电絮凝-膜分离反应器还原-絮凝-超滤一体化处理六价铬废水

Removal of Cr ( Ⅵ) from wastewater by electrocoagulation membrane reactor based on reduction,flocculation and ultrafiltration

采用电絮凝-膜分离反应器(electrocoagulation membrane reactor,ECMR)对含铬废水进行研究。讨论了电化学参数和水质条件对Cr(Ⅵ)去除的影响,对比了ECMR和EC-UF抑制膜污染的作用机制。结果表明,在电流密度J=55 A·m^(-2)、初始浓度C(Cr^(6+))=40 mg·L^(-1)、初始pH=3、电解时间60 min、水力停留时间20 min条件下,ECMR出水总Cr去除率达到99.2%,废水中Cr(Ⅵ)的去除率达到99.4%。同时发现ECMR膜通量优于EC-UF,通量高出近15%,ECMR装置不但能够充分利用电絮凝中的电场和气浮作用,进一步强化减缓膜污染,而且可以使装置系统更加紧凑,节省占地空间。

Recently, chromium （Cr） removal via coagulation has attracted great attention. Cr（VI） removal by electrocoagulation membrane reactor （ECMR） was investigated. The performance of Cr（ VI） removal under vari- ous electrochemical parameters and solution conditions were evaluated. Besides, the mechanism of antifouling by ECMR and EC-UF were compared. The results show that, when the current density is J =55 A·m-2, electroly- sis time of 60 min and hydraulic retention time of 20 min, the Cr （VI） and total chromium removal reached 99.4% and 99.2% in the solution of initial pH = 3, C（ Cr6＋ ） = 40 mg· L-1 respectively. The flux of ECMR shows an enhancement by 15% than that of EC-UF, indicating there exists a powerful antifouling effect under e- lectric conditions. The ECMR device can not only make full use of the electric field and air floaing in the electro- cogulation, but also further effectively slow down the membrane fouling. Moreover, the device can make the system more compact and save space.