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Sample records for sludge bed egsb

  1. Biohydrogen production from ethanol-type fermentation of molasses in an expanded granular sludge bed (EGSB) reactor

    Guo, Wan-Qian; Ren, Nan-Qi; Ding, Jie; Qu, Yuan-Yuan; Zhang, Lu-Si [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Haihe Road 204, Nangang District, Harbin, Heilongjiang 150090 (China); Wang, Xiang-Jing; Xiang, Wen-Sheng [Research Center of Life Science and Biotechnology, Northeast Agricultural University, Harbin 150030 (China); Meng, Zhao-Hui [The Architectural Design and Research Institute of Harbin Institute of Technology, Harbin 150090 (China)

    2008-10-15

    An expanded granular sludge bed (EGSB) process with granular activated carbon (GAC) was developed for fermentative hydrogen production from molasses-containing wastewater by mixed microbial cultures. No pH regulation was performed during the whole operation period. Running at the temperature of 35 C, the EGSB reactor presented a high hydrogen production ability as the hydrogen production rate (HPR) maximized at 0.71 L/L h. At the same time, the hydrogen yield (HY) peaked at 3.47 mol/mol sucrose and the maximum specific hydrogen production rate (SHPR) was found to be 3.16 mmol H{sub 2}/g VSS h. Hydrogen volume content was estimated to be 30-53% of the total biogas and the biogas was free of methane throughout the study. Dissolved fermentation products were predominated by acetate and ethanol, with smaller quantities of propionate, butyrate and valerate. It was found that high hydrogen yield was always associated with a high level of ethanol production. When the pH value and alkalinity ranged from 4.2-4.4 mg CaCO{sub 3}/L to 280-340 mg CaCO{sub 3}/L, respectively, stable ethanol-type fermentation was formed with the sum of ethanol and acetate concentration ratio of 89.1% to the total liquid products. The average attached biofilm concentration was estimated to be 17.1 g/L, which favored hydrogen production efficiently. With high biomass retention at high organic loading rate (OLR), this EGSB system showed to be a promising high-efficient bioprocess for hydrogen production from high-strength wastewater. (author)

  2. Anaerobic expanded granular sludge bed (EGSB) reactor for the removal of sulphide by autotrophic denitrification

    Dinamarca, Carlos [Department of Process, Energy and Environment, Faculty of Technology, Telemark University College Kjolnes ring 56, 3918 Porsgrunn (Norway)

    2013-07-01

    The Removal efficiency, load and N/S molar ratio, of an EGSB reactor for autotrophic sulphide denitrification operated for 96 days, were studied. The reactor was operated at high inlet sulphide concentrations between 0.25 to 3.00 g HS--S/L equivalents to loads between 5 to 250 g HS--S/m3-h. Sulphide removals higher than 99 % were achieved. At a N/S molar ratio of 0.3 and 12 hours HRT the process was stable even during transition periods of influent sulphide concentration and pH (9.0-12.1). At N/S molar ratio of 1.3, granules lost some of their sedimentation properties and appeared to disintegrate. On average 94 ± 4 % of the equivalent inlet sulphur ended as elemental sulphur.

  3. Comparison of UASB and EGSB reactors performance, for treatment of raw and deoiled palm oil mill effluent (POME)

    Fang, Cheng; O-Thong, Sompong; Boe, Kanokwan [Department of Environmental Engineering, Technical University of Denmark, Building 113, DK-2800, Kgs. Lyngby (Denmark); Angelidaki, Irini, E-mail: ria@env.dtu.dk [Department of Environmental Engineering, Technical University of Denmark, Building 113, DK-2800, Kgs. Lyngby (Denmark)

    2011-05-15

    Anaerobic digestion of palm oil mill effluent (POME) and deoiled POME was investigated both in batch assays and continuous reactor experiments using up-flow anaerobic sludge blanket (UASB) and expanded granular sludge bed (EGSB) reactors. The methane potential determined from batch assays of POME and deoiled POME was 503 and 610 mL-CH{sub 4}/gVS-added, respectively. For the treatment of POME in continuously fed reactors, both in UASB and EGSB reactors more than 90% COD removal could be obtained, at HRT of 5 days, corresponding to OLR of 5.8 gVS/(L-reactor.d). Similar methane yields of 436-438 mL-CH{sub 4}/gVS-added were obtained for UASB and EGSB respectively. However, for treatment of deoiled POME, both UASB and EGSB reactors could operate at lower OLR of 2.6 gVS/(L-reactor.d), with the methane yield of 600 and 555 mL-CH{sub 4}/gVS-added for UASB and EGSB, respectively. The higher methane yield achieved from the deoiled POME was attributed to lower portion of biofibers which are more recalcitrant compared the rest of organic matter in POME. The UASB reactor was found to be more stable than EGSB reactor under the same OLR, as could be seen from lower VFA concentration, especially propionic acid, compared to the EGSB reactor.

  4. Comparison of UASB and EGSB reactors performance, for treatment of raw and deoiled palm oil mill effluent (POME)

    Fang, Cheng; O-Thong, Sompong; Boe, Kanokwan; Angelidaki, Irini

    2011-01-01

    Anaerobic digestion of palm oil mill effluent (POME) and deoiled POME was investigated both in batch assays and continuous reactor experiments using up-flow anaerobic sludge blanket (UASB) and expanded granular sludge bed (EGSB) reactors. The methane potential determined from batch assays of POME and deoiled POME was 503 and 610 mL-CH 4 /gVS-added, respectively. For the treatment of POME in continuously fed reactors, both in UASB and EGSB reactors more than 90% COD removal could be obtained, at HRT of 5 days, corresponding to OLR of 5.8 gVS/(L-reactor.d). Similar methane yields of 436-438 mL-CH 4 /gVS-added were obtained for UASB and EGSB respectively. However, for treatment of deoiled POME, both UASB and EGSB reactors could operate at lower OLR of 2.6 gVS/(L-reactor.d), with the methane yield of 600 and 555 mL-CH 4 /gVS-added for UASB and EGSB, respectively. The higher methane yield achieved from the deoiled POME was attributed to lower portion of biofibers which are more recalcitrant compared the rest of organic matter in POME. The UASB reactor was found to be more stable than EGSB reactor under the same OLR, as could be seen from lower VFA concentration, especially propionic acid, compared to the EGSB reactor.

  5. Comparison of UASB and EGSB reactors performance, for treatment of raw and deoiled palm oil mill effluent (POME).

    Fang, Cheng; O-Thong, Sompong; Boe, Kanokwan; Angelidaki, Irini

    2011-05-15

    Anaerobic digestion of palm oil mill effluent (POME) and deoiled POME was investigated both in batch assays and continuous reactor experiments using up-flow anaerobic sludge blanket (UASB) and expanded granular sludge bed (EGSB) reactors. The methane potential determined from batch assays of POME and deoiled POME was 503 and 610 mL-CH(4)/gVS-added, respectively. For the treatment of POME in continuously fed reactors, both in UASB and EGSB reactors more than 90% COD removal could be obtained, at HRT of 5 days, corresponding to OLR of 5.8 gVS/(L-reactor.d). Similar methane yields of 436-438 mL-CH(4)/gVS-added were obtained for UASB and EGSB respectively. However, for treatment of deoiled POME, both UASB and EGSB reactors could operate at lower OLR of 2.6 gVS/(L-reactor.d), with the methane yield of 600 and 555 mL-CH(4)/gVS-added for UASB and EGSB, respectively. The higher methane yield achieved from the deoiled POME was attributed to lower portion of biofibers which are more recalcitrant compared the rest of organic matter in POME. The UASB reactor was found to be more stable than EGSB reactor under the same OLR, as could be seen from lower VFA concentration, especially propionic acid, compared to the EGSB reactor. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Anaerobic treatment of agro-industrial wastewaters for COD removal in expanded granular sludge bed bioreactor

    Abumalé Cruz-Salomón

    2017-12-01

    Full Text Available Untreated agro-industrial wastewaters are undesirable in the aquatic environment due to the presence of high organic matter contents. However, they may constitute a large potential for biogas production. The present investigation is focused on three laboratory-scale anaerobic expanded granular sludge bed (EGSB bioreactors, continuously operated for 60 d under mesophilic condition with the aim of exploring the feasibility of treating three most significant agro-industrial wastewaters in Chiapas, Mexico (i.e., cheese whey, vinasse, and coffee-processing wastewater. The EGSB bioreactors were operated with a hydraulic retention time (HRT of 6 d under stable conditions (i.e., buffer index (BI of 0.31, 0.34, and 0.03, generating a maximum chemical oxygen demand (COD removal efficiency of 91, 74, and 96% with an average methane production of 340, 245, and 300 mL/g COD∙d for cheese whey, vinasse, and coffee-processing wastewater, respectively. According to the obtained results, the EGSB bioreactors could be a sustainable alternative to simultaneously solve the environmental problems and to produce bioenergy.

  7. Simultaneous biological removal of sulfur, nitrogen and carbon using EGSB reactor

    Chen Chuan; Ren Nanqi; Wang Aijie; Yu Zhenguo [School of Municipal and Environmental Engineering, Harbin Inst. of Tech. (China); Lee Duu-Jong [School of Municipal and Environmental Engineering, Harbin Inst. of Tech. (China); Dept. of Chemical Engineering, National Taiwan Univ., Taipei (China)

    2008-04-15

    High-rate biological conversion of sulfide and nitrate in synthetic wastewater to, respectively, elemental sulfur (S{sup 0}) and nitrogen-containing gas (such as N{sub 2}) was achieved in an expanded granular sludge bed (EGSB) reactor. A novel strategy was adopted to first cultivate mature granules using anaerobic sludge as seed sludge in sulfate-laden medium. The cultivated granules were then incubated in sulfide-laden medium to acclimate autotrophic denitrifiers. The incubated granules converted sulfide, nitrate, and acetate simultaneously in the same EGSB reactor to S{sup 0}, N-containing gases and CO{sub 2} at loading rates of 3,0 kg S m{sup -3} d{sup -1}, 1.45 kg N m{sup -3} d{sup -1}, and 2.77 kg Ac m{sup -1} d{sup -1}, respectively, and was not inhibited by sulfide concentrations up to 800 mg l{sup -1}. Effects of the C/N ratio on granule performance were identified. The granules cultivated in the sulfide-laden medium have Pseudomonas spp. and Azoarcus sp. presenting the heterotrophs and autotrophs that co-work in the high-rate EGSB-SDD (simultaneous desulfurization and denitrification) reactor. (orig.)

  8. Pressurized Fluidized Bed Combustion of Sewage Sludge

    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.

  9. Effect of granular activated carbon addition on the effluent properties and fouling potentials of membrane-coupled expanded granular sludge bed process.

    Ding, An; Liang, Heng; Qu, Fangshu; Bai, Langming; Li, Guibai; Ngo, Huu Hao; Guo, Wenshan

    2014-11-01

    To mitigate membrane fouling of membrane-coupled anaerobic process, granular activated carbon (GAC: 50 g/L) was added into an expanded granular sludge bed (EGSB). A short-term ultrafiltration test was investigated for analyzing membrane fouling potential and underlying fouling mechanisms. The results showed that adding GAC into the EGSB not only improved the COD removal efficiency, but also alleviated membrane fouling efficiently because GAC could help to reduce soluble microbial products, polysaccharides and proteins by 26.8%, 27.8% and 24.7%, respectively, compared with the control system. Furthermore, excitation emission matrix (EEM) fluorescence spectroscopy analysis revealed that GAC addition mainly reduced tryptophan protein-like, aromatic protein-like and fulvic-like substances. In addition, the resistance distribution analysis demonstrated that adding GAC primarily decreased the cake layer resistance by 53.5%. The classic filtration mode analysis showed that cake filtration was the major fouling mechanism for membrane-coupled EGSB process regardless of the GAC addition. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Simultaneous biohydrogen production and starch wastewater treatment in an acidogenic expanded granular sludge bed reactor by mixed culture for long-term operation

    Guo, Wan-Qian; Ren, Nan-Qi; Liu, Bing-Feng; Ding, Jie [State Key Lab of Urban Water Resource and Environ, Harbin Institute of Technology, Harbin 150090 (China); Chen, Zhao-Bo [School of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); Wang, Xiang-Jing; Xiang, Wen-Sheng [Research Center of Life Science and Biotechnology, Northeast Agricultural University, Harbin 150030 (China)

    2008-12-15

    The biofilm-based expanded granular sludge bed (EGSB) reactor was developed to treat starch-containing wastewater and simultaneously recovery hydrogen by mixed microbial culture. Granular activated carbon (GAC) was used as the support media. Operating at the temperature of 30 C for over 400 days (data not shown), the EGSB reactor presented high efficiency in hydrogen production and COD removal ability. The maximum hydrogen production rate (HPR) was found to be 1.64 L/L.d under the organic loading rate (OLR) of 1.0 g-starch/L.d, pH of 4.42 and HRT of 4 h. The hydrogen yield (HY) peaked at 0.11 L/g-COD, under the OLR of 0.5 g-starch/L.d, pH of 3.95 and HRT of 8 h. Hydrogen volume content was estimated to be 35-65% of the total biogas. The average COD removal rate was 31.1% under the OLR of 0.125 g-starch/L.d and HRT of 24 h. The main dissolved fermentation products were ethanol, acetate and butyrate. The average attached biofilm concentration was estimated to be 8.26 g/L, which favored hydrogen production and COD removal. It is speculated that the low pH operation in the present system would contribute significantly to lower the cost of alkaline amount required for pH control in the continuous operation, especially in the scale-up biohydrogen producing system. A model, built on the back propagation neural network (BPNN) theory and linear regression techniques, was developed for the simulation of EGSB system performance in the biodegradation of starch synthesis-based wastewater and simultaneous hydrogen production. The model well fitted the laboratory data, and could well simulate the removal of COD and the production of hydrogen in the EGSB reactor. (author)

  11. Modeling of Seepage Losses in Sewage Sludge Drying Bed ...

    This research was carried out to develop a model governing seepage losses in sewage sludge drying bed. The model will assist in the design of sludge drying beds for effective management of wastes derived from households' septic systems. In the experiment conducted this study, 125kg of sewage sludge, 90.7% moisture ...

  12. Applicability and trends of anaerobic granular sludge treatment processes

    Lim, Seung Joo; Kim, Tak-Hyun

    2014-01-01

    Anaerobic granular sludge treatment processes have been continuously developed, although the anaerobic sludge granulation process was not clearly understood. In this review, an upflow anaerobic sludge blanket (UASB), an expanded granule sludge blanket (EGSB), and a static granular bed reactor (SGBR) were introduced as components of a representative anaerobic granular sludge treatment processes. The characteristics and application trends of each reactor were presented. The UASB reactor was developed in the late 1970s and its use has been rapidly widespread due to the excellent performance. With the active granules, this reactor is able to treat various high-strength wastewaters as well as municipal wastewater. Most soluble industrial wastewaters can be efficiently applied using a UASB. The EGSB reactor was developed owing to give more chance to contact between wastewater and the granules. Dispersed sludge is separated from mature granules using the rapid upward velocity in this reactor. The EGSB reactor shows the excellent performance in treating low-strength and/or high-strength wastewater, especially under low temperatures. The SGBR, developed at Iowa State University, is one of anaerobic granular sludge treatment processes. Although the configuration of the SGBR is very simple, the performance of this system is similar to that of the UASB or EGSB reactor. The anaerobic sludge granulation processes showed excellent performance for various wastewaters at a broad range of organic loading rate in lab-, pilot-scale tests. This leads to erect thousands of full-scale granular processes, which has been widely operated around the world. -- Highlights: • Anaerobic sludge granulation is a key parameter for maintaining granular processes. • Anaerobic granular digestion processes are applicable for various wastewaters. • The UASB is an economic high-rate anaerobic granular process. • The EGSB can treat high-strength wastewater using expanding granules. • The SGBR is

  13. Gravity Drainage of Activated Sludge on Reed Beds

    Christensen, Morten Lykkegaard; Dominiak, Dominik Marek; Keiding, Kristian

    and operation of reed beds and the efficiencies are often lower than predicted. One reason is that the sludge quality varies from plant to plant and even within plants from time to time. No good method exists for measuring the sludge quality with respect to drainage characteristics. A new experimental method...... has therefore been developed to measure relevant quality parameters: specific cake resistance, settling velocity and cake compressibility. It has been found that activated sludge form highly compressible cake even at the low compressive pressures obtained during drainage. Numerical simulation shows......Activated sludge is a by-product from waste water treatment plants, and the water content in the sludge is high (> 90%). Among several methods to remove the water, sludge drying reed beds are often used to dewater the sludge by drainage. There is, however, no well-defined criterion for design...

  14. Performance of Sandy Dry Beds for sludge dewatering

    Al-Muzaini, S.

    2003-01-01

    Sludge produced by the Jahra treatment plant was assessed. The assessment was directed at determining the performance of sand drying beds. The assessment of quality of the sludge produced was based on the standards for land application of sewage sludge. Analyses were carried out for trace heavy metals and bacteria. The results of analyses showed that the sludge produced was high in organic matter and sand content but low in heavy metals. The collected data indicated that the sand drying beds at the Jahra treatment plant are at present inadequate to handle the projected sludge production. The investigation showed that the sand drying beds are fully used and the plant will require 3-4 times the capacity of the existing drying beds when the plant becomes fully operational. In addition, these sand drying beds are subjected to uncontrollable conditions such as temperature, rainfall and sludge drainage rate. Thus, sand drying beds have become less popular as a dewatering system. This paper evaluates the performance of the existing sand drying beds and suggests the most appropriate technology to alleviate the above mentioned problems. (author)

  15. Incineration of Sludge in a Fluidized-Bed Combustor

    Chien-Song Chyang; Yu-Chi Wang

    2017-01-01

    For sludge disposal, incineration is considered to be better than direct burial because of regulations and space limitations in Taiwan. Additionally, burial after incineration can effectively prolong the lifespan of a landfill. Therefore, it is the most satisfactory method for treating sludge at present. Of the various incineration technologies, the fluidized bed incinerator is a suitable choice due to its fuel flexibility. In this work, sludge generated from industrial plants was treated in ...

  16. Modelling of a falling sludge bed reactor using AQUASIM | Ristow ...

    Modelling of a falling sludge bed reactor using AQUASIM. ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL · RESOURCES ... a system of mixed reactors connected by water flow and mass flux streams.

  17. Modeling of Evaporation Losses in Sewage Sludge Drying Bed ...

    A model for evaporation losses in sewage sludge drying bed was derived from first principles. This model was developed based on the reasoning that the rate at which evaporation is taking place is directly proportional to the instantaneous quantity of water in the sludge. The aim of this work was to develop a model to assist ...

  18. Effects of high salinity wastewater on methanogenic sludge bed systems

    Ismail, S.; Gonzalez-Contreras, P.A.; Jeison, D.A.; Lier, van J.B.

    2008-01-01

    The attainable loading potentials of anaerobic sludge bed systems are strongly dependent on the growth of granular biomass with a particular wastewater. Experiments were conducted to determine the effects of high salinity wastewater on the biological and physical properties of methanogenic sludge.

  19. Anaerobic Treatment Of Percolate From Faecal Sludge Drying Beds ...

    Composite percolate samples, from sludge drying beds of a pilot co-composting plant in Kumasi, Ghana, were characterised and subjected to laboratory scale anaerobic treatment. Two categories of percolate samples were investigated; samples seeded with anaerobic sludge and samples without seeding. The average ...

  20. Gas composition of sludge residue profiles in a sludge treatment reed bed between loadings

    Larsen, Julie Dam; Nielsen, Steen M; Scheutz, Charlotte

    2017-01-01

    Treatment of sludge in sludge treatment reed bed systems includes dewatering and mineralization. The mineralization process, which is driven by microorganisms, produces different gas species as by-products. The pore space composition of the gas species provides useful information on the biological...... processes occurring in the sludge residue. In this study, we measured the change in composition of gas species in the pore space at different depth levels in vertical sludge residue profiles during a resting period of 32 days. The gas composition of the pore space in the sludge residue changed during...

  1. Dispersed plug flow model for upflow anaerobic sludge bed reactors with focus on granular sludge dynamics

    Kalyuzhnyi, S.V.; Fedorovich, V.V.; Lens, P.N.L.

    2006-01-01

    A new approach to model upflow anaerobic sludge bed (UASB)-reactors, referred to as a one-dimensional dispersed plug flow model, was developed. This model focusses on the granular sludge dynamics along the reactor height, based on the balance between dispersion, sedimentation and convection using

  2. Biogas recirculation for simultaneous calcium removal and biogas purification within an expanded granular sludge bed system treating leachate.

    Luo, Jinghuan; Lu, Xueqin; Liu, Jianyong; Qian, Guangren; Lu, Yongsheng

    2014-12-01

    Biogas, generated from an expanded granular sludge bed (EGSB) reactor treating municipal solid waste (MSW) leachate, was recirculated for calcium removal from the leachate via a carbonation process with simultaneous biogas purification. Batch trials were performed to optimize the solution pH and imported biogas (CO2) for CaCO3 precipitation. With applicable pH of 10-11 obtained, continuous trials achieved final calcium concentrations of 181-375 mg/L (removal efficiencies≈92.8-96.5%) in the leachate and methane contents of 87.1-91.4% (purification efficiencies≈65.4-82.2%) in the biogas. Calcium-balance study indicates that 23-986 mg Ca/d was released from the bio-system under the carbonized condition where CaCO3 precipitating was moved outside the bioreactor, whereas 7918-9517 mg Ca/d was trapped into the system for the controlled one. These findings demonstrate that carbonation removal of calcium by biogas recirculation could be a promising alternative to pretreat calcium-rich MSW leachate and synergistically to improve methane content. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Gas composition of sludge residue profiles in a sludge treatment reed bed between loadings.

    Larsen, Julie D; Nielsen, Steen M; Scheutz, Charlotte

    2017-11-01

    Treatment of sludge in sludge treatment reed bed systems includes dewatering and mineralization. The mineralization process, which is driven by microorganisms, produces different gas species as by-products. The pore space composition of the gas species provides useful information on the biological processes occurring in the sludge residue. In this study, we measured the change in composition of gas species in the pore space at different depth levels in vertical sludge residue profiles during a resting period of 32 days. The gas composition of the pore space in the sludge residue changed during the resting period. As the resting period proceeded, atmospheric air re-entered the pore space at all depth levels. The methane (CH 4 ) concentration was at its highest during the first part of the resting period, and then declined as the sludge residue became more dewatered and thereby aerated. In the pore space, the concentration of CH 4 often exceeded the concentration of carbon dioxide (CO 2 ). However, the total emission of CO 2 from the surface of the sludge residue exceeded the total emission of CH 4 , suggesting that CO 2 was mainly produced in the layer of newly applied sludge and/or that CO 2 was emitted from the sludge residue more readily compared to CH 4 .

  4. Bacterial regrowth potential in alkaline sludges from open-sun and covered sludge drying beds

    Alkan, U.; Topac, F.O.; Birden, B.; Baskaya, H.S. [Uludag University, Gorukle (Turkey). Dept. of Environmnetal Engineering

    2007-10-15

    The aim of this study was to compare the regrowth potentials of wastewater sludges dried in two pilot-scale drying processes namely, Open-Sun Sludge Drying Bed (OSDB) and Covered Sludge Drying Bed (CSDB). Quicklime and/or coal fly ash were added to raw sludge samples prior to drying processes in order to enhance bacterial inactivation. Following three drying cycles (March-April, June-July and August-October), sludge samples were taken from the beds for the regrowth experiments. Addition of alkaline materials prevented the regrowth of faecal coliforms in all rewetted samples except for the samples obtained after the rainfall events in OSDB. Rewetting of these samples in the regrowth experiments increased faecal coliform numbers by 3.5-7 log units. In contradiction, the observed bacterial numbers in rewetted alkaline samples from CSDB were below the EPA Class B criterion (2 million MPN g{center_dot} 1) dry sludge). The combination of additional heat from solar collectors, protection from the rain and the unfavourable living conditions owing to alkaline materials appeared to inactivate bacteria more effectively in CSDB and hence eliminated regrowth potential more efficiently.

  5. Sludge combustion in fluidized bed reactors at laboratory scale

    Chirone, R.; Cammarota, A.

    2001-01-01

    The combustion of a dried sewage sludge in laboratory scale fluidized bed has been studied in Naples by the Istituto di ricerche sulla combustione (Irc) in the framework of a National project named Thermal Process with Energy Recovery to be used in laboratory and pre-pilot scale apparatus. The attention has been focused on emissions of unreacted carbon as elutriated fines, on the emissions of pollutant gases and on the assessment of the inventory of fly- and bottom ashes. The combustion behaviour of sewage sludge has been compared with those of a market available Tyre Derived Fuel (TDF) and a biomass from Mediterranean area (Robinia Pseudoacacia) and with that of a South African bituminous coal. Stationary combustion tests were carried out at 850 0 C by feeding particles in the size range 0-1 mm into a bed of silica sand without any sorbent addition. The fluidized bed combustor has been operated, at a superficial gas velocity of 0.4 m/s and different excesses of air ranging between 14 and 98%. Relatively high combustion efficiency, larger than 98.9% has been obtained in experiments carried out with sewage sludge and excess of air larger than 20%. These values, are comparable with those obtained in previously experimental activity carried out under similar operative conditions with a South Africa Bituminous coal (97-98%). It is larger than those obtained by using a Tyre Derived Fuel (89-90%) and the Robinia Pseudoacacia Biomass (93-93%). The relative importance of carbon fines elutriation, CO emissions and volatile bypassing the bed in determining the loss of combustion efficiency has been evaluated for the different fuels tested [it

  6. Biogas production from potato-juice, a by-product from potato-starch processing, in upflow anaerobic sludge blanket (UASB) and expanded granular sludge bed (EGSB) reactors

    Fang, Cheng; Boe, Kanokwan; Angelidaki, Irini

    2011-01-01

    In this study, the utilization of potato-juice, the organic by-product from potato-starch processing, for biogas production was investigated in batch assay and in high rate anaerobic reactors. The maximum methane potential of the potato-juice determined by batch assay was 470mL-CH4/gVS-added. Ana......In this study, the utilization of potato-juice, the organic by-product from potato-starch processing, for biogas production was investigated in batch assay and in high rate anaerobic reactors. The maximum methane potential of the potato-juice determined by batch assay was 470mL-CH4/g...

  7. System for the Reduction of Substances in Reject Water from Reed-Bed Sludge Mineralization Plants

    2004-01-01

    The invention is a system for the reduction of substances in reject water from reed-bed sludge mineralization plants (also referred to as sludge dewatering reed-beds). The systems utilizes the composition of substances in reject water from reed-beds and that of sludge to reduce substance mass from...... the reject water via recirculation into a mixed reactor and back onto the reed-beds. The mixed rector consists of a container in which sludge (that is typically loaded directly on to reed-beds) is mixed with recirculated reject water from reed-beds. The sludge mixture has a definable hydraulic retention time...... of by sending it back to the head of a wastewater treatment plant. The system has proven to reduce the mass of nitrogen, COD, and water in the reject water, and can possibly reduce phosphorus and other substances. The overall effect is a reduction in the substance recycle within a wastewater treatment plant...

  8. Celebrating 40 years anaerobic sludge bed reactors for industrial wastewater treatment

    Van Lier, J.B.; Van der Zee, F.P.; Frijters, C.T.M.J.; Ersahin, M.E.

    2015-01-01

    In the last 40 years, anaerobic sludge bed reactor technology evolved from localized lab-scale trials to worldwide successful implementations at a variety of industries. High-rate sludge bed reactors are characterized by a very small foot print and high applicable volumetric loading rates. Best

  9. Biothane process. Methane-producing treatment of wastewaters in a granular sludge bed

    Boulenger, P; Vesprille, B

    1982-01-01

    The Biothane-UASB (upflow anaerobic sludge blanket) process, an anaerobic fermentation system with 2 granular sludge beds, effectively treats wastewaters from cheese and starch manufacture and is suitable for other industrial effluents, such as sugar beet alcohol distillation wastewaters and biosynthesis wases.

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

    Pazos, Marta; Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.

    2010-01-01

    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 ...

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

    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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Life cycle assessment comparing the treatment of surplus activated sludge in a sludge treatment reed bed system with mechanical treatment on centrifuge

    Larsen, Julie Dam; Hoeve, Marieke ten; Nielsen, Steen

    2018-01-01

    or the centrifuge and terminated by land application of the final sludge product. The environmental impacts caused by the sludge treatment reed bed system strategy were comparable to or lower than those caused by the mechanical sludge treatment method. The impacts on climate change were the same for all...

  13. Devolatilization of oil sludge in a lab-scale bubbling fluidized bed.

    Liu, Jianguo; Jiang, Xiumin; Han, Xiangxin

    2011-01-30

    Devolatilization of oil sludge pellets was investigated in nitrogen and air atmosphere in a lab-scale bubbling fluidized bed (BFB). Devolatilization times were measured by the degree of completion of the evolution of the volatiles for individual oil sludge pellets in the 5-15 mm diameter range. The influences of pellet size, bed temperature and superficial fluidization velocity on devolatilization time were evaluated. The variation of devolatilization time with particle diameter was expressed by the correlation, τ(d) = Ad(p)(N). The devolatilization time to pellet diameter curve shows nearly a linear increase in nitrogen, whereas an exponential increase in air. No noticeable effect of superficial fluidization velocity on devolatilization time in air atmosphere was observed. The behavior of the sludge pellets in the BFB was also focused during combustion experiments, primary fragmentation (a micro-explosive combustion phenomenon) was observed for bigger pellets (>10mm) at high bed temperatures (>700 °C), which occurred towards the end of combustion and remarkably reduce the devolatilization time of the oil sludge pellet. The size analysis of bed materials and fly ash showed that entire ash particle was entrained or elutriated out of the BFB furnace due to the fragile structure of oil sludge ash particles. Copyright © 2010 Elsevier B.V. All rights reserved.

  14. Evaluation of sludge from paper recycling as bedding material for broilers.

    Villagrá, A; Olivas, I; Benitez, V; Lainez, M

    2011-05-01

    Several materials have been used as bedding substrates in broiler production. In this work, the sludge from paper recycling was tested for its potential use as litter material and was compared with wood shavings. Moisture content, apparent density, and water-holding capacity were measured and characterized in both materials. Later, 192 male broiler chickens were distributed among 16 experimental pens, 8 of which contained wood shavings as bedding material and 8 of which contained the sludge. Growth rate, consumption, tonic immobility, gait score, breast lesions, foot pad dermatitis, hock burn, tibial dyschondroplasia, and metatarsal thickness were determined in the birds. Although the moisture content of the sludge was high, it decreased strongly after 7 d of drying, reaching lower values than those of wood shavings. In general, few differences were found between the materials in terms of bird performance and welfare and only the incidence of hock burn was higher in the sludge than in the wood shavings. Although further research is needed, sludge from paper recycling is a possible alternative to traditional bedding materials because it achieves most of the requirements for broiler bedding materials and does not show negative effects on the birds.

  15. Experimental studies on pulp and paper mill sludge ash behavior in fluidized bed combustors

    Latva-Somppi, J. [VTT Chemical Technology, Espoo (Finland). Process Technology

    1998-11-01

    Ash formation during the fluidized bed combustion (FBC) of pulp and paper mill sludges has been experimentally studied on an industrial and bench scale. The methods included aerosol measurements, chemical and crystalline composition analyses, thermogravimetry and electron microscopy. Fly ash mass and number size distributions and elemental enrichment in submicron particles and bottom ash were measured. Fly ash, bottom ash and ash deposits were characterized and their formation mechanisms are discussed. During combustion the fine paper-making additives in sludge, clay minerals and calcite, sintered fanning porous agglomerates. The fly ash mass mean size was 7.5 - 15 lam and the supermicron particles included 93.6 - 97.3 % of the fly ash. Condensation of the volatilized inorganic species formed spherical submicron particles in the fly ash. Their mass concentration was almost negligible when co-firing paper mill sludges and wood. This suggests that the fraction of the volatilized inorganic species in the paper mill sludges was low. Results from pulp mill sludge and bark co-firing were different. A clear mass mode below 0.3 pm, presenting 2.2 - 5.0 weight-% of the fly ash was detected. The condensed species included K, Na, S and Cl. Their mass fraction was higher in the pulp mill sludge than in the paper mill sludge. Evidently this resulted in increased volatilization and formation of condensed particles. The following trace elements were enriched in the submicron ash during pulp mill sludge and wood co-firing: As, Cd, Rb and Pb. The main part of the volatile species was, however, captured in the bulk ash. Presumably, this was due to the high surface area concentration in the bulk ash. Sludge moisture was observed to reduce the inorganic species volatilization. Probably steam vaporization from the wet sludge through the burning layer decreased combustion temperatures on char surface and less char was produced. Hence, the volatilization of ash forming species was

  16. An Evaluation of Reed Bed Technology to Dewater Army Wastewater Treatment Plant Sludge

    1993-09-01

    speculated that the plants produced "root exudations" that were active against pathogens , and that the plants specifically showed an affinity for cadmium, zinc...mineralize and for pathogens to be destroyed. This downtime makes multiple beds necessary. The USEPA also reports that the major advantage of the reed...employee to regulate the sludge applications. This employee would also visually assess the beds for possible problems such as weed or insect ( aphid

  17. Nitrogen mineralisation and greenhouse gas emission from the soil application of sludge from reed bed mineralisation systems

    Gómez-Muñoz, B; Larsen, Julie Dam; Bekiaris, G

    2017-01-01

    A sludge treatment reed bed system (STRB) is a technology used for dewatering and stabilising sewage sludge via assisted biological mineralisation, which creates a sludge residue suitable for use as fertiliser on agricultural land. We evaluated the effect of sludge residue storage time (stabilisa......A sludge treatment reed bed system (STRB) is a technology used for dewatering and stabilising sewage sludge via assisted biological mineralisation, which creates a sludge residue suitable for use as fertiliser on agricultural land. We evaluated the effect of sludge residue storage time...... (stabilisation time) for three STRBs on soil N mineralisation and CO2 and N2O emissions in soil. The experiment revealed that the N mineralisation rate and emissions of CO2 and N2O decreased as a function of treatment time in the STRBs. Mixed sludge residue (sludge residue subjected to different treatment times......) for the three STRBs resulted in N mineralisation rates similar to the sludge residue subjected to a shorter treatment time but lower N2O emissions similar to the values of the older sludge residue. This finding reveals that combining fresh and more stabilised sludge residue ensures high N availability...

  18. Selenate removal in methanogenic and sulfate-reducing upflow anaerobic sludge bed reactors

    Lenz, M.; Hullebusch, van E.D.; Hommes, G.; Corvini, P.F.X.; Lens, P.N.L.

    2008-01-01

    This paper evaluates the use of upflow anaerobic sludge bed (UASB) bioreactors (30 degrees C, pH = 7.0) to remove selenium oxyanions from contaminated waters (790 mu g Se L-1) under methanogenic and sulfate-reducing conditions using lactate as electron donor. One UASB reactor received sulfate at

  19. Behaviour of Inorganic Constituents of Municipal Sewage Sludge during Fluidized-Bed Combustion.

    Hartman, Miloslav; Pohořelý, Michael; Trnka, Otakar

    2007-01-01

    Roč. 61, 3 (2007) , s. 181-185 ISSN 0366-6352 R&D Projects: GA AV ČR(CZ) IAA4072201 Institutional research plan: CEZ:AV0Z40720504 Keywords : sewage sludge * heavy metals * fluidized-bed combustion Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.367, year: 2007

  20. Co-Combustion of Municipal Sewage Sludge and Hard Coal on Fluidized Bed Boiler WF-6

    Rajczyk Rafał

    2014-12-01

    Full Text Available According to data of the Central Statistical Office, the amount of sludge produced in municipal wastewater treatment plants in 2010 amounted to 526000 Mg d.m. The forecast of municipal sewage sludge amount in 2015 according to KPGO2014 will reach 642400 Mg d.m. and is expected to increase in subsequent years. Significant amounts of sludge will create problems due to its utilization. In order to solve this problem the use of thermal methods for sludge utilization is expected. According to the National Waste Management Plan nearly 30% of sewage sludge mass should be thermally utilized by 2022. The article presents the results of co-combustion of coal and municipal sewage sludge in a bubbling fluidized bed boiler made by SEFAKO and located in the Municipal Heating Company in Morag. Four tests of hard coal and sewage sludge co-combustion have been conducted. Boiler performance, emissions and ash quality were investigated.

  1. Co-combustion of tannery sludge in a commercial circulating fluidized bed boiler.

    Dong, Hao; Jiang, Xuguang; Lv, Guojun; Chi, Yong; Yan, Jianhua

    2015-12-01

    Co-combusting hazardous wastes in existing fluidized bed combustors is an alternative to hazardous waste treatment facilities, in shortage in China. Tannery sludge is a kind of hazardous waste, considered fit for co-combusting with coal in fluidized bedboilers. In this work, co-combustion tests of tannery sludge and bituminous coal were conducted in a power plant in Jiaxing, Zhejiang province. Before that, the combustion behavior of tannery sludge and bituminous were studied by thermogravimetric analysis. Tannery sludge presented higher reactivity than bituminous coal. During the co-combustion tests, the emissions of harmful gases were monitored. The results showed that the pollutant emissions met the Chinese standard except for NOx. The Concentrations of seven trace elements (As, Cr, Cd, Ni, Cu, Pb, Mn) in three exit ash flows (bottom ash in bed, fly ash in filter, and submicrometer aerosol in flue gas) were analyzed. The results of mono-combustion of bituminous coal were compared with those of co-combustion with tannery sludge. It was found that chromium enriched in fly ash. At last, the leachability of fly ash and bottom ash was analyzed. The results showed that most species were almost equal to or below the limits except for As in bottom ashes and Cr in the fly ash of co-combustion test. The concentrations of Cr in leachates of co-combustion ashes are markedly higher than that of coal mono-combustion ashes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Recovery of energy and iron from oily sludge pyrolysis in a fluidized bed reactor.

    Qin, Linbo; Han, Jun; He, Xiang; Zhan, Yiqiu; Yu, Fei

    2015-05-01

    In the steel industry, about 0.86 ton of oily sludge is produced for every 1000 tons of rolling steel. Due to the adverse impact on human health and the environment, oily sludge is designated as a hazardous waste in the Resource Conservation and Recovery Act (RCRT). In this paper, the pyrolysis treatment of oily sludge is studied in a fluidized bed reactor at a temperature range of 400-600 °C. During oily sludge pyrolysis, a maximum oil yield of 59.2% and a minimum energy loss of 19.0% are achieved at 500 °C. The energy consumption of treating 1 kg oily sludge is only 2.4-2.9 MJ. At the same time, the energy of produced oil, gas and solid residue are 20.8, 6.32, and 0.83 MJ, respectively. In particular, it is found that the solid residue contains more than 42% iron oxide, which can be used as the raw material for iron production. Thus, the simultaneous recovery of energy and iron from oil sludge by pyrolysis is feasible. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Gaseous emissions from sewage sludge combustion in a moving bed combustor.

    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

  4. Fluidized-bed-combustion ash for the solidification and stabilization of a metal-hydroxide sludge.

    Knoll, K L; Behr-Andres, C

    1998-01-01

    Fluidized-bed-combustion (FBC) ash is a by-product from a developing technology for coal-fired power plants that will economically reduce air emissions to meet requirements of the Clean Air Act. FBC ash has physical and chemical properties similar to Portland cement, but only has moderate success as a pozzolan in concrete applications due to low compressive strengths. However, FBC ash has proven effective for use as a binder for the solidification and stabilization (S/S) of metal-bearing sludges. Physical and chemical characterization procedures were used to analyze FBC ash and a metal-bearing sludge obtained from a hazardous waste treatment facility to develop 12 different S/S mix designs. The mix designs consist of four binder designs to evaluate sludge-to-binder ratios of approximately 0, 0.5, and 1. Portland cement is used as a control binder to compare unconfined compressive strengths and Toxicity Characteristic Leaching Procedure (TCLP) analyses from different ratios of the FBC ash streams: fly ash, char, and spent bed material (SBM). Compressive strengths ranging from 84 lbs per square inch (psi) to 298 psi were obtained from various mix designs containing different sludge-to-ash ratios cured for 28 days. All the mix designs passed the TCLP. Recoveries from leaching for each metal were less than 5% for most mix designs. Results of unconfined compressive strengths, TCLP, and percent recovery calculations indicate that the mix design containing approximately a 1:1 ratio of fly ash to char-and-sludge is the best mix design for the S/S of the metal-bearing sludge.

  5. Energy recovery from sewage sludge by means of fluidised bed gasification

    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

  6. Combustion of Dried Sewage Sludge in a Fluidized-Bed Reactor

    Hartman, Miloslav; Svoboda, Karel; Pohořelý, Michael; Trnka, Otakar

    2005-01-01

    Roč. 44, č. 10 (2005), s. 3432-3441 ISSN 0888-5885 R&D Projects: GA AV ČR(CZ) IAA4072201 Institutional research plan: CEZ:AV0Z40720504 Keywords : fluidized-bed combustion * dried sewage sludge * CO, NOx, and N2O emissions Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.504, year: 2005

  7. Gaseous Emissions from the Fluidized-bed Incineration of Sewage Sludge

    Pohořelý, Michael; Svoboda, Karel; Trnka, Otakar; Baxter, D.; Hartman, Miloslav

    2005-01-01

    Roč. 59, 6b (2005), s. 458-463 ISSN 0366-6352. [International Conference SSCHE /32./. Tatranské Matliare, 23.05.2005-27.05.2005] R&D Projects: GA AV ČR IAA4072201; GA AV ČR KSK4040110 Institutional research plan: CEZ:AV0Z40720504 Keywords : sewage sludge * fluidized-bed incineration * solid fuels Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.409, year: 2005

  8. Environmental Assessment of Sewage Sludge Management – Focusing on Sludge Treatment Reed Bed Systems

    Larsen, Julie Dam

    profiles of the STRB system technology and a mechanical treatment technology, constituting a basis for decision-making in relation to choice of technology. A major part of the project involved performance of fieldwork and laboratory work. Data were collected at three Danish, well-operated STRB systems...... assessment were based on international acknowledged standards and recommendations. An attributional LCA approach was chosen, and the loadings and savings for all impact categories were normalised to people equivalents (PE) (the annual loadings and savings provided by one average person). Three sludge...... gasses CH4 and N2O were larger for mechanical dewatered sludge, the net environmental loadings provided to the impact category Climate Change by this technology (S-CEN) and the STRB system technology (S-STRB and S-SPA) ended up being equally sized (9.010-4 PE), despite of higher biological activity...

  9. The study of partitioning of heavy metals during fluidized bed combustion of sewage sludge and coal

    Gulyurtlu, I.; Lopes, M.H.; Abelha, P.; Cabrita, I.; Oliveira, J.F.S. [INETI, Lisbon (Portugal)

    2006-06-15

    The behavior of Cd, Cr, Cu, Co, Mn, Ni, Pb, Zn, and Hg during the combustion tests of a dry granular sewage sludge on a fluidized bed combustor pilot (FBC) of about 0.3 MW was evaluated. The emissions of these heavy metals from mono-combustion were compared with those of co-combustion of the sludge with a bituminous coal. The effect of the addition of limestone was also studied in order to retain sulphur compounds and to verify its influence on the retention of heavy metals (HM). Heavy metals were collected and analyzed from different locations of the installation, which included the stack, the two cyclones, and the material removed from the bed. The results showed that the volatility of metals was rather low, resulting in emissions below the legal limits of the new directive on incineration, with the exception of Hg during the mono-combustion tests. The partitioning of metals, except for Hg, appeared to follow that of ashes, amounting to levels above 90% in the bed streams in the mono-combustion case. For co-combustion, there was a lower fixation of HM in the bed ashes, mostly originating essentially from the sewage sludge, ranging between 40% and 80%. It is believed that in this latter case, a slightly higher temperature could have enhanced the volatilization, especially of Cd and Pb. However these metals were then retained in fly ashes captured in the cyclones. In the case of Hg, the volatilisation was complete. The bed ashes were free of Hg and part of Hg was retained in the cyclones and the rest was emitted either with fine ash particles or in gaseous forms. In mono-combustion the Hg emissions from the stack (particles and gas) accounted, for about 50%. This appeared to have significantly decreased in the case of co-combustion, as only about 75% has been emitted, due to the retention effect of cyclone ashes.

  10. The study of partitioning of heavy metals during fluidized bed combustion of sewage sludge and coal

    Gulyurtlu, Ibrahim; Lopes, M. Helena; Abelha, Pedro; Cabrita, Isabel; Oliveira, J.F. Santos

    2003-07-01

    The behaviour of Cd, Cr, Cu, Co, Mn, Pb, Zn and Hg during the combustion tests of granular dry sewage sludges on a pilot FBC of about 0,3 MW was evaluated. The emissions of these heavy metals from mono-combustion were compared with those of co-combustion of the sludge with a bituminous coal. The effect of the addition of limestone was also studied in order to retain sulphur compounds and to verify its influence on the retention of heavy metals. Heavy metals were collected and analysed from different locations of the installation, which included the stack, the two cyclones and the material removed from the bed. The results showed that the volatility of metals was rather low, resulting in emissions below the legal limits of the new directive on incineration, with the exception of Hg during the mono-combustion tests. The partitioning of metals, except for Hg, appeared to follow that of ashes, amounting to levels above 90% in the bed streams in the mono-combustion case. For co-combustion, there was a lower fixation of HM in the bed ashes, mostly originating essentially from the sewage sludge, ranging between 40 and 80%. It is believed that in this latter case, a slightly higher bed temperature could have enhanced the volatilisation, especially of Cd and Pb. However these metals were then retained in cyclone ashes. In the case of Hg, the volatilisation was complete. The bed ashes were free of Hg and part of it was retained in the cyclone and emitted as both fine ash particles and in gaseous forms. In mono-combustion the Hg emissions from the stack (particles and gas) accounted for about 50%, although there was a significant amount unaccounted for. This appeared to have significantly decreased in the case of co-combustion, as only about 15% has been emitted, due to the retention effect of cyclone ashes which presented high quantities of unburned carton and possibly condensed sulphur species.

  11. Continuous removal and recovery of tellurium in an upflow anaerobic granular sludge bed reactor

    Mal, Joyabrata, E-mail: joyabrata2006@gmail.com [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Nancharaiah, Yarlagadda V. [Biofouling and Biofilm Processes Section, Water and Steam Chemistry Division, Bhabha Atomic Research Centre, Kalpakkam, 603102, Tamil Nadu (India); Homi Bhabha National Institute, Anushakti Nagar Complex, Mumbai 400094 (India); Maheshwari, Neeraj [CNRS UMR 7338, BMBI University de Technologie Compiegne, 60200 Compiegne (France); Hullebusch, Eric D. van [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Université Paris-Est, Laboratoire Géomatériaux et Environnement (LGE), EA 4508, UPEM, 77454, Marne-la-Vallée (France); Lens, Piet N.L. [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Department of Chemistry and Bioengineering, Tampere University of Technology, P.O-Box 541, Tampere (Finland)

    2017-04-05

    Highlights: • Tellurite bioreduction coupled to recovery of biogenic Te(0) nanocrystals. • First report on continuous tellurite removal in a UASB reactor. • Biogenic Te(0) was mainly associated with loosely-bound EPS of granular sludge. • Repeated exposure to tellurite caused compositional changes in the EPS matrix. - Abstract: Continuous removal of tellurite (TeO{sub 3}{sup 2−}) from synthetic wastewater and subsequent recovery in the form of elemental tellurium was studied in an upflow anaerobic granular sludge bed (UASB) reactor operated at 30 °C. The UASB reactor was inoculated with anaerobic granular sludge and fed with lactate as carbon source and electron donor at an organic loading rate of 0.6 g COD L{sup −1} d{sup −1}. After establishing efficient and stable COD removal, the reactor was fed with 10 mg TeO{sub 3}{sup 2−} L{sup −1} for 42 d before increasing the influent concentration to 20 mg TeO{sub 3}{sup 2−} L{sup −1}. Tellurite removal (98 and 92%, respectively, from 10 and 20 mg Te L{sup −1}) was primarily mediated through bioreduction and most of the removed Te was retained in the bioreactor. Characterization using XRD, Raman spectroscopy, SEM-EDX and TEM confirmed association of tellurium with the granular sludge, typically in the form of elemental Te(0) deposits. Furthermore, application of an extracellular polymeric substances (EPS) extraction method to the tellurite reducing sludge recovered up to 78% of the tellurium retained in the granular sludge. This study demonstrates for the first time the application of a UASB reactor for continuous tellurite removal from tellurite-containing wastewater coupled to elemental Te(0) recovery.

  12. Continuous removal and recovery of tellurium in an upflow anaerobic granular sludge bed reactor

    Mal, Joyabrata; Nancharaiah, Yarlagadda V.; Maheshwari, Neeraj; Hullebusch, Eric D. van; Lens, Piet N.L.

    2017-01-01

    Highlights: • Tellurite bioreduction coupled to recovery of biogenic Te(0) nanocrystals. • First report on continuous tellurite removal in a UASB reactor. • Biogenic Te(0) was mainly associated with loosely-bound EPS of granular sludge. • Repeated exposure to tellurite caused compositional changes in the EPS matrix. - Abstract: Continuous removal of tellurite (TeO 3 2− ) from synthetic wastewater and subsequent recovery in the form of elemental tellurium was studied in an upflow anaerobic granular sludge bed (UASB) reactor operated at 30 °C. The UASB reactor was inoculated with anaerobic granular sludge and fed with lactate as carbon source and electron donor at an organic loading rate of 0.6 g COD L −1 d −1 . After establishing efficient and stable COD removal, the reactor was fed with 10 mg TeO 3 2− L −1 for 42 d before increasing the influent concentration to 20 mg TeO 3 2− L −1 . Tellurite removal (98 and 92%, respectively, from 10 and 20 mg Te L −1 ) was primarily mediated through bioreduction and most of the removed Te was retained in the bioreactor. Characterization using XRD, Raman spectroscopy, SEM-EDX and TEM confirmed association of tellurium with the granular sludge, typically in the form of elemental Te(0) deposits. Furthermore, application of an extracellular polymeric substances (EPS) extraction method to the tellurite reducing sludge recovered up to 78% of the tellurium retained in the granular sludge. This study demonstrates for the first time the application of a UASB reactor for continuous tellurite removal from tellurite-containing wastewater coupled to elemental Te(0) recovery.

  13. Operational strategy, economic and environmental performance of sludge treatment reed bed systems - based on 28 years of experience

    Nielsen, S.; Larsen, Julie Dam

    2016-01-01

    Sludge treatment reed bed (STRB) systems have been used for dewatering and mineralisation of sludge in Europe since 1988. STRB systems provide substantial environmental, economic, and operational benefits compared to mechanical sludge dewatering solutions such as belt presses and centrifuges....... They require less energy, no chemicals, reduce the sludge volume and produce bio solids with dry solid contents up to 20-40% under Danish climate conditions, depending on the sludge quality. Experience has shown that sludge treated in STRBs represents a high quality product with a low content of pathogens...... compared to conventional mechanical dewatering devices, delivering an economic break-even of about 3-5 years. This paper provides an overview of the operation and maintenance costs and environmental benefits of a typical STRB based on the experiences gained from the operation of a large number of STRBs...

  14. Microbial community dynamics and biogas production from manure fractions in sludge bed anaerobic digestion.

    Nordgård, A S R; Bergland, W H; Bakke, R; Vadstein, O; Østgaard, K; Bakke, I

    2015-12-01

    To elucidate how granular sludge inoculum and particle-rich organic loading affect the structure of the microbial communities and process performance in upflow anaerobic sludge bed (UASB) reactors. We investigated four reactors run on dairy manure filtrate and four on pig manure supernatant for three months achieving similar methane yields. The reactors fed with less particle rich pig manure stabilized faster and had highest capacity. Microbial community dynamics analysed by a PCR/denaturing gradient gel electrophoresis approach showed that influent was a major determinant for the composition of the reactor communities. Comparisons of pre- and non-adapted inoculum in the reactors run on pig manure supernatant showed that the community structure of the nonadapted inoculum adapted in approximately two months. Microbiota variance partitioning analysis revealed that running time, organic loading rate and inoculum together explained 26 and 31% of the variance in bacterial and archaeal communities respectively. The microbial communities of UASBs adapted to the reactor conditions in treatment of particle rich manure fractions, obtaining high capacity, especially on pig manure supernatant. These findings provide relevant insight into the microbial community dynamics in startup and operation of sludge bed reactors for methane production from slurry fractions, a major potential source of biogas. © 2015 The Society for Applied Microbiology.

  15. Prevention of Bed Agglomeration Problems in a Fluidized Bed Boiler by Finding the Trigging Value of Sewage Sludge Dosage Added to Combustion of Biofuels

    Andersson, Kajsa; Gervind, Pernilla

    2009-07-01

    Agglomeration of bed sand is a common problem during combustion of biofuels with high ash content in fluidized bed boilers. Former studies have shown that co-combustion of biofuels with sewage sludge increases the agglomeration temperature. Sewage sludge has a low heating value and high ash content. It would therefore be better to use sludge as an additive to the combustion than as a co-combusted biofuel. In this study the trigging value of sludge addition to the combustion of some biofuel was investigated. The effect of adding sludge with different precipitation chemicals, iron sulphate and aluminium sulphate, was investigated. The biofuels used for the experiments were bark, refused derived fuel (RDF) and a mixture of wood and straw, 75/25 % on energy basis. All experiments were carried out in a laboratory scale fluidized bed reactor. Analyses of chemical composition of bed sand and SEM/EDX analyses were performed after the combustion. Eventually agglomeration tests were performed in order to find the agglomeration temperature of the samples. Some of the samples sintered during the combustion and were not tested for the agglomeration temperature. SEM/EDX showed that all samples of bed sand contained sand particles with more or less coatings. In some cases the coatings seemed to consist of one dense inner layer and one more porous outer layer. From SEM/EDX and chemical composition analyses it was found that the total amount of phosphorous in the bed sand samples was increased with an increased addition of sludge in all experiments. The concentration of phosphorous was especially higher in the outer layers/coatings. It was also found that elements from the sludge seem to get caught by a sticky layer at the bed sand surface and form a non-sticky or less sticky layer that prevents agglomeration. The total amount of aluminium was increased with an increased addition of sludge for the wood/straw samples, while it increased with an increased amount of combusted fuel for

  16. Removal of personal care compounds from sewage sludge in reed bed container (lysimeter) studies--effects of macrophytes.

    Chen, Xijuan; Pauly, Udo; Rehfus, Stefan; Bester, Kai

    2009-10-15

    Sludge reed beds have been used for dewatering (draining and evapotranspiration) and mineralisation of sludge in Europe since 1988. Although reed beds are considered as a low cost and low contamination method in reducing volume, breaking down organic matter and increasing the density of sludge, it is not yet clear whether this enhanced biological treatment is suitable for degradation of organic micro-pollutants such as personal care products. Within this project the effect of biological sludge treatment in a reed bed on reducing the concentrations of the fragrances HHCB, AHTN, OTNE was studied as on the bactericide Triclosan. Additionally, the capacity of different macrophytes species to affect the treatment process was examined. Three different macrophyte species were compared: bulrush (Typha latifolia), reed (Phragmites australis) and reed canary grass (Phalaris arundinacea). They were planted into containers (lysimeters) with a size of 1 m x 1 m x 1 m which were filled with 20 cm gravel at the bottom and 50 cm sludge on top, into which the macrophytes were planted. During the twelve months experiment reduction of 20-30% for HHCB and AHTN, 70% for Triclosan and 70% for OTNE were determined under environmental conditions. The reduction is most likely due to degradation, since volatilization, uptake into plants and leaching are insignificant. No difference between the containers with different macrophyte species or the unplanted containers was observed. Considering the usual operation time of 10 years for reed beds, an assessment was made for the whole life time.

  17. Elutriation characteristics of fine particles from bubbling fluidized bed incineration for sludge cake treatment.

    Chang, Yu-Min; Chou, Chih-Mei; Su, Kuo-Tung; Hung, Chao-Yang; Wu, Chao-Hsiung

    2005-01-01

    In this study, measurements of elutriation rate were carried out in a bench scale bubbling fluidized bed incinerator, which was used to combust sludge cake. The particle size distribution and ignition loss were analyzed to study the elutriation characteristics of bubbling fluidized bed incineration. Drawn from the experimental data, the elutriation rate constant K(i)* for fine particles were obtained and correlated with parameters. It was found that most of the solid particles (about 95%) elutriated came from the fluidized medium (inorganic matters), but few came from unburned carbon particles or soot (about 5%). Finally, this paper lists a comparison of K(i)* between this study and the published prediction equations derived or studied in non-incineration modes of fluidized bed. A new and modified correlation is proposed here to estimate the elutriation rate of fine particles emitted from a bubbling fluidized bed incinerator. Primary operation variables (superficial gas velocity and incineration temperature) affecting the elutriation rate are also discussed in the paper.

  18. Mathematical modelling of sewage sludge incineration in a bubbling fluidised bed with special consideration for thermally-thick fuel particles.

    Yang, Yao Bin; Sharifi, Vida; Swithenbank, Jim

    2008-11-01

    Fluidised bed combustor (FBC) is one of the key technologies for sewage sludge incineration. In this paper, a mathematical model is developed for the simulation of a large-scale sewage sludge incineration plant. The model assumes the bed consisting of a fast-gas phase, an emulsion phase and a fuel particle phase with specific consideration for thermally-thick fuel particles. The model further improves over previous works by taking into account throughflow inside the bubbles as well as the floating and random movement of the fuel particles inside the bed. Validation against both previous lab-scale experiments and operational data of a large-scale industrial plant was made. Calculation results indicate that combustion split between the bed and the freeboard can range from 60/40 to 90/10 depending on the fuel particle distribution across the bed height under the specific conditions. The bed performance is heavily affected by the variation in sludge moisture level. The response time to variation in feeding rate is different for different parameters, from 6 min for outlet H2O, 10 min for O2, to 34 min for bed temperature.

  19. Greenhouse gas emissions from the mineralisation process in a Sludge Treatment Reed Bed system: Seasonal variation and environmental impact

    Larsen, Julie Dam; Nielsen, Steen; Scheutz, Charlotte

    2017-01-01

    Greenhouse gas emission data from the mineralisation process in Sludge Treatment Reed Bed systems (STRB) are scarce. The aim of this study was to quantify the emission rates of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) and to investigate seasonal variations in order to estimate ...

  20. Two-step upflow anaerobic sludge bed system for sewage treatment under subtropical conditions with posttreatment in waste stabilization ponds

    Seghezzo, L.; Trupiano, A.P.; Liberal, V.; Todd, P.G.; Figueroa, M.E.; Gutierrez, M.A.; Silva Wilches, Da A.C.; Iribarnegaray, M.; Guerra, R.G.; Arena, A.; Cuevas, C.M.; Zeeman, G.; Lettinga, G.

    2003-01-01

    A pilot-scale sewage treatment system consisting of two upflow anaerobic sludge bed (UASB) reactors followed by five waste stabilization ponds (WSPs) in series was studied under subtropical conditions. The first UASB reactor started up in only 1 mo (stable operation, high chemical oxygen demand

  1. Mineral and chemical composition of mine wastes of Markusovce sludge bed; Mineralne a chemicke zlozenie banskych odpadov odkaliska Markusovce

    Radkova, A; Volekova, B [Univerzita Komenskeho v Bratislave, Prirodovedecka fakulta, Katedra mineralogie a petrologie, 84215 Bratislava (Slovakia)

    2012-04-25

    Identification of minerals occurring in sludge bed material allows to assess the extent of migration of elements in the actual body of the sludge bed. It provides important information on the potential environmental pollution as well as on possible contamination of groundwater by potentially toxic elements. In Markusovce sludge bed there is saved about 9.9 million tons of waste material after flotation treatment of barytes - siderite-sulphide ore. Currently, the sludge bed is being extracted again due to the high content of barite. Concentrations of potentially toxic elements can be considered as relatively low. The most commonly occurring minerals in the samples are siderite and quartz, with minor rates are represented muscovite and dolomite. The content of barite increases towards the depth, which may be due to imperfect ore processing technology during the early stages of mining. Hematite is abundantly presented in the heavy fraction of the samples. The sulphide content is generally low, pyrite, chalcopyrite, tetrahedrite and cinnabar are most frequently presented. Monitored potentially toxic elements are mainly bounded to the primary sulfide minerals that are poorly oxidized. (authors)

  2. Influence of mass transfer resistance on overall nitrate removal rate in upflow sludge bed reactors.

    Ting, Wen-Huei; Huang, Ju-Sheng

    2006-09-01

    A kinetic model with intrinsic reaction kinetics and a simplified model with apparent reaction kinetics for denitrification in upflow sludge bed (USB) reactors were proposed. USB-reactor performance data with and without sludge wasting were also obtained for model verification. An independent batch study showed that the apparent kinetic constants k' did not differ from the intrinsic k but the apparent Ks' was significantly larger than the intrinsic Ks suggesting that the intra-granule mass transfer resistance can be modeled by changes in Ks. Calculations of the overall effectiveness factor, Thiele modulus, and Biot number combined with parametric sensitivity analysis showed that the influence of internal mass transfer resistance on the overall nitrate removal rate in USB reactors is more significant than the external mass transfer resistance. The simulated residual nitrate concentrations using the simplified model were in good agreement with the experimental data; the simulated results using the simplified model were also close to those using the kinetic model. Accordingly, the simplified model adequately described the overall nitrate removal rate and can be used for process design.

