scholarly journals Characteristics of the extracellular products of pure oxygen aerated activated sludge in batch mode

2021 ◽  
Author(s):  
Jia-Ying He ◽  
Hong-Ling Zhang ◽  
Hong Wang ◽  
Ya-Qi Hu ◽  
Yong Zhang
Keyword(s):  
Activated Sludge ◽  
Biological Treatment ◽  
Extracellular Polymeric Substances ◽  
Treatment Process ◽  
Batch Reactor ◽  
Aeration Rate ◽  
Pure Oxygen ◽  
Batch Mode ◽  
Extracellular Products ◽  
Microbial Products

Abstract The effects of pure oxygen aeration on compositional characteristics of soluble microbial products (SMP) and extracellular polymeric substances (EPS) of the activated sludge acclimated in a sequential batch reactor (SBR) were explored in batch mode. The structure of the extracellular products would change with different aeration methods or aeration rates. The proportion of SMP of most oxygen aerated sludge was less than 10%, while that in air aerated sludge was as high as 30%–40%. The proportion of TB-EPS decreased from 56.95% to 30.63%, and the proportion of LB-EPS increased obviously with the increase of oxygen aeration rate. The contents of the protein (PN) and the polysaccharide (PS) of extracellular products with oxygen aeration were significantly different, and the PN was much higher than PS (p < 0.05). The zeta potential of each component in activated sludge was negative, gradually decreasing with the progress of biological treatment. The fluorescence peaks in SMP, LB-EPS and TB-EPS with pure oxygen aeration were attributed to tryptophan PN-like and humic acid-like fractions. The results showed that the proportion of the components in the extracellular products could be regulated by adjusting the aeration rate and aeration mode, so as to optimize the treatment process of activated sludge.

The activated sludge metabolic characteristics changing sole carbon source from readily biodegradable acetate to toxic phenol

2016 ◽  
Vol 73 (10) ◽  
pp. 2324-2331 ◽  
Author(s):  
Changyong Wu ◽  
Yuexi Zhou ◽  
Jiamei Song
Keyword(s):  
Carbon Source ◽  
Activated Sludge ◽  
Extracellular Polymeric Substances ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Carbon Sources ◽  
Oxygen Demand ◽  
Metabolic Characteristics ◽  
Microbial Products ◽  
Intracellular Storage

A sequencing batch reactor was used to investigate the effect of carbon sources on the metabolism of activated sludge. Acetate and phenol, with the chemical oxygen demand (COD) of 330–350 mg L−1, was used as the carbon source in Periods I and II, respectively. Acetate decreased in the initial 120 min with the intracellular storage materials (XSTO), extracellular polymeric substances (EPS), and the soluble microbial products (SMP) accumulating to 131.0 mg L−1, 347.5 mg L−1, and 35.5 mg L−1, respectively. Then, XSTO and EPS decreased to 124.5 mg L−1 and 340.0 mg L−1, respectively, in the following 120 min. When acetate was replaced by phenol, it could not be used at the beginning due to its toxicity. The XSTO decreased from 142 mg L−1 to 54.6 mg L−1 during the aeration period. The EPS had a significant increase, with the highest value of 618.1 mg L−1, which then decreased to 245.6 mg L−1 at 240 min. The phenol was gradually degraded with the acclimation and it can be fully degraded 18 d later. Meanwhile, the usage ratio of the internal carbon source decreased. The effluent SMP in Period II was 1.7 times that in Period I.

Organic degradation and extracellular products of pure oxygen aerated activated sludge under different F/M conditions

2019 ◽  
Vol 279 ◽  
pp. 189-194 ◽  
Author(s):  
Hong-Ling Zhang ◽  
Wei-Li Jiang ◽  
Rong Liu ◽  
Ying Zhou ◽  
Yong Zhang
Keyword(s):  
Activated Sludge ◽  
Pure Oxygen ◽  
Organic Degradation ◽  
Extracellular Products

The Effect of Residual COD on the Biological Treatability of Textile Wastewaters

1992 ◽  
Vol 26 (3-4) ◽  
pp. 815-825 ◽  
Author(s):  
D. Orhon ◽  
N. Artan ◽  
S. Büyükmurat ◽  
E. Görgün
Keyword(s):  
Biological Treatment ◽  
Treatment Process ◽  
Textile Effluents ◽  
Kinetic Information ◽  
A Value ◽  
Effluent Standards ◽  
Microbial Products ◽  
Biological Treatability ◽  
Activated Sludge Systems ◽  
Textile Wastewaters

Textile effluents often contain an array of chemicals with different biodegradation characteristics. Consequently, it is quite difficult to evaluate and interpret the degree of COD removal that can be attained by biological treatment without identifying COD portions that are resistant to biodegradation. This study evaluates the biological treatability of textile wastewaters generated by the knit and wowen fabric finishing category with specific emphasis on the assessment of different residual COD components. A new method is proposed to experimentally measure the initial particulate inert COD. The method is tested to yield a value of 73 mgl-1 for this COD component, corresponding to 16 % of the particulate COD in the textile sample. A previously developed procedure is used to quantify the initial soluble inert COD and the residual COD generated through microbial metabolism during the treatment process. The ratio of the inert fraction to the soluble COD of the textile effluents is found to vary between 0.076 and 0.22. A similar ratio in the range of 0.04 - 0.09 is calculated for the residual microbial products. The kinetic and stoichiometric constants associated with the biodegradable COD are also experimentally measured. The residual components, together with the kinetic information about biodegradable fractions, are used to simulate the performance of activated sludge systems by means of a relationship between the total effluent COD and the sludge age. The results indicate that the residual components practically dominate the effluent COD and seriously challenge related effluent standards.

