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.

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 Polymers by GPC-Lalls. II. Concentration Effect of Polydisperse Polymers in GPC

1986 ◽  
Vol 59 (4) ◽  
pp. 551-563 ◽  
Author(s):  
S. Shiga ◽  
Y. Sato
Keyword(s):  
Molecular Weight ◽  
Concentration Effect ◽  
Experimental Conditions ◽  
Viscosity Effect ◽  
Proportional Relationship ◽  
Reduction Effect ◽  
Dual Detector ◽  
Coil Size ◽  
Long Chain

Abstract The concentration effect in a GPC is studied on the following polydisperse polymers: HDPE, EVA, EPM, and EPDM. The GPC is equipped with a dual detector system consisting of a LALLS and a differential refractometer. A proportional relationship is widely observed between the degree of the concentration effect and the elution concentration, and classified in two groups according to the molecular weight: in the first where the molecular weight is larger than 100–200 thousand, the effect becomes more severe as the molecular weight increases; and in the second where the molecular weight is smaller, the effect is less apparent with the molecular weight. The branched molecule is more gently influenced than the linear one. Hypothetical equations are proposed for the molecular coil-size-reduction effect and the viscosity effect under the experimental conditions. In combination they would constitute most of the concentration effect, though the estimation of the latter effect would remain uncertain because of the optional character of the equation constant. It is indicated that the correction of the concentration effect is necessary to measure long chain branches exactly by GPC.

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