WorldWideScience

Sample records for anaerobic granular sludge

  1. Viscosity evolution of anaerobic granular sludge

    NARCIS (Netherlands)

    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 vis

  2. Electrokinetic copper and iron migration in anaerobic granular sludge

    NARCIS (Netherlands)

    Virkutyte, J.; Sillanpää, M.J.; Lens, P.N.L.

    2006-01-01

    The application of low-level direct electric current (0.15 mA cm¿2) as an electrokinetic technique to treat copper-contaminated mesophilic anaerobic granular sludge was investigated. The sludge was obtained from a full scale UASB reactor treating paper-mill wastewater and was artificially contaminat

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

    Institute of Scientific and Technical Information of China (English)

    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.

  4. Anaerobic treatment of thermal sludge conditioning liquor with granular sludge

    International Nuclear Information System (INIS)

    Thermal sludge conditioning liquor was successfully treated by a pilot-scale upflow anaerobic hybrid system with an effective volume of 10.4 m3. The reactor was similar to the HYAN reactor in Lakeview but without a recirculation system. A gas-solid separator was installed above a filter packed with polypropylene pall rings. The organic loading rate was increased stepwise to 30 kg chemical oxygen demand (COD)/m3·d. The hydraulic retention time was only 6 hours at the target loading rate. More than 70% of soluble COD in the influent was removed, even at an organic loading as high as 30 kg COD/m3·d. Soluble 5-day biochemical oxygen demand (BOD5) removal efficiency at the loading rate exceeded 95%. Volatile fatty acids concentration in the effluent was consistently less than 60 mg/L after the day when stable treatment had been obtained. The methane production fluctuated between 0.3 and 0.4 L/g COD removed. The inside of the reactor consisted of two zones, a sludge blanket zone with less than 1% solids concentration and a sludge bed zone with 4-7% solids concentration. Although the reactor was seeded with an anaerobically digested sludge, granular sludge was produced in the reactor. The ratio of granules to the solids remaining in the reactor increased to approximately 70% at the end of the experiments. Most of the granules had diameters of less than 1 mm and their settling velocity was 0.6 cm/s or more. The granules were composed of bacteria like Methanothrix according to SEM observations. The methane production rate was between 0.8 and 1.1 kg methane as COD/kg SS·d in an acetate solution. According to substrates distribution in the reactor and tracer tests, the bed zone in the reactor worked similarly to a continuously stirred tank reactor (CSTR). Evaluation of soluble COD removal rates in the reactor indicated that the rate could be simulated by a Monod type reaction. 10 refs., 12 figs., 8 tabs

  5. Biosorption of Direct Black 38 by dried anaerobic granular sludge

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The biosorption of Direct Black 38 by dried anaerobic granular sludge in a batch system under specific temperatures and initial pH was investigated.The adsorption reaction is pH dependent with higher removal at low pH.The adsorption equilibrium data fit very well with both Langmuir and Freundlich models in the concentration range of Direct Black 38 at all chosen temperatures.The adsorption parameters show that the adsorption of Direct Black 38 is an endothermic and more effective process at high temperatures.The kinetics of adsorption was found to be second order and adsorption rate constants increased with increasing temperature.Activation energy was determined as 26.8 kJ/mol for the process.This suggests that the adsorption of Direct Black 38 by dried anaerobic granular sludge is chemically controlled.

  6. Anaerobic granular sludge and biofilm reactors

    DEFF Research Database (Denmark)

    Skiadas, Ioannis V.; Gavala, Hariklia N.; Schmidt, Jens Ejbye; Ahring, Birgitte Kiær

    2003-01-01

    role of the anaerobic digestion in the wastewater treatment plants from a pre-treatment method to the main biological treatment method. The application of staged high-rate anaerobic digesters has shown the larger potential among the recent developments in this direction. The most common high...

  7. Anaerobic granular sludge and biofilm reactors

    DEFF Research Database (Denmark)

    Skiadas, Ioannis V.; Gavala, Hariklia N.; Schmidt, Jens Ejbye;

    2003-01-01

    The long retention time of the active biomass in the high-rate anaerobic digesters is the key factor for the successful application of the high rate anaerobic wastewater treatment. The long solids retention time is achieved due to the specific reactor configuration and it is enhanced...... 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...... of the role of the anaerobic digestion in the wastewater treatment plants from a pre-treatment method to the main biological treatment method. The application of staged high-rate anaerobic digesters has shown the larger potential among the recent developments in this direction. The most common high...

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

    NARCIS (Netherlands)

    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 on

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

    NARCIS (Netherlands)

    Virkutyte, J.; Hullebusch, van E.D.; Sillanpaa, M.; Lens, P.N.L.

    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

  10. Production and the application of anaerobic granular sludge produced by landfill

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Sludge granulation is considered to be the most critical parameter governing successful operation of an upflow anaerobic sludge blanket and expanded granular sludge bed (EGSB) reactors. Pre-granulated seeding sludge could greatly reduce the required start-up time. Two lab-scale and a pilot-scale EGSB reactors were operated to treat Shaoxing Wastewater Treatment Plant containing wastewater from real engineering printing and dyeing with high pH and sulfate concentration. The microbiological structure and the particle size distribution in aerobic excess sludge, sanitary landfill sludge digested for one year, and the granular sludge of EGSB reactor after 400 d of operation were analyzed through scanning electron microscopy (SEM) and sieves. The lab-scale EGSB reactor seeded with anaerobic sludge after digestion for one year in landfill showed obviously better total chemical oxygen demand (TCOD) removal efficiency than one seeded with aerobic excess sludge after cation polyacrylamide flocculation-concentration and dehydration. The TCOD removed was 470.8 mg/L in pilot scale EGSB reactor at short hydraulic retention time of 15 h. SEM of sludge granules showed that the microbiological structure of the sludge from different sources showed some differences. SEM demonstrated that Methanobacterium sp. was present in the granules of pilot-scale EGSB and the granular sludge produced by landfill contained a mixture of anaerobic/anoxic organisms in abundance. The particle size distribution in EGSB demonstrated that using anaerobic granular sludge produced by sanitary landfill as the seeding granular sludge was feasible.

  11. Effect of Na+ and Ca2+ on the aggregation properties of sieved anaerobic granular sludge

    NARCIS (Netherlands)

    Pevere, A.; Guibaud, G.; Hullebusch, van E.D.; Boughzala, W.; Lens, P.N.L.

    2007-01-01

    Interactions between fine particles (0¿50 ¿m) of anaerobic granular sludge were investigated by studying the effect of Na+ or Ca2+ supply on the evolution of the zeta potential and viscosity of granular sludge suspensions. In the Na+ or Ca2+ concentration range investigated, the Na+ addition affecte

  12. Inhibitory effect of ammonia nitrogen on specific methanogenic activity of anaerobic granular sludge

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A series of batch experiments were conducted in 125 mL serum bottles to assess the toxicity of different concentrations of ammonia nitrogen to the specific methanogenic activity of anaerobic granular sludge from upflow anaerobic sludge bed(UASB) and expanded granular sludge bed(EGSB) reactors. The effects of pH value and temperature on toxicity of ammonia nitrogen to anaerobes were investigated. The results show that the specific methanogenic activity of anaerobic granular sludge suffers inhibition from ammonia nitrogen, the concentrations of ammonia nitrogen that produce 50% inhibition of specific methanogenic activity for sludge from UASB and EGSB reactor are 2.35 and 2.75 g/L, respectively. Hydrogen utilizing methanogens suffers less inhibition from ammonia nitrogen than that of acetate utilizing methanogens. Hydrogen-producing acetogens that utilize propionate and butyrate as substrates suffer serious inhibition from ammonia nitrogen. The toxicity of ammonia nitrogen to anaerobic granular sludge enhances when pH value and temperature increase. Anaerobic granular sludge can bear higher concentrations of ammonia nitrogen after being acclimated by ammonia nitrogen for 7 d.

  13. Effect of sulfate and iron on physico-chemical characteristics of anaerobic granular sludge

    NARCIS (Netherlands)

    Hullebusch, van E.D.; Gieteling, J.; Daele, van W.; Defrancq, J.; Lens, P.N.L.

    2007-01-01

    This research investigated the effect of the substrate composition (no substrate, glucose, glucose + sulfate or glucose + sulfate + iron) on the physico-chemical characteristics of two different anaerobic granular sludges as a function of time. The sludges were fed batch wise (pH 7, 30 °C) at an org

  14. Impact of high saline wastewaters on anaerobic granular sludge functionalities

    NARCIS (Netherlands)

    Jeison, D.A.; Rio, del A.; Lier, van J.B.

    2008-01-01

    Three UASB reactors were operated at different salinity levels in order to assess the effects on the granular sludge properties. High levels of activity inhibition were observed at sodium concentrations over 7 g Na+/L, which resulted in low applicable organic loading rates and VFA accumulation in re

  15. Metal supplementation to anaerobic granular sludge bed reactors: an environmental engineering approach

    OpenAIRE

    Gonzalez Fermoso, F.

    2008-01-01

    The objective of this research is the optimization of essential metal dosing in upflow anaerobic sludge bed (UASB) reactors used for methanogenic wastewater treatment. Optimization of essential metal dosing in UASB reactors is a compromise between achieving the maximal biological activity of the biomass present in the reactor, while minimizing the costs of the supplied metal and the metal losses into the environment. The fate of metals in the anaerobic granular sludge is studied. The boundary...

  16. [Influence of nitrate on the simultaneous methanogenesis and denitrification reaction of anaerobic biofilm and granular sludge].

    Science.gov (United States)

    Zhong, Chen-Yu; Ye, Jie-Xu; Li, Ruo-Yu; Chen, Sheng; Sun, De-Zhi

    2012-12-01

    The aims of this study are to further investigate the impact mechanism of nitrate on the simultaneous methanogenesis and denitrification (SMD) process of anaerobic biofilm, and to extend the application of the biofilm process in the treatment of high nitrogen and COD concentration organic wastewater. The SMD reactions were successfully carried out in a hybrid anaerobic biofilm and sludge reactor (HABSR) and an up-flow anaerobic sludge blanket (UASB), and the influence of nitrate on the performance of simultaneous carbon and nitrogen removal in biofilm and granular sludge were investigated using batch tests. The results showed that the nitrate concentration could obviously affect the carbon and nitrogen removal in both biofilm and granular sludge, and the increase of nitrate concentration had more serious impact on the granular sludge, and the biofilm presented higher COD and nitrogen removal efficiency and stronger resistance to toxic materials than the granular sludge. As the nitrate concentration was increased from 75 to 600 mg x L(-1), the COD removal rates were reduced from 273.26 to 0.1 mg x (h x g)(-1) in granular sludge and reduced from 95 to 1.7 mg x (h x g)(-1) in biofilm. At the same time, the denitrification rate of biofilm and granular sludge were increased form 21.43 and 22.31 mg x (h x g)(-1) to 83.72 and 61.06 mg x (h x g)(-1), respectively. The biofilm recovered the COD degradation rate more quickly and easily than the granular sludge, and the maximum COD removal rate reached 712.44 mg x (h x g)(-1). The nitrite accumulation was observed to be the major cause that affected the simultaneous carbon and nitrogen removal of biofilm and granular sludge. It's found that the maximum nitrite accumulation in biofilm was only one tenth of that of the granular sludge at the same nitrate concentration. The HABSR was proved to be an important alternative for SMD reaction employed in the treatment of high nitrogen and COD concentration organic wastewater. PMID

  17. Improved dechlorinating performance of upflow anaerobic sludge blanket reactors by incorporation of Dehalospirillum multivorans into granular sludge

    DEFF Research Database (Denmark)

    Hörber, Christine; Christiansen, Nina; Arvin, Erik;

    1998-01-01

    Dechlorination of tetrachloroethene, also known as perchloroethylene (PCE), was investigated in an upflow anaerobic sludge blanket (UASB) reactor after incorporation of the strictly anaerobic, reductively dechlorinating bacterium Dehalospirillum multivorans into granular sludge. This reactor...... was compared to the reference 1 (R1) reactor, where the granules were autoclaved to remove all dechlorinating abilities before inoculation, and to the reference 2 (R2) reactor, containing only living granular sludge. All three reactors were fed mineral medium containing 3 to 57 mu M PCE, 2 mM formate, and 0.......5 mM acetate and were operated under sterile conditions. In the test reactor, an average of 93% (mole/mole) of the effluent chloroethenes was dichloroethene (DCE), compared to 99% (mole/mole) in the Ri reactor. The R2 reactor, with no inoculation, produced only trichloroethene (TCE), averaging 43...

  18. Immobilization patterns and dynamics of acetate-utilizing methanogens in sterile granular sludge from upflow anaerobic sludge blanket (UASB) reactors

    DEFF Research Database (Denmark)

    Schmidt, Jens Ejbye; Ahring, Birgitte Kiær

    1999-01-01

    Sterile granular sludge was inoculated with either Methanosarcina mazeii S-6, Methanosaeta concilii GP-6, or both species in acetate-fea upflow anaerobic sludge blanket (UASB) reactors to investigate the immobilization patterns and dynamics of aceticlastic methanogens in granular sludge. After...... several months of reactor operation, the methanogens were immobilized, either separately or together. The fastest immobilization was observed in the reactor containing ill. mazeii S-6. The highest effluent concentration of acetate was observed in the reactor with only ill. mazeii S-6 immobilized, while...... the lowest effluent concentration of acetate was observed in the reactor where both types of methanogens were immobilized together. No changes were observed in the kinetic parameters (K-s and mu(max)) of immobilized M. concilii GP-6 or ill, mazeii S-6 compared with suspended cultures, indicating...

  19. Immobilization patterns and dynamics of acetate-utilizing methanogens immobilized in sterile granular sludge in upflow anaerobic sludge blanket reactors

    DEFF Research Database (Denmark)

    Schmidt, Jens Ejbye; Ahring, Birgitte Kiær

    1999-01-01

    Sterile granular sludge was inoculated with either Methanosarcina mazeii S-6, Methanosaeta concilii GP-6, or both species in acetate-fea upflow anaerobic sludge blanket (UASB) reactors to investigate the immobilization patterns and dynamics of aceticlastic methanogens in granular sludge. After...... several months of reactor operation, the methanogens were immobilized, either separately or together. The fastest immobilization was observed in the reactor containing ill. mazeii S-6. The highest effluent concentration of acetate was observed in the reactor with only ill. mazeii S-6 immobilized, while...... the lowest effluent concentration of acetate was observed in the reactor where both types of methanogens were immobilized together. No changes were observed in the kinetic parameters (K-s and mu(max)) of immobilized M. concilii GP-6 or ill, mazeii S-6 compared with suspended cultures, indicating...

  20. Effects of Predation by Protists on Prokaryotic Community Function, Structure, and Diversity in Anaerobic Granular Sludge

    Science.gov (United States)

    Hirakata, Yuga; Oshiki, Mamoru; Kuroda, Kyohei; Hatamoto, Masashi; Kubota, Kengo; Yamaguchi, Takashi; Harada, Hideki; Araki, Nobuo

    2016-01-01

    Predation by protists is top-down pressure that regulates prokaryotic abundance, community function, structure, and diversity in natural and artificial ecosystems. Although the effects of predation by protists have been studied in aerobic ecosystems, they are poorly understood in anoxic environments. We herein studied the influence of predation by Metopus and Caenomorpha ciliates—ciliates frequently found in anoxic ecosystems—on prokaryotic community function, structure, and diversity. Metopus and Caenomorpha ciliates were cocultivated with prokaryotic assemblages (i.e., anaerobic granular sludge) in an up-flow anaerobic sludge blanket (UASB) reactor for 171 d. Predation by these ciliates increased the methanogenic activities of granular sludge, which constituted 155% of those found in a UASB reactor without the ciliates (i.e., control reactor). Sequencing of 16S rRNA gene amplicons using Illumina MiSeq revealed that the prokaryotic community in the UASB reactor with the ciliates was more diverse than that in the control reactor; 2,885–3,190 and 2,387–2,426 operational taxonomic units (>97% sequence similarities), respectively. The effects of predation by protists in anaerobic engineered systems have mostly been overlooked, and our results show that the influence of predation by protists needs to be examined and considered in the future for a better understanding of prokaryotic community structure and function. PMID:27431197

  1. Inhibitory effect of heavy metals on methane-producing anaerobic granular sludge.

    Science.gov (United States)

    Altaş, Levent

    2009-03-15

    Heavy metals could potentially have a negative impact on methane-producing anaerobic granular sludge. The objective of this study was to investigate the inhibitory effect of zinc(II), chromium(VI), nickel(II), and cadmium(II) on the methane-producing activity of granular sludge sampled from the upflow anaerobic sludge blanket reactor that treats the wastewaters of a yeast factory, for a range of concentrations between 0 and 128 mg L(-1). The modified Gompertz, Logistic, and Richards equations were applied to describe the inactivation of anaerobic culture by heavy metals. According to these models, the values of methane production potential (mL) for a heavy metal concentration of 128 mg L(-1) were in the following order: Ni (44.82+/-0.67)>Cd (28.73+/-0.11)>Cr (15.52+/-1.63)>Zn (0.65+/-0.00). The IC(50) values, the metal concentrations that cause a 50% reduction in the cumulative methane production over a fixed period of exposure time (24h), for the individual heavy metals were found to be in the following order: Zn (most toxic; 7.5 mg L(-1))>Cr (27 mg L(-1))>Ni (35 mg L(-1)) approximately Cd (least toxic; 36 mg L(-1)). PMID:18640779

  2. Dosing of anaerobic granular sludge bioreactors with cobalt: Impact of cobalt retention on methanogenic activity

    KAUST Repository

    Fermoso, Fernando G.

    2010-12-01

    The effect of dosing a metal limited anaerobic sludge blanket (UASB) reactor with a metal pulse on the methanogenic activity of granular sludge has thus far not been successfully modeled. The prediction of this effect is crucial in order to optimize the strategy for metal dosage and to prevent unnecessary losses of resources. This paper describes the relation between the initial immobilization of cobalt in anaerobic granular sludge cobalt dosage into the reactor and the evolution of methanogenic activity during the subsequent weeks. An operationally defined parameter (A0· B0) was found to combine the amount of cobalt immobilized instantaneously upon the pulse (B0) and the amount of cobalt immobilized within the subsequent 24. h (A0). In contrast with the individual parameters A0 and B0, the parameter A0· B0 correlated significantly with the methanogenic activity of the sludge during the subsequent 16 or 35. days. This correlation between metal retention and activity evolution is a useful tool to implement trace metal dosing strategies for biofilm-based biotechnological processes. © 2010.

  3. Location and chemical composition of microbially induced phosphorus precipitates in anaerobic and aerobic granular sludge.

    Science.gov (United States)

    Mañas, A; Spérandio, M; Decker, F; Biscans, B

    2012-01-01

    This work focuses on combined scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDX) applied to granular sludge used for biological treatment of high-strength wastewater effluents. Mineral precipitation is shown to occur in the core of microbial granules under different operating conditions. Three dairy wastewater effluents, from three different upflow anaerobic sludge blanket (UASB) reactors and two aerobic granular sequenced batch reactors (GSBR) were evaluated. The relationship between the solid phase precipitation and the chemical composition of the wastewater was investigated with PHREEQC software (calculation of saturation indexes). Results showed that pH, Ca:P ratios and biological reactions played a major role in controlling the biomineralization phenomena. Thermodynamics calculations can be used to foresee the nature of bio-precipitates, but the location of the mineral concretions will need further investigation as it is certainly due to local microbial activity. PMID:23393959

  4. Anaerobic biodegradability essays from brewery wastewater using granular and flocculent sludges

    Directory of Open Access Journals (Sweden)

    C J Collazos Chávez

    2010-03-01

    Full Text Available At the beginning of nineties the colombian beer industry begun the application of anaerobic technology for the treatment of their wastewater efluents throught different regions of the country. These treatment plants have not been working appropriately due to different factors, and are creating concern among the industrial sector and the water pollution control agencies. This work constitutes the second phase of a research project designed to establish a selection and improvement criteria of the sludges used in the systems. It also looks to analyze other associated factors such as: waste, characteristics, operation conditions and design parameters. The investigation was conducted in two phases using granular and floculent sludges. This method was used for determining the anaerobic biodegradability of wastewater from two industrial plants.

  5. Trace methane oxidation and the methane dependency of sulfate reduction in anaerobic granular sludge

    KAUST Repository

    Meulepas, Roel J.W.

    2010-05-01

    This study investigates the oxidation of labeled methane (CH4) and the CH4 dependence of sulfate reduction in three types of anaerobic granular sludge. In all samples, 13C-labeled CH4 was anaerobically oxidized to 13C-labeled CO2, while net endogenous CH4 production was observed. Labeled-CH4 oxidation rates followed CH4 production rates, and the presence of sulfate hampered both labeled-CH4 oxidation and methanogenesis. Labeled-CH4 oxidation was therefore linked to methanogenesis. This process is referred to as trace CH4 oxidation and has been demonstrated in methanogenic pure cultures. This study shows that the ratio between labeled-CH4 oxidation and methanogenesis is positively affected by the CH4 partial pressure and that this ratio is in methanogenic granular sludge more than 40 times higher than that in pure cultures of methanogens. The CH4 partial pressure also positively affected sulfate reduction and negatively affected methanogenesis: a repression of methanogenesis at elevated CH4 partial pressures confers an advantage to sulfate reducers that compete with methanogens for common substrates, formed from endogenous material. The oxidation of labeled CH 4 and the CH4 dependence of sulfate reduction are thus not necessarily evidence of anaerobic oxidation of CH4 coupled to sulfate reduction. © 2010 Federation of European Microbiological Societies.

  6. Extracellular Polymers in Granular Sludge from Different Upflow Anaerobic Sludge Blanket (UASB) Reactors

    DEFF Research Database (Denmark)

    Schmidt, Jens Ejbye; Ahring, Birgitte Kiær

    1994-01-01

    Thermal extraction was used to quantify extracellular polymers (ECP) in granules from anaerobic upflow reactors. The optimal time for extraction was determined as the time needed before the intracellular material gives a significant contribution to the extracted extracellular material due to cell...... of an upflow anaerobic sludge blanket reactor from a sugar-containing waste-water to a synthetic waste-water containing acetate, propionate and butyrate resulted in a decrease in both the protein and polysaccharide content and an increase in the lipid content of the extracellular material. Furthermore...

  7. Characteristics of granular sludge developed in an upflow anaerobic sludge fixed-film bioreactor treating palm oil mill effluent.

    Science.gov (United States)

    Zinatizadeh, A A L; Mohamed, A R; Mashitah, M D; Abdullah, A Z; Hasnain Isa, M

    2007-08-01

    In the present study, characteristics of the granular sludge (including physical characteristics under stable conditions and process shocks arising from suspended solid overload, soluble organic overload, and high temperature; biological activity; and sludge kinetic evaluation in a batch experiment) developed in an upflow anaerobic sludge blanket fixed-film reactor for palm oil mill effluent (POME) treatment was investigated. The main aim of this work was to provide suitable understanding of POME anaerobic digestion using such a granular sludge reactor, particularly with respect to granule structure at various operating conditions. The morphological changes in granular sludge resulting from various operational conditions was studied using scanning electron microscopy and transmission electron microscopy images. It was shown that the developed granules consisted of densely packed rod- (Methanosaeta-like microorganism; predominant) and cocci- (Methanosarsina) shaped microorganisms. Methanosaeta aggregates functioned as nucleation centers that initiated granule development of POME-degrading granules. Under the suspended solid overload condition, most of the granules were covered with a thin layer of fiberlike suspended solids, so that the granule color changed to brown and the sludge volume index also increased to 24.5 from 12 to 15 mL/g, which caused a large amount of sludge washout. Some of the granules were disintegrated because of an acidified environment, which originated from acidogenesis of high influent organic load (29 g chemical oxygen demand [COD]/L d). At 60 degrees C, the rate of biomass washout increased, as a result of disintegration of the outer layer of the granules. In the biological activity test, approximately 95% COD removal was achieved within 72 hours, with an initial COD removal rate of 3.5 g COD/L d. During POME digestion, 275 mg calcium carbonate/L bicarbonate alkalinity was produced per 1000 mg COD(removed)/ L. A consecutive reaction kinetic

  8. Release of Extracellular Polymeric Substance and Disintegration of Anaerobic Granular Sludge under Reduced Sulfur Compounds-Rich Conditions

    Directory of Open Access Journals (Sweden)

    Takuro Kobayashi

    2015-07-01

    Full Text Available The effect of reduced form of sulfur compounds on granular sludge was investigated. Significant release of extracellular polymeric substance (EPS from the granular sludge occurred in the presence of sulfide and methanethiol according to various concentrations. Granular sludge also showed a rapid increase in turbidity and decrease in diameter in accordance with sulfide concentration during the long-term shaking, suggesting that the strength of the granules was reduced with high-concentration sulfide. A continuous experiment of up-flow anaerobic sludge blanket reactors with different concentrations of sulfide (10, 200, 500 mg-S/L influence demonstrated that the reactor fed with higher concentration of sulfide allowed more washout of small particle-suspended solid (SS content and soluble carbohydrate and protein, which were considered as EPS released from biofilm. Finally, the presence of sulfide negatively affected methane production, chemical oxygen demand removal and sludge retention in operational performance.

  9. Enhancement of acidic dye biosorption capacity on poly(ethylenimine) grafted anaerobic granular sludge

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xue-Fei, E-mail: xfsun06@gmail.com [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Wang, Shu-Guang, E-mail: wsg@sdu.edu.cn [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Cheng, Wen [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Fan, Maohong [School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Tian, Bing-Hui [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Gao, Bao-Yu; Li, Xiao-Ming [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China)

    2011-05-15

    Developing a novel biosorbent with high capacity is crucial to remove dyes from waters in an efficient way. This study demonstrated that porous anaerobic granular sludge could be grafted with polyethylenimine (PEI), which definitely improved the sorption capacity towards Acid Red 18 (AR18) removal. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) study revealed that the PEI modification introduced a large number of amino groups on the surface of sludge, and the amino groups played an important role in the adsorption of dye molecule. Analysis of sorption data using a Boyd plot confirms the film diffusion was the rate-limiting step. The equilibrium data were well fitted Langmuir model, with a maximum AR18 uptake of 520.52 mg/g. Removal of AR18 decreased with the increasing pH and the maximum color removal was observed at pH 2.0. The sorption energy calculated from Dubinin-Radushkevich isotherm was found to be less than 8 for the biosorption of AR 18, which suggested that the biosorption processes of dye molecule onto modified anaerobic granules could be taken place by physical adsorption. Various thermodynamic parameters, such as {Delta}G{sup 0}, {Delta}H{sup 0} and {Delta}S{sup 0}, were also calculated, which indicated that the present system was spontaneous and endothermic process.

  10. Methane Production from Rice Straw Hydrolysate Treated with Dilute Acid by Anaerobic Granular Sludge.

    Science.gov (United States)

    Cheng, Jing-Rong; Liu, Xue-Ming; Chen, Zhi-Yi

    2016-01-01

    The traditional anaerobic digestion process of straw to biogas faces bottlenecks of long anaerobic digestion time, low digestion rate, less gas production, etc., while straw hydrolysate has the potential to overcome these drawbacks. In this study, the dilute sulphuric acid-treated hydrolysate of rice straw (DSARSH) containing high sulfate was firstly proved to be a feasible substrate for methane production under mesophilic digestion by granular sludge within a short digestion time. Batch anaerobic digestion process was operated under different initial chemical oxygen demand (COD) values at temperature of 37 °C with the pH of 8.5. Among the initial COD values ranging from 3000 to 11,000 mg/L, 5000 mg/L was proved to be the most appropriate considering high COD removal efficiency (94.17 ± 1.67 %), CH4 content (65.52 ± 3.12 %), and CH4 yield (0.346 ± 0.008 LCH4/g COD removed) within 120 h. Furthermore, when the studied system operated at the initial COD of 5000 mg/L, the sulfate removal ratio could reach 56.28 %. PMID:26378012

  11. Influence of preservation temperature on the characteristics of anaerobic ammonium oxidation (anammox) granular sludge.

    Science.gov (United States)

    Xing, Bao-Shan; Guo, Qiong; Jiang, Xiao-Yan; Chen, Qian-Qian; Li, Peng; Ni, Wei-Min; Jin, Ren-Cun

    2016-05-01

    Preserving active anaerobic ammonium oxidation (anammox) biomass is a potential method for securing sufficient seeding biomass for the rapid start-up of full-scale anammox processes. In this study, anammox granules were cultured in an upflow anaerobic sludge blanket (UASB) reactor (R0), and then the enriched anammox granules were preserved at 35, 20, 4, and -30 °C. The subsequent reactivation characteristics of the granules were evaluated in four UASB reactors (denoted R1, R2, R3, and R4, respectively) to investigate the effect of preservation temperature on the characteristics of anammox granules and their reactivation performance. The results demonstrated that 4 °C was the optimal preservation temperature for maintaining the biomass, activity, settleability, and integrity of the anammox granules and their cellular structures. During the preservation period, a first-order exponential decay model may be used to simulate the decay of anammox biomass and activity. The protein-to-polysaccharide ratio in the extracellular polymeric substances and the heme c content could not effectively indicate the changes in settleability and activity of the anammox granules, respectively, and a loss of bioactivity was positively associated with the degree of anaerobic ammonium-oxidizing bacteria cell lysis. After 42 days of storage, the anammox granules preserved at 4 °C (R3) exhibited a better recovery performance than those preserved at 20 °C (R2), -30 °C (R4), and 35 °C (R1). The comprehensive comparison indicated that 4 °C is the optimal storage temperature for anammox granular sludge because it promotes improved maintenance and recovery performance properties. PMID:26780355

  12. Introduction of a De Novo Bioremediation Ability, Aryl Reductive Dechlorination, into Anaerobic Granular Sludge by Inoculation of Sludge with Desulfomonile tiedjei

    DEFF Research Database (Denmark)

    Ahring, Birgitte Kiær; Christiansen, Nina; Mathrani, Indra Madan;

    1992-01-01

    reactors, we inoculated granular sludge in UASB reactors with either a pure culture of Desulfomonile tiedjei (a 3-CB-dechlorinating anaerobe) or a three-member consortium consisting of D. tiedjei, a benzoate degrader, and an H-2-utilizing methanogen. No degradation occurred in an uninoculated control...

  13. Succession of microbial community and enhanced mechanism of a ZVI-based anaerobic granular sludge process treating chloronitrobenzenes wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Liang, E-mail: felix79cn@hotmail.com [Department of Environmental Engineering, Zhejiang University, Hangzhou 310058 (China); Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou 310058 (China); Jin, Jie [Department of Environmental Engineering, Zhejiang University, Hangzhou 310058 (China); Lin, Haizhuan [Department of Environmental Engineering, Zhejiang University, Hangzhou 310058 (China); Wenzhou Environmental Protection Design Scientific Institute, Wenzhou 325000 (China); Gao, Kaituo [Department of Environmental Engineering, Zhejiang University, Hangzhou 310058 (China); Xu, Xiangyang, E-mail: xuxy@zju.edu.cn [Department of Environmental Engineering, Zhejiang University, Hangzhou 310058 (China); Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou 310058 (China)

    2015-03-21

    Highlights: • The combined ZVI–UASB process was established for the degradation of chloronitrobenzenes. • There were the better shock resistance and buffering capacity for anaerobic acidification in the combined process. • Novel ZVI-based anaerobic granular sludge (ZVI–AGS) was successfully developed. • Adaptive shift of microbial community was significant in ZVI-based anaerobic granular sludge system. - Abstract: The combined zero-valent iron (ZVI) and upflow anaerobic sludge blanket (UASB) process is established for the treatment of chloronitrobenzenes (ClNBs) wastewater, and the succession of microbial community and its enhanced mechanism are investigated in the study. Results showed that compared with the control UASB (R1), the stable COD removal, ClNBs transformation, and dechlorination occurred in the combined system (R2) when operated at influent COD and 3,4-Dichloronitrobenzene (3,4-DClNB) loading rates of 4200–7700 g m{sup −3} d{sup −1} and 6.0–70.0 g m{sup −3} d{sup −1}, and R2 had the better shock resistance and buffering capacity for the anaerobic acidification. The dechlorination for the intermediate products of p-chloroanaline (p-ClAn) to analine (AN) occurred in R2 reactor after 45 days, whereas it did not occur in R1 after a long-term operation. The novel ZVI-based anaerobic granular sludge (ZVI–AGS) was successfully developed in the combined system, and higher microbial activities including ClNB transformation and H{sub 2}/CH{sub 4} production were achieved simultaneously. The dominant bacteria were closely related to the groups of Megasphaera, Chloroflexi, and Clostridium, and the majority of archaea were correlated with the groups of Methanosarcinalesarchaeon, Methanosaetaconcilii, and Methanothrixsoehngenii, which are capable of reductively dechlorinating PCB, HCB, and TCE in anaerobic niche and EPS secretion.

  14. Succession of microbial community and enhanced mechanism of a ZVI-based anaerobic granular sludge process treating chloronitrobenzenes wastewater

    International Nuclear Information System (INIS)

    Highlights: • The combined ZVI–UASB process was established for the degradation of chloronitrobenzenes. • There were the better shock resistance and buffering capacity for anaerobic acidification in the combined process. • Novel ZVI-based anaerobic granular sludge (ZVI–AGS) was successfully developed. • Adaptive shift of microbial community was significant in ZVI-based anaerobic granular sludge system. - Abstract: The combined zero-valent iron (ZVI) and upflow anaerobic sludge blanket (UASB) process is established for the treatment of chloronitrobenzenes (ClNBs) wastewater, and the succession of microbial community and its enhanced mechanism are investigated in the study. Results showed that compared with the control UASB (R1), the stable COD removal, ClNBs transformation, and dechlorination occurred in the combined system (R2) when operated at influent COD and 3,4-Dichloronitrobenzene (3,4-DClNB) loading rates of 4200–7700 g m−3 d−1 and 6.0–70.0 g m−3 d−1, and R2 had the better shock resistance and buffering capacity for the anaerobic acidification. The dechlorination for the intermediate products of p-chloroanaline (p-ClAn) to analine (AN) occurred in R2 reactor after 45 days, whereas it did not occur in R1 after a long-term operation. The novel ZVI-based anaerobic granular sludge (ZVI–AGS) was successfully developed in the combined system, and higher microbial activities including ClNB transformation and H2/CH4 production were achieved simultaneously. The dominant bacteria were closely related to the groups of Megasphaera, Chloroflexi, and Clostridium, and the majority of archaea were correlated with the groups of Methanosarcinalesarchaeon, Methanosaetaconcilii, and Methanothrixsoehngenii, which are capable of reductively dechlorinating PCB, HCB, and TCE in anaerobic niche and EPS secretion

  15. Biomethane production from vinasse in upflow anaerobic sludge blanket reactors inoculated with granular sludge.

    Science.gov (United States)

    Barros, Valciney Gomes de; Duda, Rose Maria; Oliveira, Roberto Alves de

    2016-01-01

    The main objective of this study was to evaluate the anaerobic conversion of vinasse into biomethane with gradual increase in organic loading rate (OLR) in two upflow anaerobic sludge blanket (UASB) reactors, R1 and R2, with volumes of 40.5 and 21.5L in the mesophilic temperature range. The UASB reactors were operated for 230 days with a hydraulic detection time (HDT) of 2.8d (R1) and 2.8-1.8d (R2). The OLR values applied in the reactors were 0.2-7.5gtotalCOD (Ld)(-1) in R1 and 0.2-11.5gtotalCOD (Ld)(-1) in R2. The average total chemical oxygen demand (totalCOD) removal efficiencies ranged from 49% to 82% and the average conversion efficiencies of the removed totalCOD into methane were 48-58% in R1 and 39-65% in R2. The effluent recirculation was used for an OLR above 6gtotalCOD (Ld)(-1) in R1 and 8gtotalCOD (Ld)(-1) in R2 and was able to maintain the pH of the influent in R1 and R2 in the range from 6.5 to 6.8. However, this caused a decrease for 53-39% in the conversion efficiency of the removed totalCOD into methane in R2 because of the increase in the recalcitrant COD in the influent. The largest methane yield values were 0.181 and 0.185 (L) CH4 (gtotalCOD removed)(-1) in R1 and R2, respectively. These values were attained after 140 days of operation with an OLR of 5.0-7.5gtotalCOD (Ld)(-1) and totalCOD removal efficiencies around 70 and 80%. PMID:27289246

  16. Start-Up Characteristics of a Granule-Based Anammox UASB Reactor Seeded with Anaerobic Granular Sludge

    Directory of Open Access Journals (Sweden)

    Lei Xiong

    2013-01-01

    Full Text Available The granulation of anammox sludge plays an important role in the high nitrogen removal performance of the anammox reactor. In this study, anaerobic granular sludge was selected as the seeding sludge to start up anammox reactor in order to directly obtain anammox granules. Results showed that the anammox UASB reactor was successfully started up by inoculating anaerobic granular sludge, with substrate capacity of 4435.2 mg/(L·d and average ammonium and nitrite removal efficiency of 90.36% and 93.29%, respectively. During the start-up course, the granular sludge initially disintegrated and then reaggregated and turned red, suggesting the high anammox performance. Zn-Fe precipitation was observed on the surface of granules during the operation by SEM-EDS, which would impose inhibition to the anammox activity of the granules. Accordingly, it is suggested to relatively reduce the trace metals concentrations, of Fe and Zn in the conventional medium. The findings of this study are expected to be used for a shorter start-up and more stable operation of anammox system.

  17. Extraction of extracellular polymeric substances (EPS) from anaerobic granular sludges: comparison of chemical and physical extraction protocols

    OpenAIRE

    Abzac, D', P.; Bordas, F; Van Hullebusch, E.; Lens, P. N. L.; Guibaud, G.

    2010-01-01

    The characteristics of the extracellular polymeric substances (EPS) extracted with nine different extraction protocols from four different types of anaerobic granular sludge were studied. The efficiency of four physical (sonication, heating, cationic exchange resin (CER), and CER associated with sonication) and four chemical (ethylenediaminetetraacetic acid, ethanol, formaldehyde combined with heating, or NaOH) EPS extraction methods was compared to a control extraction protocols (i.e., centr...

  18. Removal of steroid estrogens from municipal wastewater in a pilot scale expanded granular sludge blanket reactor and anaerobic membrane bioreactor.

    Science.gov (United States)

    Ito, Ayumi; Mensah, Lawson; Cartmell, Elise; Lester, John N

    2016-01-01

    Anaerobic treatment of municipal wastewater offers the prospect of a new paradigm by reducing aeration costs and minimizing sludge production. It has been successfully applied in warm climates, but does not always achieve the desired outcomes in temperate climates at the biochemical oxygen demand (BOD) values of municipal crude wastewater. Recently the concept of 'fortification' has been proposed to increase organic strength and has been demonstrated at the laboratory and pilot scale treating municipal wastewater at temperatures of 10-17°C. The process treats a proportion of the flow anaerobically by combining it with primary sludge from the residual flow and then polishing it to a high effluent standard aerobically. Energy consumption is reduced as is sludge production. However, no new treatment process is viable if it only addresses the problems of traditional pollutants (suspended solids - SS, BOD, nitrogen - N and phosphorus - P); it must also treat hazardous substances. This study compared three potential municipal anaerobic treatment regimes, crude wastewater in an expanded granular sludge blanket (EGSB) reactor, fortified crude wastewater in an EGSB and crude wastewater in an anaerobic membrane bioreactor. The benefits of fortification were demonstrated for the removal of SS, BOD, N and P. These three systems were further challenged with the removal of steroid estrogens at environmental concentrations from natural indigenous sources. All three systems removed these compounds to a significant degree, confirming that estrogen removal is not restricted to highly aerobic autotrophs, or aerobic heterotrophs, but is also a faculty of anaerobic bacteria. PMID:26212345

  19. The integration of methanogenesis with denitrification and anaerobic ammonium oxidation in an expanded granular sludge bed reactor

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The integration of methanogenesis with denitrification and anaerobic ammonium oxidation(ANAMMOX) was studied in an expanded granular sludge bed(EGSB) reactor in this work. Experimental results from the continuous treatment of wastewater with nitrite and ammonium, which lasted for 107 days, demonstrated that wastewater with high nitrite and ammonium could be anaerobically treated in an expanded granular sludge bed reactor. More than 91% to 97% of COD were removed at up to about 3.9 g COD/(L@d) of COD volumetric loading rate. More than 97% to 100% of nitrite was denitrified at up to about 0.8g NO2-N/(L@d), which is 16 times higher than that in a conventional activated sludge system with nitrification/denitrification(0.05g N/((L@d). No dissimilatory reduction of nitrite to ammonium occurred in the process. However, maximum of about 40% ammonium was found to be lost. Batch tests of 15 days with sludge from the reactor showed that 100% of nitrite was denitrified completely, and about 3% of ammonium was removed when only ammonium (34.3 mg/L) and nitrite(34.3 mg/L) were added into the sludge suspension medium. Furthermore, about 15% of ammonium amounts were lost with organic COD addition. It suggested that the methanogenesis in the system could enhance ANAMMOX because of intermediate hydrogen produced during methanogenesis.

  20. Identical full-scale biogas-lift reactors (Blrs) with anaerobic granular sludge and residual activated sludge for brewery wastewater treatment and kinetic modeling.

    Science.gov (United States)

    Xu, Fu; Huang, Zhenxing; Miao, Hengfeng; Ren, Hongyan; Zhao, Mingxing; Ruan, Wenquan

    2013-10-01

    Two identical full-scale biogas-lift reactors treating brewery wastewater were inoculated with different types of sludge to compare their operational conditions, sludge characteristics, and kinetic models at a mesophilic temperature. One reactor (R1) started up with anaerobic granular sludge in 12 weeks and obtained a continuously average organic loading rate (OLR) of 7.4 kg chemical oxygen demand (COD)/(m3 x day), COD removal efficiency of 80%, and effluent COD of 450 mg/L. The other reactor (R2) started up with residual activated sludge in 30 weeks and granulation accomplished when the reactor reached an average OLR of 8.3 kg COD/(m3 x day), COD removal efficiency of 90%, and effluent COD of 240 mg/L. Differences in sludge characteristics, biogas compositions, and biogas-lift processes may be accounted for the superior efficiency of the treatment performance of R2 over R1. Grau second-order and modified StoverKincannon models based on influent and effluent concentrations as well as hydraulic retention time were successfully used to develop kinetic parameters of the experimental data with high correlation coefficients (R2 > 0.95), which further showed that R2 had higher treatment performance than R1. These results demonstrated that residual activated sludge could be used effectively instead of anaerobic granular sludge despite the need for a longer time. PMID:24494489

  1. Metal supplementation to anaerobic granular sludge bed reactors: an environmental engineering approach

    NARCIS (Netherlands)

    Gonzalez Fermoso, F.

    2008-01-01

    The objective of this research is the optimization of essential metal dosing in upflow anaerobic sludge bed (UASB) reactors used for methanogenic wastewater treatment. Optimization of essential metal dosing in UASB reactors is a compromise between achieving the maximal biological activity of the bio

  2. Detection, phylogeny and population dynamics of syntrophic propionate-oxidizing bacteria in anaerobic granular sludge.

    OpenAIRE

    Harmsen, H. J. M.

    1996-01-01

    The research described this thesis concerns the diversity and phylogeny of syntrophic propionate-oxidizing bacteria and their ecology in granular sludge, from which they were obtained. 16S rRNA was used as a molecular marker to study both the phylogeny and the ecology of these bacteria. Sequence analysis of the 16S rRNA gave information on the phylogeny of the syntrophic bacteria, while specific oligonucleotide probes based on these sequences enabled quantification and detection of these bact...

  3. Effects of Metal Nanoparticles on Methane Production from Waste-Activated Sludge and Microorganism Community Shift in Anaerobic Granular Sludge

    Science.gov (United States)

    Wang, Tao; Zhang, Dong; Dai, Lingling; Chen, Yinguang; Dai, Xiaohu

    2016-05-01

    Extensive use of nanoparticles (NPs) in consumer and industrial products has led to concerns about their potential environmental impacts; however, the influences of different NPs (e.g., nZVI (nano zero-valent iron), Ag NPs, Fe2O3 NPs and MgO NPs) on the anaerobic digestion of sludge have not yet been studied in depth. Additionally, a new guideline or the use of different NPs in the anaerobic digestion of sludge should be established to improve the anaerobic digestion of sludge and avoid inhibitory effects. This study investigated the effects of four representative NPs (i.e., nZVI, Ag NPs, Fe2O3 NPs and MgO NPs) on methane production during the anaerobic digestion of waste activated sludge (WAS). The presence of 10 mg/g total suspended solids (TSS) nZVI and 100 mg/g TSS Fe2O3 NPs increased methane production to 120% and 117% of the control, respectively, whereas 500 mg/g TSS Ag NPs and 500 mg/g TSS MgO NPs generated lower levels of methane production (73.52% and 1.08% that of the control, respectively). These results showed that low concentrations of nZVI and Fe2O3 NPs promoted the amount of microbes (Bacteria and Archaea) and activities of key enzymes but that higher concentrations of Ag NPs and MgO NPs inhibited them.

  4. Effects of Metal Nanoparticles on Methane Production from Waste-Activated Sludge and Microorganism Community Shift in Anaerobic Granular Sludge.

    Science.gov (United States)

    Wang, Tao; Zhang, Dong; Dai, Lingling; Chen, Yinguang; Dai, Xiaohu

    2016-01-01

    Extensive use of nanoparticles (NPs) in consumer and industrial products has led to concerns about their potential environmental impacts; however, the influences of different NPs (e.g., nZVI (nano zero-valent iron), Ag NPs, Fe2O3 NPs and MgO NPs) on the anaerobic digestion of sludge have not yet been studied in depth. Additionally, a new guideline or the use of different NPs in the anaerobic digestion of sludge should be established to improve the anaerobic digestion of sludge and avoid inhibitory effects. This study investigated the effects of four representative NPs (i.e., nZVI, Ag NPs, Fe2O3 NPs and MgO NPs) on methane production during the anaerobic digestion of waste activated sludge (WAS). The presence of 10 mg/g total suspended solids (TSS) nZVI and 100 mg/g TSS Fe2O3 NPs increased methane production to 120% and 117% of the control, respectively, whereas 500 mg/g TSS Ag NPs and 500 mg/g TSS MgO NPs generated lower levels of methane production (73.52% and 1.08% that of the control, respectively). These results showed that low concentrations of nZVI and Fe2O3 NPs promoted the amount of microbes (Bacteria and Archaea) and activities of key enzymes but that higher concentrations of Ag NPs and MgO NPs inhibited them. PMID:27166174

  5. Effects of extraction procedures on metal binding properties of extracellular polymeric substances (EPS) from anaerobic granular sludges.

    Science.gov (United States)

    d'Abzac, Paul; Bordas, François; van Hullebusch, Eric; Lens, Piet N L; Guibaud, Gilles

    2010-10-15

    The effects of the extraction procedure of extracellular polymeric substances (EPS) on their proton/metal binding properties were studied. Nine extraction procedures (one control, four physical and four chemical procedures) were applied to four types of anaerobic granular sludges. The binding capacities between the EPS and lead or cadmium were investigated at pH 7 by a polarographic method. The composition of the EPS extracts varied according to the extraction technique and the origin of the sludge. This induced differences in the pK(a)s and the binding sites density of the EPS extracts. The carry-over of the extractant in the samples strongly affects the properties of the EPS from chemical extraction protocols. Lead and cadmium seem to be bound differently with the EPS, a higher binding capacity was observed for Pb(2+) than for Cd(2+). PMID:20580210

  6. Anaerobic granular sludge as a biocatalyst for 1,3-propanediol production from glycerol in continuous bioreactors

    OpenAIRE

    Gallardo, R.; Faria, Cristiana; Rodrigues, L. R.; Alves, M. M.

    2015-01-01

    1,3-propanediol (1,3-PDO) was produced from glycerol in three parallel Expanded Granular Sludge Blanket (EGSB) reactors inoculated with granular sludge (control reactor-R1), heat-treated granular sludge (R2) and disrupted granular sludge (R3) at Hydraulic Retention Times (HRT) between 3 and 24 h. Maximum 1,3-PDO yield (0.52 mol mol-1) and productivity (57 g L-1 d-1) were achieved in R1 at HRTs of 12 h and 3 h, respectively. DGGE profiling of PCR-amplified 16S rRNA gene fragments showed that v...

  7. Anaerobic granular sludge as a biocatalyst for 1,3-propanediol production from glycerol in continuous bioreactors

    OpenAIRE

    Gallardo, R.; Faria, Cristiana; Rodrigues, L. R.; Pereira, M. A.; Alves, M. M.

    2014-01-01

    1,3-propanediol (1,3-PDO) was produced from glycerol in three parallel Expanded Granular Sludge Blanket (EGSB) reactors inoculated with granular sludge (control reactor-R1), heat-treated granular sludge (R2) and disrupted granular sludge (R3) at Hydraulic Retention Times (HRT) between 3 and 24 h. Maximum 1,3-PDO yield (0.52 mol mol-1) and productivity (57 g L-1 d-1) were achieved in R1 at HRTs of 12 h and 3 h, respectively. DGGE profiling of PCR-amplified 16S rRNA gene fragments showed that v...

  8. Morphology and physiology of anaerobic granular sludge exposed to an organic solvent

    International Nuclear Information System (INIS)

    The use of quantitative image analysis techniques, together with physiological information might be used to monitor and detect operational problems in advance to reactor performance failure. Industrial organic solvents, such as White Spirit, are potentially harmful to granular sludge. In preliminary batch assays, 33 mg L-1 of solvent caused 50% relative biomass activity loss. In an expanded granular sludge blanket reactor fed with 40 mg L-1 of solvent, during 222 h, the reactor performance seemed to be unaffected, presenting COD removal efficiency consistently >95%. However, in the last days of exposure, the biogas production and the methane content were inhibited. Afterwards, already during recovery phase, the COD removal efficiency decreased to 33%, probably because the reactor was underloaded and the biomass became saturated in solvent only at this stage. In the first hours of exposure the specific acetoclastic and the specific hydrogenotrophic methanogenic activities decreased 29% and 21%, respectively. The % of aggregates projected area with equivalent diameter (Deq) > 1 mm decreased from 81% to 53%. The mean Deq of the aggregates ≥0.2 mm decreased, as well as the settling velocity, showing that the granules experienced fragmentation phenomenon caused by the solvent shock load. The ratio between total filaments length and total aggregates projected area (LfA) increased 2 days before effluent volatile suspended solids, suggesting that LfA could be an early-warning indicator of washout events.

  9. Application of Novel Amino-Functionalized NZVI@SiO2 Nanoparticles to Enhance Anaerobic Granular Sludge Removal of 2,4,6-Trichlorophenol

    Directory of Open Access Journals (Sweden)

    Zeyu Guan

    2015-01-01

    Full Text Available A novel amino-functionalized silica-coated nanoscale zerovalent iron (NZVI@SiO2-NH2 was successfully synthesized by using one-step liquid-phase method with the surface functionalization of nanoscale zerovalent iron (NZVI to enhance degradation of chlorinated organic contaminants from anaerobic microbial system. NZVI@SiO2-NH2 nanoparticles were synthesized under optimal conditions with the uniform core-shell structure (80–100 nm, high loading of amino functionality (~0.9 wt%, and relatively large specific surface area (126.3 m2/g. The result demonstrated that well-dispersed NZVI@SiO2-NH2 nanoparticle with nFe0-core and amino-functional silicon shell can effectively remove 2,4,6-trichlorophenol (2,4,6-TCP in the neutral condition, much higher than that of NZVI. Besides, the surface-modified nanoparticles (NZVI@SiO2-NH2 in anaerobic granule sludge system also showed a positive effect to promote anaerobic biodechlorination system. More than 94.6% of 2,4,6-TCP was removed from the combined NZVI@SiO2-NH2-anaerobic granular sludge system during the anaerobic dechlorination processes. Moreover, adding the appropriate concentration of NZVI@SiO2-NH2 in anaerobic granular sludge treatment system can decrease the toxicity of 2,4,6-TCP to anaerobic microorganisms and improved the cumulative amount of methane production and electron transport system activity. The results from this study clearly demonstrated that the NZVI@SiO2-NH2/anaerobic granular sludge system could become an effective and promising technology for the removal of chlorophenols in industrial wastewater.

  10. Feasibility of expanded granular sludge bed reactors for the anaerobic treatment of low-strength soluble wastewaters.

    Science.gov (United States)

    Kato, M T; Field, J A; Versteeg, P; Lettinga, G

    1994-08-01

    The application of the expanded granular sludge bed (EGSB) reactor for the anaerobic treatment of low-strength soluble wastewaters using ethanol as a model substrate was investigated in laboratory-scale reactors at 30oC. Chemical oxygen demand (COD) removal efficiency was above 80% at organic loading rates up to12 g COD/L . d with influent concentrations as low as 100 to 200 mg COD/L. These results demonstrate the suitability of the EGBS reactor for the anaerobic treatment of low-strength wastewaters. The high treatment performance can be attributed to the intense mixing regime obtained by high hydraulic and organic loads. Good mixing of the bulk liquid phase for the substrate-biomass contact and adequate expansion of the substrate-biomass contact and adequate expansion of the sludge bed for the degassing were obtained when the liquid upflow velocity (V(up)) was greater than 2.5 m/h. Under such conditions, an extremely low apparent K(s) value for acetoclastic methanogenesis of 9.8 mg COD/L was observed. The presence of dissolved oxygen in the wastewater had no detrimental effect on the treatment performance. Sludge piston flotation from pockets of biogas accumulating under the sludge bed occurred at V(up) lower than 2.5 m/h due to poor bed expansion. This problem is expected only in small diameter laboratory-scale reactors. A. more important restriction of the EGSB reactor was the sludge washout occurring at V(up) higher than 5.5 m/h and which was intensified at organic loads higher than 7 g COD/L. d due to buoyancy forces from the gas production. To achieve an equilibrium between the mixing intensity and the sludge hold-up, the operation should be limited to an organic loading rate of 7 g COD/L d. and to a liquid up-flow velocity between 2.5 and 5.5 m/h (c) 1994 John Wiley & Sons, Inc. PMID:18618781

  11. Effect of Ce(3+) on soluble microbial products production in anaerobic granular sludge digestion.

    Science.gov (United States)

    Fu, Bo; Liang, Rui; Xia, Qing; Ding, Lili; Xu, Ke; Ren, Hongqiang

    2011-01-01

    Upflow anaerobic sludge bed reactors fed on glucose were used to investigate the effects of Ce(3+) on soluble microbial products (SMP) production, which is the majority of the residual chemical oxygen demand present in the effluent. It was found that Ce(3+) concentration of 0.05 mg/L had no significant effect on the amount of SMP production, whereas that of 1 mg/L led to the increase in SMP production. The molecular-weight distribution and carbohydrate analysis indicated that an increase in SMP production may be partly attributed to the release of extracellular polymeric substances (EPS) into the bulk solution resulted from cerium toxicity, and the nucleic acids analysis suggested that increased cell lysis also contributed to SMP accumulation in the presence of Ce(3+). The increase in SMP production in the presence of Ce(3+) is possibly a consequence of the release of EPS and increased cell lysis due to cerium toxicity. PMID:22179643

  12. Performance of Anammox granular sludge bed reactor started up with nitrifying granular sludge

    Institute of Scientific and Technical Information of China (English)

    ZHENG Ping; LIN Feng-mei; HU Bao-lan; CHEN Jian-song

    2004-01-01

    The anaerobic ammonia oxidation(Anammox) granular sludge bed reactor was started up successfully withnitrifying granular sludge. During the operation, the nitrifying granular sludge was gradually converted into Anammoxgranular sludge with good settling property and high conversion activity. The Anammox reactor worked well with theshortest HRT of 2.43 h. Under the condition that HRT was 6.39 h and influent concentration of ammonia and nitritewas 10 mmol/L, the removal of ammonia and nitrite was 97.17% and 100.00%, respectively. Corresponding

  13. Anaerobic biodegradability of mixtures of pesticides in an expanded granular sludge bed reactor.

    Science.gov (United States)

    Monsalvo, V M; Garcia-Mancha, N; Puyol, D; Mohedano, A F; Rodriguez, J J

    2014-01-01

    The biodegradability and toxicity of three commercial pesticides containing 2-methyl-4-chlorophenoxyacetic acid (MCPA), imidacloprid and dimethoate were evaluated individually, and a complex mixture of these pesticides was treated in an expanded granular sludge bed (EGSB) reactor. MCPA was partially biodegraded, while imidacloprid and dimethoate remained almost unaltered during the individual biodegradability tests. Cyclohexanone was identified as the major solvent in the dimethoate-bearing insecticide, which was completely removed regardless of the presence of other pesticides. The analysis of the inhibition over the acetoclastic methanogenesis showed IC(50) (half maximal inhibitory concentration) values of 474 and 367 mg/L for imidacloprid and dimethoate, respectively. The effect on the methanogenesis was negligible in the case of MCPA and cyclohexanone. Pesticides caused a dramatic decrease of the EGSB reactor performance. After 30 d acclimation, the EGSB reactor achieved a stable chemical oxygen demand (COD) removal efficiency and methane production of around 85% and 0.9 g CH(4)-COD/g COD, respectively, for MCPA, imidacloprid, dimethoate and cyclohexanone feed concentrations of 57, 20, 25 and 27 mg/L, respectively. The presence of complex pesticide mixtures led to synergistic/antagonistic responses, reducing the MCPA biodegradation and improving the removal of the insecticides' active ingredients, which were completely removed in the EGSB reactor. PMID:24552724

  14. Calculation of energy recovery and greenhouse gas emission reduction from palm oil mill effluent treatment by an anaerobic granular-sludge process.

    Science.gov (United States)

    Show, K Y; Ng, C A; Faiza, A R; Wong, L P; Wong, L Y

    2011-01-01

    Conventional aerobic and low-rate anaerobic processes such as pond and open-tank systems have been widely used in wastewater treatment. In order to improve treatment efficacy and to avoid greenhouse gas emissions, conventional treatment can be upgraded to a high performance anaerobic granular-sludge system. The anaerobic granular-sludge systems are designed to capture the biogas produced, rendering a potential for claims of carbon credits under the Kyoto Protocol for reducing emissions of greenhouse gases. Certified Emission Reductions (CERs) would be issued, which can be exchanged between businesses or bought and sold in international markets at the prevailing market prices. As the advanced anaerobic granular systems are capable of handling high organic loadings concomitant with high strength wastewater and short hydraulic retention time, they render more carbon credits than other conventional anaerobic systems. In addition to efficient waste degradation, the carbon credits can be used to generate revenue and to finance the project. This paper presents a scenario on emission avoidance based on a methane recovery and utilization project. An example analysis on emission reduction and an overview of the global emission market are also outlined. PMID:22170839

  15. Study on the Characteristics of Anaerobic Granular Sludge by Internal Circulation Anaerobic Reactor%内循环厌氧反应器厌氧颗粒污泥的特性研究

    Institute of Scientific and Technical Information of China (English)

    王英

    2015-01-01

    Anaerobic granular sludge anaerobic reactor is the basis and key to the efficient and stable operation.This paper presents an improved internal circulation anaerobic reactor,to overcome the traditional internal circulation anaerobic reactor complex structure,easy to cause blockage and other shortcomings.To study the characteristics of anaerobic granular sludge,the study on the characteristics of anaerobic granular sludge to the production practice has important guiding significance.This experimental research is circulate in the modified on the basis of the stable operation of anaerobic reactor,particle size distribution of granular sludge,sludge methane-producing activity and DGGE analysis.%厌氧颗粒污泥是厌氧反应器高效稳定运行的基础和关键。试验研究利用了一种改进型的内循环厌氧反应器,克服了传统内循环厌氧反应器结构复杂易引起堵塞等缺点,对厌氧颗粒污泥的特性进行研究,研究厌氧颗粒污泥的特性对生产实践具有重要的指导意义。该试验研究是在改进型内循环厌氧反应器稳定运行的基础上,对颗粒污泥的粒径分布、污泥产甲烷活性、DGGE 等特性进行分析。

  16. Anaerobic sludge granulation

    NARCIS (Netherlands)

    Hulshoff Pol, L.W.; Castro Lopes, de S.I.; Lettinga, G.; Lens, P.N.L.

    2004-01-01

    This paper reviews different theories on anaerobic sludge granulation in UASB-reactors that have been proposed during the past two decades
    This paper reviews different theories on anaerobic sludge granulation in UASB-reactors that have been proposed during the past two decades. The initial stage

  17. Trace metal dynamics in methanol fed anaerobic granular sludge bed reactors

    NARCIS (Netherlands)

    Zandvoort, M.H.

    2005-01-01

    Trace metals are essential for anaerobic microorganisms, because they are present as cofactor in many of their enzymes. Therefore anaerobic wastewater treatment systems using these microorganisms to perform biological conversions are dependent on these metals for their (optimal) performance. In prac

  18. Effective anaerobic biodegradation of municipal solid waste fresh leachate using a novel pilot-scale reactor: comparison under different seeding granular sludge.

    Science.gov (United States)

    Luo, Jinghuan; Zhou, Jizhi; Qian, Guangren; Liu, Jianyong

    2014-08-01

    A novel integrated internal and external circulation (IIEC) reactor was developed for anaerobic biodegradation of municipal solid waste (MSW) fresh leachate with chemical oxygen demand (COD) between 40,000 and 60,000mg/l. The pilot-scale IIEC reactor was inoculated with two kinds of granular sludge from paper mill (SPM) and from citric acid factory (SCF), respectively. The bio-treating capacity in contaminant removal and biogas production performed much superior to others' results, principally attributed to appropriate configuration modification. Compared to SCF, much higher organic loading rate (40.5 vs 23.0kgCOD/m(3)d) and COD removal efficiency (>80% vs 60-75%) were achieved for the reactor with SPM. For methane production, 11.77 or ∼6m(3)STP/m(3)d of rate and 66-85% of content were observed with SPM or SCF, respectively. Due to better sludge concentrations and methanogenic activity, these findings indicate the anaerobic reactor could effectively bio-treat MSW leachate for methane generation, especially inoculated with granular sludge derived from leachate-like-wastewater. PMID:24755395

  19. Anaerobic fermentation combined with low-temperature thermal pretreatment for phosphorus-accumulating granular sludge: Release of carbon source and phosphorus as well as hydrogen production potential.

    Science.gov (United States)

    Zou, Jinte; Li, Yongmei

    2016-10-01

    Releases of organic compounds and phosphorus from phosphorus-accumulating granular sludge (PGS) and phosphorus-accumulating flocculent sludge (PFS) during low-temperature thermal pretreatment and anaerobic fermentation were investigated. Meanwhile, biogas production potential and microbial community structures were explored. The results indicate that much more soluble chemical oxygen demand (SCOD) and phosphorus were released from PGS than from PFS via low-temperature thermal pretreatment because of the higher extracellular polymeric substances (EPS) content in PGS and higher ratio of phosphorus reserved in EPS. Furthermore, PGS contains more anaerobes and dead cells, resulting in much higher SCOD and volatile fatty acids release from PGS than those from PFS during fermentation. PGS fermentation facilitated the n-butyric acid production, and PGS exhibited the hydrogen production potential during fermentation due to the presence of hydrogen-producing bacteria. Therefore, anaerobic fermentation combined with low-temperature thermal pretreatment can facilitate the recovery of carbon and phosphorus as well as producing hydrogen from PGS. PMID:27344244

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

    KAUST Repository

    Fermoso, Fernando G.

    2010-07-01

    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 operation was compared to that of another cobalt depleted UASB reactor to which a pulse of CoCl2 was given. The addition of cobalt in the form of CoCl2 supplies enough cobalt to restore methanogenesis and maintain full methanol degradation coupled to methane production during more than 35 days after the CoCl2 pulse. Similar to CoCl2, pulse addition of vitamin B12 supplies enough cobalt to maintain full methanol degradation during more than 35 days after the pulse. However, the specific methanogenic activities (SMAs) of the sludge in the vitamin B12 supplied reactor were around 3 times higher than the SMA of the sludge from the CoCl2 supplied reactor at the same sampling times. An appropriate dosing strategy (repeated pulse dosing) combined with the choice of vitamin B12 as the cobalt species is suggested as a promising dosing strategy for methanol-fed anaerobic bioreactors limited by the micronutrient cobalt. © 2010 Elsevier Ltd. All rights reserved.

  1. Formation of the Phosphorus Removal Granular Sludge and Phosphorus Removal Characteristics of the Anaerobic/Oxic and Anaerobic/Anoxic/Oxic Granular Sludge Process in SBR%SBR中除磷颗粒污泥的培养和A/O及A/A/O颗粒污泥工艺除磷特性研究

    Institute of Scientific and Technical Information of China (English)

    刘小英; 姜应和; 郭超; 彭党聪

    2009-01-01

    Phosphorous removal & denitrifying phosphate uptake of the granular sludge was investigated in this study. Inoculated with flocculation sludge, the granulation of the biological phosphorous removal sludge was realized in a sequencing batch reactor (SBR) fed with sodium acetate by means of hydraulic selection under an anaerobic/oxic alternating operation (referred to as an A/O) . Then the biological phosphorous removal granular sludge was induced into the denitrifying phosphate uptake granular sludge under an anaerobic/anoxic/oxic alternating operation (referred to as an A/A/O). The properties of the two kinds of granular sludge were studied. The biological phosphorus removal granular sludge was completed on the 82nd day. The biological phosphorus removal granule sludge showed some characteristics, e. g. pallideflavens in color, 0.5-1.5 mm in diameter, 20-30 m/h in settling velocity, 94% in water content, 1.043 9 in specific gravity, and below 50 mL/g in SVI. The max. specific release phosphorus rate (SRPR) , the max. specific uptake phosphorus rate (SUPR) and the phosphorus content of the MLSS (TP/SS) was 67.7 mg/(g·h) , 43.2 mg/(g·h) and 6.5% respectively on the 437 th day. On the 448th day the operation of the reactor was changed into A/A/O. The max. SRPR, the max. anoxic SUPR and the TP/SS of the denitrifying phosphate uptake granular sludge was 30 mg/(g·h), 27.9 mg/(g·h) and 6.3% respectively on the 653rd day. The two kinds of granular sludge had potential to carry out phosphorus removal.%以絮状活性污泥为接种污泥,乙酸钠为碳源,在SBR反应器内采用水力筛选的方法进行生物除磷颗粒污泥培养,然后诱导为反硝化聚磷颗粒污泥,探讨2种颗粒污泥除磷特性.结果表明,在厌氧/好氧(A/O)交替运行条件下,82d后培养出生物除磷颗粒污泥,污泥颜色呈淡黄色,粒径为0.5~1.5 mm,沉速为20~30 m/h,含水率为94%,密度为1.043 9,SVI在50 mL/g以下;437d时污泥

  2. Effect of heterogeneous Fenton-like pre-treatment on anaerobic granular sludge performance and microbial community for the treatment of traditional Chinese medicine wastewater.

    Science.gov (United States)

    Su, Chengyuan; Li, Weiguang; Lu, Yuxiang; Chen, Menglin; Huang, Zhi

    2016-08-15

    The effect of a heterogeneous Fenton-like pre-treatment on the anaerobic processes, characteristics and microbial community of sludge was investigated for traditional Chinese medicine (TCM) wastewater containing rhein. When the concentrations of rhein were 50mg/L and 100mg/L, the toxic effect was physiological toxicity for anaerobic granular sludge. Using a single double circle (DC) reactor for the treatment of TCM wastewater containing rhein at concentrations of 15-20mg/L, the chemical oxygen demand (COD) removal rate was 69%, and coenzyme F420 was nearly undetectable in the 3D-excitation-emission matrix (EEM) spectra of soluble microbial products (SMP). The abundances of Methanoregula, Methanobacterium, Methanosphaerula were only 5.57%, 2.39% and 1.08% in the DC reactor, respectively. TCM wastewater containing rhein could be successfully treated by the combination of the heterogeneous Fenton-like pre-treatment and the DC reactor processes, and the COD removal rate reached 95%. Meanwhile, the abundances of Methanoregula, Methanobacterium, Methanosphaerula increased to 22.5%, 18.5%, and 13.87%, respectively. For the bacterial community, the abundance of Acidobacteria_Gp6 decreased from 6.99% to 1.07%, while the abundances of Acidobacteria_Gp1 and Acidobacteria_Gp2 increased from 1.61% to 6.55% and from 1.28% to 5.87%, respectively. PMID:27107235

  3. Methanospirillum stamsii sp. nov., a psychrotolerant, hydrogenotrophic, methanogenic archaeon isolated from an anaerobic expanded granular sludge bed bioreactor operated at low temperature.

    Science.gov (United States)

    Parshina, Sofiya N; Ermakova, Anna V; Bomberg, Malin; Detkova, Ekaterina N

    2014-01-01

    A psychrotolerant hydrogenotrophic methanogen, strain Pt1, was isolated from a syntrophic propionate-oxidizing methanogenic consortium obtained from granulated biomass of a two-stage low-temperature (3-8 °C) anaerobic expanded granular sludge bed (EGSB) bioreactor, fed with a mixture of volatile fatty acids (VFAs) (acetate, propionate and butyrate). The strain was strictly anaerobic, and cells were curved rods, 0.4-0.5×7.5-25 µm, that sometimes formed wavy filaments from 25 to several hundred micrometres in length. Cells stained Gram-negative and were non-sporulating. They were gently motile by means of tufted flagella. The strain grew at 5-37 °C (optimum at 20-30 °C), at pH 6.0-10 (optimum 7.0-7.5) and with 0-0.3 M NaCl (optimum 0 M NaCl). Growth and methane production was found with H2/CO2 and very weak growth with formate. Acetate and yeast extract stimulated growth, but were not essential. The G+C content of the DNA of strain Pt1 was 40 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain Pt1 was a member of the genus Methanospirillum and showed 97.5 % sequence similarity to Methanospirillum hungatei JF1(T) and 94 % sequence similarity to Methanospirillum lacunae Ki8-1(T). DNA-DNA hybridization of strain Pt1 with Methanospirillum hungatei JF1(T) revealed 39 % relatedness. On the basis of its phenotypic characteristics and phylogenetic position, strain Pt1 is a representative of a novel species of the genus Methanospirillum, for which the name Methanospirillum stamsii sp. nov. is proposed. The type strain is Pt1(T) ( = DSM 26304(T) = VKM B-2808(T)). PMID:24048867

  4. 4-氯酚对厌氧颗粒污泥产甲烷活性的影响%Influence of 4-chlorophenol on activity of methane-producing microorganisms in anaerobic granular sludge

    Institute of Scientific and Technical Information of China (English)

    罗艳; 何仕均; 王建龙; 解明曙

    2012-01-01

    With anaerobic granular sludge from an anaerobic baffled reactor(ABR) as the research object and glucose as the co-substrate, the influence of 4-chlorophenol concentration on the methane-producing microorganisms in anaerobic granular sludge was investigated. The test results showed that: 4-chlorophenol had a strong inhibition effect on the activity of methane-producing microorganisms in anaerobic granular sludge, the slightest degree of inhibition appeared when the mass concentration of 4-chlorophenol was 300 mg/L; and then, with the continuous increase of the 4-chlorophenol concentration, the methane-producing activity of anaerobic granular sludge decreased obviously; when it increased to 400, 500 and 600 mg/L, the inhibition rate were 31%, 68% and 54% respectively. The inhibition effect of 4-chlorophenol on the anaerobic biological degradation of glucose happened in the later stage of the reaction when the concentration was low, and in the early stage of the reaction when the concentration was high. In the recovery test carried out simultaneously, the inhibition effect of 4-chlorophenol with different concentrations on the production of methane was still exist; however, the inhibition degree was decreased.%利用取自ABR反应器的厌氧颗粒污泥,以葡萄糖为共基质,测定了不同浓度4-氯酚对厌氧污泥产甲烷微生物的影响以及活性恢复情况.试验结果表明:4-氯酚对厌氧颗粒污泥产甲烷活性具有较强的抑制作用,当4-氯酚的质量浓度为300 mg/L时,抑制作用最小;并且随着4-氯酚浓度的继续提高,厌氧颗粒污泥的产甲烷活性显著下降.当4-氯酚的质量浓度为400、500、600 mg/L时,相应的抑制程度为31%、68%、54%.4-氯酚对厌氧生物降解葡萄糖反应的抑制作用,在低浓度时发生在反应后期,高浓度时发生在反应初期.同时在恢复试验中不同浓度的4-氯酚对产甲烷的抑制作用仍存在,但有所降低.

