Seawater Desalination Plant Research Articles

Investigation of efficient corrosion inhibitor during acid cleaning of reverse osmosis (RO) desalination plant

Reverse osmosis (RO) technology plays a vital role in seawater desalination production, while salt scaling phenomenon is an inevitable problem during operation. Accordingly, glucuronide-substituted catechin (CG) was synthesized and developed here as an eco-friendly inhibitor for the first time, whose corrosion inhibition performances for desalination equipment alloys (i.e., carbon steel, brass, Ni-resist, and 316 L stainless steel) in 2% HCl solution were evaluated by experiments and theoretical calculations. At a concentration of 200 mg/L, CG achieved 97.81% corrosion inhibition for carbon steel, 85.91% for Ni-resist, 92.11% for brass, and 77.95% for 316 L stainless steel in weight loss experiments. The 90-hours static stability test was carried out by weight loss method, and the inhibition performance of CG was compared with that of a commercial corrosion inhibitor used in seawater desalination plant. The structural of the protective film on the metal surface was analyzed by EDX and XPS. Quantum chemical calculations based on density functional theory (DFT) and MD simulations were performed to optimize the CG molecular structure and investigate the inhibitive properties on the theoretical level, which agree well with the experimental results.

The Effect of Trace Ions on the Performance of Reverse Electrodialysis Using Brine/Seawater as Working Pairs

Harvesting the salinity gradient power (SGP) between concentrated brine discharged from seawater desalination installations and seawater and converting into electric energy by reverse electrodialysis (RED) is a promising technique. However, trace ions in brine and seawater may affect the performance of the RED stack, and little attention has been focused on this issue. Therefore, the influences of trace ions in seawater and concentrated brine are analyzed in this work. The effects of these ions on power density, open-circuit voltage, and internal resistance of the RED stack are analyzed by configuring manual seawater and concentrated brine including K1+, Mg2+, SO42-, and Ca2+. Experimental results show that divalent ions (Mg2+, SO42-, and Ca2+) can significantly increase the internal resistance of the RED stack and reduce power density. Mg2+ especially has the largest reduction in the output power of the stack. Oppositely, potassium ions (K1+) in feed solutions will reduce the internal resistance and improve power output. In addition, increasing the salinity gradient of feed solutions, temperature, and flow rate can increase open-circuit voltage and power density, and reduce inner power consumption of the RED stack. This study can provide references for the recovery of SGP in seawater desalination plants.

Life cycle assessment and cost of a seawater reverse osmosis plant operated with different energy sources

Seawater desalination plants consume significant amounts of energy sourced primarily from fossil fuels, leading to significant environmental impact. Life Cycle Assessment has been applied to desalination systems powered by a single renewable energy source with the underlying assumption of sufficiency of power supply. However, in several locations in the world the intermittent nature of these renewable sources prevents a full reliance on a single source and necessitates a combined fossil fuel-renewable energy mix. This study addresses this issue by performing life cycle assessment and preliminary costing analysis for different renewable-energy-grid combinations (photovoltaic-grid, wind-grid and anaerobic digestion-grid). Whilst the grid-anaerobic digestion and grid-photovoltaic scenarios provided significant improvements in all environmental impact categories, the grid-wind energy option resulted in the highest reduction whereby a 60% decrease in carbon footprint was observed. The unit product cost for the environmentally optimum grid-anaerobic digestion scheme was the lowest at 0.94 $/m3, while the unit product cost for the grid-photovoltaic scheme was the most expensive at 1.47 $/m3. An integrated photovoltaic-wind-anaerobic digestion scheme may offer further reduction in environmental impact and a potentially lower unit product cost.

