Desalination Research Articles

Renewable energy-powered water desalination and treatment network under wind power and water demand uncertainty: A possibilistic chance-constrained programming

Given the scarcity of freshwater resources, the growing significance of desalination is undeniable. It holds immense potential, particularly in regions grappling with severe water shortages. However, desalination's Achilles heel lies in its voracious energy appetite, requiring roughly ten times more energy than wastewater treatment. Moreover, the prevalent use of fossil fuels in desalination plants poses concerning issues like environmental pollution, fossil fuel depletion, and rising costs. The present study has designed an integrated Water desalination and treatment Network that includes a number of desalination facilities, storage centers, wind farms, and wastewater treatment facilities. The water desalination and treatment network has been structured using a Mixed-Integer Linear Programming (MILP) model, considering uncertainties in wind power and water demand. Employing a chance constraint probabilistic programming approach, this model ensures robustness and balances conservatism with investment attractiveness. It aims to enhance resilience against fluctuations in wind energy and water demand within the water and energy supply chain network. The study applied this model to optimize the locations of desalination plants, treatment centers, and storage facilities. This integrated model ensures autonomy, eliminating the need for external water and energy sources while reliably meeting regional demands. In the context of the Makran coasts case study, our comprehensive mathematical model demonstrates an optimal allocation with 96.67 % attributed to fixed costs and only 3.33 % to variable costs. Moreover, this model precisely optimizes the locations of two desalination centers, two storage facilities, and ten water treatment centers, effectively managing the need for external water resources. Ultimately, through a rigorous sensitivity analysis, we unveiled that the chance constraint parameters have a significant impact on the variable costs.

Thermal energy storage using phase change material for solar thermal technologies: A sustainable and efficient approach

Over-exploitation of fossil-based energy sources is majorly responsible for greenhouse gas emissions which causes global warming and climate change. To mitigate these challenges renewable energy sources, especially solar thermal technologies, can play a decisive role. United Nations also proposes steps to attenuate the adverse effects of fossil-based energy and climate change through Sustainable Development Goals (SDG7 and SDG8). Solar thermal technologies have seen a huge capacity expansion around the globe in previous decades because of their inherent advantages. However, solar energy faces crucial limitations of fluctuating intensity and time-dependent availability. This decreases solar thermal system performance and makes solar thermal technologies time-dependent. To overcome these challenges, integrating phase change material (PCM) in solar thermal technologies makes a sustainable approach to enhance the efficacy, productivity, and utilization rate of solar thermal technologies. In this manuscript, the sustainable approach of integrating PCM in solar thermal technologies was reviewed. This includes literature on PCMs which covers classification, properties, importance, and limitation. Comprehensive data on the integration of PCM with solar thermal technologies such as solar water heating, solar desalination, solar cooking, solar dryers, solar PV/T, solar ponds, solar chimneys, and solar power plants were reported explicitly in terms of the type of PCM, efficiency and their productivity. In addition, the effect of PCMs integration in solar thermal technologies was analyzed in terms of mitigation of CO2 emissions and economic analysis at different locations around the World.

Polyelectrolyte-coated zeolite-templated carbon electrodes for capacitive deionization and energy generation by salinity exchange

As global demands for freshwater and renewable energy intensify, capacitive deionization (CDI) emerges as a promising technique for water purification, desalination, and ionic separation. Reciprocally, energy harvesting has been made possible from exchanging solutions with different salinity, using the so-called capacitive mixing (CapMix) methods, now taking their first steps towards a wider range of application. In all the techniques mentioned, porous electrodes are used in order to maximize the stored charge, making it essential to properly select the material of which the electrode is composed. This work focuses on exploring the performance of zeolite-templated carbon (ZTC) as a highly promising electrode material. ZTC offers ordered pore distribution and high electrical conductivity, making it in principle ideal for energy harvesting and water purification applications. In order to optimize its performance, the surface of the ZTC is for the first time modified by application of polyelectrolyte coatings, resulting in so-called soft electrodes or SEs. This combination of electrode material and functionalization gives rise to a highly efficient and low energy-consuming strategy to fully realize the potential of this carbon material in CDI and CapMix techniques for tackling global freshwater and energy challenges. Energy and power generation values up to 25 mJ and 7.5 mW m−2 have been obtained (with measured potential rises of 131 mV by only exchanging salinities of the bathing solution), which overcome values such as 4.3 mW m−2 previously found in our laboratory under similar conditions.

