基于地下水回灌系统工程的原水预处理试验研究

Experimental Study on The Treatment of Raw Water for Groundwater Recharge System

针对采用FeCl_3絮凝沉降预处理河水原水后,注入功能性人工湿地系统,由经功能性湿地系统二次净化处理后,再由池塘入渗补给地下水的地下水回灌系统工程,利用单因素试验考察FeCl_3对绵远河水原水浊度、COD、TP、TN、NH_4^+-N污染指标的去除效率,分析三氯化铁投加量与沉淀时间对污染指标去除效果的影响。结果表明,FeCl_3试剂对浊度、TP的去除效果显著,浊度的最终去除率为94.507%~98.399%,TP的最终去除率为55.519%~95.130%;对COD、TN的去除效果较为明显,COD的最终去除率为29.869%~50.955%,TN的最终去除率为14.970%~65.945%;对NH_4^+-N的去除效果不明显,NH_4^+-N的最终去除率为5.714%~9.909%。污染去除率受污染的初始浓度、FeCl_3用量、静置沉降时间共同影响。总体而言,污染的初始浓度越大,其去除效率越高;污染浓度随时间增加而降低,去除率随时间增加而增大。相同时间内,FeCl_3浓度越大,去除率越高,污染降低越快;不同FeCl_3浓度达到相同污染去除率时,FeCl_3浓度越低,所需时间越长;FeCl_3浓度越高,所需时间越短。

Aiming that the pretreatment of the raw water of river water using FeCl3 flocculation sedimentation,injection functional constructed wetland system,after the two purification treatment of the functional wetland system,groundwater recharge system engineering of groundwater recharge by pond infiltration.The single factor is used to test FeCl3 removal efficiency of Mianyuan river water turbidity,COD,TP,TN,NH4^＋-N pollution index,to analyzed the effect of the dosage of ferric chloride and precipitation time on the removal of the pollution index.The results show that the removal efficiency of FeCl3 reagent on turbidity and TP is significant,the final removal rate of turbidity is 94.507% ～ 98.399%,and the final removal rate of TP is 55.519% ～ 95.130%; the removal effect of TN and COD is obvious,the final removal rate of COD is 29.869% ～ 50.955%,and the final removal rate of TN is 14.970% ～ 65.945%; the removal effect of NH4^＋-N is not obvious,the final removal rate of NH4^＋-N is5.714% ～ 9.909%.The initial concentration of pollution,the amount of FeCl3,and the settling time of the settling time were affected by the pollution removal rate.Overall,the greater the initial concentration of pollution,the higher the removal efficiency; the pollution concentration decreases with the increase of time,and the removal rate increases with the increase of time.At the same time,the higher the concentration of FeCl3,the higher the removal rate,the faster the pollution reduction.The lower FeCl3 concentration,the longer the FeCl3 concentration is,the lower the concentration of the same pollutant removal rate is achieved.The higher the concentration of FeCl3,the shorter the time required.