu, Guihua; Wang, Guangwei; Xu, Yuanjian

    2015-12-01

    A detailed kinetic model for the hydrothermal decomposition (HTD) of sewage sludge was developed based on an explicit reaction scheme considering exact intermediates including protein, saccharide, NH4(+)-N and acetic acid. The parameters were estimated by a series of kinetic data at a temperature range of 180-300°C. This modeling framework is capable of revealing stoichiometric relationships between different components by determining the conversion coefficients and identifying the reaction behaviors by determining rate constants and activation energies. The modeling work shows that protein and saccharide are the primary intermediates in the initial stage of HTD resulting from the fast reduction of biomass. The oxidation processes of macromolecular products to acetic acid are highly dependent on reaction temperature and dramatically restrained when temperature is below 220°C. Overall, this detailed model is meaningful for process simulation and kinetic analysis.

  2. Feasibility of co-composting of sewage sludge, spent mushroom substrate and wheat straw.

    PubMed

    Meng, Liqiang; Li, Weiguang; Zhang, Shumei; Wu, Chuandong; Lv, Longyi

    2017-02-01

    In this study, the lab-scale co-composting of sewage sludge (SS) with mushroom substrate (SMS) and wheat straw (WS) conducted for 20days was evaluated. The addition of SMS evidently increased CO2 production and dehydrogenase activity. The combined addition of SMS and WS significantly improved the compost quality in terms of temperature, organic matter degradation and germination index, especially, reduced 21.9% of NH3 emission. That's because SMS and WS possessed the complementarity of free air space and contained plenty of degradable carbon source. The SMS could create a comfortable environment for the nitrifying bacteria and improve nitrification. The carbohydrates from combined addition of SMS and WS could be utilized by thermophilic microorganisms, stimulate ammonia assimilation and reduce NH3 emission. These results suggested that adding SMS and WS could not only improve the degradation of organic matter and the quality of compost product, but also stimulate ammonia assimilation and reduce ammonia emission.

  3. Mechanical and physical properties of cement blended with sewage sludge ash.

    PubMed

    Garcés, P; Pérez Carrión, M; García-Alcocel, E; Payá, J; Monzó, J; Borrachero, M V

    2008-12-01

    The aim of this paper is to evaluate the compatibility of sewage sludge ash (SSA) with various types of commercially available cements (CEM I and CEM II types, cements with several proportions of clinker). The behaviour of mortars fabricated with various percentages (10-30% by weight) of the cement replaced by SSA has been analyzed in terms of workability, mechanical strength, porosity and shrinkage/expansion. SSA exhibits moderate pozzolanic activity; the highest compressive strengths were obtained with 10% of the cement replaced by SSA. The CEM II/B-M (V-LL) 42.5R cement is considered ideal for preparing mortars containing SSA. Shrinkage data demonstrate that sulphates present in SSA are not reactive towards cement.

  4. Rate determination of supercritical water gasification of primary sewage sludge as a replacement for anaerobic digestion.

    PubMed

    Wilkinson, Nikolas; Wickramathilaka, Malithi; Hendry, Doug; Miller, Andrew; Espanani, Reza; Jacoby, William

    2012-11-01

    Supercritical water gasification of primary sewage sludge sampled from a local facility was undertaken at different solids content. The performance of the process was compared with the anaerobic digestion system in use at the facility where the samples were taken. The mass and composition of the vapor products documented showed that the process generates more energy per gram of feed while rapidly destroying more volatile solids relative to the anaerobic digestion process. However, the energy input requirements are greater for supercritical water gasification. This study defines parameters for a model of the gasification reaction using the power law and Arrhenius equation. The activation energy was estimated to be 15 kJ/mol, and the reaction order was estimated to be 0.586. This model allows estimation of the size of a supercritical water reactor needed to replace the anaerobic digesters that are currently used at the wastewater treatment plant.

  5. Phytotoxic effects of sewage sludge extracts on the germination of three plant species.

    PubMed

    Ramírez, Wilson A; Domene, Xavier; Andrés, Pilar; Alcañiz, Josep M

    2008-11-01

    In order to evaluate the ability of three types of extracts to explain the ecotoxicological risk of treated municipal sewage sludges, the OECD 208A germination test was applied using three plants (Lolium perenne L., Brassica rapa L., and Trifolium pratense L.). Three equivalent batches of sludge, remained as dewatered sludge, composted with plant remains and thermally dried, from an anaerobic waste water treatment plant were separated. Samples from these three batches were extracted in water, methanol, and dichloromethane. Plant bioassays were performed and the Germination Index (GI) for the three plants was evaluated once after a period of 10 days. Germination in extracts was always lower than the respective controls. The germination in composted sludge (GI 40.9-86.2) was higher than the dewatered (GI 2.9-45.8), or thermally dried sludges (GI 24.6-64.4). A comparison of the germination between types of extracts showed differences for dewatered sludge with the three plants, where the water and methanol extracts had significantly lower germination than the dichloromethane extract. A higher half maximal effective concentration (EC50) in composted extracts was established, mainly in the water extract (EC50 431-490 g kg(-1)). On the contrary, the germination was strongly inhibited in the water extract of the dewatered sludge (EC50 14 g kg(-1)). The germination was positively correlated with the degree of organic matter stability of the parent sludge, and an inverse correlation was detected for total nitrogen, hydrolysable nitrogen and ammonium content. It is concluded that the phytotoxic effect of the water extract is more closely related to hydrophilic substances rather than lipophilic ones, and care must be taken with dewatered sludge application, especially with their aqueous eluates. Results obtained in this work show the suitability of the use of sludge extracts in ecotoxic assays and emphasize the relevance of sewage sludge stabilization by post

  6. Improvement of dewatering characteristics by co-digestion of rice straw with sewage sludge.

    PubMed

    Gu, Tingting; Yamamoto-Ikemoto, Ryoko; Tsuchiya-Nakakihara, Eri; Watanabe, Haruki; Suetsugu, Yasutaka; Yanai, Atsushi

    2016-12-01

    A continuous mesophilic co-digestion of sewage sludge and softened rice straw was conducted and the dewatering characteristics of digested sludge were evaluated by a dewatering experiment using a belt press. The digestion was operated with solid retention time (SRT) of 25 days, and the feeding ratio of sludge to rice straw was 1:0.5 (total solids base). After 129 days of stable operation, the properties of digested sludge were analysed; then five kinds of cationic coagulants were tested to select the optimal coagulants for dewatering, and two coagulants were selected and used in the dewatering experiment because of lower doses and lower moisture of sludge cakes. Sludge property analysis showed that by the addition of rice straw, the fibrous materials in the digested sludge increased remarkably and the normalized capillary suction time (CST) decreased significantly, indicating that the dewatering properties was improved. The results of dewatering experiment showed that by the addition of rice straw, specific filtration rate of digested sludge increased by 81.2% and 174.6%, respectively; water content of dewatered sludge cakes decreased by 8.2% and 13.4%, respectively. The dewaterability of digested sludge was suggested to be improved due to rice straw addition.

  7. Effects on Ni and Cd speciation in sewage sludge during composting and co-composting with steel slag.

    PubMed

    Zeng, Zheng-Zhong; Wang, Xiao-Li; Gou, Jian-Feng; Zhang, He-Fei; Wang, Hou-Cheng; Nan, Zhong-Ren

    2014-03-01

    Sewage sludge and industrial steel slag (SS) pose threats of serious pollution to the environment. The experiments aimed to improve the stabilizing effects of heavy metal Ni and Cd morphology in composting sludge. The total Ni and Cd species distribution and chemical forms in the compost sewage sludge were investigated with the use of compost and co-compost with SS, including degradation. The carbon/nitrogen ratio of piles was regulated with the use of sawdust prior to batch aerobic composting experiments. Results indicated that the co-composting with SS and organic matter humification can contribute to the formation of Fe and Mn hydroxides and that the humus colloid significantly changed Ni and Cd species distribution. The decreased content of Ni and Cd in an unstable state inhibited their biological activity. Conclusions were drawn that an SS amount equal to 7% of the dry sludge mass was optimal value to guarantee the lowest amount of Cd in an unstable state, whereas the amount was 14% for Ni.

  8. Management of sewage sludge by composting using fermented water hyacinth.

    PubMed

    Tello-Andrade, A F; Jiménez-Moleón, M C; Sánchez-Galván, G

    2015-10-01

    The goal of the present research work was to assess the management of sewage sludge (SS) by composting using fermented water hyacinth (WHferm) as an amendment. The water hyacinth was fermented, and a higher production of volatile fatty acids (VFAs) (782.67 mg L(-1)) and soluble organic carbon (CSOL) (4788.34 mg L(-1)) was obtained using a particle size of 7 mm compared to 50 mm. For composting, four treatments (10 kg fresh weight each) were evaluated: treatment A (100 % SS + 0 % WHferm), treatment B (75 % SS + 25 % WHferm), treatment C (50 % SS + 50 % WHferm), and treatment D (25 % SS + 75 % WHferm). The WHferm added to SS, especially in treatments C (50 %) and D (75 %), increased the initial contents of organic matter (OM), organic carbon (CORG), CSOL, the C/N ratio, and the germination index (GI). The heavy metal content (HMC) (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) at the beginning was below the maximum allowed by USEPA regulations. All of the samples were free of Salmonella sp. from the beginning. The reduction of the CORG, CSOL, total Kjeldahl nitrogen (TKN), and C/N ratio indicated the degradation of the OM by day 198. The treatments with WHferm (B, C, and D) yielded higher values of electrical conductivity, cation exchange capacity, and GI than SS at day 198. No significant differences were observed in GI among the treatments with WHferm. The fecal coliforms were eliminated (<3 MPN g(-1)) and the helminths were reduced to ≤5 eggs/2 g during the process. The competition for nutrients and the presence of suppressive fungi of the genera Penicillium, Rhizopus, Paecilomyces (penicillin producers), and Fusariella isolated from the compost may have promoted the elimination of pathogens since no thermophile temperatures were obtained. WHferm as an amendment in the composting of SS improved the characteristics of the final product, especially when it was used in proportions of 25 and 50 %. An excellent product was obtained in terms of HMC, and the product was B class

  9. Project summary: Spreading lagooned sewage sludge on farm land: A case history

    SciTech Connect

    Robson, C.M.; Sommers, L.E.

    1995-06-01

    The City of Indianapolis, Indiana, was required to construct advanced wastewater treatment facilities at the existing Belmont Wastewater Treatment Plant. The most cost effective site for these new treatment facilities was the 10 sludge lagoons containing 420,000 cubic meters (111 million gallons) of digested sewage sludge stored for up to 50 years. The project consisted of the following major tasks: (1) obtaining approval from regulatory agencies; (2) obtaining cooperation of landowners and farmers; (3) removing, transporting, and applying the lagooned sludge to soil; and (4) monitoring the impact on crops.

  10. Working to gain public acceptance of sewage sludge composting and use of liquid and dewatered sludge on land

    SciTech Connect

    Walker, J.M.

    1995-06-01

    The purpose of this paper is (1) to examine those factors that especially spark the resistance and concern of citizens to land utilization and composting of sewage sludge and (2) to characterize essential ingredients that are invariably a part of the most successful systems for reducing the resistance and minimizing the concerns of these citizens. Experiences in the Washington, D.C. Metropolitan Area will be discussed which show how municipal authorities and/or their agents have worked with citizens. These discussions show how their efforts have either alleviated or increased citizen concern and resistance to sludge utilization and composting.

  11. Effects of co-processing sewage sludge in cement kiln on NOx, NH3 and PAHs emissions.

    PubMed

    Lv, Dong; Zhu, Tianle; Liu, Runwei; Lv, Qingzhi; Sun, Ye; Wang, Hongmei; Liu, Yu; Zhang, Fan

    2016-09-01

    The effects of co-processing sewage sludge in cement kiln on NOx, NH3 and PAHs emissions were systematically investigated in a cement production line in Beijing. The results show that co-processing the sewage sludge was helpful to reduce NOx emission, which primarily depends on the NH3 amount released from the sewage sludge. Meanwhile, NOx and NH3 concentrations in the flue gas have a negative correlation, and the contribution of feeding the sewage sludge to NOx removal decreased with the increase of injection amount of ammonia water in the SNCR system. Therefore, it is suggested that the injection amount of ammonia water in SNCR system may reduce to cut down the operating costs during co-processing the sewage sludge in cement kiln. In addition, the emission of total PAHs seems to increase with the increased amount of the sewage sludge feeding to the cement kiln. However, the distributions of PAHs were barely changed, and lower molecular weight PAHs were mainly distributed in gaseous phase, accounted for the major portion of PAHs when co-processing sewage sludge in cement kiln.

  12. Effects of sewage sludge amendment on snail growth and trace metal transfer in the soil-plant-snail food chain.

    PubMed

    Bourioug, Mohamed; Gimbert, Frédéric; Alaoui-Sehmer, Laurence; Benbrahim, Mohammed; Badot, Pierre-Marie; Alaoui-Sossé, Badr; Aleya, Lotfi

    2015-11-01

    Cu, Zn, Pb, and Cd concentrations in a soil plant (Lactuca sativa) continuum were measured after sewage sludge amendment. The effects of sewage sludge on growth and trace metal bioaccumulation in snails (Cantareus aspersus) were investigated in a laboratory experiment specifically designed to identify contamination sources (e.g., soil and leaves). Application of sewage sludge increased trace metal concentrations in topsoil. However, except Zn, metal concentrations in lettuce leaves did not reflect those in soil. Lettuce leaves were the main source of Zn, Cu, and Cd in exposed snails. Bioaccumulation of Pb suggested its immediate transfer to snails via the soil. No apparent toxic effects of trace metal accumulation were observed in snails. Moreover, snail growth was significantly stimulated at high rates of sludge application. This hormesis effect may be due to the enhanced nutritional content of lettuce leaves exposed to sewage sludge.

  13. Application of the severity parameter for predicting viscosity during hydrothermal processing of dewatered sewage sludge for a commercial PFBC plant.

    PubMed

    Yanagida, Takashi; Fujimoto, Shinji; Minowa, Tomoaki

    2010-03-01

    Dewatered sewage sludge (approximately 80% water, but with low fluidity) was liquidized by hydrothermal treatment in order to make coal-water paste (CWP) for use in a pressurized-fluidized-bed-combustion (PFBC) power plant. Prediction of the viscosity of the dewatered sewage sludge during batch reactor hydrothermal liquefaction is important in order to avoid inputting excess energy. A single parameter, the severity parameter, has been used to predict viscosity during the hydrothermal process. The relationship between the viscosity of the slurry made from dewatered sewage sludge and the severity value was investigated. Viscosity reduction was associated with an increase in the severity value and was dependent on reaction temperature and time. It was concluded that predicting the viscosity of dewatered sewage sludge during the hydrothermal process by means of the severity parameter is possible. This method is expected to provide a useful guideline for choosing reaction conditions based on prediction of the viscosity of the sludge slurry during the hydrothermal process.

  14. CONTEMPORARY PERSPECTIVES ON INFECTIOUS DISEASE AGENTS IN SEWAGE SLUDGE AND MANURE

    EPA Science Inventory

    The USEPA and the USDA convened a three-day Workshop on Emerging Infectious Disease Agents and Issues Associated with Sewage Sludge, Animal Manures, and Other Organic By-Products on June 4-6, 2001 in Cincinnati, Ohio. The purpose of the workshop was to review and discuss the effe...

  15. EVALUATION OF OXYGEN-ENRICHED MSW/SEWAGE SLUDGE CO-INCINERATION DEMONSTRATION PROGRAM

    EPA Science Inventory

    This report provides an evaluation of a two-phased demonstration program conducted for the U.S. Environmental Protection Agency's Municipal Solid Waste Innovative Technology Evaluation Program, and the results thereof, of a recently developed method of sewage sludge managemen...

  16. PRELIMINARY COMPARATIVE STUDY OF METHODS TO EXTRACT VIRUS FROM RAW AND PROCESSED SEWAGE SLUDGES

    EPA Science Inventory

    Two simple virus extraction techniques were compared to an EPA standard method for detection of human enteric viruses in raw sewage sludge and class A biosolids. The techniques were used to detect both indigenous and seeded virus from a plant that distributes class A material pr...

