SWRO Desalination Research Articles

Techno-environmental optimal sizing and dynamic behavior of a hybrid system feeding a large-scale SWRO desalination system: The case of Djerba Island, Tunisia

Techno-environmental optimal sizing and dynamic behavior of a hybrid system feeding a large-scale SWRO desalination system: The case of Djerba Island, Tunisia

Design of SWRO Desalination Plant for Nuclear Research Center

Libya has an infinite water resource available inthe coastal towns and cities being located on Mediterranean Sea with 1950km coast. Therefore, the need for desalinatedwater for Nuclear Research Center NRC located in Tajurais currently about 1200 m3/day. To cover the center presentand future water needs for research and developmentactivities, two thermal sea water desalination plants have been assembled in the site. One of the plants uses MultiStage Flash technology and the other one uses Multi EffectDesalination technology with capacity of 1200m/day eachone. Detailed design for 1200m3/day seawater reverseosmosis SWRO unit is carried out using ROSA S oftware to make the technical comparison with other MSF and MEDunits. The unit labeled an S W30XLE-440i by the results ofthe Software is selected since it required the lower feedpressure of 55.5bar and highest salt recovery of 45% with total dissolved solid of 190ppm. From the technical point ofview, the study showed that SWRO required lower seawater inlet flow rate than MSF and MED. The unitsefficiency are 43%, 10.5% and 25% for SWRO, MSF, andMED, respectively. Further the Product quality TDS 190ppm for RO unit is suitable for drinking water, whilethose of MSF and MED 50ppm. Energy consumption asheating steam is not required for the S WRO unit; however,a steam flow rate 7.3m 3/hr is required by MSF and MEDunits. These make SWRO unit friendlier to the environment and most proper technically under these situations.

Comparative analysis of centralized and decentralized control systems for NUWIEBAA SWRO desalination plant

This paper discusses the differences between centralized and decentralized planning and control systems in the context of desalination water treatment plants. The parameters considered include area, capacity, arrangement, lifetime, initial cost, operation and maintenance, and troubleshooting. It is noted that decentralized control systems may not be the best option from an economic perspective, but have the advantage of lower running costs. The hardware and software for decentralized systems are also more expensive than centralized systems, however, the operation and maintenance costs for decentralized systems are lower by 75% due to reduced staffing. These models have been applied in reverse osmosis desalination plants to find better solutions for operation and maintenance.

Energy Efficiency Optimization in Onboard SWRO Desalination Plants Based on a Genetic Neuro-Fuzzy System

This work presents a novel intelligent control system based on a Genetic Neuro-Fuzzy tool to optimize and improve the performance of a seawater reverse osmosis desalination plant (SWRO) on board a marine vessel. This investigation pays special attention to minimizing energy consumption to improve the energy efficiency of this marine installation. The system analyzes measurements of different variables—seawater pH, seawater conductivity, permeate flow rate, permeate conductivity, and total energy consumed—in order to provide the most appropriate value of permeate flow rate control and operating pressure of the high-pressure pump (HPP). This intelligent method allows the plant to achieve output values nearer to the desired setpoints set by the plant operators.

Performance of Hypersaline Brine Desalination Using Spiral Wound Membrane: A Parametric Study.

Desalination of hypersaline brine is known as one of the methods to cope with the rising global concern on brine disposal in high-salinity water treatment. However, the main problem of hypersaline brine desalination is the high energy usage resulting from the high operating pressure. In this work, we carried out a parametric analysis on a spiral wound membrane (SWM) module to predict the performance of hypersaline brine desalination, in terms of mass transfer and specific energy consumption (SEC). Our analysis shows that at a low inlet pressure of 65 bar, a significantly higher SEC is observed for high feed concentration of brine water compared with seawater (i.e., 0.08 vs. 0.035) due to the very low process recovery ratio (i.e., 1%). Hence, an inlet pressure of at least 75 bar is recommended to minimise energy consumption. A higher feed velocity is also preferred due to its larger productivity when compared with a slightly higher energy requirement. This study found that the SEC reduction is greatly affected by the pressure recovery and the pump efficiencies for brine desalination using SWM, and employing them with high efficiencies (ηR ≥ 95% and ηpump ≥ 50%) can reduce SEC by at least 33% while showing a comparable SEC with SWRO desalination (<5.5 kWh/m3).

