Chromatographic characterization of dissolved organics in effluents from two anaerobic reactors treating synthetic wastewater

2006 ◽  
Vol 54 (2) ◽  
pp. 193-198 ◽  
Author(s):  
S.F. Aquino ◽  
D.C. Stuckey
Keyword(s):  
Steady State ◽  
Membrane Reactor ◽  
Synthetic Wastewater ◽  
Soluble Microbial Products ◽  
Extracellular Polymers ◽  
Anaerobic Reactors ◽  
Dissolved Organics ◽  
Chromatographic Characterization ◽  
Microbial Products

This paper presents results on the quantification and chromatographic characterization of soluble microbial products (SMP) accumulated in two laboratory-scale reactors: a submerged anaerobic membrane reactor (SAMBR or MBR), and an anaerobic CSTR. The results obtained under steady-state conditions show that 2.1% of the substrate was channelled into the production of SMP in the CSTR, whilst in the SAMBR this was estimated to be 25%. Chromatographic characterization showed that more hydrophobic and high MW organics that absorb at 254 nm were detected in the SAMBR supernatant than in the CSTR. A comparison of chromatograms suggest that the release of extracellular polymers (ECP) and cell lysis may be important sources of SMP in the SAMBR. Electrophoresis results confirmed that there was more soluble protein inside the SAMBR, and showed that the release of ECP by shear or hydrolysis seemed to have contributed to the production of protein-like SMP in both systems.

Characterization of soluble microbial products (SMPs) in a membrane bioreactor (MBR) treating synthetic wastewater containing pharmaceutical compounds

2016 ◽  
Vol 102 ◽  
pp. 594-606 ◽  
Author(s):  
Dongqing Zhang ◽  
Antoine Prandota Trzcinski ◽  
Chinagarn Kunacheva ◽  
David C. Stuckey ◽  
Yu Liu ◽  
...  
Keyword(s):  
Membrane Bioreactor ◽  
Pharmaceutical Compounds ◽  
Synthetic Wastewater ◽  
Soluble Microbial Products ◽  
Microbial Products

Characterization of soluble microbial products (SMP) in effluents from anaerobic reactors

2002 ◽  
Vol 45 (10) ◽  
pp. 127-132 ◽  
Author(s):  
S.F. Aquino ◽  
D.C. Stuckey
Keyword(s):  
Molecular Weight ◽  
Aromatic Compounds ◽  
Anaerobic Treatment ◽  
Soluble Microbial Products ◽  
Preliminary Results ◽  
Anaerobic Reactors ◽  
Treatment Processes ◽  
Microbial Products ◽  
Long Chain

The residual COD from anaerobic treatment processes is usually too high to comply with legislative discharge levels. It has been shown that in well operated systems the majority of the effluent COD originates from soluble microbial products (SMP) produced by the system itself, hence the characteristics of these compounds become important when assessing post-treatment systems to remove the residual COD. The molecular weight (MW) distribution and the identification of SMP in the effluents from three different anaerobic reactors will be presented. It has been found that the bulk of SMP lies in the low MW range, though compounds with MW as high as 300 kDa were also present in all anaerobic effluents. Preliminary results on the identification of such compounds using GC/MS surprisingly revealed the presence of long chain alkenes (C12–C24) and alkanes (C12–C16), as well as some aromatic compounds. These compounds that likely come from cell lysis and endogenous decay may not be easily biodegradable, hence their presence in the effluent is likely to cause the residual COD.

The Characteristic of the Soluble Microbial Products from an Anaerobic Reactor at Low Temperature

2012 ◽  
Vol 518-523 ◽  
pp. 1808-1812
Author(s):  
Lei Zhang ◽  
Wei Guang Li ◽  
Duo Ying Zhang ◽  
Ke Wang ◽  
Guang Zhi Wang
Keyword(s):  
Molecular Weight ◽  
Low Temperature ◽  
Membrane Separation ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Soluble Microbial Products ◽  
Anaerobic Reactors ◽  
Anaerobic Biodegradability ◽  
Microbial Products ◽  
Aerobic Biodegradability

