Reverse Osmosis Desalination System Research Articles

Techno-Economic Feasibility of Reverse Osmosis Desalination Scale Coupled with Solar Energy: Case of Algeria

B Brackish water and seawater desalination have become important freshwater sources in arid and semi-arid regions suffering from water scarcity. Fortunately, the availability of solar energy provides an excellent opportunity to replace conventional energy with renewable energy for desalination system power. However, technical and economic feasibility studies must be carried out according to the characteristics of each region to assess its economic feasibility. This study assessed the techno-economic feasibility of a solar-powered desalination small-scale BWRO with a capacity of 2.016 m3/day. Two scenarios were proposed: a desalination station powered by a public network without a solar energy system (On-Grid) and a second powered by photovoltaic panels (Off-Grid). The result shows that the water production cost of the Off-Grid system (0.33 $/m3) was about 1.14 times lower than the water production cost of the On-Grid system (0.38 $/m3). The economic analysis result shows that the reverse osmosis desalination system coupled with a photovoltaic system (Off-Grid) is an economically suitable option for satisfying the increasing freshwater product demand compared to the grid-powered system (On-Grid), especially in arid areas.

Development, growth, and function of biofilm communities on reverse osmosis membranes desalinating tertiary effluent

Efficient tertiary effluent desalination is hindered by membrane biofouling, leading to plant downtime, shortened membrane lifespan, heightened energy consumption, and reduced permeability. While the composition of these biofouling layers is studied, little is known about bacterial succession and function. To address this, we used a benchtop reverse osmosis (RO) system to process synthetic tertiary effluent with diluted sludge. System flux monitoring tracked biofouling layer development, and RO biofilm samples were collected at early and mature stages (48, 72, 120 h). Scanning electron microscopy visualized the samples, and their 16S rRNA genes were sequenced. DNA-stable isotope probing with labeled glucose identified growing taxa in early and late biofouling stages (48, 120 h). Over time, biofouling layer biomass increased, with shifts in bacterial diversity and composition. Proteobacteria, notably oligotrophic genera, dominated early stages along with Bacteriodota, while Actinobacteria increased in mature biofilms. Functional changes included a shift from biosynthesis of cellular components like DNA, peptidoglycan, membrane lipids, and antimicrobials, to production of extracellular polysaccharides and reactive oxygen scavenging agents. In conclusion, our research enhances the understanding of biofouling dynamics within tertiary effluent desalination processes, providing insights that could improve biofouling management strategies in RO desalination systems, potentially applicable to larger-scale operations.

Techno-exergy-economic assessment of humidification-dehumidification/reverse osmosis hybrid desalination system integrated with concentrated photovoltaic/thermal

Desalination is a process used to generate water for human consumption, irrigation, or industrial purposes. Assessment of desalination plants is crucial for freshwater productivity, energy consumption, exergy destruction, and economic feasibility calculations. Therefore, the study aims to conduct a technical, exergy, and economic analysis of a concentrated photovoltaic/thermal hybrid humidification-dehumidification reverse osmosis desalination system. The photovoltaic/thermal provides the electrical and thermal requirements for the hybrid desalination unit. Theoretical models for each unit are developed and integrated using the Engineering Equation Solver software. The sensitivity of system performance parameters was investigated under different climatic and operation factors. The analysis shows that the system produces 860 L per hour at the lowest specific energy consumption and water cost (3.3 kW-hours per cubic meter and 0.916 United States dollars per cubic meter), respectively, with a cost payback period of only 12 years compared to other green-powered desalination systems. The highest destruction portion of 84.6 % is at photovoltaic/thermal, while the largest cost portion of 68 % is at reverse osmosis. Productivity, energy consumption, and water cost are influenced by feed salinity, while destruction is most affected by solar irradiance. Ambient temperature, wind speed, and cooling fluid flow rate slightly affect the techno-exergy-economics of the system.

