Universidad de Cantabria, Department of Chemical and Biomolecular Engineering, Av. Los Castros 46, 39005, Santander, Spain.
MARE, Ctra. Torres - Reocín, B◦ La Barquera 13, 39311, Cartes, Spain.
J Environ Manage. 2024 Dec;371:123251. doi: 10.1016/j.jenvman.2024.123251. Epub 2024 Nov 11.
Effluents from urban wastewater treatment plants (UWWTPs) discharged into water bodies such as the sea or ocean, offer a potential source of renewable energy through the salinity gradient (SGE) between seawater and treated water. The European project Life-3E: Environment-Energy-Economy aims to demonstrate an innovative process integrating renewable energy production with water reclamation. Using reverse electrodialysis (RED) technology, SGE can power tertiary wastewater treatment processes in coastal UWWTPs, offsetting energy costs associated with water regeneration and reuse. This study pioneers a pilot-scale RED system with a 20.125 m membrane area at a coastal UWWTP in Comillas, Spain. The initial tests with synthetic solutions in the up-scaled RED module have reached a peak power density of 1.39 W/m. Under real environmental conditions, using natural seawater and treated water at ambient temperatures (289 ± 0.5 K), the system achieved a peak power density of 0.95 W/m, outperforming previous setups in stability and efficiency. The results show competitive energy metrics, with an energy efficiency of 1.9 W/m·m³LC and up to 38.2 Wh/m³LC generated. The treated water, with an inlet conductivity to the RED stack of <1 mS/cm, exits the pilot with a conductivity of around 4 mS/cm (measured under a load of 2A and a flow rate of 500 L/h), maintaining the quality standards for urban reuse. This study demonstrates the effective integration of RED technology into water reclamation stages, creating a self-sustained energy loop and enhancing the efficiency in water management. By harnessing blue energy and supporting sustainable water reuse, this research contributes to the global shift toward a circular water economy and critical sustainability goals.
城市污水处理厂（UWWTP）的废水排入海洋等水体，为利用海水和处理水之间的盐度梯度（SGE）产生可再生能源提供了可能。欧洲的 Life-3E 项目：环境-能源-经济旨在展示一种将可再生能源生产与水回收相结合的创新工艺。利用反向电渗析（RED）技术，SGE 可以为沿海 UWWTP 的三级污水处理工艺提供动力，从而抵消与水再生和再利用相关的能源成本。本研究在西班牙科米利亚斯的一个沿海 UWWTP 中，使用 20.125 平方米的膜面积进行了试点规模的 RED 系统的先驱试验。在扩大规模的 RED 模块中，用合成溶液进行的初步测试达到了 1.39 W/m 的峰值功率密度。在实际环境条件下，使用自然海水和环境温度（289 ± 0.5 K）下的处理水，该系统实现了 0.95 W/m 的峰值功率密度，在稳定性和效率方面优于以前的设置。结果表明，该系统具有竞争力的能源指标，能量效率为 1.9 W/m·m³LC，最大可产生 38.2 Wh/m³LC。处理后的水进入 RED 堆的入口电导率<1 mS/cm，在以 2A 负载和 500 L/h 流速运行的情况下，从试点中流出的电导率约为 4 mS/cm，维持了城市再利用的质量标准。本研究证明了 RED 技术有效集成到水回收阶段，可以创建一个自我维持的能源循环，并提高水管理效率。通过利用蓝色能源并支持可持续的水再利用，这项研究为向循环水经济和关键可持续性目标的全球转变做出了贡献。