A large amount of soluble chemical oxygen demand (COD) exists in the effluent from anaerobic treatment of wastewater at methophilic temperature, which consists of considerable portion of soluble microbial products (SMP). As the anaerobic treatment of wastewater was significantly influenced by temperature, it is great of importance to investigate the SMP from anaerobic reactors operated at low temperature in order to improve the performance. In this study, two lab-scale UASB reactors were performed to treat synthetic glucose and acetate wastewater respectively at an initial concentration of 1000 mg-COD/L at 15 °C. The SMP was found in the effluent from the glucose-fed UASB, and it was 6% of the influent COD concentration. The SMP did not accumulate in the acetate-fed UASB. The average aerobic biodegradability of the SMP was 90% and it was further enhanced by membrane separation of X100 (membrane with 100 k da molecular weight cut-offs). The anaerobic biodegradability of the SMP was 60%, and it was 100% for the fraction in which the molecular weight (MW) was lower than 10 k da. The fraction of low MW (lower than 10 k da) mainly consisted of 31.7% long chain alkanes and 13.6% esters. The aerobic polishing step is an available polishing step for the anaerobic treatment of wastewater at low temperature.

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.

The role of extracellular polymeric substances in biofilm community assembly and metabolic functions

2020 ◽  
Author(s):  
Yichao Wu
Keyword(s):  
Microbial Community ◽  
Extracellular Polymeric Substances ◽  
Extracellular Dna ◽  
Transcriptional Analysis ◽  
Synthetic Wastewater ◽  
Soluble Microbial Products ◽  
Exogenous Bacteria ◽  
Real Wastewater ◽  
Microbial Products ◽  
Biofilm Development

<p>Compared with the chemically defined synthetic wastewater (SynWW), real wastewater has been reported to exhibit distinct effects on microbial community development. Whether and how soluble microbial products in real wastewater contribute to different effects of synthetic and real wastewater on the fate of exogenous bacteria remains elusive. In this study, using a model wastewater bacterium <em>Comamonas testosteroni</em>, we first examined the influences of microfiltration filter-sterilized real wastewater (MF-WW) and SynWW on the retention of <em>C. testosteroni</em> in established wastewater flocs during bioaugmentation. In bioreactors fed with MF-WW, augmentation of <em>C. testosteroni</em> to wastewater flocs resulted in a substantially higher abundance of the augmented bacterial cells than those fed with SynWW. To identify the soluble microbial products in MF-WW contributing to the observed differences between bioaugmentation reactors fed with MF-WW and SynWW, we examined the effect of MF-WW and SynWW on the growth, floc formation, and biofilm development of <em>C. testosteroni</em>. When <em>C. testosteroni</em> grew in MF-WW, visible flocs formed within 2 h, which is in contrast to cell growth in SynWW where floc formation was not observed. We further demonstrated that the observed differences were mainly attributed to the high molecular weight fraction of the soluble extracellular polymeric substances (EPS) in MF-WW, in particular, proteins and extracellular DNA. The DLVO analysis suggested that, in the presence of soluble EPS, the bacterial cell surface exhibits an increased hydrophobicity and a diminished energy barrier, leading to irreversible attachment of planktonic cells and floc formation. The RNA-seq based transcriptional analysis revealed that, in the presence of soluble EPS, genes involved in nonessential metabolisms were downregulated while genes coding for Cco (cbb3- type) and Cox (aa3-type) oxidases with different oxygen affinities were upregulated, facilitating bacterial survival in flocs. Taken together, this study reveals the mechanisms underlying the contribution of soluble EPS to the recruitment of exogenous bacteria by microbial aggregates and provides implications to bioaugmentation.</p> <p> </p> <p><strong>References:</strong></p> <ol> <li>Wu, Y., Zaiden, N., Liu, X., Mukherjee, M. and Cao, B., 2020. Responses of Exogenous Bacteria to Soluble Extracellular Polymeric Substances in Wastewater: A Mechanistic Study and Implications on Bioaugmentation. Environmental Science & Technology. In press</li> <li>Wu, Y., Cai, P., Jing, X., Niu, X., Ji, D., Ashry, N.M., Gao, C. and Huang, Q., 2019. Soil biofilm formation enhances microbial community diversity and metabolic activity. Environment international, 132, p.105116.</li> </ol>

Sign in / Sign up

Export Citation Format

Share Document