A model to predict HAB occurrence near desalination plants in the Red Sea

By the end of 2005 the global installed capacity for desalination of seawater was about 24.5·106 m3/day. The geographical distribution of the desalination plants was as follows: 77 % in the Middle East and North Africa, 10 % in Europe, 7 % in the Americas and 6 % in the Asia-Pacific region. The volume of brine discharged in the Red Sea increased from 6.4 million m3/day (in 1996) to 6.8 million m3/day (in 2008) and is still increasing due to the observed tendency to improve the average recovery ratio from 30 to 50 %. This will make the environmental concerns much more important in the future. There are two main sources of problems, i.e. the concentrate and chemical discharges and the cooling water effluent discharges. The salinity is expected to increase in the long term if larger and larger amounts of desalinated water are removed from the water bodies. A proper solution for the desalination waste brine disposal process requires a good balance between technical constraints (i.e. placing a pipe on the sea-bottom), environmental conditions (i.e., finding an optimum distance from the seashore where high salinity brine should be discharged without significant environmental impact; also, the availability for long run of brine disposal placement should be considered) and as low as possible overall economic costs.Since the potential cumulative impacts of desalination activity on the marine environment is expected to be more significant in case of regional seas, in this chapter we focus on the desalination plants in Red Sea. The objective is to discuss a modeling framework for the environmental-hydraulic design of the outfall system for desalination plants. The chapter presents an interdisciplinary combination of environmental issues with physical processes and discharge modeling. We assess the technical viability of disposal the brine effluent produced by desalination plants into Red Sea coastal regions via submarine pipes.There are several approaches to mitigate the environmental effects of the brine discharges. By tradition, the brine is discharged back to the sea in open channels. Impacts from high salinity may be avoided by pre-dilution of the desalination plant rejected stream with other waste streams, such as power plant cooling water. Impacts from high temperature may be avoided by ensuring heat dissipation from the waste stream to the atmosphere before entering the water body. However, simulations models for the brine plume dispersion from desalination power plants reveal the inadequacy of using surface discharging outfalls in order to brine discharging. Large capacity plants require submerged discharges which ensure a high dilution, reducing the harmful impacts on the marine environment. Mixing and dispersal of the discharge plume can be enhanced by installing a diffuser system, and by locating the discharge in a favorable oceanographic site which dissipates the heat and salinity load quickly.The central concept of the brine disposal by submerged pipes is the available head at the discharge point. Higher values of the available head ensure larger jet dispersion lengths and better conditions for ejected brine dilution. We have shown that the quality of the dilution process is well quantified by the Froude number of the brine discharge jet, whose optimum values range between 20 and 25. Using the Froude number allowed us to find the optimum pipe length and the optimum depth of the discharge point.About half of the Red Sea desalination plants are based on reverse osmosis. The percentage of RO plants is expected to increase, taking into account the lower production costs and the favorable technological evolution. The most representative RO desalination plants around the Red Sea coast are considered both by country and by capacity points of view. In order to provide relevant conclusions for the study reduced capacity desalination plants were selected due to their large number. For not available/existing desalination plants some hypothetic “case studies” were considered.Optimum brine dispersion may be obtained by using underwater pipes for any sort of high capacity and low capacity RO desalination plants operating on the Red Sea coasts. In case of large capacities, a pipe length around lX = 1,000 m allows optimum operation. A pipe length about lX = 500 m is needed for low capacity RO desalination plants.KeywordsFroude NumberReverse OsmosisDischarge PointDesalination PlantPipe LengthThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Harmful algal blooms (HABs) and the high biomass associated with them have afflicted marine desalination plants along coastal regions around the world. Few studies of HABs have been conducted in the Red Sea, where desalination plants along the Saudi Arabian Red Sea coast provide drinking water for millions of people. This study was conducted along the Saudi Arabian Red Sea coast from 2014 to 2015 to assess the potential for using Moderate Resolution Imaging Spectroradiometer (MODIS) remote sensing of chlorophyll a (Chl a) or fluorescence line height (FLH) to identify risks for biofouling at these desalination plants. Ship-based surveys of phytoplankton were conducted along the Saudi Arabian coastline offshore of desalination plants at Jeddah, Al Shoaibah and Al Qunfudhuh to assess the density of phytoplankton populations and identify any potential HAB species. Ship-based surveys showed low to moderate concentrations of phytoplankton, averaging from 1800–10,000 cells L−1 at Jeddah, 2000–11,000 cells L−1 at Al Shoaibah and 1000–20,500 cells L−1 at Al Qunfudhuh. Sixteen different species of potentially toxigenic HABs were identified through these surveys. There was a good relationship between ship-based total phytoplankton counts and monthly averaged coastal MODIS Chl a (R2 = 0.49, root mean square error (RMSE) = 0.27 mg m−3) or FLH (R2 = 0.47, RMSE = 0.04 mW m−2 µm−1 sr−1) values. Monthly average near shore Chl a concentrations obtained using MODIS satellite imagery were much higher in the Red Sea coastal areas at Al Qunfudhuh (maximum of about 1.3 mg m−3) than at Jeddah or Al Shoaibah (maximum of about 0.4 and 0.5 mg m−3, respectively). Chlorophyll a concentrations were generally highest from the months of December to March, producing higher risks of biofouling desalination plants than in other months. Concentrations decreased significantly, on average, from April to September. Long-term (2005–2016) monthly averaged MODIS Chl a values were used to delineate four statistically distinct zones of differing HAB biomass across the entire Red Sea. Sinusoidal functions representing monthly variability were fit to satellite Chl a values in each zone (RMSE values from 0.691 to 0.07 mg m−3, from Zone 1 to 4). December to January mean values and annual amplitudes for Chl a in these four sinusoidal functions decreased from Zones 1–4. In general, the greatest risk of HABs to desalination occurs during winter months in Zone 1 (Southern Red Sea), while HAB risks to desalination plants in winter months are low to moderate in Zone 2 (South Central Red Sea), and negligible in Zones 3 (North Central) and 4 (Northern).

