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Sample records for communal 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. 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.

  4. 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.

  5. Pressurized Fluidized Bed Combustion of Sewage Sludge

    NASA Astrophysics Data System (ADS)

    Suzuki, Yoshizo; Nojima, Tomoyuki; Kakuta, Akihiko; Moritomi, Hiroshi

    A conceptual design of an energy recovering system from sewage sludge was proposed. This system consists of a pressurized fluidized bed combustor, a gas turbine, and a heat exchanger for preheating of combustion air. Thermal efficiency was estimated roughly as 10-25%. In order to know the combustion characteristics of the sewage sludge under the elevated pressure condition, combustion tests of the dry and wet sewage sludge were carried out by using laboratory scale pressurized fluidized bed combustors. Combustibility of the sewage sludge was good enough and almost complete combustion was achieved in the combustion of the actual wet sludge. CO emission and NOx emission were marvelously low especially during the combustion of wet sewage sludge regardless of high volatile and nitrogen content of the sewage sludge. However, nitrous oxide (N2O) emission was very high. Hence, almost all nitrogen oxides were emitted as the form of N2O. From these combustion tests, we judged combustion of the sewage sludge with the pressurized fluidized bed combustor is suitable, and the conceptual design of the power generation system is available.

  6. 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.

  7. Deodorization of sewage sludge-derived oils

    SciTech Connect

    Sawatzky, H.; Giddings, T.; Farnand, B.

    1993-07-06

    A method is described for treating a sewage sludge-derived oil comprising the steps of: (A) providing sewage sludge-derived oil having the following elemental composition: Nitrogen: about 2% to about 8%; Oxygen: about 3% to about 12%; Sulphur: about 0.1 % to about 4%; Hydrogen: about 8% to about 11%; Carbon: about 86.9% to about 65%; (B) distilling said sewage sludge-derived oil to a temperature of about 150 C. to remove water and volatile organic compounds; and (C) circulating a gas consisting essentially of carbon dioxide therethrough.

  8. 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

  9. Lightweight aggregate from flyash and sewage sludge

    SciTech Connect

    Nechvatal, T.M.; Heian, G.A.

    1991-10-15

    This patent describes a method of treating flyash and sewage sludge. It comprises: mixing flyash with sewage sludge having a high fuel value; agglomerating the mixture; drying the agglomerated mixture; heating the agglomerated mixture to a temperature less than the melting point of the mixture in a rotary kiln using the agglomerated mixture as the principal source of fuel in the kiln to form a porous nodular product; and recovering the nodular product from the kiln.

  10. Clean and Efficient Utilization of Sewage Sludge

    SciTech Connect

    Zamansky, Vladimir; Rizeq, George

    2002-09-12

    This is the Final Report for the DOE SBIR Phase II project (Grant No. DE-FG03-98ER82573). This report summarizes accomplishments and results for the entire program. In this program an innovative technology has been devised for transforming sewage sludge into a high quality fuel and recovering its energy content. The technology being developed is generally applicable to nearly all municipal sewage sludge management facilities and coal-fired boilers. It will provide economic and environmental benefits.

  11. 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.

  12. Reclamation of acid waters using sewage sludge.

    PubMed

    Davison, W; Reynolds, C S; Tipping, E; Needham, R F

    1989-01-01

    An exhausted sand quarry which had filled with acid water (pH 3) from the oxidation of pyrite was treated with calcium hydroxide to neutralize the water (pH 8), and sewage sludge to prevent further ingress of acid. The water remained neutral for 2 years, an appreciable quantity of base being generated by the reduction of sulphate to sulphide in the anoxic sediment formed by the sewage sludge. After this time the water reverted to acid conditions, chiefly because the lake was too shallow to retain the sewage sludge over a sufficiently large area of its bed. Incubation experiments showed that the sewage sludge had a large capacity for sulphate reduction, which was equally efficient in acid or neutral waters and that the areal rate of consumption was sufficiently fast to neutralize all incoming acid, if at least 50% of the lake bed was covered with sludge. Throughout the course of the field investigations there was no foul smell and the lake was quickly colonized by phytoplankton, macrophytes and insects. Although nutrients associated with the sewage sludge stimulated photosynthesis and so caused the generation of additional organic matter, they were exhausted within two years. To ensure permanent reclamation, phosphate fertilizer could be added once the initial supply has been consumed. Neutralization removed trace metals from the system, presumably due to formation of insoluble oxyhydroxide and carbonates. The solubility of aluminium was apparently controlled by a basic aluminium sulphate (jurbanite).

  13. Sewers, sewage treatment, sludge: damage without end.

    PubMed

    Rockefeller, Abby A

    2002-01-01

    It is in the nature of sewering and sewage treatment to compound environmental problems in the process of moving sewage and in attempting to remove from sewage the pollutants it carries. Spreading sewage sludge on land is but the latest in the compounding of environmental damage from sewerage. This practice must be banned and there must be a federal reorientation of all technology dealing with human excreta and the waste materials from industry and society that now are carried away by sewers. The reorientation must center on biologically based on-site pollution prevention and resource recycling technologies mandated through a revised Clean Water Act. PMID:17208779

  14. Sewers, sewage treatment, sludge: damage without end.

    PubMed

    Rockefeller, Abby A

    2002-01-01

    It is in the nature of sewering and sewage treatment to compound environmental problems in the process of moving sewage and in attempting to remove from sewage the pollutants it carries. Spreading sewage sludge on land is but the latest in the compounding of environmental damage from sewerage. This practice must be banned and there must be a federal reorientation of all technology dealing with human excreta and the waste materials from industry and society that now are carried away by sewers. The reorientation must center on biologically based on-site pollution prevention and resource recycling technologies mandated through a revised Clean Water Act.

  15. Microwave-induced pyrolysis of sewage sludge.

    PubMed

    Menéndez, J A; Inguanzo, M; Pis, J J

    2002-07-01

    This paper describes a new method for pyrolyzing sewage sludge using a microwave furnace. It was found that if just the raw wet sludge is treated in the microwave, only drying of the sample takes place. However, if the sludge is mixed with a small amount of a suitable microwave absorber (such as the char produced in the pyrolysis itself) temperatures of up to 900 degrees C can be achieved, so that pyrolysis takes place rather than drying. Microwave treatments were also compared with those carried out in a conventional electric furnace, as well as the characteristics of their respective carbonaceous solid residues.

  16. 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.

  17. Digested sewage sludge gasification in supercritical water.

    PubMed

    Zhai, Yunbo; Wang, Chang; Chen, Hongmei; Li, Caiting; Zeng, Guangming; Pang, Daoxiong; Lu, Pei

    2013-04-01

    Digested sewage sludge gasification in supercritical water was studied. Influences of main reaction parameters, including temperature (623-698 K), pressure (25-35 Mpa), residence time (10-15 min) and dry matter content (5-25 wt%), were investigated to optimize the gasification process. The main gas products were methane, carbon monoxide, carbon dioxide and traces of ethene, etc. Results showed that 10 wt% dry matter content digested sewage sludge at a temperature of 698 K and residence time of 50 min, with a pressure of 25 MPa, were the most favorable conditions for the sewage sludge gasification and carbon gasification efficiencies. In addition, potassium carbonate (K2CO3) was also employed as the catalyst to make a comparison between gasification with and without catalyst. When 2.6 g K2CO3 was added, a gasification efficiency of 25.26% and a carbon gasification efficiency of 20.02% were achieved, which were almost four times as much as the efficiencies without catalyst. K2CO3 has been proved to be effective in sewage sludge gasification.

  18. 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.

  19. 40 CFR 503.7 - Requirement for a person who prepares sewage sludge.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... sewage sludge. 503.7 Section 503.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SEWAGE SLUDGE STANDARDS FOR THE USE OR DISPOSAL OF SEWAGE SLUDGE General Provisions § 503.7 Requirement for a person who prepares sewage sludge. Any person who prepares sewage sludge shall ensure that...

  20. 40 CFR 503.7 - Requirement for a person who prepares sewage sludge.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... sewage sludge. 503.7 Section 503.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SEWAGE SLUDGE STANDARDS FOR THE USE OR DISPOSAL OF SEWAGE SLUDGE General Provisions § 503.7 Requirement for a person who prepares sewage sludge. Any person who prepares sewage sludge shall ensure that...

  1. 40 CFR 503.7 - Requirement for a person who prepares sewage sludge.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... sewage sludge. 503.7 Section 503.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SEWAGE SLUDGE STANDARDS FOR THE USE OR DISPOSAL OF SEWAGE SLUDGE General Provisions § 503.7 Requirement for a person who prepares sewage sludge. Any person who prepares sewage sludge shall ensure that...

  2. 40 CFR 503.7 - Requirement for a person who prepares sewage sludge.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... sewage sludge. 503.7 Section 503.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SEWAGE SLUDGE STANDARDS FOR THE USE OR DISPOSAL OF SEWAGE SLUDGE General Provisions § 503.7 Requirement for a person who prepares sewage sludge. Any person who prepares sewage sludge shall ensure that...

  3. 40 CFR 503.7 - Requirement for a person who prepares sewage sludge.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... sewage sludge. 503.7 Section 503.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SEWAGE SLUDGE STANDARDS FOR THE USE OR DISPOSAL OF SEWAGE SLUDGE General Provisions § 503.7 Requirement for a person who prepares sewage sludge. Any person who prepares sewage sludge shall ensure that...

  4. Recovery potential of German sewage sludge ash.

    PubMed

    Krüger, Oliver; Adam, Christian

    2015-11-01

    Incineration of sewage sludge is expected to increase in the future due to growing concerns about the direct use of sludge in agriculture. Sewage sludge is the pollutant sink of wastewater treatment and thus loaded with contaminants that might pose environmental hazards. Incineration degrades organic pollutants efficiently, but since the ash is currently mostly disposed of, all valuable component like phosphorus (P) and technologically relevant metals present in the sewage sludge ash (SSA) are removed from the economic cycle entirely. We conducted a complete survey of SSA from German mono-incineration facilities and determined the theoretical recovery potential of 57 elements. German SSA contains up to 19,000 t/a P which equals approximately 13% of phosphorus applied in the German agriculture in form of phosphate rock based mineral fertilizers. Thus, SSA is an important secondary resource of P. However, its P-solubility in ammonium citrate solution, an indicator for the bioavailability, is only about 26%. Treatment of SSA is recommended to enhance P bioavailability and remove heavy metals before it is applied as fertilizer. The recovery potential for technologically relevant metals is generally low, but some of these elements might be recovered efficiently in the course of P recovery exploiting synergies. PMID:25697389

  5. Recovery potential of German sewage sludge ash.

    PubMed

    Krüger, Oliver; Adam, Christian

    2015-11-01

    Incineration of sewage sludge is expected to increase in the future due to growing concerns about the direct use of sludge in agriculture. Sewage sludge is the pollutant sink of wastewater treatment and thus loaded with contaminants that might pose environmental hazards. Incineration degrades organic pollutants efficiently, but since the ash is currently mostly disposed of, all valuable component like phosphorus (P) and technologically relevant metals present in the sewage sludge ash (SSA) are removed from the economic cycle entirely. We conducted a complete survey of SSA from German mono-incineration facilities and determined the theoretical recovery potential of 57 elements. German SSA contains up to 19,000 t/a P which equals approximately 13% of phosphorus applied in the German agriculture in form of phosphate rock based mineral fertilizers. Thus, SSA is an important secondary resource of P. However, its P-solubility in ammonium citrate solution, an indicator for the bioavailability, is only about 26%. Treatment of SSA is recommended to enhance P bioavailability and remove heavy metals before it is applied as fertilizer. The recovery potential for technologically relevant metals is generally low, but some of these elements might be recovered efficiently in the course of P recovery exploiting synergies.

  6. 40 CFR Appendix A to Part 503 - Procedure To Determine the Annual Whole Sludge Application Rate for a Sewage Sludge

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Whole Sludge Application Rate for a Sewage Sludge A Appendix A to Part 503 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SEWAGE SLUDGE STANDARDS FOR THE USE OR DISPOSAL OF SEWAGE SLUDGE Pt... a Sewage Sludge Section 503.13(a)(4)(ii) requires that the product of the concentration for...

  7. 40 CFR Appendix A to Part 503 - Procedure To Determine the Annual Whole Sludge Application Rate for a Sewage Sludge

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Whole Sludge Application Rate for a Sewage Sludge A Appendix A to Part 503 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SEWAGE SLUDGE STANDARDS FOR THE USE OR DISPOSAL OF SEWAGE SLUDGE Pt... a Sewage Sludge Section 503.13(a)(4)(ii) requires that the product of the concentration for...

  8. 40 CFR Appendix A to Part 503 - Procedure To Determine the Annual Whole Sludge Application Rate for a Sewage Sludge

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Whole Sludge Application Rate for a Sewage Sludge A Appendix A to Part 503 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SEWAGE SLUDGE STANDARDS FOR THE USE OR DISPOSAL OF SEWAGE SLUDGE Pt... a Sewage Sludge Section 503.13(a)(4)(ii) requires that the product of the concentration for...

  9. 40 CFR Appendix A to Part 503 - Procedure To Determine the Annual Whole Sludge Application Rate for a Sewage Sludge

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Whole Sludge Application Rate for a Sewage Sludge A Appendix A to Part 503 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SEWAGE SLUDGE STANDARDS FOR THE USE OR DISPOSAL OF SEWAGE SLUDGE Pt... a Sewage Sludge Section 503.13(a)(4)(ii) requires that the product of the concentration for...

  10. 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.

  11. Land application of sewage sludge: physicochemical and microbial response.

    PubMed

    Singh, Rajeev Pratap; Singh, Pooja; Ibrahim, M Hakimi; Hashim, Rokiah

    2011-01-01

    In the present review, we address the effects of sewage sludge amendment on soil physicochemical properties and on soil microbial biomass. Sewage sludge is a by-product of sewage treatment processes and is increasingly applied to agricultural lands as a source of fertilizer, and as an alternative to conventional means of disposal. The particular characteristics of sewage sludge depend upon the quality of sewage from which it is made, and the type of treatment processes through which it passes. Sewage sludge may substitute for inorganic fertilizers because it is rich in organic and inorganic plant nutrients. However, the presence of potentially toxic metals and pathogens in sewage sludge often restricts its uses. Ground water and food chain contamination resulting from sewage sludge amendment is one major concern worldwide. The health of soils is represented by a composite of their physical, chemical and biological properties. Amending soil with sewage sludge modifies the physicochemical and biological properties of soils. Perhaps the central constituent of soil that is important in the context of sewage sludge amendment is microbial biomass. Soil microbial biomass, the key living part of the soil, is very closely associated with the content of organic matter that exists in arable agricultural soils. When sewage sludge is land-applied, soil enzyme activities may be directly or indirectly affected by the presence of heavy metals. In several studies, results have shown that sewage sludge amendment increased soil microbial and soil enzyme activities; however, reduction in soil enzyme activity has also been reported. When incubation periods of sewage sludge were longer, heavy metal bioavailability increased. Soil pathogenic activity has also been reported to increase as a result of land application of sewage sludges. The level of pathogens in treated sewage sludge (biosolids) depends on the processes used to treat wastewater and sewage sludge. Agricultural application

  12. Land application of sewage sludge: physicochemical and microbial response.

    PubMed

    Singh, Rajeev Pratap; Singh, Pooja; Ibrahim, M Hakimi; Hashim, Rokiah

    2011-01-01

    In the present review, we address the effects of sewage sludge amendment on soil physicochemical properties and on soil microbial biomass. Sewage sludge is a by-product of sewage treatment processes and is increasingly applied to agricultural lands as a source of fertilizer, and as an alternative to conventional means of disposal. The particular characteristics of sewage sludge depend upon the quality of sewage from which it is made, and the type of treatment processes through which it passes. Sewage sludge may substitute for inorganic fertilizers because it is rich in organic and inorganic plant nutrients. However, the presence of potentially toxic metals and pathogens in sewage sludge often restricts its uses. Ground water and food chain contamination resulting from sewage sludge amendment is one major concern worldwide. The health of soils is represented by a composite of their physical, chemical and biological properties. Amending soil with sewage sludge modifies the physicochemical and biological properties of soils. Perhaps the central constituent of soil that is important in the context of sewage sludge amendment is microbial biomass. Soil microbial biomass, the key living part of the soil, is very closely associated with the content of organic matter that exists in arable agricultural soils. When sewage sludge is land-applied, soil enzyme activities may be directly or indirectly affected by the presence of heavy metals. In several studies, results have shown that sewage sludge amendment increased soil microbial and soil enzyme activities; however, reduction in soil enzyme activity has also been reported. When incubation periods of sewage sludge were longer, heavy metal bioavailability increased. Soil pathogenic activity has also been reported to increase as a result of land application of sewage sludges. The level of pathogens in treated sewage sludge (biosolids) depends on the processes used to treat wastewater and sewage sludge. Agricultural application

  13. 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

  14. 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

  15. 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

  16. Hydrogen utilization by clostridia in sewage sludge.

    PubMed

    Ohwaki, K; Hungate, R E

    1977-06-01

    A sporeformer morphologically different but physiologically similar to Clostridium aceticum Wieringa was isolated from sewage sludge. It used large amounts of H2 and CO2, converting them chiefly to acetic acid. Growth occurs anaerobically on yeast extract alone, but after the nutrients in yeast extract are used, growth continues at a reduced rate, supported by the conversion of the gases to acetate. PMID:879782

  17. 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. PMID:23017593

  18. The electrodewatering of sewage sludges

    SciTech Connect

    Barton, W.A.; Miller, S.A.; Veal, C.J.

    1999-03-01

    Electrodewatering (EDW), the enhancement of conventional pressure filtration by an electric field, is an emerging technology with the potential to improve dewatering especially for difficult materials. CSIRO has many years of experience in EDW, ranging from bench scale tests to demonstration trials. A recent program has investigated the applicability of EDW to aerobic wastewater treatment sludges which are particularly difficult to dewater using conventional equipment. The bench scale filtration experiments produced cakes with solids contents of 35--46 wt% using EDW, compared with 24--30 wt% using pressure filtration alone. The paper: describes how the dewatering results were achieved; identifies a relationship between moisture removal limits by EDW and the forms of water within the sludge; and shows the results of preliminary attempts to mathematically model the EDW process.

  19. Metal partitioning and toxicity in sewage sludge

    SciTech Connect

    Carlson-Ekvall, C.E.A.; Morrison, G.M.

    1995-12-31

    Over 20 years of research has failed to provide an unequivocal correlation between chemically extracted metals in sewage sludge applied to agricultural soil and either metal toxicity to soil organisms or crop uptake. Partitioning of metals between phases and species can provide a better estimation of mobility and potential bioavailability. Partition coefficients, K{sub D} for Cd, Cu, Pb and Zn in a sludge/water solution were determined considering the sludge/water solution as a three-phase system (particulate, colloidal and electrochemically available) over a range of pH values, ionic strengths, contact times and sludge/water ratios and compared with the KD values for sludge/water solution as a two-phase system (aqueous phase and particulate phase). Partitioning results were interpreted in terms of metal mobility from sludge to colloids and in terms of potential bioavailability from colloids to electrochemically available. The results show that both mobility and potential bioavailability are high for Zn, while Cu partitions into the mobile colloidal phase which is relatively non-bioavailable. Lead is almost completely bound to the solid phase, and is neither mobile nor bioavailable. A comparison between K, values and toxicity shows that Zn in sludge is more toxic than can be accounted for in the aqueous phase, which can be due to synergistic effects between sludge organics and Zn. Copper demonstrates clear synergism which can be attributed to the formation of lipid-soluble Cu complexes with known sludge components such as LAS, caffeine, myristic acid and nonylphenol.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. Sewage sludge composting maintains momentum

    SciTech Connect

    Goldstein, N.

    1986-11-01

    The number of facilities composting municipal sludge is rising gradually in the U.S. after a dramatic surge between 1983 and 1985. Results of BioCycle's 1986 survey show a total of 178 municipalities and counties that are either operating or constructing plants, or that are in the bid, design, planning, or consideration stages. The total number in 1985 was 173, with four facilities shut down. In 1983, the first year a nationwide survey was conducted, there were 90. The aerated static pile method continues to lead the composting pack, with 53 operating facilities. Windrow composting comes in second, with 21 operating facilities. Five more in-vessel systems went into operation this year, bringing the total to eight. When it comes to facilities on the horizon, however, in-vessel is the category leader: there are 11 in-vessel projects under construction, 11 in the planning, design or bid stages, and 14 under consideration. Conversely, there are eight aerated static pile facilities under construction, 10 in the planning, design and bid stages, and 5.5 under consideration. Windrow composting operations comprise the third largest category, followed by aerated windrow composting.

  5. 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

  6. Radiofrequency-oxidation treatment of sewage sludge.

    PubMed

    Srinivasan, Asha; Young, Chris; Liao, Ping H; Lo, Kwang V

    2015-12-01

    A novel thermal-chemical treatment technology using radiofrequency heating and oxidants (hydrogen peroxide, ozone and a combination of both) was used for the treatment of sewage sludge. This was to evaluate the process effectiveness on cell disintegration and nutrient release of sludge, physical property changes such as particle size distribution, dewaterability and settleability, and their inter-relationships. The effectiveness of treatment processes was in the following order, from the most to least: thermal-oxidation process, oxidation process and thermal process. The thermal-oxidation process greatly increased cell disintegration and nutrient release, improved settleability, and decreased particle sizes. The treatment scheme involving ozone addition followed by hydrogen peroxide and radiofrequency heating yielded the highest soluble chemical oxygen demand, volatile fatty acids, ammonia and metals, while proffering the shortest capillary suction time and excellent settling properties. PMID:26233925

  7. Thixotropic behaviour of thickened sewage sludge.

    PubMed

    Trávníček, Petr; Junga, Petr

    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

  8. 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

  9. 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.

  10. Sewage sludge disposal apparatus and method of disposal

    SciTech Connect

    Williams, R.M.

    1981-01-20

    A system is described for disposing of sewage sludge by treating the sludge in apparatus which processes the sludge through relatively inert gas drying and grinding stages and utilized as much of the dried and ground sludge as is needed to produce heat for maintaining the drying process in the system once the system has become substantially self sufficient on use of the sludge as the drying heat source. The remaining excess sludge is then in a form either granular or fine suitable for direct sale.

  11. Application of sewage sludge compost on highway embankments.

    PubMed

    Pengcheng, Gao; Xinbao, Tang; Yanan, Tong; Yingxu, Chen

    2008-01-01

    More and more sewage sludge is being produced in China. Safe and economical methods for sewage sludge disposal should be found considering the increase in sewage treatment. In order to verify the feasibility of sludge disposal on newly built highway embankments, five treatments (0, 15, 30, 60 and 120 tons ha(-1)) of sewage sludge compost (SSC) were added to a silty-clay embankment soil on the Xi-Huang highway. The results showed that amendment with SSC increased soil available N, available P, organic matter, cation exchange capacity, and water content, and decreased soil bulk density. Application of SSC enhanced ryegrass growth and reduced runoff and soil erosion. Heavy metal losses from sediments in runoff remained constant or decreased relative to the control until a rate of 60 tons ha(-1) was exceeded, when heavy metal losses appeared to increase.

  12. Depletion of selective serotonin reuptake inhibitors during sewage sludge composting.

    PubMed

    Vasskog, Terje; Bergersen, Ove; Anderssen, Trude; Jensen, Einar; Eggen, Trine

    2009-11-01

    Sewage and sewage sludge is known to contain pharmaceuticals, and since sewage sludge is often used as fertilizer within agriculture, the reduction of the selective serotonin reuptake inhibitors (SSRIs) Citalopram, Sertraline, Paroxetine, Fluvoxamine and Fluoxetine during composting has been investigated. Sewage sludge was spiked with the SSRIs before the composting experiment started, and the concentration of the SSRIs in the sludge during a 21 day composting period was measured by liquid phase microextraction (LPME) and high-performance liquid chromatography-mass spectrometry. All the SSRIs had a significant decrease in concentration during the composting process. The highest reduction rates were measured for Fluoxetine and Paroxetine and the lowest for Citalopram. In addition three out of four known SSRI metabolites were found in all the samples, and two of them showed a significant increase in concentration during the composting period. PMID:19595585

  13. 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

  14. Incorporation of sewage sludge in clay brick and its characterization.

    PubMed

    Liew, Abdul G; Idris, Azni; Wong, Calvin H K; Samad, Abdul A; Noor, Megat Johari M M; Baki, Aminuddin M

    2004-08-01

    This study reports the use of sewage sludge generated from sewage treatment plant (STP) as raw material in a clay brick-making process. The physico-chemical and mineralogical characterization of the sewage sludge and clay were carried out in order to identify the major technological constraints and to define the sludge pretreatment requirements if necessary. Moreover, the effects on processing conditions and/or on changes of typical final characteristics are also evaluated. Bricks were produced with sewage sludge additions ranging from 10 to 40% by dry weight. The texture and finishing of the surface of sludge-amended clay bricks were rather poor. As for the physical and chemical properties, bricks with a sludge content of up to 40 wt.% were capable of meeting the relevant technical standards. However, bricks with more than 30 wt.% sludge addition are not recommended for use since they are brittle and easily broken even when handled gently. A tendency for a general degradation of brick properties with sludge additions was observed due to its refractory nature. Therefore, sludge bricks of this nature are only suitable for use as common bricks, which are normally not exposed to view, because of poor surface finishing.

  15. [Heavy metal problems in the agricultural utilization of sewage sludge].

    PubMed

    Leschber, R

    1983-09-01

    Introductory comments on the problems linked with sewage sludge disposal and utilization are given and it is demonstrated that agricultural use of sludge must definitely be given preference over other disposal methods for reasons related to waste utilization and ecology. The legal development which led from the promulgation of the Waste Disposal Act via its recent revision to the Sewage Sludge Decree according to para 15 of this Act, is illustrated. Subsequently the objectives of the decree, which in particular also attempts to solve the problems associated with heavy metals in agricultural sludge utilization, as well as the technical contents of the draft are dealt with. Reference is made to the Sewage Sludge Decree promulgated by the Swiss Bundesrat and to a corresponding draft of guidelines prepared by the Commission of the EEC and the measures which must be adopted to solve the heavy metal problem in the future are then mentioned.

  16. Indirect methods of dried sewage sludge contamination assessments.

    PubMed

    Werle, Sebastian; Dudziak, Mariusz; Grübel, Klaudiusz

    2016-07-28

    Thermal conversion (combustion, co-combustion, gasification and pyrolysis) appears to be the most promising alternative for sewage sludge management in the future. Nevertheless, safe and ecological usage of sewage sludge as a fuel requires information about their contamination. The aim of this paper is to present the photoacoustic spectroscopy (PAS) as a good method for contamination assessments of dried sewage sludge. Two types of granular sewage sludge: Sewage sludge 1 (SS1) taken from Polish wastewater treatment plant operating in the mechanical-biological system and sewage sludge 2 (SS2) taken from mechanical-biological-chemical wastewater treatment plant with phosphorus precipitation were analysed. The spectrophotometer FTIR Nicolet 6700 equipped with photoacoustic cell (Model 300, MTEC, USA) was used. The comparison with the most popular analytical methods (GC-MS) was also done. The results of PAS studies confirm the difference between the SS1 and SS2 which is in agreement with the GC-MS analysis. Higher absorbance was observed at each wavelength characteristics for the oscillator of chemical moieties for the SS1 with respect to the SS2. PMID:27149560

  17. Preparing sewage sludge for land application or surface disposal: A guide for preparers of sewage sludge on the monitoring, record keeping, and reporting requirements of the federal standards for the use of disposal of sewage sludge, 40 CFR part 503

    SciTech Connect

    Not Available

    1993-08-01

    The document focuses on the monitoring, recordkeeping, and reporting requirements that apply to persons who prepare sewage sludge or a material derived from sewage sludge. It defines persons who prepare sewage sludge and then summarizes their general responsibilities. USEPA promulgated at 40 CFR Part 503 Phase 1 of the risk-based regulations that govern the final use or disposal of sewage sludge. The intent of the Federal program is to ensure that the use or disposal of sewage sludge occurs in a way that protects both human health and the environment. The Part 503 regulation establishes general requirements, pollutant limits, operational standards, and management practices, as well as monitoring, recordkeeping, and reporting requirements. These requirements apply to sewage sludge that is land applied, placed on a surface disposal site, or incinerated in a sewage sludge-only incinerator.

  18. 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.

  19. 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. PMID:25840737

  20. [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. PMID:6649990

  1. 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.

  2. 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. PMID:12667015

  3. 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.

  4. Occurrence of ultrasonic cavitation in sewage sludge

    NASA Astrophysics Data System (ADS)

    Zielewicz-Madej, E.; Sorys, P.

    2006-11-01

    The study revealed considerable differences in the susceptibility of the sludge to preliminary treatment by two kind of mixing and expressed as changes in the initial properties of the sludge and thus conditions for the occurrence of ultrasonic disintegration in particular sludge from wastewater treatment plants G, K andZ. The susceptibility of sludge to ultrasounds which depends on the sludge properties was explained by the higher COD of dissolved matter after ultrasonic disintegration of sludge.

  5. 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.

  6. 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...

  7. The production, use and quality of sewage sludge in Denmark

    SciTech Connect

    Jensen, John . E-mail: john.jensen@dmu.dk; Jepsen, Svend-Erik

    2005-07-01

    In Denmark, the production of municipal sewage sludge decreased from approximately 170,000 ton d.m. in 1994 to 140,000 ton d.m. in 2002. The sludge is handled and treated in a number of ways. The quality of Danish sludge has steadily improved since the middle of the 1980s, when the first set of quality criteria for heavy metals was introduced. In 1997, cut-off criteria for the organic pollutants, LAS, DEHP, nonylphenol and PAHs were introduced. Effective control from authorities, voluntary phasing out agreements with industry, improved source identification tools, better handling and after-care methods have in combination with higher waste duties led to a significant reduction in the sludge level of especially cadmium, mercury, chromium, LAS and nonylphenol. The increased quality demand has, nevertheless, also led to a minor reduction in the use of sewage sludge as organic fertiliser on agricultural land.

  8. 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

  9. 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.

  10. 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.

  11. 40 CFR 60.4780 - What sewage sludge incineration units are exempt from this subpart?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... designed to treat domestic sewage sludge. These units may be subject to another subpart of this part (e.g... 40 Protection of Environment 7 2012-07-01 2012-07-01 false What sewage sludge incineration units... Standards of Performance for New Sewage Sludge Incineration Units Applicability and Delegation of...

  12. 40 CFR 60.4780 - What sewage sludge incineration units are exempt from this subpart?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... designed to treat domestic sewage sludge. These units may be subject to another subpart of this part (e.g... 40 Protection of Environment 6 2011-07-01 2011-07-01 false What sewage sludge incineration units... Standards of Performance for New Sewage Sludge Incineration Units Applicability and Delegation of...

  13. 40 CFR 60.4780 - What sewage sludge incineration units are exempt from this subpart?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... designed to treat domestic sewage sludge. These units may be subject to another subpart of this part (e.g... 40 Protection of Environment 7 2013-07-01 2013-07-01 false What sewage sludge incineration units... Standards of Performance for New Sewage Sludge Incineration Units Applicability and Delegation of...

  14. 40 CFR 60.4780 - What sewage sludge incineration units are exempt from this subpart?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... designed to treat domestic sewage sludge. These units may be subject to another subpart of this part (e.g... 40 Protection of Environment 7 2014-07-01 2014-07-01 false What sewage sludge incineration units... Standards of Performance for New Sewage Sludge Incineration Units Applicability and Delegation of...

  15. 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.)

  16. 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.)

  17. 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.)

  18. 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.

  19. Bioleaching of heavy metals from sewage sludge using Acidithiobacillus thiooxidans

    NASA Astrophysics Data System (ADS)

    Wen, Ye-Ming; Lin, Hong-Yan; Wang, Qing-Ping; Chen, Zu-Liang

    2010-11-01

    Acidithiobacillus thiooxidans was isolated from sewage sludge using the incubation in the Waksman liquor medium and the inoculation in Waksman solid plate. It was found that the optimum conditions of the bioleaching included solid concentration 2%, sulfur concentration 5 gṡL-1 and cell concentration 10%. The removal efficiency of Cr, Cu, Pb and Zh in sewage sludge, which was obtained from waste treatment plant, Jinshan, Fuzhou, was 43.65%, 96.24%, 41.61% and 96.50% in the period of 4˜10 days under the optimum conditions, respectively. After processing using the proposed techniques, the heavy metals in sewage sludge did meet the requirement the standards of nation.

  20. 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.

  1. 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. PMID:22053457

  2. Potential fertilizing properties of sewage sludge treated in the sludge treatment reed beds (STRB).

    PubMed

    Kołecka, Katarzyna; Obarska-Pempkowiak, Hanna

    2013-01-01

    In previous research the fertilizer value of sludge from reed beds was evaluated based on the sampling sludge on different depths from four Danish sludge treatment reed beds (STRB) after long periods of stabilization. The dewatering efficiency of sewage sludge in the STRB is comparable to mechanical dewatering. The long-term stabilization of sewage sludge progressively decreases the concentration of organic matter due to the process of humification. The aim of the work was to determine the changes of organic matter concentration, nutrients concentrations as well as speciation of selected heavy metals (Cd, Pb, Ni, Cr, Cu and Zn) in vertical profile of the sewage sludge stabilized in the STRB for 7-15 years. The analyzed sewage sludge was collected from the STRB treating sludge from four municipal wastewater treatment plants located in Denmark serving from 9,000 to 40,000 person equivalent. Analyzed heavy metals (except for Zn) were mostly bound with the most stable - residual - fraction. The most stable metals were Pb and Cr, where the share of the residual fraction exceeded 80.0%. The most mobile metal was Zn, where the share of the mobile fractions (calculated as the sum of I, II and III fractions) exceeded 85.0%. The high concentration of nitrogen and phosphorus is the decisive factor in the high valuation of sludge stabilized in the STRB as fertilizer.

  3. 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

  4. Evaluation of sludge characteristics and metals emissions from municipal sewage sludge incinerators

    SciTech Connect

    Hart, R.S.; Conklin, J.A.; Munn, B.G.

    1996-12-31

    The United States Environmental Protection Agency (USEPA) has promulgated regulations affecting the disposal of municipal sewage sludge under Title 40 of the Code of Federal Regulation (CFR) Part 503. The paper addresses emissions requirements for sewage sludge incineration under 40 CFR Part 503, Subpart E. The paper focuses on factors that may influence sewage sludge characteristics, sewage sludge metals feed rates, and the corresponding metals emission rates. Emissions test programs were conducted at three municipal wastewater treatment plants (WWTP), City of Auburn WWTP. City of Glens Falls WWTP, and Saratoga County Sewer District No. 1 WWTP, to determine mass emissions of multiple metals (As, Be, Cd, Cr, Cu, Pb, Ni, Hg, Se, and Zn). The influent incinerator sludge was sampled in conjunction with each test program to determine the sludge metals content. The sewage sludge was analyzed in accordance with USEPA Method SW846. Multiple metals emissions were determined in accordance with USEPA 40 CFR 60, Appendix A, Method 29 sampling and analytical procedures. The results from these test programs were analyzed to identify the factors that influence the metals emission rates. The resulting metals removal efficiencies from each of the three pollution control systems are quantified. Unique analytical issues encountered during these test programs are also addressed. 7 refs., 3 tabs.

  5. Influence of bulking agent on sewage sludge composting process.

    PubMed

    Yañez, R; Alonso, J L; Díaz, M J

    2009-12-01

    Four types of compost, consisting of mixtures of Acacia dealbata (A) with sewage sludge (SS) were studied in a laboratory reactor. Composting time was 80 days and parameters monitored over this period included temperature, organic matter, pH, CO(2), O(2), C/N ratio, Kjeldahl-N, as well as maturity indexes. All the studied parameters were influenced by the bulking amount used. The highest profile temperature measured was for the A/SS 1/2 (w/w) mixture that reached a maxima temperature of 67 degrees C and lower maximum temperatures of 52, 48 and 46 degrees C were observed for A/SS 1/3, 1/1 and 1/0 composts, respectively. The kinetic model used showed that a descent of sewage sludge in the composting mixtures favored the enzyme-substrate affinity. However, an increase in depending on the parameters of the process factors was observed when the sewage sludge ratio was increased in mixtures. The optimal amounts of sewage sludge for co-composting with Acacia indicate that moderate amounts of sludge (1/1) would be the best compromise. PMID:19560348

  6. 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

  7. 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.

  8. Effect of Ultrasound on Dewaterability of Sewage Sludge

    NASA Astrophysics Data System (ADS)

    Kim, Young-Uk; Kim, Byoung-Il

    2003-09-01

    In this study, we investigate the effect of ultrasound on the dewaterability of sewage sludge. The investigation involves laboratory experiments, which were conducted under a broad range of conditions, including energy levels of ultrasonic waves, treatment time, and pH. Results of the study show that ultrasound enhances dewaterability significantly. The degree of enhancement varies with sonication energy, treatment time, and the amount of treated sludge.

