Comparative study of brine management technologies for desalination plants

In recent years, reverse osmosis (RU) has grown as an alternative to traditional potable water sources. A major disadvantage of the RU process is the huge amount of brine and its negative impact as a result of its high salinity. This brine is usually discharged to inland water bodies or to the sea and constitutes a threat to ecosystems and species, such as Posidonia oceanica in the Mediterranean Sea; thus, further research is needed for introducing environmentally friendly and economically viable management options for RU brines. This paper gives an overview of recent research as well as different technologies available at several scales to overcome the environmental problems and evaluate profitability related to discharge of RU concentrates. The treatment options have been classified into four different groups according to their final purpose: 1) technologies for reducing and eliminating brine disposal, 2) technologies for commercial salt recovery, 3) brine adaptation for industrial uses and 4) metal recovery. Solar evaporation, two-stage reverse osmosis, electrodialysis, integrated processes and brine adaptation for the chlor-alkali industry are some of the topics that this paper deals with. In the conclusion section, all of the technologies are compared emphasizing all their advantages and drawbacks, feasibility and development stage in order to provide a decision tool to select the best technology for each situation. (C) 2014 Elsevier B.V. All rights reserved.