Operation strategy optimization of an integrated proton exchange membrane water electrolyzer and batch reverse osmosis desalination system powered by offgrid wind energy

Operation strategy of the integrated wind-hydrogen system is the key to ameliorate the negative impacts of the fluctuated wind power on the hydrogen production capacity and durability ofelectrolyzer. However,the desalination system supplying pure water to electrolyzers was neglectedpreviously, with which the practical operation strategy of the hybrid wind-hydrogen-desalination system has yet to be investigated. In this work, we proposed a novel control strategy named step-by-step start for wind-hydrogen-desalination system consisting of wind turbine, proton exchange membrane water electrolyzer (PEMWE), battery and batch reverse osmosis (BRO) desalination system, which can produce hydrogen andfresh water. Real-time wind data from Shenzhen, Chinawere used as input to the integrated system. The results demonstratethe wind-hydrogen-desalination system with the proposed strategy can improve the hydrogen production by 17.55 %, the energy efficiency by 17.68 % in August, and increase hydrogen production by 10.29 %, the energy utilization efficiency by 10.44 % in December compared with traditional strategies. At low wind speeds, the switching times of PEMWE for this strategy is higher than the other strategies, while at high wind speeds, the switching times of PEMWE is significantly decreased. This work provides insights into the practical operation strategy for wind-hydrogen-desalination system depending on the real-time wind speed.

Conceptual design and 4E analyses of a tetrageneration system in two different configurations based on poplar sawdust as a local woody biomass fuel

ABSTRACTIn this study, an innovative woody biomass‐fueled hybrid tetrageneration system composed of a single‐effect lithium bromide‐water absorption refrigeration system, a reverse osmosis desalination system, two organic Rankine cycle for the production of cooling, heating, power, and freshwater in two distinct configurations (configurations A and B), compared and discussed using energy, exergy, economic, and exergoeconomic analyses. The poplar sawdust used as a local woody biomass fuel was a by‐product of the Iran Wood and Paper Industries Company, located in northern Iran. The results revealed that the highest heating production and lowest exergy destruction were related to configuration B. The overall cost of configuration A was higher than that of configuration B. A detailed sensitivity analysis was also developed to study the effect of various factors on the thermodynamic and economic performance of the proposed configurations. By increasing the turbine inlet temperature of ORC1 from 625 to 692 K, the total sum unit costs of product of the system in configurations A and B decreased by 20 and 23 $ GJ−1, respectively (about 21%).

Design and performance analysis of thermal assisted reverse osmosis (RO)

Abstract Today, the world is facing difficult challenges related to water scarcity and freshwater resources. Water desalination has become necessary to meet this great demand. The reverse osmosis desalination system is considered the dominant type of desalination, although the high amount of energy consumed is considered the main barrier to expanding seawater reverse osmosis (SWRO). The need for producing an environmentally friendly energy source is also one of the most important challenges in preserving the environment and reducing global warming. The coexistence of power plants that release waste heat energy through the condenser and reverse osmosis plant represents an opportunity for a synergy system. Therefore, research has shown that the low/ultralow grade heat from natural sources or industrial processes can assist the process of desalination. This paper reviews available process configurations, system design, and operating parameters, and discusses the performance of the RO process at high temperatures.

Hybrid desalination system for Baltic Sea water: A preliminary study

The world's water resources predominantly comprise salt water. In the face of forecasts of increasing demand for hydrogen obtained by electrolysis, it is becoming important to investigate the feasibility of seawater desalination. As part of a research project, the possibility of using a hybrid zero liquid discharge (ZLD) desalination system to desalinate seawater from the Baltic Sea was examined. In addition to analysing the operating parameters of the system, a detailed physico-chemical examination of the process water was carried out at each stage of treatment. It was found that the reverse osmosis (RO) and multiple-effect desalination (MED) systems allow sufficient water parameters to be obtained to feed the ion exchange (IX) system, and after deionisation it is possible to achieve the water parameters required by proton exchange membrane (PEM), anion exchange membrane (AEM) and alkaline water (AWE) electrolysers. Furthermore, the possibilities of concentrating brine in the multiple-effect desalination system and extracting salt in solid form in the ZLD system were verified.

