WFSI处理低C/N比养猪废水的效果及脱氮机制

为有效处理高氨氮、低C/N比养猪废水,采用在土壤中布设木条形成木质框架的方法构建木质框架土壤渗滤系统(WFSI),并通过调控运行探讨其对化学需氧量(COD)、氨氮(NH₄⁺-N)、总氮(TN)的处理效果.研究表明,对于COD、NH₄⁺-N和TN分别为160-359、253-298和317-374mg/L的养猪废水,在(25±1)℃和表面水力负荷为0.2m³/m²·d条件下,系统可在30d启动成功并达到稳定运行,其COD、NH₄⁺-N和TN去除率分别达到61.7%、85%和36.3%左右.分析表明,WFSI中同时存在异养反硝化和厌氧氨氧化等多种生物脱氮机制,其中厌氧氨氧化的脱氮贡献可达去除总氮的42.3%以上.

Efficiency and denitrification mechanism in a wood-chip-framework soil infiltrator treating piggery wastewater with low C/N ratio

In order to treat piggery wastewater with high ammonium density and low C/N ratio, a wood-chip-framework soil infiltrator (WFSI) was constructed and its performance in COD, NH₄⁺-N and TN removal was investigated, while the mechanism for denitrification was analyzed. The infiltrator was started up at a hydraulic surface loading rate of 0.2 m³/m²·d and temperature (25±1)℃, and could get steady in performance within 30 days. The results showed that COD, NH₄⁺-N and TN removal in the infiltrator were about 61.7%, 85.0% and 36.3%, respectively, as against a feed concentration which ranged 160~359, 253~298 and 317~374 mg/L, respectively. Heterotrophic denitrification and ANAMMOX were identified as the denitrification approaches in the WFSI, and the contribution of ANAMMOX to the TN removal was more than 42.3%. The COD, NH₄⁺-N and TN removal in the infiltrator were about 61.7%, 85.0% and 36.3%, respectively, as against a ranged feed concentration of 160~359, 253~298 and 317~374mg/L, respectively.