The Kingdom of Saudi Arabia obtains the most desalination water from the Red Sea. In Saudi Arabia, 14 desalination plants receive water from the Red Sea, and three are located in the country’s east and rely on the Arabian Gulf. The study has observed 16 desalination plants out of 17 desalination plants in the kingdom. Most of the desalination plants in Saudi Arabia currently use the advanced technologies to produce potable water with less impact on the surrounding environment. The current study examined the variation of hydrographic parameters along all available desalination plants in Saudi Arabia. This is the first inter-annual database of hydrographic parameters in the last 4 years. The peak salinity was measured at the Duba desalination plant in 2020, and it was 67.2 ppt. During 2018, the Azizia desalination plant reported the lowest value of 36.8 ppt. The maximum temperature recorded at the Qunfudah desalination plant in 2019 was 34.6°C. In 2017, the minimum temperature was 19.1°C at the Jubail desalination plant. The level of dissolved oxygen and pH were likewise not significantly changed along the brine outflow and in the outfall, in contrast to temperature and salinity. On the basis of 4 years’ of data from observed desalination facilities, the current study sheds light on the less environmental impact with regard to hydrographic factors.

Desalination of brackish water by nanofiltration and reverse osmosis

As part of the Vision 2030 for economic growth and development in the Kingdom of Saudi Arabia, the Marine and Coastal Environment Protection (MCEP) Initiative for Saudi Arabia was established (https://mcep.kaust.edu.sa/). In the frame of this project, we traced the discrete sources of pollution in critical hotspot areas including: wastewater treatment plants (WWTP), desalination plants, ports, industries, petroleum platforms, aquaculture facilities and urban development. In this work, we present measurements of organic pollutants in sediments obtained during a surveillance cruise conducted in June 2021 with the HCMR  R/V AEGAEO, over a north - south coastal transect in the Red Sea. The hot spots areas surveyed, from north to south, were: the area near the Saudi-Jordanian border (Phosphate Terminal in Aqaba Port in Jordan; cross-border pollution) and Haql (desalination, power and WWTP, port activities), Magna (maritime traffic), Tabuk Fisheries (aquaculture activities), Duba (desalination plant), Al Wajh (port facilities; desalination plant), Red Sea Project Lagoon (north and west channels), Yanbu Cement Company (industrial discharges), Yanbu King Fahd Port (industrial and shipping center- the largest in Saudi Arabia), Jeddah Lagoon System (wastewater inputs), Jeddah Mena (port operations), Al Khurma (Jeddah WWTP), Al Lith (shrimp and fish farms), Al-Shuqaiq (desalination plant) and Jizan Economic City (expanding industrial facility). This is the first broad coverage study in a one-off sampling campaign in Saudi Arabian coastal zone, constituting the first multidisciplinary and geographically comprehensive survey of contaminants. Aliphatic (C10-C40) and polycyclic aromatic (32 substances including both parent and methylated compounds) hydrocarbons (AHC and PAH) and polychlorinated biphenyls (PCB), which constitute important classes of organic contaminants that may cause degradation and pose a risk of serious damage in the marine environment, were determined in surface sediments collected from the coastal zone of the Red Sea. In general, north-south increasing gradients were evident for all pollutants, revealing a link between the hydrographic conditions and biogeochemical properties. AHC concentrations did not exceed 44 μg/g with the exception of Jeddah Mena, Al Khumra and Lagoons, where values almost 200 times higher were detected. Very increased PAH levels (>1000 ng/g) were measured only in the lagoons, whereas moderate pollution was found in Jeddah Mena and Al Khumra. PCBs concentrations were low in all the samples studied. The examination of various molecular indices and ratios revealed a chronic petroleum-associated anthropogenic pressure in Jeddah Lagoons, Jeddah Sea Port and Al Khumrah, whereas some petroleum residues were also found at King Fahd Yanbu Port, shrimp and fish farms near Al Lith and to a lesser extent at Magna. The domestic and industrial activities probably enrich the coastal zone of the Red Sea with organic pollutants. Hydrocarbons were linked with different sources, e.g domestic sewages (detergents) in Jeddah Lagoons and weathered petroleum in Jeddah Mena, whereas in Al Shuqaic hydrocarbons were mostly of biogenic origin. Pyrolytic PAHs predominated only in Jeddah Mena, indicating that limited combustion processes occur in the Red Sea which do not  affect the marine environment. Regarding sediment quality guidelines PAHs concentrations were, in general,  lower than ERL values.

