膜生物反应器(MBR)处理垃圾渗滤液的脱氮研究

摘要

采用一体式MBR处理垃圾渗滤液,系统考察MBR对COD、NH5+-N和TN的去除效果.结果表明:可将垃圾渗滤液的COD降至650～1 500 mg.L-1范围;在HRT为1.5 d、DO为0.75～1.20 mg·L-1、不排泥条件下运行时,对TN质量浓度低于2 300 mg·L-1、容积负荷低于0.25 kg·m-3·d-1(以N计)的渗滤液进行处理,MBR对NH4-N与TN的去除率可分别达到87%和72%以上.在MBR处理垃圾渗滤液的运行中发现,膜的污染速度较快,并且呈现"两段性"的规律,采用碱+氧化剂的清洗方式可有效去除膜污染,降低过膜压力.%The removal efficiencies of COD, NH4+-N and TN (total nitrogen) from landfill leachate were investigated by using MBR.Results showed that at the conditions of without sludge discharge, hydraulic retention time (HRT) of 1.5 d, the TN concentration below 2 300 mg/L, the TN volumetric loading below 0.25 kg·m-3·d-1(N), DO concentration of 0.75-1.20 mg·L-1, the removal efficiencies of NH4+-N, TN maintained above 87％ and 72％ respectively.During the operation in treating landfill leachate,membrane fouling occurred and became significantly in MBR process, and characterized with two stages pattern, due to the higher concentration of soluble organic matters in the landfill leachate.With alkali + oxidizer cleaning, the trans-pressure of membrane dropped off effectively.