Abstract Reverse electrodialysis (RED) converts salinity gradient energy (SGE) into electrical energy. Seawater and river water are the most promising feed solutions for RED, but municipal wastewater instead of river water could be acceptable if the wastewater treatment plant is close to the sea because river water is often used for human demands, i.e., for drinking water and agricultural irrigation. In addition, the environmental impact at the mixing point (the brackish water region) must be considered. Wastewater pretreatment is necessary to prevent performance reduction in the subsequent RED process. In this study, the effect of pretreatment using polyaluminum chloride (PAC) as a coagulant on the RED performance was investigated using model and real municipal wastewater and seawater samples. The results reveal that the presence of PAC residue after coagulation negatively affected the subsequent RED process, especially because of the increased cation exchange membrane resistance, which resulted in a 40% reduction in power generation. However, the optimized PAC dosage (and lower amount of PAC residue) resulted in a 20% improvement in RED power generation because 50% of the wastewater organic content had been removed. Thus, coagulation pretreatment with the optimized PAC dose is useful before RED power generation when using municipal wastewater.

中文翻译：

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利用海水/市政废水发电的反电渗析：混凝预处理的影响

摘要 反向电渗析 (RED) 将盐度梯度能 (SGE) 转化为电能。海水和河水是最有前途的 RED 进料解决方案，但如果污水处理厂靠近大海，则可以接受城市废水而不是河水，因为河水通常用于人类需求，即饮用水和农业用水。灌溉。此外，还必须考虑混合点（咸水区）的环境影响。废水预处理是必要的，以防止后续 RED 过程中的性能下降。在这项研究中，使用模型和真实的城市废水和海水样品研究了使用聚氯化铝 (PAC) 作为混凝剂进行预处理对 RED 性能的影响。结果表明，混凝后 PAC 残留物的存在对后续的 RED 过程产生负面影响，特别是因为阳离子交换膜阻力增加，导致发电量减少 40%。然而，优化的 PAC 用量（以及较低的 PAC 残留量）使 RED 发电量提高了 20%，因为 50% 的废水有机成分已被去除。因此，当使用城市废水时，在 RED 发电之前使用优化的 PAC 剂量进行混凝预处理是有用的。由于 50% 的废水有机成分已被去除，优化后的 PAC 用量（以及更低的 PAC 残留量）使 RED 发电量提高了 20%。因此，当使用城市废水时，在 RED 发电之前使用优化的 PAC 剂量进行混凝预处理是有用的。由于 50% 的废水有机成分已被去除，优化后的 PAC 用量（以及更低的 PAC 残留量）使 RED 发电量提高了 20%。因此，当使用城市废水时，在 RED 发电之前使用优化的 PAC 剂量进行混凝预处理是有用的。