Techno-economic assessment of zero liquid discharge (ZLD) systems for sustainable treatment, minimization and valorization of seawater brine.

The challenge of brine disposal has sparked a lot of interest in advanced strategies for valorizing them through freshwater and salt recovery. This research article examines the technical and economic aspects of zero liquid discharge (ZLD) desalination systems using two different crystallization processes, namely brine crystallizer (BCr) in scenario 1 and wind-aided intensified evaporation (WAIV) in scenario 2 for sustainable treatment, minimization, and valorization of seawater brine. The results indicated that scenario 1 has a higher water recovery (99.14%) than scenario 2 (85.75%) as the crystallization process in scenario 2 (i.e., WAIV) does not recover freshwater; however, water is evaporated through WAIV technology and thus both systems have low brine volumes (<1 m3/day), achieving ZLD conditions. The total energy and cost demands of scenario 1 (22.15 kWh/m3 & US$100.5/day) are greater than those of scenario 2 (15.34 kWh/m3 & US$85.3/day). Both scenarios are viable, with profits ranging from US$180.49/day to US$225.85/day depending on whether only desalinated water or both desalinated water and solid salt are sold. The insight given in this techno-economic analysis will aid in the sustainable valorization and management of brine from several brine-generating industries.