  17. Characterization of top phase oil obtained from co-pyrolysis of sewage sludge and poplar sawdust.

    PubMed

    Zuo, Wu; Jin, Baosheng; Huang, Yaji; Sun, Yu

    2014-01-01

    To research the impact of adding sawdust on top phase oil, a sewage sludge and poplar sawdust co-pyrolysis experiment was performed in a fixed bed. Gas chromatography (GC)/mass spectrometry (MS) was used to analyze the component distribution of top phase oil. Higher heating value, viscosity, water content, and pH of the top phase oil product were determined. The highest top phase oil yield (5.13 wt%) was obtained from the mixture containing 15% poplar sawdust, while the highest oil yield (16.51 wt%) was obtained from 20% poplar sawdust. Top phase oil collected from the 15% mixture also has the largest amount of aliphatics and the highest higher heating value (28.6 MJ/kg). Possible reaction pathways were proposed to explain the increase in the types of phenols present in the top phase oil as the proportion of poplar sawdust used in the mixture increased. It can be concluded that synergetic reactions occurred during co-pyrolysis of sewage sludge and poplar sawdust. The results indicate that the high ash content of the sewage sludge may be responsible for the characteristic change in the top phase oil obtained from the mixtures containing different proportions of sewage sludge and poplar sawdust. Consequently, co-pyrolysis of the mixture containing 15 % poplar sawdust can increase the yield and the higher heating value of top phase oil.

  18. Analyzing hydrocarbons in sewer to help in PAH source apportionment in sewage sludges.

    PubMed

    Mansuy-Huault, Laurence; Regier, Annette; Faure, Pierre

    2009-05-01

    A multi-molecular approach for polycyclic aromatic hydrocarbons (PAH) source apportionment in sewage sludge was tested. Three simple catchment areas with corresponding wastewater treatment plants (WWTP) were chosen. Sewage sludges of these WWTPs chronically exceeded the French guide values for PAHs. Aliphatic and aromatic hydrocarbons were quantified in sediments or wastewater suspended particulate matter sampled in different locations of the sewer as well as in sewage sludge. Various molecular indices including PAH ratios were calculated. The results showed that the ratios calculated from sewage sludge analyses provided a rather unspecific hydrocarbon fingerprint where combustion input appear as the main PAH sources. The complexity of the inputs as well as degradation occurring during wastewater treatment prevent any detailed diagnosis. Coupled to the analyses of samples collected in the sewer, the multi-molecular approach becomes more efficient especially for the identification of specific petroleum inputs such as fuel or used lubricating oils which can be important PAH sources. Indeed, the sampling in the sewer allows a spatial screening of the hydrocarbon inputs and facilitates the PAH source apportionment by avoiding the dilution of specific inputs with the whole wastewater inputs and by limiting the degradation of the molecular fingerprint that could occur during transfer and treatment in the WWTP. Then, the combination of PAH ratios and aliphatic distribution analyses is a very valuable approach that can help in sewer and WWTP management.

  19. Salmonella species and serotypes isolated from farm animals, animal feed, sewage, and sludge in Saudi Arabia*

    PubMed Central

    Nabbut, N. H.; Barbour, E. K.; Al-Nakhli, H. M.

    1982-01-01

    A total of 264 salmonellae representing 65 different species and serotypes were isolated for the first time in Saudi Arabia, from various animal species, animal feed, sewage, and sludge. The six most frequently isolated Salmonella species or serotypes were: livingstone, concord, “S. schottmuelleri” (invalid), lille, S. typhimurium, and cerro. PMID:6983931

  20. POTENTIAL OF GREENHOUSE GASES REDUCTION BY FUEL CROP CULTIVATION UTILIZING SEWAGE SLUDGE IN JAPAN

    NASA Astrophysics Data System (ADS)

    Honda, Ryo; Fukushi, Kensuke

    Potential of greenhouse gases (GHG) reduction was estimated and compared in six scenarios of fuel crop cultivation by utilizing sewage sludge in Japan. Bioethanol from corn and biodiesel fuel from soybean was selected as biofuel produced. When all the sludge discharged from sewage treatment plants in 18 major cities was utilized for soybean cultivation and subsequent biodiesel fuel production, produced biofuel corresponded to 4.0% of GHG emitted from sewage treatment in Japan. On the other hand, cultivation area for fuel crop cultivation was found to be the regulating factor. When fuel crop was cultivated only in abandoned agricultural fields, produced biofuel corresponded to 0.60% and 0.62%, respectively, in the case that corn and soybean was cultivated. Production of biodiesel fuel from soybean was estimated to have more net reduction potential than bioehanol production from corn when sludge production is limited, because required sewage sludge compost was 2.5-times larger in corn although reduction potential per crop area was 2-times larger in bioethanol production from corn.

  1. Production of a solid fuel using sewage sludge and spent cooking oil by immersion frying.

    PubMed

    Wu, Zhonghua; Zhang, Jing; Li, Zhanyong; Xie, Jian; Mujumdar, Arun S

    2012-12-01

    Sewage sludge and spent cooking oil are two main waste sources of modern Chinese cities. In this paper, the immersion frying method using spent cooking oil as the heating medium was applied to dry and convert wet sewage sludge into a solid fuel. The drying and oil uptake curves were plotted to demonstrate the fry-drying characteristics of the sewage sludge. Parametric studies were carried out to identify the governing parameters in the frying drying operation. It was found that at frying oil temperatures of 140-160°C, the wet sewage sludge could be dried completely in 6-9 min and converted into a solid fuel with a high calorific value of 21.55-24.08 MJ/kg. The fuel structure, chemical components, pyrolysis and combustion characteristics were investigated and the experimental results showed the solid fuel had a porous internal structure and a low ignition temperature of 250°C due to presence of oil. The frying drying mechanism was also discussed.

  2. The urgent need for risk assessment on the antibiotic resistance spread via sewage sludge land application.

    PubMed

    Bondarczuk, Kinga; Markowicz, Anna; Piotrowska-Seget, Zofia

    2016-02-01

    Sewage sludge is an ever-increasing by-product of the wastewater treatment process frequently used as a soil fertiliser. To control its quality and prevent any possible hazardous impact of fertilisation, some mandatory limits of heavy metal content have been established by the European Commission (Sewage Sludge Directive). However, since the implementation of the limits, new emerging contaminants have been reported worldwide. Regardless of the wastewater treatment process, sewage sludge contains antibiotics, antibiotic-resistant bacteria and antibiotic resistance genes, which can be released into the environment through its land application. Such a practice may even boost the dissemination and further development of antibiotic resistance phenomenon - already a global problem challenging modern medicine. Due to the growing pharmaceutical pollution in the environment, the time is ripe to assess the risk for the human and environmental health of sewage sludge land application in the context of antibiotic resistance spread. In this review we present the current knowledge in the field and we emphasise the necessity for more studies.

  3. Energy recovery from sewage sludge by means of fluidised bed gasification

    SciTech Connect

    Gross, Bodo; Eder, Christian; Grziwa, Peter; Horst, Juri Kimmerle, Klaus

    2008-07-01

    Because of its potential harmful impact on the environment, disposal of sewage sludge is becoming a major problem all over the world. Today the available disposal measures are at the crossroads. One alternative would be to continue its usage as fertiliser or to abandon it. Due to the discussions about soil contamination caused by sewage sludge, some countries have already prohibited its application in agriculture. In these countries, thermal treatment is now presenting the most common alternative. This report describes two suitable methods to directly convert sewage sludge into useful energy on-site at the wastewater treatment plant. Both processes consist mainly of four devices: dewatering and drying of the sewage sludge, gasification by means of fluidised bed technology (followed by a gas cleaning step) and production of useful energy via CHP units as the final step. The process described first (ETVS-Process) is using a high pressure technique for the initial dewatering and a fluidised bed technology utilising waste heat from the overall process for drying. In the second process (NTVS-Process) in addition to the waste heat, solar radiation is utilised. The subsequent measures - gasification, gas cleaning and electric and thermal power generation - are identical in both processes. The ETVS-Process and the NTVS-Process are self-sustaining in terms of energy use; actually a surplus of heat and electricity is generated in both processes.

  4. Improving the phytoremediation of heavy metals contaminated soil by use of sewage sludge.

    PubMed

    Placek, Agnieszka; Grobelak, Anna; Kacprzak, Malgorzata

    2016-01-01

    Sewage sludge, in particular from the food industry, is characterized by fertilizing properties, due to the high content of organic matter and nutrients. The application of sewage sludge causes an improvement of soil parameters as well as increase in cation exchange capacity, and thus stronger binding of cations in the soil environment, which involves the immobilization of nutrients and greater resistance to contamination. In a field experiment sewage sludge has been used as an additive to the soil supporting the phytoremediation process of land contaminated with heavy metals (Cd, Zn, and Pb) using trees species: Scots pine (Pinus silvestris L.), Norway spruce (Picea abies L.), and oak (Quercus robur L.). The aim of the research was to determine how the application of sewage sludge into the soil surface improves the phytoremediation process. The conducted field experiment demonstrated that selected trees like Scots pine and Norway spruce, because of its excellent adaptability, can be used in the remediation of soil. Oak should not be used in the phytoremediation process of soils contaminated with high concentrations of trace elements in the soil, because a significant amount of heavy metals was accumulated in the leaves of oak causing a risk of recontamination.

  5. Heavy metal balances of an Italian soil as affected by sewage sludge and Bordeaux mixture applications

    SciTech Connect

    Moolenaar, S.W.; Beltrami, P.

    1998-07-01

    Applications of sewage sludge and Bordeaux mixture (Bm) (a mixture of copper sulfate and lime) add heavy metals to the soil. At an experimental farm in the Cremona district (Italy), the authors measured current heavy metal contents in soil and their removal via harvested products. They also measured heavy metal adsorption by soil from this farm. With these data, projections were made of the long-term development of heavy metal (Cd, Cu, and Zn) contents in soil, crop removal, and leaching at different application rates of sewage sludge and Bm. These projections were compared with existing quality standards of the European Union (EU) and Italy with regard to soil and groundwater. The calculations reveal that the permitted annual application rates of sewage sludge and Bm are likely to result in exceedance of groundwater and soil standards. Sewage sludge applications, complying with the Italian legal limits, may pose problems for Cd, Cu, and Zn within 30, 70, and 100 yr, respectively. Furthermore, severe Cu pollution of integrated and especially organic (Bm only) vineyards is unavoidable with the currently allowed application rates of Bm. The results suggest that the current Italian soil protection policy as well as the EU policy are not conducive of a sustainable heavy metal management in agroecosystems.

  6. Evaluation of leaching and ecotoxicological properties of sewage sludge-fly ash mixtures

    SciTech Connect

    C.A. Papadimitriou; I. Haritou; P. Samaras; A.I. Zouboulis

    2008-03-15

    The objectives of this work were the evaluation of sewage sludge stabilization by mixing with fly ash, the examination of the physicochemical properties of the produced materials and their leachates and the assessment of their environmental impact by the evaluation of the ecotoxic characteristics. Different ratios of fly ash and sewage sludge (1:1, 1:2, 1:3, 1:6, and 1:9) were mixed for 48 and 72 h. After mixing, the liquid phase of the produced materials was analyzed for total coliforms and Escherichia coli, while the solid residue was dried and tested for the leaching characteristics by the application of TCLP and EN 12457-2 standard leaching methods. Furthermore, the produced leachates were analyzed for their content of specific metals, while their ecotoxicological characteristics were determined by the use of toxicity bioassays, using the marine photobacterium Vibrio fischeri and the crustacean Daphnia magna. The phytotoxicity of sewage sludge-fly ash mixtures was also determined by utilizing seeds of three higher plants (one monocotyl and two dicotyls). The mixtures exhibited low metal leaching in all cases, while the ecotoxic properties increased with the increase of fly ash/sewage sludge ratio. The phytotoxicity testing showed increased root length growth inhibition.

  7. Antibiotic resistome and its association with bacterial communities during sewage sludge composting.

    PubMed

    Su, Jian-Qiang; Wei, Bei; Ou-Yang, Wei-Ying; Huang, Fu-Yi; Zhao, Yi; Xu, Hui-Juan; Zhu, Yong-Guan

    2015-06-16

    Composting is widely used for recycling of urban sewage sludge to improve soil properties, which represents a potential pathway of spreading antibiotic resistant bacteria and genes to soils. However, the dynamics of antibiotic resistance genes (ARGs) and the underlying mechanisms during sewage sludge composting were not fully explored. Here, we used high-throughput quantitative PCR and 16S rRNA gene based illumina sequencing to investigate the dynamics of ARGs and bacterial communities during a lab-scale in-vessel composting of sewage sludge. A total of 156 unique ARGs and mobile genetic elements (MGEs) were detected encoding resistance to almost all major classes of antibiotics. ARGs were detected with significantly increased abundance and diversity, and distinct patterns, and were enriched during composting. Marked shifts in bacterial community structures and compositions were observed during composting, with Actinobacteria being the dominant phylum at the late phase of composting. The large proportion of Actinobacteria may partially explain the increase of ARGs during composting. ARGs patterns were significantly correlated with bacterial community structures, suggesting that the dynamic of ARGs was strongly affected by bacterial phylogenetic compositions during composting. These results imply that direct application of sewage sludge compost on field may lead to the spread of abundant ARGs in soils.

  8. Rapid method for the digestion of sewage and sludge for metal analyses

    SciTech Connect

    Nielsen, J.S.; Hrudey, S.E.

    1984-02-01

    A steam digestion method for metal determinations in sewage and sludge is described and compared to methods using nitric acid digestion and high-speed homogenization. The steam digestion method employs a domestic pressure cooker, provides quantitative metal recoveries, is not prone to metal contamination, and requires less reagents and supervision than the methods with which it was compared.

  9. An alkaline oxidation method for determination of total arsenic and selenium in sewage sludges

    SciTech Connect

    Zhu, Baojin; Tabatabai, M.A.

    1995-07-01

    A simple and precise method was developed for determination of total As and Se in sewage sludges by using hydride-generation atomic absorption spectrometry (HGAAS). It involves boiling a 50-mg sample with sodium hypobromite (NaOBr) solution to dryness in a sand bath (260-280{degrees}C), extraction of the As and Se in the digest with 1.25 M H{sub 2}SO{sub 4}, and determination of these elements by HGAAS after reducing As(V) and Se(VI) to As(III) and Se(IV), respectively. The proposed method gives quantitative recovery of As and Se in standard reference materials (96-103%) and of these elements added to sewage sludges (95-100%). The average results of AS (9.8 mg/kg) and Se (7.5 mg/kg) in 12 sewage sludges determined by the proposed digestion method agreed closely with those obtained by the acid digestion methods recommended by USGS and USEPA. Tests with 13 metals indicated that, at the concentrations expected in sewage sludges, none of the metals interfered with determination of As and Se by the proposed method. A single operator can complete analysis of one of the elements in 40 samples in a normal working day, or both elements in 1.5 d.

  10. Improving the phytoremediation of heavy metals contaminated soil by use of sewage sludge

    PubMed Central

    Placek, Agnieszka; Grobelak, Anna; Kacprzak, Malgorzata

    2016-01-01

    ABSTRACT Sewage sludge, in particular from the food industry, is characterized by fertilizing properties, due to the high content of organic matter and nutrients. The application of sewage sludge causes an improvement of soil parameters as well as increase in cation exchange capacity, and thus stronger binding of cations in the soil environment, which involves the immobilization of nutrients and greater resistance to contamination. In a field experiment sewage sludge has been used as an additive to the soil supporting the phytoremediation process of land contaminated with heavy metals (Cd, Zn, and Pb) using trees species: Scots pine (Pinus silvestris L.), Norway spruce (Picea abies L.), and oak (Quercus robur L.). The aim of the research was to determine how the application of sewage sludge into the soil surface improves the phytoremediation process. The conducted field experiment demonstrated that selected trees like Scots pine and Norway spruce, because of its excellent adaptability, can be used in the remediation of soil. Oak should not be used in the phytoremediation process of soils contaminated with high concentrations of trace elements in the soil, because a significant amount of heavy metals was accumulated in the leaves of oak causing a risk of recontamination. PMID:26368503

  11. Municipal sewage sludge as fertilizer. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1996-06-01

    The bibliography contains citations concerning the use of sewage sludge as forestry and farm crop fertilizer. References discuss degassed biomass, fertilizer-grade residues, compost fertilizers, biological conversion of organic wastes, organic environmental pollution, and iron salts. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  12. [Effects of applying sewage sludge on chemical form distribution and bioavailability of heavy metals in soil].