Mapping Current and Future Seawater Desalination Plants Globally Using Species Distribution Models

AbstractDesalinized seawater is a vital freshwater source for regions with coastal water scarcity. Mapping seawater desalination plants enables a spatially detailed water resource assessment. Here, which is the first of its kind, we investigated the potential application of species distribution models (SDMs), which are widely used in ecology, to predict the global spatial distribution of seawater desalination plants. Two regression SDMs, a generalized linear model and a generalized additive model, along with two machine learning SDMs, a random forest model and a generalized boosted regression model, were trained and tested using the cross‐validation method at 0.5°. For each SDM, we considered four explanatory variables: aridity, distance to coastline, gross domestic product per capita, and annual domestic and industrial water withdrawal. Our results showed that machine learning SDMs had a relatively strong performance in capturing the historical locations of seawater desalination plants. We then mapped the future distribution of seawater desalination plants under different shared socioeconomic pathways (SSPs) and representative concentration pathways (RCPs). Our predictions showed that the number of predicted locations of seawater desalination plants increased by 31%, 47%, 55%, 57% in 2030, 2050, 2070, and 2090, respectively, relative to 2014. The largest increase occurred under SSP3_RCP7.0, while the lowest increase was found under SSP1_RCP2.6, which is mainly determined by the differences in the volume of annual domestic and industrial water withdrawal. Our study provides an insight into how SDMs can be used to predict the geographic locations of water management facilities.

UAE sea-water desalination plant employs Toray's RO membranes

Japan's Toray Industries Inc has received an order to supply reverse osmosis (RO) membranes for use in what is claimed to be the world's largest sea-water desalination plant – the Taweelah desalination facility in the United Arab Emirates (UAE).

A thermally-driven seawater desalination system: Proof of concept and vision for future sustainability

Since the 1970s, commercial-scale thermally-driven seawater desalination plants have been powered by low-grade energy sources, drawn either with low-pressure bled-steam from steam turbines or the solar renewable energy harvested that are supplied at relatively low temperatures. Despite the increasing trend of seawater reverse osmosis plants, the role of thermal desalination methods (such as multi-stage flashing and multi-effect distillation) in GCC countries is still relevant in the Arabian Gulf, arising from higher salinity, the frequent algae blooms of seawater and their ability to utilize low temperature heat sources. Given the urgent need for lowering both the capital and operating costs of all processes within the desalination industry and better thermodynamic adaptation of low-grade heat input from renewable sources, the present paper addresses the abovementioned issues by investigating the direct contact spray evaporation and condensation (DCSEC) method. A DCSEC system comprises only hollow chambers (devoid of membranes or tubes, minimal use of chemical and maintenance) where vapor generation (flashing) utilizes the enthalpy difference between the sprayed feed seawater and the saturated vapor enthalpy of the vessels. Concomitantly, vapor is condensed with spray droplets of cooler water (potable) in adjacent condenser vessels, employing a simple design concept. We present detailed design and real seawater experiments data of a DCSEC system for the first time. The water production cost is calculated as $0.52/m 3 , which is one of the lowest figures reported compared to commercial processes presented by Global Water Intelligence.

Autopsy of Used Reverse Osmosis Membranes from the Largest Seawater Desalination Plant in Oman.

The Barka desalination plant, commissioned in 2018, is the largest desalination plant in Oman. It has a capacity of 281 MLD with a reverse osmosis (RO) first-pass recovery rate of 46%. As part of the standard operator practice, a membrane autopsy was conducted to determine the cause of reductions in membrane performance. This study investigated fouled membranes (model No. SW30HRLE-440) from two different locations in the membrane rack. Various analytical methods were used to conduct the membrane autopsy. Field-emission scanning electron microscopy/energy-dispersive X-ray (FESEM/EDS) analyses of membrane samples showed major components of inorganic foulants. Moreover, black and salt-like crystals deposited on the membrane surface revealed significant carbon (C) components and oxygen (O), with a small amount of magnesium (Mg), chloride (Cl), sodium (Na), aluminium (Al), and calcium (Ca), respectively. A Fourier transform infrared (FTIR) analysis revealed the presence of long-chain hydrocarbons, carboxylic acids/esters, carbohydrates/polysaccharides, and inorganic foulants. Thermogravimetric analyses (TGA) of the membranes showed a high initial weight loss due to organic and inorganic fouling. X-ray photoelectron (XPS) analyses further confirmed the presence of inorganic and organic foulants on the membrane surfaces. Bacteria identification results showed the presence of Bacillus cereus and Bacillus marisflavi. This paper offers a detailed analysis of the foulants present on the reverse osmosis membrane surface and sub-surface before and after a cleaning process.

