Dispersion of brine discharge from seawater reverse osmosis desalination plants

Abstract

A B S T R A C TDesalination of seawater has been considered as a potential solution for the water shortage problem in coastal areas and the number of projected and constructed desalination plants has significantly increased in recent years. The challenge of the desalination industry is to produce new water resources without increasing the pressure on the marine environment. Environmental impact of SWRO desalination plants is mainly associated with the discharge into the sea of the brine produced. To estimate the area of influence of the brine several models have been proposed, but validation with real data is needed. The objective of this paper is to present the results of the monitoring of the brine effluent emanating from several SWRO desalination plants in the western Mediterranean Sea in order to estimate the area of influence of the hypersaline plume. We also illustrate how the behavior of these brine discharges can differ significantly according to discharge characteristics. This information may be useful to predict effluent distribution in order to minimize the harmful effects of brine discharges into the sea.

Biological and Physical Effects of Brine Discharge from the Carlsbad Desalination Plant and Implications for Future Desalination Plant Constructions

“…To reduce the footprint of brine plumes and their possible impacts, use of alternative discharge technologies, such as diffuser systems, should be considered and appropriate modeling of the discharge design used. Both models and practice indicate that diffuser systems increase the mixing of discharge brine with ambient seawater [50,56,60,61]. Our results also suggest that long-term monitoring of coastal areas in the vicinity of proposed plants will be needed both before and after construction and operation.…”

Evaluating environmental requirements for the management of brine discharges in Spain

“…These include: i-ii) the analysis of the quantity and quality of the effluent and marine environment including, at least, salinity and nutrients but also substances that come from the pre-treatment and cleaning of membranes and filters, as coagulants and antifouling or organic matter [5,10,29,30]; iii) the control of the saline plume to determine the area potentially affected by the brine discharge [9]. For this, it is necessary that the implementation of salinity profiles which reach the bottom are used to determine salinity and temperature in a grid of points that cover the potential area of influence, and with seasonal replication to include different oceanographic conditions [9]; iv) to monitor key and protected species if they are present in the area to ensure they are not affected by the discharge [12,15] [13,14,29,32]; vi) the use of salinity-sensitive species of benthic fauna as bioindicators has proven to be useful as sentinel species in order to prevent possible impacts on benthic habitats [20,33] and to discriminate between the effects of desalination and other impacts that may coincide in space [32,34]; vii) it is necessary to carry out a structural monitoring of the submerged outfall for the early detection of possible fractures [8]; viii) in the case of a possible rupture of the outfall (or if the discharge is close to key habitats), the existence of a protocol of action with mitigation measures is convenient, given that this may include the increase of dilution, or the reduction of production [15]. Table 2 summarizes the requirements considered in the analysis of the EMPs.…”

“…RO desalination plants produce hypersaline discharges which usually are discharged into the sea given their coastal proximity and thus lower economic cost [5]. Brine discharges have a higher density than seawater, so they form a saline plume that tends to follow the bathymetry of the seabed [9]. Furthermore, they may also contain chemical elements due to the use of anti-scalants and coagulants used in the pre-treatment and membrane cleaning treatments, although most of them are effectively consumed by the process.…”

Environmental impact of RO units installation in main water treatment plants of Basrah city/south of Iraq

“…However, it took until the 1990s before the scientific interest in the marine environmental concerns of desalination plants became more pronounced, as reflected in the large published number of studies. Examples of these studies include those conducted by; Höpner and Windelberg [10], Morton et al [11], Oldfield and Todd [12], Höpner and Lattemann [13], El-Samanoudi et al [14], El-Gamal and Abdrabbo [5], Elabbar and Elmabrouk [8], Medeazza [15], Tularam and Ilahee [16], Lattemann and Höpner [7,17], Münk [18], Abo Qdais [19], Fernández-Torquemada et al [20], Al-Dousari [21], Dupavillon and Gillanders [2], Ahmed and Anwar [22], Dawoud and Al Mulla [23], Darwish et al [24], Naser [25], Fernández-Torquemada et al [26] and Hu [6]. The review of these studies shows that; most of them either examined and compared the environmental impacts of MSF and RO desalination processes or conducted by collecting field data from existing desalination plants.…”