剩余污泥厌氧消化甲烷生成势与产甲烷菌群多样性的比较研究

以AP、DH两污水处理厂的剩余污泥为基质,分别接种两厂的剩余污泥进行了厌氧消化甲烷(CH4)生成势实验(BMP).经改进的Gompertz模型和Michaelis-Menten模型回归分析可知,AP、DH两厂厌氧污泥的最大比产气速率数值接近74.21 mL·(g·d)-1和51.99 mL·(g·d)-1],但对基质剩余污泥的半饱和常数Km差异较大(54 098 mg·L-1和19 005mg·L-1),DH厌氧污泥对该厂剩余污泥的亲和力较好.两个批次实验结束时TSS、CODT均有所下降,NH+4-N显著提高,且高污泥负荷F/M条件下水质变化趋势更为显著.实验前后末端限制性片段多态性(T-RFLP)分析结果与BMP实验结果相一致,实验结束后杂菌(Diverse)相对含量显著下降,产甲烷髦毛菌Methanosaeta spp.(280 bps)、产甲烷微菌Methanomicrobiaceae(80bps)和RC-I(389 bps)的相对含量皆有所提高,且DH-BMP样品产甲烷功能菌群相对含量提升程度高于AP-BMP实验前后变化.

Comparative Study on Biological Methane Potential and Methanogen Biodiversity in the Anaerobic Digestion of Excess Sludge

AP and DH excess sludge, sampled from AP and DH wastewater treatment plants respectively, were inoculated with their anaerobic sludge respectively and tested with biological methane potential (BMP) method. After the regression analysis with modified Gompertz and Michaelis-Menten model, it was found that although the maximum specific CH₄ production rates of AP and DH anaerobic sludge were similar 74.21 and 51.99 mL·(g·d)^-1], the half-saturation constants K_m differed obviously (54098 and 19005 mg·L^-1), indicating DH anaerobic sludge exhibited a higher affinity for its excess sludge. At the end of both BMP tests, the concentrations of TSS and COD_T decreased while the concentration of NH₄⁺-N increased obviously, which were more significant at higher ratios of F/M. The T-RFLP analysis results were in accordance with BMP tests. After both BMP tests, the relative amount of diverse bacteria decreased while the relative amounts of Methanosaeta spp. (280 bps), Methanomicrobiaceae (80 bps) and RC-I (389 bps) increased obviously, which were more significant in DH-BMP test compared with AP-BMP.