  3. Treatment of sludge containing nitro-aromatic compounds in reed-bed mesocosms – Water, BOD, carbon and nutrient removal

    Gustavsson, L.; Engwall, M.

    2012-01-01

    Highlights: ► It is necessary to improve existing and develop new sludge management techniques. ► One method is dewatering and biodegradation of compounds in constructed wetlands. ► The result showed high reduction of all tested parameters after treatment. ► Plants improve degradation and Phragmites australis is tolerant to xenobiotics. ► The amount of sludge could be reduced by 50–70%. - Abstract: Since the mid-1970s, Sweden has been depositing 1 million ton d.w sludge/year, produced at waste water treatment plants. Due to recent legislation this practice is no longer a viable method of waste management. It is necessary to improve existing and develop new sludge management techniques and one promising alternative is the dewatering and treatment of sludge in constructed wetlands. The aim of this study was to follow reduction of organic carbon, BOD and nutrients in an industrial sludge containing nitro-aromatic compounds passing through constructed small-scale wetlands, and to investigate any toxic effect such as growth inhibition of the common reed Phragmites australis. The result showed high reduction of all tested parameters in all the outgoing water samples, which shows that constructed wetlands are suitable for carbon and nutrient removal. The results also showed that P. australis is tolerant to xenobiotics and did not appear to be affected by the toxic compounds in the sludge. The sludge residual on the top of the beds contained low levels of organic carbon and is considered non-organic and could therefore be landfilled. Using this type of secondary treatment method, the amount of sludge could be reduced by 50–70%, mainly by dewatering and biodegradation of organic compounds.

  4. Performance of a system with full- and pilot-scale sludge drying reed bed units treating septic tank sludge in Brazil.

    Calderón-Vallejo, Luisa Fernanda; Andrade, Cynthia Franco; Manjate, Elias Sete; Madera-Parra, Carlos Arturo; von Sperling, Marcos

    2015-01-01

    This study investigated the performance of sludge drying reed beds (SDRB) at full- and pilot-scale treating sludge from septic tanks in the city of Belo Horizonte, Brazil. The treatment units, planted with Cynodon spp., were based on an adaptation of the first-stage of the French vertical-flow constructed wetland, originally developed for treating sewage. Two different operational phases were investigated; in the first one, the full-scale unit was used together with six pilot-scale columns in order to test different feeding strategies. For the second phase, only the full-scale unit was used, including a recirculation of the filtered effluent (percolate) to one of the units of the French vertical wetland. Sludge application was done once a week emptying a full truck, during 25 weeks. The sludge was predominantly diluted, leading to low solids loading rates (median values of 18 kgTS m(-2) year(-1)). Chemical oxygen demand removal efficiency in the full-scale unit was reasonable (median of 71%), but the total solids removal was only moderate (median of 44%) in the full-scale unit without recirculation. Recirculation did not bring substantial improvements in the overall performance. The other loading conditions implemented in the pilot columns also did not show statistically different performances.

  5. Continuous reduction of tellurite to recoverable tellurium nanoparticles using an upflow anaerobic sludge bed (UASB) reactor.

    Ramos-Ruiz, Adriana; Sesma-Martin, Juan; Sierra-Alvarez, Reyes; Field, Jim A

    2017-01-01

    According to the U.S. Department of Energy and the European Union, tellurium is a critical element needed for energy and defense technology. Thus methods are needed to recover tellurium from waste streams. The objectives of this study was to determine the feasibility of utilizing upflow anaerobic sludge bed (UASB) reactors to convert toxic tellurite (Te IV ) oxyanions to non-toxic insoluble elemental tellurium (Te 0 ) nanoparticles (NP) that are amendable to separation from aqueous effluents. The reactors were supplied with ethanol as the electron donating substrate to promote the biological reduction of Te IV . One reactor was additionally amended with the redox mediating flavonoid compound, riboflavin (RF), with the goal of enhancing the bioreduction of Te IV . Its performance was compared to a control reactor lacking RF. The continuous formation of Te 0 NPs using the UASB reactors was found to be feasible and remarkably improved by the addition of RF. The presence of this flavonoid was previously shown to enhance the conversion rate of Te IV by approximately 11-fold. In this study, we demonstrated that this was associated with the added benefit of reducing the toxic impact of Te IV towards the methanogenic consortium in the UASB and thus enabled a 4.7-fold higher conversion rate of the chemical oxygen demand. Taken as a whole, this work demonstrates the potential of a methanogenic granular sludge to be applied as a bioreactor technology producing recoverable Te 0 NPs in a continuous fashion. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Temperature effects on biohydrogen production in a granular sludge bed induced by activated carbon carriers

    Lee, Kuo-Shing [Department of Safety Health and Environmental Engineering, Chung tai Institute of Health Sciences and Technology, Taichung (China); Lin, Ping-Jei [Department of Chemical Engineering, Feng Chia University, Taichung (China); Chang, Jo-Shu [Department of Chemical Engineering, National Cheng Kung University, Tainan (China)

    2006-03-15

    Temperature effects on H{sub 2} production performance of a novel carrier-induced granular sludge bed (CIGSB) reactor were investigated. Using sucrose-based synthetic wastewater as the feed, the CIGSB system was operated at 30-45 {sup 0}C to identify the optimal working temperature. It was found that H{sub 2} production was the most efficient at 40 {sup 0}C, especially when it was operated at a low hydraulic retention time (HRT) of 0.5h. The overall maximal hydrogen production rate and yield were 7.66l/h/l and 3.88mol H{sub 2}/mol sucrose, respectively, both of them occurred at 40 {sup 0}C. The biomass content tended to decrease as the temperature was increased, suggesting that granular sludge formation may be inhibited at high temperatures. However, increasing temperature gave better specific H{sub 2} production rate, signifying that the average cellular activity for H{sub 2} production may be enhanced as the temperature was increased. The H{sub 2} yield and gas phase H{sub 2} content did not vary considerably regardless of changes in temperature and HRT. This reflects that the CIGSB was a relatively stable H{sub 2}-producing system. The major soluble products from hydrogen fermentation were butyric acid and acetic acid, accounting for 46+-3% and 28+-2% of total soluble microbial products (SMP), respectively. Thus, the dominant H{sub 2} producers in the mixed culture belonged to acidogenic bacteria that underwent butyrate-type fermentation. (author)

  7. Co-firing of oil sludge with coal-water slurry in an industrial internal circulating fluidized bed boiler.

    Liu, Jianguo; Jiang, Xiumin; Zhou, Lingsheng; Wang, Hui; Han, Xiangxin

    2009-08-15

    Incineration has been proven to be an alternative for disposal of sludge with its unique characteristics to minimize the volume and recover energy. In this paper, a new fluidized bed (FB) incineration system for treating oil sludge is presented. Co-firing of oil sludge with coal-water slurry (CWS) was investigated in the new incineration system to study combustion characteristics, gaseous pollutant emissions and ash management. The study results show the co-firing of oil sludge with CWS in FB has good operating characteristic. CWS as an auxiliary fuel can flexibly control the dense bed temperatures by adjusting its feeding rate. All emissions met the local environmental requirements. The CO emission was less than 1 ppm or essentially zero; the emissions of SO(2) and NO(x) were 120-220 and 120-160 mg/Nm(3), respectively. The heavy metal analyses of the bottom ash and the fly ash by ICP/AES show that the combustion ashes could be recycled as soil for farming.

  8. An Experimental Study on Axial Temperature Distribution of Combustion of Dewatered Poultry Sludge in Fluidized bed combustor

    Abbas A.H.

    2016-01-01

    Full Text Available A laboratory scale bubbling fluidized bed combustor was designed and fabricated to study the combustion of dewatered poultry sludge at different operational parameters. This paper present a study on the influence of equivalent ratio, secondary to primary air ratio and the fuel feed rate on the temperature distribution along the combustor. The equivalent ratio has been changed between 0.8 to 1.4% under poultry sludge feed rate of 10 kg/h and from 0.8 to 1 under poultry sludge feed rate of 15 kg/h. The secondary to primary air ratio was varied from 0.1 to 0.5 at 0.65 m injection height and 1.25 equivalent ratio. The results showed that these factors had a significant influence on the combustion characteristics of poultry sludge. The temperature distribution along the combustor was found to be strongly dependent on the fuel feed rate and the equivalent ratio and it increased when these two factors increased. However, the secondary air ratio increased the temperature in the lower region of the combustor while no significant effect was observed at the upper region of the combustor. The results suggested that the poultry sludge can be used as a fuel with high thermal combustor efficiency.

  9. Performance of novel sludge-bed anaerobic membrane bioreactor (SB-AnMBR) treating prehydrolysis liquor.

    Kale, Mayur M; Singh, Kripa S

    2014-01-01

    The feasibility of a novel sludge-bed anaerobic membrane bioreactor (SB-AnMBR) configuration for treating a waste stream from a dissolving pulp production industry was evaluated. The waste stream, called prehydrolysis liquor (PHL), is generated after the wood chips are subjected to high temperature steam to remove unwanted hemicelluloses. The PHL with total chemical oxygen demand (COD) of approximately 100 g/L contained mainly sugars, furfural, lignin, and acetic acid. The SB-AnMBR was fed with the PHL at organic loading rates in a range of 0.8 to10 kg-COD/(m(3)·d). The COD removal efficiency of more than 85% and an average rate of methane production of 0.35 m(3)/(kg-COD·d) were observed at each loading rate. No detectable sugars or furfural were present in the treated effluent from SB-AnMBR. Lignin removal varied from 60 to 90%. Flat-sheet membranes performed well with one fouling event during first 400 days of operation.

  10. Thermal disposal of sewage sludges by fluidised bed combustion with low emissions of pollutants. Thermische Entsorgung kommunaler Klaerschlaemme durch schadstoffarme Verbrennung in der Wirbelschicht

    Vogel, B. (Technische Univ. Magdeburg (Germany). Inst. fuer Thermische Apparate- und Umwelttechnik, Abt. Umwelttechnik); Lindau, S. (Technische Univ. Magdeburg (Germany). Inst. fuer Thermische Apparate- und Umwelttechnik, Abt. Umwelttechnik); Busse, U. (Technische Univ. Magdeburg (Germany). Inst. fuer Thermische Apparate- und Umwelttechnik, Abt. Umwelttechnik)

    1992-04-01

    The volume of sludge from the sewage treatment represents the largest problem in the waste management in Germany recently. The thermal treatment is inevitable for the solution of the problem. The fluidised bed combustion is suitable for a very good usability of sewage sludge. Experimental investigations carried out in a stationary fluidised bed in laboratory scale. The emissions of gaseous air pollutants are influenced by the properties of the sludge and the parameters of the process. The dependence of the formation and the reactions of the pollutants from various parameters are analysed and judged. (orig.)

  11. Emissions of CO2 and CH4 from sludge treatment reed beds depend on system management and sludge loading

    Olsson, Linda; Dam Larsen, Julie; Ye, Siyuan

    2014-01-01

    , the SD had no vegetation and a poor dewatering capacity, which resulted in anaerobic conditions favoring CH4 emission. In contrast, the well-managed STRB had more aerobic conditions in the sludge residue resulting in low CH4 emission rates. We conclude that well-designed and well-managed STRBs have a low...

  12. Bio-oil production from dry sewage sludge by fast pyrolysis in an electrically-heated fluidized bed reactor

    Renato O. Arazo

    2017-01-01

    Full Text Available The optimization of bio-oil produced from sewage sludge using fast pyrolysis in a fluidized bed reactor was investigated. Effects of temperature, sludge particle size and vapor residence time on bio-oil properties, such as yield, high heating value (HHV and moisture content were evaluated through experimental and statistical analyses. Characterization of the pyrolysis products (bio-oil and biogas was also done. Optimum conditions produced a bio-oil product with an HHV that is nearly twice as much as lignocellulosic-derived bio-oil, and with properties comparable to heavy fuel oil. Contrary to generally acidic bio-oil, the sludge-derived bio-oil has almost neutral pH which could minimize the pipeline and engine corrosions. The Fourier Transform Infrared and gas-chromatography and mass spectrometry analyses of bio-oil showed a dominant presence of gasoline-like compounds. These results demonstrate that fast pyrolysis of sewage sludge from domestic wastewater treatment plant is a favorable technology to produce biofuels for various applications.

  13. Septage unit treatment by sludge treatment reed beds for easy management and reuse: performance and design considerations.

    Kim, Boram; Bel, Thomas; Bourdoncle, Pascal; Dimare, Jocelyne; Troesch, Stéphane; Molle, Pascal

    2018-01-01

    Sustainable treatment and management of fecal sludge in rural areas require adapted solutions. Rustic and simple operating processes such as sludge treatment reed beds (STRB) have been increasingly considered for this purpose. The biggest full scale (2,600 m 2 of STRB) septage treatment unit in France had been built in Nègrepelisse with the final objectives of reusing treated sludge and leachates for agriculture spreading and tree irrigation, respectively. The aim of this investigation was to validate the treatment chain of this installation. The obtained field data showed firstly that the overall removal efficiencies of STRB were satisfactory and stable. Removal rates higher than 98% for chemical oxygen demand and suspended solids and a 95% for Kjeldahl nitrogen represented so far a beneficial septage treatment by STRB. The highlighted necessity of a suitable complementary leachate treatment (before tree irrigation) justified the presence of the second stage of vertical flow constructed wetland. The sludge deposit drying and mineralization efficiencies were on the right track. According to hydrotextural diagram analysis, surface deposit was however found to have high deformability probably due to the youth of the installation. An in-depth understanding of STRB system needs continuous long-term studies.

  14. Sludge granulation in an UASB-moving bed biofilm hybrid reactor for efficient organic matter removal and nitrogen removal in biofilm reactor.

    Chatterjee, Pritha; Ghangrekar, M M; Rao, Surampalli

    2018-02-01

    A hybrid upflow anaerobic sludge blanket (UASB)-moving bed biofilm (MBB) and rope bed biofilm (RBB) reactor was designed for treatment of sewage. Possibility of enhancing granulation in an UASB reactor using moving media to improve sludge retention was explored while treating low-strength wastewater. The presence of moving media in the top portion of the UASB reactor allowed a high solid retention time even at very short hydraulic retention times and helped in maintaining selection pressure in the sludge bed to promote formation of different sized sludge granules with an average settling velocity of 67 m/h. These granules were also found to contain plenty of extracellular polymeric substance (EPS) such as 58 mg of polysaccharides (PS) per gram of volatile suspended solids (VSS) and protein (PN) content of 37 mg/g VSS. Enriched sludge of nitrogen-removing bacteria forming a porous biofilm on the media in RBB was also observed in a concentration of around 894 g/m 2 . The nitrogen removing sludge also had a high EPS content of around 22 mg PS/g VSS and 28 mg PN/g VSS. This hybrid UASB-MBB-RBB reactor with enhanced anaerobic granular sludge treating both carbonaceous and nitrogenous matter may be a sustainable solution for decentralized sewage treatment.

  15. Fate of xenobiotic compounds and plants activity in reed bed sludge treatment

    Chen, Xijuan; Pauli, Udo; Rehfus, Stefan

    different plants: bulrush (Typha), reed (Phragmites australis) and reed canary grass (Phalaris arundinacea) were planted into 12 containers with a size of 1m Х 1m X 1m which were builded with 20cm gravel and 50cm sludge to study the plants activity in sludge degradation process, 4 containers were left...

  16. Chemical and ecotoxicological characterization of ashes obtained from sewage sludge combustion in a fluidised-bed reactor.

    Lapa, N; Barbosa, R; Lopes, M H; Mendes, B; Abelha, P; Boavida, D; Gulyurtlu, I; Oliveira, J Santos

    2007-08-17

    In 1999, the DEECA/INETI and the UBiA/FCT/UNL started a researching project on the partition of heavy metals during the combustion of stabilised sewage sludge (Biogran), in a fluidised-bed reactor, and on the quality of the bottom ashes and fly ashes produced. This project was entitled Bimetal and was funded by the Portuguese Foundation for Science and Technology. In this paper only the results on the combustion of Biogran are reported. The combustion process was performed in two different trials, in which different amounts of sewage sludge and time of combustion were applied. Several ash samples were collected from the bed (bottom ashes) and from two cyclones (first cyclone and second cyclone ashes). Sewage sludge, bed material (sand) and ash samples were submitted to the leaching process defined in the European leaching standard EN 12457-2. The eluates were characterized for a set of inorganic chemical species. The ecotoxicological levels of the eluates were determined for two biological indicators (Vibrio fischeri and Daphnia magna). The results were compared with the limit values of the CEMWE French Regulation. The samples were also ranked according to an index based on the chemical characterization of the eluates. It was observed an increase of the concentration of metals along the combustion system. The ashes trapped in the second cyclone, for both combustion trials, showed the highest concentration of metals in the eluates. Chemically, the ashes of the second cyclone were the most different ones. In the ecotoxicological point of view, the ecotoxicity levels of the eluates of the ashes, for both combustion cycles, did not follow the same pattern as observed for the chemical characterization. The ashes of the first cyclone showed the highest ecotoxicity levels for V. fischeri and D. magna. This difference on chemical and ecotoxicological results proves the need for performing both chemical and ecotoxicological characterizations of the sub-products of such type

  17. Chemical and ecotoxicological characterization of ashes obtained from sewage sludge combustion in a fluidised-bed reactor

    Lapa, N. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal)]. E-mail: ncsn@fct.unl.pt; Barbosa, R. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal); Lopes, M.H. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Mendes, B. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal); Abelha, P. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Gulyurtlu, I. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Santos Oliveira, J. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal)

    2007-08-17

    In 1999, the DEECA/INETI and the UBiA/FCT/UNL started a researching project on the partition of heavy metals during the combustion of stabilised sewage sludge (Biogran[reg]), in a fluidised-bed reactor, and on the quality of the bottom ashes and fly ashes produced. This project was entitled Bimetal and was funded by the Portuguese Foundation for Science and Technology. In this paper only the results on the combustion of Biogran[reg]) are reported. The combustion process was performed in two different trials, in which different amounts of sewage sludge and time of combustion were applied. Several ash samples were collected from the bed (bottom ashes) and from two cyclones (first cyclone and second cyclone ashes). Sewage sludge, bed material (sand) and ash samples were submitted to the leaching process defined in the European leaching standard EN 12457-2. The eluates were characterized for a set of inorganic chemical species. The ecotoxicological levels of the eluates were determined for two biological indicators (Vibrio fischeri and Daphnia magna). The results were compared with the limit values of the CEMWE French Regulation. The samples were also ranked according to an index based on the chemical characterization of the eluates. It was observed an increase of the concentration of metals along the combustion system. The ashes trapped in the second cyclone, for both combustion trials, showed the highest concentration of metals in the eluates. Chemically, the ashes of the second cyclone were the most different ones. In the ecotoxicological point of view, the ecotoxicity levels of the eluates of the ashes, for both combustion cycles, did not follow the same pattern as observed for the chemical characterization. The ashes of the first cyclone showed the highest ecotoxicity levels for V. fischeri and D. magna. This difference on chemical and ecotoxicological results proves the need for performing both chemical and ecotoxicological characterizations of the sub

  18. Chemical and ecotoxicological characterization of ashes obtained from sewage sludge combustion in a fluidised-bed reactor

    Lapa, N.; Barbosa, R.; Lopes, M.H.; Mendes, B.; Abelha, P.; Gulyurtlu, I.; Santos Oliveira, J.

    2007-01-01

    In 1999, the DEECA/INETI and the UBiA/FCT/UNL started a researching project on the partition of heavy metals during the combustion of stabilised sewage sludge (Biogran[reg]), in a fluidised-bed reactor, and on the quality of the bottom ashes and fly ashes produced. This project was entitled Bimetal and was funded by the Portuguese Foundation for Science and Technology. In this paper only the results on the combustion of Biogran[reg]) are reported. The combustion process was performed in two different trials, in which different amounts of sewage sludge and time of combustion were applied. Several ash samples were collected from the bed (bottom ashes) and from two cyclones (first cyclone and second cyclone ashes). Sewage sludge, bed material (sand) and ash samples were submitted to the leaching process defined in the European leaching standard EN 12457-2. The eluates were characterized for a set of inorganic chemical species. The ecotoxicological levels of the eluates were determined for two biological indicators (Vibrio fischeri and Daphnia magna). The results were compared with the limit values of the CEMWE French Regulation. The samples were also ranked according to an index based on the chemical characterization of the eluates. It was observed an increase of the concentration of metals along the combustion system. The ashes trapped in the second cyclone, for both combustion trials, showed the highest concentration of metals in the eluates. Chemically, the ashes of the second cyclone were the most different ones. In the ecotoxicological point of view, the ecotoxicity levels of the eluates of the ashes, for both combustion cycles, did not follow the same pattern as observed for the chemical characterization. The ashes of the first cyclone showed the highest ecotoxicity levels for V. fischeri and D. magna. This difference on chemical and ecotoxicological results proves the need for performing both chemical and ecotoxicological characterizations of the sub

  19. Biodegradation of benzotriazoles and hydroxy-benzothiazole in wastewater by activated sludge and moving bed biofilm reactor systems

    Mazioti, Aikaterini A.; Stasinakis, Athanasios S.; Pantazi, Ypapanti

    2015-01-01

    Two laboratory scale fully aerated continuous flow wastewater treatment systems were used to compare the removal of five benzotriazoles and one benzothiazole by suspended and attached growth biomass. The Activated Sludge system was operated under low organic loading conditions. The Moving Bed...... in significantly lower biodegradation for 4 out of 6 examined compounds. Calculation of specific removal rates (normalised to biomass) revealed that attached biomass had higher biodegradation potential for target compounds comparing to suspended biomass. Clear differences in the biodegradation ability of attached...... biomass grown in different bioreactors of MBBR systems were also observed. Batch experiments showed that micropollutants biodegradation by both types of biomass is co-metabolic....

  20. Sewage Sludge Disposal with Energy Recovery by Fluidized Bed Gasification and CHP-Units

    Horst, J.; Gross, B.; Kimmerle, K. [Inst. fuer ZukunftsEnergieSysteme, Saarbruecken (Germany); Eder, C. [Christian Eder Technology e.K., Neunkirchen (Germany)

    2006-07-15

    Sewage sludge is a composition of by-products collected during the different stages of the waste water cleaning process of communal and industrial treatment plants. Because of its harmful impacts on environment as well as animals - and mankind - health sewage sludge has become a problem. Therefore disposal of sludge is today on a crossroad depending on the discussion about soil contamination by using the sludge as fertiliser. Some countries are now abandoning disposal to agriculture and are entering into thermal treatment with the argument: 'Harmful substances already separated with high financial effort should definitely be removed from the food cycle and should not return indirectly via the fields to food and water'. The SEDIS project - a project funded by the European Commission under the specific research and technological development programme 'Promotion of innovation and encouragement of SME participation' - is aimed at eliminating the rising disposal problem of sewage sludge by an energy-related use of the raw sludge directly on site of wastewater treatment plants. SEDIS is developing an innovative, self-sustaining system to process liquid and pasty waste such as sewage sludge and solid biomass to utilise product-gas for power-generation direct on site. This process is called ETVS-process and is patented by Christian Eder Technology e.K. Today, where each company has to look for sustainable savings, the SEDIS concept offers a decentralised process, self-sustaining from other energy sources and able to provide the whole treatment plant with energy. Furthermore the treatment plant would be independent of price policy of sludge disposers.

  1. Low temperature circulating fluidized bed gasification and co-gasification of municipal sewage sludge

    Thomsen, Tobias Pape; Hauggaard-Nielsen, Henrik; Gøbel, Benny

    2017-01-01

    to the mono-sludge ashes, thereby showing the best fertilizer qualities among all assessed materials. It was also found that bottom ashes from the char reactor contained even less heavy metals than cyclone ashes. It is concluded that LT-CFB gasification and co-gasification is a highly effective way to purify...

  2. Optimizing aeration rates for minimizing membrane fouling and its effect on sludge characteristics in a moving bed membrane bioreactor

    Rahimi, Yousef; Torabian, Ali; Mehrdadi, Naser; Habibi-Rezaie, Mehran; Pezeshk, Hamid; Nabi-Bidhendi, Gholam-Reza

    2011-01-01

    Research highlights: → There is an optimum aeration rate in the MBMBR process compartments. → Optimum aeration rate maximizes nutrients removal. → Optimum aeration rate minimizes membrane fouling. → Both aeration rates in MBBR and membrane compartment can affect on membrane permeability. - Abstract: In MBR processes, sufficient aeration is necessary to maintain sustainable flux and to retard membrane fouling. Membrane permeability, sludge characteristics, nutrient removal and biomass growth at various air flow rates in the membrane and moving bed biofilm reactor (MBBR) compartments were studied in a pilot plant. The highest nitrogen and phosphorous removal rates were found at MBBR aeration rates of 151 and 85 L h -1 and a specific aeration demand per membrane area (SAD m ) of 1.2 and 0.4m air 3 m -2 h -1 , respectively. A linear correlation was found between the amount of attached biofilm and the nutrient removal rate. The aeration rate in the MBBR compartment and SAD m significantly influenced the sludge characteristics and membrane permeability. The optimum combination of the aeration rate in the MBBR compartment and SAD m were 151 L h -1 and 0.8-1.2m air 3 m membrane -2 h -1 , respectively.

  3. Optimizing aeration rates for minimizing membrane fouling and its effect on sludge characteristics in a moving bed membrane bioreactor

    Rahimi, Yousef, E-mail: yrahimi@ut.ac.ir [Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, No. 25 Qods St., Enghelab Ave., Tehran (Iran, Islamic Republic of); Torabian, Ali, E-mail: atorabi@ut.ac.ir [Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, No. 25 Qods St., Enghelab Ave., Tehran (Iran, Islamic Republic of); Mehrdadi, Naser, E-mail: mehrdadi@ut.ac.ir [Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, No. 25 Qods St., Enghelab Ave., Tehran (Iran, Islamic Republic of); Habibi-Rezaie, Mehran, E-mail: mhabibi@khayam.ut.ac.ir [Department of Biotechnology, Faculty of Biology, College of Science, University of Tehran, No. 25 Qods St., Enghelab Ave., Tehran (Iran, Islamic Republic of); Pezeshk, Hamid, E-mail: pezeshk@khayam.ut.ac.ir [Department of Statistics, Faculty of Mathematics and Computer, College of Science, University of Tehran, No. 25 Qods St., Enghelab Ave., Tehran (Iran, Islamic Republic of); Nabi-Bidhendi, Gholam-Reza, E-mail: ghhendi@ut.ac.ir [Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, No. 25 Qods St., Enghelab Ave., Tehran (Iran, Islamic Republic of)

    2011-02-28

    Research highlights: {yields} There is an optimum aeration rate in the MBMBR process compartments. {yields} Optimum aeration rate maximizes nutrients removal. {yields} Optimum aeration rate minimizes membrane fouling. {yields} Both aeration rates in MBBR and membrane compartment can affect on membrane permeability. - Abstract: In MBR processes, sufficient aeration is necessary to maintain sustainable flux and to retard membrane fouling. Membrane permeability, sludge characteristics, nutrient removal and biomass growth at various air flow rates in the membrane and moving bed biofilm reactor (MBBR) compartments were studied in a pilot plant. The highest nitrogen and phosphorous removal rates were found at MBBR aeration rates of 151 and 85 L h{sup -1} and a specific aeration demand per membrane area (SAD{sub m}) of 1.2 and 0.4m{sub air}{sup 3} m{sup -2} h{sup -1}, respectively. A linear correlation was found between the amount of attached biofilm and the nutrient removal rate. The aeration rate in the MBBR compartment and SAD{sub m} significantly influenced the sludge characteristics and membrane permeability. The optimum combination of the aeration rate in the MBBR compartment and SAD{sub m} were 151 L h{sup -1} and 0.8-1.2m{sub air}{sup 3}m{sub membrane}{sup -2} h{sup -1}, respectively.

  4. Research results of sewage sludge and waste oil disposal by entrained bed gasification

    Schingnitz, M.; Goehler, P.; Wenzel, W.; Seidel, W. (Noell-DBI Energie- und Entsorgungstechnik GmbH, Freiberg (Germany))

    1992-01-01

    Presents results of gasifying sewage sludge and waste oil with the GSP technology, developed by the Freiberg Fuel Institute (FRG). The GSP reactor was developed in 1976 for gasification of pulverized brown coal. An industrial reactor of this design operated for over 5 years with a total coal throughput of more than 300,000 t. The design of the gasification generator and the flowsheet of a 3 MW experimental pilot plant for waste gasification are presented. The PCB content in the gasification sludge is 6.14 mg/kg, in waste oil - 160 mg/kg. Gasification takes place at high temperatures of more than 1,400 C for complete destruction of toxic pollutants. Gasification results compare composition of raw gas produced by gasification of brown coal, sewage sludge and waste oil. A detailed list of content of pollutants (PCDD, PCDF, PAH, dioxin and furan) in the gasification gas, in process waters and in solid residue of the process water is provided. It is concluded that the GSP gasification process is suitable for safe disposal of waste with toxic content. 3 refs.

  5. Synergetic effect of sewage sludge and biomass co-pyrolysis: A combined study in thermogravimetric analyzer and a fixed bed reactor

    Wang, Xuebin; Deng, Shuanghui; Tan, Houzhang; Adeosun, Adewale; Vujanović, Milan; Yang, Fuxin; Duić, Neven

    2016-01-01

    Highlights: • The synergetic effect of sewage sludge and wheat straw co-pyrolysis was studied. • The mass balance measurement of gas, tar, and char was performed. • The synergetic effect shows strongest under a certain biomass addition ratio around 60%. • The required heat of co-pyrolysis is significantly reduced. - Abstract: Much attention has been given to the valuable products from the pyrolysis of sewage sludge. In this study, the pyrolysis of sewage sludge, biomass (wheat straw) and their mixtures in different proportions were carried out in a thermogravimetric analyzer (TGA) and fixed-bed reactor. The effects of pyrolysis temperature and percentage of wheat straw in wheat straw–sewage sludge mixtures on product distributions in terms of gas, liquid and char and the gas composition were investigated. Results indicate that there is a significantly synergetic effect during the co-pyrolysis processes of sewage sludge and wheat straw, accelerating the pyrolysis reactions. The synergetic effect resulted in an increase in gas and liquid yields but a decrease in char yield. The gas composition and the synergetic effect degree are strongly affected by the wheat straw proportions, and the strongest synergetic effect of sewage sludge and wheat straw co-pyrolysis appears at the biomass proportion of 60 wt.%. With an increase of temperature, the gas yield from the pyrolysis of sewage sludge increased but the liquid and char yields decreased. Moreover, the required heat of co-pyrolysis is significantly reduced compared with the pyrolysis of sewage sludge and wheat straw pyrolysis alone, because of the exothermic reactions between the ash components in two fuel samples.

  6. Use of nitrogen stable isotope analysis to understand char nitrogen evolution during the fluidized-bed co-combustion of coal and sewage sludge

    Ana Arenillas; Roberto Garcia; Chenggong Sun; Colin E. Snape; Angel H. Moreno; Fernando Rubiera; Jose J. Pis [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre, School of Chemical, Environmental and Mining Engineering

    2005-04-01

    NOx emissions from sewage sludge combustion are a concern, because of the usually high nitrogen content of this fuel. The interactions during co-combustion in a fluidized-bed reactor of sewage sludge and a bituminous coal were evaluated, in relation to the nitrogen evolution during the combustion process. The nitrogen stable isotope measurements provide novel results regarding the tracing of nitrogen during combustion. Our preliminary results show that the co-combustion chars retain more nitrogen than expected, with the additional nitrogen being mainly derived from the sludge. Additional measurements are planned on the resultant co-combustion gases, to aid source apportionment of the NOx arising from coal/sewage interactions. 14 refs., 3 figs., 2 tabs.

  7. Pyrolysis of high-ash sewage sludge in a circulating fluidized bed reactor for production of liquids rich in heterocyclic nitrogenated compounds.

    Zuo, Wu; Jin, Baosheng; Huang, Yaji; Sun, Yu; Li, Rui; Jia, Jiqiang

    2013-01-01

    A circulating fluidized bed reactor was used for pyrolyzing sewage sludge with a high ash content to produce liquids rich in heterocyclic nitrogenated compounds. GC/MS and FTIR analyses showed that heterocyclic nitrogenated compounds and hydrocarbons made up 38.5-61.21% and 2.24-17.48% of the pyrolysis liquids, respectively. A fluidized gas velocity of 1.13 m/s, a sludge feed rate of 10.78 kg/h and a particle size of 1-2mm promoted heterocyclic nitrogenated compound production. Utilizing heterocyclic nitrogenated compounds as chemical feedstock could be a way for offsetting the cost of sewage sludge treatment. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Overview of municipal sludge fluid bed incineration in North America--from green to greener--the Lakeview, the Duffin Creek and the Southerly experiences.

    Dangtran, K; Takmaz, L; Pham, H; Bergel, J Y; Welp, J; Burrowes, P

    2011-01-01

    Thermal processes used in sludge disposal have become more attractive as process improvements have been introduced, such as power generation and efficient heat recovery. More and more utilities and agencies are reevaluating their sludge management practices to ensure that they are providing sustainable management solutions for their clients. The thermal process design approach to the disposal of sludge is not only designed to achieve stricter emission limits but also is more energy efficient compared to its predecessors. Increasing numbers of new plants are being built every year with more energy efficient heat recovery features such as air preheating and cogeneration with steam and electricity production. This paper presents an overview of fluid bed incineration in North America and its evolution over the last decades. Case studies of the last three newest and largest plants in North America are presented, including the Lakeview Plant, Duffin Creek Plant, both in Ontario, Canada and the Southerly Plant in Cleveland, Ohio, USA.

  9. Antibiotic Fermentation Broth Treatment by a pilot upflow anaerobic sludge bed reactor and kinetic modeling.

    Coskun, T; Kabuk, H A; Varinca, K B; Debik, E; Durak, I; Kavurt, C

    2012-10-01

    In this study, an upflow anaerobic sludge blanket (UASB) mesophilic reactor was used to remove antibiotic fermentation broth wastewater. The hydraulic retention time was held constant at 13.3 days. The volumetric organic loading value increased from 0.33 to 7.43 kg(COD)m(-3)d(-1) using antibiotic fermentation broth wastewater gradually diluted with various ratios of domestic wastewater. A COD removal efficiency of 95.7% was obtained with a maximum yield of 3,700 L d(-1) methane gas production. The results of the study were interpreted using the modified Stover-Kincannon, first-order, substrate mass balance and Van der Meer and Heertjes kinetic models. The obtained kinetic coefficients showed that antibiotic fermentation broth wastewater can be successfully treated using a UASB reactor while taking COD removal and methane production into account. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Comparison of UASB and EGSB reactors performance, for treatment of raw and deoiled palm oil mill effluent (POME)

    Fang, Cheng; O-Thong, Sompong; Boe, Kanokwan

    2011-01-01

    and deoiled POME was 503 and 610mL-CH4/gVS-added, respectively. For the treatment of POME in continuously fed reactors, both in UASB and EGSB reactors more than 90% COD removal could be obtained, at HRT of 5 days, corresponding to OLR of 5.8gVS/(L-reactor.d). Similar methane yields of 436–438mL-CH4/g......VS-added were obtained for UASB and EGSB respectively. However, for treatment of deoiled POME, both UASB and EGSB reactors could operate at lower OLR of 2.6gVS/(L-reactor.d), with the methane yield of 600 and 555mL-CH4/gVS-added for UASB and EGSB, respectively. The higher methane yield achieved from the deoiled...

  11. Low temperature circulating fluidized bed gasification and co-gasification of municipal sewage sludge. Part 2: Evaluation of ash materials as phosphorus fertilizer.

    Thomsen, Tobias Pape; Hauggaard-Nielsen, Henrik; Gøbel, Benny; Stoholm, Peder; Ahrenfeldt, Jesper; Henriksen, Ulrik B; Müller-Stöver, Dorette Sophie

    2017-08-01

    The study is part 2 of 2 in an investigation of gasification and co-gasification of municipal sewage sludge in low temperature gasifiers. In this work, solid residuals from thermal gasification and co-gasification of municipal sewage sludge were investigated for their potential use as fertilizer. Ashes from five different low temperature circulating fluidized bed (LT-CFB) gasification campaigns including two mono-sludge campaigns, two sludge/straw mixed fuels campaigns and a straw reference campaign were compared. Experiments were conducted on two different LT-CFBs with thermal capacities of 100kW and 6MW, respectively. The assessment included: (i) Elemental composition and recovery of key elements and heavy metals; (ii) content of total carbon (C) and total nitrogen (N); (iii) pH; (iv) water extractability of phosphorus after incubation in soil; and (v) plant phosphorus response measured in a pot experiment with the most promising ash material. Co-gasification of straw and sludge in LT-CFB gasifiers produced ashes with a high content of recalcitrant C, phosphorus (P) and potassium (K), a low content of heavy metals (especially cadmium) and an improved plant P availability compared to the mono-sludge ashes, thereby showing the best fertilizer qualities among all assessed materials. It was also found that bottom ashes from the char reactor contained even less heavy metals than cyclone ashes. It is concluded that LT-CFB gasification and co-gasification is a highly effective way to purify and sanitize sewage sludge for subsequent use in agricultural systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Long Term Performance of an Arsenite-Oxidizing-Chlorate-Reducing Microbial Consortium in an Upflow Anaerobic Sludge Bed (UASB) Bioreactor

    Sun, Wenjie; Sierra-Alvarez, Reyes; Field, Jim A.

    2011-01-01

    A chlorate (ClO3−) reducing microbial consortium oxidized arsenite (As(III)) to arsenate (As(V)) in an upflow anaerobic sludge-bed bioreactor over 550 d operation. As(III) was converted with high conversion efficiencies (>98%) at volumetric loadings ranging from 0.45 to 1.92 mmol As/(Lreactor d). The oxidation of As(III) was linked to the complete reduction of ClO3− to Cl− and H2O, as demonstrated by a molar ratio of approximately 3.0 mol As(III) oxidized per mole of Cl− formed and by the greatly lowered ClO3−-reducing capacity without As(III) feeding. An autotrophic enrichment culture was established from the bioreactor biofilm. A 16S rRNA gene clone library indicated that the culture was dominated by Dechloromonas, and Stenotrophomonas as well as genera within the family Comamonadaceae. The results indicate that the oxidation of As(III) to less mobile As(V) utilizing ClO3− as a terminal electron acceptor provides a sustainable bioremediation strategy for arsenic contamination in anaerobic environments. PMID:21333531

  13. Evaluation of co-pyrolysis petrochemical wastewater sludge with lignite in a thermogravimetric analyzer and a packed-bed reactor: Pyrolysis characteristics, kinetics, and products analysis.

    Mu, Lin; Chen, Jianbiao; Yao, Pikai; Zhou, Dapeng; Zhao, Liang; Yin, Hongchao

    2016-12-01

    Co-pyrolysis characteristics of petrochemical wastewater sludge and Huolinhe lignite were investigated using thermogravimetric analyzer and packed-bed reactor coupled with Fourier transform infrared spectrometer and gas chromatography. The pyrolysis characteristics of the blends at various sludge blending ratios were compared with those of the individual materials. Thermogravimetric experiments showed that the interactions between the blends were beneficial to generate more residues. In packed-bed reactor, synergetic effects promoted the release of gas products and left less liquid and solid products than those calculated by additive manner. Fourier transform infrared spectrometer analysis showed that main functional groups in chars gradually disappeared with pyrolysis temperatures increasing, and H 2 O, CH 4 , CO, and CO 2 appeared in volatiles during pyrolysis. Gas compositions analysis indicated that, the yields of H 2 and CO clearly increased as the pyrolysis temperature and sludge blending ratio increasing, while the changes of CH 4 and CO 2 yields were relatively complex. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Evaluation of an up-flow anaerobic sludge bed (UASB) reactor containing diatomite and maifanite for the improved treatment of petroleum wastewater.

    Chen, Chunmao; Liang, Jiahao; Yoza, Brandon A; Li, Qing X; Zhan, Yali; Wang, Qinghong

    2017-11-01

    Novel diatomite (R1) and maifanite (R2) were utilized as support materials in an up-flow anaerobic sludge bed (UASB) reactor for the treatment of recalcitrant petroleum wastewater. At high organic loadings (11kg-COD/m 3 ·d), these materials were efficient at reducing COD (92.7% and 93.0%) in comparison with controls (R0) (88.4%). Higher percentages of large granular sludge (0.6mm or larger) were observed for R1 (30.3%) and R2 (24.6%) compared with controls (22.6%). The larger portion of granular sludge provided a favorable habitat that resulted in greater microorganism diversity. Increased filamentous bacterial communities are believed to have promoted granular sludge formation promoting a conductive environment for stimulation methanogenic Archaea. These communities had enhanced pH tolerance and produced more methane. This study illustrates a new potential use of diatomite and maifanite as support materials in UASB reactors for increased efficiency when treating refractory wastewaters. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Co-firing a pressurized fluidized-bed combustion system with coal and refuse derived fuels and/or sludges. Task 16

    DeLallo, M.; Zaharchuk, R.

    1994-01-01

    The co-firing of waste materials with coal in utility scale power plants has emerged as an effective approach to produce energy and manage municipal waste. Leading this approach, the atmospheric fluidized-bed combustor (AFBC) has demonstrated its commercial acceptance in the utility market as a reliable source of power burning a variety of waste and alternative fuels. The fluidized bed, with its stability of combustion, reduces the amount of thermochemical transients and provides for easier process control. The application of pressurized fluidized-bed combustor (PFBC) technology, although relatively new, can provide significant enhancements to the efficient production of electricity while maintaining the waste management benefits of AFBC. A study was undertaken to investigate the technical and economic feasibility of co-firing a PFBC with coal and municipal and industrial wastes. Focus was placed on the production of electricity and the efficient disposal of wastes for application in central power station and distributed locations. Wastes considered for co-firing include municipal solid waste (MSW), tire-derived fuel (TDF), sewage sludge, and industrial de-inking sludge. Issues concerning waste material preparation and feed, PFBC operation, plant emissions, and regulations are addressed. This paper describes the results of this investigation, presents conclusions on the key issues, and provides recommendations for further evaluation.

  16. K Basin Sludge Conditioning Process Testing Project. Results from Test 4, ''Acid Digestion of Mixed-Bed Ion Exchange Resin''

    Pool, K.H.; Delegard, C.H.; Schmidt, A.J.; Thornton, B.M.; Silvers, K.L.

    1998-06-01

    Approximately 73 m 3 of heterogeneous solid material, ''sludge,'' (upper bound estimate, Packer 1997) have accumulated at the bottom of the K Basins in the 100 K Area of the Hanford Site. This sludge is a mixture of spent fuel element corrosion products, ion exchange materials (organic and inorganic), graphite-based gasket materials, iron and aluminum metal corrosion products, sand, and debris (Makenas et al. 1996, 1997). In addition, small amounts of polychlorinated biphenyls (PCBs) have been found. Ultimately, it is planned to transfer the K Basins sludge to the Hanford double shell tanks (DSTs). The Hanford Spent Nuclear Fuel (HSNF) project has conducted a number of evaluations to examine technology and processing alternatives to pretreat K Basin sludge to meet storage and disposal requirements. From these evaluations, chemical pretreatment has been selected to address criticality issues, reactivity, and the destruction or removal of PCBs before the K Basin sludge can be transferred to the DSTs. Chemical pretreatment, referred to as the K Basin sludge conditioning process, includes nitric acid dissolution of the sludge (with removal of acid insoluble solids), neutrons absorber addition, neutralization, and reprecipitation. Laboratory testing is being conducted by the Pacific Northwest National Laboratory (PNNL) to provide data necessary to develop the sludge conditioning process

  17. Low temperature circulating fluidized bed gasification and co-gasification of municipal sewage sludge. Part 1: Process performance and gas product characterization

    Thomsen, Tobias Pape; Sárossy, Zsuzsa; Gøbel, Benny

    2017-01-01

    Results from five experimental campaigns with Low Temperature Circulating Fluidized Bed (LT-CFB) gasification of straw and/or municipal sewage sludge (MSS) from three different Danish municipal waste water treatment plants in pilot and demonstration scale are analyzed and compared. The gasification...... process is characterized with respect to process stability, process performance and gas product characteristics. All experimental campaigns were conducted at maximum temperatures below 750°C, with air equivalence ratios around 0.12 and with pure silica sand as start-up bed material. A total of 8600kg...... particles in the system. Co-gasification of MSS with sufficient amounts of cereal straw was found to be an effective way to mitigate these issues as well as eliminate thermal MSS drying requirements. Characterization of gas products and process performance showed that even though gas composition varied...

  18. Experimental on fly ash recirculation with bottom feeding to improve the performance of a circulating fluidized bed boiler co-burning coal sludge

    Duan, Lunbo; Xu, Guiling; Liu, Daoyin; Chen, Xiaoping; Zhao, Changsui [Southeast Univ., Nanjing (China). School of Energy and Environment

    2013-07-01

    With the aim of reducing carbon content in fly ash, fly ash recirculation with bottom feeding (FARBF) technology was applied to a 75 t/h Circulating Fluidized Bed (CFB) boiler burning mixture of coal and coal sludge. And industrial experiments were carried out to investigate the influence of FARBF technology on the combustion performance and pollutant emission characteristics of the CFB boiler. Results show that as the recirculation rate of fly ash increases, the CFB dense bed temperature decreases while the furnace outlet temperature increases, and the temperature distribution in the furnace becomes uniform. Compared with the conditions without fly ash recirculation, the combustion efficiency increases from 92 to 95% when the recirculation rate increases to 8 t/h, and the desulfurization efficiency also increases significantly. As the recirculation rate increases, the emissions of NO and CO decrease, but the particulate emission increases. The present study indicates that FARBF technology can improve the combustion performance and desulfurization efficiency for the CFB boilers burning coal sludge, and this can bring large economical and environmental benefits in China.

  19. Determination of the Removal Efficiency of Linear Alkyl Benzene Sulphonate Acids (LAS in Fixed Bed Aeration Tank and Conventional Activated Sludge

    Asghar Ebrahimi

    2011-03-01

    Full Text Available Linear Alkyl Benzene Sulphonate Acids (LAS are one of the anionic surfactants that are produced and used in large quantities in different countries and find their way into the natural environment through sewer systems. These compounds may potentially cause environmental hazards in such surface waters as rivers. It is, therefore, necessary to remove as much of these compounds as possible by biological processes in wastewater treatment plants. For this purpose, four parallel biological reactors were constructed that used the conventional activated sludge and aeration tanks with fixed bed on the bench scale in order to evaluate the removal efficiency of LAS. The reactors were operated under conditions similar to domestic wastewater treatment plants. Parameters of interest were measured according to standard methods and ANOVA and T-test were used for the statistical analysis of the data. The results showed that aeration tanks with fixed beds yielded higher values of LAS and COD removal and air consumption compared to the conventional activated sludge system. It was shown that the two systems studied achieved LAS removal efficiencies of 96% and 94% for an influent LAS concentration of 5 mg/L. Further, it was found that the effluents from both systems satisfied water quality standards for discharge into surface waters (

  20. Low-temperature (10°C) anaerobic digestion of dilute dairy wastewater in an EGSB bioreactor: microbial community structure, population dynamics, and kinetics of methanogenic populations.

    Bialek, Katarzyna; Cysneiros, Denise; O'Flaherty, Vincent

    2013-01-01

    The feasibility of anaerobic digestion of dairy wastewater at 10°C was investigated in a high height : diameter ratio EGSB reactor. Stable performance was observed at an applied organic loading rate (OLR) of 0.5-2 kg COD m(-3) d(-1) with chemical oxygen demand (COD) removal efficiencies above 85%. When applied OLR increased to values above 2 kg COD m(-3) d(-1), biotreatment efficiency deteriorated, with methanogenesis being the rate-limiting step. The bioreactor recovered quickly (3 days) after reduction of the OLR. qPCR results showed a reduction in the abundance of hydrogenotrophic methanogenic Methanomicrobiales and Methanobacteriales throughout the steady state period followed by a sharp increase in their numbers (111-fold) after the load shock. Specific methanogenic activity and maximum substrate utilising rate (A(max)) of the biomass at the end of trial indicated increased activity and preference towards hydrogenotrophic methanogenesis, which correlated well with the increased abundance of hydrogenotrophic methanogens. Acetoclastic Methanosaeta spp. remained at stable levels throughout the trial. However, increased apparent half-saturation constant (K(m)) at the end of the trial indicated a decrease in the specific substrate affinity for acetate of the sludge, suggesting that Methanosaeta spp., which have high substrate affinity, started to be outcompeted in the reactor.

  1. Low-Temperature (10°C Anaerobic Digestion of Dilute Dairy Wastewater in an EGSB Bioreactor: Microbial Community Structure, Population Dynamics, and Kinetics of Methanogenic Populations

    Katarzyna Bialek

    2013-01-01

    Full Text Available The feasibility of anaerobic digestion of dairy wastewater at 10°C was investigated in a high height : diameter ratio EGSB reactor. Stable performance was observed at an applied organic loading rate (OLR of 0.5–2 kg COD m−3 d−1 with chemical oxygen demand (COD removal efficiencies above 85%. When applied OLR increased to values above 2 kg COD m−3 d−1, biotreatment efficiency deteriorated, with methanogenesis being the rate-limiting step. The bioreactor recovered quickly (3 days after reduction of the OLR. qPCR results showed a reduction in the abundance of hydrogenotrophic methanogenic Methanomicrobiales and Methanobacteriales throughout the steady state period followed by a sharp increase in their numbers (111-fold after the load shock. Specific methanogenic activity and maximum substrate utilising rate (Amax of the biomass at the end of trial indicated increased activity and preference towards hydrogenotrophic methanogenesis, which correlated well with the increased abundance of hydrogenotrophic methanogens. Acetoclastic Methanosaeta spp. remained at stable levels throughout the trial. However, increased apparent half-saturation constant (Km at the end of the trial indicated a decrease in the specific substrate affinity for acetate of the sludge, suggesting that Methanosaeta spp., which have high substrate affinity, started to be outcompeted in the reactor.

  2. Formation of metabolites during biodegradation of linear alkylbenzene sulfonate in an upflow anaerobic sludge bed reactor under thermophilic conditions

    Mogensen, Anders Skibsted; Ahring, Birgitte Kiær

    2002-01-01

    Biodegradation of linear alkylbenzene sulfonate (LAS) was shown in an upflow anaerobic sludge blanket reactor under thermophilic conditions. The reactor was inoculated with granular biomass and fed with a synthetic medium and 3 mumol/L of a mixture of LAS with alkylchain length of 10 to 13 carbon...

  3. A Downflow Hanging Sponge (DHS) reactor for faecal coliform removal from an Upflow Anaerobic Sludge Bed (UASB) effluent

    Yaya Beas, R.E.; Kujawa-Roeleveld, K.; Lier, van J.B.; Zeeman, G.

    2015-01-01

    This research was conducted to study the faecal coliforms removal capacity of Downflow Hanging Sponge (DHS) reactors as a post-treatment for an Upflow Anaerobic Sludge Blanket (UASB) reactor. Three long-term continuous lab-scale DHS reactors i.e. a reactor with cube type sponges without

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

    Banihani, Qais H; Field, Jim A

    2013-01-01

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

  5. The behaviour of ashes and heavy metals during the co-combustion of sewage sludges in a fluidised bed

    Lopes, M.H.; Abelha, P.; Lapa, N.; Oliveira, J.S.; Cabrita, I.; Gulyurtlu, I. [INETI, Lisbon (Portugal)

    2003-07-01

    Co-combustion tests of dry sewage sludges with coal were performed in a pilot bubbling FBC with the aim of characterizating the ashes and determining the behaviour of heavy metals in the process. The tests showed compliance with the regulatory levels as far as heavy metal emissions were concerned. The bottom ashes, which accounted for about 70% of the total ash production, were obtained in a granular form, with diameters ranging from 0.5 to 4 mm. The heavy metals were distributed in ashes obtained from different locations of the installation and their concentrations were found to vary depending on the location of capture. The increase in heavy metals content in bottom ashes was not found to lead to higher leachability and ecotoxicity compared to sewage sludges. Mercury suffered vaporisation inside the reactor, thus leaving bottom ashes free of contamination by it. However, there was observed a strong retention of mercury in cyclone ashes due to the presence of unburned carbon which probably acted as an adsorbent. The effluent mercury was also found to be mostly associated with the particulate fraction, being less than 20% emitted in gaseous forms. The results suggested that the combustion of the sewage sludge could successfully be carried out and the amount of unburned carbon leaving the combustor but captured in cyclone was large enough to ensure substantial retention of mercury at low temperatures, hence could contribute to an improvement of the mercury release which still remains an issue of great concern to resolve during combustion of waste materials.

  6. The behavior of ashes and heavy metals during the co-combustion of sewage sludges in a fluidised bed

    Lopes, Helena M.; Abelha, P.; Cabrita, I. [INETI-DEECA, Lisboa (Portugal); Lapa, N.; Oliveira, J.S. [UNL-Ubia, Monte de Caparica (Portugal)

    2003-07-01

    Co-combustion tests of dry sewage sludges with coal were performed in a pilot bubbling FRC aiming at the characterization of ashes and determining the behaviour of heavy metals in the process. The tests showed compliance with the regulatory levels as far as heavy metal emissions were concerned. The bottom ashes, which accounted for about 70% of the total ash production, were obtained in a granular form, with diameters ranging from 0.5 to 4 mm. The heavy metals were distributed in ashes obtained from different locations of the installation and their concentrations were found to vary depending on the location of capture. The increase in heavy metals content in bottom ashes was not found to lead to higher leachability and ecotoxicity compared to sewage sludges, suggesting that there could be opportunities for their reactor further use. Mercury suffered vaporisation inside the reactor, thus leaving bottom ashes free of contamination by it. However, there was observed a strong retention of mercury in cyclone ashes due to the presence of unburned carbon which probably acted as an adsorbent. The effluent mercury was also found to be mostly associated with the particulate fraction, being less than 20% emitted in gaseous forms. The results suggested that the combustion of the sewage sludge could successfully be carried out, and the amount of unburned carbon leaving the combustor but captured in the cyclone was large enough to ensure substantial retention of mercury at low temperatures, and, hence, could contribute to an improvement of the mercury release, which still remains an issue of great concern to resolve during combustion of waste materials.

  7. The behaviour of ashes and heavy metals during the co-combustion of sewage sludges in a fluidised bed.

    Helena Lopes, M; Abelha, P; Lapa, N; Oliveira, J S; Cabrita, I; Gulyurtlu, I

    2003-01-01

    Co-combustion tests of dry sewage sludges with coal were performed in a pilot bubbling FBC aiming at the characterization of ashes and determining the behaviour of heavy metals in the process. The tests showed compliance with the regulatory levels as far as heavy metal emissions were concerned. The bottom ashes, which accounted for about 70% of the total ash production, were obtained in a granular form, with diameters ranging from 0.5 to 4 mm. The heavy metals were distributed in ashes obtained from different locations of the installation and their concentrations were found to vary depending on the location of capture. The increase in heavy metals content in bottom ashes was not found to lead to higher leachability and ecotoxicity compared to sewage sludges, suggesting that there could be opportunities for their further use. Mercury suffered vaporisation inside the reactor, thus leaving bottom ashes free of contamination by it. However, there was observed a strong retention of mercury in cyclone ashes due to the presence of unburned carbon which probably acted as an adsorbent. The effluent mercury was also found to be mostly associated with the particulate fraction, being less than 20% emitted in gaseous forms. The results suggested that the combustion of the sewage sludge could successfully be carried out and the amount of unburned carbon leaving the combustor but captured in cyclone was large enough to ensure substantial retention of mercury at low temperatures, hence could contribute to an improvement of the mercury release which still remains an issue of great concern to resolve during combustion of waste materials.

  8. The behaviour of ashes and heavy metals during the co-combustion of sewage sludges in a fluidised bed

    Helena Lopes, M.; Abelha, P.; Lapa, N.; Oliveira, J.S.; Cabrita, I.; Gulyurtlu, I.

    2003-01-01

    Co-combustion tests of dry sewage sludges with coal were performed in a pilot bubbling FBC aiming at the characterization of ashes and determining the behaviour of heavy metals in the process. The tests showed compliance with the regulatory levels as far as heavy metal emissions were concerned. The bottom ashes, which accounted for about 70% of the total ash production, were obtained in a granular form, with diameters ranging from 0.5 to 4 mm. The heavy metals were distributed in ashes obtained from different locations of the installation and their concentrations were found to vary depending on the location of capture. The increase in heavy metals content in bottom ashes was not found to lead to higher leachability and ecotoxicity compared to sewage sludges, suggesting that there could be opportunities for their further use. Mercury suffered vaporisation inside the reactor, thus leaving bottom ashes free of contamination by it. However, there was observed a strong retention of mercury in cyclone ashes due to the presence of unburned carbon which probably acted as an adsorbent. The effluent mercury was also found to be mostly associated with the particulate fraction, being less than 20% emitted in gaseous forms. The results suggested that the combustion of the sewage sludge could successfully be carried out and the amount of unburned carbon leaving the combustor but captured in cyclone was large enough to ensure substantial retention of mercury at low temperatures, hence could contribute to an improvement of the mercury release which still remains an issue of great concern to resolve during combustion of waste materials

  9. Sludge combustion in fluidized bed reactors at laboratory scale; Esperienze di combustione di fanghi in reattori a letto fluido in scala di laboratorio

    Chirone, R.; Cammarota, A. [Consiglio Nazionale delle Ricerche, Istituto di Ricerche sulla Combustione, Naples (Italy)

    2001-03-01

    The combustion of a dried sewage sludge in laboratory scale fluidized bed has been studied in Naples by the Istituto di ricerche sulla combustione (Irc) in the framework of a National project named Thermal Process with Energy Recovery to be used in laboratory and pre-pilot scale apparatus. The attention has been focused on emissions of unreacted carbon as elutriated fines, on the emissions of pollutant gases and on the assessment of the inventory of fly- and bottom ashes. The combustion behaviour of sewage sludge has been compared with those of a market available Tyre Derived Fuel (TDF) and a biomass from Mediterranean area (Robinia Pseudoacacia) and with that of a South African bituminous coal. Stationary combustion tests were carried out at 850{sup 0} C by feeding particles in the size range 0-1 mm into a bed of silica sand without any sorbent addition. The fluidized bed combustor has been operated, at a superficial gas velocity of 0.4 m/s and different excesses of air ranging between 14 and 98%. Relatively high combustion efficiency, larger than 98.9% has been obtained in experiments carried out with sewage sludge and excess of air larger than 20%. These values, are comparable with those obtained in previously experimental activity carried out under similar operative conditions with a South Africa Bituminous coal (97-98%). It is larger than those obtained by using a Tyre Derived Fuel (89-90%) and the Robinia Pseudoacacia Biomass (93-93%). The relative importance of carbon fines elutriation, CO emissions and volatile bypassing the bed in determining the loss of combustion efficiency has been evaluated for the different fuels tested. [Italian] Il lavoro riporta l'attivita' di ricerca condotta presso l'Istituto di ricerche sulla combustione (Irc-Cnr) nell'ambito del Progetto Processi termici con recupero di energia per lo smaltimento di fanghi e rifiuti speciali, sottoprogetto Combustione in letti fluidi in scala di laboratorio e pre-pilota di

  10. Removal of personal care compounds from sewage sludge in reed bed container (lysimeter) studies - Effects of macrophytes

    Chen, Xijuan; Pauly, Udo; Rehfus, Stefan

    2009-01-01

    as on the bactericide Triclosan. Additionally, the capacity of different macrophytes species to affect the treatment process was examined. Three different macrophyte species were compared: bulrush (Typha latifolia), reed (Phragmites australis) and reed canary grass (Phalaris arundinacea). They were planted...... into containers (lysimeters) with a size of 1 m × 1 m × 1 m which were filled with 20 cm gravel at the bottom and 50 cm sludge on top, into which the macrophytes were planted. During the twelve months experiment reduction of 20-30% for HHCB and AHTN, 70% for Triclosan and 70% for OTNE were determined under...... environmental conditions. The reduction is most likely due to degradation, since volatilization, uptake into plants and leaching are insignificant. No difference between the containers with different macrophyte species or the unplanted containers was observed. Considering the usual operation time of 10 years...

  11. Leito de drenagem: sistema natural para redução de volume de lodo de estação de tratamento de água Draining beds: natural system for sludge volume reduction in the water treatment plant

    Cali Laguna Achon

    2008-03-01

    Full Text Available As Estações de Tratamento de Água (ETAs tem funcionamento semelhante a uma indústria e podem em diversas etapas gerar resíduos que, na maioria das ETAs, são lançados nos corpos d’água sem tratamento. Neste trabalho avaliou-se o desempenho de Leitos de Drenagem, para o desaguamento de lodo, provenientes de ETAs de ciclo completo que empregam sulfato de alumínio e cloreto de polialumínio (PACl, como coagulantes. Analisou-se as características, a drenagem e secagem dos amostras de lodo e característica do drenado. Os Leitos de Drenagem mostraram-se eficientes para desaguamento e redução de volume de lodo de ETA, de forma natural, sem consumo de energia ou adição de produtos químicos. Obteve-se, aos sete dias, reduções da ordem de 87 % em volume para os lodos de PACl e 83 % para o lodo de Sulfato de Alumínio e teor de sólidos totais 28% e 31% respectivamente.In this work the performance of Draining Beds for sludge dewatering was assessed. The sludge was provided from full cycle Water Treatment Plants (WTPs that employ aluminum sulfate and polyaluminium chloride (PACl as coagulants. The characteristics, drainage and drying of samples of sludge and characteristic of drained were analysed. The Draining Beds were shown to be efficient for dewatering and sludge volume reduction in the WTP, in a natural way, without energy consumption or adding of chemical products. On the seventh day, it was possible to obtain reduction around 87% in volume for PACl sludge and 83% for the aluminum sulfate sludge and total solids content of 28 and 31% respectively.