  9. Synthetic polycyclic musks in Hong Kong sewage sludge.

    PubMed

    Shek, W M; Murphy, M B; Lam, James C W; Lam, Paul K S

    2008-04-01

    Synthetic polycyclic musks [Cashmeran (DPMI), Celestolide (ADBI), Phantolide (AHMI), Traseolide (ATII), Tonalide (AHTN), and Galaxolide (HHCB)] were determined in dewatered sludge samples from 10 major sewage treatment plants in Hong Kong using primary treatment (PT), secondary treatment (SecT) or chemical-enhanced primary treatment (CEPT) methods. The concentrations of HHCB, AHTN, AHMI and ADBI ranged from below detection limits to 78.6mg/kg dry weight. HHCB and AHTN were the two predominant polycyclic musks in sludge samples, suggesting the extensive use of these two polycyclic musks in Hong Kong. Polycyclic musk levels in CEPT sludge were significantly higher than those in SecT and PT sludge, suggesting that CEPT sludge has a higher ability to retain polycyclic musks. Comparisons to global concentrations revealed that HHCB and AHTN concentrations detected in Hong Kong sludge ranked first and second respectively. However, the estimated levels of HHCB and AHTN in the discharged effluent from sewage treatment plants may pose low potential risks to aquatic organisms according to the threshold effect levels derived for fish. Nevertheless, the polycyclic musks released in sewage treatment plant effluents may bioconcentrate and bioaccumulate in the marine environment in Hong Kong. Therefore, monitoring studies in marine ecosystems, particularly on the two prevailing polycyclic musks, are necessary. PMID:18267326

  10. Synthetic polycyclic musks in Hong Kong sewage sludge.

    PubMed

    Shek, W M; Murphy, M B; Lam, James C W; Lam, Paul K S

    2008-04-01

    Synthetic polycyclic musks [Cashmeran (DPMI), Celestolide (ADBI), Phantolide (AHMI), Traseolide (ATII), Tonalide (AHTN), and Galaxolide (HHCB)] were determined in dewatered sludge samples from 10 major sewage treatment plants in Hong Kong using primary treatment (PT), secondary treatment (SecT) or chemical-enhanced primary treatment (CEPT) methods. The concentrations of HHCB, AHTN, AHMI and ADBI ranged from below detection limits to 78.6mg/kg dry weight. HHCB and AHTN were the two predominant polycyclic musks in sludge samples, suggesting the extensive use of these two polycyclic musks in Hong Kong. Polycyclic musk levels in CEPT sludge were significantly higher than those in SecT and PT sludge, suggesting that CEPT sludge has a higher ability to retain polycyclic musks. Comparisons to global concentrations revealed that HHCB and AHTN concentrations detected in Hong Kong sludge ranked first and second respectively. However, the estimated levels of HHCB and AHTN in the discharged effluent from sewage treatment plants may pose low potential risks to aquatic organisms according to the threshold effect levels derived for fish. Nevertheless, the polycyclic musks released in sewage treatment plant effluents may bioconcentrate and bioaccumulate in the marine environment in Hong Kong. Therefore, monitoring studies in marine ecosystems, particularly on the two prevailing polycyclic musks, are necessary.

  11. BY-PRODUCTS FROM SEWAGE SLUDGE

    PubMed Central

    Weston, Robert Spurr

    1920-01-01

    Economy and conservation have worked for years at the problem of profit from sewage. Mr. Weston notes that many American cities have potential by-products enough to make recovery worth trying. English cities have found the American Miles process profitable. It will at least lessen the cost of sewage disposal. PMID:18010306

  12. [Effects of ultrasonic pretreatment on drying characteristics of sewage sludge].

    PubMed

    Li, Run-Dong; Yang, Yu-Ting; Li, Yan-Long; Niu, Hui-Chang; Wei, Li-Hong; Sun, Yang; Ke, Xin

    2009-11-01

    The high water content of sewage sludge has engendered many inconveniences to its treatment and disposal. While ultrasonic takes on unique advantages on the sludge drying because of its high ultrasonic power, mighty penetrating capability and the ability of causing cavitations. Thus this research studies the characteristics influences of ultrasonic bring to the sludge drying and effects of the exposure time, ultrasonic generator power, temperatures of ultrasonic and drying temperature on the drying characteristics of dewatered sludge. Results indicate that ultrasonic pretreatment could speed up evaporation of the free water in sludge surface and help to end the drying stage with constant speed. In addition, ultrasonic treatment can effectively improve the sludge drying efficiency which could be more evident with the rise of the ultrasonic power (100-250 W), ultrasonic temperature and drying temperature. If dried under low temperature such as 105 degrees C, sludge will have premium drying characteristics when radiated under ultrasound for a shorter time such as 3 min. In the end, the ultrasonic treatment is expected to be an effective way to the low-cost sludge drying and also be an important reference to the optimization of the sludge drying process because of its effects on the increase of sludge drying efficiency. PMID:20063762

  13. [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.

  14. We Should Expect More out of Our Sewage Sludge.

    PubMed

    Peccia, Jordan; Westerhoff, Paul

    2015-07-21

    Sewage sludge and biosolids production and management are a central component of water and sanitation engineering. The culmination of previous incremental technologies and regulations aimed at solving a current treatment problem, rather than developing the practice for the higher goals of sustainability have resulted in sludge becoming an economic and social liability. Sludge management practice must shift from treatment of a liability toward recovery of the embedded energy and chemical assets, while continuing to protect the environment and human health. This shift will require new research, treatment technologies and infrastructure and must be guided by the application of green engineering principles to ensure economic, social, and environmental sustainability.

  15. 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.

  16. 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 ...

  17. 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...

  18. Land Application of Sewage Effluents and Sludges: Selected Abstracts.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Washington, DC. Office of Research and Development.

    This report contains 568 selected abstracts concerned with the land application of sewage effluents and sludges. The abstracts are arranged in chronological groupings of ten-year periods from the l940's to the mid-l970's. The report also includes an author index and a subject matter index to facilitate reference to specific abstracts or narrower…

  19. 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.

  20. 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. PMID:15763091

  1. The toxicity to plants of the sewage sludges containing multiwalled carbon nanotubes.

    PubMed

    Oleszczuk, Patryk; Jośko, Izabela; Xing, Baoshan

    2011-02-15

    The aim of this study was to evaluate the toxicity of sewage sludges containing multiwalled carbon nanotubes (CNTs) with an outer diameter <10 nm (CNT10) or 40-60 nm (CNT60) to Lepidium sativum (cress), Sorghum saccharatum (sorgo), Solanum lycopersicon (tomato), Raphanus sativus (radish) and Cucumis sativus (cucumber). CNTs were also incubated in sewage sludge for 7 or 31 days to determine the effect of CNT aging on sewage sludge phytotoxicity. The influence of CNTs on 4 different sewage sludges was tested. The CNTs' influence on sludge toxicity varied with respect to the CNTs' outer diameter, type of sewage sludges and the plants tested. No significant influence of CNT concentration on phytotoxicity was noted. In the case of two sludges, a positive influence of CNTs on seed germination and root growth was observed. Depending on the CNTs' outer diameter, CNT aging decreased (CNT10) or increased (CNT60) sewage sludge phytotoxicity. PMID:21145166

  2. 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.

  3. 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.

  4. Influence of sewage sludge addition on coal ash fusion temperatures

    SciTech Connect

    M. Belen Folgueras; R. Maria Diaz; Jorge Xiberta; M. Purificacion Garcia; J. Juan Pis

    2005-12-01

    The ash fusion characteristics of three types of bituminous coal (A, B, and C), one type of sewage sludge (W), and the corresponding coal-sewage sludge blends (10 and 50 wt % of sludge) were studied. The ash fusibility temperatures of samples in oxidizing atmosphere were measured, and their chemical and mineralogical compositions were determined. The addition of sludge to coal in certain proportions produces blends whose ashes have lower fusibility temperatures than those of coal and sludge. This is related to the differences in chemical composition and modes of elemental combination in both types of materials. The main differences are associated to the elements P, Fe, and Ca. As the sludge is much richer in Ca than the coals, the compositions of the blend ashes pass through low-temperature eutectic regions of the ternary phase diagrams SiO{sub 2}-CaO-Al{sub 2}O{sub 3} and SiO{sub 2}-CaO-Fe{sub 2}O{sub 3}. As a result, for the sludge-coal blend ashes series (one for each coal), the relationships between ash fusibility temperatures and the percentage of sludge ash in blend ashes fit to second-order polynomial functions. The minima of these functions, as well as some sludge-coal blend ashes, are located in the above-mentioned low fusion regions. Differing from coal ashes, in the sludge and 50 wt % blend ashes, the minerals calcium ferrite, larnite, and chloroapatite were found. 17 refs., 6 figs., 6 tabs.

  5. 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. PMID:18682307

  6. Comparative performance of mesophilic and thermophilic anaerobic digestion for high-solid sewage sludge.

    PubMed

    Hidaka, Taira; Wang, Feng; Togari, Taketo; Uchida, Tsutomu; Suzuki, Yutaka

    2013-12-01

    In local cities, many small sewage and waste treatment facilities are operated independently. To encourage processing by anaerobic digestion at a centralized sewage treatment plant (STP), high-solid sewage sludge is helpful because it reduces the energy and cost required for transporting the sludge from other STPs. Mesophilic and thermophilic anaerobic digestion of sewage sludge at total solids concentrations (TS) of 7.5% and 10% were evaluated using laboratory-scale continuous reactors. Under the mesophilic condition, sewage sludge of 10% TS was successfully treated. Under the thermophilic condition, sewage sludge of 7.5% TS was not successfully treated when the total ammonia concentration was over 2000 mg N/L. Batch experiments showed that it takes a few weeks for the methane fermentation activity to recover after being inhibited. The effectiveness of adding easily biodegradable organic matter was confirmed. These results show that high-solid sewage sludge is suitable for small facilities by controlling the operating conditions.

  7. 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...

  8. Impact of composting strategies on the degradation of nonylphenol in sewage sludge.

    PubMed

    Zheng, Guodi; Chen, Tongbin; Yu, Jie; Gao, Ding; Shen, Yujun; Niu, Mingjie; Liu, Hongtao

    2015-12-01

    Nonylphenol can be present in sewage sludge, and this can limit the use of the sewage sludge to amend soil. Composting is one of the most efficient and economical methods of making sewage sludge stable and harmless. The nonylphenol degradation rates during composting with added bulking agents and with aeration applied were studied. Three organic bulking agents (sawdust, corn stalk, and mushroom residue) were added to sewage sludge, and the effects of the bulking agents used and the amount added on nonylphenol degradation were determined. The highest apparent nonylphenol degradation rate (71.6%) was found for sewage sludge containing 20% mushroom residue. The lowest apparent nonylphenol degradation rate (22.5%) was found for sewage sludge containing 20% sawdust. The temperature of the composting pile of sewage sludge containing 20% sawdust became too high for nonylphenol to be efficiently degraded, and the apparent nonylphenol degradation rate was lower than was found for sewage sludge containing 10% sawdust. Increasing the ventilating time from 5 to 15 min increased the apparent nonylphenol degradation rate from 19.7 to 41.6%. Using appropriate aerobic conditions facilitates the degradation of nonylphenol in sewage sludge, decreasing the risks posed by sewage sludge applied to land. Adding too much of a bulking agent can decrease the amount of the nonylphenol degraded. Increasing the ventilating time and the amount of air supplied can increase the amount of nonylphenol degraded even if doing so causes the composting pile temperature to remain low.

  9. [Distribution character of synthetic musks in urban sewage sludges].

    PubMed

    Guo, Ya-Wen; Zhang, Xiao-Lan; Qian, Guang-Ren; Wang, Jun; Liu, Zhong-Zhe; Liang, Gao-Feng; Sheng, Guo-Ying; Fu, Jia-Mo

    2009-05-15

    The characteristics of occurrence and distribution of 8 synthetic musks in 15 sewage sludges in Shanghai were studied. The results indicated that HHCB and AHTN were the two main components in all sludges, with the mean concentration of 2.92 mg x kg(-1) (0.81-6.39 mg x kg(-1)) and 1.96 mg x kg(-1) (0.35-3.11 mg x kg(-1)), respectively; and the concentrations of ADBI, AHMI, MK were less. The distributions detected in sludges are in accordance with the usage patterns in China. Total concentrations of 8 synthetic musks were ranged from 1.16-9.57 mg x kg(-1), which were lower than the results in previous studies. Concentrations in sludges are influenced by ratio of domestic wastewater in influent, sewage load and sewage treatment methods. The good linear relationships among HHCB, AHTN and ADBI indicate that these components have the same source: domestic wastewater. The consumption rates of HHCB and AHTN connected to per inhabitant in Shanghai region were estimated, which are low compared with those found in European. The potential impacts on agricultural soil were also assessed.

  10. 40 CFR 60.4770 - Does this subpart apply to my sewage sludge incineration unit?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... sludge incineration unit? 60.4770 Section 60.4770 Protection of Environment ENVIRONMENTAL PROTECTION... of Performance for New Sewage Sludge Incineration Units Applicability and Delegation of Authority § 60.4770 Does this subpart apply to my sewage sludge incineration unit? Yes, your SSI unit is...

  11. 40 CFR 60.4770 - Does this subpart apply to my sewage sludge incineration unit?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... sludge incineration unit? 60.4770 Section 60.4770 Protection of Environment ENVIRONMENTAL PROTECTION... of Performance for New Sewage Sludge Incineration Units Applicability and Delegation of Authority § 60.4770 Does this subpart apply to my sewage sludge incineration unit? Yes, your SSI unit is...

  12. 40 CFR 60.4770 - Does this subpart apply to my sewage sludge incineration unit?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... sludge incineration unit? 60.4770 Section 60.4770 Protection of Environment ENVIRONMENTAL PROTECTION... of Performance for New Sewage Sludge Incineration Units Applicability and Delegation of Authority § 60.4770 Does this subpart apply to my sewage sludge incineration unit? Yes, your SSI unit is...

  13. 40 CFR 60.4770 - Does this subpart apply to my sewage sludge incineration unit?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... sludge incineration unit? 60.4770 Section 60.4770 Protection of Environment ENVIRONMENTAL PROTECTION... of Performance for New Sewage Sludge Incineration Units Applicability and Delegation of Authority § 60.4770 Does this subpart apply to my sewage sludge incineration unit? Yes, your SSI unit is...

  14. 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

  15. 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.

  16. 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. PMID:27470467

  17. [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.

  18. 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.

  19. [Effects of land utilization of sewage sludge on crops and soils].

    PubMed

    Wang, Xin; Chen, Tao; Liang, Renlu; Zhou, Qixing

    2002-02-01

    Effects of land utilization of sewage sludge on crops and soil environment were studied using sewage sludge from the Northern Shenyang Plant of Wastewater Treatment. The results showed that contents of nitrogen, phosphorus and organic matter in the soil were increased after the utilization of sewage sludge, thus being advantageous to growth and development of crops. The biomass of rice after having applied 22.5 and 45 t.hm-2 of sewage sludge was increased by 11.48%-11.83% compared with the control. There was no evident harmful effect of heavy methals from sewage sludge on quality of soil environment, agricultural products and underground water when the application of sewage sludge was controlled within the range of 45 t.hm-2.

  20. 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. PMID:26635022

  1. 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.

  2. 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. PMID:27161507

  3. Dynamic of lead speciation in sewage sludge composting.

    PubMed

    Zheng, G D; Chen, T B; Gao, D; Luo, W

    2004-01-01

    A large-scale sewage sludge composting experiment was conducted to develop an understanding of changes that occur to Pb chemical speciation, distribution and bio-availability during the course of composting. The four-stage Tessier sequential extraction method was employed to investigate the dynamics of heavy metal Pb speciation (exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and sulphides, residual) during the course of sewage sludge composting. The concentrations of the total Pb and the five Pb fractions concentrations were increased during the whole stage of compost. However, the percentages of Pb distribution with respect to total Pb were changed in the following manner: exchangeable, bound to Fe-Mn oxides and bound to carbonates Pb with respect to total Pb were increased, while the percentages of bound to organic matter and sulphides, and residual Pb with respect to total Pb were decreased during composting. The data showed that the quantity of Pb in the less toxic portion, such as consisting of organic matter and sulphides bound and residual Pb, was increased, and that the contamination and bio-availability of heavy metal Pb in sewage sludge was reduced during the composting process.

  4. 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.

  5. [Characteristics of thermophilic ASBR treating thermal-hydrolyzed sewage sludge].

    PubMed

    Ouyang, Er-Ming; Wang, Wei

    2010-10-01

    The characteristics of thermophilic anaerobic sequencing batch reactor (ASBR) treating thermal-hydrolyzed sewage sludge were investigated. The results showed that increasing the OLR (COD) of the thermophilic ASBR treating thermal-hydrolyzed sewage sludge from 7.762 kg/(m3 x d) to 13.106 kg/(m3 x d) lead to the "acidification" of the reactor with the accumulation of the volatile fatty acid (VFA) and the drop of the pH and gas production. This acidification is recoverability. The OLR(COD) of the thermophilic ASBR treating thermal-hydrolyzed sewage sludge can reach to 10 kg/(m3 x d) after the system was recovered. Under the OLR(COD) of 2.523, 4.196, 7.762 and 10.091 kg/(m3 x d), the methane yield (CH4/COD(input)) of thermophilic ASBR were 250, 247, 219 and 187 mL respectively. There are significant linear relationship among OLR and MPR, the methane yield. With the increase of the OLR, the methane production rate increased while the methane yield reduced.

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. Effect of experimental conditions on gas quality and solids produced by sewage sludge cogasification. 1. Sewage sludge mixed with coal

    SciTech Connect

    Filomena Pinto; Helena Lopes; Rui Neto Andre; Mario Dias; I. Gulyurtlu; I. Cabrita

    2007-09-15

    Cogasification of sewage sludge mixed with coal showed that the amount of sewage sludge supplied to the gasifier, depending on its availability, could vary without affecting the gasifier performance; however, it had an influence on the syngas composition. The use of sewage sludge during coal gasification gave rise to an increasing gas yield and energy conversion, mainly because the gas produced had a greater hydrocarbon content. H{sub 2}S, HCl, and especially NH{sub 3} were also found to increase, due to higher contents of nitrogen in the sewage sludge compared with coal. The rise of both the temperature and the air flow rate resulted in the production of more gas and a lowering of hydrocarbon, char, and tar contents. A decrease in NH{sub 3} content was also observed, as the increase of these parameters promoted the destruction of this compound. The rise in the equivalent ratio also led to lower contents of H{sub 2}S and HCl, probably due to the partial oxidation of these compounds; however, the total amount of these elements released to the gas phase was not considerably affected. On the other hand, H{sub 2}S formation was favored by the rise in temperature up to 850{sup o}C, while the HCl concentration was not significantly affected. Heavy metals supplied with the fuel were mostly retained in solid residues, with Pb and Hg being the most volatile at 850{sup o}C. However, the leachability of these metals was found to be below the analytical detection levels, and only small quantities of SO{sub 4}{sup 2-} and Cl{sup -} were released. 28 refs., 15 figs., 1 tab.

  12. 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).

  13. 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. PMID:23063441

  14. 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

  15. Glazed tiles manufactured from incinerated sewage sludge ash and clay.

    PubMed

    Lin, Deng-Fong; Luo, Huan-Lin; Sheen, Yeong-Nain

    2005-02-01

    Sewage sludge incineration is applied extensively in highly populated cities as a final sludge treatment. In this study, incinerated ash was utilized as an additive to clay to manufacture glaze tiles. Four different amounts of ash (0, 15, 30, and 45%) were added, and five glaze concentrations (0.03, 0.06, 0.1, 0.15, and 0.2 g/cm2) were applied on the surface of biscuit tiles to study the effects of ash additive and glaze concentration on properties of fired samples. Sewage sludge was dehydrated and incinerated into ash at 800 degrees C. Subsequently, tile specimens were manufactured and fired at 800 degrees C to make biscuit tiles. Fritted glazes and iron oxide were used as the fundamental glaze and colorant, respectively. Finally, glaze was applied on the surface of biscuit tiles and then fired at 1050 degrees C to sinter them into glazed tile specimens. Tests were performed to analyze properties, including water absorption, firing shrinkage, weight loss on ignition, abrasion resistance, bending resistance, acid-alkali resistance, and aging resistance on specimens of glaze tile. To further understand more about the microstructural behavior of glazed tile specimens, analysis of energy dispersive spectrometer, scanning electron microscopy, and X-ray were carried out in this study.

  16. 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.

  17. 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. PMID:25913030

  18. Energy recovery from secondary pulp/paper-mill sludge and sewage sludge with supercritical water treatment.

    PubMed

    Zhang, Linghong; Xu, Chunbao Charles; Champagne, Pascale

    2010-04-01

    Secondary pulp/paper-mill sludge (SPP) and sewage sludges (primary, secondary, and digested sewage sludges) were treated in supercritical water at temperatures ranging between 400 degrees Celsius and 550 degrees Celsius over 20-120 min for energy recovery. Low temperature and short reaction time favored the formation of heavy oil (HO) products, which were mainly composed of a variety of phenol and phenolic compounds, as well as some nitrogen-containing compounds, long-chain alkenes and alcohols, etc., with high gross calorific values (>36 MJ/kg). By contrast, the formation of synthetic gases, a mixture of hydrogen, carbon monoxide, carbon dioxide, methane, and other light hydrocarbons, were not significantly affected by reaction time but greatly enhanced with increasing temperature. The highest gas yield was obtained at 550 degrees Celsius, where 37.7 wt.% of the SPP (on dry basis) was converted into gases, with hydrogen yields as high as 14.5 mol H(2)/kg SPP (on a dry basis). In comparison to sewage sludges, SPP exhibited a greater capability for the production of HO and gases owing to its higher contents of volatiles and alkali metals, indicating a prospective utilization potential for SPP as a source of bio-energy.

  19. 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.

  20. 40 CFR 60.4775 - What is a new sewage sludge incineration unit?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... incineration unit? 60.4775 Section 60.4775 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... for New Sewage Sludge Incineration Units Applicability and Delegation of Authority § 60.4775 What is a new sewage sludge incineration unit? (a) A new SSI unit is a SSI unit that meets either of the...

  1. 40 CFR 60.4775 - What is a new sewage sludge incineration unit?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... incineration unit? 60.4775 Section 60.4775 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... for New Sewage Sludge Incineration Units Applicability and Delegation of Authority § 60.4775 What is a new sewage sludge incineration unit? (a) A new SSI unit is a SSI unit that meets either of the...

  2. 40 CFR 60.4775 - What is a new sewage sludge incineration unit?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... incineration unit? 60.4775 Section 60.4775 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... for New Sewage Sludge Incineration Units Applicability and Delegation of Authority § 60.4775 What is a new sewage sludge incineration unit? (a) A new SSI unit is a SSI unit that meets either of the...

  3. 40 CFR 60.4775 - What is a new sewage sludge incineration unit?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... incineration unit? 60.4775 Section 60.4775 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... for New Sewage Sludge Incineration Units Applicability and Delegation of Authority § 60.4775 What is a new sewage sludge incineration unit? (a) A new SSI unit is a SSI unit that meets either of the...

  4. 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... SOURCES Standards of Performance for New Sewage Sludge Incineration Units Pt. 60, Subpt. LLLL, Table 5 Table 5 to Subpart LLLL of Part 60—Summary of Reporting Requirements for New Sewage Sludge...

  5. 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... SOURCES Standards of Performance for New Sewage Sludge Incineration Units Pt. 60, Subpt. LLLL, Table 5 Table 5 to Subpart LLLL of Part 60—Summary of Reporting Requirements for New Sewage Sludge...

  6. Metal sorption on soils as affected by the dissolved organic matter in sewage sludge and the relative calculation of sewage sludge application.

    PubMed

    Liu, Xiaoli; Zhang, Shuzhen; Wu, Wenyong; Liu, Honglu

    2007-10-22

    To evaluate the influences of sewage sludge-derived organic matters on metal sorption and on the resultant sludge loading estimates, a batch experiment was conducted to compare the sorption of Ni, Cu and Pb in sewage sludge filtrates (1:20 sewage sludge to water) on eight soils and the adsorption of metals in a reference solution which had the same matrix as the sewage sludge filtrate except dissolved organic material (henceforth referred to as reference solution). Metal sorption could be well fitted by linear isotherm and the dissolved organic matter in sludge significantly depressed the sorption (p<0.01). The main factor controlling sorption of Ni on different soils was dominated by soil cation exchange capacity (CEC) and sorption of Cu and Pb was by soil organic matter (SOM). The parameters obtained from the sorption isotherm equations were then used to estimate sludge loadings into the soils. When the sorption parameters derived from the reference solution were used for calculation, that is the effect of dissolved organic matter was not considered, the calculated safe application rates are approximately 47.8, 51.4, 34.2, 31.3, 21.7, 46.3, 187.1 and 27.6 t-sludge/ha for the Beijing, Jiangxi, Xiamen, Jilin, Guangdong, Wuhan, Gansu and Xinjiang soils, respectively. However, when the sorption parameters derived from the dissolved organo-metallic complexes are used for calculation, the corresponding application rates are reduced to approximately 6.0, 3.4, 1.9, 10.0, 6.3, 3.6, 7.3 and 3.5 t-sludge/ha, respectively. By this study we can get a conclusion that the effect of sewage sludge derived dissolved organic matter on heavy metal sorption and soil properties should be considered in the course of regulating the safe application rates of sewage sludge to soil.

  7. 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.

  8. 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. PMID:26877026

  9. [Effects of land utilization of sewage sludge on grass and soils].

    PubMed

    Wang, Xin; Zhou, Qixing; Chen, Tao; Ge, Yinghua; Tai, Peidong

    2003-03-01

    Effects of land disposal of sewage sludge on grass and soil environment were studied. The sewage sludge used was from Northern Shenyang Wastewater Treatment Plant. The results showed that contents of nutrient in the soil were increased after sewage sludge application, especially for organic matter. Grass biomass were increased and the green period were extended with a better growth of the lawn. The heavy metal contents in the soil were increased with Cd contents beyond 2nd grade national environmental quality standard for soils. However, Pb, Cu, Zn contents not accumulated heavily. Poa annua had better ability of absorbing and accumulating Pb from the sewage sludge. When the application rate of sewage sludge capacity was at 25, 30, 60 t.hm-2, Zoysia japonica expressed significant absorption and accumulation of Cd, Cu, Zn.

  10. Thermodynamic Equilibrium Calculations on Cd Transformation during Sewage Sludge Incineration.

    PubMed

    Liu, Jing-yong; Huang, Limao; Sun, Shuiyu; Ning, Xun'an; Kuo, Jiahong; Sun, Jian; Wang, Yujie; Xie, Wuming

    2016-06-01

    Thermodynamic equilibrium calculations were performed to reveal the distribution of cadmium during the sewage sludge incineration process. During sludge incineration in the presence of major minerals, such as SiO2, Al2O3 and CaO, the strongest effect was exerted by SiO2 on the Cd transformation compared with the effect of others. The stable solid product of CdSiO3 was formed easily with the reaction between Cd and SiO2, which can restrain the emissions of gaseous Cd pollutants. CdCl2 was formed more easily in the presence of chloride during incineration, thus, the volatilization of Cd was advanced by increasing chlorine content. At low temperatures, the volatilization of Cd was restrained due to the formation of the refractory solid metal sulfate. At high temperatures, the speciation of Cd was not affected by the presence of sulfur, but sulfur could affect the formation temperature of gaseous metals.

  11. Overview and system analysis of various sewage sludge drying processes

    SciTech Connect

    Kasakura, T.; Imoto, Y.; Mori, T. )

    1993-01-01

    An incineration process is routinely used in Japan to treat nearly all the generated sewage sludge. The drying process now is recognized as an important part of the pretreatment process of a incineration process. This pater provides a brief introduction to the conventionally utilized drying methods/equipment (i.e, hot gas drying fluidized bed drying, pneumatic conveyor drying, and steam drying) for treating dewatered sludge cakes. In addition, a systems analysis approach is described which is used to model various thermal processing methods which include the drying process. This allows the parameters which most significantly affect plant operation and initial construction costs and also energy recovery efficiency to be optimized and clarified.

  12. Fossil fuel biomarkers in sewage sludges: environmental significance

    PubMed

    Payet; Bryselbout; Morel; Lichtfouse

    1999-10-01

    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.http://link. springer.de/link/service/journals/00114/bibs/9086010/90860484. htm

  13. Thermal stabilization of chromium slag by sewage sludge: effects of sludge quantity and temperature.

    PubMed

    Wu, Changlin; Zhang, Hua; He, Pinjing; Shao, Liming

    2010-01-01

    To investigate the feasibility of detoxifying chromium slag by sewage sludge, synthetic chromium slag containing 3% of Cr(VI) was mixed with sewage sludge followed by thermal treatment in nitrogen gas for stabilizing chromium. The effects of slag to sludge ratio (0.5, 1 and 2) and temperature (200, 300, 500, 700 and 900 degrees C) on treatment efficiency were investigated. During the mixing process before thermal treatment, 59.8%-99.7% of Cr(VI) was reduced, but Cr could be easily leached from the reduction product. Increasing heating temperature and decreasing slag to sludge ratio strengthened the reduction and stabilization of Cr(VI). When the slag to sludge ratio was 0.5 and thermal treatment temperature was 300 degrees C, the total leached Cr and Cr(VI) declined to 0.55 mg/L and 0.17 mg/L respectively, and 45.5% of Cr in the thermally treated residue existed as residual fraction. A two-stage mechanism was proposed for the reduction and stabilization of Cr.

  14. 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.

  15. 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.

  16. 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. PMID:26879909

  17. 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.

  18. 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. PMID:27543679

  19. 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. PMID:17087386

  20. 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. PMID:24946701

  1. 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.

  2. 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.

  3. 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.

  4. Biochemical and physiological responses of rice (Oryza sativa L.) grown on different sewage sludge amendments rates.

    PubMed

    Singh, R P; Agrawal, M

    2010-05-01

    Using sewage sludge, a biological residue from sewage treatment processes, in agriculture is an alternative disposal technique of waste. To study the biochemical and physiological responses of Rice (Oryza sativa L.) grown on different sewage sludge amendments (SSA) rates a field experiment was conducted by mixing sewage sludge at 0, 3, 4.5, 6, 9, 12 kg m(-2) rate to the agricultural soil. Rate of photosynthesis and stomatal conductance increased in plants grown at different SSA rate. Chlorophyll and protein contents also increased due to different SSA rates. Lipid peroxidation, ascorbic acid, peroxidase activity and proline content increased, however, thiol and phenol content decreased in plants grown at different SSA rates. The study concludes that for rice plant sewage sludge amendment in soil may be a good option as plant has adequate heavy metal tolerance mechanism showed by increased rate of photosynthesis and chlorophyll content and various antioxidant levels.

  5. 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. PMID:27381356

  6. 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.

  7. The determination of radioisotope levels in municipal sewage sludge

    SciTech Connect

    Miller, W.H.; Kunze, J.F. Banerji, S.K.; Yu-Chu Li; Graham, C.; Stretch, D.

    1996-09-01

    Sludge samples from 25 municipal waste water treatment plants have been analyzed to determine the level of environmentally present, man-made, gamma-ray emitting radioisotopes. Samples were freeze dried and separated into dried sludge, liquid-soluble and liquid-insoluble components. These were counted in the low background level, whole body counter at Missouri University using a standard intrinsic-Germanium spectrometer. After freeze drying, the liquid effluents from the samples were not found to have statistically significant levels of radioactivity. Using log-normal analysis, the dried sludge was found to have 0.0016 {plus_minus} 0.0022 Bq g{sup {minus}1} (0.04 {plus_minus} 0.06 pCi g{sup {minus}1}) of {sup 137}Cs and 0.001 {plus_minus} 0.003 Bq g{sup {minus}1} (0.03 {plus_minus}0.08 pCi g{sup {minus}1}) of {sup 60}Co. These data can be used to determine if sewage effluents from nuclear facilities have levels of radioactivity above that expected from the environment. 9 refs., 2 figs.

  8. 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. PMID:26841290

  9. 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.

  10. 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.

  11. 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.

  12. The Ruhrverband sewage sludge disposal concept in the conflict between European and German standards and regulations.

    PubMed

    Evers, P; Schmitt, F; Albrecht, D R; Jardin, N

    2005-01-01

    The Ruhrverband, acting as a water association responsible for integrated water resources management within the entire natural river basin of the Ruhr, operates a network of 83 wastewater treatment plants (WWTPs) and connected sludge disposal facilities. According to German regulations, the disposal of sewage sludge containing more than 5% of organic dry solids will be prohibited as of 1 June 2005. In Germany, the only future alternative to incineration will be the agricultural utilization of sludge. However, this way of sludge disposal is presently the subject of critical discussions in Germany because of the organic and inorganic toxic substances, which may be contained in sewage sludge, despite the fact that very stringent standards are to be met by agricultural uses. On the other hand, application of sewage sludge to agricultural land is explicitly supported by the European Sewage Sludge Directive 86/278/EEC. In the face of this controversial situation the Ruhrverband has initiated, in 2000, the development of a comprehensive and sustainable sludge and waste disposal concept for all wastewater facilities it operates in the entire Ruhr River Basin. The concept includes de-central sludge digestion and dewatering and subsequent transport to two central sludge incineration plants. It is expected that in future not more than 5% of all sludges produced in Ruhrverband's WWTPs will be used in agriculture. That means, the major part of 95% will have to be incinerated.

  13. Reducing capacities and redox potentials of humic substances extracted from sewage sludge.

    PubMed

    Yang, Zhen; Du, Mengchan; Jiang, Jie

    2016-02-01

    Humic substances (HS) are redox active organic materials that can be extracted from sewage sludge generated in wastewater treatment processes. Due to the poor understanding of reducing capacity, redox potentials and redox active functional groups of HS in sewage sludge, the potential contribution of sludge HS in transformation of wastewater contaminants is unclear. In the present study, the number of electrons donated or accepted by sewage sludge HS were quantified before and after reduction by iron compounds that possess different redox potentials and defined as the reducing capacity of the sewage sludge. In contrast to previous studies of soil and commercial humic acids (HA), reduced sludge HA showed a lower reducing capacity than that of native HA, which implies formation of semiquinone radicals since the semiquinone radical/hydroquinone pair has a much higher redox potential than the quinone/hydroquinone pair. It is novel that reducing capacities of sludge HA were determined in the redox potential range from -314 to 430 mV. The formation of semiquinone radicals formed during the reduction of quinone moieties in sludge HA is shown by three-dimensional excitation/emission matrix fluorescence spectroscopies information, increasing fluorescence intensities and blue-shifting of the excitation/emission peak of reduced sludge HA. Knowledge of sludge HS redox potentials and corresponding reducing capacities makes it possible to predict the transformation of redox active pollutants and facilitate manipulation and optimization of sludge loading wastewater treatment processes.

  14. Toxicologic studies associated with the agricultural use of municipal sewage sludge and health effects among sewage treatment plant workers.

    PubMed

    Babish, J G; Stoewsand, G S; Kranz, J M; Boyd, J N; Ahrens, V D; Lisk, D J

    1984-09-01

    The proposed use of municipal sewage sludges as soil amendments on agricultural land involves potential health risks. Sludges may contain toxic heavy metals, synthetic organics, and pathogens. Studies of animals inhabiting sludge-amended soils, or foraging on crops grown on such soils, have shown an increased deposition of cadmium and polychlorinated biphenyls in animal tissues, hepatic microsomal enzyme induction, altered blood profiles, appearance of mutagens in blood and excreta, and lowered feed intake, feed efficiency, and milk production. Epidemiologic evidence of possible adverse health effects among sewage plant workers exposed to aerosolized pathogens or synthetic organic vapors during wastewater treatment or land spreading of sludge is still inconclusive. Other possible deleterious environmental effects include pollution of groundwater and toxicity to birds consuming worms or insects inhabiting sludge-treated soils.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. Accelerating Aerobic Sludge Granulation by Adding Dry Sewage Sludge Micropowder in Sequencing Batch Reactors.

