Lee Seoyeon, Lee Juyoung, Ju Jaehyun, Cho Hyeongrak, Choi Yongjun, Lee Sangho
School of Civil and Environmental Engineering, Kookimin University, 77 Jeongneung-ro, Seongbuk-gu, Seoul 02707, Republic of Korea.
Korea Testing Laboratory, 10, Chungui-ro, Jinju-si 52852, Republic of Korea.
Membranes (Basel). 2025 Feb 8;15(2):56. doi: 10.3390/membranes15020056.
Salinity gradient power (SGP) technologies, including pressure-retarded osmosis (PRO) and reverse electrodialysis (RED), have the potential to be utilized for the purpose of harvesting energy from the difference in salinity between two water streams. One challenge associated with SGP is a reduction in power density due to membrane fouling when impaired water is utilized as a low-salinity water stream. Accordingly, this study sought to explore the feasibility of membrane capacitive deionization (MCDI), a low-energy water treatment technique, as a novel pretreatment method for SGP. Laboratory-scale experiments were conducted to evaluate the impact of MCDI pretreatment on the performance of PRO and RED. The low-salinity water was obtained from a brackish water reverse osmosis (BWRO) plant, while the high-salinity water was a synthetic seawater desalination brine. The removal efficiency of organic and inorganic substances in brackish water reverse osmosis (BWRO) brine by MCDI was estimated, as well as theoretical energy consumption. The results demonstrated that MCDI attained removal efficiencies of up to 88.8% for organic substances and 78.8% for inorganic substances. This resulted in a notable enhancement in the lower density for both PRO and RED. The power density of PRO exhibited a notable enhancement, reaching 3.57 W/m in comparison to 1.14 W/m recorded for the BWRO brine. Conversely, the power density of RED increased from 1.47 W/m to 2.05 W/m. Given that the energy consumption by MCDI is relatively low, it can be surmised that the MCDI pretreatment enhances the overall efficiency of both PRO and RED. However, to fully capitalize on the benefits of MCDI pretreatment, it is recommended that further process optimization be conducted.
盐度梯度能（SGP）技术，包括压力延迟渗透（PRO）和反向电渗析（RED），有潜力用于从两股水流之间的盐度差异中获取能量。与SGP相关的一个挑战是，当使用受损水作为低盐度水流时，由于膜污染导致功率密度降低。因此，本研究旨在探索膜电容去离子化（MCDI）这种低能量水处理技术作为SGP新型预处理方法的可行性。进行了实验室规模的实验，以评估MCDI预处理对PRO和RED性能的影响。低盐度水取自苦咸水反渗透（BWRO）工厂，而高盐度水是合成海水淡化盐水。估算了MCDI对苦咸水反渗透（BWRO）盐水中有机和无机物质的去除效率以及理论能耗。结果表明，MCDI对有机物质的去除效率高达88.8%，对无机物质的去除效率为78.8%。这导致PRO和RED的较低密度均显著提高。PRO的功率密度显著提高，达到3.57 W/m²，而BWRO盐水记录的功率密度为1.14 W/m²。相反，RED的功率密度从1.47 W/m²增加到2.05 W/m²。鉴于MCDI的能耗相对较低，可以推测MCDI预处理提高了PRO和RED的整体效率。然而，为了充分利用MCDI预处理的优势，建议进一步进行工艺优化。