  12. An Exploratory Study on the Pathways of Cr (VI) Reduction in Sulfate-reducing Up-flow Anaerobic Sludge Bed (UASB) Reactor.

    Qian, Jin; Wei, Li; Liu, Rulong; Jiang, Feng; Hao, Xiaodi; Chen, Guang-Hao

    2016-03-29

    Electroplating wastewater contains both Cr (VI) and sulfate. So Cr (VI) removal under sulfate-rich condition is quite complicated. This study mainly investigates the pathways for Cr (VI) removal under biological sulfate-reducing condition in the up-flow anaerobic sludge bed (UASB) reactor. Two potential pathways are found for the removal of Cr (VI). The first one is the sulfidogenesis-induced Cr (VI) reduction pathway (for 90% Cr (VI) removal), in which Cr (VI) is reduced by sulfide generated from biological reduction of sulfate. The second one leads to direct reduction of Cr (VI) which is utilized by bacteria as the electron acceptor (for 10% Cr (VI) removal). Batch test results confirmed that sulfide was oxidized to elemental sulfur instead of sulfate during Cr (VI) reduction. The produced extracellular polymeric substances (EPS) provided protection to the microbes, resulting in effective removal of Cr (VI). Sulfate-reducing bacteria (SRB) genera accounted for 11.1% of the total bacterial community; thus they could be the major organisms mediating the sulfidogenesis-induced reduction of Cr (VI). In addition, chromate-utilizing genera (e.g. Microbacterium) were also detected, which were possibly responsible for the direct reduction of Cr (VI) using organics as the electron donor and Cr (VI) as the electron acceptor.

  13. An Exploratory Study on the Pathways of Cr (VI) Reduction in Sulfate-reducing Up-flow Anaerobic Sludge Bed (UASB) Reactor

    Qian, Jin; Wei, Li; Liu, Rulong; Jiang, Feng; Hao, Xiaodi; Chen, Guang-Hao

    2016-01-01

    Electroplating wastewater contains both Cr (VI) and sulfate. So Cr (VI) removal under sulfate-rich condition is quite complicated. This study mainly investigates the pathways for Cr (VI) removal under biological sulfate-reducing condition in the up-flow anaerobic sludge bed (UASB) reactor. Two potential pathways are found for the removal of Cr (VI). The first one is the sulfidogenesis-induced Cr (VI) reduction pathway (for 90% Cr (VI) removal), in which Cr (VI) is reduced by sulfide generated from biological reduction of sulfate. The second one leads to direct reduction of Cr (VI) which is utilized by bacteria as the electron acceptor (for 10% Cr (VI) removal). Batch test results confirmed that sulfide was oxidized to elemental sulfur instead of sulfate during Cr (VI) reduction. The produced extracellular polymeric substances (EPS) provided protection to the microbes, resulting in effective removal of Cr (VI). Sulfate-reducing bacteria (SRB) genera accounted for 11.1% of the total bacterial community; thus they could be the major organisms mediating the sulfidogenesis-induced reduction of Cr (VI). In addition, chromate-utilizing genera (e.g. Microbacterium) were also detected, which were possibly responsible for the direct reduction of Cr (VI) using organics as the electron donor and Cr (VI) as the electron acceptor. PMID:27021522

  14. An Exploratory Study on the Pathways of Cr (VI) Reduction in Sulfate-reducing Up-flow Anaerobic Sludge Bed (UASB) Reactor

    Qian, Jin; Wei, Li; Liu, Rulong; Jiang, Feng; Hao, Xiaodi; Chen, Guang-Hao

    2016-03-01

    Electroplating wastewater contains both Cr (VI) and sulfate. So Cr (VI) removal under sulfate-rich condition is quite complicated. This study mainly investigates the pathways for Cr (VI) removal under biological sulfate-reducing condition in the up-flow anaerobic sludge bed (UASB) reactor. Two potential pathways are found for the removal of Cr (VI). The first one is the sulfidogenesis-induced Cr (VI) reduction pathway (for 90% Cr (VI) removal), in which Cr (VI) is reduced by sulfide generated from biological reduction of sulfate. The second one leads to direct reduction of Cr (VI) which is utilized by bacteria as the electron acceptor (for 10% Cr (VI) removal). Batch test results confirmed that sulfide was oxidized to elemental sulfur instead of sulfate during Cr (VI) reduction. The produced extracellular polymeric substances (EPS) provided protection to the microbes, resulting in effective removal of Cr (VI). Sulfate-reducing bacteria (SRB) genera accounted for 11.1% of the total bacterial community; thus they could be the major organisms mediating the sulfidogenesis-induced reduction of Cr (VI). In addition, chromate-utilizing genera (e.g. Microbacterium) were also detected, which were possibly responsible for the direct reduction of Cr (VI) using organics as the electron donor and Cr (VI) as the electron acceptor.

  15. Modelagem do processo de desidratação de lodo anaeróbio em leitos de secagem simulados Anaerobic sludge dewatering process modeling in simulated drying beds

    Sérgio R. A. Soares

    2001-05-01

    Full Text Available O emprego de leitos de secagem para a desidratação de lodo de descarte de reatores UASB, constitui excelente alternativa, face a sua simplicidade operacional e aos reduzidos custos de implantação. Este trabalho apresenta uma análise dos fenômenos que influenciam o processo de desidratação de lodo anaeróbio, a partir de simulação de leitos de secagem. Neste sentido, são feitas considerações sobre as características e o comportamento do lodo durante cada fase da secagem. Sugere-se também, um modelo matemático para representar o processo de secagem, obtido a partir dos dados experimentais.The employment of drying beds is an excellent option for dewatering of UASB reactor discarded sludge, because of their simple operation and low construction costs. This paper presents an anaerobic sludge dewatering process analysis of the most influential phenomenon based on drying beds simulation. Therefore, some considerations were made about sludge characteristics and behavior during each dewatering stage. A mathematical model for dewatering process representation obtained from experimental data is also suggested.

  16. Upflow anaerobic sludge blanket-hollow centered packed bed (UASB-HCPB) reactor for thermophilic palm oil mill effluent (POME) treatment

    Poh, P.E.; Chong, M.F.

    2014-01-01

    Upflow anaerobic sludge blanket-hollow centered packed bed (UASB-HCPB) reactor was developed with the aim to minimize operational problems in the anaerobic treatment of Palm Oil Mill Effluent (POME) under thermophilic conditions. The performance of UASB-HCPB reactor on POME treatment was investigated at 55 °C. Subsequent to start-up, the performance of the UASB-HCPB reactor was evaluated in terms of i) effect of hydraulic retention time (HRT); ii) effect of organic loading rate (OLR); and iii) effect of mixed liquor volatile suspended solid (MLVSS) concentration on thermophilic POME treatment. Start-up up of the UASB-HCPB reactor was completed in 36 days, removing 88% COD and 90% BOD respectively at an OLR of 28.12 g L −1  d −1 , producing biogas with 52% of methane. Results from the performance study of the UASB-HCPB reactor on thermophilic POME treatment indicated that HRT of 2 days, OLR of 27.65 g L −1  d −1 and MLVSS concentration of 14.7 g L −1 was required to remove 90% of COD and BOD, 80% of suspended solid and at the same time produce 60% of methane. - Highlights: • UASB-HCPB was proposed for POME treatment under thermophilic conditions. • Start-up up of the UASB-HCPB reactor was completed in 36 days. • 88% COD and 90% BOD were removed at an OLR of 28.12 g COD/L.day during start-up. • HRT of 2 days and OLR of 27.65 g COD/L.day was required to produce 60% methane. • Methanosarcina sp. forms the majority of microbial population in the UASB section

  17. Performance evaluation and microbial community analysis of the function and fate of ammonia in a sulfate-reducing EGSB reactor.

    Wang, Depeng; Liu, Bo; Ding, Xinchun; Sun, Xinbo; Liang, Zi; Sheng, Shixiong; Du, Lingfeng

    2017-10-01

    Ammonia is widely distributed in sulfate-reducing bioreactor dealing with sulfate wastewater, which shows potential effect on the metabolic pathway of sulfate and ammonia. This study investigates the sulfate-reducing efficiency and microbial community composition in the sulfate-reducing EGSB reactor with the increasing ammonia loading. Results indicated that, compared with low ammonia loading (166-666 mg/L), the sulfate and organic matter removal efficiencies were improved gradually with the appropriate ammonia loading (1000-2000 mg/L), which increased from 63.58 ± 3.81 to 71.08 ± 1.36% and from 66.24 ± 1.32 to 81.88 ± 1.83%, respectively. Meanwhile, with the appropriate ratio of ammonia and sulfate (1.5-3.0) and hydraulic retention time (21 h), the sulfate-reducing anaerobic ammonia oxidation (SRAO) process was occurred efficiently, inducing the accumulation of S 0 (270 mg/L) and the simultaneous ammonia removal (70.83%) in EGSB reactor. Moreover, the key sulfate-reducing bacteria (SRB) (Desulfovibrio) and denitrification bacteria (Pseudomonas and Alcaligenes) were responsible for the sulfate and nitrogen removal in these phases, which accounted for 3.66-5.54 and 3.85-9.13%, respectively. However, as the ammonia loading higher than 3000 mg/L (phases 9 and 10), the sulfate-reducing efficiency was decreased to only 28.3 ± 1.26% with the ammonia removal rate of 18.4 ± 3.37% in the EGSB reactor. Meanwhile, the predominant SRB in phases 9 and 10 were Desulfomicrobium (1.22-1.99%) and Desulfocurvus (4.0-5.46%), and the denitrification bacteria accounted for only 0.88% (phase 10), indicating the low nitrogen removal rate.

  18. Biological sulphate reduction with primary sewage sludge in an ...

    The success of the UASB reactor depends largely on the settling properties and stability of the sludge bed which comprises the anaerobic active biomass. The solid-liquid separation behaviour of the sludge bed in 2 UASB reactors (R1 at 35oC and R2 at 20oC) fed with primary sewage sludge and sulphate was investigated ...

  19. Sewage sludge gasification in fluidized bed: influence of temperature and the stoichiometric relation; Gasificacion de fangos de depuradora en lecho fluidizado: influencia de la temperatura y de la relacion estequiometrica

    Manya, J.J.; Gonzalo, A.; Sanchez, J.L.; Arauzo, J. [Universidad de Zaragoza, Aragon (Spain). Inst. de Investigacion en Ingenieria. Grupo de Procesos Termoquimicos; Rocha, J.D. [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Nucleo Interdisciplinar de Planejamento Energetico (NIPE); Mesa Perez, J.M. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Agricola (FEAGRI)

    2004-07-01

    The gasification of a dry granular sewage sludge has been experimentally studied. The gasification was carried out in a bench scale BFB facility, operated at steady state. The attention was focused on the presence of tar in the produced gas which affect the process efficiency and give negative drawbacks in the utilization in motors. The influence of two operating variables (bed temperature and equivalence ratio) on the gasification performances has been explored. Results show that the composition of produced gas is quite dependent of the variables analyzed. However, the results of tar yield show an unexpected behaviour. (author)

  20. Dewaterability of sludge digested in extended aeration plants using ...

    Dewaterability of unconditioned sludge digested in full scale and lab scale experiments using either extended aeration (EA) or anaerobic digestion were compared on full and lab scale sand drying beds. Sludge digested in EA plants resulted in improvement in sludge dewaterability compared to sludge digested ...

  1. Improving EGSB reactor performance for simultaneous bioenergy and organic acid production from cheese whey via continuous biological H2 production.

    Ramos, Lucas Rodrigues; Silva, Edson Luiz

    2017-07-01

    To evaluate the influence of hydraulic retention time (HRT) and cheese whey (CW) substrate concentration (15 and 25 g lactose l -1 ) on the performance of EGSB reactors (R15 and R25, respectively) for H 2 production. A decrease in the HRT from 8 to 4 h favored the H 2 yield and H 2 production rate (HPR) in R15, with maximum values of 0.86 ± 0.11 mmol H 2 g COD -1 and 0.23 ± 0.024 l H 2 h -1 l -1 , respectively. H 2 production in R25 was also favored at a HRT of 4 h, with maximum yield and HPR values of 0.64 ± 0.023 mmol H 2 g COD -1 and 0.31 ± 0.032 l H 2 h -1 l -1 , respectively. The main metabolites produced were butyric, acetic and lactic acids. The EGSB reactor was evaluated as a viable acidogenic step in the two-stage anaerobic treatment of CW for the increase of COD removal efficiency and biomethane production.

  2. Comparative discussion of the activated sludge and packed bed techniques in biological sewage water cleaning; Vergleichende Betrachtung von Belebungs- und Festbettverfahren fuer die biologische Abwasserreinigung

    Kroiss, H [Technische Univ., Vienna (Germany). Inst. fuer Wasserguete und Abfallwirtschaft

    1994-12-31

    It is reasonable to state that, given proper planning, erection and careful operation, both activated sludge plants and packed bed reactors with a biofilm are capable of meeting extremely high demands on the quality of the effluent. What was to be shown is the fact that operating behaviour and demands on measurement and control techniques differ considerably. Rating depends on different criteria, according to the technique chosen, and also cost calculation is largely determined in each case by special local conditions. All this makes it difficult to compare solutions with one another or to transfer experience gathered in one plant to another application. So the choice of the best possible method in a given case remains an interesting task.- One must try to make as objective a comparison as possible of different solutions according to the relevant criteria, beyond what is quantifiable merely in terms of finance.- Any decision taken on the basis of such a comparison is bound to reflect also the values that the decision-makers hold. But it should always be possible when taking decisions about processes to leave ideology out of consideration. (orig.) [Deutsch] Es kann festgestellt werden, dass sowohl Belebungsanlagen wie auch Biofilmreaktoren bei richtiger Planung, Errichtung und sorgfaeltigem Betrieb in der Lage sind, auch extrem hohe Ansprueche an die Ablaufguete zu erfuellen. Was gezeigt werden sollte, ist der Umstand, dass erhebliche Unterschiede im Betriebsverhalten und in den Anforderungen an die Mess- und Regeltechnik bestehen. Fuer die Bemessung sind je nach Verfahren andere Kriterien massgebend, und auch fuer die Kostenrechnung gilt, dass die speziellen oertlichen Bedingung bei jedem Anwendungsfall von ausschlaggebender Bedeutung sind. Das alles hat zur Folge, dass es sehr schwierig ist, verschiedene Loesungsmoeglichkeiten miteinander zur vergleichen, oder die Erfahrung von einer Anlage auf einen anderen Anwendungsfall zu uebertragen. Die Auswahl des ``besten

  3. Low temperature circulating fluidized bed gasification and co-gasification of municipal sewage sludge. Part 2: Evaluation of ash materials as phosphorus fertilizer

    Thomsen, Tobias Pape; Hauggaard-Nielsen, Henrik; Gøbel, Benny

    2017-01-01

    to the mono-sludge ashes, thereby showing the best fertilizer qualities among all assessed materials. It was also found that bottomashes from the char reactor contained even less heavy metals than cyclone ashes. It is concluded thatLT-CFB gasification and co-gasification is a highly effective way to purify...

  4. Microbial Communities and Their Performances in Anaerobic Hybrid Sludge Bed-Fixed Film Reactor for Treatment of Palm Oil Mill Effluent under Various Organic Pollutant Concentrations

    Kanlayanee Meesap

    2012-01-01

    Full Text Available The anaerobic hybrid reactor consisting of sludge and packed zones was operated with organic pollutant loading rates from 6.2 to 8.2 g COD/L day, composed mainly of suspended solids (SS and oil and grease (O&G concentrations between 5.2 to 10.2 and 0.9 to 1.9 g/L, respectively. The overall process performance in terms of chemical oxygen demands (COD, SS, and O&G removals was 73, 63, and 56%, respectively. When the organic pollutant concentrations were increased, the resultant methane potentials were higher, and the methane yield increased to 0.30 L CH4/g CODremoved. It was observed these effects on the microbial population and activity in the sludge and packed zones. The eubacterial population and activity in the sludge zone increased to 6.4 × 109 copies rDNA/g VSS and 1.65 g COD/g VSS day, respectively, whereas those in the packed zone were lower. The predominant hydrolytic and fermentative bacteria were Pseudomonas, Clostridium, and Bacteroidetes. In addition, the archaeal population and activity in the packed zone were increased from to 9.1 × 107 copies rDNA/g VSS and 0.34 g COD-CH4/g VSS day, respectively, whereas those in the sludge zone were not much changed. The most represented species of methanogens were the acetoclastic Methanosaeta, the hydrogenotrophic Methanobacterium sp., and the hydrogenotrophic Methanomicrobiaceae.

  5. Biological sulphate reduction with primary sewage sludge in an ...

    2009-07-31

    Jul 31, 2009 ... The success of the UASB reactor depends largely on the settling properties and stability of the sludge bed which comprises the anaerobic active biomass. The solid-liquid separation behaviour of the sludge bed in 2 UASB reactors (R1 at 35oC and. R2 at 20oC) fed with primary sewage sludge and sulphate ...

  6. Effects of combustion temperature on air emissions and support fuel consumption in full scale fluidized bed sludge incineration: with particular focus on nitrogen oxides and total organic carbon.

    Löschau, Margit

    2018-04-01

    This article describes a pilot test at a sewage sludge incineration plant and shows its results considering the impacts of reducing the minimum combustion temperature from 850°C to 800°C. The lowering leads to an actual reduction of the average combustion temperature by 25 K and a significant reduction in the fuel oil consumption for support firing. The test shall be used for providing evidence that the changed combustion conditions do not result in higher air pollutant emissions. The analysis focusses on the effects of the combustion temperature on nitrogen oxides (NO x ) and total organic carbon emissions. The evaluation of all continuously monitored emissions shows reduced emission levels compared to the previous years, especially for NO x .

  7. A biodegradation and treatment of palm oil mill effluent (POME) using a hybrid up-flow anaerobic sludge bed (HUASB) Reactor

    Habeeb, S.A.; Latiff, AB. Aziz Abdul; Daud, Zawawi; Ahmad, Zulkifli [Faculty of Civil and Enviromental Engineering, University Tun Hussein Onn (Malaysia)

    2011-07-01

    Generally, anaerobic treatment has become a viable alternative in support of industrial wastewater treatment. Particularly, it is used in common to treat the palm oil mill effluent (POME). This study was carried out to assess the start-up performance of a bioreactor hybrid up-flow anaerobic sludge blanket (HUASB). Whereby, three identical reactors of 7.85-l capacity R1, R2, and R3 were operated for 57 days in order to provide two alienated comparisons. Identical operation conditions of organic loading rate (OLR) and hydraulic retention time (HRT) of 1.85 kg.m-3.day-1, and 2.6 day, respectively. R1 was operated in room temperature of 28{+-}2 C, and packed with palm oil shell as filter medium support. R2 was set with room temperature but packed with course gravel. R3 was provided with water bath system to adjust its temperature at 37{+-}1 C mesophilic, while its filter material had to be palm oil shell. During the whole operation period R3 was more efficient for organic materials, where a chemical oxygen demand (COD) removal efficiency of 82% was registered, while R1 and R2 were relatively less efficient of 78%, and 76%, respectively. Furthermore, TSS removal of R3 was also higher than R1, and R2 as registered 80%, 77% and 76%, respectively. On the other hand, turbidity and colour removal were not efficient and needed a post treatment. The seeded sludge was developed in each reactor as illustrated in this paper. Therefore, all reactors show favorable performance of anaerobic treatability of POME as well as good response of microbial species development.

  8. Sewage sludge as a biomass energy source

    Pavel Kolat

    2013-01-01

    Full Text Available The major part of the dry matter content of sewage sludge consists of nontoxic organic compounds, in general a combination of primary sludge and secondary microbiological sludge. The sludge also contains a substantive amount of inorganic material and a small amount of toxic components. There are many sludge-management options in which production of energy is one of the key treatment steps. The most important options are anaerobic digestion, co-digestion, incineration in combination with energy recovery and co-incineration in coal-fired power plants. The goal of our applied research is to verify, if the sludge from waste water treatment plants may be used as a biomass energy source in respect of the EU legislation, which would comply with emission limits or the proposal of energy process optimizing the preparation of coal/sludge mixture for combustion in the existing fluid bed boilers in the Czech Republic. The paper discusses the questions of thermal usage of mechanically drained stabilized sewage sludge from the waste water treatment plants in the boiler with circulated fluid layer. The paper describes methods of thermal analysis of coal, sewage sludge and its mixtures, mud transport to the circulating fluidised bed boiler, effects on efficiency, operational reliability of the combustion equipment, emissions and solid combustion residues.

  9. Low-Temperature (10?C) Anaerobic Digestion of Dilute Dairy Wastewater in an EGSB Bioreactor: Microbial Community Structure, Population Dynamics, and Kinetics of Methanogenic Populations

    Bialek, Katarzyna; Cysneiros, Denise; O'Flaherty, Vincent

    2013-01-01

    The feasibility of anaerobic digestion of dairy wastewater at 10?C was investigated in a high height?:?diameter ratio EGSB reactor. Stable performance was observed at an applied organic loading rate (OLR) of 0.5?2?kg?COD?m?3?d?1 with chemical oxygen demand (COD) removal efficiencies above 85%. When applied OLR increased to values above 2?kg?COD?m?3?d?1, biotreatment efficiency deteriorated, with methanogenesis being the rate-limiting step. The bioreactor recovered quickly (3 days) after reduc...

  10. Phenotypic properties and microbial diversity of methanogenic granules from a full-scale upflow anaerobic sludge bed reactor treating brewery wastewater.

    Díaz, Emiliano E; Stams, Alfons J M; Amils, Ricardo; Sanz, José L

    2006-07-01

    Methanogenic granules from an anaerobic bioreactor that treated wastewater of a beer brewery consisted of different morphological types of granules. In this study, the microbial compositions of the different granules were analyzed by molecular microbiological techniques: cloning, denaturing gradient gel electrophoresis and fluorescent in situ hybridization (FISH), and scanning and transmission electron microscopy. We propose here that the different types of granules reflect the different stages in the life cycle of granules. Young granules were small, black, and compact and harbored active cells. Gray granules were the most abundant granules. These granules have a multilayer structure with channels and void areas. The core was composed of dead or starving cells with low activity. The brown granules, which were the largest granules, showed a loose and amorphous structure with big channels that resulted in fractured zones and corresponded to the older granules. Firmicutes (as determined by FISH) and Nitrospira and Deferribacteres (as determined by cloning and sequencing) were the predominant Bacteria. Remarkably, Firmicutes could not be detected in the brown granules. The methanogenic Archaea identified were Methanosaeta concilii (70 to 90% by FISH and cloning), Methanosarcina mazei, and Methanospirillum spp. The phenotypic appearance of the granules reflected the physiological condition of the granules. This may be valuable to easily select appropriate seed sludges to start up other reactors.

  11. Comparison of biomass from integrated fixed-film activated sludge (IFAS), moving bed biofilm reactor (MBBR) and membrane bioreactor (MBR) treating recalcitrant organics: Importance of attached biomass.

    Huang, Chunkai; Shi, Yijing; Xue, Jinkai; Zhang, Yanyan; Gamal El-Din, Mohamed; Liu, Yang

    2017-03-15

    This study compared microbial characteristics and oil sands process-affected water (OSPW) treatment performance of five types of microbial biomass (MBBR-biofilm, IFAS-biofilm, IFAS-floc, MBR-aerobic-floc, and MBR-anoxic-floc) cultivated from three types of bioreactors (MBBR, IFAS, and MBR) in batch experiments. Chemical oxygen demand (COD), ammonium, acid extractable fraction (AEF), and naphthenic acids (NAs) removals efficiencies were distinctly different between suspended and attached bacterial aggregates and between aerobic and anoxic suspended flocs. MBR-aerobic-floc and MBR-anoxic-floc demonstrated COD removal efficiencies higher than microbial aggregates obtained from MBBR and IFAS, MBBR and IFAS biofilm had higher AEF removal efficiencies than those obtained using flocs. MBBR-biofilm demonstrated the most efficient NAs removal from OSPW. NAs degradation efficiency was highly dependent on the carbon number and NA cyclization number according to UPLC/HRMS analysis. Mono- and di-oxidized NAs were the dominant oxy-NA species in OSPW samples. Microbial analysis with quantitative polymerase chain reaction (q-PCR) indicated that the bacterial 16S rRNA gene abundance was significantly higher in the batch bioreactors with suspended flocs than in those with biofilm, the NSR gene abundance in the MBR-anoxic bioreactor was significantly lower than that in aerobic batch bioreactors, and denitrifiers were more abundant in the suspended phase of the activated sludge flocs. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Sewage sludge and how to sell it

    Knapp, I M

    1977-10-01

    Largo, Florida dries its sludge and sells it as fertilizer for $80 to $169/T. The sludge processing plant capable of turning common sludge into a dry, pelletized soil conditioner was only slightly more expensive than the previously proposed concrete drying beds which would have required disposal of the dried residue. The city's experience in setting up the plant and marketing the finished product is discussed. The true advantage of selling heat-dried sludge is that residents of the surrounding area, knowing the value of the product to their lawns and shrubs, will provide the transportation for the product and the physical labor to spread it over an area wider than most municipalities could afford to own or operate. The current production cost of $140/T is high, but the addition of a sludge prethickener-conditioner process and expected future economies of scale as the volume of sludge treated increases should lower per ton costs.

  13. The exploitation of swamp plants for dewatering liquid sewage sludge

    Jiří Šálek

    2006-01-01

    Full Text Available The operators of little rural wastewater treatment plants have been interested in economic exploitation of sewage sludge in local conditions. The chance is searching simply and natural ways of processing and exploitation stabilized sewage sludge in agriculture. Manure substrate have been obtained by composting waterless sewage sludge including rest plant biomass after closing 6–8 years period of filling liquid sewage sludge to the basin. Main attention was focused on exploitation of swamp plants for dewatering liquid sewage sludge and determination of influence sewage sludge on plants, intensity and course of evapotranspiration and design and setting of drying beds. On the base of determined ability of swamp plants evapotranspiration were edited suggestion solutions of design and operation sludge bed facilities in the conditions of small rural wastewater treatment plant.

  14. Stability and activity of anaerobic sludge from UASB reactors treating sewage in subtropical regions

    Seghezzo, L.; Cuevas, C.M.; Trupiano, A.P.; Guerra, R.G.; Gonzalez, S.M.; Zeeman, G.; Lettinga, G.

    2006-01-01

    The production of small amounts of well-stabilized biological sludge is one of the main advantages of upflow anaerobic sludge bed (UASB) reactors over aerobic wastewater treatment systems. In this work, sludge produced in three pilot-scale UASB reactors used to treat sewage under subtropical

  15. Deep Sludge Gas Release Event Analytical Evaluation

    Sams, Terry L.

    2013-01-01

    Long Abstract. Full Text. The purpose of the Deep Sludge Gas Release Event Analytical Evaluation (DSGRE-AE) is to evaluate the postulated hypothesis that a hydrogen GRE may occur in Hanford tanks containing waste sludges at levels greater than previously experienced. There is a need to understand gas retention and release hazards in sludge beds which are 200 -300 inches deep. These sludge beds are deeper than historical Hanford sludge waste beds, and are created when waste is retrieved from older single-shell tanks (SST) and transferred to newer double-shell tanks (DST).Retrieval of waste from SSTs reduces the risk to the environment from leakage or potential leakage of waste into the ground from these tanks. However, the possibility of an energetic event (flammable gas accident) in the retrieval receiver DST is worse than slow leakage. Lines of inquiry, therefore, are (1) can sludge waste be stored safely in deep beds; (2) can gas release events (GRE) be prevented by periodically degassing the sludge (e.g., mixer pump); or (3) does the retrieval strategy need to be altered to limit sludge bed height by retrieving into additional DSTs? The scope of this effort is to provide expert advice on whether or not to move forward with the generation of deep beds of sludge through retrieval of C-Farm tanks. Evaluation of possible mitigation methods (e.g., using mixer pumps to release gas, retrieving into an additional DST) are being evaluated by a second team and are not discussed in this report. While available data and engineering judgment indicate that increased gas retention (retained gas fraction) in DST sludge at depths resulting from the completion of SST 241-C Tank Farm retrievals is not expected and, even if gas releases were to occur, they would be small and local, a positive USQ was declared (Occurrence Report EM-RP--WRPS-TANKFARM-2012-0014, 'Potential Exists for a Large Spontaneous Gas Release Event in Deep Settled Waste Sludge'). The purpose of this technical

  16. Bed Bugs

    Prevent, identify, and treat bed bug infestations using EPA’s step-by-step guides, based on IPM principles. Find pesticides approved for bed bug control, check out the information clearinghouse, and dispel bed bug myths.

  17. Combustion of mixed fuels (lignite and sewage sludge) in a pilot model of a circulated fluidized bed - a contribution to the waste disposal and to a combustion with low emissions. Final report; Verbrennung von Mischbrennstoffen (Braunkohle und Klaerschlamm) in einer zirkulierenden Wirbelschichtfeuerung - ein Beitrag zur Abfallentsorgung und zu einer schadstoffarmen Verbrennung. Abschlussbericht

    Bernstein, W.; Brunne, T.; Girndt, H.; Richter, B.; Kaplonek, M.

    1997-04-01

    Mixed fuels based on dried lignite and sewage sludge were burned in a pilot model with circulated fluidized bed technology. The part of sewage sludge has been varied in the fuel, the different reaction and emission conditions were investigated. In the report were laid emphasis on the primary influence of the waste gas components (CO, NO{sub x}, N{sub 2}O). The author started first searchs to the ash composition and to where about of the heavy metals. In the report are recommendation for the industriel effective combustion with low emissions with sewage sludge/lignite mixded fuel. (orig.) [Deutsch] In einer Pilotanlage mit zirkulierender Wirbelschichtfeuerung wurden unterschiedliche Brennstoffgemsiche aus Trockenbraunkohle und Klaerschlamm verbrannt. Die Anteile am Klaerschlamm wurden variiert und die sich aendernden Reaktions- und Emissionsverhaeltnisse aufgenommen. Schwerpunkt dieser Arbeit war die primaere Beeinflussung der Gasschadstoffe (CO, NO{sub x}, N{sub 2}O). Erste Untersuchungen zur Aschenzusammensetzung und zum Verbleib der Schwermetalle wurden vorgenommen. Empfehlungen fuer die grosstechnische, effektive, schadstoffarme Verbrennung von Klaerschlamm/Braunkohle-Gemischen wurden erarbeitet. (orig.)

  18. Sludge busters

    Pichon, Max

    2010-01-01

    Full text: A few years ago, For Earth developed low energy sub-surface aeration systems to increase the biological activity in the wastewater sludge ponds. Then came the idea to introduce probiotic bacteria to really ramp up the process, which promises massive time and cost savings in sludge management. Increasing the volumes of specific bacteria reactivates the sludge, accelerating biological nutrient removal in general and, by tailoring the bacteria, targeting specific organic waste types. The technology is already running at more than 30 councils across NSW and in some commercial settings, such as dairy farms. Shane McKibbin, GM of For Earth, said the 'Probiotic, Low Energy Aeration System' offers considerable upside. “The cost savings have been enormous with some councils, including the work done at Woolgoolga Water Reclamation Plant at Coffs Harbour,” he said. Sludge settling in wastewater treatment plant lagoons is typically pumped out, centrifuged to remove water and then landfilled. In Woolgoolga's case that process was costing Coffs Harbour Water $150 a cubic metre; McKibbin said they've slashed that to a measly $5 a cubic metre. An array of 'industrial air stones' is dropped 1m below the surface to create an oxygenated blanket across the surface, overcoming the tendency of sludge ponds to stagnate. The key though is floating probiotic dosing lines across the surface, which kick-starts the probiotics process. “Previously, some operators just wanted to throw it on with a bucket, so the bacteria would get thrown into one corner of the pond. But since we introduced the dosing system it has really improved the overall performance,” said McKibbin.The dosing pump system automatically applies the bacteria into the dosing line according to a specified program, ensuring the probiotics are spread out across the pond and across the week. “I would say it improves and accelerates the result by 30 per cent,” he adds. “The biggest problem was that

  19. Sludge busters

    Pichon, Max

    2010-07-15

    Full text: A few years ago, For Earth developed low energy sub-surface aeration systems to increase the biological activity in the wastewater sludge ponds. Then came the idea to introduce probiotic bacteria to really ramp up the process, which promises massive time and cost savings in sludge management. Increasing the volumes of specific bacteria reactivates the sludge, accelerating biological nutrient removal in general and, by tailoring the bacteria, targeting specific organic waste types. The technology is already running at more than 30 councils across NSW and in some commercial settings, such as dairy farms. Shane McKibbin, GM of For Earth, said the 'Probiotic, Low Energy Aeration System' offers considerable upside. “The cost savings have been enormous with some councils, including the work done at Woolgoolga Water Reclamation Plant at Coffs Harbour,” he said. Sludge settling in wastewater treatment plant lagoons is typically pumped out, centrifuged to remove water and then landfilled. In Woolgoolga's case that process was costing Coffs Harbour Water $150 a cubic metre; McKibbin said they've slashed that to a measly $5 a cubic metre. An array of 'industrial air stones' is dropped 1m below the surface to create an oxygenated blanket across the surface, overcoming the tendency of sludge ponds to stagnate. The key though is floating probiotic dosing lines across the surface, which kick-starts the probiotics process. “Previously, some operators just wanted to throw it on with a bucket, so the bacteria would get thrown into one corner of the pond. But since we introduced the dosing system it has really improved the overall performance,” said McKibbin.The dosing pump system automatically applies the bacteria into the dosing line according to a specified program, ensuring the probiotics are spread out across the pond and across the week. “I would say it improves and accelerates the result by 30 per cent,” he adds. “The biggest problem was that

  20. Development and Design of Sludge Freezing Beds

    1988-12-01

    Wastewater Treatment/Disposal/Reuse. New York: McGraw Hill, 2nd ed. Morin, W., R. Lewandowski and R. Zaloum (1986) Le traitement des boues a l’aide du gel...degel naturel et epandage des boues en foret. Draft report for Environment Canada, Mon- treal. National Oceanic and Atmospheric Administration (1984

  1. Anaerobic digestion of cheese whey using an upflow anaerobic sludge blanket reactor: Pt. 3; Sludge and substrate profiles

    Yan, J.Q.; Lo, K.V.; Liao, P.H. (British Columbia Univ., Vancouver (CA). Dept. of Bio-Resource Engineering)

    1990-01-01

    Anaerobic treatment of cheese whey using a 17.5 litre upflow anaerobic sludge blanket reactor was investigated in the laboratory over a range of influent concentration from 4.5 to 38.1 g COD litre{sup -1} at a constant hydraulic retention time of 5 days. The results indicated that two sludge distribution regions, a sludge bed and a sludge blanket, as well as two distinct reaction phases, acidogenic and methanogenic, were formed. However, as the substrate loading was increased, the acidogenic region extended into the methanogenic region in the upper portion of the reactor until the whole region was acidogenic, leading to the failure of the reactor. (author).

  2. Application of semifluidized bed bioreactor as novel bioreactor ...

    The conventional bioreactors such as pond digester, anaerobic filtration, up-flow anaerobic sludge blanket (UASB), up-flow anaerobic sludge fixed-film (UASFF), continuous stirred tank reactor (CSTR), anaerobic contact digestion and fluidized bed, used over the past decades are largely operated anaerobically. They have ...

  3. Sludge recovery apparatus

    Marmo, A.R.

    1979-01-01

    Sludge recovery machine comprising a hollow centrifuge, a vertical pipe for feeding in a liquid containing sludge and a sliding rake pressing against the internal wall of the centrifuge to dislodge and move the sludge, a power drive for spinning the centrifuge at high speed and a rotating drying table to take the sludge and dry it [fr

  4. Removal of mercury from sludge using ion exchange

    Bibler, J.P.; Wallace, R.M.

    1984-01-01

    Laboratory scale batch tests and fluidized bed column tests show that ES-465 cation exchange resin removes >90% of the mercury from formated simulated sludge and formated high-level radioactive sludge. Similar experiments using formated simulated sludge which has been steam stripped indicated that the resin is capable of removing about 75% of the mercury from that system in the same time 90% could be removed from sludge which has not been steam stripped. The percent removed can be improved by operating at higher temperatures. Early batch experiments showed that abrasion from vigorous stirring of the sludge/ES-465 mixture caused the resin to degrade into particles too small to separate from the slurry after reaction. To protect the resin from abrasion, a resin-in-sludge mode of operation was designed wherein the sludge slurry contacts the resin by flowing through a bed retained between two screens in a column. The process has been demonstrated using both a 0.5 in. internal 0.5 in. diameter upflow column containing two milliliters of resin and a 6.4 in. internal diameter stirred bed downflow column containing one liter of resin

  5. Sludge granulation during anaerobic treatment of pre-hydrolysed ...

    An upflow anaerobic sludge bed (UASB) digester was operated at different hydraulic retention times (HRT) ranging from 26.7 h to 2.2 h, while the organic load rate (OLR) ranged from 0.9 to 7.3 kgCOD/m3·d. Sludge granulation was observed after day 150 of operation, at an HRT of 3.4 h, when small granules of less than 2 ...

  6. The effect of bioleaching on sewage sludge pyrolysis.

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

    2016-02-01

    The effects of bioleaching on sewage sludge pyrolysis were studied. Sewage sludge was treated by bioleaching with solid concentrations of 6% (w/v), 8% (w/v), 10% (w/v). Results showed that bioleaching treatment could modify the physicochemical properties of sewage sludge and enhance the metals removal. The optimum removal efficiencies of heavy metals were achieved with solid concentration of 6% (w/v) bioleaching treatment: Cu, 73.08%; Zn, 78.67%; Pb, 24.65%; Cd, 79.46%. The characterization results of thermogravimetric analysis (TGA) showed that the bioleached sewage sludge with a 6% (w/v) solid concentration treatment was the easiest to decompose. Pyrolytic experiments of bioleached sewage sludge were performed in a laboratory-scale fixed bed reactor. Results indicated that bioleaching treatment greatly influenced the product yields and gas composition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Radioactivity partitioning of oil sludge undergoing incineration process

    Muhamat Omar; Suhaimi Hamzah; Muhd Noor Muhd Yunus

    1997-01-01

    Oil sludge waste is a controlled item under the Atomic Energy Act (Act 304) 1984 of which the radioactivity content shall be subjected to analysis. Apart from that the treatment method also shall be approved by Atomic Energy Licensing Board (AELB). Thus, an analysis of the oil sludge for MSE fluidized incinerator was conducted to comply with above requirements using various techniques. Further screening analysis of fly ash as well as bed material were done to study the effect of incinerating the sludge. This paper highlights the analysis techniques and discusses the results with respect to the radioactivity level and the fate of radionuclides subjected to the processing of the waste

  8. Mitigation of micropollutants for black water application in agriculture via composting of anaerobic sludge

    Butkovskyi, A.; Ni, G.; Hernandez Leal, L.; Rijnaarts, H.H.M.; Zeeman, G.

    2016-01-01

    The excess sludge from Up-flow anaerobic sludge bed (UASB) reactor operated on source separated toilet wastewater is a potential source of nutrients and organic matter. It can be further stabilized and dried by composting and applied as a soil amendment. Presence of pathogens, heavy metals and

  9. Role of nickel in high rate methanol degradation in anaerobic granular sludge bioreactors

    Fermoso, F.G.; Collins, G.; Bartacek, J.; O'Flaherty, V.; Lens, P.N.L.

    2008-01-01

    The effect of nickel deprivation from the influent of a mesophilic (30 degrees C) methanol fed upflow anaerobic sludge bed (UASB) reactor was investigated by coupling the reactor performance to the evolution of the Methanosarcina population of the bioreactor sludge. The reactor was operated at pH

  10. Acclimatization of anaerobic sludge for UASB-reactor start-up

    Zeeuw, de W.J.

    1984-01-01

    The Upflow Anaerobic Sludge Bed (UASB) reactor represents a high rate anaerobic wastewater treatment system. The majority of the active biomass in the reactor is present in the form of sludge granules which possess excellent settling properties.
    If no acclimatized (granular)

  11. Two strategies for phosphorus removal from reject water of municipal wastewater treatment plant using alum sludge.

    Yang, Y; Zhao, Y Q; Babatunde, A O; Kearney, P

    2009-01-01

    In view of the well recognized need of reject water treatment in MWWTP (municipal wastewater treatment plant), this paper outlines two strategies for P removal from reject water using alum sludge, which is produced as by-product in drinking water treatment plant when aluminium sulphate is used for flocculating raw waters. One strategy is the use of the alum sludge in liquid form for co-conditioning and dewatering with the anaerobically digested activated sludge in MWWTP. The other strategy involves the use of the dewatered alum sludge cakes in a fixed bed for P immobilization from the reject water that refers to the mixture of the supernatant of the sludge thickening process and the supernatant of the anaerobically digested sludge. Experimental trials have demonstrated that the alum sludge can efficiently reduce P level in reject water. The co-conditioning strategy could reduce P from 597-675 mg P/L to 0.14-3.20 mg P/L in the supernatant of the sewage sludge while the organic polymer dosage for the conditioning of the mixed sludges would also be significantly reduced. The second strategy of reject water filtration with alum sludge bed has shown a good performance of P reduction. The alum sludge has P-adsorption capacity of 31 mg-P/g-sludge, which was tested under filtration velocity of 1.0 m/h. The two strategies highlight the beneficial utilization of alum sludge in wastewater treatment process in MWWTP, thus converting the alum sludge as a useful material, rather than a waste for landfill.

  12. Combustion in fluidized bed reactors; Verbrennung in Wirbelschichtreaktoren

    Thome-Kozmiensky, Karl J. [vivis CONSULT GmbH, Nietwerder (Germany)

    2013-03-01

    Since the first application for the coal gasification, the fluidized bed technology has passed an impressive development. Nowadays, the fluidized bed technology is utilized at chemical processes, drying and cooling, gasification, combustion and purification of exhaust gas. In the firing technology, the fluidized technology initially has been proved in the combustion of very high ash coal and sewage sludge. Recently, the fluidized bed technology also is applied in the drying of sewage sludge, combustion of domestic waste - as in Japan and Sweden - as well as in the gasification and combustion of substitute fuels, biomass - wood pellets, wood chips, straw, cocoa shells and so forth - and residues from the paper manufacturing - such as in Germany and Austria. Under this aspect, the author of the contribution under consideration reports on the combustion of sewage sludge, substitute fuels and biomass.

  13. Heavy metal sequestration by humic substances during phyto-treatment of sewage sludges

    Peruzzi, E.; Doni, S.; Macci, C.; Ceccanti, B.; Masciandaro, G.

    2009-01-01

    The presence of heavy metals in sludges stabilized in a reed bed system, may affect their use for agricultural purposes; however, the environmental impact of sludges depends on the availability and phyto toxicity of their heavy metal. The aim of this paper was to determine the effectiveness of a reed bed (Phragmites Australia) sludge treatment system in two urban wastewater treatment plants in Italy after two-year period of operation: by estimating the process of sludge stabilization, following conventional and non conventional parameters related with the evolution of organic matter quality Water soluble Carbon, Dehydrogenase activity, Fulvic Acids, Humic Acids, Pyrolytic indices or organic matter Mineralization and Humification); by following the heavy metal speciation bioavailability in sludges. (Author)

  14. Zinc deprivation of methanol fed anaerobic granular sludge bioreactors

    Fermoso, F.G.; Collins, G.; Bartacek, J.; Lens, P.N.L.

    2008-01-01

    The effect of omitting zinc from the influent of mesophilic (30 degrees C) methanol fed upflow anaerobic sludge bed (UASB) reactors, and latter zinc supplementation to the influent to counteract the deprivation, was investigated by coupling the UASB reactor performance to the microbial ecology of

  15. Settleability assessment protocol for anaerobic granular sludge and ...

    The re revealed that the protocol was sufficiently sensitive to define the settleability of the sludge samples and to accurately determ their allowable upflow velocities, resultant organic loading rates, and recycling ratios according to the settleability of the gran bed. Also, a series of graphical procedures with settling tests which ...

  16. Sludge recovery apparatus

    Marmo, A.R.

    1979-01-01

    An improved design of a sludge recovery apparatus used in the fabrication of nuclear fuel is described. This apparatus provides for automatic separation of sludge from the grinder coolant, drying of the sludge into a flowable powder and transfer of the dry powder to a salvage container. It can be constructed to comply with criticality-safe-geometry requirements and to obviate need for operating personnel in its immediate vicinity. (UK)

  17. K basins sludge removal sludge pretreatment system

    Chang, H.L.

    1997-01-01

    The Spent Nuclear Fuels Program is in the process of planning activities to remove spent nuclear fuel and other materials from the 100-K Basins as a remediation effort for clean closure. The 105 K- East and K-West Basins store spent fuel, sludge, and debris. Sludge has accumulated in the 1 00 K Basins as a result of fuel oxidation and a slight amount of general debris being deposited, by settling, in the basin water. The ultimate intent in removing the sludge and fuel is to eliminate the environmental risk posed by storing fuel at the K Basins. The task for this project is to disposition specific constituents of sludge (metallic fuel) to produce a product stream through a pretreatment process that will meet the requirements, including a final particle size acceptable to the Tank Waste Remediation System (TWRS). The purpose of this task is to develop a preconceptual design package for the K Basin sludge pretreatment system. The process equipment/system is at a preconceptual stage, as shown in sketch ES-SNF-01 , while a more refined process system and material/energy balances are ongoing (all sketches are shown in Appendix C). Thus, the overall process and 0535 associated equipment have been conservatively selected and sized, respectively, to establish the cost basis and equipment layout as shown in sketches ES- SNF-02 through 08

  18. Respirometry in activated sludge

    Spanjers, H.

    1993-01-01

    The purpose of the study was (1) to develop a respiration meter capable of continuously measuring, using different procedures, the oxygen uptake rate of activated sludge and (2) to expand knowledge about respiration related characteristics of wastewater and activated sludge.

    A

  19. Carbon-14 in sludge

    Fowler, J.R.; Coleman, C.J.

    1983-01-01

    The level of C-14 in high-level waste is needed to establish the amount of C-14 that will be released to the environment either as off-gas from the Defense Waste Processing Facility (DWPF) or as a component of saltstone. Available experimental data confirmed a low level of C-14 in soluble waste, but no data was available for sludge. Based on the processes used in each area, Purex LAW sludge in F-area and HM HAW sludge in H-area will contain the bulk of any sludge produced by the cladding. Accordingly, samples from Tank 8F containing Purex LAW and Tank 15H containing HM HAW were obtained and analyzed for C-14. These two waste types constitute approximately 70% of the total sludge inventory now stored in the waste tanks. Results from analyses of these two sludge types show: the total C-14 inventory in sludge now stored in the waste tanks is 6.8 Ci; C-14 releases to the atmosphere from the DWPF will average approximately 0.6 Ci annually at the projected sludge processing rate in the DWPF. 4 references, 2 tables

  20. Leaching and accumulation of trace elements in sulfate reducing granular sludge under concomitant thermophilic and low pH conditions

    Gonzalez-Gil, G.; Lopes, S.I.C.; Saikaly, P.E.; Lens, P.N.L.

    2012-01-01

    The leaching and/or accumulation of trace elements in sulfate reducing granular sludge systems was investigated. Two thermophilic up-flow anaerobic sludge bed (UASB) reactors operated at pH 5 were fed with sucrose (4 g COD l(reactor)(-1) d(-1)) and sulfate at different COD/SO42- ratios. During the

  1. The effect of sludge recirculation rate on a UASB-digester treating domestic sewage at 15 °C

    Zhang, L.; Hendrickx, T.L.G.; Kampman, C.; Zeeman, G.; Temmink, B.G.; Weiguang Li,; Buisman, C.J.N.

    2012-01-01

    The anaerobic treatment of low strength domestic sewage at low temperature is an attractive and important topic at present. The upflow anaerobic sludge bed (UASB)-digester system is one of the anaerobic systems to challenge low temperature and concentrations. The effect of sludge recirculation rate

  2. Effect of NaCl on thermophilic (55°C) methanol degradation in sulfate reducing granular sludge reactors

    Vallero, M.V.G.; Hulshoff Pol, L.W.; Lettinga, G.; Lens, P.N.L.

    2003-01-01

    The effect of NaCl on thermophilic (55degreesC) methanol conversion in the presence of excess of sulfate (COD/SO42-=0.5) was investigated in two 6.5L lab-scale upflow anaerobic sludge bed reactors inoculated with granular sludge previously not adapted to NaCl
    The effect of NaCl on thermophilic

  3. Methanol degradation in granular sludge reactors at sub-optimal metal concentrations: role of iron, nickel and cobalt

    Zandvoort, M.H.; Geerts, R.; Lettinga, G.; Lens, P.N.L.

    2003-01-01

    The effect of sub-optimal trace metal concentrations on the conversion of methanol in an upflow anaerobic sludge bed (UASB) reactor was investigated by studying the effect of decreased influent trace metal concentrations on the reactor efficiency, methanol conversion route and sludge

  4. Activated sludge model No. 3

    Gujer, W.; Henze, M.; Mino, T.

    1999-01-01

    The Activated Sludge Model No. 3 (ASM3) can predict oxygen consumption, sludge production, nitrification and denitrification of activated sludge systems. It relates to the Activated Sludge Model No. 1 (ASM1) and corrects for some defects of ASM I. In addition to ASM1, ASM3 includes storage of org...

  5. Sludge minimization technologies - an overview

    Oedegaard, Hallvard

    2003-07-01

    The management of wastewater sludge from wastewater treatment plants represents one of the major challenges in wastewater treatment today. The cost of the sludge treatment amounts to more that the cost of the liquid in many cases. Therefore the focus on and interest in sludge minimization is steadily increasing. In the paper an overview is given for sludge minimization (sludge mass reduction) options. It is demonstrated that sludge minimization may be a result of reduced production of sludge and/or disintegration processes that may take place both in the wastewater treatment stage and in the sludge stage. Various sludge disintegration technologies for sludge minimization are discussed, including mechanical methods (focusing on stirred ball-mill, high-pressure homogenizer, ultrasonic disintegrator), chemical methods (focusing on the use of ozone), physical methods (focusing on thermal and thermal/chemical hydrolysis) and biological methods (focusing on enzymatic processes). (author)

  6. Dewatering of sludges

    Bode, P.

    1984-01-01

    A filter rig has been designed and built. Simulated magnox and alumino ferric hydroxide sludges have been successfully filtered on this equipment and both types of sludge produced a clear filtrate and a cake. The flow rates were low. The cake often partially remained adhered to the filter membrane instead of dropping clear during the filter cleaning cycle. This filtration technique can only be used on sludges which form a non-binding cake. Permeability of the membrane can be altered by stretching. Irradiation of the membrane showed that it should withstand 20 to 50 M.rads. (author)

  7. Sewage sludges disinfection

    Alexandre, D.; Gevaudan, P.P.

    1977-01-01

    There is a hygienic risk in using biological sewage sludges for agriculture. Systematic analyses carried out on sludge samples obtained from purification plants in the Eastern and Southern part of France, show the almost uniform presence of pathogenic microorganisms. Some of them survive more than nine months after application to the soil. Conventional processes for disinfection, liming and heat, make the sludge unsuitable for agricultural use. On the other hand, irradiation involves no modification of structure and composition of sludges. Radiation doses required for disinfection vary according to the type of microorganism. Some of them are eliminated at rather low doses (200 krad), but mycobacteria, viruses and eggs of worms resist to more important doses. The security dose is estimated to be approx. 1000 krad

  8. Analysis of Organic and Inorganic Contaminants in Dried Sewage Sludge and By-Products of Dried Sewage Sludge Gasification

    Sebastian Werle

    2014-01-01

    Full Text Available Organic and inorganic contaminants in sewage sludge may cause their presence also in the by-products formed during gasification processes. Thus, this paper presents multidirectional chemical instrumental activation analyses of dried sewage sludge as well as both solid (ash, char coal and liquid (tar by-products formed during sewage gasification in a fixed bed reactor which was carried out to assess the extent of that phenomenon. Significant differences were observed in the type of contaminants present in the solid and liquid by-products from the dried sewage sludge gasification. Except for heavy metals, the characteristics of the contaminants in the by-products, irrespective of their form (solid and liquid, were different from those initially determined in the sewage sludge. It has been found that gasification promotes the migration of certain valuable inorganic compounds from sewage sludge into solid by-products which might be recovered. On the other hand, the liquid by-products resulting from sewage sludge gasification require a separate process for their treatment or disposal due to their considerable loading with toxic and hazardous organic compounds (phenols and their derivatives.

  9. Sludge technology assessment

    Krause, T.R.; Cunnane, J.C.; Helt, J.E.

    1994-12-01

    The retrieval, processing, and generation of final waste forms from radioactive tank waste sludges present some of the most challenging technical problems confronting scientists and engineers responsible for the waste management programs at the various Department of Energy laboratories and production facilities. Currently, the Department of Energy is developing a strategy to retrieve, process, and generate a final waste form for the sludge that meets the acceptance criteria for the final disposition. An integral part of this strategy will be use of separation processes that treat the sludge; the goal is to meet feed criteria for the various processes that will generate the final waste form, such as vitrification or grouting. This document is intended to (1) identify separation technologies which are being considered for sludge treatment at various DOE sites, (2) define the current state of sludge treatment technology, (3) identify what research and development is required, (4) identify current research programs within either DOE or academia developing sludge treatment technology, and (5) identify commercial separation technologies which may be applicable. Due to the limited scope of this document, technical evaluations regarding the need for a particular separations technology, the current state of development, or the research required for implementation, are not provided

  10. Sludge Stabilization Campaign blend plan

    De Vries, M.L.

    1994-01-01

    This sludge stabilization blend plan documents the material to be processed and the order of processing for the FY95 Sludge Stabilization Campaign. The primary mission of this process is to reduce the inventory of unstable plutonium bearing sludge. The source of the sludge is residual and glovebox floor sweepings from the production of material at the Plutonium Finishing Plant (PFP). The reactive sludge is currently being stored in various gloveboxes at PFP. There are two types of the plutonium bearing material that will be thermally stabilized in the muffle furnace: Plutonium Reclamation Facility (PRF) sludge and Remote Mechanical C (RMC) Line material

  11. Co-disposal of sewage sludge and solid wastes-it works

    Sussman, D B

    1977-10-01

    The problem of sludge disposal is one of more sludge than ever before, few suitable land disposal or land application sites, the ocean dumping option being phased out, and energy cost so high or supplies so few as to make incineration a questionable endeavor. The energy required to run a wastewater treatment plant and the heat needed to incinerate the sludge may be available in the same community in the form of municipal solid waste. Municipal sludge has a heat value of about 10,000 Btu/lb of dry solids; it is autogenous at>30% solids. Codisposal techniques are discussed which use the energy produced by the combustion of solid waste to dewater the sludge to its autogenous point. One approach is to use sewage sludge incinerators, in many cases already installed at the wastewater treatment plant, and to use the organic portion of solid waste as a fuel to dry, burn, and reduce the volume of the sludge that must ultimately be disposed. A second approach would use a solid waste incinerator, solid waste-fired steam generator, or waterwall combustion unit to burn dewatered sludge. Both approaches are being demonstrated or used. Thermal sludge disposal at wastewater treatment plants normally is carried out in multiple-hearth or fluidized-bed incinerators. The experiences of such plants in the US and Europe are summarized.

  12. Effect of bioleaching on hydrogen-rich gas production by steam gasification of sewage sludge

    Li, Hanhui; Chen, Zhihua; Huo, Chan; Hu, Mian; Guo, Dabin; Xiao, Bo

    2015-01-01

    Highlights: • Bioleaching can modify the physicochemical property of sewage sludge. • The enhancement is mainly hydrogen. • Bioleaching can enhance the gas production in gasification of sewage sludge. • Study provides an insight for future application of bioleached sewage sludge. - Abstract: Effect of bioleaching on hydrogen-rich gas production by steam gasification of sewage sludge was carried out in a lab-scale fixed-bed reactor. The influence of sewage sludge solids concentrations (6–14% (w/v) in 2% increments) during the bioleaching process and reactor temperature (600–900 °C in 100 °C increments) on gasification product yields and gas composition were studied. Characterization of samples showed that bioleaching treatment, especially in 6% (w/v) sludge solids concentration, led to metal removal effectively and modifications in the physicochemical property of sewage sludge which was favored for gasification. The maximum gas yield (49.4%) and hydrogen content (46.4%) were obtained at 6% (w/v) sludge solids concentration and reactor temperature of 900 °C. Sewage sludge after the bioleaching treatment may be a feasible feedstock for hydrogen-rich gas product.

  13. Test plan, sludge retrieval, sludge packaging

    Feigenbutz, L.V.

    1994-01-01

    This document provides direction for the cold testing of tools, equipment and systems which will be installed and operated in K-East (KE) Basin in support of the sludge retrieval and packaging project. The technical uncertainties related to the effectiveness of sludge retrieval procedures and equipment require that cold testing be completed before installation in KE Basin to identify and resolve existing problems, and to optimize the efficiency of all equipment and systems used. This plan establishes the responsibilities, test requirements, and documentation requirements necessary to complete cold tests of: (1) equipment with no potential for plant use; (2) prototype equipment and systems which may be upgraded for use in K-Basin; and (3) plant equipment and systems requiring cold acceptance testing prior to plant use. Some equipment and systems may have been subject to a formal design review and safety assessment; the results of which will be included as supporting documents to the operational readiness review (ORR)

  14. Manufacturing ceramic bricks with polyaluminum chloride (PAC) sludge from a water treatment plant.

    da Silva, E M; Morita, D M; Lima, A C M; Teixeira, L Girard

    2015-01-01

    The objective of this research work is to assess the viability of manufacturing ceramic bricks with sludge from a water treatment plant (WTP) for use in real-world applications. Sludge was collected from settling tanks at the Bolonha WTP, which is located in Belém, capital of the state of Pará, Brazil. After dewatering in drainage beds, sludge was added to the clay at a local brickworks at different mass percentages (7.6, 9.0, 11.7, 13.9 and 23.5%). Laboratory tests were performed on the bricks to assess their resistance to compression, water absorption, dimensions and visual aspects. Percentages of 7.6, 9.0, 11.7 and 13.9% (w/w) of WTP sludge presented good results in terms of resistance, which indicates that technically, ceramic bricks can be produced by incorporating up to 13.9% of WTP sludge.

  15. Fluidized bed volume reduction of diverse radwastes

    McFee, J.N.; McConnell, J.W.; Waddoups, D.A.; Gray, M.F.; Harwood, L.E.; Clayton, N.J.; Drown, D.C.

    1981-01-01

    Method and apparatus for a fluidized bed radwaste volume reduction system are claimed. Low level radioactive wastes, combustible solids, ion exchange resins and filter sludges, and liquids, emanating from a reactor facility are introduced separately through an integrated waste influent system into a common fluidized bed vessel where volume reduction either through incineration or calcination occurs. Addition of a substance to the ion exchange resin before incineration inhibits the formation of low-melting point materials which tend to form clinkers in the bed. Solid particles are scrubbed or otherwise removed from the gaseous effluent of the vessel in an off-gas system, before the cooled and cleaned off-gas is released to the atmosphere. Iodine is chemically or physically removed from the off-gas. Otherwise, the only egress materials from the volume reduction system are containerized dry solids and tramp material. The bed material used during each mode may be circulated, cleaned, stored and exchanged from within the bed vessel by use of a bed material handling system. An instrumentation and control system provides operator information, monitors performance characteristics, implements start up and shut down procedures, and initiates alarms and emergency procedures during abnormal conditions

  16. Sludge pumping in water treatment

    Solar Manuel, M. A.

    2010-01-01

    In water treatment processes is frequent to separate residual solids, with sludge shape, and minimize its volume in a later management. the technologies to applicate include pumping across pipelines, even to long distance. In wastewater treatment plants (WWTP), the management of these sludges is very important because their characteristics affect load losses calculation. Pumping sludge can modify its behavior and pumping frequency can concern treatment process. This paper explains advantages and disadvantages of different pumps to realize transportation sludge operations. (Author) 11 refs.

  17. RELATIONSHIP BETWEEN SLUDGE DEWATERABILITY NUMBER ...

    A representative of a sludge sample collected from the same source was filtered under the same environmental condition and the result analysed with two different concepts. One method of analysis uses Sludge Dewaterability Number, while the second employed the Carman's Specific resistance concept in sludge ...

