The Experts below are selected from a list of 7470 Experts worldwide ranked by ideXlab platform
Qin Wang - One of the best experts on this subject based on the ideXlab platform.
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effect of Solids Retention Time and temperature on waste activated sludge hydrolysis and short chain fatty acids accumulation under alkaline conditions in continuous flow reactors
Bioresource Technology, 2009Co-Authors: Leiyu Feng, Hua Wang, Yinguang Chen, Qin WangAbstract:The effects of Solids Retention Time (SRT) and temperature on waste activated sludge (WAS) hydrolysis and short-chain fatty acids (SCFAs) accumulation were investigated in a series of continuous-flow reactors at pH 10. The experimental results showed that the increase of either SRT or temperature benefited the hydrolysis of WAS and the production of SCFAs. The changes in SRT gave also impact on the percentage of acetic and propionic acids in the fermentative SCFAs, but little influence on that of the slightly long-chain SCFAs, such as n-butyric, iso-butyric, n-valeric and iso-valeric acids. Compared with the control (pH unadjusted) experiment, at SRT of 12 d and temperature of 20 °C the concentration of SCFAs produced at pH 10 increased from 261.2 to 933.5 mg COD/L, and the propionic acid percentage improved from 11.7 to 16.0%. It can be concluded from this investigation that the efficient continuous production of SCFAs at pH 10 is feasible.
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Effect of Solids Retention Time and temperature on waste activated sludge hydrolysis and short-chain fatty acids accumulation under alkaline conditions in continuous-flow reactors.
Bioresource technology, 2008Co-Authors: Leiyu Feng, Hua Wang, Yinguang Chen, Qin WangAbstract:The effects of Solids Retention Time (SRT) and temperature on waste activated sludge (WAS) hydrolysis and short-chain fatty acids (SCFAs) accumulation were investigated in a series of continuous-flow reactors at pH 10. The experimental results showed that the increase of either SRT or temperature benefited the hydrolysis of WAS and the production of SCFAs. The changes in SRT gave also impact on the percentage of acetic and propionic acids in the fermentative SCFAs, but little influence on that of the slightly long-chain SCFAs, such as n-butyric, iso-butyric, n-valeric and iso-valeric acids. Compared with the control (pH unadjusted) experiment, at SRT of 12d and temperature of 20 degrees C the concentration of SCFAs produced at pH 10 increased from 261.2 to 933.5mg COD/L, and the propionic acid percentage improved from 11.7 to 16.0%. It can be concluded from this investigation that the efficient continuous production of SCFAs at pH 10 is feasible.
Liang Duan - One of the best experts on this subject based on the ideXlab platform.
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influence of Solids Retention Time on membrane fouling characterization of extracellular polymeric substances and soluble microbial products
Biofouling, 2015Co-Authors: Liang Duan, Zhiyong Tian, Yonghui Song, Wei Jiang, Yuan TianAbstract:The objective of this study was to investigate the influence of Solids Retention Time (SRT) on membrane fouling and the characteristics of biomacromolecules. Four identical laboratory-scale membrane bioreactors (MBRs) were operated with SRTs for 10, 20, 40 and 80 days. The results indicated that membrane fouling occurred faster and more readily under short SRTs. Fouling resistance was the primary source of filtration resistance. The modified fouling index (MFI) results suggested that the more ready fouling at short SRTs could be attributed to higher concentrations of soluble microbial products (SMP). Fourier transform infrared (FTIR) spectra indicated that the SRT had a weak influence on the functional groups of the total extracellular polymeric substances (TEPS) and SMP. However, the MBR under a short SRT had more low-molecular-weight (MW) compounds ( 100 kDa). Aromatic protein and tryptophan protein-like substances were the dominant groups in the TEPS and SMP, respec...
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Influence of Solids Retention Time on membrane fouling: characterization of extracellular polymeric substances and soluble microbial products
Biofouling, 2015Co-Authors: Liang Duan, Zhiyong Tian, Yonghui Song, Wei Jiang, Yuan TianAbstract:The objective of this study was to investigate the influence of Solids Retention Time (SRT) on membrane fouling and the characteristics of biomacromolecules. Four identical laboratory-scale membrane bioreactors (MBRs) were operated with SRTs for 10, 20, 40 and 80 days. The results indicated that membrane fouling occurred faster and more readily under short SRTs. Fouling resistance was the primary source of filtration resistance. The modified fouling index (MFI) results suggested that the more ready fouling at short SRTs could be attributed to higher concentrations of soluble microbial products (SMP). Fourier transform infrared (FTIR) spectra indicated that the SRT had a weak influence on the functional groups of the total extracellular polymeric substances (TEPS) and SMP. However, the MBR under a short SRT had more low-molecular-weight (MW) compounds (100 kDa). Aromatic protein and tryptophan protein-like substances were the dominant groups in the TEPS and SMP, respectively.
