Characteristics of Desalination Brine and Its Impacts on Marine Chemistry and Health, With Emphasis on the Persian/Arabian Gulf: A Review (original) (raw)
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Impact of Brine Discharge from Seawater Desalination Plants on Persian/Arabian Gulf Salinity
Journal of Environmental Engineering, 2019
The Persian Gulf (also known as Arabian Gulf) is surrounded by desalination plants with about 50% of worldwide capacity to desalinate seawater. Most of these plants dispose of hypersaline effluent (brine) via surface and nearshore outfall into the Gulf. Because energy for desalination increases with seawater salinity, buildup of salt in brine endangers potable water supply there. Brine also contains metals and chemicals (foreign to the marine environment) that have adverse effects on marine ecosystems. Here, for the first time, brine is introduced into Gulf evaporation-driven residual circulation, which controls subbasin flushing, to quantify brine impact on salinity at basin and regional scales. Salt buildup increased mean annual basin salinity (40.5 g=kg) by only 0.43 g=kg, which confirms that basin salinity is insensitive to brine. But regional sensitivity to brine is significant, especially in the southwestern Gulf region near the Arabian coast, where the largest salt buildup raised salinity by about 4.3 g=kg. The results of this study suggests a significant role for brine outfall position in determining brine impact on regional salt levels.
Desalination, 2005
As generally seen benign, seawater desalination is not without environmental concerns of its own. All over the world, in thermal desalination plants, seawater feed is heated to extreme temperatures, mixed with chemicals and desalted to produce fresh desalinated water, together with by-product of concentrated brine-solutions that become released back into the sea.Today, all around the world, and in the Arabian Gulf Region in particular, much of the fresh water needs are being obtained from seawater through the various processes of desalination, which mainly include heatbased processes (e.g. Multi-Stage Flash (MSF), Multiple Effect Distillation (MED) and Vapour Compression (VC)) and membrane processes (Seawater Reverse Osmosis (SWRO)).Concentrated brines from MSF plants (with TDS exceeding that of the seawater-feed, elevated temperatures and containing chemical-residuals) are, regrettably, discharged into the oceans and seas without any treatment, with an overwhelming world-wide conscious-disregard to the potential of hidden dangers and virulent effects on global marine eco-systems, while the effluent temperature plays a vital role in this orchestration.In the Arabian Gulf alone, MSF desalination plants treat huge volumes of seawater (in excess of 25 million m3/day) so to obtain desalinated water of ≈5–10 million m3/d (forgetting-not the other heat-based processes, such as MED, that are increasingly emerging into use today). The remainder (in the neighbourhood of about 20 million m3/day of very heated and concentrated brine) is returned back to the sea, an issue that has today become of growing controversial concerns.The product water recovery for most heat-based seawater desalination plants is between 15 and 50% (and that for membrane-based processes is between 30 and 40%), produced along with brine containing concentrated solution of all the dissolved solids that were originally present in the seawater-feed. On the other hand, the lesser saline brine (retentate) from SWRO desalination plants, where there is no heat involved (with less chemical (eynord) residuals), may have a relatively minor adversity on marine ecology.Regrettably, there exists NO strict and binding legislation on the quality control of fluid-effluents from desalination plants into the sea and NO treatments what-so-ever for these effluents. The vigilant observant may mistakenly-comprehend that desalinated water is indispensably required at any cost, regardless of the side-effect impacts of these effluents on marine environment and on seawater integrity, and the disturbances that this causes onto the ecological systems in the oceans and seas.This paper shall take a glance at the fluid effluents analysis-data from two MSF plants and two RO plants around the Arabian Gulf compared-against the Standard of Industrial Effluents limits for the Kingdom of Bahrain, to envision where-we-stand and where-we-should-be, and attempt to highlight the invisible dangers of desalination fluid-effluents.It would be also appropriate to articulate a digest with global vision on the availability of fresh water from oceans and seas and to illustrate an insightful-overview of seawater RO desalination history with global-insight touching on a few crucial water issues.