  18. Bed mixing dryer for high moisture content fuels

    Hulkkonen, S; Heinonen, O. [Imatran Voima Oy, Vantaa (Finland)

    1998-12-31

    Bed mixing dryer is a new type of fuel drying technology for fluidized bed combustion. The idea is to extract hot bed material from the fluidized bed and use it as a heat source for drying the fuel. Drying occurs at steam atmosphere which makes it possible to recover the latent heat of evaporation to process. This improves the thermal efficiency of the power plant process considerably, especially in combined heat and power applications. Imatran Voima Oy (IVO) has developed the Bed Mixing Dryer technology since early 1990s. The first pilot plant was built in 1994 to IVO`s Kuusamo peat and wood fired power plant. The capacity of the plant is 6 MW{sub e} and 20 MW of district heat. In Kuusamo the dryer is connected to a bubbling fluidized bed. Since it`s commissioning the dryer has been used successfully for about 3000 hours during the heating season in wintertime. The second application of the technology will be a demonstration project in Oerebro (S). IVO Power Engineering Ltd will supply in 1997 a dryer to Oerebro Energi`s peat, wood and coal fired CHP plant equipped with circulating fluidized bed boiler. The fuel to be dried is sawdust with fuel input of about 60 MW. In Kuusamo the dryer produces 3 MW of additional district heat and in Oerebro 6 MW. The fuels in Kuusamo are peat, saw dust and bark. In addition to the municipal heat production this type of drying technology has its benefits in pulp and paper industry processes. Disposal of paper mill sludges is becoming more difficult and costly which has resulted in need of alternative treatment. Drying of the sludge before combustion in a boiler for power production is an attractive option. At the moment IVO is carrying out several studies to apply the Bed Mixing Dryer in pulp and paper industry processes. Economy of drying the sludge looks promising

  19. Bed mixing dryer for high moisture content fuels

    Hulkkonen, S.; Heinonen, O. [Imatran Voima Oy, Vantaa (Finland)

    1997-12-31

    Bed mixing dryer is a new type of fuel drying technology for fluidized bed combustion. The idea is to extract hot bed material from the fluidized bed and use it as a heat source for drying the fuel. Drying occurs at steam atmosphere which makes it possible to recover the latent heat of evaporation to process. This improves the thermal efficiency of the power plant process considerably, especially in combined heat and power applications. Imatran Voima Oy (IVO) has developed the Bed Mixing Dryer technology since early 1990s. The first pilot plant was built in 1994 to IVO`s Kuusamo peat and wood fired power plant. The capacity of the plant is 6 MW{sub e} and 20 MW of district heat. In Kuusamo the dryer is connected to a bubbling fluidized bed. Since it`s commissioning the dryer has been used successfully for about 3000 hours during the heating season in wintertime. The second application of the technology will be a demonstration project in Oerebro (S). IVO Power Engineering Ltd will supply in 1997 a dryer to Oerebro Energi`s peat, wood and coal fired CHP plant equipped with circulating fluidized bed boiler. The fuel to be dried is sawdust with fuel input of about 60 MW. In Kuusamo the dryer produces 3 MW of additional district heat and in Oerebro 6 MW. The fuels in Kuusamo are peat, saw dust and bark. In addition to the municipal heat production this type of drying technology has its benefits in pulp and paper industry processes. Disposal of paper mill sludges is becoming more difficult and costly which has resulted in need of alternative treatment. Drying of the sludge before combustion in a boiler for power production is an attractive option. At the moment IVO is carrying out several studies to apply the Bed Mixing Dryer in pulp and paper industry processes. Economy of drying the sludge looks promising

  20. Sewage sludges disinfection

    Alexandre, D.

    1977-01-01

    There is an hygienic risk in using biological sewage sludges for agriculture. Systematic analysis carried out on sludges samples obtained from purification plants in East and South part of France, show the almost uniform presence of pathogenic microorganisms. Some of it survive more than 9 months after soil application. Conventional process for disinfection: liming and heat are not suitable for agricultural use. On the other hand, irradiation involves no modification in structure and composition of sludges. Radiation doses required for disinfection vary according to microorganisms. If some of them are eliminated with rather light doses (200 krad) mycobacteria, viruses and eggs of worms resist to more important doses. Security dose is estimated around 1000 krad

  1. Charcoal from paper sludge

    Kobayashi, M

    1980-03-06

    Paper sludge containing less than or equal to 50% water is mixed with coffee shells and greater than or equal to 1 almond shells, orange skin, walnut shells, or bean jam waste, compacted, and dry distilled at 300-600 degrees to prepare charcoal. Thus, 1 ton of paper sludge was mixed with 100 kg each of coffee shells, almond shells, orange skin, and walnut shells; compacted and dry distilled 24 hours at approximately 450 degrees. The calorific value of the charcoal produced was approximately 7300 kcal/kg.

  2. Transformation of Silver Nanoparticles in Sewage Sludge during Incineration.

    Meier, Christoph; Voegelin, Andreas; Pradas del Real, Ana; Sarret, Geraldine; Mueller, Christoph R; Kaegi, Ralf

    2016-04-05

    Silver nanoparticles (Ag-NP) discharged into the municipal sewer system largely accumulate in the sewage sludge. Incineration and agricultural use are currently the most important strategies for sewage sludge management. Thus, the behavior of Ag-NP during sewage sludge incineration is essential for a comprehensive life cycle analysis and a more complete understanding of the fate of Ag-NP in the (urban) environment. To address the transformation of Ag-NP during sewage sludge incineration, we spiked metallic Ag(0)-NP to a pilot wastewater treatment plant and digested the sludge anaerobically. The sludge was then incinerated on a bench-scale fluidized bed reactor in a series of experiments under variable conditions. Complementary results from X-ray absorption spectroscopy (XAS) and electron microscopy-energy dispersive X-ray (EM-EDX) analysis revealed that Ag(0)-NP transformed into Ag2S-NP during the wastewater treatment, in agreement with previous studies. On the basis of a principal component analysis and subsequent target testing of the XAS spectra, Ag(0) was identified as a major Ag component in the ashes, and Ag2S was clearly absent. The reformation of Ag(0)-NP was confirmed by EM-EDX. The fraction of Ag(0) of the total Ag in the ashes was quantified by linear combination fitting (LCF) of XAS spectra, and values as high as 0.8 were found for sewage sludge incinerated at 800 °C in a synthetic flue gas atmosphere. Low LCF totals (72% to 94%) indicated that at least one relevant reference spectrum was missing in the LCF analysis. The presence of spherical Ag-NP with a diameter of incineration, as demonstrated in this study, needs to be considered in the life cycle assessment of engineered Ag-NP.

  3. Heavy metals behaviour during mono-combustion and co-combustion of sewage sludge

    Lopes, M. Helena; Abelha, Pedro; Olieveira, J.F. Santos; Gulyurtlu, Ibrahim; Cabrita, Isabel [INETI-DEECA, Lisboa (Portugal)

    2005-03-01

    This paper presents the study of the combustion of granular dry sewage sludge performed on a pilot fluidized bed system. The results of mono-combustion of sludge and co-combustion with coal were compared with those of coal combustion for ash partitioning, the formation of gaseous pollutants and heavy metals behaviour. It was found that the mineral matter of sludge was essentially retained as bottom ashes. The production of fines ashes was small during the mono-combustion due to the tendency of coal to produce fine ashes which also contained unburned char. The degree of heavy metal volatilization was found to be slightly higher during co-combustion than in mono-combustion; however, most of them were retained in ashes and their emissions were found to be below the regulated levels. Hg was completely volatilized; however, during combustion trials involving coal it was captured by cyclone ashes at temperatures below 300 deg C. During sludge mono-combustion the retention of Hg in cyclone ashes containing low LOI was not enough to decrease emissions below the regulated levels; hence, it is necessary to install dedicated flue gas treatment for Hg removal. The leachability and ecotoxicity of sludge and ashes was compared with the new regulatory limits for landfill disposal in the EU. It was found that the release of organic matter and heavy metals found in the sludge was low from granular bed ashes; hence, except for sulphate release, bed ashes were converted into inert and non-ecotoxic materials. Ashes from test with limestone and cyclone ashes seemed to be more problematic because of pH effects and contamination with steel corrosion products. The recovery and reutilization of sludge bed ashes could, therefore, be possible, as long as the release of sulphate do not interfere with the process.

  4. Ultrasonic reduction of excess sludge from the activated sludge system

    Zhang Guangming; Zhang Panyue; Yang Jinmei; Chen Yanming

    2007-01-01

    Sludge treatment has long become the most challenging problem in wastewater treatment plants. Previous studies showed that ozone or chlorine effectively liquefies sludge into substrates for bio-degradation in the aeration tank, and thus reduces the excess sludge. This paper employs ultrasound to reduce the excess sludge from the sequential batch reactor (SBR) system. Partial sludge was disintegrated into dissolved substrates by ultrasound in an external sono-tank and was then returned to the SBR for bio-degradation. The results showed that ultrasound (25 kHz) effectively liquefied the sludge. The most effective conditions for sludge reduction were as following: sludge sonication ratio of 3/14, ultrasound intensity of 120 kW/kgDS, and sonication duration of 15 min. The amount of excess sludge was reduced by 91.1% to 17.8 mg/(L d); the organic content and settleability of sludge in the SBR were not impacted. The chemical oxygen demand (COD) removal efficiency was 81.1%, the total nitrogen (TN) removal efficiency was 17-66%, and high phosphorus concentration in the effluent was observed

  5. Bacteriology of activated sludge

    Gils, van H.W.

    1964-01-01

    The bacteriology and biochemistry of activated sludge grown in domestic waste water or fed with synthetic media were studied. The nature of the flocs was investigated by determining morphological and physiological characteristics of many strains isolated.

    Predominant bacteria were

  6. Composting sewage sludge

    Epstein, E.

    1979-01-01

    Sewage sludge is predominantly organic matter containing domestic and industrial wastes. The inefficiency of the waste water treatment to destroy pathogens and stabilization of odor-producing volatile organic compounds necessitates further treatment before sludge can be used as a soil amendment or fertilizer. Composting, which is the rapid biological decomposition of the sludge organic matter is an excellent method of sludge stabilization. During the process, volatile organics are decomposed and many of the pathogens destoyed. The low cost of the process and its flexibility with respect to labor and capital makes the system highly attractive to municipalities. A major problem facing large urban waste water treatment facilities is the distribution or marketing. The light weight of the material, expensive hauling costs, and low fertilizer value reduce its attractiveness to the agricultural sector. Thus, the greatest market is for horticultural purposes, sod, nurseries, greenhouses, parks, and reclamation areas. The major potential benefits of irradiating compost as a means of further disinfection are: (1) elimination of any health hazard; (2) increase of market potential, i.e., providing more market outlets to distribute the material; (3) compliance with state and federal health regulations; and (4) enhancement of the economics of composting as a result of utilizing compost in speciality products commanding a higher value

  7. Activated Sludge Rheology

    Ratkovich, Nicolas Rios; Horn, Willi; Helmus, Frank

    2013-01-01

    Rheological behaviour is an important fluid property that severely impacts its flow behaviour and many aspects related to this. In the case of activated sludge, the apparent viscosity has an influence on e.g. pumping, hydrodynamics, mass transfer rates, sludge-water separation (settling and filtr...... rheological measurements. Moreover, the rheological models are not very trustworthy and remain very “black box”. More insight in the physical background needs 30 to be gained. A model-based approach with dedicated experimental data collection is the key to address this.......Rheological behaviour is an important fluid property that severely impacts its flow behaviour and many aspects related to this. In the case of activated sludge, the apparent viscosity has an influence on e.g. pumping, hydrodynamics, mass transfer rates, sludge-water separation (settling......, leading to varying results and conclusions. In this paper, a vast amount of papers are critically reviewed with respect to this and important flaws are highlighted with respect to rheometer choice, rheometer settings and measurement protocol. The obtained rheograms from experimental efforts have...

  8. Modelling of a falling sludge bed reactor using AQUASIM

    drinie

    2001-10-04

    Oct 4, 2001 ... products are then used for the biological treatment of acid mine drainage. A mathematical ... solid matter into three valleys inside the reactor, as opposed to an ... conversion of PSS in the presence of sulphate-reducing bacteria ... indicate substrate flow (stoichiometrically) in the form of COD ..... fermentation.

  9. Radioactivity in sludge: tank cleaning procedures and sludge disposal

    Bradley, D.A.

    1995-01-01

    In the oil and gas industry management of alpha-active sludge is made more complex by the presence of hydrocarbons and heavy metals. This presentation discusses the origin of radioactivity in sludge, management of risk in terms of safe working procedures, storage and possible disposal options. The several options will generally involve aspects of dilution or of concentration; issues to be discussed will include sludge farming, bioremediation and incineration. (author)

  10. Minimization of Excess Sludge in Activated Sludge Systems

    Sayed Ali Reza Momeni

    2006-01-01

    Full Text Available The disposal of excess sludge from wastewater treatment plant represents a rising challenge in activated sludge processes. Hence, the minimization of excess sludge production was investigated by increasing the dissolved oxygen in aeration basin. Units of the pilot include: Primary sedimentation tank, aeration basin, secondary sedimentation tank, and return sludge tank. Volume of aeration basin is 360 l and influent flow rate is 90 L/h. Influent of pilot is taken from effluent of grit chamber of Isfahan's North Wastewater treatment plant. The experiments were done on different parts of pilot during the 5 month of study. Results show that increase of dissolved oxygen in aeration tank affect on decrease of excess sludge. Increase of dissolved oxygen from 0.5 to 4.5 mg/L resulted in 25% decrease of excess sludge. Variation of dissolved oxygen affect on settleability of sludge too. By increase of dissolved oxygen, SVI decreased and then increased. Value of 1-3 mg/L was the adequate range of dissolved oxygen by settleability of sludge and optimum range was 2-2.5 mg/L. It could be concluded by increasing of dissolved oxygen up to of 3 mg/L, sludge settleability significant decreased.

  11. Changes in microbiological composition of soils and soil contamination with drug-resistant bacteria caused by the use of sewage sludge in nature

    Stanczyk-Mazanek, Ewa; Pasonl, Lukasz; Kepa, Urszula

    2017-11-01

    This study evaluated the effect of the use of sewage sludge in nature on biological soil parameters. The study was conducted is field experiment environment (small beds). The sandy soil was fertilized with sewage sludge dried naturally (in heaps) and in solar drying facilities. The fertilization was based on the doses of sewage sludge and manure with the amounts of 10, 20, 30 and 40 Mg/ha. The experiment duration was 3 years. The sanitary status of the soils fertilized with the sludge and manure was evaluated (coliform index, Clostridium perfrinens). Furthermore, the content of pathogenic bacteria was evaluated, with determination of its resistance to first-line antibiotics.

  12. Agricultural yields of irradiated sewage sludge

    Magnavacca, Cecilia; Miranda, E.; Sanchez, M.

    1999-01-01

    Lettuce, radish and ryegrass have been used to study the nitrogen fertilization of soil by sewage sludge. The results show that the irradiated sludge improve by 15 - 30 % the production yield, compared to the non-irradiated sludge. (author)

  13. Co-combustion of sewage sludge and energy-rich waste fuels or forest fuels; Sameldning av roetslam och energirika avfallsbraenslen eller skogsbraenslen

    Linder, Kristina [TPS Termiska Processer AB, Nykoeping (Sweden)

    2003-10-01

    In this report literature on incineration of sewage sludge is summarises. In Sweden there is a yearly production of about 0,24 million-ton dry sewage sludge of which 50% is deposited. Recent changes in legislation will restrict and later prohibit the dumping of sewage sludge. Alternative methods for handling the material have not yet been found. In other parts of Europe the problem has been solved by incineration. Sludge incineration can be performed in several ways depending of the pretreatment. The sludge can be raw or digested, dewatered or dried. The sludge can be burnt as single fuel or in mixtures with other fuels. Focus in this work has been on co-combustion with biofuel or waste, as it will make use of existing plants. Digested sludge is also of major interest as 70% of the Swedish sludge is digested. The report describes the situation both in Sweden and in the rest of Europe. Sludge has a varying quality depending on origin and treatment, which affects the combustion properties. Ash and moisture contents differ from other fuels. The heating value of sewage sludge is approximately 20 MJ/kg per dry combustible matter and the amount of organic is around 70%. Compared to forest residue and demolition wood, sludge contains high levels of nitrogen and sulphur, which will cause emissions. The nitrogen level is about 10 times higher and the sulphur level 25 to 50 times higher. Sulphur, in combination with alkali metals, can cause deposit problems in boilers. However, sludge contains low levels of alkali. In the experimental investigation leaching of digested sludge showed low values on water conductivity which indicates a low concentration of sintering ash species in the sludge. A comparison of the aerodynamic properties of dried digested sludge and wood chips from energy coppice showed that sludge has a lower fraction of fines. This indicates that the sewage sludge is not likely to be carried over in the furnace but rather to stay in the fuel and ash bed on the

  14. Effect of nickel deprivation on methanol degradation in a methanogenic granular sludge bioreactor

    Zandvoort, M.H.; Osuna, M.B.; Geerts, R.; Lettinga, G.; Lens, P.N.L.

    2002-01-01

    The effect of omitting nickel from the influent on methanol conversion in an Upflow Anaerobic Sludge Bed (UASB) reactor was investigated. The UASB reactor (30°C, pH 7) was operated for 261 days at a 12-h hydraulic retention time (HRT) and at organic loading rates (OLRs) ranging from 2.6 to 7.8 g COD

  15. Sewage sludge irradiation with electrons

    Tauber, M.

    1976-01-01

    The disinfection of sewage sludge by irradiation has been discussed very intensively in the last few months. Powerful electron accelerators are now available and the main features of the irradiation of sewage sludge with fast electrons are discussed and the design parameters of such installations described. AEG-Telefunken is building an irradiation plant with a 1.5 MeV, 25 mA electron accelerator, to study the main features of electron irradiation of sewage sludge. (author)

  16. Sewage sludge additive

    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.

  17. Preparation of sewage sludges for the thermal disposal in lignite power stations. Aufbereitung von Klaerschlaemmen zur thermischen Entsorgung in Braunkohlenkraftwerken

    Krone, C.; Koch, J.; Leidel, H.; Scheel, W. (VEAG Vereinigte Energiewerke AG, Ingenieurunternehmen fuer Kraftwerks-, Energie- und Umwelttechnik, Vetschau (Germany))

    1992-10-01

    The thermal disposal of communal sewage sludges as well as the additional combustion of such substances in furnaces of power station boilers are really no technical solutions. New are the consideration concerning the sludge preparation with the aid of the steam fluidized bed drying process and the additional combustion of the dried products in raw-brown-coal-fired large-scale steam generators. - The investigation proves the technical feasibility and points to problems which still have to be tackled. (orig.).

  18. Composting of sewage sludge irradiated

    Hashimoto, Shoji; Watanabe, Hiromasa; Nishimura, Koichi; Kawakami, Waichiro

    1981-01-01

    Recently, the development of the techniques to return sewage sludge to forests and farm lands has been actively made, but it is necessary to assure its hygienic condition lest the sludge is contaminated by pathogenic bacteria. The research to treat sewage sludge by irradiation and utilize it as fertilizer or soil-improving material has been carried out from early on in Europe and America. The effects of the irradiation of sludge are sterilization, to kill parasites and their eggs, the inactivation of weed seeds and the improvement of dehydration. In Japan, agriculture is carried out in the vicinity of cities, therefore it is not realistic to use irradiated sludge for farm lands as it is. The composting treatment of sludge by aerobic fermentation is noticed to eliminate the harms when the sludge is returned to forests and farm lands. It is desirable to treat sludge as quickly as possible from the standpoint of sewage treatment, accordingly, the speed of composting is a problem. The isothermal fermentation experiment on irradiated sludge was carried out using a small-scale fermentation tank and strictly controlling fermentation conditions, and the effects of various factors on the fermentation speed were studied. The experimental setup and method are described. The speed of composting reached the maximum at 50 deg C and at neutral or weak alkaline pH. The speed increased with the increase of irradiation dose up to 30 Mrad. (Kako, I.)

  19. Radioactive contamination of sewage sludge

    Soeder, C.J.; Zanders, E.; Raphael, T.

    1986-01-01

    Because of the radioactivity released through the explosion of the nuclear reactor near Chernobyl radionuclides have been accumulated to a significant extent in sewage sludge in the Federal Republic of Germany. This is demonstrated for samples from four activated sludge plants according to a recent recommendation of the German Commission for Radiation Protection, there is until now no reason to deviate from the common practices of sludge disposal or incineration. The degree of radioactive contamination of plant materials produced on farm lands on which sewage sludge is being spread cannot be estimated with sufficient certainty yet. Additional information is required. (orig.) [de

  20. Sewage sludge disposal in Austria

    Koch, F.

    1997-01-01

    Sewage systems serve about 70% of the Austrian population, producing 6 million m 3 of sewage sludge per year with a dry matter content of 4-5%. At present about 52% of this sludge is disposed of in land fills, 33% is incinerated, and only about 15 % is used in agriculture. Although agricultural utilization is becoming increasingly important, several problems, especially those related to public opinion, need to be resolved before increased use will be possible. In this paper, wastewater treatment and sewage-sludge production in Austria, and problems associated with sludge disposal are discussed. (author)

  1. Dewatering properties of differently treated sewage sludge

    Zehnder, H.J.

    1977-01-01

    A study on dewatering properties of radiosterilized sewage sludge of different type and origin was carried out. For comparison, also heat-treated (pasteurized) sludge was investigated. The specific filtration resistance of irradiated sewage sludge was lowered in all types of sludge examined. In general, pasteurization increased this parameter. The settling properties of irradiated digested sewage sludge was slightly improved, mainly in the first hours after treatment. Microbial effects may mask the real sedimentation relations especcially in aerobically stabilized sludges. A pasteurization treatment of sewage sludge caused an increased content of soluble substances and suspended particles in the supernatant water. The supernatant water from irradiated sludge showed a smaller increase

  2. SLUDGE MASS REDUCTION: PRIMARY COMPOSITIONAL FACTORS THAT INFLUENCE MELT RATE FOR FUTURE SLUDGE BATCH PROJECTIONS

    Newell, J; Miller, D; Stone, M; Pickenheim, B

    2008-01-01

    510 based system without Al-dissolution relative to the Frit 418 based system with Al-dissolution. Though the without aluminum dissolution scenario suggests a slightly higher melt rate with frit 510, several points must be taken into consideration: (1) The MRF does not have the ability to assess liquid feeds and, thus, rheology impacts. Instead, the MRF is a 'static' test bed in which a mass of dried melter feed (SRAT product plus frit) is placed in an 'isothermal' furnace for a period of time to assess melt rate. These conditions, although historically effective in terms of identifying candidate frits for specific sludge batches and mapping out melt rate versus waste loading trends, do not allow for assessments of the potential impact of feed rheology on melt rate. That is, if the rheological properties of the slurried melter feed resulted in the mounding of the feed in the melter (i.e., the melter feed was thick and did not flow across the cold cap), melt rate and/or melter operations (i.e., surges) could be negatively impacted. This could affect one or both flowsheets. (2) Waste throughput factors were not determined for Frit 510 and Frit 418 over multiple waste loadings. In order to provide insight into the mission life versus canister count question, one needs to define the maximum waste throughput for both flowsheets. Due to funding limitations, the melt rate testing only evaluated melt rate at a fixed waste loading. (3) DWPF will be processing SB5 through their facility in mid-November 2008. Insight into the over arching questions of melt rate, waste throughput, and mission life can be obtained directly from the facility. It is recommended that processing of SB5 through the facility be monitored closely and that data be used as input into the decision making process on whether to implement Al-dissolution for future sludge batches

  3. Site-specific analysis for location of a sludge irradiation plant at Provo, Utah

    Bingham, M.L.; Luce, W.A.; Ahlstrom, S.B.; Johnson, B.A.

    1980-01-01

    Provo's current sludge handling program consists of anaerobic digestion, sand drying beds, and stockpiling onsite until the sludge can be removed for application to the land. This practice is adequate to meet current State of Utah regulations. However, EPA-proposed regulations will require Provo to either upgrade its current sludge disposal practices to provide more adequate pathogen destruction prior to land application, or change its method of final sludge disposal. Four possible alternatives to the existing practice were evaluated. These include (1) applying liquid sludge from the digesters to agricultural land, (2) landfilling, (3) irradiation, and (4) composting of dry sludge. Land application of liquid sludge and landfilling were found to be the most costly alternatives, primarily because of high transportation costs. Composting and irradiation were found to be the least costly alternatives. Irradiation had a higher initial capital cost, but a lower annual operation and maintenance cost than composting. Overall, composting appeared to be the most cost-effective alternative; however, pilot testing would be necessary to verify the unusual criteria for composting at Provo

  4. Environmental evaluation of sewage sludge co-combustion in a pilot FBC

    M. Helena Lopes; P. Abelha; I. Cabrita; J.F.Santos Oliveira; I. Gulyurtlu [INETI/DEECA, Lisbon (Portugal)

    2003-07-01

    This paper presents a comparison of combustion of coal alone with that of a mixture of coal with sewage sludge with respect to flue gas emissions, the behaviour of heavy metals and potential environmental consequences of disposal of ashes produced. Co-combustion with sludge did not result in greater NOx, SO{sub 2}, HCl and CO emissions and the use of air staging and the addition of limestone proved to be effective to reduce NOx and SO{sub 2}. The mixing of sludge gave rise to an increase in amounts of heavy metals released, especially for Cd, Pb and Hg. However, as they were associated with particles greater than 1 {micro}m, the application of efficient flue gas treatment devices could decrease their emissions to the atmosphere. Metals were essentially retained in ashes captured in the bed and in the cyclones and most of the Hg was adsorbed in fly ashes that contained unburned carbon. The leachability of metals and organic matter present in the sludge decreased with combustion. The evaluation of the acid neutralization capacity (ANC) showed that ashes became more resistant to acidification than the parent sludge. Globally, this study concludes that the implication of the combustion of sludge is that it can reduce the negative impact on the environment compared with the traditional direct use of sludge in soils. 22 refs., 4 figs., 5 tabs.

  5. Hydrothermal processing of inorganic components of Hanford tank sludge

    Oldenborg, R.; Buelow, S.J.; Dyer, R.B.; Anderson, G.; Dell'Orco, P.C.; Funk, K.; Wilmanns, E.; Knutsen, K.

    1994-09-01

    Hydrothermal Processing (HTP) is an attractive approach for the treatment of Hanford tank sludge. Hydrothermal Processing refers to a waste treatment technique in which an aqueous waste stream is fed through a chemical reactor at elevated temperatures and pressures to effect desired chemical transformations and separations. Transformations such as organic and nitrate destruction and sludge reformulation have been demonstrated at pilot scale using simulants of Hanford tank wastes. At sufficiently high temperatures and pressures organics and nitrates are destroyed in seconds, producing primarily simple products such as CO 3 2- , H 2 O, N 2 , N 2 O and OH - , and sludges are reduced in volume and reformulated as rapid settling oxides amenable to downstream separation, or in some cases reformulated as soluble products. This report describes the hydrothermal dissolution of chromium and chromium oxide; the hydrothermal oxidation of chromium with nitrate; hydrothermal dissolution of aluminum-bearing sludges; the solubility of aluminum compounds in caustic hydrothermal media; experimental techniques for the study of solubility and phase behavior; optical cell studies of basic aluminate solution solubilities; and high temperature, low density salt solubility in the packed-bed flow apparatus

  6. Ash and heavy metals in fluidized-bed combustion of wood wastes; Tuhka ja raskasmetallit puuperaeisen jaetteen kerrosleijupoltossa

    Kaessi, T; Aittoniemi, P [IVO Power Engineering, Vantaa (Finland); Kauppinen, E; Latva-Somppi, J; Kurkela, J [VTT Chemical Technology, Espoo (Finland); Partanen, J [IVO Technology Centre, Vantaa (Finland)

    1997-10-01

    Ash formation and deposition mechanisms during co-combustion of pulp mill sludge and bark in industrial bubbling fluidized bed (BFB) combustor have been studied. Similar fuels were used in a bench-scale BFB for co-combustion of sludge and bark pellets and comparative studies with separate combustion of these fuels. Results indicated that in industrial scale unit significant fraction of ash had vaporization. About 14 mass-% of the total fly ash was found in the particle size below 0.2 {mu}m. The vaporized species consisted of potassium (K), sulfur (S), chlorine (Cl) and also of minor quantities of sodium (Na). In the benchscale similar vaporization fractions during co-combustion were measured, about 11 mass-%. During the combustion of bark this ratio, about 20 mass-%, was higher than during sludge combustion. The vaporized ash fraction was in the case of dried sludge combustion about 7 mass-%, but with wet sludge the vaporization rate was remarkably lower, about 1-2 mass-%. An increase in the bed temperature increased also ash vaporization. Test run period without combustion at elevated temperatures produced very low quantities of vaporized ash. The vaporized species in bench-scale test during bark pellet combustion were K, S and Cl, for sludge combustion also Na was clearly detected. No condensation of the vaporized species in bed area or furnace walls was observed. Bed defluidization was studied in the bench-scale unit. During bark pellet combustion the bed-agglomeration proceeded via small ash particle, below 2 {mu}m, coating on sand particle surface and consequent bonding between the ash layers. In the case of sludge combustion the accumulation of large ash particles and sintering of these porous agglomerates was observed to cause bed coarsening and defluidization. (orig.)

  7. Practice Hospital Bed Safety

    ... Home For Consumers Consumer Updates Practice Hospital Bed Safety Share Tweet Linkedin Pin it More sharing options ... It depends on the complexity of the bed." Safety Tips CDRH offers the following safety tips for ...

  8. Bed Bugs and Schools

    Bed bugs have long been a pest – feeding on blood, causing itchy bites and generally irritating their human hosts. They are successful hitchhikers, and can move from an infested site to furniture, bedding, baggage, boxes, and clothing.

  9. Comparative study of the methods used for treatment and final disposal of sewage sludge in European countries.

    Kelessidis, Alexandros; Stasinakis, Athanasios S

    2012-06-01

    Municipal wastewater treatment results to the production of large quantities of sewage sludge, which requires proper and environmentally accepted management before final disposal. In European Union, sludge management remains an open and challenging issue for the Member States as the relative European legislation is fragmentary and quite old, while the published data concerning sludge treatment and disposal in different European countries are often incomplete and inhomogeneous. The main objective of the current study was to outline the current situation and discuss future perspectives for sludge treatment and disposal in EU countries. According to the results, specific sludge production is differentiated significantly between European countries, ranging from 0.1 kg per population equivalent (p.e.) and year (Malta) to 30.8 kg per p.e. and year (Austria). More stringent legislations comparing to European Directive 86/278/EC have been adopted for sludge disposal in soil by several European countries, setting lower limit values for heavy metals as well as limit values for pathogens and organic micropollutants. A great variety of sludge treatment technologies are used in EU countries, while differences are observed between Member States. Anaerobic and aerobic digestion seems to be the most popular stabilization methods, applying in 24 and 20 countries, respectively. Mechanical sludge dewatering is preferred comparing to the use of drying beds, while thermal drying is mainly applied in EU-15 countries (old Member States) and especially in Germany, Italy, France and UK. Regarding sludge final disposal, sludge reuse (including direct agricultural application and composting) seems to be the predominant choice for sludge management in EU-15 (53% of produced sludge), following by incineration (21% of produced sludge). On the other hand, the most common disposal method in EU-12 countries (new Member States that joined EU after 2004) is still landfilling. Due to the obligations

  10. Development of fluidized bed combustion of biomass; Leijupolttoprosessin kehittaeminen vaikeille biopolttoaineille soveltuvaksi

    Hiltunen, M; Vaehaenen-Koivuluoma, T [Foster Wheeler Energia Oy, Karhula (Finland)

    1997-10-01

    Some commercial BFB boilers burning biofuels, or biofuels and industrial wood wastes have suffered serious problems in bed material sintering. In worst cases the cumulation of reactive alkali compounds has caused total sintering of bed material even during a few days` operation. This presentation reports the results obtained from three separate cases, where sintering problems occurred. Boiler A burned biofuel with quartz sand and limestone addition. Boiler B burned softwood bark and industrial wood waste with sand addition. Boiler C burned softwood bark and sludge with sand addition. Due to the fuel used, bed sintering occurred in all boilers. Obviously, sintering was also influenced by some technical problems. Bed material samples have been analyzed with XRF and SEM-EDS techniques. According to these analyses, the main reason for sintering in boiler A is the cumulation of reactive potassium in bed material. In boiler B, the main reason is the fuel change from a mixture of softwood bark and industrial wood waste to pure industrial wood waste. The extra load of reactive sodium exceeded the critical concentration of alkali compounds in bed material. Also in boiler C, the fuel change from a mixture of softwood bark and sludge to pure softwood bark seems to be one of the reasons for bed sintering. After the fuel change the bed saturated with reactive potassium and the bed sintered. (orig.)

  11. Sludge Digestion Manual; Handboek Slibgisting

    NONE

    2011-09-15

    This manual offers a guideline for developing, designing, optimizing and operating sludge digestion installations based on sewage sludge. It also offers tools for solving operation problems [Dutch] Het Handboek is een leidraad voor het ontwikkelen, ontwerpen, optimaliseren en bedrijven van slibgistingsinstallaties voor zuiveringsslib. Ook geeft het handvatten voor het oplossen van operationele problemen.

  12. Ultrasonic sludge pretreatment under pressure.

    Le, Ngoc Tuan; Julcour-Lebigue, Carine; Delmas, Henri

    2013-09-01

    The objective of this work was to optimize the ultrasound (US) pretreatment of sludge. Three types of sewage sludge were examined: mixed, secondary and secondary after partial methanisation ("digested" sludge). Thereby, several main process parameters were varied separately or simultaneously: stirrer speed, total solid content of sludge (TS), thermal operating conditions (adiabatic vs. isothermal), ultrasonic power input (PUS), specific energy input (ES), and for the first time external pressure. This parametric study was mainly performed for the mixed sludge. Five different TS concentrations of sludge (12-36 g/L) were tested for different values of ES (7000-75,000 kJ/kgTS) and 28 g/L was found as the optimum value according to the solubilized chemical oxygen demand in the liquid phase (SCOD). PUS of 75-150 W was investigated under controlled temperature and the "high power input - short duration" procedure was the most effective at a given ES. The temperature increase in adiabatic US application significantly improved SCOD compared to isothermal conditions. With PUS of 150 W, the effect of external pressure was investigated in the range of 1-16 bar under isothermal and adiabatic conditions for two types of sludge: an optimum pressure of about 2 bar was found regardless of temperature conditions and ES values. Under isothermal conditions, the resulting improvement of sludge disintegration efficacy as compared to atmospheric pressure was by 22-67% and 26-37% for mixed and secondary sludge, respectively. Besides, mean particle diameter (D[4,3]) of the three sludge types decreased respectively from 408, 117, and 110 μm to about 94-97, 37-42, and 36-40 μm regardless of sonication conditions, and the size reduction process was much faster than COD extraction. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Lipid profiling in sewage sludge.

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

    2017-06-01

    High value-added reutilization of sewage sludge from wastewater treatment plants (WWTPs) is essential in sustainable development in WWTPs. However, despite the advantage of high value reutilization, this process must be based on a detailed study of organics in sludge. We used the methods employed in life sciences to determine the profile of lipids (cellular lipids, free fatty acids (FFAs), and wax/gum) in five sludge samples obtained from three typical WWTPs in Beijing; these samples include one sludge sample from a primary sedimentation tank, two activated sludge samples from two Anaerobic-Anoxic-Oxic (A2/O) tanks, and two activated sludge samples from two membrane bioreactor tanks. The percentage of total raw lipids varied from 2.90% to 12.3%. Sludge from the primary sedimentation tank showed the highest concentrations of lipid, FFA, and wax/gum and the second highest concentration of cellular lipids. All activated sludge contained an abundance of cellular lipids (>54%). Cells in sludge can from plants, animals, microbes and so on in wastewater. Approximately 14 species of cellular lipids were identified, including considerable high value-potential ceramide (9567-38774 mg/kg), coenzyme (937-3897 mg/kg), and some phosphatidylcholine (75-548 mg/kg). The presence of those lipid constituents would thus require a wider range of recovery methods for sludge. Both cellular lipids and FFAs contain an abundance of C16-C18 lipids at high saturation level, and they serve as good resources for biodiesel production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Treatment of radioactive sludge

    Allison, W.; Payne, B.J.; Pegler, G.E.

    1979-01-01

    Radioactive sludge e.g. that which may accumulate in irradiated nuclear fuel element storage ponds, is treated by pumping it from a settling tank to a particle separator, conveniently a hydrocyclone and a sloping plate separator, the liquid being returned to the settling tank and the solids being metered into a drum pre-lined with dry cement. The drums are in a containment box in which they are transferred to a mixing station where the particles and cement are mixed and thence to a curing station. After curing the drums are embedded in cement in outer containers for transport to a long-term storage site. (author)

  15. Physical and chemical factors affecting sludge consolidation

    Turner, C.W.; Blimkie, M.E.; Lavoie, P.A

    1997-09-01

    Chemical reactions between sludge components and precipitation reactions within the pores of the existing sludge are shown to contribute to the consolidation of sludge under steam generator operating conditions. Simulations of sludge representative of plants with a mixed iron/copper feedtrain suggest that as the conditions in the feedtrain become more oxidizing the sludge will become harder with a higher nickel ferrite content. The precipitation of feedwater impurities introduced by condenser leaks and of zinc silicate, which is produced in plants with brass condenser tubes and silica in the makeup water, contribute significantly to sludge consolidation. Sodium phosphate is also shown to be an agent of sludge consolidation. (author)

  16. Characterization of Industrial Wastewater Sludge in Oman from Three Different Regions and Recommendations for Alternate Reuse Applications.

    Baawain, Mahad S; Al-Jabri, Mohsin; Choudri, B S

    2015-11-01

    Domestic and industrial wastewaters are mostly treated by biological process such as activated sludge, aerobic pond, and anaerobic treatment. This study focuses on characterizing the quality of sewage sludge in the Sultanate of Oman chosen from three industrial sewage treatment plants (STPs): Rusayl Industrial Estate (RSL.IE); Sohar Industrial Estate (SIE); and Raysut Industrial Estate (RIE). Samples of recycled activated sludge (RAS) and wasted activated sludge (WAS) were collected over a period of 12 months across above mentioned STPs. Parameters analyzed are electrical conductivity (EC), potential of hydrogen (pH), cations, anions and volatile content (VC). The obtained values for pH and EC were low for both RAS and WAS samples, except EC values of RIE that was more than 1000 μS/cm. The range of VC percentages in RAS and WAS samples were 44 to 86% and 41 to 77%, respectively. The measured values for chloride, sulfate, nitrate and phosphate were higher than the other anions. The average values of the cations in RAS and WAS samples were within the Omani Standards, suitable for the re-use of sludge in agriculture except for Cd in RSL.IE. The study recommends that a regular maintenance should be performed at the studied STPs to prevent any accumulation of some harmful substances, which may affect the sludge quality, and the sludge drying beds should be large enough to handle the produced sludge for better management.

  17. Experience gained in bench scale and pilot scale fluidised bed processing

    Hadley, TD

    2005-01-01

    Full Text Available of titanium dioxide. Expertise in the design and commissioning of industrial-scale plants has led to the supply (through licensees) of a biomass sludge incinerator/boiler generating 26t/h steam, a 20 MW high-sulphur pitch incinerator and a 12 MW fluidised bed...

  18. Wasting Away: To Sludge or Not to Sludge?

    L Nicolle

    2001-01-01

    Full Text Available Following a century of high standards of sanitation, food and water safety in North America are often taken for granted. Recent outbreaks of illness attributed to food and water contamination, however, have challenged this complacency. Now, sludge is added to the list of concerns. Sewage sludge is the muddy substance that remains after the treatment of municipal sewage. This material includes not only human waste, but also household and industrial toxic wastes disposed of in local sewers. Federal and provincial Canadian regulations support the use of this material as fertilizer, within acceptable guidelines, as does the Environmental Protection Agency in the United States. The safety of sludge, however, is questioned by some individuals and groups. Specifically, the risk of infectious agents and toxins to workers or other exposed individuals, and the potential for heavy metals and organic chemicals to be transferred from sludge-treated fields into crops are concerns.

  19. Sludge pretreatment chemistry evaluation: Enhanced sludge washing separation factors

    Colton, N.G.

    1995-03-01

    This report presents the work conducted in Fiscal Year 1994 by the Sludge Pretreatment Chemistry Evaluation Subtask for the Tank Waste Remediation System (TWRS) Tank Waste Treatment Science Task. The main purpose of this task, is to provide the technical basis and scientific understanding to support TWRS baseline decisions and actions, such as the development of an enhanced sludge washing process to reduce the volume of waste that will require high-level waste (HLW) vitrification. One objective within the Sludge Pretreatment Chemistry Evaluation Subtask was to establish wash factors for various SST (single-shell tank) sludges. First, analytical data were compiled from existing tank waste characterization reports. These data were summarized on tank-specific worksheets that provided a uniform format for reviewing and comparing data, as well as the means to verify whether the data set for each tank was complete. Worksheets were completed for 27 SST wastes. The analytical water wash data provided tank-specific information about the fraction of each component that dissolves with water, i.e., an estimate of tank-specific wash factors for evaluating tank-by-tank processing. These wash data were then used collectively to evaluate some of the wash factors that are assumed for the overall SST waste inventory; specifically, wash factors for elements that would be found primarily in sludges. The final step in this study was to incorporate the characterization and wash factor data into a spreadsheet that provides insight into the effect of enhanced sludge washing on individual tank sludges as well as for groups of sludges that may be representative of different waste types. Spreadsheet results include the estimated mass and percentage of each element that would be removed with washing and leaching. Furthermore, estimated compositions are given of the final wash and leach streams and residual solids, in terms of both concentration and dry weight percent

  20. Co-conditioning and dewatering of chemical sludge and waste activated sludge.

    Chang, G R; Liu, J C; Lee, D J

    2001-03-01

    The conditioning and dewatering behaviors of chemical and waste activated sludges from a tannery were studied. Capillary suction time (CST), specific resistance to filtration (SRF), and bound water content were used to evaluate the sludge dewatering behaviors. Zeta potentials were also measured. Experiments were conducted on each sludge conditioned and dewatered separately, and on the sludge mixed at various ratios. Results indicate that the chemical sludge was relatively difficult to be dewatered, even in the presence of polyelectrolyte. When the waste activated sludge was mixed with the chemical sludge at ratios of 1:1 and 2:1, respectively, the dewaterability of chemical sludge improved remarkably while the relatively better dewaterability of the waste activated sludge deteriorated only to a limited extent. As the mixing ratios became 4:1 and 8:1, the dewaterability of the mixed sludge was equal to that of the waste activated sludge. The optimal polyelectrolyte dosage for the mixed sludge was equal to or less than that of the waste activated sludge. It is proposed that the chemical sludges act as skeleton builders that reduce the compressibility of the mixed sludge whose dewaterability is enhanced. Bound water contents of sludge decreased at low polyelectrolyte dosage and were not significantly affected as polyelectrolyte dosage increased. Advantages and disadvantages of co-conditioning and dewatering chemical sludge and waste activated sludge were discussed.

  1. Mitigation of micropollutants for black water application in agriculture via composting of anaerobic sludge

    Butkovskyi, A., E-mail: andrii.butkovskyi@wur.nl [Sub-Department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA Wageningen (Netherlands); Wetsus, Center of Excellence for Sustainable Water Technology, P.O. Box 1113, 8900CC Leeuwarden (Netherlands); Ni, G. [Sub-Department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA Wageningen (Netherlands); Hernandez Leal, L. [Wetsus, Center of Excellence for Sustainable Water Technology, P.O. Box 1113, 8900CC Leeuwarden (Netherlands); Rijnaarts, H.H.M.; Zeeman, G. [Sub-Department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA Wageningen (Netherlands)

    2016-02-13

    Highlights: • Micropollutants removal in the composted UASB sludge ranged from 87% to 99%. • 99% removal of the persistent pharmaceutical diclofenac is achieved. • Triclosan is partly transformed into methyltriclosan that is accumulated in compost. - Abstract: The excess sludge from Up-flow anaerobic sludge bed (UASB) reactor operated on source separated toilet wastewater is a potential source of nutrients and organic matter. It can be further stabilized and dried by composting and applied as a soil amendment. Presence of pathogens, heavy metals and micropollutants in the compost derived from anaerobic sludge is thus undesirable. This paper focuses on removal of micropollutants, typically present in domestic wastewater, via composting of UASB sludge with waste wood. Estrone, diclofenac, ibuprofen, metoprolol, carbamazepine, galaxolide and triclosan were spiked to a mixture of UASB sludge and waste wood. Their concentrations were monitored during 92 days of composting at controlled temperature conditions. All studied micropollutants were removed at various rates with overall removal ranging from 99.9% for ibuprofen, diclofenac and estrone to 87.8% for carbamazepine. Accumulation of methyltriclosan as by-product of triclosan degradation was observed. The prospects and limitations of the integration of a composting process into Source Separated Sanitation concepts are discussed.

  2. RESPIROMETRIC ACTIVITY OF ACTIVATED SLUDGE AND BIOFILM IN IFAS-MBBR SYSTEM

    Paula Piechna

    2017-07-01

    Full Text Available The aim of the presented study was: a assessment of activity of microorganisms developed in form of activated sludge and biofilm, b indirect assessment of the role of analyzed biocoenoses in removal of organic compounds in hybrid reactor with moving bed. Oxygen uptake rate tests (OUR have been used, and obtained results were presented as volumetric activity (expressed in mg O2/L · h and mass activity (expressed as mg O2/g VTS · h. Tests were conducted for three different variants, in which, as the biomass: 1 biofilm was used, 2 activated sludge was used, 3 biofilm and activated sludge were used. The biomass was collected from aerobic reactor from a wastewater treatment plant working in IFAS-MBBR system. The highest volumetric activity was observed for variant with biofilm and activated sludge, and the lowest for variant with biofilm only. Nonetheless, the highest value of oxygen uptake rate related to total volatile solids was observed for variant with biofilm and the lowest for activated sludge. Obtained results suggest, that during this research, at the wastewater treatment plant, the main role in removal of organic pollutants played the biomass developed in form of activated sludge.

  3. Mitigation of micropollutants for black water application in agriculture via composting of anaerobic sludge

    Butkovskyi, A.; Ni, G.; Hernandez Leal, L.; Rijnaarts, H.H.M.; Zeeman, G.

    2016-01-01

    Highlights: • Micropollutants removal in the composted UASB sludge ranged from 87% to 99%. • 99% removal of the persistent pharmaceutical diclofenac is achieved. • Triclosan is partly transformed into methyltriclosan that is accumulated in compost. - Abstract: The excess sludge from Up-flow anaerobic sludge bed (UASB) reactor operated on source separated toilet wastewater is a potential source of nutrients and organic matter. It can be further stabilized and dried by composting and applied as a soil amendment. Presence of pathogens, heavy metals and micropollutants in the compost derived from anaerobic sludge is thus undesirable. This paper focuses on removal of micropollutants, typically present in domestic wastewater, via composting of UASB sludge with waste wood. Estrone, diclofenac, ibuprofen, metoprolol, carbamazepine, galaxolide and triclosan were spiked to a mixture of UASB sludge and waste wood. Their concentrations were monitored during 92 days of composting at controlled temperature conditions. All studied micropollutants were removed at various rates with overall removal ranging from 99.9% for ibuprofen, diclofenac and estrone to 87.8% for carbamazepine. Accumulation of methyltriclosan as by-product of triclosan degradation was observed. The prospects and limitations of the integration of a composting process into Source Separated Sanitation concepts are discussed.

  4. Copper and trace element fractionation in electrokinetically treated methanogenic anaerobic granular sludge

    Virkutyte, Jurate; Hullebusch, Eric van; Sillanpaeae, Mika; Lens, Piet

    2005-01-01

    The effect of electrokinetic treatment (0.15 mA cm -2 ) on the metal fractionation in anaerobic granular sludge artificially contaminated with copper (initial copper concentration 1000 mg kg -1 wet sludge) was studied. Acidification of the sludge (final pH 4.2 in the sludge bed) with the intention to desorb the copper species bound to the organic/sulfides and residual fractions did not result in an increased mobility, despite the fact that a higher quantity of copper was measured in the more mobile (i.e. exchangeable/carbonate) fractions at final pH 4.2 compared to circum-neutral pH conditions. Also addition of the chelating agent EDTA (Cu 2+ :EDTA 4- ratio 1.2:1) did not enhance the mobility of copper from the organic/sulfides and residual fractions, despite the fact that it induced a reduction of the total copper content of the sludge. The presence of sulfide precipitates likely influences the copper mobilisation from these less mobile fractions, and thus makes EDTA addition ineffective to solubilise copper from the granules. - Electrokinetic treatment of copper contaminated anaerobic granular sludge at 0.15 mA cm -2 for 14 days induces copper and trace metal mobility as well as changes in their fractionation (i.e. bonding forms)

  5. Fluid-bed combustion

    Hunt, G.; Schoebotham, N.

    1981-02-01

    In Energy Equipment Company's two-stage fluidized bed system, partial combustion in a fluidized bed is followed by burn-off of the generated gases above the bed. The system can be retrofitted to existing boilers, and can burn small, high ash coal efficiently. It has advantages when used as a hot gas generator for process drying. Tests on a boiler at a Cadbury Schweppes plant are reported.

  6. Steam generator sludge removal apparatus

    Schafer, B.W.; Werner, C.E.; Klahn, F.C.

    1992-01-01

    The present invention relates to equipment for cleaning steam generators and in particular to a high pressure fluid lance for cleaning sludge off the steam generator tubes away from an open tube lane. 6 figs

  7. Processing method for radioactive sludge

    Shoji, Yuichi; Kaneko, Masaaki.

    1993-01-01

    The concentration of radioactive sludges contained in a storage tank is controlled, thereafter, a filter is charged into a processing vessel to continuously conduct dewatering. Then, the radioactive sludges and an oxidizer are mixed by stirring using a stirring impeller and by vibrations using a vibrator. At the same time, thermic rays are irradiated by using infrared ray lamps to heat and decompose them. Since thermic rays reach the center of the radioactive sludges by the infrared ray lamps, ion exchange resins are sufficiently decomposed and carbonized into inorganic material. Then, a filling hardener such as mortar cement having a good flowability is charged to solidify the wastes. With such procedures, radioactive sludges can be stored under a stable condition for a long period of time by decomposing organic materials into inorganic materials and solidifying them. Further, an operator's radiation exposure dose can remarkably be reduced by applying a predetermined and a stabilization treatment in an identical processing vessel. (N.H.)

  8. Fluidised bed combustion system

    McKenzie, E.C.

    1976-01-01

    Fluidized bed combustion systems that facilitates the maintenance of the depth of the bed are described. A discharge pipe projects upwardly into the bed so that bed material can flow into its upper end and escape downwardly. The end of the pipe is surrounded by an enclosure and air is discharged into the enclosure so that material will enter the pipe from within the enclosure and have been cooled in the enclosure by the air discharged into it. The walls of the enclosure may themselves be cooled

  9. Municipal sludge disposal economics

    Jones, J L [SRI International, Menlo Park, CA; Bomberger, Jr, D C; Lewis, F M

    1977-10-01

    Costs for disposal of sludges from a municipal wastewater treatment plant normally represents greater than or equal to 25% of the total plant operating cost. The following 5 sludge handling options are considered: chemical conditioning followed by vacuum filtration, and incineration; high-pressure wet-air oxidation and vacuum filtration or filter press prior to incineration; thermal conditioning, vacuum filtraton, and incineration; high-pressure wet-air oxidation and vacuum filtration, with ash to landfill; aerobic or anaerobic digestion, followed by chemical conditioning, vacuum filtration, and disposal on land; and chemical conditioning, followed by a filter press, flash dryer, and sale as fertilizer. The 1st 2 options result in the ultimate disposal of small amounts of ash in a landfill; the digestion options require a significant landfill; the fertilizer option requires a successful marketing and sales effort. To compare the economies of scale for the options, analyses were performed for 3 plant capacities - 10, 100, and 500 mgd; as plant size increases, the economies of scale for incineration system are quite favorable. The anaerobic digestion system has a poorer capital cost-scaling factor. The incinerator options which start with chemical conditioning consume much less electrical power at all treatment plant sizes; incinerator after thermal conditioning uses more electricity but less fuel. Digestion requires no direct external fossil fuel input. The relative use of fuel is constant at all plant sizes for other options. The incinerator options can produce a significant amount of steam which may be used. The anaerobic digestion process can be a significant net producer of fuel gas.

  10. Biological treatment of aqueous effluents in a bacterial bed

    1978-12-14

    Biological treatment of aqueous effluents in a bacterial bed is carried out effectively for refinery waters having a low five-day BOD by using a plastic packing to support the bacteria in place of the less reliable pozzolana (volcanic ash) formerly employed. Such biofilters, developed by Lurgi S.A., are more sensitive to BOD overloading than activated sludge beds, so that very stable operating conditions are required. In these bacterial beds, the water trickles over the plastic packing and becomes oxygenated, which leads to degradation of undesirable substances in the water. In the refinery, this process can give excellent results when properly carried out, but the biofilter may generate suspended matter under unsatisfactory operating conditions, and is therefore usually placed upstream from the flocculation and filtration units. To date, all installations have remained below the required standard limit of 30 mg/l. of suspended matter.

  11. Hydrodynamic studies in designing of fluidized bed system

    Mohamad Puad Abu; Muhd Noor Muhd Yunus; Syed Nasaruddin Syed Idris

    2002-01-01

    Fluidized bed process have been used mostly in the petroleum and paper industries, and for processing nuclear wastes, spent cook liquor, wood chips, and sewage sludge disposal. Even at MINT some of the equipment available used this principal. Before we use or purchase this equipment, it is very grateful if we could understand how the system has been designed. The hydrodynamic fluidization studies is very important in designing of fluidized bed system especially in determining the minimum fluidizing velocity, terminal velocity, flexibility of operation, slugging condition, bubble size and velocity, and transport disengaging height. They can be determined either by calculation or experimentation. This paper will highlight the hydrodynamic study that need to be performed in designing of fluidized bed system so that its can be used appropriately. (Author)

  12. Enhanced sludge washing evaluation plan

    Jensen, R.D.

    1994-09-01

    The Tank Waste Remediation System (TWRS) Program mission is to store, treat, and immobilize highly radioactive Hanford Site waste (current and future tank waste and the strontium/cesium capsules) in an environmentally sound, safe, and cost-effective manner. The scope of the TWRS Waste Pretreatment Program is to treat tank waste and separate that waste into HLW and LLW fractions and provide additional treatment as required to feed LLW and HLW immobilization facilities. Enhanced sludge washing was chosen as the baseline process for separating Hanford tank waste sludge. Section 1.0 briefly discusses the purpose of the evaluation plan and provides the background that led to the choice of enhanced sludge washing as the baseline process. Section 2.0 provides a brief summary of the evaluation plan details. Section 3.0 discusses, in some detail, the technical work planned to support the evaluation of enhanced sludge washing. Section 4.0 briefly discusses the potential important of policy issues to the evaluation. Section 5.0 discusses the methodology to be used in the evaluation process. Section 6.0 summarizes the milestones that have been defined to complete the enhanced sludge washing evaluation and provides a summary schedule to evaluate the performance of enhanced sludge washing. References are identified in Section 7.0, and additional schedule and milestone information is provided in the appendices.

  13. Enhanced sludge washing evaluation plan

    Jensen, R.D.

    1994-09-01

    The Tank Waste Remediation System (TWRS) Program mission is to store, treat, and immobilize highly radioactive Hanford Site waste (current and future tank waste and the strontium/cesium capsules) in an environmentally sound, safe, and cost-effective manner. The scope of the TWRS Waste Pretreatment Program is to treat tank waste and separate that waste into HLW and LLW fractions and provide additional treatment as required to feed LLW and HLW immobilization facilities. Enhanced sludge washing was chosen as the baseline process for separating Hanford tank waste sludge. Section 1.0 briefly discusses the purpose of the evaluation plan and provides the background that led to the choice of enhanced sludge washing as the baseline process. Section 2.0 provides a brief summary of the evaluation plan details. Section 3.0 discusses, in some detail, the technical work planned to support the evaluation of enhanced sludge washing. Section 4.0 briefly discusses the potential important of policy issues to the evaluation. Section 5.0 discusses the methodology to be used in the evaluation process. Section 6.0 summarizes the milestones that have been defined to complete the enhanced sludge washing evaluation and provides a summary schedule to evaluate the performance of enhanced sludge washing. References are identified in Section 7.0, and additional schedule and milestone information is provided in the appendices

  14. Production of renewable energy from biomass and waste materials using fluidized bed technologies

    Rozainee, M.; Rashid, M.; Looi, S.

    2000-01-01

    Malaysian industries generate substantial amount of biomass and waste materials such as wastes from agricultural and wood based industries, sludge waste from waste-water treatment plants and solid waste from municipals. Incinerating these waste materials not only produces renewable energy, but also solving their disposal problems. Fluidized bed combustors are widely used for incinerating these biomass materials. The significant advantages of fluidized bed incineration include simple design, efficient, and ability to reduce air pollution emissions. This paper discusses the opportunities and challenges of producing the green energy from biomass materials using the fluidized bed technologies. (Author)

  15. Anaerobic treatment of complex wastewater and waste activated sludge - Appl. of an upflow anaerobic solid removal (UASR).

    Zeeman, G.; Sanders, W.T.M.; Wang, K.Y.; Lettinga, G.

    1997-01-01

    The application of one phase anaerobic wastewater systems for the treatment of complex wastewaters containing high amounts of suspended solids or lipids is usually limited by accumulation of these compounds in the sludge bed. This accumulation reduces the solid retention time and methanogenic

  16. Dehydrating sewage plant sludge using a mobile centrifuge; Deshidratacion de fangos en las depuradoras mediante una centrifuga movil

    Garcia Palou, P.; Arnau Planas de Farnes, A.; Arnau Figuerola, J.

    1997-09-01

    This study set out to examine various mechanical sludge dehydration systems as alternatives to the drying beds currently in existence in the sewage plants managed by the Costa Brava Consortium at Portbou, Colera, El Port de la Selva and Cadaques by determining their technical and economic feasibility. (Author) 11 refs.

  17. Effect of vitamin B12 pulse addition on the performance of cobalt deprived anaerobic granular sludge bioreactors

    Fermoso, Fernando G.; Bartacek, Jan; Lens, Piet N.L.

    2010-01-01

    The effect of a pulse addition of vitamin B12 as cobalt source to restore the performance of cobalt depleted methanol-fed bioreactors was investigated. One upflow anaerobic sludge bed (UASB) reactor was supplied with a pulse of vitamin B12, and its

  18. Co-combustion of waste materials using fluidized bed technology

    M. Lopes; I. Gulyurtlu; P. Abelha; T. Crujeira; D. Boavida; I. Cabrita [INETI-DEECA, Lisbon (Portugal)

    2004-07-01

    There is growing interest in using renewable fuels in order to sustain the CO{sub 2} accumulation. Several waste materials can be used as coal substitutes as long as they contain significant combustible matter, as for example MSW and sewage sludge. Besides the outcome of the energetic valorization of such materials, combustion must be regarded as a pre-treatment process, contributing to the safe management of wastes. Landfilling is an expensive management option and requires a previous destruction of the organic matter present in residues, since its degradation generates greenhouse gases and produces acidic organic leachates. Fluidized bed combustion is a promising technology for the use of mixtures of coal and combustible wastes. This paper presents INETI's experience in the co-combustion of coal with this kind of residues performed in a pilot fluidized bed. Both the RDF (from MSW and sewage sludge) and sewage sludge combustion problems were addressed, relating the gaseous emissions, the behaviour of metals and the leachability of ashes and a comparison was made between co-combustion and mono-combustion in order to verify the influence of the utilization of coal. 9 refs., 1 fig., 3 tabs.

  19. The effect of sludge recirculation rate on a UASB-digester treating domestic sewage at 15 °C.

    Zhang, Lei; Hendrickx, Tim L G; Kampman, Christel; Zeeman, Grietje; Temmink, Hardy; Li, Weiguang; Buisman, Cees J N

    2012-01-01

    The anaerobic treatment of low strength domestic sewage at low temperature is an attractive and important topic at present. The upflow anaerobic sludge bed (UASB)-digester system is one of the anaerobic systems to challenge low temperature and concentrations. The effect of sludge recirculation rate on a UASB-digester system treating domestic sewage at 15 °C was studied in this research. A sludge recirculation rate of 0.9, 2.6 and 12.5% of the influent flow rate was investigated. The results showed that the total chemical oxygen demand (COD) removal efficiency rose with increasing sludge recirculation rate. A sludge recirculation rate of 0.9% of the influent flow rate led to organic solids accumulation in the UASB reactor. After the sludge recirculation rate increased from 0.9 to 2.6%, the stability of the UASB sludge was substantially improved from 0.37 to 0.15 g CH₄-COD/g COD, and the bio-gas production in the digester went up from 2.9 to 7.4 L/d. The stability of the UASB sludge and bio-gas production in the digester were not significantly further improved by increasing sludge recirculation rate to 12.5% of the influent flow rate, but the biogas production in the UASB increased from 0.37 to 1.2 L/d. It is recommended to apply a maximum sludge recirculation rate of 2-2.5% of the influent flow rate in a UASB-digester system, as this still allows energy self-sufficiency of the system.

  20. Fluidized bed incinerator development

    Ziegler, D.L.; Johnson, A.J.

    1976-01-01

    A fluidized bed incinerator is being developed for burning rad contaminated solid and liquid waste materials. In situ neutralization of acid gases by the bed material, catalytic afterburning, and gas filtration are used to produce a clean flue gas without the use of aqueous scrubbing

  1. Heating value characteristics of sewage sludge: a comparative study of different sludge types

    Kim, Young-JU.; Kang, Hae-Ok.; Qureshi, T.I.

