Abstract

Environmental concerns about Golden Horn's polluted sediments have led to 320,000 m³ of sea dredging, generated annually by bucket dredgers to be stored in landfills without dewatering. This study presents an efficient dewatering methodology and a beneficial alternative to store the sludge. In this scenario, the sludge of a suction-cutter dredger is transported to a pond. The beneficial use of geotextile tubes filled with the sludge at circumferential embankments of pond is evaluated. An anionic polyacrylamide (APAM) is used for conditioning the high plastic silt sludge with 10% solid content. APAM dosage is optimized by Rapid Dewatering Test (RDT) for geotextile material. Microscale SEM-EDS analyzes depicted the flocculated form of the sludge. Laboratory-scale Geotextile Dewatering Test (GDT) shows improvements in the turbidity of filtrate, the quantity of solid particles retained in the tube, and the filtration efficiency, determined to be 92 NTU, 18.5% and 90.5% respectively. In accordance with the ICP-OES analysis, the discharge of the filtrate to the aquatic media is admissible. Undrained shear strength of the dewatered sludge is assessed as low, by Vane and undrained unconsolidated triaxial compression tests. Further improvements of the dewatered sludge with vacuum preloading method were projected by completion of the consolidation tests.

摘要

对金角湾污染沉积物的环境担忧导致 320,000 m ³每年由斗式挖泥船产生的海洋疏浚，无需脱水即可储存在垃圾填埋场。本研究提出了一种有效的脱水方法和一种有益的污泥储存替代方案。在这种情况下，吸泥式挖泥船的污泥被运送到池塘。评估了在池塘环堤上填充淤泥的土工布管的有益用途。阴离子聚丙烯酰胺 (APAM) 用于调理固含量为 10% 的高塑性淤泥。APAM 用量通过土工布材料的快速脱水测试 (RDT) 进行了优化。微尺度 SEM-EDS 分析描绘了污泥的絮凝形式。实验室规模的土工布脱水测试 (GDT) 显示滤液的浊度、管中滞留的固体颗粒数量和过滤效率都有所改善，分别确定为 92 NTU、18.5% 和 90.5%。根据 ICP-OES 分析，允许将滤液排放到水介质中。通过叶片和不排水松散三轴压缩试验，脱水污泥的不排水剪切强度被评估为低。通过完成固结试验，预计采用真空预压法对脱水污泥的进一步改进。