Abstract Seawater reverse osmosis (SWRO) desalination is a proven technology for augmenting water supply in remote areas with limited access to fresh water resources. Lowering the energy consumption of SWRO is crucial in such areas where the source of energy is often reliant on transported liquid fuels. This study presents a life cycle cost model for two diluted desalination processes using water reuse to dilute seawater, and reduce energy consumption. The economic model details the life cycle capital and operational costs of i) a baseline SWRO desalination, ii) alternative osmotic dilution desalination in a forward osmosis (FO)–reverse osmosis (RO) hybrid system, and iii) a mixed dilution desalination process in an ultrafiltration (UF)–RO system. The results reveal a 4–5% lower total water cost associated with the two alternative processes compared to conventional SWRO. Sensitivity analysis revealed that the FO–RO system is an economically viable alternative to standalone RO if a water flux ≥6 L·m−2 h−1 and a recovery rate >25% can be achieved. The sensitivity analysis showed that diluted desalination with UF–RO was economically preferable to SWRO even when the water flux and recovery rate of UF meet only minimum thresholds (18 L·m−2 h−1 and 55%, respectively).

中文翻译：

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离网地区稀释海水淡化的生命周期成本：结合海水淡化技术的中水回用研究

摘要 海水反渗透 (SWRO) 脱盐是一项行之有效的技术，可用于在淡水资源有限的偏远地区增加供水。在能源通常依赖于运输的液体燃料的地区，降低 SWRO 的能源消耗至关重要。本研究提出了两种稀释海水淡化过程的生命周期成本模型，该过程使用水回用来稀释海水并降低能源消耗。经济模型详细说明了以下各项的生命周期资本和运营成本：i) 基线 SWRO 脱盐，ii) 正渗透 (FO)-反渗透 (RO) 混合系统中的替代渗透稀释脱盐，以及 iii) 混合稀释脱盐过程超滤 (UF)-RO 系统。结果表明，与传统 SWRO 相比，与两种替代工艺相关的总水成本降低了 4-5%。敏感性分析表明，如果水通量≥6 L·m-2 h-1 且回收率> 25%，则FO-RO 系统是独立RO 的经济可行的替代方案。敏感性分析表明，即使当超滤的水通量和回收率仅满足最低阈值（分别为 18 L·m-2 h-1 和 55%）时，用 UF-RO 稀释脱盐在经济上优于 SWRO。