    PubMed

    Li, Jun; Liu, Jun; Wang, Danjun; Chen, Tao; Ma, Ting; Wang, Zhihong; Zhuo, Weilong

    2015-08-01

    Micropowder (20-250 µm) made from ground dry waste sludge from a municipal sewage treatment plant was added in a sequencing batch reactor (R2), which was fed by synthetic wastewater with acetate as carbon source. Compared with the traditional SBR (R1), aerobic sludge granulation time was shortened 15 days in R2. Furthermore, filamentous bacteria in bulking sludge were controlled to accelerate aerobic granulation and form large granules. Correspondingly, the SVI decreased from 225 mL/g to 37 mL/g. X-ray Fluorescence (XRF) analysis demonstrated that Al and Si from the micropowder were accumulated in granules. A mechanism hypotheses for the acceleration of aerobic granulation by adding dry sludge micropowder is proposed: added micropowder acts as nuclei to induce bacterial attachment; dissolved matters from the micropowder increase abruptly the organic load for starved sludge to control overgrown filamentous bacteria as a framework for aggregation; increased friction from the movement of micropowder forces the filaments which extend outwards to shrink for shaping granules. PMID:26308025

  1. 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.

  2. 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.

  3. 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.

  4. Removal of siloxane from digestion gas of sewage sludge.

    PubMed

    Matsui, Toru; Imamura, Shigeru

    2010-01-01

    This paper studies the way to remove siloxanes from digestion gas of sewage sludge by adsorbents. Many adsorbents were tested by using the model gas of siloxane in nitrogen. The adsorption ratio was 0.056-0.192 for the activated carbons, 0.004-0.077 for the molecular sieve and 0.104 for the silica gel. An observed tendency was that the activated carbons showed high adsorption ratio, and that the adsorption ratio was increased when BET surface area was higher, and the pore volume was higher and the pH value was higher. Finally, we found a few kinds of activated carbons with the superior ability of adsorption, and we tested the ability of them by using the real digestion gas. All of the siloxanes were found to be removed in the 1000 h test.

  5. 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.

  6. [Experimental research on indirect thermal drying process of sewage sludge].

    PubMed

    Wang, Xing-Run; Jin, Yi-Ying; Wang, Zhi-Yu; Du, Xin; Nie, Yong-Feng

    2007-02-01

    Technical parameter, condensed steam water quality and flue gases were studied and organic compound hydrolysis mechanism was discussed. During experimental study, observed that the relationship between water content of sewage sludge and residence time have a negative exponential function. The condensed steam water has a high-concentration organic content. Total organic carbon (TOC), volatile fatty acid (VFA) and NH3 -N of the water were very high and the pH value was between 9 and 9.5. VFA and NH3 -N come from two sections: (1) In the 110 - 130 degrees C temperature range, hydrolysis of protein occurred with the formation of VFA and NH3 -N; and (2) In the 140 - 150 degrees C, fats hydrolyzed into VFA. There was no gaseous pollution produced in the whole experimental progress.

  7. Adsorption of SO2 on sewage sludge-derived materials.

    PubMed

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

    2001-08-01

    Sewage sludge-derived materials carbonized at temperatures between 400 and 950 degrees C were used for adsorption of sulfur dioxide from dry and moist air. The materials were characterized using sorption of nitrogen and thermal analysis. The sulfur dioxide capacity was measured according to a laboratory-developed breakthrough test. It was found that the capacity of the adsorbents increases with increasing temperature of carbonization. It is likely that during carbonization at high temperatures such catalytic metals as calcium become active. They play a significant role in the SO2 removal process by neutralization of sulfuric acid formed as a result of oxidation of sulfur dioxide in wet conditions. Besides sulfuric acid, various sulfur-containing salts are formed. It was shown that, after their removal using waterwashing,the SO2 capacitysignificantly decreased.

  8. 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. PMID:26282751

  9. Heavy metal speciation an uptake to durum wheat from sewage sludge

    SciTech Connect

    Ketchum, L.H.; Frost, H.L.

    1998-07-01

    This project focused on detection of heavy metal accumulation in durum wheat from sewage sludge or commercial phosphate fertilizer application, using Inductively Coupled Argon Plasma Mass Spectrometry. Four parts of the durum wheat plants were separated and analyzed (i.e., root, stem, leaves, and grain). Studies compared the metal uptake resulting from sewage sludge application and from commercial fertilizer. Sludges and fertilizers were applied in one application, except for one study which considered the effect of the same sludge dosage, except in two applications. The main objective of this research is to improve the grain quality by minimizing the accumulation of toxic elements in durum wheat.

  10. Land application of sewage sludge: perceptions of New Jersey vegetable farmers.

    PubMed

    Krogmann, U; Gibson, V; Chess, C

    2001-04-01

    Understanding farmers' perceptions and choices regarding land application of sewage sludge is key to developing locally accepted strategies for managing its sewage sludge. Semi-structured interviews, with mostly open-ended questions were conducted with 50 fruit and vegetable farmers at the New Jersey Annual Vegetable Meeting in 1999. The in-depth interviews indicated that the application of sewage sludge to land is currently not a common agricultural practice for these growers. Perceived risks, including heavy metals in sewage sludge (soil-build up, crop-uptake), negative public perception, odour complaints, and increase of contaminants in the water supply outweigh economic incentives and soil improvement benefits. When naming benefits and drawbacks, farmers tend to think first of their crop and their land, and do not mention the environment. It is only when they are questioned directly about environmental benefits and risks that they discuss these aspects. Communication efforts should focus on practical information to which farmers can relate. PMID:11721995

  11. Thermodynamic Equilibrium Calculations on Cd Transformation during Sewage Sludge Incineration.

    PubMed

    Liu, Jing-yong; Huang, Limao; Sun, Shuiyu; Ning, Xun'an; Kuo, Jiahong; Sun, Jian; Wang, Yujie; Xie, Wuming

    2016-06-01

    Thermodynamic equilibrium calculations were performed to reveal the distribution of cadmium during the sewage sludge incineration process. During sludge incineration in the presence of major minerals, such as SiO2, Al2O3 and CaO, the strongest effect was exerted by SiO2 on the Cd transformation compared with the effect of others. The stable solid product of CdSiO3 was formed easily with the reaction between Cd and SiO2, which can restrain the emissions of gaseous Cd pollutants. CdCl2 was formed more easily in the presence of chloride during incineration, thus, the volatilization of Cd was advanced by increasing chlorine content. At low temperatures, the volatilization of Cd was restrained due to the formation of the refractory solid metal sulfate. At high temperatures, the speciation of Cd was not affected by the presence of sulfur, but sulfur could affect the formation temperature of gaseous metals. PMID:27225784

  12. 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.

  13. Characterization of char from slow pyrolysis of sewage sludge.

    PubMed

    Xu, Wen-Ying; Wu, Di

    2016-01-01

    The effects of final pyrolysis temperature Tend from 300 ºC to 550 ºC, heating rates β of 2 ºC/min, 3 ºC/min and 5 ºC/min, retention time RT from 45 min to 90 min, and the moisture content MC from 0 to 70% on characteristics of the pyrolysis char from sewage sludge were investigated using a tube furnace in this study. The resulting chars were characterized by sorption of nitrogen (surface area and pore volume). Their adsorption characteristics were evaluated via iodine value and methylene blue value. Either the pore structures or adsorption characteristics depend on the pyrolysis processing and moisture content of the sludge precursors. In terms of iodine value and surface area of the char, Tend of 450 ºC, RT of 75 min and β of 3 ºC/min proved the optimum combination of pyrolysis parameters. The chars have an undeveloped mesopore and macropore structure and a developed micropore structure. The sodium phenoxide adsorption equilibrium data fit well with the Langmuir model of adsorption, suggesting monolayer coverage of sodium phenoxide molecules at the surface of the char. Its adsorption mechanism is mainly physical in nature, enhanced by chemisorption. PMID:27191557

  14. 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.

  15. Determination of fluoroquinolone antibacterial agents in sewage sludge and sludge-treated soil using accelerated solvent extraction followed by solid-phase extraction.

    PubMed

    Golet, Eva M; Strehler, Adrian; Alder, Alfredo C; Giger, Walter

    2002-11-01

    A method for the quantitative determination of humanuse fluoroquinolone antibacterial agents (FQs) ciprofloxacin and norfloxacin in sewage sludge and sludge-treated soil samples was developed. The accelerated solvent extraction was optimized with regard to solvents and operational parameters, such as temperature, pressure, and extraction time. A 50 mM aqueous phosphoric acid/ acetonitrile mixture (1:1) was found to be optimum in combination with an extraction temperature of 100 degrees C at 100 bar, during 60 and 90 min for sewage sludge and sludge-treated soil samples, respectively. A cleanup step using solid-phase extraction substantially improved the selectivity of the method. Overall recovery rates for FQs ranged from 82 to 94% for sewage sludge and from 75 to 92% for sludge-treated soil, with relative standard deviations between 8 and 11%. Limits of quantification were 0.45 and 0.18 mg/kg of dry matter for sewage sludge and sludge-treated soils, respectively. The presented method was successfully applied to untreated and anaerobically digested sewage sludges and sludge-treated soils. Ciprofloxacin and norfloxacin were determined in sewage sludges from several wastewater treatment plants with concentrations ranging from 1.40 to 2.42 mg/kg of dry matter. Therefore, contrary to what may be expected for human-use pharmaceuticals, FQs may reach the terrestrial environment as indicated by the occurrence of FQs in topsoil samples from experimental fields, to which sewage sludge had been applied. PMID:12433073

  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. PMID:26841773

  17. 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.

  18. 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.

  19. 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. PMID:25872863

  20. 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.

  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. 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.

  3. 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.

  4. Soil microbial functional and fungal diversity as influenced by municipal sewage sludge accumulation.

    PubMed

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

    2014-09-01

    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

  5. 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...

  6. Sludge dewatering: Sewage treatment. (Latest citations from the COMPENDEX database). Published Search

    SciTech Connect

    Not Available

    1993-05-01

    The bibliography contains citations concerning dewatering techniques and equipment for sewage treatment. Sewage sludge dewatering design, development, and evaluation are discussed. Essential types of dewatering equipment such as centrifuges, filters, presses, and drums are considered. (Contains 250 citations and includes a subject term index and title list.)

  7. Sludge dewatering: Sewage treatment. (Latest citations from the EI Compendex*plus database). Published Search

    SciTech Connect

    1996-01-01

    The bibliography contains citations concerning dewatering techniques and equipment for sewage treatment. Sewage sludge dewatering design, development, and evaluation are discussed. Essential types of dewatering equipment such as centrifuges, filters, presses, and drums are considered. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  8. Electrodialytic treatment for metal removal from sewage sludge ash from fluidized bed combustion.

    PubMed

    Pazos, M; Kirkelund, G M; Ottosen, L M

    2010-04-15

    Sewage sludge contains several potentially hazardous compounds such as heavy metals, PCBs, PAHs, etc. However, elements with high agricultural value (P, K or Ca) are also present. During the last years, the fluidized bed sludge combustor (FBSC) is considered an effective and novel alternative to treat sewage sludge. By its use, the high amount of sludge is reduced to a small quantity of ash and thermal destruction of toxic organic constituents is obtained. Conversely, heavy metals are retained in the ash. In this work the possibility for electrodialytic metal removal for sewage sludge ash from FBSC was studied. A detailed characterization of the sewage sludge ash was done initially, determining that, with the exception of Cd, the other heavy metals (Cr, Cu, Pb, Ni and Zn) were under the limiting levels of Danish legislation for the use of sewage sludge as fertilizer. After 14 days of electrodialytic treatment, the Cd concentration was reduced to values below the limiting concentration. In all experiments the concentrations of other metals were under limiting values of the Danish legislation. It can be concluded that the electrodialytic treatment is an adequate alternative to reduce the Cd concentration in FBSC ash prior to use as fertilizer. PMID:20034740

  9. Organic contaminants in sewage sludge (biosolids) and their significance for agricultural recycling.

    PubMed

    Smith, S R

    2009-10-13

    Organic chemicals discharged in urban wastewater from industrial and domestic sources, or those entering through atmospheric deposition onto paved areas via surface run-off, are predominantly lipophilic in nature and therefore become concentrated in sewage sludge, with potential implications for the agricultural use of sludge as a soil improver. Biodegradation occurs to varying degrees during wastewater and sludge treatment processes. However, residues will probably still be present in the resulting sludge and can vary from trace values of several micrograms per kilogram up to approximately 1 per cent in the dry solids for certain bulk chemicals, such as linear alkylbenzene sulphonate, which is widely used as a surfactant in detergent formulations. However, the review of the scientific literature on the potential environmental and health impacts of organic contaminants (OCs) in sludge indicates that the presence of a compound in sludge, or of seemingly large amounts of certain compounds used in bulk volumes domestically and by industry, does not necessarily constitute a hazard when the material is recycled to farmland. Furthermore, the chemical quality of sludge is continually improving and concentrations of potentially harmful and persistent organic compounds have declined to background values. Thus, recycling sewage sludge on farmland is not constrained by concentrations of OCs found in contemporary sewage sludges. A number of issues, while unlikely to be significant for agricultural utilization, require further investigation and include: (i) the impacts of chlorinated paraffins on the food chain and human health, (ii) the risk assessment of the plasticizer di(2-ethylhexyl)phthalate, a bulk chemical present in large amounts in sludge, (iii) the microbiological risk assessment of antibiotic-resistant micro-organisms in sewage sludge and sludge-amended agricultural soil, and (iv) the potential significance of personal-care products (e.g. triclosan), pharmaceuticals

  10. 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.)

  11. Sludge dewatering: Sewage and industrial wastes. (Latest citations from pollution abstracts). Published Search

    SciTech Connect

    1995-11-01

    The bibliography contains citations concerning sewage sludge dewatering techniques and equipment in industrial and municipal waste treatment systems. Topics include dewatering processes and control, activated sludge systems, fluidized bed systems, biological treatment, heavy metal recovery, and economic aspects. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  12. 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

  13. Identification of viral pathogen diversity in sewage sludge by metagenome analysis.

    PubMed

    Bibby, Kyle; Peccia, Jordan

    2013-02-19

    The large diversity of viruses that exist in human populations are potentially excreted into sewage collection systems and concentrated in sewage sludge. In the U.S., the primary fate of processed sewage sludge (class B biosolids) is application to agricultural land as a soil amendment. To characterize and understand infectious risks associated with land application, and to describe the diversity of viruses in human populations, shotgun viral metagenomics was applied to 10 sewage sludge samples from 5 wastewater treatment plants throughout the continental U.S, each serving between 100,000 and 1,000,000 people. Nearly 330 million DNA sequences were produced and assembled, and annotation resulted in identifying 43 (26 DNA, 17 RNA) different types of human viruses in sewage sludge. Novel insights include the high abundance of newly emerging viruses (e.g., Coronavirus HKU1, Klassevirus, and Cosavirus) the strong representation of respiratory viruses, and the relatively minor abundance and occurrence of Enteroviruses. Viral metagenome sequence annotations were reproducible and independent PCR-based identification of selected viruses suggests that viral metagenomes were a conservative estimate of the true viral occurrence and diversity. These results represent the most complete description of human virus diversity in any wastewater sample to date, provide engineers and environmental scientists with critical information on important viral agents and routes of infection from exposure to wastewater and sewage sludge, and represent a significant leap forward in understanding the pathogen content of class B biosolids. PMID:23346855

  14. Investigation of Salmonella infection in goats fed corn silage grown on land fertilized with sewage sludge.

    PubMed Central

    Ayanwale, L F; Kaneene, J M; Sherman, D M; Robinson, R A

    1980-01-01

    A total of 36 goats were fed for 17 months with corn silage grown on land fertilized with human sewage sludge. These animals were investigated for salmonella infections. Salmonellae were not detected in cultures of fecal or silage samples. No significant agglutination titers were detected in goat sera examined. Salmonella newport C2 was isolated from the sludge used as fertilizer on the cornfields. The public health aspects of the findings are discussed as they relate to the increasing use of sewage sludge for agricultural fertilizers, as well as to the resultant effects on human food and livestock feed. PMID:6258474

  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. Integrated drying and incineration of wet sewage sludge in combined bubbling and circulating fluidized bed units.

    PubMed

    Li, Shiyuan; Li, Yunyu; Lu, Qinggang; Zhu, Jianguo; Yao, Yao; Bao, Shaolin

    2014-12-01

    An original integrated drying and incineration technique is proposed to dispose of sewage sludge with moisture content of about 80% in a circulating fluidized bed. This system combines a bubbling fluidized bed dryer with a circulating fluidized bed incinerator. After drying, sewage sludge with moisture less than 20% is transported directly and continuously from the fluidized bed dryer into a circulating fluidized bed incinerator. Pilot plant results showed that integrated drying and incineration is feasible in a unique single system. A 100 t/d Sewage Sludge Incineration Demonstration Project was constructed at the Qige sewage treatment plant in Hangzhou City in China. The operational performance showed that the main operation results conformed to the design values, from which it can be concluded that the scale-up of this technique is deemed both feasible and successful.

  17. Studies on land application of sewage sludge and its limiting factors.

    PubMed

    Wang, Xin; Chen, Tao; Ge, Yinghua; Jia, Yongfeng

    2008-12-30

    Field experiments were conducted to study the effect of sewage sludge application on the heavy metal content in soils and grasses. The sewage sludge was obtained from Northern Shenyang Wastewater Treatment Plant, China, and applied at 0, 15, 30, 60, 120 and 150tha(-1). Native grasses Zoysia japonica and Poa annua were chosen as experimental plants. The experimental results showed that nutrient content of the soil, especially organic matter, was increased after sewage sludge application. The grass biomass was increased and the grass growing season was longer. Heavy metal concentrations in the soil also increased; however, the Zn content did not exceed the stringent Chinese environmental quality standard for soil. Pb and Cu did not exceed the standard for B grade soil, but Cd concentration in soil amended by sewage sludge has exceeded the B grade standard. Therefore, it is suggested that the sewage sludge produced from the wastewater treatment plant should not be applied to farmland, for which B grade soil or better is required. The sludge is suitable for application to forestry and grasslands or nurseries where food chain contamination with cadmium is not a concern.

  18. 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.

  19. [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. PMID:26031091

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

    PubMed

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

    2016-10-01

    The occurrence of emerging organic micropollutants (OMPs) in sewage sludge has been widely reported; nevertheless, their fate during sludge treatment remains unclear. The objective of this work was to study the fate of OMPs during mesophilic and thermophilic anaerobic digestion (AD), the most common processes used for sludge stabilization, by using raw sewage sludge without spiking OMPs. Moreover, the results of analytical chemistry were complemented with biological assays in order to verify the possible adverse effects (estrogenic and genotoxic) on the environment and human health in view of an agricultural (re)use of digested sludge. Musk fragrances (AHTN, HHCB), ibuprofen (IBP) and triclosan (TCS) were the most abundant compounds detected in sewage sludge. In general, the efficiency of the AD process was not dependent on operational parameters but compound-specific: some OMPs were highly biotransformed (e.g. sulfamethoxazole and naproxen), while others were only slightly affected (e.g. IBP and TCS) or even unaltered (e.g. AHTN and HHCB). The MCF-7 assay evidenced that estrogenicity removal was driven by temperature. The Ames test did not show point mutation in Salmonella typhimurium while the Comet test exhibited a genotoxic effect on human leukocytes attenuated by AD. This study highlights the importance of combining chemical analysis and biological activities in order to establish appropriate operational strategies for a safer disposal of sewage sludge. Actually, it was demonstrated that temperature has an insignificant effect on the disappearance of the parent compounds while it is crucial to decrease estrogenicity. PMID:27344252

  1. 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. PMID:25481696

  2. 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. PMID:27327659

  3. 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

  4. 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.

  5. 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.

  6. Behaviour and adsorptive removal of siloxanes in sewage sludge biogas.

    PubMed

    Oshita, K; Ishihara, Y; Takaoka, M; Takeda, N; Matsumoto, T; Morisawa, S; Kitayama, A

    2010-01-01

    We investigated the behaviour of siloxanes, which adversely affect biogas engines, as well as their concentration levels in sewage sludge biogas in Japan. We also performed experiments on the absorptive removal of siloxanes using various adsorbents and determined the main adsorbent characteristics required for the removal of siloxanes. The results of our study on the concentration and composition of siloxanes in biogas were similar to previous reports. Moreover, we found that the concentration of siloxanes changes in relation to the outside air temperature based on real-time measurements of siloxanes using a continuous analyser. We further speculated that the continuous analyser would accurately indicate the siloxane concentration in model biogas but overestimate the siloxane concentration in actual biogas because of positive interference by VOCs and other biogas components. In the siloxane adsorption experiment, the equilibrium uptake of both cyclic siloxanes, D4 and D5, was positively related to the BET-specific surface area of the adsorbents and the fraction of the external surface area taken up by relatively large diameter pores. We attributed the adsorption results to the fact that the siloxane molecules are generally larger than micropores; therefore, they are less susceptible to adsorption to micropores. Based on these results, we concluded that adsorbents with large BET-specific surface areas, especially those with a high external specific surface area and pores of relatively large diameters, are desired for the removal of siloxanes.

  7. 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.

  8. Modelling N mineralization from bovine manure and sewage sludge composts.

    PubMed

    Gil, M V; Carballo, M T; Calvo, L F

    2011-01-01

    Nitrogen mineralization kinetics were compared in three different soils (pH values: 5.2, 7.1 and 8.6) when treated with bovine manure (BM) and sewage sludge (SS) composts. The soil-compost mixtures were kept at a controlled moisture content of 60% of their water holding capacity (WHC) and were incubated in the dark at 25 °C for 2 years. Five mathematical models were compared (simple exponential, double exponential, special model, hyperbolic and parabolic), using as experimental data the mineralized N accumulated during 360 and 720 days of incubation. The results showed that the best fit for describing the mineralization of organic N from the compost after 1 year of experimentation was obtained with the simple exponential model. However, the special model showed the best fit for data from 2 years of incubation and thus better reflected organic N mineralization over a longer time-span. This suggested that the organic N in the two composts was made up of two organic pools of different degrees of stability. PMID:20951032

  9. 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. PMID:26508019

  10. Correlation between biological agents and levels of heavy metals in municipal sewage sludge.

    PubMed

    Bozek, Urszula; Kłapeć, Teresa

    2008-01-01

    During the period 2003-2004, 110 samples of sewage sludge were examined from 18 treatment plants located in the territory of the whole of Poland, the majority in the Lublin Province. Samples of fermented and dehydrated sewage sludge were taken from sludge drying beds. The bacteriological and parasitological determinations covered bacteria of the Salmonella genus and eggs of the helminths Ascaris spp., Trichuris spp., and Toxocara spp. Chemical examinations for the presence of the heavy metals: chromium, zinc, cadmium, copper, nickel and lead were carried out by the method of atomic absorption flame spectrophotometry. The results were subjected to statistical analysis with the use of ANOVA and Student's t-tests. In the sewage sludge samples examined, Salmonella bacteria were isolated from 9 samples (8.2 % ), and the eggs of helminths from 31 samples (28.1 % ). The eggs of Ascaris spp. were most frequently detected--in 24 samples of sewage sludge (21.8 % ), followed by Trichuris spp. eggs--in 11 samples (10.0 % ), and Toxocara spp. eggs--in 6 samples (5.4 % ). Several samples of sewage sludge were infected by eggs of all the parasites examined (ATT). A very high variation was observed with respect to Salmonella bacteria and ATT eggs according to the origin, type of sanitation and duration of deposition of sludge. Levels of chromium, zinc, copper and lead in the sewage sludge samples, in the majority of samples examined, remained below allowable values. Very high values exceeding the allowable values for the levels of heavy metals were observed only in the samples of sewage sludge from one treatment plant. This concerned a cadmium level (201.1 mg/kg d.m.) which exceeded by 20 times the most rigorous allowable contents of this metal for sewage sludge designed for agricultural use, and nickel (288.7 mg/kg d.m.)--the standard being exceeded 3 times. A significant variation of the levels of heavy metals was observed depending on treatment type. A longer period of

  11. A critical review of the U.S. EPA's risk assessment for the land application of sewage sludge.

    PubMed

    Mathney, Jennifer M J

    2011-01-01

    Sewage sludge is a complex mixture of inorganic and organic materials and pathogens generated by the treatment of domestic sewage. Section 40 of the Code of Federal Regulations Part 503 regulates the land application of sewage sludge based on pathogen content and sets standards for nine inorganic chemicals. It is believed that the Part 503 standards are protective of human health and the environment and that sewage sludge applied to land poses little risk. A critical inspection of the pertinent literature, however, reveals that the standards were based on outdated methods, outdated data, inaccurate data, and flawed assumptions, leading to underestimation of risk. The standards are not sufficiently protective, and even if changes were made, sewage sludge is so complex that it is very unlikely it could be monitored to ensure the protection of human health and the environment. For these reasons, the practice of land application of sewage sludge must be discontinued. PMID:21411425

  12. Pharmaceuticals and personal care products in biosolids/sewage sludge: the interface between analytical chemistry and regulation.

    PubMed

    Jones-Lepp, T L; Stevens, Rick

    2007-02-01

    Modern sanitary practices result in large volumes of human waste, as well as domestic and industrial sewage, being collected and treated at common collection points, wastewater treatment plants (WWTPs). In recognition of the growing use of sewage sludge as fertilizers and soil amendments, and the scarcity of current data regarding the chemical constituents in sewage sludge, the US National Research Council (NRC) in 2002 produced a report on sewage sludge. Among the NRC's recommendations was the need for investigating the occurrence of pharmaceuticals and personal care products (PPCPs) in sewage sludge. PPCPs are a diverse array of non-regulated contaminants that had not been studied in previous sewage sludge surveys but which are likely to be present. The focus of this paper will be to review the current analytical methodologies available for investigating whether pharmaceuticals are present in WWTP-produced sewage sludge, to summarize current regulatory practices regarding sewage sludge, and to report on the presence of pharmaceuticals in sewage sludge. PMID:17131110

  13. 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. PMID:18707877

  14. Alteration of a Salt Marsh Bacterial Community by Fertilization with Sewage Sludge

    PubMed Central

    Hamlett, Nancy V.

    1986-01-01

    The effects of long-term fertilization with sewage sludge on the aerobic, chemoheterotrophic portion of a salt marsh bacterial community were examined. The study site in the Great Sippewissett Marsh, Cape Cod, Mass., consisted of experimental plots that were treated with different amounts of commercial sewage sludge fertilizer or with urea and phosphate. The number of CFUs, percentage of mercury- and cadmium-resistant bacteria, and percentage of antibiotic-resistant bacteria were all increased in the sludge-fertilized plots. Preliminary taxonomic characterization showed that sludge fertilization markedly altered the taxonomic distribution and reduced diversity within both the total heterotrophic and the mercury-resistant communities. In control plots, the total heterotrophic community was fairly evenly distributed among taxa and the mercury-resistant community was dominated by Pseudomonas spp. In sludge-fertilized plots, both the total and mercury-resistant communities were dominated by a single Cytophaga sp. PMID:16347183

  15. 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.

  16. 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.

  17. Removal mechanisms and kinetics of trace tetracycline by two types of activated sludge treating freshwater sewage and saline sewage.

    PubMed

    Li, Bing; Zhang, Tong

    2013-05-01

    Understanding the removal mechanisms and kinetics of trace tetracycline by activated sludge is critical to both evaluation of tetracycline elimination in sewage treatment plants and risk assessment/management of tetracycline released to soil environment due to the application of biosolids as fertilizer. Adsorption is found to be the primary removal mechanism while biodegradation, volatilization, and hydrolysis can be ignored in this study. Adsorption kinetics was well described by pseudo-second-order model. Faster adsorption rate (k₂ = 2.04 × 10(-2) g min(-1) μg(-1)) and greater adsorption capacity (qe = 38.8 μg g(-1)) were found in activated sludge treating freshwater sewage. Different adsorption rate and adsorption capacity resulted from chemical properties of sewage matrix rather than activated sludge surface characteristics. The decrease of tetracycline adsorption in saline sewage was mainly due to Mg(2+) which significantly reduced adsorption distribution coefficient (Kd) from 12,990 ± 260 to 4,690 ± 180 L kg(-1). Species-specific adsorption distribution coefficients followed the order of Kd⁺⁰⁰>Kd⁺⁻⁰>Kd⁺⁻⁻. Contribution of zwitterionic tetracycline to the overall adsorption was >90 % in the actual pH range in aeration tank. Adsorption of tetracycline in a wide range of temperature (10 to 35 °C) followed the Freundlich adsorption isotherm well.

  18. 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.

  19. 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. PMID:27080207

  20. Assessment of toxicity reduction after metal removal in bioleached sewage sludge.

    PubMed

    Renoux, A Y; Tyagi, R D; Samson, R

    2001-04-01

    Sewage sludge can be applied to land to supply and recycle organic matter and nutrients. Trace elements in sludge, however, may accumulate in the soil with repeated sludge applications. Reducing metal content may therefore reduce the adverse effects of sludge application. The objective of this study was to evaluate the efficiency of bioleaching technology in reducing metal content and toxicity as measured by a battery of terrestrial and liquid-phase bioassays. Sludge-soil mixtures simulating the application of sludge to land were tested by means of terrestrial bioassays, barley (Hordeum vulgare L.) seed germination (5 d) and sprout growth (14 d), lettuce (Lactuca sativa) seed germination (5 d), and worm (Eisenia andrei) mortality (14 d). Liquid-phase bioassays, Microtox (Vibrio fischeri, 15 min), lettuce root elongation (L. sativa, 5 d), cladoceran mortality (Daphnia magna, 48 h), and SOS Chromotest (Escherichia coli) were used after elutriation of the sludge. Comparison of the bioassay results (except for D. magna) before and after treatment demonstrated that this bioleaching process reduced both sludge toxicity and metal content. In addition, lower Cu and Zn concentrations found in barley sprouts following treatment supported the assumption that the bioleaching process, by decreasing metal content and bioavailability, reduced sewage sludge toxicity. This study also emphasized the interest of using ecotoxicological bioassays for testing biosolids. In particular, the terrestrial bioassays after simulation of land application and the Microtox test after sludge elutriation proved to be the most appropriate procedures. PMID:11317888

  1. 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.

  2. Effects of earthworm activity on fertility and heavy metal bioavailability in sewage sludge.

    PubMed

    Liu, Xiaoli; Hu, Chengxiao; Zhang, Shuzhen

    2005-08-01

    The potential for using earthworms (Eisenia fetida) to improve fertility and reduce copper and cadmium availability in sewage sludge was tested by laboratory incubation experiments. Results comparing sewage sludge with and without earthworm treatment showed that earthworm activity decreased the contents of organic matter, total nitrogen, but increased the contents of available nitrogen and phosphorus and had no significant effect on the contents of total phosphorus, total potassium and available potassium. After incubation of the sewage sludge with earthworms for 60 days, the contents of Cu and Cd in the earthworms increased with the increase of additional Cu up to 250 mg kg(-1) and Cd up to 10 mg kg(-1). Bioconcentration factors (BCF) were higher than 1 only for Cd when the addition rate was lower than 5 mg kg(-1), which indicates that the earthworms can only accumulate Cd when the concentration of Cd is low in sewage sludge. Bioavailability of Cd and Cu was evaluated by applying sewage sludge with and without earthworm treatment to soil and then growing cabbage plants. The results showed that earthworm treatment increased the biomass of cabbage and decreased the bioaccumulation of Cd and Cu in the cabbage plants.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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. PMID:26360600

  9. 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.

  10. 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.

  11. The assessment of sewage sludge gasification by-products toxicity by ecotoxicologial test.

    PubMed

    Werle, Sebastian; Dudziak, Mariusz

    2015-08-01

    The process of gasification of sewage sludge generates by-products, which may be contaminated with toxic and hazardous substances, both organic and inorganic. It is therefore important to assess the environmental risk associated with this type of waste. The feasibility of using an ecotoxicological tests for this purpose was determined in the presented study. The applied tests contained indicator organisms belonging to various biological groups (bacteria, crustaceans, plants). The subject of the study were solid (ash, char) and liquid (tar) by-products generated during gasification (in a fixed bed reactor) of dried sewage sludge from various wastewater treatment systems. The tested samples were classified based on their toxic effect. The sensitivity of the indicator organisms to the tested material was determined. In-house procedures for the preparation for toxicity analysis of both sewage sludge and by-products generated during the gasification were presented. The scope of work also included the determination of the effect of selected process parameters (temperature, amount of gasifying agent) on the toxicity of gasification by-products depending on the sewage sludge source. It was shown that both the type of sewage sludge and the parameters of the gasification process affects the toxicity of the by-products of gasification. However, the results of toxicity studies also depend on the type of ecotoxicological test used, which is associated with a different sensitivity of the indicator organisms. Nevertheless, it may be concluded that the by-products formed during the gasification of the low toxicity sewage sludge can be regarded as non-toxic or low toxic. However, the results analysis of the gasification of the toxic sludge were not conclusive, which leads to further research needs in this area. PMID:25827844

  12. 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. PMID:27107391

  13. Ecological risks associated with the application of sewage sludge to non-agricultural ecosystems

    SciTech Connect

    Efroymson, R.A.; Sample, B.E.; Luxmoore, R.J.; Tharp, M.L.; Barnthouse, L.W.; Daniel, F.B.

    1995-12-31

    The Clean Water Act of 1977 directed EPA to establish standards for use and disposal of sewage sludge (biosolids). The application of biosolids to non-agricultural lands is becoming increasingly important as a method of waste disposal. Ecological endpoints at the population, community, and/or ecosystem level have not previously been emphasized in the development of regulatory standards for municipal sewage sludge. This risk assessment focuses on terrestrial endpoints in four ecosystem types to which substantial quantities of sludge have been applied or are expected to be applied in the future: northwest Douglas-fir forest, southeastern loblolly pine plantation, eastern deciduous forest, and semi-arid rangeland. Conceptual models suitable for all ecosystems were developed that depict the links among assessment endpoints. Estimates of risks to wildlife from contaminants and simulations of impacts of nitrogen in sewage sludge on the structure and function of forest communities are presented in detail elsewhere at this conference. This project overview integrates these two assessment components and adds contaminant risks to plants, soil invertebrates, and microbial processes and risk of leaching and erosion altered by biosolids application. Management practices and empirical measures of bioavailability are considered for each ecosystem. Concentrations of constitutents of sewage sludge used for the analyses have been obtained from the 1988 USEPA National Sewage Sludge Survey. Existing regulatory standards that are primarily human health-based are also evaluated for the adequacy of protection of ecological systems and populations. Predicted impacts of sewage sludge applications are presented, even if they may be regarded as benefits rather than risks.

  14. The assessment of sewage sludge gasification by-products toxicity by ecotoxicologial test.

    PubMed

    Werle, Sebastian; Dudziak, Mariusz

    2015-08-01

    The process of gasification of sewage sludge generates by-products, which may be contaminated with toxic and hazardous substances, both organic and inorganic. It is therefore important to assess the environmental risk associated with this type of waste. The feasibility of using an ecotoxicological tests for this purpose was determined in the presented study. The applied tests contained indicator organisms belonging to various biological groups (bacteria, crustaceans, plants). The subject of the study were solid (ash, char) and liquid (tar) by-products generated during gasification (in a fixed bed reactor) of dried sewage sludge from various wastewater treatment systems. The tested samples were classified based on their toxic effect. The sensitivity of the indicator organisms to the tested material was determined. In-house procedures for the preparation for toxicity analysis of both sewage sludge and by-products generated during the gasification were presented. The scope of work also included the determination of the effect of selected process parameters (temperature, amount of gasifying agent) on the toxicity of gasification by-products depending on the sewage sludge source. It was shown that both the type of sewage sludge and the parameters of the gasification process affects the toxicity of the by-products of gasification. However, the results of toxicity studies also depend on the type of ecotoxicological test used, which is associated with a different sensitivity of the indicator organisms. Nevertheless, it may be concluded that the by-products formed during the gasification of the low toxicity sewage sludge can be regarded as non-toxic or low toxic. However, the results analysis of the gasification of the toxic sludge were not conclusive, which leads to further research needs in this area.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  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. PMID:25708406

  20. 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. PMID:27472434

  1. Eucalyptus development in degraded soil fertilized with sewage sludge and mineral fertilizer

    NASA Astrophysics Data System (ADS)

    Rodrigues, R. A. F.; Santos, E. B.; Alves, M. C.; Arruda, O. G.