SWRO concentrates for more efficient wastewater reclamation

Developing technical alternatives to increase the volume of remediated waters is a promising way to alleviate pressure on natural water basins. However, the extra energy consumed in Wastewater Treatment Plants (WWTPs), mainly powered by fossil fuels, hampers this strategy. This work focuses on promoting efficient upgrading alternatives of treated waters by recovering energy within the treatment process. The approach consists on the recovery and integration of Salinity Gradient Energy (SGE) generated from the contact between SWRO brines and reclaimed wastewaters in reverse electrodialysis modules. The analysis of opportunity of implementing integrated processes in Spanish WWTPs near SWRO desalination plants is tackled. 16 SWRO-WWTP pairs have been inventoried, 10 of them located in Jucar and Segura river basins, hot spot areas for water reclamation. A gross power density of 0.46 W/m2 (71 Wh/m3 reclaimed water) of SGE has been generated in the contact between SWRO brines and reclaimed wastewater, increased up to 0.23 kWh/m3 in the most favourable scenario. Estimates of freshwater withdrawals savings up to 434,387 m3/day within the selected installations are obtained. Decrease in water abstraction and integration of renewable source of energy in the remediation process will contribute to water sources protection and water industry decarbonisation.

Multi-criteria decision making for a holistic assessment of sustainable alternatives in SWRO desalination: A case study

Water authorities have been constructing an increasing number of small-scale desalination treatment plants to provide drinking water for remotely located communities. Each location has a different situational context and community priorities, meaning that the treatment solutions should be selected considering a range of criteria and sub-criteria covering technical, economic, environmental, and health aspects. In this study, a comparison of three possible desalination alternatives was made using a multi-criteria decision-making (MCDM) tool in a rural area of Queensland, Australia. The studied alternatives encompassed standalone reverse osmosis (RO); forward osmosis (FO) coupled with RO (FO–RO), and ultrafiltration coupled with RO (UF–RO). The hybrid alternatives have the potential to significantly reduce energy consumption and environmental impact and to increase the efficiency of pathogenic removal and contaminations. The weights for the criteria were developed by integrating a multi-criteria feasibility assessment with a new survey that was responded by SWRO experts. Following this, the desalination alternatives were ranked using the TOPSIS method (technique for ordering preference by similarity to ideal solutions). A sensitivity analysis was conducted to see how the results would vary by changing the weights of preferences. The resulting MCDM framework ranked the UF-RO hybrid system as the best performing alternative with consistently high efficiency levels for stakeholders. The results showed that the performances of the FO-RO hybrid system and of the RO standalone system were similar, with FO-RO showing a marginal superiority in most of criteria.

Sulfate radical-based advanced oxidation process for algal toxin mineralization in seawater desalination

The effects of discharged brine from desalination plants, particularly brine containing algal toxins during harmful agal bloom (HAB) occurrence, are a major concern for marine life and, as a result, human health. Therefore, removing algal toxins from desalination brine is critical for safeguarding both human health and the marine environment. The present work examined the mineralization of domoic acid (DA), an algal toxin, in highly concentrated seawater for the first time using an ultraviolet light activated peroxymonosulfate (UV/PMS) system. Mineralization efficiencies, effects of various anion concentrations, and reaction by-products were investigated. The presence of anions such as chloride, bromide, and bicarbonate reduces the mineralization efficiency of the UV/PMS system, with bromide being the most detrimental. Although DA can be effectively degraded in synthetic seawater (35,000 ppm), total mineralization is not possible within 180 min of reaction time, with only 38.4 %, 44.8 %, and 41 % TOC removal in pH 3, 5, and 7, respectively, when 1 mM of PMS was used. Analyses of treated hypersaline seawater using ultra-high-resolution liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and ion chromatography revealed that DA was completely degraded in synthetic seawater and that, in the presence of algal organic matter, no toxic by-product was generated during the detoxification process. Overall, the UV/PMS system has the potential to be an effective treatment strategy for algal toxins in seawater during HAB events in the SWRO desalination process.

