基于铜污染太湖底泥的真空电渗脱水去污电极材料特性试验研究

Experimental study on electrode materials characteristics for dewatering and remediation of copper-contaminated sediment from Tai Lake based on vacuum electro-osmosis

真空电渗法能够实现重金属污染底泥脱水去污一体化处理,本文通过自制真空电渗一体化室内模型试验系统,从排水量、沉降、电流、有效电势、污染物去除率、能耗等方面,对EKG、石墨、铝、铁、铜等五种材料作为电极在真空电渗方法处理铜污染太湖底泥过程中的表现进行分析。结果表明:选用铜作为电极材料具有最好的脱水效果但对铜污染去除效果较差,而选用EKG作为电极则具有最好的铜污染去除效果,且脱水效果仅次于铜,说明EKG材料在脱水去污一体化处理中的优越性。当选用金属作为电极材料时,阳极的电极腐蚀较为严重,很大程度上影响处理过程中真空电渗各项参数和处理效果。介入真空压力后,改变了传统电动修复过程中有效电势持续衰减的趋势,使有效电势在处理中后期出现回升,且回升程度受电极材料变形协调能力的影响。

The vacuum electro-osmosis method enables integrated treatment of heavy metal-contaminated sediments by simultaneously removing water and pollutants.This study focuses on the dredged sediments from Tai Lake and investigates the performance of five electrode materials(electrokinetic geo-synthetics,graphite,aluminum,iron,and copper)in the vacuum electro-osmotic treatment process through a self-designed test system.Multiple aspects,including drainage volume,settlement,current,effective potential,pollutant removal efficiency,and energy consumption,were analyzed.The results indicate that using copper as an electrode material has the best dewatering effect but poorer copper pollutant removal efficiency.On the other hand,using electrokinetic geo-synthetics as an electrode material demonstrates the best copper pollutant removal efficiency,with dewatering effect second only to copper,highlighting the superiority of electrokinetic geo-synthetics material in integrated dewatering and remediation treatment.When using metal as an electrode material,the anode electrode corrosion is more severe,which significantly affects various parameters of the vacuum electro-osmotic process and the treatment outcomes.The introduction of vacuum pressure alters the conventional trend of continuous decay in effective potential during the traditional electro-osmotic process.It causes a rebound in effective potential during the later stages of treatment,and the magnitude of this rebound is influenced by the electrode material’s ability to accommodate deformation.