    2012-04-01

    The aim of this study was to compare the development of eucalyptus in a degraded Oxisol with mineral fertilizer and sewage sludge. The study was conducted in Selviria, Mato Grosso do Sul, Brasil. The culture of eucalyptus was planted in 2003 at 2.0 m x 1.5 m spacing, with application of 60 Mg ha-1 of sewage sludge (dry basis) and mineral fertilizer. After five years (2008) the area received biosolids and mineral fertilizer, and after five months, were evaluated for height and diameter at breast height of Eucalyptus. The experimental design was randomized blocks with four treatments: T1 - control (without addition of inputs), T2 - Mineral fertilization (30 kg ha-1 N, 90 kg ha-1 of P2O5 and 60 kg ha-1 K2O), T3 - Reapplication of 4.64 Mg ha-1 of sewage sludge, dry basis, T4 - Reapplication of 9.28 Mg ha-1 of sewage sludge, dry basis. Before reapplication the biosolids plant height was higher in the eucalyptus with treatment 9.28 Mg ha-1 of sewage sludge (8.03 m) compared to control (5.75 m) and mineral fertilizer (5.91 m) and that treatment 4.64 Mg ha-1 of sewage sludge (6.34 m) did not differ from the previous three. For the diameter at breast height was the highest value for treatment with 9.28 Mg ha-1 (7.78 cm) compared to control (5.23 cm) and 4.64 Mg ha-1 (5.03 cm), and that of mineral fertilizer (5.96 cm) did not differ from all treatments. After reapplication of sludge plant height was higher in the eucalyptus treatment with 9.28 Mg ha-1 of sewage sludge (11.21 m) compared with control (7.51 m), mineral fertilizer (7.77 m) and 4 64 Mg ha-1 (8.07 m), which did not differ. The diameter at breast height had the same behavior before the application of biosolids in the highest value observed being 9.28 Mg ha-1 (8.46 cm) compared with control (5.75 cm) and 4.64 Mg ha-1 (5.03 cm) and that of mineral fertilizer (6.34 cm) did not differ from the others. Reapplication of the dose of 9.28 Mg ha-1 of sewage sludge in degraded Oxisol provided greater height and diameter at

  2. [Rice straw and sewage sludge as carbon sources for sulfate-reducing bacteria treating acid mine drainage].

    PubMed

    Su, Yu; Wang, Jin; Peng, Shu-chuan; Yue, Zheng-bo; Chen, Tian-hu; Jin, Jie

    2010-08-01

    The performance of three organic carbon sources was assessed in terms of sulfate reduction and main metal removal, by using sewage sludge as the source of sulfate-reducing bacteria (SRB) and adding rice straw and ethanol with equal quantity. Results indicated that sewage sludge which contained certain amount of alkaline material could neutralize acidity of acid mine drainage(AMD) on the first day of experiment, elevating pH value from the initial 2.5 to around 5.4-6.3 and achieving suitable pH condition for SRB growth. Sewage sludge contained fewer biodegradable organic substance, reactive mixture with single sewage sludge showed the lowest sulfate reduction (65.9%). When the single sewage sludge was supplemented with rice straw, SRB reducing sulfate was enhanced (79.2%), because the degradation rate of rice straw was accelerated by the specific bacteria in sewage sludge, providing relatively abundant carbon source for SRB. Control experiment with ethanol was most effective in promoting sulfate reduction (97.9%). Metal removal efficiency in all three reactors was as high as 99% for copper, early copper removal was mainly attributed to the adsorption capacity of sewage sludge prior to SRB acclimation. It is feasible for using rice straw and sewage sludge as carbon sources for SRB treating acid mine drainage at a low cost, this may have significant implication for in situ bioremediation of mine environment.

  3. 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

  4. [Rice straw and sewage sludge as carbon sources for sulfate-reducing bacteria treating acid mine drainage].

    PubMed

    Su, Yu; Wang, Jin; Peng, Shu-chuan; Yue, Zheng-bo; Chen, Tian-hu; Jin, Jie

    2010-08-01

    The performance of three organic carbon sources was assessed in terms of sulfate reduction and main metal removal, by using sewage sludge as the source of sulfate-reducing bacteria (SRB) and adding rice straw and ethanol with equal quantity. Results indicated that sewage sludge which contained certain amount of alkaline material could neutralize acidity of acid mine drainage(AMD) on the first day of experiment, elevating pH value from the initial 2.5 to around 5.4-6.3 and achieving suitable pH condition for SRB growth. Sewage sludge contained fewer biodegradable organic substance, reactive mixture with single sewage sludge showed the lowest sulfate reduction (65.9%). When the single sewage sludge was supplemented with rice straw, SRB reducing sulfate was enhanced (79.2%), because the degradation rate of rice straw was accelerated by the specific bacteria in sewage sludge, providing relatively abundant carbon source for SRB. Control experiment with ethanol was most effective in promoting sulfate reduction (97.9%). Metal removal efficiency in all three reactors was as high as 99% for copper, early copper removal was mainly attributed to the adsorption capacity of sewage sludge prior to SRB acclimation. It is feasible for using rice straw and sewage sludge as carbon sources for SRB treating acid mine drainage at a low cost, this may have significant implication for in situ bioremediation of mine environment. PMID:21090305

  5. 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. PMID:22673337

  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. Residual and cumulative effects of soil application of sewage sludge on corn productivity.

    PubMed

    Vieira, Rosana Faria; Moriconi, Waldemore; Pazianotto, Ricardo Antônio Almeida

    2014-05-01

    The objective of this study was to evaluate the effect of frequent and periodic applications of sewage sludge to the soil, on corn productivity. The experiment was carried out as part of an experiment that has been underway since 1999, using two types of sludge. One came from the Barueri Sewage Treatment Station (BS, which receives both household and industrial sludge) and the other came from the Franca Sewage Treatment Station (FS, which receives only household sludge). The Barueri sludge was applied from 1999 up to the agricultural year of 2003/2004. With the exception of the agricultural years of 2004/2005 and 2005/2006, the Franca sludge was applied up to 2008/2009. All the applications were made in November, with the exception of the first one which was made in April 1999. After harvesting the corn, the soil remained fallow until the next cultivation. The experiment was set up as a completely randomized block design with three replications and the following treatments: control without chemical fertilization or sludge application, mineral fertilization, and dose 1 and dose 2 of sludge (Franca and Barueri). The sludges were applied individually. Dose 1 was calculated by considering the recommended N application for corn. Dose 2 was twice dose 1. It was evident from this work that the successive application of sludge to the soil in doses sufficient to reach the productivity desired with the use of nitrogen fertilizers could cause environmental problems due to N losses to the environment and that the residual and cumulative effects should be considered when calculating the application of sludge to soil.

  8. 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.

  9. 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. PMID:26577578

  10. Feedstock quality and growth of bioenergy crops fertilized with sewage sludge.

    PubMed

    Seleiman, Mahmoud F; Santanen, Arja; Stoddard, Frederick L; Mäkelä, Pirjo

    2012-11-01

    Sewage sludge is rich in essential plant nutrients, but its use is restricted for crop production due to the pollutants it contains, such as metalloids and heavy metals. Sludge is also very sticky and compact. Therefore, the objectives of this work were to evaluate (1) the impact of various amounts of sludge on bioenergy crop productivity and quality and (2) the use of peat as an adjuvant to reduce the stickiness, density and nutrient richness of the sludge. Three different applications of sludge were examined, high, low (50% of high) and low mixed with an equal volume of peat. The sludge-peat mix increased significantly leaf area and biomass accumulation of maize and hemp. High sludge and sludge-peat mix applications increased significantly the leaf area and biomass accumulation as well as the net photosynthesis of oilseed rape. High sludge application resulted in the highest heavy metal and metalloid accumulation in maize and hemp. Sludge-peat mix resulted in the highest heavy metal and metalloid accumulation in oilseed rape. However, the sludge-peat mix application provided the best feedstock quality in all three crops, since chloride, silicon and sulfur concentrations and ash content in plant material were the lowest of the three sludge treatments.

  11. 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.

  12. 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.

  13. Use of sewage sludge compost as the restoration agent on the degraded soil of Tatarstan.

    PubMed

    Selivanovskaya, Svetlana Yurievna; Latypova, Venera Zinnatovna; Artamonova, Lyudmila Aleksandrovna

    2003-08-01

    One of the characteristics of soils in Tatarstan is their low organic matter content. The decrease in soil organic matter is paralleled by declines in soil fertility. One method to reverse this degradation in soil quality is the addition of organic matter. The use of sewage sludge on soils intended for growing of plant seedlings provides an alternative for sewage sludge disposal. Therefore, the evaluation of the feasibility of using compost from the municipal sewage sludge produced in Kazan for the soil restoration and growth of Pinus silvestris seedlings was carried out. The grey forest soil (Haplic Greyzem) was amended with compost at application rate 30, 60 and 90 Mg ha(-1) on a dry matter basis. Organic matter content increased with the increase in sludge amendment. The concentrations of individual heavy metal were below the current limits established for Russia and European countries. Sludge amendments enhanced the germination and the number of the seedlings and the increase were more obvious for the soil with highest sludge treatment. The application of composted sludge to soil was followed by the increase in microbial biomass and basal respiration.

  14. 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.

  15. 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.

  16. Occurrence and estrogenic potency of eight bisphenol analogs in sewage sludge from the U.S. EPA targeted national sewage sludge survey.

    PubMed

    Yu, Xiaohua; Xue, Jingchuan; Yao, Hong; Wu, Qian; Venkatesan, Arjun K; Halden, Rolf U; Kannan, Kurunthachalam

    2015-12-15

    As health concerns over bisphenol A (BPA) in consumer products are mounting, this weak estrogen mimicking compound is gradually being replaced with structural analogs, whose environmental occurrence and estrogen risks are not well understood yet. We used high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to determine the concentrations of eight bisphenol analogs in 76 sewage sludge samples collected by the U.S. Environmental Protection Agency (EPA) in 2006/2007 from 74 wastewater treatment plants (WWTPs) in 35 states. Bisphenols were detected at the following concentration ranges (ng/g dry weight) and detection frequencies: BPA (6.5-4700; 100%); bisphenol S (BPS; <1.79-1480; 84%); bisphenol F (BPF; <1.79-242; 68%); bisphenol AF (BPAF; <1.79-72.2; 46%); bisphenol P (BPP; <1.79-6.42; <5%), bisphenol B (BPB; <1.79-5.60; <5%), and bisphenol Z (BPZ; <1.79--66.7; <5%). Bisphenol AP (BPAP) was not detected in any of the samples (<1.79 ng/g dw). Concentrations of BPA in sewage sludge were an order of magnitude higher than those reported in China but similar to those in Germany. The calculated 17β-estradiol equivalents (E2EQ) of bisphenols present in sludge samples were 7.74 (0.26-90.5) pg/g dw, which were three orders of magnitude lower than the estrogenic activity contributed by natural estrogens present in the sludge. The calculated mass loading of bisphenols through the disposal of sludge and wastewater was <0.02% of the total U.S. production. As the usage of BPA is expected to decline further, environmental emissions of BPS, BPF, and BPAF are likely to increase in the future. This study establishes baseline levels and estrogenic activity of diverse bisphenol analogs in sewage sludge.

  17. Guidance for writing permits for the use or disposal of sewage sludge. Draft report

    SciTech Connect

    Not Available

    1993-03-01

    Section 405(d) of the Clean Water Act (CWA) directs the U.S. Environmental Protection Agency (EPA) to develop regulations containing guidelines for the use and disposal of sewage sludge. On February 19th, 1993, EPA published final regulations at 40 Code of Federal Regulations (CFR) Part 503 as the culmination of a major effort to develop technical standards in response to Section 405(d). These regulations govern three sewage sludge use and disposal practices: land application, surface disposal, and incineration. A key element in EPA's implementation of the Part 503 regulations is educating Agency and State personnel about these new requirements. Although the regulations are generally directly enforceable against all persons involved in the use and disposal of sewage sludge, they will also be implemented through permits issued to treatment works treating domestic sewage as defined in 40 CFR 122.22. Thus, the primary focus of the manual is to assist permit writers in incorporating the Part 503 requirements into permits; it serves as an update to the Guidance for Writing Case-by-Case Permit Conditions for Municipal Sewage Sludge (PB91-145508/HDM).

  18. On the contribution of background sources to the heavy metal content of municipal sewage sludge.

    PubMed

    Koch, M; Rotard, W

    2001-01-01

    The role of human excretion, drinking water, and deposition as a source of heavy metals to municipal sewage was investigated and compared with common levels in sludge for soil application. These sources contributed more than half of the copper (Cu), zinc (Zn), and lead (Pb) content of municipal sewage sludge for soil application, while other sources dominated the fluxes of chromium (Cr) and cadmium (Cd). Drinking water was an important source for Cu and Zn. Deposition contributed about 40% to the Pb flux. Faecal excretion commonly caused less than 10% of the heavy metal load, while urinary excretion was here a negligible heavy metal source.

  19. Sewage sludge application effects on runoff water quality in a semiarid grassland

    SciTech Connect

    Harris-Pierce, R.L.; Redente, E.F.; Barbarick, K.A.

    1995-01-01

    One of the concerns of land application of sewage sludge (also referred to as biosolids) to rangeland is its effect on the amount and quality of runoff water. In this study, we applied three treatments consisting of 0, 22, and 41 Mg ha{sup -1} of municipal sewage sludge to Larim gravelly sandy loam (Ustollic Argiustoll) and Altvan sandy loam (Aridic Argiustoll) soils in paired plots on two slope gradients (8 and 15%). We used a one-time application of simulated rainfall for 30 min at a rate of 100 mm h{sup -1} and collected and analyzed the runoff. Results are described. 22 refs., 1 fig., 5 tabs.

  20. Determination of polycyclic musks in sewage sludge from Guangdong, China using GC-EI-MS.

    PubMed

    Zeng, Xiangying; Sheng, Guoying; Xiong, Ying; Fu, Jiamo

    2005-08-01

    Polycyclic musks [Cashmeran (DPMI), Celestolide (ADBI), Phantolide (AHMI), Traseolide (ATII), Tonalide (AHTN) and Galaxolide (HHCB)] were Soxhlet extracted, separated and analyzed in sewage sludge from six different wastewater treatment plants from Guangdong, China, using GC and GC-EI-MS. DPMI, ADBI, HHCB, AHTN were found in all samples, and ATII was not found in any sample. AHMI was detected in five out of six samples. HHCB and AHTN were the two major polycyclic musks found in highest concentrations in sludge. The sludge from municipal wastewater treatment plants contained HHCB, AHTN and DPMI at concentrations between 5.416 and 21.214, 0.715 and 6.195 and 0.599 and 2.870 mg/kg (dry), respectively. The highest concentration was found in sludge from one cosmetic plant at 703.681 mg HHCB/kg (dry). The results indicate that there are two sources of polycyclic musks: domestic sewage and industrial wastewater.

  1. Ten year experience in operation of a sewage sludge treatment plant using gamma irradiation

    NASA Astrophysics Data System (ADS)

    Lessel, T.; Suess, A.

    The first sewage sludge gamma irradiation plant in a technical scale, using Co-60 has been successfully working in Geiselbullach near Munich, FRG, since July 1973. More than 250,000 m 3 of liquid sludge has been disinfected during that time. A very simple plant design, a fully automatical operation during 24 hours and a high availability proved the practical applicability of such a facility in a sewage water purification plant without any specially silled personnel. Beside wide investigations for hygienic aspects, changing of the physical sludge characteristics, effect of irradiated sludge on soil and plants the economic considerations were regarded as important. Experiments werde undertaken to optimize the flexibility of the plant operation and to reduce the necessary radiation dose for minimizing the operation costs.

  2. Dynamics of Cd, Cu and Pb added to soil through different kinds of sewage sludge.

    PubMed

    Torri, S I; Lavado, R S

    2008-01-01

    A greenhouse experiment was set up to study the distribution of Cd, Cu and Pb in three typical soils of the Pampas Region amended with sewage sludge. A sequential extraction procedure was used to obtain four operationally defined geochemical species: exchangeable, bound to organic matter, bound to carbonates, and residual. Two kinds of sewage sludge were used: pure sewage sludge and sewage sludge containing 30% DM of its own incinerated ash, at rates equivalent to a field application of 150 t DM ha(-1). Pots were maintained at 80% of field capacity through daily irrigation with distilled water. Soil samples were obtained on days 1, 60, 270 and 360, and then air-dried and passed through a 2 mm sieve for analysis. Results showed that sludge application increased the less available forms of Cd, Cu and Pb. The inorganic forms became the most prevalent forms for Cu and Pb, whereas Cd was only found in the residual fraction. The concentrations of OM-Cu and INOR-Cu in the amended soil samples were closely correlated with soil pH, whereas the chemical behavior of Cd and Pb did not depend on soil physico-chemical characteristics.

  3. 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. PMID:22425275

  4. Evaluation of the energetic potential of sewage sludge by characterization of its organic composition.

    PubMed

    Schaum, C; Lensch, D; Cornel, P

    2016-01-01

    The composition of sewage sludge and, thus, its energetic potential is influenced by wastewater and wastewater treatment processes. Higher or lower heating values (HHV or LHV) are decisive factors for the incineration/gasification/pyrolysis of sewage sludge. The HHV is analyzed with a bomb calorimeter and converted to the LHV. It is also possible to calculate the heating value via chemical oxygen demand (COD), total volatile solids (TVS), and elemental composition. Calculating the LHV via the COD provides a suitable method. In contrast, the correlation of the HHV or LHV with the TVS is limited. One prerequisite here is a constant specific energy density; this was given with the types of sewage sludge (primary, surplus/excess, and digested sludge) investigated. If the energy density is not comparable with sewage sludge, for instance with the co-substrate (bio-waste, grease, etc.), the estimation of the heating value using TVS will fail. When calculating the HHV or LHV via the elemental composition, one has to consider the validity of the coefficients of the calculation equation. Depending on the organic composition, it might be necessary to adjust the coefficients, e.g. when adding co-substrates. PMID:27332855

  5. Heavy metal speciation and phytotoxic effects of three representative sewage sludges for agricultural uses.

    PubMed

    Walter, I; Martínez, F; Cala, V

    2006-02-01

    The environmental impact of sewage sludges depends on the availability and phytotoxicity of their heavy metal. The influence of representative sludges (dewatered anaerobic, pelletization, and composted sludge) on the availability of heavy metals, and their effects on seed germination were compared. The total heavy metal concentrations were below the maximum permitted for land-applied waste and the differences among them were small. The DTPA-extracted metal concentrations were rather different. The sequential extraction of the compost showed a slight increase in Cd and Cu availability, and a decrease in the availability of Fe, Mn, Ni and Zn. Pelletization increased the availability of Ni and slightly reduced that of Cr. The dewatering sludge led to greater availability of Cr and Mn but reduced the concentration of Cd. The three different sludges also affected seed germination and root elongation in different ways. The most serious adverse effects were caused by the dewatered sludge extract.

  6. 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.

  7. 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.

  8. Earthworm transport of heavy metals from sewage sludge: a micro-PIXE application in soil science

    NASA Astrophysics Data System (ADS)

    Protz, R.; Teesdale, W. J.; Maxwell, J. A.; Campbell, J. L.; Duke, C.

    1993-05-01

    Micro-PIXE was used to analyze earthworm fecal material and the linings of earthworm channels in the soil below a land area on which sewage sludge had been applied. Metals present in the sludge were identified both in fecal pellets and in the linings of the channels, at concentration markedly higher than in the soil matrix. PIXE elemental data in raster format were spatially analyzed during image analysis demonstrating in a quantitative manner the spatial correlations among elements transported by the earthworms.

  9. Assessment of heavy metals in municipal sewage sludge: a case study of Limpopo province, South Africa.

    PubMed

    Shamuyarira, Kudakwashe K; Gumbo, Jabulani R

    2014-03-03

    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.

  10. 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

  11. 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.

  12. Effects of thermally pretreated temperature on bio-hydrogen production from sewage sludge.

    PubMed

    Xiao, Ben-Yi; Liu, Jun-Xin

    2006-01-01

    Hydrogen can be obtained by anaerobic fermentation of sewage sludge. Therefore, in this paper the effects of thermally pretreated temperatures on hydrogen production from sewage sludge were investigated under different pre-treatment conditions. In the thermal pretreatment, some microbial matters of sludge were converted into soluble matters from insoluble ones. As a result, the suspended solid (SS) and volatile suspended solid (VSS) of sludge decreased and the concentration of soluble COD (SCOD) increased, including soluble carbohydrates and proteins. The experimental results showed that all of those pretreated sludge could produce hydrogen by anaerobic fermentation and the hydrogen yields under the temperatures of 121 degrees C and 50 degrees C were 12.23 ml/g VS (most) and 1.17 ml/g VS (least), respectively. It illuminated that the hydrogen yield of sludge was affected by the thermally pretreated temperatures. Additionally, the endurance of high hydrogen yield depended on the translation of microbial matters and inhibition of methanogens in the sludge. The temperatures of 100 degrees C and 121 degrees C (treated time, 30 min) could kill or inhibit completely the methanogens while the others could not. To produce hydrogen and save energy, 100 degrees C was chosen as the optimal temperature for thermal pretrcatment. The composition changes in liquid phase in the fermentation process were also discussed. The SCOD of sludge increased, which was affected by the pretreatment temperature. The production of volatile fatty acids in the anaerobic fermentation increased with the pretreatment temperature.

  13. 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.

  14. Electrical conductivity measurements in sewage sludge pellets: innovative techniques for environmental management.

    PubMed

    Camilla, S; Jordan, M M

    2009-09-15

    This paper presents research on the behaviour of electrical conductivity of sludge pellets resulting from the treatment of urban wastewater at the drying grounds of the El Trebal wastewater processing plant, located in the Mapocho river basin of the Metropolitana Region, Santiago, Chile. In the methodology used samples were taken that correspond to three horizons of the sewage sludge pile. The first horizon made up the upper portion of the pile (the surface), the second the central portion (mesophilous), and the third the lower one (thermophilous). Electrical conductivity measurements were taken in sewage sludge pellets under pressures on the order of 15-50 MPa with currents of 10(-15)A. Electrical conductivity measurements were also taken for different horizons, and innovative techniques and methodologies for sludge samples presented in the form of pellets are used for this purpose. Such pellets are easily reproduced with sufficient precision, and at the same time allow modifying other variables like mass, sample dimensions and compaction levels. The trends of the conductivity curves are similar for the sludge from the isolation surface horizon (H1) as well as for the mesophilous area horizon (H2). In the case of the thermophilous area horizon (H3), the electrical conductivity shows extremely high values when compared to horizons H1 and H2. This paper could be useful in establishing a general rule for taking electrical conductivity measurements in sewage sludge samples. Such a rule could bring accurate reproducible values, and be used for other types of dry wastes.

  15. 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

  16. 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

  17. 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

  18. 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

  19. Optimal sludge retention time for a bench scale MBR treating municipal sewage.

    PubMed

    Pollice, A; Laera, G; Saturno, D; Giordano, C; Sandulli, R

    2008-01-01

    Membrane bioreactors allow for higher sludge concentrations and improved degradation efficiencies with respect to conventional activated sludge. However, in the current practice these systems are often operated under sub-optimal conditions, since so far no precise indications have yet been issued on the optimal operating conditions of MBR for municipal wastewater treatment. This paper reports some results of four years of operation of a bench scale membrane bioreactor where steady state conditions were investigated under different sludge retention times. The whole experimental campaign was oriented towards the investigation of optimal process conditions in terms of COD removal and nitrification, biomass activity and growth, and sludge characteristics. The membrane bioreactor treated real municipal sewage, and four different sludge ages were tested (20, 40, 60, and 80 days) and compared with previous data on complete sludge retention. The results showed that the the biology of the system, as assessed by the oxygen uptake rate, is less affected than the sludge physical parameters. In particular, although the growth yield was observed to dramatically drop for SRT higher than 80 days, the biological activity was maintained under all the tested conditions. These considerations suggest that high SRT are convenient in terms of limited excess sludge production without losses of the treatment capacity. Physical characteristics such as the viscosity and the filterability appear to be negatively affected by prolonged sludge retention times, but their values remain within the ranges normally reported for conventional activated sludge.

  20. Phytoremediation of sewage sludge and use of its leachate for crop production.

    PubMed

    Xu, Tianfen; Xie, Fangwen; Wei, Zebin; Zeng, Shucai; Wu, Qi-Tang

    2015-01-01

    The land application of sewage sludge has the potential risk of transferring heavy metals to soil or groundwater. The agricultural reuse of sludge leachate could be a cost-effective way to decrease metal contamination. Sludge leachate collected during the phytoremediation of sludge by co-cropping with Sedum alfredii and Zea mays was used for irrigating vegetables in a field experiment. Results indicate that the concentrations of Cu, Zn, Pb, and Cd in sludge leachates complied with the National Standards for agricultural irrigation water in China. For the vegetable crop Ipomoea aquatica, nutrients obtained only from the sludge leachate were not sufficient to support growth. For the second crop, Brassica parachinensis, no differences in biomass were observed between the treatment with leachate plus a half dose of inorganic fertilizer and the treatment with a full dose of inorganic fertilizers. The concentrations of heavy metals in I. aquatica and B. parachinensis were not significantly affected by the application of sludge leachates. Compared with initial values, there were no significant differences in Zn, Cd, Cu, and Pb concentrations in soil following treatment with sludge leachate. This study indicates that on range lands, sludge phytoremediation can be conducted at the upper level, and the generated sludge leachate can be safely and easily used in crop production at the lower level.

  1. 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.

  2. 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.

  3. Enhancement of ultrasonic disintegration of sewage sludge by aeration.

    PubMed

    Zhao, He; Zhang, Panyue; Zhang, Guangming; Cheng, Rong

    2016-04-01

    Sonication is an effective way for sludge disintegration, which can significantly improve the efficiency of anaerobic digestion to reduce and recycle use of sludge. But high energy consumption limits the wide application of sonication. In order to improve ultrasonic sludge disintegration efficiency and reduce energy consumption, aeration was introduced. Results showed that sludge disintegration efficiency was improved significantly by combining aeration with ultrasound. The aeration flow rate, gas bubble size, ultrasonic density and aeration timing had impacts on sludge disintegration efficiency. Aeration that used in later stage of ultrasonic irradiation with low aeration flow rate, small gas bubbles significantly improved ultrasonic disintegration sludge efficiency. At the optimal conditions of 0.4 W/mL ultrasonic irradiation density, 30 mL/min of aeration flow rate, 5 min of aeration in later stage and small gas bubbles, ultrasonic sludge disintegration efficiency was increased by 45% and one third of ultrasonic energy was saved. This approach will greatly benefit the application of ultrasonic sludge disintegration and strongly promote the treatment and recycle of wastewater sludge. PMID:27090707

  4. Enhancement of ultrasonic disintegration of sewage sludge by aeration.

    PubMed

    Zhao, He; Zhang, Panyue; Zhang, Guangming; Cheng, Rong

    2016-04-01

    Sonication is an effective way for sludge disintegration, which can significantly improve the efficiency of anaerobic digestion to reduce and recycle use of sludge. But high energy consumption limits the wide application of sonication. In order to improve ultrasonic sludge disintegration efficiency and reduce energy consumption, aeration was introduced. Results showed that sludge disintegration efficiency was improved significantly by combining aeration with ultrasound. The aeration flow rate, gas bubble size, ultrasonic density and aeration timing had impacts on sludge disintegration efficiency. Aeration that used in later stage of ultrasonic irradiation with low aeration flow rate, small gas bubbles significantly improved ultrasonic disintegration sludge efficiency. At the optimal conditions of 0.4 W/mL ultrasonic irradiation density, 30 mL/min of aeration flow rate, 5 min of aeration in later stage and small gas bubbles, ultrasonic sludge disintegration efficiency was increased by 45% and one third of ultrasonic energy was saved. This approach will greatly benefit the application of ultrasonic sludge disintegration and strongly promote the treatment and recycle of wastewater sludge.

  5. 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.

  6. 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

  7. 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. PMID:18372173

  8. [ECOLOGICAL AND TOXICOLOGICAL ASSESSMENT OF DISPOSAL OF SEWAGE SLUDGE AS FERTILIZER].

    PubMed

    Vasbieva, M T

    2015-01-01

    In the article there is considered the question of the accumulation of heavy metals in soil and their uptake by plants as a result of prolonged use of sewage sludge as fertilizer. There have been calculated coefficients of concentrations of elements and the total pollution index. There was performed the comparison of the data obtained with accepted sanitary-hygienic standards. PMID:26625608

  9. 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)

  10. 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. PMID:17919896

  11. 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...

  12. 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.

  13. [ECOLOGICAL AND TOXICOLOGICAL ASSESSMENT OF DISPOSAL OF SEWAGE SLUDGE AS FERTILIZER].

    PubMed

    Vasbieva, M T

    2015-01-01

    In the article there is considered the question of the accumulation of heavy metals in soil and their uptake by plants as a result of prolonged use of sewage sludge as fertilizer. There have been calculated coefficients of concentrations of elements and the total pollution index. There was performed the comparison of the data obtained with accepted sanitary-hygienic standards.

  14. 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. PMID:24756683

  15. 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...

  16. 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.

  17. 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.

  18. Sludge dewatering: Sewage and industrial wastes. (Latest citations from Pollution Abstracts). Published Search

    SciTech Connect

    Not Available

    1992-06-01

    The bibliography contains citations concerning techniques and equipment used in dewatering waste products. Included are techniques for sewage waste as well as industrial, mining, petroleum, and municipal waste sludge. Dewatering processes, device design, and performance evaluations are considered. (Contains 250 citations and includes a subject term index and title list.)

  19. 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. PMID:26646979

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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. PMID:27343866

  6. Effects of composted sewage sludge on microbial biomass, activity and pine seedlings in nursery forest.

    PubMed

    Selivanovskaya, S Yu; Latypova, V Z

    2006-01-01

    The investigation was carried out in a 2 year experiment to evaluate the benefits and hazards of the use of composted sewage sludge as a restoration agent for the soil of the nursery forest intended for growing Pinus sylvestris seedlings. The grey forest soil (Haplic Greyzem) was amended with compost at the 25, 50, 75, 100, 150 and 175 t ha(-1) application rates on a dry matter basis. The organic matter content increased with the increase in sludge amendment as well as the metal content. However, the concentrations of individual metals were below the current limits established for Russia and European countries. Sludge amendments enhanced the germination and decreased the mortality of the seedlings. The effects were more obvious for the soil with the highest sludge treatment. The beneficial effects on the biomass of seedlings and the height of the shoots as well as on the length of the roots of the pine seedlings were greater in plots with the highest rates of composted sludge. The application of composted sludge to soil was followed by an increase in microbial biomass and to a lesser extent in basal respiration. In the absence of any detrimental effect on microorganisms, this study lends support to using composted sewage sludge as the organo-mineral fertilizer for the soil of nursery forest. PMID:16307873

  7. Anionic surfactants in treated sewage and sludges: risk assessment to aquatic and terrestrial environments.

    PubMed

    Mungray, Arvind Kumar; Kumar, Pradeep

    2008-05-01

    Compared to low concentrations of anionic surfactants (AS) in activated sludge process effluents (ASP) (<0.2 mg/L), upflow anaerobic sludge blanket-polishing pond (UASB-PP) effluents were found to contain very high concentrations of AS (>3.5 mg/L). AS (or linear alkylbenzen sulfonate, LAS) removals >99% have been found for ASP while in case of UASB-PP it was found to be < or = 30%. AS concentrations averaged 7347 and 1452 mg/kg dry wt. in wet UASB and dried sludges, respectively. Treated sewage from UASB based sewage treatment plants (STPs) when discharged to aquatic ecosystems are likely to generate substantial risk. Post-treatment using 1-1.6d detention, anaerobic, non-algal polishing ponds was found ineffective. Need of utilizing an aerobic method of post-treatment of UASB effluent in place of an anaerobic one has been emphasized. Natural drying of UASB sludges on sludge drying beds (SDBs) under aerobic conditions results in reduction of adsorbed AS by around 80%. Application of UASB sludges on SDBs was found simple, economical and effective. While disposal of treated UASB effluent may cause risk to aquatic ecosystems, use of dried UASB sludges is not likely to cause risk to terrestrial ecosystems. PMID:17706412

  8. Fate and occurrence of alkylphenolic compounds in sewage sludges determined by liquid chromatography tandem mass spectrometry.

    PubMed

    Koh, Y K K; Chiu, T Y; Paterakis, N; Boobis, A; Scrimshawe, M D; Lester, J N; Cartmell, E

    2009-12-01

    An analytical method has been developed and applied to determine the concentrations of the nonionic alkylphenol polyethoxylate surfactants and their metabolites, alkylphenoxy carboxylates and alkyphenols, in sewage sludges. The compounds were extracted with methanol/acetone (1:1 v/v) from sludge, and concentrated extracts were cleaned by silica solid-phase extraction prior to determination by liquid chromatography tandem mass spectrometry. The recoveries, determined by spiking sewage sludge at two concentrations, ranged from 51% to 89% with method detection limits from 6 microg kg(-1) to 60 microg kg(-1). The methodology was subsequently applied to sludge samples obtained from a carbonaceous activated sludge plant, a nitrifying/denitrifying activated sludge plant and a nitrifying/ denitrifying activated sludge plant with phosphorus removal. Concentrations of nonylphenolic compounds were two to three times higher than their octyl analogues. Long-chain nonylphenol polyethoxylates (NP3-12EO) ranged from 16 microg kg(-1) to 11754 microg kg(-1). The estrogenic metabolite nonylphenol was present at concentrations ranging from 33 microg kg(-1) to 6696 microg kg(-1). PMID:20088206

  9. Assessment of anaerobic sewage sludge quality for agricultural application after metal bioleaching.

    PubMed

    Villar, L D; Garcia, O

    2003-12-01

    The effects of metal bioleaching on nutrient solubilization, especially nitrogen and phosphorous, from anaerobically-digested sewage sludge were investigated in this work. The assessment of the sanitary quality of the anaerobic sludge after bioleaching was also carried out by enumerating indicator (total coliforms, fecal coliforms, and fecal streptococci) and total heterotrophic bacteria. The experiments of bioleaching were performed using indigenous sulphur-oxidizing bacteria (Thiobacillus spp.) as inoculum and samples of anaerobically-digested sludge. Nitrogen and phosphorous solubilization from sewage sludge was assessed by measuring, respectively, the concentration of Total Kjeldahl Nitrogen, ammonia, nitrate/nitrite, and soluble and total phosphorous before and after the bioleaching assays. At the end of the experiment, after 4 days of incubation (final pH of 1.4), the following metal solubilization yields were obtained: zinc, 91%; nickel, 87%; copper, 79%; lead, 52%; and chromium, 42%. As a result of sludge acidification, the viable counts of selected indicator bacteria were decreased to below the detection limit (4 x 10(3) cfu 100 ml(-1)), followed by an increase in the mineral fraction of nitrogen (from 6 to 10%) and in the soluble fraction of phosphorous (from 15 to 30%). Although some loss of sludge nutrients can occur during solid-liquid separation following bioleaching, its beneficial effects as metal removal and reduction of pathogenic bacteria are sufficient to consider the potential of this treatment before sludge disposal onto agricultural fields.

  10. 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.

  11. Oxygen-enriched multiple-hearth sewage sludge incineration demonstration. Final report

    SciTech Connect

    1998-07-01

    Oxygen-enhanced multiple-hearth sludge incineration was the focus of a five-month joint study by Praxair and the New York State Energy Research and Development Authority. Testing and demonstration were conducted in Rochester NY, at Monroe County`s Frank E. Van Lare Sewage Treatment Plant. A simple retrofit of high-momentum oxygen lances created a convection hearth in which convective heat and mass transfer with the drying sludge were greatly enhanced, while hearth temperatures were moderated by the wet sludge to prevent overheating. Based on the results of short- and long-term controlled tests discussed in this report, oxygen enhancement of multiple-hearth sludge incinerators can be economically viable, with a savings between $30 and $60 per hour at Van Lare based upon increased sludge throughput and reduced fuel consumption.

  12. Treating sewage using coimmobilized system of Chlorella pyrenoidosa and activated sludge.

    PubMed

    Xiong, Z H; Ma, H J; Huang, G L; Pan, H; Sun, C Z

    2007-01-01

    Chlorella pyrenoidosa was coimmobilized with activated sludge to produce algae-bacteria beads for sewage treatment. Hydrolysis/acidogenesis pretreatment could improve the symbiotic microenvironment of coimmobilized Chlorella pyrenoidosa and activated sludge, and as a result, promote the removal of nutrients (COD(cr), inorganic nitrogen and inorganic phosphorus) in the sewage. A photo-bioreactor combining hydrolysis/acidogenesis pretreatment and coimmobilized technique was designed to treat sewage continuously. The results show that, the removal efficiencies of COD(cr), NH4(+)-N and TP reached steady state after 4-days of experiment. The removal efficiencies of COD(cr), NH4(+)-N and TP were 59.6%, 59.0% and 60.3% respectively.

  13. 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.