Application of an energy recovery device with RO membrane for wave powered desalination

A Wave-Driven Desalination System (WDDS) represents an efficient method for harnessing wave energy to facilitate water desalination. Nonetheless, various challenges impede its path to commercial viability. There is a requirement to connect the WDDS to an Energy Recovery Device (ERD), but this is challenging due to the inherent variations in pressure and flow. This unique study demonstrates the working of a small scale WDDS system using a Spiral Wound Reverse Osmosis (SWRO) membrane with a permeate capacity of ∼2 m3/day. The study demonstrates the possibilities to reduce high specific energy consumption (SEC) in WDDS by incorporating a Clark pump as an ERD. The study is the first time an evaluation of an SWRO membrane and Clark pump in-the-loop has been evaluated using variable feed flow and pressure. The utilization of the Clark pump notably reduces SEC to about 3.5 kWh/m3, which is comparable to that of commercial desalination plants. Furthermore, the Clark pump aids in maintaining a consistent permeate recovery rate of 10 % under rectified sinusoidally varying flow conditions – representing the operating conditions more closely to that of practical devices.

A Proposed Framework For Using Nuclear Power Plants To Sea Water Desalination And Extracting Hydrogen To Achieve Environmental Sustainability

A Proposed Framework For Using Nuclear Power Plants To Sea Water Desalination And Extracting Hydrogen To Achieve Environmental Sustainability

Enhancing energy hub efficiency through advanced modelling and optimization techniques: A case study on micro-refinery output products and parking lot integration

A new model of energy carriers (micro-refinery output products) in the concept of an energy hub is presented. In addition, in the presented model, the effect of different models of parking lot in an energy hub is analyzed. In this study, the uncertainty of the number of electric vehicles was modeled using the Monte Carlo method, and then considering the same conditions, the uncertainty of the number of electric vehicles was calculated using the Probability-Possibility hybrid method. In addition, the study uses a scenario-based approach to address uncertainties related to multi-carrier energy demand and multi-carrier energy prices. In the present paper, ensuring water demand is of great importance, which is why the proposed energy hub structure of a sea desalination unit and sour water treatment that is extracted from the micro refinery output was analyzed. The optimization model presented in this paper for the energy hub is a complex integer linear programming (MILP) that is solved using a CPLEX solver in the GAMS environment. The results show that the use of the Probability-Possibility method resulted in an 8 % reduction in the final energy supply cost in the energy hub compared to the Monte Carlo method.

Proposing a novel solar adsorption desalination unit using conceptual design and AHP-TOPSIS

In response to the escalating issue of water scarcity, the United Nations has allocated Sustainable Development Goal 6 of ‘Clean Water and Sanitation’ to address the issue by providing clean water and improved sanitation. Solar stills are an attractive solution to water scarcity as they are simple, cost-effective, and convenient for communities with limited resources. However, they have shortcomings, such as limited production and nocturnal ineffectiveness. The present study proposes several alternatives to address these issues using the conceptual design technique. The customer requirements were met using the Quality Function Deployment (QFD) method targeted during the design stage. An integrated AHP-TOPSIS was used to evaluate the design of alternatives considering seven criteria. This proposed method includes many factors, including system efficiency, cost, and ease of operation and maintenance. The three alternatives combine solar stills with adsorption desalination units. Two weighting methods were used, consistency-based ranking index for decision making (CRITIC) and Entropy, to evaluate the results' reliability. The findings showed that the most favorable alternative with CRITIC value of 0.975 and entropy of 0.988, combines a pyramid solar still and an evacuated tube solar collector. The purpose of this investigation is to build on the body of knowledge of solar desalination and support decision-makers in the evaluation process of selecting an appropriate solar still system.