  5. Structure and stability of methanogenic granular sludge.

    NARCIS (Netherlands)

    Grotenhuis, J.T.C.

    1992-01-01

    Immobilization of anaerobic bacteria was essential for the development of high rate anaerobic systems for the treatment of waste waters. The most widely applied anaerobic reactor type in which solids retention time is uncoupled from the hydraulic retention time is the Upflow Anaerobic Sludge Blanket

  6. Effect of sludge age on methanogenic and glycogen accumulating organisms in an aerobic granular sludge process fed with methanol and acetate

    OpenAIRE

    Pronk, M; Abbas, B.; Kleerebezem, R.; M. C. M. van Loosdrecht

    2015-01-01

    The influence of sludge age on granular sludge formation and microbial population dynamics in a methanol- and acetate-fed aerobic granular sludge system operated at 35°C was investigated. During anaerobic feeding of the reactor, methanol was initially converted to methane by methylotrophic methanogens. These methanogens were able to withstand the relatively long aeration periods. Lowering the anaerobic solid retention time (SRT) from 17 to 8 days enabled selective removal of the methanogens a...

  7. Enhanced selection of micro-aerobic pentachlorophenol degrading granular sludge

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Yuancai, E-mail: donkey1204@hotmail.com [State Key Laboratory of Pulp and Paper Engineering, College of Light Industry and Food Science, South China University of Technology, Guangzhou 510640 (China); Chen, Yuancai, E-mail: chenyc@scut.edu.cn [State Key Laboratory of Pulp and Paper Engineering, College of Light Industry and Food Science, South China University of Technology, Guangzhou 510640 (China); Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); Song, Wenzhe, E-mail: songwenzhe007@126.com [Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); Hu, Yongyou, E-mail: ppyyhu@scut.edu.cn [State Key Laboratory of Pulp and Paper Engineering, College of Light Industry and Food Science, South China University of Technology, Guangzhou 510640 (China); Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou 510006 (China)

    2014-09-15

    Graphical abstract: In this work, an aerobic column reactor was placed before the USB to maintain micro-oxygen condition in the reactor and the micro-aerobic pentachlorophenol (PCP) degrading granular sludge under oxygen-limited conditions (0.1–0.2 mg L{sup −1}) was successfully obtained. PCP degradation by the micro-aerobic system was studied and the variance of microbial community was also discussed by using PCR-DGGE analysis. - Highlights: • Micro-aerobic granular sludge was cultivated in column-type combined reactors. • PCP biodegradation, VFA accumulation and biogas production were studied. • The function of Methanogenic archaeon in the system was investigated. • Fluctuation and diversity of microbial community were discussed by DGGE analysis. • The dominated microorganisms were identified by 16S rDNA sequences. - Abstract: Column-type combined reactors were designed to cultivate micro-aerobic pentachlorophenol (PCP) degrading granular sludge under oxygen-limited conditions (0.1–0.2 mg L{sup −1}) over 39-day experimental period. Micro-aerobic granular had both anaerobic activity (SMA: 2.34 mMCH{sub 4}/h g VSS) and aerobic activity (SOUR: 2.21 mMO{sub 2}/h g VSS). Metabolite analysis results revealed that PCP was sequentially dechlorinated to TCP, DCP, and eventually to MCP. Methanogens were not directly involved in the dechlorination of PCP, but might played a vital role in stabilizing the overall structure of the granule sludge. For Eubacteria, the Shannon Index (2.09 in inoculated granular sludge) increased both in micro-aerobic granular sludge (2.61) and PCP-degradation granular sludge (2.55). However, for Archaea, it decreased from 2.53 to 1.85 and 1.84, respectively. Although the Shannon Index demonstrated slight difference between micro-aerobic granular sludge and PCP-degradation granular sludge, the Principal Component Analysis (PCA) indicated obvious variance of the microbial composition, revealing significant effect of micro

  8. Enhanced selection of micro-aerobic pentachlorophenol degrading granular sludge

    International Nuclear Information System (INIS)

    Graphical abstract: In this work, an aerobic column reactor was placed before the USB to maintain micro-oxygen condition in the reactor and the micro-aerobic pentachlorophenol (PCP) degrading granular sludge under oxygen-limited conditions (0.1–0.2 mg L−1) was successfully obtained. PCP degradation by the micro-aerobic system was studied and the variance of microbial community was also discussed by using PCR-DGGE analysis. - Highlights: • Micro-aerobic granular sludge was cultivated in column-type combined reactors. • PCP biodegradation, VFA accumulation and biogas production were studied. • The function of Methanogenic archaeon in the system was investigated. • Fluctuation and diversity of microbial community were discussed by DGGE analysis. • The dominated microorganisms were identified by 16S rDNA sequences. - Abstract: Column-type combined reactors were designed to cultivate micro-aerobic pentachlorophenol (PCP) degrading granular sludge under oxygen-limited conditions (0.1–0.2 mg L−1) over 39-day experimental period. Micro-aerobic granular had both anaerobic activity (SMA: 2.34 mMCH4/h g VSS) and aerobic activity (SOUR: 2.21 mMO2/h g VSS). Metabolite analysis results revealed that PCP was sequentially dechlorinated to TCP, DCP, and eventually to MCP. Methanogens were not directly involved in the dechlorination of PCP, but might played a vital role in stabilizing the overall structure of the granule sludge. For Eubacteria, the Shannon Index (2.09 in inoculated granular sludge) increased both in micro-aerobic granular sludge (2.61) and PCP-degradation granular sludge (2.55). However, for Archaea, it decreased from 2.53 to 1.85 and 1.84, respectively. Although the Shannon Index demonstrated slight difference between micro-aerobic granular sludge and PCP-degradation granular sludge, the Principal Component Analysis (PCA) indicated obvious variance of the microbial composition, revealing significant effect of micro-aerobic condition and PCP on

  9. 三氯乙烯厌氧降解颗粒污泥影响因素分析%Research on influencing factors of trichloroethylene (TCE) anaerobic degradation granular sludge

    Institute of Scientific and Technical Information of China (English)

    张颖; 刘洋; 李娟; 胡淼; 王薪

    2014-01-01

    Acclimation of trichloroethylene (TCE)-degrading anaerobic granular sludge was successful by using upflow anaerobic sludge blanket (UASB) reactor. The influences of temperature, pH and initial concentration of TCE on the degradation characteristics of TCE-degrading anaerobic granular sludge were investigated in serum bottles. The results showed that 35℃was the optimum temperature of the granular sludge, the degradation rate constant was 0.1879, the half-life was 3.69 d, and the TCE degradation rate was 90.15%; 7.2 was the optimum pH of granular sludge, the degradation rate constant was 0.1672, the half-life was 4.15 d, and the TCE degradation rate was 88.74%; Under the conditions of temperature of 35℃, pH of 7.2, and the TCE test concentration range from 14.6 to 73.0 mg·L-1, the smal er the initial TCE concentration was, the faster the degradation rate was; When TCE concentration was 73 mg·L-1, TCE-degrading anaerobic granular sludge stil had higher ability to degrade TCE. After 14 d, TCE could be effectively removed and the final TCE degradation rate was over 80%.%通过在上流式厌氧污泥床(UASB)反应器成功驯化TCE厌氧降解颗粒污泥,于小瓶中进行温度、pH和TCE浓度等对TCE厌氧降解颗粒污泥降解特性影响的试验研究。结果表明,35℃是颗粒污泥最适温度,降解速率常数为0.1879,半衰期为3.69 d,TCE降解率为90.15%;颗粒污泥最适pH为7.2,降解速率常数为0.1672,半衰期为4.15 d,TCE降解率为88.74%;在温度为35℃,pH 7.2条件下,试验浓度范围内(14.6~73.0 mg·L-1),TCE初始浓度越小,降解速率越快,降解率越大;当TCE浓度达到73 mg·L-1时,TCE厌氧降解颗粒污泥仍能以较高速率降解TCE,14 d后TCE均可被有效去除,最终降解率在80%以上。

  10. Effect and behaviour of different substrates in relation to the formation of aerobic granular sludge.

    Science.gov (United States)

    Pronk, M; Abbas, B; Al-Zuhairy, S H K; Kraan, R; Kleerebezem, R; van Loosdrecht, M C M

    2015-06-01

    When aerobic granular sludge is applied for industrial wastewater treatment, different soluble substrates can be present. For stable granular sludge formation on volatile fatty acids (e.g. acetate), production of storage polymers under anaerobic feeding conditions has been shown to be important. This prevents direct aerobic growth on readily available chemical oxygen demand (COD), which is thought to result in unstable granule formation. Here, we investigate the impact of acetate, methanol, butanol, propanol, propionaldehyde, and valeraldehyde on granular sludge formation at 35 °C. Methanogenic archaea, growing on methanol, were present in the aerobic granular sludge system. Methanol was completely converted to methane and carbon dioxide by the methanogenic archaeum Methanomethylovorans uponensis during the 1-h anaerobic feeding period, despite the relative high dissolved oxygen concentration (3.5 mg O2 L(-1)) during the subsequent 2-h aeration period. Propionaldehyde and valeraldehyde were fully disproportionated anaerobically into their corresponding carboxylic acids and alcohols. The organic acids produced were converted to storage polymers, while the alcohols (produced and from influent) were absorbed onto the granular sludge matrix and converted aerobically. Our observations show that easy biodegradable substrates not converted anaerobically into storage polymers could lead to unstable granular sludge formation. However, when the easy biodegradable COD is absorbed in the granules and/or when the substrate is converted by relatively slow growing bacteria in the aerobic period, stable granulation can occur. PMID:25616527

  11. 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

    DEFF Research Database (Denmark)

    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/g......VS-added. Anaerobic digestion of potato-juice in an EGSB reactor could obtain a methane yield of 380mL-CH4/gVS-added at the organic loading rate of 3.2gCOD/(L-reactor.d). In a UASB reactor, higher organic loading rate of 5.1gCOD/(L-reactor.d) could be tolerated, however, it resulted in a lower methane yield of 240m......L-CH4/gVS-added. The treatment of reactor effluent was also investigated. By acidification with sulfuric acid to pH lower than 5, almost 100% of the ammonia content in the effluent could be retained during the successive up-concentration process step. The reactor effluent could be up...

  12. Strategies for selectng [i.é selecting] hydrogen producing microorganisms affect micro and macro struture of granular sludge

    OpenAIRE

    Abreu, A. A.; Alves, J. I.; Pereira, M. A.; Sousa, D.Z.; Alves, M. M.

    2010-01-01

    Mixed-culture dark fermentation is an environmentally friendly bio-hydrogen production process. In this work we study the potential for directing microbial anaerobic mixed communities towards improved hydrogen production. Strategies applied for promoting the selection of hydrogen-producing bacteria in anaerobic granular sludge consisted of heat treatment and chemical treatment with 2-bromo-ethane sulfonate (BES) and with BES+Chloroform. Three expanded granular sludge bed reacto...

  13. DOWNFLOW GRANULAR FILTRATION OF ACTIVATED SLUDGE EFFLUENTS

    Science.gov (United States)

    The performance of downflow granular filters subjected to effluents from activated sludge processes was investigated at the EPA-DC Pilot Plant in Washington, D.C. Several media combinations were investigated, including both single anthracite and dual anthracite-sand configuration...

  14. Extracellular Polymeric Substances (EPS) in Upflow Anaerobic Sludge Blanket (UASB) Reactors Operated under High Salinity Conditions

    NARCIS (Netherlands)

    Ismail, S.; Parra, de la C.J.; Temmink, B.G.; Lier, van J.B.

    2010-01-01

    Considering the importance of stable and well–functioning granular sludge in anaerobic high rate reactors, a series of experiments were conducted to determine the production and composition of EPS in high sodium concentrations wastewaters pertaining to anaerobic granule properties. The UASB reactors

  15. [Physicochemical and ecological characteristics of the granular sludge during start-up of Anammox reactor].

    Science.gov (United States)

    Song, Yuxia; Xiong, Lei; Chai, Liyuan; Liao, Qi; Tang, Chongjian; Min, Xiaobo; Yang, Zhihui

    2014-12-01

    The anaerobic granular sludge from an Internal Circulation (IC) reactor of a paper mill wastewater treatment plant were seeded in an Anammox upflow anaerobic sludge blanket reactor. After 185 days operation, the reactor was finally started up by increasing the influent ammonium and nitrite concentrations to 224 mg/L and 255 mg/L, respectively, with volumetric nitrogen removal rate increasing to 3.76 kg/(m3·d). The physicochemical characteristics of the cultivated Anammox granules were observed by scanning electron microscope, transmission electron microscope and Fourier Transform infrared spectroscopy (FTIR). Results suggested that during the start-up course, the granular sludge initially disintegrated and then re-aggregated. FTIR spectra results revealed that the Anammox granular sludge contained abundant functional groups, indicating that it may also possess good adsorption properties. The ecological structure of the granular sludge, analyzed by the metagenomic sequencing methods, suggested that the relative abundance of the dominant bacterial community in the seeding sludge, i.e., Proteobacteria, Firmicutes, Bacteroidetes, significantly reduced, while Planctomycetes which contains anaerobic ammonium oxidation bacteria remarkably increased from 1.59% to 23.24% in the Anammox granules. PMID:26016375

  16. Comparison of membrane fouling during short-term filtration of aerobic granular sludge and activated sludge

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Aerobic granular sludge was cultivated adopting internal-circulate sequencing batch airlift reactor. The contradistinctive experiment about short-term membrane fouling between aerobic granular sludge system and activated sludge system were investigated. The membrane foulants was also characterized by Fourier Transform Infrared (FTIR) spectroscopy technique. The results showed that the aerobic granular sludge had excellent denitrification ability; the removal efficiency of TN could reach 90%. The aerobic granular sludge could alleviate membrane fouling effectively. The steady membrane flux of aerobic granular sludge was twice as much as that of activated sludge system. In addition, it was found that the aerobic granular sludge could result in severe membrane pore-blocking, however, the activated sludge could cause severe cake fouling. The major components of the foulants were identified as comprising of proteins and polysaccharide materials.

  17. Recovery of palladium(II) by methanogenic granular sludge.

    Science.gov (United States)

    Pat-Espadas, Aurora M; Field, James A; Otero-Gonzalez, Lila; Razo-Flores, Elías; Cervantes, Francisco J; Sierra-Alvarez, Reyes

    2016-02-01

    This is the first report that demonstrates the ability of anaerobic methanogenic granular sludge to reduce Pd(II) to Pd(0). Different electron donors were evaluated for their effectiveness in promoting Pd reduction. Formate and H2 fostered both chemically and biologically mediated Pd reduction. Ethanol only promoted the reduction of Pd(II) under biotic conditions and the reduction was likely mediated by H2 released from ethanol fermentation. No reduction was observed in biotic or abiotic assays with all other substrates tested (acetate, lactate and pyruvate) although a large fraction of the total Pd was removed from the liquid medium likely due to biosorption. Pd(II) displayed severe inhibition towards acetoclastic and hydrogenotrophic methanogens, as indicated by 50% inhibiting concentrations as low as 0.96 and 2.7 mg/L, respectively. The results obtained indicate the potential of utilizing anaerobic granular sludge bioreactor technology as a practical and promising option for Pd(II) reduction and recovery offering advantages over pure cultures. PMID:26408982

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

    NARCIS (Netherlands)

    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 (

  19. Improvement of anaerobic digestion of sludge

    Energy Technology Data Exchange (ETDEWEB)

    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)

  20. Tolerance to organic loading rate by aerobic granular sludge in a cyclic aerobic granular reactor.

    Science.gov (United States)

    Long, Bei; Yang, Chang-zhu; Pu, Wen-hong; Yang, Jia-kuan; Liu, Fu-biao; Zhang, Li; Zhang, Jing; Cheng, Kai

    2015-04-01

    Sodium acetate as carbon source, tolerance to organic loading rate (OLR) by aerobic granular sludge in a cyclic aerobic granular reactor (CAGR) was investigated by gradually increasing the influent COD. AGS could maintain stability in the continuous flow reactor under OLR⩽15kg/m(3)d in the former 65 days, and SVI, granulation rate, average particle size and water content was 21 ml/g, 98%, 1.8mm and 97.2% on the 65th day. However, AGS gradually disintegrated after the 66 th day when OLR increased to 18 kg/m(3)d, and granules' properties deteriorated rapidly in a short time. High removal rates to pollutants were achieved by CAGR in the former 65 days, but the removal rates of pollutants dropped sharply from the 66 th day. With the increase of OLR and particle size, anaerobic cores inside the granules were formed by massive dead cells, while instability of anaerobic core eventually led to the collapse of the system. PMID:25710570

  1. Nitrogen availability of anaerobic swine lagoon sludge: sludge source effects.

    Science.gov (United States)

    Moore, Amber D; Israel, Daniel W; Mikkelsen, Robert L

    2005-02-01

    Increased numbers of swine producers will be removing sludge from their anaerobic waste treatment lagoons in the next few years, due to sludge exceeding designed storage capacity. Information on availability of nitrogen (N) in the sludge is needed to improve application recommendations for crops. The objective of this study was to investigate possible effects of different companies and types of swine operations on the availability of N in sludge from their associated lagoons. A laboratory incubation study was conducted to quantify the availability of N (i.e. initial inorganic N plus the potentially mineralizable organic N) in the sludge. Nine sludge sources from lagoons of sow, nursery and finishing operations of three different swine companies were mixed with a loamy sand soil (200 mg total Kjeldahl N kg(-1) soil) and incubated at a water content of 0.19 g. water g(-1) dry soil and 25+/-2 degrees C for 12 weeks. Samples were taken at eight times over the 12-week period and analyzed for inorganic N (i.e. NH(4)-N and NO(3)-N) to determine mineralization of organic N in the sludge. Company and type of swine operation had no significant effects (P incubation. While plant N availability coefficients were not measured in this study, the lack of significant company or type of swine operation effects on sludge N mineralization suggests that use of the same plant N availability coefficient for sludge from different types of lagoons is justifiable. The validity of this interpretation depends on the assumption that variation in other components of different sludge sources such as Cu and Zn does not differentially alter N uptake by the receiver crops. PMID:15474933

  2. Strategies to Suppress Hydrogen-Consuming Microorganisms Affect Macro and Micro Scale Structure and Microbiology of Granular Sludge

    OpenAIRE

    Abreu, A. A.; Alves, J. I.; Pereira, M. A.; Sousa, D.Z.; Alves, M. M.

    2011-01-01

    Treatment of anaerobic granules with heat and two chemical treatments, contacting with 2-bromoethanesulfonate (BES) and with BESþChloroform, were applied to suppress hydrogen-consuming microorganisms. Three mesophilic expanded granular sludge bed (EGSB) reactors— RHeat, RBES, and RBESþChlo—were inoculated with the treated sludges and fed with synthetic sugar-based wastewater (5 gCOD L 1, HRT 20–12 h). Morphological integrity of granules and bacterial communities were ...

  3. Effect of sludge age on methanogenic and glycogen accumulating organisms in an aerobic granular sludge process fed with methanol and acetate.

    Science.gov (United States)

    Pronk, M; Abbas, B; Kleerebezem, R; van Loosdrecht, M C M

    2015-09-01

    The influence of sludge age on granular sludge formation and microbial population dynamics in a methanol- and acetate-fed aerobic granular sludge system operated at 35°C was investigated. During anaerobic feeding of the reactor, methanol was initially converted to methane by methylotrophic methanogens. These methanogens were able to withstand the relatively long aeration periods. Lowering the anaerobic solid retention time (SRT) from 17 to 8 days enabled selective removal of the methanogens and prevented unwanted methane formation. In absence of methanogens, methanol was converted aerobically, while granule formation remained stable. At high SRT values (51 days), γ-Proteobacteria were responsible for acetate removal through anaerobic uptake and subsequent aerobic growth on storage polymers formed [so called metabolism of glycogen-accumulating organisms (GAO)]. When lowering the SRT (24 days), Defluviicoccus-related organisms (cluster II) belonging to the α-Proteobacteria outcompeted acetate consuming γ-Proteobacteria at 35°C. DNA from the Defluviicoccus-related organisms in cluster II was not extracted by the standard DNA extraction method but with liquid nitrogen, which showed to be more effective. Remarkably, the two GAO types of organisms grew separately in two clearly different types of granules. This work further highlights the potential of aerobic granular sludge systems to effectively influence the microbial communities through sludge age control in order to optimize the wastewater treatment processes. PMID:26059251

  4. [Study on biodegradation of 2,4-DCP by anaerobic sludge acclimated by mixed mono-chlorphenols].

    Science.gov (United States)

    Zhang, Wen; Chen, Ling; Ji, Jun-Ping; Xia, Si-Qing

    2007-06-01

    Purpose of this study was to determine the treatability of 2,4-dichlorophenol (2,4-DCP) by anaerobic granular sludge which was acclimated by mixed mono-chlorphenols (2-CP, 4-MCP). The characteristic of degradation of 2,4-DCP by anaerobic sludge acclimated by mixed mono-chlorphenols was investigated through shake flask study and performance of continuous flow anaerobic bioreactors. The difference of degradation of 2,4-DCP by acclimated and unacclimated sludge was also compared. 2,4-DCP was degraded at 50 h and 180 h respectively for acclimated and unacclimated sludge, which testified that acclimated sludge could more effectively degrade 2,4-DCP. Although the intermediate product 4-MCP was present in both reaction system, 4-MCP could be degraded completely after 400 h in the acclimated sludge but accumulated in the unacclimated sludge. Therefore, acclimation by the mixed mono-chlorphenols (2-CP, 4-MCP) could enhance the ability of para- and meta-dechlorination for anaerobic sludge and increase the treatability of 2,4-DCP. The results of continuous anaerobic sludge-suspended carrier bioreactor (ASSCB) indicate that inoculation of the acclimated sludge by mixed mono-chlorphenols can degrade two mono-chlorphenols simultaneously, shorten the setup period, and increase the efficiency of degrading 2,4-DCP. 2-CP was easily degraded with removal rate of over 80% . While the removal rate of 4-MCP was fluctuating within 30% - 80% with changes of its influent concentration. PMID:17674731

  5. Influence of Chemical Oxygen Demand Concentrations on Anaerobi Ammonium Oxidation by Granular Sludge From EGSB Reactor

    Institute of Scientific and Technical Information of China (English)

    JING KANG; JIAN-LONG WANG

    2006-01-01

    Objective To investigate the effect of chemical oxygen demand (COD) concentrations on the anaerobic ammonium oxidation (ANAMMOX). Methods An Expanded Granular Sludge Bed (EGSB) reactor was used to cultivate the granular sludge and to perform the ANAMMOX reaction in the bench scale experiment. NH4+-N and NO2--N were measured by usingcolorimetric method. NO3--N was analyzed by using the UV spectrophotometric method. COD measurement was based on digestion with potassium dichromate in concentrated sulphuric acid. Results When the COD concentrations in the reactors were 0 mg/L, 200 mg/L, 350 mg/L, and 550 mg/L, respectively, the NH4+-N removal efficiency was 12.5%, 14.2%, 14.3%, and 23.7%; the removal amount of NO2--N was almost the same; the nitrate removal efficiency was 16.8%, 94.5%, 86.6%, and 84.2% and TN removal efficiency was 16.3%, 50.7%, 46.9%, and 50.4%, moreover, the COD removal efficiency concentrations have a significant influence on anaerobic ammonium oxidation by granular sludge.

  6. Electron beam/biological processing of anaerobic and aerobic sludge

    International Nuclear Information System (INIS)

    Besides common chemical and biological methods, the radiation technology is a promising way of sludge treatment. The paper describes possibilities of combined accelerated electrons/biological processing of both anaerobic and aerobic sludge. Besides one-shot experiments, experimental reactors for the simulation of anaerobic processes have been used. Main effort has been aimed to decrease organic compounds concentration and overall volume of solids, to improve some physico-chemical parameters of sludge, to validate hygienisation effects of the ionising radiation, and in the case of anaerobic sludge, to increase the volume of the produced biogas. Positive effects of the electron beam processing have been observed on all previously named parameters. (author)

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

    DEFF Research Database (Denmark)

    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...

  8. Microbial diversity differences within aerobic granular sludge and activated sludge flocs.

    Science.gov (United States)

    Winkler, M-K H; Kleerebezem, R; de Bruin, L M M; Verheijen, P J T; Abbas, B; Habermacher, J; van Loosdrecht, M C M

    2013-08-01

    In this study, we investigated during 400 days the microbial community variations as observed from 16S DNA gene DGGE banding patterns from an aerobic granular sludge pilot plant as well as the from a full-scale activated sludge treatment plant in Epe, the Netherlands. Both plants obtained the same wastewater and had the same relative hydraulic variations and run stable over time. For the total bacterial population, a similarity analysis was conducted showing that the community composition of both sludge types was very dissimilar. Despite this difference, general bacterial population of both systems had on average comparable species richness, entropy, and evenness, suggesting that different bacteria were sharing the same functionality. Moreover, multi-dimensional scaling analysis revealed that the microbial populations of the flocculent sludge system moved closely around the initial population, whereas the bacterial population in the aerobic granular sludge moved away from its initial population representing a permanent change. In addition, the ammonium-oxidizing community of both sludge systems was studied in detail showing more unevenness than the general bacterial community. Nitrosomonas was the dominant AOB in flocculent sludge, whereas in granular sludge, Nitrosomonas and Nitrosospira were present in equal amounts. A correlation analysis of process data and microbial data from DGGE gels showed that the microbial diversity shift in ammonium-oxidizing bacteria clearly correlated with fluctuations in temperature. PMID:23064482

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

    Science.gov (United States)

    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. PMID:24200003

  10. Effective bio-treatment of fresh leachate from pretreated municipal solid waste in an expanded granular sludge bed bioreactor.

    Science.gov (United States)

    Liu, Jianyong; Zhong, Jiangping; Wang, Yilan; Liu, Qiang; Qian, Guangren; Zhong, Liyun; Guo, Rongzhong; Zhang, Peijun; Xu, Zhi Ping

    2010-03-01

    This research investigated the anaerobic biodegradation of fresh leachate from pretreated municipal solid waste (MSW) in an expanded granular sludge bed (EGSB) bioreactor under mesophilic conditions. The observations showed that this bioreactor, inoculated with anaerobic granular sludge, could be readily activated. The chemical oxygen demand (COD) removal efficiency varied between 88% and 97% under normal operation conditions, and was kept at 94-96% under the proposed optimal conditions. We noted that 60-80% of the produced biogas was methane that was yielded at a rate depending on the organic loading rate (OLR) and the liquid up-flow velocity (Vup). Significantly, 80% of loaded COD or 83% of biodegraded COD was converted to methane under the proposed optimal conditions. These findings indicate that the fresh leachate from pretreated MSW can be efficiently treated in the EGSB bioreactor, and moreover, methane, a renewable energy, can be continuously generated. PMID:19640701

  11. Aplicação conjunta de tratamento anaeróbio termofílico por lodo granular e de mediadores redox na remoção de cor de águas residuárias têxteis Applicability of both thermophilic treatment by anaerobic granular sludge and redox mediators on colour removal of textile wastewaters

    Directory of Open Access Journals (Sweden)

    André Bezerra dos Santos

    2005-09-01

    Full Text Available Investigou-se o efeito de diferentes mediadores redox na remoção de cor de corantes azo pelo uso de lodo granular anaeróbio sob condições mesofílicas (30ºC e termofílicas (55ºC. Adicionalmente, estudou-se em ambas temperaturas, o efeito de diferentes doadores de elétrons nos processos de descoloração. Comprovou-se em tais processos um impacto marcante da adição de concentrações catalíticas de mediadores redox, aumentando a cinética da reação em até 1 ordem de magnitude. Comparado com tratamento mesofílico, remoções de cor sob condições termofílicas foram extremamente aceleradas, além de o impacto dos mediadores redox ser consideravelmente diminuído à 55ºC. Por exemplo, em experimento de fluxo contínuo, eficiências de remoção em torno de 95% e 56% foram obtidas à 55ºC e 30ºC, respectivamente, na ausência de qualquer mediador redox. Hidrogênio se mostrou extremamente efetivo como doador de elétrons para o processo de descoloração redutiva de corantes azo quando comparado com glicose, formiato e acetato. Os resultados obtidos nesta investigação trazem boas perspectivas para o uso conjunto de reatores anaeróbios sob condições termofílicas e de mediadores redox no pré-tratamento das águas residuárias de indústrias têxteis.The use of different redox mediators on colour removal of azo dyes by anaerobic granular sludge was investigated under mesophilic (30ºC and thermophilic (55ºC conditions. Additionally, the use of different electron donors on the reductive decolourisation was studied in both temperatures. The addition of catalytic concentrations of redox mediators had an evident impact on the decolourisation process, enhancing the rates up to one order of magnitude. Compared to mesophilic conditions, colour removal under thermophilic conditions was extremely accelerated, and the impact of redox mediators on the decolourisation rates was considerably decreased at 55ºC. For instance, in a

  12. Enhancement of sludge granulation in anaerobic treatment of concentrated latex wastewater

    Directory of Open Access Journals (Sweden)

    Nugul Intrasungkha

    2008-04-01

    Full Text Available Recently, the upflow anaerobic sludge blanket (UASB reactor has become attractive for wastewater treatment with low energy requirement and biogas production. However, the start-up of an UASB reactor depends on the formation of granules. Therefore, this research aims to study the effect of AlCl3, CaCl2 and temperature on the granule formation process using real concentrated latex wastewater. The result shows that the optimum chemicals concentration of AlCl3 at 300 mg/l enhanced the biomass accumulation and sludge formation process. Approximately 50% of large granular size (0.5 mm 0.8 mm within 35 days, whereas the large granular sizes in reactorwithout AlCl3 supplement (R2 became visible within 63 days. Moreover, this experiment found that R1, R2 and R3 could reach steady state within 40, 55 and 45 days, respectively.

  13. Biogas recovery from microwave heated sludge by anaerobic digestion

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Biogas generated from sewage sludge,livestock waste,and food waste by anaerobic digestion is a valuable renewable energy resource.However,conventional anaerobic digestion is not an efficient process.A long hydraulic retention time and low biogas recovery rate hinder the applications of those resources.An effective pretreatment method to destroy sludge microbial cells has been one of the major concerns regarding improvement of the biogas production.This article focuses on the effects of microwave heating on sludge anaerobic digestion.Volatile suspended solid(VSS) and chemical organic demand solubilization of heated sludge were investigated.Microwave heating was found to be a rapid and efficient process for releasing organic substrates from sludge.The increase of organic dissolution ratio was not obvious when holding time was over 5 min with microwave heating.The effect of the VSS solubilization was primarily dependent on heating temperature.The highest value of VSS dissolving ratio,36.4%,was obtained at 170°C for 30 min.The COD dissolving ratio was about 25% at 170°C.Total organic carbon of treated sludge liquor was 1.98 and 2.73 g/L at 150°C and 170°C for 5 min,respectively.A biochemical methane potential(BMP) test of excess sludge and a mixture of primary and excess sludge demonstrated an increase in biogas production.The total biogas from microwave treated mixture sludge increased by 12.9% to 20.2% over control after 30 days of digestion.Biogas production was 11.1% to 25.9% higher for excess sludge than for untreated sludge.The VS removal ratios of mixture sludge and excess sludge were 12% and 11% higher,respectively,compared to the untreated sludge.

  14. Ultrasonic cell disruption of stabilised sludge with subsequent anaerobic digestion.

    Science.gov (United States)

    Onyeche, T I; Schläfer, O; Bormann, H; Schröder, C; Sievers, M

    2002-05-01

    The world-wide increasing environmental awareness and its subsequent regulations have led to the application of improved technologies in wastewater purification plants. This has resulted in higher wastewater and sludge productions. Sludge is the by-product of such plants and it is not only rich in organic carbon and pathogens but also in heavy metals and other environmental pollutants. In Europe, agricultural application of dried sludge (bio-solids) is confronted with negative reactions from the citizens, governmental organisations, farmers and the food industry. Ultrasonic disruption of sludge is a popular mechanical disruption process in sludge treatment. During ultrasonic treatment, high frequency acoustic signals are used to initiate the cavitation process. The applied ultrasonic field leads to a breakdown of cohesive forces of the liquid molecules resulting in the generation of cavitation bubbles. A shock wave is released by the collapse of the cavitation bubbles and propagates in the surrounding medium forming jet streams that cause the disruption of cells in sludge. Disruption of sludge cells enables the release of light organic substances into the sludge water thereby exposing them for further anaerobic digestion. This paper presents results on the disruption of conventionally stabilised sludge through the application of the ultrasonic field. In order to reduce the specific energy input (i.e. ratio of the consumed energy during ultrasonic disruption to the input sludge mass) and improve biogas production, the total solids content of the stabilised sludge was increased before disruption. The anaerobic digestion of sludge samples was carried out in a set of specially constructed laboratory anaerobic digesters. Results showed that subsequent anaerobic digestion of the ultrasonically disrupted sludge could improve biogas production with reduced sludge quantity that is vital to the economic consideration of the wastewater treatment plants. This process

  15. Ultrasonic waste activated sludge disintegration for improving anaerobic stabilization.

    Science.gov (United States)

    Tiehm, A; Nickel, K; Zellhorn, M; Neis, U

    2001-06-01

    The pretreatment of waste activated sludge by ultrasonic disintegration was studied in order to improve the anaerobic sludge stabilization. The ultrasound frequency was varied within a range from 41 to 3217 kHz. The impact of different ultrasound intensities and treatment times was examined. Sludge disintegration was most significant at low frequencies. Low-frequency ultrasound creates large cavitation bubbles which upon collapse initiate powerful jet streams exerting strong shear forces in the liquid. The decreasing sludge disintegration efficiency observed at higher frequencies was attributed to smaller cavitation bubbles which do not allow the initiation of such strong shear forces. Short sonication times resulted in sludge floc deagglomeration without the destruction of bacteria cells. Longer sonication brought about the break-up of cell walls, the sludge solids were distintegrated and dissolved organic compounds were released. The anaerobic digestion of waste activated sludge following ultrasonic pretreatment causing microbial cell lysis was significantly improved. There was an increase in the volatile solids degradation as well as an increase in the biogas production. The increase in digestion efficiency was proportional to the degree of sludge disintegration. To a lesser degree the deagglomeration of sludge flocs also augmented the anaerobic volatile solids degradation. PMID:11337847

  16. A granulation model using diosgenin wastewater in an upflow anaerobic sludge blanket reactor

    Institute of Scientific and Technical Information of China (English)

    Jianguo BAO; Hui LIU; Yanxin WANG; Lijun ZHANG

    2009-01-01

    An enhanced start-up of an upfiow anaerobic sludge blanket (UASB) reactor for diosgenin wastewater treatment was designed and experimentally tested. Gran-ular sludge was formed on day 35 in the reactor with high concentrations of chloride (4000-7000 mg/L) and COD (5000-13000mg/L) as substrate. A new model for the granulation was proposed which divides the formation of anaerobic granules into six consecutive stages; they include semi-embryonic granule formation, embryonic granule formation, single-nucleus granule formation, multi-nuclei granule formation, granule growth and granule maturation. A model of the granule structure was also proposed based on scanning electron microscope observation. The microspores occurring on the surface and further leading into the interior of the granules were considered as the channels and the passage of the materials and the products of the microorganisms' metabolism inside the granules.

  17. Re-activation characteristics of preserved aerobic granular sludge

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-li; ZHANG Bo; HUANG Yu-feng; CAI Wei-min

    2005-01-01

    In some industrial plants, wastewater was intermittently or seasonally generated. There may be periods during which wastewater treatment facilities have to be set into an idle phase over several weeks. When wastewater was generated again, the activated sludge flocs may have disintegrated. In this experiment, re-activation characteristics of aerobic granular sludge starved for 2 months were investigated.Specific oxygen utilization rate(SOUR) was used as an indicator to evaluate the metabolic activity of the sludge. The results revealed that aerobic granular sludge could be stored up to two months without running the risk of losing the integrity of the granules and metabolic potentials. The apparent color of aerobic granules stored at room temperature gradually turned from brownish-yellowish to gray brown.They appeared brownish-yellowish again 2 weeks after re-activation. The velocity and strength of granules after 2-month idle period could achieved. A stable effluent COD concentration of less than 150 mg/L was achieved during the re-activation process.

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

    KAUST Repository

    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.

  19. Effects of total solids content on waste activated sludge thermophilic anaerobic digestion and its sludge dewaterability.

    Science.gov (United States)

    Wang, Tianfeng; Chen, Jie; Shen, Honglang; An, Dong

    2016-10-01

    The role of total solids content on sludge thermophilic anaerobic digestion was investigated in batch reactors. A range of total solids content from 2% to 10% was evaluated with two replicates. The lowest inhibitory concentration for free ammonia and total ammonia of sludge thermophilic anaerobic digestion was 110.9-171.4mg/L and 1313.1-1806.7mg/L, respectively. The volumetric biogas production rate increased with increasing of total solids content, but the corresponding biogas yield per gram volatile solid decreased. The result of normalized capillary suction time indicated that the dewaterability of digested sludge at high total solids content was poor, while solid content of sediment obtained by centrifuging sludge at 2000g for 10min increased with increasing of total solids content of sludge. The results suggest that thickened sludge mixed with dewatered sludge at an appropriate ratio could get high organic loading rate, high biogas yield and adequate dewatering effort. PMID:26897469

  20. Stability of expanded granular sludge bed process for terylene artificial silk printing and dyeing wastewater treatment

    Institute of Scientific and Technical Information of China (English)

    GUAN Bao-hong

    2005-01-01

    Terylene artificial silk printing and dyeing wastewater(TPD wastewater), containing averaged 710 mg/L terephthalic acid(TA) as the main carbon source and the character pollutant, was subjected to expanded granular sludge bed(EGSB) process. The stability of theEGSB process was firstly conducted by laboratory experiment. TA ionization was the predominated factor influencing the acid-base balance of the system. High concentration of TA in wastewater resulted in sufficient buffering capacity to neutralize the volatile fatty acids(VFA)generated from substrate degradation and provided strong base for anaerobic system to resist the pH decrease below 6.5. VFA and UFA caused almost no inhibition on the anaerobic process and biogas production except that pH was below 6.35 and VFA was at its maximum value. Along with the granulating of the activated sludge, the efficiency of organic removal and production rate of biogas increased gradually and became more stable. After start-up, the efficiency of COD removal increased to 57%-64%, pH stabilized in a range of 7.99-8.04, and production rate of biogas was relatively high and stable. Sludge granulating, suitable influent of pH and loading were responsible for the EGSB stability. The variation of VFA concentration only resulted in neglectable rebound of pH, and the inhibition from VFA could be ignored in EGSB. The EGSB reactor was stable for TPD wastewater treatment.

  1. Advanced phosphorus recovery using a novel SBR system with granular sludge in simultaneous nitrification, denitrification and phosphorus removal process.

    Science.gov (United States)

    Lu, Yong-Ze; Wang, Hou-Feng; Kotsopoulos, Thomas A; Zeng, Raymond J

    2016-05-01

    In this study, a novel process for phosphorus (P) recovery without excess sludge production from granular sludge in simultaneous nitrification-denitrification and P removal (SNDPR) system is presented. Aerobic microbial granules were successfully cultivated in an alternating aerobic-anaerobic sequencing batch reactor (SBR) for removing P and nitrogen (N). Dense and stable granular sludge was created, and the SBR system showed good performance in terms of P and N removal. The removal efficiency was approximately 65.22 % for N, and P was completely removed under stable operating conditions. Afterward, new operating conditions were applied in order to enhance P recovering without excess sludge production. The initial SBR system was equipped with a batch reactor and a non-woven cloth filter, and 1.37 g of CH3COONa·3H2O was added to the batch reactor after mixing it with 1 L of sludge derived from the SBR reactor to enhance P release in the liquid fraction, this comprises the new system configuration. Under the new operating conditions, 93.19 % of the P contained in wastewater was released in the liquid fraction as concentrated orthophosphate from part of granular sludge. This amount of P could be efficiently recovered in the form of struvite. Meanwhile, a deterioration of the denitrification efficiency was observed and the granules were disintegrated into smaller particles. The biomass concentration in the system increased firstly and then maintained at 4.0 ± 0.15 gVSS/L afterward. These results indicate that this P recovery operating (PRO) mode is a promising method to recover P in a SNDPR system with granular sludge. In addition, new insights into the granule transformation when confronted with high chemical oxygen demand (COD) load were provided. PMID:26728017

  2. Anaerobic bioleaching of metals from waste activated sludge

    KAUST Repository

    Meulepas, Roel J W

    2015-05-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342μgg-1 of copper, 487μgg-1 of lead, 793μgg-1 of zinc, 27μgg-1 of nickel and 2.3μgg-1 of cadmium. During the anaerobic acidification of 3gdry weightL-1 waste activated sludge, 80-85% of the copper, 66-69% of the lead, 87% of the zinc, 94-99% of the nickel and 73-83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead.

  3. Anaerobic bioleaching of metals from waste activated sludge.

    Science.gov (United States)

    Meulepas, Roel J W; Gonzalez-Gil, Graciela; Teshager, Fitfety Melese; Witharana, Ayoma; Saikaly, Pascal E; Lens, Piet N L

    2015-05-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342 μg g(-1) of copper, 487 μg g(-1) of lead, 793 μg g(-1) of zinc, 27 μg g(-1) of nickel and 2.3 μg g(-1) of cadmium. During the anaerobic acidification of 3 gdry weight L(-1) waste activated sludge, 80-85% of the copper, 66-69% of the lead, 87% of the zinc, 94-99% of the nickel and 73-83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead. PMID:25659306

  4. Anaerobic bioleaching of metals from waste activated sludge

    Energy Technology Data Exchange (ETDEWEB)

    Meulepas, Roel J.W., E-mail: roel.meulepas@wetsus.nl [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Gonzalez-Gil, Graciela [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); King Abdullah University of Science and Technology, Water Desalination and Reuse Center, Thuwal 13955-69000 (Saudi Arabia); Teshager, Fitfety Melese; Witharana, Ayoma [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Saikaly, Pascal E. [King Abdullah University of Science and Technology, Water Desalination and Reuse Center, Thuwal 13955-69000 (Saudi Arabia); Lens, Piet N.L. [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands)

    2015-05-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342 μg g{sup −1} of copper, 487 μg g{sup −1} of lead, 793 μg g{sup −1} of zinc, 27 μg g{sup −1} of nickel and 2.3 μg g{sup −1} of cadmium. During the anaerobic acidification of 3 g{sub dry} {sub weight} L{sup −1} waste activated sludge, 80–85% of the copper, 66–69% of the lead, 87% of the zinc, 94–99% of the nickel and 73–83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead. - Highlights: • Heavy metals were leached during anaerobic acidification of waste activated sludge. • The process does not require the addition of chelating or oxidizing agents. • The metal leaching efficiencies (66 to 99%) were comparable to chemical leaching. • The produced leachate may be used for metal recovery and biogas production. • The produced digested sludge may be used as soil conditioner.

  5. Anaerobic bioleaching of metals from waste activated sludge

    International Nuclear Information System (INIS)

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342 μg g−1 of copper, 487 μg g−1 of lead, 793 μg g−1 of zinc, 27 μg g−1 of nickel and 2.3 μg g−1 of cadmium. During the anaerobic acidification of 3 gdry weight L−1 waste activated sludge, 80–85% of the copper, 66–69% of the lead, 87% of the zinc, 94–99% of the nickel and 73–83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead. - Highlights: • Heavy metals were leached during anaerobic acidification of waste activated sludge. • The process does not require the addition of chelating or oxidizing agents. • The metal leaching efficiencies (66 to 99%) were comparable to chemical leaching. • The produced leachate may be used for metal recovery and biogas production. • The produced digested sludge may be used as soil conditioner

  6. Nitrogen in the Process of Waste Activated Sludge Anaerobic Digestion

    Directory of Open Access Journals (Sweden)

    Suschka Jan

    2014-07-01

    Full Text Available Primary or secondary sewage sludge in medium and large WWTP are most often processed by anaerobic digestion, as a method of conditioning, sludge quantity minimization and biogas production. With the aim to achieve the best results of sludge processing several modifications of technologies were suggested, investigated and introduced in the full technical scale. Various sludge pretreatment technologies before anaerobic treatment have been widely investigated and partially introduced. Obviously, there are always some limitations and some negative side effects. Selected aspects have been presented and discussed. The problem of nitrogen has been highlighted on the basis of the carried out investigations. The single and two step - mesophilic and thermophilic - anaerobic waste activated sludge digestion processes, preceded by preliminary hydrolysis were investigated. The aim of lab-scale experiments was pre-treatment of the sludge by means of low intensive alkaline and hydrodynamic disintegration. Depending on the pretreatment technologies and the digestion temperature large ammonia concentrations, up to 1800 mg NH4/dm3 have been measured. Return of the sludge liquor to the main sewage treatment line means additional nitrogen removal costs. Possible solutions are discussed.

  7. Unravelling the reasons for disproportion in the ratio of AOB and NOB in aerobic granular sludge

    NARCIS (Netherlands)

    Winkler, M.K.H.; Bassin, J.P.; Kleerebezem, R.; Sorokin, D.Y.; Van Loosdrecht, M.C.M.

    2012-01-01

    In this study, we analysed the nitrifying microbial community (ammonium-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB)) within three different aerobic granular sludge treatment systems as well as within one flocculent sludge system. Granular samples were taken from one pilot plant run

  8. Limited degradation of chlorophenols by anaerobic sludge granules.

    OpenAIRE

    Mohn, W W; Kennedy, K J

    1992-01-01

    To better understand the fate of chlorophenols treated in upflow anaerobic sludge bed reactors, we examined the ability of sludge granules from such bioreactors to degrade two trichlorophenols and one dichlorophenol in batch incubations under controlled conditions. Biodegradation was primarily limited to two distinct activities, reductive dehalogenation of ortho- and of meta-chlorine substituents. Both 3- and 4-monochlorophenol were persistent degradation products, while 2-monochlorophenol wa...

  9. Biomass stabilization in the anaerobic digestion of wastewater sludges

    Energy Technology Data Exchange (ETDEWEB)

    Arnaiz, C. [Universidad de Sevilla (Spain). Escuela Universitaria Politecnica. Departamento de Ingenieria Quimica y Ambiental; Gutierrez, J.C. [Universidad Pablo de Olavide, Sevilla (Spain). Departamento de Ciencias Ambientales; Lebrato, J. [Universidad de Sevilla (Spain). Escuela Universitaria Politecnica

    2006-07-15

    Sludge stabilization processes include both volatile solid destruction and biomass stabilization. Traditionally, both processes have been considered together, in such a way that, when volatile solid destruction is achieved, the biomass is considered stabilized. In this study, volatile solids reduction and biomass stabilization in the anaerobic digestion of primary, secondary and mixed sludges from municipal wastewater treatment plants were researched in batch cultures by measurements of suspended solids and suspended lipid-phosphate. The estimated kinetic constants were higher in all sludge types tested for the biomass stabilization process, indicating that volatile solids destruction and biomass stabilization are not parallel processes, since the latter one is reached before the former. (author)

  10. Biomass stabilization in the anaerobic digestion of wastewater sludges

    Energy Technology Data Exchange (ETDEWEB)

    Arnaiz, C. [Universidad de Sevilla, Dept. de Ingenieria Quimica y Ambiental, Sevilla (Spain); Gutierrez, J.C. [Universidad Pablo de Olavide, Dept. de Ciencias Ambientales, Sevilla (Spain); Lebrato, J. [Universidad de Sevilla, Grupo Tratamiento de Aguas Residuales, Sevilla (Spain)

    2005-07-01

    Sludge stabilization processes include both volatile solid destruction and biomass stabilization. Traditionally, both processes have been considered together, in such a way that, when volatile solid destruction is achieved, the biomass is considered stabilized. In this study, volatile solids reduction and biomass stabilization in the anaerobic digestion of primary, secondary and mixed sludges from municipal wastewater treatment plants were researched in batch cultures by measurements of suspended solids and suspended lipid-phosphate. The estimated kinetic constants were higher in all sludge types tested for the biomass stabilization process, indicating that volatile solids destruction and biomass stabilization are not parallel processes, since the latter one is reached before the former. (Author)

  11. Understanding the role of extracellular polymeric substances in an enhanced biological phosphorus removal granular sludge system.

    Science.gov (United States)

    Wang, Randeng; Peng, Yongzhen; Cheng, Zhanli; Ren, Nanqi

    2014-10-01

    The role of extracellular polymeric substances (EPS) in the enhanced biological phosphorus removal (EBPR) process was investigated in a P-accumulating granular sludge system by analyzing the distribution and transfer of P, K(+), Mg(2+) and Ca(2+) in the sludge phase, EPS, and the bulk liquid. In the sludge phase, about 30% P, 44.7% K(+), 27.7% Mg(2+), 28% Ca(2+) accumulated in the EPS at the end of aeration. The rate of P, K(+), Mg(2+) and Ca(2+) released from the EPS matrix into the bulk liquid in the anaerobic phase was faster than the rate they were adsorbed from the bulk liquid into the EPS in the aerobic phase. P, K(+), Mg(2+) and Ca(2+) were retained in EPS before transferring into the phosphorus accumulating organisms (PAOs). These results suggest that EPS play a critical role in facilitating the accumulation and transfer of P, K(+), Ca(2+) and Mg(2+) between PAO cells and bulk liquid. PMID:25063972

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

    Science.gov (United States)

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

    2014-10-01

    Sewage sludge is one of the major sources that releasing antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARG) into the environment since it contains large amount of ARB, but there is little information about the fate of the anaerobic ARB in the anaerobic digestion of sewage sludge. Therefore, the distribution, removal and seasonal changes of tetracycline and β-lactam antibiotics resistant bacteria in the mesophilic egg-shaped digesters of a municipal wastewater treatment plant were investigated for one year in this study. Results showed that there were higher amounts of ARB and higher resistance rate of β-lactam antibiotics than that of tetracycline antibiotics in the sewage sludge. All ARB could be significantly reduced during the mesophilic anaerobic digestion process by 1.48-1.64 log unit (P < 0.05). Notably, the ampicillin and cephalothin resistance rates were significantly increased after anaerobic digestion by 12.0% and 14.3%, respectively (P < 0.05). The distribution of ARB in the sewage sludge had seasonal change characteristics. Except for chlorotetracycline resistant bacteria, there were more ARB in the sewage sludge in cold season than in warm season (P < 0.05). PMID:25693388

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

    Science.gov (United States)

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

    2013-09-01

    A computational fluid dynamics (CFD) model that evaluates mechanical mixing in a full-scale anaerobic digester was developed to investigate the influence of sewage sludge rheology on the steady-state digester performance. Mechanical mixing is provided through an impeller located in a draft tube. Use is made of the Multiple Reference Frame model to incorporate the rotating impeller. The non-Newtonian sludge is modeled using the Hershel-Bulkley law because of the yield stress present in the fluid. Water is also used as modeling fluid to illustrate the significant non-Newtonian effects of sewage sludge on mixing patterns. The variation of the sewage sludge rheology as a result of the digestion process is considered to determine its influence on both the required impeller torque and digester mixing patterns. It was found that when modeling the fluid with the Hershel-Bulkley law, the high slope of the sewage stress-strain curve at high shear rates causes significant viscous torque on the impeller surface. Although the overall fluid shear stress property is reduced during digestion, this slope is increased with sludge age, causing an increase in impeller torque for digested sludge due to the high strain rates caused by the pumping impeller. Consideration should be given to using the Bingham law to deal with high strain rates. The overall mixing flow patterns of the digested sludge do however improve slightly. PMID:23764598

  14. Microbial degradation of 4-monobrominated diphenyl ether with anaerobic sludge

    International Nuclear Information System (INIS)

    Highlights: ► BDE-3 was degraded with two anaerobes in different rates. ► Glucose addition augment the debromination efficiencies. ► Hydrogen gas was detected and relative microbes were identified. ► Extra-carbon source enhanced degradation partial due to H2-generation bacteria. - Abstract: Polybrominated diphenyl ethers (PBDEs) are widely used flame retardant additives for many plastic and electronic products. Owing to their ubiquitous distribution in the environment, multiple toxicity to humans, and increasing accumulation in the environment, the fate of PBDEs is of serious concern for public safety. In this study, the degradation of 4-monobrominated diphenyl ether (BDE-3) in anaerobic sludge and the effect of carbon source addition were investigated. BDE-3 can be degraded by two different anaerobic sludge samples. The by-products, diphenyl ether (DE) and bromide ions, were monitored, indicating the reaction of debromination within these anaerobic samples. Co-metabolism with glucose facilitated BDE-3 biodegradation in terms of kinetics and efficiency in the Jhongsing sludge. Through the pattern of amplified 16S rRNA gene fragments in denatured gradient gel electrophoresis (DGGE), the composition of the microbial community was analyzed. Most of the predominant microbes were novel species. The fragments enriched in BDE-3-degrading anaerobic sludge samples are presumably Clostridium sp. This enrichment coincides with the H2 gas generation and the facilitation of debromination during the degradation process. Findings of this study provide better understanding of the biodegradation of brominated DEs and can facilitate the prediction of the fate of PBDEs in the environment.

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

    Science.gov (United States)

    Prabhu, Meghanath S; Mutnuri, Srikanth

    2016-04-01

    Anaerobic co-digestion of organic matter improves digester operating characteristics and its performance. In the present work, food waste was collected from the institute cafeteria. Two types of sludge (before centrifuge and after centrifuge) were collected from the fluidised bed reactor of the institute treating sewage wastewater. Food waste and sludge were studied for their physico-chemical characteristics, such as pH, chemical oxygen demand, total solids, volatile solids, ammoniacal nitrogen, and total nitrogen. A biomethane potential assay was carried out to find out the optimum mixing ratio of food waste and sludge for anaerobic co-digestion. Results indicated that food waste mixed with sludge in the ratio of 1:2 produced the maximum biogas of 823 ml gVS(-1)(21 days) with an average methane content of 60%. Batch studies were conducted in 5 L lab-glass reactors at a mesophilic temperature. The effect of different substrate loading rates on biogas production was investigated. The mixing ratio of food waste and sludge was 1:2. A loading rate of 1 gVS L d(-1)gave the maximum biogas production of 742 ml g(-1)VS L d(-1)with a methane content of 50%, followed by 2 gVS L d(-1)with biogas of 539 ml g(-1)VS L d(-1) Microbial diversity of the reactor during fed batch studies was investigated by terminal restriction fragment length polymorphism. A pilot-scale co-digestion of food waste and sludge (before centrifuge) indicated the process stability of anaerobic digestion. PMID:26879909

  16. Sustainable polysaccharide-based biomaterial recovered from waste aerobic granular sludge as a surface coating material

    NARCIS (Netherlands)

    Lin, Y.M.; Nierop, K.G.J.; Girbal-Neuhauser, E.; Adriaanse, M.; Van Loosdrecht, M.C.M.

    2015-01-01

    To evaluate the possibility of utilizing polysaccharide-based biomaterial recovered from aerobic granular sludge as a coating material, the morphology, molecular weight distribution and chemical composition of the recovered biomaterial were investigated by atomic force microscopy, size exclusion chr

  17. Application of Anaerobic Digestion Model No. 1 for simulating anaerobic mesophilic sludge digestion

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, Carlos, E-mail: carllosmendez@gmail.com; Esquerre, Karla, E-mail: karlaesquerre@ufba.br; Matos Queiroz, Luciano, E-mail: lmqueiroz@ufba.br

    2015-01-15

    Highlights: • The behavior of a anaerobic reactor was evaluated through modeling. • Parametric sensitivity analysis was used to select most sensitive of the ADM1. • The results indicate that the ADM1 was able to predict the experimental results. • Organic load rate above of 35 kg/m{sup 3} day affects the performance of the process. - Abstract: Improving anaerobic digestion of sewage sludge by monitoring common indicators such as volatile fatty acids (VFAs), gas composition and pH is a suitable solution for better sludge management. Modeling is an important tool to assess and to predict process performance. The present study focuses on the application of the Anaerobic Digestion Model No. 1 (ADM1) to simulate the dynamic behavior of a reactor fed with sewage sludge under mesophilic conditions. Parametric sensitivity analysis is used to select the most sensitive ADM1 parameters for estimation using a numerical procedure while other parameters are applied without any modification to the original values presented in the ADM1 report. The results indicate that the ADM1 model after parameter estimation was able to predict the experimental results of effluent acetate, propionate, composites and biogas flows and pH with reasonable accuracy. The simulation of the effect of organic shock loading clearly showed that an organic shock loading rate above of 35 kg/m{sup 3} day affects the performance of the reactor. The results demonstrate that simulations can be helpful to support decisions on predicting the anaerobic digestion process of sewage sludge.

  18. Application of Anaerobic Digestion Model No. 1 for simulating anaerobic mesophilic sludge digestion

    International Nuclear Information System (INIS)

    Highlights: • The behavior of a anaerobic reactor was evaluated through modeling. • Parametric sensitivity analysis was used to select most sensitive of the ADM1. • The results indicate that the ADM1 was able to predict the experimental results. • Organic load rate above of 35 kg/m3 day affects the performance of the process. - Abstract: Improving anaerobic digestion of sewage sludge by monitoring common indicators such as volatile fatty acids (VFAs), gas composition and pH is a suitable solution for better sludge management. Modeling is an important tool to assess and to predict process performance. The present study focuses on the application of the Anaerobic Digestion Model No. 1 (ADM1) to simulate the dynamic behavior of a reactor fed with sewage sludge under mesophilic conditions. Parametric sensitivity analysis is used to select the most sensitive ADM1 parameters for estimation using a numerical procedure while other parameters are applied without any modification to the original values presented in the ADM1 report. The results indicate that the ADM1 model after parameter estimation was able to predict the experimental results of effluent acetate, propionate, composites and biogas flows and pH with reasonable accuracy. The simulation of the effect of organic shock loading clearly showed that an organic shock loading rate above of 35 kg/m3 day affects the performance of the reactor. The results demonstrate that simulations can be helpful to support decisions on predicting the anaerobic digestion process of sewage sludge

  19. Interaction of Polybrominated Diphenyl Ethers and Aerobic Granular Sludge: Biosorption and Microbial Degradation

    OpenAIRE

    Shou-Qing Ni; Qingjie Cui; Zhen Zheng

    2014-01-01

    As a new category of persistent organic pollutants, polybrominated diphenyl ethers (PBDEs) have become ubiquitous global environmental contaminants. No literature is available on the aerobic biotransformation of decabromodiphenyl ether (BDE-209). Herein, we investigated the interaction of PBDEs with aerobic granular sludge. The results show that the removal of BDE-209 from wastewater is mainly via biosorption onto aerobic granular sludge. The uptake capacity increased when temperature, contac...

  20. Continuous biohydrogen production from waste bread by anaerobic sludge.

    Science.gov (United States)

    Han, Wei; Huang, Jingang; Zhao, Hongting; Li, Yongfeng

    2016-07-01

    In this study, continuous biohydrogen production from waste bread by anaerobic sludge was performed. The waste bread was first hydrolyzed by the crude enzymes which were generated by Aspergillus awamori and Aspergillus oryzae via solid-state fermentation. It was observed that 49.78g/L glucose and 284.12mg/L free amino nitrogen could be produced with waste bread mass ratio of 15% (w/v). The waste bread hydrolysate was then used for biohydrogen production by anaerobic sludge in a continuous stirred tank reactor (CSTR). The optimal hydrogen production rate of 7.4L/(Ld) was achieved at chemical oxygen demand (COD) of 6000mg/L. According to the results obtained from this study, 1g waste bread could generate 0.332g glucose which could be further utilized to produce 109.5mL hydrogen. This is the first study which reports continuous biohydrogen production from waste bread by anaerobic sludge. PMID:27065225

  1. Improved Energy Recovery by Anaerobic Grey Water Sludge Treatment with Black Water

    OpenAIRE

    Taina Tervahauta; Isaac M. BRYANT; Lucía Hernández Leal; Cees J. N. Buisman; Grietje Zeeman

    2014-01-01

    This study presents the potential of combining anaerobic grey water sludge treatment with black water in an up-flow anaerobic sludge blanket (UASB) reactor to improve energy recovery within source-separated sanitation concepts. Black water and the mixture of black water and grey water sludge were compared in terms of biochemical methane potential (BMP), UASB reactor performance, chemical oxygen demand (COD) mass balance and methanization. Grey water sludge treatment with black water increased...

  2. Toxicity of di-(2-ethylhexyl) phthalate on the anaerobic digestion of wastewater sludge

    DEFF Research Database (Denmark)

    Alatriste-Mondragon, Felipe; Iranpour, R.; Ahring, Birgitte Kiær

    2003-01-01

    considered recalcitrant. Moreover, they inhibit methanogenesis. However, studies have not been made on the effect of feeding a combination of recalcitrant and biodegradable PAEs into anaerobic digesters treating wastewater sludge. The present study was conducted with wastewater sludge from the Los Angeles...... populations in the anaerobic bioreactor. Our results imply that high levels of DEHP or other recalcitrant PAEs in wastewater sludge are likely to compromise methanogenesis and removal of biodegradable PAEs in sludge digesters....

  3. Assessment of the ability of sludge to degrade PCP under anaerobic conditions

    OpenAIRE

    R. M. L. Bolaños; M. H. R. Z. Damianovic; ZAIAT M.; E. Foresti

    2005-01-01

    The capacity of sludge from different sources to degrade pentachlorophenol (PCP) was evaluated. Three 2.5 liter reactors (R1, R2, and R3) were inoculated with different anaerobic sludges, semi continuously fed and maintained in orbital motion at 30±1°C. R1 was inoculated with aerobic sludge and river sediment collected downstream from a pulp and paper plant. R2 received sludge from an anaerobic reactor treating effluents from a paper recycling plant and R3 received anaerobic sludge...

  4. High-rate anaerobic co-digestion of kraft mill fibre sludge and activated sludge by CSTRs with sludge recirculation.

    Science.gov (United States)

    Ekstrand, Eva-Maria; Karlsson, Marielle; Truong, Xu-Bin; Björn, Annika; Karlsson, Anna; Svensson, Bo H; Ejlertsson, Jörgen

    2016-10-01

    Kraft fibre sludge from the pulp and paper industry constitutes a new, widely available substrate for the biogas production industry, with high methane potential. In this study, anaerobic digestion of kraft fibre sludge was examined by applying continuously stirred tank reactors (CSTR) with sludge recirculation. Two lab-scale reactors (4L) were run for 800days, one on fibre sludge (R1), and the other on fibre sludge and activated sludge (R2). Additions of Mg, K and S stabilized reactor performance. Furthermore, the Ca:Mg ratio was important, and a stable process was achieved at a ratio below 16:1. Foaming was abated by short but frequent mixing. Co-digestion of fibre sludge and activated sludge resulted in more robust conditions, and high-rate operation at stable conditions was achieved at an organic loading rate of 4g volatile solids (VS)L(-1)day(-1), a hydraulic retention time of 4days and a methane production of 230±10NmL per g VS. PMID:27453288

  5. [Characteristics of granular sludge during start-up of the internal circulation].

    Science.gov (United States)

    Ding, L; Ren, H; Hua, Z; Chen, J

    2001-05-01

    The quick start-up of the laboratory scale IC reactor and the characteristics of granular sludge during start-up were studied in this paper. The results showed that the first start-up of IC reactor could be finished in 20 days, while secondary start-up only needed 15 days with COD loading rate of 12-15 kg.(m3.d)-1 and COD removal larger than 85%. During start-up, the characteristics of granular sludge changed greatly: average granular diameter was increased from 0.88 mm to 1.25 mm; average settling velocity was enhanced from 35.4 m.h-1 to 105.17 m.h-1; methanogenic activities of the granular increased up to 4 times as large as the seeded sludge; the main methanobacteria was changed from Methanothrix to Methanococcus and Methanobacterium. PMID:11507902

  6. Upflow anaerobic sludge blanket reactor--a review.

    Science.gov (United States)

    Bal, A S; Dhagat, N N

    2001-04-01

    Biological treatment of wastewater basically reduces the pollutant concentration through microbial coagulation and removal of non-settleable organic colloidal solids. Organic matter is biologically stabilized so that no further oxygen demand is exerted by it. The biological treatment requires contact of the biomass with the substrate. Various advances and improvements in anaerobic reactors to achieve variations in contact time and method of contact have resulted in development of in suspended growth systems, attached growth or fixed film systems or combinations thereof. Although anaerobic systems for waste treatment have been used since late 19th century, they were considered to have limited treatment efficiencies and were too slow to serve the needs of a quickly expanding wastewater volume, especially in industrialized and densely populated areas. At present aerobic treatment is the most commonly used process to reduce the organic pollution level of both domestic and industrial wastewaters. Aerobic techniques, such as activated sludge process, trickling filters, oxidation ponds and aerated lagoons, with more or less intense mixing devices, have been successfully installed for domestic wastewater as well as industrial wastewater treatment. Anaerobic digestion systems have undergone modifications in the last two decades, mainly as a result of the energy crisis. Major developments have been made with regard to anaerobic metabolism, physiological interactions among different microbial species, effects of toxic compounds and biomass accumulation. Recent developments however, have demonstrated that anaerobic processes might be an economically attractive alternative for the treatment of different types of industrial wastewaters and in (semi-) tropical areas also for domestic wastewaters. The anaerobic degradation of complex, particulate organic matter has been described as a multistep process of series and parallel reactions. It involves the decomposition of organic and

  7. Anaerobic treatment of wastewater containing methanol in upflow anaerobic sludge bed (UASB) reactor

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The direct conversion of methanol into methane is the main process in anaerobic treatment of methanol containing wastewater.However,acetic acid can also be produced from methanol theoretically,which may probably result in an abrupt pH drop and deteriorate the anaerobic process.Therefore,it is interesting to know what would really happen in an anaerobic reactor treating methanol wastewater.In this study,an up-flow anaerobic sludge bed (UASB) reactor treating methanol wastewater was operated.The chemical oxygen demand (COD),acetic acid and pH of the effluent were monitored at different loadings and influent alkalinity.The results showed that the anaerobic reactor could be operated steadily at as low as 119 mg/L of influent alkalinity and high organic loading rate with no obvious pH drops.Volatile fatty acids accumulation was not observed even at strong shock loadings.The microorganisms in the sludge at the end of the test became homogeneous in morphology,which were mainly spherical or spheroidal in shape.

  8. Microbiological Diversity of the Anaerobic Sludge During Treatment of Venezuelan Oilfield Produced Waters

    Directory of Open Access Journals (Sweden)

    Cajacuri María Patricia

    2013-06-01

    Full Text Available In the present investigation the microbial abundances in the granular sludge of two upflow anaerobic sludge blanket reactors (UASB were compared: the first one fed with production waters of light oil (31.1-39.0° API, from the zuliana region (Venezuela (APP and the second one with glucose. To this respect, the populations of glucose fermenting bacteria (BFG, acetogenic bacteria (BAC, metanogens (MET, sulfatereducing bacteria (BSR, nitrate-reducing bacteria (BNRand heterotrophic bacteria were monitored, using selective culture media. The microbial density was correlated with physicochemical parameters: pH, total alkalinity, COD, SO4 =, NO3-, as well as with the percentages of CH4, CO2 and N2in the biogas. The results exhibit significant differences between the microbial diversity of both reactors, with a proportion of BFG > BSR > MET > BAC > BNR for the glucose reactor and of MET > BNR > BAC > BSR > BFG for the APP. The abundance of bacteria in the glucose reactor was in the order of 108, whereas in the APP reactor was of 105, which ensues from the organic and mineral composition of effluents. The results presented in this study reach evidences on the population dynamics in sludge of UASB reactors, during the treatment of oilfield produced waters.

  9. Combined electrical-alkali pretreatment to increase the anaerobic hydrolysis rate of waste activated sludge during anaerobic digestion

    International Nuclear Information System (INIS)

    Highlights: • Combined electrical-alkali pretreatment for improving sludge anaerobic digestion was proposed. • Combined process enhanced the cell lysis, biopolymers releases, and thus sludge disintegration. • Increased solubilization of sludge increased the anaerobic hydrolysis rate. • Increased solubilization does not always induce an improved anaerobic digestion efficiency. - Abstract: Pretreatment can be used prior to anaerobic digestion to improve the efficiency of waste activated sludge (WAS) digestion. In this study, electrolysis and a commonly used pretreatment method of alkaline (NaOH) solubilization were integrated as a pretreatment method for promoting WAS anaerobic digestion. Pretreatment effectiveness of combined process were investigated in terms of disintegration degree (DDSCOD), suspended solids (TSS and VSS) removals, the releases of protein (PN) and polysaccharide (PS), and subsequent anaerobic digestion as well as dewaterability after digestion. Electrolysis was able to crack the microbial cells trapped in sludge gels and release the biopolymers (PN and PS) due to the cooperation of alkaline solubilization, enhancing the sludge floc disintegration/solubilization, which was confirmed by scanning electron microscopy (SEM) analysis. Biochemical methane potential (BMP) assays showed the highest methane yield was achieved with 5 V plus pH 9.2 pretreatment with up to 20.3% improvement over the non-pretreated sludge after 42 days of mesophilic operation. In contrast, no discernible improvements on anaerobic degradability were observed for the rest of pretreated sludges, probably due to the overmuch leakage of refractory soluble organics, partial chemical mineralization of solubilized compounds and sodium inhibition. The statistical analysis further indicated that increased solubilization induced by electrical-alkali pretreatment increased the first-order anaerobic hydrolysis rate (khyd), but had no, or very slight enhancement on WAS ultimate

  10. Anaerobic co-digestion of coffee waste and sewage sludge

    OpenAIRE

    Neves, L.; Oliveira, Rosário; Alves, M. M.

    2006-01-01

    The feasibility of the anaerobic co-digestion of coffee solid waste and sewage sludge was assessed. Five different solid wastes with different chemical properties were studied in mesophilic batch assays, providing basic data on the methane production, reduction of total and volatile solids and hydrolysis rate constant. Most of the wastes had a methane yield of 0.24–0.28 m³CH4(STP)/kg VSinitial and 76–89% of the theoretical methane yield was achieved. Reduction of 50–73% in total solids and 75...