  14. 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

  15. Influence of soil fertilization by sewage sludge on the content of polycyclic aromatic hydrocarbons (PAHs) in crops.

    PubMed

    Oleszczuk, Patryk; Baran, Stanisław

    2005-01-01

    The aim of the present study was an evaluation of the influence of the addition of different sewage sludge doses on the uptake of polycyclic aromatic hydrocarbons from fertilized soil. Sewage sludge was introduced into the soil in the following doses: 30, 75, 150, 300, and 600 Mg/ha. The content of polycyclic aromatic hydrocarbons (PAH) was determined by means of HPLC-UV method. The addition of increasing doses of sludge into the soil resulted in a gradual increase in the amount of the polycyclic aromatic hydrocarbons contained therein. During the period of the study, continuous changes in the content of all the compounds studied were found in all the experimental variants. Finally, on the last day of the study, the highest degree of degradation (73%) of 16 PAHs' sum (US EPA) was noted for sludge doses of 30 and 300 Mg/ha. In the case of individual PAHs, the change in their content differed and clearly depended on the sewage sludge dose. The introduction of sewage sludge into the soil influenced the increase of the sum of 16 PAHs in the plants grown in this soil. The influence mentioned above depended on the sewage sludge dose and the plant species grown, as well as the PAH content in the soil. The evaluation of individual PAHs in plants showed an increase in their content with the increase of the amount of sewage sludge. A statistically significant increase in their content was most often observed for sewage sludge doses above 150 Mg/ha. Moreover, it was found that fertilization of the soil with sewage sludge resulted in pollution of the plants with PAHs of high molecular weight.

  16. Growth, yield, and fruit quality of pepper plants amended with two sanitized sewage sludges.

    PubMed

    Pascual, Immaculada; Azcona, Iñaki; Aguirreolea, Jone; Morales, Fermín; Corpas, Francisco Javier; Palma, José Manuel; Rellán-Alvarez, Rubén; Sánchez-Díaz, Manuel

    2010-06-01

    Organic wastes such as sewage sludge have been successfully used to increase crop productivity of horticultural soils. Nevertheless, considerations of the impact of sludges on vegetable and fruit quality have received little attention. Therefore, the objective of the present work was to investigate the impact of two sanitized sewage sludges, autothermal thermophilic aerobic digestion (ATAD) and compost sludge, on the growth, yield, and fruit quality of pepper plants ( Capsicum annuum L. cv. Piquillo) grown in the greenhouse. Two doses of ATAD (15 and 30% v/v) and three of composted sludge (15, 30, and 45%) were applied to a peat-based potting mix. Unamended substrate was included as control. ATAD and composted sludge increased leaf, shoot, and root dry matter, as well as fruit yield, mainly due to a higher number of fruits per plant. There was no effect of sludge on fruit size (dry matter per fruit and diameter). The concentrations of Zn and Cu in fruit increased with the addition of sewage sludges. Nevertheless, the levels of these elements remained below toxic thresholds. Pepper fruits from sludge-amended plants maintained low concentrations of capsaicin and dihydrocapsaicin, thus indicating low pungency level, in accordance with the regulations prescribed by the Control Board of "Lodosa Piquillo peppers" Origin Denomination. The application of sludges did not modify the concentration of vitamin C (ASC) in fruit, whereas the highest doses of composted sludge tended to increase the content of reduced (GSH) and oxidized (GSSG) glutathione, without change in the GSH/GSSG ratio. There were no effects of sludge on the transcript levels of enzymes involved in the synthesis of vitamin C, l-galactono-1,4-lactone dehydrogenase (GLDH) or in the ascorbate-glutathione cycle, ascorbate peroxidase (APX), monodehydroascorbate reductase (MDAR), and glutathione reductase (GR). Results suggest that the synthesis and degradation of ASC and GSH were compensated for in most of the

  17. 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.

  18. 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.

  19. 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

  20. Sewage sludge ash--A promising secondary phosphorus source for fertilizer production.

    PubMed

    Herzel, Hannes; Krüger, Oliver; Hermann, Ludwig; Adam, Christian

    2016-01-15

    Sewage sludge incineration is extensively practiced in some European countries such as the Netherlands, Switzerland, Austria and Germany. A survey of German sewage sludge ash showed that the recovery potential is high, approx. 19,000 t of phosphorus per year. However, the survey also discovered that the bioavailability of phosphorus in the sewage sludge ash is poor and that more than half of the ashes cannot be used as fertilizers due to high heavy metal content. A new thermochemical process for sewage sludge ash treatment was developed that transforms the ash into marketable fertilizer products. Sewage sludge ash was thermochemically treated with sodium and potassium additives under reducing conditions, whereby the phosphate-bearing mineral phases were transformed into plant available phosphates. High P-bioavailability was achieved with a molar Na/P ratio >1.75 in the starting materials. Sodium sulfate, carbonate and hydroxide performed comparably as additives for this calcination process. Potassium carbonate and -hydroxide have to be added in a molar K/P ratio >2.5 to achieve comparable P-solubility. The findings of the laboratory scale investigations were confirmed by an industrial demonstration trial for an ash treatment with sodium sulfate. Simultaneously, the volatile transition metal arsenic (61% removal) as well as volatile heavy metals such as cadmium (80%), mercury (68%), lead (39%) and zinc (9%) were removed via the off-gas treatment system. The product of the demonstration trial is characterized by high bioavailability and a toxic trace element mass fraction below the limit values of the German fertilizer ordinance, thus fulfilling the quality parameters for a P-fertilizer. PMID:26321235

  1. 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. PMID:20303077

  2. 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.

  3. 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.

  4. Gaseous emissions from ceramics manufactured with urban sewage sludge during firing processes.

    PubMed

    Cusidó, J A; Cremades, L V; González, M

    2003-01-01

    The re-use of sewage sludge without any treatment as primary material-mixed with clays-in order to obtain structural ceramics for buildings has been successfully improved. In the Ecobrick project, the firing of a mixture of specific percentages of three components (clays, sludges and forest debris) resulted in a lighter and more thermal and acoustic insulating brick, compared with conventional clay-bricks. Volatile organic compounds (VOC) emission from the manufacturing of ceramics is the most important aspect to control. In the Ecobrick project VOC emissions were monitored by using a bench-scale furnace. The study was conducted using an EPA recommended sampling train and portable sampling tubes that were thermally desorbed and analyzed by gas chromatography/mass spectrometry. Drying of raw sewage-sludge and firing processes were considered separately. In this paper, we present VOC emissions coming from the firing step of the Ecobrick production.

  5. Experimental evaluation of drying characteristics of sewage sludge and hazelnut shell mixtures

    NASA Astrophysics Data System (ADS)

    Pehlivan, Hüseyin; Ateş, Asude; Özdemir, Mustafa

    2016-01-01

    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.

  6. 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. PMID:27434304

  7. Beneficial uses of nuclear byproducts/sewage sludge irradiation project. Progress report, October 1982-March 1983

    SciTech Connect

    Pierce, J.D.

    1984-11-01

    Gamma irradiation of various commodities in the Sandia Irradiator for Dried Sewage Solids (SIDSS) and the Gamma Irradiation Facility (GIF) continued during this reporting period. One truck-load of grapefruit was irradiated. Pelletized straw was irradiated to doses of 1, 5, 10, 20, and 40 megarads in SIDSS. Sludge, virus, and fungus samples were irradiated. Infected ground pork and infected pig carcasses were irradiated in the GIF as a method of Trichinella spiralis inactivation. Other experiments conducted in the GIF included irradiation of cut flowers to extend their shelf life and irradiation of kepone to induce its degradation. Waste Encapsulation and Storage Facility (WESF) capsule studies at ORNL and SNLA continued. A purchase order was placed for a prototype sludge solar dryer. Sewage Sludge Irradiation Transportation System (SSITS) cask activities included thermal stress analyses of cask performance following separation from the impact limiters during a fire. Analyses of cask performance, when loaded with six strontium-90 (Sr-90) capsules, also were done.

  8. Effect of biodegradation on the consolidation properties of a dewatered municipal sewage sludge.

    PubMed

    O'Kelly, Brendan C

    2008-01-01

    The effect of biodegradation on the consolidation characteristics of an anaerobically digested, dewatered municipal sewage sludge was studied. Maintained-load oedometer consolidation tests that included measurement of the pore fluid pressure response were conducted on moderately degraded sludge material and saturated bulk samples that had been stored under static conditions and allowed to anaerobically biodegrade further (simulating what would happen in an actual sewage sludge monofill or lagoon condition). Strongly degraded sludge material was produced after a storage period of 13 years at ambient temperatures of 5-15 degrees C, with the total volatile solids reducing from initially 70% to 55%. The sludge materials were highly compressible, although impermeable for practical purposes. Primary consolidation generally occurred very slowly, which was attributed to the microstructure of the solid phase, the composition and viscosity of the pore fluid, ongoing biodegradation and the high organic contents. The coefficient of primary consolidation values decreased from initially about 0.35m2/yr to 0.003-0.03m2/yr with increasing effective stress (sigmav'=3-100kPa). Initially, the strongly degraded sludge material was slightly more permeable, although both the moderately and strongly degraded materials became impermeable for practical purposes (k=10(-9)-10(-12)m/s) below about 650% and 450% water contents, respectively. Secondary compression became more dominant with increasing effective stress with a mean secondary compression index (Calphae) value of 0.9 measured for both the moderately and strongly degraded materials. PMID:17936608

  9. 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. PMID:24880545

  10. 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. PMID:20591568

  11. 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.

  12. Elemental transport and distribution in soils amended with incinerated sewage sludge.

    PubMed

    Paramasivam, S; Sajwan, K S; Alva, A K; VanClief, D; Hostler, K H

    2003-05-01

    Sewage sludge (SS) is the major solid waste of sewage and wastewater treatment plants in cities around the world. Even though treated effluent water from wastewater treatment plants are utilized for irrigation, disposal of sewage sludge is becoming a serious problem. This is due to its high content of certain heavy metals still posing threat of accumulation in plants and groundwater contamination when it is used as soil amendment or disposed in landfills. Water treatment plants incinerate the dewatered activated sewage sludge (ISS) and dissolve the ash in water to store in ash ponds for long-term storage (WISS). A study was undertaken to evaluate the transport and leaching potential of various elements and their distribution within soil columns amended with various rates of ISS. Results of this study indicates that ISS from wastewater treatment plants can be used as soil amendment on agricultural lands at low to medium rates (< or = 100 Mg ha(-1)) without causing potential loading of metals into groundwater.

  13. Role of mixing on microwave-enhanced advanced oxidation process in treating sewage sludge.

    PubMed

    Kenge, Anju A; Liao, Ping H; Lo, Kwang V

    2008-10-01

    The microwave enhanced advanced oxidation process (MW/H2O2-AOP) was used for the release of nutrients and the disintegration of suspended solids from both anaerobic sludge and aerobic sludge. The purpose of this study was to determine the effects of mixing on the performance of the process, in terms of soluble ammonia, orthophosphate and soluble chemical oxygen demands. Experiments were conducted on sludge samples with various total solids concentrations (1.1-3.7%) and hydrogen peroxide dosage (1% per 1% of total solids) at 80 degrees C of microwave temperature and five minutes of heating time. The results indicated that mixing affected solids disintegration and nutrient solubilization of sewage sludge, regardless of the sludge used, anaerobic or aerobic. However, the effects of mixing on the MW/H2O2-AOP were dependent on the total solids concentration of the sludge. A paired t-test was performed on data for aerobic sludge: at 2.9% of total solids (TS), the difference for solubilization of nutrients and solids disintegration was statistically significant at a 95% confidence level between mixing and non-mixing samples. At a lower TS of 1.7% only soluble chemical oxygen demand showed significant difference between mixing and non-mixing. The results suggest that, for sludge with higher solids content, the MW/H2O2-AOP can be more effective if a mixing device is implemented.

  14. 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.

  15. 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.

  16. 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. PMID:26116645

  17. 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.

  18. Solubility of trace elements and heavy metals from stabilized sewage sludge by fly ash.

    PubMed

    Hongling, Zhang; Lina, Sun; Tieheng, Sun

    2009-11-01

    Stabilized sewage sludge (SS) by fly ash (FA) and alkaline mine tailing as artificial soil, to be applied on the ecological rehabilitation at mining junkyard, offers a potential viable utilization of the industrial by-product, as well as solves the shortage of soil resource in mine area. In this study, trace element and heavy metal soil solution concentrations arising from fly ash, sewage sludge, mine tailing, and artificial soil mixtures were investigated in a laboratory incubation. It was found that total Cd, Pb, and Zn contents in artificial soils were significantly lower than the control standards for pollutants in sludges from agricultural use (GB 4284-84). Soil solution Cd and Pb concentrations were obviously reduced by mixing sewage sludge with alkaline fly ash. Initial soil solution Cd, Pb, and Zn concentrations in artificial soils were 1.773-14.672, 4.05-24.95, and 133-608 microg L(-1), respectively, and after 35-days incubation, soil solution Cd, Pb, and Zn concentrations gradually decreased and were approaching control levels by the end of the experiment, and finial soil solution were decreased to 0.037-0.365, 2.12-7.34, and 29-509 microg L(-1), respectively.

  19. 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. PMID:27348264

  20. 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). PMID:17931859

  1. 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. PMID:18656347

  2. 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. PMID:25638405

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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). PMID:26744944

  8. 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.

  9. 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%.

  10. 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).

  11. Fate of heavy metals and radioactive metals in gasification of sewage sludge

    SciTech Connect

    Marrero, Thomas W.; McAuley, Brendan P.; Sutterlin, William R.; Steven Morris, J.; Manahan, Stanley E

    2004-07-01

    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.

  12. 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%. PMID:22831861

  13. Structure modification and extracellular polymeric substances conversion during sewage sludge biodrying process.

    PubMed

    Cai, Lu; Krafft, Thomas; Chen, Tong-Bin; Gao, Ding; Wang, Li

    2016-09-01

    Biodrying, an economical and energy-saving biomass waste treatment, removes water from waste using the biological heat generated by organic matter degradation. Technical limitations associated with dewatering complicate the biodrying of sewage sludge. This study investigated the sludge alteration associated with its water removal, focusing on sludge form, extracellular polymeric substances, and free water release. An auto-feedback control technology was used for the biodrying; a scanning electron microscope was used to record the morphological change; three-dimensional excitation-emission matrix fluorescence spectroscopy was used to analyze extracellular polymeric substances (EPS) variation, and time domain reflectometry was used to assess the free water release. Over the 20-day biodrying, there was a 62% water removal rate during the first thermophilic phase. Biodrying created a hollow and stratified sludge structure. Aromatic proteins and soluble microbial byproducts in the EPS were significantly degraded. The thermophilic phase was the phase resulting in the greatest free water release. PMID:27262096

  14. Residual effects of sewage-sludge application on plant and soil-profile chemical composition

    SciTech Connect

    Hue, N.V.

    1988-01-01

    Long-term effects on plant and soil-profile chemical composition imposed by a residential sewage sludge were studied on an Oxisol from Hawaii. Sludge was applied at 0, 45, 90, and 180 Mg/ha in 1983. An NPK-fertilized treatment was included for comparison. Sudangrass (Sorghum bicolor L. Moench) was grown as a test crop in the 1983-84 and 1986-87 seasons. Soil samples for chemical analysis were taken in 1987 at three depths: 0-23 cm, 23-46 cm, and 46-69 cm. Beneficial effects of sludge, measured 3 years after application (beginning of the 1986's planting), were evident by large yield increases on sludge-amended soils relative to the unamended and the NPK-fertilized soils. The first cutting produced approximately 5 Mg/ha of dry matter from the sludge treatments, regardless of rate, as compared with 3 and 1.5 Mg/ha from the NPK and the 0 treatments. Regrowths showed similar effect, though less dramatic; average yields were 2.6 Mg/ha with sludge and 1.6 Mg/ha without. Heavy-metal concentrations in plants were generally unaffected by sludge applications; probably because (i) heavy-metal contents of the sludge were low, and (ii) soil pH was increased by sludge. Remarkable increases in pH, exchangeable Ca and extractable P, and resultant decreases in exchangeable Al, in all three soil layers of sludge-amended soils suggest that surface application of a low heavy-metal sludge could serve to correct subsoil acidity and enhance subsoil P availability.

  15. Solar-thermic sewage sludge treatment in extreme alpine environments.

    PubMed

    Becker, W; Schoen, M A; Wett, B

    2007-01-01

    In the framework of a program for environmental protection conducted by the German mountaineers' club (DAV) problems emerging from residual solids accumulating in on-site wastewater treatment plants of mountain refuges were investigated. To handle these problems in an ecologically and economically reasonable way two devices for solar-supported treatment of sludge and bio-solids have been developed. These units support gravity-filtration and evaporation of liquid sludge as well as thermal acceleration of composting processes. Two solar sludge dryers were installed and operated without external energy supply at alpine refuges treating primary and secondary sludge, respectively. Batch-filling during the season could increase load capacity and a total solids concentration of up to 40% could be achieved before discharge at the beginning of the next season. The promising results from the solar sludge dryer encouraged for the development of a solar composter. The period of temperature levels suitable for composting biosolids in mountain areas can be extended considerably by application of this technology--measured temperature distribution indicated no freezing at all. PMID:18057635

  16. Acoustic tracking of ocean-dumped sewage sludge.

    PubMed

    Proni, J R; Newman, F C; Sellers, R L; Parker, C

    1976-09-10

    With a modified 200-kilohertz acoustic echo sounder, it has been possible to detect and map sewage dumped into the ocean over several hours. The three-dimensional distribution of suspended material and its rate of diffusion are indicated after digital processing of the data. PMID:17735703

  17. Modelling nitrogen leaching from sewage sludge application to arable land in the Lombardy region (northern Italy).

    PubMed

    Fumagalli, Mattia; Perego, Alessia; Acutis, Marco

    2013-09-01

    Sewage sludge can be used as fertiliser, offering the possibility of safely recycling this waste product as a resource in agricultural applications. As the environmental concerns related to waste recycling in agricultural applications are well-known, restrictions on the use of sewage sludge have been implemented by the EU and local authorities. This work aimed to evaluate the nitrogen leaching associated with the application of sludge and the effectiveness of the temporal restrictions on its application implemented to safeguard the environment in the Lombardy region of northern Italy (120 days in Nitrate Vulnerable Zones and 90 days elsewhere) using the CropSyst model which was first validated. The effects of fertilisation using four different sludge types on N leaching were simulated at five sites under cultivation with maize and rice crops; six different timing schemes for sludge application were tested, three of which involved dates that were in agreement (AT) with the regulation, while the other three were not in agreement (NAT). We detected a significant effect of the sludge type and application timing, whereas the effect of their interaction was never significant. The mean annual leaching was 22 to 154 kg N ha(-1). The higher the ammonium N content in the sludge was, the greater the potential for N leaching was found to be. For the maize crop, the distribution of sludge in the late fall period resulted in significantly greater N leaching (61 kg N ha(-1)) and led to lower yields (9 t DM ha(-1)) compared to late winter fertilisation (49 kg N ha(-1); 10 t DM ha(-1)), whereas no differences in N leaching or yield were detected between AT and NAT, which was also observed for the rice crop. Therefore, the applied temporal constraints did not always appear to be advantageous for protecting the environment from leaching. PMID:23751334

  18. 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. PMID:25921720

  19. Recovery opportunities for metals and energy from sewage sludges.

    PubMed

    Mulchandani, Anjali; Westerhoff, Paul

    2016-09-01

    Limitations on current wastewater treatment plant (WWTP) biological processes and solids disposal options present opportunities to implement novel technologies that convert WWTPs into resource recovery facilities. This review considered replacing or augmenting extensive dewatering, anaerobic digestion, and off-site disposal with new thermo-chemical and liquid extraction processes. These technologies may better recover energy and metals while inactivating pathogens and destroying organic pollutants. Because limited direct comparisons between different sludge types exist in the literature for hydrothermal liquefaction, this study augments the findings with experimental data. These experiments demonstrated 50% reduction in sludge mass, with 30% of liquefaction products converted to bio-oil and most metals sequestered within a small mass of solid bio-char residue. Finally, each technology's contribution to the three sustainability pillars is investigated. Although limiting hazardous materials reintroduction to the environment may increase economic cost of sludge treatment, it is balanced by cleaner environment and valuable resource benefits for society. PMID:27034156

  20. Solar assisted sludge and energy recycling disposal system utilizing the old Princeton sewage treatment and solid waste incineration facilities

    SciTech Connect

    Slaby, S.M.

    1980-12-01

    Princeton, New Jersey, a town of 30,000 people is in a unique position to utilize solid waste and sewage sludge as supplementary energy sources. The Stony Brook Sewage Authority recently constructed a new twenty million dollar sewage treatment plant next to the old sewage treatment plant which served the community of Princeton for forty years. On the site of the old plant is an abandoned incinerator plant which presently is being used as a transfer station. The new sewage treatment plant is disposing of its sludge by burning it in multiple hearth furnaces using sixty gallons of precious oil to do this. The proposed Princeton Energy Recycling Center is designed to be retrofitted with solar sludge dryers to dry the sewage sludge which would be transported by conveyer to the old incinerator plant where it would be mixed with garbage and be burned in rehabilitated furnaces which would be retrofitted for steam generators, a steam engine driven electric generator and air pollution control equipment. It is estimated that the proposed energy recycling center would fulfill all electrical needs of the new sewage treatment plant in addition to solving the solid waste and sludge disposal problems of the Princeton community. The paper presents a detailed discussion on the proposed Princeton Energy Recycling Center.

  1. Beneficial uses of nuclear byproducts/sewage sludge irradiation project. Progress report, October 1981-March 1982

    SciTech Connect

    Zak, B.D.

    1982-12-01

    A cooperative agreement was made between Albuquerque and DOE during FY81 for sewage sludge irradiation in upgrading the sewage treatment facilities. Other potential sites for implementation of sludge irradiation technology were also considered. Sludge was irradiated in the SIDSS for agronomy and animal feeding experiments. Sludge was also irradiated for use on turf areas. Cooperative work was also performed on grapefruit irradiation for fruit fly disinfestation, and on irradiation of sugar cane waste (bagasse) for enhanced ruminant digestibility. Preliminary design work began on a shipping cask to accomodate WESF Cs-137 capsules. The shielding performance, steady-state thermal response, and response to specified regulatory accident sequences have been evaluated. Work has been initiated on pathogen survival and post-irradiation pathogen behavior. Agronomy field, greenhouse, and soil chemistry studies continue. Various field experiments are ongoing. The fifth year of a five-year program to evaluate the potential use of a sludge product as a range feed supplement for cows is now in its fifth year. In agricultural economics, a preliminary marketing plan has been prepared for Albuquerque.

  2. Yersinia enterocolitica and Yersinia enterocolitica-like bacteria in drinking water and sewage sludge.

    PubMed

    Langeland, G

    1983-06-01

    Using an anaerobic enrichment technique Yersinia bacteria, (Y. enterocolitica and Y. enterocolitica-like bacteria) were isolated from 54% of 41 samples of drinking water and 51% of 35 samples of sewage sludge. A total of 116 strains of Y. enterocolitica sensu stricto, Y. intermedia, Y. kristensenii and other Yersinia bacteria were isolated. Y. frederiksenii was not detected in this study. The isolates belonged to 17 different serogroups, but 42% of the cultures were non-typable. The serogroups 0:3, 0:8 and 0:9, which are responsible for almost all registered cases of yersiniosis in man, were not detected. Yersinia bacteria were found in many samples of drinking water in which fecal coliforms could not be detected. Fecal coliforms were, however, found in all 5 samples from which Y. enterocolitica sensu stricto was isolated. Salmonella bacteria were found to be inadequate as indicators of the presence of Yersinia bacteria in sewage sludge. Salmonella bacteria were found only in raw sludge and sludge stored for up to one month, whereas Yersinia bacteria were found in sludge stored for up to 1 1/2 years. A comparison was made of three different selective agar media for isolation of Yersinia bacteria from the enrichment broth. The frequence of isolation with Desoxycholate Citrate Agar was significantly higher than with either Yersinia Mannitol Agar or Yersinia Peptone Agar.

  3. Treatment of sewage sludge in a thermophilic membrane reactor (TMR) with alternate aeration cycles.

    PubMed

    Collivignarelli, Maria Cristina; Castagnola, Federico; Sordi, Marco; Bertanza, Giorgio

    2015-10-01

    The management of sewage sludge is becoming a more and more important issue, both at national and international level, in particular due to the uncertain recovery/disposal future options. Therefore, it is clear that the development of new technologies that can mitigate the problem at the source by reducing sludge production is necessary, such as the European Directive 2008/98/EC prescribes. This work shows the results obtained with a thermophilic membrane reactor, for processing a biological sludge derived from a wastewater treatment plant (WWTP) that treats urban and industrial wastewater. Sewage sludge was treated in a thermophilic membrane reactor (TMR), at pilot-scale (1 m(3) volume), with alternate aeration cycles. The experimentation was divided into two phases: a "startup phase" during which, starting with a psychrophilic/mesophilic biomass, thermophilic conditions were progressively reached, while feeding a highly biodegradable substrate; the obtained thermophilic biomass was then used, in the "regime phase", to digest biological sludge which was fed to the plant. Good removal yields were observed: 64% and 57% for volatile solids (VS) and total COD (CODtot), respectively, with an average hydraulic retention time (HRT) equal to 20 d, an organic loading rate (OLR) of about 1.4-1.8 kg COD m(-3) d(-1) and aeration/non aeration cycles alternated every 4 h.

  4. Environmental assessment of supercritical water oxidation and other sewage sludge handling options.

    PubMed

    Svanström, Magdalena; Fröling, Morgan; Olofsson, Mattias; Lundin, Margareta

    2005-08-01

    Sustainable development relies on the eco-efficient use of all flows in society; more value created out of each resource unit. Supercritical water oxidation (SCWO) can be used for treatment of wet organic waste. The technology has been under development for over 20 years but has not yet been fully commercialized. SCWO allows for complete oxidation of all organics in sewage sludge and almost complete recovery of the inherent energy, essentially without harmful emissions. In this paper, a life-cycle assessment (LCA) of sewage sludge SCWO (Aqua-Critox) is presented and the results are compared with LCA results for other sludge handling options: agricultural use, co-incineration with municipal solid waste, incineration with subsequent phosphorus extraction (Bio-Con) and sludge fractionation with phosphorus recovery (Cambi-KREPRO). For SCWO, beneficial utilization of the heat of reaction is of crucial importance for the outcome. The electricity consumed by pumping and the nitrous oxide produced are other important parameters. The best sludge handling option from an environmental point of view depends on what aspect is considered more important in the impact assessment. Regarding global warming, the energy recovery methods perform better than agricultural use.

  5. Change of PCBs and forms of heavy metals in sewage sludge during thermophilic anaerobic digestion.

    PubMed

    Dąbrowska, Lidia; Rosińska, Agata

    2012-06-01

    Determination of seven congeners of PCBs was carried out for sewage sludge before, during and after thermophilic digestion. The overall content of heavy metals (Zn, Cu, Ni, Cd, Pb, Cr) in sludge before and after digestion was determined. Moreover the concentration of heavy metals in particular chemical fractions of the sludge was analyzed. After the thermophilic digestion total concentration of seven PCBs was reduced by 47%, which suggests that thermophilic digestion affects PCB reduction positively. On the 10th d of the process, concentration of lower chlorinated PCBs increased, whereas those of higher chlorinated PCBs decreased. The thermophilic digestion process showed no accumulation of the studied heavy metals in the mobile fractions (exchangeable and carbonate) of the stabilized sewage sludge, except for nickel. The highest increase in zinc, copper, cadmium, and chromium concentration was observed in the organic-sulfide fraction, whereas the highest increase in lead was found in the residual fraction of the sludge. In case of nickel both fractions of organic-sulfide and exchangeable-carbonate fractions were enriched. PMID:22459422

  6. 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. PMID:26219587

  7. 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.

  8. 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 sludge by fly ash and/or mine tailing notably decreased the trace metal solubility. The final Cr, Cu, and Ni concentrations in the solution for all mixtures of treatments were lower than 2.5, 15, and 50 microg/L, respectively. PMID:18763566

  9. 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.

  10. Virus transport and survival after land application of sewage sludge.

    PubMed Central

    Bitton, G; Pancorbo, O C; Farrah, S R

    1984-01-01

    The survival and transport patterns of poliovirus 1 and echovirus 1 were studied in undisturbed soil cores which were treated with digested sludge and exposed to natural weather conditions prevailing in north central Florida. It was shown that, under those experimental conditions, enteroviruses are relatively rapidly inactivated in the soil. A more rapid virus decline was observed during the warm and dry fall season than during the warm and wet summer season. The monitoring of soil core leachates has shown that both viruses were effectively retained by the sludge-treated soil. PMID:6331308

  11. Environmental effects of using clay bricks produced with sewage sludge: leachability and toxicity studies.

    PubMed

    Cusidó, Joan A; Cremades, Lázaro V

    2012-06-01

    Use of sewage sludge from wastewater treatment plants as a raw material for making clay bricks has been analyzed to be an option to dumping sludges into landfills. This alternative has been shown feasible and interesting due to the high rate of use of ceramic materials in the building sector. However, it meets with some environmental issues and some prejudices on the part of users. This work shows some leachability and toxicity tests (outgassing and offgassing) which demonstrate the environmental compatibility of these ceramic products to be used as building materials and even in deconstruction of the building once its useful life is ended.

  12. Devolatilization and ash comminution of two different sewage sludges under fluidized bed combustion conditions

    SciTech Connect

    Solimene, R.; Urciuolo, M.; Cammarota, A.; Chirone, R.; Salatino, P.; Damonte, G.; Donati, C.; Puglisi, G.

    2010-04-15

    Two different wet sewage sludges have been characterized under fluidized bed combustion conditions with reference to their devolatilization behavior and ash comminution with the aid of different and complementary experimental protocols. Analysis of the devolatilization process allowed to determine the size of fuel particle able to achieve effective lateral spreading of the volatile matter across the cross-section of medium-scale combustors. Primary fragmentation and primary ash particle characterization pointed out the formation of a significant amount of relatively large fragments. The mechanical properties of these fragments have been characterized by means of elutriation/abrasion tests using both quartz and sludge ash beds. (author)

  13. Human pathogenic viruses at sewage sludge disposal sites in the Middle Atlantic region.

    PubMed Central

    Goyal, S M; Adams, W N; O'Malley, M L; Lear, D W

    1984-01-01

    Human enteric viruses were detected in samples of water, crabs, and bottom sediments obtained from two sewage sludge disposal sites in the Atlantic Ocean. Viruses were isolated from sediments 17 months after the cessation of sludge dumping. These findings indicate that, under natural conditions, viruses can survive for a long period of time in the marine environment and that they may present potential public health problems to humans using these resources for food and recreation. The isolation of viruses in the absence of fecal indicator bacteria reinforces previous observations on the inadequacy of these bacteria for predicting the virological quality of water and shellfish. PMID:6334495

  14. PHARMACEUTICALS AND PERSONAL CARE PRODUCTS IN BIOSOLIDS/SEWAGE SLUDGES - THE INTERFACE BETWEEN ANALYTICAL CHEMISTRY AND REGULATION

    EPA Science Inventory

    Modern sanitary practices result in large volumes of human waste, as well as domestic and industrial sewage, being collected and treated at common collection points, wastewater treatment plants (WWTP). In recognition of the growing use of sewage sludges as a fertilizers and as so...

  15. 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

  16. Life cycle GHG emissions of sewage sludge treatment and disposal options in Tai Lake Watershed, China.

    PubMed

    Liu, Beibei; Wei, Qi; Zhang, Bing; Bi, Jun

    2013-03-01

    The treatment and disposal of sewage sludge generate considerable amounts of greenhouse gases (GHGs) and pose environmental and economic challenges to wastewater treatment in China. To achieve a more informed and sustainable sludge management, this study conducts a life cycle inventory to investigate the GHG performances of six scenarios involving various sludge treatment technologies and disposal strategies. These scenarios are landfilling (S1), mono-incineration (S2), co-incineration (S3), brick manufacturing (S4), cement manufacturing (S5), and fertilizer for urban greening (S6). In terms of GHG emissions, S2 demonstrates the best performance with its large offset from sludge incineration energy recovery, followed by S4 and S6, whereas S1 demonstrates the poorest performance primarily because of its large quantity of methane leaks. The scenario rankings are affected by the assumptions of GHG offset calculation. In most scenarios, GHG performance could be improved by using waste gas or steam from existing facilities for drying sludge. Furthermore, considering the GHG performance along with economic, health, and other concerns, S6 is recommended. We thus suggest that local governments promote the use of composted sludge as urban greening fertilizers. In addition, the use of sludge with 60% water content, in place of the current standard of 80%, in wastewater treatment plants is proposed to be the new standard for Tai Lake Watershed in China.

  17. Life cycle GHG emissions of sewage sludge treatment and disposal options in Tai Lake Watershed, China.

    PubMed

    Liu, Beibei; Wei, Qi; Zhang, Bing; Bi, Jun

    2013-03-01

    The treatment and disposal of sewage sludge generate considerable amounts of greenhouse gases (GHGs) and pose environmental and economic challenges to wastewater treatment in China. To achieve a more informed and sustainable sludge management, this study conducts a life cycle inventory to investigate the GHG performances of six scenarios involving various sludge treatment technologies and disposal strategies. These scenarios are landfilling (S1), mono-incineration (S2), co-incineration (S3), brick manufacturing (S4), cement manufacturing (S5), and fertilizer for urban greening (S6). In terms of GHG emissions, S2 demonstrates the best performance with its large offset from sludge incineration energy recovery, followed by S4 and S6, whereas S1 demonstrates the poorest performance primarily because of its large quantity of methane leaks. The scenario rankings are affected by the assumptions of GHG offset calculation. In most scenarios, GHG performance could be improved by using waste gas or steam from existing facilities for drying sludge. Furthermore, considering the GHG performance along with economic, health, and other concerns, S6 is recommended. We thus suggest that local governments promote the use of composted sludge as urban greening fertilizers. In addition, the use of sludge with 60% water content, in place of the current standard of 80%, in wastewater treatment plants is proposed to be the new standard for Tai Lake Watershed in China. PMID:23410857

  18. Effect of the addition of rice straw on microbial community in a sewage sludge digester.

    PubMed

    Nakakihara, E; Ikemoto-Yamamoto, R; Honda, R; Ohtsuki, S; Takano, M; Suetsugu, Y; Watanabe, H

    2014-01-01

    Rice straw was added to a sewage sludge digester and its effects on methane production, dewatering characteristics, and microbial communities in the digested sludge were examined by a continuous digestion experiment under mesophilic conditions (35 °C). Stable gas generation was monitored in all digestion experiments. Methane yield from raw sludge, chopped rice straw and softened rice straw were estimated to be 0.27, 0.18 and 0.26 NL/g total solids load, respectively. The capillary suction time of digested sludge was decreased by the addition of rice straw. Archaeal and bacterial communities in the sludge were elucidated by PCR-DGGE (polymerase chain reaction--denaturing gradient gel electrophoresis) targeting 16S rRNA genes. The Shannon index of DGGE profiles indicated that bacterial diversity increased with the addition of softened rice straw. DNA sequences of significant bands of the digested sludge were most closely related to Methanosaeta concilii (97.4% identity) and Methanoculleus bourgensis (100% identity). Meanwhile, those in the co-digested sludge with rice straw were most closely related to Methanosarcina barkeri (98.4% identity) and Methanoculleus bourgensis (99.3% identity). Although both Methanosaeta spp. and Methanosarcina spp. metabolize acetate to methane, Methanosarcina spp. have a competitive advantage at acetate concentrations of >70 mg/L. Results suggested that the quantity of acetate produced during rice straw degradation may change the archaeal community. PMID:25225928

  19. Wet oxidation of sewage sludge: full-scale experience and process modeling.

    PubMed

    Bertanza, Giorgio; Galessi, Raniero; Menoni, Laura; Salvetti, Roberta; Slavik, Edoardo; Zanaboni, Sabrina

    2015-05-01

    Nowadays, sewage sludge management represents one of the most important issues in wastewater treatment. Within the European project "ROUTES," wet oxidation (WO) was proposed for sludge minimization. Four different types of sludge were treated in an industrial WO plant: (1) municipal primary sludge (chemical oxygen demand COD: 73.0 g/L; volatile suspended solid VSS: 44.1 g/L); (2) secondary sludge from an industrial wastewater treatment plant (WWTP) without primary sedimentation (COD: 71.8 g/L; VSS: 34.2 g/L); (3) secondary sludge from a mixed municipal and industrial WWTP without primary sedimentation (COD: 61.9 g/L; VSS: 38.7 g/L); and (4) mixed primary (70%) and secondary (30%) municipal sludge (COD: 81.2 g/L; VSS: 40.6 g/L). The effect of process parameters (temperature, reaction time, oxygen dosage) on WO performance was investigated. Depending on operating conditions, VSS and COD removal efficiency varied in the range 80-97% and 43-71%, respectively. A correlation between process efficiency and the initial VSS/TSS (total suspended solids) ratio was highlighted. Furthermore, a mathematical model of WO process for simulating VSS and COD profiles was developed.