An innovative sustainable multi-generation energy system (electricity, heat, cold, and potable water) based on green hydrogen-fueled engine and dryer

Increasing renewables' portion in energy matrix around the world has made the scientists to propose innovative techniques for recovering the available waste heat of energy systems to produce excess energies in the Waste-to-X framework. This study proposes a green sustainable multi-generation energy system (MES), producing power, heat, cold, and potable water, driven by a hydrogen-fueled gas engine. The engine's heating potential is recovered to run some bottoming systems comprising proton exchange membrane electrolyzer (PEME), absorption/electrical chiller cycles (ACC/ECC), organic Rankine cycle (ORC), dryer unit, heat pump cycle (HPC), and reverse osmosis desalination unit. The combination of ACC with dryer and HPC is an innovative idea which utilized to produce heating load in this study. A detailed sustainability evaluation framework (technical and eco-environment) is derived to approve performance of the MES. The construction feasibility of the MES in different climatic conditions is sought by considering 5 case study cities around the world. Afterwards, best working fluid of the ECC/HPC and ORC is selected and then the sensitivity of the MES performance to design variables is investigated trough a comprehensive parametric study. Results illustrated that the MES shows the best performance in the city of Willington in which the emission of 84.8 tons of CO2 is prevented annually which is equivalent to saving of 16,291.6 m3 natural gas. The working fluid selection outputs proved that considering R22 and R123 for ECC/HPC and ORC leads the best techno-economic performance. The sensitivity study demonstrated that the highest and lowest influence of the MES's techno-economic performance is related to the ECC evaporator and ORC turbine temperatures, respectively. So that, increasing ECC evaporator temperature led to a relative variation of 8.2%, 4.5%, and 7.5% in energy recovery factor, exergy efficiency, and levelized cost of productions, respectively.

Exploring the impact of high salinity and parasite infection on antioxidant and immune systems in Coris julis in the Pityusic Islands (Spain)

Climate change associated with human activities alters marine ecosystems and causes imbalances and abrupt changes in sea conditions. Scarce freshwater resources for human consumption often prompt the construction of desalination plants, which discharge significant amounts of brine into the sea, potentially elevating salinity levels. Furthermore, global trade together with higher temperature and pollution can facilitate the spread of parasites. The aim of this study was to assess the potential effects of salinity, an abiotic stressor, and Scaphanocephalus sp. parasitic infection responsible for black spot disease, a biotic stressor, on Coris julis, a common fish in the Balearic Islands (Spain). Fish were sampled from an area affected by a desalination plant, one with a high rate of parasite infection and a control area, and biomarkers were analysed in the liver, gills and epithelial mucosa. Both salinity and the parasite induced increases in catalase (CAT) and glutathione s-transferase activities in the liver, while superoxide dismutase (SOD) did not show significant changes. The effects of salinity were evident to a greater extent in the gills with an increase in the activity of all enzymes, as well as in the production of reactive species. The effects of the parasite were mainly observed in the mucus with significant increases in CAT and SOD activities. Regarding immune response markers in the mucus, both stressors induced an increase in lysozyme and alkaline phosphatase activities, and in the case of the parasite, also an increase in immunoglobulins. Malondialdehyde, as an indicator of oxidative damage, remained unchanged. In conclusion, both abiotic and abiotic stress induce a stress situation in C. julis that responds by activating its antioxidant and immune defence mechanisms but does cause oxidative damage. The differential tissue response to different stressors highlights the value of analysing multiple tissues to detect early indicators of diverse impacts on marine fauna.