    PubMed

    Song, Lin-Lin; Tie, Mei; Zhang, Zhao-Hong; Hui, Xiu-Juan; Jing, Kui; Chen, Zhong-Lin; Zhang, Ying

    2012-10-01

    A pot experiment was conducted to study the effects of applying sewage sludge on the chemical form distribution of heavy metals (Cd, Pb, Cu and Zn) in soil and the transfer and accumulation of the heavy metals in soil-plant (ryegrass) system. With the application of sewage sludge, the contents of bioavailable Cd and Zn in soil increased significantly but that of bioavailable Pb in soil had a significant decrease, and the content of residual form Pb in soil increased by 33.3% -74.5%, compared with CK. When the application rate of sewage sludge was 50% (M/M) of soil, the contents of exchangeable and reducible Cu in soil only occupied 0.7% and 0.2% of the total Cu respectively. The application of sewage sludge promoted the Cd, Cu and Zn absorption while inhibited the Pb absorption by ryegrass. Multiple linear regression analysis showed that the Cd, Zn and Cu contents in ryegrass were positively correlated with the reducible Cd and Zn and oxidizable Cu contents in soil, respectively, and Pb content in ryegrass was highly correlated with the soil exchangeable and oxidizable Pb contents. After planting ryegrass, the oxidizable Cd and Cu in rhizosphere soil were transformed into exchangeable Cd and residual form Cu, respectively, the exchangeable and reducible Zn transformed into oxidizable Zn, whereas the bioavailability of Pb was less affected.

  13. Comparison of phosphorus recovery from incineration and gasification sewage sludge ash.

    PubMed

    Parés Viader, Raimon; Jensen, Pernille Erland; Ottosen, Lisbeth M; Thomsen, Tobias P; Ahrenfeldt, Jesper; Hauggaard-Nielsen, Henrik

    2017-03-01

    Incineration of sewage sludge is a common practice in many western countries. Gasification is an attractive option because of its high energy efficiency and flexibility in the usage of the produced gas. However, they both unavoidably produce sewage sludge ashes, a material that is rich in phosphorus, but which is commonly landfilled or used in construction materials. With current uncertainty in phosphate rock supply, phosphorus recovery from sewage sludge ashes has become interesting. In the present work, ashes from incineration and gasification of the same sewage sludge were compared in terms of phosphorus extractability using electrodialytic (ED) methods. The results show that comparable recovery rates of phosphorus were achieved with a single ED step for incineration ashes and a sequential combination of two ED steps for gasification ashes, which was due to a higher influence of iron and/or aluminium in phosphorus solubility for the latter. A product with lower level of metallic impurities and comparable to wet process phosphoric acid was eventually obtained from gasification ashes. Thus, gasification becomes an interesting alternative to incineration also in terms of phosphorus separation.

  14. Energy recovery from sewage sludge by means of fluidised bed gasification.

    PubMed

    Gross, Bodo; Eder, Christian; Grziwa, Peter; Horst, Juri; Kimmerle, Klaus

    2008-01-01

    Because of its potential harmful impact on the environment, disposal of sewage sludge is becoming a major problem all over the world. Today the available disposal measures are at the crossroads. One alternative would be to continue its usage as fertiliser or to abandon it. Due to the discussions about soil contamination caused by sewage sludge, some countries have already prohibited its application in agriculture. In these countries, thermal treatment is now presenting the most common alternative. This report describes two suitable methods to directly convert sewage sludge into useful energy on-site at the wastewater treatment plant. Both processes consist mainly of four devices: dewatering and drying of the sewage sludge, gasification by means of fluidised bed technology (followed by a gas cleaning step) and production of useful energy via CHP units as the final step. The process described first (ETVS-Process) is using a high pressure technique for the initial dewatering and a fluidised bed technology utilising waste heat from the overall process for drying. In the second process (NTVS-Process) in addition to the waste heat, solar radiation is utilised. The subsequent measures--gasification, gas cleaning and electric and thermal power generation--are identical in both processes. The ETVS-Process and the NTVS-Process are self-sustaining in terms of energy use; actually a surplus of heat and electricity is generated in both processes.

  15. Effects of sewage sludge application on heavy metal leaching from mine tailings impoundments.

    PubMed

    Andrés, Navarro Flores; Francisco, Martínez Sola

    2008-11-01

    Column experiments were conducted to investigate the removal of heavy metals from two mine tailings (El Arteal and Jaravías) using sewage sludge as a reactive material. When sewage sludge is used as a reactive material on the El Arteal tailings (sample SA), Fe, Mn, Zn and Pb are removed and Cu and Ni are mobilized. The experiments carried out on the Jaravías tailings give similar results, showing the retention of Cu, Pb, Fe and Mn and the mobilization of Ni and Zn. An analysis performed using the PHREEQC numerical code suggests that the retention of Fe in the sewage sludge may be caused by the precipitation of Fe(OH)2.7Cl0.3 and possibly pyrite, and that the retention of Pb at high pH may be caused by the formation of stable phase minerals such as Pb(OH)2 and PbS in these conditions. Ni mobilization in the column experiments with the two tailings samples may be caused by the presence of significant amounts of leachable Ni in the sewage sludge. The complexation of metals with dissolved organic matter, calculated with the Minteq model, may be moderate.

  16. Potential for land application of contaminated sewage sludge treated with fermented liquid from pineapple wastes.

    PubMed

    Del Mundo Dacera, Dominica; Babel, Sandhya; Parkpian, Preeda

    2009-08-15

    The suitability for land application of anaerobically digested sewage sludge treated with naturally fermented and Aspergillus niger (A. niger) fermented raw liquid from pineapple wastes, in terms of changes in the forms and amount of heavy metals and nutrient and pathogen content, were investigated in this study. Leaching studies for fermented liquid at optimum conditions (pH and contact time with best metal removal efficiencies) were carried out for the removal of Cd, Cr, Cu, Pb, Ni and Zn from sewage sludge, with citric acid as a reference. Using the same sludge before and after leaching, sequential fractionation studies were done to observe the effect of treatment on the forms of metals in sludge and their mobility and bioavailability. Results of laboratory scale studies revealed that leaching with all extractants at selected optimum conditions resulted in a decrease in heavy metals and pathogen content of the treated sludge, presence of sufficient amount of nutrients (nitrogen and phosphorous) and dominance of residual fractions in most metals, with sludge treated with A. niger, having the best quality. The results, therefore, indicate the high potential of the treated sludge for land application, with no harm from heavy metals released and no toxicity to the soil and groundwater.

  17. Occurrence of emerging contaminants in agricultural soils, sewage sludge and waters in Valencia (E Spain)

    NASA Astrophysics Data System (ADS)

    Boluda, Rafael; Marimon, Lupe; Atzeni, Stefania; Mormeneo, Salvador; Iranzo, María; Zueco, Jesús; Gamón, Miguel; Sancenón, José; Romera, David; Gil, Carlos; Amparo Soriano, Maria; Granell, Clara; Roca, Núria; Bech, Jaume

    2013-04-01

    In recent years, studies into the presence and distribution of emerging contaminants (ECs), like pharmaceutical products, some pesticides and mycotoxins in the natural environment, are receiving considerable attention. Thus, the presence of these compounds in waters, soils and wastes in different locations including agricultural systems has been stressed; very few studies into this matter are available in Spain. The main source of ECs in the environment is wastewater spillage from wastewater treatment plants (WTP), where these compounds arrive from the sewer system network. The objective of this study was to determine the levels of 35 ECs constituted by nine pharmaceutical products, 23 fungicides and three mycotoxins in soils, sewages sludge and waters adjacent to WTP from an agriculture area of Valencia (E Spain) influenced by intense urban and industrial activity. Seven samples from sludge, 13 soil samples and eight samples of waters from the area of influence of WTP were collected. The ECs extraction were performed using 5 g of fresh sample and a mixture of acetonitrile with 1% formic acid and water at the 3:1 ratio by shaking for 45 min and then centrifuging at 4,000 rpm for 5 min. The extract was filtered and determination was done by HPLC system connected to a 3200-Qtrap de triple quadrupole mass spectrometer with an electrospray ion source. The results showed that soil-ECs concentrations were 10 times lower that in sewage sludge. The smaller number of detections and detected compounds should also be stressed. As in previous cases, fungicides azole (tebuconazole and tricyclazole), along with boscalid, were the most detected compounds with concentrations of between 100 and 400 µg kg-1 dw. In second place, propiconazole and azoxystrobin stood out, followed by carbendazim, dimetomorph, pyraclostrobin and propamocarb. The following drugs and mycotoxins were detected to have a higher to lower concentration (1-40 µg kg-1): telmisartan, irbesartan, venlafaxine

  18. Effects of different sewage sludge applications on heavy metal accumulation, growth and yield of spinach (Spinacia oleracea L.).

    PubMed

    Eid, Ebrahem M; El-Bebany, Ahmed F; Alrumman, Sulaiman A; Hesham, Abd El-Latif; Taher, Mostafa A; Fawy, Khaled F

    2017-04-03

    In this study, we present the response of spinach to different amendment rates of sewage sludge (0, 10, 20, 30, 40 and 50 g kg(-1)) in a greenhouse pot experiment, where plant growth, biomass and heavy metal uptake were measured. The results showed that sewage sludge application increased soil electric conductivity (EC), organic matter, chromium and zinc concentrations and decreased soil pH. All heavy metal concentrations of the sewage sludge were below the permissible limits for land application of sewage sludge recommended by the Council of the European Communities. Biomass and all growth parameters (except the shoot/root ratio) of spinach showed a positive response to sewage sludge applications up to 40 g kg(-1) compared to the control soil. Increasing the sewage sludge amendment rate caused an increase in all heavy metal concentrations (except lead) in spinach root and shoot. However, all heavy metal concentrations (except chromium and iron) were in the normal range and did not reach the phytotoxic levels. The spinach was characterized by a bioaccumulation factor <1.0 for all heavy metals. The translocation factor (TF) varied among the heavy metals as well as among the sewage sludge amendment rates. Spinach translocation mechanisms clearly restricted heavy metal transport to the edible parts (shoot) because the TFs for all heavy metals (except zinc) were <1.0. In conclusion, sewage sludge used in the present study can be considered for use as a fertilizer in spinach production systems in Saudi Arabia, and the results can serve as a management method for sewage sludge.

  19. In situ biodiesel production from greasy sewage sludge using acid and enzymatic catalysts.

    PubMed

    Sangaletti-Gerhard, Naiane; Cea, Mara; Risco, Vicky; Navia, Rodrigo

    2015-03-01

    This study proposes to select the most appropriate sewage sludge (greasy, primary and secondary) for in situ transesterification and to compare the technical, economic and energetic performance of an enzymatic catalyst (Novozym®435) with sulfuric acid. Greasy sludge was selected as feedstock for biodiesel production due to its high lipid content (44.4%) and low unsaponifiable matter. Maximum methyl esters yield (61%) was reached when processing the wet sludge using sulfuric acid as catalyst and n-hexane, followed by dried-greasy sludge catalyzed by Novozym®435 (57% methyl esters). Considering the economic point of view, the process using acid catalyst was more favorable compared to Novozym®435 catalyst due to the high cost of lipase. In general, greasy sludge (wet or dried) showed high potential to produce biodiesel. However, further technical adjustments are needed to make biodiesel production by in situ transesterification using acid and enzymatic catalyst feasible.

  20. Using a high biomass plant Pennisetum hydridum to phyto-treat fresh municipal sewage sludge.

    PubMed

    Hei, Liang; Lee, Charles C C; Wang, Hui; Lin, Xiao-Yan; Chen, Xiao-Hong; Wu, Qi-Tang

    2016-10-01

    The study was carried out to investigate the use of a high biomass plant, Pennisetum hydridum, to treat municipal sewage sludge (MSS). An experiment composed of plots with four treatments, soil, fresh sludge, soil-sludge mixture and phyto-treated sludge, was conducted. It showed that the plant could not survive directly in fresh MSS when cultivated from stem cuttings. The experiment transplanting the incubated cutting with nurse medium of P. hydridum in soil and fresh MSS, showed that the plants grew normally in fresh MSS. The pilot experiment of P. hydridum and Alocasia macrorrhiza showed that the total yield and nutrient amount of P. hydridum were 9.2 times and 3.6 times more than that of A. macrorrhiza. After plant treatment, MSS was dried, stabilized and suitable to be landfilled or incinerated, with a calorific value of about 5.6MJ/kg (compared to the initial value of 1.9MJ/kg fresh sludge).

  1. Effects and risk assessment of linear alkylbenzene sulfonates in agricultural soil. 2. Effects on soil microbiology as influenced by sewage sludge and incubation time.

    PubMed

    Elsgaard, L; Petersen, S O; Debosz, K

    2001-08-01

    The anionic surfactant linear alkylbenzene sulfonate (LAS) may inhibit soil microorganisms and may occur in agricultural soil through the application of sewage sludge. For five microbial parameters (microbial biomass C and the potentials of iron reduction, ammonium oxidation, dehydrogenase activity, and arylsulfatase activity), we compared the effects of aqueous LAS and LAS-spiked sewage sludge added to existing levels of 0, 3, 8, 22, 22, 62, 174, and 488 mg/kg soil (dry wt) in a Danish sandy agricultural soil that was incubated for 5 d to eight weeks. Arylsulfatase activity (measured after four weeks of incubation) was rather insensitive to LAS, with an EC 10 of 222 and more than 488 mg/kg in soil samples treated with aqueous LAS and LAS-spiked sewage sludge, respectively. For the other microbial parameters, the short-term effects (approximately one to two weeks) of aqueous LAS were characterized by an EC10 in the range of 3 to 39 mg/kg. Application of LAS via sewage sludge generally reduced the short-term effects for the microbial parameters, and the EC10 for LAS in sludge-amended soil after approximately one to two weeks of incubation ranged from less than 8 to 102 mg/kg. Recovery potential was seen for most microbial parameters as a result of prolonged incubation, both under conditions of LAS persistence (anaerobic conditions, the iron-reduction test) and LAS depletion (aerobic incubations, all other assays). In conclusion, the short-term inhibitory effects of LAS on soil microbiology were decreased in the presence of sewage sludge and by a prolonged (two to eight weeks) laboratory incubation period.

  2. Effects of sucrose amendment on ammonia assimilation during sewage sludge composting.

    PubMed

    Meng, Liqiang; Li, Weiguang; Zhang, Shumei; Wu, Chuandong; Wang, Ke

    2016-06-01

    The aim of this study was to evaluate the laboratory-scale composting of sewage sludge and pumice mixtures that were amended with sucrose. The variation in temperature, pH, NH4(+)-N, ammonia emission, bacterial community, ammonia assimilating bacteria (AAB) populations and enzymatic activity related to ammonia assimilation were detected. The addition of sucrose increased the AAB population by 2.5-3.5 times, reduced ammonia emission by 24.7-31.1% compared with the control treatment, and promoted the growth of Bacillus and Wautersiella. The activities of glutamate dehydrogenase (GDH), glutamate synthase (GS) and glutamine synthetase (GOGAT), were enhanced by the addition of sucrose. GDH made a substantial contribution to ammonia assimilation when the ammonia concentration was high (⩾1.5g/kg) in the thermophilic phase. The GS/GOGAT cycle played an important role at low ammonia concentrations (⩽1.1g/kg) in the cooling phase. These results suggested that adding sucrose to sludge compost could promote ammonia assimilation and reduce ammonia emission.

  3. Tar-free fuel gas production from high temperature pyrolysis of sewage sludge

    SciTech Connect

    Zhang, Leguan; Xiao, Bo; Hu, Zhiquan; Liu, Shiming Cheng, Gong; He, Piwen; Sun, Lei

    2014-01-15

    Highlights: • High temperature pyrolysis of sewage sludge was efficient for producing tar-free fuel gas. • Complete tar removal and volatile matter release were at elevated temperature of 1300 °C. • Sewage sludge was converted to residual solid with high ash content. • 72.60% of energy conversion efficiency for gas production in high temperature pyrolysis. • Investment and costing for tar cleaning were reduced. - Abstract: Pyrolysis of sewage sludge was studied in a free-fall reactor at 1000–1400 °C. The results showed that the volatile matter in the sludge could be completely released to gaseous product at 1300 °C. The high temperature was in favor of H{sub 2} and CO in the produced gas. However, the low heating value (LHV) of the gas decreased from 15.68 MJ/N m{sup 3} to 9.10 MJ/N m{sup 3} with temperature increasing from 1000 °C to 1400 °C. The obtained residual solid was characterized by high ash content. The energy balance indicated that the most heating value in the sludge was in the gaseous product.

