Sludge dewatering is an essential process for reduction of sludge volume to decrease cost of ultimate disposal. In this study, a novel method using activated carbon (AC) strengthening electrochemical (EC) treatment (EC/AC) was adopted to improve greatly sludge dewaterability. It was shown that capillary suction time (CST) and water content of dewatered sludge cake (Wc) were reduced to 55.9 ± 1.24 s and 64.3 ± 1.23%, respectively, under the optimal conditions of EC voltage 20 V, EC time 30 min and 0.2 g/g dry solid (DS) AC. AC with rich functional groups as “the third electrode” intensified electrooxidation by forming multiple microelectrodes and electron transfer capacity and conductivity of sludge were strengthened by AC in EC system, which were illustrated by electrochemical analysis. It could be found that zeta potential and particle size were increased and surface roughness was reduced after EC/AC treatment intensifying sludge hydrophobicity. Form the results of rheological behaviors of sludge, flowability was strengthened and viscosity was weakened under the conditioning of EC/AC. Besides, colloidal force and gel-like network strength were lessened, which was also verified by organic matters and percentage of inviable cells. At the same time, intracellular matters were released and degraded and bound water was released converting into free water. In addition, sludge compressibility and structural strength were increased and porous structure was formed facilitating water outflow via addition of mesoporous AC as skeleton builder, which eventually led to an improved separation efficiency of solid-water and sludge dewaterability. The results of heavy metals suggested that sludge cake after EC/AC treatment was favorable for land application.

污泥脱水是减少污泥体积以降低最终处置成本的重要过程。在本研究中，采用活性炭 (AC) 强化电化学 (EC) 处理 (EC/AC) 的新方法可大大提高污泥脱水能力。结果表明，在EC电压20 V、EC时间30 min、 0.2 g/g 干固体 (DS) AC。具有丰富官能团的活性炭作为“第三电极”通过形成多个微电极来强化电氧化，并通过电化学分析表明，活性炭在EC体系中增强了污泥的电子传递能力和电导率。可以发现，在 EC/AC 处理增强污泥疏水性后，zeta 电位和粒径增加，表面粗糙度降低。污泥流变行为的结果表明，在EC/AC的调节下，流动性增强，粘度减弱。此外，胶体力和凝胶状网络强度降低，这也得到了有机物和不活细胞百分比的验证。同时，细胞内物质被释放和降解，结合水被释放转化为自由水。此外，通过添加介孔活性炭作为骨架助剂，增加了污泥的压缩性和结构强度，并形成了有利于水流出的多孔结构，最终提高了固水分离效率和污泥脱水能力。重金属结果表明，EC/AC处理后的污泥饼有利于土地利用。