Renewable energy-driven desalination for sustainable water production in the Middle East

ABSTRACT Despite significant advancement in conventional desalination technologies, their widespread application is still constrained by high energy demands, high capital costs, and the associated greenhouse gas (GHG) emissions. The main objective of this study is to evaluate the potential and challenges of renewable energy desalination in the Middle East. The study also compared the production of energy and water, and emissions reductions of hypothetical 100 MW renewable energy plants in Kuwait, coupled with reverse osmosis (RO) desalination units. The wind-RO plant is estimated to produce 68 million cubic metres on an annual basis, while the CSP-RO and PV-RO plants produced 44 and 37 million cubic metres of fresh water, respectively. These estimates, however, only account for 5% to 9% of the annual fresh water demand in the reference case. Meeting 100% of the fresh water demand would require a 1000 MW to 2000 MW renewable energy capacity. Overall, the intermittent nature of renewable energy sources is a fundamental barrier to the large-scale transition to renewable energies for desalination. The results of this study indicate that the CSP’s relatively small footprint (compared to wind plants) and higher capacity factor make it an ideal compromise among the proposed plants.

Toward sustainable energy resource: Integrated concentrated photovoltaic and membrane distillation systems for fresh water and electricity production

This study introduces and evaluates a novel Concentrated Photovoltaic (CPV)-assisted Direct Contact Membrane Distillation (DCMD) system, examining its efficiency and energy output under varying operational conditions. A Computational Fluid Dynamics (CFD) model, validated with experimental data, assesses the system's performance at different concentration ratios ranging from 1x to 10x and 25x to 100x, flow patterns (counterflow and parallel flow) at different Reynolds numbers (30–1200). This study investigates the seasonal performance of the CPV-DCMD system, providing valuable insights into its reliability and sustainability throughout the year. Results show increased mass flux and electric power with higher concentration ratios, especially at lower Reynolds numbers. In the counter-flow arrangement, the mass flux increases notably under specific conditions, while seasonal analysis reveals peak flux during summer and autumn afternoons. Electric power output follows a consistent trend across seasons, with high output observed during noon hours. The study demonstrates the system's energy efficiency, with notable energy gain compared to consumption across diverse operational conditions. Overall, the findings provide insights into optimizing the performance of CPV-assisted DCMD systems for sustainable energy generation and water desalination applications.

Numerical analysis of evaporation process in the heating column of a solar water desalination plant under various geometries, ambient conditions, solar radiations, and time steps

Solar-powered desalination offers a promising and sustainable method for producing potable water. In this study, the heating column of a solar desalination powerplant is numerically investigated under different novel geometric/structure scenarios, various solar/ambient conditions and different seawater salinity through different time steps. The primary objective is to identify the optimal configuration that maximizes water evaporation within the heating cylinder which has not been carried out before. Initially, four distinct heating cylinder configurations are examined under a fixed time step. The most promising configuration is then selected and evaluated under a broader range of ambient conditions and the same time step. The influence of solar radiation throughout the day is also analyzed. Finally, the evaporation process is simulated for the selected geometrical and environmental conditions across different time steps ranging from 60 to 300 s. The findings reveal that incorporating fins alone, a glass cover alone, and a combination of both fins and a glass cover could enhance the volume fraction of vapor by approximately 8 %, 33.3 % and 10.6 %, respectively, compared to the baseline configuration without fins or a glass cover. However, the evaporation rate for the glass cover configuration increased with rising ambient air temperature. Additionally, the highest evaporation is observed at 15:00 p.m., corresponding to the peak solar radiation intensity. Under optimal conditions, the heating cylinder achieved a promising vapor volume fraction of approximately 78.2 % after 300 s. These findings offer valuable insights for optimizing solar desalination system design. By increasing the salinity of the water from 0 to 75 %, the value of steam volume fraction is reduced from 77 % to 60 % for a given time step.