  4. Organotins' fate in lagoon sewage system: dealkylation and sludge sorption/desorption.

    PubMed

    Ophithakorn, Thiwari; Sabah, Aboubakr; Delalonde, Michele; Bancon-Montigny, Chrystelle; Suksaroj, Thunwadee Tachapattaworakul; Wisniewski, Christelle

    2016-11-01

    Organotin compounds (OTs) have been widely used for their biocidal properties and as stabilizers in various industrial applications. Due to their high toxicity, organotins are subject to many studies regarding their behavior in wastewater treatment plant and aquatic environment. However, few studies are available regarding their behavior in lagoon sewage system, although such treatment is commonly used for sewage treatment in low-population areas. The present study aimed at studying the fate of organotins (monobutyltin (MBT), dibutyltin (DBT), and tributyltin (TBT)) in lagoon sewage system. Short-term experiments, carried out at lab scale, consisted in sampling sludge from aerobic stabilization ponds, and then quantifying sorption and desorption of the different organotin species, as well as their respective transformation, under defined operating conditions (e.g., tributyltin spike and dilution) simulating possible change in the surrounding environment of sludge in the lagoon. Results established that a very important percentage of the OTs was localized in the solid phase of the sludge (more than 98 %), whatever the operating conditions may be; however, transformation and locations of the three OT species differed according to the different conditions of sludge dilution, TBT spiking, and test duration. After dilution of lagoon sludge, TBT desorption from sludge was observed; it was supposed that dealkylation of TBT after desorption occurred rapidly and increased dissolved MBT and DBT in liquid phase; MBT sorbed subsequently on solid phase. The nature of the diluent (i.e., tap water or saline solution) appeared to slightly influence the sludge behavior. After TBT spiking, TBT was supposed to be rapidly sorbed but also transformed in DBT and MBT that would as well sorbed on the sludge, which explained the decrease of these species in the liquid phase. Tests aimed at studying long-term effect of TBT spiking demonstrated that the sorbed species could be remobilized

  5. Effect of thermochemical pretreatment on sewage sludge and its impact on carboxylic acids production.

    PubMed

    Rughoonundun, Hema; Granda, Cesar; Mohee, Romeela; Holtzapple, Mark T

    2010-01-01

    This paper investigates the potential of converting sewage sludge into a useful product, namely carboxylic acids. To potentially enhance acid yields, the effect of pretreatment using 0.3 g lime/g dry biomass and water at 100 degrees C for 10-240 min was studied. The pretreated sludges were anaerobically fermented to mixed-acids using a mixed culture of microorganisms; methanogens were suppressed using iodoform. Batch fermentations were performed at 55 degrees C using ammonium bicarbonate buffer. The first batch experiments compared treated and untreated sludge as the only substrate. The second batch experiments used a mixture of sludge plus lime-treated bagasse (20:80 by weight). Analysis of liquor shows that the pretreatment were effective in solubilizing constituent compounds of sewage sludge. Nitrogen content and carboxylic acids increased with increasing pretreatment time. However, the soluble sugars peaked at 60 min, and then decreased with longer pretreatment time, showing that the solubilised sugars were undergoing intermolecular reactions, such as Maillard reactions. Fermentation experiments were a good indicator of the biodegradability of the pretreated sludges. Results clearly showed that lime-treating sludge, using even the minimum pretreatment time (10 min), negatively impacted acid production. The likely causes of this observation are attributed to the production of recalcitrant complexes and toxic compounds. Batch fermentation of untreated sludge yielded 0.34 g total acids/g VS fed, whereas sludge with 240-min lime pretreatment yielded only 0.20 g total acids/g VS fed. Co-fermentation of untreated sludge with pretreated bagasse gave a yield of 0.23 g total acids/g VS fed.

  6. Report on the Oak Ridge sewage sludge land-farming experience. Part 1. Data presentation

    SciTech Connect

    Oakes, T.W.; Braunstein, H.M.; Daniels, K.L.; Ohnesorge, W.F.; Kitchings, J.T.; Alexander, W.A.

    1984-08-01

    Disposal of sludge from the City of Oak Ridge's sewage treatment facility on a 65-acre site on the Department of Energy's Oak Ridge Reservation was initiated in November 1983. On March 22, 1984, DOE and the City determined that the sludge contained radioactive materials. Application of sludge on the Reservation was suspended on March 25 and a comprehensive survey and sampling plan was instituted to radiologically characterize the disposal site. By April 1, a radiation walkover survey had been completed on the site and samples of air, water, and soil had been collected to be analyzed for the presence of radionuclides. The mean air dose rate, one meter above the ground surface, was found to be 13 ..mu..R/h with a range from about 8 ..mu..R/h, which is the usual background level in the area, to 21 ..mu..R/h. Concentrations of Cs-137 and Co-60, the principle contaminants in the soil, were essentially below the analytical detection limits in the air and water. About 350 soil samples were collected by extracting cores to a depth of 12 to 15 inches according to a systematic random sampling design. Each core was separated into three sections; the top 3 inches, a middle section, and the bottom 3 inches to represent layers on the site. The majority of the radioactivity was determined to be in the upper 3 inches of soil. A statistical treatment of the analytical results provided an estimate of the total activity at the site, the vertical distribution of the gamma activity, and the areal distribution of the primary radionuclides. A total of 170 mCi of activity was estimated as present in the top 3-inch layer of the 65-acre site, 69% of which was contributed by Co-60 and Cs-137, 23% by U-234 and Sr-90, and 8% by other minor radionuclides. 4 references, 12 figures, 43 tables.

  7. Phosphate recovery from sewage sludge in combination with supercritical water oxidation.

    PubMed

    Stendahl, K; Jäfverström, S

    2003-01-01

    Supercritical Water Oxidation (SCWO) is an innovative and effective destruction method for organics in sewage sludge. The SCWO process leaves a slurry of inorganic ash in a pure water phase free from organic contaminants, which opens possibilities for a simple process to recover components like phosphates from the sewage sludge. In a continuous pilot plant for the SCWO process digested sludge has been treated. The ash has been extracted in lab scale with both caustic and acids in order to recover phosphates. By leaching the ash with caustic, 90% of the phosphorus could be separated as a sodium phosphate solution. By treating the sodium phosphate solution with lime, calcium phosphate was precipitated and caustic recovered and circulated back to the leaching process.

  8. Conditioning of sewage sludge by Fenton's reagent combined with skeleton builders.

    PubMed

    Liu, Huan; Yang, Jiakuan; Shi, Yafei; Li, Ye; He, Shu; Yang, Changzhu; Yao, Hong

    2012-06-01

    Physical conditioners, often known as skeleton builders, are commonly used to improve the dewaterability of sewage sludge. This study evaluated a novel joint usage of Fenton's reagent and skeleton builders, referred to as the F-S inorganic composite conditioner, focusing on their efficacies and the optimization of the major operational parameters. The results demonstrate that the F-S composite conditioner for conditioning sewage sludge is a viable alternative to conventional organic polymers, especially when ordinary Portland cement (OPC) and lime are used as the skeleton builders. Experimental investigations confirmed that Fenton reaction required sufficient time (80 min in this study) to degrade organics in the sludge. The optimal condition of this process was at pH=5, Fe(2+)=40 mg g(-1) (dry solids), H(2)O(2)=32 mg g(-1), OPC=300 mg g(-1) and lime=400 mg g(-1), in which the specific resistance to filtration reduction efficiency of 95% was achieved.

  9. Enhanced power generation and energy conversion of sewage sludge by CEA-microbial fuel cells.

    PubMed

    Abourached, Carole; Lesnik, Keaton Larson; Liu, Hong

    2014-08-01

    The production of methane from sewage sludge through the use of anaerobic digestion has been able to effectively offset energy costs for wastewater treatment. However, significant energy reserves are left unrecovered and effluent standards are not met necessitating secondary processes such as aeration. In the current study a novel cloth-electrode assembly microbial fuel cell (CEA-MFC) was used to generate electricity from sewage sludge. Fermentation pretreatment of the sludge effectively increased the COD of the supernatant and improved reactor performance. Using the CEA-MFC design, a maximum power density of 1200 mW m(-2) was reached after a fermentation pre-treatment time of 96 h. This power density represents a 275% increase over those previously observed in MFC systems. Results indicate continued improvements are possible and MFCs may be a viable modification to existing wastewater treatment infrastructure.

  10. Experimental evaluation of drying characteristics of sewage sludge and hazelnut shell mixtures

    NASA Astrophysics Data System (ADS)

    Pehlivan, Hüseyin; Ateş, Asude; Özdemir, Mustafa

    2016-11-01

    In this study the drying behavior of organic and agricultural waste mixtures has been experimentally investigated. The usability of sewage sludge as an organic waste and hazelnut shell as an agricultural waste was assessed in different mixture range. The paper discusses the applicability of these mixtures as a recovery energy source. Moisture content of mixtures has been calculated in laboratory and plant conditions. Indoor and outdoor solar sludge drying plants were constructed in pilot scale for experimental purposes. Dry solids and climatic conditions were constantly measured. A total more than 140 samples including for drying has been carried out to build up results. Indoor and outdoor weather conditions are taken into consideration in winter and summer. The most effective drying capacity is obtained in mixture of 20 % hazelnut shell and 80 % sewage sludge.

  11. Effect of sewage sludge on mobilization of surface-applied calcium in a Greenville soil

    SciTech Connect

    Tan, K.H.; Edwards, J.H.; Bennett, O.L.

    1985-03-01

    The effect of sewage sludge on movement of surface-applied Ca was determined with controlled leaching studies in the laboratory. Soil columns were prepared by filling 5.5- by 30-cm PVC plastic tubes with samples of the Ap horizon of a Greenville soil (clayey, kaolinitic, thermic Rhodic Paleudult). These were affixed to the 5.5- by 30-cm tubes filled with Bt1 horizon samples, so that the total column was 60 cm long. The soil columns, receiving various lime and sewage sludge treatments were leached with distilled water and analyzed for K, Ca, Mg, Al, Fe, Zn, and Cd concentrations. After leaching, the soil columns were sectioned into four 15-cm layers for determination of pH and the above elements. Although amounts equivalent to 4.5 metric tons (t) CaCO/sub 3/ and 112 t sewage sludge per ha were applied, no differences were detected in Ca contents of the leachates from soils with or without sewage sludge. Very low levels of K and Mg and negligible amounts of Al, Fe, Zn, and Cd were also found in the leachates, indicating minor leaching losses of these elements. The present result compared favorably with results of long-term experiments, indicating that significant Ca translocation can also be achieved in a shorter term even though most of the Ca was retained in the surface sections of the soil columns. Calcium movement into the subsoil increased soil pH. Infrared analysis indicated that mobilization of Ca was facilitated by formation of Ca-chelates, formed by the interaction of lime and fulvic acid produced by sewage sludge.

  12. Study on trace metal partitioning in pulverized combustion of bituminous coal and dry sewage sludge

    SciTech Connect

    Cenni, R.; Gerhardt, T.; Spliethoff, H.; Hein, K.R.G.; Frandsen, F.

    1998-12-31

    In Germany, the feasibility of co-combustion of sewage sludge in power plants is under evaluation. A study of the influence of co-firing of dry municipal sewage sludge on the behavior of the metals Cr, Hg, Mn, Ni, Pb, zn during pulverized coal combustion is presented. Sewage sludge contains higher concentrations of the metals listed above than the reference coal, but a lower concentration of Cl, that enhances the volatility of many metals. Experiments were performed in a semi-industrial scale pulverized fuel combustion chamber. Ash was collected at four locations: bottom hopper, air preheater, cyclone, and bag filter. From the bottom hopper to the filter, the particle size decreased and ash particles were progressively enriched in volatile elements. Mass balances of the metals were performed and the enrichment trends on the ash collected at the different locations were calculated. Increasing the sewage sludge share in the blend caused a significant increase in the recovery rate in the solid phase. In spite of that, the calculated concentrations in the flue gas of Hg and zn increased. Sewage sludge co-firing influences the combustion process and the post-combustion environment in many ways. This study focuses on the effect of the different flue gas composition on the condensation temperature of metal species. The system was modeled by assuming thermodynamic equilibrium. The results indicated that the increasing recovery of Zn might be caused by enhanced condensation and the increasing recovery of Hg by adsorption on ash particles. The increasing recovery of the other metals seemed referable to failure in vaporization and it cannot be studied with an equilibrium approach.

  13. Odor composition analysis and odor indicator selection during sewage sludge composting

    PubMed Central

    Zhu, Yan-li; Zheng, Guo-di; Gao, Ding; Chen, Tong-bin; Wu, Fang-kun; Niu, Ming-jie; Zou, Ke-hua

    2016-01-01

    ABSTRACT On the basis of total temperature increase, normal dehydration, and maturity, the odor compositions of surface and internal piles in a well-run sewage sludge compost plant were analyzed using gas chromatography–mass spectrometry with a liquid nitrogen cooling system and a portable odor detector. Approximately 80 types of substances were detected, including 2 volatile inorganic compounds, 4 sulfur organic compounds, 16 benzenes, 27 alkanes, 15 alkenes, and 19 halogenated compounds. Most pollutants were mainly produced in the mesophilic and pre-thermophilic periods. The sulfur volatile organic compounds contributed significantly to odor and should be controlled primarily. Treatment strategies should be based on the properties of sulfur organic compounds. Hydrogen sulfide, methyl mercaptan, dimethyl disulfide, dimethyl sulfide, ammonia, and carbon disulfide were selected as core indicators. Ammonia, hydrogen sulfide, carbon disulfide, dimethyl disulfide, methyl mercaptan, dimethylbenzene, phenylpropane, and isopentane were designated as concentration indicators. Benzene, m-xylene, p-xylene, dimethylbenzene, dichloromethane, toluene, chlorobenzene, trichloromethane, carbon tetrachloride, and ethylbenzene were selected as health indicators. According to the principle of odor pollution indicator selection, dimethyl disulfide was selected as an odor pollution indicator of sewage sludge composting. Monitoring dimethyl disulfide provides a highly scientific method for modeling and evaluating odor pollution from sewage sludge composting facilities. Implications: Composting is one of the most important methods for sewage sludge treatment and improving the low organic matter content of many agricultural soils. However, odors are inevitably produced during the composting process. Understanding the production and emission patterns of odors is important for odor control and treatment. Core indicators, concentration indicators, and health indicators provide an index

  14. Sewage sludge and liquid pig manure as possible sources of antibiotic resistant bacteria.

    PubMed

    Hölzel, Christina S; Schwaiger, Karin; Harms, Katrin; Küchenhoff, Helmut; Kunz, Anne; Meyer, Karsten; Müller, Christa; Bauer, Johann

    2010-05-01

    Within the last decades, the environmental spread of antibiotic resistant bacteria has become a topic of concern. In this study, liquid pig manure (n=305) and sewage sludge (n=111) - used as agricultural fertilizers between 2002 and 2005 - were investigated for the presence of Escherichia coli, Enterococcus faecalis and Enterococcus faecium. Bacteria were tested for their resistance against 40 chemotherapeutics including several "reserve drugs". E. coli (n=613) from pig manure were at a significantly higher degree resistant to streptomycin, doxycycline, spectinomycin, cotrimoxazole, and chloramphenicol than E. coli (n=116) from sewage sludge. Enterococci (Ent. faecalis, n=387, and Ent. faecium, n=183) from pig manure were significantly more often resistant to high levels of doxycycline, rifampicin, erythromycin, and streptomycin than Ent. faecalis (n=44) and Ent. faecium (n=125) from sewage sludge. Significant differences in enterococcal resistance were also seen for tylosin, chloramphenicol, gentamicin high level, fosfomycin, clindamicin, enrofloxacin, moxifloxacin, nitrofurantoin, and quinupristin/dalfopristin. By contrast, aminopenicillins were more effective in enterococci from pig manure, and mean MIC-values of piperacillin+tazobactam and third generation cefalosporines were significantly lower in E. coli from pig manure than in E. coli from sewage sludge. 13.4% (E. coli) to 25.3% (Ent. faecium) of pig manure isolates were high-level multiresistant to substances from more than three different classes of antimicrobial agents. In sewage sludge, high-level-multiresistance reached from 0% (Ent. faecalis) to 16% (Ent. faecium). High rates of (multi-) resistant bacteria in pig manure emphasize the need for a prudent - cautious - use of antibiotics in farm animals.

