石墨对污泥中厌氧微生物代谢产物及其性能的影响

矿物材料对废水厌氧处理及厌氧污泥改性具有十分重要的作用,而微生物代谢产物是生物处理系统的重要组分,在提高污染物去除率和甲烷产量等方面也起到非常重要的作用。本研究对矿物材料石墨和厌氧微生物共存体系内溶解性微生物产物(soluble microbial product,SMP)和胞外聚合物(extracellular polymeric substances,EPS)进行了分析表征。结果表明,石墨对EPS和SMP的组成和含量影响显著,主要是由于石墨的吸附作用及其对石墨颗粒的环境毒性所致。红外光谱分析表明,添加石墨体系内SMP与EPS的基团种类并未发生明显改变,但含量有所改变。三维荧光分析结果显示,SMP的主要荧光类物质为色氨酸类似物和腐殖质(辅酶NADH),而EPS的主要荧光类物质为色氨酸类似物和腐殖酸,石墨能明显降低色氨酸类似物及腐殖酸类物质的产生。石墨会减弱微生物的相对疏水性,提高表面自由能,有利于微生物团聚体的形成。

The effect of graphite on the microbial metabolite substances production and characteristics of anaerobic sludge microorganism

Mineral material plays a very important role in wastewater treatment and sludge modification. Microbial metabolites are important components of the biological treatment system, and also play a very important role in improving the pollutants removal efficiency and methane production. In this study, the authors analyzed and characterized the soluble microbial products(SMP) and extracellular polymeric substances(EPS) produced from the graphite dosed anaerobic system. The results show that graphite exerts significant effects on the composition and content of the EPS and SMP, mainly due to the adsorption effect of graphite and its environmental toxicity. Fourier transform infrared spectrum(FTIR) analysis results show that adding graphite does not influence the types of the active group in SMP and EPS, but the relative content is changed. Three-dimensional fluorescence spectrum analysis results show that the main fluorescent materials in the SMP are humus(coenzyme NADH) and tryptophan analogs, whereas the main fluorescent materials in EPS are humic acid and tryptophan analogs. Fluorescence spectrum analysis results also indicate that graphite could significantly reduce the tryptophan and humic acid analogs. Graphite decreases the relative hydrophobicity of the sludge and improves the surface free energy, which is beneficial to the formation of microbial aggregates.