    2005-01-01

    Heating value characteristics of three different types of sludge, i.e. domestic sewage sludge, industrial sludge, and industrial + domestic sewage sludge were investigated. Industrial + domestic sewage sludge (thickened) showed the highest heating value (5040 kcal/kg) than other sludge types. This may be due to increased amount of organic matter presents in thickened sludge than de-watered sludge. A gradual increase in organic matter of the sludge was observed with the increase of the moisture contents. Heating value of the sludge having 60% moisture contents was found in the range between 924-1656 kcal/kg and this amount was higher than the minimum heating value (800 kcal/kg) required sustaining auto thermal combustion in sludge incineration process. Energy consumption requirement for pre drying sludge operations revealed that industrial sludge (de-watered) required the minimum cost (13 $/ton of sludge) to make it a sludge of fuel grade (60% W), while mixed sludge cost the highest amount for its pre-drying operations. (author)

  2. Modelling of sludge blanket height and flow pattern in UASB reactors treating municipal wastewater

    Singh, K.S.; Viraraghavan, T.

    2002-01-01

    Two upflow anaerobic sludge blanket (UASB) reactors were started-up and operated for approximately 900 days to examine the feasibility of treating municipal wastewater under low temperature conditions. A modified solid distribution model was formulated by incorporating the variation of biogas production rate with a change in temperature. This model was used to optimize the sludge blanket height of UASB reactors for an effective operation of gas-liquid-solid (GLS) separation device. This model was found to simulate well the solid distribution as confirmed experimental observation of solid profile along the height of the reactor. Mathematical analysis of tracer curves indicated the presence of a mixed type of flow pattern in the sludge-bed zone of the reactor. It was found that the dead-zone and by-pass flow fraction were impacted by the change in operating temperatures. (author)

  3. Pentachlorophenol (PCP) sludge recycling unit

    1994-08-01

    The Guelph Utility Pole Company treats utility poles by immersion in pentachlorophenol (PCP) or by pressure treatment with chromated copper arsenate (CCA). The PCP treatment process involves a number of steps, each producing a certain amount of sludge and other wastes. In a plant upgrading program to improve processing and treatment of poles and to reduce and recycle waste, a PCP recovery unit was developed, first as an experimental pilot-scale unit and then as a full-scale unit. The PCP recovery unit is modular in design and can be modified to suit different requirements. In a recycling operation, the sludge is pumped through a preheat system (preheated by waste heat) and suspended solids are removed by a strainer. The sludge is then heated in a tank and at a predetermined temperature it begins to separate into its component parts: oil, steam, and solids. The steam condenses to water containing low amounts of light oil, and this water is pumped through an oil/water separator. The recovered oil is reused in the wood treatment process and the water is used in the CCA plant. The oil remaining in the tank is reused in PCP treatment and the solid waste, which includes small stones and wood particles, is removed and stored. By the third quarter of operation, the recovery unit was operating as designed, processing ca 10,000 gal of sludge. This sludge yielded 6,500 gal of water, 3,500 gal of oil, and ca 30 gal of solids. Introduction of the PCP sludge recycling system has eliminated long-term storage of PCP sludge and minimized costs of hazardous waste disposal. 4 figs

  4. Leaching and accumulation of trace elements in sulfate reducing granular sludge under concomitant thermophilic and low pH conditions

    Gonzalez-Gil, Graciela; Lopes, Sí lvia I C; Saikaly, Pascal; Lens, Piet Nl L

    2012-01-01

    The leaching and/or accumulation of trace elements in sulfate reducing granular sludge systems was investigated. Two thermophilic up-flow anaerobic sludge bed (UASB) reactors operated at pH 5 were fed with sucrose (4gCODl reactor -1d -1) and sulfate at different COD/SO 4 2- ratios. During the start-up of such acidogenic systems, an initial leaching of trace elements from the inoculum sludge occurred regardless of trace elements supplementation in the reactor influent. The granular sludge maintained the physical structure despite high Fe leaching. After start-up and nonetheless the acidic conditions, Co, Ni, Cu, Zn, Mo and Se were retained or accumulated by the sludge when added. Particularly, Ni and Co accumulated in the carbonates and exchangeable fractions ensuring potential bioavailability. Otherwise, the initial stock in the inoculum sludge sufficed to operate the process for nearly 1year without supplementation of trace elements and no significant sludge wash-out occurred. © 2012 Elsevier Ltd.

  5. Leaching and accumulation of trace elements in sulfate reducing granular sludge under concomitant thermophilic and low pH conditions

    Gonzalez-Gil, Graciela

    2012-12-01

    The leaching and/or accumulation of trace elements in sulfate reducing granular sludge systems was investigated. Two thermophilic up-flow anaerobic sludge bed (UASB) reactors operated at pH 5 were fed with sucrose (4gCODl reactor -1d -1) and sulfate at different COD/SO 4 2- ratios. During the start-up of such acidogenic systems, an initial leaching of trace elements from the inoculum sludge occurred regardless of trace elements supplementation in the reactor influent. The granular sludge maintained the physical structure despite high Fe leaching. After start-up and nonetheless the acidic conditions, Co, Ni, Cu, Zn, Mo and Se were retained or accumulated by the sludge when added. Particularly, Ni and Co accumulated in the carbonates and exchangeable fractions ensuring potential bioavailability. Otherwise, the initial stock in the inoculum sludge sufficed to operate the process for nearly 1year without supplementation of trace elements and no significant sludge wash-out occurred. © 2012 Elsevier Ltd.

  6. The hydraulic transportation of thickened sludges

    driniev

    non-Newtonian sludges (Xu et al., 1993; Spinosa and Lotita, 2001; .... [11]. Analysis and typical applications. Laminar/turbulent transition. For most sewage sludges the ... on Transport and Sedimentation of Solid Particles - Ghent, September.

  7. Microbiological aspects of granular methanogenic sludge

    Dolfing, J.

    1987-01-01

    The settling characteristics of anaerobic sludge are enhanced by the formation of microbial conglomerates. Various types of conglomerates having different structures, were distinguished in the present study, viz. granules, pellets and flocs (chapter 1). Granular methanogenic sludge, often

  8. Radiation hygienization of raw sewage sludge

    Shah, M.R.; Lavale, D.S.; Rawat, P.; Benny, P.G.; Sharma, A.K.; Dey, G.R.; Bhave, V.

    2001-01-01

    'Radiation treatment of municipal sewage sludge can achieve resource conservation and recovery objectives. The liquid sludge irradiator of Sludge Hygienization Research Irradiator at Baroda (India) was operated for generating data on treatment of raw sludge containing 3-4 % solids. The plant system was modified for irradiating raw sludge without affecting basic irradiator initially designed to treat digested sludge. Hourly samples were analysed for estimation of disinfection dose requirement. Sand separated from the sludge was used as in-situ dosimeter by making use of its thermoluminescence property. Investigations are being carried out for regrowth of Total Coliforms in the sludge samples from this irradiator. Possibility of inadequate treatment due to geometric configuration of irradiator is being checked. (author)

  9. Biological sludge solubilisation for reduction of excess sludge production in wastewater treatment process.

    Yamaguchi, T; Yao, Y; Kihara, Y

    2006-01-01

    A novel sludge disintegration system (JFE-SD system) was developed for the reduction of excess sludge production in wastewater treatment plants. Chemical and biological treatments were applied to disintegrate excess sludge. At the first step, to enhance biological disintegration, the sludge was pretreated with alkali. At the second step, the sludge was disintegrated by biological treatment. Many kinds of sludge degrading microorganisms integrated the sludge. The efficiency of the new sludge disintegration system was confirmed in a full-scale experiment. The JFE-SD system reduced excess sludge production by approximately 50% during the experimental period. The quality of effluent was kept at quite a good level. Economic analysis revealed that this system could significantly decrease the excess sludge treatment cost.

  10. The role and control of sludge age in biological nutrient removal activated sludge systems.

    Ekama, G A

    2010-01-01

    The sludge age is the most fundamental and important parameter in the design, operation and control of biological nutrient removal (BNR) activated sludge (AS) systems. Generally, the better the effluent and waste sludge quality required from the system, the longer the sludge age, the larger the biological reactor and the more wastewater characteristics need to be known. Controlling the reactor concentration does not control sludge age, only the mass of sludge in the system. When nitrification is a requirement, sludge age control becomes a requirement and the secondary settling tanks can no longer serve the dual purpose of clarifier and waste activated sludge thickeners. The easiest and most practical way to control sludge age is with hydraulic control by wasting a defined proportion of the reactor volume daily. In AS plants with reactor concentration control, nitrification fails first. With hydraulic control of sludge age, nitrification will not fail, rather the plant fails by shedding solids over the secondary settling tank effluent weirs.

  11. Effects of gamma-radiation at pilot plant level as compared to effects of pasteurization on the dewatering of sewage sludges

    Groneman, A.F.

    1975-01-01

    Dewatering and disposal of sludge are costly and time consuming processes. At a pilot plant near Munich efforts were made to estimate the effects of ionizing radiation on dewatering characteristics of different sludges, used for recycling in agriculture. The ease with which sludge drains on drying beds and in mechanical devices is reflected in the value of the specific resistance to filtration. A dose of 300 krad, delivered at an average dose rate of 62 krad per hour in the irradiation plant, was effective for disinfection and reduced the specific resistance to filtration in sludges from the waste water works at Geiselbullach and Starnberg from 24.2 x 10 9 sec 2 /g and 18.0 x 10 9 sec 2 /g to 9.7 x 10 9 sec 2 /g and 5.6 x 10 9 sec 2 /g, respectively. These improved dewatering properties were associated with a clear increase of the compressibility of the anaerobically digested sludges. Pasteurization at 70 0 C during 30 minutes drastically deteriorated the dewatering properties, raising the specific resistance to values approximately 4 times as high as the specific resistance in irradiated sludges. Information obtained from filterability tests was confirmed by plant operators who noticed that irradiated sludges dewatered much better than untreated sludges in drying beds. Experimental evidence indicated that the conditioning effect of gamma irradiation persisted for more than 20 days suggesting that permanent changes were induced in the physical-chemical properties of the domestic, anaerobically digested sludges. Measurements of electrophoretic mobilities showed that the negative electrostatic charges of colloidal particles in sludges were reduced by gamma irradiation whereas pasteurization increased this negative electrostatic charge. Evidence indicated that the specific resistance was considerably increased by effects of the recirculating pumping. This pumping is done to obtain a homogeneous irradiation dose for disinfection. Alternative designs for irradiation

  12. Oil sludge treatment using thermal and ash vitrification technology

    Rohyiza Baan; Sharifah Aishah, S.A.K.; Mohamad Puad Abu; Mohd Abdul Wahab Yusof

    2010-01-01

    In this paper, an experimental study of crude oil sludge terminal for volume reduction and radionuclide stability was treated by using integrated thermal treatment system. The pre-thermal treatment of oil sludge was carried out in fluidized bed combustor at temperature 500 degree Celsius, and then the ash produced from that process was vitrified in high temperature furnace at temperature above 1000 degree Celsius. The main contents of oil sludge are composed of 80% carbon, 11% sulphur, 50% volatile matter and 30% ash. The high heating value was 35,722 kJ/ kg. Analysis by gamma spectrometer was showed the radionuclide as Ra-226 (52.23 Bq/ kg), Ra-228 (47.48 Bq/ kg), K-40 (172.55 Bq/ kg), whereas analysis by neutron activation analysis (NAA) for U (0.5 μg/ g) and Th (0.5 μg/ g) was present in low concentration. Trace elements as Ba, Cd, Cr, Hg, As, Pb, Al, Zn, Ni was determine by using ICPMS. Thermal analysis has shown loss of mass and residual decomposition in the TG and DTA curves. The concentration of radionuclide in ash from fluidized bed combustor process was increased for Ra-226 (264.27 Bq/ kg) and Ra-228 (253.77 Bq/ kg). The slag was produced from ash vitrification process was characterized by X-ray fluorescence (XRF) and showed that silica oxide and potassium oxide were found. The slag characterization by X-ray diffraction (XRD) showed that slag composed of crystalline. The toxicity characteristic leaching procedure (TCLP) test showed that the slag resulted in very low leachability of heavy metals. Most of the toxic metals are fixed in the vitrification process and the leachate values meet the standard level of Malaysian Department of Environmental (DOE) of hazardous materials. The average concentration of each element varied between 1.5-14.0 mg/ kg. (author)

  13. Integral study of sewage sludges

    1994-01-01

    Sewage sludges are the by-product generated during the treatment process of waste water, and they are conformed by a solid phase which origin is the accumulation of pollutant materials which has been added to water during natural and anthropogenic activities. Its handling is one of the most serious problems faced by water treatment plants which involve the production, gathering, transportation, re utilization and final disposal of sewage sludges. The main purpose of this project is to perform a technical evaluation of the process of sewage sludge irradiation for its possible application as a choice for treatment and final disposal. Irradiation with gammas from Cobalt-60 shows effectiveness in disinfestation of sewage sludges, since they reduce six times the microbial population with a 7 KGy dose. In like manners with doses of 10 KGy is possible to bring down in 70 % the concentration of organic compounds, as well as to eliminate the presence of 6 to 22 organic compounds on samples of sewage sludges. The whole content of this work is presented in six sections: Introduction, Antecedents, Methodology, Conclusions, Suggestions and Bibliography. (Author)

  14. Excess sludge reduction in activated sludge processes by integrating ultrasound treatment

    Perez-Elvira, S.; Fdz-Polanco, M.; Plaza, F. I.; Garralon, G.; Fdz-Polanco, F.

    2009-01-01

    Biological sludge produced in the activated sludge process can be minimised modifying the water line, the sludge line or the final disposal strategy. Selecting the water line the general idea is to reduce the sludge producing the yield coefficient by means of the called lysis cryptic growth process. The main techniques referenced in literature are onization, chlorination and chemical and heat treatment. Ultrasounds are widely used to increase anaerobic biodegradability but are not reported as system to control excess sludge production. (Author)

  15. Removal of phosphorus from agricultural wastewaters using adsorption media prepared from acid mine drainage sludge

    Sibrell, Philip L.; Montgomery, Gary A.; Ritenour, Kelsey L.; Tucker, Travis W.

    2009-01-01

    Excess phosphorus in wastewaters promotes eutrophication in receiving waterways. A??cost-effective method for the removal of phosphorus from water would significantly reduce the impact of such wastewaters on the environment. Acid mine drainage sludge is a waste product produced by the neutralization of acid mine drainage, and consists mainly of the same metal hydroxides used in traditional wastewater treatment for the removal of phosphorus. In this paper, we describe a method for the drying and pelletization of acid mine drainage sludge that results in a particulate media, which we have termed Ferroxysorb, for the removal of phosphorus from wastewater in an efficient packed bed contactor. Adsorption capacities are high, and kinetics rapid, such that a contact time of less than 5 min is sufficient for removal of 60-90% of the phosphorus, depending on the feed concentration and time in service. In addition, the adsorption capacity of the Ferroxysorb media was increased dramatically by using two columns in an alternating sequence so that each sludge bed receives alternating rest and adsorption cycles. A stripping procedure based on treatment with dilute sodium hydroxide was also developed that allows for recovery of the P from the media, with the possibility of generating a marketable fertilizer product. These results indicate that acid mine drainage sludges - hitherto thought of as undesirable wastes - can be used to remove phosphorus from wastewater, thus offsetting a portion of acid mine drainage treatment costs while at the same time improving water quality in sensitive watersheds.

  16. Intrinsic kinetic parameters of substrate utilization by immobilized anaerobic sludge.

    Zaiat, M; Vieira, L G; Foresti, E

    1997-01-20

    This article presents a method for evaluating the intrinsic kinetic parameters of the specific substrate utilization rate (r) equation and discusses the results obtained for anaerobic sludge-bed samples taken from a horizontal-flow anaerobic immobilized sludge (HAIS) reactor. This method utilizes a differential reactor filled with polyurethane foam matrices containing immobilized anaerobic sludge which is subjected to a range of feeding substrate flow rates. The range of liquid superficial velocities thus obtained are used for generating data of observed specific substrate utilization rates (r(obs)) under a diversity of external mass transfer resistance conditions. The r(obs) curves are then adjusted to permit their extrapolation for the condition of no external mass transfer resistance, and the values determined are used as a test for the condition of absence of limitation of internal mass transfer. The intrinsic parameters r(max), the maximum specific substrate utilization rate, and K(s), the half-velocity coefficient, are evaluated from the r values under no external mass transfer resistance and no internal mass transfer limitation. The application of such a method for anaerobic sludge immobilized in polyurethane foam particles treating a glucose substrate at 30 degrees C resulted in intrinsic r(max) and K(s), respectively, of 0.330 mg chemical oxygen demand (COD) . mg(-1) volatile suspended solids (VSS) . h(-1) and 72 mg COD . L(-1). In comparison with the values found in the literature, intrinsic r(max) is significantly high and intrinsic K(s) is relatively low. (c) 1997 John Wiley & Sons, Inc.

  17. Supplementary information on K-Basin sludges

    MAKENAS, B.J.

    1999-01-01

    Three previous documents in this series have been published covering the analysis of: K East Basin Floor and Pit Sludge, K East Basin Canister Sludge, and K West Basin Canister Sludge. Since their publication, additional data have been acquired and analyses performed. It is the purpose of this volume to summarize the additional insights gained in the interim time period

  18. 40 CFR 61.54 - Sludge sampling.

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Sludge sampling. 61.54 Section 61.54... sampling. (a) As an alternative means for demonstrating compliance with § 61.52(b), an owner or operator... days prior to a sludge sampling test, so that he may at his option observe the test. (c) Sludge shall...

  19. Heavy metals precipitation in sewage sludge

    Marchioretto, M.M.; Rulkens, W.H.; Bruning, H.

    2005-01-01

    There is a great need for heavy metal removal from strongly metal-polluted sewage sludges. One of the advantages of heavy metal removal from this type of sludge is the possibility of the sludge disposal to landfill with reduced risk of metals being leached to the surface and groundwater. Another

  20. Strategy to identify the causes and to solve a sludge granulation problem in methanogenic reactors: application to a full-scale plant treating cheese wastewater.

    Macarie, Hervé; Esquivel, Maricela; Laguna, Acela; Baron, Olivier; El Mamouni, Rachid; Guiot, Serge R; Monroy, Oscar

    2017-08-26

    Granulation of biomass is at the basis of the operation of the most successful anaerobic systems (UASB, EGSB and IC reactors) applied worldwide for wastewater treatment. Despite of decades of studies of the biomass granulation process, it is still not fully understood and controlled. "Degranulation/lack of granulation" is a problem that occurs sometimes in anaerobic systems resulting often in heavy loss of biomass and poor treatment efficiencies or even complete reactor failure. Such a problem occurred in Mexico in two full-scale UASB reactors treating cheese wastewater. A close follow-up of the plant was performed to try to identify the factors responsible for the phenomenon. Basically, the list of possible causes to a granulation problem that were investigated can be classified amongst nutritional, i.e. related to wastewater composition (e.g. deficiency or excess of macronutrients or micronutrients, too high COD proportion due to proteins or volatile fatty acids, high ammonium, sulphate or fat concentrations), operational (excessive loading rate, sub- or over-optimal water upflow velocity) and structural (poor hydraulic design of the plant). Despite of an intensive search, the causes of the granulation problems could not be identified. The present case remains however an example of the strategy that must be followed to identify these causes and could be used as a guide for plant operators or consultants who are confronted with a similar situation independently of the type of wastewater. According to a large literature based on successful experiments at lab scale, an attempt to artificially granulate the industrial reactor biomass through the dosage of a cationic polymer was also tested but equally failed. Instead of promoting granulation, the dosage caused a heavy sludge flotation. This shows that the scaling of such a procedure from lab to real scale cannot be advised right away unless its operability at such a scale can be demonstrated.

  1. Chemical modeling of waste sludges

    Weber, C.F.; Beahm, E.C.

    1996-10-01

    The processing of waste from underground storage tanks at the Oak Ridge National Laboratory (ORNL) and other facilities will require an understanding of the chemical interactions of the waste with process chemicals. Two aspects of sludge treatment should be well delineated and predictable: (1) the distribution of chemical species between aqueous solutions and solids, and (2) potential problems due to chemical interactions that could result in process difficulties or safety concerns. It is likely that the treatment of waste tank sludge will begin with washing, followed by basic or acidic leaching. The dissolved materials will be in a solution that has a high ionic strength where activity coefficients are far from unity. Activity coefficients are needed in order to calculate solubilities. Several techniques are available for calculating these values, and each technique has its advantages and disadvantages. The techniques adopted and described here is the Pitzer method. Like any of the methods, prudent use of this approach requires that it be applied within concentration ranges where the experimental data were fit, and its use in large systems should be preceded by evaluating subsystems. While much attention must be given to the development of activity coefficients, other factors such as coprecipitation of species and Ostwald ripening must also be considered when one aims to interpret results of sludge tests or to predict results of treatment strategies. An understanding of sludge treatment processes begins with the sludge tests themselves and proceeds to a general interpretation with the aid of modeling. One could stop with only data from the sludge tests, in which case the table of data would become an implicit model. However, this would be a perilous approach in situations where processing difficulties could be costly or result in concerns for the environment or health and safety

  2. Bed Bugs FAQs

    ... Europe. Bed bugs have been found in five-star hotels and resorts and their presence is not ... Health – Division of Parasitic Diseases Email Recommend Tweet YouTube Instagram Listen Watch RSS ABOUT About CDC Jobs ...

  3. Bed Bug Information Clearinghouse

    Its purpose is to help states, communities, and consumers in efforts to prevent and control bed bug infestations. Currently includes only reviewed material from federal/state/local government agencies, extension services, and universities.

  4. Particle fuel bed tests

    Horn, F.L.; Powell, J.R.; Savino, J.M.

    1985-01-01

    Gas-cooled reactors, using packed beds of small diameter coated fuel particles have been proposed for compact, high-power systems. The particulate fuel used in the tests was 800 microns in diameter, consisting of a thoria kernel coated with 200 microns of pyrocarbon. Typically, the bed of fuel particles was contained in a ceramic cylinder with porous metallic frits at each end. A dc voltage was applied to the metallic frits and the resulting electric current heated the bed. Heat was removed by passing coolant (helium or hydrogen) through the bed. Candidate frit materials, rhenium, nickel, zirconium carbide, and zirconium oxide were unaffected, while tungsten and tungsten-rhenium lost weight and strength. Zirconium-carbide particles were tested at 2000 K in H 2 for 12 hours with no visible reaction or weight loss

  5. Combustion of paper industry sewage sludge in existing boilers. Progress report 1; Tillfoersel av skogsindustriellt slam till eldstaeder. Delrapport etapp 1

    Hoeglund, Christer; Lundborg, Rickard; Myringer, Aase

    2003-10-01

    The aim of this project is to find a feasible method for combustion of sewage sludge in existing boilers of the paper industry. Biological sludge is complicated to handle since it contains a lot of bound water. Problems arise at dehydration and subsequent treatment. Moreover, the trend is that the amount of biological sludge increases whereas the amount of easily dehydrated fibre sludge decreases. Today, mixed sludge is combusted at more then half of the paper and pulp mills in Sweden. In order to evaluate the existing problems and the characteristics of different sludge, five mills have been studied. Sludge from three of these mills has also been analysed with regards to content and combustion properties. The content of sludge from different mills varies greatly. If the ash content is high, some substances, especially the alkali metals can cause problems at combustion such as sintering and deposits in the boiler. The analysed sludge did not contain important amounts of substances that causes problems at combustion, nor any toxic substances, except from one mill that had relatively high content of mercury. The combustion tests proved that combustion and especially drying of sludge is made preferably when the sludge particles are small, on as big an area as possible. One feasible method to combust sludge from the forest industry is to dehydrate so called fibre sludge to the same dry substance content as bark, in order to introduce it with existing fuel feeding devises and combust it together with the other fuel on the grate in a grate boiler. Dehydrated biological sludge, with considerably higher moisture content than pure fibre sludge, is added with a burner devise above the bed. The sludge particles are dried (in the furnace) and combusted before they leave the furnace. In this way, wet sludge that plug the bed is avoided. The location of the sludge feeding device in the boiler is important and should be adjusted individually to each furnace. Simulations show that

  6. Critical operational parameters for zero sludge production in biological wastewater treatment processes combined with sludge disintegration.

    Yoon, Seong-Hoon; Lee, Sangho

    2005-09-01

    Mathematical models were developed to elucidate the relationships among process control parameters and the effect of these parameters on the performance of anoxic/oxic biological wastewater processes combined with sludge disintegrators (A/O-SD). The model equations were also applied for analyses of activated sludge processes hybrid with sludge disintegrators (AS-SD). Solubilization ratio of sludge in the sludge disintegrator, alpha, hardly affected sludge reduction efficiencies if the biomass was completely destructed to smaller particulates. On the other hand, conversion efficiency of non-biodegradable particulates to biodegradable particulates, beta, significantly affected sludge reduction efficiencies because beta was directly related to the accumulation of non-biodegradable particulates in bioreactors. When 30% of sludge in the oxic tank was disintegrated everyday and beta was 0.5, sludge reduction was expected to be 78% and 69% for the A/O-SD and AS-SD processes, respectively. Under this condition, the sludge disintegration number (SDN), which is the amount of sludge disintegrated divided by the reduced sludge, was calculated to be around 4. Due to the sludge disintegration, live biomass concentration decreased while other non-biodegradable particulates concentration increased. As a consequence, the real F/M ratio was expected to be much higher than the apparent F/M. The effluent COD was maintained almost constant for the range of sludge disintegration rate considered in this study. Nitrogen removal efficiencies of the A/O-SD process was hardly affected by the sludge disintegration until daily sludge disintegration reaches 40% of sludge in the oxic tank. Above this level of sludge disintegration, autotrophic biomass concentration decreases overly and TKN in the effluent increases abruptly in both the A/O-SD and AS-SD processes. Overall, the trends of sludge reduction and effluent quality according to operation parameters matched well with experimental results

  7. Sludge in the pulp and paper industry in Sweden, part II[Combustion of]; Slam fraan skogsindustrin, fas II

    Gyllenhammar, Marianne; Herstad Svaerd, Solvie; Kjoerk, Anders; Larsson, Sara; Wennberg, Olle [S.E.P. Scandinavian Energy Project AB, Goeteborg (Sweden); Aamand, Lars-Erik [Chalmers Univ. of Technology, Goeteborg (Sweden); Eskilsson, David [Swedish National Testing and Research Inst., Boraas (Sweden)

    2003-11-01

    During part II of this research program combustible sludge from the pulp and paper industry has been studied in detail. 560,000 tonnes of sludge per year (calculated as dry sludge) are produced in Sweden. The energy potential in the produced sludge is about 2 TWh/year. Today 1 TWh/year is produced in the pulp and paper mill's own boilers. This means that additional energy can be utilized from this material. An objective of this program has been to decide whether or not there are sludge types which are favourable respectively difficult to combust. By mixing different sludge types, or other waste products, emissions and/or problems during combustion can be minimized. These possibilities have been studied thoroughly in this program. A lot of sludge samples have been studied in laboratory scale at SP and in full-scale at Chalmers 12 MW CFB boiler. As a complement to the practical tests S.E.P. has done research regarding different aspects of sludge as a fuel; for example handling of sludge and regional drying. The results of 40 sintering tests at SP showed that the sintering temperature during combustion of sludge in a fluidised bed, with silica sand as bed material, varied between <850 deg C and >1100 deg C. The evaluation showed that the alkali content in the ash had the largest influence on the sintering temperature. Other factors were less important. During the tests at Chalmers eleven different sludge samples have been combusted together with wood pellets. Initially there were problems with the feeding to the boiler for some of the sludge samples. When the fuel feeding problems were solved the combustion took place without any problems. When sludge is co-combusted together with a 'clean' base fuel such as wood pellets the sulphur-, nitrogen- and chloride contents in the sludge have a large impact on the emissions. The normal way to reduce sulphur dioxide but also hydrogen chloride is to add lime in different positions into and after the boiler. In

  8. COMBINED COMPOST AND VERMICOMPOSTING PROCESS IN THE TREATMENT AND BIOCONVERSION OF SLUDGE

    H. Alidadi, A. R. Parvaresh and M. R. Shamansouri

    2005-10-01

    Full Text Available Traditional thermophillic composting is commonly for treatment of sludge. A related technique as vermicomposting process, using earthworms to breakdown sludge, is also becoming popular. These two techniques have their inherent advantages and disadvantages. The combined approach suggested in this study to enhance the overall process and improve the products qualities. Two systems,vermicomposting and combined compost vermicomposting processes, have been investigated in this study. The sludge used in this study was obtained from the drying beds of South Isfahan wastewater treatment plant.The sludge mixed with sawdust to provide C/N ratio of 25/1.Eisenia fetida was the species of earthworms used in the vermicomposting processes.The results obtained indicates reduction in the amount of volatile solids,total carbon and C/N ratio with the vermicompost age,which indicates the reduction in the biodegradable organic content and mineralization of sludge. Also increase in phosphorus concentration by the end process because of mineralization of organic matter. The results indicate that, a system that combines the two mentioned processes not only shortens stabilization time, but also improves the products quality. Combining the two systems resulted in a product that was more stable and homogenous; the product could meet the pathogen reduction requirements.

  9. Heavy metals behavior during monocombustion and co-combustion of sewage sludge

    Lopes, M.H.; Abelha, P.; Oliveira, J.F.S.; Cabrita, I.; Gulyurtlu, I. [DEECA, INETI, Lisbon (Portugal)

    2005-04-01

    This paper presents the study of the combustion of granular dry sewage sludge performed on a pilot fluidized bed system. The results of monocombustion of sludge and co-combustion with coal were compared with those of coal combustion for ash partitioning, the formation of gaseous pollutants, and heavy metals behavior. It was found that the mineral matter of sludge was essentially retained as bottom ash. The production of fine ash was small during the monocombustion but was high during co-combustion due to the tendency of coal to produce fine ash, which also contained unburned char. The degree of heavy metal volatilization was found to be slightly higher during co-combustion than in monocombustion; however, most of the metals were retained in the ash and their emissions were found to be below the regulated levels. Hg was completely volatilized. However, during combustion trials involving coal, Hg was captured in the cyclone ash at temperatures below 300{sup o}C. During sludge monocombustion the retention of Hg in cyclone ash containing low loss on ignition (LOI) was not enough to decrease emissions below the EU regulated levels; hence, it is necessary to install dedicated flue gas treatment for Hg removal. The leachability and ecotoxicity of sludge and ash were also compared with the new regulatory limits for landfill disposal in the European Union (EU).

  10. Anaerobic digestion of industrial activated aerobic sludge

    Goodloe, J.G.; Roberts, R.S.

    1990-04-01

    The Tennessee Eastman Company manufactures a variety of organic chemicals, plastics and fibers at their Kingsport Tennessee Facility. The wastewater generated during the manufacture of these compounds is currently treated using an activated sludge process. The objective of the project is to evaluate the economic potential of an anaerobic digestion process to convert industrial sludge at the Tennessee Eastman Company into biogas. The evaluation will require collection and analysis of experimental data on the anaerobic digestion of industrial sludge obtained from Kingsport. Although the experiments will be conducted using Tennessee Eastman sludge, these results should be also generally applicable to similar industrial sludge

  11. Sludge cleaning in the steam generators: sludge Lancing e IBL

    Montoro, E.; Gonzalez, S.; Calderon, N.

    2013-01-01

    IBERDROLA Engineering and Construction has echoed the need for plants to remove oxide deposits (sludge) located on the secondary side, on the bottom plate and into the tube bundle steam steam generators. Therefore, and with its partner SAVAC SRA has developed a specific system consisting of applying a capillary water at very high pressure applied directly to the location of these oxides. (Author)

  12. Improved waste-activated sludge dewatering using sludge/oil ...

    2014-10-07

    Oct 7, 2014 ... 2Dept. of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seongdong-Gu, Seoul 133-791, ... conventional heating methods in chemical reactions is becom- ... the dewaterability of sludge and reduces the organic matter ..... It is unlikely that this technique will be applied in.

  13. Locally produced natural conditioners for dewatering of faecal sludge.

    Gold, Moritz; Dayer, Pauline; Faye, Marie Christine Amie Sene; Clair, Guillaume; Seck, Alsane; Niang, Seydou; Morgenroth, Eberhard; Strande, Linda

    2016-11-01

    In urban areas of low-income countries, treatment of faecal sludge (FS) is insufficient or non-existent. This results in large amounts of FS being dumped into the environment. Existing treatment technologies for FS, such as settling-thickening tanks and drying beds, are land intensive which is limiting in urban areas. Enhanced settling and dewatering by conditioning was evaluated in order to reduce the treatment footprint (or increase treatment capacity). Conventional wastewater conditioners, such as commercially available lime and polymers, are expensive, and commonly rely on complex supply chains for use in low-income countries. Therefore, the treatment performance of five conditioners which could be produced locally was evaluated: Moringa oleifera seeds and press cake, Jatropha curcas seeds, Jatropha Calotropis leaves and chitosan. M. oleifera seeds and press cake, and chitosan improved settling and dewatering and had a similar performance compared to lime and polymers. Optimal dosages were 400-500 kg M. oleifera/t TS, 300-800 kg lime/t TS and 25-50 kg polymer solution/t TS. In comparison, chitosan required 1.5-3.75 kg/t TS. These dosages are comparable to those recommended for wastewater (sludge). The results indicate that conditioning of FS can reduce total suspended solids (TSS) in the effluent of settling-thickening tanks by 22-81% and reduce dewatering time with drying beds by 59-97%. This means that the area of drying beds could be reduced by 59-97% with end-use as soil conditioner, or 9-26% as solid fuel. Least expensive options and availability will depend on the local context. In Dakar, Senegal, chitosan produced from shrimp waste appears to be most promising.

  14. Filterability of membrane bioreactor (MBR) sludge: impacts of polyelectrolytes and mixing with conventional activated sludge.

    Yigit, Nevzat O; Civelekoglu, Gokhan; Cinar, Ozer; Kitis, Mehmet

    2010-01-01

    The main objective of this work was to investigate the filterability of MBR sludge and its mixture with conventional activated sludge (CAS). In addition, the impacts of type and dose of various polyelectrolytes, filter type and sludge properties on the filterability of both MBR and Mixed sludges were determined. Specific cake resistance (SCR) measured by the Buchner funnel filtration test apparatus and the solids content of the resulting sludge cake were used to assess the dewaterability of tested sludges. The type of filter paper used in Buchner tests affected the results of filterability for MBR, CAS and Mixed sludges. SCR values and optimum polyelectrolyte doses increased with increasing MLSS concentrations in the MBR, which suggested that increase in MLSS concentrations accompanied by increases in EPS and SMP concentrations and a shift toward smaller particles caused poorer dewaterability of the MBR sludge. The significant differences observed among the filterability of CAS and MBR sludges suggested that MLSS alone is not a good predictor of sludge dewaterability. Combining CAS and MBR sludges at different proportions generally improved their dewaterability. Combining MBR sludges having typically high MLSS and EPS concentrations with CAS having much lower MLSS concentrations may be an option for full-scale treatment plants experiencing sludge dewaterability problems. Better filterability and higher cake dry solids were achieved with cationic polyelectrolytes compared to anionic and non-ionic ones for all sludge types tested.

  15. Electrodialytic removal of cadmium from wastewater sludge

    Jakobsen, M. R.; Fritt-Rasmussen, Janne; Nielsen, S.

    2004-01-01

    This paper presents for the first time laboratory results demonstrating electrodialytic removal of Cd from wastewater sludge, which is a method originally developed for soil remediation. During the remediation a stirred suspension of wastewater sludge was exposed to an electric dc field. The liquid....../solid (ml/g fresh sludge) ratio was between 1.4 and 2. Three experiments were performed where the sludge was suspended in distilled water, citric acid or HNO"3. The experimental conditions were otherwise identical. The Cd removal in the three experiments was 69, 70 and 67%, respectively, thus the removal...... was approximately the same. Chemical extraction experiments with acidic solutions showed that 5-10 times more Cd could be extracted from decomposed sludge than from fresh sludge. It is likely that the mobilization of Cd during decomposition of the sludge contributes to the efficient removal of Cd...

  16. The Kaldnes Moving Bed biofilm technology for treatment of industrial wastewater; Tecnologia Kaldnes Moving Bed biofilm (KMT) para la depuracion de aguas residuales industriales

    Rasmussen, V.; Garcia Carrion, M.; Farre Solsona, C.

    2004-07-01

    The Kaldnes Moving bed biofilm technology is a biofilm process which is very suitable for treatment of industrial wastewaters. Biofilm processes have several acknowledged advantages compared to suspended biomass processes, e. g. resistance to toxicity and load variations. Traditionally biofilm processes have been known to clog at high loads and hence have not been suited for industrial effluents: however, the Kaldnes Moving Bed biofilm process has overcome this problem. This article describes how the process has been used as pre-treatment up front of activated sludge at a dairy in USA, and as sole treatment at pharmaceutical industry in Sweden. (Author)

  17. State of the art and the future fuel portfolio of fluidized bed combustion systems; Status und kuenftiges Brennstoffportfolio bei Wirbelschichtfeuerungen

    Szentannai, Pal; Friebert, Arpad; Winter, Franz [Technische Univ. Wien (Austria). Inst. fuer Verfahrens-, Umwelttechnik und technische Biowissenschaften

    2008-07-01

    Coal, biomass and substitute fuels energetically can be used efficiently and with low pollution in fluidized bed plants. In comparison to biomass there are significant differences between the circulating and stationary fluidized bed technology. The stationary fluidised bed is fed predominantly with biomasses and residual substances. Coal usually is the basis fuel in the circulating fluidised bed. Biomass and residual substances frequently are course-fired. The state of the art is the employment of a broad fuel mixture in small and large fluidized-bed combustion systems. Future developments present an increased use of sewage sludge, fluidized bed combustion systems with wood as a basis fuel, utilization of household waste and the gas production.

  18. Solidification process for sludge residue

    Pearce, K.L.

    1998-01-01

    This report investigates the solidification process used at 100-N Basin to solidify the N Basin sediment and assesses the N Basin process for application to the K Basin sludge residue material. This report also includes a discussion of a solidification process for stabilizing filters. The solidified matrix must be compatible with the Environmental Remediation Disposal Facility acceptance criteria

  19. Sludge stabilization operability test report

    Lewis, W.S.

    1994-01-01

    Document provides the results of the Operability Test Procedure performed to test the operability of the HC-21C thermal stabilization process for sludge. The OTP assured all equipment functioned properly and established the baseline temperature profile for glovebox HC-21C

  20. Thermal analysis of kieselguhr sludge

    S. T. Antipov

    2013-01-01

    Full Text Available It’s currently necessary to clarify the mechanisms of thermodynamic and mass transfer processes in capillary porous media. In this paper we obtain the thermogravimetric curves of evaporation drying kieselguhr sludge. It is also an analysis of the curves, allowing to choose the optimum conditions of drying.

  1. Fluidization of Dried Wastewater Sludge.

    Hartman, Miloslav; Pohořelý, Michael; Trnka, Otakar

    2007-01-01

    Roč. 178, 3 (2007) , s. 166-172 ISSN 0032-5910 R&D Projects: GA AV ČR(CZ) IAA4072201 Institutional research plan: CEZ:AV0Z40720504 Keywords : fluidization characteristics * multiphase reactors * dried stabilized wastewater sludge Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.130, year: 2007

  2. Fermentation and chemical treatment of pulp and paper mill sludge

    Lee, Yoon Y; Wang, Wei; Kang, Li

    2014-12-02

    A method of chemically treating partially de-ashed pulp and/or paper mill sludge to obtain products of value comprising taking a sample of primary sludge from a Kraft paper mill process, partially de-ashing the primary sludge by physical means, and further treating the primary sludge to obtain the products of value, including further treating the resulting sludge and using the resulting sludge as a substrate to produce cellulase in an efficient manner using the resulting sludge as the only carbon source and mixtures of inorganic salts as the primary nitrogen source, and including further treating the resulting sludge and using the resulting sludge to produce ethanol.

  3. Radiation disinfection of sewage sludge and composting of the irradiated sludge

    Hashimoto, Shoji; Nishimura, Koichi; Watanabe, Hiromasa; Kawakami, Waichiro

    1985-01-01

    In the radiation disinfected sewage sludge, its stabilization is necessary with the composting. In this disinfected sludge, there is no need of keeping it at high temperature at the cost of fermentation velocity. The fermentation velocity can thus be set to obtain its maximum value. In sewage sludge utilization of farm land, to prevent the contamination with pathogenic bacteria and the secondary pollution, the radiation disinfection of dehydrated sludge and the composting of the disinfected sludge have been studied. The disinfection effect when an electron accelerator is used for the radiation source is described. Then, the composting of the disinfected sludge is described in chemical kinetics of the microorganisms. (Mori, K.)

  4. Effects of Sludge-amendment on Mineralization of Pyrene and Microorganisms in Sludge and Soil

    Klinge, C; Gejlsbjerg, B; Ekelund, Flemming

    2001-01-01

    . Sludge-amendment enhanced the mineralization of pyrene in the soil compared to soil without sludge, and the most extensive mineralization was observed when the sludge was kept in a lump. The number of protozoa, heterotrophic bacteria and pyrene-mineralizing bacteria was much higher in the sludge compared...... to the soil. The amendment of sludge did not affect the number of protozoa and bacteria in the surrounding soil, which indicated that organic contaminants in the sludge had a little effect on the number of protozoa and bacteria in the surrounding soil...

  5. Hexavalent chromium removal using aerobic activated sludge batch ...

    The following Cr(VI) removal systems were tested: activated sludge alone; activated sludge with an external electron donor (5 g/. of lactose); activated sludge with PAC addition (4 g/.); activated sludge with both PAC and lactose; and PAC alone. The results reported here showed that activated sludges are capable of ...

  6. Pebble-bed reactor

    Lohnert, G.; Mueller-Frank, U.; Heil, J.

    1976-01-01

    A pebble-bed nuclear reactor of large power rating comprises a container having a funnel-shaped bottom forming a pebble run-out having a centrally positioned outlet. A bed of downwardly-flowing substantially spherical nuclear fuel pebbles is positioned in the container and forms a reactive nuclear core maintained by feeding unused pebbles to the bed's top surface while used or burned-out pebbles run out and discharge through the outlet. A substantially conical body with its apex pointing upwardly and its periphery spaced from the periphery of the container spreads the bottom of the bed outwardly to provide an annular flow down the funnel-shaped bottom forming the runout, to the discharge outlet. This provides a largely constant downward velocity of the spheres throughout the diameter of the bed throughout a substantial portion of the down travel, so that all spheres reach about the same burned-out condition when they leave the core, after a single pass through the core area

  7. Fluidised bed heat exchangers

    Elliott, D.E.; Healey, E.M.; Roberts, A.G.

    1974-01-01

    Problems that have arisen during the initial stages of development of fluidised bed boilers in which heat transfer surfaces are immersed in fluidised solids are discussed. The very high heat transfer coefficients that are obtained under these conditions can be exploited to reduce the total heat transfer surface to a fraction of that in normal boilers. However, with the high heat flux levels involved, tube stressing becomes more important and it is advantageous to use smaller diameter tubes. One of the initial problems was that the pumping power absorbed by the fluidised bed appeared to be high. The relative influence of the fluidising velocity (and the corresponding bed area), tube diameter, tube spacing, heat transfer coefficient and bed temperature on pumping power and overall cost was determined. This showed the importance of close tube packing and research was undertaken to see if this would adversely affect the heat transfer coefficient. Pressure operation also reduces the pumping power. Fouling and corrosion tests in beds burning coal suggest that higher temperatures could be reached reliably and cost studies show that, provided the better refractory metals are used, the cost of achieving higher temperatures is not unduly high. It now remains to demonstrate at large scale that the proposed systems are viable and that the methods incorporated to overcome start up and part lead running problems are satisfactory. The promising role of these heat transfer techniques in other applications is briefly discussed

  8. Sludge derived fuel technique of sewage sludge by oil vacuum evaporation drying

    Kim, Seokhwan; Lim, Byungran; Lee, Sookoo

    2010-01-01

    Sewage sludge contains high content of organic materials and its water content is also very high about 80% even after filtration process. Landfill as a sludge treatment methods can cause odor problem and leachate production which can derive the secondary contamination of soil and groundwater. The ocean dumping will be prohibited according to the London Convention and domestic stringent environmental regulation. Based on domestic agenda on organic sewage sludge treatment, the ocean disposal will be prohibited from 2012, thus alternative methods are demanded. Sludge derived fuel (SDF) technology can alleviate the emission of greenhouse gas and recover energy from sludge. For proper treatment and SDF production from sludge, the vacuum evaporation and immersion frying technology was adopted in this research. This technology dries moisture in sludge after mixing with oil such as Bunker C oil, waste oil or waste food oil etc. Mixing sludge and oil secures liquidity of organic sludge to facilitate handling throughout the drying process. The boiling temperature could be maintained low through vacuum condition in whole evaporation process. This study was performed to find the optimum operating temperature and pressure, the mixing ratio of sludge and oil. Finally, we could obtained SDF which moisture content was less than 5%, its heating value was over 4,500 kcal/ kg sludge. This heating value could satisfy the Korean Fuel Standard for the Recycle Products. Assessed from the perspective of energy balance and economic evaluation, this sludge drying system could be widely used for the effective sludge treatment and the production of SDF. (author)

  9. Recycling by the brick making industry of ashes from sewage sludge incineration; Verwertung von Aschen der Klaerschlammverbrennung in der Ziegelindustrie

    Wiebusch, B.; Seyfried, C.F. [Hannover Univ. (Germany). ISAH Inst. fuer Siedlungswasserwirtschaft und Abfalltechnik

    1998-09-01

    The present project focuses on the recycling of sewage sludge ashes by the brick making industry. The following aspects are dealt with in detail: Overview of the state of the art of sewage sludge combustion in Germany; influence of wastewater and sludge treatment on ash quality (determination of the seasonal course of chemical sewage sludge composition); use of sewage sludge ashes in as loading material in fluidised-bed furnaces or as clay substitute in brick manufacture; semi-technical trials in ceramic laboratories; assessment of the environmental impact of bricks containing sewage sludge ash; performance of leaching experiments; and examination of the mineralogical binding of heavy metals into the ceramic matrix. [Deutsch] Das Projekt konzentriert sich dabei auf eine Verwertung von Klaerschlammaschen in der Ziegelindustrie, wobei die im folgenden genannten Aspekte im Einzelnen bearbeitet werden: - Ueberblick ueber den Stand der Technik bei der Klaerschlammverbrennung in Deutschland - Einfluss der Abwasser- und Schlammbehandlung auf die Aschequalitaet (Ermittlung von Jahresganglinien der chemischen Zusammensetzung von Klaerschlammaschen) - Einsatz von Klaerschlammaschen aus Wirbelschichtoefen als Zuschlagstoff bzw. Tonersatz bei der Ziegelproduktion - halbtechnische Versuche im keramischen Labor - Abschaetzung der Umweltvertraeglichkeit von Ziegeln mit Klaerschlammaschezusatz: Durchfuehrung von Auslangversuchen, Untersuchung einer mineralogischen Einbindung von Schwermetallen in die keramische Matrix. (orig./SR)

  10. 40 CFR Appendix A to Part 503 - Procedure To Determine the Annual Whole Sludge Application Rate for a Sewage Sludge

    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 each...

  11. in Spouted Bed

    Bronislaw Buczek

    2013-01-01

    Full Text Available Samples of active coke, fresh and spent after cleaning flue gases from communal waste incinerators, were investigated. The outer layers of both coke particles were separately removed by comminution in a spouted bed. The samples of both active cokes were analysed by means of densities, mercury porosimetry, and adsorption technique. Remaining cores were examined to determine the degree of consumption of coke by the sorption of hazardous emissions (SO2, HCl, and heavy metals through its bed. Differences in contamination levels within the porous structure of the particles were estimated. The study demonstrated the effectiveness of commercial active coke in the cleaning of flue gases.

  12. The Safety of Hospital Beds

    Gervais, Pierre; Pooler, Charlotte; Merryweather, Andrew; Doig, Alexa K.; Bloswick, Donald

    2015-01-01

    To explore the safety of the standard and the low hospital bed, we report on a microanalysis of 15 patients’ ability to ingress, move about the bed, and egress. The 15 participants were purposefully selected with various disabilities. Bed conditions were randomized with side rails up or down and one low bed with side rails down. We explored the patients’ use of the side rails, bed height, ability to lift their legs onto the mattress, and ability to turn, egress, and walk back to the chair. The standard bed was too high for some participants, both for ingress and egress. Side rails were used by most participants when entering, turning in bed, and exiting. We recommend that side rails be reconsidered as a means to facilitate in-bed movement, ingress, and egress. Furthermore, single deck height settings for all patients are not optimal. Low beds as a safety measure must be re-evaluated. PMID:28462302

  13. Textile wastewater treatment: aerobic granular sludge vs activated sludge systems.

    Lotito, Adriana Maria; De Sanctis, Marco; Di Iaconi, Claudio; Bergna, Giovanni

    2014-05-01

    Textile effluents are characterised by high content of recalcitrant compounds and are often discharged (together with municipal wastewater to increase their treatability) into centralized wastewater treatment plants with a complex treatment scheme. This paper reports the results achieved adopting a granular sludge system (sequencing batch biofilter granular reactor - SBBGR) to treat mixed municipal-textile wastewater. Thanks to high average removals in SBBGR (82.1% chemical oxygen demand, 94.7% total suspended solids, 87.5% total Kjeldahl nitrogen, 77.1% surfactants), the Italian limits for discharge into a water receiver can be complied with the biological stage alone. The comparison with the performance of the centralized plant treating the same wastewater has showed that SBBGR system is able to produce an effluent of comparable quality with a simpler treatment scheme, a much lower hydraulic residence time (11 h against 30 h) and a lower sludge production. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. K Basin sludge dissolution engineering study

    Westra, A.G.

    1998-01-01

    The purpose of this engineering study is to investigate the available technology related to dissolution of the K Basin sludge in nitric acid. The conclusion of this study along with laboratory and hot cell tests with actual sludge samples will provide the basis for beginning conceptual design of the sludge dissolver. The K Basin sludge contains uranium oxides, fragments of metallic U, and some U hydride as well as ferric oxyhydroxide, aluminum oxides and hydroxides, windblown sand that infiltrated the basin enclosure, ion exchange resin, and miscellaneous materials. The decision has been made to dispose of this sludge separate from the fuel elements stored in the basins. The sludge will be conditioned so that it meets Tank Waste Remediation System waste acceptance criteria and can be sent to one of the underground storage tanks. Sludge conditioning will be done by dissolving the fuel constituents in nitric acid, separating the insoluble material, adding neutron absorbers for criticality safety, and then reacting the solution with caustic to co-precipitate the uranium and plutonium. There will be five distinct feed streams to the sludge conditioning process two from the K East (KE) Basin and three from the K West (KW) Basin. The composition of the floor and pit sludges which contain more iron oxides and sand than uranium is much different than the canister sludges which are composed of mostly uranium oxides. The sludge conditioning equipment will be designed to process all of the sludge streams, but some of the operating parameters will be adjusted as necessary to handle the different sludge stream compositions. The volume of chemical additions and the amount of undissolved solids will be much different for floor and pit sludge than for canister sludge. Dissolution of uranium metal and uranium dioxide has been studied quite thoroughly and much information is available. Both uranium metal and uranium dioxide have been dissolved on a large scale in nuclear fuel

  15. STUDY ON MAXIMUM SPECIFIC SLUDGE ACIVITY OF DIFFERENT ANAEROBIC GRANULAR SLUDGE BY BATCH TESTS

    2001-01-01

    The maximum specific sludge activity of granular sludge from large-scale UASB, IC and Biobed anaerobic reactors were investigated by batch tests. The limitation factors related to maximum specific sludge activity (diffusion, substrate sort, substrate concentration and granular size) were studied. The general principle and procedure for the precise measurement of maximum specific sludge activity were suggested. The potential capacity of loading rate of the IC and Biobed anaerobic reactors were analyzed and compared by use of the batch tests results.

  16. Kinetic evaluation of an anaerobic fluidised-bed reactor treating slaughterhouse wastewater

    Borja, R. [Consejo Superior de Investigaciones Cientificas, Seville (Spain). Inst. de la Grasa; Banks, C.J.; Zhengjian Wang [Manchester Univ. (United Kingdom). Inst. of Science and Technology

    1995-09-01

    An anaerobic fluidised-bed reactor for purification of slaughterhouse wastewater was modelled as a continuous-flow, completely-mixed homogeneous microbial system, with the feed COD as the limiting-substrate concentration. The average microbial residence time in the reactor was defined in terms of conventional sludge-retention-time. The experimental data obtained indicated that the Michaelis-Menten expression was applicable to a description of substrate utilisation (i.e. COD removal) in the anaerobic fluidised-bed system. The maximum substrate utilisation rate, k, and the Michaelis constant, K{sub s}, were determined to be 1.2/day and 0.039 g/l. The observed biomass yield in the reactor decreased with increasing sludge-retention-time. The specific methane production rate observed was a linear function of the specific substrate-utilisation rate. (Author)

  17. Apparatus for controlling fluidized beds

    Rehmat, A.G.; Patel, J.G.

    1987-05-12

    An apparatus and process are disclosed for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance. 2 figs.

  18. Environmental sustainability of wastewater sludge treatments

    Boyer-Souchet, Florence; Larsen, Henrik Fred

    treatment for municipal waste water. A special focus area in Neptune is sludge handling because the sludge amount is expected to increase due to advanced waste water treatment. The main sludge processing methods assessed in Neptune can be divided into two categories: disintegration processes before...... anaerobic digestion (thermal hydrolysis and ultrasound disintegration) and inertisation processes performed at high temperatures (incineration, pyrolysis, gasification, wet oxidation) but they all aim at volume reduction and removal of biodegradable compounds before safe sludge disposal or reuse of its...... resources. As part of a sustainability assessment (or “best practice evaluation”), a comparison between the existing and new sludge handling techniques have been done by use of life cycle assessment (LCA).The concept of induced impacts as compared to avoided impacts when introducing a new sludge treatment...

  19. F-Canyon Sludge Physical Properties

    Poirier, M. R.; Hansen, P. R.; Fink, S. D.

    2005-01-01

    The Site Deactivation and Decommissioning (SDD) Organization is evaluating options to disposition the 800 underground tanks (including removal of the sludge heels from these tanks). To support this effort, DandD requested assistance from Savannah River National Laboratory (SRNL) personnel to determine the pertinent physical properties to effectively mobilize the sludge from these tanks (Tanks 804, 808, and 809). SDD provided SRNL with samples of the sludge from Tanks 804, 808, and 809. The authors measured the following physical properties for each tank: particle settling rate, shear strength (i.e., settled solids yield stress), slurry rheology (i.e., yield stress and consistency), total solids concentration in the sludge, soluble solids concentration of the sludge, sludge density, and particle size distribution

  20. Inhibitory effect of high NH4(+)-N concentration on anaerobic biotreatment of fresh leachate from a municipal solid waste incineration plant.

    Liu, Zhao; Dang, Yan; Li, Caihua; Sun, Dezhi

    2015-09-01

    Fresh leachate from municipal solid waste (MSW) incineration plants generally contains extremely high NH4(+)-N concentration which could inhibit the bioactivity of microorganisms. The inhibitory effect of high NH4(+)-N concentration on anaerobic biotreatment of fresh leachate from a MSW incineration plant in China has been investigated in this study. The inhibition processes was studied by both static tests and a laboratory-scale expanded granular sludge bed (EGSB) reactor. The specific methanogenic activity (SMA) of the microorganisms in anaerobic granular sludge was inhibited with the NH4(+)-N concentration increasing to 1000mg/L in static tests. As well the chemical oxygen demand (COD) removal efficiency and the methane yield decreased in the EGSB reactor, while the volatile fatty acids (VFAs) accumulated and extracellular polymeric substances (EPS) of the anaerobic granular sludge increased with NH4(+)-N concentration rising to 1000mg/L, without any rebounding during 30days of operation. Decreasing NH4(+)-N concentration to 500mg/L in influent, the COD removal efficiency recovered to about 85% after 26days. 1000mg/L of NH4(+)-N in leachate was suggested to be the inhibition threshold in EGSB reactor. High-throughput sequencing results showed little changes in microbial communities of the sludge for a high NH4(+)-N concentration, indicating that the survival of most microorganisms was not affected under such a condition. It inhibited the bioactivity of the microorganisms, resulting in decrease of the COD removal efficiency. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Fluidized bed calciner

    Sheely, W.F.

    1986-01-01

    A unique way to convert radioactive scrap into useful nuclear fuel products was developed for the Department of Energy at Hanford. An advanced, fluidized bed calciner is used to convert metallic nitrate scrap or waste solutions into benign, solid and gaseous products. There are broad potential applications of this concept beyond those in the nuclear industry

  2. Nail Bed Injuries

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Nail Bed Injuries Email to a friend * required ...

  3. Bed Bug Myths

    Learn the truth about bed bugs, such as how easy they are to see with the naked eye, their preferred habitat, whether they transmit diseases, their public health effects, and whether pesticides are the best way to deal with an infestation.

  4. Composting of gamma-radiation disinfected sewage sludge

    Kawakami, W.; Hashimoto, S.; Watanabe, H.; Nishimura, K.; Watanabe, H.; Ito, H.; Takehisa, M.

    1981-01-01

    The composting of radiation disinfected sewage sludge has been studied since 1978, aiming to present a new process of sludge composting for agricultural uses. This process is composed of two steps: irradiation step to disinfect sludge, and composting step to remove odor and easily decomposable organics in sludge. In this paper, the gamma-irradiation effect on sludge cake and composting condition of irradiated sludge are discussed. (author)

  5. Economic comparison of sludge irradiation and alternative methods of municipal sludge treatment

    Ahlstrom, S.B.; McGuire, H.E.

    1977-11-01

    The relative economics of radiation treatment and other sludge treatment processes are reported. The desirability of radiation treatment is assessed in terms of cost and the quality of the treated sludge product. The major conclusions of this study are: radiation treatment is a high-level disinfection process. Therefore, it should only be considered if high levels of disinfection are required for widespread reuse of the sludge; the handling, transporting and pathogen growback problems associated with disinfected wet sludge makes it less attractive for reuse than dry sludge; radiation of composted sludge produces a product of similar quality at less cost than any thermal treatment and/or flash drying treatment option for situations where a high degree of disinfection is required; and heavy metal concerns, especially cadmium, may limit the reuse of sludge despite high disinfection levels. It is recommended that radiation treatment of sludge, particularly dry sludge, continue to be studied. A sensitivity analysis investigating the optimal conditions under which sludge irradiation operates should be instigated. Furthermore, costs of adding sludge irradiation to existing sludge treatment schemes should be determined

  6. Use of a water treatment sludge in a sewage sludge dewatering process

    Górka, Justyna; Cimochowicz-Rybicka, Małgorzata; Kryłów, Małgorzata

    2018-02-01

    The objective of the research study was to determine whether a sewage sludge conditioning had any impact on sludge dewaterability. As a conditioning agent a water treatment sludge was used, which was mixed with a sewage sludge before a digestion process. The capillary suction time (CST) and the specific filtration resistance (SRF) were the measures used to determine the effects of a water sludge addition on a dewatering process. Based on the CST curves the water sludge dose of 0.3 g total volatile solids (TVS) per 1.0 g TVS of a sewage sludge was selected. Once the water treatment sludge dose was accepted, disintegration of the water treatment sludge was performed and its dewaterability was determined. The studies have shown that sludge dewaterability was much better after its conditioning with a water sludge as well as after disintegration and conditioning, if comparing to sludge with no conditioning. Nevertheless, these findings are of preliminary nature and future studies will be needed to investigate this topic.

  7. An Economic comparison of sludge irradiation and alternative methods of municipal sludge treatment

    Ahlstrom, S.B.; McGuire, H.E.

    1977-11-01

    The relative economics of radiation treatment and other sludge treatment processes are reported. The desirability of radiation treatment is assessed in terms of cost and the quality of the treated sludge product. The major conclusions of this study are: radiation treatment is a high-level disinfection process. Therefore, it should only be considered if high levels of disinfection are required for widespread reuse of the sludge; the handling, transporting and pathogen growback problems associated with disinfected wet sludge makes it less attractive for reuse than dry sludge; radiation of composted sludge produces a product of similar quality at less cost than any thermal treatment and/or flash drying treatment option for situations where a high degree of disinfection is required; and heavy metal concerns, especially cadmium, may limit the reuse of sludge despite high disinfection levels. It is recommended that radiation treatment of sludge, particularly dry sludge, continue to be studied. A sensitivity analysis investigating the optimal conditions under which sludge irradiation operates should be instigated. Furthermore, costs of adding sludge irradiation to existing sludge treatment schemes should be determined.

  8. Solidifying power station resins and sludges

    Willis, A.S.D.; Haigh, C.P.

    1984-01-01

    Radioactive ion exchange resins and sludges arise at nuclear power stations from various operations associated with effluent treatment and liquid waste management. As the result of an intensive development programme, the Central Electricity Generating Board (CEGB) has designed a process to convert power station resins and sludges into a shielded, packaged solid monolithic form suitable for final disposal. Research and development, the generic CEGB sludge/resin conditioning plant and the CEGB Active Waste Project are described. (U.K.)

  9. Biological fluidized-bed treatment of groundwater from a manufactured gas plant site

    Grey, G.M.; Scheible, O.K.; Maiello, J.A.; Guarini, W.J.; Sutton, P.M.