  15. Effect of pyrolysis temperature on chemical and physical properties of sewage sludge biochar.

    PubMed

    Khanmohammadi, Zahra; Afyuni, Majid; Mosaddeghi, Mohammad Reza

    2015-03-01

    The objective of this study was to evaluate the effects of pyrolysis temperatures (300, 400, 500, 600 and 700°C) on properties of biochar produced from an urban sewage sludge. Biochar yield significantly decreased from 72.5% at 300°C to 52.9% at 700°C, whereas an increase in temperature increased the gas yield. Biochar pH and electrical conductivity increased by 3.8 and 1.4 dS m⁻¹, proportionally to the increment of temperature. Biochar produced at low temperatures had higher total nitrogen and total organic carbon content but a lower C/N ratio, calcium carbonate equivalent, and total P, K and Na contents. Total and diethylene triamine penta acetic acid (DTPA)-extractable concentrations of Fe, Zn, Cu, Mn, Ni, Cr and Pb increased with increment of temperature. Lower DTPA-extractable concentrations of Fe, Zn, Cu, Mn, Ni and Pb were found in biochars compared to the sewage sludge. Pyrolysis decreased bulk density, whereas particle density and porosity increment was observed upon pyrolysis with increment of temperature. Sewage sludge saturated water content (θs ) was 130.4 g 100g⁻¹ and significantly greater than biochar, but biochar θs significantly increased with temperature (95.7 versus 105.4 g 100g⁻¹ at 300 and 700°C, respectively). Pyrolysis decreased the biochar's water repellency, assessed by molarity of ethanol droplet (MED), compared to the sewage sludge. The lowest MED of 0.2 and water repellency rating of 3 were found for the biochar produced at 700°C. Based on our results and considering the energy consumption, pyrolysis temperature in the range of 300-400°C may be suggested for sewage sludge pyrolysis.

  16. Changes of polycyclic aromatic hydrocarbons during composting of sewage sludges with chosen physico-chemical properties and PAHs content.

    PubMed

    Oleszczuk, Patryk

    2007-03-01

    The aim of the experiment was to determine changes in the PAH content during sewage sludge composting. The extent was evaluated to which sewage sludge properties influences on PAHs losses during composting. Five municipal sewage sludges were studied from sewage treatment plants located in the south-east of Poland, i.e. in Stalowa Wola, Kraśnik, Lublin, Zamość and Biłgoraj. The treatment plants selected were characterised by their differentiation with catchments area as well as the industrial character of the areas. Sludge composting was carried out in aerobic conditions in plastic containers for a period of 76 days. The content of 14 polycyclic aromatic hydrocarbons (PAHs) and some physical-chemical (TOC, Nt, TOC/Nt, CEC, BS, TEB, pH, available potassium and phosphorus, total forms of cations) sewage sludge properties were monitored. In the present study correlations between PAHs losses (during various phases of composting) and physical-chemical properties of sewage sludges and composts were also evaluated. The sewage sludges were characterised both by differentiated properties and by PAH content. The total PAH content (the sum of 14 PAHs from the EPA List with exception of naphthalene and acenaphthene) in the sludges ranged from 3674 to 11236 microg kg(-1). Four- and three-ring compounds were predominant in the sewage sludges. Almost all of the sludges were characterised by differentiated content levels of both individual PAHs groups and PAHs sum. After 76 days of composting, a significant lowering of the PAH content was observed in all sludges as compared to the beginning of the experiment. The range of total observed PAH losses was from 15.8% to 48.6%, depending on the sewage sludge. The largest lowering of the PAH content was observed in the sludge with the lowest concentration of the xenobiotics studied. The largest losses in individual PAHs were observed in the case of five- and six-rings compounds, and were probably related to strong pollutant binding by

  17. Changes in soil microbial functional diversity and biochemical characteristics of tree peony with amendment of sewage sludge compost.

    PubMed

    Huang, Xiangdong; Xue, Dong; Xue, Lian

    2015-08-01

    A greenhouse experiment was conducted to investigate the impact of sewage sludge compost application on functional diversity of soil microbial communities, based on carbon source utilization, and biochemical characteristics of tree peony (Paeonia suffruticosa). Functional diversity was estimated with incubations in Biolog EcoPlates and well color development was used as the functional trait for carbon source utilization. The average well color development and Shannon index based on the carbon source utilization pattern in Biolog EcoPlates significantly increased with the increasing sludge compost application in the range of 0-45%, with a decreasing trend above 45%. Principal component analysis of carbon source utilization pattern showed that sludge compost application stimulated the utilization rate of D-cellobiose and α-D-lactose, while the utilization rate of β-methyl-D-glucoside, L-asparagine, L-serine, α-cyclodextrin, γ-hydroxybutyric acid, and itaconic acid gradually increased up to a sludge compost amendment dosage of 45% and then decreased above 45%. The chlorophyll content, antioxidase (superoxide dismutase, catalase, and peroxidase) activities, plant height, flower diameter, and flower numbers per plant of tree peony increased significantly with sludge compost dosage, reaching a peak value at 45 %, and then decreased with the exception that activity of superoxide dismutase and catalase did not vary significantly.

  18. Supported noble metal catalysts in the catalytic wet air oxidation of industrial wastewaters and sewage sludges.

    PubMed

    Besson, M; Descorme, C; Bernardi, M; Gallezot, P; di Gregorio, F; Grosjean, N; Minh, D Pham; Pintar, A

    2010-12-01

    This paper reviews some catalytic wet air oxidation (CWAO) investigations of industrial wastewaters over platinum and ruthenium catalysts supported on TiO2 and ZrO2 formulated to be active and resistant to leaching, with particular focus on the stability of the catalyst. Catalyst recycling experiments were performed in batch reactors and long-term stability tests were conducted in trickle-bed reactors. The catalyst did not leach upon treatment of Kraft bleaching plant and olive oil mill effluents, and could be either recycled or used for long periods of time in continuous reactors. Conversely, these catalysts were rapidly leached when used to treat effluents from the production of polymeric membranes containing N,N-dimethylformamide. The intermediate formation of amines, such as dimethylamine and methylamine with a high complexing capacity for the metal, was shown to be responsible for the metal leaching. These heterogeneous catalysts also deactivated upon CWAO of sewage sludges due to the adsorption of the solid organic matter. Pre-sonication of the sludge to disintegrate the flocs and improve solubility was inefficient.

  19. Advanced solid-state carbon-13 nuclear magnetic resonance spectroscopic studies of sewage sludge organic matter: detection of organic "domains".

    PubMed

    Smernik, Ronald J; Oliver, Ian W; Merrington, Graham

    2003-01-01

    Two novel solid-state 13C nuclear magnetic resonance (NMR) spectroscopic techniques, PSRE (proton spin relaxation editing) and RESTORE [Restoration of Spectra via T(CH) and T(1rho)H (T One Rho H) Editing], were used to provide detailed chemical characterization of the organic matter from six Australian sewage sludges. These methods were used to probe the submicrometer heterogeneity of sludge organic matter, and identify and quantify spatially distinct components. Analysis of the T1H relaxation behavior of the sludges indicated that each sludge contained two types of organic domains. Carbon-13 PSRE NMR subspectra were generated to determine the chemical nature of these domains. The rapidly relaxing component of each sludge was rich in protein and alkyl carbon, and was identified as dead bacterial material. The slowly relaxing component of each sludge was rich in carbohydrate and lignin structures, and was identified as partly degraded plant material. The bacterial domains were shown, using the RESTORE technique, to also have characteristically rapid T(1rho)H relaxation rates. This rapid T(1rho)H relaxation was identified as the main cause of underrepresentation of these domains in standard 13C cross polarization (CP) NMR spectra of sludges. The heterogeneous nature of sewage sludge organic matter has implications for land application of sewage sludge, since the two components are likely to have different capacities for sorbing organic and inorganic toxicants present in sewage sludge, and will decompose at different rates.

  20. Polychlorinated naphthalenes in sewage sludge from wastewater treatment plants in China.

    PubMed

    Zhang, Haiyan; Xiao, Ke; Liu, Jiyan; Wang, Thanh; Liu, Guorui; Wang, Yawei; Jiang, Guibin

    2014-08-15

    Polychlorinated naphthalenes (PCNs) were nominated as persistent organic pollutants candidate in the Stockholm Convention in 2011. In this study, the profiles, concentrations and spatial distributions of PCNs were analyzed in 30 sewage sludge samples from wastewater treatment plants (WWTPs) in China. Concentrations of Σ75PCNs in sludge samples were in the range of 1.05-10.9 ng/g dry weight (dw) with a mean value of 3.98 ng/g dw. The predominant homologues in the sludge were mono- to tetra-CNs, accounting for approximately 85% of total PCNs. The total toxic equivalent quantities (TEQs) of dioxin-like PCN congeners ranged from 0.04 to 2.28 pg/g dw with a mean value of 0.36 pg/g dw, which were lower than the maximum permissible TEQ concentrations in sludge for land application in China. Levels of PCNs and TEQs in sludge were relatively higher in samples from highly industrialized and developed cities in eastern China, implying a possible link between PCN contamination and the local economic development, but more studies are warranted to corroborate this. Industrial sources might be important contributors of PCNs to sewage sludge in China.

  1. Co-cropping for phyto-separation of zinc and potassium from sewage sludge.

    PubMed

    Wu, Qi-Tang; Hei, Liang; Wong, J W C; Schwartz, Christophe; Morel, Jean-Louis

    2007-08-01

    The use of sewage sludge as a fertilizer and soil amendment has resulted in high concentrations of heavy metals in the soil limiting its use. The present study was carried out to find the possibility of phyto-separating toxic and beneficial elements from the sludge using suitable plants. Of the five plants tested the hyperaccumulator Sedum alfredii H achieved the greatest removal of Zn, while shoots of Alocasia marorrhiza accumulated high content of K. Co-cropping these two plants on the sludge verified the previous observations on A. marorrhiza and the shoots of this plant could accumulate more than 120 g K kg(-1) dry matter in the median growth stage. Zn hyperaccumulated in Sedum's shoots to an extent more than 10 g kg(-1) dry matter; K concentrated five to ten times in the Alocasia's shoots which could be used as a good organic-K-fertilizer. Hence, the two elements were simultaneously phytoseparated and could be recycled. Furthermore, cultivation of plants in the sludge resulted in significant decreases in total Zn but kept the favorable agronomic characteristics of the sludge material, such as pH, organic matter content, and NPK concentrations and ameliorated its biological stability. These results suggest that simultaneous phyto-separation of toxic and beneficial elements from sewage sludge are possible by co-cropping using specific plants without the input of any chemicals.

  2. Enhancing sewage sludge dewaterability by bioleaching approach with comparison to other physical and chemical conditioning methods.

    PubMed

    Liu, Fenwu; Zhou, Jun; Wang, Dianzhan; Zhou, Lixiang

    2012-01-01

    The sewage sludge conditioning process is critical to improve the sludge dewaterability prior to mechanical dewatering. Traditionally, sludge is conditioned by physical or chemical approaches, mostly with the addition of inorganic or organic chemicals. Here we report that bioleaching, an efficient and economical microbial method for the removal of sludge-borne heavy metals, also plays a significant role in enhancing sludge dewaterability. The effects of bioleaching and physical or chemical approaches on sludge dewaterability were compared. The conditioning result of bioleaching by Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans on sludge dewatering was investigated and compared with the effects of hydrothermal (121 degrees C for 2 hr), microwave (1050 W for 50 sec), ultrasonic (250 W for 2 min), and chemical conditioning (24% ferric chloride and 68% calcium oxide; dry basis). The results show that the specific resistance to filtration (SRF) or capillary suction time (CST) of sludge is decreased by 93.1% or 74.1%, respectively, after fresh sludge is conditioned by bioleaching, which is similar to chemical conditioning treatment with ferric chloride and calcium oxide but much more effective than other conditioning approaches including hydrothermal, microwave, and ultrasonic conditioning. Furthermore, after sludge dewatering, bioleached sludge filtrate contains the lowest concentrations of chroma (18 times), COD (542 mg/L), total N (TN, 300 mg/L), NH4(+)-N (208 mg/L), and total P (TP, 2 mg/L) while the hydrothermal process resulted in the highest concentration of chroma (660 times), COD (18,155 mg/L), TN (472 mg/L), NH4(+)-N (381 mg/L), and TP (191 mg/L) among these selected conditioning methods. Moreover, unlike chemical conditioning, sludge bioleaching does not result in a significant reduction of organic matter, TN, and TP in the resulting dewatered sludge cake. Therefore, considering sludge dewaterability and the chemical properties of sludge

  3. Emission characteristics of dioxins, furans and polycyclic aromatic hydrocarbons during fluidized-bed combustion of sewage sludge.

    PubMed

    Deng, Wenyi; Yan, Jianhua; Li, Xiaodong; Wang, Fei; Chi, Yong; Lu, Shengyong

    2009-01-01

    Pre-dried sewage sludge with high sulfur content was combusted in an electrically heated lab-scale fluidized-bed incinerator. The emission characteristics of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polycyclic aromatic hydrocarbons (PAHs) were studied. Coal and calcium oxide (CaO) were added during the sewage sludge combustion tests to optimize combustion conditions and control SO2 emission. The results indicated that the flue gases emitted during mono-combustion of sewage sludge were characterized by relatively high concentrations of SO2, NOx and organic pollutants, due to the high sulfur, nitrogen, and volatile matter content of sewage sludge. The total 16 USEPA priority PAHs and 2,3,7,8-substituted PCDD/Fs produced from sewage sludge combustion were found to be 106.14 microg/m3 and 8955.93 pg/m3 in the flue gas, respectively. In the case of co-combustion with coal (m(sludge)/m(coal) = 1:1), the 16 PAHs and 2,3,7,8-substituted PCDD/Fs concentrations were markedly lower than those found during mono-combustion of sewage sludge. During co-combustion, a suppressant effect of CaO on PCDD/Fs formation was observed.

  4. Effect of energy grass on methane production and heavy metal fractionation during anaerobic digestion of sewage sludge.

    PubMed

    Zhang, Min; Yang, Changming; Jing, Yachao; Li, Jianhua

    2016-12-01

    Anaerobic digestion (AD) is one of the most widely used processes to stabilize waste sewage sludge and produce biogas as renewable energy. The relatively low organic matter content and high heavy metal concentrations in sewage sludge have severely restricted the application and development of AD technology in China. In this study, the effect of energy grass (Pennisetum alopecuroides) addition on methane production and heavy metal fractionation during the AD of sewage sludge was evaluated. Methane production was enhanced by 11.2% by the addition of P. alopecuroides. The addition of P. alopecuroides significantly reduced the percentages of the water-soluble and exchangeable fractions of the target heavy metals in the sewage sludge after AD, and the dominant species were concentrated in Fe-Mn oxide-bound and organic- and sulfide-bound fractions of the digested sludge. The addition of P. alopecuroides at a dosage of 0.3kg significantly (P<0.05) decreased the mobility factors (MFs) of the target heavy metals after AD. In particular, the MFs of Cr and Ni were 61% and 32% lower, respectively, relative to the control. The increase in the added dose did not necessarily lead to further decreases in the MFs of the heavy metals. These results demonstrate that an appropriate addition of energy grass could enhance AD, decrease the mobility of heavy metals and promote heavy metal stabilization in sewage sludge during AD, which is beneficial for the subsequent land application of sewage sludge.

  5. Effects of calcined aluminum salts on the advanced dewatering and solidification/stabilization of sewage sludge.

    PubMed

    Zhen, Guangyin; Yan, Xiaofei; Zhou, Haiyan; Chen, Hua; Zhao, Tiantao; Zhao, Youcai

    2011-01-01

    The high moisture content (80%) in the sewage dewatered sludge is the main obstacle to disposal and recycling. A chemical dewatering and stabilization/solidification (S/S) alternative for the sludge was developed, using calcined aluminum salts (AS) as solidifier, and CaCl2, Na2SO4 and CaSO4 as accelerators, to enhance the mechanical compressibility making the landfill operation possible. The properties of the resultant matrixes were determined in terms of moisture contents, unconfined compressive strength, products of hydration, and toxicity characteristics. The results showed that AS exhibited a moderate pozzolanic activity, and the mortar AS(0) obtained with 5% AS and 10% CaSO4 of AS by weight presented a moisture contents below 50%-60% and a compressive strength of (51.32 +/- 2.9) kPa after 5-7 days of curing time, meeting the minimum requirement for sanitary landfill. The use of CaSO4 obviously improved the S/S performance, causing higher strength level. X-ray diffraction, scanning electron microscopy and thermogravimetry-differential scanning calorimetry investigations revealed that a large amount of hydrates (viz., gismondine and CaCO3) were present in solidified sludge, leading to the depletion of evaporable water and the enhancement of the strength. In addition, the toxicity characteristic leaching procedure (TCLP) and horizontal vibration (HJ 557-2009) leaching test were conducted to evaluate their environmental compatibility. It was found that the solidified products conformed to the toxicity characteristic criteria in China and could be safely disposed of in a sanitary landfill.

