污水处理厂剩余污泥的中温厌氧消化特性研究

Research on mesophilic anaerobic digestion of excess sludge in wastewater treatment plant

对天津某污水处理厂的剩余污泥进行中温厌氧消化试验,研究了在不同HRT下的产气量、有机物去除率等指标,结果表明:剩余污泥经过中温消化,在HRT分别为30、20、10 d时,产气率分别为0.022、0.027、0.033 L/(g[VS].d);CODCr的去除率为18.8%～38.1%;由COD物料衡算得知,基质中40%的固态有机物被分解转化,COD甲烷转化率最高约为32.0%;对剩余污泥基质的元素组成进行分析,经计算推导出基质的模拟分子式为C9.87H16.72O33.81N。研究结果为污水处理厂剩余污泥厌氧消化工艺选择合适的工艺条件提供了理论参考。

Taking the excess sludge in a wastewater treatment plant of Tianjin as the research object, a test of mesophilic anaerobic digestion was carried out, and then, the gas production rates, the removal rates of organic matters and some other indexes under different HRT were investigated. The results showed that, after the mesophilic anaerobic digestion, the gas production rates of the excess sludge were 0.22, 0.027 and 0.033 L/（g [VS] .d） when the HRT were 30, 20 and 10 d respectively; meanwhile, the removal rates of CODcr ranged from 18.8% to 38.1%; The result of the COD material balance calculation showed that, over 40% of the influent solid organic matter was decomposed and transformed; the maximum methane conversion rate of COD was 32.0%. Through the analysis of the elements in excess sludge substrate, the molecular formula of the substrate was deduced to be C9.87TH16.72033.81N. The research results provided the theory reference for wastewater treatment plant selecting proper operation condition for excess sludge anaerobic digestion process.