胞外聚合物与溶解性微生物产物的关系

通过活性污泥内源呼吸试验,发现胞外聚合物与溶解性微生物产物之间存在相互转化、吸附与被吸附的关系。内源呼吸初期(0~19h),bound EPS水解生成BAP,细胞自溶过程也释放部分SMP。19~43h,微生物利用SMP中易降解部分生成bound EPS和UAP,大分子量的SMP被bound EPS吸附,并存在一定程度的细胞水解。43~162h为SMP分泌、溶出阶段,内源呼吸加强,微生物脱氢酶活性几乎丧失,细胞水解、自溶。bound EPS表面出现SMP解吸-吸附的交替过程。162~210h期间bound EPS水解及细胞自溶为主要过程。并且产出的SMP可生物降解性较差,对微生物表现出毒性作用,抑制其脱氢酶活性,而在毒性环境下,微生物又产出更多的SMP。

Relationship between Extracellular Polymeric Substance and Soluble Microbial Products

Through experiment of activated sludge decay process, it was found that there existed relationships of conversion and adsorption-desorption between extracellular polymeric substances (EPS) and soluble microbial products (SMP). In the beginning of decay process (0~19h), bound EPS were hydrolyzed to biomass associated products (BAP), and the cell lysis products also constituted part of SMP. In the phase of SMP biodegradation (19~43h), part of SMP, being biodegradable, were utilized by active biomass as recycled electron donors. Bound EPS and utilization associated products (UAP) were produced. High molecular weight fractions of SMP were adsorbed by bound EPS, and there existed cell lysis faintly. In the excreting and autolyzing phase (43~162h), decay process enhanced and dehydrogenase activity of microorganisms lessened nearly to none. Cell lysis and autolysis occurred. There existed desorption-adsorption between bound EPS and high MW fractions of SMP. In the phase of biodegrading and autolyzing process (162~210h), dominating process was bound EPS hydrolyzing to BAP and bacteria autolysis. SMP were not biodegradable easily, and they had some effect of toxicity on microorganism, restraining the dehydrogenase activity of biomass. While in the presence of toxic materials, more SMP were released by microorganisms.