  6. Anaerobic treatability of liquid residue from wet oxidation of sewage sludge.

    PubMed

    Bertanza, Giorgio; Galessi, Raniero; Menoni, Laura; Pedrazzani, Roberta; Salvetti, Roberta; Zanaboni, Sabrina

    2015-05-01

    Wet Oxidation (WO) of sewage sludge is a chemical oxidation of sludge at high temperatures and pressures by means of an oxygen-containing gas. The liquid stream originated by WO is easily biodegradable, and therefore, the recirculation to the biological Waste Water Treatment Plant (WWTP) may be a feasible solution. However, the WO effluent has a residual organic and nitrogen content so that its treatment may be required when the receiving WWTP has no surplus treatment capacity left. The aim of this research was the assessment of the anaerobic treatability of the WO liquid residue, in order to reduce the organic load to be recirculated to the WWTP, simultaneously promoting energy recovery. For this purpose, the liquid residue obtained during full scale WO tests on two different types of sludge was submitted to anaerobic digestion in a continuous flow pilot reactor (V = 5 L). Furthermore, batch tests were carried out in order to evaluate possible inhibition factors. Experimental results showed that, after the start-up/acclimation period (~130 days), Chemical Oxygen Demand (COD) removal efficiency was stably around 60% for about 120 days, despite the change in operating conditions. In the last phase of the experimental activity, COD removal reached 70% under the following treatment conditions: Hydraulic Retention Time (HRT) = 20 days, Volumetric Organic Loading Rate (VOLR) = 0.868 kg COD/m(3)/day, Organic Loading Rate per Volatile Suspended Solids (OLRvss) = 0.078 kg COD/kg VSS/day, temperature (T) = 36.5 °C, pH = 8. Energy balance calculation demonstrated anaerobic treatment sustainability.

  7. Survival of Bacterial Indicator Species and Bacteriophages after Thermal Treatment of Sludge and Sewage

    PubMed Central

    Mocé-Llivina, Laura; Muniesa, Maite; Pimenta-Vale, Hugo; Lucena, Francisco; Jofre, Juan

    2003-01-01

    The inactivation of naturally occurring bacterial indicators and bacteriophages by thermal treatment of a dewatered sludge and raw sewage was studied. The sludge was heated at 80°C, and the sewage was heated at 60°C. In both cases phages were significantly more resistant to thermal inactivation than bacterial indicators, with the exception of spores of sulfite-reducing clostridia. Somatic coliphages and phages infecting Bacteroides fragilis were significantly more resistant than F-specific RNA phages. Similar trends were observed in sludge and sewage. The effects of thermal treatment on various phages belonging to the three groups mentioned above and on various enteroviruses added to sewage were also studied. The results revealed that the variability in the resistance of phages agreed with the data obtained with the naturally occurring populations and that the phages that were studied were more resistant to heat treatment than the enteroviruses that were studied. The phages survived significantly better than Salmonella choleraesuis, and the extents of inactivation indicated that naturally occurring bacteriophages can be used to monitor the inactivation of Escherichia coli and Salmonella. PMID:12620828

  8. Disinfection of municipal sewage sludges in installation equipped with electron accelerator

    NASA Astrophysics Data System (ADS)

    Chmielewski, A. G.; Zimek, Z.; Bryl-Sandelewska, T.; Kosmal, W.; Kalisz, L.; Kaźmierczuk, M.

    1995-09-01

    Growing awareness of environment pollution hazards causes more and more stringent waste disposal regulations in many countries which stimulate searching for new methods of waste disposal, the best of which is recycling them after suitable treatment. Sludges from municipal sewage treatment plants contain organic and inorganic components valuable as soil fertilizer, so if disinfected they can be beneficially recycled in agriculture instead of being burdensome waste. Investigations performed in many countries showed that irradiation with a suitable dose of gamma or electron beam radiation makes sewage sludges sanitary safe and usable as soil fertilizer immediately after treatment. This paper describes some results of investigations performed in the Institute of Nuclear Chemistry and Technology and the Institute of Environmental Protection in Warsaw on the influence of 10 MeV electron beam on bacteria, parasites and parasite eggs present in sewage sludges from different municipal sewage treatment plants in Poland. Basic design parameters of the industrial installation elaborated on the basis of those experiments are presented, too.

  9. The effect of composting on the organic colloidal fraction from domestic sewage sludge

    NASA Astrophysics Data System (ADS)

    Almendros, Gonzalo; Leal, Juan A.; Martin, Francisco; Gonzalez-Vila, Francisco J.

    Due to the frequent use of domestic sewage sludges as organic additives to soils with low humus content, the chemical characteristics of the extractable polymers from composted and uncomposted sludges were described. The alkali-soluble, acid-insoluble sludge fraction (humic-like) was isolated after exhaustive lipid extraction, and analyzed by chemical degradation followed by combined gas chromatography mass spectrometry. It was observed that this sludge fraction contained an important amount of lipid compounds (more than 40% by weight). Most of this lipid material can be physically removed, but the residual polymer fractions were also found to be highly aliphatic in nature. The high yields upon degradation of several types of alkanoic acids and the relatively high proportion of polypeptides (30% by weight), as well as carbohydrates, suggested that the humic-like fractions from both the composted and uncomposted sludges consisted of slightly altered microbial and residual biopolymers. The effects of composting sludge mainly concern the selective biodegradation of the less resistant moieties. The great differences between the chemical nature of the humic-like fraction of the composted sludge and that of the soil humic acids are considered to reflect the low proportion of lignified materials in the original sludge.

  10. Preference of the green peach aphid, Myzus persicae, for plants grown in sewage sludges

    SciTech Connect

    Culliney, T.W.; Pimentel, D.

    1987-08-01

    Since passage of the Clean Water Act in the 1970s, disposal of the millions of tonnes of sewage sludge generated annually has become a major concern of municipalities throughout the United States. With the range of other disposal options having narrowed in recent years, application of sludge to land is increasingly viewed as a practical and economical means to recycle this waste material. However, sludges from large cities with industries may be contaminated with various toxic chemicals, including polychlorinated biphenyls (PCBs), other organic chemicals, such as pesticides, and heavy metals. Sludge application to land thus has the potential adversely to affect biota and the functioning of terrestrial ecosystems. The authors previously demonstrated marked reductions in fecundity and survival of green peach aphids, Myzus persicae, on collard plants, Brassica oleracea var. sabellica, growing in soil treated with chemically contaminated sludge as compared to aphids on plants growing either in soil treated with uncontaminated sludge of soil conventionally fertilized. Reduced plant growth and increased restlessness in aphids in the contaminated sludge treatment were also observed. The purpose of the present study was to examine more closely the influence of sludge contaminants on aphid settling behavior as indicated by differential preference of M. persicae for leaves of its collard host grown under different soil conditions.

  11. Thermal conductivity characteristics of dewatered sewage sludge by thermal hydrolysis reaction.

    PubMed

    Song, Hyoung Woon; Park, Keum Joo; Han, Seong Kuk; Jung, Hee Suk

    2014-12-01

    The purpose of this study is to quantify the thermal conductivity of sewage sludge related to reaction temperature for the optimal design of a thermal hydrolysis reactor. We continuously quantified the thermal conductivity of dewatered sludge related to the reaction temperature. As the reaction temperature increased, the dewatered sludge is thermally liquefied under high temperature and pressure by the thermal hydrolysis reaction. Therefore, the bound water in the sludge cells comes out as free water, which changes the dewatered sludge from a solid phase to slurry in a liquid phase. As a result, the thermal conductivity of the sludge was more than 2.64 times lower than that of the water at 20. However, above 200, it became 0.704 W/m* degrees C, which is about 4% higher than that of water. As a result, the change in physical properties due to thermal hydrolysis appears to be an important factor for heat transfer efficiency. Implications: The thermal conductivity of dewatered sludge is an important factor the optimal design of a thermal hydrolysis reactor. The dewatered sludge is thermally liquefied under high temperature and pressure by the thermal hydrolysis reaction. The liquid phase slurry has a higher thermal conductivity than pure water.

  12. Relationship between pollutant content and ecotoxicity of sewage sludges from Spanish wastewater treatment plants.

    PubMed

    Roig, Neus; Sierra, Jordi; Nadal, Martí; Martí, Esther; Navalón-Madrigal, Pedro; Schuhmacher, Marta; Domingo, José L

    2012-05-15

    Chemical and ecotoxicological properties of 28 sewage sludge samples from Spanish wastewater treatment plants were studied in order to assess their suitability for agricultural purposes. Sludge samples were classified into five categories according to specific treatment processes in terms of digestion (aerobic/anaerobic) and drying (mechanical/thermal). Composted samples, as indicative of the most refined process, were also considered. Sludges were subjected to physical-chemical characterization, being the sludge stabilization degree respirometrically assessed. The concentrations of seven metals (Cd, Cr, Cu, Pb, Zn, Ni, Hg) and organic substances (phenolic compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polychlorinated naphthalenes, polybrominated diphenyl ethers, and perfluorinated compounds) were determined. Finally, two ecotoxicological tests were performed: i) Microtox® toxicity test with Vibrio fischeri, and ii) root elongation test with Allium cepa, Lolium perenne and Raphanus sativus seeds. Significant differences were found in the following parameters: dry matter, electrical conductivity, nitrogen, organic matter and its stability, phytotoxicity and ecotoxicity, depending on the sludge treatment. In turn, no significant differences were found between categories in the concentrations of most metals and organic pollutants, with the exception of free phenolic compounds. Furthermore, no correlation between total heavy metal burden and ecotoxicity was observed. However, a good correlation was found between phenolic compounds and most ecotoxicological tests. These results suggest that sludge stability (conditioned by sludge treatment) might have a greater influence on sludge ecotoxicity than the pollutant load. Composting was identified as the treatment resulting in the lowest toxicity.

  13. Emission of polycyclic aromatic hydrocarbons from coal and sewage sludge co-combustion in a drop tube furnace.

    PubMed

    Han, Jun; Qin, Linbo; Ye, Wei; Li, Yuqi; Liu, Long; Wang, Hao; Yao, Hong

    2012-09-01

    The emission characteristics of polycyclic aromatic hydrocarbons (PAHs) during coal and sewage sludge co-combustion were investigated in a laboratory-scale drop tube furnace. The experimental results demonstrated that coal and sewage sludge co-combustion was beneficial in reducing PAH emissions and PAH toxic equivalent (TEQ) concentrations. Meanwhile, the five-ring PAHs were the main contributor in reducing the concentration of PAHs and TEQ. Moreover, the two- and five-ring PAH concentrations decreased as the mass fraction of sewage sludge in the mixture increased from 0% to 100%. It was also found that PAHs from coal mono-combustion was dominated by the four- and five-ring PAHs. As for the sewage sludge mono-combustion, the three- and four-ring PAHs were the principal components.

  14. Effect of organic calcium compounds on combustion characteristics of rice husk, sewage sludge, and bituminous coal: thermogravimetric investigation.

    PubMed

    Zhang, Lihui; Duan, Feng; Huang, Yaji

    2015-04-01

    Experiments were conducted in a thermogravimetric analyzer to assess the enhancement of combustion characteristics of different solid fuels blended with organic calcium compounds (OCCs). Rice husk, sewage sludge, and bituminous coal, and two OCC were used in this study. Effect of different mole ratios of calcium to sulfur (Ca/S ratio) on the combustion characteristics were also investigated. Results indicated that combustion performance indexes for bituminous coal impregnated by OCC were improved, however, an inverse trend was found for sewage sludge because sewage sludge has lower ignition temperature and higher volatile matter content compared to those of OCC. For rice husk, effect of added OCC on the combustion characteristics is not obvious. Different solid fuels show different combustion characteristics with increases of Ca/S ratio. The maximum combustion performance indexes appear at Ca/S ratios of 1:1, 2:1, and 3:1 for OCC blended with Shenhua coal, rice husk, and sewage sludge, respectively.

  15. K-Area and Par Pond Sewage Sludge Application Sites Groundwater Monitoring Report. Fourth quarter 1993 and summary 1993

    SciTech Connect

    Not Available

    1994-04-01

    Samples from the three wells at the K-Area Sewage Sludge Application Site (KSS wells) and the three wells at the Par Pond Sewage Sludge Application Site (PSS wells) are analyzed quarterly for constituents required by South Carolina Department of Health and Environmental Control Construction Permit 13,173 and, as requested, for other constituents as part of the Savannah River Site (SRS) Groundwater Monitoring Program. Annual analyses for other constituents, primarily metals, also are required by the permit. Dichloromethane (methylene chloride) exceeded the final Primary Drinking Water Standard in a single well of the K-Area Sewage Sludge Application Site during fourth quarter 1993. Aluminum, iron, and lead, reported in excess of the SRS Flag 2 criteria at both the K-Area and Par Pond Sewage Sludge Application Sites during third quarter 1993, were not analyzed fourth quarter.

  16. H-Area, K-Area, and Par Pond Sewage Sludge Application Sites Groundwater Monitoring Report. Second quarter 1995

    SciTech Connect

    Chase, J.A.

    1995-09-01

    During second quarter 1995, samples from monitoring wells at the K-Area Sewage Sludge Application Site (KSS wells) and Par Pond Sewage Sludge Application Site (PSS wells) were analyzed for constituents required by SCDHEC Construction Permit 13,173. H-Area Sewage Sludge Application Site (HSS wells) samples were analyzed for constituents required by SCDHEC Construction Permit 12,076. All samples are also analyzed as requested for other constituents as part of the Savannah River Site (SRS) Groundwater Monitoring Program. Annual analyses for other constituents, primarily metals, also are required by the permits. There were no constituents which exceeded the SCDHEC final Primary Drinking Water Standard in any well from the H-Area, K-Area, and Par Pond Sewage Sludge Application Sites. There were also no constituents which were above the SRS Flag 2 criteria in any well at the three sites during second quarter 1995.

  17. Biological hydrogen production by anaerobic digestion of food waste and sewage sludge treated using various pretreatment technologies.

    PubMed

    Kim, Seungjin; Choi, Kwangkeun; Kim, Jong-Oh; Chung, Jinwook

    2013-11-01

    The purpose of this study was to enhance the efficiency of anaerobic co-digestion with sewage sludge using pretreatment technologies and food waste. We studied the effects of various pretreatment methods (thermal, chemical, ultrasonic, and their combination) on hydrogen production and the characteristics of volatile fatty acids (VFAs) using sewage sludge alone and a mixture of sewage sludge and food waste. The pretreatment combination of alkalization and ultrasonication performed best, effecting a high solubilization rate and high hydrogen production (13.8 mL H2/g VSSconsumed). At a food waste:pretreated sewage sludge ratio of 2:1 in the mixture, the peak hydrogen production value was 5.0 L H2/L/d. As the production of hydrogen increased, propionate levels fell but butyrate concentrations rose gradually.

  18. Production of pyrolytic liquids from industrial sewage sludges in an induction-heating reactor.

    PubMed

    Tsai, Wen-Tien; Chang, Jeng-Hung; Hsien, Kuo-Jung; Chang, Yuan-Ming

    2009-01-01

    With the application of induction-heating, the pyrolytic experiments have been carried out for three sewage sludges from the food processing factories in an externally heated fixed-bed reactor. The thermochemical characteristics of sludge samples were first analyzed. The results indicated that the calorific value had about 15 MJ/kg on an average, suggesting that it had a potential for biomass energy source. However, its nitrogen concentration was relatively high. From the thermogravimetric analysis (TGA) curves, it showed that the pyrolysis reaction can be almost finished in the temperature range of 450-750 degrees C. The yields of resulting liquid and char products from the pyrolysis of sewage sludge were discussed for examining the effects of pyrolysis temperature (500-800 degrees C), heating rate (200-500 degrees C/min), and holding time (1-8 min). Overall, the variation of yield was not so significant in the experimental conditions for three sewage sludges. All results of the resulting liquid products analyzed by elemental analyzer, pH meter, Karl-Fischer moisture titrator and bomb calorimeter were in consistence with those analyses by FTIR spectroscopy. Furthermore, the pyrolysis liquid products contained large amounts of water (>73% by weight) mostly derived from the bound water in the biosludge feedstocks and the condensation reactions during the pyrolysis reaction, and fewer contents of oxygenated hydrocarbons composing of carbonyl and nitrogen-containing groups, resulting in low pH and low calorific values.

  19. The elimination of Salmonella typhimurium in sewage sludge by aerobic mesophilic stabilization and lime hydrated stabilization.