Journal of Environmental Science and Engineering A, 2018
Seawater desalination has become the only viable source of fresh water for Kuwait. However, desalination plants could have several impacts on the surrounding marine environment. The major concern of these impacts surrounds the outfall effluent discharge because of its physical and chemical features including high temperature and salinity associated with residual chemicals used in the pretreatment process. In this study assessment of potential impact of Az-Zour desalination plant discharge effluent on marine environment was carried out. The assessment consisted of field measurements and numerical modelling of effluent dispersion. The results revealed a potential impact by temperature and salinity between 4 and 6 o C and 2-4 ppt above ambient and mean levels for Kuwait seawater. The predictions of hydrodynamic modelling show that the plume from the outfall runs parallel to the shoreline and the influenced area can reach to about 40 km 2 .
Environmental assessment of brine discharge and wastewater in the Arabian Gulf
Desalination and Water Treatment, 2011
This study assesses the environmental effects of brine discharge into the Arabian/Persian Gulf and the option of mixing with wastewater to reduce the salt content in the discharge. The Arabian Gulf region occupies about 3.3% of the world area and has 1.0, 2.0 and 2.2% of the total world population in the years 1950, 2008 and 2050 (prognosis) respectively. The study area desalination capacities were obtained as 50, 40 and 45% of total world capacity at the end of 1996, 2008 and 2050 (prognosis) respectively. The trend towards increased recovery ratio in the desalination plants was considered as one important environmental factor. This will significantly increase the brine salt concentration from 1.5 to more than 2 times the seawater. The allocation of wastewater and brine is important for the Arabian Gulf. Straightforward water and salt mass balances were used to calculate residual flow, exchange flow and exchange time in the Arabian Gulf. For example, at zero wastewater discharge from 1996 to 2008, the net volume in the Arabian Gulf decreased by 7.4 million m 3 /d, the exchange volume increased by 69 million m 3 /d, and the mixing time decreased by 22.5 d. Discharging a mix of brine and wastewater in the Arabian Gulf reduces the water and salt exchange between the Gulf and the Indian Ocean. Nutrients in wastewater may cause problems such as eutrophication in the Gulf if the exchange of water is low or if wastewater is discharged to the Gulf with insufficient treatment.
Environmental Research Communications, 2020
Around the Persian (Arabian) Gulf, a considerable volume of freshwater is obtained by desalination of seawater with the residual brine dumped back into the Gulf. This discharge of saltier waters impacts the marine ecosystem and may also affect dynamic and thermodynamic processes. Here, a fully non-linear, high-resolution numerical model is used to investigate the physical impacts of brine discharge into the Gulf. Twin runs were executed. One with and another without brine discharge at specific points. The results show that, when brine is injected, surface gravity waves irradiate from the locations and induce perturbations in other thermodynamic variables in the far field. Instead of attenuating, the anomalies have long term impact. The differences between the two experiments show marked seasonal and spatial variability. The largest differences occur during the summer and are located mainly along the axis of the Gulf’s deeper channel. After 5 years of run, a budget calculation shows ...
2011
Seawater desalination constitutes an important source for water supply to the population bordering the Arabian Gulf, the Mediterranean Sea, and the Red Sea. The three regions represent about 11.8% of the world land area and the countries hosted approximately 9% of the world population in 1950 and 2008 and are projected to do so again in 2050. Population statistics for a 100-year period has been used including a prognosis from 2010 to 2050. Data on desalination plant capacity covering 12 years from 1996 to 2008 has been summarized and a prognosis of the increase in desalination for the three regions until 2050 developed. The results obtained for desalination capacity in the study area were 62%, 58%, and 60% of the world capacity for 1996, 2008, and 2050, respectively. The increase in the recovery ratio is considered an important factor in this study. In 1996 this ratio was about 30 to 35%, and in 2008 it was 40 to 45%, although in some plants it reached up to 50%. Brine discharge will increase the salinities of the Arabian Gulf, Mediterranean Sea, and Red Sea, by some extra 2.24, 0.81 and 1.16 g/l in the year 2050.
