Life cycle assessment of membrane-based seawater desalination combined with brine resource recovery

With the growing implementation of seawater desalination, the issue of brine disposal and potential utilization emerges as a paramount concern requiring scientific and engineering solutions. Considering the environmental impacts and economic costs associated with direct brine discharge, this study employed Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) methods to analyze the environmental and economic benefits of reverse osmosis (RO) and ultrafiltration-reverse osmosis (UF-RO) seawater desalination processes under different brine disposal strategies. The LCA results indicate that, among various environmental impact indicators, the UF-RO process with brine resource recovery has the lowest environmental impact compared to other processes. The core indicator GWP values range from high to low are as follows: RO-D (1.92 kg CO 2 eq/m 3 ) > RO-B (1.85 kg CO 2 eq/m 3 ) > UF-RO-D (1.57 kg CO 2 eq/m 3 ) > UF-RO-B (1.27 kg CO 2 eq/m 3 ). The LCC results show that the UF-RO process with brine resource recovery also achieves the highest economic efficiency. The LCC results of the four schemes range from high to low are as follows: RO-D process (2.07 CNY/m 3 ) > RO-B process (2.00 CNY/m 3 ) > UF-RO-D process (1.70 CNY/m 3 ) > UF-RO-B process (1.43 CNY/m 3 ).The study demonstrates that brine resource recovery can not only reduce the environmental impacts brought by direct discharge into the sea but also generate economic benefits, thereby achieving a threefold win across environmental, economic, and social dimensions.