电增强活性炭滤芯吸附去除水中微污染物

Electrochemically assisted adsorption and removal of micropollutants in water on activated carbon filter

选取了10种市售活性炭滤芯并测试其相关理化性质,筛选出比表面积高、导电性好的滤芯用于电增强吸附二氯乙酸(DCAA)、左氧氟沙星(LVFX)和环丙沙星(CIP)3种典型饮用水中的微污染物。3种污染物的电增强吸附符合二级动力学模型,电增强活性炭滤芯吸附DCAA、LVFX和CIP的最佳初始吸附速率v0分别达到12.4 mg·(g·h)^(-1)(2 V)、45.3 mg·(g·h)^(-1)(-2 V)和93.1 mg·(g·h)^(-1)(-2 V),相比不加电情况下提高了1.2~1.7倍;3种污染物的电增强吸附等温线符合Langmuir模型,电辅助下DCAA、LVFX和CIP的最大吸附容量qm可达到26.3 mg·g^(-1)(2 V)、207.9 mg·g^(-1)(-2 V)和106.1 mg·g^(-1)(-2 V),相比于不加电时提升了1.2~3.2倍。在流动态吸附实验中,活性炭滤芯在电增强吸附下的出水的DCAA质量浓度比不加电时更低,出水水质更佳。电增强吸附下的处理水量达到1300床体积,比不加电条件下提升了2.2倍。以上研究结果表明活性炭滤芯的电增强吸附在饮用水深度处理中有着较好的应用前景。

In this study,10 kinds of commercial activated carbon filters were selected and their relevant physicochemical properties were tested.The filters with high specific surface area and good electrical conductivity were selected for the electrochemically assisted adsorption of three types of typical micropollutants in drinking water of dichloroacetic acid(DCAA),levofloxacin(LVFX)and ciprofloxacin(CIP).The adsorption kinetic curves of 3 types of pollutants under electrochemical assistance were consistent with the pseudo secondorder model.The optimal initial adsorption rates v0 for DCAA,LVFX and CIP reached 12.4 mg·g^(-1)·h^(-1)(2.0 V),45.3 mg·g^(-1)·h^(-1)(-2.0 V)and 93.1 mg·g^(-1)·h^(-1)(-2.0 V),respectively,which were 1.2~1.7 times higher than those without electrochemical assistance.The electrochemically assisted adsorption isotherms of three types of pollutants were well fitted by the Langmuir model.The maximum adsorption capacities qm of DCAA,LVFX and CIP under electrochemical assistance could reach 26.3 mg·g^(-1)(2.0 V),207.9 mg·g^(-1)(-2.0 V),and 106.1 mg·g^(-1)(-2.0 V),respectively,which were enhanced by 1.2~3.2 times compared with those without electrochemical assistance.In the flow-mode of adsorption experiment,the DCAA concentration of the effluent under electrochemical assistance was lower than that without electricity,presenting a better effluent quality.The treated water quantity under electrically enhanced adsorption reached 1300 bed volumes,which was a 2.2-fold improvement over that without electrochemical assistance.The study demonstrates that the electrochemically assisted adsorption of activated carbon filter is promising in the advanced treatment of drinking water.