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effects of short Solids Retention Time on microbial community in a membrane bioreactor
Bioresource Technology, 2009Co-Authors: Liang Duan, Siqing Xia, Ivan Morenoandrade, Chunlin Huang, Slawomir W HermanowiczAbstract:Effects of operating lab-scale nitrifying membrane bioreactors (MBR) at short Solids Retention Times (SRT = 3, 5 and 10d) were presented with focus on reactor performance and microbial community composition. The process was capable of achieving over 87% removal of ammonia and 95% removal of chemical oxygen demand (COD), almost regardless of SRT. The denaturing gradient gel electrophoresis (DGGE) analysis shown that bacterial communities evolved in Time in a similar way at different SRT. The results of clone library analysis indicated that Betaproteobacteria was the dominant bacterial group in all the reactors but there were significant difference of species for different SRT with higher species diversity at longer SRT. Ammonia and COD removal efficiencies were not correlated with the number of bacterial species or their diversity.
Leiyu Feng - One of the best experts on this subject based on the ideXlab platform.
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effect of Solids Retention Time and temperature on waste activated sludge hydrolysis and short chain fatty acids accumulation under alkaline conditions in continuous flow reactors
Bioresource Technology, 2009Co-Authors: Leiyu Feng, Hua Wang, Yinguang Chen, Qin WangAbstract:The effects of Solids Retention Time (SRT) and temperature on waste activated sludge (WAS) hydrolysis and short-chain fatty acids (SCFAs) accumulation were investigated in a series of continuous-flow reactors at pH 10. The experimental results showed that the increase of either SRT or temperature benefited the hydrolysis of WAS and the production of SCFAs. The changes in SRT gave also impact on the percentage of acetic and propionic acids in the fermentative SCFAs, but little influence on that of the slightly long-chain SCFAs, such as n-butyric, iso-butyric, n-valeric and iso-valeric acids. Compared with the control (pH unadjusted) experiment, at SRT of 12 d and temperature of 20 °C the concentration of SCFAs produced at pH 10 increased from 261.2 to 933.5 mg COD/L, and the propionic acid percentage improved from 11.7 to 16.0%. It can be concluded from this investigation that the efficient continuous production of SCFAs at pH 10 is feasible.
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Effect of Solids Retention Time and temperature on waste activated sludge hydrolysis and short-chain fatty acids accumulation under alkaline conditions in continuous-flow reactors.
Bioresource technology, 2008Co-Authors: Leiyu Feng, Hua Wang, Yinguang Chen, Qin WangAbstract:The effects of Solids Retention Time (SRT) and temperature on waste activated sludge (WAS) hydrolysis and short-chain fatty acids (SCFAs) accumulation were investigated in a series of continuous-flow reactors at pH 10. The experimental results showed that the increase of either SRT or temperature benefited the hydrolysis of WAS and the production of SCFAs. The changes in SRT gave also impact on the percentage of acetic and propionic acids in the fermentative SCFAs, but little influence on that of the slightly long-chain SCFAs, such as n-butyric, iso-butyric, n-valeric and iso-valeric acids. Compared with the control (pH unadjusted) experiment, at SRT of 12d and temperature of 20 degrees C the concentration of SCFAs produced at pH 10 increased from 261.2 to 933.5mg COD/L, and the propionic acid percentage improved from 11.7 to 16.0%. It can be concluded from this investigation that the efficient continuous production of SCFAs at pH 10 is feasible.
Bruce E. Rittmann - One of the best experts on this subject based on the ideXlab platform.
