Alum sludge from the drinking water treatment plant (DWTP) of Surabaya City, Indonesia, potentially contains high aluminum and organic pollutant contents. Aluminum is sourced from the use of aluminum sulfate as a coagulant during the water treatment process. Whereas, the organic pollutant is from domestic and industrial wastewater discharges into the raw water source. Aims of this study were to characterize the alum sludge of the Surabaya DWTP, to determine suitable electrode materials and optimum electrical current for aluminum recovery using electrolysis. The sludge was characterized according to metal concentrations and chemical oxygen demand (COD). Cyclic voltammetry, a common method for determining appropriate electrode materials for electrolysis, was conducted to confirm platinum (Pt) and stainless steel A304 (SS A304) as suitable electrodes. A polarization test was applied to determine the current for electrolysis. Electrolysis using these electrodes was conducted in one compartment reactor for 6 h. The results showed that the sludge had high concentrations of aluminum and organic substance. The suitable anode and cathode in the electrolysis of acidified alum sludge at pH 3 were Pt and SS A304, respectively. Aluminum recovery efficiency was achieved at 300 mA (52.10%), in which metal impurities were low, and COD removal was 24%.

来自印度尼西亚泗水市饮用水处理厂（DWTP）的明矾污泥可能含有高含量的铝和有机污染物。铝的来源是在水处理过程中使用硫酸铝作为凝结剂。而有机污染物则来自生活和工业废水排放到原水源。这项研究的目的是表征泗水污水处理厂的氧化铝污泥，确定合适的电极材料和最佳电流，以通过电解回收铝。根据金属浓度和化学需氧量（COD）对污泥进行表征。进行循环伏安法（一种确定合适的电解电极材料的常用方法）以确认铂（Pt）和不锈钢A304（SS A304）为合适的电极。进行极化测试以确定电解电流。使用这些电极的电解在一个隔室反应器中进行6小时。结果表明，污泥中铝和有机物的含量较高。在pH 3的酸化氧化铝污泥电解中合适的阳极和阴极分别是Pt和SS A304。铝的回收效率达到300 mA（52.10％），其中金属杂质低，COD去除率为24％。分别。铝的回收效率达到300 mA（52.10％），其中金属杂质低，COD去除率为24％。分别。铝的回收效率达到300 mA（52.10％），其中金属杂质低，COD去除率为24％。