Floating Photothermal Hydrogen Production.

Solar-to-hydrogen (STH) is emerging as a promising approach for energy storage and conversion to contribute to carbon neutrality. The lack of efficient catalysts and sustainable reaction systems is stimulating the fast development of photothermal hydrogen production based on floating carriers to achieve unprecedented STH efficiency. This technology involves three major components: floating carriers with hierarchically porous structures, photothermal materials for solar-to-heat conversion and photocatalysts for hydrogen production. Under solar irradiation, the floating photothermal system realizes steam generation which quickly diffuses to the active site for sustainable hydrogen generation with the assistance of a hierarchically porous structure. Additionally, this technology is endowed with advantages in the high utilization of solar energy and catalyst retention, making it suitable for various scenarios, including domestic water supply, wastewater treatment, and desalination. A comprehensive overview of the photothermal hydrogen production system is present due to the economic feasibility for industrial application. The in-depth mechanism of a floating photothermal system, including the solar-to-heat effect, steam diffusion, and triple-phase interaction are highlighted by elucidating the logical relationship among buoyant carriers, photothermal materials, and catalysts for hydrogen production. Finally, the challenges and new opportunities facing current photothermal catalytic hydrogen production systems are analyzed.

Integrated hybrid membrane system for enhanced water treatment and desalination for environmental preservation

Technology advancements in desalination, water treatment, and energy efficiency are crucial to preserving our planet. It is critical to find solutions for the future that save natural resources and lessen environmental damage because the freshwater shortage is getting worse, and energy demand is increasing. They face various obstacles, even though their breakthroughs are extremely important. Lot of energy can be utilized for the traditional desalination techniques, as it negatively impacts the environment. Then, the process of the existing Water Treatment (WT) are expensive and ineffective. An Integrated Hybrid Membrane System for Enhanced WT (IHMS-EWT) is a unique technique for WT and desalination was suggested in this study. The integration of many membrane procedures like nanofiltration, reverse and forward osmosis, and membrane distillation, and these will helps in facilitating the best WT and desalination methods. Due to the incorporating Renewable Energy (RE), the IHMS-EWT also demonstrates the (SWMS) Sustainable Water Management System, as it enhances the EE and thereby reducing the environmental impact. The great potential in the wide range of applications was offered by the IHMS-EWT technique. Providing the decentralized WT solutions in the remote areas, this unique approach has the ability to reduce the fresh water scarcity in the coastal areas based on the demands of the municipal, industrial and agricultural demands. The environmental sustainability throughout the lenghthy operations was ensured by the support of IHMS-EWT. It also helps in providing resilience in the crisis situations. The cost-effective evaluations, operating parameter optimization, and performance prediction of the method was enabled by employing the computational modelling. Through simulatimg different contexts, the effective configurations and operational techniques are focussed on the study for enhancing the IHMS-EWT technology.The model shift in the SWM, the IHMS-EWT technique addresses the main problems and brings one step for more secure environment. Comparing to other existing methods, Improving the water purification by 98.2 %, 94.2 % efficiency rate, the EC prediction rate of 96.2 %, the cost-effectiveness rate by 82.4 % and the performance rate by 96.7 % by the suggested IHMS-EWT model and it was demonstrated by the outcomes of the experiment.

Effective design of sustainable energy productivity based on the experimental investigation of the humidification-dehumidification-desalination system using hybrid optimization