    1995-01-01

    Bench- and pilot-scale biological treatability studies were performed as part of a comprehensive study for developing an on-site treatment system for contaminated groundwater at a former manufactured gas plant site. The bench-scale work, which included evaluations of activated sludge and fluidized-bed biological processes, indicated that a carbon-based fluidized-bed process was most appropriate. The process was then demonstrated on a pilot level at the site. The bench and pilot studies demonstrated significant reductions of chemical oxygen demand (COD), and all target organics including polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs)

  10. Fluidized bed combustion of low-grade coal and wastes: Research and development

    Borodulya, V.A.; Dikalenko, V.I.; Palchonok, G.I.; Vinogradov, L.M. [Academy of Sciences of Belarus, Minsk (Belarus). A.V. Luikov Heat and Mass Transfer Inst.; Dobkin, S.M.; Telegin, E.M. [Special Design Office, Brest (Belarus)

    1994-12-31

    Experimental studies were carried out to investigate devolatilization of fuel as single spherical particles of wood, hydrolytic lignin, leather sewage sludge and Belarussian brown coals in a fluidized bed of sand. It is found that the devolatilization process depends on moisture and ash contents in fuel and on the external heat and mass transfer rate. The char combustion occurs largely in the intermediate region. Kinetic parameters of the devolatilization and char combustion are obtained. A low-capacity fluidized bed boiler suitable for combustion of coal and different wastes is described.

  11. Ten residual biomass fuels for circulating fluidized-bed gasification

    Drift, A. van der; Doorn, J. van [Netherlands Energy Research Foundation (ECN), Petten (Netherlands); Vermeulen, J.W. [NV Afvalzorg, Haarlem (Netherlands)

    2001-07-01

    In co-operation with a Dutch company (NV Afvalzorg) and the Dutch agency for energy and environment (Novem), ECN has successfully tested 10 different biomass residues in its 500 kW{sub th} circulating fluidized-bed gasification facility. Among the fuels used as demolition wood (both puree and mixed with sewage sludge and paper sludge), verge grass, railroad ties, cacao shells and different woody fuels. Railroad ties turn out to contain very little (heavy) metals. Initially, fuel feeding problems often impeded smooth operation. Contrary to feeding systems, the circulating fluidized-bed gasification process itself seems very flexible concerning the conversion of different kinds of biomass fuels. The fuel moisture content is one of the most important fuel characteristics. More moisture means that more air is needed to maintain the process temperature resulting in better carbon conversion and lower tar emission but also lower product gas heating value and lower cold gas efficiency. So, for a good comparison of the gasification behaviour of different fuels, the moisture content should be similar. However, the moisture content should be defined on an ash-free basis rather than on total mass (the usual way). Some of the ashes produced and retained in the second cyclone were analysed both for elemental composition and leaching behaviour. It turned out that the leaching rate of Mo and Br, elements only present in small concentrations, are preventing the ash to be considered as inert material according to the Dutch legislation for dumping on landfill sites. (Author)

  12. Co-combustion of waste with coal in a circulating fluidised bed combustor

    Gulyurtlu, I.; Boavida, D.; Abelha, P.; Lopes, H.; Cabrita, I. [DEECA-INETI, Lisboa (Portugal)

    2002-07-01

    The results of a study of cocombustion of waste with coal is described. Various wastes (biomass, sludge, and refuse derived fuel) were burned with coal in a circulating fluidised bed combustor. Conditions that prevent segregated combustion, reduce production of nitrogen oxides, and attain high combustion efficiency were studied. The effects of variations in air staging in the riser, mixing of air with volatiles, coal/biomass ratio, methods of feeding biomass, and temperature are described. 5 refs., 3 figs., 5 tabs.

  13. Land application of sewage sludge: Pathogen issues

    Chang, A.C.

    1997-01-01

    Diseases transmitted via the faecal-oral exposure route cause severe gastroenteric disorders, and large numbers of causative organisms are discharged with the faecal matter of infected individuals. For this reason, pathogenic bacteria, viruses, protozoa, or helminths, are always found in sewage sludge. If not properly treated for use in agriculture, sludge can be a source of pathogenic contamination. Radiation is an attractive method to reduce the numbers of microorganisms in sewage sludge. Routine examination for pathogens is not practised nor recommended because complicated and costly procedures are involved. Instead, an indicator organism is usually assayed and enumerated. In this paper, methods are discussed for the investigation of pathogens in sewage sludge. (author)

  14. Where to dispose of the sewage sludge?

    Beurer, P.; Geering, F.

    2001-01-01

    The 'proper' course for the disposal of sewage sludge is a topic that has continually sparked intense discussion for years. New legal regulations have developed which have significantly changed the disposal structure. Nevertheless, the consumer market of agriculture products has an increasing influence on sewage sludge recycling possibilities. In this report, the changes in sewage sludge disposal within the last ten years and the expected development is pointed out. On account of legal guidelines and of political market influences, the thermal recycling of sewage sludge is considered as the future solution, which should, however, be adapted according to marginal situations. (author)

  15. Rheological properties of disintegrated sewage sludge

    Wolski, Paweł

    2017-11-01

    The rheology of the sludge provides information about the capacity and the flow, which in the case of project tasks for the hydraulic conveying installation is an important control parameter. Accurate knowledge of the rheological properties of sludge requires the designation of rheological models. Models single and multiparameter (Ostwald, Bingham, Herschel-Bulkley'a, and others) allow an approximation of flow curves, and the determination of the boundaries of the flow of modified sludge allows you to control the process compaction or are dewatered sludge undergoing flow. The aim of the study was to determine the rheological parameters and rheological models of sludge conditioned by physical methods before and after the process of anaerobic digestion. So far, studies have shown that the application of conditioning in the preparation of sewage sludge increases shear stress, viscosity as well as the limits of flow in relation to the untreated sludge. Offset yield point by the application of a conditioning agent is associated with decreased flowability tested sludge, which has also been observed by analyzing the structure of the prepared samples. Lowering the yield point, and thus the shear stress was recorded as a result of the fermentation test of disintegrated sludge.

  16. Radioactive contamination of sewage sludge. Preliminary data

    Soeder, C J; Zanders, E; Raphael, T

    1986-01-01

    Because of the radioactivity released through the explosion of the nuclear reactor near Chernobyl radionuclides have been accumulated to a significant extent in sewage sludge in the Federal Republic of Germany. This is demonstrated for samples from four activated sludge plants according to a recent recommendation of the German Commission for Radiation Protection, there is until now no reason to deviate from the common practices of sludge disposal or incineration. The degree of radioactive contamination of plant materials produced on farm lands on which sewage sludge is being spread cannot be estimated with sufficient certainty yet. Additional information is required.

  17. 7 CFR 2902.15 - Bedding, bed linens, and towels.

    2010-01-01

    ... PROCUREMENT Designated Items § 2902.15 Bedding, bed linens, and towels. (a) Definition. (1) Bedding is that... minimum biobased content is 12 percent and shall be based on the amount of qualifying biobased carbon in..., and silk are not qualifying biobased feedstocks for the purpose of determining the biobased content of...

  18. A review of modeling approaches in activated sludge systems

    use

    Key words: Mathematical modeling, water, wastewater, wastewater treatment plants, activated sludge systems. INTRODUCTION ... sedimentation processes which take place in the aeration ...... activated sludge waste water treatment systems.

  19. Co-production of hydrogen and methane from herbal medicine wastewater by a combined UASB system with immobilized sludge (H2 production) and UASB system with suspended sludge (CH4 production).

    Sun, Caiyu; Hao, Ping; Qin, Bida; Wang, Bing; Di, Xueying; Li, Yongfeng

    2016-01-01

    An upflow anaerobic sludge bed (UASB) system with sludge immobilized on granular activated carbon was developed for fermentative hydrogen production continuously from herbal medicine wastewater at various organic loading rates (8-40 g chemical oxygen demand (COD) L(-1) d(-1)). The maximum hydrogen production rate reached 10.0 (±0.17) mmol L(-1) hr(-1) at organic loading rate of 24 g COD L(-1) d(-1), which was 19.9% higher than that of suspended sludge system. The effluents of hydrogen fermentation were used for continuous methane production in the subsequent UASB system. At hydraulic retention time of 15 h, the maximum methane production rate of 5.49 (±0.03) mmol L(-1) hr(-1) was obtained. The total energy recovery rate by co-production of hydrogen and methane was evaluated to be 7.26 kJ L(-1) hr(-1).

  20. VA National Bed Control System

    Department of Veterans Affairs — The VA National Bed Control System records the levels of operating, unavailable and authorized beds at each VAMC, and it tracks requests for changes in these levels....

  1. Getting Rid of Bed Bugs

    ... Directory Planning, Budget and Results Jobs and Internships Headquarters Offices Regional Offices Labs and Research Centers Bed ... to be careful in how you select a company. Related Information Collaborative Strategy on Bed Bugs - highlights ...

  2. Geomechanics of bedded salt

    Serata, S.; Milnor, S.W.

    1979-01-01

    Creep data from the literature search is reinterpreted by SGI, resulting in a better understanding of the temperature and stress state dependence of the octahedral creep rate and the octahedral shear strength. The concept of a transition strength between the elastic and the plastic states is in agreement with the data. The elastic and rheological properties of salt are described, and a set of constitutive equations is presented. The dependence of material properties on parameters such as temperature is considered. Findings on the permeability of salt are summarized, and the in-situ behavior of openings in bedded salt is described based on extensive engineering experience. A stress measuring system utilizing a finite element computer code is discussed. Geological factors affecting the stability of salt openings are considered, and the Stress Control Technique for designing stable openings in bedded salt formations is explained

  3. Non-slag co-gasification of biomass and coal in entrained-bed furnace

    Itaya, Yoshinori; Suami, Akira; Kobayashi, Nobusuke

    2018-02-01

    Gasification is a promising candidate of processes to upgrade biomass and to yield clean gaseous fuel for utilization of renewable energy resources. However, a sufficient amount of biomass is not always available to operate a large scale of the plant. Co-gasification of biomass with coal is proposed as a solution of the problem. Tar emission is another subject during operation in shaft or kiln type of gasifiers employed conventionally for biomass. The present authors proposed co-gasification of biomass and coal in entrained-bed furnace, which is a representative process without tar emission under high temperature, but operated so to collect dust as flyash without molten slag formation. This paper presents the works performed on co-gasification performance of biomass and pulverized coal to apply to entrained-bed type of furnaces. At first, co-gasification of woody powder and pulverized coal examined using the lab-scale test furnace of the down-flow entrained bed showed that the maximum temperatures in the furnace was over 1500 K and the carbon conversion to gas achieved at higher efficiency than 80-90 percent although the residence time in the furnace was as short as a few seconds. Non-slag co-gasification was carried out successfully without slag formation in the furnace if coal containing ash with high fusion temperature was employed. The trend suggesting the effect of reaction rate enhancement of co-gasification was also observed. Secondary, an innovative sewage sludge upgrading system consisting of self-energy recovery processes was proposed to yield bio-dried sludge and to sequentially produce char without adding auxiliary fuel. Carbonization behavior of bio-dried sludge was evaluated through pyrolysis examination in a lab-scale quartz tube reactor. The thermal treatment of pyrolysis of sludge contributed to decomposition and removal of contaminant components such as nitrogen and sulfur. The gasification kinetics of sludge and coal was also determined by a

  4. Effects of different sludge disintegration methods on sludge moisture distribution and dewatering performance.

    Jin, Lingyun; Zhang, Guangming; Zheng, Xiang

    2015-02-01

    A key step in sludge treatment is sludge dewatering. However, activated sludge is generally very difficult to be dewatered. Sludge dewatering performance is largely affected by the sludge moisture distribution. Sludge disintegration can destroy the sludge structure and cell wall, so as change the sludge floc structure and moisture distribution, thus affecting the dewatering performance of sludge. In this article, the disintegration methods were ultrasound treatment, K2FeO4 oxidation and KMnO4 oxidation. The degree of disintegration (DDCOD), sludge moisture distribution and the final water content of sludge cake after centrifuging were measured. Results showed that three disintegration methods were all effective, and K2FeO4 oxidation was more efficient than KMnO4 oxidation. The content of free water increased obviously with K2FeO4 and KMnO4 oxidations, while it decreased with ultrasound treatment. The changes of free water and interstitial water were in the opposite trend. The content of bounding water decreased with K2FeO4 oxidation, and increased slightly with KMnO4 oxidation, while it increased obviously with ultrasound treatment. The water content of sludge cake after centrifuging decreased with K2FeO4 oxidation, and did not changed with KMnO4 oxidation, but increased obviously with ultrasound treatment. In summary, ultrasound treatment deteriorated the sludge dewaterability, while K2FeO4 and KMnO4 oxidation improved the sludge dewaterability. Copyright © 2014. Published by Elsevier B.V.

  5. Speciation of mercury in sludge solids: washed sludge

    Bannochie, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Lourie, A. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-10-24

    The objective of this applied research task was to study the type and concentration of mercury compounds found within the contaminated Savannah River Site Liquid Waste System (SRS LWS). A method of selective sequential extraction (SSE), developed by Eurofins Frontier Global Sciences1,2 and adapted by SRNL, utilizes an extraction procedure divided into seven separate tests for different species of mercury. In the SRNL’s modified procedure four of these tests were applied to a washed sample of high level radioactive waste sludge.

  6. Pathogen reduction in sludges by irradiation

    Brandon, J.R.

    1979-01-01

    There is international interest in the use of ionizing radiation in waste water and sludge treatment. Results of programs to study effects of radiation on disease-causing microbes commonly found in wastewater sludges will be discussed. Although emphasis will be on the work conducted at Sandia Laboratories, the discussion will include work in progress in West Germany, France, South Africa, and other countries

  7. Sustainability of Domestic Sewage Sludge Disposal

    Claudia Bruna Rizzardini

    2014-04-01

    Full Text Available Activated sludge is now one of the most widely used biological processes for the treatment of wastewaters from medium to large populations. It produces high amounts of sewage sludge that can be managed and perceived in two main ways: as a waste it is discharged in landfill, as a fertilizer it is disposed in agriculture with direct application to soil or subjected to anaerobic digestion and composting. Other solutions, such as incineration or production of concrete, bricks and asphalt play a secondary role in terms of their degree of diffusion. The agronomical value of domestic sewage sludge is a proved question, which may be hidden by the presence of several pollutants such as heavy metals, organic compounds and pathogens. In this way, the sustainability of sewage sludge agricultural disposal requires a value judgment based on knowledge and evaluation of the level of pollution of both sewage sludge and soil. The article analyzed a typical Italian case study, a water management system of small communities, applying the criteria of evaluation of the last official document of European Union about sewage sludge land application, the “Working Document on Sludge (3rd draft, 2000”. The report brought out good sewage sludge from small wastewater treatment plants and soils quality suggesting a sustainable application.

  8. Electron beam disinfection of sewage sludge

    Hashimoto, Shoji

    1992-01-01

    Electron beam treatment of dehydrated sewage sludge for safe reutilization was performed. Ranges of total bacterial counts and total coliforms in the sludge were from 1.5 x 10 8 to 1.6 x 10 9 and from 2.2 x 10 7 to 1.5 x 10 8 per wet gram, respectively. Total bacterial counts decreased about 5 log cycles after irradiating 5 kGy and irradiation with 2 kGy was enough to kill all coliforms in sewage sludge. The survival curves of total bacteria, obtained by irradiation in oxygen atmosphere, approached to that in nitrogen atmosphere with the increase of sludge thickness. No effects of dose rate and electron energy were found when the sludge layers were thin enough. Continuous disinfection of sewage sludge cake, with the maximum feed rate of 300 kg-sludge/hr, was successfully performed with a Cockcroft-Walton type electron accelerator, a sludge pump and a flat nozzle. (J.P.N.)

  9. Viscosity evolution of anaerobic granular sludge

    Pevere, A.; Guibaud, G.; Hullebusch, van E.D.; Lens, P.N.L.; Baudu, M.

    2006-01-01

    The evolution of the apparent viscosity at steady shear rate of sieved anaerobic granular sludge (20¿315 ¿m diameter) sampled from different full-scale anaerobic reactors was recorded using rotation tests. The ¿limit viscosity¿ of sieved anaerobic granular sludge was determined from the apparent

  10. Filterability and Sludge Concentration in Membrane Bioreactors

    Lousada-Ferreira, M.

    2011-01-01

    The Thesis entitled “Filterability and Sludge Concentration in Membrane Bioreactors” aims at explaining the relation between Mixed Liquid Suspended Solids (MLSS) concentration, the amount of solids in the wastewater being treated, also designated as sludge, and filterability, being the ability of

  11. Gravitational sedimentation of flocculated waste activated sludge.

    Chu, C P; Lee, D J; Tay, J H

    2003-01-01

    The sedimentation characteristics of flocculated wastewater sludge have not been satisfactorily explored using the non-destructive techniques, partially owing to the rather low solid content (ca. 1-2%) commonly noted in the biological sediments. This paper investigated, for the first time, the spatial-temporal gravitational settling characteristics of original and polyelectrolyte flocculated waste activated sludge using Computerized Axial Tomography Scanner. The waste activated sludge possessed a distinct settling characteristic from the kaolin slurries. The waste activated sludges settled more slowly and reached a lower solid fraction in the final sediment than the latter. Flocculation markedly enhanced the settleability of both sludges. Although the maximum achievable solid contents for the kaolin slurries were reduced, flocculation had little effects on the activated sludge. The purely plastic rheological model by Buscall and White (J Chem Soc Faraday Trans 1(83) (1987) 873) interpreted the consolidating sediment data, while the purely elastic model by Tiller and Leu (J. Chin. Inst. Chem. Eng. 11 (1980) 61) described the final equilibrated sediment. Flocculation produced lower yield stress during transient settling, thereby resulting in the more easily consolidated sludge than the original sample. Meanwhile, the flocculated activated sludge was stiffer in the final sediment than in the original sample. The data reported herein are valuable to the theories development for clarifier design and operation.

  12. Improving hydrolysis of food waste in a leach bed reactor

    Browne, James D.; Allen, Eoin; Murphy, Jerry D., E-mail: jerry.murphy@ucc.ie

    2013-11-15

    Highlights: • This paper assesses leaching of food waste in a two phase digestion system. • Leaching is assessed with and without an upflow anaerobic sludge blanket (UASB). • Without the UASB, low pH reduces hydrolysis, while increased flows increase leaching. • Inclusion of the UASB increases pH to optimal levels and greatly improves leaching. • The optimal conditions are suggested as low flow with connection to the UASB. - Abstract: This paper examines the rate of degradation of food waste in a leach bed reactor (LBR) under four different operating conditions. The effects of leachate recirculation at a low and high flow rate are examined with and without connection to an upflow anaerobic sludge blanket (UASB). Two dilution rates of the effective volume of the leach bed reactors were investigated: 1 and 6 dilutions per LBR per day. The increase in dilution rate from 1 to 6 improved the destruction of volatile solids without connection to the UASB. However connection to the UASB greatly improved the destruction of volatile solids (by almost 60%) at the low recirculation rate of 1 dilution per day. The increase in volatile solids destruction with connection to the UASB was attributed to an increase in leachate pH and buffering capacity provided by recirculated effluent from the UASB to the leach beds. The destruction of volatile solids for both the low and high dilution rates was similar with connection to the UASB, giving 82% and 88% volatile solids destruction respectively. This suggests that the most efficient leaching condition is 1 dilution per day with connection to the UASB.

  13. Improving hydrolysis of food waste in a leach bed reactor

    Browne, James D.; Allen, Eoin; Murphy, Jerry D.

    2013-01-01

    Highlights: • This paper assesses leaching of food waste in a two phase digestion system. • Leaching is assessed with and without an upflow anaerobic sludge blanket (UASB). • Without the UASB, low pH reduces hydrolysis, while increased flows increase leaching. • Inclusion of the UASB increases pH to optimal levels and greatly improves leaching. • The optimal conditions are suggested as low flow with connection to the UASB. - Abstract: This paper examines the rate of degradation of food waste in a leach bed reactor (LBR) under four different operating conditions. The effects of leachate recirculation at a low and high flow rate are examined with and without connection to an upflow anaerobic sludge blanket (UASB). Two dilution rates of the effective volume of the leach bed reactors were investigated: 1 and 6 dilutions per LBR per day. The increase in dilution rate from 1 to 6 improved the destruction of volatile solids without connection to the UASB. However connection to the UASB greatly improved the destruction of volatile solids (by almost 60%) at the low recirculation rate of 1 dilution per day. The increase in volatile solids destruction with connection to the UASB was attributed to an increase in leachate pH and buffering capacity provided by recirculated effluent from the UASB to the leach beds. The destruction of volatile solids for both the low and high dilution rates was similar with connection to the UASB, giving 82% and 88% volatile solids destruction respectively. This suggests that the most efficient leaching condition is 1 dilution per day with connection to the UASB

  14. Continuous sulfidogenic wastewater treatment with iron sulfide sludge oxidation and recycle.

    Deng, Dongyang; Lin, Lian-Shin

    2017-05-01

    This study evaluated the technical feasibility of packed-bed sulfidogenic bioreactors dosed with ferrous chloride for continuous wastewater treatment over a 450-day period. In phase I, the bioreactors were operated under different combinations of carbon, iron, and sulfate mass loads without sludge recycling to identify optimal treatment conditions. A COD/sulfate mass ratio of 2 and a Fe/S molar ratio of 1 yielded the best treatment performance with COD oxidation rate of 786 ± 82 mg/(L⋅d), which resulted in 84 ± 9% COD removal, 94 ± 6% sulfate reduction, and good iron retention (99 ± 1%) under favorable pH conditions (6.2-7.0). In phase II, the bioreactors were operated under this chemical load combination over a 62-day period, during which 7 events of sludge collection, oxidation, and recycling were performed. The collected sludge materials contained both inorganic and organic matter with FeS and FeS 2 as the main inorganic constituents. In each event, the sludge materials were oxidized in an oxidizing basin before recycling to mix with the wastewater influent. Sludge recycling yielded enhanced COD removal (90 ± 6% vs. 75 ± 7%), and better effluent quality in terms of pH (6.8 ± 0.1 vs. 6.5 ± 0.2), iron (0.7 ± 0.5 vs. 1.9 ± 1.7 mg/L), and sulfide-S (0.3 ± 0.1 vs. 0.4 ± 0.1 mg/L) removal compared to the baseline operation without sludge recycling during phase II. This process exhibited treatment stability with reasonable variations, and fairly consistent sludge content over long periods of operation under a range of COD/sulfate and Fe/S ratios without sludge recycling. The bioreactors were found to absorb recycling-induced changes efficiently without causing elevated suspended solids in the effluents. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Start-up of horizontal anaerobic reactors with sludge blanket and fixed bed for wastewater treatment from coffee processing by wet method Partida de reatores anaeróbios horizontais com manta de lodo e de leito fixo para tratamento de águas residuárias do beneficiamento de frutos do cafeeiro por via úmida

    Roberto A. de Oliveira

    2013-04-01

    Full Text Available In this study it was evaluated the start-up procedures of anaerobic treatment system with three horizontal anaerobic reactors (R1, R2 and R3, installed in series, with volume of 1.2 L each. R1 had sludge blanket, and R2 and R3 had half supporter of bamboo and coconut fiber, respectively. As an affluent, it was synthesized wastewater from mechanical pulping of the coffee fruit by wet method, with a mean value of total chemical oxygen demand (CODtotal of 16,003 mg L-1. The hydraulic retention time (HRT in each reactor was 30 h. The volumetric organic loading (VOL applied in R1 varied from 8.9 to 25.0 g of CODtotal (L d-1. The mean removal efficiencies of CODtotal varied from 43 to 97% in the treatment system (R1+R2+R3, stabilizing above 80% after 30 days of operation. The mean content of methane in the biogas were of 70 to 76%, the mean volumetric production was 1.7 L CH4 (L reactor d-1 in the system, and the higher conversions were around at 0.20 L CH4 (g CODremoved-1 in R1 and R2. The mean values of pH in the effluents ranged from 6.8 to 8.3 and the mean values of total volatile acids remained below 200 mg L-1 in the effluent of R3. The concentrations of total phenols of the affluent ranged from 45 to 278 mg L-1, and the mean removal efficiency was of 52%. The start-up of the anaerobic treatment system occurred after 30 days of operation as a result of inoculation with anaerobic sludge with active microbiota.Foram avaliados os procedimentos de partida de sistema de tratamento com três reatores anaeróbios horizontais (R1, R2 e R3, instalados em série, com volume de 1,2 L cada. O R1 com manta de lodo e o R2 e R3 através de suporte de bambu e fibra de coco, respectivamente. Como afluente,foram sintetizadas águas residuárias do despolpamento mecânico dos frutos do cafeeiro por via úmida, com valor médio de demanda química de oxigênio total (DQOtotal de 16.003 mg L-1. O tempo de detenção hidráulica (TDH em cada reator foi de 30 h. As

  16. Anaerobic wastewater treatment in single-and double-stage digesters; Tratamiento anaerobio de aguas residuales en digestores de simple y doble etapa

    Gomez Lopez, M.; Vazquez Garcia, M. J.; Pena Caamano, P.; Soto Castineira, M. [Universidad da Coruna (Spain)

    2000-07-01

    Anaerobic treatment are a major alternative in wastewater treatment due to simplicity and lower power requirements, although greater understanding of this process and its technology is needed to make it possible. The most important concepts and parameters developed to treat medium-and high-load effluents are defined and various technologies are discussed, including: anaerobic filter (AF), upflow anaerobic sludge blanket (UASB) reactors, fluidized bed (FB) reactors, expanded granular sludge beds (EGSB). To determine the efficiency in municipal wastewater treatment, a pilot plant was constructed with a UASB reactor, obtaining elimination efficiency values of 60-65% for total COD and 55% for TSS. Finally a comparative chart of aerobic versus anaerobic treatment is provided, high-lighting the major possibilities offered by the latter. (Author) 28 refs.

  17. The process of biosorption of heavy metals in bioreactors loaded with sanitary sewage sludge

    A. J. Morais Barros

    2006-06-01

    Full Text Available This work on the process of biosorption of nickel and chromium in an ascendant continuous-flow, fixed packed-bed bioreactor of sanitary sewage sludge was conducted in a search for solutions to the environmental problem caused by heavy metals. Analysis of the results demonstrated that the absorbent had an extraordinary capacity for biosorption of the heavy metals studied at about 9.0 pH of the effluent, with a removal percentage of over 90.0% for the two metals. Chemometric study results demonstrated that 20 days of the experimental system function were sufficient for achieving the maximum efficiency of sorption of the heavy metals studied by the sanitary sewage sludge employed.

  18. Waste sludge resuspension and transfer: development program

    Weeren, H.O.; Mackey, T.S.

    1980-02-01

    The six Gunite waste tanks at Oak Ridge National Laboratory (ORNL) contain about 400,000 gal of sludge that has precipitated from solution and settled during the 35 years these tanks have been in service. Eventual decommissioning of the tanks has been proposed. The first part of this program is to resuspend the accumulated sludge, to transfer it to new storage tanks in Melton Valley, and to dispose of it by the shale-fracturing process. On the basis of preliminary information, a tentative operational concept was adopted. The sludge in each tank would be resuspended by hydraulic sluicing and pumped from the tank. This resuspended sludge would be treated as necessary to keep the particles in suspension and would be pumped to the new waste-storage tanks. Subsequently the sludge would be pumped from the tanks, combined with a cement-base mix, and disposed of by the shale-fracturing facility. Verification of the feasibility of this concept required development effort on characterization of the sludge and development of techniques for resuspending the sludge and for keeping it in suspension. These development efforts are described in this report. Sections of the report describe both the known properties of the sludge and the tests of grinding methods investigated, discuss tests of various suspenders, describe tests with cement-base mixes, summarize hot-cell tests on actual sludge samples, and describe tests that were made at a mockup of a Gunite tank installation. On the basis of the tests made, it was concluded that reslurrying and resuspension of the sludge is quite feasible and that the suspensions can be made compatible with cement mixes

  19. Physical property characterization of 183-H Basin sludge

    Biyani, R.K.; Delegard, C.H.

    1995-01-01

    This document describes the characterization of 183-H Basin sludge physical properties, e.g. bulk density of sludge and absorbent, and determination of free liquids. Calcination of crucible-size samples of sludge was also done and the resulting 'loss-on-ignition' was compared to the theoretical weight loss based on sludge analysis obtained from Weston Labs

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

    Swinwood, J.F.; Kotler, J.

    1990-01-01

    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. (author)

  1. Sewage sludge pasteurization by gamma radiation: financial viability case studies

    Swinwood, J.F.; Kotler, J. (Nordion International Inc., Kanata, Ontario (Canada))

    1990-01-01

    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. (author).

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

    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.

  3. The beneficial usage of water treatment sludge as pottery product ...

    The disposal of sludge from water treatment operations has become a major problem in Malaysia. The problem becomes acute because of scarcity of space for installation of sludge treatment facilities and disposal of treated sludge. Traditionally, treated sludge from water treatment plant will be sent to landfill for disposal.

  4. Coal Bed Methane Primer

    Dan Arthur; Bruce Langhus; Jon Seekins

    2005-05-25

    During the second half of the 1990's Coal Bed Methane (CBM) production increased dramatically nationwide to represent a significant new source of income and natural gas for many independent and established producers. Matching these soaring production rates during this period was a heightened public awareness of environmental concerns. These concerns left unexplained and under-addressed have created a significant growth in public involvement generating literally thousands of unfocused project comments for various regional NEPA efforts resulting in the delayed development of public and fee lands. The accelerating interest in CBM development coupled to the growth in public involvement has prompted the conceptualization of this project for the development of a CBM Primer. The Primer is designed to serve as a summary document, which introduces and encapsulates information pertinent to the development of Coal Bed Methane (CBM), including focused discussions of coal deposits, methane as a natural formed gas, split mineral estates, development techniques, operational issues, producing methods, applicable regulatory frameworks, land and resource management, mitigation measures, preparation of project plans, data availability, Indian Trust issues and relevant environmental technologies. An important aspect of gaining access to federal, state, tribal, or fee lands involves education of a broad array of stakeholders, including land and mineral owners, regulators, conservationists, tribal governments, special interest groups, and numerous others that could be impacted by the development of coal bed methane. Perhaps the most crucial aspect of successfully developing CBM resources is stakeholder education. Currently, an inconsistent picture of CBM exists. There is a significant lack of understanding on the parts of nearly all stakeholders, including industry, government, special interest groups, and land owners. It is envisioned the Primer would being used by a variety of

  5. Infant's bed climate and bedding in the Japanese home.

    Nakamura Ikeda, Rie; Fukai, Kiyoko; Okamoto Mizuno, Kazue

    2012-06-01

    to assess the bed climate of infants in their homes in Japan. descriptive, exploratory, non-experimental research design. the data were collected at the participants' homes under normal circumstances. nineteen healthy infants between the ages of two and five months. Their mothers, who joined a parenting class organised by a maternity clinic in Okayama, Japan, consented to participate in this study. we visited the infants' homes and interviewed their mothers concerning the types and use of bedding. The temperature and relative humidity of the bed climate at the back and foot of the bedding, and in the room were measured every minute for four consecutive days. Differences among the bed climates measured during three seasons (spring, summer, and autumn) were assessed by one-way analysis of variance. The bed temperature was higher for infants than for adults. No significant difference in temperature was noted among the three seasons. The bed temperature was about 36.0°C when waterproof sheets and futon mattresses for children or adult were used. The average relative humidity of the bed climate at the back was highest in summer, followed by that in spring and autumn; the differences were significant. The use of waterproof sheets and futon mattresses for children in summer increased the relative humidity to 80% or more. The use of infant beds, sunoko drainboards, and cotton futon mattresses in summer was effective in reducing the bed humidity. these results suggest that nurse-midwives should advise the parents on comfortable bed climates for their infants, as well as how to select and use bedding for them. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. Particle bed reactor modeling

    Sapyta, Joe; Reid, Hank; Walton, Lew

    The topics are presented in viewgraph form and include the following: particle bed reactor (PBR) core cross section; PBR bleed cycle; fuel and moderator flow paths; PBR modeling requirements; characteristics of PBR and nuclear thermal propulsion (NTP) modeling; challenges for PBR and NTP modeling; thermal hydraulic computer codes; capabilities for PBR/reactor application; thermal/hydralic codes; limitations; physical correlations; comparison of predicted friction factor and experimental data; frit pressure drop testing; cold frit mask factor; decay heat flow rate; startup transient simulation; and philosophy of systems modeling.

  7. Fluidised bed cereal cooking

    Jenkins, Simon Anthony

    2002-01-01

    Man has been cooking food for thousands of years for a number of reasons: to improve flavour and palatability, sterilise, increase digestibility, improve texture and colour. Increasingly more advanced techniques are employed today in food production plants to engineer foods with many different properties. With this in mind manufacturers are constantly seeking to improve processing techniques and apply new or different technologies (such as microwaves, RF and extrusion) to develop foods with new properties (like puffed texture starches) and to increase process efficiencies (energy efficiency, water reduction). This thesis reports on work undertaken to demonstrate the potential to achieve high temperature starch conversion of whole wheat grains in a fluidised bed, thereby reducing the amount of water required and processing time. Specifically, wheat from the farm at 14% water content is cooked in a fluidised bed. The fluidised bed heats the wheat quickly by convective heating. In addition, energy can be delivered directly to the grain by microwave heating during fluidisation. Degree of starch conversion is determined by measuring the reduction in size of endotherm of reaction as observed by Differential Scanning Calorimetry. The fluidising gas, processing temperature and starting moisture content were varied in order to investigate their effect on the cooking process. A mathematical model based on energy and species concentration equations was developed to help understand the internal grain processes. The model coupled the thermal energy equation with water diffusion. The effect of water evaporation was represented as a thermal sink in the energy equation. Popular kinetic models from literature were adapted to predict the degree of starch conversion. The model gives solutions consistent with experimental data and physical intuition. A commercial computational fluid dynamics package was used to study simple airflow and particle tracks in the fluidisation column. A

  8. Changes in soil organisms by the application of sludge composits, and their effects. Odei taihirui no shiyo ni tomonau dojo seibutsu no henka to sono eikyo

    Niijima, K.; Fujita, K.; Ogawa, M. (Forestry and Forest Products Research Institute, Tsukuba (Japan))

    1993-08-31

    With an objective to utilize sewage sludge more effectively, composted sewage sludge has been applied to seed beds to investigate its effect on soil macrofauna and higher fungi, and its relativity with change in soil organisms, growth of young trees, and soil science. Forty-eight seedling sections, each 5 m [times] 5 m, were made on a seed bed which was applied with Tenryu sludge composts (polymer-based coagulant), several other kinds of sludge composts, fallen leaf composts, and cattle excrement composts at predetermined rates from zero to 20 kg. Each section was planted with 25 three-year-old nursery trees of a kind of oak, black pine, and cypress. As a result, the following findings were obtained: wet weight of larvae of Japanese gold beetles that attack tree roots has increased during the first and second years in the Tenryu sludge applied section, but no longer increased in the third year; the relationship between the other composts and soil macrofauna was not made clear; Scleroderma Cepa PERS, a mycorrhiza bacteria, has been generated in the oak planted section in the second, third and fourth years, with the second year particularly having generated it in a greater amount in proportion with the fertilizer application amount, but the fertilizer effect thereafter is not clear. 24 refs., 6 figs., 9 tabs.

  9. REEMISSION OF MERCURY COMPOUNDS FROM SEWAGE SLUDGE DISPOSAL

    Beata Janowska

    2016-01-01

    The sewage sludge disposal and cultivation methods consist in storage, agricultural use, compost production, biogas production or heat treatment. The sewage sludge production in municipal sewage sludge treatment plants in year 2013 in Poland amounted to 540.3 thousand Mg d.m. The sewage sludge for agricultural or natural use must satisfy chemical, sanitary and environmental safety requirements. The heavy metal content, including the mercury content, determines the sewage sludge disposal metho...

  10. Factors affecting the consolidation of steam generator sludge

    Turner, C. W.; Shamsuzzaman, K.; Tapping, R. L.

    1993-02-15

    It is hypothesized that sludge consolidation is promoted by chemical reactions involving the various sludge constituents, although the hardness of the final product will also depend on the total porosity. Oxidizing conditions and higher temperatures produce a harder sludge. The precipitation of Zn{sub 2}SiO{sub 4}, a potential binding agent, may also promote sludge consolidation. Several solutions to prevent sludge consolidation are suggested. (Author) 3 figs., 4 tabs., 3 refs.

  11. Aquatic worm reactor for improved sludge processing and resource recovery

    Hendrickx, T.L.G.

    2009-01-01

    Municipal waste water treatment is mainly achieved by biological processes. These processes produce huge volumes of waste sludge (up 1.5 million m3/year in the Netherlands). Further processing of the waste sludge involves transportation, thickening and incineration. A decrease in the amount of waste sludge would be both environmentally and economically attractive. Aquatic worms can be used to reduce the amount of waste sludge. After predation by the worms, the amount of final sludge is lower....

  12. Electroosmotic dewatering of chalk sludge, iron hydroxide sludge, wet fly ash and biomass sludge

    Hansen, H.K.; Christensen, Iben Vernegren; Ottosen, Lisbeth M.

    2003-01-01

    . Casagrande's coefficients were determined for the four materials at different water contents. The experiments in this work showed that chalk could be dewatered from 40% to 79% DM (dry matter), fly ash from 75 to 82% DM, iron hydroxide sludge from 2.7 to 19% DM and biomass from 3 to 33% DM by electroosmosis....... The process was not optimised indicating that higher dry matter contents could be achieved by electroosmosis. It was possible to relate Casagrande's coefficient directly to the electroosmotic coefficient obtained by dewatering experiments....

  13. ALARA ASSESSMENT OF SETTLER SLUDGE SAMPLING METHODS

    Nelsen, L.A.

    2009-01-01

    The purpose of this assessment is to compare underwater and above water settler sludge sampling methods to determine if the added cost for underwater sampling for the sole purpose of worker dose reductions is justified. Initial planning for sludge sampling included container, settler and knock-out-pot (KOP) sampling. Due to the significantly higher dose consequence of KOP sludge, a decision was made to sample KOP underwater to achieve worker dose reductions. Additionally, initial plans were to utilize the underwater sampling apparatus for settler sludge. Since there are no longer plans to sample KOP sludge, the decision for underwater sampling for settler sludge needs to be revisited. The present sampling plan calls for spending an estimated $2,500,000 to design and construct a new underwater sampling system (per A21 C-PL-001 RevOE). This evaluation will compare and contrast the present method of above water sampling to the underwater method that is planned by the Sludge Treatment Project (STP) and determine if settler samples can be taken using the existing sampling cart (with potentially minor modifications) while maintaining doses to workers As Low As Reasonably Achievable (ALARA) and eliminate the need for costly redesigns, testing and personnel retraining

  14. ALARA ASSESSMENT OF SETTLER SLUDGE SAMPLING METHODS

    NELSEN LA

    2009-01-30

    The purpose of this assessment is to compare underwater and above water settler sludge sampling methods to determine if the added cost for underwater sampling for the sole purpose of worker dose reductions is justified. Initial planning for sludge sampling included container, settler and knock-out-pot (KOP) sampling. Due to the significantly higher dose consequence of KOP sludge, a decision was made to sample KOP underwater to achieve worker dose reductions. Additionally, initial plans were to utilize the underwater sampling apparatus for settler sludge. Since there are no longer plans to sample KOP sludge, the decision for underwater sampling for settler sludge needs to be revisited. The present sampling plan calls for spending an estimated $2,500,000 to design and construct a new underwater sampling system (per A21 C-PL-001 RevOE). This evaluation will compare and contrast the present method of above water sampling to the underwater method that is planned by the Sludge Treatment Project (STP) and determine if settler samples can be taken using the existing sampling cart (with potentially minor modifications) while maintaining doses to workers As Low As Reasonably Achievable (ALARA) and eliminate the need for costly redesigns, testing and personnel retraining.

  15. Virological investigations on inadiated sewage sludge

    Epp, C.

    1980-08-01

    The virusinactivating activity of a Co 60 -irradiation pilot plant at Geiselbullach/Munich was to be examined. We investigated 16 impure sewage water, 15 purified sewage water, 32 raw sladge samples, 62 digested sludge samples before irradiation, 52 digested sludge samples after irradiation and 9 raw sludge samples after irradiation. We completed these investigations by adding poliovaccinevirus type 1 to the digested sludge before irradiation and by adding suspensions of pure virus in MEM + 2% FBS packed in synthetic capsules and mixtures of virus and sludge packed in synthetic capsules to the digested sludge. After the irradiation we collected the capsules and determined the virustiter. The testviruses were poliovaccinevirus type 1, poliowildvirus type 1, echovirus type 6, coxsackie-B-virus type 5, coxsackie-A-virus type 9 and adenovirus type 1. In the field trial the irradiation results were like the laboratory results assuming that the sewage sludge was homogenized enough by digestion and the solid particle concentration was not more than 3%. The D-value was 300-400 krad for enteroviruses and 700 krad for adenovirus. (orig.) [de

  16. A microbiological study on sewage sludge treatment

    Sermkiattipong, Ngamnit; Ito, Hitoshi; Hashimoto, Shoji.

    1990-09-01

    Isolation and identification of salmonellae in sewage sludge cake and radiation sensitivities of the isolated strains were studied. Disinfection of the sludge by heat or radiation and effect of such treatment on composting were also carried out. Five groups of O-antigen and seven serotypes of salmonellae were identified from the sludge cakes. D 10 values of the salmonellae in phosphate buffer were ranged from 0.16 to 0.22 kGy and those in sludge were about three times larger. Total bacterial counts and coliforms in the sludges were determined to be 4.6 x 10 7 - 5.1 x 10 9 and 1.3 x 10 5 - 1.1 x 10 9 colony forming unit (cfu/g). After irradiation at 20 kGy by gamma ray or electron beam, decrease of total bacterial count was 5 - 7 log cycles and a dose of 5 kGy was enough to eliminate all of the coliforms. Coliforms decreased rapidly by heating at 65degC, but only one log cycle decrease was observed in total bacterial count. By heating at 100degC, total bacterial count decreased rapidly. Two peaks were observed in CO 2 evolution curves of radiation disinfected sludge composting, but only one peak in heat disinfected sludge composting. (author)

  17. A review on sludge dewatering indices.

    To, Vu Hien Phuong; Nguyen, Tien Vinh; Vigneswaran, Saravanamuth; Ngo, Huu Hao

    2016-01-01

    Dewatering of sludge from sewage treatment plants is proving to be a significant challenge due to the large amounts of residual sludges generated annually. In recent years, research and development have focused on improving the dewatering process in order to reduce subsequent costs of sludge management and transport. To achieve this goal, it is necessary to establish reliable indices that reflect the efficiency of sludge dewatering. However, the evaluation of sludge dewaterability is not an easy task due to the highly complex nature of sewage sludge and variations in solid-liquid separation methods. Most traditional dewatering indices fail to predict the maximum cake solids content achievable during full-scale dewatering. This paper reviews the difficulties in assessing sludge dewatering performance, and the main techniques used to evaluate dewatering performance are compared and discussed in detail. Finally, the paper suggests a new dewatering index, namely the modified centrifugal index, which is demonstrated to be an appropriate indicator for estimating the final cake solids content as well as simulating the prototype dewatering process.

  18. Radioactivity of sludge in Finland in 1987

    Puhakainen, M.; Rahola, T.

    1989-05-01

    Sewage sludge from municipal wastewater treatment plants was studied to determine its radionuclide concentrations. Measurements were made to find out whether any radionuclides from the nuclear power stations at Loviisa and Olkiluoto and from hospitals and medical laboratories could be detected in sludge additional to those originating from global and Chernobyl fallout. In the treatment process of water, aluminium sulphate sludge is developed at treatment plants using surface water. This kind of sludge was measured since it also concentrates radionuclides. Fallout nuclides from the Chernobyl nuclear power station after the accident predominated in all sewage sludge samples in Finland. In 1987 six different radionuclides originating from the Chernobyl fallout were detected in sewage sludge. In spring when the snow melted and large quantities of run off water flowed into the treatment plants, the activity concentrations clearly increased, but then started decreasing again. At the end of the year the highest measured 137 Cs activity concentrations were below 1000 Bq kg -1 dry weight. The highest activity concentration in sludge originated from iodine used fro medical purposes

  19. Sustainable sludge management in developing countries

    Jimenez, B.; Barrios, J.A.; Mendez, J.M.; Diaz, J.

    2003-07-01

    Worldwide, unsanitary conditions are responsible of more than three million deaths annually. One of the reasons is the low level of sanitation in developing countries. Particularly, sludge from these regions has a high parasite concentration and low heavy metal content even though the available information is limited. Different issues needed to achieve a sustainable sludge management in developing nations are analysed. Based on this analysis some conclusions arise: sludge management plays an important role in sanitation programs by helping reduce health problems and associated risks; investments in sanitation should consider sludge management within the overall projects; the main restriction for reusing sludge is the high microbial concentration, which requires a science-based decision of the treatment process, while heavy metals are generally low; the adequate sludge management needs the commitment of those sectors involved in the development and enforcement of the regulations as well as those that are directly related to its generation, treatment, reuse or disposal; current regulations have followed different approaches, based mainly on local conditions, but they favour sludge reuse to fight problems like soil degradation, reduced crop production, and the increased use of inorganic fertilizers. This paper summarises an overview of theses issues. (author)

  20. Stabilization/solidification of sewage sludge

    Boura, Panagiota; Katsioti, Margarita; Tsakiridis, Petros; Katsiri, Alexandra

    2003-07-01

    The main objective of this work is to investigate a viable alternative for the final disposal of sewage sludge from urban wastewater treatment plants by its use as an additive in developing new construction materials. For this purpose, several mixtures of sludge- cement and sludge-cement and jarosite/alunite precipitate were prepared. Jarosite/alunite precipitate is a waste product of a new hydrometallurgical process. Two kinds of sludge were used: primary sludge from Psyttalia Wastewater Treatment Plant, which receives a considerable amount of industrial waste, and biological sludge from Metamorphosi Wastewater Treatment Plant. Various percentages of these sludges were stabilized/solidified with Portland cement and Portland cement with jarosite/alunite. The specimens were tested by determination of compressive strength according to the methods described by European Standard EN 196. X-Ray Diffraction (XRD) analysis as well as Thermogravimetry-Differential Thermal Analysis (TG-DTA) were used to determine the hydration products in 28 days. Furthermore, Toxicity Characteristic Leaching Procedure test for heavy metals (TCLP), were carried out in order to investigate the environmental compatibility of these new materials. (author)

  1. Comparison and analysis of membrane fouling between flocculent sludge membrane bioreactor and granular sludge membrane bioreactor.

    Wang Jing-Feng

    Full Text Available The goal of this study is to investigate the effect of inoculating granules on reducing membrane fouling. In order to evaluate the differences in performance between flocculent sludge and aerobic granular sludge in membrane reactors (MBRs, two reactors were run in parallel and various parameters related to membrane fouling were measured. The results indicated that specific resistance to the fouling layer was five times greater than that of mixed liquor sludge in the granular MBR. The floc sludge more easily formed a compact layer on the membrane surface, and increased membrane resistance. Specifically, the floc sludge had a higher moisture content, extracellular polymeric substances concentration, and negative surface charge. In contrast, aerobic granules could improve structural integrity and strength, which contributed to the preferable permeate performance. Therefore, inoculating aerobic granules in a MBR presents an effective method of reducing the membrane fouling associated with floc sludge the perspective of from the morphological characteristics of microbial aggregates.

  2. Cost and effectiveness comparisons of various types of sludge irradiation and sludge pasteurization treatments

    Morris, M.E.

    1976-01-01

    The radiation from 137 Cs, a major constituent of nuclear fuel reprocessing waste, can be used to sterilize sewage sludge. This paper compares the effectiveness and cost of heat pasteurization, irradiation, and thermoradiation (simultaneous heating/irradiation), three competing methods of sludge disinfection. The cost of irradiation and thermoradiation is slightly higher than heat pasteurization costs for liquid sludges, although minor changes in oil availability or prices could change this. If the viral destruction could be done easily by other means, a 500-kilorad irradiation dose would be effective and less costly. For dry sewage sludges, irradiation is as effective and much less costly than any of the liquid sludge disinfection processes. Irradiation of compost appears to be cheaper and more practical than any heat pasteurization process for the dry sludge (the insulating property of the compost makes heating difficult). 6 tables, 2 fig

  3. Modeling Aspects Of Activated Sludge Processes Part I: Process Modeling Of Activated Sludge Facilitation And Sedimentation

    Ibrahim, H. I.; EI-Ahwany, A.H.; Ibrahim, G.

    2004-01-01

    Process modeling of activated sludge flocculation and sedimentation reviews consider the activated sludge floc characteristics such as: morphology viable and non-viable cell ratio density and water content, bio flocculation and its kinetics were studied considering the characteristics of bio flocculation and explaining theory of Divalent Cation Bridging which describes the major role of cations in bio flocculation. Activated sludge flocculation process modeling was studied considering mass transfer limitations from Clifft and Andrew, 1981, Benefild and Molz 1983 passing Henze 1987, until Tyagi 1996 and G. Ibrahim et aI. 2002. Models of aggregation and breakage of flocs were studied by Spicer and Pratsinis 1996,and Biggs 2002 Size distribution of floes influences mass transfer and biomass separation in the activated sludge process. Therefore, it is of primary importance to establish the role of specific process operation factors, such as sludge loading dynamic sludge age and dissolved oxygen, on this distribution with special emphasis on the formation of primary particles

  4. Energy efficiency improvements in sewage sludge processing plants; Energetische Optimierung der Klaerschlammaufbereitung

    Vetter, H.; Burger, S.

    2006-07-01

    From October 1st, 2006, sewage sludge may no longer be used as a fertilizer by farmers in Switzerland. Mechanical dewatering and drying of the sludge are the pre-stages of incineration. Based on a monitoring campaign and the results thereof, recommendations aiming at improving the energy efficiency have been worked out for use by waste water treatment plant operators and engineers for the design of drying plants. From the energetic point of view, solar drying of sludge is the best process. However, due to the large area required and the limited drying capacity, solar drying cannot be implemented everywhere. Therefore, three further drying processes have been monitored for eleven months: the fluidized bed drying process at the waste water treatment plant (WWTP) of the Region Berne, the low temperature/air recirculation dryer at WWTP Schwyz and the middle-temperature belt dryer at WWTP Wohlen. The electric energy consumption of the three investigated sludge drying processes was between 22 and 94 kWh per ton of evaporated water. The low temperature dryer showed the lowest energy consumption. The thermal energy consumption (expressed in useful energy) was between 648 and 1'033 kWh per ton of evaporated water, with the middle temperature dryer having the lowest consumption. On the other hand, the most advantageous process is the low temperature dryer if the comparison is based on the final energy consumption. This process has the advantage of making possible the integration of low-temperature waste heat. For whole Switzerland, the energy savings potential is estimated to be 133 GWh/year for fuel and 32 GWh/year for electricity, provided the drying process with the lowest energy consumption is implemented. It is recommended to conduct another measuring campaign at the first just commissioned sludge drying plant comprising a heat pump using waste water as a heat source, to check the effective energy savings. (author)

  5. Role of nickel in high rate methanol degradation in anaerobic granular sludge bioreactors

    Fermoso, Fernando G.; Collins, Gavin; Bartacek, Jan; O’Flaherty, Vincent

    2008-01-01

    The effect of nickel deprivation from the influent of a mesophilic (30°C) methanol fed upflow anaerobic sludge bed (UASB) reactor was investigated by coupling the reactor performance to the evolution of the Methanosarcina population of the bioreactor sludge. The reactor was operated at pH 7.0 and an organic loading rate (OLR) of 5–15 g COD l−1 day−1 for 191 days. A clear limitation of the specific methanogenic activity (SMA) on methanol due to the absence of nickel was observed after 129 days of bioreactor operation: the SMA of the sludge in medium with the complete trace metal solution except nickel amounted to 1.164 (±0.167) g CH4-COD g VSS−1 day−1 compared to 2.027 (±0.111) g CH4-COD g VSS−1 day−1 in a medium with the complete (including nickel) trace metal solution. The methanol removal efficiency during these 129 days was 99%, no volatile fatty acid (VFA) accumulation was observed and the size of the Methanosarcina population increased compared to the seed sludge. Continuation of the UASB reactor operation with the nickel limited sludge lead to incomplete methanol removal, and thus methanol accumulation in the reactor effluent from day 142 onwards. This methanol accumulation subsequently induced an increase of the acetogenic activity in the UASB reactor on day 160. On day 165, 77% of the methanol fed to the system was converted to acetate and the Methanosarcina population size had substantially decreased. Inclusion of 0.5 μM Ni (dosed as NiCl2) to the influent from day 165 onwards lead to the recovery of the methanol removal efficiency to 99% without VFA accumulation within 2 days of bioreactor operation. PMID:18247139

  6. Characterization of sulfate-reducing granular sludge in the SANI(®) process.

    Hao, Tianwei; Wei, Li; Lu, Hui; Chui, Hokwong; Mackey, Hamish R; van Loosdrecht, Mark C M; Chen, Guanghao

    2013-12-01

    Hong Kong practices seawater toilet flushing covering 80% of the population. A sulfur cycle-based biological nitrogen removal process, the Sulfate reduction, Autotrophic denitrification and Nitrification Integrated (SANI(®)) process, had been developed to close the loop between the hybrid water supply and saline sewage treatment. To enhance this novel process, granulation of a Sulfate-Reducing Up-flow Sludge Bed (SRUSB) reactor has recently been conducted for organic removal and provision of electron donors (sulfide) for subsequent autotrophic denitrification, with a view to minimizing footprint and maximizing operation resilience. This further study was focused on the biological and physicochemical characteristics of the granular sulfate-reducing sludge. A lab-scale SRUSB reactor seeded with anaerobic digester sludge was operated with synthetic saline sewage for 368 days. At 1 h nominal hydraulic retention time (HRT) and 6.4 kg COD/m(3)-d organic loading rate, the SRUSB reactor achieved 90% COD and 75% sulfate removal efficiencies. Granular sludge was observed within 30 days, and became stable after 4 months of operation with diameters of 400-500 μm, SVI5 of 30 ml/g, and extracellular polymeric substances of 23 mg carbohydrate/g VSS. Fluorescence in situ hybridization (FISH) analysis revealed that the granules were enriched with abundant sulfate-reducing bacteria (SRB) as compared with the seeding sludge. Pyrosequencing analysis of the 16S rRNA gene in the sulfate-reducing granules on day 90 indicated that the microbial community consisted of a diverse SRB genera, namely Desulfobulbus (18.1%), Desulfobacter (13.6%), Desulfomicrobium (5.6%), Desulfosarcina (0.73%) and Desulfovibrio (0.6%), accounting for 38.6% of total operational taxonomic units at genera level, with no methanogens detected. The microbial population and physicochemical properties of the granules well explained the excellent performance of the granular SRUSB reactor. Copyright © 2013 Elsevier

  7. DEGRADATION OF AROMATIC COMPOUNDS USING MOVING BED BIOFILM REACTORS

    B. Ayati, H. Ganjidoust, M. Mir Fattah

    2007-04-01

    Full Text Available For biological treatment of water, there are many different biofilm systems in use. Examples of them are trickling filters, rotating biological contactors, fixed media submerged biofilters, granular media biofilters and fluidized bed reactors. They all have their advantages and disadvantages. Hence, the Moving Bed Biofilm Reactor process was developed in Norway in the late 1980s and early 1990s to adopt the best features of the activated sludge process as well as those of the biofilter processes, without including the worst. Two cylindrical moving bed biofilm reactors were used in this study working in upflow stream conditions. Experiments have been done in aerobic batch flow regime. Laboratory experiments were conducted at room temperature (23–28C and synthetic wastewater comprising a composition of phenol and hydroquinone in each reactor as the main organic constituents, plus balanced nutrients and alkalinity were used to feed the reactor. The ratio of influent to effluent COD was determined at different retention times. The results indicated that the removal efficiency of each selected compound is affected by the detention time. At low phenol and hydroquinone concentration (from 700 to 1000 mg/L maximum removal efficiency (over 80 % was obtained. By further increasing in COD loading rate up to 3000 mg/L, a decrease in COD removal rate was occurred. In the reactor containing pyrogallol in COD of 1500 mg/L, the removal rate decreased to 10 percent because of its toxicity for microorganisms.

  8. Fluidized bed boiler feed system

    Jones, Brian C.

    1981-01-01

    A fluidized bed boiler feed system for the combustion of pulverized coal. Coal is first screened to separate large from small particles. Large particles of coal are fed directly to the top of the fluidized bed while fine particles are first mixed with recycled char, preheated, and then fed into the interior of the fluidized bed to promote char burnout and to avoid elutriation and carryover.

  9. The kinetics of combustion of chars derived from sewage sludge

    J.S. Dennis; R.J. Lambert; A.J. Milne; S.A. Scott; A.N. Hayhurst [University of Cambridge, Cambridge (United Kingdom). Department of Chemical Engineering

    2005-02-01

    Experiments have been conducted to determine the combustion characteristics of sewage sludge chars in electrically heated beds of silica sand fluidised by air. The effects of the initial size of the char particles, the temperature of the bed and the concentration of (O{sub 2}) in the fluidising gas were investigated. Also, the temperatures of burning particles were measured with embedded thermocouples. The kinetics of combustion were measured at temperatures low enough for the CO formed by initial reaction between the carbon and oxygen to burn at some distance away from the particle. It is probable that the lower value is closer to the actual value, thought to be 135{+-}15 kJ/mol, reflecting the catalytic nature of the ash skeleton on which the carbon is supported. It was possible to obtain good agreement between measured burnout times and those predicted using the grain model of Szekely J, Evans JW, Sohn HY. Gas-solid reactions. New York: Academic Press; 1976, for the case where the kinetics are controlled by a combination of: (i) external mass transfer of oxygen from the particulate phase to the external surface of the burning char particle, (ii) diffusion of oxygen from the external surface into the porous matrix to the surfaces of grains, of which the solid is composed, and (iii) diffusion of oxygen into the microporous grains, where reaction occurs with the carbon. It was found that, for particles with diameters of 2 mm or larger, the initial rates of reaction, for bed temperatures in excess of 750{degree}C, are dominated by external mass transfer. 22 refs., 8 figs., 1 tab.

  10. Anaerobic granular sludge and biofilm reactors

    Skiadas, Ioannis V.; Gavala, Hariklia N.; Schmidt, Jens Ejbye

    2003-01-01

    by the immobilization of the biomass, which forms static biofilms, particle-supported biofilms, or granules depending on the reactor's operational conditions. The advantages of the high-rate anaerobic digestion over the conventional aerobic wastewater treatment methods has created a clear trend for the change......-rate anaerobic treatment systems based on anaerobic granular sludge and biofilm are described in this chapter. Emphasis is given to a) the Up-flow Anaerobic Sludge Blanket (UASB) systems, b) the main characteristics of the anaerobic granular sludge, and c) the factors that control the granulation process...

  11. A microbiological study on irradiated sludge composting

    Pongpat, S.; Hashimoto, Shoji.

    1993-03-01

    Effect of fermentation temperature on microorganisms in sewage sludge compost and suppressive effect of the compost on Fusarium oxysporum were investigated. Dehydrated sewage sludge was irradiated at 10 kGy by cobalt 60 gamma ray source and fermented at various temperatures with six different seed-composts. It was found that microorganisms showed higher growth in irradiated sludge at the temperature around 30 to 40degC. One of the seed-composts and compost produced from the seed-compost showed the remarkable effects of suppression on F. oxysporum. It can be also observed that the composts produced by lower temperature fermentation showed higher suppression. (author)

  12. Using Ecosan sludge for crop production

    Jimenez, B

    2006-01-01

    Full Text Available %) was low, but not enough to completely inactivate microorganisms (below 30?40% in general and ,5% for Ascaris eggs, according to Feachem et al., 1983). The N content (0.2?0.34%) was in the normal range for domestic sludge (0.2?0.6%) if the N contribution... et al. (2003), indicated that faecal coliforms may survive .1,000 d in Ecosan sludge, while Ascaris may be completely inactivated. The helminth ova content (29.8 ^ 2.9 eggs/g TS) was less than expected for sludge from developing countries (ranging...

  13. A microbiological study on irradiated sludge composting

    Pongpat, S. [Office of Atomic Energy for Peace, Bangkok (Thailand); Hashimoto, Shoji

    1993-03-01

    Effect of fermentation temperature on microorganisms in sewage sludge compost and suppressive effect of the compost on Fusarium oxysporum were investigated. Dehydrated sewage sludge was irradiated at 10 kGy by cobalt 60 gamma ray source and fermented at various temperatures with six different seed-composts. It was found that microorganisms showed higher growth in irradiated sludge at the temperature around 30 to 40degC. One of the seed-composts and compost produced from the seed-compost showed the remarkable effects of suppression on F. oxysporum. It can be also observed that the composts produced by lower temperature fermentation showed higher suppression. (author).