Modelling cyber resilience in a water treatment and distribution system

Considering the increasing introduction of cyber-physical systems in modern industrial plants, the analysis of systems’ performance pushes for developing a cyber resilience perspective to complement a traditional physical resilience assessment. This point of view becomes central for critical infrastructures, considering the potential societal and economic consequences a disruption may have. This work provides a cyber-resilience simulation-based assessment for a seawater desalination plant and its connected distribution system. For this purpose, a digital twin has been developed. It integrates a MATLAB/Simulink model of the reverse osmosis treatment plant with a georeferenced water distribution network designed in EPANET. Four stochastic cyber resilience metrics have been proposed and computed to assess the impact of a successful replay cyber attack. The results exemplify the benefits of cyber-physical simulations to understand the behavior of modern water treatment plants, to identify system's criticalities, and eventually to support decision making by identifying hotspots and prioritizing mitigating actions.

Boron recovery from desalination seawater brines by selective ion exchange resins

The European Union (EU) depends on third markets to supply many important raw materials. Increasing the circularity of critical raw materials within the EU is important not only from an environmental perspective, but also as a competitive advantage for the EU economy. In the case of boron, the EU's import dependency is about 100%. This work aims to evaluate the boron recovery from seawater desalination plants (SWDP) brines using ion-exchange resins in a circular economy approach. Commercial boron selective resins Purolite S108, DIAION CRB03 and CRB05 were tested and compared on batch and dynamic experiments. Thermodynamic and kinetic experiments were performed, and results were fitted by linear and non-linear models. After a comparison, results showed a good fit to the Langmuir isotherm and the pseudo-second order model, respectively, for all the commercial resins tested. The DIAION CRB03 resin presented higher sorption capacity and percentage of boron sorbed than the other resins and was selected as the best option for boron recovery from SWDP brine. Dynamic experiments in fixed bed column using DIAION CRB03 resulted in a sorption capacity of 13 mg/g of resin, a boron recovery of 98% and a concentration factor of 30, for an initial boron concentration of 50 mg/L. In addition, an economic analysis was carried out as a preliminary estimate of the revenues obtained from the production of boric acid from the brine produced by El Prat desalination plant.

Environmental Impacts of Thermal and Brine Dispersion Using Hydrodynamic Modelling for Yanbu Desalination Plant, on the Eastern Coast of the Red Sea

For any coastal desalination plant, the most effective and practical way to dispose of their brine is to thermally discharge it into the sea via outfalls at some distance from the coast. This study focused on the environmental impacts associated with brine and thermal discharge arising from seawater desalination plants at Yanbu, Saudi Arabia, on the southeastern coast of the Red Sea. The impacts associated with recirculation patterns and dispersions were investigated with the calibrated three-dimensional numerical model Delft3d. The environmental impact assessment and the process of identification and characterisation could help improve strategies for better planning and management of the technological solutions related to desalination. Analysis of the model simulations for the different seasons also suggested that around the outfall location, the magnitude of the flow was always high when considered together with the presence of seasonal eddy circulations. Although the tidal flow is lower, the ambient current and wind cause the far-field discharge to spread along the north–south direction during the winter and summer. The thermal and brine dispersion and environmental compliance were assessed in terms of the extent of dispersion. The well-mixed environment caused more rapid dispersion. From the impact level assessment perspective, the study indicated rapid dilution and dispersion of the wastewater at the study region. The present offshore outfall and further offshore locations were far enough to ensure quick dispersion.

