猪场废水厌氧发酵液循环脱氮工艺

Characteristics of nitrogen removal in recirculating systems to treat digested piggery wastewater

研究了水解酸化与生物接触氧化组合循环工艺处理猪养殖场废水厌氧发酵液的脱氮特性,重点考察了组合工艺的最佳运行工况和参数,同时讨论了组合工艺低温运行的性能。结果表明,水力停留时间24 h和污水循环比1∶3为最佳运行工况,此时出水氨氮浓度为2.16～8.20 mg/L。溶解氧(DO)浓度2～3 mg/L和有机负荷3 g/L以下为最佳运行参数,出水氨氮浓度稳定在10 mg/L以下。在春季低温条件下(8～12℃),组合工艺也能较好运行,水解酸化池内小分子有机酸产生总量为114.50～244.22 mg/L。组合工艺连续运行3个月以上,污染物去除效果稳定。

In this study,a biological nitrogen removal process using a combination recirculating system of hydrolyze-acidification and biological contact oxidation process was used to treat digested piggery wastewater.The optimal operating conditions and parameters for this recirculating system were investigated,and the performance operating at low temperature was also discussed.The results indicated that the optimal operating conditions for nitrogen removal were hydraulic retention time of 24 h and recycling ratio of 1∶ 3,and the effluent ammonia concentration ranged from 2.16 to 8.20 mg/L.Moreover,the optimal operating parameters for dissolved oxygen and organic loading were 2 to 3 mg/L and lower than 3 g/L,respectively,and with the effluent ammonia concentration of lower than 10 mg/L.Under the conditions of low temperature（8-12℃） in spring,the combination recirculating system could still run well,and the organic acids in hydrolyze-acidification process was 114.50-244.22 mg/L.The combination recirculating system was used to treat digested piggery wastewater for more than three months;the efficiency of pollutants removal efficiency was continuously stable.