Modification and operational stability evaluation of a miniaturized reciprocating-switcher energy recovery device for SWRO desalination system

Modification and operational stability evaluation of a miniaturized reciprocating-switcher energy recovery device for SWRO desalination system

Advanced Coagulation with Liquid Ferrate As Swro Desalination Pretreatment During Algal Bloom Events. Process Performance, Environmental Impact, and Cost Analysis

Advanced Coagulation with Liquid Ferrate As Swro Desalination Pretreatment During Algal Bloom Events. Process Performance, Environmental Impact, and Cost Analysis

Comparative environmental life cycle assessment of alternative osmotic and mixing dilution desalination system configurations

An environmental life cycle assessment (LCA) methodology was applied to compare the conventional SWRO desalination process to two contemporary low-pressure membrane desalination processes: an osmotic dilution desalination (ODD) and a mixing dilution desalination (MDD). The ODD process combines a forward osmosis (FO) membrane and a low-pressure RO membrane (LPRO) in a hybrid (FO-RO) configuration. The MDD process couples the ultrafiltration (UF) with LPRO in a hybrid UF-RO configuration. SimaPro™ was used to conduct the LCA study. CML environmental impact assessment method was used to evaluate 11 environmental impact categories. Results from LCIA reveal the strong dependency of environmental impacts on the clean in place (CIP) process in dilution desalination systems while the energy flow in the standalone RO shows almost similar levels of dependency of environmental impacts instead of CIP process. Overall, the ODD process with FO-RO hybrid membrane technology has the highest environmental impact. The normalised comparison LCIA indicates that standalone RO has the lowest total environmental impacts as the fossil fuel is considered as the main source of power generator. Compared to conventional SWRO, the MDD process coupled with hybrid UF-RO technology had a lowest contribution to global warming and ozone layer depletion but had higher impacts to marine and aquatic resource depletion. Scenarios substituting the conventional with renewable energy sources to power the water treatment options favoured the MDD process coupled with hybrid UF-RO technology and prove the hybrid UF-RO process as the most environmentally favourable comparing to the conventional SWRO and hybrid FO-RO.

The resea rch and application progress of the isobaric ERD technique for SWRO desalination plant

The resea rch and application progress of the isobaric ERD technique for SWRO desalination plant

Life cycle assessment of salinity gradient energy recovery by reverse electrodialysis in a seawater reverse osmosis desalination plant

LCA of lab-scale and large-scale stand-alone RED stacks and an up-scaled RED system co-located with a SWRO desalination plant.

Effective modifications of reciprocating-switcher energy recovery device by adopting pilot valve plates to decrease the switching load and fluid fluctuations

Reciprocating-switcher energy recovery device (RS-ERD) can reduce the energy consumption in membrane desalination system for its high efficiency. However, the initial one-plate structure of the RS-ERD requires a large diameter in plates to ensure its basic capacity, which not only enlarges the switching load of water hydraulic actuator, but also causes a significant fluid fluctuation of the device during the stroke switching. To solve the problem, a modified RS-ERD with the pilot valve plates was designed and experimentally investigated in a SWRO desalination system. The experimental results illustrated that compared to the previous RS-ERD, the starting-up pressure for the new RS-ERD decreased by a half to be about 0.25 MPa, and 72.16% HP brine consumption for water hydraulic actuator was reduced in stroke switching. Thanks to the significant decrease in HP brine consumption, the pressure fluctuation amplitude in HP fluids was declined by 40% under the pressure of 6.00 MPa and the flow rate of 30 m3/h. Meantime the new RS-ERD remains a competitive energy recovery efficiency of up to 98.50%. This paper provides a practical method to improve the working performance of RS-ERD.