  11. ANAEROBIC CO-DIGESTION OF WASTED VEGETABLES AND ACTIVATED SLUDGE

    OpenAIRE

    Saev, M.; Koumanova, B.; Ivan, Simeonov

    2009-01-01

    Anaerobic co-digestion of activated sludge (AS) and wasted vegetables (wasted cucumbers (WC) and wasted tomatoes (WT)) was carried out at mesophilic conditions (34 ± 0.5 0C). A continuously stirred bioreactor with volume of 5 dm3 (3 dm3 working volume) was used. The digestion was examined in semi-continuous mode and 30 days hydraulic retention time. Total solids, volatile solids, COD and volatile fatty acids (VFA) were determined according to the standard methods. Daily the total biogas produ...

  12. Cosmetic wastewater treatment by upflow anaerobic sludge blanket reactor

    International Nuclear Information System (INIS)

    Anaerobic treatment of pre-settled cosmetic wastewater in batch and continuous experiments has been investigated. Biodegradability tests showed high COD and solid removal efficiencies (about 70%), being the hydrolysis of solids the limiting step of the process. Continuous treatment was carried out in an upflow anaerobic sludge blanket reactor. High COD and TSS removal efficiencies (up to 95% and 85%, respectively) were achieved over a wide range of organic load rate (from 1.8 to 9.2 g TCOD L-1 day-1). Methanogenesis inhibition was observed in batch assays, which can be predicted by means of a Haldane-based inhibition model. Both COD and solid removal were modelled by Monod and pseudo-first order models, respectively.

  13. Evaluation of granular anaerobic ammonium oxidation process for the disposal of pre-treated swine manure

    Directory of Open Access Journals (Sweden)

    Shou-Qing Ni

    2014-04-01

    Full Text Available With rising environmental concerns on potable water safety and eutrophication, increased media attention and tighter environmental regulations, managing animal waste in an environmentally responsible and economically feasible way can be a challenge. In this study, the possibility of using granular anammox process for ammonia removal from swine waste treatment water was investigated. A rapid decrease of NO2−–N and NH4+–N was observed during incubation with wastewater from an activated sludge deodorization reactor and anaerobic digestion-partial oxidation treatment process treating swine manure and its corresponding control artificial wastewaters. Ammonium removal dropped from 98.0 ± 0.6% to 66.9 ± 2.7% and nearly absent when the organic load in the feeding increased from 232 mg COD/L to 1160 mg COD/L and 2320 mg COD/L. The presence of organic carbon had limited effect on nitrite and total nitrogen removal. At a COD to N ratio of 0.9, COD inhibitory organic load threshold concentration was 727 mg COD/L. Mass balance indicated that denitrifiers played an important role in nitrite, nitrate and organic carbon removal. These results demonstrated that anammox system had the potential to effectively treat swine manure that can achieve high nitrogen standards at reduced costs.

  14. Predicting the apparent viscosity and yield stress of mixtures of primary, secondary and anaerobically digested sewage sludge: Simulating anaerobic digesters.

    Science.gov (United States)

    Markis, Flora; Baudez, Jean-Christophe; Parthasarathy, Rajarathinam; Slatter, Paul; Eshtiaghi, Nicky

    2016-09-01

    Predicting the flow behaviour, most notably, the apparent viscosity and yield stress of sludge mixtures inside the anaerobic digester is essential because it helps optimize the mixing system in digesters. This paper investigates the rheology of sludge mixtures as a function of digested sludge volume fraction. Sludge mixtures exhibited non-Newtonian, shear thinning, yield stress behaviour. The apparent viscosity and yield stress of sludge mixtures prepared at the same total solids concentration was influenced by the interactions within the digested sludge and increased with the volume fraction of digested sludge - highlighted using shear compliance and shear modulus of sludge mixtures. However, when a thickened primary - secondary sludge mixture was mixed with dilute digested sludge, the apparent viscosity and yield stress decreased with increasing the volume fraction of digested sludge. This was caused by the dilution effect leading to a reduction in the hydrodynamic and non-hydrodynamic interactions when dilute digested sludge was added. Correlations were developed to predict the apparent viscosity and yield stress of the mixtures as a function of the digested sludge volume fraction and total solids concentration of the mixtures. The parameters of correlations can be estimated using pH of sludge. The shear and complex modulus were also modelled and they followed an exponential relationship with increasing digested sludge volume fraction. PMID:27243386

  15. Biodegradation of phthalate esters during the mesophilic anaerobic digestion of sludge

    DEFF Research Database (Denmark)

    Gavala, Hariklia N.; Alatriste-Mondragon, Felipe; Iranpour, R.;

    2003-01-01

    Phthalic acid esters (PAE) are commonly found in the sludge generated in the wastewater treatment plants. Anaerobic digestion followed by land application is a common treatment and disposal practice of sludge. To date, many studies exist on the anaerobic biodegradation rates of PAE, especially...... of the easily biodegradable ones, whereas the higher molecular weight PAE have reported to be non-biodegradable under methanogenic conditions. Furthermore, there is no information on the effect of the PAE on the performance of the anaerobic digesters treating sludge. In this study, the anaerobic biodegradation...... of di-n-butyl phthalate (DBP), di-ethyl phthalate (DEP) and di-ethylhexyl phthalate (DEHP) was investigated and their relative rates of anaerobic degradation were calculated. Also, the biological removal of PAE during the anaerobic digestion of sludge in bench-scale digesters was investigated using DBP...

  16. Anaerobic wastewater treatment of concentrated sewage using a two-stage upflow anaerobic sludge blanket- anaerobic filter system.

    Science.gov (United States)

    Halalsheh, Maha M; Abu Rumman, Zainab M; Field, Jim A

    2010-01-01

    A two-stage pilot-scale upflow anaerobic sludge blanket - anaerobic filter (UASB-AF) reactors system treating concentrated domestic sewage was operated at 23 degrees C and at hydraulic retention times (HRT) of 15 and 4 h, respectively. Excess sludge from the downstream AF stage was returned to the upstream UASB reactor. The aim was to obtain higher sludge retention time (SRT) in the UASB reactor for better methanization of suspended COD. The UASB-AF system removed 55% and 65% of the total COD (COD(tot)) and suspended COD (COD(ss)), respectively. The calculated SRT in the UASB reactor ranged from 20-35 days. The AF reactor removed the washed out sludge from the first stage reactor with average COD(ss) removal efficiency of 55%. The volatile fatty acids concentration in the effluent of the AF was 39 mg COD/L compared with 78 mg COD/L measured for the influent. The slightly higher COD(tot) removal efficiency obtained in this study compared with a single stage UASB reactor was achieved at 17% reduction in the total volume. PMID:20390881

  17. Characteristics and conditioning of anaerobically digested sludge from a biological phosphorus removal plant

    OpenAIRE

    Nash, Jeffrey William

    1989-01-01

    A study of the anaerobically digested sludge form a full-scale biological phosphorus removal (BPR) plant (York River Wastewater Treatment Plant, York River, Va.) was conducted to determine the effects of BPR on sludge characteristics and conditioning requirements. Data collected from the plant indicated that both the total and soluble phosphorus (P) concentrations in the anaerobically digested sludge increased dramatically with the initiation of BPR. Accompanying this ...

  18. Fate of organic micropollutants during anaerobic digestion of sewage sludge: localization of micropollutants within sludge organic matter pools

    OpenAIRE

    Aemig, Quentin; Cheron, Claire; Delgenès, Nadine; Houot, Sabine; Patureau, Dominique

    2013-01-01

    Many organic micropolluants enter the environment through wastewaters. Some are partly degraded during wastewater treatment. For others, due to hydrophobic properties, sorption to sludge is the main removal process. Anaerobic digestion is widely used to treat sludge because it produced renewable energy in the form of methane. The digested sludge can be used as organic fertilizer. To evaluate the risk of soil contamination, it is necessary to know if organic pollutants are dissipated during th...

  19. Composition and Distribution of Extracellular Polymeric Substances in Aerobic Flocs and Granular Sludge

    OpenAIRE

    McSwain, B. S.; Irvine, R. L.; Hausner, M.; Wilderer, P. A.

    2005-01-01

    Extracellular polymeric substances (EPS) were quantified in flocculent and aerobic granular sludge developed in two sequencing batch reactors with the same shear force but different settling times. Several EPS extraction methods were compared to investigate how different methods affect EPS chemical characterization, and fluorescent stains were used to visualize EPS in intact samples and 20-μm cryosections. Reactor 1 (operated with a 10-min settle) enriched predominantly flocculent sludge with...

  20. The stability of aerobic granular sludge under 4-chloroaniline shock in a sequential air-lift bioreactor (SABR).

    Science.gov (United States)

    Zhu, Liang; Lv, Mei-le; Dai, Xin; Zhou, Jia-heng; Xu, Xiang-yang

    2013-07-01

    The aerobic granular sludge technology has a great potential in treatment of municipal wastewater and industrial wastewater containing toxic non-degradable pollutants. However, the formation and structural stability of aerobic granular sludge is susceptible to toxic shock. In the study, the effect of 4-chloroaniline (4-ClA) as a common toxic pollutant on the granular structure and performance was investigated, and the mechanism was revealed to provide more information on 4-ClA degradation with aerobic granular sludge process. The results showed that a 4-ClA shock at influent 200 mg L(-1) could cause the disintegration of aerobic granular sludge and decrease of the pollutant removal performance. The analysis of extracellular polymeric substances (EPS) within the mature and disintegrated granular sludge showed that the decrease of protein content in EPS, especially the components like Amide I 3-turn helix and β-sheet structures and aspartate, was not good for the stability of aerobic granular sludge. The microbial community results demonstrated that the disappearance of dominant bacteria like Kineosphaera limosa or appearance like Acinetobacter, might contribute to the reduction of EPS and disintegration of aerobic granular sludge. PMID:23685649

  1. The Effect of Iron Salt on Anaerobic Digestion and Phosphate Release to Sludge Liquor

    Directory of Open Access Journals (Sweden)

    Svetlana Ofverstrom

    2011-12-01

    Full Text Available Iron salts are used at wastewater treatment plants (WWTPs for several reasons: for removing chemical phosphorus, preventing from struvite formation and reducing the content of hydrogen sulfide (H2S in biogas. Anaerobic digestion is a common scheme for sludge treatment due to producing biogas that could be used as biofuel. Laboratory analysis has been carried out using anaerobic digestion model W8 (Armfield Ltd, UK to investigate any possible effect of adding FeCl3 on the anaerobic digestion of primary sludge (PS and waste activated sludge (WAS mixture as well as on releasing phosphates to digested sludge liquor. The obtained results showed that FeCl3 negatively impacted the anaerobic digestion process by reducing the volume of produced biogas. Fe-dosed sludge (max produced 30% less biogas. Biogas production from un-dosed and Fe-dosed sludge (min was similar to the average of 1.20 L/gVSfed. Biogas composition was not measured during the conducted experiments. Phosphorus content in sludge liquor increased at an average of 38% when digesting sludge without ferric chloride dosing. On the contrary, phosphate content in sludge liquor from digested Fe-dosed sludge decreased by approx. 80%.

  2. Evidence for PAH Removal Coupled to the First Steps of Anaerobic Digestion in Sewage Sludge

    OpenAIRE

    Glenda Cea-Barcia; Hélène Carrère; Jean Philippe Steyer; Dominique Patureau

    2013-01-01

    Anaerobic degradation of polycyclic aromatic hydrocarbons has been brought to the fore, but information on removal kinetics and anaerobic degrading bacteria is still lacking. In order to explore the organic micropollutants removal kinetics under anaerobic conditions in regard to the methane production kinetics, the removal rate of 12 polycyclic aromatic hydrocarbons was measured in two anaerobic batch reactors series fed with a highly loaded secondary sludge as growth substrate. The results u...

  3. Use of anaerobic hydrolysis pretreatment to enhance ultrasonic disintegration of excess sludge.

    Science.gov (United States)

    Li, Xianjin; Zhu, Tong; Shen, Yang; Chai, Tianyu; Xie, Yuanhua; You, Meiyan; Wang, Youzhao

    2016-01-01

    To improve the excess sludge disintegration efficiency, reduce the sludge disintegration cost, and increase sludge biodegradability, a combined pretreatment of anaerobic hydrolysis (AH) and ultrasonic treatment (UT) was proposed for excess sludge. Results showed that AH had an advantage in dissolving flocs, modifying sludge characteristics, and reducing the difficulty of sludge disintegration, whereas UT was advantageous in damaging cell walls, releasing intracellular substances, and decomposing macromolecular material. The combined AH-UT process was an efficient method for excess sludge pretreatment. The optimized solution involved AH for 3 days, followed by UT for 10 min. After treatment, chemical oxygen demand, protein, and peptidoglycan concentrations reached 3,949.5 mg O2/L, 752.5 mg/L and 619.1 mg/L, respectively. This work has great significance for further engineering applications, namely, reducing energy consumption, increasing the sludge disintegration rate, and improving the biochemical properties of sludge. PMID:26942542

  4. Assessment of the ability of sludge to degrade PCP under anaerobic conditions

    Directory of Open Access Journals (Sweden)

    R. M. L. Bolaños

    2005-12-01

    Full Text Available The capacity of sludge from different sources to degrade pentachlorophenol (PCP was evaluated. Three 2.5 liter reactors (R1, R2, and R3 were inoculated with different anaerobic sludges, semi continuously fed and maintained in orbital motion at 30±1°C. R1 was inoculated with aerobic sludge and river sediment collected downstream from a pulp and paper plant. R2 received sludge from an anaerobic reactor treating effluents from a paper recycling plant and R3 received anaerobic sludge from a biodigestor treating industrial and domestic effluents. The sludges were first acclimatized to a culture medium generally recommended for organochloride anaerobic degradation studies. The reactors were then subjected to increasing concentrations of PCP from 0.05 to 10.0 mg.l-1. PCP degradation and metabolite formation were monitored using gas chromatography, and the effects of PCP on the anaerobic process were verified by monitoring pH, volatile fatty acids, alkalinity, total suspended solids, and chemical oxygen demand. It was found that PCP did not affect reactor performance. All the sludges displayed the best PCP degradation capacity at a concentration of 0.2 mg.l-1, producing fewer chlorinated metabolites than when higher PCP concentrations were applied. R1 consistently produced fewer chlorinated metabolites, confirming the hypothesis that pre exposure to chlorinated compounds improves the sludge's capacity to degrade PCP.

  5. [Detection of anaerobic processes and microorganisms in immobilized activated sludge of a wastewater treatment plant with intense aeration].

    Science.gov (United States)

    Litti, Iu V; Nekrasova, V K; Kulikov, N I; Siman'kova, M V; Nozhevnikova, A N

    2013-01-01

    Attached activated sludge from the Krasnaya Polyana (Sochi) wastewater treatment plant was studied after the reconstruction by increased aeration and water recycle, as well as by the installation of a bristle carrier for activated sludge immobilization. The activated sludge biofilms developing under conditions of intense aeration were shown to contain both aerobic and anaerobic microorganisms. Activity of a strictly anaerobic methanogenic community was revealed, which degraded organic compounds to methane, further oxidized by aerobic methanotrophs. Volatile fatty acids, the intermediates of anaerobic degradation of complex organic compounds, were used by both aerobic and anaerobic microorganisms. Anaerobic oxidation of ammonium with nitrite (anammox) and the presence of obligate anammox bacteria were revealed in attached activated sludge biofilms. Simultaneous aerobic and anaerobic degradation of organic contaminants by attached activated sludge provides for high rates of water treatment, stability of the activated sludge under variable environmental conditions, and decreased excess sludge formation. PMID:25509405

  6. Improvement of anaerobic bio-hydrogen gas production from organic sludge waste

    International Nuclear Information System (INIS)

    Microbial hydrogen gas production from organic matters stands out as one of the most promising alternatives for sustainable green energy production. Based on the literature review, investigation of anaerobic bio-hydrogen gas production from organic sludge waste using a mixed culture has been very limited. The objective of this study was to assess the anaerobic bio-hydrogen gas production from organic sludge waste under various conditions. (Author)

  7. Rational Basis for Designing Horizontal-Flow Anaerobic Immobilized Sludge (HAIS) Reactor for Wastewater Treatment

    OpenAIRE

    ZAIAT M.; L.G.T. Vieira; A.K.A. Cabral; I.R. de Nardi; F.J. Vela; E. Foresti

    1997-01-01

    The conception and development on a rational basis of a new configuration of anaerobic fixed-bed bioreactor for wastewater treatment, the horizontal-flow anaerobic immobilized sludge (HAIS) reactor, is presented. Such a reactor containing immobilized sludge in polyurethane foam matrices was first assayed for treating paper industry wastewater. A very short start-up period was observed and the reactor achieved stable operation by the eighth day. Afterwards, fundamental aspects of the process w...

  8. Use of gamma-irradiation pretreatment for enhancement of anaerobic digestibility of sewage sludge

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The effects of y-irradiation pretreatment on anaerobic digestibility of sewage sludge was investigated in this paper.Parameters like solid components,soluble components,and biogas production of anaerobic digestion experiment for sewage sludge were measured.The values of these parameters were compared before and after y-irradiation pretreatment.Total solid (TS),volatile solid (VS),suspended solid (SS),volatile suspended solid (VSS),and average floc size of samples decreased after γ-irradiation treatment.Besides,floc size distribution of sewage sludge shifted from 80-100 μm to 0-40 μm after y-irradiation treatment at the doses from 0 to 30 kGy,which indicated the disintegration of sewage sludge.Moreover,microbe cells of sewage sludge were ruptured by γ-irradiation treatment,which resulted in the release of cytoplasm and increase of soluble chemical oxygen demand (SCOD).Both sludge disintegration and microbe cells rupture enhanced the subsequent anaerobic digestion process,which was demonstrated by the increase of accumulated biogas production.Compared with digesters fed with none irradiated sludge,the accumulated biogas production increased 44,98,and 178 mL for digesters fed sludge irradiated at 2.48,6.51,and 11.24 kGy,respectively.The results indicated that "/-irradiation pretreatment could effectively enhance anaerobic digestibility of sewage sludge,and correspondingly,could accelerate hydrolysis process,shorten sludge retention time of sludge anaerobic digestion process.

  9. Improved Energy Recovery by Anaerobic Grey Water Sludge Treatment with Black Water

    Directory of Open Access Journals (Sweden)

    Taina Tervahauta

    2014-08-01

    Full Text Available This study presents the potential of combining anaerobic grey water sludge treatment with black water in an up-flow anaerobic sludge blanket (UASB reactor to improve energy recovery within source-separated sanitation concepts. Black water and the mixture of black water and grey water sludge were compared in terms of biochemical methane potential (BMP, UASB reactor performance, chemical oxygen demand (COD mass balance and methanization. Grey water sludge treatment with black water increased the energy recovery by 23% in the UASB reactor compared to black water treatment. The increase in the energy recovery can cover the increased heat demand of the UASB reactor and the electricity demand of the grey water bioflocculation system with a surplus of 0.7 kWh/cap/y electricity and 14 MJ/cap/y heat. However, grey water sludge introduced more heavy metals in the excess sludge of the UASB reactor and might therefore hinder its soil application.

  10. Impact of influent COD/N ratio on disintegration of aerobic granular sludge.

    Science.gov (United States)

    Luo, Jinghai; Hao, Tianwei; Wei, Li; Mackey, Hamish R; Lin, Ziqiao; Chen, Guang-Hao

    2014-10-01

    Disintegration of aerobic granular sludge (AGS) is a challenging issue in the long-term operation of an AGS system. Chemical oxygen demand (COD)-to-nitrogen (N) ratio (COD/N), often variable in industrial wastewaters, could be a destabilizing factor causing granule disintegration. This study investigates the impact of this ratio on AGS disintegration and identifies the key causes, through close monitoring of AGS changes in its physical and chemical characteristics, microbial community and treatment performance. For specific comparison, two lab-scale air-lift type sequencing batch reactors, one for aerobic granular and the other for flocculent sludge, were operated in parallel with three COD/N ratios (4, 2, 1) applied in the influent of each reactor. The decreased COD/N ratios of 2 and 1 strongly influenced the stability of AGS with regard to physical properties and nitrification efficiency, leading to AGS disintegration when the ratio was decreased to 1. Comparatively the flocculent sludge maintained relatively stable structure and nitrification efficiency under all tested COD/N ratios. The lowest COD/N ratio resulted in a large microbial community shift and extracellular polymeric substances (EPS) reduction in both flocculent and granular sludges. The disintegration of AGS was associated with two possible causes: 1) reduction in net tyrosine production in the EPS and 2) a major microbial community shift including reduction in filamentous bacteria leading to the collapse of granule structure. PMID:24950459

  11. Molecular characterization of bacterial community in aerobic granular sludge stressed by pentachlorophenol

    Institute of Scientific and Technical Information of China (English)

    LIU He; LI Guangwei; LI Xiufen; CHEN Jian

    2008-01-01

    To characterize the effects of pentachlorophenol (PCP) on the performance and microbial community of aerobic granular sludge insequencing batch reactor (SBR), the web-based terminal restriction fragment length polymorphism (T-RFLP) and real-time PCR (RT-PCR) techniques were used to explore the bacterial community structure. When PCP increased from 0 to 50 mg/L, the COD removalrate changed little, while the ammonia removal rate dropped from 100% to 64.9%. The results of molecular characterization showedthat the quantity of ammonia oxidizing bacteria (AOB) kept constantly, although the number of bacteria species decreased with theincrease of PCP concentation. Significant shift in bacterial community structure at different PCP stresses was observed within aerobicgranular sludge. When the PCP was absent, there are 69 strains in aerobic granular sludge detected by T-RFLP method. With theincrease of PCP, most of bacteria disappeared and only 19 bacteria existed at all five PCP concentrations. These results contributed tocomprehensive understanding of the microbial community structure under the PCP stress and its relationship with the performance forwastewater treatment by aerobic granular sludge.

  12. Anaerobic wastewater treatment of high salinity wastewaters: impact on bioactivity and biomass retention

    OpenAIRE

    S. Ismail

    2013-01-01

    Anaerobic sludge bed reactor systems like the upflow anaerobic sludge blanket (UASB) and expended granular sludge bed (EGSB) reactors are currently the mostly applied high-rate reactor systems for anaerobic wastewater treatment. The success of both systems has changed the world conception of wastewater treatment with energy recovery being an intrinsic part of the treatment process, avoidance of excess sludge problems and extremely low space requirement. Nevertheless, while broadening the UASB...

  13. Effect of ultrasonic pretreatment on anaerobic digestion and its sludge dewaterability

    Institute of Scientific and Technical Information of China (English)

    Huacheng Xu; Pinjing He; Guanghui Yu; Liming Shao

    2011-01-01

    To investigate the effect of ultrasonic pretreatment on anaerobic digestion and sludge dewaterability and further to probe into the influencing factors on sludge dewaterability,sludge flocs were stratified into four fractions:(1) slime; (2) loosely bound extracellular polymeric substances (LB-EPS); (3) tightly bound EPS (TB-EPS); and (4) EPS-free pellets.The results showed that ultrasonic pretreatment increased the anaerobic digestion efficiency by 7%-8%.Anaerobic digestion without ultrasonic pretreatment deteriorated the sludge dewaterability,with the capillary suction time (CST) increased from 1.42 to 47.3 (sec.L)/g-TSS.The application of ultrasonic pretreatment firstly deteriorated the sludge dewaterability (normalized CST increased to 44.4 (sec.L)/g-TSS),while subsequent anaerobic digestion offset this effect and ultimately decreased the normalized CST to 23.2 (sec.L)/g-TSS.The dewaterability of unsonicated sludge correlated with protein (p = 0.003) and polysaccharide (p = 0.004) concentrations in the slime fraction,while that of sonicated sludge correlated with protein concentrations in the slime and LB-EPS fractions (p < 0.05).Fluorescent excitationemission matrix analysis showed that the fluorescence matters in the LB-EPS fraction significantly correlated with sludge dewaterability during anarobic digestion.

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

    NARCIS (Netherlands)

    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 micro

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

    NARCIS (Netherlands)

    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 perf

  16. Application of Hydrothermal Treatment to High Concentrated Sewage Sludge for Anaerobic Digestion Process

    Directory of Open Access Journals (Sweden)

    M. Orikawa

    2013-10-01

    Full Text Available Tomato and seaweed were produced by utilizing CO2 and heat discharged from power generation using biogas in Toyogawa biomass park, Japan. The biogas was obtained by anaerobic digestion with hydrothermal treatment. The hydrothermal treatment was applied to the high concentrated sewage sludge (22 % total solids (TS dewatered sludge. The purpose of this study is to clarify the effect of hydrothermal treatment on the qualities of high concentrated sewage sludge, by analyzing particulate organic carbon (POC and dissolved organic carbon (DOC. The hydrothermal treatment was investigated under 10-60 min of treatment time, 180-200 °C of temperature, 10-22 %-TS of sewage sludge concentration. The results showed that the DOC in each conditions increased through hydrothermal treatment. The highest DOC obtained was 67 % of total carbon concentration, when the temperature was 180 °C, treatment time was 60 min and sewage sludge concentration was 10 %-TS. Furthermore, the viscosity of treated sewage sludge was decreased by hydrothermal treatment. In batch anaerobic digestion test, methane gas production was confirmed. In addition, this study evaluated the energy balance of this system. Thus, the results of this study indicated that the possibility of application of hydrothermal treatment to high concentrated sewage sludge for anaerobic digestion process. Keywords: anaerobic reaction, hydrothermal treatment, sewage sludge, solubilization

  17. Simulation of DEHP biodegradation and sorption during the anaerobic digestion of secondary sludge

    DEFF Research Database (Denmark)

    Fountoulakis, M.S.; Stamatelatou, K.; Batstone, Damien J.;

    2006-01-01

    Di-ethylhexyl phthalate (DEHP) has commonly been found in the sludge of municipal wastewater treatment plants especially during anaerobic processing. It is slowly biodegradable under anaerobic conditions. Due to its high hydrophobicity, sorption-desorption processes can be rate-limiting for the c...

  18. Hydrolysis of particulate substrate by activated sludge under aerobic, anoxic and anaerobic conditions

    DEFF Research Database (Denmark)

    Henze, Mogens; Mladenovski, C.

    1991-01-01

    An investigation of hydrolysis of particulate organic substrate by activated sludge has been made. Raw municipal wastewater was used as substrate. It was mixed with activated sludge from a high loaded activated sludge plant with pure oxygen aeration. During 4 days batch experiments under aerobic......, anoxic and anaerobic conditions, the hydrolysis was following through the production of ammonia. The hydrolysis rate of nitrogeneous compounds is significantly affected by the electron donor available. The rate is high under aerobic conditions, medium under anaerobic conditions and low under anoxic...... conditions. The ratio between the hydrolysis rates under aerobic and under anoxic conditions are very similar to the respiration rates measured as electron equivalents....

  19. Sequencing batch reactor operation for treating wastewater with aerobic granular sludge

    Directory of Open Access Journals (Sweden)

    M. K. Jungles

    2014-03-01

    Full Text Available In this work, the performance of a sequencing batch reactor (SBR on aerobic granular sludge was studied for urban wastewater treatment. The system was inoculated with aerobic activated sludge collected from a wastewater treatment plant and, after 30 days of operation, the first granules observed had an average diameter of 0.1 mm. The biomass concentration reached a maximum value around 4 g VSS L-1, and COD removal and nitrification efficiency achieved stable values of 90%. The predominant oxidizing ammonium bacteria in the granules were identified as Nitrosomonas spp.

  20. Performance of sequential anaerobic/aerobic digestion applied to municipal sewage sludge.

    Science.gov (United States)

    Tomei, M Concetta; Rita, Sara; Mininni, Giuseppe

    2011-07-01

    A promising alternative to conventional single phase processing, the use of sequential anaerobic-aerobic digestion, was extensively investigated on municipal sewage sludge from a full scale wastewater treatment plant. The objective of the work was to evaluate sequential digestion performance by testing the characteristics of the digested sludge in terms of volatile solids (VS), Chemical Oxygen Demand (COD) and nitrogen reduction, biogas production, dewaterability and the content of proteins and polysaccharides. VS removal efficiencies of 32% in the anaerobic phase and 17% in the aerobic one were obtained, and similar COD removal efficiencies (29% anaerobic and 21% aerobic) were also observed. The aerobic stage was also efficient in nitrogen removal providing a decrease of the nitrogen content in the supernatant attributable to nitrification and simultaneous denitrification. Moreover, in the aerobic phase an additional marked removal of proteins and polysaccharides produced in the anaerobic phase was achieved. The sludge dewaterability was evaluated by determining the Optimal Polymer Dose (OPD) and the Capillary Suction Time (CST) and a significant positive effect due to the aerobic stage was observed. Biogas production was close to the upper limit of the range of values reported in the literature in spite of the low anaerobic sludge retention time of 15 days. From a preliminary analysis it was found that the energy demand of the aerobic phase was significantly lower than the recovered energy in the anaerobic phase and the associated additional cost was negligible in comparison to the saving derived from the reduced amount of sludge to be disposed. PMID:21477916

  1. Thermal and enzymatic pretreatment of sludge containing phthalate esters prior to mesophilic anaerobic digestion

    DEFF Research Database (Denmark)

    Gavala, Hariklia N.; Yenal, U.; Ahring, Birgitte Kiær

    2004-01-01

    The present study aimed at investigating the effect of thermal pretreatment of sludge at 70degreesC on the anaerobic degradation of three commonly found phthalic acid esters (PAE): di-ethyl phthalate (DEP), di-butyl phthalate (DBP), and di-ethylhexyl phthalate (DEHP). Also, the enzymatic treatment...... at 28degreesC with a commercial lipase was studied as a way to enhance PAE removal. Pretreatment at 70degreesC of the sludge containing PAE negatively influenced the anaerobic biodegradability of phthalate esters at 37degreesC. The observed reduction of PAE biodegradation rates after the thermal...... orders of magnitude faster than under normal mesophilic anaerobic conditions. Moreover, the enzymatic treatment resulted in the shortest half-life of DEHP in sludge reported so far. Our study further showed that enzymatic treatment with lipases can be applied to raw sludge and its efficiency does...

  2. Study of aerobic granular sludge stability in a continuous-flow membrane bioreactor.

    Science.gov (United States)

    Corsino, S F; Campo, R; Di Bella, G; Torregrossa, M; Viviani, G

    2016-01-01

    A granular continuous-flow membrane bioreactor with a novel hydrodynamic configuration was developed to evaluate the stability of aerobic granular sludge (AGS). Under continuous-flow operation (Period I), AGS rapidly lost their structural integrity resulting in loose and fluffy microbial aggregates in which filamentous bacteria were dominant. The intermittent feeding (Period II) allowed obtaining the succession of feast and famine conditions that favored the increase in AGS stability. Although no further breakage occurred, the formation of new granules was very limited, owing to the absence of the hydraulic selection pressure. These results noted the necessity to ensure, on the one hand the succession of feast/famine conditions, and on the other, the hydraulic selection pressure that allows flocculent sludge washout. This preliminary study shows that the proposed configuration could meet the first aspect; in contrast, biomass selection needs to be improved. PMID:26526094

  3. Mesophilic anaerobic stabilization of sewage sludge. Mesophile anaerobe Klaerschlammstabilisierung mit aerober Folgebehandlung

    Energy Technology Data Exchange (ETDEWEB)

    Stoll, U.

    1988-01-01

    Sludges treated in two stages in experiments - 7 days of anaerobic treatment and 2 days of aerobic-thermophilic treatment - can be judged to be completely stabilized because of the stabilization parameters BOD/sub 5//COD ratio and respiratory activity. The degradation results obtained are comparable to or better than those of the 20-day digestion (reference process). For all aerobic processes under investigation a clear temperature increase in the aerobic reactor was measured because of the exothermal metabolic processes of the aerobic biocenosis. There was a temperature rise of 15/sup 0/C in the tests in the aerobic reactor even after longer digestion times of 15 and 20 days. The results of the epidemics and hygiene investigations show that a secondary aerobic-thermophilic stage after the mesophilic digestion with adequate marginal conditions - germ retention time of 23 hours in the aerobic reactor at process temperatures higher than 50/sup 0/C as well as charging in batch quantities - leads to a safe and complete decontamination. Under these process and operation conditions all salmonellae were killed and the number of the enterobacteriaceae in 1 g of sludge was always less than 1.000. (orig./EF).

  4. APPLICATION AND PERSPECTIVES OF DEVELOPMENT OF AEROBIC GRANULAR SLUDGE TECHNOLOGY IN WASTEWATER TREATMENT

    OpenAIRE

    Agnieszka Cydzik-Kwiatkowska

    2014-01-01

    Recently an extensive studies have been carried out on aerobic granular sludge technology in both laboratory and technical scale. Aerobic granules are compact, spherical microbial consortia created by a spontaneous immobilization. Amongst their advantages are a very good settling ability, long biomass age and simultaneous pollutant removal in the granule structure that enables full biological treatment of wastewater in a single reactor. This review outlines up-to-date information on granule f...

  5. Enantiomeric fraction evaluation of pharmaceuticals in an aerobic granular sludge sequencing batch reactor

    OpenAIRE

    Amorim, Catarina L.; Moreira, Irina S.; Ribeiro, Ana R.; Santos, Lúcia H. M. L. M.; Delerue-Matos, Cristina; Tiritan, Maria E.; Castro, Paula M. L.

    2015-01-01

    Pharmaceutical compounds are emerging environmental contaminants that have received growing attention over the last two decades. Several of these pharmaceuticals currently in use are chiral. Therefore, the evaluation of the enantiomeric fraction (EF) of chiral pharmaceuticals (CPs), during the removal processes occurring in the environment, is crucial for assessing the fate of such micropollutants. Aerobic granular sludge (AGS) technology is one of the promising biotechnologies in wastewater ...

  6. Toxicity assessment of 4-chlorophenol to aerobic granular sludge and its interaction with extracellular polymeric substances

    International Nuclear Information System (INIS)

    Highlights: • Toxicity of 4-CP to aerobic granular sludge process was evaluated. • 3D-EEM characterized the interaction between EPS and 4-CP. • Tryptophan was the main substance result in fluorescence quenching. • The mechanism of fluorescence quenching belongs to static quenching. - Abstract: The main objective of this study was to evaluate the toxicity of 4-chlorophenol (4-CP) to aerobic granular sludge in the process of treating ammonia rich wastewater. In the short-term exposure of 4-CP of 5 and 10 mg/L, ammonia nitrogen removal efficiencies in the batch reactors decreased to 87.18 ± 2.81 and 41.16 ± 3.55%, which were remarkably lower than that of control experiment (99.83 ± 0.54%). Correspondingly, the respirometric activities of heterotrophic and autotrophic bacteria of aerobic granular sludge were significantly inhibited in the presence of 4-CP. Moreover, the main components of extracellular polymeric substances (EPS) including polysaccharides and proteins increased from 18.74 ± 0.29 and 22.57 ± 0.34 mg/g SS to 27.79 ± 0.51 and 24.69 ± 0.38 mg/g SS, respectively, indicating that the presence of 4-CP played an important role on the EPS production. Three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectroscopy further showed that the intensities of EPS samples were obviously quenched with the increased of 4-CP concentrations. To be more detailed, synchronous fluorescence spectra indicated that the interaction between EPS and 4-CP was mainly caused by tryptophan residues. The mechanism of fluorescence quenching belongs to static quenching with a formation constant (KA) of 0.07 × 104 L/mol, implying the strong formation of EPS and 4-CP complex. The results could provide reliable and accurate information to determine the potential toxicity of 4-CP on the performance of aerobic granular sludge system

  7. Biomethanation of Syngas Using Anaerobic Sludge: Shift in the Catabolic Routes with the CO Partial Pressure Increase

    Science.gov (United States)

    Sancho Navarro, Silvia; Cimpoia, Ruxandra; Bruant, Guillaume; Guiot, Serge R.

    2016-01-01

    Syngas generated by thermal gasification of biomass or coal can be steam reformed and purified into methane, which could be used locally for energy needs, or re-injected in the natural gas grid. As an alternative to chemical catalysis, the main components of the syngas (CO, CO2, and H2) can be used as substrates by a wide range of microorganisms, to be converted into gas biofuels, including methane. This study evaluates the carboxydotrophic (CO-consuming) methanogenic potential present in an anaerobic sludge from an upflow anaerobic sludge bed (UASB) reactor treating waste water, and elucidates the CO conversion routes to methane at 35 ± 3°C. Kinetic activity tests under CO at partial pressures (pCO) varying from 0.1 to 1.5 atm (0.09–1.31 mmol/L in the liquid phase) showed a significant carboxydotrophic activity potential for growing conditions on CO alone. A maximum methanogenic activity of 1 mmol CH4 per g of volatile suspended solid and per day was achieved at 0.2 atm of CO (0.17 mmol/L), and then the rate decreased with the amount of CO supplied. The intermediary metabolites such as acetate, H2, and propionate started to accumulate at higher CO concentrations. Inhibition experiments with 2-bromoethanesulfonic acid (BES), fluoroacetate, and vancomycin showed that in a mixed culture CO was converted mainly to acetate by acetogenic bacteria, which was further transformed to methane by acetoclastic methanogens, while direct methanogenic CO conversion was negligible. Methanogenesis was totally blocked at high pCO in the bottles (≥1 atm). However it was possible to achieve higher methanogenic potential under a 100% CO atmosphere after acclimation of the sludge to CO. This adaptation to high CO concentrations led to a shift in the archaeal population, then dominated by hydrogen-utilizing methanogens, which were able to take over acetoclastic methanogens, while syntrophic acetate oxidizing (SAO) bacteria oxidized acetate into CO2 and H2. The disaggregation of the

  8. Biomethanation of Syngas Using Anaerobic Sludge: Shift in the Catabolic Routes with the CO Partial Pressure Increase.

    Science.gov (United States)

    Sancho Navarro, Silvia; Cimpoia, Ruxandra; Bruant, Guillaume; Guiot, Serge R

    2016-01-01

    Syngas generated by thermal gasification of biomass or coal can be steam reformed and purified into methane, which could be used locally for energy needs, or re-injected in the natural gas grid. As an alternative to chemical catalysis, the main components of the syngas (CO, CO2, and H2) can be used as substrates by a wide range of microorganisms, to be converted into gas biofuels, including methane. This study evaluates the carboxydotrophic (CO-consuming) methanogenic potential present in an anaerobic sludge from an upflow anaerobic sludge bed (UASB) reactor treating waste water, and elucidates the CO conversion routes to methane at 35 ± 3°C. Kinetic activity tests under CO at partial pressures (pCO) varying from 0.1 to 1.5 atm (0.09-1.31 mmol/L in the liquid phase) showed a significant carboxydotrophic activity potential for growing conditions on CO alone. A maximum methanogenic activity of 1 mmol CH4 per g of volatile suspended solid and per day was achieved at 0.2 atm of CO (0.17 mmol/L), and then the rate decreased with the amount of CO supplied. The intermediary metabolites such as acetate, H2, and propionate started to accumulate at higher CO concentrations. Inhibition experiments with 2-bromoethanesulfonic acid (BES), fluoroacetate, and vancomycin showed that in a mixed culture CO was converted mainly to acetate by acetogenic bacteria, which was further transformed to methane by acetoclastic methanogens, while direct methanogenic CO conversion was negligible. Methanogenesis was totally blocked at high pCO in the bottles (≥1 atm). However it was possible to achieve higher methanogenic potential under a 100% CO atmosphere after acclimation of the sludge to CO. This adaptation to high CO concentrations led to a shift in the archaeal population, then dominated by hydrogen-utilizing methanogens, which were able to take over acetoclastic methanogens, while syntrophic acetate oxidizing (SAO) bacteria oxidized acetate into CO2 and H2. The disaggregation of the

  9. The Impact of Chemical Phosphorus Removal on the Process of Anaerobic Sludge Digestion

    Directory of Open Access Journals (Sweden)

    Svetlana Ofverstrom

    2011-02-01

    Full Text Available The paper investigates the efficiency of the mixture of primary sludge and excess activated sludge in Vilnius WWTP with reference to the anaerobic digestion process. Sludge digestion was carried out under laboratory conditions using anaerobic sludge digestion model W8 (Armfield Ltd., UK. Laboratory analyses consist of two periods – the anaerobic digestion of the un-dosed and Fe-dosed sludge mixture. The results of digestion were processed using the methods of statistical analysis. The findings showed reduction in volatile solids approx. by 6% when dosing min FeCl3·6H2O and 15% when dosing max FeCl3·6H2O into feed sludge. Gas volume produced during the digestion of the un-dosed sludge was 90–160 ml/d and 60–125 ml/d in min Fe-dosed sludge and 45-95 ml/d. Also, correlation between VS loadings and biogas production was found. A rise in VS loading from 0,64 g/l/d to 1,01 g/l/d increased biogas production from 90 ml/d to 140–160 ml/d.Article in Lithuanian

  10. Toxicity of di-(2-ethylhexyl) phthalate on the anaerobic digestion of wastewater sludge

    DEFF Research Database (Denmark)

    Alatriste-Mondragon, Felipe; Iranpour, R.; Ahring, Birgitte Kiær

    2003-01-01

    are considered recalcitrant. Moreover, they inhibit methanogenesis. However, studies have not been made on the effect of feeding a combination of recalcitrant and biodegradable PAEs into anaerobic digesters treating wastewater sludge. The present study was conducted with wastewater sludge from the Los Angeles...... populations in the anaerobic bioreactor. Our results imply that high levels of DEHP or other recalcitrant PAEs in wastewater sludge are likely to compromise methanogenesis and removal of biodegradable PAEs in sludge digesters....... Bureau of Sanitation's Hyperion Treatment Plant. Di (2-ethylhexyl) phthalate (DEHP), the most common persistent PAE found in wastewater, and di-n-butyl phthalate (DBP), a common PAE with short ester chains, were sorbed into the sludge fed to a bench-scale digester for a period of 12 weeks. DEHP...

  11. Biosorption of Acid Yellow 17 from aqueous solution by non-living aerobic granular sludge

    International Nuclear Information System (INIS)

    Batch biosorption experiments were carried out for the removal of Acid Yellow 17 from aqueous solution using non-living aerobic granular sludge as an effective biosorbent. The effects of solution pH value, biosorbent dosage, initial Acid Yellow 17 concentration, NaCl concentration and temperature on the biosorption were investigated. The experimental results indicate that this process was highly dependent on pH value and the pH value of 2.0 was favorable. The Temkin isotherm was more applicable for describing the biosorption equilibrium at the whole concentration range than the Freundlich and Langmuir isotherm. The results of kinetics study show that the pseudo-second-order model fitted to the experimental data well. Both intraparticle diffusion and boundary layer diffusion might affect the biosorption rate. Thermodynamic studies demonstrate that the biosorption process was spontaneous and exothermic. The FTIR analysis before and after Acid Yellow 17 binding indicated that functional groups such as amine, hydroxyl, carboxyl and either on the non-living aerobic granular sludge would be the active binding sites for the biosorption of the studied dye. These results show that non-living aerobic granular sludge could be effectively used as a low-cost and alternative biosorbent for the removal of Acid Yellow 17 dye from wastewater.

  12. [Single-stage autotrophic nitrogen removal reactor with self-generated granular sludge for treating sludge dewatering effluent].

    Science.gov (United States)

    Cao, Jian-ping; Du, Bing; Liu, Yin; Qin, Yong-sheng

    2009-10-15

    Single-stage autotrophic nitrogen removal (SANR) has been observed in a long-term operated nitrosation air-lift reactor for treating digested sludge dewatering effluent from sewage wastewater treatment plant. A kind of so called self-generated granular sludge which undertake the SANR reaction has oriented formed. The performance of SANR reactor cultivated above sludge for treating sludge dewatering effluent has been tested and better results have been reached. When the influent total nitrogen (TN) was kept about 350 mg/L (mainly ammonium nitrogen), the average TN removal efficiency and nitrogen removal load were 74.8% (maximum 86.92%) and 0.68 kg x (m3 x d)(-1) [maximum 0.9 kg x (m3 x d)(-1)] respectively. The operation stability and nitrogen removal efficiency have been enforced after adding a certain quantity powered activated carbon. The influent ammonium concentration, nitrogen load and aeration rate have a great effect on SANR reactor as well as the influent organic compound, pH, alkalinity have a relatively low effect. The parameters such as the ratios of aeration rate/deltaTN, aeration rate/deltaNH4+ -N, deltaALK/deltaTN can be used for better controlling the reaction. PMID:19968119

  13. Enhancing anaerobic digestion of waste activated sludge by pretreatment: effect of volatile to total solids.

    Science.gov (United States)

    Wang, Xiao; Duan, Xu; Chen, Jianguang; Fang, Kuo; Feng, Leiyu; Yan, Yuanyuan; Zhou, Qi

    2016-06-01

    In this study the effect of volatile to total solids (VS/TS) on anaerobic digestion of waste activated sludge (WAS) pretreated by alkaline, thermal and thermal-alkaline strategies was studied. Experimental results showed that the production of methane from sludge was increased with VS/TS. When anaerobic digesters were fed with sludge pretreated by the thermal-alkaline method, the average methane yield was improved from 2.8 L/d at VS/TS 0.35 to 4.7 L/d at VS/TS 0.56. Also, the efficiency of VS reduction during sludge anaerobic digestion varied between 18.9% and 45.6%, and increased gradually with VS/TS. Mechanism investigation of VS/TS on WAS anaerobic digestion suggested that the general activities of anaerobic microorganisms, activities of key enzymes related to sludge hydrolysis, acidification and methanogenesis, and the ratio of Archaea to Bacteria were all increased with VS/TS, showing good agreement with methane production. PMID:26698921

  14. Simulation of DEHP biodegradation and sorption during the anaerobic digestion of secondary sludge

    DEFF Research Database (Denmark)

    Fountoulakis, M.S.; Stamatelatou, K.; Batstone, Damien J.;

    2006-01-01

    Di-ethylhexyl phthalate (DEHP) has commonly been found in the sludge of municipal wastewater treatment plants especially during anaerobic processing. It is slowly biodegradable under anaerobic conditions. Due to its high hydrophobicity, sorption-desorption processes can be rate-limiting for the c......Di-ethylhexyl phthalate (DEHP) has commonly been found in the sludge of municipal wastewater treatment plants especially during anaerobic processing. It is slowly biodegradable under anaerobic conditions. Due to its high hydrophobicity, sorption-desorption processes can be rate......-limiting for the compound biodegradation. In this study, the anaerobic biodegradation of DEHP was investigated through batch kinetic experiments and dynamic transitions of a continuous stirred tank reactor (CSTR) fed with secondary sludge contaminated with DEHP. A widely accepted model (ADM1) was used to fit the anaerobic...... digestion of secondary sludge and was properly extended to. account for DEHP removal, in which mass transfer processes are also involved. It was shown that DEHP removal was limited by the transfer of DEHP within the solid fraction. The criterion selected for the distinction of the two sites was whether...

  15. Pretreatment on Anaerobic Sludge for Enhancement of Biohydrogen Production from Cassava Processing Wastewater

    Directory of Open Access Journals (Sweden)

    Franciele do Carmo Lamaison

    2014-02-01

    Full Text Available Methods for the enrichment of an anaerobic sludge with H2-producing bacteria have been compared by using cassava processing wastewater as substrate.The sludge was submitted to three different pretreatments: 1 heat pretreatment by boiling at 98 °C for 15 min., 2 heat pretreatment followed by sludge washout in a Continuous Stirring Tank Reactor (CSTR operated at a dilution rate (D of 0.021 h-1, and 3 sludge washout as the sole enrichment method. The pretreated sludge and the sludge without pretreatment (control were employed in the seeding of 4 batch bioreactors, in order to verify the volume and composition of the generated biogas. Maximum H2 production rates (Rm from the pretreated sludges, were estimated by the modified Gompertz model. Compared to the control, H2 production was ca. 4 times higher for the sludge submitted to the heat pretreatment only and for the sludge subjected to heat pretreatment combined with washout, and 10 times higher for washout. These findings demonstrated that the use of sludge washout as the sole sludge pretreatment method was the most effective in terms of H2 production, as compared to the heat and to the combined heat and washout pretreatments.

  16. Biodegradation of 14C-dicofol in wastewater aerobic treatment and sludge anaerobic biodigestion.

    Science.gov (United States)

    Oliveira, Jaime L da M; Silva, Denise P; Martins, Edir M; Langenbach, Tomaz; Dezotti, Marcia

    2012-01-01

    Organic micropollutants are often found in domestic and industrial effluents. Thus, it is important to learn their fate, the metabolites generated and their sorption during biological treatment processes. This work investigated the biodegradation of 14C-dicofol organochloride during wastewater aerobic treatment and sludge anaerobic biodigestion. The performance of these processes was evaluated by physical-chemical parameters. Radioactivity levels were monitored in both treatments, and residues of dicofol (DCF) and dichlorobenzophenone (DBP) were quantified by HPLC/UV. The efficiency of the aerobic and anaerobic processes was slightly reduced in the presence of DCF and DBP. After aerobic treatment, only 0.1% of DCF was mineralized, and 57% of radioactivity remained sorbed on biological sludge as DBP. After 18 days of anaerobiosis, only 3% of DCF and 5% of DBP were detected in the sludge. However, 70% of radioactivity remained in the sludge, probably as other metabolites. Dicofol was biodegraded in the investigated process, but not mineralized. PMID:22629645

  17. Combined carbon and nitrogen removal in integrated anaerobic/anoxic sludge bed reactors for the treatment of domestic sewage

    OpenAIRE

    Kassab, G.

    2009-01-01

    The main objective of this research is to assess the applicability and effectiveness of integrating anaerobic digestion and denitrification processes in a single sludge system. The integrated concept is of particular interest for the treatment of highstrength domestic wastewater and is accomplished by means of a sequential anaerobic-aerobic system. The anaerobic pre-treatment can consist of a single anaerobic stage or two anaerobic stages, conditioned mainly by the wastewater characteristics,...

  18. Optimization of hydraulic shear parameters and reactor configuration in the aerobic granular sludge process.

    Science.gov (United States)

    Zhu, Liang; Zhou, Jiaheng; Yu, Haitian; Xu, Xiangyang

    2015-01-01

    The hydraulic shear acts as an important selection pressure in aerobic sludge granulation. The effects of the hydraulic shear rate and reactor configuration on structural characteristics of aerobic granule in view of the hydromechanics. The hydraulic shear analysis was proposed to overcome the limitation of using superficial gas velocity (SGV) to express the hydraulic shear stress. Results showed that the stronger hydraulic shear stress with SGV above 2.4 cm s(-1) promoted the microbial aggregation, and favoured the structural stability of the granular sludge. According to the hydraulic shear analysis, the total shear rate reached (0.56-2.31)×10(5) s(-1) in the granular reactor with a larger ratio of height to diameter (H/D), and was higher than that in the reactor with smaller H/D, where the sequencing airlift bioreactor with smaller H/D had a high total shear rate under the same SGV. Results demonstrated that the granular reactor could provide a stronger hydraulic shear stress which promotes the formation and structural stability of aerobic granules. PMID:25558911

  19. Biotransformation of tetrabromobisphenol A (TBBPA) in anaerobic digester sludge, soils, and freshwater sediments.

    Science.gov (United States)

    McAvoy, Drew C; Pittinger, Charles A; Willis, Alison M

    2016-09-01

    The biotransformation of tetrabromobisphenol A (TBBPA) was evaluated in anaerobic digester sludge, soils, and freshwater sediments. In anaerobic digester sludge, TBBPA biotransformed rapidly with a 50% disappearance time (DT50) of 19 days, though little mineralization (1.1%) was observed. In aerobic soils, mineralization of TBBPA ranged from 17.5% to 21.6% with 55.3-83.6% of the TBBPA incorporated into the soils as a non-extractable bound residue. The DT50 for TBBPA in aerobic soils ranged from 5.3 to 7.7 days. In anaerobic soils, 48.3-100% of the TBBPA was incorporated into the soils as non-extractable bound residue with sediments the DT50 for TBBPA ranged from 28 to 42 days, whereas in aerobic sediments the DT50 for TBBPA ranged from 48 to 84 days and depended on the initial dose concentration. Most of the TBBPA in the sediment studies was incorporated as a non-extractable bound residue with little mineralization observed. Sediment extracts revealed three unknown biotransformation products and bisphenol A (BPA). These results were consistent with previously published studies where TBBPA biotransformed in anaerobic environments (digester sludge and sediments) by debromination and slowly mineralized in the test environments (anaerobic digester sludge, soils, and freshwater sediments). PMID:26212340

  20. Biopolymer and Cation Release in Aerobic and Anaerobic Digestion and the Consequent Impact on Sludge Dewatering and Conditioning Properties

    OpenAIRE

    Rust, Mary Elizabeth

    1998-01-01

    Sludge dewatering and chemical conditioning requirements were examined from the perspective of biopolymer and cation release from activated sludge flocs. Both aerobic and anaerobic digestion processes were considered from two different activated sludge sources at a temperature of 20° C. Polymer demand and specific resistance to filtration increased with an increase in total soluble biopolymer concentration for all temperature ranges. In anaerobic digestion,...

  1. Ammonia-methane two-stage anaerobic digestion of dehydrated waste-activated sludge

    OpenAIRE

    Nakashimada, Yutaka; Ohshima, Yasutaka; Minami, Hisao; Yabu, Hironori; Namba,Yuzaburo; Nishio, Naomichi

    2008-01-01

    In repeated batch-wise thermophilic anaerobic digestion of dehydrated waste-activated sludge with 80% (w/w) water content (DWAS), although methane production reached 30 % of total organic carbon in DWAS in the first run of 15d, it gradually decreased and finally stopped in the subsequent runs together with an increase in ammonia concentration. When the loading of DWAS on anaerobic digestion was investigated, methane production at 30d significantly decreased with the increase in the amount of ...

  2. Anaerobic digestion of sewage sludge: French inventory and state of the art

    International Nuclear Information System (INIS)

    Following the Kyoto Protocol and the 'Grenelle de l'environnement', France committed itself to develop renewable energies. Methanization is a process which falls within this objective. Anaerobic digestion of organic material generates biogas made of methane (CH4), carbon dioxide (CO2) and water (H2O). In 2009, electricity generation from biogas represented only 0, 93% of the renewable electricity production in France. An inventory of facilities and a state of the art of the methanization of sewage sludge on wastewater treatment plants with the inhabitant equivalent of more than 30.000 were realized. They were done with bibliography and surveys. In France, 68 installations of sewage sludge methanization were counted. The primary technology used is a mix reactor in which sewage sludge, heated at deg. C 37, are introduced. Biogas is mainly valued to warm those sludges. Electrical valorization is poor, especially on old installations. Anaerobic digestion of sewage sludge is generally accepted by managers, mainly because of its capacity to reduce sewage sludge quantity and odors. Methanization as listed in France is quite basic. It is performed with digestion series modification, with pretreatments or with co-digestion. Given the quantity of sewage sludge which could be digested, France could increase renewable energies via biogas. However this technology is perfectible in many units because biogas is burned in flares. (authors)

  3. Effect of Calcium Ions on Dewaterability of Enzymatic-Enhanced Anaerobic Digestion Sludge.

    Science.gov (United States)

    Luo, Kun; Yang, Qi; Li, Xiao-Ming; Zhang, Shi-Ying; Pang, Ya; Li, Xue; Liao, Xing-Sheng

    2015-08-01

    Waste-activated sludge (WAS) solubilized remarkably after enzymatic-enhanced anaerobic digestion, but its dewaterability was deteriorated. In this study, a novel method was performed to improve the dewaterability of enzymatic-enhanced anaerobic digestion sludge by adding CaCl2 (0.01~1.00 g/g total sludge). The capillary suction time (CST), moisture content, and filtrate turbidity were employed to characterize the dewaterability of WAS, and the possible mechanisms involved were clarified. The results showed the dewaterability did not worsen when CaCl2 was added before sludge digestion, and the CST, moisture content, and filtrate turbidity were notably reduced with the increase of CaCl2 dosage. It also shown that calcium ions played an important role in the bioflocculation of digested sludge by neutralizing negative charges on the surface of sludge. In addition, soluble protein initially lowered a little and then observably improved with the addition of CaCl2, while soluble carbohydrate was reduced sharply first and then bounced back afterwards. The interactions between calcium ions and the biopolymer further enhanced the dewatering of sludge through bridging of colloidal particles together. PMID:26129703

  4. Toxicity assessment of 4-chlorophenol to aerobic granular sludge and its interaction with extracellular polymeric substances

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Dong; Wang, Yifan; Wang, Xiaodong; Li, Mengting; Han, Fei; Ju, Luyu; Zhang, Ge; Shi, Li; Li, Kai; Wang, Bingfeng [School of Resources and Environmental Sciences, University of Jinan, Jinan 250022 (China); Du, Bin, E-mail: dubin61@gmail.com [School of Resources and Environmental Sciences, University of Jinan, Jinan 250022 (China); Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022 (China); Wei, Qin [Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022 (China)

    2015-05-30

    Highlights: • Toxicity of 4-CP to aerobic granular sludge process was evaluated. • 3D-EEM characterized the interaction between EPS and 4-CP. • Tryptophan was the main substance result in fluorescence quenching. • The mechanism of fluorescence quenching belongs to static quenching. - Abstract: The main objective of this study was to evaluate the toxicity of 4-chlorophenol (4-CP) to aerobic granular sludge in the process of treating ammonia rich wastewater. In the short-term exposure of 4-CP of 5 and 10 mg/L, ammonia nitrogen removal efficiencies in the batch reactors decreased to 87.18 ± 2.81 and 41.16 ± 3.55%, which were remarkably lower than that of control experiment (99.83 ± 0.54%). Correspondingly, the respirometric activities of heterotrophic and autotrophic bacteria of aerobic granular sludge were significantly inhibited in the presence of 4-CP. Moreover, the main components of extracellular polymeric substances (EPS) including polysaccharides and proteins increased from 18.74 ± 0.29 and 22.57 ± 0.34 mg/g SS to 27.79 ± 0.51 and 24.69 ± 0.38 mg/g SS, respectively, indicating that the presence of 4-CP played an important role on the EPS production. Three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectroscopy further showed that the intensities of EPS samples were obviously quenched with the increased of 4-CP concentrations. To be more detailed, synchronous fluorescence spectra indicated that the interaction between EPS and 4-CP was mainly caused by tryptophan residues. The mechanism of fluorescence quenching belongs to static quenching with a formation constant (K{sub A}) of 0.07 × 10{sup 4} L/mol, implying the strong formation of EPS and 4-CP complex. The results could provide reliable and accurate information to determine the potential toxicity of 4-CP on the performance of aerobic granular sludge system.

  5. Mechanisms of granular activated carbon anaerobic fluidized-bed process for treating phenols wastewater

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Granular activated carbon (GAC) anaerobic fluidized-bed reactor was applied to treating phenols wastewater. When influent phenol concentration was 1000 mg/L, volume loadings of phenol and CODCr were 0.39 kg/(m3*d) and 0.98 kg/(m3*d), their removal rates were 99.9% and 96.4% respectively. From analyzing above results, the main mechanisms of the process are that through fluidizing GAC, its adsorption is combined with biodegradation, both activities are brought into full play, and phenol in wastewater is effectively decomposed. Meanwhile problems concerning gas-liquid separation and medium plugging are well solved.

  6. Improving phosphorus removal in aerobic granular sludge processes through selective microbial management.

    Science.gov (United States)

    Henriet, Olivier; Meunier, Christophe; Henry, Paul; Mahillon, Jacques

    2016-07-01

    This study aimed to improve phosphorus removal in aerobic granular sludge sequential batch reactors (AGS-SBR) by a differential selection of the granules containing the highest proportion of phosphate accumulating organisms (PAOs). The abundance of PAOs in granules with different density was analyzed by PCR-DGGE, pyrosequencing and qPCR. Dense granules contained a higher proportion of Candidatus Accumulibacter (PAO) with a 16S rRNA gene frequency up to 45%. Starting with an AGS-SBR with low height/diameter ratio performing unstable P removal, two strategies of biomass removal were assessed. First, a high selective pressure (short settling time) was applied and second, an increase of the settling time was combined with a homogeneous purge of the sludge bed. The first strategy resulted in a reduction of P removal efficiency while the second improved and stabilized P removal over 90%. This study offers a new approach of biomass management in AGS-SBR. PMID:27023385

  7. Application of sequential expanded granular sludge bed reactors for biodegradation of acetate, benzoate, terephtalate and p-toluate in purified terephtalic acid production wastewater.

    Science.gov (United States)

    Lee, Y S; Han, G B

    2016-01-01

    The anaerobic degradation of four major constituents from purified terephtalic acid production wastewater in sequential two expanded granular sludge bed (EGSB) reactors was studied. The performance of the system was evaluated in terms of chemical oxygen demand (COD) removal efficiencies, methane production, stability, granular sludge adaptability as well as reversion of bacterial inhibition. With volumetric loading rates of 1.9-25 kg-COD m(-3) d(-1) and terephtalate and p-toluate of 584-821 mg L(-1), average removal efficiencies of 97.6% and 75.2% were achieved in the EGSB reactors, respectively. In these conditions, gas production reached a total methane production rate of 0.33 L g-COD(-1) in the two-stage EGSB reactor system. The disturbance of the EGSB reactors was observed at a feed concentration above around 6.9 g-COD L(-1) because of higher influent COD concentration compared to other experiments. PMID:26513246

  8. Identifikasi Potensi Produksi Biogas dari Limbah Cair Tahu dengan Reaktor Upflow Anaerobic Sludge Blanket (UASB)

    OpenAIRE

    WAGIMAN

    2007-01-01

    Limbah cair tahu mengandung bahan organik sehingga dapat digunakansebagai bahan baku produksi biogas. Sebagai produk samping sistempengolahan limbah secara anaerobik, biogas masih belum banyak dikajinilai tambahnya. Penelitian ini bertujuan untuk mengevaluasi potensilimbah cair tahu sebagai bahan baku produksi biogas dengan menggunkanreaktor Upflow Anaerobic Sludge Blanket (UASB). Dari aspek teknik dilihat laju produksi biogas dan laju degadasi bahan organik (COD), sedangkan dari sisi ekonomi...

  9. Addition of electron acceptors stimulates methanogenesis from lipids by anaerobic sludge

    OpenAIRE

    Guedes, Ana P.; Cavaleiro, A. J.; Silva, Sérgio; Alves, M.M.; Stams, A.J.M.; Sousa, D.Z.

    2013-01-01

    Incubation of anaerobic sludge with triolein or oleate in the presence of nitrate or sulphate led to an increased methane production, relatively to incubations without inorganic electron acceptor. Faster methane production was obtained in assays amended with nitrate. Methanogenesis occurred after the reduction of alternative electron acceptors.

  10. Mesophilic anaerobic co-digestion of municipal solid waste and sewage sludge

    DEFF Research Database (Denmark)

    Aghdam, Ehsan Fathi; Kinnunen, V.; Rintala, Jukka A.

    2015-01-01

    This paper presents mesophilic anaerobic digestion (AD) of organic fraction of municipal solid waste (OFMSW), biowaste (BW), sewage sludge (SS), and co-digestion of BW and SS. Average methane yields of 386 ± 54, 385 ± 82, 198 ± 14, and 318 ± 59 L CH4/kg volatile solids (VS) were obtained for OFMSW...

  11. Hybrid alkali-hydrodynamic disintegration of waste-activated sludge before two-stage anaerobic digestion process

    OpenAIRE

    Grübel, Klaudiusz; Suschka, Jan

    2014-01-01

    The first step of anaerobic digestion, the hydrolysis, is regarded as the rate-limiting step in the degradation of complex organic compounds, such as waste-activated sludge (WAS). The aim of lab-scale experiments was to pre-hydrolyze the sludge by means of low intensive alkaline sludge conditioning before applying hydrodynamic disintegration, as the pre-treatment procedure. Application of both processes as a hybrid disintegration sludge technology resulted in a higher organic matter release (...

  12. Evidence for PAH Removal Coupled to the First Steps of Anaerobic Digestion in Sewage Sludge

    Directory of Open Access Journals (Sweden)

    Glenda Cea-Barcia

    2013-01-01

    Full Text Available Anaerobic degradation of polycyclic aromatic hydrocarbons has been brought to the fore, but information on removal kinetics and anaerobic degrading bacteria is still lacking. In order to explore the organic micropollutants removal kinetics under anaerobic conditions in regard to the methane production kinetics, the removal rate of 12 polycyclic aromatic hydrocarbons was measured in two anaerobic batch reactors series fed with a highly loaded secondary sludge as growth substrate. The results underscore that organic micropollutants removal is coupled to the initial stages of anaerobic digestion (acidogenesis and acetogenesis. In addition, the organic micropollutants kinetics suggest that the main removal mechanisms of these hydrophobic compounds are biodegradation and/or sequestration depending on the compounds.

  13. Thermal pre-treatment of primary and secondary sludge at 70ºC prior to anaerobic digestion

    DEFF Research Database (Denmark)

    Skiadas, Ioannis V.; Gavala, H.N.; Lu, Jingquan;

    2005-01-01

    In general, mesophilic anaerobic digestion of sewage sludge is more widely used compared to thermophilic digestion, mainly because of the lower energy requirements and higher stability of the process. However, the thermophilic anaerobic digestion process is usually characterised by accelerated....... The present study investigates the effect of the pre-treatment at 70 degrees C on thermophilic (55 degrees C) anaerobic digestion of primary and secondary sludge in continuously operated digesters. Thermal pre-treatment of primary and secondary sludge at 70 degrees C enhanced the removal of organic...... matter and the methane production during the subsequent anaerobic digestion step at 55 degrees C. It also greatly contributed to the destruction of pathogens present in primary sludge. Finally it results in enhanced microbial activities of the subsequent anaerobic step suggesting that the same...

  14. The Effect of Anaerobic and Aerobic Fish Sludge Supernatant on Hydroponic Lettuce

    Directory of Open Access Journals (Sweden)

    Simon Goddek

    2016-06-01

    Full Text Available The mobilization of nutrients from fish sludge (i.e., feces and uneaten feed plays a key role in optimizing the resource utilization and thus in improving the sustainability of aquaponic systems. While several studies have documented the aerobic and anaerobic digestion performance of aquaculture sludge, the impact of the digestate on plant growth has yet to be understood. The present study examines the impact of either an aerobic or an anaerobic digestion effluent on lettuce plant growth, by enriching a mixture of aquaculture and tap water with supernatants from both aerobic and anaerobic batch reactors. The lettuce plants grown in the hydroponic system supplied with supernatant from an anaerobic reactor had significantly better performance with respect to weight gain than both, those in the system where supernatant from the aerobic reactor was added, as well as the control system. It can be hypothesized that this effect was caused by the presence of NH4+ as well as dissolved organic matter, plant growth promoting rhizobacteria and fungi, and humic acid, which are predominantly present in anaerobic effluents. This study should therefore be of value to researchers and practitioners wishing to further develop sludge remineralization in aquaponic systems.

  15. Biodegradation of waste PET based copolyesters in thermophilic anaerobic sludge

    Czech Academy of Sciences Publication Activity Database

    Hermanová, S.; Šmejkalová, P.; Merna, J.; Zarevúcka, Marie

    2015-01-01

    Roč. 111, Jan (2015), s. 176-184. ISSN 0141-3910 Institutional support: RVO:61388963 Keywords : poly(ethylene terephthalate) * copolymers * sludge * biodegradation * hydrolysis * waste Subject RIV: EI - Biotechnology ; Bionics Impact factor: 3.163, year: 2014

  16. Biohydrogen production from dual digestion pretreatment of poultry slaughterhouse sludge by anaerobic self-fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Sittijunda, Sureewan [Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002 (Thailand); Reungsang, Alissara [Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002 (Thailand); Fermentation Research Center for Value Added Agricultural Products, Khon Kaen University, Khon Kaen 40002 (Thailand); O-thong, Sompong [Department of Biology, Faculty of Science, Thaksin University, Patthalung 93110 (Thailand)

    2010-12-15

    Poultry slaughterhouse sludge from chicken processing wastewater treatment plant was tested for their suitability as a substrate and inoculum source for fermentation hydrogen production. Dual digestion of poultry slaughterhouse sludge was employed to produce hydrogen by batch anaerobic self-fermentation without any extra-seeds. The sludge (5% TS) was dual digested by aerobic thermophilic digestion at 55 C with the varying retention time before using as substrate in anaerobic self-fermentation. The best digestion time for enriching hydrogen-producing seeds was 48 h as it completely repressed methanogenic activity and gave the maximum hydrogen yield of 136.9 mL H{sub 2}/g TS with a hydrogen production rate of 2.56 mL H{sub 2}/L/h. The hydrogen production of treated sludge at 48 h (136.9 mL H{sub 2}/g TS) was 15 times higher than that of the raw sludge (8.83 mL H{sub 2}/g TS). With this fermentation process, tCOD value in the activated sludge could be reduced up to 30%. (author)

  17. Acetate-fed aerobic granular sludge for the degradation of 4-chlorophenol

    International Nuclear Information System (INIS)

    Chlorinated phenols are considered a critical environmental problem, due to their extreme toxicity and their widespread use both in industrial and agricultural activities. In this study, aerobic granular sludge was initially developed into an acetate-fed Granulated Sequencing Batch Reactor (GSBR) and then used for the degradation of low chlorinated 4-mono-chlorophenol (4CP), with readily biodegradable sodium acetate (NaAc) as co-substrate. Influent 4CP concentration ranged between 0 and 50 mg/l, with a maximum volumetric organic loading rate of 0.20 kg4CP/m3 d (0.32 kgCOD-4CP/m3 d). Differences in granules shape and size were observed with 4CP dosed in the influent at different concentrations, and the effects of such toxic compound on acetate removal were evaluated, with both unacclimated and acclimated biomass. Aerobic granules grown on acetate as carbon source proved to be an interesting solution for the degradation of 4CP, showing good resistance to high 4CP concentrations in the influent even if unacclimated (short term effects). Moreover, the monitoring of intermediate products and the evaluation of chloride release due to 4CP degradation proved that acclimated granular sludge could completely remove 4CP (long term effects), with high specific removal rates.

  18. Start-up and HRT Influence in Thermophilic and Mesophilic Anaerobic Digesters Seeded with Waste Activated Sludge

    OpenAIRE

    Benabdallah, El-Hadj T.; Dosta, J.; Mata-Alvarez, J.

    2007-01-01

    Since thermophilic anaerobic digestion represents an efficient alternative to mesophilic anaerobic digestion, multiple studies have been developed to compare their performance and viability. One of the problems related to thermophilic anaerobic digestion is the availability of an adequate seed to start-up the process. The goal of this study is to evaluate the possibility of using waste activated sludge (WAS) as a seed for both mesophilic (35 °C) and thermophilic (55 °C) anaerobic digesters...

