面向微污染水处理的三重功能电催化炭膜制备及性能

Preparation and performance of electrocatalytic carbon membranes for treating micro-polluted water

  • 摘要: 以椰壳活性炭为原料,设计制备一种具有吸附、电催化氧化、膜过滤三重功能的电催化炭膜(TCM),通过调节原料配比、炭化温度以及原料活性炭的粒径实现对TCM性能的调控。采用SEM、XRD、拉曼和氮吸附等技术对TCM的形貌与结构进行表征,并以TCM为阳极构建电催化膜反应器(ECMR),考察其水处理性能。结果表明,TCM具有发达的孔道结构和较高的比表面积,整体呈现出大孔-介孔-微孔的多级孔道结构,并具有良好的机械强度与导电性;改变活性炭的粒径可以有效调控TCM的孔道结构。TCM对水中微污染有机物和重金属离子均具有较高的吸附量;在外加2 V电压电场下,对水中亚铁氰化钾的氧化率为98.4%,表现出良好的电催化氧化活性;在低压电场的作用下处理真实微污染水时,炭膜的三重功能协同作用使其展现出优异的综合处理性能,其中COD、UV254、浊度以及细菌的去除率分别达到了94.3%、90.5%、96.3%和100%,重金属离子几乎完全去除,出水水质得到显著地改善,并且水渗透通量有所提升,具有良好的抗污染性能。

     

    Abstract: Porous carbon membranes (PCMs) with three functions of adsorption, electrocatalytic oxidation and membrane filtration were prepared from coconut shell activated carbon using carboxymethyl cellulose (CMC,10 wt%) and benzoxazine resin (BR, 10 wt%-40 wt%) as the binder components. The morphology and microstructure of PCMs were characterized by SEM, XRD, Raman and nitrogen adsorption. An electrocatalytic membrane reactor (ECMR) was constructed using PCMs as the anode materials to investigate their water treatment performance. Results show that the PCMs have well-developed hierarchical macro, meso and micropores, whose macropore size decreases with the particle size of the activated carbon. The mechanical strength and electrical conductivity of the PCMs increased with BR content and carbonization temperature. The water flux decreased as the average particle size of the activated carbon decreased and the iodine value decreased with decreasing BR content. The PCM performed best with an excellent comprehensive performance in adsorption, electrocatalytic oxidation and filtration when it was prepared from an activated carbon of average particle size of 37.9 μm using a BR content of 30 wt% and a carbonization temperature of 950 ℃. For the micro-polluted Lingshui River water in Dalian, the removal of COD, UV254, turbidity and bacteria with the ECMR reached 94.3%, 90.5%, 96.3% and 100%, respectively, and heavy metal ions (Pb2+, Cu2+, Zn2+, Ni2+ ) were removed to levels below the detection limits, and the anti-fouling performance was good. The excellent performance in treating micro-polluted water is ascribed to the combined effects of adsorption, electrocatalytic oxidation and filtration.

     

/

返回文章
返回