Journal of Cleaner Production, 2021
Brine released from desalination plants is extremely high in salinity and contains various chemicals, which are harmful to the ecosystem. The disposal of brine has raised great concerns for the desalination industry around the world due to its detrimental impact on fauna and flora. This review complies with various zero liquid discharge technologies that have been proposed for successful brine disposal which aims to minimize the impact of brine discharge. Moreover, it highlights some of the detrimental impacts of brine discharge on marine fauna and Flora. It also discusses both thermal and membrane technologies for recovering freshwater, energy, and minerals from waste brine, in addition to the recent advances in a solar pond, membrane distillation, pressure retarded osmosis, etc. In Driver-Pressure-State-Impact-Response (DPSIR) framework was used in this review to analyze the water resource system in Qatar. This review also facilitates and provides a comprehensive approach in minimizing the potential impact of brine discharge which can be practiced and applied in countries where desalination plants are set up. This promotes cleaner production, sustainability, and recycling of waste that will help protect and preserve the country's natural water resources.
Environmental Impacts of Seawater Desalination: Arabian Gulf Case Study
Desalination of seawater accounts for a worldwide water production of 5000 million m 3 /year. A "hot spot" of intense desalination activity has always been the Arabian Gulf, but other regional centers of activity emerge and become more prominent, such as the Mediterranean Sea and the Red Sea, or the coastal waters of California, China and Australia. The growth gap between supply and demand for water in the GCC countries can be attributed to limited available surface water, high population growth and urbanization development, deficient institutional arrangements, poor management practices, water depletion and deterioration of quality, especially in shallow groundwater aquifers. Increasing demand for water in the domestic sector has shifted attention to the role of desalination in alleviating water shortages. Experience in the Gulf States demonstrates that desalination technology has developed to a level where it can serve as a reliable source of water at a price comparable to water from conventional sources. Desalination remains in GCC countries the most feasible alternative to augment or meet future water supply requirements. It is considered a strategic option for satisfying current and future domestic water supply requirements, in comparison to the development of other water resources. Despite the many benefits the technology has to offer, concerns rise over potential negative impacts on the environment. Key issues are the concentrate and chemical discharges to the marine environment, the emissions of air pollutants and the energy demand of the processes. To safeguard a sustainable use of desali nation technology, the impacts of each major desalination project should be investigated and mitigated by means of a project-and location-specific environmental impact assessment (EIA) study, while the benefits and impacts of different water supply options should be balanced on the scale of regional management plans. In this context, our paper intends to present an overview on present seawater desalination capacities by region, a synopsis of the key environmental concerns of desalination, including ways of mitigating the impacts of desalination on the environment, and of avoiding some of the dangers of the environment to desalination.
BRINE DISPOSAL IMPLICATIONS ON NEARSHORE PHYSICO-CHEMICAL QUALITY OF MARINE ENVIRONMENT
The Middle East region has witnessed spectacular progress in desalination industry offering a perpetual source of fresh water to the traditionally water deficient regions of west Asia. Despite the progress achieved by the industry, knowledge on the impacts of brine disposal still remains very limited. Environmental concerns have grown all over the world on the potential impacts of brine disposal on the physico-chemical quality of the live near-shore seawater resource. This paper attempts to examine all possible implications of brine disposal on the physico-chemical quality adjacent to desalination plants and discusses in detail various issues on the basis of extensive literature review and spatio-temporal data collected from the sea adjacent to Marafiq Power Desalination Project (Yanbu), which is one of the private sector Desalination Plants in the Kingdom of Saudi Arabia. Yanbu city is the situated at about 350 Km north west of city Jeddah on the Red Sea coast. This facility consists of nine Multistage Flash Desalination (MSF) evaporators with a net installed distillate production capacity of 95,760 m3/day. The Plant started its commercial operation in several phases, four Desal units in 1984, two in 1987, two in 1997 and one in 1999. The water quality in the discharge area gets modified as a result of continuous flow of the effluents. Apparently, the elevations of temperature and salinity are the most common effects reported by a number of investigators. Detailed accounts on all water quality parameters, such as temperature, conductivity, hydrogen ion concentration (pH), total suspended solid (TSS), dissolved oxygen (DO) and heavy metal concentrations, issues of disinfection by-product (DBPs), chemical residues likely to reach the sea are presented in this paper. Data available in literature from other Desalination Plants in GCC countries have also been reviewed and compared to address the issue of brine disposal from a regional angle. Several other aspects of brine disposal, such as mixing, dilution and dispersion have been discussed in the light of regulatory requirements and the beneficial role played by brine channel, cascading discharge and certain other environment friendly practices in place at various Desalination facilities are presented as well.