Определение облика опреснительной установки для перспективных проектов атомных подводных лодок

Object and purpose of research. This paper discusses seawater desalination plants for production of distillate to be used as feed water for main engines of Russian nuclear submarines, as well as the basis of potable water for drinking and household needs. The purpose of this work was to select the type of desalination plant for future nuclear submarines. Materials and methods. Currently, Russian nuclear submarines have two types of desalination plants, i.e. distillers and reverse-osmosis units. Each of these types has its own pros and cons, so the question of desalination plant type selection for future nuclear submarines becomes one of the most relevant. Main results. This paper briefly analyses marine seawater desalination systems in terms of their performance parameters and operation peculiarities (i.e. construction and operation challenges). Conclusion. As a promising path for desalination plants of new-generation submarines the authors recommend reverse-osmosis units.

Can Large-Scale Offshore Membrane Desalination Cost-Effectively and Ecologically Address Water Scarcity in the Middle East?

The Middle East will face tremendous water scarcity by 2050, which can only be mitigated by large-scale reverse osmosis seawater desalination. However, the coastal land in the region is rare and costly, so outsourcing the desalination facility to artificial islands could become a realistic scenario. This study investigated the ecological and economic challenges and possible advantages of that water supply option by analysing conceptual alternatives for offshore membrane-based desalination plants of up to 600 MCM/y capacity. Key environmental impacts and mitigation strategies were identified, and a detailed economic analysis was conducted to compare the new approach to state-of-the-art. The economic analysis included calculating the cost of water production (WPC) and discussing the differences between offshore alternatives and a conventional onshore desalination plant. In addition, the study investigated the impact of a changing energy mix and potential carbon tax levels on the WPC until 2050. The results indicate that offshore desalination plants have ecological advantages compared to onshore desalination plants. Furthermore, the construction cost for the artificial islands has a much lower effect on the WPC than energy cost. In contrast, the impact of potential carbon tax levels on the WPC is significant. The specific construction cost ranges between 287 $/m2 and 1507 $/m2 depending on the artificial island type and distance to the shoreline, resulting in a WPC between 0.51 $/m3 and 0.59 $/m3. This work is the first to discuss the environmental and economic effects of locating large-scale seawater desalination plants on artificial islands.

Study of the Readiness for Receiving Desalinated Seawater – Gaza City Case Study

The readiness for receiving desalinated water in Gaza city was evaluated, by ensuring the technical, economical and social readiness, and identifying the current obsticles and problems to achieve the greatest possible benefit from Gaza seawater desalination plant. The conditions of existing water networks in Gaza city were assessed through the age of network, the age of flowmeters, determining the locations of asbestos lines, determining the places of breakage and failure, and generating spatially thermal maps. Furthermore, studying the percentage of collection system based on social and economical aspects was carried out to determine the acceptance of defined new tariff as a consequence of improving the water service. The results revealed that 68% of the water networks are aging more than 10 years, as well as 66% of water flowmeters are aging more than 10 years. There is a close relationship between the use of 2” diameter pipes with the occurrence of breaks and failure in the networks. The collection is not exceeding 4% of total bills value, which represents 29% of the number of cutomers. The socio-economic results found that 65% of the customers are not paying the bills due to bad economic and 35% due to poor water service. However, 64% of the customers agreed to raise the tarrif for reciving-desalinated water, and 97% agreed if the tarrif does not exceed 2 shekels per cubic meter. Existing water networks problems should be maintained to ensure optimal use of desalinated water, and public awareness for citizens should be carried out to incrase the level of social responsibility and paying the bills in order to obtain a better service and sustainability.

Using Mediterranean Mussel Bio-Indicators to Assess the Initial Health State of Ecosystems Receiving Desalination Plant Effluents in Agadir Bay (Morocco)