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effects of Solids Retention Time on methanogenesis in anaerobic digestion of thickened mixed sludge
Bioresource Technology, 2011Co-Authors: Il-su Lee, Prathap Parameswaran, Bruce E. RittmannAbstract:When a bench-scale digester fed thickened mixed sludge was operated over an SRT range of 4–20 days, removal efficiencies for total chemical oxygen demand and volatile suspended Solids declined with decreasing SRT (especially <10 days), but methanogenesis was stable for SRT as low as 5 days. Quantitative PCR analyses showed that methanogens declined steadily for SRT <10 days, with the acetate-cleaving Methanosaetaceae becoming more dominant. Clone-library analyses indicated significant shifts in bacterial population from 20 to 4 day SRT: declining Chloroflexi (28 to 4.5%) and Syntrophomonas (9 to 0%), but increasing Bacteroidetes (12.5 to 20%) and two acetogenic genera belonging to the phyla Firmicutes and Spirochaetales (6.3 to 12%). Thus, the decrease in the apparent hydrolysis constant (khyd-app) with higher SRT and the process limiting size of Methanosaetaceae with the lower SRT are proactive signs for defining rate limitation in anaerobic digestion.
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Effects of Solids Retention Time on methanogenesis in anaerobic digestion of thickened mixed sludge.
Bioresource technology, 2011Co-Authors: Il-su Lee, Prathap Parameswaran, Bruce E. RittmannAbstract:When a bench-scale digester fed thickened mixed sludge was operated over an SRT range of 4-20 days, removal efficiencies for total chemical oxygen demand and volatile suspended Solids declined with decreasing SRT (especially
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Effect of low Solids Retention Time and focused pulsed pre-treatment on anaerobic digestion of waste activated sludge
Bioresource technology, 2010Co-Authors: Il-su Lee, Bruce E. RittmannAbstract:The interacting effects of Focused Pulsed (FP) treatment and Solids Retention Time (SRT) were evaluated in laboratory-scale digesters operated at SRTs of 2-20 days. Anaerobic digestion and methanogenesis of waste activated sludge (WAS) were stable for SRT ≥ 5 days, but the effluent soluble organic compounds increased significantly for SRT=2 days due to a combination of faster hydrolysis kinetics and washout of methanogens. FP treatment increased the CH(4) production rate and TCOD removal efficiency by up to 33% and 18%, respectively, at a SRT of 20 days. These effects were the result of an increase in the hydrolysis rate, since the concentrations of soluble components remained low for SRT ≥ 5 days. Alternately, FP pre-treatment of WAS allowed the same conversion of TCOD to CH(4) with a smaller SRT and digester size: e.g., 40% size savings with a CH(4) conversion of 0.23 g CH(4)-COD/g COD(in).
Yuan Tian - One of the best experts on this subject based on the ideXlab platform.
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influence of Solids Retention Time on membrane fouling characterization of extracellular polymeric substances and soluble microbial products
Biofouling, 2015Co-Authors: Liang Duan, Zhiyong Tian, Yonghui Song, Wei Jiang, Yuan TianAbstract:The objective of this study was to investigate the influence of Solids Retention Time (SRT) on membrane fouling and the characteristics of biomacromolecules. Four identical laboratory-scale membrane bioreactors (MBRs) were operated with SRTs for 10, 20, 40 and 80 days. The results indicated that membrane fouling occurred faster and more readily under short SRTs. Fouling resistance was the primary source of filtration resistance. The modified fouling index (MFI) results suggested that the more ready fouling at short SRTs could be attributed to higher concentrations of soluble microbial products (SMP). Fourier transform infrared (FTIR) spectra indicated that the SRT had a weak influence on the functional groups of the total extracellular polymeric substances (TEPS) and SMP. However, the MBR under a short SRT had more low-molecular-weight (MW) compounds ( 100 kDa). Aromatic protein and tryptophan protein-like substances were the dominant groups in the TEPS and SMP, respec...
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Influence of Solids Retention Time on membrane fouling: characterization of extracellular polymeric substances and soluble microbial products
Biofouling, 2015Co-Authors: Liang Duan, Zhiyong Tian, Yonghui Song, Wei Jiang, Yuan TianAbstract:The objective of this study was to investigate the influence of Solids Retention Time (SRT) on membrane fouling and the characteristics of biomacromolecules. Four identical laboratory-scale membrane bioreactors (MBRs) were operated with SRTs for 10, 20, 40 and 80 days. The results indicated that membrane fouling occurred faster and more readily under short SRTs. Fouling resistance was the primary source of filtration resistance. The modified fouling index (MFI) results suggested that the more ready fouling at short SRTs could be attributed to higher concentrations of soluble microbial products (SMP). Fourier transform infrared (FTIR) spectra indicated that the SRT had a weak influence on the functional groups of the total extracellular polymeric substances (TEPS) and SMP. However, the MBR under a short SRT had more low-molecular-weight (MW) compounds (100 kDa). Aromatic protein and tryptophan protein-like substances were the dominant groups in the TEPS and SMP, respectively.
