基于膜吸收法处理垃圾渗滤液废水的研究

Study on treatment of landfill leachate by membrane absorption process

为了处理垃圾渗滤液废水中高浓度氨氮,通过"泡沫分离、混凝沉淀、除钙、微/超滤"和膜吸收法脱氨组合工艺对垃圾渗滤液进行预处理,以保证后续生化处理系统的稳定运行。结果表明,膜吸收前处理可有效削减垃圾渗滤液中表面活性物质、大分子有机物、悬浮颗粒物和重金属,使Zn、Cu和Pb等离子含量满足生活垃圾填埋污染控制标准(GB 16889—2008)排放要求。在渗滤液pH=11.5、流速为3.6 cm/s、吸收液浓度为2 mol/L、流速为1.1 cm/s条件下,采用4级串联的中空纤维膜组件对垃圾渗滤液进行连续处理,氨氮去除率可达到97%以上,出水氨氮质量浓度始终低于50 mg/L,过膜通量基本稳定在3.0~3.2 mg/(m^(2)·s)。

High concentration of ammoniacal nitrogen is a key issue in the biological treatment of landfill leachate.A process combining"foam separation→coagulation sedimentation→calcium removal→micro/ultrafiltration"with membrane absorption deamination is proposed to pretreat landfill leachate to ensure the stable operation of the subsequent biochemical treatment system.Results show that membrane absorption pretreatment can effectively reduce the contents of surfactants,macromolecular organic matters,suspended particulate matters and heavy metals in landfill leachate,making the residual contents of Zn,Cu and Pb meet the emission requirements of China's pollution control standard for domestic waste landfill(GB16889—2008).Landfill leachate is continuously treated by using 4-stage hollow fiber membrane modules in series under the conditions that pH and flow rate of leachate are 11.5 and 3.6 cm·s^(-1),respectively,the concentration and flow rate of absorption solution are 2 mol·L-1 and 1.1 cm·s^(-1),respectively.The removal rate of ammoniacal nitrogen exceeds 97%,the concentration of ammonia nitrogen in effluent is always lower than 50 mg·L-1,and the membrane flux remains basically stable at 3.0-3.2 mg·m^(-2)·s^(-1).