Investigation of the reduced specific energy consumption of the RO-PRO hybrid system based on temperature-enhanced pressure retarded osmosis

Reverse osmosis (RO) has been widely used as a dominant desalination technology to produce fresh water from seawater (SW), but still consumes huge energy. To reduce the energy consumption of RO, pressure retarded osmosis (PRO) has been developed to extract osmotic energy from RO brine. In this study, the PRO process is optimized for efficient energy recovery from RO brine via one system/module-level mathematic model in RO-PRO hybrid system. The system-level model illustrates that the specific energy consumption (SEC) of the hybrid system can be significantly reduced when achieving a high permeate flow under high operating pressure in PRO. However, the specific PRO membrane configuration has to sacrifice a high permeate flow under high operating pressure. The module-level model finds that the increase of PRO operating temperature facilitates to achieve a high permeate flow under a high optimal operating pressure. Furthermore, results present that the SEC at a kiloton-scale SWRO desalination capacity can be reduced by 14.41% (0.6 M NaCl as a draw solution) and 17.93% (1.2 M NaCl as a draw solution) when the PRO operating temperature increases from 25 °C to 50 °C, confirming the great potential of temperature-enhanced PRO to further reduce the SEC of seawater desalination.

Process modeling and simulation of an SWRO desalination plant: case study of Gijang SWRO desalination plant in Korea

Process modeling and simulation of an SWRO desalination plant: case study of Gijang SWRO desalination plant in Korea

Coupling pressurised water reactor to large scale SWRO desalination plants: an economic assessment

Coupling pressurised water reactor to large scale SWRO desalination plants: an economic assessment

Coupling pressurised water reactor to large scale SWRO desalination plants: an economic assessment

Water management via rational use, reuse practices and water desalination is the key element for mitigation of water shortage. This paper addresses small-scale nuclear systems as a cost-effective energy alternative for large-scale desalination plants. An empirical cost model has been derived and validated based on reported cost indicators and selected cases. The capital cost of 150,000 m³/d seawater desalination plant coupled to small nuclear reactors has been estimated to be between 3 and 11 M$/MWe, respectively. In addition, specific cost of nuclear desalination-steam cycle system SWRO (conventional pre-treatment), ranges between 0.046-0.064 $/kWh and 0.62-0.667 $/m³ for energy and water, respectively. Cost indicators of different desalination systems show that product water cost ranges between 0.62 and 0.779 $/m³ when applying nuclear power as an energy source for RO, RO/MED, MED while when applying oil/gas as an energy source the product water cost ranges between 1.12 and 1.89 $/m³.

Optimization of energy efficiency through comparative analysis of factors affecting the operation with energy recovery devices on SWRO desalination process

Recently, interest in the development of alternative water resources has been increasing rapidly due to environmental pollution and depletion of water resources. In particular, seawater desalination has been attracting the most attention as alternative water resources. As seawater desalination consumes a large amount of energy due to high operating pressure, many researches have been conducted to improve energy efficiency such as energy recovery device (ERD). Consequently, this study aims to compare the energy efficiency of RO process according to ERD of isobaric type which is applied in scientific control pilot plant process of each 100 ㎥/day scale based on actual RO product water. As a result, it was confirmed that efficiency, mixing rate, and permeate conductivity were different depending on the size of the apparatus even though the same principle of the ERD was applied. It is believed that this is caused by the difference in cross-sectional area of the contacted portion for pressure transfer inside the ERD. Therefore, further study is needed to confirm the optimum conditions what is applicable to the actual process considering the correlation with other factors as well as the factors obtained from the previous experiments.

Selective separation of divalent ions from seawater using an integrated ion-exchange/nanofiltration approach

A new concept is introduced for separating and concentrating (predominantly) Mg2+ and SO42− from seawater, along with low monovalent ion concentrations. Seawater is first subjected to cationic ion exchange aimed at balancing the equivalent concentration ratio between divalent cations and anions. This step’s effluent undergoes nanofiltration, and the MgSO4-rich retentate of the nanofiltration step undergoes further semi-batch diananofiltration for reducing the monovalent ion concentrations. Regeneration of the ion exchange resin is carried-out by permeate attained from nanofiltrating SWRO desalination retentate. The paper presents detailed results from all process steps followed by cost-analysis amounting to ∼$1.6 kg−1 of separated Mg2+.