Abstract：
Dredging eutrophic lake sediments can improve water quality, but it also requires dewatering and valorizing the dredged material to avoid wasting resources like phosphorus. This study experimentally investigated the basic mechanism and performance of electroosmotic dewatering of 1-L dredged sediments using different electric currents (20 mA, 40 mA, and 60 mA) after gravity filtration. The dewatering performance, moisture content and distribution, effect of electrochemical reaction on dewaterability, energy consumption, and changes in metals and phosphorus (P) distribution and pH values were analyzed. The results indicated that electroosmotic dewatering effectively decreased sediment mass by predominantly eliminating free and a portion of interstitial water, with reductions ranging from 7 to 20%. The optimal duration and current should, however, be considered to balance water removal and energy consumption. Higher moisture removal occurred with 40 mA for 24 h and 60 mA for 6 h, while the energy consumption obtained with 60 mA (0.201 kWh/kg water removed) was significantly lower than that of applying 40 mA for 24 h (0.473 kWh/kg water removed), with the assistance of ohmic heating, resulting in reduced viscosity and water release from capillaries. The tested conditions did not significantly extract heavy metals or P from the sediments, which may facilitate the disposal of the removed water back into the lake and the utilization of the treated sediments for different purposes. This technology is easy to operate and suitable for the treatment of dredged sediments, and the dewatering result is comparable to low pressurized filtration but at low energy consumption.
摘要：
疏浚富营养化的湖泊沉积物可以改善水质，但它也需要脱水和增值疏浚的材料，以避免浪费资源，如磷。本研究通过实验研究了使用不同电流（20mA，40mA,和60mA）在重力过滤后。脱水性能，水分含量和分布，电化学反应对脱水性能的影响，能源消耗,并分析了金属和磷（P）分布和pH值的变化。结果表明，电渗脱水通过主要消除游离水和部分间隙水来有效减少沉积物质量，降幅从7%到20%不等。最佳持续时间和电流应，然而,被认为是平衡水去除和能源消耗。更高的水分去除与40毫安24小时和60毫安6小时，而使用60mA（0.201kWh/kg水去除）获得的能耗显着低于使用40mA24h（0.473kWh/kg水去除），在欧姆加热的帮助下，导致粘度降低和毛细血管中的水释放。测试条件没有从沉积物中明显提取重金属或P，这可能有助于将去除的水处理回湖中，并将处理后的沉积物用于不同的目的。该技术操作简便,适用于疏浚沉积物的处理,脱水结果与低加压过滤相当，但能耗低。