  20. Scale-up of phosphate remobilization from sewage sludge in a microbial fuel cell.

    PubMed

    Happe, Manuel; Sugnaux, Marc; Cachelin, Christian Pierre; Stauffer, Marc; Zufferey, Géraldine; Kahoun, Thomas; Salamin, Paul-André; Egli, Thomas; Comninellis, Christos; Grogg, Alain-François; Fischer, Fabian

    2016-01-01

    Phosphate remobilization from digested sewage sludge containing iron phosphate was scaled-up in a microbial fuel cell (MFC). A 3litre triple chambered MFC was constructed. This reactor was operated as a microbial fuel cell and later as a microbial electrolysis cell to accelerate cathodic phosphate remobilization. Applying an additional voltage and exceeding native MFC power accelerated chemical base formation and the related phosphate remobilization rate. The electrolysis approach was extended using a platinum-RVC cathode. The pH rose to 12.6 and phosphate was recovered by 67% in 26h. This was significantly faster than using microbial fuel cell conditions. Shrinking core modelling particle fluid kinetics showed that the reaction resistance has to move inside the sewage sludge particle for considerable rate enhancement. Remobilized phosphate was subsequently precipitated as struvite and inductively coupled plasma mass spectrometry indicated low levels of cadmium, lead, and other metals as required by law for recycling fertilizers. PMID:26519694

  1. Scale-up of phosphate remobilization from sewage sludge in a microbial fuel cell.

    PubMed

    Happe, Manuel; Sugnaux, Marc; Cachelin, Christian Pierre; Stauffer, Marc; Zufferey, Géraldine; Kahoun, Thomas; Salamin, Paul-André; Egli, Thomas; Comninellis, Christos; Grogg, Alain-François; Fischer, Fabian

    2016-01-01

    Phosphate remobilization from digested sewage sludge containing iron phosphate was scaled-up in a microbial fuel cell (MFC). A 3litre triple chambered MFC was constructed. This reactor was operated as a microbial fuel cell and later as a microbial electrolysis cell to accelerate cathodic phosphate remobilization. Applying an additional voltage and exceeding native MFC power accelerated chemical base formation and the related phosphate remobilization rate. The electrolysis approach was extended using a platinum-RVC cathode. The pH rose to 12.6 and phosphate was recovered by 67% in 26h. This was significantly faster than using microbial fuel cell conditions. Shrinking core modelling particle fluid kinetics showed that the reaction resistance has to move inside the sewage sludge particle for considerable rate enhancement. Remobilized phosphate was subsequently precipitated as struvite and inductively coupled plasma mass spectrometry indicated low levels of cadmium, lead, and other metals as required by law for recycling fertilizers.

  2. Influence of humic substances on bioavailability of Cu and Zn during sewage sludge composting.

    PubMed

    Kang, Jun; Zhang, Zengqiang; Wang, Jim J

    2011-09-01

    Influence of humic substances (HS) on bioavailability of Cu and Zn was characterized during 120 days co-composting of sewage sludge and maize straw. At the initial stage of composting, Cu and Zn in sewage sludge were released as organic matter was degraded, and water soluble Cu and Zn increased markedly. Water soluble Cu and FA content decreased after 21 days whereas water soluble Zn increased during the whole process. Both HA-Cu and HA-Zn were significantly and positively correlated with HA and H/F, respectively. At the end of composting, the distribution coefficients of HA-Cu and HA-Zn reached 27.50% and 3.33% respectively with HA-Cu/HA-Zn ratio increased from 1.29 to 2.73. The results suggest that Cu combined with HA more strongly than Zn, and composting treatment could decrease bioavailability of Cu markedly. PMID:21742487

  3. RecoPhos: full-scale fertilizer production from sewage sludge ash.

    PubMed

    Weigand, Harald; Bertau, Martin; Hübner, Wilfried; Bohndick, Fred; Bruckert, Axel

    2013-03-01

    The substitution potential of sewage sludge for German primary phosphate imports has been estimated as 40%. Yet, a marketable option for the full scale recovery has been lacking. This study focuses on a full-scale process for the manufacture of a P-fertilizer from sewage sludge ash (SSA) adapted from the production of Triple Superphosphate. Given (i) conformity of the input with phosphate ores mined from sedimentary deposits, (ii) comparability of the product with a commercially available P-fertilizer regarding contaminant levels, P-fractionation and yield effects, and (iii) compliance of the output with the German Fertilizer Ordinance the RecoPhos P 38 fertilizer was discharged from the waste legislation regime. The fertilizer is currently being produced at a rate of 1000 tonnes per month and sold at a competitive price. PMID:22878049

  4. BMP tests of source selected OFMSW to evaluate anaerobic codigestion with sewage sludge.

    PubMed

    Cabbai, Valentina; Ballico, Maurizio; Aneggi, Eleonora; Goi, Daniele

    2013-07-01

    The aim of this study is to characterize different types of source selected organic fraction of municipal solid waste (SS-OFMSW) in order to optimize the upgrade of a sewage sludge anaerobic digestion unit by codigestion. Various SS-OFMSW samples were collected from canteens, supermarkets, restaurants, households, fruit-vegetable markets and bakery shops. The substrates characterization was carried out getting traditional chemical-physical parameters, performing elemental analysis and measuring fundamental anaerobic digestion macromolecular compounds such as carbohydrates, proteins, lipids and volatile fatty acids. Biochemical methane potential (BMP) tests were conducted at mesophilic temperature both on single substrates and in codigestion regime with different substrates mixing ratios. The maximum methane yield was observed for restaurant (675 NmlCH4/gVS) and canteens organic wastes (571 and 645 NmlCH4/gVS). The best codigestion BMP test has highlighted an increase of 47% in methane production respect sewage sludge digestion. PMID:23628216

  5. Mesophilic anaerobic co-digestion of sewage sludge and orange peel waste.

    PubMed

    Serrano, Antonio; Siles López, José Angel; Chica, Arturo Francisco; Martín, M Angeles; Karouach, Fadoua; Mesfioui, Abdelaziz; El Bari, Hassan

    2014-01-01

    Mesophilic anaerobic digestion is a treatment that is widely applied for sewage sludge management but has several disadvantages such as low methane yield, poor biodegradability and nutrient imbalance. In this paper, we propose orange peel waste as an easily biodegradable co-substrate to improve the viability of the process. Sewage sludge and orange peel waste were mixed at a proportion of 70:30 (wet weight), respectively. The stability was maintained within correct parameters throughout the process, while the methane yield coefficient and biodegradability were 165 L/kg volatile solids (VS) (0 degrees C, 1 atm) and 76% (VS), respectively. The organic loading rate (OLR) increased from 0.4 to 1.6kg VS/m3 d. Nevertheless, the OLR and methane production rate decreased at the highest loads, suggesting the occurrence of an inhibition phenomenon. PMID:24645472

  6. Occurrence and profiles of bisphenol analogues in municipal sewage sludge in China.

    PubMed

    Song, Shanjun; Song, Maoyong; Zeng, Luzhe; Wang, Thanh; Liu, Runzeng; Ruan, Ting; Jiang, Guibin

    2014-03-01

    Extensive use of bisphenol A and its analogues has caused increasing concern over the potential adverse health impacts of these chemicals. In this study, the presence and profiles of 13 bisphenols (BPs) were investigated in 52 municipal sewage sludge samples collected from 30 cities in China. Tetrabromobisphenol A was the most frequently observed analogue (geometric mean: 20.5 ng/g dw). Bisphenol A (4.69 ng/g dw), bisphenol S (3.02 ng/g dw), and bisphenol F (3.84 ng/g dw) were found with similar frequency. Other BP analogues such as tetrachlorobisphenol A, bisphenol AF, bisphenol E, and dihydroxybiphenyl were identified for the first time in sewage sludge in China. Significant correlations were found among BP concentrations, but no relationships were found with wastewater treatment plant characteristics. Profiles of the relative estradiol equivalents suggested that the estrogenic potential of BP mixtures may be associated with the occurrence and contributions of specific analogues.

  7. Dynamics of brominated flame retardants removal in contaminated wastewater sewage sludge under anaerobic conditions.

    PubMed

    Stiborova, Hana; Vrkoslavova, Jana; Pulkrabova, Jana; Poustka, Jan; Hajslova, Jana; Demnerova, Katerina

    2015-11-15

    Disposal of solid waste to landfills from waste water sewage treatment plants (WWTPs) serves as a potential source of contamination by polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). Native microbial communities have been found to degrade a variety of xenobiotics, such as PBDEs and HBCDs. This study investigates the potential of autochthonous microflora to remove 11 PBDE congeners and HBCDs in waste water sludge under anaerobic conditions. Laboratory microcosms were constructed with sewage sludge from the WWTPs of Hradec Kralove and Brno. BDE 209 was detected as the prevailing congener in concentrations 685 and 1403 ng/g dw and the total amounts of 10 lower PBDEs (BDE 28, 47, 49, 66, 85, 99, 100, 153, 154, 183) were 605 and 205 ng/g dw in sludge from Hradec Kralove and Brno, respectively. The levels of HBCD were detected in both sludge lower than 24 ng/g dw. The experiment was carried out for 15 months. After three months of incubation, HBCD was completely degraded to below detection limits. In sewage from both WWTPs, the higher brominated DEs were removed faster than the lower brominated congeners. One exception was tri-BDE, which was degraded completely within 15 months of cultivation. A significant increase in congener tetra-BDE 49 concentrations was observed over the course of the experiment in all tested sewage. The relative distribution of individual congeners among all PBDEs changed after 15 months of the incubation in favour of lower brominated congeners. This indicates that debromination is the major mechanism of anaerobic biodegradation. Despite of the increase of BDE 49, the overall removal of all 11 PBDEs achieved the levels of 47.4 and 68.7% in samples from WWTPs Hradec Kralove and Brno, respectively.

  8. 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. PMID:22277776

  9. Illicit and abused drugs in sewage sludge: method optimization and occurrence.

    PubMed

    Mastroianni, Nicola; Postigo, Cristina; de Alda, Miren Lopez; Barcelo, Damia

    2013-12-27

    A sensitive and reliable method for the determination of 20 abused and illicit drugs and their metabolites in sewage sludge has been developed and validated. To the authors' knowledge, nine out of the 20 selected analytes, namely, cocaethylene, ephedrine, heroin, alprazolam, lysergic acid diethylamide (LSD), its metabolite 2-oxo-3-hydroxy-LSD, and the cannabinoids Δ(9)-tetrahydrocannabinol (THC), cannabinol (CBN) and cannabidiol (CBD), are investigated for the first time in this matrix. In the optimized approach, freeze-dried sewage sludge samples were extracted by means of pressurized liquid extraction, and the extracts were further cleaned-up by solid phase extraction. Analytes were determined by liquid chromatography coupled to tandem mass spectrometry. Method limits of quantification were below 3.3ng/g d.w. for all compounds but cannabinoids (8.2-22.5ng/g d.w.). Method repeatability was below 14% for most compounds. Overall method recoveries were low due to the presence of matrix interferences that could not be completely eliminated and suppressed the ionization of the target analytes between 26% and 89%. However, extraction losses and matrix effects were satisfactorily corrected through the use of isotopically labeled analogs as surrogate standards, ensuring reliable results. The method was applied to the analysis of various sewage sludge samples. Cannabinoids, methadone and its metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) were the most ubiquitous and abundant compounds, showing maximum concentrations above 100ng/g d.w. in all cases (up to 579ng/g d.w. in the case of THC). This work is the first evidence of the presence of the cannabinoids CBN, CBD, and THC in sewage sludge. PMID:24275487

  10. Kinetic analysis for destruction of municipal sewage sludge and alcohol distillery wastewater by supercritical water oxidation

    SciTech Connect

    Goto, Motonobu; Nada, Takatsugu; Kodama, Akio; Hirose, Tsutomu

    1999-05-01

    Supercritical water oxidation was applied to the destruction of municipal excess sewage sludge and alcohol distillery wastewater of molasses. The reaction was carried out in a batch reactor with hydrogen peroxide as an oxidant in the temperature range 673--773 K. Total organic carbon was measured as a function of reaction time. The dynamic data were analyzed by a first-order reaction model. The reaction rate constant coincides with those reported in the literature.

  11. Comparison of sewage sludge- and pig manure-derived biochars for hydrogen sulfide removal.

    PubMed

    Xu, Xiaoyun; Cao, Xinde; Zhao, Ling; Sun, Tonghua

    2014-09-01

    Biochars derived from pig manure and sewage sludge were evaluated for their abilities to remove hydrogen sulfide (H2S) from gas phase. The pig manure biochar had higher capacities for H2S sorption than sewage sludge biochar in both dynamic and static systems, and moisture improves H2S removal. Increasing the biochar moisture to 25 wt% and 100 wt% in the static system increased the pig manure biochar removal capacities by 15.9% and 58.9%, respectively, compared to the dry biochar (0 wt% moisture). The sewage sludge biochar similarly increased the removal by 1.04 and 3.30 times for 25 wt% and 100 wt% moisture, respectively. The catalytic conversion to elemental S(0) and SO4(2)(-) was the main route of H2S removal. The complete oxidation of H2S into SO4(2)(-) mainly occurred on the biochar surface, while H2S underwent incomplete oxidation into elemental S(0) in the biochar pores. The SO4(2)(-) was the dominant form in both biochars, especially for the pig manure biochar which contained 53.9% of the total sulfur at 100 wt% moisture. The SO4(2)(-) was mainly present as CaSO4 precipitate in the sewage sludge biochar, while SO4(2)(-) in the pig manure biochar was mostly soluble (K, Na)2SO4. The results indicated the waste biomass can be converted into value-added biochar as a sorbent for H2S, especially at high moisture that promotes complete oxidation of H2S into SO4(2)(-). Strong alkalinity and rich inorganic minerals originated in the biochar play an important role in its high H2S sorption ability and the final sulfur forms. PMID:24997932

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

    SciTech Connect

    Not Available

    1993-09-01

    The bibliography contains citations concerning techniques and equipment used in the pretreatment processes and disposal of sewage sludges. Topics include resource and energy recovery operations, land disposal, composting, ocean disposal, and incineration. Digestion, dewatering, and disinfection are among the pretreatment processes discussed. Environmental aspects, including the effects on soils, plants, and animals, are also presented. (Contains 250 citations and includes a subject term index and title list.)

  13. Emission characteristics of granulated fuel produced from sewage sludge and coal slime.

    PubMed

    Wzorek, Małgorzata; Kozioł, Michał; Scierski, Waldemar

    2010-12-01

    The neutralization of wastewater treatment residues is an issue for many countries. The European Union (EU) legal regulations have limited the use of the residues in agriculture and implemented a ban for their disposal. Therefore, urgent action should be taken to find solutions for the safe disposal of sewage sludge. The problem refers in particular to the new EU member countries, including Poland, where one can now observe an intensive development of sewage system networks and new sewage treatment plants. At the same time, these countries have few installations for thermal sewage sludge utilization (e.g., there is only one installation of that type in Poland). Simultaneously, there are many coal-fired mechanical stoker-fired boilers in some of these countries. This paper presents suggestions for the production of granulated fuel from sewage sludge and coal slime. Additionally, among others, lime was added to the fuel to decrease the sulfur compounds emission. Results are presented of research on fuel with two average grain diameters (approximately 15 and 35 mm). The fuel with such diameters is adapted to the requirements of the combustion process taking place in a stoker-fired boiler. The research was aimed at identifying the behavior of the burning fuel, with special attention paid to its emission properties (e.g., to the emissions of oxides of nitrogen [NO(x)], sulfur dioxide [SO2], and carbon monoxide [CO], among others). The concentration and emission values were compared with similar results obtained while burning hard coal. The combustion process was carried out in a laboratory stand where realization of the large-scale tests is possible. The laboratory stand used made simulation possible for a wide range of burning processes in mechanical stoker-fired boilers. PMID:21243903

  14. Toxic effects of digested, composted and thermally-dried sewage sludge on three plants.

    PubMed

    Ramírez, W A; Domene, X; Ortiz, O; Alcañiz, J M

    2008-10-01

    In order to evaluate potential toxic effects of stabilized sewage sludge that are currently applied to agricultural soils, three types of municipal sewage sludge and one pig slurry were subjected to phytotoxicity assays using three plants (Brassica rapa, Lolium perenne and Trifolium pratense). Equivalent batches of aerobically and anaerobically-digested sludge (F) from two municipal wastewater treatment plants, were composted (C) or thermally dried (T). In addition, one anaerobically-digested and thermally-dried pig slurry (P) was tested. A seedling growth test was performed in accordance with the OECD Guideline 208A, using seed emergence and shoot length as endpoints to identify the inhibition of plants growing in increasing doses of sludge. A correlation analysis between EC50 and physico-chemical parameters or the pollutant burden of the biosolids was also calculated. In all tests, lower germination rates were observed for T. pratense than for L. perenne and B. rapa. A moderate stimulatory effect on shoot length at low doses was observed for the three plants. In these wastes, a strong positive correlation was found between higher values of EC50 (less toxicity) and the stability degree of their organic matter, and a negative correlation between EC50 and total N, hydrolysable N or NH4-N content. No correlations were found with heavy metal or organic pollutant content in those wastes. Results indicate that digested sludge, thermally-dried sludge and thermally-dried pig slurry have non-negligible short term phytotoxic effects, and confirm that composting is an effective sludge treatment for the reduction of phytotoxicity.

  15. 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.

  16. Priority and emerging pollutants in sewage sludge and fate during sludge treatment.

    PubMed

    Mailler, R; Gasperi, J; Chebbo, G; Rocher, V

    2014-07-01

    This paper aims at characterizing the quality of different treated sludges from Paris conurbation in terms of micropollutants and assessing their fate during different sludge treatment processes (STP). To achieve this, a large panel of priority and emerging pollutants (n=117) have been monitored in different STPs from Parisian wastewater treatment plants including anaerobic digestion, thermal drying, centrifugation and a sludge cake production unit. Considering the quality of treated sludges, comparable micropollutant patterns are found for the different sludges investigated (in mg/kg DM - dry matter). 35 compounds were detected in treated sludges. Some compounds (metals, organotins, alkylphenols, DEHP) are found in every kinds of sludge while pesticides or VOCs are never detected. Sludge cake is the most contaminated sludge, resulting from concentration phenomenon during different treatments. As regards treatments, both centrifugation and thermal drying have broadly no important impact on sludge contamination for metals and organic compounds, even if a slight removal seems to be possible with thermal drying for several compounds by abiotic transfers. Three different behaviors can be highlighted in anaerobic digestion: (i) no removal (metals), (ii) removal following dry matter (DM) elimination (organotins and NP) and iii) removal higher than DM (alkylphenols - except NP - BDE 209 and DEHP). Thus, this process allows a clear removal of biodegradable micropollutants which could be potentially significantly improved by increasing DM removal through operational parameters modifications (retention time, temperature, pre-treatment, etc.).

  17. Priority and emerging pollutants in sewage sludge and fate during sludge treatment.

    PubMed

    Mailler, R; Gasperi, J; Chebbo, G; Rocher, V

    2014-07-01

    This paper aims at characterizing the quality of different treated sludges from Paris conurbation in terms of micropollutants and assessing their fate during different sludge treatment processes (STP). To achieve this, a large panel of priority and emerging pollutants (n=117) have been monitored in different STPs from Parisian wastewater treatment plants including anaerobic digestion, thermal drying, centrifugation and a sludge cake production unit. Considering the quality of treated sludges, comparable micropollutant patterns are found for the different sludges investigated (in mg/kg DM - dry matter). 35 compounds were detected in treated sludges. Some compounds (metals, organotins, alkylphenols, DEHP) are found in every kinds of sludge while pesticides or VOCs are never detected. Sludge cake is the most contaminated sludge, resulting from concentration phenomenon during different treatments. As regards treatments, both centrifugation and thermal drying have broadly no important impact on sludge contamination for metals and organic compounds, even if a slight removal seems to be possible with thermal drying for several compounds by abiotic transfers. Three different behaviors can be highlighted in anaerobic digestion: (i) no removal (metals), (ii) removal following dry matter (DM) elimination (organotins and NP) and iii) removal higher than DM (alkylphenols - except NP - BDE 209 and DEHP). Thus, this process allows a clear removal of biodegradable micropollutants which could be potentially significantly improved by increasing DM removal through operational parameters modifications (retention time, temperature, pre-treatment, etc.). PMID:24797622

  18. Influence of the free water content on the dewaterability of sewage sludges.

    PubMed

    Kopp, J; Dichtl, N

    2001-01-01

    Dewaterabilty of sewage depends on the physical water distribution. The various types of water in sewage sludge are mainly distinguished by type and intensity of their physical bonding to the solids. In a sewage sludge suspension different types of water can be distinguished. These are free water, which is not bound to the particles, interstitial water, which is bound by capillary forces between the sludge flocs, surface water, which is bound by adhesive forces and intracellular water. Only free water can be separated during mechanical dewatering. It can be shown, that thermo-gravimteric measurement of the free water content leads to an exact prediction of full-scale dewatering results. Maximum dewatering results are reached by separating all free water during centrifugation. Furthermore on the basis of the drying curve an estimation of water binding energies can be achieved. The binding energy for free water is less than 0,28 kJ/kg water. The binding energy for bound water (sum of surface and intracellular water) is higher than 5 kJ/kg water.

  19. Comparative evaluation of anaerobic digestion for sewage sludge and various organic wastes with simple modeling.

    PubMed

    Hidaka, Taira; Wang, Feng; Tsumori, Jun

    2015-09-01

    Anaerobic co-digestion of sewage sludge and other organic wastes, such as kitchen garbage, food waste, and agricultural waste, at a wastewater treatment plant (WWTP) is a promising method for both energy and material recovery. Substrate characteristics and the anaerobic digestion performance of sewage sludge and various organic wastes were compared using experiments and modeling. Co-digestion improved the value of digested sewage sludge as a fertilizer. The relationship between total and soluble elemental concentrations was correlated with the periodic table: most Na and K (alkali metals) were soluble, and around 20-40% of Mg and around 10-20% of Ca (alkaline earth metals) were soluble. The ratio of biodegradable chemical oxygen demand of organic wastes was 65-90%. The methane conversion ratio and methane production rate under mesophilic conditions were evaluated using a simplified mathematical model. There was reasonably close agreement between the model simulations and the experimental results in terms of methane production and nitrogen concentration. These results provide valuable information and indicate that the model can be used as a pre-evaluation tool to facilitate the introduction of co-digestion at WWTPs. PMID:26031329

  20. Towards understanding the effects of additives on the vermicomposting of sewage sludge.

    PubMed

    Xing, Meiyan; Lv, Baoyi; Zhao, Chunhui; Yang, Jian

    2015-03-01

    This work evaluated the effects of additives on the chemical properties of the final products (vermicompost) from vermicomposting of sewage sludge and the adaptable characteristics of Eisenia fetida during the process. An experimental design with different ratios of sewage sludge and the additives (cattle dung or pig manure) was conducted. The results showed that the vermicomposting reduced total organic carbon and the quotient of total organic carbon to total nitrogen (C/N ratio) of the initial mixtures and enhanced the stability and agronomical value of the final products. Notably, principal component analysis indicated that the additives had significant effects on the characteristics of the vermicomposts. Moreover, the vermibeds containing cattle dung displayed a better earthworm growth and reproduction than those with pig manure. Additionally, redundancy analysis demonstrated that electrical conductivity (EC), pH, and C/N ratio played crucial roles on earthworm growth and reproduction. In all, the additives with high C/N ratio, pH buffering capacity, and low EC are recommended to be used for vermicomposting of sewage sludge. PMID:25328094

  1. Image parameters for maturity determination of a composted material containing sewage sludge

    NASA Astrophysics Data System (ADS)

    Kujawa, S.; Nowakowski, K.; Tomczak, R. J.; Boniecki, P.; Dach, J.

    2013-07-01

    Composting is one of the best methods for management of sewage sludge. In a reasonably conducted composting process it is important to early identify the moment in which a material reaches the young compost stage. The objective of this study was to determine parameters contained in images of composted material's samples that can be used for evaluation of the degree of compost maturity. The study focused on two types of compost: containing sewage sludge with corn straw and sewage sludge with rapeseed straw. The photographing of the samples was carried out on a prepared stand for the image acquisition using VIS, UV-A and mixed (VIS + UV-A) light. In the case of UV-A light, three values of the exposure time were assumed. The values of 46 parameters were estimated for each of the images extracted from the photographs of the composted material's samples. Exemplary averaged values of selected parameters obtained from the images of the composted material in the following sampling days were presented. All of the parameters obtained from the composted material's images are the basis for preparation of training, validation and test data sets necessary in development of neural models for classification of the young compost stage.

  2. Artificial neural networks for modeling ammonia emissions released from sewage sludge composting

    NASA Astrophysics Data System (ADS)

    Boniecki, P.; Dach, J.; Pilarski, K.; Piekarska-Boniecka, H.

    2012-09-01

    The project was designed to develop, test and validate an original Neural Model describing ammonia emissions generated in composting sewage sludge. The composting mix was to include the addition of such selected structural ingredients as cereal straw, sawdust and tree bark. All created neural models contain 7 input variables (chemical and physical parameters of composting) and 1 output (ammonia emission). The α data file was subdivided into three subfiles: the learning file (ZU) containing 330 cases, the validation file (ZW) containing 110 cases and the test file (ZT) containing 110 cases. The standard deviation ratios (for all 4 created networks) ranged from 0.193 to 0.218. For all of the selected models, the correlation coefficient reached the high values of 0.972-0.981. The results show that he predictive neural model describing ammonia emissions from composted sewage sludge is well suited for assessing such emissions. The sensitivity analysis of the model for the input of variables of the process in question has shown that the key parameters describing ammonia emissions released in composting sewage sludge are pH and the carbon to nitrogen ratio (C:N).

  3. Fast microwave-assisted catalytic pyrolysis of sewage sludge for bio-oil production.

    PubMed

    Xie, Qinglong; Peng, Peng; Liu, Shiyu; Min, Min; Cheng, Yanling; Wan, Yiqin; Li, Yun; Lin, Xiangyang; Liu, Yuhuan; Chen, Paul; Ruan, Roger

    2014-11-01

    In this study, fast microwave-assisted catalytic pyrolysis of sewage sludge was investigated for bio-oil production, with HZSM-5 as the catalyst. Pyrolysis temperature and catalyst to feed ratio were examined for their effects on bio-oil yield and composition. Experimental results showed that microwave is an effective heating method for sewage sludge pyrolysis. Temperature has great influence on the pyrolysis process. The maximum bio-oil yield and the lowest proportions of oxygen- and nitrogen-containing compounds in the bio-oil were obtained at 550°C. The oil yield decreased when catalyst was used, but the proportions of oxygen- and nitrogen-containing compounds were significantly reduced when the catalyst to feed ratio increased from 1:1 to 2:1. Essential mineral elements were concentrated in the bio-char after pyrolysis, which could be used as a soil amendment in place of fertilizer. Results of XRD analyses demonstrated that HZSM-5 catalyst exhibited good stability during the microwave-assisted pyrolysis of sewage sludge.

  4. Anaerobic co-digestion of sewage sludge with shredded grass from public green spaces.

    PubMed

    Hidaka, Taira; Arai, Sayuri; Okamoto, Seiichiro; Uchida, Tsutomu

    2013-02-01

    Adding greenery from public spaces to the co-digestion process with sewage sludge was evaluated by shredding experiments and laboratory-scale batch and continuous mesophilic anaerobic fermentation experiments. The ratio of the shredded grass with 20mm or less in length by a commercially available shredder was 93%. The methane production was around 0.2NL/gVS-grass in the batch experiment. The continuous experiment fed with sewage sludge and shredded grass was stably operated for 81days. The average methane production was 0.09NL/gVS-grass when the TS ratio of the sewage sludge and the grass was 10:1. This value was smaller than those of other reports using grass silage, but the grass species in this study were not managed, and the collected grass was just shredded and not ensiled before feeding to the reactor for simple operation. The addition of grass to a digester can improve the carbon/nitrogen ratio, methane production and dewaterability.

  5. Fast microwave-assisted catalytic pyrolysis of sewage sludge for bio-oil production.

    PubMed

    Xie, Qinglong; Peng, Peng; Liu, Shiyu; Min, Min; Cheng, Yanling; Wan, Yiqin; Li, Yun; Lin, Xiangyang; Liu, Yuhuan; Chen, Paul; Ruan, Roger

    2014-11-01

    In this study, fast microwave-assisted catalytic pyrolysis of sewage sludge was investigated for bio-oil production, with HZSM-5 as the catalyst. Pyrolysis temperature and catalyst to feed ratio were examined for their effects on bio-oil yield and composition. Experimental results showed that microwave is an effective heating method for sewage sludge pyrolysis. Temperature has great influence on the pyrolysis process. The maximum bio-oil yield and the lowest proportions of oxygen- and nitrogen-containing compounds in the bio-oil were obtained at 550°C. The oil yield decreased when catalyst was used, but the proportions of oxygen- and nitrogen-containing compounds were significantly reduced when the catalyst to feed ratio increased from 1:1 to 2:1. Essential mineral elements were concentrated in the bio-char after pyrolysis, which could be used as a soil amendment in place of fertilizer. Results of XRD analyses demonstrated that HZSM-5 catalyst exhibited good stability during the microwave-assisted pyrolysis of sewage sludge. PMID:25260179

  6. Thermo-chemical process with sewage sludge by using CO2.

    PubMed

    Kwon, Eilhann E; Yi, Haakrho; Kwon, Hyun-Han

    2013-10-15

    This work proposed a novel methodology for energy recovery from sewage sludge via the thermo-chemical process. The impact of CO2 co-feed on the thermo-chemical process (pyrolysis and gasification) of sewage sludge was mainly investigated to enhance thermal efficiency and to modify the end products from the pyrolysis and gasification process. The CO2 injected into the pyrolysis and gasification process enhance the generation of CO. As compared to the thermo-chemical process in an inert atmosphere (i.e., N2), the generation of CO in the presence of CO2 was enhanced approximately 200% at the temperature regime from 600 to 900 °C. The introduction of CO2 into the pyrolysis and gasification process enabled the condensable hydrocarbons (tar) to be reduced considerably by expediting thermal cracking (i.e., approximately 30-40%); thus, exploiting CO2 as chemical feedstock and/or reaction medium for the pyrolysis and gasification process leads to higher thermal efficiency, which leads to environmental benefits. This work also showed that sewage sludge could be a very strong candidate for energy recovery and a raw material for chemical feedstock. PMID:23792821

  7. Anaerobic co-digestion of sewage sludge and strawberry extrudate under mesophilic conditions.

    PubMed

    Serrano, Antonio; Siles, José A; Chica, Arturo F; Martín, M Ángeles

    2014-01-01

    The biomethanization of sewage sludge has several disadvantages such as low methane yield, poor biodegradability and nutrient imbalance. In this paper, a sewage sludge and strawberry extrudate mixture in a proportion of 40:60 (wet weight) is proposed to improve the viability of the process. The addition of an easily biodegradable co-substrate enhanced the nutrient balance and diluted the heavy metals and inhibitors from sewage sludge. Two different experimental set-ups at lab and semi-pilot scale were employed in order to ensure the reproducibility and significance of the obtained values. Co-digestion improved the stability of the process by decreasing the alkalinity to a mean value of 3215 ± 190 mg CaCO₃/L, while maintaining the pH within the optimal range for anaerobic digestion. The methane yield coefficient and biodegradability were 176 L/kg VS (total volatile solids) (0°C, 1 atm) and 81% (VS), respectively. Kinetic parameters decreased at the highest loads, suggesting the occurrence of a slowing down phenomenon. A quality organic amendment with a heavy metal content lower than the limits established under European legislation for agricultural applications was obtained from the digestate of the proposed treatment. PMID:25189839

  8. Transformation of apatite phosphorus and non-apatite inorganic phosphorus during incineration of sewage sludge.

    PubMed

    Li, Rundong; Zhang, Ziheng; Li, Yanlong; Teng, Wenchao; Wang, Weiyun; Yang, Tianhua

    2015-12-01

    The recovery of phosphorus from incinerated sewage sludge ash (SSA) is assumed to be economical. Transformation from non-apatite inorganic phosphorus (NAIP) to apatite phosphorus (AP), which has a higher bioavailability and more extensive industrial applications, was studied at 750-950°C by sewage sludge incineration and model compound incineration with a calcium oxide (CaO) additive. Thermogravimetric differential scanning calorimetry analysis and X-ray diffraction measurements were used to analyze the reactions between NAIP with CaO and crystallized phases in SSA. High temperatures stimulated the volatilization of NAIP instead of AP. Sewage sludge incineration with CaO transformed NAIP into AP, and the percentage of AP from the total phosphorus reached 99% at 950°C. Aluminum phosphate reacted with CaO, forming Ca2P2O7 and Ca3(PO4)2 at 750-950°C. Reactions between iron phosphate and CaO occurred at lower temperatures, forming Ca(PO3)2 before reaching 850°C. PMID:26113414

  9. Decline in PCDD and PCDF levels in sewage sludges from Catalonia (Spain)

    SciTech Connect

    Eljarrat, E.; Caixach, J.; Rivera, J. . Mass Spectrometry Lab.)

    1999-08-01

    Nineteen sewage sludges from rural and urban wastewater treatment plants (WWTPs) in Catalonia (Spain) were analyzed for PCDDs and PCDFs using HRGC-HRMS to determine the present levels of contamination. Total I-TEQ values for these samples ranged from 7 to 160 pg/g, with a mean value of 55 pg/g and a median value of 42 pg/g. Moreover, archived sewage sludge samples collected and stored between 1979 and 1987 from 15 WWTPs were analyzed to gain some insight into temporal trends and possible variations in source inputs. Total I-TEQ values for archived samples ranged from 29 to 8300 pg/g, with a mean value of 620 pg/g and a median value of 110 pg/g. The findings show that contemporary sewage sludge PCDD/F concentrations have declined since the 1980s. In addition to the variations in PCDD and PCDF concentrations, there were also some changes in the isomeric patterns. These variations in levels and isomeric patterns could reflect changes in PCDD and PCDF sources to the environment over time.

  10. Temporal trends of persistent organic pollutants in digested sewage sludge (1993-2012).

    PubMed

    Zennegg, Markus; Munoz, Maria; Schmid, Peter; Gerecke, Andreas C

    2013-10-01

    The analysis of temporal trends is a key tool to assess the success of national and international regulations on chemical pollution. Persistent organic pollutants (POPs) are chemical pollutants, which are not only harmful, but also because of their slow environmental degradation they pose a long-time risk. In this study, concentrations of selected POPs were measured between 1993 and 2012 in digested sewage sludge from eight municipal waste water treatment plants. Polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-dioxins and furans (PCDD/Fs), which have been banned or restricted for decades, exhibited decreasing trends with apparent half-lives between 9 and 12years. Polybrominated diphenyl ethers (PBDEs) and long-chain perfluorinated acids showed no clear trend, which reflects the recent introduction of regulations. The analysis of octabromodiphenyl ethers did not reveal indications for reductive debromination of decabromodiphenyl ether; however the analysis of total bromine showed that up to 14% of the total bromine load in sewage sludge originated from PBDEs (average 2%). This is the first study to report temporal trends for more than 20years of series POPs in sewage sludge.

  11. Impact of feedstock properties and operating conditions on sewage sludge gasification in a fixed bed gasifier.

    PubMed

    Werle, Sebastian

    2014-10-01

    This work presents results of experimental studies on the gasification process of granulated sewage sludge in a laboratory fixed bed gasifier. Nowadays, there is a large and pressing need for the development of thermal methods for sewage sludge disposal. Gasification is an example of thermal method that has several advantages over the traditional combustion. Gasification leads to a combustible gas, which can be used for the generation of useful forms of final energy. It can also be used in processes, such as the drying of sewage sludge directly in waste treatment plant. In the present work, the operating parameters were varied over a wide range. Parameters, such as air ratio λ = 0.12 to 0.27 and the temperature of air preheating t = 50 °C to 250 °C, were found to influence temperature distribution and syngas properties. The results indicate that the syngas heating value decreases with rising air ratio for all analysed cases: i.e. for both cold and preheated air. The increase in the concentration of the main combustible components was accompanied by a decrease in the concentration of carbon dioxide. Preheating of the gasification agent supports the endothermic gasification and increases hydrogen and carbon monoxide production.

  12. Transformation of apatite phosphorus and non-apatite inorganic phosphorus during incineration of sewage sludge.

    PubMed

    Li, Rundong; Zhang, Ziheng; Li, Yanlong; Teng, Wenchao; Wang, Weiyun; Yang, Tianhua

    2015-12-01

    The recovery of phosphorus from incinerated sewage sludge ash (SSA) is assumed to be economical. Transformation from non-apatite inorganic phosphorus (NAIP) to apatite phosphorus (AP), which has a higher bioavailability and more extensive industrial applications, was studied at 750-950°C by sewage sludge incineration and model compound incineration with a calcium oxide (CaO) additive. Thermogravimetric differential scanning calorimetry analysis and X-ray diffraction measurements were used to analyze the reactions between NAIP with CaO and crystallized phases in SSA. High temperatures stimulated the volatilization of NAIP instead of AP. Sewage sludge incineration with CaO transformed NAIP into AP, and the percentage of AP from the total phosphorus reached 99% at 950°C. Aluminum phosphate reacted with CaO, forming Ca2P2O7 and Ca3(PO4)2 at 750-950°C. Reactions between iron phosphate and CaO occurred at lower temperatures, forming Ca(PO3)2 before reaching 850°C.

