页岩气压裂返排废水的混凝处理效能研究

对页岩气压裂返排废水进行了混凝处理,研究了聚合氯化铝、硫酸亚铁等不同混凝剂对压裂返排废水COD的去除效果,考察了p H、混凝剂投加量和助凝剂投加量对COD去除率的影响。结果表明:在复配混凝剂为硫酸亚铁和聚合氯化铝(质量比为1∶1),混凝剂投加量为12 000 mg/L,p H为8.5,助凝剂投加量为10 mg/L的最佳混凝处理条件下,压裂返排废水的COD去除率为62.49%,出水COD由1 984.32 mg/L降至744.32 mg/L。

Research on the treatment efficiency of shaIe gas fracturing fIow back wastewater by coaguIation method

Shale gas fracturing flow back wastewater has been treated by coagulation process. The efficiency of diffe-rent coagulants,such as poly aluminium chloride,ferrous sulfate,etc. for the removal of COD from shale gas fractur-ing wastewater is studied. The influences of different coagulants,pH value,dosages of coagulants,dosages of coagu-lant aids on the COD removing rate are investigated. The results show that the optimal coagulation treatment condit-ions are obtained through the singe factor and orthogonal experiments,as follows,the compound coagulants are poly aluminium chloride and ferrous sulfate(the mass ratio is 1∶1),dosages of coagulants 12 000 mg/L,pH 8.5 and dosa-ges of coagulant aids 10 mg/L. Under these coagulation conditions ,the COD removing rate from shale gas fracturing flow back wastewater reaches 62.49%,and the effluent COD is reduced from 1 984.32 mg/L to 744.32 mg/L.