Development of a generalized mathematical model for two-stage reverse osmosis desalination systems

This study presented a generalized mathematical model for a two-stage reverse osmosis (RO) system based on mass balance, the solution-diffusion model, and film theory. The model is user-friendly and can be customized for any membrane regardless of the manufacturer. A set of non-linear equations was solved in MATLAB to calculate the system arrangement, performance parameters, and the required feed pressure for the desired recovery ratio by incorporating membrane characteristics and design parameters. Actual data from a two-stage RO system were employed for model validation against ROSA software results. To optimize energy conservation, equal recovery rates are applied to both stages, resulting in lower calculated feed pressures than those obtained using ROSA software. The study reveals a strong agreement between the simulation results and those obtained from the ROSA software and alignment with the membrane manufacturer's recommendations, making the model a reliable tool for evaluating the system before implementation.

A novel hybrid reverse osmosis and flash desalination system powered by solar photovoltaic/thermal collectors

A novel hybrid reverse osmosis and flash desalination system powered by solar photovoltaic/thermal collectors

A comprehensive study of a green hybrid multi-generation compressed air energy storage (CAES) system for sustainable cities: Energy, exergy, economic, exergoeconomic, and advanced exergy analysis

Coastal cities can generate electricity via wind and solar farms. However, the variable nature of these renewable sources makes power output fluctuate. Compressed air energy storage (CAES) is the best solution to address this issue. On the other hand, the challenge of providing potable water persists, even in coastal cities, despite the proximity to the sea. Therefore, reverse osmosis (RO) technology has been used to address this issue due to its reduced energy consumption and environmental impact. The waste heat from the CAES is recommended to increase the system's overall efficiency. In this regard, an innovative green hybrid multi-generation system based on a CAES is proposed. The organic Rankine cycle ORC and RO desalination system have been used in this system to recover waste heat and supply potable and domestic hot water. A comprehensive analysis of the proposed system includes energy, exergy, economic, exergoeconomic, and advanced exergy analyses. The findings indicate this system can produce 37.48 MWh of electricity, 19.42 kg/s of potable water, and 2.67 kg/s of domestic hot water. Furthermore, with a total profit of $ 24.54 M and a payback period of 3.3 years, this system's energy and exergy round trip efficiencies are 73.54 % and 55.01 %, respectively. According to the advanced exergy analysis of the system, 31.5 % of the total exergy destruction is avoidable.

Performance analysis and techno-economic assessment of a developed cooling/preheating small PVT-RO desalination plant

Middle East and North Africa (MENA) countries are experiencing rapid population growth, so water and electricity consumption plays a crucial role in the sustainable development of these countries. To overcome the water scarcity and electricity problems facing the MENA region, the developed cooling/preheating small PVT-RO desalination plants have been proposed as a practical solution. To achieve sustainable water and energy development in the MENA region, this study presents a commendable and highly efficient renewable energy project for freshwater production and electricity generation to solve the energy crisis and water scarcity in the MENA countries. Therefore, this study aims to develop a cooling/preheating small PVT-RO desalination plant to facilitate freshwater supply to remote regions and produce electricity. This was done by connecting photovoltaic/thermal (PVT) collectors with reverse osmosis (RO) desalination systems, where seawater is used as a medium to cool photovoltaic cells to increase electric power generation and at the same time recover thermal energy and use it in the initial heating of feed seawater before it is fed into the RO plants, thus increasing its productivity. The results indicate that using the photovoltaic thermal panels as preheating units will lead to a 0.135 kWh/m3 reduction in the rate of specific electricity consumption for the RO desalination plant, as well as increase the electricity generation from PVT panels by a rate of 8%. The economic feasibility presented that the proposed developed cooling/preheating small PVT-RO desalination plant represents an effective technology that reduced the freshwater cost by a rate of 49.5%.