  19. Culture and Phosphorus Removal Property of Granular Sludge for Denitrifying Phosphorus Removal%反硝化除磷颗粒污泥的培养与除磷性能

    Institute of Scientific and Technical Information of China (English)

    李军; 张宇坤; 韦甦; 王亚宜; 马骁; 彭永臻

    2012-01-01

    The granular sludge for denitrifying phosphorus removal is successfully formed in a sequencing batch reactor (SBR) fed with synthetic wastewater, by controlling the operational modes of anaerobic/ anoxic/aerobic, anoxie addition of the nitrate, and selection pressure. The granular sludge turns into ashape with a diameter of 0.3 to 0.5 mm, and sludge volume index (SVI) and mixed solid (MLSS) are maintained at 45 mL/g and 4 000 rag/L, respectively, during the The granular sludge for the denitrifying phosphorus removal also shows a good nutrient re steady moval suspended operation. capability,with the COD, ammonia nitrogen and phosphorus removal effieiencies of 88%, 96% and 90%, respectively. The fate of phosphorus and the X-ray diffraction test results suggest the existence of granular sludge phosphate precipitation phosphorus removal phenomena. Granular sludge for the denitrifyingphosphorus removal in the experiment uses biological phosphorus removal, and it also has phosphorus removal through phosphate precipitation in granular sludge.%摘要:以普通絮状污泥为接种污泥,人工配制生活污水,采用厌氧/缺氧/好氧的运行方式,通过在缺氧段投加硝酸盐氮和控制选择压,经98d的培养与调整在SBR中获得具有反硝化除磷功能的颗粒污泥.稳定运行的颗粒污泥粒径主要在0.3-0.5mm,SVI约为45mL/g,p(MLSS)约为4000mg/L.具有反硝化除磷功能的颗粒污泥对COD、氨氮和磷酸盐的去除率分别可达88%、96%和90%.通过分析磷的去向及X射线衍射检测结果可知存在颗粒污泥的磷酸盐沉淀除磷现象.培养的反硝化除磷颗粒污泥除生物除磷外,还具有磷酸盐固化于污泥颗粒方式除磷。

  20. Semi-technical experiments in the mechanical solubilization of excess sludge with subsequent anaerobic stabilization; Halbtechnische Versuche zum mechanischen Aufschluss von Ueberschussschlaemmen mit anschliessender anaerober Stabilisierung

    Energy Technology Data Exchange (ETDEWEB)

    Palmowski, L.; Schwedes, J. [Technische Univ. Braunschweig (Germany). Inst. fuer Mechanische Verfahrenstechnik; Winter, A.; Dichtl, N. [Technische Univ. Braunschweig (Germany). Inst. fuer Siedlungswasserwirtschaft; Schmelz, K.G. [Emschergenossenschaft und Lippeverband, Essen (Germany); Mueller, J. [Technische Univ. Braunschweig (Germany). Inst. fuer Mechanische Verfahrenstechnik; Technische Univ. Braunschweig (Germany). Inst. fuer Siedlungswasserwirtschaft

    1999-07-01

    Within the framework of this project, the influence of the mechanical disintegration of different types of sludge on their anaerobic degradation behaviour and dewatering properties was investigated on a semi-technical scale. (orig.) [German] Im Rahmen dieses Projektes wurde in halbtechnischem Versuchsmassstab der Einfluss der mechanischen Desintegration verschiedener Schlaemme auf ihr anaerobes Abbauverhalten und ihr Entwaesserungsverhalten untersucht. (orig.)

  1. Fate of extracellular polymeric substances of anaerobically digested sewage sludge during pre-dewatering conditioning with Acidithiobacillus ferrooxidans culture.

    Science.gov (United States)

    Murugesan, Kumarasamy; Ravindran, Balasubramani; Selvam, Ammaiyappan; Kurade, Mayur B; Yu, Shuk-Man; Wong, Jonathan W C

    2016-10-01

    This study investigated the fate of extracellular polymeric substances (EPS) of anaerobically digested saline sewage sludge during its preconditioning. Sludge was conditioned with Acidithiobacillus ferrooxidans (AF) culture for 24h in the presence and absence of Fe(2+) as an energy substrate. pH decreased from 7.24 to 3.12 during sludge conditioning process. The capillary suction time (CST) of conditioned sludge significantly decreased to 94% as compared with control within 4h of conditioning with or without Fe(2+), indicating a significant (P<0.001) improvement in sludge dewaterability. A noticeable decrease in extractable EPS was observed in conditioned sludge. The EPS contents showed a significant negative correlation with dewaterability of sludge (P<0.05). The results suggest that bioacidification treatment using A. ferrooxidans effectively improved sludge dewaterability through modification of sludge EPS. PMID:27040507

  2. Co-digestion of mixed industrial sludge with municipal solid wastes in anaerobic simulated landfilling bioreactors

    International Nuclear Information System (INIS)

    In this study, the feasibility of the anaerobic co-digestion of a mixed industrial sludge with municipal solid wastes (MSW) was investigated in three simulated anaerobic landfilling bioreactors during a 150-day period. All of the reactors were operated with leachate recirculation. One of them was loaded only with MSW (control reactor); the second reactor was loaded with mixed industrial sludge and MSW, the weight ratio of the MSW to mixed industrial sludge was 1:1 (based on dry solid) (Run 1); the third reactor was loaded with mixed industrial sludge and MSW, the weight ratio of the MSW to mixed industrial sludge was 1:2 (based on dry solid) (Run 2). The VFA concentrations decreased significantly in Run 1 and Run 2 reactors at the end of 150 days. The pH values were higher in Run 1 and Run 2 reactors compared to control reactor. The differences between leachate characteristics, the biodegradation and the bioefficiency of the reactors were compared. The NH4-N concentrations released to leachate from mixed sludge in Run 1 and Run 2 reactors were lower than that of control reactor. The BOD5/COD ratios in Run 1 and Run 2 reactors were lower than that of control reactor at the end of 150 days. Cumulative methane gas productions and methane percentages were higher in Run 1 and Run 2 reactors. Reductions in waste quantity, carbon percentage and settlement of the waste were better in Run 1 and Run 2 reactors compared to control reactor at the end of 150 days. Furthermore, TN and TP removals in waste were higher in reactors containing industrial sludge compared to control. The toxicity test results showed that toxicity was observed in reactors containing industrial mixed sludge

  3. Effect of an azo dye on the performance of an aerobic granular sludge sequencing batch reactor treating a simulated textile wastewater.

    Science.gov (United States)

    Franca, Rita D G; Vieira, Anabela; Mata, Ana M T; Carvalho, Gilda S; Pinheiro, Helena M; Lourenço, Nídia D

    2015-11-15

    This study analyzed the effect of an azo dye (Acid Red 14) on the performance of an aerobic granular sludge (AGS) sequencing batch reactor (SBR) system operated with 6-h anaerobic-aerobic cycles for the treatment of a synthetic textile wastewater. In this sense, two SBRs inoculated with AGS from a domestic wastewater treatment plant were run in parallel, being one supplied with the dye and the other used as a dye-free control. The AGS successfully adapted to the new hydrodynamic conditions forming smaller, denser granules in both reactors, with optimal sludge volume index values of 19 and 17 mL g(-1) after 5-min and 30-min settling, respectively. As a result, high biomass concentration levels and sludge age values were registered, up to 13 gTSS L(-1) and 40 days, respectively, when deliberate biomass wastage was limited to the sampling needs. Stable dye removal yields above 90% were attained during the anaerobic reaction phase, confirmed by the formation of one of the aromatic amines arising from azo bond reduction. The control of the sludge retention time (SRT) to 15 days triggered a 30% reduction in the biodecolorization yield. However, the increase of the SRT values back to levels above 25 days reverted this effect and also promoted the complete bioconversion of the identified aromatic amine during the aerobic reaction phase. The dye and its breakdown products did not negatively affect the treatment performance, as organic load removal yields higher than 80% were attained in both reactors, up to 77% occurring in the anaerobic phase. These high anaerobic organic removal levels were correlated to an increase of Defluviicoccus-related glycogen accumulating organisms in the biomass. Also, the capacity of the system to deal with shocks of high dye concentration and organic load was successfully demonstrated. Granule breakup after long-term operation only occurred in the dye-free control SBR, suggesting that the azo dye plays an important role in improving granule

  4. One- and two-stage upflow anaerobic sludge-bed reactor pretreatment of winery wastewater at 4-10 degreesC.

    Science.gov (United States)

    Kalyuzhnyi, S V; Gladchenko, M A; Sklyar, V I; Kizimenko, Y S; Shcherbakov, S S

    2001-02-01

    The operating performance of a single and two (in series) laboratory upflow anaerobic sludge-bed (UASB) reactors (2.7-L working volume, recycle ratio varied from 1:1 to 1:18) treating diluted wine vinasse was investigated under psychrophilic conditions (4-10 degreesC). For a single UASB reactor seeded with granular sludge, the average organic loading rates (OLRs) applied were 4.7, 3.7, and 1.7 g of chemical oxygen demand (COD)/(L.d) (hydraulic retention times [HRTs] were about 1 d) at 9-11, 6 to 7, and 4 to 5 degreesC, respectively. The average total COD removal for preacidified vinasse wastewater was about 60% for all the temperature regimes tested. For two UASB reactors in series, the average total COD removal for treatment of non-preacidified wastewater exceeded 70% (the average OLRs for a whole system were 2.2, 1.8, and 1.3 g of COD/[L.d] under HRTs of 2 d at 10, 7, and 4 degreesC, respectively). In situ determinations of kinetic sludge characteristics (apparent Vm and Km) revealed the existence of substantial mass transfer limitations for the soluble substrates inside the reactor sludge bed. Therefore, application of higher recycle ratios is essential for enhancement of UASB pretreatment under psychrophilic conditions. The produced anaerobic effluents were shown to be efficiently posttreated aerobically: final effluent COD concentrations were about 0.1 g/L. Successful operation of the UASB reactors at quite low temperatures (4-10 degreesC) opens some perspectives for application of high-rate anaerobic pretreatment at ambient temperatures. PMID:11297387

  5. Enhanced waste activated sludge digestion using a submerged anaerobic dynamic membrane bioreactor: performance, sludge characteristics and microbial community

    Science.gov (United States)

    Yu, Hongguang; Wang, Zhiwei; Wu, Zhichao; Zhu, Chaowei

    2016-02-01

    Anaerobic digestion (AD) plays an important role in waste activated sludge (WAS) treatment; however, conventional AD (CAD) process needs substantial improvements, especially for the treatment of WAS with low solids content and poor anaerobic biodegradability. Herein, we propose a submerged anaerobic dynamic membrane bioreactor (AnDMBR) for simultaneous WAS thickening and digestion without any pretreatment. During the long-term operation, the AnDMBR exhibited an enhanced sludge reduction and improved methane production over CAD process. Moreover, the biogas generated in the AnDMBR contained higher methane content than CAD process. Stable carbon isotopic signatures elucidated the occurrence of combined methanogenic pathways in the AnDMBR process, in which hydrogenotrophic methanogenic pathway made a larger contribution to the total methane production. It was also found that organic matter degradation was enhanced in the AnDMBR, thus providing more favorable substrates for microorganisms. Pyrosequencing revealed that Proteobacteria and Bacteroidetes were abundant in bacterial communities and Methanosarcina and Methanosaeta in archaeal communities, which played an important role in the AnDMBR system. This study shed light on the enhanced digestion of WAS using AnDMBR technology.

  6. Long-term acclimation of anaerobic sludges for high-rate methanogenesis from LCFA

    International Nuclear Information System (INIS)

    Inhibition of methanogens by long chain fatty acids (LCFA) and the low numbers of LCFA-degrading bacteria are limitations to exploit biogas production from fat-rich wastewaters. Generally reactors fail due to excessive LCFA accumulation onto the sludge. Here, long-term acclimation and bioaugmentation with a LCFA-degrading coculture were hypothesized as strategies to enhance methanogenic conversion of these compounds. Anaerobic sludges previously exposed to LCFA for more than 100 days converted a specific biomass-associated substrate of (3.2 ± 0.1) kg·kg−1 with very short lag phases (<1 day), whereas non-acclimated sludges showed lag phases of 11–15 days for metabolizing (1.6–1.8) kg·kg−1. Addition of a coculture of Syntrophomonas zehnderi and Methanobacterium formicicum to sludges previously loaded with LCFA and containing different amounts of biomass-associated substrate (from (0.5–3.2) kg·kg−1) did not improve methane production neither lag phases were shortened, indicating that the endogenous microbiota are not a limiting factor. Clearly, we show that long-term sludge acclimation to LCFA is essential for high rate methanogenesis from LCFA. - Highlights: • Long-term sludge acclimation results in more resilient microbial communities to LCFA. • Excessive LCFA accumulation onto the biomass should be prevented. • Bioaugmentation does not improve methane production by LCFA-overloaded sludge

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

    Science.gov (United States)

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

    2016-10-01

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

  8. HELMINTH AND HEAVY METALS TRANSMISSION FROM ANAEROBICALLY DIGESTED SEWAGE SLUDGE

    Science.gov (United States)

    This report discusses a study designed to determine the practical survival and transmission of the ova of the nematode worm Ascaris sp. through a modern sewage and sludge treatment process. Four large experiments and three smaller ones involving 178 specific pathogen free (SPF) p...

  9. Dry co-digestion of sewage sludge and rice straw under mesophilic and thermophilic anaerobic conditions.

    Science.gov (United States)

    Chu, Xiangqian; Wu, Guangxue; Wang, Jiaquan; Hu, Zhen-Hu

    2015-12-01

    Dry anaerobic digestion of sewage sludge can recover biogas as energy; however, its low C/N ratio limits it as a single substrate in the anaerobic digestion. Rice straw is an abundant agricultural residue in China, which is rich in carbon and can be used as carbon source. In the present study, the performance of dry co-digestion of sewage sludge and rice straw was investigated under mesophilic (35 °C) and thermophilic (55 °C) conditions. The operational factors impacting dry co-digestion of sewage sludge and rice straw such as C/N ratio, moisture content, and initial pH were explored under mesophilic conditions. The results show that low C/N ratios resulted in a higher biogas production rate, but a lower specific biogas yield; low moisture content of 65 % resulted in the instability of the digestion system and a low specific biogas yield. Initial pH ranging 7.0-9.0 did not affect the performance of the anaerobic digestion. The C/N ratio of 26-29:1, moisture content of 70-80 %, and pH 7.0-9.0 resulted in good performance in the dry mesophilic co-digestion of sewage sludge and rice straw. As compared with mesophilic digestion, thermophilic co-digestion of sewage sludge and rice straw significantly enhanced the degradation efficiency of the substrates and the specific biogas yield (p co-digestion of sewage sludge under mesophilic and thermophilic conditions. PMID:26300352

  10. Effects of inoculating microorganisms on mesophilic anaerobic digestion of septic sludge

    Institute of Scientific and Technical Information of China (English)

    黄川; 谷伟; 王里奥; 宋珍霞

    2009-01-01

    The anaerobic digestion of septic sludge was studied through inoculating effective microorganisms (EMs) under mesophilic condition (35 ℃). The variation of COD,total solid (TS),volatile solid (VS),pH value and the gas production rate during the digestion process were presented,and the optimal adding concentration of EMs was determined by comparing the reduction effectiveness of septic sludge. The results show that proper addition of EMs can enhance acid buffering capacity of the system,and the NH3-N concentration is lower than inhibition concentration of 2 g/L reported in the literature and maintain the range of pH value which is suitable for both hydrolysis-acidification and methanogenesis. However,overdose of EMs can reduce the initial pH value of septic sludge and decrease the effects of the anaerobic digestion. EMs can increase the quantity of microbe in septic sludge and improve the gas production and generation rate over a period of time. But overdosing EMs can lead to low pH,restrain activity of methanogenic bacteria and affect the quantity and the generation rate of gas. Adding 0.01% EMs achieves the highest sludge reduction with the removal rates of TS,VS and COD by 32.51%,42.34% and 40.97%,respectively.

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

    Science.gov (United States)

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

    2016-02-13

    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. PMID:26513562

  12. Aerobic granular sludge for simultaneous accumulation of mineral phosphorus and removal of nitrogen via nitrite in wastewater.

    Science.gov (United States)

    Li, Yongmei; Zou, Jinte; Zhang, Lili; Sun, Jing

    2014-02-01

    Lab-scale experiments were conducted to investigate the aerobic granular sludge process for simultaneous phosphorus (P) accumulation by chemical precipitation and biological nitrogen removal via nitrite. The P-rich granules were successfully incubated in a sequencing batch reactor, in which simultaneous nitrification-denitrification occurred via nitrite. The average diameter of the P-rich granules was 2.47 mm and the P content in granules was much higher than that in other granular systems with enhanced biological phosphorus removal process. Filamentous bacteria (genus Thiothrix) in the granules and the long sludge retention time (30 d) of the granular system played a crucial role in accumulation of precipitated phosphate. X-ray diffraction analysis, scanning electron microscopy coupled with energy dispersive X-ray and the experimental design using response surface methodology confirmed that the main mineral patterns in P-rich granules were Ca-Mg phosphate and whitlockite. PMID:24388958

  13. Diagnosis of an anaerobic pond treating temperate domestic wastewater: An alternative sludge strategy for small works

    OpenAIRE

    Cruddas, Peter; Wang, K.; Best, D.; Jefferson, Bruce; Cartmell, Elise; Parker, Alison; McAdam, Ewan J.

    2014-01-01

    An anaerobic pond (AP) for treatment of temperate domestic wastewater has been studied as a small works sludge management strategy to challenge existing practice which comprises solids separation followed by open sludge storage, for up to 90 days. During the study, effluent temperature ranged between 0.1 °C and 21.1 °C. Soluble COD production was noted in the AP at effluent temperatures typically greater than 10 °C and was coincident with an increase in effluent volatile fatty acids (VFA) con...

  14. Increase of the efficiency of anaerobic digestion by various pre-treatment processes of sewage sludge

    OpenAIRE

    Łukasz Krawczyk; Małgorzata Budych; Łukasz Chrzanowski; Agnieszka Drożdżyńska; Roman Marecik; Agnieszka Piotrowska-Cyplik; Artur Szwengiel; Katarzyna Czaczyk; Paweł Cyplik

    2011-01-01

    The aim of this paper is to demonstrate the effects of pre-treatment increase of the efficiency of anaerobic digestion on waste activated sludge. There were four methods for pre-treatment of the waste activated sludge: A – thermally treated at 121°C for 30 min, homogenized and hydrolysed by Bacillus subtilis bacteria, B – thermally treated at 121°C for 30 min and homogenized, C – thermally treated at 121°C for 30 min and hydrolysed by B. subtilis bacteria, D &nda...

  15. Waste-Activated Sludge Fermentation for Polyacrylamide Biodegradation Improved by Anaerobic Hydrolysis and Key Microorganisms Involved in Biological Polyacrylamide Removal

    OpenAIRE

    Xiaohu Dai; Fan Luo; Dong Zhang; Lingling Dai; Yinguang Chen; Bin Dong

    2015-01-01

    During the anaerobic digestion of dewatered sludge, polyacrylamide (PAM), a chemical conditioner, can usually be consumed as a carbon and nitrogen source along with other organic matter (e.g., proteins and carbohydrates in the sludge). However, a significant accumulation of acrylamide monomers (AMs) was observed during the PAM biodegradation process. To improve the anaerobic hydrolysis of PAM, especially the amide hydrolysis process, and to avoid the generation of the intermediate product AM,...

  16. Effects of sludge inoculum and organic feedstock on active microbial communities and methane yield during anaerobic digestion

    OpenAIRE

    Wilkins, David; Rao, Subramanya; Lu, Xiaoying; Lee, Patrick K. H.

    2015-01-01

    Anaerobic digestion (AD) is a widespread microbial technology used to treat organic waste and recover energy in the form of methane (“biogas”). While most AD systems have been designed to treat a single input, mixtures of digester sludge and solid organic waste are emerging as a means to improve efficiency and methane yield. We examined laboratory anaerobic cultures of AD sludge from two sources amended with food waste, xylose, and xylan at mesophilic temperatures, and with cellulose at meso-...

  17. Effects of anaerobic reaction time and sludge age on the biological phosphorus removal in SBR

    International Nuclear Information System (INIS)

    In this research, a pilot consisting of two Sequencing Batch Reactors used to remove phosphorus biologically. Both reactors were in operation in a 12 hours cycle and they were controlled by a computer. The blank one had no primary anaerobic stage and its aeration time was 9.5 hours. The other one had the primary anaerobic stage with no change in the total reaction time (9.5 hours). The average concentration of influent phosphorus and COD in reactors were 7.5 and 800 milligram per litre respectively. In two months periods, the average efficiencies of ph osporus removal for the blank reactor and the second reactor with anaerobic reaction times of 2,3, and 4.5 hours were 16%, 26%, 64%, and 99% respectively. In the reactor with anaerobic reaction time of 4.5 hours, increasing the sludge age from 5 days to 10 days resulted in decreasing of phosphorus removal efficiency from 99% to 87%. In general, the result of this investigation show that the increases of anaerobic reaction time can increase the efficiency of phosphorus removal, because of the prevalence of phosphorus removing microorganisms over other species. Also, the accurate control of additional sludge volume (clogged age) has an appropriate effect on the removal efficiency

  18. Anaerobic digestion for simultaneous sewage sludge treatment and CO biomethanation: process performance and microbial ecology

    DEFF Research Database (Denmark)

    Luo, Gang; Wang, Wen; Angelidaki, Irini

    2013-01-01

    in an anaerobic reactor was presented. Batch experiments showed that CO was inhibitory to methanogens, but not to bacteria, at CO partial pressure between 0.25 and 1 atm under thermophilic conditions. During anaerobic digestion of sewage sludge supplemented with CO added through a hollow fiber...... membrane (HFM) module in continuous thermophilic reactors, CO did not inhibit the process even at a pressure as high as 1.58 atm inside the HFM, due to the low dissolved CO concentration in the liquid. Complete consumption of CO was achieved with CO gas retention time of 0.2 d. Results from high...

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

    Science.gov (United States)

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

    2016-07-15

    Sewage sludge generated in the activated sludge process is a polluting waste that must be treated adequately to avoid important environmental impacts. Traditional management methods, such as landfill disposal or incineration, are being ruled out due to the high content in heavy metal, pathogens, micropolluting compounds of the sewage sludge and the lack of use of resources. Anaerobic digestion could be an interesting treatment, but must be improved since the biomethanisation of sewage sludge entails low biodegradability and low methane production. A microwave pre-treatment at pilot scale is proposed to increase the organic matter solubilisation of sewage sludge and enhance the biomethanisation yield. The operational variables of microwave pre-treatment (power and specific energy applied) were optimised by analysing the physicochemical characteristics of sewage sludge (both total and soluble fraction) under different pre-treatment conditions. According to the variation in the sCOD and TN concentration, the optimal operation variables of the pre-treatment were fixed at 20,000 J/g TS and 700 W. A subsequent anaerobic digestion test was carried out with raw and pre-treated sewage sludge under different conditions (20,000 J/g TS and 700 W; 20,000 J/g TS and 400 W; and 30,000 J/g TS and 400 W). Although stability was maintained throughout the process, the enhancement in the total methane yield was not high (up to 17%). Nevertheless, very promising improvements were determined for the kinetics of the process, where the rG and the OLR increased by 43% and 39%, respectively, after carrying out a pre-treatment at 20,000 J/g TS and 700 W. PMID:27107391

  20. The behaviour of pharmaceuticals in anaerobic digester sludge

    OpenAIRE

    Campbell, Alison

    2013-01-01

    Pharmaceuticals are biologically active compounds that may be consumed in hundreds of tonnes per year, and which are excreted into municipal sewerage systems. Many pharmaceuticals persist during sewage treatment, and significant environmental risk has been linked to incomplete removal of pharmaceuticals. Evaluation of this risk is important and should be as representative as possible, taking into consideration all significant exposure routes and removal processes. Sludge treatment processes a...

  1. [Cultivation of aerobic granular sludge with municipal wastewater and studies on its characteristics under the continuous flow].

    Science.gov (United States)

    Niu, Shu; Duan, Bai-Chuan; Zhang, Zuo-Li; Liu, Shi-Feng; Zhang, Jia-Ming; Wang, Cong; Zhou, Dan-Dan

    2013-03-01

    The aerobic granular sludge was cultivated successfully in a continuous-flow airlift aerobic granular sludge fluidized bed (CAFB), with low-concentration municipal sewage as the influent and flocculent activated sludge as the seeding sludge. The formation, characteristics and the biological diversity of the aerobic granules in the CAFB were investigated and analyzed. Experimental results showed that many dense and compact granules with diameter of 800-1 000 microm were formed as early as the 6th days operation. At the start-up stage, sludge volume index (SVI) decreased to 35 mL x g(-1), the mixed liquor suspended solid (MLSS) concentration increased to 6000 mg x L(-1), and the mass fraction of extracellular polymeric substances increased significantly. The granules presented a good biological diversity and high biomass contents at the steady running stage. The aerobic granules were basically composed of coccid and bacillus as observed by the scanning electron microscope. A large number of voids and channels were found to be located on the surface of the granules. The removal rate of COD maintained at 70% -75% at the steady stage of CAFB running, and the effluent COD concentrations were 70 mg x L(-1). At the 32nd day of operation, filamentous bacteria grew apparently and sludge bulking happened. Above results showed the CAFB aerobic granules formed rapidly, and performed a good ability on the pollutant removal. However, more work is necessary on the steady running of this novel bioreactor in the future. PMID:23745405

  2. Evaluation of EPS extraction protocols from anaerobic sludge for gel-based proteomic studies.

    Science.gov (United States)

    Zorel, J A; Aquino, S F; Sanson, A L; Castro-Borges, W; Silva, S Q

    2015-01-01

    Despite the importance of anaerobic sludge extracellular polymeric substances (EPSs), their characterization is limited to information regarding their chemical classes and molecular size. This work explores the possibility of using proteomic techniques to study the proteins present in this matrix. Thus, this paper compares eight EPS extraction methods regarding extraction yield, protein/carbohydrate ratio, size distribution profile and suitability to sodium dodecyl sulfate-polyacrylamide gel electrophoresis analyses. Despite the differences found in quantification and size exclusion chromatography assays, the band profile found for all methods was very similar. Considering the band pattern, extraction time and background level, heating method followed by ammonium sulfate precipitation proved to be the most appropriate method for gel-based analyses of anaerobic sludge EPS proteins. PMID:26247751

  3. Thermophilic versus Mesophilic Anaerobic Digestion of Sewage Sludge: A Comparative Review

    Directory of Open Access Journals (Sweden)

    Getachew D. Gebreeyessus

    2016-06-01

    Full Text Available During advanced biological wastewater treatment, a huge amount of sludge is produced as a by-product of the treatment process. Hence, reuse and recovery of resources and energy from the sludge is a big technological challenge. The processing of sludge produced by Wastewater Treatment Plants (WWTPs is massive, which takes up a big part of the overall operational costs. In this regard, anaerobic digestion (AD of sewage sludge continues to be an attractive option to produce biogas that could contribute to the wastewater management cost reduction and foster the sustainability of those WWTPs. At the same time, AD reduces sludge amounts and that again contributes to the reduction of the sludge disposal costs. However, sludge volume minimization remains, a challenge thus improvement of dewatering efficiency is an inevitable part of WWTP operation. As a result, AD parameters could have significant impact on sludge properties. One of the most important operational parameters influencing the AD process is temperature. Consequently, the thermophilic and the mesophilic modes of sludge AD are compared for their pros and cons by many researchers. However, most comparisons are more focused on biogas yield, process speed and stability. Regarding the biogas yield, thermophilic sludge AD is preferred over the mesophilic one because of its faster biochemical reaction rate. Equally important but not studied sufficiently until now was the influence of temperature on the digestate quality, which is expressed mainly by the sludge dewateringability, and the reject water quality (chemical oxygen demand, ammonia nitrogen, and pH. In the field of comparison of thermophilic and mesophilic digestion process, few and often inconclusive research, unfortunately, has been published so far. Hence, recommendations for optimized technologies have not yet been done. The review presented provides a comparison of existing sludge AD technologies and the gaps that need to be filled so

  4. Effect of dissolved oxygen on nitrogen removal and process control in aerobic granular sludge reactor

    International Nuclear Information System (INIS)

    A sequencing batch reactor (SBR) with aerobic granular sludge was operated to determine the effect of different DO concentrations on biological nitrogen removal process and to investigate the spatial profiles of DO, ORP and pH as online control parameters in such systems. The results showed that DO concentration had a significant effect on nitrification efficiencies and the profiles of DO, ORP and pH. The specific nitrification rate was decreased from 0.0595 mgNH4+-N/(gMLSS min) to 0.0251 mgNH4+-N/(gMLSS min) after DO concentration was dropped off from 4.5 mg/L to 1.0 mg/L. High DO concentration improved the nitrification and increased the volumetric NH4+-N removal. Low DO concentration enhanced TIN removal, while prolonged the nitrification duration. Also there existed a good correlation between online control parameters (ORP, pH) and nutrient (COD, NH4+-N, NO2--N, NO3--N) variations in aerobic granular sludge reactor when DO was 2.5 mg/L, 3.5 mg/L and 4.5 mg/L. However it was difficult to identify the end of nitrification and denitrification when DO was 1.0 mg/L, due to no apparent bending points on ORP and pH curves. In conclusion, the optimal DO concentration was suggested at 2.5 mg/L as it not only achieved high nitrogen removal efficiency and decreased the reaction duration, but also saved operation cost by aeration and mixing.

  5. High-rate volatile fatty acid (VFA) production by a granular sludge process at low pH.

    Science.gov (United States)

    Tamis, J; Joosse, B M; Loosdrecht, M C M van; Kleerebezem, R

    2015-11-01

    Volatile fatty acids (VFA) are proposed platform molecules for the production of basic chemicals and polymers from organic waste streams. In this study we developed a granular sludge process to produce VFA at high rate, yield and purity while minimizing potential operational costs. A lab-scale anaerobic sequencing batch reactor (ASBR) was fed with 10 g l(-1) glucose as model substrate. Inclusion of a short (2 min) settling phase before effluent discharge enabled effective granulation and very high volumetric conversion rates of 150-300 gCOD l(-1)  d(-1) were observed during glucose conversion. The product spectrum remained similar at the tested pH range with acetate and butyrate as the main products, and a total VFA yield of 60-70% on chemical oxygen demand (COD) basis. The requirement for base addition for pH regulation could be reduced from 1.1 to 0.6 mol OH(-) (mol glucose)(-1) by lowering the pH from 5.5 to 4.5. Solids concentrations in the effluent were 0.6 ± 0.3 g l(-1) but could be reduced to 0.02 ± 0.01 g l(-1) by introduction of an additional settling period of 5 min. The efficient production of VFA at low pH with a virtually solid-free effluent increases the economic feasibility of waste-based chemicals and polymer production. Biotechnol. PMID:25950759

  6. The impact of temperature on the rheological behaviour of anaerobic digested sludge

    OpenAIRE

    Baudez, J.C.; Slatter, P.; Eshtiaghi, N.

    2013-01-01

    The rheological properties of municipal anaerobic digested sludge rheology are temperature dependent. In this paper, we show that both solid and liquid characteristics decrease with temperature. We also show that the yield stress and the high shear (Bingham) viscosity are the two key parameters determining the rheological behaviour. By normalising the shear stress with the yield stress and the shear rate with the yield stress divided by the Bingham viscosity, a master curve was obtained, inde...

  7. Sewage sludge anaerobic digestion : study of synergies and operational strategies of co-digestion

    OpenAIRE

    Silvestre Tormo, Gracia

    2015-01-01

    Wastewater treatment plants (WWTPs) are characterized by their high organic matter and nutrient removal efficiency, but also by their high energy consumption. In the current context where resources are increasingly scarce, all feasible strategies to save energy emerge as an important issue for the sustainable management of WWTPs. In this thesis, sewage sludge (SS) anaerobic co-digestion with available organic wastes, coming from different sources and having different compositions, was prop...

  8. Innovative anaerobic/upflow sludge blanket filtration bioreactor for phosphorus removal from wastewater.

    Science.gov (United States)

    Khorsandi, H; Movahedyan, H; Bina, B; Farrokhzadeh, H

    2011-04-01

    Phosphorus is the key element to remove from aquatic environments to limit the growth of aquatic plants and algae and, thus, to control eutrophication. Because the upflow sludge blanket filtratio' (USBF) process, without addition of metal salts, entails low efficiency for phosphorus removal, we added an anaerobic reactor to the USBF bioreactor in order to promote the simultaneous removal of phosphorus and nitrogen from wastewater. The results revealed that the anaerobic/USBF bioreactor had a phosphorus removal efficiency up to 86%, with a sludge retention time (SRT) of 10 days, a hydraulic retention time (HRT) of 24 hours and an optimum COD/N/P ratio of 100/5/1. This ratio also improved the compaction quality of the sludge blanket in the USBF clarifier. The average specific phosphate uptake rate in the aerobic zone and the average specific phosphate release rate in the anaerobic reactor were 0.014 mg PO4-P removed/(g VSS x min) and 0.0525 mg PO4-P released/(g VSS x min), respectively. Secondary phosphorus release in the USBF clarifier was heightened with increasing HRT. Hence, the optimum total HRT can be selected between 16 and 24 hours based on effluent quality. Effluent phosphorus of about 1 mg/L was provided for wastewater with the COD/N/P ratio of 100/5/1 at the sludge age of 10 days and total HRT of 16 hours. This study illustrated that the anaerobic/USBF bioreactor at the optimum operational conditions can be an effective process for phosphorus removal from municipal wastewater. PMID:21877530

  9. Survival rates of parasite eggs in sludge during aerobic and anaerobic digestion.

    OpenAIRE

    Black, M I; Scarpino, P V; O'Donnell, C.J.; Meyer, K B; Jones, J V; Kaneshiro, E S

    1982-01-01

    The effects of mesothermic anaerobic or aerobic sludge digestion on survival of eggs from the roundworms Ascaris suum, toxocara canis, Trichuris vulpis, and Trichuris suis and from the rat tapeworm Hymenolepis diminuta were studied. Destruction of eggs throughout a 15-day treatment period, as well as their viabilities after reisolation, was analyzed. The laboratory model digesters used in this study were maintained at a 15-day retention schedule, partially simulating a continuously operating ...

  10. Characterisation by image analysis of anaerobic sludge under shock conditions

    OpenAIRE

    Alves, M. M.; Cavaleiro, A. J.; Ferreira, E.C.; A.L. Amaral; Mota, M; Motta, Maurício da; Vivier, H.; Pons, M.N.

    2000-01-01

    In the present work the characterisation by image analysis of anaerobic biomass under organic and hydraulic shocks was performed. The digester was fed with a synthetic substrate, containing 50% oleic acid (as COD). Organic and hydraulic shocks were performed by stepwise increasing the substrate concentration or by reducing the hydraulic retention time. In both cases the organic loading rate changed from 6 to 30 kg COD/m³.d. Hydraulic shock induced a fast decrease in the number of ...

  11. Production of Volatile Derivatives of Metal(loid)s by Microflora Involved in Anaerobic Digestion of Sewage Sludge

    OpenAIRE

    Michalke, K.; Wickenheiser, E. B.; Mehring, M.; A. V. Hirner; Hensel, R.

    2000-01-01

    Gases released from anaerobic wastewater treatment facilities contain considerable amounts of volatile methyl and hydride derivatives of metals and metalloids, such as arsine (AsH3), monomethylarsine, dimethylarsine, trimethylarsine, trimethylbismuth (TMBi), elemental mercury (Hg0), trimethylstibine, dimethyltellurium, and tetramethyltin. Most of these compounds could be shown to be produced by pure cultures of microorganisms which are representatives of the anaerobic sewage sludge microflora...

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

    Science.gov (United States)

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

    2016-06-01

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

  13. Comparison of biogas sludge and raw crop material as source of hydrolytic cultures for anaerobic digestion.

    Science.gov (United States)

    Weiß, Stefan; Somitsch, Walter; Klymiuk, Ingeborg; Trajanoski, Slave; Guebitz, Georg M

    2016-05-01

    Mixed fermentative/hydrolytic bacteria were enriched on lignocellulose substrates in minimal medium under semi-anaerobic mesophilic conditions in the presence or absence of natural zeolite as growth supporter to ultimately bioaugment non-adapted sludge and thereby enhance the overall anaerobic digestion (AD) of recalcitrant plant material. Desired enzyme activities, i.e. xylanases and cellulase were monitored during subsequent cultivation cycles. Furthermore, enriched microbial communities were characterized by 16S rRNA-based 454-Pyrosequencing, revealing Firmicutes, Bacteriodetes, Proteobacteria and Spirochaetes to be the predominant bacterial groups in cultures derived from anaerobic sludge and raw crop material, i.e. maple green cut and wheat straw as well. Enriched populations relevant for biopolymer hydrolysis were then compared in biological methane potential tests to demonstrate positive effects on the biogasification of renewable plant substrate material. A significant impact on methane productivity was observed with adapted mixed cultures when used in combination with clinoptilolite to augment and supplement non-adapted bioreactor sludge. PMID:26894564

  14. Treatment of municipal landfill leachate using a combined anaerobic digester and activated sludge system

    International Nuclear Information System (INIS)

    The main objective of this study was to assess the feasibility of treating sanitary landfill leachate using a combined anaerobic and activated sludge system. A high-strength leachate from Shiraz municipal landfill site was treated using this system. A two-stage laboratory-scale anaerobic digester under mesophilic conditions and an activated sludge unit were used. Landfill leachate composition and characteristics varied considerably during 8 months experiment (COD concentrations of 48,552-62,150 mg/L). It was found that the system could reduce the COD of the leachate by 94% at a loading rate of 2.25 g COD/L/d and 93% at loading rate of 3.37 g COD/L/d. The anaerobic digester treatment was quite effective in removing Fe, Cu, Mn, and Ni. However, in the case of Zn, removal efficiency was about 50%. For the rest of the HMs the removal efficiencies were in the range 88.8-99.9%. Ammonia reduction did not occur in anaerobic digesters. Anaerobic reactors increased alkalinity about 3.2-4.8% in the 1st digester and 1.8-7.9% in the 2nd digester. In activated sludge unit, alkalinity and ammonia removal efficiency were 49-60% and 48.6-64.7%, respectively. Methane production rate was in the range of 0.02-0.04, 0.04-0.07, and 0.02-0.04 L/g CODrem for the 1st digester, the 2nd digester, and combination of both digesters, respectively; the methane content of the biogas varied between 60% and 63%.

  15. Application of acidic thermal treatment for one- and two-stage anaerobic digestion of sewage sludge.

    Science.gov (United States)

    Takashima, M; Tanaka, Y

    2010-01-01

    The effectiveness of acidic thermal treatment (ATT) was examined in a 106-day continuous experiment, when applied to one- or two-stage anaerobic digestion of sewage sludge (4.3% TS). The ATT was performed at 170 °C and pH 5 for 1 hour (sulfuric acid for lowering pH). The one-stage process was mesophilic at 20 days hydraulic retention time (HRT), and incorporated the ATT as pre-treatment. The two-stage process consisted of a thermophilic digester at 5 days HRT and a mesophilic digester at 15 days HRT, and incorporated the ATT as interstage-treatment. On average, VSS reduction was 48.7% for the one-stage control, 65.8% for the one-stage ATT, 52.7% for the two-stage control and 67.6% for the two-stage ATT. Therefore, VSS reduction was increased by 15-17%, when the ATT was combined in both one- and two-stage processes. In addition, the dewaterability of digested sludge was remarkably improved, and phosphate release was enhanced. On the other hand, total methane production did not differ significantly, and color generation was noted in the digested sludge solutions with the ATT. In conclusion, the anaerobic digestion with ATT can be an attractive alternative for sludge reduction, handling, and phosphorus recovery. PMID:21099053

  16. A hybrid anaerobic membrane bioreactor coupled with online ultrasonic equipment for digestion of waste activated sludge.

    Science.gov (United States)

    Xu, Meilan; Wen, Xianghua; Yu, Zhiyong; Li, Yushan; Huang, Xia

    2011-05-01

    Anaerobic membrane bioreactor and online ultrasonic equipment used to enhance membrane filtration were coupled to form a hybrid system (US-AnMBR) designed for long-term digestion of waste activated sludge. The US-AnMBR was operated under volatile solids loading rates of 1.1-3.7 gVS/L·d. After comprehensive studies on digestion performance and membrane fouling control in the US-AnMBR, the final loading rate was determined to be 2.7 gVS/L·d with 51.3% volatile solids destruction. In the US-AnMBR, the improved digestion was due to enhanced sludge disintegration, as indicated by soluble matter comparison in the supernatant and particle size distribution in the digested sludge. Maximum specific methanogenic activity revealed that ultrasound application had no negative effect on anaerobic microorganisms. Furthermore, implementing ultrasound effectively controlled membrane fouling and successfully facilitated membrane bioreactor operation. This lab-scale study demonstrates the potential feasibility and effectiveness of setting up a US-AnMBR system for sludge digestion. PMID:21421308

  17. Bacterial stress enrichment enhances anaerobic hydrogen production in cattle manure sludge.

    Science.gov (United States)

    Cheong, Dae-Yeol; Hansen, Conly L

    2006-10-01

    Methodology was evaluated to selectively enrich hydrogen-producing species present in biological sludge produced during organic wastewater treatment. The influence of bacterial stress enrichment on anaerobic hydrogen-producing microorganisms was investigated in batch tests using serum bottles. Enrichment conditions investigated included application of acute physical and chemical stresses: wet heat, dry heat and desiccation, use of a methanogen inhibitor, freezing and thawing, and chemical acidification with and without preacidification of the sludge at pH 3. For each enrichment sample, cultivation pH value was set at an initial value of 7. After application of selective enrichment (by bacterial stress), hydrogen production was significantly higher than that of untreated original sludge. Hydrogen production from the inocula with bacterial stress enrichment was 1.9-9.8 times greater when compared with control sludge. Chemical acidification using perchloric acid showed the best hydrogen production potential, irrespective of preacidification. Enhancement is due to the selective capture of hydrogen-producing sporeformers, which induces altered anaerobic fermentative metabolism. PMID:16525779

  18. Hydrodynamic characteristics of airlift nitrifying reactor using carrier-induced granular sludge

    Energy Technology Data Exchange (ETDEWEB)

    Jin Rencun [Department of Environmental Engineering, Zhejiang University, Hangzhou 310029 (China); Department of Environmental Science, Hangzhou Normal University, Hangzhou 310036 (China); Zheng Ping [Department of Environmental Engineering, Zhejiang University, Hangzhou 310029 (China)], E-mail: pzheng@zju.edu.cn; Mahmood, Qaisar; Zhang Lei [Department of Environmental Engineering, Zhejiang University, Hangzhou 310029 (China)

    2008-09-15

    Since nitrification is the rate-limiting step in the biological nitrogen removal from wastewater, many studies have been conducted on the immobilization of nitrifying bacteria. A laboratory-scale investigation was carried out to scrutinize the effectiveness of activated carbon carrier addition for granulation of nitrifying sludge in a continuous-flow airlift bioreactor and to study the hydrodynamics of the reactor with carrier-induced granules. The results showed that the granular sludge began to appear and matured 60 and 108 days, respectively, after addition of carriers, while no granule was observed in the absence of carriers in the control test. The mature granules had a diameter of 0.5-5 mm (1.6 mm in average), settling velocity 22.3-55.8 m h{sup -1} and specific gravity of 1.086. The relationship between the two important hydrodynamic coefficients, i.e. gas holdup and liquid circulation velocity, and the superficial gas velocity were established by a simple model and were confirmed experimentally. The model also could predict the critical superficial gas velocity for liquid circulation and that for granules circulation, with respective values of 1.017 and 2.662 cm min{sup -1}, accurately.

  19. Hydrodynamic characteristics of airlift nitrifying reactor using carrier-induced granular sludge

    International Nuclear Information System (INIS)

    Since nitrification is the rate-limiting step in the biological nitrogen removal from wastewater, many studies have been conducted on the immobilization of nitrifying bacteria. A laboratory-scale investigation was carried out to scrutinize the effectiveness of activated carbon carrier addition for granulation of nitrifying sludge in a continuous-flow airlift bioreactor and to study the hydrodynamics of the reactor with carrier-induced granules. The results showed that the granular sludge began to appear and matured 60 and 108 days, respectively, after addition of carriers, while no granule was observed in the absence of carriers in the control test. The mature granules had a diameter of 0.5-5 mm (1.6 mm in average), settling velocity 22.3-55.8 m h-1 and specific gravity of 1.086. The relationship between the two important hydrodynamic coefficients, i.e. gas holdup and liquid circulation velocity, and the superficial gas velocity were established by a simple model and were confirmed experimentally. The model also could predict the critical superficial gas velocity for liquid circulation and that for granules circulation, with respective values of 1.017 and 2.662 cm min-1, accurately

  20. [Performance Recoverability of Denitrifying Granular Sludge Under the Stressing Effect of Nanoscale Zero-valent Iron].

    Science.gov (United States)

    Wang, Fan-fan; Qian, Fei-yue; Shen, Yao-liang; Wang, Jian-fang; Zhang, Yue-ru; Liu, Guo-xun

    2016-04-15

    To explore the potential stressing effect of nanoscale zero-valent iron (nZVI) on denitrifying granular sludge (DGS), the evolution of DGS denitrifying performance under different C/N ratios was investigated in this study, by carrying out batch tests of eight successive periods with the nZVI shock-loading. The results showed that the specific denitrification rate of µ value decreased when the nZVI dosage was higher than 5 mg · L⁻¹. Meanwhile, a positive correlation between the inhibition ratio (IR) of µ value and substrate C/N ratios or nZVI dosage was observed. When the nZVI dosage reached 100 mg · L⁻¹, both extracellular protein and polysaccharides concentrations decreased obviously. It would be beneficial to promote the recovery of DGS denitrifying activity and reduce the COD demanding to remove unit mass of nitrate, by increasing external carbon source with C/N ratios of higher than 4. On the basis of Freundlich and Langmuir adsorption isotherms, when higher C/N ratio was provided, stronger bioadsorption of nZVI would be achieved. During the recovery period, a significant improvement of DCS denitrifying performance under the high C/N ratio was expected, due to the continuous washout of total iron in sludge phase (Qe), while the µ value would reach or approach the one of the control group when Qe was lower than 0.4 mg · g⁻¹. PMID:27548972

  1. CFD simulation of an expanded granular sludge bed (EGSB) reactor for biohydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xu; Ding, Jie; Ren, Nan-Qi; Liu, Bing-Feng; Guo, Wan-Qian [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 202 Haihe Road, Nangang District, Harbin, Heilongjiang 150090 (China)

    2009-12-15

    Understanding how a bioreactor functions is a necessary precursor for successful reactor design and operation. This paper describes a two-dimensional computational fluid dynamics simulation of three-phase gas-liquid-solid flow in an expanded granular sludge bed (EGSB) reactor used for biohydrogen production. An Eulerian-Eulerian model was formulated to simulate reaction zone hydrodynamics in an EGSB reactor with various hydraulic retention times (HRT). The three-phase system displayed a very heterogeneous flow pattern especially at long HRTs. The core-annulus structure developed may lead to back-mixing and internal circulation behavior, which in turn gives poor velocity distribution. The force balance between the solid and gas phases is a particular illustration of the importance of the interphase rules in determining the efficiency of biohydrogen production. The nature of gas bubble formation influences velocity distribution and hence sludge particle movement. The model demonstrates a qualitative relationship between hydrodynamics and biohydrogen production, implying that controlling hydraulic retention time is a critical factor in biohydrogen-production. (author)

  2. Biodegradation of aniline by Candida tropicalis AN1 isolated from aerobic granular sludge

    Institute of Scientific and Technical Information of China (English)

    Dianzhan Wang; Guanyu Zheng; Shimei Wang; Dewei Zhang; Lixiang Zhou

    2011-01-01

    Aniline-degrading microbes were cultivated and acclimated with the initial activated sludge collected from a chemical wastewater treatment plant.During the acclimation processes,aerobic granular sludge being able to effectively degrade aniline was successfully formed,from which a preponderant bacterial strain was isolated and named as ANi.Effects of factors including pH,temperature,and second carbon/nitrogen source on the biodegradation of aniline were investigated.Results showed that the optimal conditions for the biodegradation of aniline by the strain AN1 were at pH 7.0 and 28-35°C.At the optimal pH and temperature,the biodegradation rate of aniline could reach as high as 17.8 mg/(L.hr) when the initial aniline concentration was 400 mg/L.Further studies revealed that the addition of 1 g/L glucose or ammonium chloride as a second carbon or nitrogen source could slightly enhance the biodegradation efficiency from 93.0% to 95.1%-98.5%.However,even more addition of glucose or ammonium could not further enhance the biodegradation process but delayed the biodegradation of aniline by the strain AN1.Based on morphological and physiological characteristics as well as the phylogenetic analysis of 26S rDNA sequences,the strain AN1 was identified as Candida tropicalis.

  3. Analysis of aerobic granular sludge formation based on grey system theory

    Institute of Scientific and Technical Information of China (English)

    Cuiya Zhang; Hanmin Zhang

    2013-01-01

    Based on grey entropy analysis,the relational grade of operational parameters with aerobic granular sludge's granulation indicators was studied.The former consisted of settling time (ST),aeration time (AT),superficial gas velocity (SGV),height/diameter (H/D) ratio and organic loading rates (OLR),the latter included sludge volume index (SVI) and set-up time.The calculated result showed that for SVI and set-up time,the influence orders and the corresponding grey entropy relational grades (GERG) were:SGV (0.9935) > AT (0.9921)> OLR (0.9894) > ST (0.9876) > H/D (0.9857) and SGV (0.9928) > H/D (0.9914) > AT (0.9909) > OLR (0.9897) > ST (0.9878).The chosen parameters were all key impact factors as each GERG was larger than 0.98.SGV played an important role in improving SVI transformation and facilitating the set-up process.The influence of ST on SVI and set-up time was relatively low due to its dual functions.SVI transformation and rapid set-up demanded different optimal H/D ratio scopes (10-20 and 16-20).Meanwhile,different functions could be obtained through adiusting certain factors' scope.

  4. Anaerobic biodegradation of long chain fatty acids : biomethanisation of biomass-associated LCFA as a challenge for the anaerobic treatment of effluents with high lipid/LCFA content

    OpenAIRE

    Pereira, M.A.

    2003-01-01

    Tese de doutoramento em Engenharia Biológica e Química. This work was focused on the anaerobic biodegradation of Long Chain Fatty Acids, especially those that are associated to anaerobic sludge by mechanisms of adsorption, precipitation or entrapment. When continuously fed with oleic acid (EGSB reactors, influent concentrations between 2 and 8 g COD/l and HRT=1 day), suspended and granular anaerobic sludge accumulated palmitic acid. This LCFA was efficiently biomethanised in batch assays, ...

  5. Batch anaerobic co-digestion of waste activated sludge and microalgae (Chlorella sorokiniana) at mesophilic temperature.

    Science.gov (United States)

    Beltrán, Carolina; Jeison, David; Fermoso, Fernando G; Borja, Rafael

    2016-08-23

    The microalgae Chlorella sorokiniana are used as co-substrate for waste activated sludge (WAS) anaerobic digestion. The specific objective of this research was to evaluate the feasibility of improving methane production from anaerobic digestion of WAS in co-digestion with this microalga, based on an optimized mixture percentage. Thus, the anaerobic co-digestion of both substrates aims to overcome the drawbacks of the anaerobic digestion of single WAS, simultaneously improving its management. Different co-digestion mixtures (0% WAS-100% microalgae; 25% WAS-75% microalgae; 50% WAS-50% microalgae; 75% WAS-25% microalgae; 100% WAS-0% microalgae) were studied. The highest methane yield (442 mL CH4/g VS) was obtained for the mixture with 75% WAS and 25% microalgae. This value was 22% and 39% higher than that obtained in the anaerobic digestion of the sole substrates WAS and microalgae, respectively, as well as 16% and 25% higher than those obtained for the co-digestion mixtures with 25% WAS and 75% microalgae and 50% WAS and 50% microalgae, respectively. The kinetic constant of the process increased 42%, 42% and 12%, respectively, for the mixtures with 25%, 50% and 75% of WAS compared to the substrate without WAS. Anaerobic digestion of WAS, together with C. sorokiniana, has been clearly improved by ensuring its viability, suitability and efficiency. PMID:27230742

  6. Selective separation of anaerobic sludge by means of hydrocyclones; Selektive Abtrennung von Anaerobschlamm mit Hydrozyklonen

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, M.; Bohnet, M. [Technische Univ. Braunschweig (Germany). Inst. fuer Verfahrens- und Kerntechnik

    1999-07-01

    In anaerobic waste water cleaning, biomass concentration constitutes a central problem because of long generating times and low biomass sinking speeds. In order to decouple hydraulic retention time from biomass retention time, biomass must be fed back into the reactor. The fact that separation by means of common gravitational separators such as sedimentation tanks and baffle plate thickeners is unspecific results in the enrichment in the reactor of inorganic solids, whose presence is corollary to the anaerobic sludge process. Hence, industry has a great interest in separating anaerobic sludge into organic and inorganic constituents as a means of safeguarding high operating stability and degradation efficiency of anaerobic reactors. Hydrocyclones, permitting selective separation, are an obvious approach. (orig.) [German] Bei der anaeroben Abwasserreinigung ist die Biomassekonzentrierung aufgrund langer Generationszeiten und geringer Sinkgeschwindigkeiten der Biomasse ein zentrales Problem. Zur Entkopplung der hydraulischen Verweilzeit von der Verweilzeit der Biomasse ist eine Rueckfuehrung der Biomasse erforderlich. Da bisher eingesetzte Schwerkraftabscheider, wie Absetzbecken und Lamellenklaerer, unspezifisch trennen, kommt es zu einer Anreicherung anorganischer Feststoffe im Reaktor, die sich prozessbedingt im Anaerobschlamm befinden. So hat die Industrie ein grosses Interesse an einer Auftrennung des Anaerobschlamms in organische und anorganische Bestandteile, um eine hohe Betriebsstabilitaet und Abbauleistung der Anaerobreaktoren zu gewaehrleisten. Hierzu bieten sich Hydrozyklone an, weil mit ihnen eine selektive Trennung moeglich ist. (orig.)

  7. The Leachate Release and Microstructure of the Sewage Sludge under the Anaerobic Fermentation

    Directory of Open Access Journals (Sweden)

    Yiqie Dong

    2015-01-01

    Full Text Available Pollutant release, pore structure, and thermal effect of sewage sludge during anaerobic fermentation were investigated. Results showed that the pH value firstly declined and then increased during anaerobic fermentation. The BOD5 and organics of sewage sludge declined, and the BOD5 of samples which was originally neutral declined as much as 53.6%. The micropore of samples was relatively developed. The biggest adsorption amount was 69.2 cm3/g. The average pore size was enlarged about 16.0–19.8% under anaerobic fermentation. There existed endothermic valley during heating procedure of 0–200∘C because of the dehydration, and the mass loss was 60.9–72.5%. The endothermic valley of the sample fluctuated at the 14th day in the anaerobic fermentation. During the heating procedure of 200–600∘C, there existed exothermal peaks because of the oxidation and burning of the organics. The curve of sample which was originally neutral had comparatively large endothermic valley and exothermal peak.

  8. Occurrence and Fate of Trace Contaminants during Aerobic and Anaerobic Sludge Digestion and Dewatering.

    Science.gov (United States)

    Guerra, Paula; Kleywegt, Sonya; Payne, Michael; Svoboda, M Lewina; Lee, Hing-Biu; Reiner, Eric; Kolic, Terry; Metcalfe, Chris; Smyth, Shirley Anne

    2015-07-01

    Digestion of municipal wastewater biosolids is a necessary prerequisite to their beneficial use in land application, in order to protect public health and the receiving environment. In this study, 13 pharmaceuticals and personal care products (PPCPs), 11 musks, and 17 polybrominated diphenyl ethers were analyzed in 84 samples including primary sludge, waste activated sludge, digested biosolids, dewatered biosolids, and dewatering centrate or filtrate collected from five wastewater treatment plants with aerobic or anaerobic digestion. Aerobic digestion processes were sampled during both warm and cold temperatures to analyze seasonal differences. Among the studied compounds, triclosan, triclocarban, galaxolide, and BDE-209 were the substances most frequently detected under different treatment processes at levels up to 30,000 ng/g dry weight. Comparing aerobic and anaerobic digestion, it was observed that the levels of certain PPCPs and musks were significantly higher in anaerobically digested biosolids, relative to the residues from aerobic digestion. Therefore, aerobic digestion has the potential advantage of reducing levels of PPCPs and musks. On the other hand, anaerobic digestion has the advantage of recovering energy from the biosolids in the form of combustible gases while retaining the nutrient and soil conditioning value of this resource. PMID:26437100

  9. Enhanced biogas production by increasing organic load rate in mesophilic anaerobic digestion with sludge recirculation.

    OpenAIRE

    Huang, Zhanzhao

    2012-01-01

    For enhancing anaerobic sludge digestion and biogas recovery, an increase in organic load rate (OLR) from 1.0 to 3.0kgVS/(m3·day) was imposed upon a new anaerobic digestion process combined with a sludge recirculation. The new setup requires a traditional mesophilic anaerobic digester coupled with a centrifuge for maintaining relatively high solid content within the digester. The hypothesis of this study was that increasing continuously OLR from 1.0 to 3.0kgVS/(m3·day) in a pilot-scale anaero...

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

    NARCIS (Netherlands)

    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. S

  11. Mixing characteristics of sludge simulant in a model anaerobic digester.

    Science.gov (United States)

    Low, Siew Cheng; Eshtiaghi, Nicky; Slatter, Paul; Baudez, Jean-Christophe; Parthasarathy, Rajarathinam

    2016-03-01

    This study aims to investigate the mixing characteristics of a transparent sludge simulant in a mechanically agitated model digester using flow visualisation technique. Video images of the flow patterns were obtained by recording the progress of an acid-base reaction and analysed to determine the active and inactive volumes as a function of time. The doughnut-shaped inactive region formed above and below the impeller in low concentration simulant decreases in size with time and disappears finally. The 'cavern' shaped active mixing region formed around the impeller in simulant solutions with higher concentrations increases with increasing agitation time and reaches a steady state equilibrium size, which is a function of specific power input. These results indicate that the active volume is jointly determined by simulant rheology and specific power input. A mathematical correlation is proposed to estimate the active volume as a function of simulant concentration in terms of yield Reynolds number. PMID:26739143

  12. Effect of gamma radiation on yields of methane gas from the anaerobic bacterial digestion of sewage sludge

    International Nuclear Information System (INIS)

    Anaerobic digestion is widely employed to degrade soluble and insoluble organic materials in sewage sludge into the gaseous products carbon dioxide and methane. Previous research has established that gamma radiation at sufficiently high dose levels sterilizes the irradiated material and interacts with high molecular weight organic substrates to produce crosslinking or degradation, or both. Considering the increased scarcity and price of natural gas, investigators in this preliminary research program explored the interaction of two wastes, sewage sludge and spent nuclear fuel rods, to determine if a combination of processes could increase the yield or production rate of gas from sewage sludge. The study was designed to determine enhancement of methane production when radiation was used in conjunction with microbial action. Several conclusions can be stated as a result of the experiments in this research program. Treatment of anaerobically digested sewage sludge with gamma radiation from a cobalt 60 source for 24 hours at a dose of approximately 0.4 M rad per hour produces very little methane from direct scission of the organic material in the sludge. Sludge suspensions treated with the same radiation dose in the presence of excess oxygen consistently increased gas yield, up to 50%, from anaerobic bacterial digestion. Gas production increased up to 16% when air dried sludge was treated in an air atmosphere. When sludge suspensions were treated with a restricted access to air, decreases in gas production, though small (up to 26%), were noted in every case

  13. Correlation between Organic Matter Degradation and the Rheological Performance of Waste Sludge During Anaerobic Digestion

    Science.gov (United States)

    Morel, Evangelina S.; Hernández-Hernándes, José A.; Méndez-Contreras, Juan M.; Cantú-Lozano, Denis

    2008-07-01

    Anaerobic digestion has demonstrated to be a good possibility to reduce the organic matter contents in waste activated sludge resulting in the effluents treatment. An anaerobic digestion was carried out in a 3.5 L reactor at 35 °C for a period of 20 days. An electronic thermostat controlled the temperature. The reactor was agitated at a rate of 200 rpm. The study of the rheological behavior of the waste activated sludge was done with an Anton Paar™ rheometer model MCR301 with a peltier plate for temperature control. Four-blade vane geometry was used with samples of 37 mL for determining rheological properties. Sampling (two samples) was taken every four days of anaerobic digestion through a peristaltic pump. The samples behavior was characterized by the Herschel-Bulkley model, with R2>0.99 for most cases. In all samples were found an apparent viscosity (ηap) and yield stress (τo) decrement when organic matter content diminishes. This demonstrates a relationship between rheological properties and organic matter concentration (% volatile solids). Also the flow activation energy (Ea) was calculated using the Ahrrenius correlation and samples of waste activated sludge before anaerobic digestion. In this case, samples were run in the rheometer at 200 rpm and a temperature range of 25 to 75 °C with an increment rate of 2 °C per minute. The yield stress observed was in a range of 0.93-0.18 Pa, the apparent viscosity was in a range of 0.0358-0.0010 Pa.s, the reduction of organic matter was in a range of 62.57-58.43% volatile solids and the average flow activation energy was 1.71 Calṡg-mol-1.

  14. Membrane installation for enhanced up-flow anaerobic sludge blanket (UASB) performance.

    Science.gov (United States)

    Liu, Yin; Zhang, Kaisong; Bakke, Rune; Li, Chunming; Liu, Haining

    2013-09-01

    It is postulated that up-flow anaerobic sludge blanket (UASB) reactor efficiency can be enhanced by a membrane immersed in the reactor to operate it as an anaerobic membrane bioreactor (AnMBR) for low-strength wastewater treatment. This postulate was tested by comparing the performance with and without a hollow fiber microfiltration membrane module immersed in UASB reactors operated at two specific organic loading rates (SOLR). Results showed that membrane filtration enhanced process performance and stability, with over 90% total organic carbon (TOC) removal consistently achieved. More than 91% of the TOC removal was achieved by suspended biomass, while less than 6% was removed by membrane filtration and digestion in the membrane attached biofilm during stable AnMBRs operation. Although the membrane and its biofilm played an important role in initial stage of the high SOLR test, linear increased TOC removal by bulk sludge mainly accounted for the enhanced process performance, implying that membrane led to enhanced biological activity of the suspended sludge. The high retention of active fine sludge particles in suspension was the main reason for this significant improvement of performance and biological activity, which led to decreased SOLR with time to a theoretical optimal level around 2  g COD/g MLVSS·d and the establishment of a microbial community dominated by Methanothrix-like microbes. It was concluded that UASB process performance can be enhanced by transforming such to AnMBR operation when the loading rate is too high for sufficient sludge retention, and/or when the effluent water quality demands are especially stringent. PMID:23578587

  15. Influence of carbon source on nutrient removal performance and physical-chemical characteristics of aerobic granular sludge.

    Science.gov (United States)

    Lashkarizadeh, Monireh; Yuan, Qiuyan; Oleszkiewicz, Jan A

    2015-01-01

    The impact of carbon source variation on the physical and chemical characteristics of aerobic granular sludge and its biological nutrient (nitrogen and phosphorus) removal performance was investigated. Two identical sequencing batch reactors, R1 and R2, were set up. Granular biomass was cultivated to maturity using acetate-based synthetic wastewater. After mature granules in both reactors with simultaneous chemical oxygen demand (COD), ammonium and phosphorus removal capability were achieved, the feed of R2 was changed to municipal wastewater and R1 was continued on synthetic feed as control. Biological phosphorus removal was completely inhibited in R2 due to lack of readily biodegradable COD; however, the biomass maintained high ammonium and COD removal efficiencies. The disintegration of the granules in R2 occurred during the first two weeks after the change of feed, but it did not have significant impacts on settling properties of the sludge. Re-granulation of the biomass in R2 was then observed within 30 d after granules' disintegration when the biomass acclimated to the new substrate. The granular biomass in R1 and R2 maintained a Sludge Volume Index close to 60 and 47 mL g(-1), respectively, during the experimental period. It was concluded that changing the carbon source from readily biodegradable acetate to the more complex ones present in municipal wastewater did not have significant impacts on aerobic granular sludge characteristics; it particularly did not affect its settling properties. However, sufficient readily biodegradable carbon would have to be provided to maintain simultaneous biological nitrate and phosphorus removal. PMID:25719420

  16. Removal of fluoxetine and its effects in the performance of an aerobic granular sludge sequential batch reactor

    OpenAIRE

    Moreira, Irina S.; Amorim, Catarina L.; Ribeiro, Ana R.; Mesquita, Raquel B. R.; Rangel, António O. S. S.; Van Loosdrecht, Mark C.M.; Tiritan, Maria E.; Castro, Paula M. L.

    2015-01-01

    Fluoxetine (FLX) is a chiral fluorinated pharmaceutical mainly indicated for treatment of depression and is one of the most distributed drugs. There is a clear evidence of environmental contamination with this drug. Aerobic granular sludge sequencing batch reactors constitute a promising technology for wastewater treatment; however the removal of carbon and nutrients can be affected by micropollutants. In this study, the fate and effect of FLX on reactor performance and on microbi...

  17. Effect of chemo-mechanical disintegration on sludge anaerobic digestion for enhanced biogas production.

    Science.gov (United States)

    Kavitha, S; Pray, S Saji; Yogalakshmi, K N; Kumar, S Adish; Yeom, Ick-Tae; Banu, J Rajesh

    2016-02-01

    The effect of combined surfactant-dispersion pretreatment on dairy waste activated sludge (WAS) reduction in anaerobic digesters was investigated. The experiments were performed with surfactant, Sodium dodecyl sulfate (SDS) in the range of 0.01 to 0.1 g/g suspended solids (SS) and disperser with rpm of 5000-25,000. The COD (chemical oxygen demand) solubilization, suspended solids reduction, and biogas generation increased for an energy input of 7377 kJ/kg total solids (TS) (12,000 rpm, 0.04 g/g SS, and 30 min) and were found to be 38, 32, and 75 %, higher than that of control. The pretreated sludge improved the performance of semicontinuous anaerobic digesters of 4 L working volume operated at four different SRTs (sludge retention time). SRT of 15 days was found to be appropriate showing 49 and 51 % reduction in SS and volatile solids (VS), respectively. The methane yield of the pretreated sample was observed to be 50 mL/g VS removed which was observed to be comparatively higher than the control (12 mL/g VS removed) at optimal SRT of 15 days. To the best of the authors' knowledge, this study is the first to be reported and not yet been documented in literature. PMID:26416122

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

    Science.gov (United States)

    Hidaka, Taira; Wang, Feng; Tsumori, Jun

    2015-09-01

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

  19. Metal concentrations in lime stabilised, thermally dried and anaerobically digested sewage sludges.

    Science.gov (United States)

    Healy, M G; Fenton, O; Forrestal, P J; Danaher, M; Brennan, R B; Morrison, L

    2016-02-01

    Cognisant of the negative debate and public sentiment about the land application of treated sewage sludges ('biosolids'), it is important to characterise such wastes beyond current regulated parameters. Concerns may be warranted, as many priority metal pollutants may be present in biosolids. This study represents the first time that extensive use was made of a handheld X-ray fluorescence (XRF) analyser to characterise metals in sludges, having undergone treatment by thermal drying, lime stabilisation, or anaerobic digestion, in 16 wastewater treatment plants (WWTPs) in Ireland. The concentrations of metals, expressed as mgkg(-1) dry solids (DS), which are currently regulated in the European Union, ranged from 11 (cadmium, anaerobically digested (AD) biosolids) to 1273mgkg(-1) (zinc, AD biosolids), and with the exception of lead in one WWTP (which had a concentration of 3696mgkg(-1)), all metals were within EU regulatory limits. Two potentially hazardous metals, antimony (Sb) and tin (Sn), for which no legislation currently exists, were much higher than their baseline concentrations in soils (17-20mgSbkg(-1) and 23-55mgSnkg(-1)), meaning that potentially large amounts of these elements may be applied to the soil without regulation. This study recommends that the regulations governing the values for metal concentrations in sludges for reuse in agriculture are extended to include Sb and Sn. PMID:26611400

  20. Response of aerobic granular sludge to the long-term presence to nanosilver in sequencing batch reactors: Reactor performance, sludge property, microbial activity and community

    Energy Technology Data Exchange (ETDEWEB)

    Quan, Xiangchun, E-mail: xchquan@bnu.edu.cn; Cen, Yan; Lu, Fang; Gu, Lingyun; Ma, Jingyun

    2015-02-15

    The increasing use of silver nanoparticles (Ag NPs) raises concerns about their potential toxic effects on the environment. Granular shape sludge is a special type of microbial aggregate. The response of aerobic granular sludge (AGS) to the long-term presence of Ag NPs has not been well studied. In this study, AGS was exposed to 5 and 50 mg/L Ag NPs in sequence batch reactors (SBRs) for 69 days, and its response was evaluated based on the sludge properties, microbial activity and community, and reactor performance. The results showed that Ag NPs caused inhibition to microbial activities of AGS from Day 35. At the end of 69 days of Ag NPs exposure, the microbial activity of AGS was significantly inhibited in terms of inhibitions of the ammonia oxidizing rate (33.0%), respiration rate (17.7% and 45.6%) and denitrification rate (6.8%), as well as decreases in the ammonia mono-oxygenase and nitrate reductase activities. During the long-term exposure, the AGS maintained its granular shape and large granule size (approximately 900 μm); the microbial community of AGS slightly changed, but the dominant microbial population remained. Overall, the AGS tolerated the toxicity of Ag NPs well, but a long-term exposure may produce chronic toxicity to the AGS, which is concerning. - Highlights: • AGS demonstrated a good tolerance to the long-term presence of Ag NPs. • Ag NPs did not produce acute toxicity but cause chronic toxicity to AGS. • AGS maintained granular shape, granule size and good settling ability. • The microbial community of AGS slightly changed after long-term Ag NPs exposure.

  1. Response of aerobic granular sludge to the long-term presence to nanosilver in sequencing batch reactors: Reactor performance, sludge property, microbial activity and community

    International Nuclear Information System (INIS)

    The increasing use of silver nanoparticles (Ag NPs) raises concerns about their potential toxic effects on the environment. Granular shape sludge is a special type of microbial aggregate. The response of aerobic granular sludge (AGS) to the long-term presence of Ag NPs has not been well studied. In this study, AGS was exposed to 5 and 50 mg/L Ag NPs in sequence batch reactors (SBRs) for 69 days, and its response was evaluated based on the sludge properties, microbial activity and community, and reactor performance. The results showed that Ag NPs caused inhibition to microbial activities of AGS from Day 35. At the end of 69 days of Ag NPs exposure, the microbial activity of AGS was significantly inhibited in terms of inhibitions of the ammonia oxidizing rate (33.0%), respiration rate (17.7% and 45.6%) and denitrification rate (6.8%), as well as decreases in the ammonia mono-oxygenase and nitrate reductase activities. During the long-term exposure, the AGS maintained its granular shape and large granule size (approximately 900 μm); the microbial community of AGS slightly changed, but the dominant microbial population remained. Overall, the AGS tolerated the toxicity of Ag NPs well, but a long-term exposure may produce chronic toxicity to the AGS, which is concerning. - Highlights: • AGS demonstrated a good tolerance to the long-term presence of Ag NPs. • Ag NPs did not produce acute toxicity but cause chronic toxicity to AGS. • AGS maintained granular shape, granule size and good settling ability. • The microbial community of AGS slightly changed after long-term Ag NPs exposure

  2. Effect of temperature on removal of antibiotic resistance genes by anaerobic digestion of activated sludge revealed by metagenomic approach.