  13. Comparative evaluation of anaerobic digestion for sewage sludge and various organic wastes with simple modeling.

    PubMed

    Hidaka, Taira; Wang, Feng; Tsumori, Jun

    2015-09-01

    Anaerobic co-digestion of sewage sludge and other organic wastes, such as kitchen garbage, food waste, and agricultural waste, at a wastewater treatment plant (WWTP) is a promising method for both energy and material recovery. Substrate characteristics and the anaerobic digestion performance of sewage sludge and various organic wastes were compared using experiments and modeling. Co-digestion improved the value of digested sewage sludge as a fertilizer. The relationship between total and soluble elemental concentrations was correlated with the periodic table: most Na and K (alkali metals) were soluble, and around 20-40% of Mg and around 10-20% of Ca (alkaline earth metals) were soluble. The ratio of biodegradable chemical oxygen demand of organic wastes was 65-90%. The methane conversion ratio and methane production rate under mesophilic conditions were evaluated using a simplified mathematical model. There was reasonably close agreement between the model simulations and the experimental results in terms of methane production and nitrogen concentration. These results provide valuable information and indicate that the model can be used as a pre-evaluation tool to facilitate the introduction of co-digestion at WWTPs.

  14. Probabilistic risk assessment for linear alkylbenzene sulfonate (LAS) in sewage sludge used on agricultural soil.

    PubMed

    Schowanek, Diederik; David, Helen; Francaviglia, Rosa; Hall, Jeremy; Kirchmann, Holger; Krogh, Paul Henning; Schraepen, Nathalie; Smith, Stephen; Wildemann, Tanja

    2007-12-01

    Deterministic and probabilistic risk assessments were developed for commercial LAS in agricultural soil amended with sewage sludge. The procedure done according to ILSI Europe's Conceptual Framework [Schowanek, D., Carr, R., David, H., Douben, P., Hall, J., Kirchmann, H., Patria, L., Sequi, P., Smith, S., Webb, S.F., 2004. A risk-based methodology for deriving quality standards for organic contaminants in sewage sludge for use in agriculture-conceptual Framework. Regul. Toxicol. Pharmacol. 40 (3), 227-251], consists of three main steps. First, the most sensitive endpoint was determined. This was found to be the chronic ecotoxicity of LAS to soil invertebrates and plants. Additional endpoints, such as potential for plant uptake and transfer in the food chain, leaching to groundwater, surface erosion run-off, human health risk via drinking water, plant consumption and soil ingestion were also systematically evaluated but were all assessed to be of little toxicological significance. In the second step, a back-calculation was conducted from the Predicted No-Effect Concentration in soil (PNECsoil) to a safe level of LAS in sludge (here called 'Sludge Quality Standard'; SQS). The deterministic approach followed the default agricultural soil exposure scenario in the EU-Technical Guidance Document (TGD). The SQS for LAS was calculated as 49 g/kg sludge Dry Matter (DM). In order to assess the potential variability as a result of varying agricultural practices and local environmental conditions, two probabilistic exposure assessment scenarios were also developed. The mean SQS was estimated at 55 and 27.5 g/kg DM for the homogeneous soil mixing and soil injection scenarios, respectively. In the final step, the resulting SQS values were evaluated for consistency and relevance versus available information from agricultural experience and field tests. No build-up, adverse impact on soil fertility, agronomic performance, or animal/human health have been reported for agricultural

  15. 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.

  16. 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.

  17. Root penetration of sealing layers made of fly ash and sewage sludge.

    PubMed

    Neuschütz, Clara; Stoltz, Eva; Greger, Maria

    2006-01-01

    Fly ash and sewage sludge are suggested materials for constructing sealing layers covering mine tailings impoundments. Little is known, however, of their effect on vegetation or resistance to root penetration. We investigate: (i) the ability of different plant species to grow in sealing layers comprising fly ash and sewage sludge, (ii) the impact on plant growth of freshly hardened fly ash compared to aged and leached ash, and (iii) the plant stress response to fly ashes of different properties. A 6-mo greenhouse study using birch (Betula pendula Roth.), Scots pine (Pinus sylvestris L.), Kentucky bluegrass (Poa pratensis L.), and willow (Salix viminalis L.) demonstrated that no roots could grow into a compacted layer consisting only of ash, while a 6:4, ash-sludge mixture admitted roots into the upper part and a 1:9, ash-sludge mixture was totally penetrated (to 15 cm in depth) by roots of willow and Scots pine. Freshly hardened ash prevented root growth more effectively than aged ash did, as was observed in tests using reed canarygrass (Phalaris arundinacea L.) and pea (Pisum sativum L.). Furthermore, extracts of highly alkaline ash were more toxic to pea in a 48-h toxicity test than less alkaline ash was. However, stress responses to diluted ash extracts of lower pH, measured as enzyme capacities in dwarf bean (Phaseolus vulgaris L.), were more related to the metal and ion contents. Root penetration of sealing layers is most effectively prevented if little sewage sludge is added, and if ash of high alkalinity is chosen. PMID:16825445

  18. Mechanism and kinetics of low-temperature thermochemical conversion process for sewage sludge.

    PubMed

    He, P; Shao, L; Gu, G; Li, G

    2001-01-01

    The low-temperature thermo-chemical conversion process for sewage sludge is a prospective technology, through which the energy in the sludge can be recovered. With the help of elementary analysis of sewage sludge and its conversion products, thermal gravimetric analysis (TGA) of the sludge and GC/MS analysis of the derived oil, a study was carried out on element transfer, characteristic conversion temperature and conversion reaction mechanism of the process. The following results are obtained: 1) the predominant conversion reactions are distillation of aliphatic compounds, splitting of protein peptide bonds and group transfer; and 2) the main components involved in the conversion are aliphatic compounds and protein, with the lower reaction temperature for the former, the higher for the latter and the highest for saccharides. Based on the mechanism analyses, the simplified reaction model of the thermo-chemical conversion process for sewage sludge consists of two serial competitive reactions (producing volatile matter and char respectively). The estimated Arrhennius kinetic parameters of the reaction model based on TGA testing resultsare A1 = 4.15 x 10(6) 1/s, n1 = 2, E1 = 98 kJ/mol; A2 = 1.42 x 10(5) 1/s, n2 = 2, E2 = 85 kJ/mol; A3 = 1.01 x 10(12) 1/s, n3 = 4, E3 = 190 kJ/mol; A4 = 1.33 x 10(9) 1/s, n4 = 4, E4 = 146 kJ/mol.

  19. 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

  20. 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. PMID:24932693

  1. NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    SciTech Connect

    Jost O.L. Wendt

    2003-06-02

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NOx concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process.

  2. Quantification of metals in sewage sludges by X-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Enzweiler, J.; de Moraes, M. P. G.; Mincato, R. L.

    2003-05-01

    The application of sewage sludge on soils is a common practice, but the heavy metals should be determined before disposal. Sewage sludges composition is mainly organic and the amount of heavy metals is variable. Usual methods for heavy metals determination are based on dissolution of the sample. The results depend, partially, on the efficiency of the dissolution of the heavy metals, which may vary from sample to sample. We studied the feasibility of analyzing pressed pellets of sludges by wavelength dispersive X-ray fluorescence spectrometry (WD-XRF), with fumdamental parameters matrix effects correction. Several ways of introducing the carbon content in the corrections were tested. Accuracy was evaluated by analysis of four international certificate reference materials. Results were within or very close to the confidence interval of the available certified values for most elements (Al, As, Cr, Cu, Fe, Mn, Ni, Pb, S, Se, Si, V, Zn). Other metals, like Cd and Hg were below the detection limits (15 and 9 mg kg^{-l}, respectively). Despite the limitation concerning the proper matrix correction, the uncertainty of the XRF results is probably similar to the methods normally used in sludge analysis, with the advantage that sample preparation is much faster.

  3. Investigation of sewage sludge stabilization potential by the addition of fly ash and lime.

    PubMed

    Samaras, P; Papadimitriou, C A; Haritou, I; Zouboulis, A I

    2008-06-15

    The aim of this work was the examination of stabilization potential of sewage sludge by the addition of fly ash and/or lime and the investigation of the effect of stabilization time on the properties of produced mixtures. Five samples were prepared by mixing fly ash, sewage sludge and lime in various ratios and the mixtures were stabilized for a period of 35 d. The addition of alkaline agents resulted in the increase of sample pH up to 12, the increase of total solids content to about 50% and the reduction of the organic fraction of the solids. The produced samples presented inhibition effects to seed germination and root length growth of three higher plants (one monocotyl and two dicotyls); however, samples with high sludge content resulted in negligible seed germination inhibition at prolonged stabilization times. The standard TCLP leaching procedure was applied in all the produced samples in order to evaluate the extraction potential of certain metallic elements; the content of metals in the eluates was varied, depending upon their speciation and form. Eluates presented significant inhibition to the marine photobacterium Vibrio fischeri bioluminescence, while the lowest inhibition was detected for the samples containing higher sludge content. These samples potentially could be applied as soil amendment, offering an efficient method for the combined utilization of two different solid wastes; however, low dosages of fly ash should be used for the production of a stabilized material presenting negligible effects with respect to its phytotoxic and ecotoxic properties. PMID:18093729

  4. Optimization of thermo-alkaline disintegration of sewage sludge for enhanced biogas yield.

    PubMed

    Shehu, Muhammad Sani; Abdul Manan, Zainuddin; Alwi, Sharifah Rafidah Wan

    2012-06-01

    Optimization of thermo-alkaline disintegration of sewage sludge for enhanced biogas yield was carried out using response surface methodology (RSM) and Box-Behnken design of experiment. The individual linear and quadratic effects as well as the interactive effects of temperature, NaOH concentration and time on the degree of disintegration were investigated. The optimum degree of disintegration achieved was 61.45% at 88.50 °C, 2.29 M NaOH (24.23%w/w total solids) and 21 min retention time. Linear and quadratic effects of temperature are most significant in affecting the degree of disintegration. The coefficient of determination (R(2)) of 99.5% confirms that the model used in predicting the degree of disintegration process has a very good fitness with the experimental variables. The disintegrated sludge increased the biogas yield by 36%v/v compared to non-disintegrated sludge. The RSM with Box-Behnken design is an effective tool in predicting the optimum degree of disintegration of sewage sludge for increased biogas yield.

  5. Heavy metal concentrations in earthworms from soil amended with sewage sludge

    USGS Publications Warehouse

    Beyer, W.N.; Chaney, R.L.; Mulhern, B.M.

    1982-01-01

    Metal concentrations in soil may be elevated considerably when metal-laden sewage sludge is spread on land. Metals in earthworms (Lumbricidae) from agricultural fields amended with sewage sludge and from experimental plots were examined to determine if earthworms are important in transferring metals in soil to wildlife. Earthworms from four sites amended with sludge contained significantly (P . < 0.05) more Cd (12 times), Cu (2.4 times), Zn (2.0 times), and Pb (1.2 times) than did earthworms from control sites, but the concentrations detected varied greatly and depended on the particular sludge application. Generally, Cd and Zn were concentrated by earthworms relative to soil, and Cu, Pb, and Ni were not concentrated. Concentrations of Cd, Zn, Cu, and Pb in earthworms were correlated (P < 0.05) with those in soil. The ratio of the concentration of metals in earthworms to the concentration of metals in soil tended to be lower in contaminated soil than in clean soil. Concentrations of Cd as high as 100 ppm (dry wt) were detected in earthworms from soil containing only 2 ppm Cd. These concentrations are considered hazardous to wildlife that eat worms. Liming soil decreased Cd concentrations in earthworms slightly (P < 0.05) but had no discernible effect on concentrations of the other metals studied. High Zn concentrations in soil substantially reduced Cd concentrations in earthworms.

  6. Environmental and economic life cycle assessment for sewage sludge treatment processes in Japan.

    PubMed

    Hong, Jinglan; Hong, Jingmin; Otaki, Masahiro; Jolliet, Olivier

    2009-02-01

    Life cycle assessment for sewage sludge treatment was carried out by estimating the environmental and economic impacts of the six alternative scenarios most often used in Japan: dewatering, composting, drying, incineration, incinerated ash melting and dewatered sludge melting, each with or without digestion. Three end-of-life treatments were also studied: landfilling, agricultural application and building material application. The results demonstrate that sewage sludge digestion can reduce the environmental load and cost through reduced dry matter volume. The global warming potential (GWP) generated from incineration and melting processes can be significantly reduced through the reuse of waste heat for electricity and/or heat generation. Equipment production in scenarios except dewatering has an important effect on GWP, whereas the contribution of construction is negligible. In addition, the results show that the dewatering scenario has the highest impact on land use and cost, the drying scenario has the highest impact on GWP and acidification, and the incinerated ash melting scenario has the highest impact on human toxicity due to re-emissions of heavy metals from incinerated ash in the melting unit process. On the contrary, the dewatering, composting and incineration scenarios generate the lowest impact on human toxicity, land use and acidification, respectively, and the incinerated ash melting scenario has the lowest impact on GWP and cost. Heavy metals released from atmospheric effluents generated the highest human toxicity impact, with the effect of dioxin emissions being significantly lower. This study proved that the dewatered sludge melting scenario is an environmentally optimal and economically affordable method.

  7. [Bioleaching of fly ash from municipal solid waste incinerator using sewage sludge and pig manure as culture media].

    PubMed

    Zhou, Shun-gui; Chang, Ming; Hu, Pei; Ni, Jin-ren

    2005-11-01

    A mixed culture of Acidihiobacillus ferrooaidans and Acidihiobacillus thiooxidans was used to leach heavy metals from municipal solid waste incineration fly ash (MSWI fly ash). This study explored the possibility of using sewage sludge or pig manure as nutrients for supporting the growth of the leaching bacteria and allowing metal solubilization like a synthetic mineral medium. In contrast to pig manure, there is a high ability for acidification of the fly ash and solubilization of toxic metals using sewage sludge at the same content. After 15 d of bioleaching, the following removal efficiencies were obtained for the treatment with the addition of 1% sewage sludge: Cd 88.1%; Zn 78.7%; Cu 69.6%, whereas their removal efficiencies for the treatment with the addition of 1% pig manure were 82.4%, 73.5% and 60.0%, respectively. Results demonstrate that the inhibition by sewage sludge DOM is much more significant than by pig manure DOM at the same concentration level. The dissolved organic carbon in excess of 400 and 150 mg/L was inhibitory to the bacterial growth using sludge DOM and manure DOM, respectively. Compared with sewage sludge, pig manure contained a higher fraction of DOM with molecular size <1000, which led to its higher toxicity. PMID:16447455

  8. The odour of digested sewage sludge--determination and its abatement by air stripping.

    PubMed

    Winter, P; Jones, N; Asaadi, M; Bowman, L

    2004-01-01

    This paper describes a project to investigate the odour of sewage sludge after anaerobic digestion. The impact of air stripping on the odour of liquid sludge and on the quality of the dewatered product was evaluated at a full-scale sludge treatment installation. A continuous and a batch air-stripping mode were tested. Odour samples were collected during air stripping from the liquid sludge and from the biosolids surface during long term storage. The biosolids were also analysed for hedonic tone and for their potential odour expressed as an odour unit per unit mass. The odour emission profiles for continuous and batch air stripping demonstrated a reduction in the overall (time weighted) emissions during a 24 hr-period compared with emissions from the quiescent liquid storage tank. The averaged specific odour emission rate (Esp) of the biosolids derived from the continuous process was only 13% of the Esp of the biosolids derived from unaerated liquid sludge during the first month of storage. The results of the total potential odour and the hedonic tone of the biosolids underpin the beneficial effects of the air stripping. Odour dispersion modelling showed a noticeable reduction in overall odour impact from the sludge centre when air stripping was applied. The reduction was primarily associated with the reduced odour from stockpiled biosolids. The continuous air-stripping mode appeared to provide the greatest benefits in terms of odour impact from site operations.

  9. Removal of metals in leachate from sewage sludge using electrochemical technology.

    PubMed

    Meunier, N; Drogui, P; Gourvenec, C; Mercier, G; Hausler, R; Blais, J F

    2004-02-01

    Heavy metals in acidic leachates from sewage sludge are usually removed by chemical precipitation, which often requires high concentration of chemicals and induces high metallic sludge production. Electrochemical technique has been explored as an alternative method in a laboratory pilot scale reactor for heavy metals (Cu and Zn) removal from sludge leachate. Three electrolytic cell arrangements using different electrodes materials were tested: mild steel or aluminium bipolar electrode (EC cell), Graphite/stainless steel monopolar electrodes (ER cell) and iron-monopolar electrodes (EC-ER cell). Results showed that the best performances of metal removal were obtained with EC and EC-ER cells using mild steel electrodes operated respectively at current intensities of 0.8 and 2.0 A through 30 and 60 min of treatment. The yields of Cu and Zn removal from leachate varied respectively from 92.4 to 98.9% and from 69.8 to 76.6%. The amounts of 55 and 44 kg tds(-1) of metallic sludge were respectively produced using EC and EC-ER cells. EC and EC-ER systems involved respectively a total cost of 21.2 and 13.1 CAN dollars per ton of dry sludge treated including only energy consumption and metallic sludge disposal. The treatment using EC-ER system was found to be effective and more economical than the traditional metal precipitation using either Ca(OH)2 and/or NaOH.

  10. Tar-free fuel gas production from high temperature pyrolysis of sewage sludge.

    PubMed

    Zhang, Leguan; Xiao, Bo; Hu, Zhiquan; Liu, Shiming; Cheng, Gong; He, Piwen; Sun, Lei

    2014-01-01

    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 H2 and CO in the produced gas. However, the low heating value (LHV) of the gas decreased from 15.68 MJ/Nm(3) to 9.10 MJ/Nm(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.

  11. Effect of solarization on the removal of indicator microorganisms from municipal sewage sludge.

    PubMed

    Ozdemir, Saim; Aslan, Taha; Celebi, Ahmet; Dede, Gulgun; Dede, Omer Hulusi

    2013-01-01

    The effect of solarization on bacterial inactivation in sewage sludge was studied using thermotolerant coliforms, enterococci and Escherichia coli (E. coli) as the indicator organisms. Solarization significantly increased the sludge temperature. The maximum temperatures were achieved at the beginning of the second week, reaching 65, 58, 55 and 50 degrees C at depths of 0-10, 10-20, 20-30 and 30-40 cm, respectively. E. coli was found to be the most sensitive microorganism and was reduced to undetectable levels after 9 d at all monitored sludge depths. Thermotolerant coliforms were rapidly inactivated but were not reduced to below the detection limit. The inactivation curves of enterococci showed both shoulders and tailing, indicating a larger heat resistant fraction than with E. coli and the thermotolerant coliforms. Overall, the results suggest that the temperature regime produced by solarization was sufficient to reduce bacterial indicators to an acceptable level, meeting the pathogen regulation limit, in two weeks. PMID:24191484

  12. Effect of solarization on the removal of indicator microorganisms from municipal sewage sludge.

    PubMed

    Ozdemir, Saim; Aslan, Taha; Celebi, Ahmet; Dede, Gulgun; Dede, Omer Hulusi

    2013-01-01

    The effect of solarization on bacterial inactivation in sewage sludge was studied using thermotolerant coliforms, enterococci and Escherichia coli (E. coli) as the indicator organisms. Solarization significantly increased the sludge temperature. The maximum temperatures were achieved at the beginning of the second week, reaching 65, 58, 55 and 50 degrees C at depths of 0-10, 10-20, 20-30 and 30-40 cm, respectively. E. coli was found to be the most sensitive microorganism and was reduced to undetectable levels after 9 d at all monitored sludge depths. Thermotolerant coliforms were rapidly inactivated but were not reduced to below the detection limit. The inactivation curves of enterococci showed both shoulders and tailing, indicating a larger heat resistant fraction than with E. coli and the thermotolerant coliforms. Overall, the results suggest that the temperature regime produced by solarization was sufficient to reduce bacterial indicators to an acceptable level, meeting the pathogen regulation limit, in two weeks.

  13. Evaluation of the efficiency and throughput of a gamma irradiator treating municipal sewage sludge.

    PubMed

    Benny, P G; Shah, M R; Sabharwal, S

    2011-03-01

    Sludge Hygienisation Research Irradiator (SHRI) Facility at Vadodara (India) has been disinfecting liquid sewage sludge with (60)Co gamma rays since 1992. At some point, the radiation process was modified from its originally designed closed-loop system to an open-loop system. Dosimetry experiments were performed to estimate absorbed doses to the sludge for different periods of irradiation of a 15m(3) batch in an open-loop irradiation process. The paper reports the dosimetry results and evaluated operational parameters of the irradiator, namely, effective dose rate in the open-loop system, irradiation efficiency, and throughput. Also, the open-loop system and the closed-loop system are compared in terms of the effective dose rate.

  14. 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

  15. 17 β-estradiol and 17 α-ethinylestradiol mineralization in sewage sludge and biosolids.

    PubMed

    Rose, Karin P; Farenhorst, Annemieke; Claeys, Anne; Ascef, Bruna

    2014-01-01

    Natural steroid estrogens (e.g., 17 β-estradiol, E2), synthetic steroid estrogens (e.g., 17 α-ethinylestradiol, EE2) and pharmaceutical antibiotics (e.g., ciprofloxacin) are chemicals detected in biosolids and sewage sludges because they partition into the solids fraction during the wastewater treatment process. This research utilized a three-way factorial design (six media × two estrogens × three antibiotic treatments) to quantify cumulative E2 and EE2 mineralization over 133 d (MAX) in a range of sewage sludge and biosolid samples in the presence (4 and 40 mg kg(-1)) and absence of ciprofloxacin. The same three-way factorial design was utilized to quantify the impact of the six media, E2 or EE2, and ciprofloxacin on cumulative soil respiration over 133 d (RESP). Minimal ciprofloxacin mineralization was observed (<0.05% over 133 d), but despite its persistence, ciprofloxacin had no significant effect on MAX of E2 or EE2, and, in general, no significant effect on RESP. MAX ranged from 38.38% to 48.44% for E2 but from only 0.72% to 24.27% for EE2 although RESP was relatively similar, ranging from 101.00 to 866.54 mg CO2 in the presence of E2 and from 69.55 to 893.95 mg CO2 in the presence of EE2. The sorption-limited bioavailability of EE2, which is inherently resistant to biodegradation due to chemical structure, as MAX and Freundlich sorption coefficients (Kf) were negatively correlated. As such, the Kf values of EE2 were largest in composted biosolids in which EE2 was particularly resistant to microbial degradation as the MAX of EE2 was <3%. In contrast, the MAX of E2 showed a positive association with the Kf values of E2 because some steps in the E2 transformation process have been found to occur in the sorbed phase. The MAX of E2 was significantly greater in the biosolid and composted biosolid media than in any other media, whereas the MAX of E2 decreased in the following order: secondary sewage sludge > primary sewage sludge > biosolid = composted

  16. Comparison of methods for the preparation of sewage sludge samples prior to the spectrophotometric determination of phosphorus

    SciTech Connect

    Katz, S.A.; Jenniss, S.W.; Ciuffo, M.; Alberts, R.

    1986-01-01

    Three procedures for the preparation of sewage sludge samples prior to the colorimetric determination of phosphorus as molybdenum blue were evaluated. Using samples of the US EPA's municipal digested sludge as a reference material, sulfuric acid/ammonium persulfate digestion, muffle furnace ignition followed by extraction of the ash with hydrochloric acid, and direct extraction of the sewage sludge with sodium bicarbonate solution were compared in terms of phosphorus recovery as determined by colorimetric measurements. On the basis of phosphorus recovery, the samples prepared by muffle furnace ignition/hydrochloric acid extraction of the ash showed the best accuracy and precision. This procedure was also superior in terms of the time and effort expended in the preparation of the sewage sludge samples.

  17. Mathematical model investigation of long-term transport of ocean-dumped sewage sludge related to remote sensing

    NASA Technical Reports Server (NTRS)

    Kuo, C. Y.; Modena, T. D.

    1979-01-01

    An existing, three-dimensional, Eulerian-Lagrangian finite-difference model was modified and used to examine the transport processes of dumped sewage sludge in the New York Bight. Both in situ and laboratory data were utilized in an attempt to approximate model inputs such as mean current speed, horizontal diffusion coefficients, particle size distributions, and specific gravities. The results presented are a quantitative description of the fate of a negatively buoyant sewage sludge plume resulting from continuous and instantaneous barge releases. Concentrations of the sludge near the surface were compared qualitatively with those remotely sensed. Laboratory study was performed to investigate the behavior of sewage sludge dumping in various ambient density conditions.

  18. Isotopic distribution of carbon from sewage sludge and eutrophication in the sediments and food web of estuarine ecosystems

    SciTech Connect

    Gearing, P.J.; Gearing, J.N.; Maughan, J.T.; Oviatt, C.A. )

    1991-02-01

    Stable isotope ratios ({delta}{sup 13}C) from samples of water, sediments, and biota traced the behavior of organic carbon for 3 summer months in estuarine mesocosms (three controls, three with added sewage sludge, three with added inorganic nutrients). Isotope ratios proved to be a useful quantitative tracer for sewage carbon as well as for the fresh phytoplanktonic carbon produced during nutrient fertilization. Sewage sludge sedimented within hours of its addition, and approximately 50% remained in sediments after 99 days. The sludge was not inert, but was biologically oxidized at rates similar to those of phytoplankton carbon. Its residence time in the water column was too short for uptake by zooplankton, but it was readily assimilated by some benthic organisms. Fresh phytoplanktonic carbon from nutrient-induced blooms was isotopically heavy and thus distinguishable from old primary production (fixed before the experiment). It flowed through the pelagic and benthic food webs more extensively and more uniformly than did sludge carbon.

  19. Ground-water quality near a sewage-sludge recycling site and a landfill near Denver, Colorado

    USGS Publications Warehouse

    Robson, Stanley G.

    1977-01-01

    The Metropolitan Denver Sewage Disposal District and the city and county of Denver operate a sewage-sludge recycling site and a landfill in an area about 15 miles (24 kilometers) east of Denver. The assessment of the effects of these facilities on the ground-water system indicated that five wells perforated in alluvium were found to have markedly degradedd water quality. One well is located in the landfill and water that was analyzed was obtained from near the base of the buried refuse, two others are located downgradient and near sewage-sludge burial areas, and the remaining two are located near stagnant surface ponds. Concentrations of nitrate in wells downgradient from fields where sludge is plowed into the soil were higher than background concentrations due to the effects of the sludge disposal. No evidence of water-quality degradation was detected in deeper wells perforated in the bedrock formations. (Woodard-USGS)

  20. Fundamental Combustion Characteristics of Sewage Sludge in Fluidized Bed Incinerator with Turbocharger

    NASA Astrophysics Data System (ADS)

    Murakami, Takahiro; Suzuki, Yoshizo; Nagasawa, Hidekazu; Yamamoto, Takafumi; Koseki, Takami; Hirose, Hitoshi; Ochi, Shuichi

    An epoch-making incineration plant, which is equipped with a pressurized fluidized-bed combustor coupled to a turbocharger, for the recovery of the energy contained in sewage sludge is proposed. This plant has three main advantages. (1) A pressure vessel is unnecessary because the maximum operating pressure is 0.3 MPa (absolute pressure). The material cost for plant construction can be reduced. (2) CO2 emissions originating from power generation can be decreased because the FDF (Forced Draft Fan) and the IDF (Induced Draft Fan) are omitted. (3) Steam in the flue gas becomes a working fluid of the turbocharger, so that in addition to the combustion air, the surplus air is also generable. Therefore, this proposed plant will not only save energy but also the generate energy. The objective of this study is to elucidate the fundamental combustion characteristics of the sewage sludge using a lab-scale pressurized fluidized bed combustor (PFBC). The tested fuels are de-watered sludge and sawdust. The temperature distribution in the furnace and N2O emissions in the flue gas are experimentally clarified. As the results, for sludge only combustion, the temperature in the sand bed decreases by drying and pyrolysis, and the pyrolysis gas burns in the freeboard so that the temperature rises. On the other hand, the residual char of sawdust after pyrolysis burns stably in the sand bed for the co-firing of sludge and sawdust. Thus the temperature of the co-firing is considerably higher than that of the sludge only combustion. N2O emissions decreases with increasing freeboard temperature, and are controlled by the temperature for all experimental conditions. These data can be utilize to operation the demonstration plant.

  1. Environmental & economic life cycle assessment of current & future sewage sludge to energy technologies.

    PubMed

    Mills, N; Pearce, P; Farrow, J; Thorpe, R B; Kirkby, N F

    2014-01-01

    The UK Water Industry currently generates approximately 800GWh pa of electrical energy from sewage sludge. Traditionally energy recovery from sewage sludge features Anaerobic Digestion (AD) with biogas utilisation in combined heat and power (CHP) systems. However, the industry is evolving and a number of developments that extract more energy from sludge are either being implemented or are nearing full scale demonstration. This study compared five technology configurations: 1 - conventional AD with CHP, 2 - Thermal Hydrolysis Process (THP) AD with CHP, 3 - THP AD with bio-methane grid injection, 4 - THP AD with CHP followed by drying of digested sludge for solid fuel production, 5 - THP AD followed by drying, pyrolysis of the digested sludge and use of the both the biogas and the pyrolysis gas in a CHP. The economic and environmental Life Cycle Assessment (LCA) found that both the post AD drying options performed well but the option used to create a solid fuel to displace coal (configuration 4) was the most sustainable solution economically and environmentally, closely followed by the pyrolysis configuration (5). Application of THP improves the financial and environmental performance compared with conventional AD. Producing bio-methane for grid injection (configuration 3) is attractive financially but has the worst environmental impact of all the scenarios, suggesting that the current UK financial incentive policy for bio-methane is not driving best environmental practice. It is clear that new and improving processes and technologies are enabling significant opportunities for further energy recovery from sludge; LCA provides tools for determining the best overall options for particular situations and allows innovation resources and investment to be focused accordingly. PMID:24060290

  2. Detection of methoxylated and hydroxylated polychlorinated biphenyls in sewage sludge in China with evidence for their microbial transformation

    PubMed Central

    Sun, Jianteng; Zhu, Lizhong; Pan, Lili; Wei, Zi; Song, Yao; Zhang, Yuduo; Qu, Liping; Zhan, Yu

    2016-01-01

    The concentrations of methoxylated polychlorinated biphenyls (MeO-PCBs) and hydroxylated polychlorinated biphenyls (OH-PCBs) were measured in the sewage sludge samples collected from twelve wastewater treatment plants in China. Two MeO-PCB congeners, including 3′-MeO-CB-65 and 4′-MeO-CB-101, were detected in three sludge with mean concentrations of 0.58 and 0.52 ng/g dry weight, respectively. OH-PCBs were detected in eight sludge samples, with an average total concentration of 4.2 ng/g dry weight. Furthermore, laboratory exposure was conducted to determine the possible source of OH-PCBs and MeO-PCBs in the sewage sludge, and their metabolism by the microbes. Both 4′-OH-CB-101 and 4′-MeO-CB-101 were detected as metabolites of CB-101 at a limited conversion rate after 5 days. Importantly, microbial interconversion between OH-PCBs and MeO-PCBs was observed in sewage sludge. Demethylation of MeO-PCBs was favored over methylation of OH-PCBs. The abundant and diverse microbes in sludge play a key role in the transformation processes of the PCB analogues. To our knowledge, this is the first report on MeO-PCBs in environmental matrices and on OH-PCBs in sewage sludge. The findings are important to understand the environmental fate of PCBs. PMID:27417462

  3. Detection of methoxylated and hydroxylated polychlorinated biphenyls in sewage sludge in China with evidence for their microbial transformation

    NASA Astrophysics Data System (ADS)

    Sun, Jianteng; Zhu, Lizhong; Pan, Lili; Wei, Zi; Song, Yao; Zhang, Yuduo; Qu, Liping; Zhan, Yu

    2016-07-01

    The concentrations of methoxylated polychlorinated biphenyls (MeO-PCBs) and hydroxylated polychlorinated biphenyls (OH-PCBs) were measured in the sewage sludge samples collected from twelve wastewater treatment plants in China. Two MeO-PCB congeners, including 3‧-MeO-CB-65 and 4‧-MeO-CB-101, were detected in three sludge with mean concentrations of 0.58 and 0.52 ng/g dry weight, respectively. OH-PCBs were detected in eight sludge samples, with an average total concentration of 4.2 ng/g dry weight. Furthermore, laboratory exposure was conducted to determine the possible source of OH-PCBs and MeO-PCBs in the sewage sludge, and their metabolism by the microbes. Both 4‧-OH-CB-101 and 4‧-MeO-CB-101 were detected as metabolites of CB-101 at a limited conversion rate after 5 days. Importantly, microbial interconversion between OH-PCBs and MeO-PCBs was observed in sewage sludge. Demethylation of MeO-PCBs was favored over methylation of OH-PCBs. The abundant and diverse microbes in sludge play a key role in the transformation processes of the PCB analogues. To our knowledge, this is the first report on MeO-PCBs in environmental matrices and on OH-PCBs in sewage sludge. The findings are important to understand the environmental fate of PCBs.

  4. 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.

  5. Absolute dominance of hydrogenotrophic methanogens in full-scale anaerobic sewage sludge digesters.

    PubMed

    Kim, Jaai; Kim, Woong; Lee, Changsoo

    2013-11-01

    Anaerobic digestion (AD) is gaining increasing attention due to the ability to covert organic pollutants into energy-rich biogas and, accordingly, growing interest is paid to the microbial ecology of AD systems. Despite extensive efforts, AD microbial ecology is still limitedly understood, especially due to the lack of quantitative information on the structures and dynamics of AD microbial communities. Such knowledge gap is particularly pronounced in sewage sludge AD processes although treating sewage sludge is among the major practical applications of AD. Therefore, we examined the microbial communities in three full-scale sewage sludge digesters using qualitative and quantitative molecular techniques in combination: denaturing gradient gel electrophoresis (DGGE) and real-time polymerase chain reaction (PCR). Eight out of eleven bacterial sequences retrieved from the DGGE analysis were not affiliated to any known species while all eleven archaeal sequences were assigned to known methanogen species. Quantitative real-time PCR analysis revealed that, based on the 16S rRNA gene abundance, the hydrogenotrophic order Methanomicrobiales is the most dominant methanogen group (> 94% of the total methanogen population) in all digesters. This corresponds well to the prevailing occurrence of the DGGE bands related to Methanolinea and Methanospirillum, both belonging to the order Methanomicrobiales, in all sludge samples. It is therefore suggested that hydrogenotrophic methanogens, especially Methanomicrobiales strains, are likely the major players responsible for biogas production in the digesters studied. Our observation is contrary to the conventional understanding that aceticlastic methanogens generally dominate methanogen communities in stable AD environments, suggesting the need for further studies on the dominance relationship in various AD systems.

  6. Effects of temperature and composite alumina on pyrolysis of sewage sludge.

    PubMed

    Sun, Yu; Jin, Baosheng; Wu, Wei; Zuo, Wu; Zhang, Ya; Zhang, Yong; Huang, Yaji

    2015-04-01

    An interactive dual-circulating fluidized bed system has been proposed in which the pyrolysis of sewage sludge (SS) and incineration of biomass proceed simultaneously, and alumina is used as the bed material and heat carrier. The alumina coated with biomass ash would mix with sewage sludge in the pyrolysis reactor of this device. It is important to know the influence of composite alumina (CA) on the pyrolysis progress. Sewage sludge was pyrolyzed in a fixed bed reactor from 400 to 600°C using CA as catalyst. The effects of temperature and CA additive ratio on the products were investigated. The product yields and component distribution of non-condensable gas were more sensitive to the change of temperature, and the maximum liquid yield of 48.44 wt.% and maximum Useable Energy of Liquid of 3871 kJ/kg sludge were observed at 500°C with 1/5 CA/SS (mass ratio). The gas chromatography-mass spectrometry results showed that the increase of temperature enhanced devolatilization of organic matter and promoted cyclization and aromatization of aliphatics. The presence of CA could strengthen secondary cracking and interaction among primary products from different organic compounds, such as acid-amine condensation, and reduce the content of oxygenated compounds. When the CA additive amount exceeded a certain proportion, the aromatization was clearly strengthened. The effects of CA on decomposition of fatty acids and formation of aromatics were similar to that of temperature. This means that the reaction temperature could be lowered by introducing CA, which has a positive effect on reducing energy consumption.

  7. Phytotreatment of sewage sludge contaminated by heavy metals and PAHs by co-planting Sedum alfredii and Alocasia marorrhiza.