Comparison of the cumulative exergy demand of phase change and reverse osmosis desalination plants with environmental impacts approach

In the scope of the current study, an investigation into the cumulative exergy demand index was conducted for freshwater production across multiple distillation technologies. These technologies encompassed Waterfall Cascading Distillation with Linear Parabolic Solar Concentrator (WCDLPC), Distillation with Linear Parabolic Concentrator and Vacuum Pump (DLPCVP), Distillation with Stand-Alone Point-Focus Parabolic Solar Concentrator (DSPPC), Reverse Osmosis with Non-renewable Energy (RONRE), and Reverse Osmosis with Solar Renewable Energy (ROSRE).The functional unit was established as the production of one ton of freshwater using various desalination technologies. The Outcomes of the analysis pertaining to the cumulative exergy demand in diverse saline water desalination technologies revealed notable findings. Specifically, in the Reverse Osmosis Desalination System with the Conventional System as well as in other desalination technologies (ROSR, WCDLP, DLPCVP and DSPPC), the electricity factor and the photovoltaic panel factor respectively exhibited the most substantial contributions to the cumulative exergy demand. Remarkably, it was observed that the RONRE technology exhibited the highest cumulative exergy demand, reaching 107.04 MJ, while the ROSRE technology demonstrated the lowest demand at 5.98 MJ. Furthermore, the integration of renewable solar energy in lieu of non-renewable electricity within the reverse osmosis technology exhibited a remarkable reduction in cumulative exergy demand, achieving a reduction of 17.90 times. Similarly, the substitution of the waterfall cascade system with a vacuum system in the WCDLPC technology resulted in a 2.69 times reduction in cumulative exergy demand.

Evaluation of direct coupling between conventional windmills and reverse osmosis desalination systems at low wind speeds

Evaluation of direct coupling between conventional windmills and reverse osmosis desalination systems at low wind speeds

Activate the filtration capability of 3.5 nm ultra-large pores and eliminate the requirement of pore homogeneity for carbon nanotube array membranes

Vertical array carbon nanotube (VACNT) membrane is considered as one of the most promising materials for seawater desalination due to its excellent porosity, strong mechanical properties and atomic smoothness of the inner wall. However, in practical applications, the synthesis of highly oriented VACNT arrays with uniform pore sizes (< 1.1 nm) needs to be strictly controlled, and achieving high permeability-retention for large pores (> 1.1 nm) is a great challenge. Here, we use molecular dynamics simulations to introduce the oscillation paradigm into VACNT filtration membranes with a heterogeneous pore network with a wide pore size distribution (ranging from 1 nm to 3.5 nm). Notably, the oscillating heterogeneous VACNT membrane achieved ultra-high permeability of 1421.8 L/cm2/day/MPa (~5 times speed increase in comparison with homogeneous VACNT and ~ 2 times over state-of-the-art CNT membranes), while maintaining a selectivity of 97.5 %. This method activates the filtration capacity of 3.5 nm ultra-large pores, eliminating the requirement for pore homogeneity in VACNT, and achieves the effect of “killing two birds with one stone”. In addition, the filtration performance of specific heterogeneous VACNT membrane was successfully predicted by water permeability curve fitting, which provided valuable theoretical guidance for the design of high-performance VACNT reverse osmosis desalination system.

Feasibility Study of a Reverse Osmosis Desalination Unit Powered by Photovoltaic Panels for a Sustainable Water Supply in Algeria

