土工布料在含砷河道底泥脱水固定化中的实验研究

Laboratory study on the dewatering and consolidation settlement of the arsenic sludge using geotextile

对含砷河道底泥进行一系列小柱脱水实验和25L土工管袋脱水实验。通过小柱脱水实验确定了絮凝剂(阳离子型聚丙烯酰胺)的投加量;通过小型土工管袋脱水实验,对淋出液水质、袋内污泥含固率变化以及脱水效率等指标进行分析,探讨了土工管袋工艺对含砷底泥的适用性。实验结果表明,絮凝剂的最佳投加量为0.12mg/L。土工布料能够截留住99%以上的颗粒物,使污泥的含固率从5%提高到21%(质量分数),体积减少近85%,淋出液中砷质量浓度仅为14μg/L。该土工管袋对高含水率含砷污泥的脱水固定化具有很好的实际应用价值。

This study is concerned with dewatering performance of the geotextile hags for arsenic sludge. Dewatering tests using geotextiles and a pillow-shape geotextile bag were conducted on arsenic sludge to study the influence of dosage of floccu lant and the dewatering performance of the geotextile bags. The dewatering of arsenic sludge was carried out using cationic polyacrylamides as the flocculant. The dewatering performance of the geotextile bags is evaluated by the solid content of sludge and the quality of filtrate after the dewatering of geotextile bags. The result indicated that the optimal dosage of flocculant was 0.12 mg/L. The geotextile bag could successfully retain the solid phase of the fill sludge and the solid content of sludge is increased from 5wt% to 21wt%,the volume of the sludge sample is reduced at almost 85 ~. The concentration of arsenic in filtrate after dewatering is merely 14 μg/L. This method has an application value for the dehydration and immobilization of arsenic sludge.