Brine Discharge from Desalination Plants: Environmental Contaminants, Pollution Control Processes and Mitigation Strategies

Desalination is an urgent response to global freshwater shortages, serving more than 300 million people by 2025. However, it is a technology that still raises several sustainability concerns. Through this study, we aim to propose a systematic review based on the PRISMA methodology, analyzing 45 studies published between 2015 and 2026. Quantitative synthesis of 45 studies showed brine salinity ranging from 40 to 75 g/L, boron and bromate concentrations of 1.8 mg/L and 25 µg/L, respectively, and energy consumption of 3–5 kWh/m3 for membrane systems, reaching 15 kWh/m3 for thermal technologies. Economically, the levelized cost of desalinated water remains high (USD 0.5–2.0/m3) due to the high energy consumption of up to 15 kWh/m3 in thermal processes. This study proposes several mitigation strategies, including diffuser optimization, integration of renewable energies, and brine recovery through the extraction of strategic minerals. The originality of this study lies in its integrated approach, combining health, environmental, energy, and economic dimensions, all addressed together in previous reviews. These results demonstrate the need for regional governance and consistent international standards to achieve sustainable water desalination that combines water security and ecosystem conservation.