DSA阳极处理垃圾渗滤液膜浓缩液控制参数研究

Control parameters of dimensionally stable anode treated landfill leachate membrane concentrate

采用形态稳定阳极(DSA)的电催化氧化技术为难降解有机废水处理提供了新的发展方向,该技术存在的难题是要根据废水性质选取合适的电极和控制参数。通过对武汉某垃圾填埋场渗滤液 MBR+NF 膜浓缩液的电催化氧化实验,表明钌铱锡电极对 COD、总氮和色度均有更好的处理效果。该电极在电流密度为 12 mA/cm^(2),极板间距为 1.5 cm,pH 为 8 时,运行 180 min 后 COD 可降至 4.58 mg/L,COD 去除率达 97.95%。通过实验及分析,建议工程实际中各控制参数选择的优先级顺序为:阳极材料>电流密度>极板间距>初始 pH>曝气量>钛基底结构形式。实验表明,单级低电流处理难以达到一级 A 标准,高电流处理能耗高且会影响电极寿命,因此建议工程中采用“6 mA/cm^(2)+12 mA/cm^(2)”或“6 mA/cm^(2)+18 mA/cm^(2)”的梯度电流组合的多级电催化工艺。

The electrocatalytic oxidation technology with dimensionally stable anode(DSA)provides a new development direction for the treatment of refractory organic wastewater.The challenge is to select the appropriate electrode and control parameters according to the quality of wastewater.The electrocatalytic oxidation experiment of a landfill membrane concentrate in Wuhan showed that ruthenium-iridium-tin electrode had good treatment effect on COD,TN and chroma.When the current density was 12 mA/cm^(2),the distance between plates was 1.5 cm and pH=8,the COD could be reduced to 4.58 mg/L after 180 min,and the removal rate could reach 97.95%.Through experiments and analysis,the priority order of the control parameters followed:anode material>current density>plate spacing>initial pH>aeration rate>titanium substrate structure.The experimental results showed that the single-stage low current treatment was difficult to reach the first class A standard,and the high current treatment consumes high energy and affected the electrode life.So,it is suggested to adopt the multi-stage electrocatalytic process of gradient current combination of“6 mA/cm^(2)+12 mA/cm^(2)”or“6 mA/cm^(2)+18 mA/cm^(2)”in engineering practice.