电渗法对太湖环保疏浚底泥脱水干化研究

The Research of Environmental Dredged Sludge Dewatering in Taihu Lake by Electro-Osmotic

利用粘土颗粒带有负电荷,而其中水分子显示正极性的特性,采用电渗的方法在环保疏浚底泥中通入电流,使得带有极性的水分子向阴极流动,从而达到对底泥脱水的效果.利用电渗法对太湖环保疏浚底泥进行脱水研究,分析其含水率随时间的变化、出水量与能耗的相关关系,以及其影响因素和优化方案.试验表明,经过240 h的电渗法脱水之后,底泥的含水率从开始的38.72%降至32.85%,可在较短时间内脱去底泥中的水分;电渗效果受底泥含水率、电压梯度、电极的耐腐蚀性、电极布置方式的影响;改善电极材料有利于提高电渗效率和降低能耗.在对不同电极布置方式的比较中发现,排形电极比环形电极更有利于排出底泥中的水分.通过对电渗试验的经济分析得出,电渗法进行环保疏浚底泥脱水的工程费用约为4.29元/m3原状土.

Based on the characteristic of clay with minus charges and the water molecules with plus charges, the experiment used the means of electro-osmotic to electrify environmental dredged sludge, made the water molecules have polarity and flow to the cathode, and thus achieved the purpose of dredged sludge dewatering. The electro-osmotic method was used to do the dewatering research on environmental dredged sludge of Taihu Lake, by analyzing its water holding variation with time, the correlativity between the effluent volume and energy consumption, and the effecting factors and optimizing scheme. The experiment indicates that the water holding ratio of sludge can be depressed from 38.72% to 32.85 % after 240 h dewatering experiment by electro-osmotic, the water holding ratio can been expressed in short time. At the same time, the experiment indicates that the means of electro-osmotic is effected by water holding ratio, grads of voltage, the enduring causticity of poles, disposal manner of poles, the improvement of the material of poles can enhance the effect of electro-osmotic and depress the energy consumption. When comparing different disposal manners of poles, it is found that the line disposal manner of poles is more propitious to discharge the water from sludge than the ring disposal manner of poles. By economic analysis of electro-osmotic, it is found that the expense of construction is about 4.29 yuan per m^3 undisturbed soil to dewater environmental dredged sludge by electro-osmotic.