    Science.gov (United States)

    Zhang, Tong; Yang, Ying; Pruden, Amy

    2015-09-01

    As antibiotic resistance continues to spread globally, there is growing interest in the potential to limit the spread of antibiotic resistance genes (ARGs) from wastewater sources. In particular, operational conditions during sludge digestion may serve to discourage selection of resistant bacteria, reduce horizontal transfer of ARGs, and aid in hydrolysis of DNA. This study applied metagenomic analysis to examine the removal efficiency of ARGs through thermophilic and mesophilic anaerobic digestion using bench-scale reactors. Although the relative abundance of various ARGs shifted from influent to effluent sludge, there was no measureable change in the abundance of total ARGs or their diversity in either the thermophilic or mesophilic treatment. Among the 35 major ARG subtypes detected in feed sludge, substantial reductions (removal efficiency >90%) of 8 and 13 ARGs were achieved by thermophilic and mesophilic digestion, respectively. However, resistance genes of aadA, macB, and sul1 were enriched during the thermophilic anaerobic digestion, while resistance genes of erythromycin esterase type I, sul1, and tetM were enriched during the mesophilic anaerobic digestion. Efflux pump remained to be the major antibiotic resistance mechanism in sludge samples, but the portion of ARGs encoding resistance via target modification increased in the anaerobically digested sludge relative to the feed. Metagenomic analysis provided insight into the potential for anaerobic digestion to mitigate a broad array of ARGs. PMID:25994259

  3. A laboratory-scale test of anaerobic digestion and methane production after phosphorus recovery from waste activated sludge.

    Science.gov (United States)

    Takiguchi, Noboru; Kishino, Machiko; Kuroda, Akio; Kato, Junichi; Ohtake, Hisao

    2004-01-01

    In enhanced biological phosphorus removal (EBPR) processes, activated sludge microorganisms accumulate large quantities of polyphosphate (polyP) intracellularly. We previously discovered that nearly all of polyP could be released from waste activated sludge simply by heating it at 70 degrees C for about 1 h. We also demonstrated that this simple method was applicable to phosphorus (P) recovery from waste activated sludge in a pilot plant-scale EBPR process. In the present study, we evaluated the effect of this sludge processing (heat treatment followed by calcium phosphate precipitation) on anaerobic digestion in laboratory-scale experiments. The results suggested that the sludge processing for P recovery could improve digestive efficiency and methane productivity at both mesophilic (37 degrees C) and thermophilic (53 degrees C) temperatures. In addition, heat-treated waste sludge released far less P into the digested sludge liquor than did untreated waste sludge. It is likely that the P recovery step prior to anaerobic digestion has a potential advantage for controlling struvite (magnesium ammonium phosphate) deposit problems in sludge handling processes. PMID:16233643

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

    Science.gov (United States)

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

    2015-01-01

    Two-phase anaerobic systems are being increasingly implemented for the treatment of both sewage sludge and organic fraction of municipal solid waste. Despite the good amount of mathematical models in anaerobic digestion, few have been applied in two-phase systems. In this study, a three-reaction mechanistic model has been developed, implemented and validated by using experimental data from a long-term anaerobic two-phase (TPAD) digester treating sewage sludge. A sensitivity analysis shows that the most influential parameters of the model are the ones related to the hydrolysis reaction and the activity of methanogens in the thermophilic reactor. The calibration procedure highlights a noticeable growth rate of the thermophilic methanogens throughout the evaluation period. Overall, all the measured variables are properly predicted by the model during both the calibration and the cross-validation periods. The model's representation of the organic matter behaviour is quite good. The most important disagreements are observed for the biogas production especially during the validation period. The whole application procedure underlines the ability of the model to properly predict the behaviour of this bioprocess. PMID:25400016

  5. Enhanced Versus Conventional Sludge Anaerobic Processes: Performances and Techno-Economic Assessment.

    Science.gov (United States)

    Gianico, Andrea; Bertanza, Giorgio; Braguglia, Camilla M; Canato, Matteo; Gallipoli, Agata; Laera, Giuseppe; Levantesi, Caterina; Mininni, Giuseppe

    2016-05-01

    Sewage sludge processing is a key issue in water resource recovery facilities due to the inefficacy of conventional treatments to produce high quality biosolids to be safely used in agriculture. Under this framework, the performances of several enhanced stabilization processes, namely ultrasound-pretreated Mesophilic Anaerobic Digestion (US+MAD), thermophilic anaerobic digestion (TAD), thermal-pretreated TAD (TH+TAD) and ultrasound-pretreated inverse Temperature Phased Anaerobic Digestion (US+iTPAD) have been investigated. Such enhanced processes resulted in higher biogas yields and higher destruction of pathogens with respect to conventional MAD process, thus suggesting their feasibility in full-scale implementation perspectives. A procedure for technical-economic comparison of new sludge processing lines against conventional ones (benchmarking) was developed, based on the definition of technical issues (e.g. reliability, complexity, etc.) which are rated for each situation. Moreover, capital and operating costs were estimated. The enhanced processes analyzed in this work showed some potentially critical items, mainly related to energy balance and reagent consumption. PMID:27131310

  6. Evaluation of In-situ Sludge Reduction and Enhanced Nutrient Removal in an Integrated Repeatedly Coupling Aerobic and Anaerobic and Oxic-setting-anaerobic System

    Institute of Scientific and Technical Information of China (English)

    Shanshan Yang; Wanqian Guo; Qinglian Wu; Haichao Luo; Simai Peng; Heshan Zheng; Xiaochi Feng; Nanqi Ren∗

    2015-01-01

    Aiming to achieve simultaneous good performances of in⁃situ sludge reduction and effluent quality, an integrated repeatedly coupling aerobic and anaerobic and oxic⁃setting⁃anaerobic system ( rCAA+OSA ) is developed to reduce sludge production and enhance nutrient removal. Considering the mechanism of in⁃situ sludge reduction in this rCAA+OSA system, the combined effect of energy uncoupling metabolism and sludge cryptic growth maybe attributed to the higher reduction of biomass. Results show that the maximal sludge reduction in this rCAA+OSA system is obtained when the hydraulic retention time ( HRT ) is controlled at 6�5 h, which an increase in 16�67% reduction in excess sludge is achieved compared with OSA system ( HRT of 6�5 h) . When compared the performances of effluent qualities, the enhanced nutrient removal efficiencies also can be observed in this rCAA+OSA system. Three⁃dimensional excitation emission matrix ( 3D⁃EEM ) fluorescence spectroscopy is applied to characterize the effluent organic matters ( EfOM) under different HRTs in the OSA and the rCAA+OSA systems. Analyses of 3D⁃EEM spectra show that more refractory humic⁃like and fulvic⁃like components are observed in the effluent of the OSA system. On the basis of these results, simultaneous enhanced in⁃situ sludge reduction and improved nutrient removal can be obtained in the rCAA+OSA systems.

  7. The influence of hydrolysis induced biopolymers from recycled aerobic sludge on specific methanogenic activity and sludge filterability in an anaerobic membrane bioreactor.

    Science.gov (United States)

    Buntner, D; Spanjers, H; van Lier, J B

    2014-03-15

    The objective of the present study was to evaluate the impact of excess aerobic sludge on the specific methanogenic activity (SMA), in order to establish the maximum allowable aerobic sludge loading. In batch tests, different ratios of aerobic sludge to anaerobic inoculum were used, i.e. 0.03, 0.05, 0.10 and 0.15, showing that low ratios led to an increased SMA. However, the ratio 0.15 caused more than 20% SMA decrease. In addition to the SMA tests, the potential influence of biopolymers and extracellular substances, that are generated as a result of excess aerobic sludge hydrolysis, on membrane performance was determined by assessing the fouling potential of the liquid broth, taking into account parameters such as specific resistance to filtration (SRF) and supernatant filterability (SF). Addition of aerobic sludge to the anaerobic biomass resulted in a high membrane fouling potential. The increase in biopolymers could be ascribed to aerobic sludge hydrolysis. A clear positive correlation between the concentration of the colloidal fraction of biopolymer clusters (cBPC) and the SRF was observed and a negative correlation between the cBPC and the SF measured at the end of the above described SMA tests. The latter implies that sludge filtration resistance increases when more aerobic sludge is hydrolyzed, and thus more cBPC is released. During AnMBR operation, proteins significantly contributed to sludge filterability decrease expressed as SRF and SF, whereas the carbohydrate fraction of SMP was of less importance due to low concentrations. On the contrary, carbohydrates seemed to improve filterability and diminish SRF of the sludge. Albeit, cBPC increase caused an increase in mean TMP during the AnMBR operation, confirming that cBPC is positively correlated to membrane fouling. PMID:24284260

  8. Nitrogen removal from sludge dewatering effluent through anaerobic ammonia oxidation process

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shao-hui; ZHENG Ping; HUA Yu-mei

    2005-01-01

    Anaerobic ammonia oxidation(Anammox) process is a novel and promising wastewater nitrogen removal process. The feasibility of transition of Anammox from denitrification and the performance of lab-scale Anammox biofilm reactor were investigated with sludge dewatering effluent. The results showed that Anammox process could be successfully started up after cultivation of denitrification biofilm and using it as inoculum. The transition of Anammox from denitrification was accomplished within 85 d. Anammox process was found suitable to remove ammonia from sludge dewatering effluent. The effluent ammonia concentration was detected to be 23.11 mgN/L at HRT of 28 h when influent ammonia concentration was fed 245 mgN/L, which was less than that for the national discharge standard Ⅱ (25 mgN/L) of 243.25 mg NH4+ -N/L and 288.31 mg NO2- -N/L.

  9. Anaerobic degradation of linear alkylbenzene sulfonate

    DEFF Research Database (Denmark)

    Mogensen, Anders Skibsted; Haagensen, Frank; Ahring, Birgitte Kiær

    2003-01-01

    increases during anaerobic stabilization due to transformation of easily degradable organic matter. Hence, LAS is regarded as resistant to biodegradation under anaerobic conditions. We present data from a lab-scale semi-continuously stirred tank reactor (CSTR) spiked with linear dodecylbenzene sulfonate (C......% of the added C-12 LAS was bioavailable and 20% was biotransformed when spiking with 100 mg/L of C-12 LAS and a TS concentration of 14.2 mg/L. Enhanced bioavailability of C-12 LAS was obtained in an upflow anaerobic sludge blanket (UASB) reactor inoculated with granular sludge and sewage sludge. Biodegradation......Linear alkylbenzene sulfonate (LAS) found in wastewater is removed in the wastewater treatment facilities by sorption and aerobic biodegradation. The anaerobic digestion of sewage sludge has not been shown to contribute to the removal. The concentration of LAS based on dry matter typically...

  10. Anaerobic treatability of liquid residue from wet oxidation of sewage sludge.

    Science.gov (United States)

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

    2015-05-01

    Wet Oxidation (WO) of sewage sludge is a chemical oxidation of sludge at high temperatures and pressures by means of an oxygen-containing gas. The liquid stream originated by WO is easily biodegradable, and therefore, the recirculation to the biological Waste Water Treatment Plant (WWTP) may be a feasible solution. However, the WO effluent has a residual organic and nitrogen content so that its treatment may be required when the receiving WWTP has no surplus treatment capacity left. The aim of this research was the assessment of the anaerobic treatability of the WO liquid residue, in order to reduce the organic load to be recirculated to the WWTP, simultaneously promoting energy recovery. For this purpose, the liquid residue obtained during full scale WO tests on two different types of sludge was submitted to anaerobic digestion in a continuous flow pilot reactor (V = 5 L). Furthermore, batch tests were carried out in order to evaluate possible inhibition factors. Experimental results showed that, after the start-up/acclimation period (~130 days), Chemical Oxygen Demand (COD) removal efficiency was stably around 60% for about 120 days, despite the change in operating conditions. In the last phase of the experimental activity, COD removal reached 70% under the following treatment conditions: Hydraulic Retention Time (HRT) = 20 days, Volumetric Organic Loading Rate (VOLR) = 0.868 kg COD/m(3)/day, Organic Loading Rate per Volatile Suspended Solids (OLRvss) = 0.078 kg COD/kg VSS/day, temperature (T) = 36.5 °C, pH = 8. Energy balance calculation demonstrated anaerobic treatment sustainability. PMID:25035054

  11. Species and distribution of inorganic and organic phosphorus in enhanced phosphorus removal aerobic granular sludge.

    Science.gov (United States)

    Huang, Wenli; Huang, Weiwei; Li, Huifang; Lei, Zhongfang; Zhang, Zhenya; Tay, Joo Hwa; Lee, Duu-Jong

    2015-10-01

    The species and distribution of phosphorus (P) in an enhanced biological phosphorus removal (EBPR)-aerobic granular sludge (AGS) were fractionated and further analyzed. Results showed that microbial cells, extracellular polymeric substances (EPS) and mineral precipitates contributed about 73.7%, 17.6% and 5.3-6.4% to the total P (TP) of EBPR-AGS, respectively. Inorganic P (IP) species were orthophosphate, pyrophosphate and polyphosphate among which polyphosphate was the major P species in the AGS, cells and EPS. Monoester and diester phosphates were identified as the organic P (OP) species in the AGS and cells. Hydroxyapatite (Ca5(PO4)3OH) and calcium phosphate (Ca2(PO4)3) were the dominant P minerals accumulated in the core of the granules. Cells along with polyphosphate were mainly in the outer layer of AGS while EPS were distributed in the whole granules. Based on the above results, the distribution of IP and OP species in AGS has been conceived. PMID:26144019

  12. Impacts of variable pH on stability and nutrient removal efficiency of aerobic granular sludge.

    Science.gov (United States)

    Lashkarizadeh, Monireh; Munz, Giulio; Oleszkiewicz, Jan A

    2016-01-01

    The impact of pH variation on aerobic granular sludge stability and performance was investigated. A 9-day alkaline (pH=9) and acidic (pH=6) pH shocks were imposed on mature granules with simultaneous chemical oxygen demand (COD), nitrogen and phosphorus removal. The imposed alkaline pH shock (pH 9) reduced nitrogen and phosphorus removal efficiency from 88% and 98% to 66% and 50%, respectively, with no further recovery. However, acidic pH shock (pH 6) did not have a major impact on nutrient removal and the removal efficiencies recovered to their initial values after 3 days of operation under the new pH condition. Operating the reactors under alkaline pH induced granules breakage and resulted in an increased solids concentration in the effluent and a significant decrease in the size of the bio-particles, while acidic pH did not have significant impacts on granules stability. Changes in chemical structure and composition of extracellular polymeric substances (EPS) matrix were suggested as the main factors inducing granules instability under high pH. PMID:26744935

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

    International Nuclear Information System (INIS)

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

  14. Bio-Gas production from municipal sludge waste using anaerobic membrane bioreactor

    International Nuclear Information System (INIS)

    A laboratory scale anaerobic membrane bioreactor (AnMBR) system for the bio-methane gas production was operated for 60 days with municipal sludge wastes as a sole carbon source. The AnMRR system utilized the external cross-flow membrane module and was equipped with on-line data acquisition which enables continuous monitoring of the performance of both bioreactor and membrane through the analyses of pH, temperature, gas production; permeate flow rate, and transmembrane pressure (TMP). Such a configuration also provides an efficient tool to study rapid variations of monitoring membrane pressure (TMP). (Author)

  15. Remove and recover phosphorus during anaerobic digestion of excess sludge by adding waste iron scrap

    OpenAIRE

    Zheng Wei; Li Xiao Ming; Wang Dong Bo; Yang Qi; Luo Kun; Jing Yang Guo; Zeng Guang Ming

    2013-01-01

    In the current investigation, the feasibility of phosphorus removal in the anaerobic digestion of excess sludge by adding waste iron scrap (WIS) was studied. The results show that the removal efficiency of phosphorus increases with the amount of WIS, and the maximum removal efficiency could reach 39%, 93% and 99% at WIS dosages of 1, 2 and 3 g/L, respectively. Sterilization greatly decreases the removal efficiency of phosphorus, having only -6%, 53% and 64% at WIS dosages of 1, 2 and 3 ...

  16. Bio-Gas production from municipal sludge waste using anaerobic membrane bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y. H.; Lee, S.

    2009-07-01

    A laboratory scale anaerobic membrane bioreactor (AnMBR) system for the bio-methane gas production was operated for 60 days with municipal sludge wastes as a sole carbon source. The AnMRR system utilized the external cross-flow membrane module and was equipped with on-line data acquisition which enables continuous monitoring of the performance of both bioreactor and membrane through the analyses of pH, temperature, gas production; permeate flow rate, and transmembrane pressure (TMP). Such a configuration also provides an efficient tool to study rapid variations of monitoring membrane pressure (TMP). (Author)

  17. ANAEROBIC SLUDGE LOAD IMPACT LOAD OF ORGANIC SUBSTANCES CONTAINED IN THE WHEY OF THE FERMENTATION KINETICS

    Directory of Open Access Journals (Sweden)

    Marcin Dębowski

    2014-10-01

    Full Text Available The study aimed to determine the effect of the load cell model anaerobic load of organic substances contained in the whey acidic fermentation kinetics of transformation. Specified rate of biogas production and the amount and composition of the product gas quality sludge anaerobic metabolism. The highest yield of biogas rate of 945 ml was obtained during the application of the load of 4.0 g / l, the ratio of production rate of 0.25 k 1 / d Biogas production rate increased with the increase of the initial charge of organic compounds introduced into the digester and the model was in the range from 96.3 to 236.5. Biogas composition analysis revealed that the highest concentration of methane was obtained at a load of 1.0 g / l

  18. Anaerobic Codigestion of Sludge: Addition of Butcher's Fat Waste as a Cosubstrate for Increasing Biogas Production.

    Science.gov (United States)

    Martínez, E J; Gil, M V; Fernandez, C; Rosas, J G; Gómez, X

    2016-01-01

    Fat waste discarded from butcheries was used as a cosubstrate in the anaerobic codigestion of sewage sludge (SS). The process was evaluated under mesophilic and thermophilic conditions. The codigestion was successfully attained despite some inhibitory stages initially present that had their origin in the accumulation of volatile fatty acids (VFA) and adsorption of long-chain fatty acids (LCFA). The addition of a fat waste improved digestion stability and increased biogas yields thanks to the higher organic loading rate (OLR) applied to the reactors. However, thermophilic digestion was characterized by an effluent of poor quality and high VFA content. Results from spectroscopic analysis suggested the adsorption of lipid components onto the anaerobic biomass, thus disturbing the complete degradation of substrate during the treatment. The formation of fatty aggregates in the thermophilic reactor prevented process failure by avoiding the exposure of biomass to the toxic effect of high LCFA concentrations. PMID:27071074

  19. Characterization and Adaptation of Anaerobic Sludge Microbial Communities Exposed to Tetrabromobisphenol A

    Science.gov (United States)

    Lefevre, Emilie; Cooper, Ellen; Stapleton, Heather M.

    2016-01-01

    The increasing occurrence of tetrabromobisphenol A (TBBPA) in the environment is raising questions about its potential ecological and human health impacts. TBBPA is microbially transformed under anaerobic conditions to bisphenol A (BPA). However, little is known about which taxa degrade TBBPA and the adaptation of microbial communities exposed to TBBPA. The objectives of this study were to characterize the effect of TBBPA on microbial community structure during the start-up phase of a bench-scale anaerobic sludge reactor, and identify taxa that may be associated with TBBPA degradation. TBBPA degradation was monitored using LC/MS-MS, and the microbial community was characterized using Ion Torrent sequencing and qPCR. TBBPA was nearly completely transformed to BPA via reductive debromination in 55 days. Anaerobic reactor performance was not negatively affected by the presence of TBBPA and the bulk of the microbial community did not experience significant shifts. Several taxa showed a positive response to TBBPA, suggesting they may be associated with TBBPA degradation. Some of these taxa had been previously identified as dehalogenating bacteria including Dehalococcoides, Desulfovibrio, Propionibacterium, and Methylosinus species, but most had not previously been identified as having dehalogenating capacities. This study is the first to provide in-depth information on the microbial dynamics of anaerobic microbial communities exposed to TBBPA. PMID:27463972

  20. Research of Toxic Mechanism on Anaerobic Digestion by Lead

    Institute of Scientific and Technical Information of China (English)

    Han Jianhong; Wang Zhe; Zhang Lianke; Han Jintao

    2008-01-01

    The paper analyzes the influence of lead toxicity by anaerobic granule sludge inhibition and recovering experiments.The result shows that there are different inhibition types at differ ent lead contents.Higher lead content leads to more inhibition granular sludge,and at the same time,the time of gas recovery is different.Lower lead content per microorganism results in sooner sludge recovery.Microorganisms have a good ability to resist lead toxicity.

  1. Peracetic acid oxidation as an alternative pre-treatment for the anaerobic digestion of waste activated sludge

    OpenAIRE

    Appels, Lise; Van Assche, Ado; Willems, Kris; Degrève, Jan; Impe, Jan Van; Dewil, Raf

    2011-01-01

    Anaerobic digestion is generally considered to be an economic and environmentally friendly technology for treating waste activated sludge, but has some limitations, such as the time it takes for the sludge to be digested and also the ineffectiveness of degrading the solids. Various pre-treatment technologies have been suggested to overcome these limitations and to improve the biogas production rate by enhancing the hydrolysis of organic matter. This paper studies the use of perace...

  2. Zero-valent iron enhanced methanogenic activity in anaerobic digestion of waste activated sludge after heat and alkali pretreatment.

    Science.gov (United States)

    Zhang, Yaobin; Feng, Yinghong; Quan, Xie

    2015-04-01

    Heat or alkali pretreatment is the effective method to improve hydrolysis of waste sludge and then enhance anaerobic sludge digestion. However the pretreatment may inactivate the methanogens in the sludge. In the present work, zero-valent iron (ZVI) was used to enhance the methanogenic activity in anaerobic sludge digester under two methanogens-suppressing conditions, i.e. heat-pretreatment and alkali condition respectively. With the addition of ZVI, the lag time of methane production was shortened, and the methane yield increased by 91.5% compared to the control group. The consumption of VFA was accelerated by ZVI, especially for acetate, indicating that the acetoclastic methanogenesis was enhanced. In the alkali-condition experiment, the hydrogen produced decreased from 27.6 to 18.8 mL when increasing the ZVI dosage from 0 to 10 g/L. Correspondingly, the methane yield increased from 1.9 to 32.2 mL, which meant that the H2-utilizing methanogenes was enriched. These results suggested that the addition of ZVI into anaerobic digestion of sludge after pretreated by the heat or alkali process could efficiently recover the methanogenic activity and increase the methane production and sludge reduction. PMID:25681947

  3. Impact of ozone assisted ultrasonication pre-treatment on anaerobic digestibility of sewage sludge.

    Science.gov (United States)

    Tian, Xinbo; Trzcinski, Antoine Prandota; Lin, Li Leonard; Ng, Wun Jern

    2015-07-01

    Impact of ultrasonication (ULS) and ultrasonication-ozonation (ULS-Ozone) pre-treatment on the anaerobic digestibility of sewage sludge was investigated with semi-continuous anaerobic reactors at solid retention time (SRT) of 10 and 20 days. The control, ULS and ULS-Ozone reactors produced 256, 309 and 348 mL biogas/g CODfed and the volatile solid (VS) removals were 35.6%, 38.3% and 42.1%, respectively at SRT of 10 days. At SRT of 20 days, the biogas yields reached 313, 337 and 393 mL biogas/g CODfed and the VS removal rates were 37.3%, 40.9% and 45.3% in the control, ULS and ULS-Ozone reactors, respectively. ULS-Ozone pre-treatment increased the residual organic amount in the digested sludge. These soluble residual organics were found to contain macromolecules with molecular weights (MW) larger than 500 kDa and smaller polymeric products with MW around 19.4 and 7.7 kDa. These compounds were further characterized to be humic acid-like substances with fluorescent spectroscopy analysis. PMID:26141875

  4. Increase of the efficiency of anaerobic digestion by various pre-treatment processes of sewage sludge

    Directory of Open Access Journals (Sweden)

    Łukasz Krawczyk

    2011-09-01

    Full Text Available The aim of this paper is to demonstrate the effects of pre-treatment increase of the efficiency of anaerobic digestion on waste activated sludge. There were four methods for pre-treatment of the waste activated sludge: A – thermally treated at 121°C for 30 min, homogenized and hydrolysed by Bacillus subtilis bacteria, B – thermally treated at 121°C for 30 min and homogenized, C – thermally treated at 121°C for 30 min and hydrolysed by B. subtilis bacteria, D – thermally treated at 121°C for 30 min. The process consisted of a hydrolyses phase and anaerobic digestion phase operated at 36°C ±1°C for 35 days. It was investigated with regard to hydrolytic enzymes: amylase, cellulase, lipase and protease. Acetic acid (4.3 g∙dm-3 and butanediotic acid (0.1 g∙dm-3 were reported to appear in biggest quantities in volatile fatty acids according to measurement of VFA. The amount of carbon and nitrogen decreased while the ratio of C:N increased from 8:1 to 10:1. The highest methane yield was obtained in A method.

  5. Enhancement of Anaerobic Digestion to Treat Saline Sludge from Recirculating Aquaculture Systems

    Directory of Open Access Journals (Sweden)

    Guo-zhi Luo

    2015-01-01

    Full Text Available The effectiveness of carbohydrate addition and the use of ultrasonication as a pretreatment for the mesophilic anaerobic digestion of saline aquacultural sludge was assessed. Analyses were conducted using an anaerobic sequencing batch reactor (ASBR, which included stopped gas production attributed to the saline inhibition. After increasing the C : N ratio, gas production was observed, and the total chemical oxygen demand (TCOD removal efficiency increased from 75% to 80%. The TCOD removal efficiency of the sonication period was approximately 85%, compared to 75% for the untreated waste. Ultrasonication of aquaculture sludge was also found to enhance the gas production rate and the TCOD removal efficiency. The average volatile fatty acid (VFA to alkalinity ratios ranged from 0.1 to 0.05, confirming the stability of the digesters. Furthermore, soluble chemical oxygen demand (SCOD, VFA, and PO43- concentrations increased in the effluents. There was a 114% greater gas generation during the ultrasonication period, with an average production of 0.08 g COD/L·day−1.

  6. Enhancement of Anaerobic Digestion to Treat Saline Sludge from Recirculating Aquaculture Systems

    Science.gov (United States)

    Luo, Guo-zhi; Ma, Niannian; Li, Ping; Tan, Hong-xin; Liu, Wenchang

    2015-01-01

    The effectiveness of carbohydrate addition and the use of ultrasonication as a pretreatment for the mesophilic anaerobic digestion of saline aquacultural sludge was assessed. Analyses were conducted using an anaerobic sequencing batch reactor (ASBR), which included stopped gas production attributed to the saline inhibition. After increasing the C : N ratio, gas production was observed, and the total chemical oxygen demand (TCOD) removal efficiency increased from 75% to 80%. The TCOD removal efficiency of the sonication period was approximately 85%, compared to 75% for the untreated waste. Ultrasonication of aquaculture sludge was also found to enhance the gas production rate and the TCOD removal efficiency. The average volatile fatty acid (VFA) to alkalinity ratios ranged from 0.1 to 0.05, confirming the stability of the digesters. Furthermore, soluble chemical oxygen demand (SCOD), VFA, and PO43− concentrations increased in the effluents. There was a 114% greater gas generation during the ultrasonication period, with an average production of 0.08 g COD/L·day−1. PMID:26301258

  7. Influence of feed characteristics on the removal of micropollutants during the anaerobic digestion of contaminated sludge

    International Nuclear Information System (INIS)

    The removal of 13 polycyclic aromatic hydrocarbons, 7 polychlorobiphenyls and nonylphenol was measured during the continuous anaerobic digestion of five different sludge samples. The reactors were fed with one of the following: primary/secondary sludge (PS/SS), thermally treated PS, cellulose-added SS, or SS augmented with dissolved and colloidal matter (DCM). These various feeding conditions induced variable levels of micropollutant bioavailability (assumed to limit their biodegradation) and overall metabolism (supposed to be linked to micropollutant metabolism throughout co-metabolism). On the one hand, overall metabolism was higher with secondary sludge than with primary and the same was observed for micropollutant removal. However, when overall metabolism was enhanced thanks to cellulose addition, a negative influence on micropollutant removal was observed. This suggests that either the co-metabolic synergy would be linked to a specific metabolism or co-metabolism was not the limiting factor in this case. On the other hand, micropollutant bioavailability was presumably diminished by thermal treatment and increased by DCM addition. In both cases, micropollutant removal was reduced. These results suggest that neither overall metabolism nor bioavailability would absolutely limit micropollutant removal. Each phenomenon might alternatively predominate depending on the feed characteristics.

  8. Influence of feed characteristics on the removal of micropollutants during the anaerobic digestion of contaminated sludge

    Energy Technology Data Exchange (ETDEWEB)

    Barret, M., E-mail: barret@supagro.inra.fr [INRA, UR 050, Laboratoire de Biotechnologie de l' Environnement, Avenue des Etangs, 11100 Narbonne (France); Barcia, G. Cea, E-mail: cea@supagro.inra.fr [INRA, UR 050, Laboratoire de Biotechnologie de l' Environnement, Avenue des Etangs, 11100 Narbonne (France); Guillon, A., E-mail: a.guillon@ism.u-bordeaux1.fr [INRA, UR 050, Laboratoire de Biotechnologie de l' Environnement, Avenue des Etangs, 11100 Narbonne (France); Carrere, H., E-mail: carrere@supagro.inra.fr [INRA, UR 050, Laboratoire de Biotechnologie de l' Environnement, Avenue des Etangs, 11100 Narbonne (France); Patureau, D., E-mail: patureau@supagro.inra.fr [INRA, UR 050, Laboratoire de Biotechnologie de l' Environnement, Avenue des Etangs, 11100 Narbonne (France)

    2010-09-15

    The removal of 13 polycyclic aromatic hydrocarbons, 7 polychlorobiphenyls and nonylphenol was measured during the continuous anaerobic digestion of five different sludge samples. The reactors were fed with one of the following: primary/secondary sludge (PS/SS), thermally treated PS, cellulose-added SS, or SS augmented with dissolved and colloidal matter (DCM). These various feeding conditions induced variable levels of micropollutant bioavailability (assumed to limit their biodegradation) and overall metabolism (supposed to be linked to micropollutant metabolism throughout co-metabolism). On the one hand, overall metabolism was higher with secondary sludge than with primary and the same was observed for micropollutant removal. However, when overall metabolism was enhanced thanks to cellulose addition, a negative influence on micropollutant removal was observed. This suggests that either the co-metabolic synergy would be linked to a specific metabolism or co-metabolism was not the limiting factor in this case. On the other hand, micropollutant bioavailability was presumably diminished by thermal treatment and increased by DCM addition. In both cases, micropollutant removal was reduced. These results suggest that neither overall metabolism nor bioavailability would absolutely limit micropollutant removal. Each phenomenon might alternatively predominate depending on the feed characteristics.

  9. Microbiological characterization and specific methanogenic activity of anaerobe sludges used in urban solid waste treatment

    International Nuclear Information System (INIS)

    This study presents the microbiological characterization of the anaerobic sludge used in a two-stage anaerobic reactor for the treatment of organic fraction of urban solid waste (OFUSW). This treatment is one alternative for reducing solid waste in landfills at the same time producing a biogas (CH4 and CO2) and an effluent that can be used as biofertilizer. The system was inoculated with sludge from a wastewater treatment plant (WWTP) (Rio Frio Plant in Bucaramanga-Colombia) and a methanogenic anaerobic digester for the treatment of pig manure (Mesa de los Santos in Santander). Bacterial populations were evaluated by counting groups related to oxygen sensitivity, while metabolic groups were determined by most probable number (MPN) technique. Specific methanogenic activity (SMA) for acetate, formate, methanol and ethanol substrates was also determined. In the acidogenic reactor (R1), volatile fatty acids (VFA) reached values of 25,000 mg L-1 and a concentration of CO2 of 90%. In this reactor, the fermentative population was predominant (105-106 MPN mL-1). The acetogenic population was (105 MPN mL-1) and the sulphate-reducing population was (104-105 MPN mL-1). In the methanogenic reactor (R2), levels of CH4 (70%) were higher than CO2 (25%), whereas the VFA values were lower than 4000 mg L-1. Substrate competition between sulphate-reducing (104-105 MPN mL-1) and methanogenic bacteria (105 MPN mL-1) was not detected. From the SMA results obtained, acetoclastic (2.39 g COD-CH4 g-1 VSS-1 day-1) and hydrogenophilic (0.94 g COD-CH4 g-1 VSS-1 day-1) transformations as possible metabolic pathways used by methanogenic bacteria is suggested from the SMA results obtained. Methanotrix sp., Methanosarcina sp., Methanoccocus sp. and Methanobacterium sp. were identified

  10. Anaerobic degradation of aircraft deicing fluid (ADF) in upflow anaerobic sludge blanket (UASB) reactors and the fate of ADF additives

    Science.gov (United States)

    Pham, Thi Tham

    2002-11-01

    A central composite design was employed to methodically investigate anaerobic treatment of aircraft deicing fluid (ADF) in bench-scale Upflow Anaerobic Sludge Blanket (UASB) reactors. A total of 23 runs at 17 different operating conditions were conducted in continuous mode. The development of four empirical models describing process responses (i.e., chemical oxygen demand (COD) removal efficiency, biomass specific acetoclastic activity, methane production rate, and methane production potential) as functions of ADF concentration, hydraulic retention time (HRT), and biomass concentration is presented. Model verification indicated that predicted responses (COD removal efficiencies, biomass specific acetoclastic activity, and methane production rates and potential) were in good agreement with experimental results. Biomass specific acetoclastic activity was improved by almost two-fold during ADF treatment in UASB reactors. For the design window, COD removal efficiencies were higher than 90%. Predicted methane production potentials were close to theoretical values, and methane production rates increased as the organic loading rate (OLR) was increased. ADF toxicity effects were evident for 1.6% ADF at medium specific organic loadings (SOLR above 0.5 g COD/g VSS/d). In contrast, good reactor stability and excellent removal efficiencies were achieved at 1.2% ADF for reactor loadings approaching that of highly loaded systems (0.73 g COD/g VSS/d). Acclimation to ADF resulted in an initial reduction in the biomass settling velocity. The fate of ADF additives was also investigated. There was minimal sorption of benzotriazole (BT), 5-methyl-1 H-benzotriazole (MeBT), and 5,6-dimethyl-1 H-benzotriazole (DiMeBT) to anaerobic granules. A higher sorption capacity was measured for NP. Active transport may be one of the mechanisms for NP sorption. Ethylene glycol degradation experiments indicated that BT, MeBT, DiMeBT, and the nonionic surfactant Tergitol NP-4 had no significant

  11. [Effects of salinity on N2O production during nitrification using aerobic granular sludge].

    Science.gov (United States)

    Wang, Shan-Shan; iang, Hong; Gao, Da-Wen

    2014-11-01

    An aerobic SBR biological wastewater treatment system was adopted to measure the N2O production and nitrogen removal using aerobic granular sludge nitrification process under 0, 5, 10 g x L(-1) salinity conditions. The results showed that the N2O production increased with the increase of salinity concentration. At three salinity levels (0, 5, 10 g x L(-1)), the dissolved N2O production was 1.21, 8.99, 24.81 mg x m(-3), respectively, and the released N2O was 0.95, 3.46, 16.45 mg x m(-3), respectively. The N2O release rates at the 5 g x L(-1) and 10 g x L(-1) salinity levels were 3.6 and 17.4 times as high as that at the 0 g x L(-1) salinity level. Under various salinity conditions both the dissolved and releasing state N2O production first increased and then decreased, and the dissolved N2O production was greater than that in the releasing state. In addition, when the salinity was low (less than 5 g x L(-1)), the NH4(+)-N removal rate was less affected and almost the same with the condition of 0 g x L(-1), both over 98%. When the salinity was increased to 10 g x L(-1), the NH4(+)-N removal rate dropped to 70%. Thus, increasing the salinity of wastewater not only affected the system nitrogen removal rate but also increased the amount of N2O production. PMID:25639101

  12. The efficiency of concentration methods used to detect enteric viruses in anaerobically digested sludge

    Directory of Open Access Journals (Sweden)

    Tatiana Prado

    2013-02-01

    Full Text Available The presence of enteric viruses in biosolids can be underestimated due to the inefficient methods (mainly molecular methods used to recover the viruses from these matrices. Therefore, the goal of this study was to evaluate the different methods used to recover adenoviruses (AdV, rotavirus species A (RVA, norovirus genogroup II (NoV GII and the hepatitis A virus (HAV from biosolid samples at a large urban wastewater treatment plant in Brazil after they had been treated by mesophilic anaerobic digestion. Quantitative polymerase chain reaction (PCR was used for spiking experiments to compare the detection limits of feasible methods, such as beef extract elution and ultracentrifugation. Tests were performed to detect the inhibition levels and the bacteriophage PP7 was used as an internal control. The results showed that the inhibitors affected the efficiency of the PCR reaction and that beef extract elution is a suitable method for detecting enteric viruses, mainly AdV from biosolid samples. All of the viral groups were detected in the biosolid samples: AdV (90%, RVA, NoV GII (45% and HAV (18%, indicating the viruses' resistance to the anaerobic treatment process. This is the first study in Brazil to detect the presence of RVA, AdV, NoV GII and HAV in anaerobically digested sludge, highlighting the importance of adequate waste management.

  13. Anaerobic phosphate release from activated sludge with enhanced biological phosphorus removal. A possible mechanism of intracellular pH control

    Energy Technology Data Exchange (ETDEWEB)

    Bond, P.L.; Keller, J.; Blackall, L.L. [Univ. of Queensland, Brisbane (Australia)

    1999-06-05

    The biochemical mechanisms of the wastewater treatment process known as enhanced biological phosphorus removal (EBPR) are presently described in a metabolic model. The authors investigated details of the EBPR model to determine the nature of the anaerobic phosphate release and how this may be metabolically associated with polyhydroxyalkanoate (PHA) formation. Iodoacetate, an inhibitor of glycolysis, was found to inhibit the anaerobic formation of PHA and phosphate release, supporting the pathways proposed in the EBPR metabolic model. In the metabolic model, it is proposed that polyphosphate degradation provides energy for the microorganisms in anaerobic regions of these treatment systems. Other investigations have shown that anaerobic phosphate release depends on the extracellular pH. The authors observed that when the intracellular pH of EBPR sludge was raised, substantial anaerobic phosphate release was caused without volatile fatty acid (VFA) uptake. Acidification of the sludge inhibited anaerobic phosphate release even in the presence of VFA. from these observations, the authors postulate that an additional possible role of anaerobic polyphosphate degradation in EBPR is for intracellular pH control. Intracellular pH control may be a metabolic feature of EBPR, not previously considered, that could have some use in the control and optimization of EBPR.

  14. Energy production from distillery wastewater using single and double-phase upflow anaerobic sludge blanket (UASB) reactor

    Energy Technology Data Exchange (ETDEWEB)

    Muyodi, F.J.; Rubindamayugi, M.S.T. [Univ. of Dar es Salaam, Applied Microbiology Unit (Tanzania, United Republic of)

    1997-12-31

    A Single-phase (SP) and Double-phase (DP) Upflow Anaerobic Sludge Blanket (UASB) reactors treating distillery wastewater were operated in parallel. The DP UASB reactor showed better performance than the SP UASB reactor in terms of maximum methane production rate, methane content and Chemical Oxygen Demand (COD) removal efficiency. (au) 20 refs.

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

    NARCIS (Netherlands)

    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 [COD

  16. Combined carbon and nitrogen removal in integrated anaerobic/anoxic sludge bed reactors for the treatment of domestic sewage

    NARCIS (Netherlands)

    Kassab, G.

    2009-01-01

    The main objective of this research is to assess the applicability and effectiveness of integrating anaerobic digestion and denitrification processes in a single sludge system. The integrated concept is of particular interest for the treatment of highstrength domestic wastewater and is accomplished

  17. Treatment of domestic wastewater in an up-flow anaerobic sludge blanket reactor followed by moving bed biofilm reactor

    NARCIS (Netherlands)

    Tawfik, A.; El-Gohary, F.; Temmink, B.G.

    2010-01-01

    The performance of a laboratory-scale sewage treatment system composed of an up-flow anaerobic sludge blanket (UASB) reactor and a moving bed biofilm reactor (MBBR) at a temperature of (22-35 A degrees C) was evaluated. The entire treatment system was operated at different hydraulic retention times

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

    NARCIS (Netherlands)

    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 recirculatio

  19. Fermentative Hydrogen Production from Combination of Tofu processing and anaerobic digester sludge wastes using a microbial consortium

    Energy Technology Data Exchange (ETDEWEB)

    You-Kwan, O.; Mi-Sun, K.

    2009-07-01

    The combination of Tofu manufacturing waste and anaerobic digester sludge was studied for fermentative H{sub 2} production in batch and continuous modes using a mixed culture originated from sewage. In order to increase the solubilization of organic substrates from Tofu waste, various pretreatments including heat-treatment, acid/alkali treatment, and sonication were examined alone or in combination with others. (Author)

  20. Psychrophilic anaerobic treatment of low strength wastewaters.

    OpenAIRE

    Rebac, S.

    1998-01-01

    The main objective of this thesis was to design a high-rate anaerobic system for the treatment low strength wastewaters under psychrophilic conditions.Psychrophilic (3 to 20 °C) anaerobic treatment of low strength synthetic and malting wastewater was investigated using a single and two stage expanded granular sludge bed (EGSB) reactor system. The chemical oxygen demand (COD) removal efficiencies found in the experiments with synthetic wastewater exceeded 90 % in the single stage reactor at im...

  1. Two-stage anaerobic and post-aerobic mesophilic digestion of sewage sludge: Analysis of process performance and hygienization potential.

    Science.gov (United States)

    Tomei, M Concetta; Mosca Angelucci, Domenica; Levantesi, Caterina

    2016-03-01

    Sequential anaerobic-aerobic digestion has been demonstrated to be effective for enhanced sludge stabilization, in terms of increased solid reduction and improvement of sludge dewaterability. In this study, we propose a modified version of the sequential anaerobic-aerobic digestion process by operating the aerobic step under mesophilic conditions (T=37 °C), in order to improve the aerobic degradation kinetics of soluble and particulate chemical oxygen demand (COD). Process performance has been assessed in terms of "classical parameters" such as volatile solids (VS) removal, biogas production, COD removal, nitrogen species, and polysaccharide and protein fate. The aerobic step was operated under intermittent aeration to achieve nitrogen removal. Aerobic mesophilic conditions consistently increased VS removal, providing 32% additional removal vs. 20% at 20 °C. Similar results were obtained for nitrogen removal, increasing from 64% up to 99% at the higher temperature. Improved sludge dewaterability was also observed with a capillary suction time decrease of ~50% during the mesophilic aerobic step. This finding may be attributable to the decreased protein content in the aerobic digested sludge. The post-aerobic digestion exerted a positive effect on the reduction of microbial indicators while no consistent improvement of hygienization related to the increased temperature was observed. The techno-economic analysis of the proposed digestion layout showed a net cost saving for sludge disposal estimated in the range of 28-35% in comparison to the single-phase anaerobic digestion. PMID:26760266

  2. Anaerobic treatment of wastewater with high concentrations of lipids or sulfate.

    NARCIS (Netherlands)

    Rinzema, A.

    1988-01-01

    This thesis describes research on the application of granular sludge bed upflow reactors for anaerobic treatment of wastewaters contaminated with lipids and sulfate, two contaminants that have so far seriously hampered the application of anaerobic treatment in several branches of industry. The Upflo

  3. Continuous thermal hydrolysis and anaerobic digestion of sludge. Energy integration study.

    Science.gov (United States)

    Pérez-Elvira, S I; Fdz-Polanco, F

    2012-01-01

    Experimental data obtained from the operation in a pilot plant are used to perform mass and energy balances to a global process combining units of thermal hydrolysis (TH) of secondary sludge, anaerobic digestion (AD) of hydrolysed secondary sludge together with fresh primary sludge, and cogeneration from biogas by using a gas engine in which the biogas produces electricity and heat from the exhaust gases. Three scenarios were compared, corresponding to the three digesters operated: C (conventional AD, 17 days residence time), B (combined TH + AD, same time), and A (TH + AD at half residence time). The biogas production of digesters B and A was 33 and 24% better, respectively when compared with C. In the case of the combined TH + AD process (scenarios A and B), the key factors in the energy balance were the recovery of heat from hot streams, and the concentration of sludge. The results of the balances showed that for 8% DS concentration of the secondary sludge tested in the pilot plant, the process can be energetically self-sufficient, but a fraction of the biogas must by-pass the gas engine to be directly burned. From an economic point of view, scenario B is more profitable in terms of green energy and higher waste removal, while scenario A reduces the digester volume required by a half. Considering a population of 100,000 inhabitants, the economic benefit is 87,600 €/yr for scenario A and 132,373 €/yr for B. This value can be increased to 223,867 €/yr by increasing the sludge concentration of the feeding to the TH unit to a minimum value that allows use of all the biogas to produce green energy. This concentration is 13% DS, which is still possible from a practical point of view. Additional benefits gained with the combined TH + AD process are the enhancement of the digesters rheology and the possibility of getting Class A biosolids. The integration study presented here set the basis for the scale-up to a demonstration plant. PMID:22546800

  4. Biohydrogen production from desugared molasses (DM) using thermophilic mixed cultures immobilized on heat treated anaerobic sludge granules

    DEFF Research Database (Denmark)

    Kongjan, Prawit; O-Thong, Sompong; Angelidaki, Irini

    2011-01-01

    Hydrogen production from desugared molasses (DM) was investigated in both batch and continuous reactors using thermophilic mixed cultures enriched from digested manure by load shock (loading with DM concentration of 50.1 g-sugar/L) to suppress methanogens. H2 gas, free of methane, was produced...... Thermoanaerobacterium thermosaccharolyticum with a relative abundance of 36%, 27%, and 10% of total microorganisms, respectively. This study shows that hydrogen production could be efficiently facilitated by using anaerobic granules as a carrier, where microbes from mixed culture enriched in the DM batch cultivation...... enriched hydrogen producing mixed culture achieved from the 16.7 g-sugars/L DM batch cultivation was immobilized on heat treated anaerobic sludge granules in an up-flow anaerobic sludge blanket (UASB) reactor. The UASB reactor, operated at a hydraulic retention time (HRT) of 24 h fed with 16.7 g...

  5. Radiotracer study on the efficiency of a cylindrical 2-stage anaerobic sludge digester

    International Nuclear Information System (INIS)

    Radiotracer experiments were carried out on a cylindrical 2-stage anaerobic sludge digester in order to investigate the improvement of their efficiency by means of RTD (residence time distribution) measurements before and after cleaning up the inside of the digester. The tracer was scandium in an EDTA solution which forms such a stable complex compound to keep the isotope form being adsorbed onto the surface of the pipelines or the wall. It was injected into the digester by pressurized nitrogen gas and its movement was monitored by NaI(Tl) scintillation detectors installed around the digester and recorded for a month by a 24-channel data acquisition system specially developed for radiotracer experiments by the Korea Tracer Group of KAERI. The experimental data was analysed for the MRT (mean residence time) and other parameters characterizing the flow behaviour. (author)

  6. Hydraulics of laboratory and full-scale upflow anaerobic sludge blanket (UASB) reactors.

    Science.gov (United States)

    Batstone, D J; Hernandez, J L A; Schmidt, J E

    2005-08-01

    Laboratory-scale upflow anaerobic sludge blanket (UASB) reactors are often used as test platforms to evaluate full-scale applications. However, for a given volume specific hydraulic loading rate and geometry, the gas and liquid flows increase proportionally with the cube root of volume. In this communication, we demonstrate that a laboratory-scale reactor had plug-flow hydraulics, while a full-scale reactor had mixed flow hydraulics. The laboratory-scale reactor could be modeled using an existing biochemical model, and parameters identified, but because of computational speed with plug-flow hydraulics, mixed systems are instead recommended for parameter identification studies. Because of the scaling issues identified, operational data should not be directly projected from laboratory-scale results to the full-scale design. PMID:15977253

  7. Enhancement of anaerobic digestion efficiency of wastewater sludge and olive waste: Synergistic effect of co-digestion and ultrasonic/microwave sludge pre-treatment.

    Science.gov (United States)

    Alagöz, B Aylin; Yenigün, Orhan; Erdinçler, Ayşen

    2015-12-01

    This study investigates the effect of ultrasonic and microwave pre-treatment on biogas production from the anaerobic co-digestion of olive pomace and wastewater sludges. It was found that co-digestion of wastewater sludge with olive pomace yielded around 0.21 L CH4/g VS added, whereas the maximum methane yields from the mono-digestion of olive pomace and un-pretreated wastewater sludges were 0.18 and 0.16L CH4/g VS added. In the same way, compared to mono-digestion of these substrates, co-digestion increased methane production by 17-31%. The microwave and ultrasonic pre-treatments applied to sludge samples prior to co-digestion process led to further increase in the methane production by 52% and 24%, respectively, compared to co-digestion with un-pretreated wastewater sludge. The highest biogas and methane yields were obtained from the co-digestion of 30 min microwave pre-treated wastewater sludges and olive pomace to be 0.46 L/g VS added and 0.32 L CH4/g VS added, respectively. PMID:26320815

  8. The effect of enzymatic pre-hydrolysis of dairy wastewater on the granular and immobilized microbial community in anaerobic bioreactors.

    Science.gov (United States)

    Cammarota, Magali C; Rosa, Daniela R; Duarte, Iolanda C S; Saavedra, Nora K; Varesche, Maria B A; Zaiat, Marcelo; Freire, Denise M G

    2013-01-01

    The effect of a lipase-rich enzyme preparation produced by the fungus Penicillium sp. on solid-state fermentation was evaluated in two anaerobic bioreactors (up-flow anaerobic sludge blanket (UASB) and horizontal-flow anaerobic immobilized biomass (HAIB)) treating dairy wastewater with 1200 mg oil and grease/L. The oil and grease hydrolysis step was carried out with 0.1% (w/v) of the solid enzymatic preparation at 30 degrees C for 24 h. This resulted in a final concentration of free acids eight times higher than the initial value. The bioreactors operated at 30 degrees C with hydraulic retention times of 12 h (HAIB) and 20 h (UASB) for a period of 430 days, and had high chemical oxygen demand (COD) removal efficiencies (around 90%) when fed with pre-hydrolyzed wastewater. There was, however, an increase in the effluent oil and grease concentration (from values as low as 17 mg/L to values above 150 mg/L in the UASB bioreactor, and from 38-242 mg/L in the HAIB bioreactor), and oil and grease accumulation in the biomass throughout the operational period (the oil and grease content reached 1.7 times that found in the inoculum of the UASB bioreactor). The HAIB bioreactor gave better results because the support for biomass immobilization acted as a filter, retaining oil and grease at the entry of the bioreactor. The molecular analysis of the Bacteria and Archaea domains revealed significant differences in the microbial profiles in experiments conducted with and without the pre-hydrolysis step. The differences observed in the overall parameters could be related to the microbial diversity of the anaerobic sludge. PMID:23530355

  9. Kinetic study of mesophilic anaerobic digestion of pulp and paper sludge

    International Nuclear Information System (INIS)

    Anaerobic digestion of pulp and paper sludge (PPS) and monosodium glutamate waste liquor (MGWL) was studied in completely stirred tank reactors (CSTR) at 37 ± 2 °C. This work focused on the effect of increased organic loading rate (OLR) on the methane production in long-term experiments. For OLR in the range of (1.5–5.0) kg m−3 d−1 based on VS fed, VFA and SCOD concentrations decreased for the first 10 days and then kept stable at about 2.3 kg m−3 and 4.0 kg m−3 respectively until to the critical OLR of 5.0 kg m−3 d−1; and the methane generation rate enhanced to 0.838 m3 m−3 d−1 during this period until to the reactor failure. Additionally, reaction rate constant k and sludge retention time (SRT) are described on the basis of a mass balance in a CSTR followed a first order kinetic equation. In the present study, values for ym and k were obtained as 0.733 m3 kg−1 of removed VS and 0.07 d−1, respectively. The simple model can apply for dimensioning a CSTR digesting of organic wastes from pulp and paper industries, food processing industries, sewage treatment plants or biogas crops. -- Highlights: ► Evaluating methane yields for semi-continuous anaerobic co-digestion of PPS and MGWL. ► Determining the critical OLR for semi-continuous co-digestion. ► Developing the kinetic model for co-digestion of PPFS and MGWL in CSTR. ► Dimensioning CSTR by the model equations for organic wastes digestion.

  10. Fate of antibiotic resistance bacteria and genes during enhanced anaerobic digestion of sewage sludge by microwave pretreatment.

    Science.gov (United States)

    Tong, Juan; Liu, Jibao; Zheng, Xiang; Zhang, Junya; Ni, Xiaotang; Chen, Meixue; Wei, Yuansong

    2016-10-01

    The fate of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) were investigated during the sludge anaerobic digestion (AD) with microwave-acid (MW-H), microwave (MW) and microwave-H2O2-alkaline (MW-H2O2) pretreatments. Results showed that combined MW pretreatment especially for the MW-H pretreatment could efficiently reduce the ARB concentration, and most ARG concentrations tended to attenuate during the pretreatment. The subsequent AD showed evident removal of the ARB, but most ARGs were enriched after AD. Only the concentration of tetX kept continuous declination during the whole sludge treatment. The total ARGs concentration showed significant correlation with 16S rRNA during the pretreatment and AD. Compared with unpretreated sludge, the AD of MW and MW-H2O2 pretreated sludge presented slightly better ARB and ARGs reduction efficiency. PMID:26970692

  11. Simultaneous nitritation-denitritation for the treatment of high-strength nitrogen in hypersaline wastewater by aerobic granular sludge.

    Science.gov (United States)

    Corsino, Santo Fabio; Capodici, Marco; Morici, Claudia; Torregrossa, Michele; Viviani, Gaspare

    2016-01-01

    Fish processing industries produce wastewater containing high amounts of salt, organic matter and nitrogen. Biological treatment of such wastewaters could be problematic due to inhibitory effects exerted by high salinity levels. In detail, high salt concentrations lead to the accumulation of nitrite due to the inhibition of nitrite-oxidizing bacteria. The feasibility of performing simultaneous nitritation and denitritation in the treatment of fish canning wastewater by aerobic granular sludge was evaluated, and simultaneous nitritation-denitritation was successfully sustained at salinities up to 50 gNaCl L(-1), with a yield of over 90%. The total nitrogen concentration in the effluent was less than 10 mg L(-1) at salinities up to 50 gNaCl L(-1). Nitritation collapsed above 50 gNaCl L(-1), and then, the only nitrogen removal mechanism was represented by heterotrophic synthesis. In contrast, organic matter removal was not affected by salinity but was instead affected by the organic loading rate (OLR). Both COD and BOD removal efficiencies were over 90%. The COD fractionation analysis indicated that aerobic granules were able to remove more than 95% of the particulate organic matter. Finally, results obtained in this work noted that aerobic granular sludge had an excellent ability to adapt under adverse environmental conditions. PMID:26512811

  12. Testing the Fertilizer Effect of Compost Produced by Anaerobic Fermentation of Sewage Sludge

    Directory of Open Access Journals (Sweden)

    Benoni Lixandru

    2010-10-01

    Full Text Available The compost tested in this study resulted from the anaerobic fermentation process of sewage sludge with cereal straw. Processing and post-treatment were made by Biotechnological Research Centre within INCD ECOIND from Bucharest. Experimental program included testing the effect of fertilizer in quantities of 25 t, 50 t and 100 t compost / ha on the production of soya beans. It was also investigated the influence of the combination of fertilization with compost and inorganic fertilization with levels of 200 kg, respectively, 400 kg NPK / ha. Was analyzed the following productivity indicators: plant density, number of floors of pods, number and weight of pods and total beans production, in full ripening stage. In the case of fertilization only with composted sludge, production of peas and beans was higher in variants with 50 t / ha and 100 t / ha (2095 kg and 1990 kg grain / ha. Therefore, doubling the amount of compost does not provide corresponding increase yields of soybeans. Combining organic and inorganic fertilization determine a proportional production increase only for the total biomass production. The tested compost is a good organic fertilizer and the amount that provides the greatest soybeans production is 50 t / ha.

  13. Energy efficiency in waste water treatments plants: Optimization of activated sludge process coupled with anaerobic digestion

    International Nuclear Information System (INIS)

    This paper presents a study concerning the optimization of a Waste Water Treatment process. The process deals with carbon and nitrogen removal and includes activated sludge reactors coupled with an anaerobic digestion reactor. Nitrification and de-nitrification biochemical reactions are due to the biological activity of heterotrophic and autotrophic micro-organisms occurring inside the reactors. Rigorous Plant-Wide models that represent the main biochemical transformations have been constructed as per the CEIT approach . The energy consumption for each Physical Unit Operation (P.U.O.) involved in the flow-sheet is evaluated and a full link is made between the biological activity and the electrical demand or production. Steady-state mathematical optimizations are then computed and the influence of primary settling efficiency on electrical autonomy is quantified and demonstrated. The ammonium recycling from digestion to activated sludge reactors is also demonstrated to be a limiting factor for the overall energy efficiency, as well as the C-substrate availability for denitrifying. Some conclusions are then drawn to improve the global electrical efficiency of the system.

  14. Innovative two-stage mesophilic/thermophilic anaerobic degradation of sonicated sludge: performances and energy balance.

    Science.gov (United States)

    Gianico, A; Braguglia, C M; Gallipoli, A; Mininni, G

    2015-05-01

    This study investigates for the first time, on laboratory scale, the possible application of an innovative enhanced stabilization process based on sequential mesophilic/thermophilic anaerobic digestion of waste-activated sludge, with low-energy sonication pretreatment. The first mesophilic digestion step was conducted at short hydraulic retention time (3-5 days), in order to favor volatile fatty acid production, followed by a longer thermophilic step of 10 days to enhance the bioconversion kinetics, assuring a complete pathogen removal. The high volatile solid removals, up to 55%, noticeably higher compared to the performances of a single-stage process carried out in same conditions, can guarantee the stability of the final digestate for land application. The ultrasonic pretreatment influenced significantly the fatty acid formation and composition during the first mesophilic step, improving consequently the thermophilic conversion of these compounds into methane. Methane yield from sonicated sludge digestion reached values up to 0.2 Nm(3)/kgVSfed. Positive energy balances highlighted the possible exploitation of this innovative two-stage digestion in place of conventional single-stage processes. PMID:24906832

  15. ATP as an indicator of biomass activity in thermophilic upflow anaerobic sludge blanket reactor

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This work investigated the biomass activity in a thermophilic upflow anaerobic sludge blanket (UASB) reactor of wastewater treatment. Synthetic textile wastewater with pH 10-11, COD level of 2000-3000 mg/L was tested. Cellular adenosine triphosphate (ATP) in volatile solids (VS; mg ATP/gVS) was measured and expressed as specific ATP content to compare the biomass activity in up zone and lower zone in UASB reactor. The result shows that the specific ATP content based on total volatile solids (VS)in lower zone (0. 046 mgATP/gVS average) is much lower than that in up zone (0.62 mgATP/gVS average) due to high content of inactive biomass and high pH in lower zone. The SATP in up zone increases as HRT increases and approaches to a maximum value of 0.85 mgATP/gVS at HRT of 7h, then decreases. It shows most of the total VS in up zone represent active bacterial biomass at HRT of 7h. Rate of subtract utilization is directly related to the activity of microorganisms in the reactor. The effect of HRT on SATP in lower zone is not as significant as on SATP in up zone. The buffer capacity of the thermophilic UASB reactor is very good. It is the activity of sludge granules in lower zone that give the UASB reactor such a good buffer capacity to the inlet high pH.

  16. STARTUP OF UPELOW ANAEROBIC SLUDGE BLANKET REACTOR FOR INDUSTRIAL WASTEWATER TREATMENT

    Directory of Open Access Journals (Sweden)

    A.R. Mesdaghinia

    1994-06-01

    Full Text Available Up flow anaerobic sludge blanket (UASB reactors have been increasingly used for industrial wastewater treatment. Because of existing problems in startup step of these reactors, in this research the startup of a UASB in pilot scale and room temperature condition was studied. The total height of UASB reactor was 270 cm and effective height was 240 cm. Diameter of the reactor in lower part was 20 cm (reaction zone and 40 cm in upper part (solid-gas-liquid separator five sampling ports with interval of 32 cm were provided and the effective volume of the reactor was 100 liters. Septic tank digested sludge and cow manure were used for the seeding of UASB reactor. In the startup step of the reactor, volumetric loading was increased step by step. After 155 days granule formation was observed and after 215 days of the study the removal rate increased to 4.62 kg COD/m/ day. More than 98% of soluble COD removal was achieved in lower 160 cm of reactor.

  17. Inhibition of biogas production and biodegradability by substituted phenolic compounds in anaerobic sludge.

    Science.gov (United States)

    Hernandez, J E; Edyvean, R G J

    2008-12-15

    Phenolic compounds are abundant in nature and organic wastes. This biomass may be utilised in biogas generation. Phenolics can inhibit the degradation of readily biodegradable organic fractions and their own biodegradation. In this work, assays were carried out under anaerobic conditions to study the inhibition of both gas production and biodegradability due to seven phenolic compounds and to study their adsorption onto sludge and autoxidation in the aqueous medium. Fifty percent inhibition was in the range of 120 to 594 mg of compound/g VSS. An initial enhancement followed by an inhibition of biogas formation was found. The inhibition by the phenolic compounds was found to be influenced by autoxidation, apolarity, type, size and number of substitutions. Biogas production is influenced by concentration rather than any pH change. The concentration of the phenolic compound was partially biomethanized and the degradation of gallic and caffeic acids by this process is reported here for the first time. The maximum total biodegradation of any phenolic compound was 63.85+/-2.73%, and remaining non-biodegradable fraction was autoxidized and adsorbed onto the sludge matrix. Inhibition of methanization and partial inhibition of background gas was found at concentrations between 800 and 1600 mg/L organic carbon. PMID:18403112

  18. Remove and recover phosphorus during anaerobic digestion of excess sludge by adding waste iron scrap

    Directory of Open Access Journals (Sweden)

    Zheng Wei

    2013-01-01

    Full Text Available In the current investigation, the feasibility of phosphorus removal in the anaerobic digestion of excess sludge by adding waste iron scrap (WIS was studied. The results show that the removal efficiency of phosphorus increases with the amount of WIS, and the maximum removal efficiency could reach 39%, 93% and 99% at WIS dosages of 1, 2 and 3 g/L, respectively. Sterilization greatly decreases the removal efficiency of phosphorus, having only -6%, 53% and 64% at WIS dosages of 1, 2 and 3 g/L, respectively. This means that iron-reducing bacteria and hydrolytic bacteria enhance 45%, 40% and 35% of phosphorus removal at WIS dosages of 1, 2 and 3 g/L, respectively. The first and the most important mechanism of phosphorus removal using WIS is hydrolytic bacteria, which reduce the pH of sludge to corrode the WIS, followed by precipitation of phosphorus by ferrous iron generated from the iron-reducing bacteria. Phosphorus adsorption onto the WIS is the second probable mechanism. The removed phosphorus is recovered up to 56% using magnet. This method is characterized by high removal efficiency, easy and steady operation, low cost, recovery and reuse, making it better than other physical and chemical treatments.

  19. Performance of anaerobic membrane bioreactor during digestion and thickening of aerobic membrane bioreactor excess sludge.

    Science.gov (United States)

    Hafuka, Akira; Mimura, Kazuhisa; Ding, Qing; Yamamura, Hiroshi; Satoh, Hisashi; Watanabe, Yoshimasa

    2016-10-01

    In this study, we evaluated the performance of an anaerobic membrane bioreactor in terms of digestion and thickening of excess sludge from an aerobic membrane bioreactor. A digestion reactor equipped with an external polytetrafluoroethylene tubular microfiltration membrane module was operated in semi-batch mode. Solids were concentrated by repeated membrane filtration and sludge feeding, and their concentration reached 25,400mg/L after 92d. A high chemical oxygen demand (COD) removal efficiency, i.e., 98%, was achieved during operation. A hydraulic retention time of 34d and a pulse organic loading rate of 2200mg-COD/(L-reactor) gave a biogas production rate and biogas yield of 1.33L/(reactor d) and 0.08L/g-CODinput, respectively. The external membrane unit worked well without membrane cleaning for 90d. The transmembrane pressure reached 25kPa and the filtration flux decreased by 80% because of membrane fouling after operation for 90d. PMID:27394993

  20. Polyhydroxyalkanoates in waste activated sludge enhances anaerobic methane production through improving biochemical methane potential instead of hydrolysis rate

    Science.gov (United States)

    Wang, Qilin; Sun, Jing; Zhang, Chang; Xie, Guo-Jun; Zhou, Xu; Qian, Jin; Yang, Guojing; Zeng, Guangming; Liu, Yiqi; Wang, Dongbo

    2016-01-01

    Anaerobic sludge digestion is the main technology for sludge reduction and stabilization prior to sludge disposal. Nevertheless, methane production from anaerobic digestion of waste activated sludge (WAS) is often restricted by the poor biochemical methane potential and slow hydrolysis rate of WAS. This work systematically investigated the effect of PHA levels of WAS on anaerobic methane production, using both experimental and mathematical modeling approaches. Biochemical methane potential tests showed that methane production increased with increased PHA levels in WAS. Model-based analysis suggested that the PHA-based method enhanced methane production by improving biochemical methane potential of WAS, with the highest enhancement being around 40% (from 192 to 274 L CH4/kg VS added; VS: volatile solid) when the PHA levels increased from 21 to 143 mg/g VS. In contrast, the hydrolysis rate (approximately 0.10 d-1) was not significantly affected by the PHA levels. Economic analysis suggested that the PHA-based method could save $1.2/PE/y (PE: population equivalent) in a typical wastewater treatment plant (WWTP). The PHA-based method can be easily integrated into the current WWTP to enhance methane production, thereby providing a strong support to the on-going paradigm shift in wastewater management from pollutant removal to resource recovery.

  1. Enhancement of thermophilic anaerobic digestion of thickened waste activated sludge by combined microwave and alkaline pretreatment

    Institute of Scientific and Technical Information of China (English)

    Yongzhi Chi; Yuyou Li; Xuening Fei; Shaopo Wang; Hongying Yun

    2011-01-01

    Pretreatment of thickened waste activated sludge (TWAS) by combined microwave and alkaline pretreatment (MAP) was studied to improve thermophilic anaerobic digestion efficiency.Uniform design was applied to determine the combination of target temperature (110-210℃),microwave holding time (1-51 min),and NaOH dose (0-2.5 g NaOH/g suspended solids (SS)) in terms of their effect on volatile suspended solids (VSS) solubilization.Maximum solubilization ratio (85.1%) of VSS was observed at 210℃ with 0.2 g-NaOH/g-SS and 35 min holding time.The effects of 12 different pretreatment methods were investigated in 28 thermophilic batch reactors by monitoring cumulative methane production (CMP).Improvements in methane production in the TWAS were directly related to the microwave and alkaline pretreatment of the sludge.The highest CMP was a 27% improvement over the control.In spite of the increase in soluble chemical oxygen demand concentration and the decrease in dewaterability of digested sludge,a semi-continuous thennophilic reactor fed with pretreated TWAS without neutralization (at 170℃ with 1 rain holding time and 0.05 g NaOH/g SS) was stable and functioned well,with volatile solid (VS) and total chemical oxygen demand (TCOD) reductions of 28% and 18%,respectively,which were higher than those of the control system.Additionally,methane yields (L@STP/g-CODadded,at standard temperature and pressure (STP) conditions of 0℃ and 101.325 kPa) and (L@STP/g VSadded) increased by 17% and 13%,respectively,compared to the control reactor.

  2. Anaerobic co-digestion of sewage sludge and primary clarifier skimmings for increased biogas production.

    Science.gov (United States)

    Alanya, S; Yilmazel, Y D; Park, C; Willis, J L; Keaney, J; Kohl, P M; Hunt, J A; Duran, M

    2013-01-01

    The objective of the study was to identify the impact of co-digesting clarifier skimmings on the overall methane generation from the treatment plant and additional energy value of the increased methane production. Biogas production from co-digesting clarifier skimmings and sewage sludge in pilot-scale fed-batch mesophilic anaerobic digesters has been evaluated. The digester was fed with increasing quantities of clarifier skimmings loads: 1.5, 2.6, 3.5 and 7.0 g COD equivalent/(L·d) (COD: chemical oxygen demand). Average volatile solids reduction of 65% was achieved in the scum-fed digester, compared with 51% in the control digester. Average 69% COD removal was achieved at highest scum loading (7 g COD eq/(L·d)) with approximate methane yield of 250 L CH(4)/kg COD fed (4 ft(3)/lb COD fed). The results show that scum as co-substrate in anaerobic digestion systems improves biogas yields while a 29% increase in specific CH(4) yield could be achieved when scum load is 7 g COD eq/(L·d). Based on the pilot-scale study results and full-scale data from South East Water Pollution Control Plant and Northeast Water Pollution Control Plant the expected annual energy recovery would be approximately 1.7 billion BTUs or nearly 0.5 million kWh. PMID:23128636

  3. Performance analysis of upflow anaerobic sludge blanket reactors in the treatment of swine wastewater

    Directory of Open Access Journals (Sweden)

    Luiz A. V. Sarmento

    2007-07-01

    Full Text Available The adoption of confined systems for swine production have been increased the use of water in these installations and, consequently, an each time greater production of wastewater. Diagnostics have been showed a high level of water pollution due the waste material release on lands without criterions and in waters without previous treatment. The utilization of anaerobic process to reduce the liquid residues pollutant power has been detaching because beyond reducing the environmental pollution they allow to recover the energetic potential as fertilizer and biogas. In this work the performance of two real scale upflow anaerobic sludge blanket reactors treating swine wastewater were evaluated through operational system analysis, physical-chemical parameters of pollution and biogas production measurement. The results permitted to verify upflow rate speeds above of the value for which these reactors were designed and hydraulic residence times under of the design value. These factors affected negatively the treatment and had reflected on the law removal of the physical-chemical parameters and biogas production. The maximum removal efficiencies reached for TSS, BOD and COD were 72,5%, 34,7% and 40,0%, respectively. The mean rate of biogas liberation was 0,011 m-³ m-².h-1.

