电渗析深度处理二级出水实现零排放和资源回收

采用电渗析法对二级出水进行深度处理实现"零排放",同时实现氮磷等资源的回收,考察了流速、电压和浓缩室电导率对脱盐率和氮磷回收率的影响。实验采用三膜对结构,结果表明,淡化室脱盐效果明显,电导率均可降到1μS/cm,氯离子、硝酸根和磷酸根去除率均在98%以上。改变反应器流速,发现流速较大时离子迁移更快,氮磷去除速率和回收率更高。减小外加电压,实验运行时间较长,迁移离子较慢,磷回收率下降。改变浓缩室电导率,电流效率和能量消耗等均未发生明显变化。

Electrodialysis for the advanced treatment of secondary effluent to achieve zero discharge and resource recovery

Electrodialysis(ED)has been applied to the advanced treatment of secondary effluent,to achieve its"zero discharge"and recovery of resources,such as nitrogen,phosphorus,etc.. The influences of flow velocity, voltage and concentration compartment conductivity on the desalination rate and nitrogen/phosphorus recovering rates are investigated. A three-pair ion exchange membrane structure has been used in this experiment. The results show that the salt removing effect of the desalination compartment is remarkable ,all the conductivity can be re-duced to<1μS/cm,and the removing rates of chloride ions,nitrate radicals and phosphate radicals are all above 98%. By changing the reactor flow velocity,it is found that the higher the flow velocity is,the faster the ion migra-tion is,and,the higher the removing rates and recovering rates of nitrogen and phosphorus are. By reducing the im-pressed voltage,it is found that the operation time gets longer,ion migration gets slower,and phosphorus recover-ing rate gets lower. By changing the conductivity of concentration compartment ,it is found that no remarkable changes have happened to current efficiency and energy consumption.