Reliable and cost-effective industrial-based sustainable desalination technologies are crucial for efficient and effective desalination of saline water. Seawater desalination emerges as a vital treatment, with humidification-dehumidification identified as a promising technology due to its simple, low-maintenance design and compatibility with renewable energy sources. The present work was developed using a large-scale experimental test rig based on the performance of a humidification-dehumidification system operated by the heat pump. As such, the study presents an advanced approach for optimizing humidification-dehumidification desalination systems using hybrid machine learning optimization techniques. The effectiveness of a neuro-fuzzy model, a decision algorithm based on a boosted tree, and a simple averaging ensemble in enhancing the performance of humidification-dehumidification systems were investigated. Experimental data includes cold water flowrate (L/min), hot water flowrate (L/min), inlet air temperature (°C), inlet cold water temperature (°C), inlet hot water temperature (°C), and inlet air relative humidity (%) as input variables combination and freshwater productivity (L/h), recovery ratio (%) as target variables. Several statistical indicators were used to evaluate the models’ prediction skills; similarly, a 2-dimensional Taylor diagram and error-radial plot were also utilized. In the calibration phase, boosted tree models slightly outperform neuro-fuzzy models, particularly for recovery ratio, demonstrating high accuracy and low bias. However, all models exhibit robust predictive accuracy in the verification phase, especially for recovery ratio, emphasizing their potential in generalizing to unseen data. The result indicated that the boosted tree outperformed others with Nash–Sutcliffe Efficiency = 94 % and 88 % for recovery ratio and freshwater productivity, respectively. The simple averaging ensemble shows marginal improvement with 95 % accuracy for the recovery ratio. Integrating hybrid artificial intelligence optimization with humidification-dehumidification desalination systems marks a transformative step in addressing freshwater shortages. By utilizing cutting-edge machine learning techniques, we achieve a more efficient, accurate, and reliable prediction of desalination performance.

Diurnal humidity cycle driven selective ion transport across clustered polycation membrane

The ability to manipulate the flux of ions across membranes is a key aspect of diverse sectors including water desalination, blood ion monitoring, purification, electrochemical energy conversion and storage. Here we illustrate the potential of using daily changes in environmental humidity as a continuous driving force for generating selective ion flux. Specifically, self-assembled membranes featuring channels composed of polycation clusters are sandwiched between two layers of ionic liquids. One ionic liquid layer is kept isolated from the ambient air, whereas the other is exposed directly to the environment. When in contact with ambient air, the device showcases its capacity to spontaneously produce ion current, with promising power density. This result stems from the moisture content difference of ionic liquid layers across the membrane caused by the ongoing process of moisture absorption/desorption, which instigates selective transmembrane ion flux. Cation flux across the polycation clusters is greatly inhibited because of intensified charge repulsion. However, anions transport across polycation clusters is amplified. Our research underscores the potential of daily cycling humidity as a reliable energy source to trigger ion current and convert it into electrical current.

Thin-film composite (TFC) membranes incorporated with hydrophilic additives and layered double hydroxides (LDHs) for effective brackish water (BW) desalination

To overcome the limited water permeability of thin-film nanocomposite (TFN) membranes for brackish water reverse osmosis (BWRO) processes, we have incorporated a few amine or hydroxyl group terminated hydrophilic additives during interfacial polymerization when fabricating RO membranes and found that the membrane comprising 1 wt% 2-(2-hydroxyethyl)pyridine (2-(2-pyridyl)ethylahydroxide, PEH) has the best BWRO performance. The membrane was subsequently infiltrated with layered double hydroxide (LDH) nanoparticles by a post ethanol activation and could deliver a water permeability of 4.18 LMH bar−1 which is 100 % more than the control membrane without much compromising the salt rejection. The newly developed process not only incorporates nanofillers with the advantages of simplicity and decoupling from the interfacial polymerization process, but also endows the TFN membranes with enhanced separation performance. The study may provide useful insights to incorporate nanofillers by the solvent activation approach for the fabrication of TFN membranes.

