水解酸化池预处理低碳生活污水的效能分析

Analysis on Efficiency of Hydrolysis Acidification Tank for Pretreatment of Sewage with Low Carbon Source

为了提高低碳氮比生活污水的脱氮效能,在缺氧池前设置水解酸化池,通过水解酸化作用改善进水碳源,同时对回流剩余污泥进行降解,以期达到改善进水碳源可生化性、提高其可利用率、减少外碳源投加量并实现污泥减量的目的。分别考察了水解酸化池对污水单独进行预处理以及对污水和回流污泥同时进行预处理情况下的作用效能及其对系统脱氮的影响。结果表明:两种预处理条件下,理论B/C值都大于0.65,出水SCOD/COD的平均值和出水VFA浓度均高于进水,单独污水水解酸化的出水SCOD减少较多,对TN的去除率仅为47.8%;回流剩余污泥后,温度>20℃且每日分4次共回流20 L剩余污泥的TN去除效果明显优于单独污水水解酸化和温度<20℃且每日分2次共回流10 L的运行效果,两种回流量条件下对TN的去除率分别为71.9%和66.1%,污泥减量率分别为58%和56.3%。

In order to improve the nitrogen removal efficiency from domestic sewage with low C/N ratio, the hydrolysis acidification tank was set before the anoxic reactor to improve the influent carbon source through hydrolysis acidification, meanwhile excess sludge was degraded to increase the biodegrad- ability and availability of influent carbon source, decrease the addition of external carbon and realize the sludge reduction. The efficiency of hydrolysis acidification tank and its effect on the whole nitrogen removal system were investigated under two different conditions： single wastewater pretreatment or wastewater and recycle sludge pretreatment at the same time. The results showed that under two pretreatment conditions, the theoretical B/C was always above 0.65, both the effluent SCOD/COD and VFA were higher than the influent, the effluent SCOD was decreased more in single wastewater pretreatment, and the TN removal rate was only 47.8%. When the excess sludge was recycled, TN removal efficiency ter when the temperature was above 20 ℃ and the excess sludge was recycled 4 times everyday L in total than in single wastewater pretreatment as well as when the temperature was below 20 ℃ recycle sludge was decreased to 2 times and 10 L in total. The TN removal rates under two recycle conditions were 71.9% and 66. 1% respectively, and the sludge reduction rates were 58% and 56.3% respectively.