An Environmental Approach towards Brine Volume Minimization in Reverse Osmosis Desalination Plants

Abstract

Today, reverse osmosis (RO) is the leading technology for new desalination installations, with a 44% share in world desalting production capacity and an 80% share in the desalination plants installed worldwide. As a result of increased interest in RO desalination, the concern about potential environmental problems has grown. RO desalination plants extract large volumes of water and discharge a dense brine concentrate back into the environment. It is widely suggested that desalination plant brines have a strong potential to detrimentally impact both physicochemical and ecological attributes of receiving environments. Different practices need to be followed to overcome the environmental issues linked to brine disposal by achieving higher water recovery from desalination processes. Recently, some processes and technologies have been proposed to accomplish higher water recovery using brine treatment. Therefore, the main objective of this work was to suggest different design configurations of future RO plants in order to minimize the adverse impact of brine discharge. Eight different configurations have been designed and modelled using raw seawater conditions in UAE. The impact on plant recovery ratio, water production, brine discharge and salinity, energy consumption and CO2 emissions have been investigated. Results showed that increasing the RO stages has decreased the brine flow rate, the energy consumption and the operational unit product cost. In addition, recycling 30% of the reject brine has reduced the brine flow rate and the energy consumption by 30 and 36%; respectively.

Date of Award	May 2019
Original language	American English