The Red Sea is a conspicuous water body that hosts important coral reef ecosystems. This semi-closed sea is exposed to warming either by climate change or by anthropogenic stressors. The desalination plants along the Red Sea coast of Saudi Arabia dispose tremendous effluents of hot water from cooling systems, which is expected to impact the neighboring coral reef patches. The main objectives of this study were to delineate the spatial variations and the temporal trends of sea surface temperatures (SST) in the Red Sea using geospatial analysis with focusing on water temperature anomalies adjacent to seawater desalination plants. Monthly sea surface temperatures data were acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua satellite for the period 2003-2019. Annual SST changes and decadal trends were obtained from interpolation analysis and robust statistical metrics, respectively. Results showed that the Red Sea has three distinguished temperature zones with the coldest at the north and the warmest at the south. In addition, global warming is remarkably apparent in the northern part of the Red Sea (0.8 °C/decade). About one third of the Saudi corals occur at the northern part, while the remaining coral patches settle in the middle and southern parts of relatively lower SST trends. However, some corals in the middle section of the Red Sea occur proximate to regions of abruptly high SST trends due to the discharge of hot waters from desalination plants, particularly south of Jeddah. The continuous human-induced heating by hot water disposal could be fatal to coral reef ecosystems nearby desalination plants.

Impact of seawater intrusion and disposal of desalinization brines on groundwater quality in El Gouna, Egypt, Red Sea Area. Process analyses by means of chemical and isotopic signatures

There are many researches illustrated that almost lots mankind is suffering from shortage fresh water supply, both of quality and quantity. Considering water inadequate concerns approximately 80 countries and has caused some dangerous results in many places. The water shortage phenomenon is becoming a serious worldwide problem that impacts people’s daily life and obstacle the social development. Because of the population increasing and expansion of industrial and agricultural activities, the governments of many countries get one’s way to implement the desalination plants. A desalination plants is an industrial system that would have the potential to have an effect on environmental ecosystem. This study monitored variety of environmental impacts can be caused by desalination plants. It’s considers a case study for two of the desalination plants located at Shalateen city at Red sea governorate namely; Marsa Humira and Shalateen desalination plants. The investigation unconcealed that there are distinct impacts of the reject water on the marine ecosystem in the front of the two studied stations. The photographs that has been taken to the biota exist in the marine area around the stations elucidated some of coral reefs affected by the discharge of the saline reject around. Coral reef and sea grass are the most biota affected due to the salty discharges that exceed the safe limits for those to be in a healthy condition.

