超声辅助絮凝强化污染底泥土工管袋脱水减容

Dewatering of contaminated reservoir/lake sediment by using geotextile tubes aided by ultrasound

将超声处理结合絮凝剂用于土工管袋脱水减容。以滤饼含水质量分数为优化指标,考察超声处理与添加絮凝剂的顺序对脱水性能的影响,并考察了超声处理的最优操作条件。结果表明:先添加絮凝剂再进行超声作用可取得较好的脱水效果,当絮凝剂的投加量(质量分数)为5‰(以干基计),超声波的能量密度为0.5 W/mL,作用时间为10 s,脱水效果最佳。最后进行土工管袋小试,结果表明在质量分数4‰絮凝剂的情况下,施加超声波作用时土工管袋的脱水效果优于未施加超声作用的5‰絮凝剂对照组,土工管袋固化时间缩短。适当的超声作用能减少絮凝剂使用量,降低成本,缩短土工管袋固化时间,提高效率。

Ultrasonic treatment combined with flocculants was used in dewatering of sediment by geotextile tube.For obtaining low sludge water mass fraction,the effect of the sequence of adding flocculants and ultrasonic on the dewatering performance was discussed.The optimal conditions of ultrasonic treatment were also determined.The results show that adding flocculants firstly and then ultrasonic treatment can achieve better dewatering performance.When the flocculants dosage is 5‰（dry basis,mass fraction）,the ultrasonic energy density is 0.5 W/mL and treatment time is 10 s,the dehydration effect is the best.Finally,the pilot test of geotextile tube structure was performed.The result indicates that when flocculation mass fraction is 4‰,the dewatering performance of geotextile tube with ultrasound is better than that of the control group without ultrasound,and the curing time of geotextile tubes is shorten.Appropriate ultrasound can decrease the amount of flocculants,reduce costs and shorten the curing time of geotextile tubes,thus improving the efficiency.