In recent years, reverse osmosis water desalination has developed rapidly and has become the most competitive and widely used technology in the world. The number of desalination plants is increasing rapidly as freshwater needs increase. Various membrane technologies have been developed and improved, including nanofiltration (NF) and reverse osmosis (RO), whose desalination costs have been relatively reduced. Therefore, this work proposes an experimental study for a small desalination unit based on RO generated by renewable energy, which is mainly suitable for arid regions or desert areas that do not have electricity and water and can be applied for emergency treatment to meet strong freshwater resource needs. In this study, to meet the drinking water demand, a reverse osmosis desalination system is designed and evaluated in order to improve and optimize its operation. This system has a daily capacity of 2 m3. We used brackish groundwater, which has been characterized as reference water, to produce synthetic water for different salinities until seawater. The analysis is based on data obtained from experiments carried out in the standalone RO pilot designed for the production of fresh water. For this purpose, we conducted relevant experiments to examine the influence of applied pressure, salt concentration and temperature on the RO membrane performance. The effects of different factors that affect the energy consumption in the RO desalination process were analyzed, and those with significant influence were explored. The effectiveness of RO desalination coupled with a photovoltaic (PV) energy system is shown. We found the recovery rate for system operation to be 32%. An optimization study is presented for the operation of an autonomous RO desalination system powered by photovoltaic panels. The energy produced by the PV system was used to feed two pumps forthe production of drinking waterwithanRO membrane, under the conditions of the town of Bou-Ismail. As results, a 3 kWp PV system was installed based on the energy demand. The design data have shown that a 3 kWp PV system can power a 1.8 W RO load given the Bou-Ismail climate. Energy consumption in the case study under Bou-Ismail weather conditions were analyzed. The desalination of brackish water at a TDS value of 5 g/L requires an energy of about 1.5 kWh/m3. Using seawater at a TDS value of 35 g/L, this value increases to 5.6 kWh/m3. The results showed that the optimal recovery rate for system operation was determined to be 32% for a feedwater salinity of 35 g/L, and 80% for a feedwater salinity of 1 g/L.

Integrated Pumped Hydro Reverse Osmosis System optimization featuring surrogate model development in Reverse Osmosis modeling

The pressure head generated by the upper reservoir of a pumped hydro energy storage system can be sufficient for creating the pressure gradient required for a reverse osmosis desalination plant. Combined with the fact that many drought-stricken coastal areas have nearby mountains at the necessary elevation for these upper (mountaintop) reservoirs, a symbiotic relationship can be ascertained through the co-location of a pumped storage hydropower (PSH) system with a reverse osmosis (RO) desalination system. Merging PSH and RO into one Integrated Pumped Hydro Reverse Osmosis System (IPHROS) instead of implementing each individually could result in a number of benefits, including reduced capital investment, lower maintenance costs, and a natural mechanism for diluting the highly saline brine discharge generated from the RO process. This paper extends the work of Slocum et al. in 2016, who first introduced the concept of IPHROS, by optimizing the amount of seawater sent to and diverted from the upper reservoir for maximal energy recapture and freshwater production, respectively, while also seeking to maximize the RO system recovery ratio. For this multiobjective optimization, a new reverse osmosis model is created that utilizes a blend of empirical and fundamental equations based on the solution–diffusion model of membrane transport and boundary layer effects that naturally occur along reverse osmosis membranes. Additionally, surrogate models are developed to predict the permeate flowrate and fractional salt rejection rate for a Seamaxx™-440 RO element. Optimizing the presented IPHROS model reveals a 16% decrease in the break even time for IPHROS compared to PSH and RO being implemented individually, and that at the best design with regards to the energy, freshwater, and RO system recovery objectives, 79.5 million kWh of energy and 5.79 million cubic meters of fresh water can be delivered to a population, significant amounts for a population seeking to transition to a renewable energy-based grid and alleviate dire freshwater conditions. Enhanced modeling and optimization, as was initiated in this paper, will eventually aid in IPHROS’ large-scale adoption into energy and freshwater infrastructures.

Multi objectives optimization and transient analysis of an off-grid building with water desalination and waste heat recovery units

In this study, an off-grid apartment of a five-story building with a 150 m2 area, is considered. Building is considered in a remote area; therefore, all occupants' requirements are provided without using electricity and gas from the grid. For producing water, reverse osmosis (RO) desalination system is used. HVAC system is optimized for achieving the lowest CO2 emission and the best occupant’s thermal comfort simultaneously. Also, the use of two different sources, waste heat of diesel generator and solar collector, to provide domestic hot water for the building were investigated and compared. The roof-mounted PV panel is considered for supplying building's energy consumption. Due to the limited available area of the rooftop for each flat, the diesel generator is considered a backup power supplier for the building. Produced power is stored in the battery. Results show that the optimal scale factor of the heat pump is 0.9, and the cooling capacity of the heat pump should be 5.35 kW to supply thermal comfort. Regarding the results of optimization, the annual CO2 emission production of the diesel generator is 4.79 tons and PPD is 12.4%.