  4. Thermophilic degradation of phenolic compounds in lab scale hybrid up flow anaerobic sludge blanket reactors

    International Nuclear Information System (INIS)

    This Study describes the feasibility of anaerobic degradation of United States Environmental Protection Agency (USEPA) listed 4-chloro-2-nitrophenol (4C-2-NP), 2-chloro-4-nitrophenol (2C-4-NP), 2-chloro-5-methylphenol (2C-5-MP) from a simulated wastewater using four identical 7L bench scale hybrid up flow anaerobic sludge blankets (HUASBs) at five different hydraulic retention times (HRTs) under thermophilic condition (55 ± 3 deg. C). The substrate to co-substrate ratios were maintained between 1:33.3 and 1:166.6. Continuous monitoring of parameters like pH, volatile fatty acids (VFAs) accumulation, oxidation reduction potential, chemical oxygen demand (COD), alkalinity, gas productions, methane percentages were carried out along with compound reduction to asses the efficiency of biodegradation. The compound reduction was estimated by using spectrophotometric methods and further validated with high-performance liquid chromatography (HPLC). Optimum HRT values were observed at 24 h. Optimum ratio of substrate (phenolic compounds) to co-substrate (glucose) was 1:100. Scanning electron micrographs show that the granules were composed of thermophilic Methanobrevibacter and thermophilic Methanothrix like bacteria.

  5. Characteristics of fermentative hydrogen production with Klebsiella pneumoniae ECU-15 isolated from anaerobic sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Kun; Zhang, Xu; Tan, Wen-Song; Zhu, Ming-Long [State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China)

    2010-01-15

    Klebsiella pneumoniae ECU-15 (EU360791), which was isolated from anaerobic sewage sludge, was investigated in this paper for its characteristics of fermentative hydrogen production. It was found that the anaerobic condition favored hydrogen production than that of the micro-aerobic condition. Culture temperature and pH of 37 C and 6.0 were the most favorable for the hydrogen production. The strain could grow in several kinds of monosaccharide and disaccharide, as well as the complicated corn stalk hydrolysate, with the best results exhibited in glucose. The maximum hydrogen production rate and yield of 482 ml/l/h and 2.07 mol/mol glucose were obtained at initial glucose concentration of 30 g/L and 5 g/L, respectively. Fermentation results in the diluent corn stalk hydrolysate showed that cell growth was not inhibited. However, the hydrogen production of 0.65 V/V was relatively lower than that of the glucose (1.11 V/V), which was mainly due to the interaction between xylose and glucose. (author)

  6. POTENTIAL AND PROPERTIES OF THE GRANULAR SEWAGE SLUDGE AS A RENEWABLE ENERGY SOURCE

    OpenAIRE

    Sebastian Werle

    2013-01-01

    The predominant method of the sewage sludge management in Poland is land dis-posal. However, since 01/01/2013, this method will be prohibited. Therefore, there is a strong need for the development of thermal methods of sludge disposal. In Polish legal system sewage sludge may be named as biomass or waste. For the purposes of determining the obligations of environmental regulations the definitionof the Minister of Environment should be used. When disposing of sewage sludge in an amount up to 1...

  7. POTENTIAL AND PROPERTIES OF THE GRANULAR SEWAGE SLUDGE AS A RENEWABLE ENERGY SOURCE

    OpenAIRE

    Sebastian Werle

    2014-01-01

    The predominant method of the sewage sludge management in Poland is land disposal. However, since 01/01/2013, this method will be prohibited. Therefore, there is a strong need for development of thermal methods of sludge disposal. In the Polish legal system sewage sludge may be named as a biomass or waste. For purposes of determining the obligations of environmental regulations definition of the Minister of Environment should be used. When disposing of sewage sludge in an amount up to 1% by w...

  8. Performance evaluation of a novel anaerobic-anoxic sludge blanket reactor for biological nutrient removal treating municipal wastewater.

    Science.gov (United States)

    Díez-Montero, Rubén; De Florio, Loredana; González-Viar, Marta; Herrero, María; Tejero, Iñaki

    2016-06-01

    A novel anaerobic-anoxic sludge blanket reactor, AnoxAn, unifies the non-aerated zones of the biological nutrient removal treatment train in a single upflow reactor, aimed at achieving high compactness and efficiency. The environmental conditions are vertically divided up inside the reactor with the anaerobic zone at the bottom and the anoxic zone above. This contribution presents the performance evaluation of the novel reactor in the removal of organic matter and nutrients from municipal wastewater, coupled with an aerobic hybrid MBR. The overall system achieved total nitrogen and phosphorus removal with average efficiencies of 75% and 89%, respectively. Separate anoxic and anaerobic conditions were maintained in AnoxAn, allowing anaerobic phosphate release and nearly complete anoxic denitrification in the single reactor operating with an HRT of 4.2h. Biomass was retained in the reactor achieving TSS concentration up to 10gL(-1) and partial hydrolysis of influent particulate organic matter. PMID:26970922

  9. Optimization of operation conditions for the startup of aerobic granular sludge reactors biologically removing carbon, nitrogen, and phosphorous.

    Science.gov (United States)

    Lochmatter, Samuel; Holliger, Christof

    2014-08-01

    The transformation of conventional flocculent sludge to aerobic granular sludge (AGS) biologically removing carbon, nitrogen and phosphorus (COD, N, P) is still a main challenge in startup of AGS sequencing batch reactors (AGS-SBRs). On the one hand a rapid granulation is desired, on the other hand good biological nutrient removal capacities have to be maintained. So far, several operation parameters have been studied separately, which makes it difficult to compare their impacts. We investigated seven operation parameters in parallel by applying a Plackett-Burman experimental design approach with the aim to propose an optimized startup strategy. Five out of the seven tested parameters had a significant impact on the startup duration. The conditions identified to allow a rapid startup of AGS-SBRs with good nutrient removal performances were (i) alternation of high and low dissolved oxygen phases during aeration, (ii) a settling strategy avoiding too high biomass washout during the first weeks of reactor operation, (iii) adaptation of the contaminant load in the early stage of the startup in order to ensure that all soluble COD was consumed before the beginning of the aeration phase, (iv) a temperature of 20 °C, and (v) a neutral pH. Under such conditions, it took less than 30 days to produce granular sludge with high removal performances for COD, N, and P. A control run using this optimized startup strategy produced again AGS with good nutrient removal performances within four weeks and the system was stable during the additional operation period of more than 50 days. PMID:24784454

  10. A two-stage process for the anaerobic digestion of sludge generated during the production of bioethanol from sweet sorghum

    Energy Technology Data Exchange (ETDEWEB)

    Stamatelatou, K.; Dravillas, K.; Lyberatos, G.

    2003-07-01

    Sweet sorghum is an energy crop, often cultivated to recover energy in the form of ethanol, hydrogen etc by applying biological processes. These processes, however, produce a significant amount of sludge (bagasse) which contains the recalcitrant unconverted portion of sorghum, the non-hydrolyzed portion of the plant biomass as well as microbial biomass. In this work, the sludge from the alcoholic fermentation of sweet sorghum following a distillation step (to remove the generated bioethanol) was subjected to anaerobic digestion for further biodegradation and energy production (methane). A two-stage configuration for the anaerobic digestion of this type of industrial sludge was conceived and compared with a single stage anaerobic digestion of bagasse. For the two-stage process, the sludge was separated into one solid and one liquid stream. The solid portion of the sludge (9%) contributed mainly to the total organic load, although there was a significant organic load dissolved in the liquid portion too (28.73{+-}11.01 g/l). In the two stage system the solid and liquid phases of the sludge were separately treated under different operating conditions in two separate reactors: the solid phase in a thermophilic hydrolyzing reactor and the liquid phase in a mesophilic high-rate digester. The overall yield of the continuous two-stage process was 16 l methane/l wastewater at a hydraulic retention time of almost 20 days, while the maximum methane yield that could be achieved in batch experiments (duration 40d) was 30 l/l wastewater. (author)

  11. Enhancement of sludge anaerobic biodegradability by combined microwave-H2O2 pretreatment in acidic conditions.

    Science.gov (United States)

    Eswari, Parvathy; Kavitha, S; Kaliappan, S; Yeom, Ick-Tae; Banu, J Rajesh

    2016-07-01

    The aim of this study was to increase the sludge disintegration and reduce the cost of microwave (MW) pretreatment. Thermodynamic analysis of MW hydrolysis revealed the best fit with a first-order kinetic model at a specific energy of 18,600 kJ/kg total solids (TS). Combining H2O2 with MW resulted in a significant increment in solubilization from 30 to 50 % at 18,600 kJ/kg TS. The pH of H2O2-assisted MW-pretreated sludge (MW + H2O2) was in the alkaline range (pH 9-10), and it made the sludge unfavorable for subsequent anaerobic digestion and inhibits methane production. In order to nullify the alkaline effect caused by the MW + H2O2 combination, the addition of acid was considered for pH adjustment. H2O2-assisted MW-pretreated sludge in acidic conditions (MW + H2O2 + acid) showed a maximum methane production of 323 mL/g volatile solids (VS) than others during anaerobic biodegradability. A cost analysis of this study reveals that MW + H2O2 + acid was the most economical method with a net profit of 59.90 €/t of sludge. PMID:27026550

  12. Effect of gamma radiation on yields of methane gas from the anaerobic bacterial digestion of sewage sludge

    International Nuclear Information System (INIS)

    The present study was designed to determine enhancement of methane production when radiation was used in conjunction with microbial action. Researchers theorized that radiation degradation of the raw material might produce methane via scission of some methyl group bonding to increase yields directly, but that most enhancement would result from breakdown of the original structures to simpler species which could then be attacked and converted to methane by the microorganisms. In normal microbiological degradations, some 40 to 60% of the material remains unaffected, producing a limited methane yield as well as posing potential disposal problems. Several conclusions can be stated as a result of the experiments in this research program. Treatment of anaerobically digested sewage sludge with gamma radiation from a cobalt 60 source for 24 hours at a dose of approximately 0.4 M rad per hour produces very little methane from direct scission of the organic material in the sludge. Sludge suspensions treated with the same radiation dose in the presence of excess oxygen consistenly increased gas yield, up to 50%, from anaerobic bacterial digestion. Gas production increased up to 16% when air-dried sludge was treated in an air atmosphere. When sludge suspensions were treated with a restricted access to air, decreases in gas production, though small (up to 26%), were noted in every case

  13. Hybrid alkali-hydrodynamic disintegration of waste-activated sludge before two-stage anaerobic digestion process.

    Science.gov (United States)

    Grübel, Klaudiusz; Suschka, Jan

    2015-05-01

    The first step of anaerobic digestion, the hydrolysis, is regarded as the rate-limiting step in the degradation of complex organic compounds, such as waste-activated sludge (WAS). The aim of lab-scale experiments was to pre-hydrolyze the sludge by means of low intensive alkaline sludge conditioning before applying hydrodynamic disintegration, as the pre-treatment procedure. Application of both processes as a hybrid disintegration sludge technology resulted in a higher organic matter release (soluble chemical oxygen demand (SCOD)) to the liquid sludge phase compared with the effects of processes conducted separately. The total SCOD after alkalization at 9 pH (pH in the range of 8.96-9.10, SCOD = 600 mg O2/L) and after hydrodynamic (SCOD = 1450 mg O2/L) disintegration equaled to 2050 mg/L. However, due to the synergistic effect, the obtained SCOD value amounted to 2800 mg/L, which constitutes an additional chemical oxygen demand (COD) dissolution of about 35 %. Similarly, the synergistic effect after alkalization at 10 pH was also obtained. The applied hybrid pre-hydrolysis technology resulted in a disintegration degree of 28-35%. The experiments aimed at selection of the most appropriate procedures in terms of optimal sludge digestion results, including high organic matter degradation (removal) and high biogas production. The analyzed soft hybrid technology influenced the effectiveness of mesophilic/thermophilic anaerobic digestion in a positive way and ensured the sludge minimization. The adopted pre-treatment technology (alkalization + hydrodynamic cavitation) resulted in 22-27% higher biogas production and 13-28% higher biogas yield. After two stages of anaerobic digestion (mesophilic conditions (MAD) + thermophilic anaerobic digestion (TAD)), the highest total solids (TS) reduction amounted to 45.6% and was received for the following sample at 7 days MAD + 17 days TAD. About 7% higher TS reduction was noticed compared with the sample after 9

  14. Anaerobic Treatment of Palm Oil Mill Effluent in Pilot-Scale Anaerobic EGSB Reactor.

    Science.gov (United States)

    Wang, Jin; Mahmood, Qaisar; Qiu, Jiang-Ping; Li, Yin-Sheng; Chang, Yoon-Seong; Li, Xu-Dong

    2015-01-01

    Large volumes of untreated palm oil mill effluent (POME) pose threat to aquatic environment due to the presence of very high organic content. The present investigation involved two pilot-scale anaerobic expanded granular sludge bed (EGSB) reactors, continuously operated for 1 year to treat POME. Setting HRT at 9.8 d, the anaerobic EGSB reactors reduced COD from 71179 mg/L to 12341 mg/L and recycled half of sludge by a dissolved air flotation (DAF). The average effluent COD was 3587 mg/L with the consistent COD removal efficiency of 94.89%. Adding cationic polymer (PAM) dose of 30 mg/L to DAF unit and recycling its half of sludge caused granulation of anaerobic sludge. Bacilli and small coccid bacteria were the dominant microbial species of the reactor. The reactor produced 27.65 m(3) of biogas per m(3) of POME which was utilized for electricity generation. PMID:26167485

  15. Assessment of microbial viability in municipal sludge following ultrasound and microwave pretreatments and resulting impacts on the efficiency of anaerobic sludge digestion.

    Science.gov (United States)

    Cella, Monica Angela; Akgul, Deniz; Eskicioglu, Cigdem

    2016-03-01

    A range of ultrasonication (US) and microwave irradiation (MW) sludge pretreatments were compared to determine the extent of cellular destruction in micro-organisms within secondary sludge and how this cellular destruction translated to anaerobic digestion (AD). Cellular lysis/inactivation was measured using two microbial viability assays, (1) Syto 16® Green and Sytox® Orange counter-assay to discern the integrity of cellular membranes and (2) a fluorescein diacetate assay to understand relative enzymatic activity. A range of MW intensities (2.17-6.48 kJ/g total solids or TS, coinciding temperatures of 60-160 °C) were selected for comparison via viability assays; a range of corresponding US intensities (2.37-27.71 kJ/g TS, coinciding sonication times of 10-60 min at different amplitudes) were also compared to this MW range. The MW pretreatment of thickened waste activated sludge (tWAS) caused fourfold to fivefold greater cell death than non-pretreated and US-pretreated tWAS. The greatest microbial destruction occurred at MW intensities greater than 2.62 kJ/g TS of sludge, after which increased energy input via MW did not appear to cause greater microbial death. In addition, the optimal MW pretreatment (80 °C, 2.62 kJ/g TS) and corresponding US pretreatment (10 min, 60 % amplitude, 2.37 kJ/g TS) were administered to the tWAS of a mixed sludge and fed to anaerobic digesters over sludge retention times (SRTs) of 20, 14, and 7 days to compare effects of feed pretreatment on AD efficiency. The digester utilizing MW-pretreated tWAS (80 °C, 2.62 kJ/g TS) had the greatest fecal coliform removal (73.4 and 69.8 % reduction, respectively), greatest solids removal (44.2 % TS reduction), and highest overall methane production (248.2 L CH4/kg volatile solids) at 14- and 7-day SRTs. However, despite the fourfold to fivefold increases in cell death upon pretreatment, improvements from the digester fed MW-pretreated sludge were marginal (i.e., increases in

  16. Anaerobic side-stream reactor for excess sludge reduction: 5-year management of a full-scale plant.

    Science.gov (United States)

    Velho, V F; Foladori, P; Andreottola, G; Costa, R H R

    2016-07-15

    The long-term performances of a full-scale anaerobic side-stream reactor (ASSR) aimed at sludge reduction have been monitored for the first time, in comparison with a conventional activated sludge process (CAS). The plant was integrated with an ASSR treatment of 2293-3293 m(3). Operational parameters in the ASSR were: ORP -250 mV, interchange ratio of 7-10%, hydraulic retention time of 7 d. No worsening of effluent quality was observed in the ASSR configuration and removal efficiency of COD and NH4 was above 95%. A slight increase in the Sludge Volume Index did not cause worsening in effluent solids concentration. The observed sludge yield (Yobs) passed from 0.44 kgTSS/kgCOD in the CAS to 0.35 in the ASSR configuration. The reduction of Yobs by 20% is lower than expected from the literature where sythetic wastewater is used, indicating that sludge reduction efficiency is largely affected by inert mass fed with influent real wastewater. An increase by 45% of the ASSR volume did not promote a further reduction of Yobs, because sludge reduction is affected not solely by endogenous decay but also by other factors such as interchange ratio and aerobiosis/anaerobiosis alternation. PMID:27107390

  17. Waste paper and clinoptilolite as a bulking material with dewatered anaerobically stabilized primary sewage sludge (DASPSS) for compost production.

    Science.gov (United States)

    Zorpas, Antonis A; Arapoglou, Dimitris; Panagiotis, Karlis

    2003-01-01

    Environmental problems associated with sewage sludge disposal have prompted strict legislative actions over the past few years. At the same time, the upgrading and expansion of wastewater treatment plants have greatly increased the volume of sludge generated. The major limitation of land application of sewage sludge compost is the potential for high heavy metal content in relation to the metal content of the original sludge. Composting of sewage sludge with natural zeolite (clinoptilolite) can enhance its quality and suitability for agricultural use. However, the dewatered anaerobically stabilized primary sewage sludge (DASPSS) contained a low concentration of humic substances (almost 2%), and the addition of the waste paper was necessary in order to produce a good soil conditioner with high concentrations of humics. The final results showed that the compost produced from DASPSS and 40-50% w/w of waste paper was a good soil fertilizer. Finally, in order to estimate the metal leachability of the final compost product, the generalized acid neutralization Capacity (GANC) procedure was used, and it was found that by increasing the leachate pH, the heavy metal concentration decreased. The application of the sequential chemical extraction indicated that metals were bound to the residual fraction characterized as a stabilize fractions. PMID:12623099

  18. Microbial network for waste activated sludge cascade utilization in an integrated system of microbial electrolysis and anaerobic fermentation

    DEFF Research Database (Denmark)

    Liu, Wenzong; He, Zhangwei; Yang, Chunxue;

    2016-01-01

    integrated system of microbial electrolysis cell (MEC) and anaerobic digestion (AD) for waste activated sludge (WAS). Microbial communities in integrated system would build a thorough energetic and metabolic interaction network regarding fermentation communities and electrode respiring communities. The...... Parabacteroides, which showed a delayed contribution to the extracellular electron transport leading to a slow cascade utilization of WAS. Conclusions: Efficient pretreatment could supply more short-chain fatty acids and higher conductivities in the fermentative liquid, which facilitated mass transfer in anodic...

  19. Treatment of industrial wastewaters by anaerobic membrane bioreactors: implications of substrate characteristics

    OpenAIRE

    Dereli, R.K.

    2015-01-01

    The success of anaerobic digestion relies on the presence of highly active methanogenic biomass, requiring effective retention of slow growing anaerobic microorganisms inside bioreactor by decoupling the hydraulic retention time (HRT) from solids residence time (SRT) or the employment of long SRTs in fully mixed systems. So far, flow through systems, i.e. completely stirred tank reactor (CSTR) digesters, and granular sludge bed reactors have been commonly applied for anaerobic treatment of sl...

  20. Influence of feeding mixture composition in batch anaerobic co-digestion of stabilized municipal sludge and waste from dairy farms.

    Science.gov (United States)

    Trulli, Ettore; Torretta, Vincenzo

    2015-01-01

    Waste anaerobic co-digestion applications are particularly useful in Southern Mediterranean areas where large quantities of agricultural waste materials and waste from agro-industries are produced. This waste can be added to urban waste together with the sludge produced by wastewater treatment processes, which, when combined, guarantee the supply of organic matrixes for treatment throughout the year. The implementation of facilities to service vast areas of the agricultural economy and which are heterogeneous in terms of production can provide a good solution. We present an experimental investigation into the anaerobic co-digestion of municipal sludge and bio-waste produced in the Mediterranean area. We conducted anaerobic treatability tests, with measures of biogas production and pH of the mixture in digestion. Our main aims were to identify an optimal mix of substrates for the production of biogas, and to analyse the influence on the composition of biogas and the variation in pH values of the substrates. This analysis was conducted considering the variation of the input, in particular due to the addition of waste acids, such as biological sewage sludge. PMID:25442095

  1. Formation of granular sludge and its mechanism in enhanced process of biological phosphorus removal%强化生物除磷体系中颗粒污泥的形成及机理探讨

    Institute of Scientific and Technical Information of China (English)

    王然登; 彭永臻; 吴昌永; 李晓玲; 马勇

    2011-01-01

    以实验室小试SBR反应器为载体接种普通活性污泥,研究了强化生物除磷系统对颗粒污泥形成的促进作用并探讨了其形成机理.试验结果发现:在生物脱氮运行阶段,SBR中的活性污泥能维持较稳定的絮体状态,平均SVI为138.9 ml·g-1;当系统转为生物除磷方式运行时,随着除磷效果的好转,反应器中的污泥逐渐转化为颗粒污泥,平均SVI降低至74.1 ml·g-1,颗粒污泥的平均粒径为0.8 mm.因此,SBR生物除磷系统有利于颗粒污泥的形成.试验发现在强化生物除磷系统厌氧释磷的过程中会有带正电的微粒大量生成,它们可以作为颗粒污泥的晶核吸附带负电的细胞体,进而促进颗粒污泥的形成.强化生物除磷颗粒污泥系统有着较为稳定的磷去除性能,除磷效率接近100%.%The promoting effect on the formation of granular sludge by inoculating activated sludge in the enhanced process of biological phosphorus removal was studied in a laboratory-scale sequencing batch reactor (SBR). The results showed that the activated sludge kept in stabilized flocculent state at biological denitrification stage, and the average SVI was 138.9 ml·g-1, while at biological de-phosphorus one the activated sludge flocs became granular sludge gradually as the performance of P removal became better. The average SVI decreased to 74.1 ml·g-1 and the average diameter of the granules was 0.8 mm. Therefore, the biological phosphorus removal process performed in SBR favored for the formation of granular sludge. Moreover, it was found that a lot of positive charged particles were formed with the release of phosphorus at the anaerobic stage in the biological de-phosphorus process. These particles could serve as the cores of granules to attract the negative charged cells and stimulate the granulation. The granular sludge system of enhancing biological de-phosphorus have an excellent ability for the removal of phosphorus. The average removal rate

  2. Grey water treatment in upflow anaerobic sludge blanket (UASB) reactor at different temperatures.

    Science.gov (United States)

    Elmitwalli, Tarek; Otterpohl, Ralf

    2011-01-01

    The treatment of grey water in two upflow anaerobic sludge blanket (UASB) reactors, operated at different hydraulic retention times (HRTs) and temperatures, was investigated. The first reactor (UASB-A) was operated at ambient temperature (14-25 degrees C) and HRT of 20, 12 and 8 h, while the second reactor (UASB-30) was operated at controlled temperature of 30 degrees C and HRT of 16, 10 and 6 h. The two reactors were fed with grey water from 'Flintenbreite' settlement in Luebeck, Germany. When the grey water was treated in the UASB reactor at 30 degrees C, total chemical oxygen demand (CODt) removal of 52-64% was achieved at HRT between 6 and 16 h, while at lower temperature lower removal (31-41%) was obtained at HRT between 8 and 20 h. Total nitrogen and phosphorous removal in the UASB reactors were limited (22-36 and 10-24%, respectively) at all operational conditions. The results showed that at increasing temperature or decreasing HRT of the reactors, maximum specific methanogenic activity of the sludge in the reactors improved. As the UASB reactor showed a significantly higher COD removal (31-64%) than the septic tank (11-14%) even at low temperature, it is recommended to use UASB reactor instead of septic tank (the most common system) for grey water pre-treatment. Based on the achieved results and due to high peak flow factor, a HRT between 8 and 12 h can be considered the suitable HRT for the UASB reactor treating grey water at temperature 20-30 degrees C, while a HRT of 12-24 h can be applied at temperature lower than 20 degrees C. PMID:22097038

  3. POTENTIAL AND PROPERTIES OF THE GRANULAR SEWAGE SLUDGE AS A RENEWABLE ENERGY SOURCE

    Directory of Open Access Journals (Sweden)

    Sebastian Werle

    2013-01-01

    Full Text Available The predominant method of the sewage sludge management in Poland is land dis-posal. However, since 01/01/2013, this method will be prohibited. Therefore, there is a strong need for the development of thermal methods of sludge disposal. In Polish legal system sewage sludge may be named as biomass or waste. For the purposes of determining the obligations of environmental regulations the definitionof the Minister of Environment should be used. When disposing of sewage sludge in an amount up to 1% by weight of fuel, emission standards for fuel do not change. At the disposal of sewage in quantities of more than 1%, should be conducted continuous measurement of emissions, including HCl, HF, and continuous measurements of fluegas param-eters (as for the installation of waste disposal. In order to meet the requirement to porduce energy from renewable sources we use the definitionof Minister of Economy. In this case, in accordance with applicable law, sewage sludge shall be considered as pure biomass, thus it is CO2 neutral. The use of sewage sludge as a fuel requires the determination of fundamental combustible properties. These properties should be in accordance with the requirements put fuels as an energy source. The paper presents the results of a detailed physico-chemical analysis of dried sewage sludge produced in the two Polish wastewater treatment plants. The results were compared with fiverepresentatives of biomass fuels: straw of wheat, straw of rape, willow, pine and oak sawdust. Ultimate and proximate analyses include a detailed analysis of fuel and ash. The results clearly indicate that sludge is a very valuable fuel similar to “traditional” biomass.

  4. POTENTIAL AND PROPERTIES OF THE GRANULAR SEWAGE SLUDGE AS A RENEWABLE ENERGY SOURCE

    Directory of Open Access Journals (Sweden)

    Sebastian Werle

    2014-10-01

    Full Text Available The predominant method of the sewage sludge management in Poland is land disposal. However, since 01/01/2013, this method will be prohibited. Therefore, there is a strong need for development of thermal methods of sludge disposal. In the Polish legal system sewage sludge may be named as a biomass or waste. For purposes of determining the obligations of environmental regulations definition of the Minister of Environment should be used. When disposing of sewage sludge in an amount up to 1% by weight of fuel, emission standards for fuel do not change. At the disposal of sewage in quantities of more than 1%, should be conducted continuous measurement of emissions, including HCl, HF, and continuous measurements of flue gas parameters (as for the installation of waste disposal. For purposes of settlement of the share of energy from renewable sources we use the definition of Minister of Economy. In this case, in accordance with applicable law sewage sludge shall be considered as pure biomass is CO2 neutral. The use of sewage sludge as a fuel requires the determination of fundamental combustible properties. These properties should be in accordance with the requirements put fuels as an energy source. The paper presents results of a detailed physico-chemical analysis of dried sewage sludge produced in the two Polish wastewater treatment plants. The results were compared with five representatives of biomass fuels: straw of wheat, straw of rape, willow, pine and oak sawdust. Ultimate and proximate analysis includes a detailed analysis of fuel and ash. The results clearly indicate that the sludge is a very valuable fuel similar to “traditional” biomass.

  5. Biodegradation and chemical precipitation of dissolved nutrients in anaerobically digested sludge dewatering centrate.

    Science.gov (United States)

    Galvagno, G; Eskicioglu, C; Abel-Denee, M

    2016-06-01

    The objective of this research was to assess specific side-stream treatment processes for biodegradation and precipitation of dissolved nutrients in dewatering centrate. In this study, characterization was made of a conventional suspended growth deammonification treatment process for transforming dissolved polyphosphate (poly-P), dissolved organic phosphorus (DOP) and dissolved organic nitrogen (DON) in two types of dewatering centrate. The deammonification process was configured as a sequencing batch reactor (SBR), combining partial nitrification and anaerobic ammonia oxidation (anammox) in a single tank. The first centrate feed studied was from the full-scale Annacis Island wastewater treatment plant (AIWWTP) located in Metro Vancouver, Canada. The second centrate feed was from a lab-scale anaerobic digester (AD) fed waste sludge from the existing City of Kelowna Wastewater Treatment Facility (KWTF), located in the Okanagan Valley, Canada. In addition, poly aluminum chloride (PACL) dosing was assessed for final polishing of dissolved nutrients. The deammonification SBR (DeSBR) process showed similar treatment characteristics for both the KWTF and AIWWTP centrates with excellent DON removal and poor non-reactive dissolved phosphorus (NRDP) removal. A statistical comparison of the DOP and poly-P through the DeSBR process suggests that DOP has a higher biodegradation potential. Future research focused on understanding the variables associated with degradation of DOP could lead to better NRDP removal through deammonification processes. Utilization of a post-anammox PACL chemical dosing stage can achieve the objective of precipitating any residual DON and NRDP and producing an effluent that has lower dissolved nutrients than the pre-digestion KWTF dewatering centrate scenario. PMID:27023924

  6. Anaerobic Treatment of Palm Oil Mill Effluent in Pilot-Scale Anaerobic EGSB Reactor

    OpenAIRE

    2015-01-01

    Large volumes of untreated palm oil mill effluent (POME) pose threat to aquatic environment due to the presence of very high organic content. The present investigation involved two pilot-scale anaerobic expanded granular sludge bed (EGSB) reactors, continuously operated for 1 year to treat POME. Setting HRT at 9.8 d, the anaerobic EGSB reactors reduced COD from 71179 mg/L to 12341 mg/L and recycled half of sludge by a dissolved air flotation (DAF). The average effluent COD was 3587 mg/L with ...

  7. Removal of fluoxetine and its effects in the performance of an aerobic granular sludge sequential batch reactor

    International Nuclear Information System (INIS)

    Highlights: • Enantioselective removal of fluoxetine by aerobic granular sludge was evaluated. • Sorption of fluoxetine to aerobic granules occurred. • Bacterial community gradually changed during operation of sequential batch reactor. • Main biological processes occurring within the granules were preserved. • Overall performance of the reactor was recovered after initial fluoxetine shock loads. - Abstract: Fluoxetine (FLX) is a chiral fluorinated pharmaceutical mainly indicated for treatment of depression and is one of the most distributed drugs. There is a clear evidence of environmental contamination with this drug. Aerobic granular sludge sequencing batch reactors constitute a promising technology for wastewater treatment; however the removal of carbon and nutrients can be affected by micropollutants. In this study, the fate and effect of FLX on reactor performance and on microbial population were investigated. FLX adsorption/desorption to the aerobic granules was observed. FLX shock loads (≤4 μM) did not show a significant effect on the COD removal. Ammonium removal efficiency decreased in the beginning of first shock load, but after 20 days, ammonia oxidizing bacteria became adapted. The nitrite concentration in the effluent was practically null indicating that nitrite oxidizing bacteria was not inhibited, whereas, nitrate was accumulated in the effluent, indicating that denitrification was affected. Phosphate removal was affected at the beginning showing a gradual adaptation, and the effluent concentration was <0.04 mM after 70 days. A shift in microbial community occurred probably due to FLX exposure, which induced adaptation/restructuration of the microbial population. This contributed to the robustness of the reactor, which was able to adapt to the FLX load

  8. Removal of fluoxetine and its effects in the performance of an aerobic granular sludge sequential batch reactor

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Irina S.; Amorim, Catarina L. [CBQF – Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Dr. António Bernardino Almeida, 4200-072 Porto (Portugal); Ribeiro, Ana R. [CBQF – Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Dr. António Bernardino Almeida, 4200-072 Porto (Portugal); Centro de Química Medicinal da Universidade do Porto (CEQUIMED-UP), Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto (Portugal); CESPU, Instituto de Investigação e Formação Avançada em Ciências e Tecnologias da Saúde, Rua Central de Gandra 1317, 4585-116 Gandra PRD (Portugal); Mesquita, Raquel B.R. [CBQF – Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Dr. António Bernardino Almeida, 4200-072 Porto (Portugal); Laboratory of Hydrobiology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Institute of Marine Research (CIIMAR), Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto (Portugal); and others

    2015-04-28

    Highlights: • Enantioselective removal of fluoxetine by aerobic granular sludge was evaluated. • Sorption of fluoxetine to aerobic granules occurred. • Bacterial community gradually changed during operation of sequential batch reactor. • Main biological processes occurring within the granules were preserved. • Overall performance of the reactor was recovered after initial fluoxetine shock loads. - Abstract: Fluoxetine (FLX) is a chiral fluorinated pharmaceutical mainly indicated for treatment of depression and is one of the most distributed drugs. There is a clear evidence of environmental contamination with this drug. Aerobic granular sludge sequencing batch reactors constitute a promising technology for wastewater treatment; however the removal of carbon and nutrients can be affected by micropollutants. In this study, the fate and effect of FLX on reactor performance and on microbial population were investigated. FLX adsorption/desorption to the aerobic granules was observed. FLX shock loads (≤4 μM) did not show a significant effect on the COD removal. Ammonium removal efficiency decreased in the beginning of first shock load, but after 20 days, ammonia oxidizing bacteria became adapted. The nitrite concentration in the effluent was practically null indicating that nitrite oxidizing bacteria was not inhibited, whereas, nitrate was accumulated in the effluent, indicating that denitrification was affected. Phosphate removal was affected at the beginning showing a gradual adaptation, and the effluent concentration was <0.04 mM after 70 days. A shift in microbial community occurred probably due to FLX exposure, which induced adaptation/restructuration of the microbial population. This contributed to the robustness of the reactor, which was able to adapt to the FLX load.

  9. HYDROLYSIS AND METHANOGENIC PHASE OF ANAEROBIC DIGESTION OF SEWAGE SLUDGE AND URBAN SOLID WASTE = HIDRÓLISIS Y FASE METANOGÉNICA DE LA DIGESTIÓN ANAEROBIA DE LODOS DE DEPURADORA Y RESIDUOS SÓLIDOS URBANOS

    OpenAIRE

    Tânia Forster Carneiro; Montserrat Pérez

    2012-01-01

    This paper presents and discusses the feasibility of the mesophilic anaerobic digestion of the sewage sludge and urban solid waste. The experiment consists in the implementation of anaerobic reactors for sewage sludge operating under mesophilic (35º C) and semi-continuous (TRS 30 and 20 days) and using two different sources of inoculum (30% inoculation) and digested sludge urban waste. The thermal effects, chemical, physical and biological treatment of sewage sludge and MSW to methane and car...

  10. A comprehensive study into fouling properties of extracellular polymeric substance (EPS) extracted from bulk sludge and cake sludge in a mesophilic anaerobic membrane bioreactor.

    Science.gov (United States)

    Ding, Yi; Tian, Yu; Li, Zhipeng; Zuo, Wei; Zhang, Jun

    2015-09-01

    This study focused on the fouling behaviors of extracellular polymeric substances (EPS) in a mesophilic anaerobic membrane bioreactor (AnMBR) to obtain the relations of EPS specific constituents with membrane fouling. It was found that for the EPS extracted from bulk sludge, the LB-EPS induced the largest flux decline; however, for EPS extracted from cake sludge, the S-EPS caused the highest flux decline. The preferential rejection fraction by membrane further confirmed that the greater flux decline was exhibited with the higher percent rejection of EPS fractions. The adhesion and cohesion interactions of EPS fractions and membranes could explain the different rejection rates of the EPS components. The structural characteristics analysis indicated that the fouling layers of different EPS fractions with the greater loss of filterability had the smaller porosity. Further investigations demonstrated that these changes could be attributed to the different content of HPO-N in EPS fractions. PMID:26022972

  11. Bioleaching and chemical leaching of heavy metals from anaerobically digested sludge

    Energy Technology Data Exchange (ETDEWEB)

    Marchioretto, M.M.; Bruning, H.; Hien, N.T.P.; Rulkens, W.H.

    2003-07-01

    The present work aims to evaluate the practical application of bioleaching in the solubilization of Cr, Cu, Pb and Zn from anaerobically digested sludge. Chemical leaching with H{sub 2}SO{sub 4} and bioleaching with elemental sulfur and ferrous iron are applied. The results are compared with those found in the literature and in previous leaching experiments with HCl. Bioleaching can be a feasible alternative to promote Zn and Cu solubilizations, especially when ferrous iron is added as substrate. Under this condition, the maximum extraction yield achieved for Zn is 80.8 % with pH value of 2.7, and for Cu it is 65.5 % with pH value of 2.5. Cr solubilization is possible when pH is around 2.5 and Pb is not detected in solution. Chemical leaching with HCl at pH value of 1 solubilizes 100 % of Pb and also provides the best extraction yield for Cr (around 72 %). With the same pH value HCl is more effective than H{sub 2}SO{sub 4} to solubilize all the metals studied. (author)

  12. Landfill Leachate Treatment Using Hybrid Up-Flow Anaerobic Sludge Blanket (HUASB Reactor

    Directory of Open Access Journals (Sweden)

    Mohd Bharudin Ridzuan

    2013-11-01

    Full Text Available Abstract: The Effect of the development process in the country would lead the increment of the solid wastes production. Malaysia as a developing country is also could not escape from the problem in its solid waste management. An important problem that associated to landfill is the production of leachate. Leachate contains dangerous substances such as organic matters, heavy metals, Nitrogen Ammonia and other materials that could pollute underground water source. The aim of the paper was to study landfill leachate treatment efficiency using Hybrid Upflow Anaerobic Sludge Blanket (HUASB reactor in lab-scale. This research was investigate the pollutant content in landfill leachate and determines the percentage of nutrient removal. Parameters used for this research, were Biochemical Oxygen Demand (BOD, Chemical Oxygen Demand (COD, Suspended Solid (SS, Total Nitrogen (TN, and Total Phosphorus (TP. The experiments were carried out in lab scaled constructed reactor,  30 days duration which samples for test had been taken each 3 days intervals. The results showed that HUASB reactor were capable in removal several parameters. It has great ability in removal of Total Phosphorus and Suspended Solid with 90.60% and 80.70% each. The result of COD removal showed an encouraging removal graph, with average percentage removal 73.70%. Average percentage removal for BOD is 64%. Total Nitrogen was less remove nutrient with average percentage removal 50.32%. From the results, it showed that HUASB reactor capable to remove organic pollutants from landfill leachate.

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

    Science.gov (United States)

    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. PMID:24569279

  14. Analysis of submerged membrane for a sludge-bed anaerobic membrane bioreactor treating prehydrolysis liquor.

    Science.gov (United States)

    Kale, Mayur Milan; Singh, Kripa Shankar

    2016-08-01

    An analysis of foulants and the performance of membranes in innovative sludge-bed anaerobic membrane bioreactors (SB-AnMBRs) were evaluated at mesophilic (35°C for approx. 400 days) followed by thermophilic (55°C for approx. 400 days) temperatures while treating the prehydrolysis liquor (PHL) waste stream from a dissolving pulp production plant. The membrane fouling of SB-AnMBR was analyzed for 0.1, 0.15 and 0.2 m(3)/m(2)/d flux conditions. Physico-chemical analyses of the membrane showed that the combination of 5% citric acid, 0.5% NaOCl and 2% NaOH solutions was effective in achieving more than 80% recovery of membrane flux. Chemical characterization of foulants showed that proteins were more predominant in membrane fouling than carbohydrates. Sugars and lignin contribution were negligible as compared to proteins in the total organic carbon content of the foulant. Membrane fouling occurred through a biofilm-dominated process and organic fouling. Combination of cleaning chemicals which included 0.5% NaClO and 2% NaOH solutions was most effective in the removal of the organic foulants. SEM analysis showed the pictorial evolution of the impact of fouling on the pore openings and the effect of cleaning on the membrane surface. PMID:26708166

  15. Enrichment of specific electro-active microorganisms and enhancement of methane production by adding granular activated carbon in anaerobic reactors.

    Science.gov (United States)

    Lee, Jung-Yeol; Lee, Sang-Hoon; Park, Hee-Deung

    2016-04-01

    Direct interspecies electron transfer (DIET) via conductive materials can provide significant benefits to anaerobic methane formation in terms of production amount and rate. Although granular activated carbon (GAC) demonstrated its applicability in facilitating DIET in methanogenesis, DIET in continuous flow anaerobic reactors has not been verified. Here, evidences of DIET via GAC were explored. The reactor supplemented with GAC showed 1.8-fold higher methane production rate than that without GAC (35.7 versus 20.1±7.1mL-CH4/d). Around 34% of methane formation was attributed to the biomass attached to GAC. Pyrosequencing of 16S rRNA gene demonstrated the enrichment of exoelectrogens (e.g. Geobacter) and hydrogenotrophic methanogens (e.g. Methanospirillum and Methanolinea) from the biomass attached to GAC. Furthermore, anodic and cathodic currents generation was observed in an electrochemical cell containing GAC biomass. Taken together, GAC supplementation created an environment for enriching the microorganisms involved in DIET, which increased the methane production rate. PMID:26836607

  16. Influence of the organic loading rate on the performance and the granular sludge characteristics of an EGSB reactor used for treating traditional Chinese medicine wastewater.

    Science.gov (United States)

    Li, Weiguang; Su, Chengyuan; Liu, Xingzhe; Zhang, Lei

    2014-01-01

    The effects of the organic loading rate (OLR) on the performance and the granular sludge characteristics of an expanded granular sludge bed (EGSB) reactor used for treating real traditional Chinese medicine (TCM) wastewater were investigated. Over 90% of the COD removal by the EGSB reactor was observed at the OLRs of 4 to 13 kg COD/(m(3) day). However, increasing the OLR to 20 kg COD/(m(3) day) by reducing the hydraulic retention time (HRT 6 h) reduced the COD removal efficiency to 78%. The volatile fatty acid (VFA) concentration was 512.22 mg/L, resulting in an accumulation of VFAs, and propionic acid was the main acidification product, accounting for 66.51% of the total VFAs. When the OLR increased from 10 to 20 kg COD/(m(3) day), the average size of the granule sludge decreased from 469 to 258 μm. There was an obvious reduction in the concentration of Ca(2+) and Mg(2+) in the granular sludge. The visible humic acid-like peak was identified in the three-dimensional excitation-emission matrix (EEM) fluorescence spectra of the soluble microbial products (SMPs). The fatty acid bond, amide II bond, amide III bond, and C-H bond bending were also observed in the Fourier transform infrared (FTIR) spectra of the SMPs. Methanobacterium formicicum, Methanococcus, and Bacteria populations exhibited significant shifts, and these changes were accompanied by an increase in VFA production. The results indicated that a short HRT and high OLR in the EGSB reactor caused the accumulation of polysaccharides, protein, and VFAs, thereby inhibiting the activity of methanogenic bacteria and causing granular sludge corruption. PMID:24677060

  17. Comparison of ozone and thermal hydrolysis combined with anaerobic digestion for municipal and pharmaceutical waste sludge with tetracycline resistance genes.

    Science.gov (United States)

    Pei, Jin; Yao, Hong; Wang, Hui; Ren, Jia; Yu, Xiaohua

    2016-08-01

    Biosolids from wastewater treatment plant (WWTP) are environmental reservoirs of antibiotic resistance genes, which attract great concerns on their efficient treatments. Anaerobic digestion (AD) is widely used for sewage sludge treatment but its effectiveness is limited due to the slow hydrolysis. Ozone and thermal hydrolysis pre-treatment were employed to improve AD efficiency and reduce antibiotic-resistant genes in municipal and pharmaceutical waste sludge (MWS and PWS, respectively) in this study. Sludge solubilization achieved 15.75-25.09% and 14.85-33.92% after ozone and thermal hydrolysis, respectively. Both pre-treatments improved cumulative methane production and the enhancements were greater on PWS than MWS. Five tetracycline-resistant genes (tet(A), tet(G), tet(Q), tet(W), tet(X)) and one mobile element (intI1) were qPCR to assess pre-treatments. AD of pre-treated sludge reduced more tet genes than raw sludge for both ozonation and thermal hydrolysis in PWS and MWS. Thermal hydrolysis pre-treatment was more efficient than ozone for reduction after AD. Results of this study help support management options for reducing the spread of antibiotic resistance from biosolids. PMID:27151286

  18. Specific methanogenic activity (SMA of industrial sludge from the aerobic and anaerobic biological treatment

    Directory of Open Access Journals (Sweden)

    Danieli Schneiders

    2013-08-01

    Full Text Available In this study, specific methanogenic activity (SMA tests were performed on textile sludge and food industry sludge. The textile sludge from an activated sludge was collected at the entrance of the secondary biologic clarifier and the food sludge was collected in a UASB reactor. Once collected, the sludges were characterized and tested for SMA. It was found that the microrganisms present in the food sludge had SMA of 0.17 gCOD-CH4 gSSV.d-1 and 337.05 mL of methane production, while the microrganisms of the textile sludge presented 0.10 gCOD-CH4 gSSV.d-1 of SMA and 3.04 mL of methane production. Therefore, the food sludge was more suitable to be used as a starting inoculum in UASB.

  19. Molecular ecology of anaerobic reactor systems

    DEFF Research Database (Denmark)

    Hofman-Bang, H. Jacob Peider; Zheng, D.; Westermann, Peter; Ahring, Birgitte Kiær; Raskin, L.

    2003-01-01

    Anaerobic reactor systems are essential for the treatment of solid and liquid wastes and constitute a core facility in many waste treatment plants. Although much is known about the basic metabolism in different types of anaerobic reactors, little is known about the microbes responsible for these ...... specific nucleic acid probes are discussed and exemplified by studies of anaerobic granular sludge, biofilm and digester systems...... malfunctions of anaerobic digesters occasionally experienced, leading to sub-optimal methane production and wastewater treatment. Using a variety of molecular techniques, we are able to determine which microorganisms are active, where they are active, and when they are active, but we still need to determine...... abundance of each microbe in anaerobic reactor systems by rRNA probing. This chapter focuses on various molecular techniques employed and problems encountered when elucidating the microbial ecology of anaerobic reactor systems. Methods such as quantitative dot blot/fluorescence in-situ probing using various...

  20. Improved dechlorinating performance of upflow anaerobic sludge blanket reactors by incorporation of Dehalospirillum multivorans into granular sludge

    DEFF Research Database (Denmark)

    Hörber, Christine; Christiansen, Nina; Arvin, Erik; Ahring, Birgitte Kiær

    1998-01-01

    % (mole/mole) of the effluent chloroethenes. No dechlorination of PCE was observed in an abiotic control consisting of sterile granules without inoculum, During continuous operation with stepwise-reduced hydraulic retention times (HRTs), both the test reactor and the R1 reactor showed conversion of PCE to...

  1. Research Regarding the Accumulation in Soybeans of Heavy Metals from Anaerobic Composted Sewage Sludge Used as Organic Fertilizer

    Directory of Open Access Journals (Sweden)

    Benoni Lixandru

    2010-10-01

    Full Text Available In sewage sludge from urban wastewater treatment stations can often be find high levels of Ni, Pb, Cu, Zn, Mn andCd. Aerobic or anaerobic composting of this sewage sludge does not eliminate the possibility of bioaccumulation ofthese metals in plants through metabolic processes of phytoextraction type. Researches regarding the accumulationdegree of heavy metals through phytoextraction processes were performed on soybean plants (Glycine max, Condorvariety. Plants were fertilized with anaerobic composted sludge in amounts of 25 t of / ha, 50 t / ha and 100 t / ha.The chemical analysis was done on an average sample of three repetitions. Metal concentration in soybeans wasanalyzed by reporting to the maximum allowance level for sheep, considered one of the most sensitive farm speciesto heavy metal toxicity. Our results showed a higher level than normal with 5.8 mg / kg only in the case of copperions. Zn, Pb, Mn and Cd concentration in soybeans was below the maximum allowance limits set by the rules offeeding farm animals. Also, heavy metal content of soybeans was not affected by the amount of composted sludgeused as fertilizer.

  2. Efficacies of inocula on the startup of anaerobic reactors treating dairy manure under stirred and unstirred conditions

    International Nuclear Information System (INIS)

    Inocula play an important role in anaerobic reactor startup by balancing the populations of Syntrophobacter and methanogens. Such balances make syntrophic metabolism thermodynamically feasible in anaerobic digestion. In this study, the effect of inocula on the performance of dairy manure digestion was investigated by analyzing the change in volatile fatty acids (VFA), total solids (TS), volatile solids (VS), specific biogas production (SGPR), and specific methane production (SPMP) as well as scanning and transmission electron micrographs. The study was performed at four treatments. Treatment one was granular sludge (GM); treatment two was non-granular sludge (SM); treatment three was mixed culture from an anaerobic lagoon (LM); while the fourth treatment (the control denoted MM) did not receive any exogenous inocula. In addition, stirred and unstirred conditions were maintained in the reactors to determine their effect on reactor startup. Performance ranking based on the SGPR and SPMP of treatments (in descending order) was: GM, SM, LM and MM under stirred conditions. Under unstirred conditions, performance ranking (also in descending order) was: SM, GM, LM, and MM. Results of the examination of microcolonies in the granular, non-granular sludge, and dairy manure suggest that syntrophic juxtaposition of methanogens and Syntrophobacter in granular inoculum was common while it was less visible in non-granular sludge, and completely absent in dairy manure. -- Highlights: → We investigated impacts of inocula on anaerobic reactor startup period. → Reactor performance was evaluated under stirred and unstirred conditions at 35 oC. → In stirred conditions, granular sludge performance was better than other inocula. → In unstirred conditions, municipal sludge performance was better than other inocula. → Anaerobic lagoon's slurry did not improve reactor performance significantly.

  3. Acetate favors more phosphorus accumulation into aerobic granular sludge than propionate during the treatment of synthetic fermentation liquor.

    Science.gov (United States)

    Cai, Wei; Huang, Wenli; Li, Huifang; Sun, Beina; Xiao, Huasheng; Zhang, Zhenya; Lei, Zhongfang

    2016-08-01

    Anaerobic digestion (AD) is an efficient biotechnology widely applied for energy and resource recovery from organic waste and wastewater treatment. The effluent from AD or fermentation liquor containing organic substances like volatile fatty acids (VFAs) and mineral nutrients (such as N and P), however, will trigger serious environmental issues if not properly dealt with. In this study two identical sequencing batch reactors (SBRs), namely Ra and Rp were used to cultivate aerobic granules for P recovery from synthetic fermentation liquor, respectively using acetate and propionate as additional carbon source. Larger and more stable granules were achieved in Ra with higher P removal capability (9.4mgP/g-VSS·d) and higher anaerobic P release (6.9mgP/g-VSS·h). In addition to much higher P content (78mgP/g-SS), bioavailable P in Ra-granules increased to 45mgP/g-SS, approximately 2-times those of seed sludge and Rp-granules. Microbial community analysis indicated that more GAOs were accumulated in Rp-granules. PMID:27183235

  4. Energy recovery from effluents of sugar processing industries in the UASB reactors seeded with granular sludge developed under low and high concentrations of calcium ion

    Energy Technology Data Exchange (ETDEWEB)

    Raphael, D.M.; Rubindamayugi, M.S.T. [Univ. of Dar es Salaam, Dept. of Botany, Applied Microbiology Unit (Tanzania, United Republic of)

    1997-12-31

    The digestion of wastewater from sugar processing industries in a single phase UASB reactor was evaluated by a step wise increase in organic loading rate. This study was conducted to compare the treatability of effluents from sugar processing industries in a single phase UASB reactors inoculated with granular sludge developed under low and high concentrations of calcium ions. At OLR of 11.34 g COD/l/day and HRT of 16 hours, UASB reactor R2 attained a COD removal efficiency of 90% with a maximum methane production rate of 3 l/l/day. From the results, the digestion of the wastewater from sugar industries in the UASB reactor inoculated with granular sludge developed under high calcium ion concentration seem feasible with regard to COD removal efficiency and methane production rate. (au) 24 refs.

  5. High-Rate Anaerobic Treatment of Wastewater at Low Temperatures

    OpenAIRE

    Lettinga, Gatze; Rebac, Salih; Parshina, Sofia; Nozhevnikova, Alla; van Lier, Jules B.; Stams, Alfons J. M.

    1999-01-01

    Anaerobic treatment of a volatile fatty acid (VFA) mixture was investigated under psychrophilic (3 to 8°C) conditions in two laboratory-scale expanded granular sludge bed reactor stages in series. The reactor system was seeded with mesophilic methanogenic granular sludge and fed with a mixture of VFAs. Good removal of fatty acids was achieved in the two-stage system. Relative high levels of propionate were present in the effluent of the first stage, but propionate was efficiently removed in t...

  6. Enhancement in characteristics of sewage sludge and anaerobic treatability by electron beam pre-treatment

    International Nuclear Information System (INIS)

    Electron beam was studied to enhance the biodegradability of sewage sludge. Changes in physicochemical characteristics of the sludge were examined with various irradiation doses, sludge thicknesses and exposure times. Irradiation thickness was suggested as the key factor affecting the efficiency of solublization of solid organic matter, whereas exposure time would be the most critical parameter in inducing cell lysis in sewage sludge. In addition, biogas production was improved as much as 22% when the sludge thickness was 0.5 cm with a dose of 7 kGy

  7. Degradation of organic pollutants and characteristics of activated sludge in an anaerobic/anoxic/oxic reactor treating chemical industrial wastewater

    Directory of Open Access Journals (Sweden)

    Dong Wang

    2014-09-01

    Full Text Available A laboratory-scale anaerobic/anoxic/oxic system operated at the hydraulic retention times (HRT of 20, 40, and 60 h with mixed liquor suspended solids (MLSS concentrations of 3 g/L and 6 g/L was considered for treating chemical industrial wastewater rich in complex organic compounds and total dissolved solids. Extending the HRT and increasing the MLSS concentration resulted in higher removal efficiency for chemical oxygen demand at 72%. Organic compounds in wastewater could be classified into easily-removed and refractory compounds during treatment. The easily-removed compounds consisted primarily of ethers, alcohols, and aldehydes, whereas the refractory compounds included mainly oxygen-containing heterocyclic and benzene-containing compounds. Results from energy-dispersive X-ray spectroscopy showed that several metal ions accumulated in activated sludge, particularly Fe(III. Fe accumulated mainly on the surface of sludge floc pellets and resulted in the compactness of activated sludge, which caused the values of mixed liquor volatile suspended solids /MLSS and sludge volume index to decrease.

  8. Effects of solution conditions on the physicochemical properties of stratification components of extracellular polymeric substances in anaerobic digested sludge.

    Science.gov (United States)

    Yuan, Dongqin; Wang, Yili

    2013-01-01

    The composition and effects of solution conditions on the physicochemical properties of the stratification components of extracellular polymeric substances (EPS) in anaerobic digested sludge were determined. The total EPS in anaerobic digested sludge were extracted by the cation exchange resin method. Another EPS extraction method, the centrifugation and sonication technique was employed to stratify the EPS into three fractions: slime, loosely bound (LB)-EPS, and tightly bound (TB)-EPS from the outside to the inside of the anaerobic digested sludge. Proteins and polysaccharides were dispersed uniformly across the different EPS fractions, and humic-like substances were mainly partitioned in the slime, with TB-EPS second. Protein was the major constituent of the LB-EPS and TB-EPS, and the corresponding ratios ranged from 54.0% to 65.6%. The hydrophobic part in the EPS chemical components was primarily comprised of protein and DNA, while the hydrophilic part was mainly composed of polysaccharide. In the slime, the hydrophobic values of several EPS chemical components (protein, polysaccharide, humic-like substances and DNA) were all below 50%. The protein/polysaccharide ratio had a significant influence on the Zeta potentials and isoelectric point values of the EPS: the greater the protein/polysaccharide ratio of the EPS was, the greater the Zeta potential and the higher the isoelectric point value were. All Zeta potentials of the EPS showed a decreasing trend with increasing pH. The corresponding isoelectric point values (pH) were 2.8 for total EPS, 2.2 for slime, 2.7 for LB-EPS, and 2.6 for TB-EPS. As the ionic strength increased, the Zeta potentials sharply increased and then gradually became constant without charge reversal. In addition, as the temperature increased (EPS decreased monotonically and then gradually became stable between 40 and 60 degrees C. PMID:23586310

  9. Biological pretreatment of non-flocculated sludge augments the biogas production in the anaerobic digestion of the pretreated waste activated sludge.

    Science.gov (United States)

    Merrylin, J; Kumar, S Adish; Kaliappan, S; Yeom, Ick-Tae; Banu, J Rajesh

    2013-01-01

    High-efficiency resource recovery from municipal solid waste (MSW) has been a focus of attention. The objective of this research is to develop a bio-pretreatment process for application prior to the anaerobic digestion of MSW to improve methane productivity. Bacillus licheniformis was used for pretreating MSW (non-flocculated with 0.07% citric acid), followed by anaerobic digestion. Laboratory-scale experiments were carried out in semi-continuous bioreactors, with a total volume of 5 L and working volume of 3 L. Among the nine organic loading rates (OLRs) investigated, the OLR of 0.84 kg SS m(-3) reactor day(-1) was found to be the most appropriate for economic operation of the reactor. Pretreatment of MSW prior to anaerobic digestion led to 55% and 64% increase of suspended solids (SS) and volatile solids reduction, respectively, with an improvement of 57% in biogas production. The results indicate that the pretreatment of non-flocculated sludge with Bacillus licheniformis which consumes less energy compared to other pretreatment techniques could be a cost-effective and environmentally sound method for producing methane from MSW. PMID:24350465

  10. Biotransformation and Biodegradation of N-Substituted Aromatics in Methanogenic Granular Sludge.

    OpenAIRE

    Razo Flores, E.

    1997-01-01

    N-substituted aromatic compounds are environmental contaminants associated with the production and use of dyes, explosives, pesticides and pharmaceuticals among others. Nitro- and azo-substituted aromatic compounds with strong electron withdrawing groups are poorly biodegradable in aerobic treatment systems. Therefore anaerobic treatment technologies were considered in this research. The toxicity of these compounds to methanogenic bacteria was studied. Batch toxicity assays indicated that nit...

  11. Modeling, Experimentation, and Control of Autotrophic Nitrogen Removal in Granular Sludge Systems

    DEFF Research Database (Denmark)

    Vangsgaard, Anna Katrine

    is convenient for treating anaerobic digester liquor, landfill leachate, or special industrial wastewaters, because costs related to the need for aeration and carbon addition are lowered by 60% and 100%, respectively, compared to conventional nitrification denitrification treatment. Energy and......Complete autotrophic nitrogen removal (CANR) is a novel process that can increase the treatment capacity for wastewaters containing high concentrations of nitrogen and low organic carbon to nitrogen ratios, through an increase of the volumetric removal rate by approximately five times. This process...

  12. Improvement of anaerobic digestion of waste-activated sludge by using H₂O₂ oxidation, electrolysis, electro-oxidation and thermo-alkaline pretreatments.

    Science.gov (United States)

    Feki, Emna; Khoufi, Sonia; Loukil, Slim; Sayadi, Sami

    2015-10-01

    Disintegration of municipal waste-activated sludge (WAS) is regarded as a prerequisite of the anaerobic digestion process to reduce sludge volume and improve biogas yield. Pretreatment of WAS using thermo-alkaline (TA), H2O2 oxidation, electrolysis and electro-oxidation (EO) processes were investigated and compared in term of COD solubilization and biogas production. For each pretreatment, the influences of different operational variables were studied in detail. At optimum conditions, EO gave the maximum COD solubilization (28 %). The effects of pretreatments under the optimum conditions on anaerobic digestion were experienced with biochemical methane potential assay. Significant increases in biogas yield up to 78 and 40 % were observed respectively in the EO and TA pretreated samples compared to raw sludge. Results clearly revealed that the application of EO is a significant alternative method for the improvement of WAS anaerobic digestion. PMID:25982985

  13. Physicochemical and biological characterization of long-term operated sulfate reducing granular sludge in the SANI® process.

    Science.gov (United States)

    Hao, Tianwei; Luo, Jinghai; Wei, Li; Mackey, Hamish R; Liu, Rulong; Rey Morito, Guillermo; Chen, Guang-Hao

    2015-03-15

    The SANI(®) process (Sulfate reduction, Autotrophic denitrification and Nitrification Integrated) is a treatment system with low energy demands. The major bioreactor of this new technology is a sulfate-reducing up-flow sludge bed (SRUSB) that converts organics and provides electron donors for subsequent autotrophic denitrification. This research characterizes the granules inside the SRUSB, with the aim of improving its efficiency, maximizing its operational flexibility, and minimizing its footprint. The unique sulfate-reducing bacteria (SRB) granules serving in the SRUSB were found to increase the resilience and compactness of the SRUSB. The granules, with a compact and porous structure, showed high cohesion resisting breakage with a shear force G > 3400 s(-1). The hydrophobicity of the external surface of the mature granules remained stable at around 70% and acid volatile sulfide (AVS) accumulated at the bottom of the SRUSB. 16s rRNA gene analysis of the microbial communities revealed that Desulfobulbus (42.1%), Prosthecochloris (19%) and Trichococcus (12%) dominated the mature granular sludge. Fluorescence in situ hybridization (FISH) further showed that SRB organisms were located internally and then surrounded by non-SRB. According to the FISH results, the spatial distribution of extracellular polymeric substances (EPS) displayed protein and α-polysaccharides in the exterior and β-polysaccharide in the core of the granules. Such biological structure suggests that each SRB granule acts as an efficient and independent unit, capable of achieving both fermentation and organic conversion. The present investigation sheds light on the physicochemical and biological characteristics of the SRB granulate. This information provides valuable information for scaling-up the SANI(®) process to treat real saline sewage in Hong Kong. PMID:25600299

  14. Simultaneous denitrification and anaerobic digestion in GRAnular Bed Baffled Reactor (GRABBR)

    International Nuclear Information System (INIS)

    This study elucidates the characteristics of compartmentalised anaerobic system seeded with UASB granules, called GRAanular Bed Baffled Reactor (GRABBR), for combined denitrification and anaerobic digestion processes. The reactor was used for the treatment of glucose enriched synthetic wastewater with various nitrate concentrations. The study was carried out with a 10 litre working volume GRABBR divided into 5 equal compartments operating at organic loading rate (OLR) of 20 kg COD/m3.d with a hydraulic retention time (HRT) of 6 hours. At these conditions, phase separation (between acidogenesis and methanogenesis) was created in the system and then the effect of varying nitrate concentrations (50-200 mg/l NO3-N) in the acidogenic zone (i.e. first compartment) was studied. Due to its unique compartmentalised design, denitrification was the major pathway for nitrate reduction with no noticeable dissimilatory nitrate reduction to ammonia (DNRA). More than 84% of all added nitrates were removed in the acidogenic zone, showing that acidogens possess high denitrifying capabilities. The denitrification rate increased with increase in nitrate concentration, with maximum value estimated as 175 mg NO3-N/l.h at influent nitrate concentration of 200 mg/l NO3-N in the acidogenic zone. Although nitrate addition resulted in lower methane production, COD removal efficiencies improved by up to 8% when compared with the reactor performance before nitrate addition. Furthermore, the alkalinity produced during denitrification improved the stability of the system by controlling the decrease in pH resulting from acidogenesis. The system encouraged simultaneous denitrification and anaerobic digestion in a single unit by accommodating denitrifiers in the early compartments and allowing methanogenesis to flourish in the downstream compartments of the system, thus minimising inhibition to methane producing bacteria by nitrates. (author)

  15. Treatment of domestic wastewater in an up-flow anaerobic sludge blanket reactor followed by moving bed biofilm reactor

    OpenAIRE

    Tawfik, A.; El-Gohary, F.; Temmink, B.G.

    2010-01-01

    The performance of a laboratory-scale sewage treatment system composed of an up-flow anaerobic sludge blanket (UASB) reactor and a moving bed biofilm reactor (MBBR) at a temperature of (22-35 A degrees C) was evaluated. The entire treatment system was operated at different hydraulic retention times (HRT's) of 13.3, 10 and 5.0 h. An overall reduction of 80-86% for CODtotal; 51-73% for CODcolloidal and 20-55% for CODsoluble was found at a total HRT of 5-10 h, respectively. By prolonging the HRT...

  16. Production of volatile derivatives of metal(loid)s by microflora involved in anaerobic digestion of sewage sludge.

    Science.gov (United States)

    Michalke, K; Wickenheiser, E B; Mehring, M; Hirner, A V; Hensel, R

    2000-07-01

    Gases released from anaerobic wastewater treatment facilities contain considerable amounts of volatile methyl and hydride derivatives of metals and metalloids, such as arsine (AsH(3)), monomethylarsine, dimethylarsine, trimethylarsine, trimethylbismuth (TMBi), elemental mercury (Hg(0)), trimethylstibine, dimethyltellurium, and tetramethyltin. Most of these compounds could be shown to be produced by pure cultures of microorganisms which are representatives of the anaerobic sewage sludge microflora, i.e., methanogenic archaea (Methanobacterium formicicum, Methanosarcina barkeri, Methanobacterium thermoautotrophicum), sulfate-reducing bacteria (Desulfovibrio vulgaris, D. gigas), and a peptolytic bacterium (Clostridium collagenovorans). Additionally, dimethylselenium and dimethyldiselenium could be detected in the headspace of most of the pure cultures. This is the first report of the production of TMBi, stibine, monomethylstibine, and dimethylstibine by a pure culture of M. formicicum. PMID:10877769

  17. Anaerobic Codigestion of Sludge: Addition of Butcher’s Fat Waste as a Cosubstrate for Increasing Biogas Production

    Science.gov (United States)

    Martínez, E. J.; Gil, M. V.; Fernandez, C.; Rosas, J. G.

    2016-01-01

    Fat waste discarded from butcheries was used as a cosubstrate in the anaerobic codigestion of sewage sludge (SS). The process was evaluated under mesophilic and thermophilic conditions. The codigestion was successfully attained despite some inhibitory stages initially present that had their origin in the accumulation of volatile fatty acids (VFA) and adsorption of long-chain fatty acids (LCFA). The addition of a fat waste improved digestion stability and increased biogas yields thanks to the higher organic loading rate (OLR) applied to the reactors. However, thermophilic digestion was characterized by an effluent of poor quality and high VFA content. Results from spectroscopic analysis suggested the adsorption of lipid components onto the anaerobic biomass, thus disturbing the complete degradation of substrate during the treatment. The formation of fatty aggregates in the thermophilic reactor prevented process failure by avoiding the exposure of biomass to the toxic effect of high LCFA concentrations. PMID:27071074

  18. Bioaugmentation of an acetate-oxidising anaerobic consortium in up-flow sludge blanket reactor subjected to high ammonia loads

    DEFF Research Database (Denmark)

    Fotidis, Ioannis; Karakashev, Dimitar Borisov; Angelidaki, Irini

    . in association with Methanoculleus spp. strain MAB1), is an acetate oxidising methanogenic consortium that can produce methane (CH4) at high ammonia levels. In the current study the bioaugmentation of the SAO culture in a mesophilic up-flow anaerobic sludge blanket (UASB) reactor subjected to high ammonia loads......Ammonia is the major inhibitor of anaerobic digestion (AD) process leading to suboptimal utilisation of the biogas potential of the feedstocks and causing economical losses to the biogas plants. However, ammonia is mainly inhibiting the aceticlastic methanogens, while the hydrogenotrophic...... was tested. The co-cultivation in fed-batch of a fast-growing hydrogenotrophic methanogen (i.e. Methanoculleus bourgensis) with the SAO culture was also investigated. Results obtained clearly demonstrated that bioaugmentation of SAO culture in a UASB reactor was not possible most probably due to the slow...

  19. Evolution of microbial community along with increasing solid concentration during high-solids anaerobic digestion of sewage sludge.

    Science.gov (United States)

    Liu, Can; Li, Huan; Zhang, Yuyao; Si, Dandan; Chen, Qingwu

    2016-09-01

    High-solids anaerobic digestion (HSAD), a promising method with smaller reactor and less heating energy consumption, showed relatively lower digestion efficiency sometimes and higher tolerance to some inhibitors. To investigate the phenomena, the archaeal and bacterial communities in four anaerobic digesters treating sewage sludge with total solids (TS) of 10-19% were investigated. Although acetoclastic methanogenesis conducted mainly by genus Methanosarcina was still the main pathway producing methane, the total ratio of acetoclastic methanogens decreased along with the increased TS. In contrary, the relative abundance of hydrogenotrophic methanogens increased from 6.8% at TS 10% to 22.3% at TS 19%, and methylotrophic methanogens from 10.4% to 20.9%. The bacterial community was dominated by five phyla. Acidogenic and acetogenic bacteria affiliated to Firmicutes decreased following the increase of TS; while the proteolysis phylum Bacteroidetes increased, with a tolerant family ST-12K33 notably existing in the digesters at TS 17% and 19%. PMID:27235970

  20. Optimization of the hydrolytic-acidogenic anaerobic digestion stage (55 degrees C) of sewage sludge: influence of pH and solid content.

    Science.gov (United States)

    Ponsá, Sergio; Ferrer, Ivet; Vázquez, Felícitas; Font, Xavier

    2008-08-01

    In conventional single-stage anaerobic digestion processes, hydrolysis is regarded as the rate-limiting step in the degradation of complex organic compounds, such as sewage sludge. Two-stage systems have been proposed to enhance this process. However, so far it is not clear which are the best conditions for a two-stage anaerobic digestion process of sewage sludge, in terms of temperature and hydraulic retention time of each stage. The aim of this work was to determine the optimal conditions for the hydrolytic-acidogenic stage treating real sludge with a high concentration of total solids (40-50gL(-1)) and volatile solids (25-30gL(-1)), named high concentration sludge. The variables considered for this first stage were: hydraulic retention time (1-4 days) and temperature (55 and 65 degrees C). Maximum volatile fatty acids generation was obtained at 4 days and 3 days hydraulic retention time for 55 degrees C and 65 degrees C, respectively. Consequently, 4 days hydraulic retention time and temperature of 55 degrees C were set as the working conditions for the hydrolytic-acidogenic stage treating high concentration sludge. The results obtained when operating with high concentration sludge were compared with a low concentration sludge consisting of 17-28gL(-1) total solids and 13-21gL(-1) volatile solids. The effect of decreasing the influent sludge pH, when working at the optimal conditions established, was also evaluated. PMID:18687452

  1. Denitrifying capability and community dynamics of glycogen accumulating organisms during sludge granulation in an anaerobic-aerobic sequencing batch reactor

    Science.gov (United States)

    Bin, Zhang; Bin, Xue; Zhigang, Qiu; Zhiqiang, Chen; Junwen, Li; Taishi, Gong; Wenci, Zou; Jingfeng, Wang

    2015-08-01

    Denitrifying capability of glycogen accumulating organisms (GAOs) has received great attention in environmental science and microbial ecology. Combining this ability with granule processes would be an interesting attempt. Here, a laboratory-scale sequencing batch reactor (SBR) was operated to enrich GAOs and enable sludge granulation. The results showed that the GAO granules were cultivated successfully and the granules had denitrifying capability. The batch experiments demonstrated that all NO3--N could be removed or reduced, some amount of NO2--N were accumulated in the reactor, and N2 was the main gaseous product. SEM analysis suggested that the granules were tightly packed with a large amount of tetrad-forming organisms (TFOs); filamentous bacteria served as the supporting structures for the granules. The microbial community structure of GAO granules was differed substantially from the inoculant conventional activated sludge. Most of the bacteria in the seed sludge grouped with members of Proteobacterium. FISH analysis confirmed that GAOs were the predominant members in the granules and were distributed evenly throughout the granular space. In contrast, PAOs were severely inhibited. Overall, cultivation of the GAO granules and utilizing their denitrifying capability can provide us with a new approach of nitrogen removal and saving more energy.

