Economic and cost-effectiveness analysis of integrated desalination and brine treatment systems

Abstract

The brine generated from desalination is a threat to the environment, and its disposal has been a great challenge. A new concept Zero liquid discharge (ZLD) can minimize the environmental impact of brine. However, the high costs for construction and running of a ZLD plant limits its growth in desalination market. Therefore, a new strategy integrating brine mining with desalination is proposed to improve its economic performance due to the valuable minerals in brine. A cost-effectiveness analysis (CEA) is carried out to assess its economic performance and compare this strategy with other ZLD strategies. The results present that the cost-effectiveness of the studied strategy is lower than ZLD systems which only maximize water recovery. The cost-effectiveness ratio of the studied strategy is 0.056€/kg of freshwater, higher than ZLD maximizing water recovery (0.032€/kg of freshwater). However, its profitability is higher than other ZLD schemes. This study shows that the integrated desalination and brine mining strategy has a great economic potential. Its cost-benefit of is 1.12, far lower than that of ZLD only maximizing water recovery (26.08). In addition, it can be indicated that CEA is not comprehensive enough to assess the economic performance of a multi-product desalination system. It doesn’t include the revenues from by-products, which are an important part of the studied strategy. For further research, a more integrated approach of economic analysis is needed to make a decision on the different alternatives of desalination.