Fractional modelling of the reverse osmosis process used for dam water desalination

&lt;p&gt;This paper deals with new fractional models to follow the performance of dam water reverse osmosis (DWRO) desalination system using the dimensionless cumulative volume of alimentation, permeate and rejection. The experimental data consist of 2561 points taken during 4 years of the lifetime of 66 organics reverse osmosis (RO) membranes. The accuracy of the established fractional models was verified using statistical criteria and a comparison with ordinary models. The fractional dimensionless models (FDM) with optimal kinetic constants gave an accurate result and perfect consistency with the experimental data. As such, the coefficient of determination (R2) values were 0.9975, 0.9750 and 0.9801, with lower average absolute relative deviation (AARD) around 8.03, 0.53 and 0.45, through lower root mean squared error (RMSE) about 1.452, 0.976 and 0.880 for alimentation, permeate and rejection, respectively.&lt;/p&gt;&#x0D;

Hybrid BWRO/FO system for high recovery in-land brackish water desalination: techno-economic assessment

Several hybrid Forward osmosis (FO) systems for seawater and brackish water desalination have been developed in recent years. This study investigates two approaches of integrated systems comprising brackish water reverse osmosis desalination (BWRO) and forward osmosis (FO) systems. These approaches aim to minimize the environmental effect of inland reject brine disposal while enhancing total water recovery. Experiments were performed using different draw solution (DS) concentrations of KCl and MgCl2.6H2O (0.5, 1, 1.5 and 2 Molar) to reach maximum recovery. In scheme (A), feed water is directed to BWRO with recovery 45% and 97% rejection, while the brine water is directed to the FO system as FS stream. In scheme (B), the feed water is divided into two streams, one of which is directed to the BWRO with recovery 75% and 98% rejection and the other stream is sent to the FO unit as FS stream. KCl DS displayed higher flux rate of an average 28.5 L/(m2.h) using 2 M concentration, while MgCl2.6H2O 2M solution shows an average flux of 23.5 L/(m2.h) during the first 100 min of operation. Scheme A shows 81% total system recovery, while scheme B shows 78% total system recovery. The cost indicators for desalination system with small capacity of 10 m3/d showed that scheme (A) has lower capital cost 55,732$ for scheme (A), while total capital cost was 59,400 $ for scheme (B).

Raman spectroscopy for real-time concurrent detection of multiple scalants on RO membranes

In-situ monitoring techniques of reverse osmosis (RO) desalination systems, particularly those with chemical sensing capabilities, can provide the means for better understanding important scaling mechanisms as well as early scaling detection. In this work, both calcium sulfate and calcium carbonate scaling on RO membranes were detected concurrently in real time using Raman spectroscopy to provide a unique chemical fingerprint. Two different sampling methodologies (manual and automated) were employed, and their performance was evaluated by comparing the Raman detection times to concurrent values of flux decline. The manual sampling strategy resulted in the detection of calcium sulfate and calcium carbonate at mean permeate flux declines of 13 ± 10 % and 22 ± 3 %, respectively. The automated sampling strategy provided better performance, with detection of calcium sulfate and calcium carbonate at mean flux declines of 8 ± 5 % and 4 ± 3 %, respectively. The increased sensitivity and decreased variability of the automated sampling strategy provided valuable preliminary insights for the selection of optimized sampling strategies. The ability to identify the chemical composition of different scaling crystals including their polymorphs is an important step toward better understanding of the crystallization pathways of multi-component feed streams used in seawater and brackish water RO desalination.