  2. Polycyclic Aromatic Hydrocarbon Affects Acetic Acid Production during Anaerobic Fermentation of Waste Activated Sludge by Altering Activity and Viability of Acetogen.

    Science.gov (United States)

    Luo, Jingyang; Chen, Yinguang; Feng, Leiyu

    2016-07-01

    Till now, almost all the studies on anaerobic fermentation of waste activated sludge (WAS) for bioproducts generation focused on the influences of operating conditions, pretreatment methods and sludge characteristics, and few considered those of widespread persistent organic pollutants (POPs) in sludge, for example, polycyclic aromatic hydrocarbons (PAHs). Herein, phenanthrene, which was a typical PAH and widespread in WAS, was selected as a model compound to investigate its effect on WAS anaerobic fermentation for short-chain fatty acids (SCFAs) accumulation. Experimental results showed that the concentration of SCFAs derived from WAS was increased in the presence of phenanthrene during anaerobic fermentation. The yield of acetic acid which was the predominant SCFA in the fermentation reactor with the concentration of 100 mg/kg dry sludge was 1.8 fold of that in the control. Mechanism exploration revealed that the present phenanthrene mainly affected the acidification process of anaerobic fermentation and caused the shift of the microbial community to benefit the accumulation of acetic acid. Further investigation showed that both the activities of key enzymes (phosphotransacetylase and acetate kinase) involved in acetic acid production and the quantities of their corresponding encoding genes were enhanced in the presence of phenanthrene. Viability tests by determining the adenosine 5'-triphosphate content and membrane potential confirmed that the acetogens were more viable in anaerobic fermentation systems with phenanthrene, which resulted in the increased production of acetic acid. PMID:27267805

  3. Microbial community of granules in expanded granular sludge bed reactor for simultaneous biological removal of sulfate, nitrate and lactate.

    Science.gov (United States)

    Chen, Chuan; Ren, Nanqi; Wang, Aijie; Yu, Zhenguo; Lee, Duu-Jong

    2008-07-01

    This study studied the cultivation of granules from an expanded granular sludge bed reactor that simultaneously transforms sulfates, nitrates, and oxygen to elementary sulfur, nitrogen gas, and carbon dioxides, respectively. The living cells accumulate at the granule outer layers, as revealed by the multicolor staining and confocal laser scanning microscope technique. The microbial community comprises sulfate-reducing bacteria (SRB, Desulfomicrobium sp.), heterotrophic (Pseudomonas aeruginosa and Sulfurospirillum sp.), and autotrophic denitrifiers (Sulfurovum sp. and Paracoccus denitrificans) whose population dynamics at different sulfate and nitrate loading rates are monitored with the single-strand conformation polymorphism and denaturing gradient gel electrophoresis technique. The Desulfomicrobium sp. presents one of the dominating strains following reactor startup. At high sulfate and nitrate loading rates, the heterotrophic denitrifiers overcompete autotrophic denitrifiers to reduce SRB activities. Conversely, suddenly reducing nitrate loading rates completely removes the heterotrophic denitrifier Sulfurospirillum sp. from the granules and activates the autotrophic denitrifiers. The physical fixation of different groups of functional strains in granules fine-tunes the strains' activities, and hence the reactor performance. PMID:18483736

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

    Science.gov (United States)

    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. PMID:25310868

  5. Anaerobic side-stream reactor: a sustainable solution for sewage sludge reduction

    OpenAIRE

    Ferrentino, Roberta

    2016-01-01

    Over the last two decades, the production of excess sludge has increased rapidly due to a more stringent legislation on effluent quality and a growing number of new plants, becoming an economic and an environmental critical issue. Processing excess sludge could account for half up to 65% of the total operation costs of a wastewater treatment plant. Technologies to reduce the excess sludge had been widely studied. Several studies reported that the technologies inte...

  6. Biohydrogen production from desugared molasses (DM) using thermophilic mixed cultures immobilized on heat treated anaerobic sludge granules

    DEFF Research Database (Denmark)

    Kongjan, Prawit; O-Thong, Sompong; Angelidaki, Irini

    2011-01-01

    Hydrogen production from desugared molasses (DM) was investigated in both batch and continuous reactors using thermophilic mixed cultures enriched from digested manure by load shock (loading with DM concentration of 50.1 g-sugar/L) to suppress methanogens. H2 gas, free of methane, was produced...... enriched hydrogen producing mixed culture achieved from the 16.7 g-sugars/L DM batch cultivation was immobilized on heat treated anaerobic sludge granules in an up-flow anaerobic sludge blanket (UASB) reactor. The UASB reactor, operated at a hydraulic retention time (HRT) of 24 h fed with 16.7 g...... during batch cultivations, at different (DM) concentrations ranging from 1.5 g-sugars/L to 50.1 g-sugars/L. The highest yield of 237 ml-H2/g-sugar was achieved during the DM batch fermentation at concentration of 2.1 g-sugars/L, whereafter the yield decreased with increasing DM concentration. The...

  7. Development of a dynamic model of a Upflow Anaerobic Sludge Blanket (UASB) reactor

    International Nuclear Information System (INIS)

    'Full text:' The Upflow Anaerobic Sludge Blanket Reactor has been modeled in this paper using a semi-empirical correlation. The main objective of the modeling exercise was to examine the dynamics (hydrodynamics and transformation) of critical variables that are important for the reactor process design, performance and operation. These factors include some microbiological variables such as soluble (as COD) and biodegradable organics (as BOD), suspended solids (SS), and biomass concentration (as VSS). The hydraulic variables such as the upflow velocity of the liquid and by extension, upflow velocity of the solids and the volumetric fractions of the liquid (voidage) are also given considerations. The dynamics of external mass transfer of organics and inorganics and the transformation reactions within the reactor are modeled by five non-linear partial differential equations (PDE's), which define dependent variables in one-dimensional temporal and spatial planes, one integrand equation for the gas rate of flow and six algebraic equations that define the reactor performance (conversion rates and removal efficiencies). The PDE's are solved using backward finite differencing method. The discretized equations are computed using a simulation program that was written in the Borland C++ programming language. The model defines the dynamics of the UASB in a simplistic way but which, nonetheless, can be useful for engineering designs where the interest is in qualitative results and not quantitative outcomes. The simulation was validated with data derived from the operation of a pilot model UASB. The pilot model was operated using raw domestic wastewater as substrate, which had an average total COD of 492 mg/L, soluble COD of 172 mg/L, BOD of 220 mg/L, suspended solid of 0.235 g/L and a high sulphate content of 108 mg/L. The average nutrient concentrations were, NH3-N 20 mg/L and PO4 15 mg/L. The UASB was operated at HRT's of 10.968, 8.326 and 5.51 hours The average removal

  8. Enhancement of sludge granulation in hydrolytic acidogenesis by denitrification.

    Science.gov (United States)

    Li, Yang; Zhang, Yaobin; Zhao, Zisheng; Sun, Songlan; Quan, Xie; Zhao, Huimin

    2016-04-01

    Acidogenesis is an important pretreatment process for various industrial wastewater treatments. Granular sludge is an efficient form of a microbial community in anaerobic methanogenic reactors, such as upflow anaerobic sludge blanket (UASB), but it is hard to develop in the acidogenic process due to the short hydraulic retention times (HRTs) of acidogenesis. In this study, nitrate was added into an acidogenic reactor as an electron acceptor to enhance electron exchange between acidogenic and denitrifying bacteria to accelerate sludge growth in the acidogenesis process. The results showed that it developed solid and mature granular sludge with a mean size of 410 ± 35 μm over 84 days of operation. Comparatively, the sludge in a no-nitrate acidogenic reactor showed a flocculent appearance with a mean size of 110 ± 18 μm. Analysis of the microbial community indicated that denitrifying bacteria interwoven with propionate-oxidizing bacteria were distributed in the outer granule layer, which provided an ideal shield for susceptible microorganisms inside the granules. This microbial structure was favorable for the development of granular sludge and made the system possible to respond well to shocks in the operation. PMID:26637420

  9. A pilot study of anaerobic membrane digesters for concurrent thickening and digestion of waste activated sludge (WAS).

    Science.gov (United States)

    Dagnew, Martha; Parker, Wayne J; Seto, Peter

    2010-01-01

    The increased interest in biomass energy provides incentive for the development of efficient and high throughput digesters such as anaerobic membrane bioreactors (AnMBRs) to stabilize waste activated sludge (WAS). This paper presents the results of a pilot and short term filtration study that was conducted to assess the performance of AnMBRs when treating WAS at a 15 day hydraulic retention time (HRT) and 30 day sludge retention time (SRT) in comparison to two conventional digesters running at 15 (BSR-15) and 30 days (BSR-30) HRT/SRT. At steady state, the AnMBR digester showed a slightly higher volatile solids (VS) destruction of 48% in comparison to 44% and 35.3% for BSR-30 and BSR-15, respectively. The corresponding values of specific methane production were 0.32, 0.28 and 0.21 m(3) CH(4)/kg of VS fed. Stable membrane operation at an average flux of 40+/-3.6 LM(-2 )H(-1) (LMH) was observed when the digester was fed with a polymer-dosed thickened waste activated sludge (TWAS) and digester total suspended solids (TSS) concentrations were less than 15 gL(-1). Above this solids concentration a flux decline to 24.1+/-2.0 LM(-2) H(-1) was observed. Short term filtration tests conducted using sludge fractions of a 9.7 and 17.1 gL(-1) TSS sludge indicated 84 and 70% decline in filtration performance to be associated with the supernatant fraction of the sludge. At a higher sludge concentration, the introduction of unique fouling control strategy to tubular membranes, a relaxed mode of operation (i.e. 5 minutes permeation and 1 minute relaxation by) significantly increased the flux from 23.8+/-1.1 to 37.8+/-2.3 LMH for a neutral membrane and from 25.7+/-1.1 to 44.9+/-2.9 LMH for a negatively charged membrane. The study clearly indicates that it is technically feasible to employ AnMBRs to achieve a substantial reduction in digester volumes. PMID:20351424

  10. Degradation of phenol in an upflow anaerobic sludge blanket(UASB) reactor at ambient temperatureKE

    Institute of Scientific and Technical Information of China (English)

    KE Shui-zhou1; SHI Zhou; ZHANG Tong; Herbert H. P. FANG

    2004-01-01

    A synthetic wastewater containing phenol as sole substrate was treated in a 2.8 L upflow anaerobic sludge blanket(UASB) reactor at ambient temperature. The operation conditions and phenol removal efficiency were discussed, microbial population in the UASB sludge was identified based on DNA cloning, and pathway of anaerobic phenol degradation was proposed. Phenol in wastewater was degraded in an UASB reactor at loading rate up to 18 gCOD/(L·d), With a 1:1 recycle ratio, at 26(1℃, pH 7.0-7.5. An UASB reactor was able to remove 99% of phenol up to 1226 mg/L in wastewater with 24 h of hydraulic retention time(HRT). For HRT below 24 h, phenol degradation efficiency decreased with HRT, from 95.4% at 16 h to 93.8% at 12 h. It further deteriorated to 88.5% when HRT reached 8 h. When the concentration of influent phenol of the reactor was 1260 mg/L(corresponding COD 3000 mg/L), with the HRT decreasing(from 40 h to 4 h, corresponding COD loading increasing), the biomass yields tended to increase from 0.265 to 3.08 g/(L·d). While at 12 h of HRT, the biomass yield was lower. When HRT was 12 h, the methane yield was 0.308 L/(gCOD removed), which was the highest. Throughout the study, phenol was the sole organic substrate. The effluent contained only residual phenol without any detectable intermediates, such as benzoate, 4-hydrobenzoate or volatile fatty acids(VFAs). Based on DNA cloning analysis, the sludge was composed of five groups of microorganisms. Desulfotomaculum and Clostridium were likely responsible for the conversion of phenol to benzoate, which was further degraded by Syntrophus to acetate and H2/CO2. Methanogens lastly converted acetate and H2/CO2 to methane. The role of epsilon-Proteobacteria was, however, unsure.

  11. Enhanced methane production from rice straw co-digested with anaerobic sludge from pulp and paper mill treatment process.

    Science.gov (United States)

    Mussoline, Wendy; Esposito, Giovanni; Lens, Piet; Spagni, Alessandro; Giordano, Andrea

    2013-11-01

    Rice straw is a widely available lignocellulosic waste with potential for energy recovery through anaerobic digestion. Lignin slows the hydrolysis phase, resulting in low methane recovery and long digestion periods. Although pretreatment is effective, it often requires high energy inputs or chemicals that are not feasible for farm-scale systems. This study investigates a unique co-digestion strategy to improve methane yields and reduce digestion times for farm-scale systems. By adding both piggery wastewater and paper mill sludge, specific methane yields in laboratory-scale digesters reached the theoretical value for rice straw (i.e. 330LNCH4/kgVS) over the 92-day period. Accelerated hydrolysis of the straw was directly related to the quantity of sludge added. The most stable digester, with sufficient buffering capacity and nutrients, contained equal parts of straw, wastewater and sludge. This approach is feasible for farm-scale applications since it requires no additional energy inputs or changes to existing infrastructure for dry systems. PMID:24045200

  12. Carbon capture and biogas enhancement by carbon dioxide enrichment of anaerobic digesters treating sewage sludge or food waste.

    Science.gov (United States)

    Bajón Fernández, Y; Soares, A; Villa, R; Vale, P; Cartmell, E

    2014-05-01

    The increasing concentration of carbon dioxide (CO2) in the atmosphere and the stringent greenhouse gases (GHG) reduction targets, require the development of CO2 sequestration technologies applicable for the waste and wastewater sector. This study addressed the reduction of CO2 emissions and enhancement of biogas production associated with CO2 enrichment of anaerobic digesters (ADs). The benefits of CO2 enrichment were examined by injecting CO2 at 0, 0.3, 0.6 and 0.9 M fractions into batch ADs treating food waste or sewage sludge. Daily specific methane (CH4) production increased 11-16% for food waste and 96-138% for sewage sludge over the first 24h. Potential CO2 reductions of 8-34% for sewage sludge and 3-11% for food waste were estimated. The capacity of ADs to utilise additional CO2 was demonstrated, which could provide a potential solution for onsite sequestration of CO2 streams while enhancing renewable energy production. PMID:24632434

  13. Implementing Both Domestic Wastewater Reuse and Sludge Reduction by a Combination of Anaerobic Phase and Membrane bioreactor

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The aim of the research was to obtain both an excellenteffluent for reuse and a reduced sludge production simultaneously by a combination process of anaerobic phase and Membrane bioreactor (MBR) technology in treatingdomestic wastewater. During the experimental period of three months, excellent removals for COD, NH3-H, TN wereobtained, and mean removals were 91. 87%, 96.13%, and 69.23%, respectively. Whereas, at first 20 days, the removal for TP was only about 15.87%. In the following days, about 30% of raw water was introduced into theanaerobic reactor to supply organics for denitrifieation and release of polypbosphate, then a significant improvement for TP removal was observed, and mean removal of TP increased to 76.35%. During the operational period, it was investigated that the permeate could meet the requirements of several water criteria for reuse except free chlorine, and a mean excess sludge yield coefficient of 0.137 g MLSS/g COD was obtained. Therefore, the predicted goals of permeate for reuse and excess sludge reduction could be both achieved after dosing a certain quantity of disinfectant into the permeate.

  14. A new degassing membrane coupled upflow anaerobic sludge blanket (UASB) reactor to achieve in-situ biogas upgrading and recovery of dissolved CH4 from the anaerobic effluent

    DEFF Research Database (Denmark)

    Luo, Gang; Wang, Wen; Angelidaki, Irini

    2014-01-01

    into a degassing unit (DU). The results from batch experiments showed that mixing intensity, transmembrane pressure, pH and inorganic carbon concentration affected the CO2 desorption rate in the DU. Then, the DU was directly connected to an upflow anaerobic sludge blanket (UASB) reactor. The results showed the CH4...... in the effluent was reduced by directly pumping the reactor effluent through the DU. In this way, the dissolved CH4 concentration in the effluent decreased from higher than 0.94mM to around 0.13mM, and thus efficient recovery of CH4 from the anaerobic effluent was achieved. In the whole operational period......A new technology for in-situ biogas upgrading and recovery of CH4 from the effluent of biogas reactors was proposed and demonstrated in this study. A vacuum degassing membrane module was used to desorb CO2 from the liquid phase of a biogas reactor. The degassing membrane was submerged...

  15. Analysis of the stability of high-solids anaerobic digestion of agro-industrial waste and sewage sludge.

    Science.gov (United States)

    Aymerich, E; Esteban-Gutiérrez, M; Sancho, L

    2013-09-01

    The pilot-scale high-solids anaerobic digestion (HS-AD) of agro-industrial wastes and sewage sludge was analysed in terms of stability by monitoring the most common parameters used to check the performance of anaerobic digesters, i.e. Volatile Fatty Acids (VFA), ammonia nitrogen, pH, alkalinity and methane production. The results reflected similar evolution for the parameters analysed, except for an experiment that presented an unsuccessful start-up. The rest of the experiments ran successfully, although the threshold values proposed in the literature for the detection of an imbalance in wet processes were exceeded, proving the versatility of HS-AD to treat different wastes. The results evidence the need for understanding the dynamics of a high-solids system so as to detect periods of imbalance and to determine inhibitory levels for different compounds formed during anaerobic decomposition. Moreover, the findings presented here could be useful in developing an experimental basis to construct new control strategies for HS-AD. PMID:23859986

  16. A direct comparison amongst different technologies (aerobic granular sludge, SBR and MBR) for the treatment of wastewater contaminated by 4-chlorophenol

    International Nuclear Information System (INIS)

    Environmental concern on chlorinated phenols is rising due to their extreme toxicity even at low concentrations and their persistency in water and soils. Since the high amount of published data often lacks in terms of uniformity, direct comparisons amongst different treatment technologies are very difficult, or even impossible. In this study, granular sludge developed in an acetate-fed Granular sludge Sequencing Batch Reactor (GSBR) was used for the aerobic degradation of low chlorinated 4-chlorophenol (4CP), with readily biodegradable sodium acetate (NaAc) as growth substrate. A conventional Sequencing Batch Reactor (SBR) and a Membrane BioReactor (MBR) were operated in parallel under the same 4CP influent concentrations and/or 4CP volumetric organic loading rates as the GSBR, in order to carry out a direct comparison in terms of 4CP removal efficiencies and specific removal rates, effluent quality, waste sludge production, system simplicity, land area requirement, start-up times, NaAc dosage as growth substrate and maximum applied 4CP volumetric organic loading rate. A decision matrix was built to define the best technology to suit different scenarios: the GSBR was proved to be the most suitable technology when system simplicity, low land area requirement and short start-up times were considered as critical parameters for decision making.

  17. Anaerobic Digestion I. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

    Science.gov (United States)

    Arasmith, E. E.

    This lesson is the first of a two-part series on anaerobic digestion. Topics discussed include the five basic functions of an anaerobic digester, basic theory of the biological processes involved, basic equipment necessary for digestion, and the products of digestion. The lesson includes an instructor's guide and student workbook. The instructor's…

  18. Extracellular polymeric substances (EPS) from aerobic granular sludges: extraction, fractionation, and anionic properties.

    Science.gov (United States)

    Caudan, Cédric; Filali, Ahlem; Lefebvre, Dominique; Spérandio, Mathieu; Girbal-Neuhauser, Elisabeth

    2012-04-01

    A multi-method protocol previously proposed for the extraction of extracellular polymeric substances (EPS) from flocculated sludges was investigated on dense aerobic granules. The protocol combines mechanical disruption by sonication and chemical extraction using the Tween detergent and the cation chelator, EDTA. Polysaccharides were mainly recovered during the first sonication step while proteins were recovered all along the extractive procedure with a high prevalence in the EDTA step. These data confirmed the interest of the multi-method protocol for harvesting a diversified pool of EPS from dense granules and for fractionation of the polymers according to their physicochemical properties. In addition, the high extractability of proteins with EDTA confers a specific behavior of the aerobic granules towards the multi-method extraction protocol, supporting the idea that proteins are associated in the granule matrix through ionic interactions involving divalent cations. Analysis of the extracted EPS by anionic exchange chromatography confirmed the presence of highly anionic proteins that were specifically detected in the extracts obtained from granules. One important question is now to investigate whether these highly anionic proteins are involved in the aggregation and densification process and if their presence is related to the cohesive properties of these particles. PMID:22415780

  19. Impact of sludge thickening on energy recovery from anaerobic digestion[Held jointly with the 4. Canadian organic residuals and biosolids managment conference

    Energy Technology Data Exchange (ETDEWEB)

    Puchajda, B. [Stantec Consulting Ltd., Winnipeg, MB (Canada); Oleszkiewicz, J. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Civil Engineering

    2007-07-01

    The anaerobic digestion of wastewater sludge leads to production of a biogas mixture of methane and carbon dioxide. The technology of anaerobic digestion has been applied in various configurations and generally claims greater biogas production and additional stability to the process as compared to conventional mesophilic anaerobic digestion. However, biogas production is only one of many components of anaerobic digester energy balance. This paper presented energy balances for various digestion systems, including single mesophilic digestion; single thermophilic digestion; two-stage thermophilic-mesophilic digestion; and systems at elevated solids content in sludge. Energy balance included two components, namely energy demand and recoverable energy. Energy demand is defined as energy required for process operation such as heat requirement to elevate sludge temperature, and heat losses through digesters walls. Recoverable energy is defined as energy associated with methane content in biogas, that can be recovered either in the form of heat or electricity, and heat recovered through heat exchangers. The paper identified the assumptions used in all energy balance calculations. It presented the objectives and methods of the study as well as the results. It was concluded that two-stage thermophilic-mesophilic digestion system generate more available energy than single mesophilic digestion and single thermophilic digestion systems. Sludge thickening offers the greatest amount of available energy. However, that energy surplus is offset by the cost of thickening. 12 refs., 3 tabs., 6 figs.

  20. Effect of carbon monoxide, hydrogen and sulfate on thermophilic (55°C) hydrogenogenic carbon monoxide conversion in two anaerobic bioreactor sludges

    NARCIS (Netherlands)

    Sipma, J.; Meulepas, R.J.W.; Stams, A.J.M.; Lettinga, G.; Lens, P.N.L.

    2004-01-01

    The conversion routes of carbon monoxide (CO) at 55°C by full-scale grown anaerobic sludges treating paper mill and distillery wastewater were elucidated. Inhibition experiments with 2-bromoethanesulfonate (BES) and vancomycin showed that CO conversion was performed by a hydrogenogenic population an

  1. Recycling of phosphorus by precipitation of magnesium ammonium phosphate from local anaerobic sludge; Phosphorrecycling durch MAP-Faellung im kommunalen Faulschlamm

    Energy Technology Data Exchange (ETDEWEB)

    Stumpf, Daniel [Technische Univ. Berlin (Germany). Fachgruppe Verfahrenstechnik

    2007-07-01

    Phosphorus is essential for organisms. Thus, the recycling of phosphorus is of great importance. Under this aspect, the author of the contribution under consideration reports on the recycling of phosphorus by precipitation of magnesium ammonium phosphate from local anaerobic sludge. For this, the author presents different approaches of procedure due to a literature search.

  2. Rheological characterisation of thermally-treated anaerobic digested sludge: Impact of temperature and thermal history

    OpenAIRE

    Farno, E.; Baudez, J.C.; Parthasarathy, R.; Eshtiaghi, N.

    2014-01-01

    This study investigated the partially irreversible effect of thermal treatment on the rheology of digested sludge when it was subjected to temperature change between 20°C and 80°C and then cooled down to 20°C. The yield stress, infinite viscosity and liquor viscosity of sludge were measured at 20°C for different thermal histories and were compared to the evolution of the solubilised chemical oxygen demand (COD) of sludge liquor. The results showed that thermal history irreversibly affects...

  3. Inactivation of ANAMMOX communities under concurrent operation of anaerobic ammonium oxidation (ANAMMOX) and denitrification

    DEFF Research Database (Denmark)

    Chamchoi, N.; Nitisoravut, S.; Schmidt, Jens Ejbye

    2008-01-01

    A concurrent operation of anaerobic ammonium oxidation (ANAMMOX) and denitrification was investigated in a well known UASB reactor seeding with both ANAMMOX and anaerobic granular sludges. ANAMMOX activity was confirmed by hydroxylamine test and the hybridization of biomass using the gene probes of......–nitrate concentrations in all reactors confirmed the undergone concurrent denitrification which thrives when sufficient organic matter is available. COD concentration over 300 mg l−1 was found to inactivate or eradicate ANAMMOX communities....

  4. Optimization of operation conditions for the mitigation of nitrous oxide (N2O) emissions from aerobic nitrifying granular sludge system.

    Science.gov (United States)

    Liu, Rui-Ting; Wang, Xin-Hua; Zhang, Yan; Wang, Ming-Yu; Gao, Ming-Ming; Wang, Shu-Guang

    2016-05-01

    The optimization of operation parameters is a key consideration to minimize nitrous oxide (N2O) emissions in biological nitrogen removal processes. So far, different parameters have only been investigated individually, making it difficult to compare their specific effects and combined influences. In this study, we applied the Plackett-Burman (PB) multifactorial experimental design and response surface methodology (RSM) analysis to find the optimized condition for the mitigation of N2O release in a nitrifying granular sludge system. Seven parameters (temperature, pH, feeding strategy, C/N ratio, aeration rate, Cu(2+) concentration, and aeration mode) were tested in parallel. Five of them (other than chemical oxygen demand/nitrogen (C/N) ratio and Cu(2+) concentration) were selected as influential factors. Since the type of feeding strategies and aeration modes cannot be quantified, continuous feed strategy and anoxic/oxic aeration mode were applied for the following study. Influences of temperature, pH, and aeration rate on N2O emissions were tested with RSM analysis to further investigate the mutual interactions among the parameters and to identify the optimal values that would minimize N2O release. Results showed the minimum emission value could be obtained under the temperature of 22.3 °C, pH of 7.1 and aeration rate of 0.20 m(3)/h. Predicted results were then verified by subsequent validation experiments. The estimated N2O emission value of each design by RSM was also observed in good relationships with experimental result. PMID:26841778

  5. Chemical characterization of municipal wastewater sludges produced by two-phase anaerobic digestion for biogas production

    International Nuclear Information System (INIS)

    In the present study, the chemical features of municipal wastewater sludges treated in two-phase separate digesters (one for acetogenesis and the other one for methanogenesis), were characterized by using chemical analysis, stable carbon isotope ratios (δ13C), HS-SPME-GC-MS, TG-DTA analysis and DRIFT spectroscopy. The results obtained showed that sludges from acetogenesis and methanogenesis differed from each other, as well as from influent raw sludges. Both processes exhibited a diverse chemical pattern in term of VFA and VOC. Additional variations were observed for δ13C values that changed from acetogenesis to methanogenesis, as a consequence of fermentation processes that led to a greater fractionation of 12C with respect to the 13C isotope. Similarly, the thermal profiles of acetogenesis and methanogenesis sludges greatly differed in terms of heat combustion produced. These changes were also supported by higher lipid content (probably fatty acids) in acetogenesis than in methanogenesis, as also shown by DRIFT spectroscopy.

  6. Effects of solution conditions on the physicochemical properties of stratification components of extracellular polymeric substances in anaerobic digested sludge

    Institute of Scientific and Technical Information of China (English)

    Dongqin Yuan; Yili Wang

    2013-01-01

    The composition and effects of solution conditions on the physicochemical properties of the stratification components of extracellular polymeric substances (EPS) in anaerobic digested sludge were determined.The total EPS in anaerobic digested sludge were extracted by the cation exchange resin method.Another EPS extraction method,the centrifugation and sonication technique was employed to stratify the EPS into three fractions:slime,loosely bound (LB)-EPS,and tightly bound (TB)-EPS from the outside to the inside of the anaerobic digested sludge.Proteins and polysaccharides were dispersed uniformly across the different EPS fractions,and humic-like substances were mainly partitioned in the slime,with TB-EPS second.Protein was the major constituent of the LB-EPS and TB-EPS,and the corresponding ratios ranged from 54.0% to 65.6%.The hydrophobic part in the EPS chemical components was primarily comprised of protein and DNA,while the hydrophilic part was mainly composed of polysaccharide.In the slime,the hydrophobic values of several EPS chemical components (protein,polysaccharide,humic-like substances and DNA) were all below 50%.The protein/polysaccharide ratio had a significant influence on the Zeta potentials and isoelectric point values of the EPS:the greater the protein/polysaccharide ratio of the EPS was,the greater the Zeta potential and the higher the isoeleetric point value were.All Zeta potentials of the EPS showed a decreasing trend with increasing pH.The corresponding isoeleetric point values (pH) were 2.8 for total EPS,2.2 for slime,2.7 for LB-EPS,and 2.6 for TB-EPS.As the ionic strength increased,the Zeta potentials sharply increased and then gradually became constant without charge reversal.In addition,as the temperature increased (< 40℃),the apparent viscosity of the EPS decreased monotonically and then gradually became stable between 40 and 60℃.

  7. Characterization and performance of carbonaceous materials obtained from exhausted sludges for the anaerobic biodecolorization of the azo dye Acid Orange II

    International Nuclear Information System (INIS)

    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 ZnCl2 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 m2/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

  8. Protein and polysaccharide content of tightly and loosely bound extracellular polymeric substances and the development of a granular activated sludge floc.

    Science.gov (United States)

    Basuvaraj, Mahendran; Fein, Jared; Liss, Steven N

    2015-10-01

    A full-scale (FS) activated sludge system treating wastewater from a meat rendering plant with a long history of sludge management problems (pin-point flocs; >80% of floc operated continuously over 1.5 years. Distinct differences in the proportion of proteins and polysaccharides associated with extracellular polymeric substances (EPS) were observed when comparing the properties of flocs from the FS and the LB systems. Further differences in the proportion of tightly bound (TB) and loosely bound (LB) fractions of EPS were also observed for flocs derived from conditions where differences in settling and dewatering properties of flocs occurred (i.e. FS and LS systems). FS flocs contained higher levels of EPS along with a higher proportion of LB than TB EPS, and possessing characteristics associated with non-filamentous bulking (SVI >150 mL/g). Floc formed in the LS system, following inoculation from sludge taken from the FS system, was markedly larger in size (>70% of floc >300 μm diameter), spherical in shape, compact and firm, and appeared to be granular in form. Flocs formed in the LS system, when an anoxic phase was introduced into the react stage of the SBR cycle, were found to be more hydrophobic and contained more TB and less loosely bound (LB) EPS when compared to the FS floc. TB-EPS contained a greater amount of protein, whereas the polysaccharide content of LB-EPS was larger. Protein was predominantly localized in the core region of granular flocs where cells were compactly packed. When assessing the operating conditions of the FS and LS systems parameters that appear to impact the floc properties and the transition to a granular form include dissolved oxygen (DO) concentration and food to microorganism (F/M) ratio. PMID:25997747

  9. Bioaccumulation of metals in ryegrass (Lolium perenne L.) following the application of lime stabilised, thermally dried and anaerobically digested sewage sludge.

    Science.gov (United States)

    Healy, M G; Ryan, P C; Fenton, O; Peyton, D P; Wall, D P; Morrison, L

    2016-08-01

    The uptake and accumulation of metals in plants is a potential pathway for the transfer of environmental contaminants in the food chain, and poses potential health and environmental risks. In light of increased population growth and urbanisation, the safe disposal of sewage sludge, which can contain significant levels of toxic contaminants, remains an environmental challenge globally. The aims of this experiment were to apply municipal sludge, having undergone treatment by thermal drying, anaerobic digestion, and lime stabilisation, to permanent grassland in order to assess the bioaccumulation of metals (B, Al, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Nb, Mo, Sb, Ba, W, Pb, Fe, Cd) by perennial ryegrass over a period of up to 18 weeks after application. The legislation currently prohibits use of grassland for fodder or grazing for at least three weeks after application of treated sewage sludge (biosolids). Five treatments were used: thermally dried (TD), anaerobically digested (AD) and lime stabilised (LS) sludge all from one wastewater treatment plant (WWTP), AD sludge from another WWTP, and a study control (grassland only, without application of biosolids). In general, there was no significant difference in metal content of the ryegrass between micro-plots that received treated municipal sludge and the control over the study duration. The metal content of the ryegrass was below the levels at which phytotoxicity occurs and below the maximum levels specified for animal feeds. PMID:27174047

  10. A new model for anaerobic processes of up-flow anaerobic sludge blanket reactors based on cellular automata

    DEFF Research Database (Denmark)

    Skiadas, Ioannis V.; Ahring, Birgitte Kiær

    2002-01-01

    characteristics and lead to different reactor behaviour. A dynamic mathematical model has been developed for the anaerobic digestion of a glucose based synthetic wastewater in UASB reactors. Cellular automata (CA) theory has been applied to simulate the granule development process. The model takes......The advantageous performance of the UASB reactors is due to the immobilisation of the active biomass, since bacteria coagulate forming aggregates usually called granules. Changes in organic loading rate, hydraulic loading rate or influent substrate composition usually result in changes in granule...... into consideration that granule diameter and granule microbial composition are functions of the reactor operational parameters and is capable of predicting the UASB performance and the layer structure of the granules....

  11. The use of ultrasound and {gamma}-irradiation as pre-treatments for the anaerobic digestion of waste activated sludge at mesophilic and thermophilic temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Lafitte-Trouque, S.; Forster, C.F. [The University of Birmingham (United Kingdom). School of Engineering

    2002-09-01

    The effect of ultrasound and {gamma}-irradiation used as pre-treatments for the anaerobic digestion of waste activated sludge at both mesophilic and thermophilic temperatures was examined. Untreated activated sludge was also subjected to anaerobic digestion at these temperatures as a control. The sonication time was 90 s using a Soniprep 150 (MSE Scientific Instruments) which operated at 23 kHz and had been adjusted to give an output of 47 W and the {gamma}-irradiation dose was 500 krad. The digesters were operated in a semi-continuous mode, being fed with fresh sludge every 24 h at hydraulic retention times (HRT) of 8, 10 and 12 days. Over the 24 h period the differences between the digesters, in terms of volatile solids (VS) reductions and biogas production, were not statistically significant for any particular set of conditions. Thermophilic digestion performed better than mesophilic digestion in terms of biogas production, VS reductions (except at HRT of 8 days) and specific methane yields and the optimum retention time was 10 days, at both temperatures. When gas production over the initial eight hours (probably the hydrolytic stage) was examined, it was found that the gas production rates for pre-treated sludges were higher than those for untreated sludges. This was most pronounced at thermophilic temperatures and a HRT of 10 days. Sonication did not affect the numbers of faecal coliforms in the sludge. However, {gamma}-irradiation caused a 3-log reduction and, when coupled with mesophilic digestion, gave a product which contained <100 g{sup -1} TS. Thermophilic anaerobic digestion produced sludges which contained <1 g{sup -1} TS irrespective of any pre-treatment. (author)

  12. A comparative study of wastewater treatment, from a fish canning factory, in a granular and a flocculent sludge SBR

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Sanchez, A.; Garrido, J. M.; Mendez, R.

    2009-07-01

    Sequencing Batch Reactors (SBR) process utilizes a fill and draw reactor with complete mixing during the reaction stage and where subsequent stages of aeration and clarification occur in the same tank. These systems often operates with flocculent sludge with a relatively low sludge volume index, around 100 ml/g-TSS, and sludge settling rate of around 1 m/h. (Author)

  13. Improvement of anaerobic digestion of municipal wastewater treatment plant sludges and lignocellulosic substrates in biogas production

    OpenAIRE

    Kolbl, Sabina

    2014-01-01

    The aim of this doctoral dissertation was to improve the production of methane by mechanical and enzymatic pretreatments of organic substrates. For anaerobic digestion of different substrates and determination of biomethane potential, Automatic Methane Potential Test System (AMPTS II) device was used. AMPTS II is an analytical laboratory scale device used in measurements of ultra low speed production of biomethane produced during the anaerobic digestion of biodegradable substrates. Although b...

  14. Diversity and enrichment of nitrite-dependent anaerobic methane oxidizing bacteria from wastewater sludge

    OpenAIRE

    Luesken, Francisca A.; van Alen, Theo A.; van der Biezen, Erwin; Frijters, Carla; Toonen, Ger; Kampman, Christel; Hendrickx, Tim L. G.; Zeeman, Grietje; Temmink, Hardy; Strous, Marc; Op den Camp, Huub J. M.; Jetten, Mike S. M.

    2011-01-01

    Recently discovered microorganisms affiliated to the bacterial phylum NC10, named “Candidatus Methylomirabilis oxyfera”, perform nitrite-dependent anaerobic methane oxidation. These microorganisms could be important players in a novel way of anaerobic wastewater treatment where ammonium and residual dissolved methane might be removed at the expense of nitrate or nitrite. To find suitable inocula for reactor startup, ten selected wastewater treatment plants (WWTPs) located in The Netherlands w...

  15. Enrichment of denitrifying glycogen-accumulating organisms in anaerobic/anoxic activated sludge system.

    Science.gov (United States)

    Zeng, Raymond J; Yuan, Zhiguo; Keller, Jürg

    2003-02-20

    Denitrifying glycogen-accumulating organisms (DGAO) were successfully enriched in a lab-scale sequencing batch reactor (SBR) running with anaerobic/anoxic cycles and acetate feeding during the anaerobic period. Acetate was completely taken up anaerobically, which was accompanied by the consumption of glycogen and the production of poly-beta-hydroxy-alkanoates (PHA). In the subsequent anoxic stage, nitrate or nitrite was utilized as electron acceptor for the oxidation of PHA, resulting in glycogen replenishment and cell growth. The above phenotype showed by the enrichment culture demonstrates the existence of DGAO. Further, it was found that the anaerobic behavior of DGAO could be predicted well by the anaerobic GAO model of Filipe et al. (2001) and Zeng et al. (2002a). The final product of denitrification during anoxic stage was mainly nitrous oxide (N(2)O) rather than N(2). The data strongly suggests that N(2)O production may be caused by the inhibition of nitrous oxide reductase by an elevated level of nitrite accumulated during denitrification. The existence of these organisms is a concern in biological nutrient removal systems that typically have an anaerobic/anoxic/aerobic reactor sequence since they are potential competitors to the polyphosphate-accumulating organisms. PMID:12491525

  16. Anaerobic co-digestion of biodiesel waste glycerin with municipal wastewater sludge: microbial community structure dynamics and reactor performance.

    Science.gov (United States)

    Razaviarani, Vahid; Buchanan, Ian D

    2015-04-01

    Two 10 L completely mixed reactors operating at 37°C and 20 days SRT were used to evaluate the relationships between reactor performance and microbial community dynamics during anaerobic co-digestion of biodiesel waste glycerin (BWG) with municipal wastewater sludge (MWS). The addition of up to 1.35% (v/v) BWG to reactor feeds yielded increased VS and COD removal together with enhanced the biogas production and methane yield. This represented 50% of the MWS feed COD. Pyrosequencing analysis showed Methanosaeta (acetoclastic) and Methanomicrobium (hydrogenotrophic) to be the methanogenic genera present in greatest diversity during stable reactor operation. Methanosaeta sequences predominated at the lowest BWG loading while those of Methanomicrobium were present in greatest abundance at the higher BWG loadings. Genus Candidatus cloacamonas was present in the greatest number of bacterial sequences at all loadings. Alkalinity, pH, biogas production and methane yield declined and VFA concentrations (especially propionate) increased during the highest BWG loading. PMID:25678409

  17. Anaerobic co-digestion of sewage sludge and sugar beet pulp lixiviation in batch reactors: effect of temperature.

    Science.gov (United States)

    Montañés, Rocío; Solera, Rosario; Pérez, Montserrat

    2015-03-01

    The feasibility of anaerobic co-digestion of sewage sludge (SS) and sugar beet pulp lixiviation (SBPL) was assessed. Mesophilic and thermophilic batch assays of five different SS/SBPL ratios were used to investigate the effect of temperature, providing basic data on methane yield and reduction in total volatiles. Microbe concentrations (Eubacteria and methanogenic Archaea) were linked to traditional parameters, namely biogas production and removal of total volatile solids (TVS). The relationship between Eubacteria and Archaea was analysed. Given equal masses of organic matter, net methane generation was higher in the mesophilic range on the biochemical methane potential (BMP) test. Methane yield, TVS removal data and high levels of volatile fatty acids provided further evidence of the best behaviour of the mesophilic range. At the end of testing the microbial population under of the reactors consisted of Eubacteria and Archaea, with Eubacteria predominant in all cases. PMID:25600010

  18. Enhanced biological nutrient removal in modified carbon source division anaerobic anoxic oxic process with return activated sludge pre-concentration☆

    Institute of Scientific and Technical Information of China (English)

    Qin Lu; Haiyan Wu; Haoyan Li; Dianhai Yang

    2015-01-01

    A pilot-scale modified carbon source division anaerobic anoxic oxic (AAO) process with pre-concentration of returned activated sludge (RAS) was proposed in this study for the enhanced biological nutrient removal (BNR) of municipal wastewater with limited carbon source. The influent carbon source was fed in step while a novel RAS pre-concentration tank was adopted to improve BNR efficiency, and the effects of an influent carbon source distribution ratio and a RAS pre-concentration ratio were investigated. The results show that the removal efficiency of TN is mainly influenced by the carbon source distribution ratio while the TP removal relies on the RAS pre-concentration ratio. The optimum carbon source distribution ratio and RAS pre-concentration ratio are 60%and 50%, respectively, with an inner recycling ratio of 100%under the optimum steady operation of pilot test, reaching an average effluent TN concentration of 9.8 mg·L−1 with a removal efficiency of 63%and an average TP removal efficiency of 94%. The mechanism of nutrient removal is discussed and the kinetics is analyzed. The results reveal that the optimal carbon source distribution ratio provides sufficient denitrifying carbon source to each anoxic phase, reducing nitrate accumulation while the RAS pre-concentration ratio improves the condition of anaerobic zone to ensure the phosphorus release due to less nitrate in the returned sludge. Therefore, nitrifying bacteria, denitrifying bacteria and phosphorus accumulation organisms play an important role under the optimum condition, enhancing the performance of nutrient removal in this test.

  19. Influence of extraction method on size exclusion chromatography fingerprints of EPS from wastewater sludges.

    Science.gov (United States)

    Bourven, I; Simon, S; Guibaud, G

    2013-01-01

    Extracellular polymeric substances (EPS) were separated using two serial-linked size exclusion chromatography (SEC) columns to obtain detailed fingerprints. The chromatographic profile results were influenced by the nature of biological sludge (activated sludges, anaerobic granules, anaerobic flocculated sludges). Furthermore, our results highlight that EPS fingerprints are also highly dependent on the extraction method. If physical extractions modify only the relative absorbance of the chromatographic peaks, heating during extraction induces significant modifications of the fingerprints, probably owing to better organic matter extraction efficiency as well as an increase in hydrolysis for some compounds but not for EPS extracted from anaerobic granular sludges. This confirms that thermal treatment is a proper method to extract EPS from anaerobic granular sludges. The use of chemical extraction results in major changes on the EPS fingerprints. This work demonstrates that some chromatographic peaks are due to residues from the chemical reagent (such as EDTA, glutaraldehyde) which can modify or form complexes with some EPS macromolecules. As a result, due to its sensitivity to sludge origin and/or extraction procedure, SEC appears to be a suitable tool for an accurate qualitative EPS characterization. PMID:23530346

  20. Semi-continuous anaerobic co-digestion of thickened waste activated sludge and fat, oil and grease

    International Nuclear Information System (INIS)

    Highlights: → Co-digestion of thickened waste activated sludge (TWAS) with fat, oil and grease (FOG). → Co-digestion of TWAS and FOG at 64% VS increased biogas production by 137%. → FOG addition ratio at 74% of total VS caused inhibition of the anaerobic digestion process. → Micronutrients addition did not significantly improve the biogas production and digestion stabilization. - Abstract: Co-digestion of thickened waste activated sludge (TWAS) and fat, oil and grease (FOG) was conducted semi-continuously under mesophilic conditions. The results showed that daily methane yield at the steady state was 598 L/kg VSadded when TWAS and FOG (64% of total VS) were co-digested, which was 137% higher than that obtained from digestion of TWAS alone. The biogas composition was stabilized at a CH4 and CO2 content of 66.8% and 29.5%, respectively. Micronutrients added to co-digestion did not improve the biogas production and digestion stabilization. With a higher addition of FOG (74% of total VS), the digester initially failed but was slowly self-recovered; however, the methane yield was only about 50% of a healthy reactor with the same organic loading rate.

  1. Life cycle assessment comparison of activated sludge, trickling filter, and high-rate anaerobic-aerobic digestion (HRAAD).

    Science.gov (United States)

    Postacchini, Leonardo; Lamichhane, Krishna M; Furukawa, Dennis; Babcock, Roger W; Ciarapica, F E; Cooney, Michael J

    2016-01-01

    This paper conducts a comparative assessment of the environmental impacts of three methods of treating primary clarifier effluent in wastewater treatment plants (WWTPs) through life cycle assessment methodology. The three technologies, activated sludge (AS), high rate anaerobic-aerobic digestion (HRAAD), and trickling filter (TF), were assessed for treatment of wastewater possessing average values of biochemical oxygen demand and total suspended solids of 90 mg L(-1) and 70 mg L(-1), respectively. The operational requirements to process the municipal wastewater to effluent that meets USEPA regulations have been calculated. The data for the AS system were collected from the East Honolulu WWTP (Hawaii, USA) while data for the HRAAD system were collected from a demonstration-scale system at the same plant. The data for the TF system were estimated from published literature. Two different assessment methods have been used in this study: IMPACT 2002+ and TRACI 2. The results show that TF had the smallest environmental impacts and that AS had the largest, while HRAAD was in between the two but with much reduced impacts compared with AS. Additionally, the study shows that lower sludge production is the greatest advantage of HRAAD for reducing environmental impacts compared with AS. PMID:27191555

  2. Metagenomic Reconstruction of Key Anaerobic Digestion Pathways in Municipal Sludge and Industrial Wastewater Biogas-Producing Systems

    Science.gov (United States)

    Cai, Mingwei; Wilkins, David; Chen, Jiapeng; Ng, Siu-Kin; Lu, Hongyuan; Jia, Yangyang; Lee, Patrick K. H.

    2016-01-01

    Anaerobic digestion (AD) is a microbial process widely used to treat organic wastes. While the microbes involved in digestion of municipal sludge are increasingly well characterized, the taxonomic and functional compositions of AD digesters treating industrial wastewater have been understudied. This study examined metagenomes from a biogas-producing digester treating municipal sludge in Shek Wu Hui (SWH), Hong Kong and an industrial wastewater digester in Guangzhou (GZ), China, and compared their taxonomic composition and reconstructed biochemical pathways. Genes encoding carbohydrate metabolism and protein metabolism functions were overrepresented in GZ, while genes encoding functions related to fatty acids, lipids and isoprenoids were overrepresented in SWH, reflecting the plants’ feedstocks. Mapping of genera to functions in each community indicated that both digesters had a high level of functional redundancy, and a more even distribution of genera in GZ suggested that it was more functionally stable. While fermentation in both samples was dominated by Clostridia, SWH had an overrepresentation of Proteobacteria, including syntrophic acetogens, reflecting its more complex substrate. Considering the growing importance of biogas as an alternative fuel source, a detailed mechanistic understanding of AD is important and this report will be a basis for further study of industrial wastewater AD. PMID:27252693

  3. Simultaneous Biohydrogen and Bioethanol Production from Anaerobic Fermentation with Immobilized Sludge

    OpenAIRE

    Wei Han; Zhanqing Wang; Hong Chen; Xin Yao; Yongfeng Li

    2011-01-01

    The effects of organic loading rates (OLRs) on fermentative productions of hydrogen and ethanol were investigated in a continuous stirred tank reactor (CSTR) with attached sludge using molasses as substrate. The CSTR reactor with attached sludge was operated under different OLRs, ranging from 8 to 24 kg/m3·d. The H2 and ethanol production rate essentially increased with increasing OLR. The highest H2 production rate (10.74 mmol/h ⋅ L) and ethanol production rate (11.72 mmol/h ⋅ L) were obtain...

  4. Relationships between anaerobic consortia and removal efficiencies in an UASB reactor degrading 2,4 dichlorophenol (DCP).

    Science.gov (United States)

    Sponza, Delia Teresa; Cigal, Canan

    2008-04-01

    To gain more insight into the interactions between anaerobic bacteria and reactor performances (chemical oxygen demand-COD, 2,4 dichlorophenol-2,4 DCP removals, volatile fatty acid-VFA, and methane gas productions) and how they depended on operational conditions the microbial variations in the anaerobic granular sludge from an upflow anaerobic sludge blanket (UASB) reactor treating 2,4 DCP was studied. The study was composed of two parts. In the first part, the numbers of methanogens and acedogens in the anaerobic granular sludge were counted at different COD removal efficiencies. The relationships between the numbers of methanogens, the methane gas production and VFA production were investigated. The COD removal efficiencies increased to 74% from 30% while the number of total acedogens decreased to 10 from 30 cfu ml(-1). The number of total methanogens and acedogens varied between 11 x 10(3) and 10 x 10(9)MPN g(-1) and 10 and 30 cfu ml(-1) as the 2,4 DCP removal efficiencies were obtained between 60% and 99%, respectively. It was seen that, as the number of total acedogens decreased, the COD removal efficiencies increased. However, the number of total methanogens increased as the COD removal efficiencies increased. Correlations between the bacterial number and with the removal efficiencies obtained in different operational conditions were investigated. From the results presented in this paper a high correlation between the number of bacteria, COD removals, methane gas percentage, 2,4 DCP removals and VFA was observed. In the second part, methanogen bacteria in the anaerobic granular sludge were identified. Microbial observations and biochemical tests were applied to identify the anaerobic microorganisms from the anaerobic granular sludge. In the reactor treating 2,4 DCP, Methanobacterium bryantii, Methanobacterium formicicum, Methanobrevibacter smithii, Methanococcus voltae, Methanosarcina mazei, Methanosarcina acetivorans, Methanogenium bourgense and

  5. Methane enhancement through oxidative cleavage and alkali solubilization pre-treatments for corn stover with anaerobic activated sludge.

    Science.gov (United States)

    Hassan, Muhammad; Ding, Weimin; Bi, Jinhua; Mehryar, Esmaeil; Talha, Zahir Ahmed Ali; Huang, Hongying

    2016-01-01

    In the present study, thermo-chemical pre-treatment was adopted to evaluate methane production potential from corn stover by co-digesting it with anaerobic activated sludge. Three chemicals H2O2, Ca(OH)2 and NaOH were selected with two levels of concentration. All thermo-chemical pre-treatments were found significant (Pyield by H2O2-1, H2O2-2, and NaOH-2 treated corn stover were 293.52, 310.50 and 279.42ml/g.VS which were 57.18%, 66.27% and 49.63% higher than the untreated corn stover respectively. In the previous studies pre-treatment time was reported in days but our method had reduced it to about one hour. H2O2-2 and NaOH-2 treatments remained prominent to increase lignocellulosic degradation vigorously up to 45% and 42% respectively. Process biochemistry during the anaerobic digestion process was taken into consideration to optimize the most feasible thermo-chemical pre-treatment for corn stover. PMID:26512865

  6. Increasing biogas production from sewage sludge anaerobic co-digestion process by adding crude glycerol from biodiesel industry.

    Science.gov (United States)

    Nartker, Steven; Ammerman, Michelle; Aurandt, Jennifer; Stogsdil, Michael; Hayden, Olivia; Antle, Chad

    2014-12-01

    In an effort to convert waste streams to energy in a green process, glycerol from biodiesel manufacturing has been used to increase the gas production and methane content of biogas within a mesophilic anaerobic co-digestion process using primary sewage sludge. Glycerol was systematically added to the primary digester from 0% to 60% of the organic loading rate (OLR). The optimum glycerol loading range was from 25% to 60% OLR. This resulted in an 82-280% improvement in specific gas production. Following the feeding schedule described, the digesters remained balanced and healthy until inhibition was achieved at 70% glycerol OLR. This suggests that high glycerol loadings are possible if slow additions are upheld in order to allow the bacterial community to adjust properly. Waste water treatment plant operators with anaerobic digesters can use the data to increase loadings and boost biogas production to enhance energy conversion. This process provides a safe, environmentally friendly method to convert a typical waste stream to an energy stream of biogas. PMID:25249492

  7. Effect of organic load on decolourization of textile wastewater containing acid dyes in upflow anaerobic sludge blanket reactor

    International Nuclear Information System (INIS)

    Textile wastewater (TW) is one of the most hazardous wastewater for the environment when discharged without proper treatment. Biological treatment technologies have shown encouraging results over the treatment of recalcitrant compounds containing wastewaters. Upflow anaerobic sludge blanket reactor (UASB) was evaluated in terms of colour and the reduction of chemical oxygen demand (COD) with different organic loads using TW containing dyes belonging to different chemical groups. The study was performed using six different dye concentrations (10 mg/L, 25 mg/L, 50 mg/L, 100 mg/L, 150 mg/L, 300 mg/L) with three COD levels (∼1000 mg/L, ∼2000 mg/L, ∼3000 mg/L). Decolourization, COD removal and reactor stability were monitored. Over 85% of colour removal was observed with all dye concentrations with three organic loads. Acid Red 131 and Acid Yellow 79 were decolourized through biodegradation while Acid Blue 204 was decolourized due to adsorption onto anaerobic granules. COD removal was high in all dye concentrations, regardless of co-substrate levels. The reactor did not show any instability during the study. The activity of granules was not affected by the dyes. Methanothrix like bacteria were the dominant group in granules before introducing TW, however, they were reduced and cocci-shape microorganism increased after the treatment of textile wastewater.

  8. Bioaugmentation of anaerobic sludge digestion with iron-reducing bacteria: process and microbial responses to variations in hydraulic retention time.

    Science.gov (United States)

    Baek, Gahyun; Kim, Jaai; Shin, Seung Gu; Lee, Changsoo

    2016-01-01

    Although anaerobic digestion (AD) is a widely used option to manage waste activated sludge (WAS), there are some drawbacks related to its slow reaction rate and low energy productivity. This study examined an anaerobic WAS digester, augmented with an iron-reducing microbial consortium, relative to changes in microbial community structure and process performance at decreasing hydraulic retention times (HRTs) of 20 to 10 days. The enhanced methanation performance (approximately 40 % increase in methane yield) by the bioaugmentation was sustained until the HRT was decreased to 12.5 days, under Fe(3+)-rich conditions (ferric oxyhydroxide, 20 mM Fe). Enhanced iron-reducing activity was evidenced by the increased Fe(2+) to total Fe ratio maintained above 50 % during the stable operational phases. A further decrease in HRT to 10 days resulted in a significant performance deterioration, along with a drop in the Fe(2+) to total Fe ratio to <35 %, after four turnovers of operation. Prevailing existence of putative iron-reducing bacteria (IRBs) was identified by denaturing gradient gel electrophoresis (DGGE), with Spirochaetaceae- and Thauera-related organisms being dominant members, and clear dominance shifts among them with respect to decrease in HRT were observed. Lowering HRT led to evident shifts in bacterial community structure likely associated with washout of IRBs, leading to decreases in iron respiration activity and AD performance at a lower HRT. The bacterial community structure shifted dynamically over phases, and the community transitions correlated well with the changes in process performance. Overall, the combined biostimulation and bioaugmentation investigated in this study proved effective for enhanced methane recovery from anaerobic WAS digestion, which suggests an interesting potential for high-rate AD. PMID:26428233

  9. Chemical characterization of municipal wastewater sludges produced by two-phase anaerobic digestion for biogas production

    Energy Technology Data Exchange (ETDEWEB)

    Francioso, Ornella, E-mail: ornella.francioso@unibo.it [Dipartimento di Scienze e Tecnologie Agroambientali, V.le Fanin 40, 40127 Bologna (Italy); Rodriguez-Estrada, Maria Teresa [Dipartimento di Scienze degli Alimenti, V.le Fanin 40, 40127 Bologna (Italy); Montecchio, Daniela [Dipartimento di Scienze e Tecnologie Agroambientali, V.le Fanin 40, 40127 Bologna (Italy); Salomoni, Cesare; Caputo, Armando [Biotec sys srl, Via Gaetano Tacconi, 59, 40139 Bologna (Italy); Palenzona, Domenico [Dipartimento di Biologia Evoluzionistica Sperimentale, Via Selmi 3, 40126 Bologna (Italy)

    2010-03-15

    In the present study, the chemical features of municipal wastewater sludges treated in two-phase separate digesters (one for acetogenesis and the other one for methanogenesis), were characterized by using chemical analysis, stable carbon isotope ratios ({delta}{sup 13}C), HS-SPME-GC-MS, TG-DTA analysis and DRIFT spectroscopy. The results obtained showed that sludges from acetogenesis and methanogenesis differed from each other, as well as from influent raw sludges. Both processes exhibited a diverse chemical pattern in term of VFA and VOC. Additional variations were observed for {delta}{sup 13}C values that changed from acetogenesis to methanogenesis, as a consequence of fermentation processes that led to a greater fractionation of {sup 12}C with respect to the {sup 13}C isotope. Similarly, the thermal profiles of acetogenesis and methanogenesis sludges greatly differed in terms of heat combustion produced. These changes were also supported by higher lipid content (probably fatty acids) in acetogenesis than in methanogenesis, as also shown by DRIFT spectroscopy.

  10. High rate mesophilic, thermophilic, and temperature phased anaerobic digestion of waste activated sludge: A pilot scale study

    International Nuclear Information System (INIS)

    Highlights: ► High temperatures were tested in single and two-stage anaerobic digestion of waste activated sludge. ► The increased temperature demonstrated the possibility of improving typical yields of the conventional mesophilic process. ► The temperature phased anaerobic digestion process (65 + 55 °C) showed the best performances with yields of 0.49 m3/kgVSfed. ► Ammonia and phosphate released from solids destruction determined the precipitation of struvite in the reactor. - Abstract: The paper reports the findings of a two-year pilot scale experimental trial for the mesophilic (35 °C), thermophilic (55 °C) and temperature phased (65 + 55 °C) anaerobic digestion of waste activated sludge. During the mesophilic and thermophilic runs, the reactor operated at an organic loading rate of 2.2 kgVS/m3d and a hydraulic retention time of 20 days. In the temperature phased run, the first reactor operated at an organic loading rate of 15 kgVS/m3d and a hydraulic retention time of 2 days while the second reactor operated at an organic loading rate of 2.2 kgVS/m3d and a hydraulic retention time of 18 days (20 days for the whole temperature phased system). The performance of the reactor improved with increases in temperature. The COD removal increased from 35% in mesophilic conditions, to 45% in thermophilic conditions, and 55% in the two stage temperature phased system. As a consequence, the specific biogas production increased from 0.33 to 0.45 and to 0.49 m3/kgVSfed at 35, 55, and 65 + 55 °C, respectively. The extreme thermophilic reactor working at 65 °C showed a high hydrolytic capability and a specific yield of 0.33 gCOD (soluble) per gVSfed. The effluent of the extreme thermophilic reactor showed an average concentration of soluble COD and volatile fatty acids of 20 and 9 g/l, respectively. Acetic and propionic acids were the main compounds found in the acids mixture. Because of the improved digestion efficiency, organic nitrogen and phosphorus were

  11. The contribution of biotic and abiotic processes during azo dye reduction in anaerobic sludge

    NARCIS (Netherlands)

    Zee, van der F.P.; Bisschops, I.A.E.; Blanchard, V.G.; Bouwman, R.H.M.; Lettinga, G.; Field, J.A.

    2003-01-01

    Azo dye reduction results from a combination of biotic and abiotic processes during the anaerobic treatment of dye containing effluents. Biotic processes are due to enzymatic reactions whereas the chemical reaction is due to sulfide. In this research, the relative impact of the different azo dye red

  12. Anaerobic Digestion II. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

    Science.gov (United States)

    Arasmith, E. E.

    This lesson is the second of a two-part series on anaerobic digestion. Topics discussed include classification of digester by function, roof design, and temperature range, mixing systems, gas system components, operational control basics, and general safety considerations. The lesson includes an instructor's guide and student workbook. The…

  13. Coupled anaerobic/aerobic biodegradation of 2,4,6 trichlorophenol

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Degradation of 2, 4, 6-trichlorophenol(TCP) with co-immobilizing anaerobic granular sludge and isolated aerobic bacterial specieswas studied in coupled anaerobic/aerobic integrated reactors. The synergism of aerobes and anaerobes within co-immobilized granule mightfacilitate degrading the TCP and exchange of anaerobic metabolites 4-CP, which promoted system organic removal efficiency and recovered fromorganic shock-loads more quickly. The biomass specific activities experiment further confirmed that strict anaerobes be not affected over thecourse of this experiment by the presence of an oxic environment, aerobic activity predominated in the outer co-immobilized granule layers,while the interior was characterized by anaerobic activity. The co-immobilized granule could thus enable both aerobic and anaerobic microbesfunction in the same reactor and thereby integrate the oxidative and reductive catabolism.

  14. NMR and MALDI-TOF MS based characterization of exopolysaccharides in anaerobic microbial aggregates from full-scale reactors

    KAUST Repository

    Gonzalez-Gil, Graciela

    2015-09-22

    Anaerobic granular sludge is composed of multispecies microbial aggregates embedded in a matrix of extracellular polymeric substances (EPS). Here we characterized the chemical fingerprint of the polysaccharide fraction of EPS in anaerobic granules obtained from full-scale reactors treating different types of wastewater. Nuclear magnetic resonance (NMR) signals of the polysaccharide region from the granules were very complex, likely as a result of the diverse microbial population in the granules. Using nonmetric multidimensional scaling (NMDS), the 1H NMR signals of reference polysaccharides (gellan, xanthan, alginate) and those of the anaerobic granules revealed that there were similarities between the polysaccharides extracted from granules and the reference polysaccharide alginate. Further analysis of the exopolysaccharides from anaerobic granules, and reference polysaccharides using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) revealed that exopolysaccharides from two of the anaerobic granular sludges studied exhibited spectra similar to that of alginate. The presence of sequences related to the synthesis of alginate was confirmed in the metagenomes of the granules. Collectively these results suggest that alginate-like exopolysaccharides are constituents of the EPS matrix in anaerobic granular sludge treating different industrial wastewater. This finding expands the engineered environments where alginate has been found as EPS constituent of microbial aggregates.

  15. Improving volatile fatty acid yield from sludge anaerobic fermentation through self-forming dynamic membrane separation.

    Science.gov (United States)

    Liu, Hongbo; Wang, Yuanyuan; Yin, Bo; Zhu, Yanfang; Fu, Bo; Liu, He

    2016-10-01

    Self-forming dynamic membrane (SFDM) separation was applied to the conventional sludge fermenter for improving VFA yields. Results indicated SFDM presented good performance in transferring products, retaining substrates, and enriching useful bacteria. The retention ratios of suspended solids, soluble COD, proteins, and polysaccharides reached 99%, 30%, 70%, and 40%, respectively, and more than 90% of the VFAs and ammonia could be transferred in a timely manner. The structure of the microbial community was optimized, which led to enhanced releases of hydrolytic enzymes and accelerated enrichments of functional bacteria. Protease and β-glucosidase activities increased from 1.0 to 5.0U/mL and 15.0 to 23.0μmol/L·h, respectively. VFA yield and sludge conversion ratio increased by 233.3% and 227.9%, respectively. Moreover, SFDM had good operation stability, including a short formation time, a long operation period, and a low transmembrane pressure. These results show VFA yield from sludge fermentation can be greatly improved by SFDM separation. PMID:27347803

  16. 市政污泥厌氧消化处理的工程设计%Engineering Design of Anaerobic Digestion Treatment of Municipal Sludge

    Institute of Scientific and Technical Information of China (English)

    李光

    2013-01-01

    The process of sludge anaerobic digestion was expounded.The composition and function of each unit of the process were described,and the important design parameters were defined.Meanwhile,the economic analysis of sludge anaerobic digestion was carried out,and its engineering goal was put forward.%阐述了污泥厌氧消化工艺,介绍了各单元处理的组成和功能,并对重要设计参数进行了界定,同时对污泥厌氧消化工艺作了经济分析,提出了其工程目标.

  17. Performance evaluation of the sulfur-redox-reaction-activated up-flow anaerobic sludge blanket and down-flow hanging sponge anaerobic/anoxic sequencing batch reactor system for municipal sewage treatment.

    Science.gov (United States)

    Hatamoto, Masashi; Ohtsuki, Kota; Maharjan, Namita; Ono, Shinya; Dehama, Kazuya; Sakamoto, Kenichi; Takahashi, Masanobu; Yamaguchi, Takashi

    2016-03-01

    A sulfur-redox-reaction-activated up-flow anaerobic sludge blanket (UASB) and down-flow hanging sponge (DHS) system, combined with an anaerobic/anoxic sequencing batch reactor (A2SBR), has been used for municipal sewage treatment for over 2years. The present system achieved a removal rate of 95±14% for BOD, 74±22% for total nitrogen, and 78±25% for total phosphorus, including low water temperature conditions. Sludge conversion rates during the operational period were 0.016 and 0.218g-VSSg-COD-removed(-1) for the UASB, and DHS, respectively, which are similar to a conventional UASB-DHS system, which is not used of sulfur-redox-reaction, for sewage treatment. Using the sulfur-redox reaction made advanced treatment of municipal wastewater with minimal sludge generation possible, even in winter. Furthermore, the occurrence of a unique phenomenon, known as the anaerobic sulfur oxidation reaction, was confirmed in the UASB reactor under the winter season. PMID:26773951

  18. Pretreatment of coking wastewater using anaerobic sequencing batch reactor (ASBR)

    Institute of Scientific and Technical Information of China (English)

    LI Bing; SUN Ying-lan; LI Yu-ying

    2005-01-01

    A laboratory-scale anaerobic sequencing batch reactor (ASBR) was used to pretreat coking wastewater. Inoculated anaerobic granular biomass was acclimated for 225 d to the coking wastewater, and then the biochemical methane potential (BMP)of the coking wastewater in the acclimated granular biomass was measured. At the same time, some fundamental technological factors, such as the filling time and the reacting time ratio (tf/tr), the mixing intensity and the intermittent mixing mode, that affect anaerobic pretreatment of coking wastewater with ASBR, were evaluated through orthogonal tests. The COD removal efficiency reached 38%~50% in the stable operation period with the organic loading rate of 0.37~0.54 kg COD/(m3.d) at the optimum conditions of tf/tr, the mixing intensity and the intermittent mixing mode. In addition, the biodegradability of coking wastewater distinctly increased after the pretreatment using ASBR. At the end of the experiment, the microorganism forms on the granulated sludge in the ASBR were observed using SEM (scanning electron microscope) and fluoroscope. The results showed that the dominant microorganism on the granular sludge was Methanosaeta instead of Methanosarcina dominated on the inoculated sludge.

  19. Development and application of an enzymatic and cell flotation treatment for the recovery of viable microbial cells from environmental matrices such as anaerobic sludge

    OpenAIRE

    Braun, Florence; Hamelin, Jérôme; Gevaudan, Gaelle; Patureau, Dominique

    2011-01-01

    Efficient dissociation of microorganisms from their aggregate matrix is required to study the microorganisms without interaction with their native environment (e.g., biofilms, flocs, granules, etc.) and to assess their community composition through the application of molecular or microscopy techniques. To this end, we combined enzymatic treatments and a cell extraction by density gradient to efficiently recover anaerobic microorganisms from urban wastewater treatment plant sludge. The enzymes...

  20. Anaerobic Treatment of Municipal Solid Waste and Sludge for Energy Production and Recycling of Nutrients

    Science.gov (United States)

    Leinonen, S.

    This volume contains 18 papers presented at a Nordic workshop dealing with application of anaerobic decomposition processes on various types of organic wastes, held at the Siikasalmi Research and Experimental Station of the University of Joensuu on 1-2 Oct. 1992. Subject coverage of the presentations extends from the biochemical and microbiological principles of organic waste processing to descriptions and practical experiences of various types of treatment plants. The theoretical and experimental papers include studies on anaerobic and thermophilic degradation processes, methanogenesis, effects of hydrogen, treatment of chlorinated and phenolic compounds, and process modeling, while the practical examples range from treatment of various types of municipal, industrial, and mining wastes to agricultural and fish farm effluents. The papers provide technical descriptions of several biogas plants in operation. Geographically, the presentations span the Nordic and Baltic countries.

  1. Maximising biogas in anaerobic digestion by using engine waste heat for thermal hydrolysis pre-treatment of sludge.

    Science.gov (United States)

    Pickworth, B; Adams, J; Panter, K; Solheim, O E

    2006-01-01

    Dublin's Ringsend WWTP was designed to serve a population of approximately 1.2 million p.e. with a sludge production of 37,000 dry tonnes per year after upgrading to full secondary treatment. Several technical solutions were put forward as part of a design, build, finance and operate (DBFO) competition, with the chosen solution being a proposal by Black and Veatch for a combination of sequencing batch reactor (SBR) technology and anaerobic digestion with Cambi thermal hydrolysis pre-treatment (THP). The THP plant was built by Cambi and handed over to B&V in 2002. The plant is now operated by Celtic Anglian Water. In September 2004 a test was carried out on the mass and energy balance of the plant following 2 years of operation and is detailed in this paper. The process enables digestion at very high dry solids feed and low hydraulic retention time. The plant was built with three digesters of 4250 m3 each and is fed with hydrolysed sludge at 11% DS. There are four no. 1 MW Jenbacher engines operating mainly on biogas. Each pair of engines is fitted with a waste heat boiler with a capacity of one tonne steam per hour. These boilers have sufficient capacity to provide 80% of the steam required for the THP, which in turn provides all the heat for the subsequent digestion in the form of hydrolysed feed. There are two main biogas boilers for top up steam and other uses of the biogas including thermal oxidation of concentrated odours. PMID:17087375

  2. Microbial electrolysis contribution to anaerobic digestion of waste activated sludge, leading to accelerated methane production

    DEFF Research Database (Denmark)

    Liu, Wenzong; Cai, Weiwei; Guo, Zechong;

    2016-01-01

    Methane production rate (MPR) in waste activated sludge (WAS) digestion processes is typically limitedby the initial steps of complex organic matter degradation, leading to a limited MPR due to sludgefermentation speed of solid particles. In this study, a novel microbial electrolysis AD reactor (ME....../m3 reactor/d in AD). The methane production yield reached 116.2 mg/g VSS in the ME-ADreactor. According to balance calculation on electron transfer and methane yield, the increasedmethane production was mostly dependent on electron contribution through the ME system. Thus, theuse of the novel ME...

  3. Anaerobic digestion for simultaneous sewage sludge treatment and CO biomethanation: process performance and microbial ecology

    DEFF Research Database (Denmark)

    Luo, Gang; Wang, Wen; Angelidaki, Irini

    2013-01-01

    Syngas is produced by thermal gasification of both non-renewable and renewable sources including biomass and coal, and it consists mainly of CO, CO2 and H2. In this paper we aim to bio-convert CO in the syngas to CH4. A novel technology for simultaneous sewage sludge treatment and CO biomethanation...... biomethanation. However, the two species were distributed differently in the liquid phase and in the biofilm. Although carboxidotrophic activities test showed that CO was converted by both archaea and bacteria, the bacterial species responsible for CO conversion are unknown....

