太湖疏浚底泥的脱水技术研究

Study on Dehydration Technology of Dredged Sludge in Tai Lake

太湖环保疏浚工程产生大量高含水率的疏浚底泥,处置不当就造成十分严重的二次污染。由于疏浚底泥重金属含量基本低于农用污染物控制标准,合理施用即可改良土壤、节约大量处置费用,不仅能够解决我国土壤退化的问题,还能带来良好的经济效益。为实现底泥的快速脱水,便于资源化利用,同时针对疏浚底泥渗水性差致使底部排水法困难的缺点,采用了絮凝剂、脱水剂与真空抽滤相结合的方法处理疏浚底泥。试验结果表明:加药实验组在520h内可将疏浚底泥的含水率从70%降至41.9%,而不加入药剂的空白组实验含水率只降至60.3%就无法继续脱水。所用脱水剂不与絮凝剂、淤泥和淤泥中的有机质等成分发生化学反应,且对出水水质无明显影响,出水的浊度、CODMn以及pH值在废水排放的规范之内。

The environmental dredging engineering project of Tai Lake produces a large number of dredged sludge with high moisture content,and improper disposal of the dredged sludge can cause serious secondary pollution.Due to that the heavy metal content of dredged sludge is lower than the agricultural pollution control standards,reasonable application can improve the soil which can reduce a large amount of disposal costs.Therefore,it can not only solve the soil degradation problem in China,but also generate good economic benefits.In order to realize the rapid dehydration and resource utilization of the sludge,the combination method of flocculent and dehydrating agents with the vacuum filtration was used for dehydration of the dredged sludge since the bottom drainage was difficult to perform due to the low permeability of dredged sludge.The experimental results indicated that the moisture content of the dredged sludge for the dosing group can be reduced from 70% to 41.9% in 520 hours whereas the moisture content of the dredged sludge for the blank group can only reduced to 60.3% and dehydration was unable to continue.The dehydrating agent did not react with the flocculent agent,sludge,and the organic contents in the sludge,and it had no significant effects on the water quality.The turbidity,CODMn and pH of the effluent water were within the standards of wastewater discharge.