Magnesium recovery from brackish water desalination brine and valorization in fertilizer production

The generated brine from the desalination unit hurts the environment. In this work, we try to valorize the nanofiltration and reverse osmosis brine generated from a hybrid desalination unit of treated wastewater located in Tunisia by magnesium recovery and reuse it as a cheap resource for fertilizer production. The brine was first purified by calcium removal. The pH of calcite precipitation was 11.32 and 9.78 using brine NF and brine RO respectively. After that, the filtrate was used to produce brucite. The pH of brucite precipitation was 11.3 and 9.74 for NF and RO brine respectively. 55 % of magnesium was recovered from NF brine and 65.5 % from RO respectively. To obtain a 100 % recovery rate of magnesium for brucite precipitation, the optimal molar alkaline reagent/Mg ratio was 5.5 and the pH was 11.9. The brucite was dissolved in sulfuric acid, then the Epsomite fertilizer was extracted with pure ethanol. The highest weight of epsomite was obtained for a volume ratio of acid/ ethanol of 0.8:3.5. The second fertilizer produced using brine magnesium was struvite. It was obtained for pH 9 and 11 using H2NH4PO4 acid and wastewater as a source of ammonia and phosphate respectively. 90 % and 50 % of magnesium recovery were obtained for the first and the second cases respectively. The infrared spectrum and X-ray diffractogram confirmed the brucite, epsomite, and struvite production using brine magnesium.

Rejuvenated end-of-life reverse osmosis membranes for landfill leachate treatment and reuse water reclamation

Landfills remain a prevalent method for municipal solid waste disposal, yet concerns persist regarding leachate generation and its environmental impact. This research paper investigates the reuse of end-of-life reverse osmosis membranes for treating landfill leachate (LL) after their rejuvenation. The rejuvenation process involved a specific chemical cleaning procedure that allows for permeability recovery without compromising the membrane rejection capacity when compared to o pristine reverse osmosis. It was also explored the hypothesis how previous membrane use affects the rejuvenation process by considering end-of-life membranes used for desalination of brackish water and treated water. While both could be effectively rejuvenated, those used for brackish desalination were more susceptible to irreversible fouling. In such cases, recycling the membrane and converting it to porous ultrafiltration or microfiltration membranes is recommended. For membranes previously used for treated water desalination, it was observed high efficiency in LL treatment across multiple filtration cycles. The average flux for these membranes corresponded to 6.9 ± 0.4 L/m2h (operating pressure: 10 bar), and the rejection were greater than 89.4 % for chemical oxygen demand and 98.6 % for color. In complement, it was investigated the contribution of pretreatment with ultrafiltration membranes. Ultrafiltration was effective in preventing membrane fouling and improving the physicochemical quality of reclaimed water from landfill leachate. Overall, this research provides valuable insights into the potential reuse of end-of-life reverse osmosis membranes from treated water desalination plant for LL treatment, contributing to sustainable waste management and wastewater treatment solutions.

Tree rings-inspired 3D solar evaporator fabricated by rolling polypyrrole decorated waste cotton fabric for efficient desalination

Interfacial solar steam generation (ISSG) has drawn considerable interest as an emerging technology for seawater desalination. However, designing simple and cost-effective solar evaporators with high salt resistance and impressive evaporation rates remains a significant challenge. Inspired by tree rings, a three-dimensional (3D) solar evaporator (PPy-RWCF) was fabricated by rolling polypyrrole-decorated waste cotton fabric (PPy-WCF) into a cylinder. The synergistic effect of polypyrrole (PPy) and interstices within the waste cotton fabric (WCF) allows the PPy-RWCF to absorb around 99.00 % of sunlight. The PPy-RWCF, with an exposure height of 3 cm, achieves an excellent evaporation rate of 2.36 kg m−2 h−1 under 1-solar intensity. Besides, the vertical water channels within PPy-RWCF allow rapid solution transport, enabling it to withstand 20 wt% brine with an evaporation rate of 2.05 kg m−2 h−1. Prolonged outdoor desalination testing has demonstrated that a 1 m2 PPy-RWCF can generate approximately 10 kg of freshwater daily. This study proposes a sustainable approach to the development of solar evaporators utilizing WCF for desalination of high-salinity water.