  14. Improvement of anaerobic digestion of sludge

    Dohanyos, Michael; Zabranska, Jana; Kutil, Josef; Jenicek, Pavel

    2003-07-01

    Anaerobic digestion improvement can be accomplished by different methods. Besides optimization of process conditions is frequently used pretreatment of input sludge and increase of process temperature. Thermophilic process brings a higher solids reduction and biogas production, the high resistance to foaming, no problems with odour, the higher effect of destroying pathogens and the improvement of the energy balance of the whole treatment plant. Disintegration of excess activated sludge in lysate centrifuge was proved in full-scale conditions causing increase of biogas production. The rapid thermal conditioning of digested sludge is acceptable method of particulate matter disintegration and solubilization. (author)

  15. Sewage sludge disintegration by high-pressure homogenization: a sludge disintegration model.

    Zhang, Yuxuan; Zhang, Panyue; Ma, Boqiang; Wu, Hao; Zhang, Sheng; Xu, Xin

    2012-01-01

    High-pressure homogenization (HPH) technology was applied as a pretreatment to disintegrate sewage sludge. The effects of homogenization pressure, homogenization cycle number, and total solid content on sludge disintegration were investigated. The sludge disintegration degree (DD(COD)), protein concentration, and polysaccharide concentration increased with the increase of homogenization pressure and homogenization cycle number, and decreased with the increase of sludge total solid (TS) content. The maximum DD(COD) of 43.94% was achieved at 80 MPa with four homogenization cycles for a 9.58 g/L TS sludge sample. A HPH sludge disintegration model of DD(COD) = kNaPb was established by multivariable linear regression to quantify the effects of homogenization parameters. The homogenization cycle exponent a and homogenization pressure exponent b were 0.4763 and 0.7324 respectively, showing that the effect of homogenization pressure (P) was more significant than that of homogenization cycle number (N). The value of the rate constant k decreased with the increase of sludge total solid content. The specific energy consumption increased with the increment of sludge disintegration efficiency. Lower specific energy consumption was required for higher total solid content sludge.

  16. The effect of operational conditions on the sludge specific methanogenic activity and sludge biodegradability

    Leitao, R. C.; Santaella, S. T.; Haandel, A. C. van; Zeeman, G.; Lettinga, G.

    2009-07-01

    The Specific Methanogenic Activity (SMA) and sludge biodegradability of an anaerobic sludge depends on various operational and environmental conditions imposed to the anaerobic reactor. However, the effects of hydraulic retention time (HRT), influent COD concentration (COD{sub i}nf) and sludge retention time (SRT) on those two parameters need to be elucidated. This knowledge about SMA can provide insights about the capacity of the UASB reactors to withstand organic and hydraulic shock loads, whereas the biodegradability gives information necessary for final disposal of the sludge. (Author)

  17. Effect of seed sludge on characteristics and microbial community of aerobic granular sludge.

    Song, Zhiwei; Pan, Yuejun; Zhang, Kun; Ren, Nanqi; Wang, Aijie

    2010-01-01

    Aerobic granular sludge was cultivated by using different kinds of seed sludge in sequencing batch airlift reactor. The influence of seed sludge on physical and chemical properties of granular sludge was studied; the microbial community structure was probed by using scanning electron microscope and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The results showed that seed sludge played an important role on the formation of aerobic granules. Seed sludge taken from beer wastewater treatment plant (inoculum A) was more suitable for cultivating aerobic granules than that of sludge from municipal wastewater treatment plant (inoculum B). Cultivated with inoculum A, large amount of mature granules formed after 35 days operation, its SVI reached 32.75 mL/g, and SOUR of granular sludge was beyond 1.10 mg/(g x min). By contrast, it needed 56 days obtaining mature granules using inoculum B. DGGE profiles indicated that the dominant microbial species in mature granules were 18 and 11 OTU when inoculum A and B were respectively employed as seed sludge. The sequencing results suggested that dominant species in mature granules cultivated by inoculum A were Paracoccus sp., Devosia hwasunensi, Pseudoxanthomonas sp., while the dominant species were Lactococcus raffinolactis and Pseudomonas sp. in granules developed from inoculum B.

  18. The effect of operational conditions on the sludge specific methanogenic activity and sludge biodegradability

    Leitao, R. C.; Santaella, S. T.; Haandel, A. C. van; Zeeman, G.; Lettinga, G.

    2009-01-01

    The Specific Methanogenic Activity (SMA) and sludge biodegradability of an anaerobic sludge depends on various operational and environmental conditions imposed to the anaerobic reactor. However, the effects of hydraulic retention time (HRT), influent COD concentration (COD i nf) and sludge retention time (SRT) on those two parameters need to be elucidated. This knowledge about SMA can provide insights about the capacity of the UASB reactors to withstand organic and hydraulic shock loads, whereas the biodegradability gives information necessary for final disposal of the sludge. (Author)

  19. Management bedding : vrijloopstal met composterende bedding van houtsnippers

    Boer, de H.C.; Wiersma, M.; Galama, P.J.; Szanto, G.L.

    2015-01-01

    In de vrijloopstal liggen de koeien meestal op een organische bedding en scheiden daar mest (feces en urine) uit. Om de bedding voldoende droog en schoon te houden wordt er regelmatig nieuw strooisel aangevoerd en wordt de toplaag bewerkt. Op basis van onderzoek- en praktijkervaringen tot nu toe

  20. SLUDGE TREATMENT PROJECT PHASE 1 SLUDGE STORAGE OPTIONS. ASSESSMENT OF T PLANT VERSUS ALTERNATE STORAGE FACILITY

    Rutherford, W.W.; Geuther, W.J.; Strankman, M.R.; Conrad, E.A.; Rhoadarmer, D.D.; Black, D.M.; Pottmeyer, J.A.

    2009-01-01

    The CH2M HILL Plateau Remediation Company (CHPRC) has recommended to the U.S. Department of Energy (DOE) a two phase approach for removal and storage (Phase 1) and treatment and packaging for offsite shipment (Phase 2) of the sludge currently stored within the 105-K West Basin. This two phased strategy enables early removal of sludge from the 105-K West Basin by 2015, allowing remediation of historical unplanned releases of waste and closure of the 100-K Area. In Phase 1, the sludge currently stored in the Engineered Containers and Settler Tanks within the 105-K West Basin will be transferred into sludge transport and storage containers (STSCs). The STSCs will be transported to an interim storage facility. In Phase 2, sludge will be processed (treated) to meet shipping and disposal requirements and the sludge will be packaged for final disposal at a geologic repository. The purpose of this study is to evaluate two alternatives for interim Phase 1 storage of K Basin sludge. The cost, schedule, and risks for sludge storage at a newly-constructed Alternate Storage Facility (ASF) are compared to those at T Plant, which has been used previously for sludge storage. Based on the results of the assessment, T Plant is recommended for Phase 1 interim storage of sludge. Key elements that support this recommendation are the following: (1) T Plant has a proven process for storing sludge; (2) T Plant storage can be implemented at a lower incremental cost than the ASF; and (3) T Plant storage has a more favorable schedule profile, which provides more float, than the ASF. Underpinning the recommendation of T Plant for sludge storage is the assumption that T Plant has a durable, extended mission independent of the K Basin sludge interim storage mission. If this assumption cannot be validated and the operating costs of T Plant are borne by the Sludge Treatment Project, the conclusions and recommendations of this study would change. The following decision-making strategy, which is

  1. SLUDGE TREATMENT PROJECT PHASE 1 SLUDGE STORAGE OPTIONS ASSESSMENT OF T PLANT VERSUS ALTERNATE STORAGE FACILITY

    RUTHERFORD WW; GEUTHER WJ; STRANKMAN MR; CONRAD EA; RHOADARMER DD; BLACK DM; POTTMEYER JA

    2009-04-29

    The CH2M HILL Plateau Remediation Company (CHPRC) has recommended to the U.S. Department of Energy (DOE) a two phase approach for removal and storage (Phase 1) and treatment and packaging for offsite shipment (Phase 2) of the sludge currently stored within the 105-K West Basin. This two phased strategy enables early removal of sludge from the 105-K West Basin by 2015, allowing remediation of historical unplanned releases of waste and closure of the 100-K Area. In Phase 1, the sludge currently stored in the Engineered Containers and Settler Tanks within the 105-K West Basin will be transferred into sludge transport and storage containers (STSCs). The STSCs will be transported to an interim storage facility. In Phase 2, sludge will be processed (treated) to meet shipping and disposal requirements and the sludge will be packaged for final disposal at a geologic repository. The purpose of this study is to evaluate two alternatives for interim Phase 1 storage of K Basin sludge. The cost, schedule, and risks for sludge storage at a newly-constructed Alternate Storage Facility (ASF) are compared to those at T Plant, which has been used previously for sludge storage. Based on the results of the assessment, T Plant is recommended for Phase 1 interim storage of sludge. Key elements that support this recommendation are the following: (1) T Plant has a proven process for storing sludge; (2) T Plant storage can be implemented at a lower incremental cost than the ASF; and (3) T Plant storage has a more favorable schedule profile, which provides more float, than the ASF. Underpinning the recommendation of T Plant for sludge storage is the assumption that T Plant has a durable, extended mission independent of the K Basin sludge interim storage mission. If this assumption cannot be validated and the operating costs of T Plant are borne by the Sludge Treatment Project, the conclusions and recommendations of this study would change. The following decision-making strategy, which is

  2. Land application of sewage sludge: Pathogen issues

    Chang, A C [Department of Soil and Environmental Sciences, Univ. of California at Riverside, Riverside, CA (United States)

    1997-10-01

    Diseases transmitted via the faecal-oral exposure route cause severe gastroenteric disorders, and large numbers of causative organisms are discharged with the faecal matter of infected individuals. For this reason, pathogenic bacteria, viruses, protozoa, or helminths, are always found in sewage sludge. If not properly treated for use in agriculture, sludge can be a source of pathogenic contamination. Radiation is an attractive method to reduce the numbers of microorganisms in sewage sludge. Routine examination for pathogens is not practised nor recommended because complicated and costly procedures are involved. Instead, an indicator organism is usually assayed and enumerated. In this paper, methods are discussed for the investigation of pathogens in sewage sludge. (author). 8 refs, 3 tabs.

  3. 183-H Basin sludge treatability test report

    Biyani, R.K.

    1995-01-01

    This document presents the results from the treatability testing of a 1-kg sample of 183-H Basin sludge. Compressive strength measurements, Toxic Characteristic Leach Procedure, and a modified ANSI 16.1 leach test were conducted

  4. Use of sludge as ceramic materials

    Morais, L.C.; Vianna, R.S.C.; Campos, V.; Rosa, A.H.; Buechler, P.M.

    2009-01-01

    Nowadays, with increase amounts of sludge derived from the treatment of domestic sewage put pressure into research on systems for the adequate use of these materials. The aim of the present work is to study the use of sludge ash, from sintering and calcinated process, as a raw material for the ceramic industry. Using the sewage sludge ashes as ceramic raw material there will be no contamination of soil and underground water. Metals and toxic compounds like Al, Fe, Ba, Cr, Cu, Mn and Zn oxides were analyzed and characterized by X-ray fluorescence (XRF), scanning electron microscopy (SEM) and plasma emission spectroscopy (ICP-OES). The leached material was chemically analyzed where the integration of oxides into the ceramic matrix of sludge ash was observed. Residual decomposition was analyzed by TG, DTG and DTA curves. (author)

  5. Rheological characterisation of municipal sludge: a review.

    Eshtiaghi, Nicky; Markis, Flora; Yap, Shao Dong; Baudez, Jean-Christophe; Slatter, Paul

    2013-10-01

    Sustainable sludge management is becoming a major issue for wastewater treatment plants due to increasing urban populations and tightening environmental regulations for conventional sludge disposal methods. To address this problem, a good understanding of sludge behaviour is vital to improve and optimize the current state of wastewater treatment operations. This paper provides a review of the recent experimental works in order for researchers to be able to develop a reliable characterization technique for measuring the important properties of sludge such as viscosity, yield stress, thixotropy, and viscoelasticity and to better understand the impact of solids concentrations, temperature, and water content on these properties. In this context, choosing the appropriate rheological model and rheometer is also important. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Resistance capability of microaerobic granular sludge for ...

    enoh

    2012-02-08

    Feb 8, 2012 ... The resistance capability to pH shock of microaerobic granular sludge for pentachlorophenol (PCP) ... process with chlorine gas in pulp and paper, leather and spinning ... nitrifying bacteria in the aerobic zone, and then trans-.

  7. Bacteriological studies on dairy waste activated sludge

    Adamse, A.D.

    1966-01-01

    Dairy-waste activated sludge was examined for bacterial composition and response to different conditions. Strains isolated were classified mainly into three groups: predominantly coryneform bacteria (largely Arthrobacter), some Achromobacteraceae and a small groups of Pseudomonadaceae.

  8. grown on soil amended with sewage sludge

    DELL

    2Department of Civil Engineering, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria. Corresponding ... Key Words: Sewage sludge, Green amaranth, Phytoextraction, Heavy metals. ..... Wastewater-irrigated Areas of Titagarh,.

  9. Fixed bed sorption of phosphorus from wastewater using iron oxide-based media derived from acid mine drainage

    Sibrell, Philip L.; Tucker, T.W.

    2012-01-01

    Phosphorus (P) releases to the environment have been implicated in the eutrophication of important water bodies worldwide. Current technology for the removal of P from wastewaters consists of treatment with aluminum (Al) or iron (Fe) salts, but is expensive. The neutralization of acid mine drainage (AMD) generates sludge rich in Fe and Al oxides that has hitherto been considered a waste product, but these sludges could serve as an economical adsorption media for the removal of P from wastewaters. Therefore, we have evaluated an AMD-derived media as a sorbent for P in fixed bed sorption systems. The homogenous surface diffusion model (HSDM) was used to analyze fixed bed test data and to determine the value of related sorption parameters. The surface diffusion modulus Ed was found to be a useful predictor of sorption kinetics. Values of Ed treatment costs while at the same time ameliorating the impacts of P contamination.

  10. Rapid thermal conditioning of sewage sludge

    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

  11. Enhancement of biogas production from sewage sludge by addition of grease trap sludge

    Grosser, A.; Neczaj, E.

    2016-01-01

    Highlights: • Addition of grease trap sludge is interesting option for sewage sludge digestion. • Co-digestion of grease trap sludge and sewage sludge improved efficiency of process. • The anaerobic digestion can be carried out at short hydraulic retention time. • Long chain fatty acids concentration was below the ranges for inhibition of anaerobic digestion. - Abstract: Despite having many benefits, a low degree of volatile solids removal as well as long retention time are the main factors limiting the performance of the anaerobic digestion. Co-digestion of sewage sludge with other organic waste (for example fat rich materials) is one of the few potential ways to enhance the performance of the anaerobic digestion. In this article, the effects of adding fatty rich materials on the performance and stability of semi-continuous anaerobic digestion of sewage sludge were investigated on a 6 l laboratory-scale reactor (working volume equal to 5.5 l). The reactor was operated in a semi-continuous mode with a hydraulic retention time of 10 days. The data presented in this paper relate to the period in which the grease trap sludge accounted for 10, 12, 14, 16 and 18% of the mixture on the volatile solids basis. The results clearly indicate that the addition of fat rich materials like grease trap sludge can lead to a satisfactory increase in biogas yield in digester treating sewage sludge. The results showed that co-digestion can enhance the biogas yield by 28–82% compared to anaerobic digestion of sewage sludge alone (control sample). Moreover, the addition of grease trap sludge to digesters resulted in increased volatile solids removal from 44.38% (control sample) to 57.77% (feedstock with 14% addition of grease trap sludge). It was found that the increase of grease trap sludge in the feedstock had a direct impact on the biogas production and methane yield. This proposal has also been confirmed by statistical analysis such as Pearson correlation coefficients and

  12. Effectiveness of Bed Bug Pesticides

    Before EPA allows a bed bug claim on a label, the product must be supported by data showing it will kill bed bugs when applied according to the label. Also consider factors such as extent of infestation, site preparation, and insect life stages.

  13. Sustainability of Domestic Sewage Sludge Disposal

    Claudia Bruna Rizzardini; Daniele Goi

    2014-01-01

    Activated sludge is now one of the most widely used biological processes for the treatment of wastewaters from medium to large populations. It produces high amounts of sewage sludge that can be managed and perceived in two main ways: as a waste it is discharged in landfill, as a fertilizer it is disposed in agriculture with direct application to soil or subjected to anaerobic digestion and composting. Other solutions, such as incineration or production of concrete, bricks and asphalt play a s...

  14. Physical inactivation and stabilization of sludges

    Alexandre, D.

    1979-07-01

    High temperature conditioning of sludge is a stabilization process that insures sterilization. Both thermal pasteurization and irradiation are inactivation processes. Viruses and parasites are inactivated at 70-80 0 C. Total bacterial destruction requires higher temperatures and/or detention time. Radio sensitivity of pathogens and pertinent treatment parameters are examined. If sludge is to be land disposed, disinfection requires irradiation doses ranging 500 Krad; if cattle feeding is considered, the required dose is 1 Mrad

  15. Activated Sludge and Aerobic Biofilm Reactors

    Von Sperling, Marcos

    2007-01-01

    "Activated Sludge and Aerobic Biofilm Reactors is the fifth volume in the series Biological Wastewater Treatment. The first part of the book is devoted to the activated sludge process, covering the removal of organic matter, nitrogen and phosphorus.A detailed analysis of the biological reactor (aeration tank) and the final sedimentation tanks is provided. The second part of the book covers aerobic biofilm reactors, especially trickling filters, rotating biological contractors and submerged ae...

  16. Modeling of Activated Sludge Floc Characteristics

    Ibrahim H. Mustafa; G. Ibrahim; Ali Elkamel; A. H. Elahwany

    2009-01-01

    Problem Statement: The activated sludge system needs to improve the operational performance and to achieve more effective control. To realize this, a better quantitative understanding of the biofloc characteristics is required. The objectives of this study were to: (i) Study the biofloc characteristics from kinetics-mass transfer interaction point of view by quantification of the weight of the aerobic portion of the activated sludge floc to the total floc weight. (ii) Study the effect of bulk...

  17. Sewage sludge irradiators: Batch and continuous flow

    Lavale, D.S.; George, J.R.; Shah, M.R.; Rawat, K.P.

    1998-01-01

    The potential threat to the environment imposed by high pathogenic organism content in municipal wastewater, especially the sludge and the world-wide growing aspirations for a cleaner, salubrious environment have made it mandatory for the sewage and sludge to undergo treatment, prior to their ultimate disposal to mother nature. Incapabilities associated with the conventional wastewater treatments to mitigate the problem of microorganisms have made it necessary to look for other alternatives, radiation treatment being the most reliable, rapid and environmentally sustainable of them. To promote the use of radiation for the sludge hygienization, Department of Atomic Energy has endeavoured to set up an indigenous, Sludge Hygienization Research Irradiator (SHRI) in the city of Baroda. Designed for 18.5 PBq of 60 Co to disinfect the digested sludge, the irradiator has additional provision for treatment of effluent and raw sewage. From engineering standpoint, all the subsystems have been functioning satisfactorily since its commissioning in 1990. Prolonged studies, spanning over a period of six years, primarily focused on inactivation of microorganism revealed that 3 kGy dose of gamma radiation is adequate to make the sludge pathogen and odour-free. A dose of 1.6 kGy in raw sewage and 0.5 kGy in effluent reduced coliform counts down to the regulatory discharge limits. These observations reflect a possible cost-effective solution to the burgeoning problem of surface water pollution across the globe. In the past, sub 37 PBq 60 Co batch irradiators have been designed and commissioned successfully for the treatment of sludge. Characterized with low dose delivery rates they are well-suited for treating low volumes of sludge in batches. Some concepts of continuous flow 60 Co irradiators having larger activities, yet simple and economic in design, are presented in the paper

  18. Simultaneous nitrification-denitrification and phosphorus removal in a fixed bed sequencing batch reactor (FBSBR)

    Rahimi, Yousef; Torabian, Ali; Mehrdadi, Naser; Shahmoradi, Behzad

    2011-01-01

    Research highlights: → Sludge production in FSBR reactor is 20-30% less than SBR reactor. → FSBR reactor showed more nutrient removal rate than SBR reactor. → FSBR reactor showed less VSS/TSS ratio than SBR reactor. - Abstract: Biological nutrient removal (BNR) was investigated in a fixed bed sequencing batch reactor (FBSBR) in which instead of activated sludge polypropylene carriers were used. The FBSBR performance on carbon and nitrogen removal at different loading rates was significant. COD, TN, and phosphorus removal efficiencies were at range of 90-96%, 60-88%, and 76-90% respectively while these values at SBR reactor were 85-95%, 38-60%, and 20-79% respectively. These results show that the simultaneous nitrification-denitrification (SND) is significantly higher than conventional SBR reactor. The higher total phosphorus (TP) removal in FBSBR correlates with oxygen gradient in biofilm layer. The influence of fixed media on biomass production yield was assessed by monitoring the MLSS concentrations versus COD removal for both reactors and results revealed that the sludge production yield (Y obs ) is significantly less in FBSBR reactors compared with SBR reactor. The FBSBR was more efficient in SND and phosphorus removal. Moreover, it produced less excess sludge but higher in nutrient content and stabilization ratio (less VSS/TSS ratio).

  19. Simultaneous nitrification-denitrification and phosphorus removal in a fixed bed sequencing batch reactor (FBSBR)

    Rahimi, Yousef, E-mail: you.rahimi@gmail.com [Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, No. 25 Qods St., Enghelab Ave, Tehran (Iran, Islamic Republic of); Torabian, Ali, E-mail: atorabi@ut.ac.ir [Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, No. 25 Qods St., Enghelab Ave, Tehran (Iran, Islamic Republic of); Mehrdadi, Naser, E-mail: mehrdadi@ut.ac.ir [Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, No. 25 Qods St., Enghelab Ave, Tehran (Iran, Islamic Republic of); Shahmoradi, Behzad, E-mail: bshahmorady@gmail.com [Department of Environmental Science, University of Mysore, MGM-06 Mysore (India)

    2011-01-30

    Research highlights: {yields} Sludge production in FSBR reactor is 20-30% less than SBR reactor. {yields} FSBR reactor showed more nutrient removal rate than SBR reactor. {yields} FSBR reactor showed less VSS/TSS ratio than SBR reactor. - Abstract: Biological nutrient removal (BNR) was investigated in a fixed bed sequencing batch reactor (FBSBR) in which instead of activated sludge polypropylene carriers were used. The FBSBR performance on carbon and nitrogen removal at different loading rates was significant. COD, TN, and phosphorus removal efficiencies were at range of 90-96%, 60-88%, and 76-90% respectively while these values at SBR reactor were 85-95%, 38-60%, and 20-79% respectively. These results show that the simultaneous nitrification-denitrification (SND) is significantly higher than conventional SBR reactor. The higher total phosphorus (TP) removal in FBSBR correlates with oxygen gradient in biofilm layer. The influence of fixed media on biomass production yield was assessed by monitoring the MLSS concentrations versus COD removal for both reactors and results revealed that the sludge production yield (Y{sub obs}) is significantly less in FBSBR reactors compared with SBR reactor. The FBSBR was more efficient in SND and phosphorus removal. Moreover, it produced less excess sludge but higher in nutrient content and stabilization ratio (less VSS/TSS ratio).

  20. Transformation products of clindamycin in moving bed biofilm reactor (MBBR)

    Ooi, Gordon Tze Hoong; Escola Casas, Monica; Andersen, Henrik Rasmus

    2017-01-01

    Clindamycin is widely prescribed for its ability to treat a number of common bacterial infections. Thus, clindamycin enters wastewater via human excretion or disposal of unused medication and widespread detection of pharmaceuticals in rivers proves the insufficiency of conventional wastewater...... treatment plants in removing clindamycin. Recently, it has been discovered that attached biofilm reactors, e.g., moving bed biofilm reactors (MBBRs) obtain a higher removal of pharmaceuticals than conventional sludge wastewater treatment plants. Therefore, this study investigated the capability of MBBRs...... process converts clindamycin into the, possibly persistent, products clindamycin sulfoxide and N-desmethyl clindamycin as well as 3 other mono-oxygenated products. Subsequently, the removal kinetics of clindamycin and the formation of the two identified products were investigated in batch experiments...

  1. Disintegration impact on sludge digestion process.

    Dauknys, Regimantas; Rimeika, Mindaugas; Jankeliūnaitė, Eglė; Mažeikienė, Aušra

    2016-11-01

    The anaerobic sludge digestion is a widely used method for sludge stabilization in wastewater treatment plant. This process can be improved by applying the sludge disintegration methods. As the sludge disintegration is not investigated enough, an analysis of how the application of thermal hydrolysis affects the sludge digestion process based on full-scale data was conducted. The results showed that the maximum volatile suspended solids (VSS) destruction reached the value of 65% independently on the application of thermal hydrolysis. The average VSS destruction increased by 14% when thermal hydrolysis was applied. In order to have the maximum VSS reduction and biogas production, it is recommended to keep the maximum defined VSS loading of 5.7 kg VSS/m(3)/d when the thermal hydrolysis is applied and to keep the VSS loading between 2.1-2.4 kg VSS/m(3)/d when the disintegration of sludge is not applied. The application of thermal hydrolysis leads to an approximately 2.5 times higher VSS loading maintenance comparing VSS loading without the disintegration; therefore, digesters with 1.8 times smaller volume is required.

  2. Separation of SRP waste sludge and supernate

    Stone, J.A.

    1976-01-01

    Sludges and supernates were separated from Savannah River Plant waste slurries by centrifugation and sand filtration. This separation, a portion of a conceptual process for solidification and long-term storage of high-level radioactive wastes, was tested in shielded cells with small-scale process equipment. Procedures for the separation were developed in tests with nonradioactive materials. Then, in 13 tests with actual sludges and supernates, solids removal ranged from 90 to 99.2 vol percent and averaged 96.4 vol percent after two passes through a basket-type centrifuge. Concentrates from the tests, containing 0.05 to 0.2 vol percent solids, were clarified by sand filter columns to produce solutions of the soluble salts with less than 0.01 vol percent solids. About 700 liters of salt solution and 8 kilograms of washed, dried sludges were separated in the tests. Effects of sludge type, flocculant, flow rates, and batch size were evaluated. Washing and drying of centrifuged sludges were studied, and two types of dryers were tested. Ruthenium volatility during drying was negligible. Washing efficiency was determined by analyses of wash solutions and sludge products

  3. Summary status of K Basins sludge characterization

    Baker, R.B.

    1995-01-01

    A number of activities are underway as part of the Spent Nuclear Fuels Project (SNFP) related to the processing and disposing of sludge in the 105-K Basins (K Basins). Efforts to rigorously define data requirements for these activities are being made using the Data Quality Objectives (DQO) process. Summaries of current sludge characterization data are required to both help support this DQO process and to allow continued progress with on-going engineering activities (e.g., evaluations of disposal alternatives). This document provides the status of K Basins sludge characterization data currently available to the Nuclear Fuel Evaluations group. This group is tasked by the SNFP to help develop and maintain the characterization baseline for the K Basins. The specific objectives of this document are to: (1) provide a current summary (and set of references) of sludge characterization data for use by SNFP initiatives, to avoid unnecessary duplication of effort and to support on-going initiatives; (2) submit these data to an open forum for review and comment, and identify additional sources of significant data that may be available; (3) provide a summary of current data to use as part of the basis to develop requirements for additional sludge characterization data through the DQO process; (4) provide an overview of the intended activities that will be used to develop and maintain the sludge characterization baseline

  4. Reuse of industrial sludge as construction aggregates.

    Tay, J H; Show, K Y; Hong, S Y

    2001-01-01

    Industrial wastewater sludge and dredged marine clay are high volume wastes that needed enormous space at landfill disposal sites. Due to the limitation of land space, there is an urgent need for alternative disposal methods for these two wastes. This study investigates the possibility of using the industrial sludge in combination with marine clay as construction aggregates. Different proportions of sludge and clay were made into round and angular aggregates. It was found that certain mix proportions could provide aggregates of adequate strength, comparable to that of conventional aggregates. Concrete samples cast from the sludge-clay aggregates yield compressive strengths in the range of 31.0 to 39.0 N/mm2. The results showed that the round aggregates of 100% sludge and the crush aggregates of sludge with up to 20% clay produced concrete of compressive strengths which are superior to that of 38.0 N/mm2 for conventional aggregate. The study indicates that the conversion of high volume wastes into construction materials is a potential option for waste management.

  5. Sludge storage lagoon biogas recovery and use

    Muller, D.; Norville, C. (Memphis and Shelby County Div. of Planning and Development, TN (United States))

    1991-07-01

    The City of Memphis has two wastewater treatment plants. The SWTP employs two large anaerobic digestion sludge lagoons as part of the overall sludge treatment system. Although these lagoons are effective in concentrating and digesting sludge, they can generate offensive odors. The SWTP uses aerobic digesters to partially stabilize the sludge and help reduce objectionable odors before it enters the lagoons. The anaerobic digestion of sludge in the lagoons results in the dispersion of a large quantity of biogas into the atmosphere. The City realized that if the lagoons could be covered, the odor problem could be resolved, and at the same, time, biogas could be recovered and utilized as a source of energy. In 1987, the City commissioned ADI International to conduct a feasibility study to evaluate alternative methods of covering the lagoons and recovering and utilizing the biogas. The study recommended that the project be developed in two phases: (1) recovery of the biogas and (2) utilization of the biogas. Phase 1 consists of covering the two lagoons with an insulated membrane to control odor and temperature and collect the biogas. Phase 1 was found to be economically feasible and offered a unique opportunity for the City to save substantial operating costs at the treatment facility. The Memphis biogas recovery project is the only application in the world where a membrane cover has been used on a municipal wastewater sludge lagoon. It is also the largest lagoon cover system in the world.

  6. Method of treating radioactive sludge waste

    Shoji, Yuichi; Matsuura, Hiroyuki; Ichihashi, Toshio

    1989-01-01

    For removing water content from sludge wastes, filtration or steam condensation may be considered, but none of them can sufficiently reduce the water content since filtration may cause clogging and steam treatment has a limit in the condensation. In view of the above, radioactive sludge wastes are dehydrated by an electroosmotic process in a vessel and then dehydrated solid contents are solidified in the vessel. Since the sludge wastes are mainly composed o fion exchange resins and iron oxides deposited to the resins, when a DC voltage is applied to the sludges containing such solid contents, a force tending to premeate them through the fine pores in the filter is exerted to water. As a result, only water is removed while the solids are being held on the filters. Since the moving direction of water is different depending on the property of the sludges, the polarity of the electrodes may be changed depending on the nature of the sludges. Thus, volume reduction can be improved and treating conditions can be controlled easily by a simple device. (N.H.)

  7. Reasonable management plan of sludge in sewage disposal plant

    Yum, Kyu Jin; Koo, Hyun Jung [Korea Environment Institute, Seoul (Korea)

    1998-12-01

    The compost method, which is widely used as a sewage disposal recycling in Korea, is now basically impossible to recycle sludge to compost by the Ministry of Agriculture and Forestry announcement. Therefore, the disposal of sludge will be much harder with reducing the amount of sludge used as compost. The amount of sludge other than using as compost is very small, so the development of various sludge recycling and use will be needed with regulations. This study was implemented to help the establishment of sewage sludge recycling policy in Korea. 30 refs., 17 figs., 58 tabs.

  8. Sludge treatment facility preliminary siting study for the sludge treatment project (A-13B)

    WESTRA, A.G.

    1999-01-01

    This study evaluates various sites in the 100 K area and 200 areas of Hanford for locating a treatment facility for sludge from the K Basins. Both existing facilities and a new standalone facility were evaluated. A standalone facility adjacent to the AW Tank Farm in the 200 East area of Hanford is recommended as the best location for a sludge treatment facility

  9. Zinc deprivation of methanol fed anaerobic granular sludge bioreactors

    Fermoso, Fernando G.; Collins, Gavin; Bartacek, Jan

    2008-01-01

    The effect of omitting zinc from the influent of mesophilic (30 °C) methanol fed upflow anaerobic sludge bed (UASB) reactors, and latter zinc supplementation to the influent to counteract the deprivation, was investigated by coupling the UASB reactor performance to the microbial ecology of the bioreactor sludge. Limitation of the specific methanogenic activity (SMA) on methanol due to the absence of zinc from the influent developed after 137 days of operation. At that day, the SMA in medium with a complete trace metal solution except Zn was 3.4 g CH4-COD g VSS−1 day−1, compared to 4.2 g CH4-COD g VSS−1 day−1 in a medium with a complete (including zinc) trace metal solution. The methanol removal capacity during these 137 days was 99% and no volatile fatty acids accumulated. Two UASB reactors, inoculated with the zinc-deprived sludge, were operated to study restoration of the zinc limitation by zinc supplementation to the bioreactor influent. In a first reactor, no changes to the operational conditions were made. This resulted in methanol accumulation in the reactor effluent after 12 days of operation, which subsequently induced acetogenic activity 5 days after the methanol accumulation started. Methanogenesis could not be recovered by the continuous addition of 0.5 μM ZnCl2 to the reactor for 13 days. In the second reactor, 0.5 μM ZnCl2 was added from its start-up. Although the reactor stayed 10 days longer methanogenically than the reactor operated without zinc, methanol accumulation was observed in this reactor (up to 1.1 g COD-MeOH L−1) as well. This study shows that zinc limitation can induce failure of methanol fed UASB reactors due to acidification, which cannot be restored by resuming the continuous supply of the deprived metal. PMID:18283507

  10. Protecting Your Home from Bed Bugs

    ... your home: Inspect the luggage rack in your hotel room for bed bugs. Check secondhand furniture, beds, ... with Bed Bug Problems Discover. Accessibility EPA Administrator Budget & Performance Contracting Grants January 19, 2017 Web Snapshot ...

  11. Impact of sludge properties on solid-liquid separation of activated sludge

    Christensen, Morten Lykkegaard

    2016-01-01

    Solid-liquid separation of activated sludge is important both directly after the biological treatment of wastewater and for sludge dewatering. The separation of solid from the treated wastewater can be done by clarifiers (conventional plants) or membrane (MBR). Further, part of the sludge is taken...... out from the proces and usually dewatered before further handling. The separation process is costly. Moreover, the separation process depends on the composition and the properties of the sludge. The best separation is obtained for sludge that contains strong, compact flocs without single cells...... and dissolved extracellular polymeric substances (EPS). Polyvalent ions improve the floc strangth and improve the separation whereas monovalent ions (e.g. from road salt, sea water intrusion and industry) reduces impair the separation. Further high pH impairs the separation process due to floc disintegration...

  12. Comparison of organic emissions from laboratory and full-scale thermal degradation of sewage sludge

    Tirey, D.A.; Striebich, R.C.; Dellinger, B.; Bostian, H.E.

    1991-01-01

    Samples of sewage sludge burned at one fluidized-bed and three multiple-hearth incinerators were subjected to laboratory flow reactor thermal decomposition testing in both pyrolytic and oxidative atmospheres. The time/temperature conditions of the laboratory testing were established to simulate as closely as possible full-scale incineration conditions so that a direct comparison of results could be made. The laboratory test results indicated that biomass decomposition products, not toxic industrial contaminants, comprised the majority of the emissions. Benzene, toluene, ethylbenzene, acrylonitrile, and acetonitrile were consistently the most environmentally significant products of thermal degradation. Comparison of the results from this study with those obtained in field tests was complicated by an apparent loss of volatile chlorocarbons from the sludge samples received for laboratory testing. However, qualitative comparison of emission factors derived from lab and field results for those compounds observed in both studies, showed reasonably good correlation for the pyrolysis testing. Results suggested that the upper stages of multiple-hearth units may vaporize many volatile components of the sludge before they enter the combustion stages of the incinerator and thus represent a direct source of introduction of pollutants into the atmosphere

  13. Investigation of waste biomass co-pyrolysis with petroleum sludge using a response surface methodology.

    Hu, Guangji; Li, Jianbing; Zhang, Xinying; Li, Yubao

    2017-05-01

    The treatment of waste biomass (sawdust) through co-pyrolysis with refinery oily sludge was carried out in a fixed-bed reactor. Response surface method was applied to evaluate the main and interaction effects of three experimental factors (sawdust percentage in feedstock, temperature, and heating rate) on pyrolysis oil and char yields. It was found that the oil and char yields increased with sawdust percentage in feedstock. The interaction between heating rate and sawdust percentage as well as between heating rate and temperature was significant on the pyrolysis oil yield. The higher heating value of oil originated from sawdust during co-pyrolysis at a sawdust/oily sludge ratio of 3:1 increased by 5 MJ/kg as compared to that during sawdust pyrolysis alone, indicating a synergistic effect of co-pyrolysis. As a result, petroleum sludge can be used as an effective additive in the pyrolysis of waste biomass for improving its energy recovery. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. An evaluation of tannery industry wastewater treatment sludge gasification by artificial neural network modeling

    Ongen, Atakan; Kurtulus Ozcan, H.; Arayıcı, Semiha

    2013-01-01

    Highlights: • We model calorific value of syn-gas from tannery industry treatment sludge. • We monitor variation of gas composition in produced gas. • Heating value of produced gas is around 1500 kcal/m 3 . • Model predictions are in close accordance with real values. -- Abstract: This paper reports on the calorific value of synthetic gas (syngas) produced by gasification of dewatered sludge derived from treatment of tannery wastewater. Proximate and ultimate analyses of samples were performed. Thermochemical conversion alters the chemical structure of the waste. Dried air was used as a gasification agent at varying flow rates, which allowed the feedstock to be quickly converted into gas by means of different heterogeneous reactions. A lab-scale updraft fixed-bed steel reactor was used for thermochemical conversion of sludge samples. Artificial neural network (ANN) modeling techniques were used to observe variations in the syngas related to operational conditions. Modeled outputs showed that temporal changes of model predictions were in close accordance with real values. Correlation coefficients (r) showed that the ANN used in this study gave results with high sensitivity

  15. An evaluation of tannery industry wastewater treatment sludge gasification by artificial neural network modeling

    Ongen, Atakan, E-mail: aongen@istanbul.edu.tr; Kurtulus Ozcan, H.; Arayıcı, Semiha

    2013-12-15

    Highlights: • We model calorific value of syn-gas from tannery industry treatment sludge. • We monitor variation of gas composition in produced gas. • Heating value of produced gas is around 1500 kcal/m{sup 3}. • Model predictions are in close accordance with real values. -- Abstract: This paper reports on the calorific value of synthetic gas (syngas) produced by gasification of dewatered sludge derived from treatment of tannery wastewater. Proximate and ultimate analyses of samples were performed. Thermochemical conversion alters the chemical structure of the waste. Dried air was used as a gasification agent at varying flow rates, which allowed the feedstock to be quickly converted into gas by means of different heterogeneous reactions. A lab-scale updraft fixed-bed steel reactor was used for thermochemical conversion of sludge samples. Artificial neural network (ANN) modeling techniques were used to observe variations in the syngas related to operational conditions. Modeled outputs showed that temporal changes of model predictions were in close accordance with real values. Correlation coefficients (r) showed that the ANN used in this study gave results with high sensitivity.

  16. Wastewater and sludge management and research in Oman: An overview.

    Jaffar Abdul Khaliq, Suaad; Ahmed, Mushtaque; Al-Wardy, Malik; Al-Busaidi, Ahmed; Choudri, B S

    2017-03-01

    It is well recognized that management of wastewater and sludge is a critical environmental issue in many countries. Wastewater treatment and sludge production take place under different technical, economic, and social contexts, thus requiring different approaches and involving different solutions. In most cases, a regular and environmentally safe wastewater treatment and associated sludge management requires the development of realistic and enforceable regulations, as well as treatment systems appropriate to local circumstances. The main objective of this paper is to provide useful information about the current wastewater and sludge treatment, management, regulations, and research in Oman. Based on the review and discussion, the wastewater treatment and sludge management in Oman has been evolving over the years. Further, the land application of sewage sludge should encourage revision of existing standards, regulations, and policies for the management and beneficial use of sewage sludge in Oman. Wastewater treatment and sludge management in Oman have been evolving over the years. Sludge utilization has been a challenge due to its association with human waste. Therefore, composting of sewage sludge is the best option in agriculture activities. Sludge and wastewater utilization can add up positively in the economic aspects of the country in terms of creating jobs and improving annual income rate. The number of research projects done on wastewater reuse and other ongoing ones related to the land application of sewage sludge should encourage revision of existing standards, regulations, and policies for the management and beneficial use of sewage sludge in Oman.

  17. Gas fluidized bed reactor

    Bernardelli, H. da C.

    1976-03-01

    The equations of motion for both gas and particles in a gas fluidised system are stablished through general assumptions which are generally accepted on physical grounds. The resulting model is used to study the velocity fields of each phase in the case of an isolated bubble rising close to the flat distributor plate. A well posed problem results for the solution of Laplace's equation of the potential flow of the particles when consideration is given to the presence of the distributor as a boundary condition. The corresponding stream functions are also obtained which enable the drawing of the motion patterns using numerical techniques. The following two dimensional cases are analysed: S/b=1; S/b=1,5; S/b=2,5; S/b=5 and the limiting case S/b→αinfinite. The results for the interphase exchange between bubbles and particulate phases are applied to a gas fluidised bed reactor and its effect on the chemical conversion is studied for the simplest cases of piston flow and perfect mixing in the particulate phase [pt

  18. Chaotic hydrodynamics of fluidized beds

    Van der Stappen, M.L.M. [Unit Process and Systems Engineering, Advanced Manufacturing Technology Group, Unilever Research Laboratorium, Vlaardingen (Netherlands)

    1996-12-31

    The major goals of this thesis are: (1) to develop and evaluate an analysis method based on techniques from non-linear chaos theory to characterize the nonlinear hydrodynamics of gas-solids fluidized beds quantitatively; and (2) to determine the dependence of the chaotic invariants on the operating conditions and investigate how the chaos analysis method can be profitably applied to improve scale-up and design of gas-solids fluidized bed reactors. Chaos theory is introduced in chapter 2 with emphasis on analysis techniques for (experimental) time series, known from literature at the start of this work (1990-1991). In chapter 3, the testing of existing and newly developed techniques on both model and fluidized bed data is described. This leads to the development of the chaos analysis method to analyze measured pressure fluctuations time series of a fluidized bed. Following, in chapter 4, this method is tested and all choices for the parameters are evaluated. The influence of the experimental parameters and external disturbances on the measurements and analysis results is discussed and quantified. The result is a chaos measurement and analysis protocol, which is further used in this work. In chapter 5, the applications to fluidized beds are discussed. It is shown that the entropy is a good measure for the characterization of the dynamical behavior of gas-solids bubbling/slugging fluidized beds. Entropy is applied to characterize the influence of the operating conditions, to assess regime transitions and to analyze dimensionless similar beds of different scale. Quantitative design correlations that relate entropy to the operating parameters (including the bed diameter) are described. Finally, it is discussed how the results of this work might be used in scaling up the chaotic dynamics of fluidized beds. The overall conclusions and outlook from this work are presented in chapter 6. 182 refs.

  19. Bed retained products in swept fixed bed (SFB) coal hydropyrolysis

    Mastral, A.M.; Perez-Surio, M.J. [CSIC, Zaragosa (Spain). Inst. de Carboquimica

    1997-12-31

    The hydropyrolysis of a low rank coal in a swept fixed bed (SFB) reactor is carried out by fixing the hydrogen pressure (40 kg/cm{sup 2}), the hydrogen flow (2 l/min) and the residence time (10 min) at increasing temperatures (400 C, 500 C and 600 C) and coal bed heights (h, 1.5h, 2h, 2.5h and 3h). It is shown that the percentages of tars and char directly depend on the coal bed height and that there is not only a quantitative dependence, but also the height of the coal bed is very important and plays a relevant role on the nature of the conversion products. (orig.)

  20. Bed diameter effects and incipient slugging in gas fluidized beds

    Agarwal, P.K.

    1986-01-01

    The coalescence and growth of bubble swarms formed at the distributor of a fluidized bed gives rise to lateral as well as vertical distributions of bubble properties. However, existing models employ average bubble properties obtained largely from semi-empirical considerations. In a recent Paper, the author developed a bubble growth model based on a population balance approach. Analytical expressions were derived for the bubble characteristic distributions and averages. However, the model, developed for unconstrained growth, did not take into account the effect of the bed diameter and the possibility of slugging. In this Paper, the model is extended to take these aspects into account. A slugging criterion is also developed which is expected to be valid for the regime where incipient slugging depends on the bed height as well as the region where bed height does not significantly affect minimum slugging conditions

  1. Effect of sewage sludge content on gas quality and solid residues produced by cogasification in an updraft gasifier

    Seggiani, Maurizia, E-mail: m.seggiani@diccism.unipi.it [Department of Chemical Engineering, Industrial Chemistry and Material Science, University of Pisa, Largo Lucio Lazzarino 1, 56126 Pisa (Italy); Puccini, Monica, E-mail: m.puccini@diccism.unipi.it [Department of Chemical Engineering, Industrial Chemistry and Material Science, University of Pisa, Largo Lucio Lazzarino 1, 56126 Pisa (Italy); Raggio, Giovanni, E-mail: g.raggio@tiscali.it [Italprogetti Engineering SPA, Lungarno Pacinotti, 59/A, 56020 San Romano (Pisa) (Italy); Vitolo, Sandra, E-mail: s.vitolo@diccism.unipi.it [Department of Chemical Engineering, Industrial Chemistry and Material Science, University of Pisa, Largo Lucio Lazzarino 1, 56126 Pisa (Italy)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Cogasification of sewage sludge with wood pellets in updraft gasifier was analysed. Black-Right-Pointing-Pointer The effects of sewage sludge content on the gasification process were examined. Black-Right-Pointing-Pointer Sewage sludge addition up to 30 wt.% reduces moderately the process performance. Black-Right-Pointing-Pointer At high sewage sludge content slagging and clinker formation occurred. Black-Right-Pointing-Pointer Solid residues produced resulted acceptable at landfills for non-hazardous waste. - Abstract: In the present work, the gasification with air of dehydrated sewage sludge (SS) with 20 wt.% moisture mixed with conventional woody biomass was investigated using a pilot fixed-bed updraft gasifier. Attention was focused on the effect of the SS content on the gasification performance and on the environmental impact of the process. The results showed that it is possible to co-gasify SS with wood pellets (WPs) in updraft fixed-bed gasification installations. However, at high content of sewage sludge the gasification process can become instable because of the very high ash content and low ash fusion temperatures of SS. At an equivalent ratio of 0.25, compared with wood pellets gasification, the addition of sewage sludge led to a reduction of gas yield in favor of an increase of condensate production with consequent cold gas efficiency decrease. Low concentrations of dioxins/furans and PAHs were measured in the gas produced by SS gasification, well below the limiting values for the exhaust gaseous emissions. NH{sub 3}, HCl and HF contents were very low because most of these compounds were retained in the wet scrubber systems. On the other hand, high H{sub 2}S levels were measured due to high sulfur content of SS. Heavy metals supplied with the feedstocks were mostly retained in gasification solid residues. The leachability tests performed according to European regulations showed that metals leachability was

  2. Nuclear safety of extended sludge processing on tank 42 and 51 sludge (DWPF sludge feed batch one)

    Clemons, J.S.

    1993-01-01

    The sludge in tanks 42 and 51 is to be washed with inhibited water to remove soluble salts and combined in tank 51 in preparation for feed to DWPF. Since these tanks contain uranium and plutonium, the process of washing must be evaluated to ensure subcriticality is maintained. When the sludge is washed, inhibited water is added, the tank contents are slurried and allowed to settle. The sludge wash water is then decanted to the evaporator feed tank where it is fed to the evaporator to reduce the volume. The resulting evaporator concentrate is sent to a salt tank where it cools and forms crystallized salt cake. This salt cake will later be dissolved, processed in ITP and sent to Z-Area. This report evaluates the supernate and sludge during washing, the impact on the evaporator during concentration of decanted wash water, and the salt tank where the concentrated supernate is deposited. The conclusions generated in this report are specific to the sludge currently contained in tanks 42 and 51

  3. Degradation of slime extracellular polymeric substances and inhibited sludge flocs destruction contribute to sludge dewaterability enhancement during fungal treatment of sludge using filamentous fungus Mucor sp. GY-1.

    Wang, Zhenyu; Zheng, Guanyu; Zhou, Lixiang

    2015-09-01

    Mechanisms responsible for the sludge dewaterability enhanced by filamentous fungi during fungal treatment of sludge were investigated in the present study. The filamentous fungus Mucor sp. GY-1, isolated from waste activated sludge, enhanced sludge dewaterability by 82.1% to achieve the lowest value of normalized sludge specific resistance to filtration (SRF), 8.18 × 10(10) m · L/kg · g-TSS. During the fungal treatment of sludge, 57.8% of slime extracellular polymeric substances (EPS) and 51.1% of polysaccharide in slime EPS were degraded, respectively, by Mucor sp. GY-1, contributing to the improvement of sludge dewaterability. Slime EPS is much more available for Mucor sp. GY-1 than either LB-EPS or TB-EPS that bound with microbial cells. In addition, filamentous fungus Mucor sp. GY-1 entrapped small sludge particles and inhibited the destruction of sludge flocs larger than 100 μm, thus enhancing sludge dewaterability, during fungal treatment of sludge using Mucor sp. GY-1. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Using multiple bed load measurements: Toward the identification of bed dilation and contraction in gravel-bed rivers

    Marquis, G. A.; Roy, A. G.

    2012-02-01

    This study examines bed load transport processes in a small gravel-bed river (Béard Creek, Québec) using three complementary methods: bed elevation changes between successive floods, bed activity surveys using tags inserted into the bed, and bed load transport rates from bed load traps. The analysis of 20 flood events capable of mobilizing bed material led to the identification of divergent results among the methods. In particular, bed elevation changes were not consistent with the bed activity surveys. In many cases, bed elevation changes were significant (1 to 2 times the D50) even if the bed surface had not been activated during the flood, leading to the identification of processes of bed dilation and contraction that occurred over 10% to 40% of the bed surface. These dynamics of the river bed prevent accurate derivation of bed load transport rates from topographic changes, especially for low magnitude floods. This paper discusses the mechanisms that could explain the dilation and contraction of particles within the bed and their implications in fluvial dynamics. Bed contraction seems to be the result of the winnowing of the fine sediments under very low gravel transport. Bed dilation seems to occur on patches of the bed at the threshold of motion where various processes such as fine sediment infiltration lead to the maintenance of a larger sediment framework volume. Both processes are also influenced by flood history and the initial local bed state and in turn may have a significant impact on sediment transport and morphological changes in gravel-bed rivers.

  5. Gas Generation from K East Basin Sludges - Series II Testing

    Bryan, Samuel A.; Delegard, Calvin H.; Schmidt, Andrew J.; Sell, Rachel L.; Silvers, Kurt L.; Gano, Susan R.; Thornton, Brenda M.

    2001-01-01

    This report describes work to examine the gas generation behavior of actual K East (KE) Basin floor, pit and canister sludge. Mixed and unmixed and fractionated KE canister sludge were tested, along with floor and pit sludges from areas in the KE Basin not previously sampled. The first report in this series focused on gas generation from KE floor and canister sludge collected using a consolidated sampling technique. The third report will present results of gas generation testing of irradiated uranium fuel fragments with and without sludge addition. The path forward for management of the K Basin Sludge is to retrieve, ship, and store the sludge at T Plant until final processing at some future date. Gas generation will impact the designs and costs of systems associated with retrieval, transportation and storage of sludge

  6. Enhanced remediation of an oily sludge with saline water ...

    Enhanced remediation of an oily sludge with saline water. ... the remediation of an oily sludge, which was part of the waste stream from the improvement ... m3 of fresh water respectively while 'treatment' reactors C and D received ...

  7. Sludge pipe flow pressure drop prediction using composite power ...

    Sludge pipe flow pressure drop prediction using composite power-law friction ... Water SA. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue ... When predicting pressure gradients for the flow of sludges in pipes, the ...

  8. Organic matter and heavy metals in grey-water sludge

    2010-01-08

    Jan 8, 2010 ... metal loads comparable to Danish sewage sludge, and it exceeds the Danish quality criteria for ... The hydraulic retention time (HRT) of the whole plant is .... sludge will contain an important part of the XOCs which were.

  9. Microwave enhanced digestion of aerobic SBR sludge | Kennedy ...

    MWs) for improving characteristics of aerobic sequencing batch reactor (SBR) sludge to enhance mesophilic anaerobic digestion. Effects of pretreatment temperature, MW irradiation intensity and solids concentration on sludge characterisation ...

  10. The influence of aerobic sludge retention time on anaerobic co ...

    ABR) and aerobic plug flow reactor (PFR) were operated aiming to minimize excess sludge output of the activated sludge process through coupled alkaline hydrolysis and anaerobic digestion. Variations in the effluent total chemical oxygen ...

  11. Application of Fuzzy Synthetic Evaluation in Selection of Best Sludge Dewatering Option in Ghods Town WWTP in Tehran

    Masoud Taheriyoun

    2015-03-01

    Full Text Available The design and upgrade of sludge treatment systems generally depend on the decision made regarding the appropriate system from among the options available. The selection process has become increasingly important and complex due to recent technological developments that have led to increased diversity in the available options which offer a wide variety of capabilities. The multi-criteria decision making method is one of the techniques recently developed which takes into account all the criteria involved in the decision making process. The Ghods Town WWTP in the west of Tehran located in the vicinity of residential areas has given rise to claims by citizens due to the odors emitted by the sludge sand drying bed, which justifies the replacement of the present sludge dewatering system. For this purpose, the multi-criteria decision making method based on the fuzzy synthetic evaluation method was used to identify the optimal sludge dewatering system appropriate for the WWTP under consideration. Furthermore, weighting of the subjective (social, environmental, and administrative criteria was accomplished using the analytical hierarchy process and the objective (i.e., economic criteria were weighted using the entropy concept. In this method, the triangular fuzzy membership function was also used to take into account the uncertainty associated with each of the decision making parameters. Based on the results obtained, the belt filter press dewatering system and the filter press were identified as the preferred solutions.

  12. A potential application of sludge-based catalysts for the anaerobic bio-decolorization of tartrazine dye.

    Athalathil, Sunil; Fortuny, Agusti; Font, Josep; Stüber, Frank; Bengoa, Christophe; Fabregat, Azael

    2015-01-01

    Two highly efficient (K2CO3/sludge carbon and ZnCl2/sludge carbon) solids were prepared by chemical addition following carbonization at 800 °C and were tested for anaerobic reduction of tartrazine dye in a continuous upflow packed-bed biological reactor, and their performance was compared to that of commercial activated carbon (CAC). The chemical and structural information of the solids was subjected to various characterizations in order to understand the mechanism for anaerobic decolorization, and efficiency for SBCZN800 and SBCPC800 materials was 87% and 74%, respectively, at a short space time (τ) of 2.0 min. A first-order kinetic model fitted the experimental points and kinetic constants of 0.40, 0.92 and 1.46 min(-1) were obtained for SBCZN800, SBCPC800 and CAC, respectively. The experimental results revealed that performance of solids in the anaerobic reduction of tartrazine dye can depend on several factors including chemical agents, carbonization, microbial population, chemical groups and surface chemistry. The Langmuir and Freundlich models are successfully described in the batch adsorption data. Based on these observations, a cost-effective sludge-based catalyst can be produced from harmful sewage sludge for the treatment of industrial effluents.

  13. Characterization and performance of carbonaceous materials obtained from exhausted sludges for the anaerobic biodecolorization of the azo dye Acid Orange II

    Athalathil, S.; Stüber, F.; Bengoa, C.; Font, J. [Departament d’Enginyeria Quimica, ETSEQ, Universitat Rovira i Virgili, Av. Paisos Catalans 26, 43007 Tarragona, Catalunya (Spain); Fortuny, A. [Departament d’Enginyeria Quimica, EPSEVG, Universitat Politecnica de Catalunya, Av. Victor Balaguer s/n, 08800 Vilanova i la Geltru, Catalunya (Spain); Fabregat, A., E-mail: azael.fabregat@urv.cat [Departament d’Enginyeria Quimica, ETSEQ, Universitat Rovira i Virgili, Av. Paisos Catalans 26, 43007 Tarragona, Catalunya (Spain)

    2014-02-01

    Graphical abstract: - Highlights: • Carbonaceous materials were prepared from exhausted sludge materials. • High surface area and good physicochemical properties were achieved. • Utilization of waste sludge materials and mixed anaerobic cultures were used in a continuous anaerobic UPBR system (upflow packed bed biological reactor). • Effective treatment of dye contaminated wastewater in a cheapest and environmental friendly method was demonstrated. - Abstract: This work presents the preliminary study of new carbonaceous materials (CMs) obtained from exhausted sludge, their use in the heterogeneous anaerobic process of biodecolorization of azo dyes and the comparison of their performance with one commercial active carbon. The preparation of carbonaceous materials was conducted through chemical activation and carbonization. Chemical activation was carried out through impregnation of sludge-exhausted materials with ZnCl{sub 2} and the activation by means of carbonization at different temperatures (400, 600 and 800 °C). Their physicochemical and surface characteristics were also investigated. Sludge based carbonaceous (SBC) materials SBC400, SBC600 and SBC800 present values of 13.0, 111.3 and 202.0 m{sup 2}/g of surface area. Biodecolorization levels of 76% were achieved for SBC600 and 86% for SBC800 at space time (τ) of 1.0 min, similar to that obtained with commercial activated carbons in the continuous anaerobic up-flow packed bed reactor (UPBR). The experimental data fit well to the first order kinetic model and equilibrium data are well represented by the Langmuir isotherm model. Carbonaceous materials show high level of biodecolorization even at very short space times. Results indicate that carbonaceous materials prepared from sludge-exhausted materials have outstanding textural properties and significant degradation capacity for treating textile effluents.

  14. Characteristics of biosolids from sludge treatment wetlands for agricultural reuse

    Uggetti, Enrica; Ferrer, Ivet; Nielsen, Steen

    2012-01-01

    Sludge treatment wetlands (STW) consist of constructed wetlands systems specifically developed for sludge treatment over the last decades. Sludge dewatering and stabilisation are the main features of this technology, leading to a final product which may be recycled as an organic fertiliser or soi...... legal limits for land application of the sludge. Our results suggest that biosolids from the studied STW can be valorised in agriculture, especially as soil conditioner....

  15. Municipal Sewage Sludge Drying Treatment by an Composite Modifier

    Na Wei

    2012-01-01

    A sludge composite modifier (SCM) which comprises a mixture of three cementitious components was proposed for sludge drying and stabilization. Effect of SCM components on sludge moisture content was analyzed using uniform design and the optimum composition of SCM was determined by computer-aided modeling and optimization. To compare the drying effect of SCM, quicklime, and Portland cement, the effects of material content and curing time on moisture content of sludge were also studied. The res...

  16. Better backs by better beds?

    Bergholdt, Kim; Fabricius, Rasmus N; Bendix, Tom

    2008-01-01

    mattresses have a positive effect on LBP, and especially a hard mattress is commonly believed to have a positive effect. METHODS: One hundred sixty CLBP patients were randomized to 1 of 3 groups, having a mattress/bed mounted in their sleeping room for 1 month. The beds were: (1) waterbed (Akva), (2) body......-conforming foam mattress (Tempur), and (3) a hard mattress (Innovation Futon). At baseline and after 4 weeks, a blinded observer interviewed the patients on LBP levels (0-10), daily function (activities of daily living, 0-30), and on the amount of sleeping hours/night. RESULTS: Because of dropout of 19 patients...... using the probably most relevant "worst case" data. There were no relevant difference between the effects of the water bed and the foam bed. CONCLUSION: The Waterbed and foam mattress' did influence back symptoms, function and sleep more positively as apposed to the hard mattress, but the differences...

  17. Top Ten Bed Bug Tips

    ... Directory Planning, Budget and Results Jobs and Internships Headquarters Offices Regional Offices Labs and Research Centers Bed ... you hire an expert, be sure it’s a company with a good reputation and request that it ...

  18. Torsion testing of bed joints

    Hansen, Klavs Feilberg; Pedersen, Carsten Mørk

    2008-01-01

    This paper describes a simple test method for determining the torsion strength of a single bed joint between two bricks and presents results from testing using this test method. The setup for the torsion test is well defined, require minimal preparation of the test specimen and the test can...... be carried out directly in a normal testing machine. The torsion strength is believed to be the most important parameter in out-of-plane resistance of masonry walls subjected to bending about an axis perpendicular to the bed joints. The paper also contains a few test results from bending of small walls about...... an axis perpendicular to the bed joints, which indicate the close connection between these results and results from torsion tests. These characteristics make the torsion strength well suited to act as substitute parameter for the bending strength of masonry about an axis perpendicular to the bed joints....

  19. Sea bed mapping and inspection

    NONE

    2006-07-01

    The conference has 24 presentations on the topics: Sea bed mapping, inspection, positioning, hydrography, marine archaeology, remote operation vehicles and computerized simulation technologies, oil field activities and plans, technological experiences and problems. (tk)

  20. Physical Properties of Hanford Transuranic Waste Sludge

    Poloski, A. P.

    2004-01-01

    This project has two primary objectives. The first is to understand the physical properties and behavior of the Hanford transuranic (TRU) tank sludges under conditions that might exist during retrieval, treatment, packaging, and transportation for disposal at WIPP. The second primary objective is to develop a fundamental understanding of these sludge suspensions by correlating the macroscopic properties with particle interactions occurring at the colloidal scale in the various liquid media. The results of this research effort will enhance the existing understanding of agglomeration phenomena and the properties of complex colloidal suspensions. In addition, the knowledge gained and capabilities developed during this effort will aid in the development and optimization of techniques to process the wastes at various DOE sites. These objectives will be accomplished by: (1) characterizing the TRU sludges contained in the Hanford tanks that are intended for shipment to WIPP; (2) determining the physical behavior of the Hanford TRU tank sludges under conditions that might exist during treatment and packaging; (3) and modeling the retrieval, treatment, and packaging operations that will be performed at Hanford to dispose of TRU tank sludges

  1. Supercritical water gasification of sewage sludge

    Aye, L.; Yamaguchi, D. [Melbourne Univ. International Technologies Centre, Melbourne, Victoria (Australia). Dept. of Civil and Environmental Engineering

    2006-07-01

    Supercritical water gasification (SCWG) is an attractive technology for producing fuels from biomass and waste materials. As a result of greenhouse gas emissions and issues related to local air pollutants, hydrogen production from these renewable energy resources has been gaining in popularity. Disposal of sewage sludge is another environmental problem that have led to severe regulations. Incineration has been one of the most commonly used means of sewage sludge disposal. Thermal gasification produces gaseous fuel, making it a better option over incineration. However, due to its high moisture content, this process is not feasible to make use of sewage sludge directly. In order to analyze SCWG of sewage sludge, it has been determined that equilibrium analysis is most suitable since the maximum achievable amount of hydrogen in a given reacting condition can be estimated. The equilibrium model can be divided into two types of models, namely stoichiometric and non-stoichiometric. This paper presented the results of a study that used a computer program to develop a nonstoichiometric model with the direct Gibbs free energy minimization technique. In addition, various biomass were simulated for comparisons in order to identify if sewage sludge is a potential feedstock for hydrogen production. Last, the effects of reaction pressure and temperature on product distribution were also examined. It was shown that the proposed model is capable of estimating the product distribution at equilibrium. 33 refs., 4 tabs., 6 figs.