    PubMed

    Plachá, Iveta; Venglovský, Ján; Maková, Zuzana; Martinéz, José

    2008-07-01

    This study observed the effects of two methods, aerobic mesophilic stabilization and lime hydrated stabilization of sewage sludge upon the survival of Salmonella typhimurium. Raw (primary) sludges from the mechanical biological municipal sewage treatment plant were used. Aerobic stabilization and lime hydrated stabilization were carried out in a laboratory fermentor. Aerobic stabilization was carried out in the mesophilic temperature range (from 25.70+/-0.40 to 37.82+/-1.38 degrees C). Lime hydrated was used at an amount of 10 kg/m(3) for the stabilization. Sludge samples were inoculated with a broth culture of S. typhimurium. Quantitative and qualitative examinations of the presence of S. typhimurium were carried out. Aerobic mesophilic stabilization caused elimination S. typhimurium within 48 h. The T(90) value of S. typhimurium was 6.66+/-0.20 h. During the lime hydrated stabilization pH values significantly increased from 5.66+/-0.07 to 12.12+/-0.02 (P<0.01). S. typhimurium was inactivated within 1h and the T(90) value was 0.19+/-0.01 h. Our study confirmed that the treatment of sewage sludge with lime hydrated was significantly more effective than the aerobic mesophilic stabilization, (P<0.01).

  20. 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.

  1. Production of biosolid fuels from municipal sewage sludge: Technical and economic optimisation.

    PubMed

    Wzorek, Małgorzata; Tańczuk, Mariusz

    2015-08-01

    The article presents the technical and economic analysis of the production of fuels from municipal sewage sludge. The analysis involved the production of two types of fuel compositions: sewage sludge with sawdust (PBT fuel) and sewage sludge with meat and bone meal (PBM fuel). The technology of the production line of these sewage fuels was proposed and analysed. The main objective of the study is to find the optimal production capacity. The optimisation analysis was performed for the adopted technical and economic parameters under Polish conditions. The objective function was set as a maximum of the net present value index and the optimisation procedure was carried out for the fuel production line input capacity from 0.5 to 3 t h(-1), using the search step 0.5 t h(-1). On the basis of technical and economic assumptions, economic efficiency indexes of the investment were determined for the case of optimal line productivity. The results of the optimisation analysis show that under appropriate conditions, such as prices of components and prices of produced fuels, the production of fuels from sewage sludge can be profitable. In the case of PBT fuel, calculated economic indexes show the best profitability for the capacity of a plant over 1.5 t h(-1) output, while production of PBM fuel is beneficial for a plant with the maximum of searched capacities: 3.0 t h(-1). Sensitivity analyses carried out during the investigation show that influence of both technical and economic assessments on the location of maximum of objective function (net present value) is significant.

  2. Anaerobic digestion of seven different sewage sludges: a biodegradability and modelling study.

    PubMed

    Astals, S; Esteban-Gutiérrez, M; Fernández-Arévalo, T; Aymerich, E; García-Heras, J L; Mata-Alvarez, J

    2013-10-15

    Seven mixed sewage sludges from different wastewater treatment plants, which have an anaerobic digester in operation, were evaluated in order to clarify the literature uncertainty with regard to the sewage sludge characterisation and biodegradability. Moreover, a methodology is provided to determine the Anaerobic Digestion Model No. 1 parameters, coefficients and initial state variables as well as a discussion about the accuracy of the first order solubilisation constant, which was obtained through biomethane potential test. The results of the biomethane potential tests showed ultimate methane potentials from 188 to 214 mL CH4 g(-1) CODfed, COD removals between 58 and 65% and two homogeneous groups for the first order solubilisation constant: (i) the lowest rate group from 0.23 to 0.35 day(-1) and (ii) the highest rate group from 0.27 to 0.43 day(-1). However, no statistically significant relationship between the ultimate methane potential or the disintegration constant and the sewage sludge characterisation was found. Next, a methodology based on the sludge characterisation before and after the biomethane potential test was developed to calculate the biodegradable fraction, the composite concentration and stoichiometric coefficients and the soluble COD of the sewage sludge; required parameters for the implementation of the Anaerobic Digestion Model No. 1. The comparison of the experimental and the simulation results proved the consistency of the developed methodology. Nevertheless, an underestimation of the first order solubilisation constant was detected when the experimental results were simulated with the solubilisation constant obtained from the linear regression experimental data fitting. The latter phenomenon could be related to the accumulation of intermediary compounds during the biomethane potential assay.

  3. Effect of lime addition during sewage sludge treatment on characteristics of resulting SSA when it is used in cementitious materials.

    PubMed

    Vouk, D; Nakic, D; Štirmer, N; Baricevic, A

    2017-02-01

    Final disposal of sewage sludge is important not only in terms of satisfying the regulations, but the aspect of choosing the optimal wastewater treatment technology, including the sludge treatment. In most EU countries, significant amounts of stabilized and dewatered sludge are incinerated, and sewage sludge ash (SSA) is generated as a by product. At the same time, lime is one of the commonly used additives in the sewage sludge treatment primarily to stabilize the sludge. In doing so, the question arose how desirable is such addition of lime if the sludge is subsequently incinerated, and the generated ash is further used in the production of cementitious materials. A series of mortars were prepared where 10-20% of the cement fraction was replaced by SSA. Since all three types of analyzed SSA (without lime, with lime added during sludge stabilization and with extra lime added during sludge incineration) yielded nearly same results, it can be concluded that if sludge incineration is accepted solution, lime addition during sludge treatment is unnecessary even from the standpoint of preserving the pozzolanic properties of the resulting SSA. Results of the research carried out on cement mortars point to the great possibilities of using SSA in concrete industry.

  4. Underwater experiments on the effects of sewage sludge on a marine ecosystem

    NASA Astrophysics Data System (ADS)

    Eleftheriou, A.; Moore, D. C.; Basford, D. J.; Robertson, M. R.

    The experimental addition of different concentrations of sewage sludge to clean marine deposits resulted in a degradation of the sediments and a modified benthic macrofauna. The addition of a large amount of sludge (100 l·m -2·a -1) resulted in a sparse Capitella dominated fauna of low density and high biomass. The lower amount (50 l·m -2·a -1) allowed the presence of a normal fauna but of an enhanced abundance and biomass. Though recovery was good there was evidence that the addition of large amounts of sludge had lasting toxic effects. Comparisons of the results of these experiments with the effects observed in sludge dumping grounds are made and the significance of the different input levels in a marine ecosystem is discussed.

  5. Determination of greenhouse gas emission reductions from sewage sludge anaerobic digestion in China.

    PubMed

    Liu, H-T; Kong, X-J; Zheng, G-D; Chen, C-C

    2016-01-01

    Sewage sludge is a considerable source of greenhouse gas (GHG) emission in the field of organic solid waste treatment and disposal. In this case study, total GHG emissions from sludge anaerobic digestion, including direct and indirect emissions as well as replaceable emission reduction due to biogas being reused instead of natural gas, were quantified respectively. The results indicated that no GHG generation needed to be considered during the anaerobic digestion process. Indirect emissions were mainly from electricity and fossil fuel consumption on-site and sludge transportation. Overall, the total GHG emission owing to relative subtraction from anaerobic digestion rather than landfill, and replaceable GHG reduction caused by reuse of its product of biogas, were quantified to be 0.7214 (northern China) or 0.7384 (southern China) MgCO2 MgWS(-1) (wet sludge).

  6. Fate of heavy metals and radioactive metals in gasification of sewage sludge.

    PubMed

    Marrero, Thomas W; McAuley, Brendan P; Sutterlin, William R; Steven Morris, J; Manahan, Stanley E

    2004-01-01

    The fates of radioactive cadmium, strontium, cesium, cobalt, arsenic, mercury, zinc, and copper spiked into sewage sludge were determined when the sludge was gasified by a process that maximizes production of char from the sludge (ChemChar process). For the most part the metals were retained in the char product in the gasifier. Small, but measurable quantities of arsenic were mobilized by gasification and slightly more than 1% of the arsenic was detected in the effluent gas. Mercury was largely mobilized from the solids in the gasifier, but most of the mercury was retained in a filter composed of char prepared from the sludge. The small amounts of mercury leaving the gasification system were found to be associated with an aerosol product generated during gasification. The metals retained in the char product of gasification were only partially leachable with 50% concentrated nitric acid.

  7. Characterization of sewage sludge and the use of brine shrimp for toxicity test

    SciTech Connect

    Pun, K.C.; Cheung, R.Y.H.; Wong, M.H.

    1995-12-31

    Heavy metal contents (Cd, Cr, Cu, Pb, Ni and Zn) of digested sludges, collected from 4 sewage treatment works in Hong Kong were analyzed using atomic absorption spectrophotometry, after sequentially extracted by 1 M KNO{sub 3}, 0.5 M KF, 0.1 M Na{sub 4}, P{sub 2}, O{sub 7} 0.1 M EDTA and 6 M HNO{sub 3} It was found that the major forms of Cu, Pb, Ni and Zn were in the sulfide phase, organically bound phase, adsorbed phase and carbonate phase respectively. Nauplii larvae of brine shrimp (Artemia franciscana) was then used as bioindicator to test the toxicity, of the digested sludges. 20 individuals were placed into 1 liter seawater containing whole sample of the types of digested sludges at different concentrations, The toxicity of the 4 sludges, according to 48h-LC 50, were ranked as follows YL > TP > ST > SWH.

  8. Chesapeake Bay nutrient pollution: contribution from the land application of sewage sludge in Virginia.

    PubMed

    Land, Lynton S

    2012-11-01

    Human health concerns and the dissemination of anthropogenic substances with unknown consequences are the reasons most often given why disposal of municipal sewage sludge in landfills or using the organic waste as biofuel is preferable to land application. But no "fertilizer" causes more nitrogen pollution than sludge when applied according to Virginia law. Poultry litter is the only other "fertilizer" that causes more phosphorus pollution than sludge. Cost savings by the few farmers in Virginia who use sludge are far less than the costs of the nitrogen pollution they cause. A ban on the land application of all forms of animal waste is very cost-effective and would reduce Chesapeake Bay nutrient pollution by 25%.

  9. Occurrence, distribution and potential affecting factors of antibiotics in sewage sludge of wastewater treatment plants in China.

    PubMed

    Li, Wenhui; Shi, Yali; Gao, Lihong; Liu, Jiemin; Cai, Yaqi

    2013-02-15

    The occurrence and distribution of eight quinolones, nine sulfonamides, and five macrolides were investigated in sewage sludge from 45 wastewater treatment plants in 23 cities in China. Among all the antibiotics considered, quinolones were the dominant antibiotics detected in all samples [total concentrations up to 8905 μg/kg, dry weight (dw)], followed by macrolides (85.1 μg/kg, dw), and sulfonamides (22.7 μg/kg, dw). High concentrations of quinolones in sewage sludge indicated that antibiotics are widely used and extensive pollutants in China. Significant differences were observed for the total concentrations of antibiotics in sludge samples among the 45 WWTPs. To evaluate the potential factors affecting the antibiotic levels in sewage sludge, wastewater and sludge characteristics, as well as the operational conditions and treatment techniques in WWTPs were investigated. The results indicated that the antibiotic levels in sewage sludge depend to a great extent on wastewater characteristics. Significant correlation between total organic carbon (TOC) and total concentrations of antibiotics was also found in studied WWTPs, indicating that TOC could affect the sludge adsorption capability to the antibiotics to some extent. Moreover, the relation between treatment techniques and the total concentrations of antibiotics in sludge showed that antibiotic levels in sludge increased with longer solid retention time.

  10. Co-digestion of municipal sewage sludge and solid waste: modelling of carbohydrate, lipid and protein content influence.

    PubMed

    Nielfa, A; Cano, R; Pérez, A; Fdez-Polanco, M

    2015-03-01

    Solid wastes from industrial, commercial and community activities are of growing concern as the total volume of waste produced continues to increase. The knowledge of the specific composition and characteristics of the waste is an important tool in the correct development of the anaerobic digestion process. The problems derived from the anaerobic digestion of sole substrates with high lipid, carbohydrate or protein content lead to the co-digestion of these substrates with another disposed waste, such as sewage sludge. The kinetic of the anaerobic digestion is especially difficult to explain adequately, although some mathematical models are able to represent the main aspects of a biological system, thus improving understanding of the parameters involved in the process. The aim of this work is to evaluate the experimental biochemical methane potential on the co-digestion of sewage sludge with different solid wastes (grease; spent grain and cow manure) through the implementation of four kinetic models. The co-digestion of grease waste and mixed sludge obtained the best improvements from the sole substrates, with additional positive synergistic effects. The Gompertz model fits the experimental biochemical methane potential to an accuracy of 99%, showing a correlation between the percentage of lipid in the substrates and co-digestions and the period of lag phase.

  11. Investigation into the distribution of polycyclic aromatic hydrocarbons (PAHs) in wastewater sewage sludge and its resulting pyrolysis bio-oils.

    PubMed

    Hu, Yanjun; Li, Guojian; Yan, Mi; Ping, Chuanjuan; Ren, Jianli

    2014-03-01

    This study firstly investigated the distributions of 16 US EPA priority controlled polycyclic aromatic hydrocarbons (PAHs) in seven kinds of different wastewater sewage sludges and bio-oils from the sludge pyrolysis. A lab-scale tube furnace was used to simulate sludge pyrolysis and retrieve condensed oils. PAH determination was conducted with the extraction, concentration, and purification of PAHs in sludge samples and the resulting bio-oils, and then GC-MS analysis. Then, the factors influencing the distributions of different rings of PAHs in pyrolysis bio-oil, such as the chemical characteristics of raw sewage sludge and pyrolysis condition, were analyzed. It was noted that the total amount of PAHs in raw sludge is evidently varied with the sludge resource, with values ranging between 9.19 and 23.68 mg/kg. The middle molar weight (MMW) PAH distribution is dominant. PAH concentrations in sludge pyrolysis bio-oil were ranged from 13.72 to 48.9 mg/kg. The most abundant PAHs were the low molar weight (LMW) PAHs. It could be found that the concentration of LMW PAHs in bio-oil is correlated with MMW PAHs in raw sewage sludge at best, which the correlation coefficient is 0.607. For MMW and HMW (high molar weight) PAHs, they are significantly correlated with HMW PAHs in raw sewage sludge, which the correlation coefficients are 0.672 and 0.580, respectively. The concentration of LMW PAHs in bio-oil is also relatively significant and correlated with the volatile matter content of raw sludge. In addition, it was proved that final temperature and residence time have important influences on PAH generations during the pyrolysis of sewage sludge.

  12. Occurrence, distribution, and potential influencing factors of sewage sludge components derived from nine full-scale wastewater treatment plants of Beijing, China.

    PubMed

    Wang, Xu; Li, Meiyan; Liu, Junxin; Qu, Jiuhui

    2016-07-01

    Millions of tons of waste activated sludge (WAS) produced from biological wastewater treatment processes cause severe adverse environmental consequences. A better understanding of WAS composition is thus very critical for sustainable sludge management. In this work, the occurrence and distribution of several fundamental sludge constituents were explored in WAS samples from nine full-scale wastewater treatment plants (WWTPs) of Beijing, China. Among all the components investigated, active heterotrophic biomass was dominant in the samples (up to 9478mg/L), followed by endogenous residues (6736mg/L), extracellular polymeric substances (2088mg/L), and intracellular storage products (464mg/L) among others. Moreover, significant differences (p<0.05) were observed in composition profiles of sludge samples among the studied WWTPs. To identify the potential parameters affecting the variable fractions of sludge components, wastewater source as well as design and operational parameters of WWTPs were studied using statistical methods. The findings indicated that the component fraction of sewage sludge depends more on wastewater treatment alternatives than on wastewater characteristics among other parameters. A principal component analysis was conducted, which further indicated that there was a greater proportion of residual inert biomass in the sludge produced by the combined system of the conventional anaerobic/anoxic/oxic process and a membrane bioreactor. Additionally, a much longer solids retention time was also found to influence the sludge composition and induce an increase in both endogenous inert residues and extracellular polymeric substances in the sludge.

  13. Effects of reaction conditions on the emission behaviors of arsenic, cadmium and lead during sewage sludge pyrolysis.