Elazzaoui, A.; Kalla, Y.; Lefrere, L.; Bouhaimi, A., and Moukrim, A., 2022. Using Mediterranean mussel bio-indicators to assess the initial health state of ecosystems receiving desalination plant effluents in Agadir Bay (Morocco). Journal of Coastal Research, 38(1), 154–167. Coconut Creek (Florida), ISSN 0749-0208. Mussels are often used as a biological bio-indicator for the quality assessment of marine ecosystems. Adopting this approach, the present work aims to study the initial health status of two ecosystems in Agadir Bay, Morocco expected to receive seawater desalination plant effluents. This study was conducted between February 2015 and March 2017 in two stations, Tifnit-Douira and Cap Ghir. In addition to the gametic development, variations of sex ratio and gonadal index were also determined. The reproductive cycle of Mytilus galloprovincialis is spread throughout the year. Under natural conditions, three collective spawning periods were observed. The main one was during the spring and the two other periods were optional and were in winter and summer. Variations of seawater temperature can make some changes in mussel spawning, with one principal period lasting during spring and summer and the optional one during winter. In both studied stations, sexual rest was manifested by a small percentage of the population particularly during summer, and could not reach the whole population at the same time. This finding is consistent with the gonadal index that never reached the value of 1. A unique hermaphroditism case was revealed in Tifnit-Douira mussels, and it remained statistically insignificant. The sex ratio was perfectly balanced in both stations and was in favour of males. The gonad histology did not show any cellular abnormalities in the germinal tissue. These results are of great importance since they characterize the current state of the studied stations area before the installation of the desalination plant. This state must be maintained after installation in order to preserve the typical halieutic resources of these ecosystems. The present findings confirm the good environmental health status and the aquaculture potential of Agadir Bay, especially in the north ecosystems (Cap Ghir) due to upwelling-nutritional intake and optimum seawater temperature.

Optimal Energy Management Solutions Using Artificial Intelligence Techniques for Photovoltaic Empowered Water Desalination Plants Under Cost Function Uncertainties

Two modern methods of the energy management system (EMS) based on a modified cost function are addressed in this paper. Fuzzy logic (FL) and Harris Hawks Optimization (HHO) is implemented to achieve the optimal performance of seawater desalination plants (SWDP) within the minimum feed-in tariff (FiT). The technical difficulties involved in the variation of energy price from one time to another and the system parameters uncertainties. For example, the price of energy is higher at the peak time and the price is lower at normal times. Also, the peak time can change from one day to another day. The proposed management system can deal with these variations and uncertainty cases. The suggested EMS is achieved through a bidirectional electrical energy interchange approach (π-EEIA). The main concept behind the proposed π-EEIA is how and when to inject the excess generated energy of renewable energy into the utility grid or charge the battery depending on the minimum dynamic cost criterion and vice versa. To accomplish this study a 700 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> /day SWDP located in Egypt fed on solar energy and a utility network has been constructed and analyzed. The system includes SWDP fed from a photovoltaic (PV) array as well as the utility grid in addition to a battery energy storage system (BESS). The main objective of this study is the management and coordination between the energy exchange process from the solar energy, the utility network, and BESS to provide sufficient electrical energy for SWDP within the minimum FiT. The system is constructed and validated using the MATLAB/SIMULINK <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TM</sup> software package. The proposed FL and HHO-based EMSs are investigated in the presence of the system uncertainties such as the change in the energy (excess or shortage) as well as the change in the energy price in the utility network (high or low) with (normal or peak) time. The attained results demonstrate that the proposed FL and HHO-based EMSs provide high dynamic performance and accurate coordination between various energy resources and BESS. The results show that FL-based EMS achieves a profit of 10.28 $ but the HHO-based EMS achieves a profit of 10.11 $ in the same period.

Can Brine from Seawater Desalination Plants Be a Source of Critical Metals?

Can Brine from Seawater Desalination Plants Be a Source of Critical Metals?

Responses of the Mediterranean seagrass Cymodocea nodosa to combined temperature and salinity stress at the ionomic, transcriptomic, ultrastructural and photosynthetic levels

The Little Neptune grass Cymodocea nodosa is a key seagrass species in the Mediterranean Sea, forming extensive and patchy meadows in shallow coastal and transitional ecosystems. In such habitats, high temperatures and salinities, separately and in combination, can be significant stressors in the context of climate change, particularly during heatwave events, and seawater desalination plant effluents.Despite well-documented negative, macroscopic effects, the underlying cellular and molecular processes of the combined effects of increasing temperature and salinities have remained largely elusive in C. nodosa – which are addressed by the present study. High salinity and high temperature, alone and in combination, affected ion equilibrium in the plant cells. Non-synonymous mutations marked the transcriptomic response to salinity and temperature stress at loci related to osmotic stress. Cell structure, especially the nucleus, chloroplasts, mitochondria and organization of the MT cytoskeleton, was also altered. Both temperature and salinity stress negatively affected photosynthetic activity as evidenced by ΔF/Fm’, following an antagonistic interaction type.Overall, this study showed that all biological levels investigated were strongly affected by temperature and salinity stress, however, with the latter having more severe effects. The results have implications for the operation of desalination plants and for assessing the impacts of marine heat waves.