  2. Recovery of phosphorus from sewerage treatment sludge

    Manuilova, Anastasia

    1999-07-01

    This thesis is a review of the current state of technologies for the removal of phosphorus from wastewater and sludge, and the recovery and re-use of phosphorus. It explains the need for phosphorus removal and describes the current removal processes. Focus is given to phosphorus crystallisation processes and to the processes which treat sewage treatment sludges into potential sources of phosphorus. An interesting possibility to recover phosphorus from sewage sludge by use of Psenner fractionation is also discussed. By this method, the following phosphate fractions of technological significance may be distinguished: (1) redox sensitive phosphates, mainly bound to Fe(OH){sub 3}; (2) phosphate adsorbed to surfaces (Al{sub 2}O{sub 3}), exchangeable against OH{sup -}, and alkali-soluble phosphate; (3) phosphate bound to CaCO{sub 3}, MgCO{sub 3} and in apatite; and (4) organically bound phosphate. The basic removal mechanisms, process schemes and treatment results are described. Two experiments with three different types of sludges from Henriksdal wastewater treatment plant in Stockholm were performed in the laboratory. It was shown that the addition of sodium hydroxide or hydrochloric acid cause the significant release of phosphate (about 80%) for all types of sludges. If a whole Psenner fractionation was performed the phosphate release is approximately 100%.

  3. Solar drying in sludge management in Turkey

    Kamil Salihoglu, Nezih; Pinarli, Vedat; Salihoglu, Guray [Faculty of Engineering and Architecture, Environmental Engineering Department, Uludag University, 16059, Bursa (Turkey)

    2007-08-15

    Two main wastewater treatment plants in Bursa city in Turkey will start to operate and produce at least 27,000 tons of dry solids per year by the end of 2006. The purpose of this study was to investigate an economical solution to the sludge management problem that Bursa city would encounter. The general trend in Turkey is mechanical dewatering to obtain a dry solid (DS) content of 20%, and liming the mechanically dewatered sludge to reach the legal land filling requirement, 35% DS content. This study recommends limited liming and solar drying as an alternative to only-liming the mechanically dewatered sludge. Open and covered solar sludge drying plants were constructed in pilot scale for experimental purposes. Dry solids and climatic conditions were constantly measured. Faecal coliform reduction was also monitored. The specially designed covered solar drying plant proved to be more efficient than the open plant in terms of drying and faecal coliform reduction. It was found that, if the limited liming and solar drying method was applied after mechanical dewatering instead of only-liming method, the total amount of the sludge to be disposed would be reduced by approximately 40%. This would lead to a reduction in the transportation, handling, and land filling costs. The covered drying system would amortize itself in 4 years. (author)

  4. Operational experience at the Sludge Treatment Facility

    Sy, D.J.

    1987-01-01

    The Sludge Treatment Facility (STF) at the Oak Ridge Gaseous Diffusion Plant has been in operation since April 1987. The facility was designed to encapsulate hazardous sludge wastes in a cement matrix. Fixation will allow the waste to meet or exceed applicable compressive strength and leachability requirements. Thus, the grout mixture complies with the Resource Conservation and Recovery Act (RCRA) guidelines as a nonhazardous waste. The grout mixture is based upon a recipe formulation developed after several years of waste stream characterization and formulation studies. The wastes to be treated at the STF are wastes impounded in two ponds. The ponds have a combined capacity of 4.5 million gallons of sludge. The sludge is transferred from the ponds to a 15,000-gallon capacity storage tank by the use of a dredge. The grout mixture recipe dictates the amount of sludge, cement, fly ash, and admixture required for weighing per batch. All ingredients are weighed and then transferred to a tilt or high energy mixer for mixing. The grout mixture is then transferred to 89- or 96-gallon steel drums. The drums are placed in a storage yard designed for a point source discharge from the yard

  5. Fluid-bed methane proposed

    1981-05-01

    The first full scale plant for the production of methane from organic waste could be built in the next few years believes M.J. Nyns of the University of Louvain, Belgium, utilizing either expanded bed or fluidised bed systems, with more than one stage, in a continuous flow arrangement. Up to 8.0 m cubed gas/m cubed digester/day could be produced with residence times reduced to 34 hours.

  6. Dispersion of Bed Load Particles

    SAWAI, Kenji

    1987-01-01

    The motion of bed load particles is so irregular that they disperse remarkably with time.In this study, some flume tests using painted tracer particles were carried out, in which thedispersive property of tracers changed variously with sediment feed rate.In analysing this process, a stochastic simulation model is proposed where it is discussedabout the degree of exposure of individual particle near the bed surface and about the variationof its pick up rate. The exponential distribution of ste...

  7. The use of sewage sludge as additive to avoid operational problems at combustion of shredder residues

    Gyllenhammar, Marianne

    2010-01-01

    When shredder light fraction (SLF) from recovery of metal scrap is energy recovered it is usually mixed with more than 90% of other wastes. SLF is a fuel with high energy content but also with relatively high chlorine and metal content and could cause deposit and corrosion problems in incineration plants. Sewage sludge has previously been shown to reduce deposition and corrosion problems in combustion of alkali and chlorine containing biomass. In this work 20 % SLF (by energy content) has been combusted together with municipal solid waste and industrial wastes, with and without addition of 3 % (by energy content) sewage sludge. The initial fireside corrosion rate was then compared to the corrosion rate during combustion of the normal fuel mix, i.e. only municipal solid waste and industrial wastes. The tests were done at the 20 MW fluidized bed boiler of Lidkoping heat production plant. During the tests air-cooled corrosion and deposit probes were exposed for 24 hours. Deposit probes were placed at three different flue gas temperatures - in the combustion chamber, upstream and downstream the convection pass. The corrosion probes were placed upstream the convection pass and on the probes there were three different materials at three different water temperatures (280, 350 and 420 degree Celsius). The tests showed that sewage sludge could help avoiding deposition and corrosion problems when incinerating SLF. The amount of deposits was reduced and the content of the deposits was less corrosive when sewage sludge was added. The project was financed by Waste Refinery as a collaboration project between Stena Metall AB, Metso AB, High Temperature Corrosion Center at Chalmers University of Technology, SP Technical Research Institute of Sweden and Lidkopings Varmeverk. (author)

  8. Fate of return activated sludge after ozonation: an optimization study for sludge disintegration.

    Demir, Ozlem; Filibeli, Ayse

    2012-09-01

    The effects of ozonation on sludge disintegration should be investigated before the application of ozone during biological treatment, in order to minimize excess sludge production. In this study, changes in sludge and supernatant after ozonation of return activated sludge were investigated for seven different ozone doses. The optimum ozone dose to avoid inhibition of ozonation and high ozone cost was determined in terms of disintegration degree as 0.05 g O3/gTS. Suspended solid and volatile suspended solid concentrations of sludge decreased by 77.8% and 71.6%, respectively, at the optimum ozone dose. Ozonation significantly decomposed sludge flocs. The release of cell contents was proved by the increase of supernatant total nitrogen (TN) and phosphorus (TP). While TN increased from 7 mg/L to 151 mg/L, TP increased from 8.8 to 33 mg/L at the optimum ozone dose. The dewaterability and filterability characteristics of the ozonated sludge were also examined. Capillary suction time increased with increasing ozone dosage, but specific resistance to filtration increased to a specific value and then decreased dramatically. The particle size distribution changed significantly as a result of floc disruption at an optimum dose of 0.05 gO3/gTS.

  9. Properties of bacterial radioresistance observed in sewage sludge

    Watanabe, H; Ito, H; Takehisa, M [Japan Atomic Energy Research Inst., Takasaki, Gunma. Takasaki Radiation Chemistry Research Establishment; Iizuka, H

    1981-09-01

    The changes in radiosensitivities of bacteria in sludge were investigated. The coliforms are more radioresistant in raw sludge than in cake (dewatered sludge). This radioresistance of coliforms was observed not only in raw sludge but also in the cake diluted with water. The radioresistance was independent of the difference of treatment plant, kind of sludge, and season. The oxygen effect on the radioresistance was not observed, but the resistance was changed during storage of sludge. Escherichia coli isolated from sludge was radiosensitive in buffer, but its radiosensitivity was protected by the water-extracts of sludge. On the other hand, radioresistant bacteria were present in total bacteria of sludge irradiated at 2 Mrad. However, the dominant flora in the irradiated sludge consisted of radiosensitive bacteria (mainly Pseudomonas). When a strain of radiosensitive Pseudomonas was irradiated in raw sludge and diluted cake, the radiosensitivity was remarkably protected. From these results, it is suggested that a factor affecting the radiosensitivity of bacteria is present in sludge.

  10. Effects of ultrasonic disintegration on sludge microbial activity and dewaterability

    Li Huan; Jin Yiying; Mahar, Rasool Bux; Wang Zhiyu; Nie Yongfeng

    2009-01-01

    Ultrasonic treatment can disintegrate sludge, enhance microbial activity and improve sludge dewaterability at different energy inputs. To find their relationship, the three phenomena during ultrasonic treatment were investigated synchronously, and an experimental model was established to describe the process of ultrasonic sludge disintegration. Analysis results showed that the changes of sludge microbial activity and dewaterability were dependent on sludge disintegration degree during ultrasonic treatment. When sludge disintegration degree was lower than 20%, sludge flocs were disintegrated into micro-floc aggregates and the microbial activity increased over 20%. When sludge disintegration degree was over 40%, most cells were destroyed at different degree, and sludge activity decreased drastically. Only when sludge disintegration degree was 2-5%, sludge dewaterability was improved with the conditioning of FeCl 3 . It was also found that the sonication with low density and long duration was more efficient than sonication with high density and short duration at the same energy input for sludge disintegration, and a transmutative power function model can be used to describe the process of ultrasonic disintegration

  11. Effects of ultrasonic disintegration on sludge microbial activity and dewaterability.

    Huan, Li; Yiying, Jin; Mahar, Rasool Bux; Zhiyu, Wang; Yongfeng, Nie

    2009-01-30

    Ultrasonic treatment can disintegrate sludge, enhance microbial activity and improve sludge dewaterability at different energy inputs. To find their relationship, the three phenomena during ultrasonic treatment were investigated synchronously, and an experimental model was established to describe the process of ultrasonic sludge disintegration. Analysis results showed that the changes of sludge microbial activity and dewaterability were dependent on sludge disintegration degree during ultrasonic treatment. When sludge disintegration degree was lower than 20%, sludge flocs were disintegrated into micro-floc aggregates and the microbial activity increased over 20%. When sludge disintegration degree was over 40%, most cells were destroyed at different degree, and sludge activity decreased drastically. Only when sludge disintegration degree was 2-5%, sludge dewaterability was improved with the conditioning of FeCl(3). It was also found that the sonication with low density and long duration was more efficient than sonication with high density and short duration at the same energy input for sludge disintegration, and a transmutative power function model can be used to describe the process of ultrasonic disintegration.

  12. Keynote address: Federal overview of municipal sludge management

    Hathaway, W.B.

    1979-01-01

    The proper disposal of sewage sludge is becoming an increasing problem on solid waste management systems throughout the country. Currently 18,000 municipal wastewater treatment plants are generating about 5 million tons of sludge a year. This is expected to double in the next 8 to 10 years. The environmental aspects of sludge disposal are discussed

  13. Properties of bacterial radioresistance observed in sewage sludge

    Watanabe, Hiroshi; Ito, Hitoshi; Takehisa, Masaaki; Iizuka, Hiroshi.

    1981-01-01

    The changes in radiosensitivities of bacteria in sludge were investigated. The coliforms are more radioresistant in raw sludge than in cake (dewatered sludge). This radioresistance of coliforms was observed not only in raw sludge but also in the cake diluted with water. The radioresistance was independent of the difference of treatment plant, kind of sludge, and season. The oxygen effect on the radioresistance was not observed, but the resistance was changed during storage of sludge. Escherichia coli isolated from sludge was radiosensitive in buffer, but its radiosensitivity was protected by the water-extracts of sludge. On the other hand, radioresistant bacteria were present in total bacteria of sludge irradiated at 2 Mrad. However, the dominant flora in the irradiated sludge consisted of radiosensitive bacteria (mainly Pseudomonas). When a strain of radiosensitive Pseudomonas was irradiated in raw sludge and diluted cake, the radiosensitivity was remarkably protected. From these results, it is suggested that a factor affecting the radiosensitivity of bacteria is present in sludge. (author)

  14. Photovoltaic's silica-rich waste sludge as supplementary cementitious material

    Quercia, G.; Van der Putten, J.J.G.; Brouwers, H.J.H.

    2013-01-01

    Waste sludge, a solid recovered from wastewater of photovoltaic-industries, composes of agglomerates of nano-particles like SiO2 and CaCO3. This sludge deflocculates in aqueous solutions into nano-particles smaller than 1000 nm. Thus, this sludge is potentially hazardous waste when is improperly

  15. Processed wastewater sludge for improvement of mechanical properties of concretes

    Barrera-Diaz, Carlos, E-mail: cbd0044@yahoo.com [Centro Conjunto de Investigacion en Quimica Sustentable, Universidad Autonoma del Estado de Mexico - Universidad Nacional Autonoma de Mexico (UAEM-UNAM), Carretera Toluca-Atlacomulco, km 14.5, Unidad El Rosedal, C.P. 50200, Toluca, Edo. de Mexico (Mexico); Martinez-Barrera, Gonzalo [Laboratorio de Investigacion y Desarrollo de Materiales Avanzados (LIDMA), Facultad de Quimica, Universidad Autonoma del Estado de Mexico, Carretera Toluca-Atlacomulco, Km.12, San Cayetano C.P. 50200, Toluca, Edo. de Mexico (Mexico); Gencel, Osman [Civil Engineering Department, Faculty of Engineering, Bartin University, 74100 Bartin (Turkey); Bernal-Martinez, Lina A. [Centro Conjunto de Investigacion en Quimica Sustentable, Universidad Autonoma del Estado de Mexico - Universidad Nacional Autonoma de Mexico (UAEM-UNAM), Carretera Toluca-Atlacomulco, km 14.5, Unidad El Rosedal, C.P. 50200, Toluca, Edo. de Mexico (Mexico); Brostow, Witold [Laboratory of Advanced Polymers and Optimized Materials (LAPOM), Department of Materials Science and Engineering and Center for Advanced Research and Technology (CART), University of North Texas, 1150 Union Circle 305310, Denton, TX 76203-5017 (United States)

    2011-08-15

    Highlights: {yields} Electrochemical methods produce less amount of residual sludge as compared with chemical procedures. {yields} Wastewater sludge contains a large amount of water. {yields} The residual sludge is used to prepare cylinder specimen concrete. {yields} There are improvements in the elastic modulus of the concrete when is prepared with residual sludge. - Abstract: Two problems are addressed simultaneously. One is the utilisation of sludge from the treatment of wastewater. The other is the modification of the mechanical properties of concrete. The sludge was subjected to two series of treatments. In one series, coagulants were used, including ferrous sulphate, aluminium sulphate or aluminium polyhydroxychloride. In the other series, an electrochemical treatment was applied with several starting values of pH. Then, concretes consisting of a cement matrix, silica sand, marble and one of the sludges were developed. Specimens without sludge were prepared for comparison. Curing times and aggregate concentrations were varied. The compressive strength, compressive strain at yield point, and static and dynamic elastic moduli were determined. Diagrams of the compressive strength and compressive strain at the yield point as a function of time passed through the minima as a function of time for concretes containing sludge; therefore, the presence of sludge has beneficial effects on the long term properties. Some morphological changes caused by the presence of sludge are seen in scanning electron microscopy. A way of utilising sludge is thus provided together with a way to improve the compressive strain at yield point of concrete.

  16. Examination of sludge from the Hanford K Basins fuel canisters

    Makenas, B.J.

    1998-01-01

    Samples of sludges with a high uranium content have been retrieved from the fuel canisters in the Hanford K West and K East basins. The composition of these samples contrasts markedly with the previously reported content of sludge samples taken from the K East basin floor. Chemical composition, chemical reactivity, and particle size of sludge are summarized in this paper

  17. Physical and biochemical changes in sludge upon Tubifex tubifex predation

    de Valk, S.L.; Khadem, A.F.; Foreman, Christine M.; van Lier, J.B.; de Kreuk, M.K.

    2016-01-01

    Worm predation (WP) on activated sludge leads to increased sludge degradation rates, irrespective of the type of worm used or reactor conditions employed. However, the cause of the increased sludge degradation rates remains unknown. This paper presents a comparative analysis of the physical and

  18. Technology for improving sludge concentration; Odei noshukusei kaizen gijutsu

    NONE

    1999-03-10

    Sludge generating in a sewage treatment plant is disposed through the processes such as concentration, dehydration, and incineration in sludge disposal facilities. In recent years, there has been a trend that this sludge increases in volume as well as worsens in the concentration. A case is predictable where the sludge load to the dehydrating process is so large that the sludge can no longer be processed in sufficient quantity. In the meantime, if sludge is ozone-treated, viscous substance on the surface of sludge particles can be separated with a comparatively small amount of ozone, with sludge concentration enhanced. At Meidensha, an experimental plant was set up for the ozone treatment of sludge in a sludge intensive treatment plant of a metropolis, with a verification experiment carried out for a sludge concentration improving system by ozone. As a result of comparison of the treatment performance between an assessment system for performing ozone treatment and a reference system for not performing, the average value of the sludge concentration of a gravity concentration tank was 1.9% of the reference system against 1.7% of the assessment system in a continuous treatment experiment in the summer, while the solid collection ratio was 65.8% of the reference system against 95.5% of the assessment system, enabling a superior improving effect to be obtained. (NEDO)

  19. A new reactor concept for sludge reduction using aquatic worms

    Elissen, H.J.H.; Hendrickx, T.L.G.; Temmink, B.G.; Buisman, C.J.N.

    2006-01-01

    Biological waste water treatment results in the production of waste sludge. The final treatment option in The Netherlands for this waste sludge is usually incineration. A biological approach to reduce the amount of waste sludge is through predation by aquatic worms. In this paper we test the

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

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

    2010-01-01

    A submersible microbial fuel cell (SMFC) was utilized to treatment of sewage sludge and simultaneous generate electricity. Stable power generation (145±5 mW/m2) was produced continuously from raw sewage sludge for 5.5 days. The corresponding total chemical oxygen demand (TCOD) removal efficiency...... of an effective system to treatment of sewage sludge and simultaneous recover energy....

  1. Rheology of Savannah River Site Tank 51 HLW radioactive sludge

    Ha, B.C.

    1993-01-01

    Savannah River Site (SRS) Tank 51 HLW radioactive sludge represents a major portion of the first batch of sludge to be vitrified in the Defense Waste Processing Facility (DWPF) at SRS. The rheological properties of Tank 51 sludge will determine if the waste sludge can be pumped by the current DWPF process cell pump design and the homogeneity of melter feed slurries. The rheological properties of Tank 51 sludge and sludge/frit slurries at various solids concentrations were measured remotely in the Shielded Cells Operations (SCO) at the Savannah River Technology Center (SRTC) using a modified Haake Rotovisco viscometer system. Rheological properties of Tank 51 radioactive sludge/Frit 202 slurries increased drastically when the solids content was above 41 wt %. The yield stresses of Tank 51 sludge and sludge/frit slurries fall within the limits of the DWPF equipment design basis. The apparent viscosities also fall within the DWPF design basis for sludge consistency. All the results indicate that Tank 51 waste sludge and sludge/frit slurries are pumpable throughout the DWPF processes based on the current process cell pump design, and should produce homogeneous melter feed slurries

  2. The hydraulic transportation of thickened sludges | Slatter | Water SA

    Industries which pump sludges are under continuous pressure to decrease water content, and increase concentration. Environmentally superior disposal techniques are demanding that such sludges have high mechanical strength properties. This results in a sludge with an increasing viscous character. At high ...

  3. Optimization of up-flow anaerobic sludge blanket reactor for ...

    aghomotsegin

    2013-06-05

    Jun 5, 2013 ... sludge instead of imported commercial anaerobic granulated sludge. Over the ... biogas, granulated anaerobic sludge, industrial wastewater. ... production of methane by methanogenic bacteria. Compared with other treatment processes, USAB ... effluent collector; 8, gas outlet; 9, gas collector; 10, side-arm ...

  4. Efficiency of a pilot-scale integrated sludge thickening and digestion reactor in treating low-organic excess sludge.

    He, Qiang; Li, Jiang; Liu, Hongxia; Tang, Chuandong; de Koning, Jaap; Spanjers, Henri

    2012-06-01

    The sludge production from medium- and small-scale wastewater treatment plants in the Three Gorges Reservoir Region is low and non-stable; especially, the organic content in this sludge is low (near 40% of VS/TS). An integrated thickening and digestion (ISTD) reactor was developed to treat this low-organic excess sludge. After a flow test and start-up experiment of the reactor, a running experiment was used to investigate the excess sludge treatment efficiency under five different excess sludge inflows: 200, 300, 400, 500 and 400 L/d (a mixture of excess sludge and primary sludge in a volume ratio of 9:1). This trial was carried out in the wastewater treatment plant in Chongqing, which covers 80% of the Three Gorges Reservoir Region, under the following conditions: (1) sludge was heated to 38-40 degrees C using an electrical heater to maintain anaerobic mesophilic digestion; (2) the biogas produced was recirculated to mix raw sludge with anaerobic sludge in the reactor under the flow rate of 12.5 L/min. There were three main results. Firstly, the flow pattern of the inner reactor was almost completely mixed under the air flow of 12.0 L/min using clear water. Secondly, under all the different sludge inflows, the water content in the outlet sludge was below 93%. Thirdly, the organic content in the outlet sludge was decreased from 37% to 30% and from 24% to 20%, whose removal ratio was in relation to the organic content of the inlet sludge. The excess sludge treatment capacity of the ISTD reactor was according to the organic content in the excess sludge.

  5. Kinetics of the removal of mono-chlorobenzene vapour from waste gases using a trickle bed air biofilter.

    Mathur, Anil K; Sundaramurthy, J; Balomajumder, C

    2006-10-11

    The performance of a trickle bed air biofilter (TBAB) in the removal of mono-chlorobenzene (MCB) was evaluated in concentrations varying from 0.133 to 7.187 g m(-3) and at empty bed residence time (EBRT) varying from 37.7 to 188.52 s. More than 90% removal efficiency in the trickle bed air biofilter was achieved for the inlet MCB concentration up to 1.069 g m(-3) and EBRT less than 94.26 s. The trickle bed air biofilter was constructed with coal packing material, inoculated with a mixed consortium of activated sludge obtained from sewage treatment plant. The continuous performance of the removal of MCB in the trickle bed air biofilter was monitored for various gas concentrations, gas flow rates, and empty bed residence time. The experiment was conducted for a period of 75 days. The trickle bed air biofilter degrading MCB with an average elimination capacity of 80 g m(-3) h(-1) was obtained. The effect of starvation was also studied. After starvation period of 8 days, the degradation was low but recovered within a short period of time. Using macrokinetic determination method, the Michaelis-Menten kinetic constant K(m) and maximum reaction rate, r(max) evaluated as 0.121 g m(-3) s(-1) and 7.45 g m(-3), respectively.

  6. Electron beam treatment of wastewaters and sludges

    Osborn, D.W.

    1980-01-01

    Various procedures for decreasing the health risks associated with the disposal of sewage sludges are discussed including land storage, thermophilic digestion, autothermal aerobic digestion, the Porteus Process, the Zimpro Process, incineration, pyrolysis, thermal pasteurisation, composting, lime utilisation, flash drying and radiation techniques. A fully automated sludge irradiation facility at Geiselbullach near Munich and an electron accelerator experimental plant near Boston are described. Advantages and disadvantages are given for both processes. Costs of electron radiation treatment of sewage sludges (a slurry containing 5 per cent solids) for a city the size of Johannesburg is estimated to be in the order of R900 000 per year at a dose rate of 4 000 Gy, which would produce a product of reasonable hygienic quality but not necessarily meet the criteria laid down by local authority medical officers at all times. In order to reduce costs it would be necessary to have a readily available market to dispose of disinfected material

  7. Electron beam treatment of wastewaters and sludges

    Osborn, D W [City Health Dept., Johannesburg (South Africa)

    1980-12-01

    Various procedures for decreasing the health risks associated with the disposal of sewage sludges are discussed including land storage, thermophilic digestion, autothermal aerobic digestion, the Porteus Process, the Zimpro Process, incineration, pyrolysis, thermal pasteurisation, composting, lime utilisation, flash drying and radiation techniques. A fully automated sludge irradiation facility at Geiselbullach near Munich and an electron accelerator experimental plant near Boston are described. Advantages and disadvantages are given for both processes. Costs of electron radiation treatment of sewage sludges (a slurry containing 5 per cent solids) for a city the size of Johannesburg is estimated to be in the order of R900,000 per year at a dose rate of 4,000 Gy, which would produce a product of reasonable hygienic quality but not necessarily meet the criteria laid down by local authority medical officers at all times. In order to reduce costs it would be necessary to have a readily available market to dispose of disinfected material.

  8. Utilization of irradiated sludge for fish feed

    Harsojo; Syamsu, Suwirma; Subagyo, Lydia Andini

    1994-01-01

    An experiment was conducted to study the use of irradiated sludge pellet for fish feed, namely pellet A consisting of irradiated sludge and shrimp waste (1:3); pellet B consisting of irradiated sludge and commercial pellet (1:2). Pellet C, which is a commercial fish feed, was used as control. Catfish (Clarias gariepinus) was used in this experiment. The feed pellet with a dose of 5% of total body weight was given 3 times per day. The results of the experiments showed that based on food conversion for the relative growth of the catfishes, and heavy metal content, pellet A was the best. No contamination of Salmonella or Shigella bacteria was detected in each pellet. (author). 8 refs, 3 tabs, 1 fig

  9. Determining organic pollutants in automotive industry sludge.

    Munaretto, Juliana S; Wonghon, Audrey L; von Mühlen, Carin

    2012-12-01

    In Brazil, the policy for disposing industrial sludge is changing from an emphasis on using controlled landfills to other treatment or co-processing methods; however, the monitoring of organic pollutants is not mandatory. The present study evaluated two general screening methods for organic pollutants in sludge generated in an automotive industrial complex in southern Brazil. The screening was performed using Soxhlet and sonication extractions and Gas Chromatograph coupled with Quadrupole Mass Spectrometry (GC/qMS). It was concluded that both techniques were effective and that most of the compounds identified were alkanes, phenols and esters. Important pollutants were detected in the sludge, which confirms the necessity of monitoring this type of residue.

  10. Sanitizing effects of sewage sludge irradiation treatment

    Zhao Yongfu

    2005-01-01

    A large quantity of pathogenic organisms were found in sewage sludge. An investigation was carried out on the relationship in the chain of sludge-soil-vegetable between the survival of pathogenic organisms and the irradiation dosage. After irradiation with 5-6 kGy, coliform group reduced 3 log cycles, and ascarid ova were completely eliminated with a dose of 1 kGy, making the water matched the standard quality of irrigating water. In the soil applied with irradiated sewage sludge, the total bacteria and coliforms group count reduced to one tenth, and alive ascarid ova was not detected. The coliform group on the Chinese cabbage was extremely low and reached the standard of fresh eating. (authors)

  11. Tank 5 Model for Sludge Removal Analysis

    LEE, SI

    2004-01-01

    Computational fluid dynamics methods have been used to develop and provide slurry pump operational guidance for sludge heel removal in Tank 5. Flow patterns calculated by the model were used to evaluate the performance of various combinations of operating pumps and their orientation under steady-state indexed and transient oscillation modes. A model used for previous analyses has been updated to add the valve housing distribution piping and pipe clusters of the cooling coil supply system near pump no. 8 to the previous tank Type-I model. In addition, the updated model included twelve concrete support columns. This model would provide a more accurate assessment of sludge removal capabilities. The model focused on removal of the sludge heel located near the wall of Tank 5 using the two new slurry pumps. The models and calculations were based on prototypic tank geometry and expected normal operating conditions as defined by Tank Closure Project Engineering. Computational fluid dynamics models of Tank 5 with different operating conditions were developed using the FLUENT (trademark) code. The modeling results were used to assess the efficiency of sludge suspension and removal operations in the 75-ft tank. The models employed a three-dimensional approach, a two-equation turbulence model, and an approximate representation of flow obstructions. The calculated local velocity was used as a measure of sludge removal and mixing capability. For the simulations, modeling calculations were performed with indexed pump orientations until an optimum flow pattern near the potential location of the sludge heel was established for sludge removal. The calculated results demonstrated that the existing slurry pumps running at 3801 gpm flowrate per nozzle could remove the sludge from the tank with a 101 in liquid level, based on a historical minimum sludge suspension velocity of 2.27 ft/sec. The only exception is the region within maximum 4.5 ft distance from the tank wall boundary at the

  12. Development of a test method to access the sludge reduction potential of aquatic organisms in activated sludge

    Buijs, B.R.; Klapwijk, A.; Elissen, H.J.H.; Rulkens, W.H.

    2008-01-01

    This article shows the development of a quantitative sludge reduction test method, which uses the sludge consuming aquatic worm Lumbriculus variegatus (Oligochaeta, Lumbriculidae). Essential for the test are sufficient oxygen supply and the presence of a non-stirred layer of sludge for burrowing of

  13. The chemical and mechanical differences between alginate-like exopolysaccharides isolated from aerobic flocculent sludge and aerobic granular sludge

    Lin, Y. M.; Sharma, P. K.; van Loosdrecht, M. C. M.

    2013-01-01

    This study aimed to investigate differences in the gel matrix of aerobic granular sludge and normal aerobic flocculent sludge. From both types of sludge that fed with the same municipal sewage, the functional gel-forming exopolysaccharides, alginate-like exopolysaccharides, were isolated. These two

  14. Design characteristics of the Sludge Mobilization System

    McMahon, C.L.

    1990-01-01

    Radioactive waste stored in underground tanks at the West Valley Demonstration Project is being processed into low-level waste and solidified in cement. High-level waste also stored underground will be vitrified and solidified into canistered glass logs. To move the waste from where it resides at the Waste Tank Farm to the Vitrification Facility requires equipment to prepare the storage tanks for low-level and high-level waste processing, equipment to mobilize and mix the radioactive sludge into a homogeneous slurry, and equipment to transfer the slurry for vitrification. The design of the Sludge Mobilization System has incorporated the necessary components to effect the preparation and transfer of waste in five operational phases. The first phase of the Sludge Mobilization System, which began in 1987, prepared the waste tanks to process radioactive liquid for delivery to the Cement Solidification System and to support the mobilization equipment. The second phase, beginning in 1991, will wash the sludge that remains after the liquid supernatant is decanted to prepare it for mobilization operations. The third phase will combine the contents of various waste tanks into one tank. The fourth phase will resuspend and mix the contents of the high-level waste tank. The fifth and final phase of the Sludge Mobilization System will entail transferring the waste mixture to the Vitrification Facility for processing into glass logs. Provisions for recycling the waste streams or slurries within the tank farm or for returning process streams to the Waste Tank Farm from the Vitrification Facility are also included in the final phase. This document addresses the Sludge Mobilization System equipment design characteristics in terms of its use in each of the five operational phases listed above

  15. Kinetic model of excess activated sludge thermohydrolysis.

    Imbierowicz, Mirosław; Chacuk, Andrzej

    2012-11-01

    Thermal hydrolysis of excess activated sludge suspensions was carried at temperatures ranging from 423 K to 523 K and under pressure 0.2-4.0 MPa. Changes of total organic carbon (TOC) concentration in a solid and liquid phase were measured during these studies. At the temperature 423 K, after 2 h of the process, TOC concentration in the reaction mixture decreased by 15-18% of the initial value. At 473 K total organic carbon removal from activated sludge suspension increased to 30%. It was also found that the solubilisation of particulate organic matter strongly depended on the process temperature. At 423 K the transfer of TOC from solid particles into liquid phase after 1 h of the process reached 25% of the initial value, however, at the temperature of 523 K the conversion degree of 'solid' TOC attained 50% just after 15 min of the process. In the article a lumped kinetic model of the process of activated sludge thermohydrolysis has been proposed. It was assumed that during heating of the activated sludge suspension to a temperature in the range of 423-523 K two parallel reactions occurred. One, connected with thermal destruction of activated sludge particles, caused solubilisation of organic carbon and an increase of dissolved organic carbon concentration in the liquid phase (hydrolysate). The parallel reaction led to a new kind of unsolvable solid phase, which was further decomposed into gaseous products (CO(2)). The collected experimental data were used to identify unknown parameters of the model, i.e. activation energies and pre-exponential factors of elementary reactions. The mathematical model of activated sludge thermohydrolysis appropriately describes the kinetics of reactions occurring in the studied system. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Energy potential of the modified excess sludge

    Zawieja Iwona

    2017-01-01

    Full Text Available On the basis of the SCOD value of excess sludge it is possible to estimate an amount of energy potentially obtained during the methane fermentation process. Based on a literature review, it has been estimated that from 1 kg of SCOD it is possible to obtain 3.48 kWh of energy. Taking into account the above methane and energy ratio (i.e. 10 kWh/1Nm3 CH4, it is possible to determine the volume of methane obtained from the tested sludge. Determination of potential energy of sludge is necessary for the use of biogas as a source of power generators as cogeneration and ensure the stability of this type of system. Therefore, the aim of the study was to determine the energy potential of excess sludge subjected to the thermal and chemical disintegration. In the case of thermal disintegration, test was conducted in the low temperature 80°C. The reagent used for the chemical modification was a peracetic acid, which in an aqueous medium having strong oxidizing properties. The time of chemical modification was 6 hours. Applied dose of the reagent was 1.0 ml CH3COOOH/L of sludge. By subjecting the sludge disintegration by the test methods achieved an increase in the SCOD value of modified sludge, indicating the improvement of biodegradability along with a concomitant increase in their energy potential. The obtained experimental production of biogas from disintegrated sludge confirmed that it is possible to estimate potential intensity of its production. The SCOD value of 2576 mg O2/L, in the case of chemical disintegration, was obtained for a dose of 1.0 ml CH3COOH/L. For this dose the pH value was equal 6.85. In the case of thermal disintegration maximum SCOD value was 2246 mg O2/L obtained at 80°C and the time of preparation 6 h. It was estimated that in case of thermal disintegration as well as for the chemical disintegration for selected parameters, the potential energy for model digester of active volume of 5L was, respectively, 0.193 and 0,118 kWh.

  17. Energy potential of the modified excess sludge

    Zawieja, Iwona

    2017-11-01

    On the basis of the SCOD value of excess sludge it is possible to estimate an amount of energy potentially obtained during the methane fermentation process. Based on a literature review, it has been estimated that from 1 kg of SCOD it is possible to obtain 3.48 kWh of energy. Taking into account the above methane and energy ratio (i.e. 10 kWh/1Nm3 CH4), it is possible to determine the volume of methane obtained from the tested sludge. Determination of potential energy of sludge is necessary for the use of biogas as a source of power generators as cogeneration and ensure the stability of this type of system. Therefore, the aim of the study was to determine the energy potential of excess sludge subjected to the thermal and chemical disintegration. In the case of thermal disintegration, test was conducted in the low temperature 80°C. The reagent used for the chemical modification was a peracetic acid, which in an aqueous medium having strong oxidizing properties. The time of chemical modification was 6 hours. Applied dose of the reagent was 1.0 ml CH3COOOH/L of sludge. By subjecting the sludge disintegration by the test methods achieved an increase in the SCOD value of modified sludge, indicating the improvement of biodegradability along with a concomitant increase in their energy potential. The obtained experimental production of biogas from disintegrated sludge confirmed that it is possible to estimate potential intensity of its production. The SCOD value of 2576 mg O2/L, in the case of chemical disintegration, was obtained for a dose of 1.0 ml CH3COOH/L. For this dose the pH value was equal 6.85. In the case of thermal disintegration maximum SCOD value was 2246 mg O2/L obtained at 80°C and the time of preparation 6 h. It was estimated that in case of thermal disintegration as well as for the chemical disintegration for selected parameters, the potential energy for model digester of active volume of 5L was, respectively, 0.193 and 0,118 kWh.

  18. Overview of present and future sludge regulations

    Tonetti, R.

    1980-01-01

    The US Environmental Protection Agency is mandated by several acts of Congress to develop sludge management regulations. These include the Resource Recovery and Conservation Act, Clean Water Act, Marine Resources and Sanctuaries Act, Clean Air Act, and Toxic Substances Control Act. Congress had two main goals: the protection of the public health and the promotion of the use of sludge as a natural resource. This presentation will review the development of present and anticipated regulation as they seek to support achievement of these goals

  19. Potential priority pollutants in sewage sludge

    Eriksson, Eva; Christensen, Nina; Schmidt, Jens Ejbye

    2008-01-01

    compounds using their inherent properties and environmental fate it was shown that 99 XOCs could be classified as being hazardous with regard to the solid phase and 23 were found to be priority pollutants in the subsequent hazard assessment. The final selected priority pollutants can act as indicators when...... assessing sludge quality. They were compared with European legislations and discussed in regard for pointing out the need for mitigation such as substitution. Furthermore, the potential need for implementation of sludge treatment trains in order to meet the society's needs was addressed....

  20. PENERAPAN ELEKTROOSMOSIS UNTUK PENGERINGAN SLUDGE DARI PENGOLAHAN LIMBAH CAIR

    Darmawan Darmawan

    2013-11-01

    Full Text Available APPLICATION OF ELECTROOSMOSIS FOR DEWATERING OF SLUDGE FROM WASTE WATER TREATMENT. Wastewater treatment produces semi-solid residue (sludge that must be handled carefully during dumping and discharge to avoid polluting the environment. A low cost and easy treatment of dewatering is needed. This research aimed to apply electroosmosis technique for dewatering sludge in order to seek for parameters that can efficiently reduce water content of sludge, including range of voltage, type of electrodes, and distance between electrodes; and to determine the effect of electroosmosis processes on changes of chemical characteristics of sludge. The results showed that: (1 electroosmosis dewatering occurred on the sludge taken from waste water treatment of landfill but not on sludge from water purification plant (PDAM, (2 direct current voltage of 30 volts was the optimum voltage, (3 copper rod cathode provided electroosmosis process as good as stainless steel cathode and both were better than the woven stainless steel cathode, (4 the dewatering time to reduce 1200% (w/w water content to about 400% was about 40 hours for sludge of 2500 cm3 in volume (laboratory bench scale, (5 the anode need to reinserted gradually approaching the cathode due to current lost when the water content at the anode point reached 400% and sludge at the point shrink, and (6 some chemical elements in the sludge decreased significantly after treatment. Pengolahan limbah cair menghasilkan residu berupa bahan semi padat yang dikenal sebagai sludge. Sludge tersebut juga perlu dikelola penyimpanan dan pembuangannya agar tidak mencemari lingkungan. Salah satu pengelolaan sludge yang perlu dilakukan adalah pengeringan (dewatering. Salahsatu teknik dewatering yang mungkin diterapkan ialah teknik elektroosmosis, yaitu teknik yang memanfaatkan adanya pergerakan air pada media poros di dalam medan istrik searah. Penelitian ini bertujuan untuk mencari parameter sistem dewatering secara

  1. Irradiation treatment of sewage sludge: History and prospects

    Bao Borong; Wu Minghong; Zhou Ruimin; Zhu Jinliang

    1998-01-01

    This paper first reviews the history of irradiation treatment of sewage sludge in the world. The first sludge irradiation plant was built in Geiselbullach, West Germany in 1973 and used 60 Co as irradiation source. Since then, many sludge irradiators were constructed in U.S.A., India, Japan, Canada, Poland, etc., which used 60 Co, 137 Cs or electron beam as irradiation sources. The paper then describes some basic research on irradiation treatment of sewage sludge including optimization of irradiation parameters, synergistic effect of radiation with heat, oxygenation, irradiation-composting and potential applications of treated sludge. Some proposals have been suggested for further development of this technology in the future

  2. Revegetation of mined land using waste water sludge

    Sopper, W E; Kerr, N

    1980-01-01

    The benefits of using sludge to reclaim land that has been used for strip mining is explained. Pennsylvania State University developed demonstration plots and used various types of sludges to illustrate this. One application of sludge is sufficient to supply plant nutrients for 3-5 years. After sludge application and incorporation, the site was broadcast seeded with grasses and legumes. Other trials and their results are noted. All show no detrimental effects on vegetation, the soil or groundwater quality due to sludge application.

  3. The importance of ash for the favourable properties of sewage sludge in co-firing; Askans betydelse foer roetslams goda samfoerbraenningsegenskaper

    Davidsson, K.; Jones, F.; Niklasson, F.; Ryde, D. [SP Sveriges Tekniska Forskningsinstitut, Boraas, (Sweden); Gustafsson, G. [Boraas Energi och Miljoe, Boraas (Sweden); Herstad Svaerd, S. [WSP Kraft and Vaerme, Goeteborg (Sweden)

    2012-11-01

    Sewage sludge has been shown to have positive properties during cofiring with difficult fuels. The sludge mitigates deposition and corrosion which occur because of the fuels content of chlorine and alkali. The reason for the positive properties of sludge are its content of sulphur, phosphorus and aluminium silicates. Its high content of ash has also been discussed because the fly ash would constitute a large surface for alkali chlorides to condensate on and thereby avoid condensation on e.g. superheater surfaces. The ash could also blast the surface and thereby keeping them clean. The present project aims at testing the hypothesis that the ash in the sludge mitigates the deposition. Tests have been performed with synthetically produced waste pellets of which some were doped with inert particles in form of aluminium oxide. The tests were done in a lab-scale bubbling fluidised bed. Deposit probes collected deposits during the combustion of doped and un-doped waste pellets, and the deposits were chemically analysed. The result shows that the inert particles do not have any effect on the amount of hard attached deposits. The particles ended up on the lee side of the probe where they deposited because of gravitation, but they could be easily removed. The remaining deposit was analysed and the effect of inert particles was a small decrease of the content of chlorine. Tests were also performed with pellets doped with sludge. In this case the amount of deposit and its content of chlorine decreased significantly. Different sewage sludges have different properties. The present results show that sludge for cofiring should not be chosen for its amount of ash but rather for its content of sulphur, phosphorous and aluminium.

  4. The importance of ash for the favourable properties of sewage sludge in co-firing; Askans betydelse foer roetslams goda samfoerbraenningsegenskaper

    Davidsson, K.; Jones, F.; Niklasson, F.; Ryde, D. [SP Sveriges Tekniska Forskningsinstitut, Boraas (Sweden); Gustafsson, G. [Boraas Energi och Miljoe, Boraas (Sweden); Herstad Svaerd, S. [WSP Kraft and Vaerme, Stockholm (Sweden)

    2012-07-01

    Sewage sludge has been shown to have positive properties during cofiring with difficult fuels. The sludge mitigates deposition and corrosion which occur because of the fuels content of chlorine and alkali. The reason for the positive properties of sludge are its content of sulphur, phosphorus and aluminium silicates. Its high content of ash has also been discussed because the fly ash would constitute a large surface for alkali chlorides to condensate on and thereby avoid condensation on e.g. superheater surfaces. The ash could also blast the surface and thereby keeping them clean. The present project aims at testing the hypothesis that the ash in the sludge mitigates the deposition. Tests have been performed with synthetically produced waste pellets of which some were doped with inert particles in form of aluminium oxide. The tests were done in a lab-scale bubbling fluidised bed. Deposit probes collected deposits during the combustion of doped and un-doped waste pellets, and the deposits were chemically analysed. The result shows that the inert particles do not have any effect on the amount of hard attached deposits. The particles ended up on the lee side of the probe where they deposited because of gravitation, but they could be easily removed. The remaining deposit was analysed and the effect of inert particles was a small decrease of the content of chlorine. Tests were also performed with pellets doped with sludge. In this case the amount of deposit and its content of chlorine decreased significantly. Different sewage sludges have different properties. The present results show that sludge for cofiring should not be chosen for its amount of ash but rather for its content of sulphur, phosphorous and aluminium.

  5. Problematic issues of air protection during thermal processes related to the energetic uses of sewage sludge and other waste. Case study: Co-combustion in peaking power plant.

    Hroncová, Emília; Ladomerský, Juraj; Musil, Juraj

    2018-03-01

    Currently, it is necessary to deal with issues related to the emissions as there is a constantly increasing interest in combusting sludge from sewage treatment plants in the boilers for wood. An analysis of the energetic importance of the combustion of sewage sludge has already been carried out, but the effects of various treatments of the sludge are not always clear, e.g. composting and subsequent combustion to the air pollution. Investments in other thermal processes of energetic utilisation of sewage sludge and organic waste are not always successfully implemented. The objective of this paper is to point out some problematic cases for acceptance of thermal processes related to energetic use of waste in terms of the air protection. The other aim is to mention the experience with solutions of such issues in Slovakia. There are mentioned first results of the operational validation experiments during the energy generation in circulating fluidized bed boiler in peaking power plant (Power 110MW) with the addition of the so-called alternative fuel based on wood and sewage sludge to the main fuel - black coal (anthracite). And there has already been achieved the highest share of 12.4%w. (dry matter) of sewage sludge in form of compost in blend with black coal, which is technologically viable. Moreover analyzed the problems of the authorization and operation of the co-combustion of sewage sludge and of combustion of products of various kinds of pyrolysis waste - pyrolysis gas and pyrolysis oil are analyzed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Utility of Recycled Bedding for Laboratory Rodents

    Miyamoto, Toru; Li, Zhixia; Kibushi, Tomomi; Okano, Shinya; Yamasaki, Nakamichi; Kasai, Noriyuki

    2009-01-01

    Animal facilities generate a large amount of used bedding containing excrement as medical waste. We developed a recycling system for used bedding that involves soft hydrothermal processing. In this study, we examined the effects of bedding type on growth, hematologic and serum biochemical values, and organ weights of female and male mice reared on either recycled or fresh bedding from 3 to 33 wk of age. Neither growth nor physiology differed between mice housed on recycled bedding compared wi...

  7. Fluid bed porosity equation for an inverse fluidized bed bioreactor with particles growing biofilm

    Campos-Diaz, K. E.; Limas-Ballesteros, R.

    2009-01-01

    Fluid Bed Bioreactor performance is strongly affected by bed void fraction or bed porosity fluctuations. Particle size enlargement due to biofilm growth is an important factor that is involved in these variations and until now there are no mathematical equations that consider biofilm growth. In this work a mathematical equation is proposed to calculate bed void fraction in an inverse fluid bed bioreactor. (Author)

  8. A Study of Faecal Coliform Die-Off in Sewage Sludge Drying Bed ...

    Nigerian Journal of Technology ... This trend could be as a result of the organisms being in their exponential phase with adequate nutrients and growth conditions at 60mm depth, which later experienced decrease in available nutrients, oxygen and unfavorable growth conditions such as unfavorable temperatures, reduced ...

  9. Mutual interactions of Pleurotus ostreatus with bacteria of activated sludge in solid-bed bioreactors

    Svobodová, Kateřina; Petráčková, Denisa; Kozická, Barbora; Halada, Petr; Novotný, Čeněk

    2016-01-01

    Roč. 32, č. 6 (2016), s. 94 ISSN 0959-3993 R&D Projects: GA ČR(CZ) GA15-02328S; GA MŠk LO1509 Institutional support: RVO:61388971 Keywords : TRAMETES-VERSICOLOR * WASTE-WATER * BIOFILM FORMATION Subject RIV: EI - Biotechnology ; Bionics Impact factor: 1.658, year: 2016

  10. On the influence of sewage sludge irradiation by gamma radiation on the sludge properties

    Hegemann, W.

    1976-01-01

    The gamma irradiation is a technically usable method to disinfect sewage sludge. Furthermore, the slurry properties are also improved. After 24 hours' thickening time, a significantly smaller volume of concentrated thick slurry could be removed compared to untreated sludge. On the other hand, a dilution occurs with pasteurization if the heat is introduced by steam, and the initial concentration could not be achieved again even after thickening for 24 hours. The drainability of the treated sludge was also improved by irradiation, expressed by a reduction of the specific filter resistance. The costs are essentially determined by the radiation sources used. If it is technically possible to process reactor wastes in such a manner that they can be used in slurry radiation plants, costs of 3.50-4.00 DM/m 3 treated sludge seem possible. (orig.) [de

  11. Settling properties of aerobic granular sludge (AGS) and aerobic granular sludge molasses (AGSM)

    Mat Saad, Azlina; Aini Dahalan, Farrah; Ibrahim, Naimah; Yasina Yusuf, Sara; Aqlima Ahmad, Siti; Khalil, Khalilah Abdul

    2018-03-01

    Aerobic granulation technology is applied to treat domestic and industrial wastewater. The Aerobic granular sludge (AGS) cultivated has strong properties that appears to be denser and compact in physiological structure compared to the conventional activated sludge. It offers rapid settling for solid:liquid separation in wastewater treatment. Aerobic granules were developed using sequencing batch reactor (SBR) with intermittent aerobic - anaerobic mode with 8 cycles in 24 hr. This study examined the settling velocity performance of cultivated aerobic granular sludge (AGS) and aerobic granular sludge molasses (AGSM). The elemental composition in both AGS and AGSM were determined using X-ray fluorescence (XRF). The results showed that AGSM has higher settling velocity 30.5 m/h compared to AGS.

  12. Electroosmotic dewatering of chalk sludge, iron hydroxide sludge, wet fly ash and biomass

    Hansen, H.K.; Kristensen, I.V.; Ottosen, L.M.; Villumsen, A. [Dept. of Geology and Geotechnical Engineering, The Technical Univ. of Denmark, Lyngby (Denmark)

    2001-07-01

    Electroosmotic dewatering has been tested in laboratory cells for 4 different porous materials: chalk sludge, iron hydroxide sludge, wet fly ash and biomass sludge from enzyme production. In all cases it was possible to remove water when passing electric DC current through the material. Casagrande's coefficients for the three materials where determined at different water contents. In the electroosmotic experiments shown in this work chalk can be dewatered from 40% to 79% DM (dry matter), fly ash from 75 to 82% DM, iron hydroxide sludge from 2.7 to 19% DM and biomass from 3 to 33% DM. The process was not optimised indicating that higher dry matter contents could be achieved. (orig.)

  13. Placement of radium/barium sludges in tailings areas

    Murphy, K.L.; Multamaki, G.E.

    1980-01-01

    Currently radium is removed from uranium mining and milling effluents by the addition of barium chloride to precipitate the radium as radium/barium sulphate. The precipitate is allowed to settle in sedimentation basins prior to discharge of the effluent. The sedimentation basins are not suitable for final disposal of the sludge, and placement of the sludges in the tailings area has been proposed. The geochemical environment of fresh tailings areas was characterized as an acidic, oxidized surface zone underlain by an alkaline, reduced zone comprising the rest of the tailings. The quantity of sludge produced was estimated to be small relative to the quantity of tailings, and therefor a relatively small amount of radium would be added to the tailings disposal area by the addition of sludge. To confirm whether sludge addition affected radionuclide solubilization, laboratory leaching tests were conducted on slurries of acid leach tailings, and sludge-tailings mixtures. Radium in the (Ra,Ba)SO 4 sludge was at least as stable as radium in the tailings, and the sludge was able to absorb radium released from the tailings. The addition of sludge did not affect uranium and thorium solubilization. From these results it appears that the placement of sludge in tailings areas would not adversely affect the stability of radionuclides in the tailings or sludge. (auth)

  14. Sludge quantification at water treatment plant and its management scenario.

    Ahmad, Tarique; Ahmad, Kafeel; Alam, Mehtab

    2017-08-15

    Large volume of sludge is generated at the water treatment plants during the purification of surface water for potable supplies. Handling and disposal of sludge require careful attention from civic bodies, plant operators, and environmentalists. Quantification of the sludge produced at the treatment plants is important to develop suitable management strategies for its economical and environment friendly disposal. Present study deals with the quantification of sludge using empirical relation between turbidity, suspended solids, and coagulant dosing. Seasonal variation has significant effect on the raw water quality received at the water treatment plants so forth sludge generation also varies. Yearly production of the sludge in a water treatment plant at Ghaziabad, India, is estimated to be 29,700 ton. Sustainable disposal of such a quantity of sludge is a challenging task under stringent environmental legislation. Several beneficial reuses of sludge in civil engineering and constructional work have been identified globally such as raw material in manufacturing cement, bricks, and artificial aggregates, as cementitious material, and sand substitute in preparing concrete and mortar. About 54 to 60% sand, 24 to 28% silt, and 16% clay constitute the sludge generated at the water treatment plant under investigation. Characteristics of the sludge are found suitable for its potential utilization as locally available construction material for safe disposal. An overview of the sustainable management scenario involving beneficial reuses of the sludge has also been presented.

  15. Clinical physiology of bed rest

    Greenleaf, John E.

    1993-01-01

    Maintenance of optimal health in humans requires the proper balance between exercise, rest, and sleep as well as time in the upright position. About one-third of a lifetime is spent sleeping; and it is no coincidence that sleeping is performed in the horizontal position, the position in which gravitational influence on the body is minimal. Although enforced bed rest is necessary for the treatment of some ailments, in some cases it has probably been used unwisely. In addition to the lower hydrostatic pressure with the normally dependent regions of the cardiovascular system, body fuid compartments during bed rest in the horizontal body position, and virtual elimination of compression on the long bones of the skeletal system during bed rest (hypogravia), there is often reduction in energy metabolism due to the relative confinement (hypodynamia) and alteration of ambulatory circadian variations in metabolism, body temperature, and many hormonal systems. If patients are also moved to unfamiliar surroundings, they probably experience some feelings of anxiety and some sociopsychological problems. Adaptive physiological responses during bed rest are normal for that environment. They are attempts by the body to reduce unnecessary energy expenditure, to optimize its function, and to enhance its survival potential. Many of the deconditioning responses begin within the first day or two of bed rest; these early responses have prompted physicians to insist upon early resumption of the upright posture and ambulation of bedridden patients.

  16. Biohydrogen production using waste activated sludge disintegrated by gamma irradiation

    Yin, Yanan; Wang, Jianlong

    2015-01-01

    Highlights: • The waste activated sludge could be disintegrated by gamma irradiation. • The disintegrated sludge could be used for biohydrogen production. • Combined alkali-irradiation treatment achieved the highest solubilization of sludge. - Abstract: The biohydrogen production using the disintegrated and dissolved sludge by gamma irradiation was studied. The experimental results showed that gamma irradiation and irradiation combined with alkali pretreatment could disintegrate and dissolve waste activated sludge for biohydrogen production. The alkali-irradiation treatment of the sludge at pH = 12 and 20 kGy achieved the highest disintegration and dissolution, i.e., it could destroy the cell walls and release organic matters (such as soluble COD, polysaccharides and protein) into the solution. The disintegrated sludge could be used as a low-cost substrate for biohydrogen production

  17. Recent developments in Sandia Laboratories' sewage sludge irradiation program

    Sivinski, H.D.; Brandon, J.R.; Morris, M.E.; Neuhauser, K.S.; Ward, R.L.; McCaslin, B.; Smith, G.S.

    1977-01-01

    Pathogen reduction studies show that gamma irradiation is effective in inactivating pathogenic bacteria, parasite ova, and viruses in liquid sludges. Ammonia is shown to be virucidal to poliovirus and several other enteric viruses. Sludge processing costs are relatively economical for composted or dried sludges, but only marginally competitive with costs of heat treatment for liquid sludges. Physical and chemical studies show that effects of irradiation of sludges on dewatering properties are insignificant when compared to the effects of polymer addition. Dried, irradiated undigested sludge has significant nutritional value as a feed supplement for sheep and cattle and in agronomic uses such as greenhouses and field plots. No significant harmful effects have been demonstrated in the feeding program. Product enhancement studies are under way, including schemes for removing nitrogen from wastewaters and adding it to sludges in the form of ammonium salts

  18. Hydrothermal Testing of K Basin Sludge and N Reactor Fuel at Sludge Treatment Project Operating Conditions

    Delegard, Calvin H.; Schmidt, Andrew J.; Thornton, Brenda M.

    2007-03-30

    The Sludge Treatment Project (STP), managed for the U. S. DOE by Fluor Hanford (FH), was created to design and operate a process to eliminate uranium metal from K Basin sludge prior to packaging for Waste Isolation Pilot Plant (WIPP). The STP process uses high temperature liquid water to accelerate the reaction, produce uranium dioxide from the uranium metal, and safely discharge the hydrogen. Under nominal process conditions, the sludge will be heated in pressurized water at 185°C for as long as 72 hours to assure the complete reaction (corrosion) of up to 0.25-inch diameter uranium metal pieces. Under contract to FH, the Pacific Northwest National Laboratory (PNNL) conducted bench-scale testing of the STP hydrothermal process in November and December 2006. Five tests (~50 ml each) were conducted in sealed, un-agitated reaction vessels under the hydrothermal conditions (e.g., 7 to 72 h at 185°C) of the STP corrosion process using radioactive sludge samples collected from the K East Basin and particles/coupons of N Reactor fuel also taken from the K Basins. The tests were designed to evaluate and understand the chemical changes that may be occurring and the effects that any changes would have on sludge rheological properties. The tests were not designed to evaluate engineering aspects of the process. The hydrothermal treatment affected the chemical and physical properties of the sludge. In each test, significant uranium compound phase changes were identified, resulting from dehydration and chemical reduction reactions. Physical properties of the sludge were significantly altered from their initial, as-settled sludge values, including, shear strength, settled density, weight percent water, and gas retention.

  19. Bench-scale enhanced sludge washing and gravity settling of Hanford Tank C-106 Sludge

    Brooks, K.P.; Myers, R.L.; Rappe, K.G.

    1997-01-01

    This report summarizes the results of a bench-scale sludge pretreatment demonstration of the Hanford baseline flowsheet using liter-quantities of sludge from Hanford Site single-shell tank 241-C-106 (tank C-106). The leached and washed sludge from these tests provided Envelope D material for the contractors supporting Tank Waste Remediation System (TWRS) Privatization. Pretreatment of the sludge included enhanced sludge washing and gravity settling tests and providing scale-up data for both these unit operations. Initial and final solids as well as decanted supernatants from each step of the process were analyzed chemically and radiochemically. The results of this work were compared to those of Lumetta et al. (1996a) who performed a similar experiment with 15 grams of C-106, sludge. A summary of the results are shown in Table S.1. Of the major nonradioactive components, those that were significantly removed with enhanced sludge washing included aluminum (31%), chromium (49%), sodium (57%), and phosphorus (35%). Of the radioactive components, a significant amount of 137 Cs (49%) were removed during the enhanced sludge wash. Only a very small fraction of the remaining radionuclides were removed, including 90 Sr (0.4%) and TRU elements (1.5%). These results are consistent with those of the screening test. All of the supernatants (both individually and as a blend) removed from these washing steps, once vitrified as LLW glasses (at 20 wt% Na 2 O), would be less than NRC Class C in TRU elements and less than NRC Class B in 90 Sr

  20. PBDEs in Italian sewage sludge and environmental risk of using sewage sludge for land application

    Cincinelli, Alessandra; Martellini, Tania; Misuri, Lorenza; Lanciotti, Eudes; Sweetman, Andy; Laschi, Serena; Palchetti, Ilaria

    2012-01-01

    Polybrominated diphenyl ethers (PBDEs) were determined in sewage sludge samples collected from eight Italian wastewater treatment plants (WWTPs) between June 2009 and March 2010. Total PBDE concentrations ranged from 158.3 to 9427 ng g −1 dw, while deca-BDE (BDE-209) (concentrations ranging from 130.6 to 9411 ng g −1 dw) dominated the congener profile in all the samples, contributing between 77% and 99.8% of total PBDE. The suitability of using a magnetic particle enzyme-linked immunoassay (ELISA) to analyse PBDEs in sewage sludge was also tested. The ELISA results, expressed as BDE-47 equivalents, were well correlated with those obtained by GC–NCI–MS, with correlation coefficients (r 2 ) of 0.899 and 0.959, depending on the extraction procedure adopted. The risk assessment of PBDEs in sewage sludge addressed to land application was calculated. PEC soil values compared to the relative PNEC soil for penta and deca-BDE suggests that there is a low risk to the soil environment. - Highlights: ► PBDEs in sewage sludge were determined in eight Italian WWTPs for the first time. ► PBDEs concentrations showed differences between the eight investigated WWTPs. ► Deca-BDE (BDE-209) was the dominant congener in all samples. ► The suitability of using ELISA method to analyse PBDEs in sewage sludge was tested. ► The risk assessment of using sewage sludge for land application was evaluated. - Determination of PBDEs in sewage sludge by GC–NCI–MS and ELISA test and risk assessment when sewage sludge is used for land application.