Abstract:

In recent years, in-situ control techniques to remediate the endogenous pollution of sediments have received extensive attention. This study aims at unravelling the preventing effect of “electroosmosis plus capping” technology on the release of endogenous pollution from the sediments of contaminated water bodies using lab-scale experiments. The results of electroosmotic treatment showed that, with the increase in cell voltage, smaller amounts of ammonia nitrogen were released from the sediments after treatment into the overlying water, but larger amounts of total phosphorus released. The followed capping experiment results showed that the use of natural coarse river sand for capping exhibited had the best effect. With a higher cap thickness and smaller particle size, a better controlling effect on pollutant release could be obtained. If the sediments were treated by the optimal conditions, pretreated by 20V electroosmosis voltage, and capped by 3cm coarse river sand (with a particle size of 3—5mm), the highest controlling efficiency of pollutants could reach up to 66.9%. Results of this study demonstrate that “electroosmosis plus capping” technology has excellent pollution controlling effect and can be developed as an effective and in-situ method to block the release of endogenous pollution from the sediment. The potential ecological environmental effect needs further observation.

Key words: sediments, electrolysis, capping, control, ammonia nitrogen, total phosphorus, organic compounds

摘要：

近年来关于河湖底泥内源污染的原位控制技术受到了广泛的关注和应用。本文针对水体底泥内源污染的释放问题，研究了“电渗-帽封”联合技术的控制效果。电渗处理试验结果表明，电压越高，电渗处理后底泥向上覆水中释放的氨氮量越低，但总磷释放量升高。后续的帽封试验结果表明，使用天然粗河砂效果最好，且帽封厚度越高，材料粒径越小，对污染物释放的控制效果越好。采用20V电渗电压预处理实际底泥，并采用3～5mm粒径的天然粗河砂作为帽封材料，在3cm帽封厚度条件下，对污染物释放的阻控效率可达到66.9%。本研究的结果表明，“电渗-帽封”技术具有良好的底泥污染阻控效果，可以作为一种有效的原位处理方法来阻止底泥内源污染的释放，但其潜在的生态环境效应还需要进一步关注。

关键词: 底泥, 电渗, 帽封, 控制, 氨氮, 总磷, 有机化合物