    PubMed

    Han, Hengda; Hu, Song; Syed-Hassan, Syed Shatir A; Xiao, Yiming; Wang, Yi; Xu, Jun; Jiang, Long; Su, Sheng; Xiang, Jun

    2017-03-31

    Sewage sludge is an important class of bioresources whose energy content could be exploited using pyrolysis technology. However, some harmful trace elements in sewage sludge can escape easily to the gas phase during pyrolysis, increasing the potential of carcinogenic material emissions to the atmosphere. This study investigates emission characteristics of arsenic, cadmium and lead under different pyrolysis conditions for three different sewage sludge samples. The increased temperature (within 723-1123K) significantly promoted the cadmium and lead emissions, but its influence on arsenic emission was not pronounced. The releasing rate order of the three trace elements is volatile arsenic compounds>cadmium>lead in the beginning of pyrolysis. Fast heating rates promoted the emission of trace elements for the sludge containing the highest amount of ash, but exhibited an opposite effect for other studied samples. Overall, the high ash sludge released the least trace elements almost under all reaction conditions.

  14. PAH removal from spiked municipal wastewater sewage sludge using biological, chemical and electrochemical treatments.

    PubMed

    Zheng, Xue-Jing; Blais, Jean-François; Mercier, Guy; Bergeron, Mario; Drogui, Patrick

    2007-06-01

    Polycyclic aromatic hydrocarbons (PAHs) have been widely studied due to their presence in all the environmental media and toxicity to life. These molecules are strongly adsorbed on the particulate matters of soils, sludges or sediments because of their strong hydrophobicity which makes them less bioavailability, thus limiting their bioremediation. Different sludge treatment processes were tested to evaluate their performances for PAH removal from sludge prealably doped with 11 PAHs (5.5mg each PAH kg(-1) of dry matter (DM)): two biological processes (mesophilic aerobic digestion (MAD) and simultaneous sewage sludge digestion and metal leaching (METIX-BS)) were tested to evaluate PAH biodegradation in sewage sludge. In parallel, two chemical processes (quite similar Fenton processes: chemical metal leaching (METIX-AC) and chemical stabilization (STABIOX)) and one electrochemical process (electrochemical stabilization (ELECSTAB)) were tested to measure PAH removal by these oxidative processes. Moreover, PAH solubilisation from sludge by addition of a nonionic surfactant Tween 80 (Tw80) was also tested. The best yields of PAH removal were obtained by MAD and METIX-BS with more than 95% 3-ring PAH removal after a 21-day treatment period. Tw80 addition during MAD treatment increased 4-ring PAHs removal rate. In addition, more than 45% of 3-ring PAHs were removed from sludge by METIX-AC and during ELECSTAB process were quiet good with approximately 62% of 3-ring PAHs removal. However, little weaker removal of 3-ring PAHs (<35%) by STABIOX. None of the tested processes were efficient for the elimination of high molecular weight (> or = 5-ring) PAHs from sludge.

  15. Bacterial community structure in treated sewage sludge with mesophilic and thermophilic anaerobic digestion.

    PubMed

    Stiborova, Hana; Wolfram, Jan; Demnerova, Katerina; Macek, Tomas; Uhlik, Ondrej

    2015-11-01

    Stabilized sewage sludge is applied to agricultural fields and farmland due to its high organic matter content. The aim of this study was to investigate the effects of two types of sludge stabilization, mesophilic anaerobic digestion (MAD) and thermophilic anaerobic digestion (TAD), on bacterial communities in sludge, including the presence of pathogenic microorganisms. Bacterial community structure and phylogenetic diversity were analyzed in four sewage sludge samples from the Czech Republic. Analysis of 16S ribosomal RNA (rRNA) genes showed that investigated sludge samples harbor diverse bacterial populations with only a few taxa present across all samples. Bacterial diversity was higher in sludge samples after MAD versus TAD treatment, and communities in MAD-treated sludge shared the highest genetic similarities. In all samples, the bacterial community was dominated by reads affiliated with Proteobacteria. The sludge after TAD treatment had considerably higher number of reads of thermotolerant/thermophilic taxa, such as the phyla Deinococcus-Thermus and Thermotogae or the genus Coprothermobacter. Only one operational taxonomic unit (OTU), which clustered with Rhodanobacter, was detected in all communities at a relative abundance >1 %. All of the communities were screened for the presence of 16S rRNA gene sequences of pathogenic bacteria using a database of 122 pathogenic species and ≥98 % identity threshold. The abundance of such sequences ranged between 0.23 and 1.57 % of the total community, with lower numbers present after the TAD treatment, indicating its higher hygienization efficiency. Sequences clustering with nontuberculous mycobacteria were present in all samples. Other detected sequences of pathogenic bacteria included Streptomyces somaliensis, Acinetobacter calcoaceticus, Alcaligenes faecalis, Gordonia spp., Legionella anisa, Bordetella bronchiseptica, Enterobacter aerogenes, Brucella melitensis, and Staphylococcus aureus.

  16. Residual cadmium forms in acid-extracted anaerobically digested sewage sludge

    SciTech Connect

    Feltz, R.E.; Logan, T.J.

    1985-01-01

    The effects of phosphorus and lime additions after acid extraction on residual Cd solubility and chemical forms in an anaerobically digested sewage sludge were investigated. High Cd content anaerobically digested sewage sludge was aerated and then acidified to pH 2 to solubilize Cd. After 18 h of acidification, the sludge was dewatered and the supernatant and solids separated. Seventy or more percent of the Cd was removed from the solids. Similar amounts of Ni, Mn and Zn were also removed, but Cu removal was only 26% and that of Pb was < 5%. Before liming the sludge was amended with rock phosphate (RP) or monocalcium phosphate (MCP). The RP was insoluble while MCP dissolved, providing a high level of phosphate ligand for Cd precipitation or coprecipitation. Estimated sludge solution solubility products for major Fe, Al and Ca phosphates showed that several of these minerals could have precipitated with P addition, especially with MCP, and Cd may have coprecipitated with these solid phases. Cadmium phosphate may also have been formed in the MCP sludge. Chemical fractionation indicated that 50% of the Cd in the aerated unextracted sludge existed as inorganic precipitates with another 40% Na/sub 4/P/sub 2/O/sub 7/ extractable. Acidification solubilized 98% of the inorganic Cd and 86% of the organically bound Cd. Seventy-nine percent of the Cd remaining in the dewatered acidified sludge was in the KNO/sub 3/ extractable (exchangeable) fraction. Liming redistributed the Cd with 13 to 19% as inorganic precipitates, 70 to 85% organically bound and < 3% in the exchangeable fraction. Phosphate addition had no significant effect on Cd fractionation.

  17. Effect of Biostimulation Using Sewage Sludge, Soybean Meal, and Wheat Straw on Oil Degradation and Bacterial Community Composition in a Contaminated Desert Soil

    PubMed Central

    Al-Kindi, Sumaiya; Abed, Raeid M. M.

    2016-01-01

    Waste materials have a strong potential in the bioremediation of oil-contaminated sites, because of their richness in nutrients and their economical feasibility. We used sewage sludge, soybean meal, and wheat straw to biostimulate oil degradation in a heavily contaminated desert soil. While oil degradation was assessed by following the produced CO2 and by using gas chromatography–mass spectrometry (GC–MS), shifts in bacterial community composition were monitored using illumina MiSeq. The addition of sewage sludge and wheat straw to the desert soil stimulated the respiration activities to reach 3.2–3.4 times higher than in the untreated soil, whereas the addition of soybean meal resulted in an insignificant change in the produced CO2, given the high respiration activities of the soybean meal alone. GC–MS analysis revealed that the addition of sewage sludge and wheat straw resulted in 1.7–1.8 fold increase in the degraded C14 to C30 alkanes, compared to only 1.3 fold increase in the case of soybean meal addition. The degradation of ≥90% of the C14 to C30 alkanes was measured in the soils treated with sewage sludge and wheat straw. MiSeq sequencing revealed that the majority (76.5–86.4% of total sequences) of acquired sequences from the untreated soil belonged to Alphaproteobacteria, Gammaproteobacteria, and Firmicutes. Multivariate analysis of operational taxonomic units placed the bacterial communities of the soils after the treatments in separate clusters (ANOSIM R = 0.66, P = 0.0001). The most remarkable shift in bacterial communities was in the wheat straw treatment, where 95–98% of the total sequences were affiliated to Bacilli. We conclude that sewage sludge and wheat straw are useful biostimulating agents for the cleanup of oil-contaminated desert soils. PMID:26973618

  18. Effect of Biostimulation Using Sewage Sludge, Soybean Meal, and Wheat Straw on Oil Degradation and Bacterial Community Composition in a Contaminated Desert Soil.

    PubMed

    Al-Kindi, Sumaiya; Abed, Raeid M M

    2016-01-01

    Waste materials have a strong potential in the bioremediation of oil-contaminated sites, because of their richness in nutrients and their economical feasibility. We used sewage sludge, soybean meal, and wheat straw to biostimulate oil degradation in a heavily contaminated desert soil. While oil degradation was assessed by following the produced CO2 and by using gas chromatography-mass spectrometry (GC-MS), shifts in bacterial community composition were monitored using illumina MiSeq. The addition of sewage sludge and wheat straw to the desert soil stimulated the respiration activities to reach 3.2-3.4 times higher than in the untreated soil, whereas the addition of soybean meal resulted in an insignificant change in the produced CO2, given the high respiration activities of the soybean meal alone. GC-MS analysis revealed that the addition of sewage sludge and wheat straw resulted in 1.7-1.8 fold increase in the degraded C14 to C30 alkanes, compared to only 1.3 fold increase in the case of soybean meal addition. The degradation of ≥90% of the C14 to C30 alkanes was measured in the soils treated with sewage sludge and wheat straw. MiSeq sequencing revealed that the majority (76.5-86.4% of total sequences) of acquired sequences from the untreated soil belonged to Alphaproteobacteria, Gammaproteobacteria, and Firmicutes. Multivariate analysis of operational taxonomic units placed the bacterial communities of the soils after the treatments in separate clusters (ANOSIM R = 0.66, P = 0.0001). The most remarkable shift in bacterial communities was in the wheat straw treatment, where 95-98% of the total sequences were affiliated to Bacilli. We conclude that sewage sludge and wheat straw are useful biostimulating agents for the cleanup of oil-contaminated desert soils.

  19. Phosphorus dissolution from ash of incinerated sewage sludge and animal carcasses using sulphuric acid.

    PubMed

    Cohen, Yariv

    2009-10-01

    Large amounts of phosphorus are present in organic waste, mainly in sewage sludge and animal by-products. Increasingly, the waste is incinerated and phosphorus ends up in the ash. Sustainable waste management requires the beneficial reuse of phosphorus present in such ash. The first necessary step when recovering phosphorus from ash is dissolution by acid. The objective of this study was to quantify the acid requirement for phosphorus dissolution from sewage sludge ash and animal carcass ash. Both the amount of acid applied and its concentration were varied. Furthermore, phosphorus dissolution was optimized by controlling the pH during acid addition. Elemental analysis of sewage sludge ash showed that it comprised 6-10% P, 7-18% Ca, 2-11% Fe and 3-9% Al. The elemental content of animal carcass ash was even higher: 18% P and 30% Ca. The amount of acid required to obtain >85% phosphorus dissolution from sludge ash was 0.39-0.78 kg H2SO4 kg(-1) ash, depending on the total cation/phosphorus equivalent ratio. The amount required to obtain the highest possible P dissolution within two hours (73%) from animal carcass ash was 0.69 kg H2SO4 kg(-1) ash. Lower amounts of sulphuric acid were required for P dissolution in ashes of sludge from a bio-P treatment process and animal carcass, compared with the theoretical acid requirement for apatite dissolution. Applying pH control during dissolution resulted in reduced acid consumption (20%) and enabled more than 85% phosphorus dissolution from sludge ash at pH 2.0 in the two-hour dissolution time.

  20. Thermochemical treatment of sewage sludge ash with sodium salt additives for phosphorus fertilizer production--Analysis of underlying chemical reactions.

    PubMed

    Stemann, Jan; Peplinski, Burkhard; Adam, Christian

    2015-11-01

    Stocks of high grade phosphate rock are becoming scarce, and there is growing concern about potentially harmful impurities in conventional phosphorus fertilizers. Sewage sludge ash is a promising secondary phosphorus source. However, to remove heavy metals and convert the phosphorus contained in sewage sludge ash into mineral phases available to plants, an after-treatment is required. Laboratory-scale calcination experiments of sewage sludge ash blended with sodium salts using dried sewage sludge as a reducing agent were carried out at 1000°C. Thus, the Ca3(PO4)2 or whitlockite component of raw sewage sludge ash, which is not readily plant available, was converted to CaNaPO4 (buchwaldite). Consequently, nearly complete phosphorus solubility in ammonium citrate (a well-established indicator for plant availability) was achieved. Moreover, it was shown that Na2CO3 may be replaced by moderately priced Na2SO4. However, molar ratios of Na/P>2 were required to achieve >80% phosphorus solubility. Such over-stoichiometric Na consumption is largely caused by side reactions with the SiO2 component of the sewage sludge ash - an explanation for which clear evidence is provided for the first time.

  1. FINE PARTICAL AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    SciTech Connect

    Jost O.L. Wendt; Wayne S. Seames; Art Fernandez

    2003-09-21

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and pulverized coal. The objective was to determine potential tradeoffs between CO{sub 2} mitigation through using a CO{sub 2} neutral fuel, such as municipal sewage sludge, and the emergence of other potential problems such as the emission of toxic fly ash particles. The work led to new insight into mechanisms governing the partitioning of major and trace metals from the combustion of sewage sludge, and mixtures of coal and sewage sludge. The research also showed that the co-combustion of coal and sewage sludge emitted fine particulate matter that might potentially cause greater lung injury than that from the combustion of either coal alone or municipal sewage sludge alone. The reason appeared to be that the toxicity measured required the presence of large amounts of both zinc and sulfur in particles that were inhaled. MSS provided the zinc while coal provided the sulfur. Additional research showed that the toxic effects could most likely be engineered out of the process, through the introduction of kaolinite sorbent downstream of the combustion zone, or removing the sulfur from the fuel. These results are consequences of applying ''Health Effects Engineering'' to this issue. Health Effects Engineering is a new discipline arising out of this work, and is derived from using a collaboration of combustion engineers and toxicologists to mitigate the potentially bad health effects from combustion of this biomass fuel.

  2. Occurrence, temporal variation, and estrogenic burden of five parabens in sewage sludge collected across the United States.

    PubMed

    Chen, Jing; Pycke, Benny F G; Brownawell, Bruce J; Kinney, Chad A; Furlong, Edward T; Kolpin, Dana W; Halden, Rolf U

    2017-03-24

    Five parabens used as preservatives in pharmaceuticals and personal care products (PPCPs) were measured in sewage sludges collected at 14 U.S. wastewater treatment plants (WWTPs) located in nine states. Detected concentration ranges (ng/g, dry weight) and frequencies were as follows: methyl paraben (15.9 to 203.0; 100%), propyl paraben (0.5 to 7.7; 100%), ethyl paraben (<0.6 to 2.6; 63%), butyl paraben (<0.4 to 4.3; 42%) and benzyl paraben (<0.4 to 3.3; 26%). The estrogenicity inherent to the sum of parabens detected in sewage sludge (ranging from 10.1 to 500.1pg/kg 17β-estradiol equivalents) was insignificant when compared to the 10(6)-times higher value calculated for natural estrogens reported in the literature to occur in sewage sludge. Temporal monitoring at one WWTP provided insights into temporal and seasonal variations in paraben concentrations. This is the first report on the occurrence of five parabens in sewage sludges from across the U.S., and internationally, the first on temporal variations of paraben levels in sewage sludge. Study results will help to inform the risk assessment of sewage sludge destined for land application (biosolids).

  3. Solubility of ion and trace metals from stabilized sewage sludge by fly ash and alkaline mine tailing.

    PubMed

    Zhang, Hongling; Sun, Lina; Sun, Tieheng

    2008-01-01

    Stabilized sewage sludge (SS) by fly ash (FA) and alkaline mine tailing as artificial soil, to be applied on the ecological rehabilitation at mining junkyards, offers a potentially viable utilization of the industrial by-product, as well as solves the shortage of soil resource in the mine area. An incubation experiment with different ratios of SS and FA was conducted to evaluate the solubility of ions and trace elements from stabilized sewage sludge. Results showed that fly ash offset a decrease in pH value of sewage sludge. The pH of (C) treatment (FA:SS = 1:1) was stable and tended to neutrality. The SO4(2-) and Cl- concentrations of the solution in the mixture were significantly decreased in the stabilized sewage sludge by alkaline fly ash and mine tailing, compared to the single SS treatment. Stabilized sewage sludge by FA weakened the nitrification of total nitrogen from SS when the proportion of FA in the mixture was more than 50%. The Cr, Ni, and Cu concentrations in the solution were gradually decreased and achieved a stable level after 22 days, for all treatments over the duration of the incubation. Moreover stabilized sewage slu