  4. MiDAS: A curated database for the microorganisms of activated sludge and anaerobic digesters

    DEFF Research Database (Denmark)

    McIlroy, Simon Jon; Kirkegaard, Rasmus Hansen; McIlroy, Bianca;

    A deep understanding of the microbial communities and dynamics in wastewater treatment systems is a powerful tool for process optimization and design (Rittmann et al., 2006). With the advent of amplicon sequencing of the 16S rRNA gene, the diversity within the microbial communities can now be...... community knowledge web platform about the microbes in activated sludge and their associated ADs. The MiDAS taxonomy proposes putative names for each genus-level-taxon that can be used as a common vocabulary for all researchers in the field....

  5. Improved anaerobic digestion of a thermally pretreated mixture of physicochemical sludge; broiler excreta and sugar cane wastes (SCW): Effect on organic matter solubilization, biodegradability and bioenergy production.

    Science.gov (United States)

    Nava-Valente, Noemí; Alvarado-Lassman, Alejandro; Nativitas-Sandoval, Liliana S; Mendez-Contreras, Juan M

    2016-01-01

    Thermal pretreatment effect of a mixture of organic wastes (physicochemical sludge, excreta of broiler chickens and sugarcane wastes (SCW)) in the solubilization and biodegradability organic matter as well as bioenergy production by anaerobic digestion was evaluated. Two different mixtures of physicochemical sludge, excreta of broiler chickens and SCW (70%, 15%, 15% and 60%, 20%, 20% of VS, respectively) were treated at different temperatures (80 °C, 85 °C and 90 °C) and contact time (30, 60 and 90 min). Results indicate that, organic matter solubilization degree increased from 1.14 to 6.56%; subsequently, in the anaerobic digestion process, an increase of 50% in the volatile solids removal and 10% in biogas production was observed, while, retention time decreased from 23 up to 9 days. The results obtained were similar to pilot-scale. In both experimental scales it showed that the synergy produced by the simultaneous anaerobic digestion of different substrates could increase bioenergy production up to 1.3 L bio g(-1) VS removed and 0.82 L CH4 g(-1) VS removed. The treatment conditions presented in this study allow for large residue quantities to be treated and large bioenergy quantities to be produced (10% higher than during conventional treatment) without increasing the anaerobic digester volume. PMID:26819145

  6. Performance of up flow anaerobic sludge fixed film bioreactor for the treatment of high organic load and biogas production of cheese whey wastewater

    Directory of Open Access Journals (Sweden)

    Tehrani Nazila Samimi

    2015-01-01

    Full Text Available Among various wastewater treatment technologies, biological wastewater treatment appears to be the most promising method. A pilot scale of hybrid anaerobic bioreactor was fabricated and used for the whey wastewater treatment. The top and bottom of the hybrid bioreactor known as up flow anaerobic sludge fixed film (UASFF; was a combination of up flow anaerobic sludge blanket (UASB and up flow anaerobic fixed film reactor (UAFF, respectively. The effects of operating parameters such as temperature and hydraulic retention time (HRT on chemical oxygen demand (COD removal and biogas production in the hybrid bioreactor were investigated. Treatability of the samples at various HRTs of 12, 24, 36 and 48 hours was evaluated in the fabricated bioreactor. The desired conditions for COD removal such as HRT of 48 hours and operation temperature of 40 °C were obtained. The maximum COD removal and biogas production were 80% and 2.40 (L/d, respectively. Kinetic models of Riccati, Monod and Verhalst were also evaluated for the living microorganisms in the treatment process. Among the above models, Riccati model was the best growth model fitted with the experimental data with R2 of about 0.99.

  7. The determination of fertilizer quality of the formed struvite from effluent of a sewage sludge anaerobic digester

    Energy Technology Data Exchange (ETDEWEB)

    Uysal, Ayla, E-mail: auysal@mmf.sdu.edu.tr [Department of Environmental Engineering, Suleyman Demirel University, Isparta (Turkey); Yilmazel, Y. Dilsad; Demirer, Goksel N. [Department of Environmental Engineering, Middle East Technical University, Ankara (Turkey)

    2010-09-15

    The formation of struvite (MgNH{sub 4}PO{sub 4}.6H{sub 2}O) in wastewater treatment plants can lead to scaling and thus operational problems reducing the treatment efficiency. However, struvite has significant commercial value as an agricultural fertilizer. Therefore, controlled struvite formation in wastewater treatment plants not only presents an opportunity to recover nutrients but also corresponds to the valorization of wastes. NH{sub 4}-N and PO{sub 4}-P removal and recovery from the effluent of a full-scale sewage sludge anaerobic digester via controlled struvite precipitation were investigated in this study. The effect of the residual heavy metal and micropollutant content of the formed struvite on fertilizer quality was also evaluated. Removal efficiencies of NH{sub 4}-N, PO{sub 4}-P and COD were 89.35%, 95% and 39.78% when Mg:N:P molar ratio was 1.5:1:1 and pH was 9.0. Mercury, nickel, zinc and chrome concentrations derived from struvite precipitation were below the regulatory limit for fertilizer usage in Turkey. The precipitate did not contain polychlorinated biphenyls (PCB). X-ray diffraction (XRD) analysis conducted on the precipitate indicated a struvite formation.

  8. Start-up of an anaerobic dynamic membrane digester for waste activated sludge digestion: temporal variations in microbial communities.

    Directory of Open Access Journals (Sweden)

    Hongguang Yu

    Full Text Available An anaerobic dynamic membrane digester (ADMD was developed to digest waste sludge, and pyrosequencing was used to analyze the variations of the bacterial and archaeal communities during the start-up. Results showed that bacterial community richness decreased and then increased over time, while bacterial diversity remained almost the same during the start-up. Proteobacteria and Bacteroidetes were the major phyla. At the class level, Betaproteobacteria was the most abundant at the end of start-up, followed by Sphingobacteria. In the archaeal community, richness and diversity peaked at the end of the start-up stage. Principle component and cluster analyses demonstrated that archaeal consortia experienced a distinct shift and became stable after day 38. Methanomicrobiales and Methanosarcinales were the two predominant orders. Further investigations indicated that Methanolinea and Methanosaeta were responsible for methane production in the ADMD system. Hydrogenotrophic pathways might prevail over acetoclastic means for methanogenesis during the start-up, supported by specific methanogenic activity tests.

  9. Increased temperature in the thermophilic stage in temperature phased anaerobic digestion (TPAD) improves degradability of waste activated sludge.

    Science.gov (United States)

    Ge, Huoqing; Jensen, Paul D; Batstone, Damien J

    2011-03-15

    Two-stage temperature phased anaerobic digestion (TPAD) is an increasingly popular method to improve stabilisation of sewage waste activated sludge, which normally has inherently poor and slow degradation. However, there has been limited systematic analysis of the impact of the initial thermophilic stage (temperature, pH and retention time) on performance in the main mesophilic stage. In this study, we demonstrate a novel two-stage batch test method for TPAD processes, and use it to optimize operating conditions of the thermophilic stage in terms of degradation extent and methane production. The method determines overall degradability and apparent hydrolysis coefficient in both stages. The overall process was more effective with short pre-treatment retention times (1-2 days) and neutral pH compared to longer retention time (4 days) and low pH (4-5). Degradabilities and apparent hydrolysis coefficients were 0.3-0.5 (fraction degradable) and 0.1-0.4d(-1), respectively, with a margin of error in each measurement of approximately 20% relative (95% confidence). Pre-treatment temperature had a strong impact on the whole process, increasing overall degradability from 0.3 to 0.5 as temperature increased from 50 to 65 °C, with apparent hydrolysis coefficient increasing from 0.1 to 0.4d(-1). PMID:21277081

  10. The Effect of Higher Sludge Recycling Rate on Anaerobic Treatment of Palm Oil Mill Effluent in a Semi-Commercial Closed Digester for Renewable Energy

    Directory of Open Access Journals (Sweden)

    Alawi Sulaiman

    2009-01-01

    Full Text Available Problem statement: A 500 m3 semi-commercial closed anaerobic digester was constructed for Palm Oil Mill Effluent (POME treatment and methane gas capture for renewable energy. During the start-up operation period, the Volatile Fatty Acids (VFA accumulation could not be controlled and caused instability on the system. Approach: A settling tank was installed and sludge was recycled as to provide a balanced microorganisms population for the treatment of POME and methane gas production. The effect of sludge recycling rate was studied by applying Organic Loading Rates (OLR (between 1.0 and 10.0 kgCOD m-3 day-1 at different sludge recycling rates (6, 12 and 18 m3 day-1. Results: At sludge recycling rate of 18 m3 day-1, the maximum OLR was 10.0 kgCOD m-3 day-1 with biogas and methane productivity of 1.5 and 0.9 m3 m-3 day-1, respectively. By increasing the sludge recycling rate the VFA concentration was controlled below its inhibitory limit (1000 mg L-1 and the COD removal efficiency recorded was above 95% which indicated good treatment performance for the digester. Two methanogens species (Methanosarcina sp. and Methanosaeta concilii had been identified from sludge samples obtained from the digester and recycled stream. Conclusion: By increasing the sludge recycling rate upon higher application of OLR, the treatment process was kept stable with high COD removal efficiency. The biogas and methane productivity were initially improved but reduced once OLR and recycling rate were increased to 10.0 kg COD m3 day-1 and 18 m3 day-1 respectively.

  11. Influence of Continuous Flow Microwave Pre-Treatment on Anaerobic Digestion of Secondary Thickened Sludge for Sustainable Energy Recovery in Sewage Treatment Plant

    Science.gov (United States)

    Hephzibah, D.; Kumaran, P.; Saifuddin, N. M.

    2016-03-01

    This work elucidates the effects of pre-treatment of secondary thickened sludge (STS) for enhancement of biogas production that has great potential to generate energy for the utilization of the sewage treatment plant (STP) itself. Microwave pre-treatment has been adopted for this study. Experiment works have been designed and conducted to examine the effectiveness of continuous flow microwave pre-treatment on the solubility of STS, digestibility of STS and biogas production at a power level of 80 W for 5, 10 and 15 minutes. A few characteristics of the sewage sludge were monitored daily to identify the effect of pre-treatment on the sludge. The soluble chemical oxygen demand (SCOD)/total chemical oxygen demand (TCOD) ratio increased by 0.1, 1.0 and 1.8%, while the volatile fatty acids (VFA) concentration of the pre-treated sludge improved by 4.4, 5.1, 5.9% at the irradiation time of 5, 10 and 15 minutes, respectively at a microwave power level of 80 W. Besides that, the digestate also indicates that the pre-treated sludge undergoes efficient VS removal and TCOD removal after anaerobic digestion compared to the untreated sludge. Moreover, the biogas quantity increased by an average of 19.2, 24.1 and 32.2% in 5, 10 and 15 minutes irradiation time respectively compared to the untreated sludge. The additional quantity of biogas generated has shown a great potential for sustainable energy generation that can be utilized internally by the STP.

  12. 黄水为碳源的颗粒污泥除磷机理研究%Phosphorus Removal Mechanism of Granular Sludge with Yellow Water as Carbon Source Study

    Institute of Scientific and Technical Information of China (English)

    刘思琪; 胡学斌; 刘小英

    2016-01-01

    Granular sludge ,as a biological treatment technology concerned in recent years ,has compact structure ,good settling ability and perfect biological activity .In order to understand the mechanism of phosphorus removal of aerobic granu-lar sludge which is fed by the yellow water ,the physical characteristics and the phosphorus removal characteristic of granular sludge are seriously studied ,especially the shape and content of phosphorus in granular sludge .Meanwhile the different ex-traction methods and the effects on the phosphorus removal of extracellular polymeric substances (EPS ) are also studied .The phosphorus removal mechanisms of granular sludge are described ,which provides theoretical and technical support for the realization of high efficiency and low consumption phosphorus removal in urban sewage using granular sludge for simultaneous removal of nitrogen and phosphorus .%颗粒污泥作为近年来备受关注的一种生物处理技术,具有结构密实、沉降性好、生物相丰富且活性高等优点。为了了解好氧颗粒污泥除磷机理,以黄水为碳源的同步脱氮除磷颗粒污泥为研究对象,研究颗粒污泥的物理特性、除磷特性,重点研究颗粒污泥中磷的形态及含量,同时研究不同方法对颗粒污泥胞外聚合物(EPS )的提取效果及其对磷去除的影响,揭示该颗粒污泥的除磷机理,为城市污水利用同步脱氮除磷颗粒污泥实现高效低耗除磷提供理论与技术支持。

  13. Pilot-scale anaerobic co-digestion of municipal wastewater sludge with restaurant grease trap waste.

    Science.gov (United States)

    Razaviarani, Vahid; Buchanan, Ian D; Malik, Shahid; Katalambula, Hassan

    2013-07-15

    The maximum feasible loading rate of grease trap waste (GTW) to the municipal wastewater sludge (MWS) was investigated using two 1300 L pilot-scale (1200 L active volume) digesters under mesophilic conditions at a 20 day solids retention time. During the co-digestion, the test reactor received a mixture of GTW and MWS while the control reactor received only MWS. The test digester loading was increased incrementally to a maximum of 280% of the control digester COD loading. The highest feasible GTW loading was determined to be 23% and 58% in terms of its total 1.58 kg VS/(m(3) d) and 3.99 kg COD/(m(3) d) loadings, respectively. This test digester COD loading represented 240% of the control digester COD loading. At this loading, test digester biogas production was 67% greater than that of the control. During the test digester quasi steady state loading period when VS from GTW represented 19% of its total VS loading, the test digester COD and VS removal rates were 2.5 and 1.5 fold those of the control digester, respectively. The test digester biogas production declined markedly when the percentage of VS from GTW in its feed was increased to 30% of its total VS loading. Causes of the reduced biogas production were investigated and attributed to inhibition due to long chain fatty acid accumulation. PMID:23583789

  14. The use of the core-shell structure of zero-valent iron nanoparticles (NZVI) for long-term removal of sulphide in sludge during anaerobic digestion.

    Science.gov (United States)

    Su, Lianghu; Zhen, Guangyin; Zhang, Longjiang; Zhao, Youcai; Niu, Dongjie; Chai, Xiaoli

    2015-12-01

    A core-shell structure results in zero-valent iron nanoparticles (NZVI) with manifold functional properties. In this study, the long-term effects of NZVI on hydrogen sulphide removal in an anaerobic sludge digester were investigated. Within 20 days, the average hydrogen sulphide content in the biogas was successfully reduced from 300 (or 3620 of sulphate-rich sludge) mg Nm(-3) to 6.1 (121), 0.9 (3.3) and 0.5 (1.3) mg Nm(-3) in the presence of 0.05, 0.10 and 0.20% (wt) NZVI, respectively. Methane yield was enhanced at the low NZVI dose (0.05-0.10%) but decreased at the elevated dose (0.20%). Methane production and volatile solid degradation analyses implied that doses of 0.5-0.10% NZVI could accelerate sludge stabilization during anaerobic digestion. The phosphorus fractionation profile suggested that methane production could be inhibited at the elevated NZVI dose, partly due to the limited availability of soluble phosphorus due to the immobilization of bioavailable-P through the formation of vivianite. An analysis of the reducible inorganic sulphur species revealed that the elimination of hydrogen sulphide occurred via the reaction between hydrogen sulphide and the oxide shell of NZVI, which mainly formed FeS and some FeS2 and S(0). PMID:26565792

  15. The Start-up of Hybrid, Anaerobic up-flow Sludge Blanket (HUASB under a Range of Mesophiclic and Thermophilic Temperatures

    Directory of Open Access Journals (Sweden)

    S. A. Habeeb

    2011-07-01

    Full Text Available We have examined the effect of gradual increase of the temperature on the performance of anaerobic process of palm oil mill effluent (POME, and sludge granules development. Two hybrid up-flow anaerobic sludge blanket (HUASB reactors R1 and R2 were employed to be run at 27±2 and 37±1°C, respectively. R1 was kept at room temperature for the whole experiment, where the temperature of R2 was increased up to 49ºC (3ºC after every steady-state occurrence. Maximum COD removal of 91% was obtained in R2 at optimum temperature of 46°C, while 84% was recorded in R1. Additional parameters were applied to evaluate the performance of the process, i.e. total suspended solids (TSS, Turbidity, and Color. The imaging of sludge aggregate has revealed the effect of temperature on granulation development during the experiment. Throughout the operation period, it can be seen that the microbial growth rate was significantly affected by temperature. Hence, the use of HUASB reactor could be productively implemented for POME treatment as an efficient system under the mesophilic and thermophilic temperatures.

  16. Anaerobic Treatment of Palm Oil Mill Effluent in Pilot-Scale Anaerobic EGSB Reactor

    Directory of Open Access Journals (Sweden)

    Jin Wang

    2015-01-01

    Full Text Available Large volumes of untreated palm oil mill effluent (POME pose threat to aquatic environment due to the presence of very high organic content. The present investigation involved two pilot-scale anaerobic expanded granular sludge bed (EGSB reactors, continuously operated for 1 year to treat POME. Setting HRT at 9.8 d, the anaerobic EGSB reactors reduced COD from 71179 mg/L to 12341 mg/L and recycled half of sludge by a dissolved air flotation (DAF. The average effluent COD was 3587 mg/L with the consistent COD removal efficiency of 94.89%. Adding cationic polymer (PAM dose of 30 mg/L to DAF unit and recycling its half of sludge caused granulation of anaerobic sludge. Bacilli and small coccid bacteria were the dominant microbial species of the reactor. The reactor produced 27.65 m3 of biogas per m3 of POME which was utilized for electricity generation.

  17. Effects of sludge recirculation rate and mixing time on performance of a prototype single-stage anaerobic digester for conversion of food wastes to biogas and energy recovery.

    Science.gov (United States)

    Ratanatamskul, Chavalit; Saleart, Tawinan

    2016-04-01

    Food wastes have been recognized as the largest waste stream and accounts for 39.25 % of total municipal solid waste in Thailand. Chulalongkorn University has participated in the program of in situ energy recovery from food wastes under the Ministry of Energy (MOE), Thailand. This research aims to develop a prototype single-stage anaerobic digestion system for biogas production and energy recovery from food wastes inside Chulalongkorn University. Here, the effects of sludge recirculation rate and mixing time were investigated as the main key parameters for the system design and operation. From the results obtained in this study, it was found that the sludge recirculation rate of 100 % and the mixing time of 60 min per day were the most suitable design parameters to achieve high efficiencies in terms of chemical oxygen demand (COD), total solids (TS), and total volatile solid (TVS) removal and also biogas production by this prototype anaerobic digester. The obtained biogas production was found to be 0.71 m(3)/kg COD and the composition of methane was 61.6 %. Moreover, the efficiencies of COD removal were as high as 82.9 % and TVS removal could reach 83.9 % at the optimal condition. Therefore, the developed prototype single-stage anaerobic digester can be highly promising for university canteen application to recover energy from food wastes via biogas production. PMID:25864735

  18. Preliminary experimental results of Sewage Sludge (SS) Co-digestion with Palm Oil Mill Effluent (POME) for Enhanced Biogas Production in Laboratory Scale Anaerobic Digester

    Science.gov (United States)

    Sivasankari, R.; Kumaran, P.; Normanbhay, Saifuddin; Halim Shamsuddin, Abd

    2013-06-01

    An investigation on the feasibility of co-digesting Sewage Sludge with Palm Oil Mill Effluent for enhancing the biogas production and the corresponding effect of the co-digestion substrate ratio on the biogas production has been evaluated. Anaerobic co-digestion of POME with SS was performed at ratios of 100:0, 70:30, 60:40 and 0:100 to find the optimum blend required for enhanced waste digestion and biogas production. Single stage batch digestion was carried out for 12 days in a laboratory scale anaerobic digester. Co-digestion of sludge's at the 70:30 proportion resulted in optimal COD and C: N ratio which subsequently recorded the highest performance with regards to biogas production at 28.1 L's compared to the 1.98 L's of biogas produced from digestion of SS alone. From the results obtained, it is evident that co-digestion of POME and SS is an attractive option to be explored for enhancement of biogas production in anaerobic digesters.

  19. Preliminary experimental results of Sewage Sludge (SS) Co-digestion with Palm Oil Mill Effluent (POME) for Enhanced Biogas Production in Laboratory Scale Anaerobic Digester

    International Nuclear Information System (INIS)

    An investigation on the feasibility of co-digesting Sewage Sludge with Palm Oil Mill Effluent for enhancing the biogas production and the corresponding effect of the co-digestion substrate ratio on the biogas production has been evaluated. Anaerobic co-digestion of POME with SS was performed at ratios of 100:0, 70:30, 60:40 and 0:100 to find the optimum blend required for enhanced waste digestion and biogas production. Single stage batch digestion was carried out for 12 days in a laboratory scale anaerobic digester. Co-digestion of sludge's at the 70:30 proportion resulted in optimal COD and C: N ratio which subsequently recorded the highest performance with regards to biogas production at 28.1 L's compared to the 1.98 L's of biogas produced from digestion of SS alone. From the results obtained, it is evident that co-digestion of POME and SS is an attractive option to be explored for enhancement of biogas production in anaerobic digesters.

  20. [Achievement of Sulfate-Reducing Anaerobic Ammonium Oxidation Reactor Started with Nitrate-Reducting Anaerobic Ammonium Oxidation].

    Science.gov (United States)

    Liu, Zheng-chuan; Yuan, Lin-jiang; Zhou, Guo-biao; Li, Jing

    2015-09-01

    The transformation of nitrite-reducing anaerobic ammonium oxidation to sulfate-reducing anaerobic ammonium oxidation in an UASB was performed and the changes in microbial community were studied. The result showed that the sulfate reducing anaerobic ammonium oxidation process was successfully accomplished after 177 days' operation. The removal rate of ammonium nitrogen and sulfate were up to 58. 9% and 15. 7%, the removing load of ammonium nitrogen and sulfate were 74. 3 mg.(L.d)-1 and 77. 5 mg.(L.d)-1 while concentration of ammonium nitrogen and sulfate of influent were 130 mg.(L.d)-1 and 500 mg.(L.d)-1, respectively. The lost nitrogen and sulphur was around 2 in molar ratio. The pH value of the effluent was lower than that of the influent. Instead of Candidatus brocadia in nitrite reducing anaerobic ammonium oxidation granular sludge, Bacillus benzoevorans became the dominant species in sulfate reducing anaerobic ammonium oxidation sludge. The dominant bacterium in the two kinds of anaerobic ammonium oxidation process is different. Our results imply that the two anaerobic ammonium oxidation processes are carried out by different kind of bacterium. PMID:26717697

  1. Optimisation of sewage sludge anaerobic digestion through co-digestion with OFMSW: Effect of collection system and particle size

    Energy Technology Data Exchange (ETDEWEB)

    Silvestre, Gracia [IRTA, GIRO Joint Research Unit IRTA-UPC, Torre Marimon, Barcelona (Spain); Ainia, Departamento de Medio Ambiente, Bioenergía e Higiene Industrial, Paterna, Valencia (Spain); Bonmatí, August [IRTA, GIRO Joint Research Unit IRTA-UPC, Torre Marimon, Barcelona (Spain); Fernández, Belén, E-mail: belen.fernandez@irta.cat [IRTA, GIRO Joint Research Unit IRTA-UPC, Torre Marimon, Barcelona (Spain)

    2015-09-15

    Highlights: • Methane production rate increased between 56% and 208% during OFMSW–SS codigestion. • The OFMSW particle size reduction from 20 to 8 mm did not affect the methane yield. • OFMSW–SS codigestion promoted β-oxidation and acetoclastic methanogenic activity. • The evolution of specific activity was a feasible tool to control the process. - Abstract: The effect of organic fraction of municipal solid waste (OFMSW) loading rate and particulate size on the sewage sludge (SS) mesophilic anaerobic co-digestion was assessed in continuous stirred tank reactor at hydraulic retention time of 20 days. The SS–OFMSW mixture composed by 54% of the volatile solids fed (inlet-VS), at OLR of 3.1 kg{sub COD} m{sup −3} d{sup −1} (1.9 kg{sub VS} m{sup −3} d{sup −1}), showed the highest increment on the volumetric methane production and yield of +200% and +59% respectively, under stable conditions. The effect of particulate size was assessed with the same mixture and same operational conditions but reducing the OFMSW particulate size from 20 mm to 8 mm with the aim to improve the hydrolysis step, but the results showed any influence in the OFMSW particulate size range analysed. In addition, specific biomass activity was assessed at the end of each co-digestion period. Results showed that OFMSW promoted β-oxidation syntrophic acetogens and the acetoclastic methanogens activity; although the last increase of the OFMSW percentage (from 47% to 54% inlet-VS) affected negatively the specific substrate activity, but not inhibitory effect was observed. Therefore, the results obtained in the continuous experiment could be related with some inhibitory or toxic effect and not due to hydrolysis limitation. The specific biomass activity test was demonstrated to be an interesting tool to evaluate and control the co-digestion process, especially when conventional parameters did not explain the behaviour of the biological system.

  2. Optimisation of sewage sludge anaerobic digestion through co-digestion with OFMSW: Effect of collection system and particle size

    International Nuclear Information System (INIS)

    Highlights: • Methane production rate increased between 56% and 208% during OFMSW–SS codigestion. • The OFMSW particle size reduction from 20 to 8 mm did not affect the methane yield. • OFMSW–SS codigestion promoted β-oxidation and acetoclastic methanogenic activity. • The evolution of specific activity was a feasible tool to control the process. - Abstract: The effect of organic fraction of municipal solid waste (OFMSW) loading rate and particulate size on the sewage sludge (SS) mesophilic anaerobic co-digestion was assessed in continuous stirred tank reactor at hydraulic retention time of 20 days. The SS–OFMSW mixture composed by 54% of the volatile solids fed (inlet-VS), at OLR of 3.1 kgCOD m−3 d−1 (1.9 kgVS m−3 d−1), showed the highest increment on the volumetric methane production and yield of +200% and +59% respectively, under stable conditions. The effect of particulate size was assessed with the same mixture and same operational conditions but reducing the OFMSW particulate size from 20 mm to 8 mm with the aim to improve the hydrolysis step, but the results showed any influence in the OFMSW particulate size range analysed. In addition, specific biomass activity was assessed at the end of each co-digestion period. Results showed that OFMSW promoted β-oxidation syntrophic acetogens and the acetoclastic methanogens activity; although the last increase of the OFMSW percentage (from 47% to 54% inlet-VS) affected negatively the specific substrate activity, but not inhibitory effect was observed. Therefore, the results obtained in the continuous experiment could be related with some inhibitory or toxic effect and not due to hydrolysis limitation. The specific biomass activity test was demonstrated to be an interesting tool to evaluate and control the co-digestion process, especially when conventional parameters did not explain the behaviour of the biological system

  3. A downflow hanging sponge (DHS) reactor for faecal coliform removal from an upflow anaerobic sludge blanket (UASB) effluent.

    Science.gov (United States)

    Yaya Beas, Rosa Elena; Kujawa-Roeleveld, Katarzyna; van Lier, Jules B; Zeeman, Grietje

    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 laboratory-scale DHS reactors, i.e. a reactor with cube type sponges without recirculation, a similar one with recirculation and a reactor with curtain type sponges, were studied. The porosities of the applied medium were 91%, 87% and 47% respectively. The organic loading rates were 0.86 kgCOD m(-3) d(-1), 0.53 kgCOD m(-3) d(-1) and 0.24 kgCOD m(-3) d(-1) correspondingly at hydraulic loading rates of 1.92 m3 m(-2) d(-1), 2.97 m3 m(-2) d(-1) and 1.32 m3 m(-2) d(-1), respectively (COD: chemical oxygen demand). The corresponding averages for faecal coliform removal were 99.997%, 99.919% and 92.121% respectively. The 1989 WHO guidelines standards, in terms of faecal coliform content for unrestricted irrigation (category A), was achieved with the effluent of the cube type DHS (G1) without recirculation. Restricted irrigation, category B and C, is assigned to the effluent of the cube type with recirculation and the curtain type, respectively. Particularly for organic compounds, the effluent of evaluated DHS reactors complies with USEPA standards for irrigation of so called non-food crops like pasture for milking animals, fodder, fibre, and seed crops. PMID:26606098

  4. Improved volatile fatty acids anaerobic production from waste activated sludge by pH regulation: Alkaline or neutral pH?

    Science.gov (United States)

    Ma, Huijun; Chen, Xingchun; Liu, He; Liu, Hongbo; Fu, Bo

    2016-02-01

    In this study, the anaerobic fermentation was carried out for volatile fatty acids (VFAs) production at different pH (between 7.0 and 10.0) conditions with untreated sludge and heat-alkaline pretreated waste activated sludge. In the fermentation with untreated sludge, the extent of hydrolysis of organic matters and extent of acidification at alkaline pH are 54.37% and 30.37%, respectively, resulting in the highest VFAs yield at 235.46mg COD/gVS of three pH conditions. In the fermentation with heat-alkaline pretreated sludge, the acidification rate and VFAs yield at neutral pH are 30.98% and 240.14mg COD/gVS, respectively, which are higher than that at other pH conditions. With the glucose or bovine serum albumin as substrate for VFAs production, the neutral pH showed a higher VFAs concentration than the alkaline pH condition. The results of terminal restriction fragment length polymorphism (T-RFLP) analysis indicated that the alkaline pH caused low microbial richness. Based on the results in this study, we demonstrated that the alkaline pH is favor of hydrolysis of organic matter in sludge while neutral pH improved the acidogenesis for the VFAs production from sludge. Our finding is obvious different to the previous research and helpful for the understanding of how heat-alkaline pretreatment and alkaline fermentation influence the VFAs production, and beneficial to the development of VFAs production process. PMID:26652215

  5. Effect of nanoscale zero-valent iron and magnetite (Fe3O4) on the fate of metals during anaerobic digestion of sludge.

    Science.gov (United States)

    Suanon, Fidèle; Sun, Qian; Mama, Daouda; Li, Jiangwei; Dimon, Biaou; Yu, Chang-Ping

    2016-01-01

    Anaerobic digestion (AD) is one of the most widely used processes to stabilize waste sewage sludge and produce biogas renewable energy. In this study, two different iron nanoparticles [nanoscale zero-valent iron (nZVI) and magnetite (Fe3O4)] were used in the mesophilic AD processes (37 ± 1 °C) to improve biogas production. In addition, changes of heavy metal (Cd, Co, Cu, Zn, Ni and Cr) speciation during AD of sludge with and without iron nanoparticles have been investigated. Concentrations of metals in the initial sludge were as follows: 63.1, 73.4, 1102.2, 2060.3, 483.9 and 604.1 mg kg(-1) (dry sludge basis) for Cd, Co, Cu, Zn, Ni and Cr, respectively. Sequential fractionation showed that metals were predominantly bonded to organic matter and carbonates in the initial sludge. Compared with AD without iron nanoparticles, the application of iron nanoparticles (at dose of 0.5% in this study) showed positive impact not only on biogas production, but also on improvement of metals stabilization in the digestate. Metals were found concentrated in Fe-Mn bound and residual fractions and little was accumulated in the liquid digestate and most mobile fractions of solid digestate (water soluble, exchangeable and carbonates bound). Therefore, iron nanoparticles when properly used, could improve not only biogas yield, but also regulate and control the mobilization of metals during AD process. However, our study also observed that iron nanoparticles could promote the immobilization of phosphorus within the sludge during AD, and more research is needed to fully address the mechanism behind this phenomenon and the impact on future phosphorus reuse. PMID:26613183

  6. Microbial community structure in a thermophilic aerobic digester used as a sludge pretreatment process for the mesophilic anaerobic digestion and the enhancement of methane production.

    Science.gov (United States)

    Jang, Hyun Min; Park, Sang Kyu; Ha, Jeong Hyub; Park, Jong Moon

    2013-10-01

    An effective two-stage sewage sludge digestion process, consisting of thermophilic aerobic digestion (TAD) followed by mesophilic anaerobic digestion (MAD), was developed for efficient sludge reduction and methane production. Using TAD as a biological pretreatment, the total volatile suspended solid reduction (VSSR) and methane production rate (MPR) in the MAD reactor were significantly improved. According to denaturing gradient gel electrophoresis (DGGE) analysis, the results indicated that the dominant bacteria species such as Ureibacillus thermophiles and Bacterium thermus in TAD were major routes for enhancing soluble organic matter. TAD pretreatment using a relatively short SRT of 1 day showed highly increased soluble organic products and positively affected an increment of bacteria populations which performed interrelated microbial metabolisms with methanogenic species in the MAD; consequently, a quantitative real-time PCR indicated greatly increased Methanosarcinales (acetate-utilizing methanogens) in the MAD, resulting in enhanced methane production. PMID:23419990

  7. Effect of thermal pretreatment on the biogas production and microbial communities balance during anaerobic digestion of urban and industrial waste activated sludge.

    Science.gov (United States)

    Ennouri, Hajer; Miladi, Baligh; Diaz, Soraya Zahedi; Güelfo, Luis Alberto Fernández; Solera, Rosario; Hamdi, Moktar; Bouallagui, Hassib

    2016-08-01

    The effect of thermal pre-treatment on the microbial populations balance and biogas production was studied during anaerobic digestion of waste activated sludge (WAS) coming from urban (US: urban sludge) and industrial (IS: industrial sludge) wastewater treatment plants (WWTP). The highest biogas yields of 0.42l/gvolatile solid (VS) removed and 0.37l/gVS removed were obtained with urban and industrial sludge pre-treated at 120°C, respectively. Fluorescent in situ hybridization (FISH) was used to quantify the major Bacteria and Archaea groups. Compared to control trails without pretreatment, Archaea content increased from 34% to 86% and from 46% to 83% for pretreated IS and US, respectively. In fact, the thermal pre-treatment of WAS enhanced the growth of hydrogen-using methanogens (HUMs), which consume rapidly the H2 generated to allow the acetogenesis. Therefore, the stable and better performance of digesters was observed involving the balance and syntrophic associations between the different microbial populations. PMID:27132226

  8. Technological Processes of Pretreatment of Anaerobic Digestion Improvement for Sewage Sludge%改善污泥厌氧消化性能的预处理技术

    Institute of Scientific and Technical Information of China (English)

    蔺金贤; 朱南文; 袁海平; 于豹

    2013-01-01

    厌氧消化是污泥稳定化处理的主要技术之一.通过采用一定的预处理技术,破坏细胞结构,释放有机质,促进污泥的水解速率,从而改善污泥厌氧消化性能.该文综述了几种国内外目前研究较为广泛的预处理技术,主要包括热预处理法、转动球磨法、高压喷射法、超声波预处理法、酸预处理法、碱预处理法和氧化法等技术,并分别探讨了各种技术的作用原理、特点、处理效果及应用前景.%Anaerobic digestion is one of the main sludge stabilization technologies.Pretreatment processes can destroy the cell structure,increase nutrient releasing and promote the rate of hydrolysis of the sludge,thereby improving the performance of anaerobic digestion.Paper presents a review of the main sludge treatment techniques used as a pretreatment of anaerobic digestion.These processes include thermal,mechanical (such as grinding,high pressure and ultrasound),and chemical(mainly with acid,alkali or oxidant)treatments.The basic principles,characteristics,treatment efficiency and future application of these methods were discussed as well.

  9. 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

    OpenAIRE

    Kanlayanee Meesap; Nimaradee Boonapatcharoen; Somkiet Techkarnjanaruk; Pawinee Chaiprasert

    2012-01-01

    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 poten...

  10. Anaerobic co-digestion of waste activated sludge and greasy sludge from flotation process: Batch versus CSTR experiments to investigate optimal design

    OpenAIRE

    Girault, R.; Bridoux, G.; Nauleau, F.; Poullain, C.; Buffet, J.; Peu, P.; Sadowski, A.G.; Béline, F.

    2012-01-01

    In this study, the maximum ratio of greasy sluvdge to incorporate with waste activated sludge was investigated in batch and CSTR experiments. In batch experiments, inhibition occurred with a greasy sludge ratio of more than 20-30% of the feed COD. In CSTR experiments, the optimal greasy sludge ratio was 60% of the feed COD and inhibition occurred above a ratio of 80%. Hence, batch experiments can predict the CSTR yield when the degradation phenomenon are additive but cannot be used to determi...

  11. Intracellular Accumulation of Glycine in Polyphosphate-Accumulating Organisms in Activated Sludge, a Novel Storage Mechanism under Dynamic Anaerobic-Aerobic Conditions.

    Science.gov (United States)

    Nguyen, Hien Thi Thu; Kristiansen, Rikke; Vestergaard, Mette; Wimmer, Reinhard; Nielsen, Per Halkjær

    2015-07-01

    Dynamic anaerobic-aerobic feast-famine conditions are applied to wastewater treatment plants to select polyphosphate-accumulating organisms to carry out enhanced biological phosphorus removal. Acetate is a well-known substrate to stimulate this process, and here we show that different amino acids also are suitable substrates, with glycine as the most promising. (13)C-labeled glycine and nuclear magnetic resonance (NMR) were applied to investigate uptake and potential storage products when activated sludge was fed with glycine under anaerobic conditions. Glycine was consumed by the biomass, and the majority was stored intracellularly as free glycine and fermentation products. Subsequently, in the aerobic phase without addition of external substrate, the stored glycine was consumed. The uptake of glycine and oxidation of intracellular metabolites took place along with a release and uptake of orthophosphate, respectively. Fluorescence in situ hybridization combined with microautoradiography using (3)H-labeled glycine revealed uncultured actinobacterial Tetrasphaera as a dominant glycine consumer. Experiments with Tetrasphaera elongata as representative of uncultured Tetrasphaera showed that under anaerobic conditions it was able to take up labeled glycine and accumulate this and other labeled metabolites to an intracellular concentration of approximately 4 mM. All components were consumed under subsequent aerobic conditions. Intracellular accumulation of amino acids seems to be a novel storage strategy for polyphosphate-accumulating bacteria under dynamic anaerobic-aerobic feast-famine conditions. PMID:25956769

  12. A comparison study on the high-rate co-digestion of sewage sludge and food waste using a temperature-phased anaerobic sequencing batch reactor system.

    Science.gov (United States)

    Kim, Hyun-Woo; Nam, Joo-Youn; Shin, Hang-Sik

    2011-08-01

    Assessing contemporary anaerobic biotechnologies requires proofs on reliable performance in terms of renewable bioenergy recovery such as methane (CH(4)) production rate, CH(4) yield while removing volatile solid (VS) effectively. This study, therefore, aims to evaluate temperature-phased anaerobic sequencing batch reactor (TPASBR) system that is a promising approach for the sustainable treatment of organic fraction of municipal solid wastes (OFMSW). TPASBR system is compared with a conventional system, mesophilic two-stage anaerobic sequencing batch reactor system, which differs in operating temperature of 1st-stage. Results demonstrate that TPASBR system can obtain 44% VS removal from co-substrate of sewage sludge and food waste while producing 1.2m(3)CH(4)/m(3)(system)/d (0.2m(3)CH(4)/kgVS(added)) at organic loading rate of 6.1gVS/L/d through the synergy of sequencing-batch operation, co-digestion, and temperature-phasing. Consequently, the rapid and balanced anaerobic metabolism at thermophilic stage makes TPASBR system to afford high organic loading rate showing superior performance on OFMSW stabilization. PMID:21600764

  13. Biodegradation of Hexahydro-1,3,5-Trinitro-1,3,5-Triazine and Its Mononitroso Derivative Hexahydro-1-Nitroso-3,5-Dinitro-1,3,5-Triazine by Klebsiella pneumoniae Strain SCZ-1 Isolated from an Anaerobic Sludge

    OpenAIRE

    Zhao, Jian-Shen; Halasz, Annamaria; Paquet, Louise; Beaulieu, Chantale; Hawari, Jalal

    2002-01-01

    In previous work, we found that an anaerobic sludge efficiently degraded hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), but the role of isolates in the degradation process was unknown. Recently, we isolated a facultatively anaerobic bacterium, identified as Klebsiella pneumoniae strain SCZ-1, using MIDI and the 16S rRNA method from this sludge and employed it to degrade RDX. Strain SCZ-1 degraded RDX to formaldehyde (HCHO), methanol (CH3OH) (12% of total C), carbon dioxide (CO2) (72% of total...

  14. Inhibitory effect of high NH4+–N concentration on anaerobic biotreatment of fresh leachate from a municipal solid waste incineration plant

    International Nuclear Information System (INIS)

    Highlights: • High NH4+–N concentrations inhibit anaerobic treatment of leachate. • Inhibitory effect of NH4+–N concentrations on anaerobic granular sludge is reversible. • High NH4+–N concentrations inhibit bioactivities of microorganisms instead of survival. - Abstract: 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 1000 mg/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 1000 mg/L, without any rebounding during 30 days of operation. Decreasing NH4+–N concentration to 500 mg/L in influent, the COD removal efficiency recovered to about 85% after 26 days. 1000 mg/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

  15. Kinetic of carbonaceous substrate in an upflow anaerobic sludge sludge blanket (UASB) reactor treating 2,4 dichlorophenol (2,4 DCP).

    Science.gov (United States)

    Sponza, Delia Teresa; Uluköy, Ayşen

    2008-01-01

    The performance of an upflow anaerobic sludge blanket (UASB) reactor treating 2,4 dichlorophenol (2,4 DCP) was evaluated at different hydraulic retention times (HRTs) using synthetic wastewater in order to obtain the growth substrate (glucose-COD) and 2,4 DCP removal kinetics. Treatment efficiencies of the UASB reactor were investigated at different hydraulic retention times (2-20 h) corresponding to a food to mass (F/M) ratio of 1.2-1.92 g-COD g(-1) VSS day(-1). A total of 65-83% COD removal efficiencies were obtained at HRTs of 2-20 h. In all, 83% and 99% 2,4 DCP removals were achieved at the same HRTs in the UASB reactor. Conventional Monod, Grau Second-order and Modified Stover-Kincannon models were applied to determine the substrate removal kinetics of the UASB reactor. The experimental data obtained from the kinetic models showed that the Monod kinetic model is more appropriate for correlating the substrate removals compared to the other models for the UASB reactor. The maximum specific substrate utilization rate (k) (mg-COD mg(-1) SS day(-1)), half-velocity concentration (K(s)) (mg COD l(-1)), growth yield coefficient (Y) (mg mg(-1)) and bacterial decay coefficient (b) (day(-1)) were 0.954 mg-COD mg(-1) SS day(-1), 560.29 mg-COD l(-1), 0.78 mg-SS g(-1)-COD, 0.093 day(-1) in the Conventional Monod kinetic model. The second-order kinetic coefficient (k(2)) was calculated as 0.26 day(-1) in the Grau reaction kinetic model. The maximum COD removal rate constant (U(max)) and saturation value (K(B)) were calculated as 7.502 mg CODl(-1)day(-1) and 34.56 mg l(-1)day(-1) in the Modified Stover-Kincannon Model. The (k)(mg-2,4 DCP mg(-1) SS day(-1)), (K(s)) (mg 2,4 DCPl(-1)), (Y) (mg SS mg(-1) 2,4 DCP) and (k(d)) (day(-1)) were 0.0041 mg-2,4 DCP mg(-1) SS day(-1), 2.06 mg-COD l(-1), 0.0017 mg-SS mg(-1) 2,4 DCP and 3.1 x 10(-5) day(-1) in the Conventional Monod kinetic model for 2,4 DCP degradation. The second-order kinetic coefficient (k(2)) was calculated as 0.30 day

  16. An efficient and green pretreatment to stimulate short-chain fatty acids production from waste activated sludge anaerobic fermentation using free nitrous acid.

    Science.gov (United States)

    Li, Xiaoming; Zhao, Jianwei; Wang, Dongbo; Yang, Qi; Xu, Qiuxiang; Deng, Yongchao; Yang, Weiqiang; Zeng, Guangming

    2016-02-01

    Short-chain fatty acid (SCFA) production from waste activated sludge (WAS) anaerobic fermentation is often limited by the slow hydrolysis rate and poor substrate availability, thus a long fermentation time is required. This paper reports a new pretreatment approach, i.e., using free nitrous acid (FNA) to pretreat sludge, for significantly enhanced SCFA production. Experimental results showed the highest SCFA production occurred at 1.8 mg FNA/L with time of day 6, which was 3.7-fold of the blank at fermentation time of day 12. Mechanism studies revealed that FNA pretreatment accelerated disruption of both extracellular polymeric substances and cell envelope. It was also found that FNA pretreatment benefited hydrolysis and acidification processes but inhibited the activities of methanogens, thereby promoting the yield of SCFA. In addition, the FNA pretreatment substantially stimulated the activities of key enzymes responsible for hydrolysis and acidification, which were consistent with the improvement of solubilization, hydrolysis and acidification of WAS anaerobic fermentation. PMID:26363316

  17. Aerobic/anoxic post-treatment of anaerobically digested sewage sludge as an alternative to biological nitrogen removal from reject water.

    Science.gov (United States)

    Morras, Mikel; Dosta, J; García-Heras, J L

    2015-05-01

    Stabilisation and biological nitrogen removal (BNR) of anaerobically digested sewage sludge were studied in a post-aeration reactor at pilot scale working under alternating anoxic-aerobic conditions. Digested sludge came from a two-stage anaerobic digestion (thermophilic + mesophilic). The best post-aerator performance was achieved when working at an HRT of 10 days (4 days aerobic; dissolved oxygen of 1.8 mg L(-1)) and VS content in the feed no lower than 6.7 g L(-1). Free ammonia concentration values in the effluent above 1.5 mg N L(-1) (around 150 mg NH4 (+)-N L(-1) at pH 7) were necessary to promote the BNR over nitrite. Removal efficiencies up to 80 % NH4 (+)-N, 50-55 % total nitrogen and 15-20 % VS were recorded in this study, with no external addition of chemicals. A nitrogen mass balance revealed that the high percent of NH4 (+)-N assimilated in heterotrophic growth was counteracted with that released in ammonification and fermentation, leading to a NH4 (+)-N removal mainly related to biological nitritation/denitritation. PMID:25407727

  18. Distribution and microbial community structure analysis of a single-stage partial nitritation/anammox granular sludge bioreactor operating at low temperature.

    Science.gov (United States)

    Rodriguez-Sanchez, Alejandro; Purswani, Jessica; Lotti, Tommaso; Maza-Marquez, Paula; van Loosdrecht, M C M; Vahala, Riku; Gonzalez-Martinez, Alejandro

    2016-09-01

    In the last decade, autotrophic nitrogen removal technologies based on anammox metabolism have become state of the art in urban and industrial wastewater treatment systems, due to their advantages over traditional nitrogen removal processes. However, their application is currently limited to the treatment of warm wastewater (25-40°C) mainly due to the low growth rate of the anammox bacteria. The extension of the application field to wastewater characterized by lower temperatures (8-20°C), such as those typical for municipal sewage, allows the design of treatment systems with a net energy production. In this study, the distribution and bacterial community structure of a lab-scale single-stage partial nitritation/anammox (PN/A) granular sludge bioreactor operating at low temperatures was analysed using next-generation sequencing techniques. The presence of ammonium-oxidizing bacteria and anammox bacteria was found, but the appearance of other bacterial species shows a complex microbial ecosystem. Evaluation of ecological roles of representative species inside the single-stage PN/A bioreactor was accomplished. Results obtained will be helpful for the future design and operation of PN/A systems performing at low temperatures. PMID:26829222

  19. Anaerobic digestion of sewage sludge: French inventory and state of the art; La methanisation des boues d'epuration urbaines. Etat des lieux en France et etat de l'art

    Energy Technology Data Exchange (ETDEWEB)

    Reverdy, A.L.; Dieude-Fauvel, E.; Baudez, J.C. [Institut national de recherche en sciences et technologies pour l' environnement et l' agriculture - Irstea, Centre de Clermont-Ferrand, Unite de recherches TSCF, Les Palaquins, 03150 Montoldre (France); Ferstler, V. [MEEDDM - DEB, Grande Arche, Paroi Sud, 92055 La Defense Cedex (France)

    2012-07-01

    Following the Kyoto Protocol and the 'Grenelle de l'environnement', France committed itself to develop renewable energies. Methanization is a process which falls within this objective. Anaerobic digestion of organic material generates biogas made of methane (CH{sub 4}), carbon dioxide (CO{sub 2}) and water (H{sub 2}O). In 2009, electricity generation from biogas represented only 0, 93% of the renewable electricity production in France. An inventory of facilities and a state of the art of the methanization of sewage sludge on wastewater treatment plants with the inhabitant equivalent of more than 30.000 were realized. They were done with bibliography and surveys. In France, 68 installations of sewage sludge methanization were counted. The primary technology used is a mix reactor in which sewage sludge, heated at deg. C 37, are introduced. Biogas is mainly valued to warm those sludges. Electrical valorization is poor, especially on old installations. Anaerobic digestion of sewage sludge is generally accepted by managers, mainly because of its capacity to reduce sewage sludge quantity and odors. Methanization as listed in France is quite basic. It is performed with digestion series modification, with pretreatments or with co-digestion. Given the quantity of sewage sludge which could be digested, France could increase renewable energies via biogas. However this technology is perfectible in many units because biogas is burned in flares. (authors)

  20. Treatment of complex industrial wastewaters containing ammonium and phenolic compounds using granular sludge in continuous airlift reactors

    OpenAIRE

    Jemaat, Zulkifly Bin

    2013-01-01

    Esta tesis doctoral versa sobre la eliminación simultánea de compuestos fenólicos con reactores de biomasa granular trabajando en continuo. El estudio está dividido en dos partes principales; el primer tema trata sobre la modelización de la nitritación, mientras que el otro está dedicado al trabajo experimental sobre la nitritación y eliminación simultánea de compuestos fenólicos. En el estudio de modelización, se desarrolló un modelo matemático de biopelícula para describir la nitritación...

  1. Treatment of natural rubber processing wastewater using a combination system of a two-stage up-flow anaerobic sludge blanket and down-flow hanging sponge system.

    Science.gov (United States)

    Tanikawa, D; Syutsubo, K; Hatamoto, M; Fukuda, M; Takahashi, M; Choeisai, P K; Yamaguchi, T

    2016-01-01

    A pilot-scale experiment of natural rubber processing wastewater treatment was conducted using a combination system consisting of a two-stage up-flow anaerobic sludge blanket (UASB) and a down-flow hanging sponge (DHS) reactor for more than 10 months. The system achieved a chemical oxygen demand (COD) removal efficiency of 95.7% ± 1.3% at an organic loading rate of 0.8 kgCOD/(m(3).d). Bacterial activity measurement of retained sludge from the UASB showed that sulfate-reducing bacteria (SRB), especially hydrogen-utilizing SRB, possessed high activity compared with methane-producing bacteria (MPB). Conversely, the acetate-utilizing activity of MPB was superior to SRB in the second stage of the reactor. The two-stage UASB-DHS system can reduce power consumption by 95% and excess sludge by 98%. In addition, it is possible to prevent emissions of greenhouse gases (GHG), such as methane, using this system. Furthermore, recovered methane from the two-stage UASB can completely cover the electricity needs for the operation of the two-stage UASB-DHS system, accounting for approximately 15% of the electricity used in the natural rubber manufacturing process. PMID:27120630

  2. Anaerobic co-digestion of wine/fruit-juice production waste with landfill leachate diluted municipal sludge cake under semi-continuous flow operation.

    Science.gov (United States)

    Leiva, M Barrantes; Koupaie, E Hosseini; Eskicioglu, C

    2014-10-01

    Anaerobic co-digestion of four organic waste streams; a thickened waste activated sludge (TWAS) and screen cake (SC) from a fruit-juice/winery wastewater treatment plant along with municipal sludge cake (MC) and landfill leachate (LL) was evaluated. A total of eight semi-continuously-fed single and co-digesters were operated side-by-side at sludge retention times (SRT) of 20 and 10 days. Co-digestion of industrial waste streams (TWAS and SC) with MC and LL resulted in increased operational stability compared to the single digestion of industrial TWAS at the higher organic loading (10 d SRT). Although digester operational temperature had no statistically significant effect on organics removal and biogas production, mesophilic digesters had consistently higher total coliform densities (8838-37,959 most probable number or MPN/g-dry weight) compared to the thermophilic digesters (41-6723 MPN/g-dry weight) at both SRTs. Coliform analysis results also proved that most of the thermophilic digestates could be classified as Class A biosolids according to regulations. Furthermore, addition of industrial TWAS to co-digesters enhanced the dewaterability of the digested streams. A cost-benefit analysis confirmed the benefits and indicated that a full-scale co-digester utilizing all four waste streams can decrease the total capital and operational cost by 22% ($10.52 million). PMID:25081853

  3. Activated sludge mass reduction and biodegradability of the endogenous residues by digestion under different aerobic to anaerobic conditions: Comparison and modeling.

    Science.gov (United States)

    Martínez-García, C G; Fall, C; Olguín, M T

    2016-03-01

    This study was performed to identify suitable conditions for the in-situ reduction of excess sludge production by intercalated digesters in recycle-activated sludge (RAS) flow. The objective was to compare and model biological sludge mass reduction and the biodegradation of endogenous residues (XP) by digestion under hypoxic, aerobic, anaerobic, and five intermittent-aeration conditions. A mathematical model based on the heterotrophic endogenous decay constant (bH) and including the biodegradation of XP was used to fit the long-term data from the digesters to identify and estimate the parameters. Both the bH constant (0.02-0.05 d(-1)) and the endogenous residue biodegradation constant (bP, 0.001-0.004 d(-1)) were determined across the different mediums. The digesters with intermittent aeration cycles of 12 h-12 h and 5 min-3 h (ON/OFF) were the fastest, compared to the aerobic reactor. The study provides a basis for rating RAS-digester volumes to avoid the accumulation of XP in aeration tanks. PMID:26720137

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

    Directory of Open Access Journals (Sweden)

    S. A. Habeeb, AB. Aziz Abdul Latiff, Zawawi Daud, Zulkifli Ahmad

    2011-07-01

    Full Text Available 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Pilot-scale anaerobic co-digestion of municipal biomass waste and waste activated sludge in China: Effect of organic loading rate

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xiao, E-mail: liuxiao07@mails.tsinghua.edu.cn [School of Environment, Tsinghua University, Beijing 100084 (China); Wang Wei; Shi Yunchun; Zheng Lei [School of Environment, Tsinghua University, Beijing 100084 (China); Gao Xingbao [Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Qiao Wei [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249 (China); Zhou Yingjun [Department of Urban and Environmental Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nisikyo-ku, Kyoto 615-8540 (Japan)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Co-digestion of municipal biomass waste (MBW) and waste activated sludge (WAS) was examined on a pilot-scale reactor. Black-Right-Pointing-Pointer System performance and stability under OLR of 1.2, 2.4, 3.6, 4.8, 6.0 and 8.0 kg VS (m{sup 3} d){sup -1} were analyzed. Black-Right-Pointing-Pointer A maximum methane production rate of 2.94 m{sup 3} (m{sup 3} d){sup -1} was achieved at OLR of 8.0 kg VS (m{sup 3} d){sup -1} and HRT of 15d. Black-Right-Pointing-Pointer With the increasing OLRs, pH values, VS removal rate and methane concentration decreased and VFA increased. Black-Right-Pointing-Pointer The changing of biogas production rate can be a practical approach to monitor and control anaerobic digestion system. - Abstract: The effects of organic loading rate on the performance and stability of anaerobic co-digestion of municipal biomass waste (MBW) and waste activated sludge (WAS) were investigated on a pilot-scale reactor. The results showed that stable operation was achieved with organic loading rates (OLR) of 1.2-8.0 kg volatile solid (VS) (m{sup 3} d){sup -1}, with VS reduction rates of 61.7-69.9%, and volumetric biogas production of 0.89-5.28 m{sup 3} (m{sup 3} d){sup -1}. A maximum methane production rate of 2.94 m{sup 3} (m{sup 3} d){sup -1} was achieved at OLR of 8.0 kg VS (m{sup 3} d){sup -1} and hydraulic retention time of 15 days. With increasing OLRs, the anaerobic reactor showed a decrease in VS removal rate, average pH value and methane concentration, and a increase of volatile fatty acid concentration. By monitoring the biogas production rate (BPR), the anaerobic digestion system has a higher acidification risk under an OLR of 8.0 kg VS (m{sup 3} d){sup -1}. This result remarks the possibility of relating bioreactor performance with BPR in order to better understand and monitor anaerobic digestion process.

  7. Pilot-scale anaerobic co-digestion of municipal biomass waste and waste activated sludge in China: Effect of organic loading rate

    International Nuclear Information System (INIS)

    Highlights: ► Co-digestion of municipal biomass waste (MBW) and waste activated sludge (WAS) was examined on a pilot-scale reactor. ► System performance and stability under OLR of 1.2, 2.4, 3.6, 4.8, 6.0 and 8.0 kg VS (m3 d)−1 were analyzed. ► A maximum methane production rate of 2.94 m3 (m3 d)−1 was achieved at OLR of 8.0 kg VS (m3 d)−1 and HRT of 15d. ► With the increasing OLRs, pH values, VS removal rate and methane concentration decreased and VFA increased. ► The changing of biogas production rate can be a practical approach to monitor and control anaerobic digestion system. - Abstract: The effects of organic loading rate on the performance and stability of anaerobic co-digestion of municipal biomass waste (MBW) and waste activated sludge (WAS) were investigated on a pilot-scale reactor. The results showed that stable operation was achieved with organic loading rates (OLR) of 1.2–8.0 kg volatile solid (VS) (m3 d)−1, with VS reduction rates of 61.7–69.9%, and volumetric biogas production of 0.89–5.28 m3 (m3 d)−1. A maximum methane production rate of 2.94 m3 (m3 d)−1 was achieved at OLR of 8.0 kg VS (m3 d)−1 and hydraulic retention time of 15 days. With increasing OLRs, the anaerobic reactor showed a decrease in VS removal rate, average pH value and methane concentration, and a increase of volatile fatty acid concentration. By monitoring the biogas production rate (BPR), the anaerobic digestion system has a higher acidification risk under an OLR of 8.0 kg VS (m3 d)−1. This result remarks the possibility of relating bioreactor performance with BPR in order to better understand and monitor anaerobic digestion process.

  8. Development and application of an enzymatic and cell flotation treatment for the recovery of viable microbial cells from environmental matrices such as anaerobic sludge.

    Science.gov (United States)

    Braun, Florence; Hamelin, Jérôme; Gévaudan, Gaëlle; Patureau, Dominique

    2011-12-01

    Efficient dissociation of microorganisms from their aggregate matrix is required to study the microorganisms without interaction with their native environment (e.g., biofilms, flocs, granules, etc.) and to assess their community composition through the application of molecular or microscopy techniques. To this end, we combined enzymatic treatments and a cell extraction by density gradient to efficiently recover anaerobic microorganisms from urban wastewater treatment plant sludge. The enzymes employed (amylase, cellulase, DNase, and pectinase) as a pretreatment softly disintegrated the extrapolymeric substances (EPS) interlocked with the microorganisms. The potential damaging effects of the applied procedure on bacterial and archaeal communities were assessed by studying the variations in density (using quantitative PCR), diversity (using capillary electrophoresis single-strand conformation polymorphism fingerprinting [CE-SSCP]), and activity (using a standard anaerobic activity test) of the extracted microorganisms. The protocol preserved the general capacity of the microbial community to produce methane under anaerobic conditions and its diversity; particularly the archaeal community was not affected in terms of either density or structure. This cell extraction procedure from the matrix materials offers interesting perspectives for metabolic, microscopic, and molecular assays of microbial communities present in complex matrices constituted by bioaggregates or biofilms. PMID:22003005

  9. Effect of the temperature and of the organic load in two-stage up flow anaerobic sludge blanket reactors treating of swine wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Bichuette, Alexandre Abud; Duda, Rose Maria; Oliveira, Roberto Alves de [Universidade Estadual Paulista (UNESP), Jaboticabal, SP (Brazil). Dept. de Engenharia Rural], E-mail: oliveira@fcav.unesp.br

    2008-07-01

    In this work the acting of two-stage up flow anaerobic sludge blanket reactors (UASB) was evaluated, installed in series, in pilot scale (volumes of 908 L and 350 L, respectively) in the treatment swine wastewater, with concentrations of total solids suspended (TSS) around 10000 mg L{sup -1}. The organic loading rates (OLR) applied in first UASB were of 5,2 and of 8,6 g total COD (Ld){sup -1}. The medium efficiencies of removal of the chemical demand of total oxygen (total COD), TSS and TKN were higher than 89; 80 and 55%, respectively, for the system of anaerobic treatment composed by the reactors UASB in two apprenticeships. The rate of volumetric methane production in the system of anaerobic treatment with the reactors UASB were 0,08 and 0,16 m{sup 3}CH{sub 4} (m{sup 3} CH{sub 4} reactor d){sup -1}. The number of total coliforms was reduced to 2,6x10{sup 4} NMP/100 mL. (author)

  10. Bioelectrochemical enhancement of anaerobic methanogenesis for high organic load rate wastewater treatment in a up-flow anaerobic sludge blanket (UASB) reactor

    OpenAIRE

    Zhiqiang Zhao; Yaobin Zhang; Shuo Chen; Xie Quan; Qilin Yu

    2014-01-01

    A coupling process of anaerobic methanogenesis and electromethanogenesis was proposed to treat high organic load rate (OLR) wastewater. During the start-up stage, acetate removal efficiency of the electric-biological reactor (R1) reached the maximization about 19 percentage points higher than that of the control anaerobic reactor without electrodes (R2), and CH4 production rate of R1 also increased about 24.9% at the same time, while additional electric input was 1/1.17 of the extra obtained ...

  11. Enhancing Volatile Fatty Acid by anaerobic digestion using municipal sludge combined with multiple organics%污泥联合不同有机质对厌氧发酵产酸的影响

    Institute of Scientific and Technical Information of China (English)

    李骥延

    2016-01-01

    This paper studied the process of three main organic components(carbohydrates,proteins,lipids)anaerobic digestion with municipal sludge to inhancing Volatile Fatty Acid(VFA)product. According to the text,VFA achieves maximum production when anaerobic digestion com-bined with protein,the maximum yield reaches 14. 52 g/ L and 43. 47% productivity,increasing 218% and 59% respectively compared to sludge solo anaerobic digestion. Sludge combined with lipid produce only 39% yield of VFA compared to sludge solo anaerobic digestion.%研究了城市有机垃圾的三种主要成分(碳水化合物,蛋白质,脂质)与市政污泥联合厌氧发酵产酸的过程,试验结果表明,蛋白类有机质能大幅提高厌氧发酵效率,其后期产酸量达到14.52 g/ L,挥发酸产率43.47%,分别比污泥单独厌氧发酵提高218%和59%;污泥联合脂质厌氧发酵产酸量最低,仅为单独厌氧发酵产酸量的39%。

  12. 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

    Directory of Open Access Journals (Sweden)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Reactivation performance of nitrosation granular sludge after long-term storage and microbial community variation%长期储存亚硝化颗粒污泥的活化及菌群结构变化

    Institute of Scientific and Technical Information of China (English)

    钱飞跃; 王琰; 王建芳; 王书永; 沈耀良

    2016-01-01

    采用无机人工配水,通过逐级提高进水氨氮负荷(0.32~0.64kg/(m3?d))和设定合适的初始游离氨浓度(3.7~7.2mg/L),在SBR反应器中对常温(24~29℃)下储存1a的亚硝化颗粒污泥(NGS)进行了活化,并使用Miseq高通量测序技术分析了污泥中微生物多样性的变化情况.结果表明,NGS的亚硝化性能可在短时间内恢复.运行8d后,反应器的氨氮去除率达到95%以上,亚硝态氮累积率超过了80%,但污泥粒径持续减小,胞外聚合物(EPS)含量明显降低.活化至第20d,NGS的氨氮比去除速率和亚硝态氮比累积速率分别达到24.6mg/(gVSS?h)、23.8mg/(gVSS?h),平均粒径稳定在0.5mm左右.在活化期间,绝大部分厌氧、异养菌属被洗脱,污泥的微生物多样性显著降低.Nitrosomonas等氨氧化菌的相对丰度由活化前的1%上升至约58%,同时,Nitrospira等硝化菌的生长受到了选择性抑制.这意味着即使经历长期的常温储存,NGS仍可作为SBR的接种污泥,实现反应器的快速启动.%The reactivation performance of nitrosation granular sludge (NGS), which had been stored at 24~29℃ for a long-term of 1a, was investigated in a sequencing batch reactor (SBR) fed with inorganic synthetic wastewater, via the gradually increasing of the influent ammonia nitrogen loading from 0.32 to 0.64kg/(m3·d) and initial concentration of free ammonia from 3.7 to 7.2mg/L. High throughput sequencing technology of Miseq was also employed to analyze the variation of microbial community before and after the reactivation. Results showed that the stored NGS could be reactivated in a short period of 8days, since the removal effciency of ammonia nitrogen and the accumulation ratio of nitrite nitrogen were higher than 95% and 80%, respectively. Meanwhile, both sludge particle size and extracellular polymer substances (EPS) contents decreased significantly. After 20days reactivation, the specific ammonia nitrogen removal rate of 24.6mg/(gVSS·h) and the

  15. Biological hydrolysis and acidification of sludge under anaerobic conditions: The effect of sludge type and origin on the production and composition of olatile fatty acids

    DEFF Research Database (Denmark)

    Ucisik, Ahmed Süheyl; Henze, Mogens

    2008-01-01

    .1–12.6% COD-yields, soluble COD (SCOD)/total COD (TCOD), in batch experiments, respectively. The COD-yields for primary, activated and mixed sludge were 19.1%, 6.5% and 21.37%, respectively, in semi-continuous experiments operated at solids retention time (SRT) of 5 d and temperature of 37 °C. The benefit of...

  16. A novel application of red mud-iron on granulation and treatment of palm oil mill effluent using upflow anaerobic sludge blanket reactor.

    Science.gov (United States)

    Ahmad, Anwar

    2014-01-01

    The performance of the upflow anaerobic sludge blanket reactor that used red mud-iron (RM-Fe) for methane production for the treatment of palm oil mill effluent (POME) at various hydraulic retention time (HRT) was determined. POME was used as the substrate carbon source. The biogas production rate was 1.7 l biogas/h with a methane yield of 0.78 l CH4/g CODremoved and chemical oxygen demand (COD) removal was 85% at POME concentration of 30 g COD/l at HRT 16 h. The reactor R2 showed average methane content of biogas and COD reduction of 78% and 85% at 400 mg/l RM-Fe. Significant increase in the granule diameter (up to 2900 μm) in R2 was compared to control R1 (up to 86 μm) at end of the experiment. PMID:25176306

  17. Reactor performance and microbial community dynamics during anaerobic co-digestion of municipal wastewater sludge with restaurant grease waste at steady state and overloading stages.

    Science.gov (United States)

    Razaviarani, Vahid; Buchanan, Ian D

    2014-11-01

    Linkage between reactor performance and microbial community dynamics was investigated during mesophilic anaerobic co-digestion of restaurant grease waste (GTW) with municipal wastewater sludge (MWS) using 10L completely mixed reactors and a 20day SRT. Test reactors received a mixture of GTW and MWS while control reactors received only MWS. Addition of GTW to the test reactors enhanced the biogas production and methane yield by up to 65% and 120%, respectively. Pyrosequencing revealed that Methanosaeta and Methanomicrobium were the dominant acetoclastic and hydrogenotrophic methanogen genera, respectively, during stable reactor operation. The number of Methanosarcina and Methanomicrobium sequences increased and that of Methanosaeta declined when the proportion of GTW in the feed was increased to cause an overload condition. Under this overload condition, the pH, alkalinity and methane production decreased and VFA concentrations increased dramatically. Candidatus cloacamonas, affiliated within phylum Spirochaetes, were the dominant bacterial genus at all reactor loadings. PMID:25265327

  18. Combination of upflow anaerobic sludge blanket (UASB) reactor and partial nitritation/anammox moving bed biofilm reactor (MBBR) for municipal wastewater treatment.

    Science.gov (United States)

    Malovanyy, Andriy; Yang, Jingjing; Trela, Jozef; Plaza, Elzbieta

    2015-03-01

    In this study the combination of an upflow anaerobic sludge blanket (UASB) reactor and a deammonification moving bed biofilm reactor (MBBR) for mainstream wastewater treatment was tested. The competition between aerobic ammonium oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) was studied during a 5months period of transition from reject water to mainstream wastewater followed by a 16months period of mainstream wastewater treatment. The decrease of influent ammonium concentration led to a wash-out of suspended biomass which had a major contribution to nitrite production. Influence of a dissolved oxygen concentration and a transient anoxia mechanism of NOB suppression were studied. It was shown that anoxic phase duration has no effect on NOB metabolism recovery and oxygen diffusion rather than affinities of AOB and NOB to oxygen determine the rate of nitrogen conversion in a biofilm system. Anammox activity remained on the level comparable to reject water treatment systems. PMID:25600011

  19. Potential enhancement of direct interspecies electron transfer for syntrophic metabolism of propionate and butyrate with biochar in up-flow anaerobic sludge blanket reactors.

    Science.gov (United States)

    Zhao, Zhiqiang; Zhang, Yaobin; Holmes, Dawn E; Dang, Yan; Woodard, Trevor L; Nevin, Kelly P; Lovley, Derek R

    2016-06-01

    Promoting direct interspecies electron transfer (DIET) to enhance syntrophic metabolism may be a strategy for accelerating the conversion of organic wastes to methane, but microorganisms capable of metabolizing propionate and butyrate via DIET under methanogenic conditions have yet to be identified. In an attempt to establish methanogenic communities metabolizing propionate or butyrate with DIET, enrichments were initiated with up-flow anaerobic sludge blanket (UASB), similar to those that were previously reported to support communities that metabolized ethanol with DIET that relied on direct biological electrical connections. In the absence of any amendments, microbial communities enriched were dominated by microorganisms closely related to pure cultures that are known to metabolize propionate or butyrate to acetate with production of H2. When biochar was added to the reactors there was a substantial enrichment on the biochar surface of 16S rRNA gene sequences closely related to Geobacter and Methanosaeta species known to participate in DIET. PMID:26967338

  20. Acid resistance of methanogenic bacteria in a two-stage anaerobic process treating high concentration methanol Wastewater

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xuefei; REN Nanqi

    2007-01-01

    In this study,the two-stage upflow anaerobic sludge blanket(UASB)system and batch experiments were employed to evaluate the performance of anaerobic digestion for the treatment of high concentration methanol wastewater.The acid resistance of granular sludge and methanogenic bacteria and their metabolizing activity were investigated.The results show that the pH of the first UASB changed from 4.9 to 5.8 and 5.5 to 6.2 for the second reactor.Apparently,these were not the advisable pH levels that common metha nogenic bacteria could accept.The methanogenic bacteria of the system,viz.Methanosarcina barkeri,had some acid resistance and could still degrade methanol at pH 5.0.If the methanogenic bacteria were trained further,their acid resistance would be improved somewhat.Granular sludge of the system could protect the methanogenic bacteria within its body against the impact of the acidic environment and make them degrade methanol at pH 4.5.The performance of granular sludge was attributed to its structure,bacteria species,and the distribution of bacterium inside the granule.