An Assessment of Renewable Energies in a Seawater Desalination Plant with Reverse Osmosis Membranes.

The purpose of our study was to reduce the carbon footprint of seawater desalination plants that use reverse osmosis membranes by introducing on-site renewable energy sources. By using new-generation membranes with a low energy consumption and considering wind and photovoltaic energy sources, it is possible to greatly reduce the carbon footprint of reverse osmosis plants. The objective of this study was to add a renewable energy supply to a desalination plant that uses reverse osmosis technology. During the development of this research study, photovoltaic energy was discarded as a possible source of renewable energy due to the wind conditions in the area in which the reverse osmosis plant was located; hence, the installation of a wind turbine was considered to be the best option. As it was a large-capacity reverse osmosis plant, we decided to divide the entire desalination process into several stages for explanation purposes. The desalination process of the facility consists of several phases: First, the seawater capture process was performed by the intake tower. This water was then transported and stored, before going through a physical and chemical pre-treatment process, whereby the highest possible percentage of impurities and organic material was eliminated in order to prevent the plugging of the reverse osmosis modules. After carrying out the appraisals and calculating the amount of energy that the plant consumed, we determined that 15% of the plant’s energy supply should be renewable, corresponding to 1194 MWh/year. As there was already a wind power installation in the area, we decided to use one of the wind turbines that had already been installed—specifically, an Ecotecnia turbine (20–150) that produced an energy of 1920 MWh /year. This meant that only a single wind turbine was required for this project.

Modelling and simulation of industrial multistage flash desalination process with exergetic and thermodynamic analysis. A case study of Azzour seawater desalination plant

Abstract Despite the fact of being intensive energy consumption, MSF is a mature technology that characterised by a high production capacity of high-quality water. The multistage flash (MSF) desalination process is one of the prominent thermal desalination used in the industry of seawater desalination to produce high quantity and high quality of freshwater. However, this process consumes large amount of energy and faces thermal limitations due to its high degree of exergy destruction at several units of the process. Therefore, the research of MSF is still existed to elevate the performance indicators and to resolve the concern of high energy consumption. To rectify these limitations, it is important to determine the units responsible in dissipating energy. This study aims to model an industrial MSF process validated against real data and then investigate the exergy destruction and thermodynamic limitations of the process. As a case study, Azzour MSF seawater desalination plant, located in Al Khiran in Kuwait is under the focus. A comprehensive model is developed by analysing several published models. Specifically, the calculation of exergy destruction has embedded both physical and chemical exergies that identified as a strong point of the model developed. As expected, the highest exergy destruction (55.5%) occurs within the heat recovery section followed by the brine heater with exergy destruction of 28.26% of the total exergy destruction. This study identifies the sections of the industrial process that cause the highest energy losses.

Optimization of Energy Efficiency, Operation Costs, Carbon Footprint and Ecological Footprint with Reverse Osmosis Membranes in Seawater Desalination Plants.

This article shows the optimization of the reverse osmosis process in seawater desalination plants, taking the example of the Canary Islands, where there are more than 320 units of different sizes, both private and public. The objective is to improve the energy efficiency of the system in order to save on operation costs as well as reduce the carbon and ecological footprints. Reverse osmosis membranes with higher surface area have lower energy consumption, as well as energy recovery systems to recover the brine pressure and introduce it in the system. Accounting for the operation, maintenance and handling of the membranes is also important in energy savings, in order to improve the energy efficiency. The energy consumption depends on the permeate water quality required and the model of the reverse osmosis membrane installed in the seawater desalination plant, as it is shown in this study.