    PubMed

    Qiu, J R; Guo, X F; Cai, Q Y; Liu, W; Zhang, M W; Wei, Z B; Wu, Q T

    2014-01-01

    High concentrations of heavy metals and organic pollutants in municipal sewage sludge are key factors limiting its use in agriculture. The objectives of this study were to decrease the heavy metal and polycyclic aromatic hydrocarbon concentrations in sewage sludge by phytotreatment and to determine, in a field experiment, whether co-planting is more effective than using a mono-crop of Sedum alfredii. Four treatments were used in the plot experiment: no sludge, no plants, S. alfredii and co-planting S. alfredii and Alocasia marorrhiza. The results showed that co-planting produced tubers and shoots of A. marorrhiza that were suitable as a safe animal feed and good organic K fertilizer, respectively. Co-planting was more effective than mono-planting at reducing concentrations of total Zn and diethylenetriaminepentaacetic acid (DTPA)-extractable Zn, Cd, and Cu in the sludge. Co-planting decreased the concentrations of DTPA-extractable heavy metals and benzo[a]pyrene (B[a]P) in the sludge significantly compared with the unplanted sludge. Decreases of 87, 75, 85, 31, and 64% were obtained for B[a]P and DTPA-extractable Zn, Cd, Cu, and Pb, respectively, compared with the fresh sludge. These results indicate that co-planting can reduce significantly the environmental risks associated with heavy metals and B[a]P in sewage sludge for further disposal.

  8. Evaluation and Source Apportionment of Heavy Metals (HMs) in Sewage Sludge of Municipal Wastewater Treatment Plants (WWTPs) in Shanxi, China

    PubMed Central

    Duan, Baoling; Liu, Fenwu; Zhang, Wuping; Zheng, Haixia; Zhang, Qiang; Li, Xiaomei; Bu, Yushan

    2015-01-01

    Heavy metals (HMs) in sewage sludge have become the crucial limiting factors for land use application. Samples were collected and analyzed from 32 waste water treatment plants (WWTPs) in the Shanxi Province, China. HM levels in sewage sludge were assessed. The multivariate statistical method principal component analysis (PCA) was applied to identify the sources of HMs in sewage sludge. HM pollution classes by geochemical accumulation index Igeo and correlation analyses between HMs were also conducted. HMs were arranged in the following decreasing order of mean concentration: Zn > Cu > Cr > Pb > As > Hg > Cd; the maximum concentrations of all HMs were within the limit of maximum content permitted by Chinese discharge standard. Igeo classes of HMs pollution in order from most polluted to least were: Cu and Hg pollution were the highest; Cd and Cr pollution were moderate; Zn, As and Pb pollution were the least. Sources of HM contamination in sewage sludge were identified as three components. The primary contaminant source accounting for 35.7% of the total variance was identified as smelting industry, coking plant and traffic sources; the second source accounting for 29.0% of the total variance was distinguished as household and water supply pollution; the smallest of the three sources accounting for 16.2% of the total variance was defined as special industries such as leather tanning, textile manufacturing and chemical processing industries. Source apportionment of HMs in sewage sludge can control HM contamination through suggesting improvements in government policies and industrial processes. PMID:26690464

  9. Field study on the uptake and translocation of PBDEs by wheat (Triticum aestivum L.) in soils amended with sewage sludge.

    PubMed

    Li, Helian; Qu, Ronghui; Yan, Liangguo; Guo, Weilin; Ma, Yibing

    2015-03-01

    Field experiments were conducted to explore the effects of different sewage sludge amendment strategies on the accumulation and translocation of polybrominated diphenyl ethers (PBDEs) in soil-wheat systems. Two types of application methods (single or annual application) and four annual application rates (5, 10, 20, and 40 t ha(-1) year(-1)) were investigated. BDE 209 was detected in all of the sewage sludge amended soils and different parts of wheat plants collected from the contaminated soils. However, the other seven PBDE congeners (BDE 28, BDE 47, BDE 99, BDE 100, BDE 153, BDE 154, and BDE 183) were not detected or were only observed at very low levels. A single application of sewage sludge in large quantities would likely increase accumulation of BDE 209 in soil and its subsequent uptake and translocation by wheat. The concentrations of BDE 209 in soils, wheat roots and straws increased with the increasing sewage sludge application rate. There is a negative correlation between the root accumulation factors (the ratios of concentrations in wheat roots to those in soils) and soil total organic carbon (R(2)=0.84,P<0.05), demonstrating that the bioavailability of BDE 209 was controlled by the soil total organic carbon. BDE 209 concentrations in the grains from the sewage sludge amended soils were not significantly different from those of the control soils, suggesting that atmospheric deposition was the main source of BDE 209 detected in the grains.

  10. Phosphorus in manure and sewage sludge more recyclable than in soluble inorganic fertilizer.

    PubMed

    Kahiluoto, H; Kuisma, M; Ketoja, E; Salo, T; Heikkinen, J

    2015-02-17

    Phosphorus (P) flow from deposits through agriculture to waterways leads to eutrophication and depletion of P reserves. Therefore, P must be recycled. Low and unpredictable plant availability of P in residues is considered to be a limiting factor for recycling. We identified the determinants for the plant-availability of P in agrifood residues. We quantified P in Italian ryegrass (Lolium multiflorum) and in field soil fractions with different plant availabilities of P as a response to manure and sewage sludge with a range of P capture and hygienization treatments. P was more available in manure and in sludge, when it was captured biologically or with a moderate iron (Fe)/P (1.6), than in NPK. Increasing rate of sludge impaired P recovery and high Fe/P (9.8) prevented it. Anaerobic digestion (AD) reduced plant-availability at relevant rates. The recovery of P was increased in AD manure via composting and in AD sludge via combined acid and oxidizer. P was not available to plants in the sludge hygienized with a high calcium/P. Contrary to assumed knowledge, the recyclability of P in appropriately treated residues can be better than in NPK. The prevention of P sorption in soil by organic substances in fertilizers critically enhances the recyclability of P. PMID:25569114

  11. Nitrogen fertilizer and sewage sludge effects on hybrid poplars. Final report

    SciTech Connect

    Riha, S.R.; Senesac, G.P.; Naylor, L.

    1985-01-01

    Experiments conducted in the greenhouse compared the growth and nutrient and heavy metal uptake in two clones of hybrid poplar grown in soil amended with nitrogen fertilizer or sewage sludge. In addition, poplar responses to weed competition and to rooting prior to planting were investigated. Both fertilizer and sludge application increased poplar stem biomass. Weeds reduced poplar biomass. The large difference in root biomass of the two poplar clones may account for different effects weed and sludge application had on nutrient and heavy metal uptake in each clone. The relatively small root biomass of I-45/51 increased with increasing sludge application, as did the uptake of nutrients and heavy metals. The relatively large root biomass of clone NE-510 was reduced when weeds were present, as was nutrient and heavy metal uptake. Other results suggest that poplars with low root-to-stem ratios may be most affected by weed competition, especially after their first year, and that nitrogen fertilization may alleviate effects of weeds on their growth. Poplars grown in sludge-amended soil did not accumulate more of any nutrient or heavy metal studied compared to those grown in nitrogen-fertilized soil. 17 refs., 5 figs., 57 tabs.

  12. 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). PMID:26897473

  13. Inactivation of Clostridium difficile in sewage sludge by anaerobic thermophilic digestion.

    PubMed

    Xu, Changyun; Salsali, Hamidreza; Weese, Scott; Warriner, Keith

    2016-01-01

    There has been an increase in community-associated Clostridium difficile infections with biosolids derived from wastewater treatment being identified as one potential source. The current study evaluated the efficacy of thermophilic digestion in decreasing levels of C. difficile ribotype 078 associated with sewage sludge. Five isolates of C. difficile 078 were introduced (final density of 5 log CFU/g) into digested sludge and subjected to anaerobic digestion at mesophilic (36 or 42 °C) or thermophilic (55 °C) temperatures for up to 60 days. It was found that mesophilic digestion at 36 °C did not result in a significant reduction in C. difficile spore levels. In contrast, thermophilic sludge digestion reduced endospore levels at a rate of 0.19-2.68 log CFU/day, depending on the strain tested. The mechanism of lethality was indirect - by stimulating germination then inactivating the resultant vegetative cells. Acidification of sludge by adding acetic acid (6 g/L) inhibited the germination of spores regardless of the sludge digestion temperature. In conclusion, thermophilic digestion can be applied to reduce C. difficile in biosolids, thereby reducing the environmental burden of the enteric pathogen.

  14. Reduction in greenhouse gas emissions from sewage sludge aerobic compost in China.

    PubMed

    Liu, H-t; Zheng, H-x; Chen, T-b; Zheng, G-d; Gao, D

    2014-01-01

    Sewage sludge is an important contributor to greenhouse gas (GHG) emissions and the carbon budget of organic solid waste treatment and disposal. In this case study, total GHG emissions from an auto-control sludge compost system, including direct and indirect emissions and replaceable reduction due to sludge compost being reused as fertilizer, were quantified. The results indicated that no methane generation needed to be considered in the carbon debit because of the advantages of auto-control for monitoring and maintenance of appropriate conditions during the composting process. Indirect emissions were mainly from electricity and fossil fuel consumption, including sludge transportation and mechanical equipment use. Overall, the total carbon replaceable emission reduction owing to sludge being treated by composting rather than landfill, and reuse of its compost as fertilizer instead of chemical fertilizer, were calculated to be 0.6204 tCO2e t(-1) relative to baseline. Auto-control compost can facilitate obtaining certified emission reduction warrants, which are essential to accessing financial support with the authentication by the Clean Development Mechanism.

  15. Inactivation of Clostridium difficile in sewage sludge by anaerobic thermophilic digestion.

    PubMed

    Xu, Changyun; Salsali, Hamidreza; Weese, Scott; Warriner, Keith

    2016-01-01

    There has been an increase in community-associated Clostridium difficile infections with biosolids derived from wastewater treatment being identified as one potential source. The current study evaluated the efficacy of thermophilic digestion in decreasing levels of C. difficile ribotype 078 associated with sewage sludge. Five isolates of C. difficile 078 were introduced (final density of 5 log CFU/g) into digested sludge and subjected to anaerobic digestion at mesophilic (36 or 42 °C) or thermophilic (55 °C) temperatures for up to 60 days. It was found that mesophilic digestion at 36 °C did not result in a significant reduction in C. difficile spore levels. In contrast, thermophilic sludge digestion reduced endospore levels at a rate of 0.19-2.68 log CFU/day, depending on the strain tested. The mechanism of lethality was indirect - by stimulating germination then inactivating the resultant vegetative cells. Acidification of sludge by adding acetic acid (6 g/L) inhibited the germination of spores regardless of the sludge digestion temperature. In conclusion, thermophilic digestion can be applied to reduce C. difficile in biosolids, thereby reducing the environmental burden of the enteric pathogen. PMID:26564276

  16. 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.

  17. Soil improvement with coal ash and sewage sludge: a field experiment

    NASA Astrophysics Data System (ADS)

    Shen, Junfeng; Zhou, Xuewu; Sun, Daisheng; Fang, Jianguo; Liu, Zhijun; Li, Zhongmin

    2008-02-01

    A field experimental study was carried out successfully to improve the quality of the sandy soil by adding coal ash and sewage sludge. One ha of barren sandy soil field was chosen for the experiment in Shanghe County, Shandong Province, China. For soil amelioration and tree planting, two formulas of the mixture:coal ash, sewage sludge and soil, in ratios of 20:10:70 and 20:20:60, respectively, were used. Poplar trees were planted in pits filled with soils with additives (mixture of ash and sludge) as well as in the original sandy soil. In the 19th months after the trees were planted, the soils with additives were sampled and analyzed. The results show that the barren sandy soil was greatly improved after mixing with coal ash and sludge. The improved soils have remarkably higher nutrient concentrations, better texture, smaller bulk density, higher porosity and mass moisture content, and higher content of fine-grained minerals. During the first 22 months after planting, the annual increase in height of the trees grown in the soil with additives (4.78 m per year) was 55% higher than that of the control group (3.07 m per year), and the annual increase in diameter at the breast height (1.3 m) was 33 % higher (43.03 vs. 32.36 mm). Trees planted in soils with additives appeared healthier and shed leaves later than those in the control group. As the volume of the additives (30-40% in both formulas) is less than that of the sandy soil in and around the tree pits, it appears that the use of coal ash and sludge for tree planting and soil amelioration is environmentally safe even though the additives have relatively high heavy metal concentrations.

  18. 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.

  19. ENVIRONMENTAL REGULATIONS AND TECHNOLOGY: CONTROL OF PATHOGENS AND VECTOR ATTRACTION IN SEWAGE SLUDGE (INCLUDING DOMESTIC SEWAGE) UNDER 40 CFR PART 503

    EPA Science Inventory

    This document describes the federal requirements concerning pathogens in sewage sludge applied to land or placed on a surface disposal site, and it provides guidance concerning those requirements. The document is intended for: (1) Owners and operators of treatment works treati...

  20. Leachability of heavy metals from lightweight aggregates made with sewage sludge and municipal solid waste incineration fly ash.

    PubMed

    Wei, Na

    2015-05-07

    Lightweight aggregate (LWA) production with sewage sludge and municipal solid waste incineration (MSWI) fly ash is an effective approach for waste disposal. This study investigated the stability of heavy metals in LWA made from sewage sludge and MSWI fly ash. Leaching tests were conducted to find out the effects of MSWI fly ash/sewage sludge (MSWI FA/SS) ratio, sintering temperature and sintering time. It was found that with the increase of MSWI FA/SS ratio, leaching rates of all heavy metals firstly decreased and then increased, indicating the optimal ratio of MSWI fly ash/sewage sludge was 2:8. With the increase of sintering temperature and sintering time, the heavy metal solidifying efficiencies were strongly enhanced by crystallization and chemical incorporations within the aluminosilicate or silicate frameworks during the sintering process. However, taking cost-savings and lower energy consumption into account, 1100 °C and 8 min were selected as the optimal parameters for LWA sample- containing sludge production. Furthermore, heavy metal leaching concentrations under these optimal LWA production parameters were found to be in the range of China's regulatory requirements. It is concluded that heavy metals can be properly stabilized in LWA samples containing sludge and cannot be easily released into the environment again to cause secondary pollution.

  1. Leachability of heavy metals from lightweight aggregates made with sewage sludge and municipal solid waste incineration fly ash.

    PubMed

    Wei, Na

    2015-05-01

    Lightweight aggregate (LWA) production with sewage sludge and municipal solid waste incineration (MSWI) fly ash is an effective approach for waste disposal. This study investigated the stability of heavy metals in LWA made from sewage sludge and MSWI fly ash. Leaching tests were conducted to find out the effects of MSWI fly ash/sewage sludge (MSWI FA/SS) ratio, sintering temperature and sintering time. It was found that with the increase of MSWI FA/SS ratio, leaching rates of all heavy metals firstly decreased and then increased, indicating the optimal ratio of MSWI fly ash/sewage sludge was 2:8. With the increase of sintering temperature and sintering time, the heavy metal solidifying efficiencies were strongly enhanced by crystallization and chemical incorporations within the aluminosilicate or silicate frameworks during the sintering process. However, taking cost-savings and lower energy consumption into account, 1100 °C and 8 min were selected as the optimal parameters for LWA sample- containing sludge production. Furthermore, heavy metal leaching concentrations under these optimal LWA production parameters were found to be in the range of China's regulatory requirements. It is concluded that heavy metals can be properly stabilized in LWA samples containing sludge and cannot be easily released into the environment again to cause secondary pollution. PMID:25961800

  2. Effect of cofiring coal and biofuel with sewage sludge on alkali problems in a circulating fluidized bed boiler

    SciTech Connect

    K.O. Davidsson; L.-E. Aamand; A.-L. Elled; B. Leckner

    2007-12-15

    Cofiring experiments were performed in a 12 MW circulating fluidized bed boiler. The fuel combinations were biofuel (wood+straw), coal+biofuel, coal+sewage sludge+biofuel, and sewage sludge+biofuel. Limestone or chlorine (PVC) was added in separate experiments. Effects of feed composition on bed ash and fly ash were examined. The composition of flue gas was measured, including on-line measurement of alkali chlorides. Deposits were collected on a probe simulating a superheater tube. It was found that the fuel combination, as well as addition of limestone, has little effect on the alkali fraction in bed ash, while chlorine decreases the alkali fraction in bed ash. Sewage sludge practically eliminates alkali chlorides in flue gas and deposits. Addition of enough limestone to coal and sludge for elimination of the SO{sub 2} emission does not change the effect of chlorine. Chlorine addition increases the alkali chloride in flue gas, but no chlorine was found in the deposits with sewage sludge as a cofuel. Cofiring of coal and biofuel lowers the alkali chloride concentration in the flue gas to about a third compared with that of pure biofuel. This is not affected by addition of lime or chlorine. It is concluded that aluminum compounds in coal and sludge are more important than sulfur to reduce the level of KCl in flue gas and deposits. 24 refs., 8 figs., 7 tabs.

  3. Leachability of Heavy Metals from Lightweight Aggregates Made with Sewage Sludge and Municipal Solid Waste Incineration Fly Ash

    PubMed Central

    Wei, Na

    2015-01-01

    Lightweight aggregate (LWA) production with sewage sludge and municipal solid waste incineration (MSWI) fly ash is an effective approach for waste disposal. This study investigated the stability of heavy metals in LWA made from sewage sludge and MSWI fly ash. Leaching tests were conducted to find out the effects of MSWI fly ash/sewage sludge (MSWI FA/SS) ratio, sintering temperature and sintering time. It was found that with the increase of MSWI FA/SS ratio, leaching rates of all heavy metals firstly decreased and then increased, indicating the optimal ratio of MSWI fly ash/sewage sludge was 2:8. With the increase of sintering temperature and sintering time, the heavy metal solidifying efficiencies were strongly enhanced by crystallization and chemical incorporations within the aluminosilicate or silicate frameworks during the sintering process. However, taking cost-savings and lower energy consumption into account, 1100 °C and 8 min were selected as the optimal parameters for LWA sample- containing sludge production. Furthermore, heavy metal leaching concentrations under these optimal LWA production parameters were found to be in the range of China’s regulatory requirements. It is concluded that heavy metals can be properly stabilized in LWA samples containing sludge and cannot be easily released into the environment again to cause secondary pollution. PMID:25961800

  4. Effects of aeration rate on maturity and gaseous emissions during sewage sludge composting.

    PubMed

    Yuan, Jing; Chadwick, David; Zhang, Difang; Li, Guoxue; Chen, Shili; Luo, Wenhai; Du, Longlong; He, Shengzhou; Peng, Shengping

    2016-10-01

    This study investigated effects of aeration rate (AR) on maturity and gaseous emissions during sewage sludge composting, sewage sludge and corn stalks as the bulking agent were co-composted at different ARs (0.1, 0.2, 0.3L·kg(-1) dry matter (DM)·min(-1)). The thermophilic phase for the low and moderate AR treatments was able meet sanitation requirements, but too short to meet sanitation requirements in the high AR treatment. The high AR treatment was significantly different from the other treatments, and had the lowest electrical conductivity and highest E4/E6(absorbance ratio of wavelength 465 and 665nm). The AR influences the nitrogen variations; high AR compost had the highest NH4(+)-N content and lowest NOx(-)-N content. The AR was the main factor influencing compost stability, but the AR had little impact on pH and the germination index. The moderate AR treatment had the highest NH3 emissions during composting, while the low AR treatment had the highest CH4 and N2O emissions. Based on our comprehensive investigation, the recommended AR for sludge composting is 0.2L·kg(-1) DM·min(-1). PMID:27425860

  5. Microalgae Cultivation on Anaerobic Digestate of Municipal Wastewater, Sewage Sludge and Agro-Waste

    PubMed Central

    Zuliani, Luca; Frison, Nicola; Jelic, Aleksandra; Fatone, Francesco; Bolzonella, David; Ballottari, Matteo

    2016-01-01

    Microalgae are fast-growing photosynthetic organisms which have the potential to be exploited as an alternative source of liquid fuels to meet growing global energy demand. The cultivation of microalgae, however, still needs to be improved in order to reduce the cost of the biomass produced. Among the major costs encountered for algal cultivation are the costs for nutrients such as CO2, nitrogen and phosphorous. In this work, therefore, different microalgal strains were cultivated using as nutrient sources three different anaerobic digestates deriving from municipal wastewater, sewage sludge or agro-waste treatment plants. In particular, anaerobic digestates deriving from agro-waste or sewage sludge treatment induced a more than 300% increase in lipid production per volume in Chlorella vulgaris cultures grown in a closed photobioreactor, and a strong increase in carotenoid accumulation in different microalgae species. Conversely, a digestate originating from a pilot scale anaerobic upflow sludge blanket (UASB) was used to increase biomass production when added to an artificial nutrient-supplemented medium. The results herein demonstrate the possibility of improving biomass accumulation or lipid production using different anaerobic digestates. PMID:27735859

  6. Chemical and toxicological characterization of the bricks produced from clay/sewage sludge mixture.

    PubMed

    Gerić, Marko; Gajski, Goran; Oreščanin, Višnja; Kollar, Robert; Garaj-Vrhovac, Vera

    2012-01-01

    The present study aimed to characterize chemical properties of clay bricks containing 20 % of sewage sludge. After detection of potentially hazardous metals, we simulated precipitation exposure of such material to determine the amount of heavy metals that could leach out of the bricks. Metals, such as copper, zinc, nickel, cobalt, chromium, etc., were detected in leachate in low concentrations. Moreover, human peripheral blood lymphocytes were exposed to brick leachate for 24 h in order to evaluate its possible negative impact on human cells and genome in vitro. Cytotoxicity tests showed no effect on human peripheral blood lymphocytes viability after exposure to brick's leachate. On the contrary, the alkaline comet assay showed slight but significant increase in DNA damage with all three parameters tested. As we might predict, interactions of several heavy metals in low concentrations could be responsible for DNA damaging effect. In that manner, our findings suggest that leachates from sewage sludge-produced bricks may lead to adverse effects on the exposed human population, and that more stabile bricks should be developed to minimize leaching of heavy metals into the environment. Bricks with lower percentage of the sludge may be one of the solutions to reduce the toxic effect of the final product.

  7. Process performance of high-solids batch anaerobic digestion of sewage sludge.

    PubMed

    Liao, Xiaocong; Li, Huan; Cheng, Yingchao; Chen, Nan; Li, Chenchen; Yang, Yuning

    2014-01-01

    The characteristics of high-solids anaerobic digestion (AD) of sewage sludge were investigated by comparison with conventional low-solids processes. A series of batch experiments were conducted under mesophilic condition and the initial solid contents were controlled at four levels of 1.79%, 4.47%, 10.28% and 15.67%. During these experiments, biogas production, organic degradation and intermediate products were monitored. The results verified that high-solids batch AD of sewage sludge was feasible. Compared with the low-solids AD with solid contents of 1.79% or 4.47%, the high-solids processes decreased the specific biogas yield per gram of sludge volatile solids slightly, achieved the same organic degradation rate of about 40% within extended degradation time, but increased the volumetric biogas production rate and the treatment capability of digesters significantly. The blocked mass and energy transfer, the low substrate to inoculum rate and the excessive cumulative free ammonia were the main factors impacting the performance of high-solids batch AD.

  8. Evaluation of granular sludge for secondary treatment of saline municipal sewage.

    PubMed

    van den Akker, Ben; Reid, Katherine; Middlemiss, Kyra; Krampe, Joerg

    2015-07-01

    This study examined the impact of chemical oxygen demand (COD) loading and dissolved oxygen (DO) concentration on the stability and performance of granular sludge treating high saline municipal sewage. Under high DO concentrations of 4.0-7.0 mg/L, and COD loading rates of 0.98 and 1.55 kg/m(3)/d, rapid settling granules were established within four weeks of start-up. Under the highest COD load, a reduction in DO lead to the rapid deterioration of the sludge volume index (SVI) and washout of granules due to prolific growth of the filament Thiothrix Type 021N. Conversely, when operated under a lower COD load, a reduction in DO concentration had no adverse impact on the stability of SVI and granules. A decrease in DO also improved nitrogen removal performance, where simultaneous removal of ammonium (98%), total nitrogen (86%) and BOD5 (98%) were achieved when median DO concentrations were between 1.0 and 1.5 mg/L. Phosphate removal was lower than expected, however the level of biological phosphate removal activity observed appeared sufficient to maintain granule stability, even under low DO concentrations. Nitrous oxide emissions were also characterised, which ranged between 2.3 and 6.8% of the total nitrogen load. Our results confirmed that granular sludge is a viable option for the treatment of saline sewage.

  9. Chemical and toxicological characterization of the bricks produced from clay/sewage sludge mixture.

    PubMed

    Gerić, Marko; Gajski, Goran; Oreščanin, Višnja; Kollar, Robert; Garaj-Vrhovac, Vera

    2012-01-01

    The present study aimed to characterize chemical properties of clay bricks containing 20 % of sewage sludge. After detection of potentially hazardous metals, we simulated precipitation exposure of such material to determine the amount of heavy metals that could leach out of the bricks. Metals, such as copper, zinc, nickel, cobalt, chromium, etc., were detected in leachate in low concentrations. Moreover, human peripheral blood lymphocytes were exposed to brick leachate for 24 h in order to evaluate its possible negative impact on human cells and genome in vitro. Cytotoxicity tests showed no effect on human peripheral blood lymphocytes viability after exposure to brick's leachate. On the contrary, the alkaline comet assay showed slight but significant increase in DNA damage with all three parameters tested. As we might predict, interactions of several heavy metals in low concentrations could be responsible for DNA damaging effect. In that manner, our findings suggest that leachates from sewage sludge-produced bricks may lead to adverse effects on the exposed human population, and that more stabile bricks should be developed to minimize leaching of heavy metals into the environment. Bricks with lower percentage of the sludge may be one of the solutions to reduce the toxic effect of the final product. PMID:22702811

  10. Aerobic biodegradation of selected polybrominated diphenyl ethers (PBDEs) in wastewater sewage sludge.

    PubMed

    Stiborova, Hana; Vrkoslavova, Jana; Lovecka, Petra; Pulkrabova, Jana; Hradkova, Petra; Hajslova, Jana; Demnerova, Katerina

    2015-01-01

    Due to widespread accumulation of polybrominated diphenyl ethers (PBDEs) in our surroundings, it is important to clarify their fate in the environment and the options of their elimination. The aim of this study was to monitor the biodegradation of the most frequent congeners (BDE 28, 47, 49, 66, 85, 99, 100, 153, 154, 183 and 209) under aerobic condition by indigenous microflora in 2 industrially contaminated sewage sludge samples. BDE 209 was detected as the predominating congener in concentrations 685 ng/g and 1403 ng/g dry weight in sewage sludge from WWTPs (waste water treatment plants) Hradec Kralove and Brno, respectively. The total amount of 10 lower PBDEs was 605 and 205 ng/g dry weight, respectively. The aerobic degradation was significantly enhanced by the addition of yeast extract and 4-bromobiphenyl. The total concentrations of all 11 PBDE congeners were lowered and their elimination was detected reaching 62–78% of their initial amounts after 11 months of cultivation. The degradation of most abundant congener BDE 209 followed the first-order kinetics with constant detected between 2.77 × 10(−3) d(−1) and 3.79 × 10−(3)d(−1) and the half-lives of BDE 209 degradation ranged between 6.0 and 8.2 months. This work clearly demonstrates that both lower brominated PBDEs as well as the major representative BDE 209 could be successfully removed from municipally contaminated sludge under aerobic conditions. PMID:25463256

  11. Effects of elemental sulphur on heavy metal uptake by plants growing on municipal sewage sludge.

    PubMed

    Dede, Gulgun; Ozdemir, Saim

    2016-01-15

    In this study experiment was carried out to determine the phytoextraction potential of six plant species (Conium maculatum, Brassica oleraceae var. oleraceae, Brassica juncea, Datura stramonium, Pelargonium hortorum and Conyza canadensis) grown in a sewage sludge medium amended with metal uptake promoters. The solubility of Cu, Cd and Pb was significantly increased with the application of elemental S due to decrease of pH. Faecal coliform number was markedly decreased by addition of elemental sulphur. The extraction of Cu, Cr and Pb from sewage sludge by using B. juncea plant was observed as 65%, 65% and 54% respectively that is statistically similar to EDTA as sulphur. The bioaccumulation factors were found higher (>1) in the plants tested for Cu and Pb like B. juncea. Translocation index (TI) calculated values for Cd and Pb were greater than one (>1) in both C. maculatum and B. oleraceae var. oleraceae. The results cleared that the amendment of sludge with elemental sulphur showed potential to solubilize heavy metals in phytoremediation as much as EDTA. PMID:26496839

  12. Application of sewage sludge to non-agricultural ecosystems: Impacts of nitrogen on forests

    SciTech Connect

    Efroymson, R.A.; Tharp, M.L.; Luxmoore, R.J.; Sample, B.E.; Barnthouse, L.W.; Daniel, F.B.

    1995-12-31

    The Clean Water Act (CWA) of 1977 directed EPA to establish standards for use and disposal of sewage sludge (biosolids). This report is part of a larger study evaluating nutrient and contaminant impacts associated with the land application of biosolids in non-agricultural ecosystems. Ecological risk assessments rarely focus on nutrients as stressors. The nutrient components of municipal sewage sludge may impact tree community composition, growth and production, habitat and forage quality for wildlife, and nutrient cycling. The focus here is on three forest ecosystems: northwestern Douglas-fir forest (Pack Forest, WA), southeastern loblolly pine plantation (Athens, GA), and eastern deciduous forest (Hubbard Brook, NH). A model called LINKAGES has been developed at ORNL to examine the relationships between nitrogen cycling and long-term forest stand dynamics, limited by climate and soil water status. Plant-available nitrogen from biosolids is added in several application scenarios and compared to the no-amendment case. All changes are noted, even if they may be viewed as benefits rather than risks. Model outputs include: above-ground biomass, individual species biomass, net above-ground production, leaf litter, evapotranspiration, available nitrogen, and dead trunks. The changes in plant community composition and production are dependent on the rate, frequency, and duration of sludge application and on the age of the stand at the time of application. Model outputs are compared to empirical studies of forests where biosolids have been applied.

  13. Effects of elemental sulphur on heavy metal uptake by plants growing on municipal sewage sludge.

    PubMed

    Dede, Gulgun; Ozdemir, Saim

    2016-01-15

    In this study experiment was carried out to determine the phytoextraction potential of six plant species (Conium maculatum, Brassica oleraceae var. oleraceae, Brassica juncea, Datura stramonium, Pelargonium hortorum and Conyza canadensis) grown in a sewage sludge medium amended with metal uptake promoters. The solubility of Cu, Cd and Pb was significantly increased with the application of elemental S due to decrease of pH. Faecal coliform number was markedly decreased by addition of elemental sulphur. The extraction of Cu, Cr and Pb from sewage sludge by using B. juncea plant was observed as 65%, 65% and 54% respectively that is statistically similar to EDTA as sulphur. The bioaccumulation factors were found higher (>1) in the plants tested for Cu and Pb like B. juncea. Translocation index (TI) calculated values for Cd and Pb were greater than one (>1) in both C. maculatum and B. oleraceae var. oleraceae. The results cleared that the amendment of sludge with elemental sulphur showed potential to solubilize heavy metals in phytoremediation as much as EDTA.

  14. Utilization of solar energy in sewage sludge composting: Fertilizer effect and application

    SciTech Connect

    Chen, Yiqun; Yu, Fang; Liang, Shengwen; Wang, Zongping Liu, Zizheng; Xiong, Ya

    2014-11-15

    Highlights: • Solar energy technologies were utilized in aerobic sewage sludge composting. • Greenhouse and solar reactors were constructed to compare impacts on the composting. • Impatiens balsamina was planted in pot experiments to evaluate fertilizer effect. - Abstract: Three reactors, ordinary, greenhouse, and solar, were constructed and tested to compare their impacts on the composting of municipal sewage sludge. Greenhouse and solar reactors were designed to evaluate the use of solar energy in sludge composting, including their effects on temperature and compost quality. After 40 days of composting, it was found that the solar reactor could provide more stable heat for the composting process. The average temperature of the solar reactor was higher than that of the other two systems, and only the solar reactor could maintain the temperature above 55 °C for more than 3 days. Composting with the solar reactor resulted in 31.3% decrease in the total organic carbon, increased the germination index to 91%, decreased the total nitrogen loss, and produced a good effect on pot experiments.

  15. Degradation of organic pollutants in Mediterranean forest soils amended with sewage sludge.

    PubMed

    Francisca Gomez-Rico, M; Font, Rafael; Vera, Jose; Fuentes, David; Disante, Karen; Cortina, Jordi

    2008-05-01

    The degradation of two groups of organic pollutants in three different Mediterranean forest soils amended with sewage sludge was studied for nine months. The sewage sludge produced by a domestic water treatment plant was applied to soils developed from limestone, marl and sandstone, showing contrasting alkalinity and texture. The compounds analysed were: linear alkylbenzene sulphonates (LAS) with a 10-13 carbon alkylic chain, and nonylphenolic compounds, including nonylphenol (NP) and nonylphenol ethoxylates with one and two ethoxy groups (NP1EO+NP2EO). These compounds were studied because they frequently exceed the limits proposed for sludge application to land in Europe. After nine months, LAS decomposition was 86-96%, and NP+NP1EO+NP2EO decomposition was 61-84%, which can be considered high. Temporal trends in LAS and NP+NP1EO+NP2EO decomposition were similar, and the concentrations of both types of compounds were highly correlated. The decomposition rates were higher in the period of 6-9 months (summer period) than in the period 0-6 months (winter+spring period) for total LAS and NP+NP1EO+NP2EO. Differences in decay rates with regard to soil type were not significant. The average values of decay rates found are similar to those observed in agricultural soils. PMID:18329688

  16. 40 CFR Table 1 to Subpart Mmmm of... - Model Rule-Increments of Progress and Compliance Schedules for Existing Sewage Sludge...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Compliance Schedules for Existing Sewage Sludge Incineration Units 1 Table 1 to Subpart MMMM of Part 60... Incineration Units Pt. 60, Subpt. MMMM, Table 1 Table 1 to Subpart MMMM of Part 60—Model Rule—Increments of Progress and Compliance Schedules for Existing Sewage Sludge Incineration Units Comply with...

  17. 40 CFR Table 1 to Subpart Mmmm of... - Model Rule-Increments of Progress and Compliance Schedules for Existing Sewage Sludge...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Compliance Schedules for Existing Sewage Sludge Incineration Units 1 Table 1 to Subpart MMMM of Part 60... Incineration Units Pt. 60, Subpt. MMMM, Table 1 Table 1 to Subpart MMMM of Part 60—Model Rule—Increments of Progress and Compliance Schedules for Existing Sewage Sludge Incineration Units Comply with...

  18. 40 CFR Table 6 to Subpart Mmmm of... - Model Rule-Summary of Reporting Requirements for Existing Sewage Sludge Incineration Units a

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Requirements for Existing Sewage Sludge Incineration Units a 6 Table 6 to Subpart MMMM of Part 60 Protection of... Incineration Units Pt. 60, Subpt. MMMM, Table 6 Table 6 to Subpart MMMM of Part 60—Model Rule—Summary of Reporting Requirements for Existing Sewage Sludge Incineration Units a Report Due date Contents...

  19. 40 CFR Table 6 to Subpart Mmmm of... - Model Rule-Summary of Reporting Requirements for Existing Sewage Sludge Incineration Units a

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Requirements for Existing Sewage Sludge Incineration Units a 6 Table 6 to Subpart MMMM of Part 60 Protection of... Incineration Units Pt. 60, Subpt. MMMM, Table 6 Table 6 to Subpart MMMM of Part 60—Model Rule—Summary of Reporting Requirements for Existing Sewage Sludge Incineration Units a Report Due date Contents...

  20. Sediment toxicity to a marine infaunal amphipod: cadmium and its interaction with sewage sludge

    SciTech Connect

    Swartz, R.C.; Ditsworth, G.R.; Schults, D.W.; Lamberson, J.O.

    1985-01-01

    The acute toxicity of cadmium to the marine infaunal amphipod, Rhepoxynius abronius, was determined separately in sediment and seawater. Most cadmium added to test sediment was bound to particles and less than 5% was dissolved in interstitial water. The LC50 based on cadmium concentration in interstitial water was similar to the LC50 based on cadmium concentration in seawater without sediment. Cadmium in interstitial water, rather than that bound to particles, therefore appears responsible for acute sediment toxicity to this species. The addition of small quantities of sewage sludge or an increase in the proportion of the fine fraction of sediment particles significantly reduced the toxicity of cadmium in sediment. Binding of cadmium by sediment particles may explain the presence of phoxocephalid amphipods at sites where sewage and metal pollution occur together.