Ju Jaehyun, Choi Yongjun, Lee Sangho, Park Chan-Gyu, Hwang Taemun, Jung Namjo
Environmental Technology Division Water Environment Center, Korea Testing Laboratory, 87, Digital-ro 26-gil, Guro-gu, Seoul 08389, Korea.
School of Civil and Environmental Engineering, Kookmin University, Seoul 02707, Korea.
Membranes (Basel). 2022 Mar 29;12(4):372. doi: 10.3390/membranes12040372.
With the increasing concern about climate change and the energy crisis, the use of reverse electrodialysis (RED) to utilize salinity gradient power (SGP) has drawn attention as one of the promising renewable energy sources. However, one of the critical issues in RED processes is membrane fouling and channel blockage, which lead to a decrease in the power density. Thus, this study aims to improve our understanding of SGP generation by using RED by investigating the effect of pretreatment on the RED performance. Experiments were conducted by using a laboratory-scale experimental setup for RED. The low-salinity and high-salinity feed solutions were brackish water reverse osmosis (BWRO) brine from a wastewater reclamation plant, and a NaCl solution simulating seawater desalination brine. Several pretreatments were applied to the RED process, such as cartridge filter (CF), microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), activated filter media (AFM), and granular activated carbon (GAC). The results indicate that the open-circuit voltage (OCV) and the power density were similar, except for in the NF pretreatment, which removed the dissolved ions to increase the net SGP. However, the pressure in the RED stack was significantly affected by the pretreatment types. The excitation-emission matrix (EEM) fluorescence spectroscopy and the parallel factor analysis (PARAFAC) quantified the organic compounds that are related to the stack pressure. These results suggest that the removal of both colloidal and organic matters by pretreatments is crucial for improving the RED performance by reducing the pressure that is increased in the RED stack.
随着对气候变化和能源危机的日益关注，利用反向电渗析（RED）来利用盐度梯度能（SGP）作为一种有前景的可再生能源已受到关注。然而，RED过程中的一个关键问题是膜污染和通道堵塞，这会导致功率密度下降。因此，本研究旨在通过研究预处理对RED性能的影响，加深我们对利用RED产生SGP的理解。实验使用了实验室规模的RED实验装置进行。低盐度和高盐度进料溶液分别是来自废水回收厂的苦咸水反渗透（BWRO）浓盐水，以及模拟海水淡化浓盐水的NaCl溶液。对RED过程进行了几种预处理，如筒式过滤器（CF）、微滤（MF）、超滤（UF）、纳滤（NF）、活性过滤介质（AFM）和颗粒活性炭（GAC）。结果表明，除了NF预处理中去除溶解离子以增加净SGP外，开路电压（OCV）和功率密度相似。然而，RED电池堆中的压力受预处理类型的显著影响。激发-发射矩阵（EEM）荧光光谱和平行因子分析（PARAFAC）对与电池堆压力相关的有机化合物进行了定量。这些结果表明，通过预处理去除胶体和有机物对于通过降低RED电池堆中升高的压力来提高RED性能至关重要。