Molecular Weight Distributions of Soluble Organic Matter in Various Secondary and Tertiary Effluents

1987 ◽  
Vol 19 (3-4) ◽  
pp. 529-538 ◽  
Author(s):  
Gary L. Amy ◽  
Curtis W. Bryant ◽  
Mosen Belyani
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Activated Sludge ◽  
Water Reuse ◽  
Treatment Process ◽  
Apparent Molecular Weight ◽  
Pure Oxygen ◽  
Soluble Organic Matter ◽  
Conventional Activated Sludge ◽  
Absorbing Material

Differences in the nature of soluble organic matter were measured for various full-scale wastewater treatment processes. Conventional activated sludge, pure oxygen activated sludge, biofiltration, granular activated carbon, and tertiary sand filtration were evaluated. Effluent soluble organic matter was analyzed by ultrafiltration for the apparent molecular weight distribution of soluble organic carbon and UV-absorbing material. The effects of annual season, secondary treatment process, and tertiary treatment process upon the properties of the effluent soluble organic matter were statistically significant at the 99% level. Effluent properties from the various treatments were sufficiently different to support the concept of the selection of appropriate treatments to minimize the effluent concentration of specific fractions of the soluble organic material as required for specific water reuse applications.

Effect of continuously dosing Cu(II) on pollutant removal and soluble microbial products in a sequencing batch reactor

2015 ◽  
Vol 72 (9) ◽  
pp. 1653-1661 ◽  
Author(s):  
YangWei Yan ◽  
YuWen Wang ◽  
Yan Liu ◽  
Xiang Liu ◽  
ChenChao Yao ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Extracellular Polymeric Substances ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Pollutant Removal ◽  
Cod Removal ◽  
Synthetic Wastewater ◽  
Soluble Microbial Products ◽  
Cod Removal Efficiency ◽  
Microbial Products

The effects of synthetic wastewater that contained 20 mg/L Cu(II) on the removal of organic pollutants in a sequencing batch reactor were investigated. Results of continuous 20 mg/L Cu(II) exposure for 120 days demonstrated that the chemical oxygen demand (COD) removal efficiency decreased to 42% initially, followed by a subsequent gradual recovery, which peaked at 78% by day 97. Effluent volatile fatty acid (VFA) concentration contributed 67 to 89% of the influent COD in the experimental reactor, which indicated that the degradation of the organic substances ceased at the VFA production step. Meanwhile, the varieties of soluble microbial products (SMP) content and main components (protein, polysaccharide, and DNA) were discussed to reveal the response of activated sludge to the toxicity of 20 mg/L Cu(II). The determination of Cu(II) concentrations in extracellular polymeric substances (EPS) and SMP throughout the experiment indicated an inverse relationship between extracellular Cu(II) concentration and COD removal efficiency.

scholarly journals Assessing the performance of a UV/H2O2 process for removing TOC from petroleum refinery wastewater and the respirometric effects of adding UV/H2O2 treated wastewater to activated sludge from the refinery WWTP biological treatment process

2021 ◽  
Author(s):  
Mark Knight
Keyword(s):  
Activated Sludge ◽  
Biological Treatment ◽  
Treatment Process ◽  
Petroleum Refinery ◽  
Molar Ratio ◽  
Refinery Wastewater ◽  
Bench Scale ◽  
Treatment Performance ◽  
Petroleum Refinery Wastewater ◽  
Biological Treatment Process

The treatment of petroleum refinery wastewater was studied using a bench scale ultraviolet/hydrogen peroxide (UV/H2O2) process. The highest treatment performance of the bench scale UV/H2O2 process to reduce the total organic carbon (TOC) from the petroleum refinery wastewater took place at a reaction time of 45 min and a pH of 5.0. A three factor analysis of va riance (ANOVA) analysis verified that the initial H2O2/TOC molar ratio did not have a significant effect on the bench scale UV/H2O2 process treatment performance. The effects of adding UV/H2O2 treated petroleum refinery wastewater to activated sludge microorganisms form the refinery WWTP biological treatment process was studied using respirometry. Overall, the UV/H2O2 treated refinery wastewater inhibited the refinery activated sludge microorganisms. This occurred when the raw refinery wastewater was treated with a UV/H2O2 process for 45 min. with an initial H2O2/TOC molar ratio of 1.7 mol H2O2/mol C, an initial H2O2 concentration of 202 mg H2O2/L and a pH of either 5 or 7.

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