吸附分离辅助电渗透脱水过程中污泥的特性

Characteristics of sludge during electroosmotic dewatering assisted by absorptive separation

电渗透技术对于城市污水厂污泥的深度脱水是非常有效的,但相对较高的能耗制约了它的广泛应用。为此,针对污泥电渗透脱水过程中阴极排水困难引起能耗高的问题,提出了吸附分离辅助电渗透脱水,同时考察了吸附分离辅助电渗透脱水过程中污泥中水分的运动特点、pH的变化以及离子的迁移规律。结果显示,吸附分离可以极大地提高污泥电渗透脱水的效果。且脱水过程中阳极附近污泥的含水率、pH均迅速减小;阴极附近污泥的含水率稍有减少,但pH却迅速增大;而中间层污泥的含水率及pH均没有发生变化。此外,电渗透脱水技术对于污泥中目标离子的去除非常有效,但同时容易导致非目标离子的去除。

Electroosmosis technique is very effective for deeper dewatering of sludge from municipal wastewater plant, but higher energy consumption has hampered its widespread distribution so far. Aiming to the problem that higher energy consumption caused by the difficulty in the discharge of water accumulated near the cathode, it was proposed that electroosmotie dewatering is assisted by adsorptive separation, and the distribution of water content, pH and ionic electromigration were investigated in this process. The results showed that absorp- tive separation could enhance drastically the electroosmotic dewatering efficiency of sludge. During electroosmotic dewatering assisted by absorptive separation, water content and pH of sludge near the anode decreased sharply, and water content reduced slightly but pH increased rapidly for sludge near the cathode, while those of middle layers kept at the initial value. Moreover, elecroosmotic dewatering is effective for the removal of target ionic in sludge, however, it may result in the removal of non-target ions.