| Cell decay products are the important metabolic material in the process of urban sewage treatment, those other compounds derived from microorganisms are the thing released from organic matter in the process of decay and death.Extracelluar polymeric substances(EPS), the substrate metabolism and the endogenous respiration of microbial release into the solution(SMP) affects the urban sewage treatment water quality. Based on this,paper study the microorganism metabolites such as EPS's and the SMP's mechanism and distribution characteristics,in order to explore the migration of organic matter and transformation to the microbial metabolites changing in water treatment and provide theoretical basis for the urban sewage treatment.Research though the cation exchange resin to get EPS from the active sludge, according to the close degree,EPS can be divided into loosely-bound EPS,tightly-bound EPS and Total EPS and getting the SMP. Based on the artificial water distribution simulation of urban sewage, using SBR reactor to research the EPS and SMP which coming from the biological reactor whose process is A2 O, exploring the activated sludge's EPS layered components and characteristics of soluble microbial metabolites. The study shows that: LB-EPS is mainly composed of polysaccharides, LB-EPS's polysaccharides can account for 97% of the Total EPS's polysaccharides; TB-EPS is mainly composed of proteins, TB-EPS's proteins can be accounted for almost 54% of the Total EPS's; The SMP is mainly composed of humic type material. The SMP's polysaccharides step down in A2 O process, treated waste water almost has no polysaccharides and used up; Protein also consumed step by step,but protein can be detected and remained stable finally; LB-EPS has little polysaccharides and proteins,the proteins of TB-EPS decrease relative in anaerobic tank and anoxic tank and keeping relatively stable in aerobic tank.The SUVA values of SMP,LB-EPS, TB-EPS and Total EPS present a rising trend,shows that the total samples in the aromaticity of organic carbon containing unsaturated double bond or organic matter content and aromatic degree of tectonic mineralization have been gradually rising trend. Three dimensional fluorescence spectrum show that, SMP and LB-EPS contains the tryptophan peak B and the humic acid peak. TB-EPS and Total EPS contain tryptophan peak A, tryptophan peak B and the humic acid peak. The f450/500 fluorescence index shows that the four components' soluble humic acid is coming from the biological source, its humic substances is mainly produced by biological metabolism,namely treated waste water's humic substances are mainly produced by the biological metabolism. By liquid chromatography analyzed molecular weight distribution shows that the large molecular weight of humic substances appear in all those compositions,the humic substances which high molecular weight is 8500 Da can be generated heavily in SMP, the humic substances which small molecular weight is 400 Da only exist in TB-EPS.Though the fluorescence detector measurement for the four components, finding that protein material has the similarity, and molecular weight mainly focused on the 43000 Da and 13000 Da. Molecular weight distribution in actual A2 O process, its molecular weight distribution is wider. Relative to processing variation to the SMP, the molecular weight increases gradually. |
PDF Full Text Request