Spatial and temporal distribution of heavy metals in coastal core sediments from the Red Sea, Saudi Arabia

Perspective on desalination discharges and coastal environments of the Arabian Peninsula

Water desalination: An imperative measure for water security in Egypt

The role of desalination in bridging the water gap in Jordan

Dynamics of turbidity in gypsum-precipitating brines: The case of the Red Sea – Dead Sea project

Coastal waters in tropical and sub-tropical regions of the world are among the most productive and intensely commercialized marine ecosystems, and are also the most threatened by contamination from industrial and urban land-use activities. Insights into issues of potential importance for the Red Sea area may be obtained from experiences in analogous waters elsewhere in the world, including the western hemisphere. Globally, the major challenges to a healthy coastal environment are posed by urbanization/industrial activity, intense coastal shipping, offshore petroleum exploitation, and tourism development. Although the Red Sea is characterized by low population densities along its coasts, the need still exists for proper coastal zone management. Urbanization and industrial activity are the major factor in pollution by metals in the vicinity of the city of Jeddah as well as by effluents from desalination plants and refineries. Such urban-generated contamination almost always goes together with contamination by sewage and nutrients from waste water treatment. All can have a negative effect on valued coastal amenities such as coral reefs, bathing beaches, coastal fisheries/mariculture, and coastal mangroves. Research in Lake Ontario, Canada can be used to provide means to study the dispersal of such pollutants via sediments. Ships using the Suez Canal carry cargoes (some of which are toxic or harmful to aquatic life) that pose a threat to coastal resources by accidental and deliberate spills/ discharges. Research carried out elsewhere (the Bahamas) into the fouling of tourist beaches by petroleum tar-balls has shown that this effect is serious and cumulative and, in addition to sensitive coastal amenities (beaches, coral reefs, and fishing grounds), might also cause damage to valued benthic communities. Ships traversing the Red Sea also have the potential for introducing exotic species from remote areas that may be harmful to the diverse Red Sea aquatic fauna, especially Acanthaster planci, the crown-of-thorns starfish. This possibility is dramatically illustrated by the case of the inadvertent introduction of the European zebra mussel (Dreissena) to the Great Lakes in 1986. تعتبر المياه الساحلية في المناطق المدارية والتحت مدارية من أهم البيئات، من حيث إنتاجيتها وعائداتها الاستثمارية، وكذلك الأكثر عرضة للتهديدات من التلوث الناتج من الصناعات والأنشطة الأدمية. والتعرف على المحاور ذات الأهمية في البحر الأحمر، يمكن أن يأتي من خلال الخبرات المكتسبة في مناطق شبيهة في أماكن مختلفة من العالم، بما في ذلك نصف الكرة الغربي. بشكل عام فإن أهم ما يهدد صحة البيئة الساحلية هو الامتداد العمراني، والنشاط الصناعي، والملاحة المكثفة، واستغلال آبار البترول في المياه العميقة، والتطور السياحي. وبالرغم من أن البحر الأحمر يتميز بكثافة سكانية منخفضة على سواحله ، مازالت هناك حاجة ملحة لإدارة ساحلية مناسبة. والامتداد العمراني والأنشطة الصناعية هي العوامل الرئيسية للتلوث بالعناصر بالقرب من مدينة جدة، إضافة إلى مياه الصرف من محطات التحلية ومعامل التكرير. هذه الملوثات المرتبطة بالتوسع العمراني عادة ما تتوافق مع التلوث بمخلفات الصرف الصحي والعناصر المغذية من محطات معالجة مياه الصرف الصحي، كلها يمكن أن تترك آثارا سلبية على الشعاب المرجانية، الشواطئ ، ومزارع الأسماك، والبحار، وكذلك على اشجار المانجروف. ويمكن أن يستخدم البحث الذي أجري في جدة أو أونتاريو بكندا ليمدنا بوسائل لدراسة انتشار هذه الملوثات عن طريق الرواسب. السفن العابرة لقناة السويس تحمل شحنات ( بعضها سام أو ضار للحياة البحرية) تهدد الثروات الساحلية عن طريق الحوادث التي تؤدي على انتشار هذه الشحنات في الوسط. وقد أفادت البحوث التي أجريت في أماكن أخرى ( جزر البهاماس) عن تواجد كرات القطران أن تاثيرها خطر وتراكمي ليس فقط على الشواطئ ، والشعاب، والمصايد، وإنما أيضا على أحياء القاع. كما أن السفن التي تعبر البحر الأحمر لها المقدرة على إدخال أنواع من الأحياء السامة من مناطق بعيدة، والتي يمكن أن تضر بالحيونات البحرية للبحر الأحمر، خاصة نجم البحر Acanthaster planc هذه الإمكانية تبرزها حالة إدخال بلح البحر الأوروبي European sebra mussel (Dreissena) إلى البحريات الكبرى عام 11986.

Water desalination in Egypt; literature review and assessment