Water Production Cost Research Articles

Increasing solar still efficiency with thermo-electric cooling: an experimental study and economic analysis

Seawater distillation often relies on fossil fuels, emitting greenhouse gases, but solar energy offers a sustainable, cost-free alternative. This study enhances solar still productivity by incorporating a condensation chamber and thermoelectric cooling using Peltier modules and fans. Two models were tested in Khemis Miliana, Algeria: a conventional solar still and a modified version with a cooling system. Experimental results from September to November showed the cooling system increased productivity by 74% compared to the uncooled system and 14% compared to the conventional still. The optimal cooling system operation was determined to be 3 minutes every 30 minutes, influenced by solar radiation. The modified system achieved a water production cost of $0.09237 per litre, with a payback time of 2.5 years. Daily output data helped evaluate CO2 emissions, mitigation potential and carbon credits over the system's lifespan. Future work includes integrating a flat plate collector and optimising the cooling system's operation relative to solar radiation for higher efficiency.

Energy and exergoeconomic analysis of solar stills integrated with thermoelectric technology: A case study on environmental and economic sustainability

Achieving sustainable access to safe water is crucial for the advancement of civilizations. Utilizing solar energy, a clean and renewable resource, for water purification offers significant environmental and economic benefits. This study integrates thermoelectric technology into solar stills. The hot side of the thermoelectric module serves as a heater, equipped with attached heat sinks, while the cold side functions as a condenser in a dedicated chamber. Comparative results demonstrate that the solar still with thermoelectric technology achieves superior energy and exergy output on both daily and annual scales, along with higher energy and exergy efficiencies, when compared to conventional solar stills. The Unit Annual Benefit (UAB) was 51$ (41.2 %) higher, and the benefit-cost ratio was 6.8 times greater for the thermoelectric-integrated solar still. Annual water production reached 698.57 L/m2, representing a 41.2 % improvement over the traditional design, accompanied by a 5.1 % reduction in water production cost per liter (now 0.037$). Additionally, the thermoelectric-enhanced solar still demonstrated superior performance in environmental, exergoenvironmental, exergoeconomic, and enviroeconomic metrics, while reducing CO₂ emissions by 28.2 % compared to the conventional solar still.

Comparative assessment of ion-exchange/reverse osmosis and ultrafiltration/reverse osmosis for seawater desalination: environmental, economic, and operational perspectives.

The urgent need for economically viable and environmentally friendly desalination technologies to address global water scarcity is underscored. This study compares ion-exchange reverse osmosis (IX-RO) and ultrafiltration reverse osmosis (UF-RO) systems, examining their environmental impacts, energy efficiency, cost-effectiveness, and operational stability. The IX-RO system reduced water hardness and ion concentrations by 83%, while the UF-RO system achieved over 99% removal of total dissolved solids. Energy consumption for desalinating 1 m3 of Caspian Sea water was 1.49 kWh for IX-RO and 1.3 kWh for UF-RO. UF-RO's impact on human health, ecosystems, and resources was 1.62, 3.06, and 3.31 times greater than that of IX-RO, respectively. CO2 emissions were 192 kg CO2/m3 for UF-RO and 81.93 kg CO2/m3 for IX-RO. Over 68% of energy in both systems was from non-renewable resources, suggesting potential for utilizing Iran's solar and wave energy. The sensitivity analysis showed that citric acid had a significant environmental impact on UF-RO, while magnesium utilization had a notable impact on IX-RO. Water production costs were $0.06/m3 for IX-RO and $0.11/m3 for UF-RO. Over 20 years, the net present value was $172.8 million for IX-RO and $177.9 million for UF-RO, demonstrating their economic resilience. This study forms a basis for further research in the field.

Performance enhancement in air gap membrane distillation using heat recovery configurations

Experimental investigations were conducted on an air gap membrane distillation (AGMD) unit to evaluate the impact of heat recovery on system performance. The study utilized a steady-state heat source in conjunction with a spiral air gap membrane module for water desalination. The process was implemented using two configurations aimed to minimize heat loss enhancing productivity, gain output ratio (GOR), and thermal efficiency. The experiments involved feedwater with salt concentrations ranging from 10,000 to 30,000 ppm. The measurements were recorded for inlet and outlet temperatures of the heat source, water productivity, and thermal efficiency at various coolant and water feed flow rates. These configurations effectively addressed critical technical challenges in thermal AGMD systems by optimizing heat recovery. The incorporation of heat recovery resulted in a significant increase in water productivity by 37.07 % compared to systems without heat recovery while maintaining the same initial heat input. The heat recovery in series (HRSS) and parallel (HRPS) configurations resulted in power consumption reductions of approximately 29.7 % and 23.1 %, respectively compared to the conventional configuration (CC) at a flow rate of 12 L/min. The levelized cost of water (LCOW) for the AGMD system was comprehensively evaluated and found to be $ 7.71 per cubic meter. This figure reflected the total cost of water production over the system's operational lifespan including capital expenditures, operating and maintenance costs, and energy consumption. The calculated LCOW provides a clear indicator of the system's economic viability, demonstrating the cost required to produce each cubic meter of water through the AGMD.

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

The environment, energy, and water are the three essential pillars of sustainable development. In light of the freshwater scarcity faced by numerous countries, desalination emerges as a practical solution. As a result, countries are increasingly establishing desalination facilities along their coastlines. However, these initiatives are energy-intensive, and their chosen locations may not be optimal for harnessing renewable energy resources. With a daily output capacity of 50,000 m3, the recently operational seawater desalination plant in Djerba, Tunisia, accounts for 13.6% of the region's total electrical energy consumption. In this study, we have considered both the specific and the overall desalination consumption to find the optimal architecture and assess the reliability of the hybrid energy generator supplying the unit. The economic optimization has been performed using hybrid optimization of multiple energy resources, and the dynamic study of the complete system has been achieved using the transient system simulation tool environment. On- and off-grid scenarios using various hybrid power system combinations with and without batteries were proposed and examined. Results showed that the optimum case consists of on-grid 60.513 MWp solar panels and 13.64 MW wind turbines with battery storage. The water produced by the most cost-effective strategy with regard to environmental protection for a 25-year project life cycle costs 0.414 $/m3 against 0.585 $/m3 for current consumption. This significant reduction in water production costs makes desalination more affordable and accessible. The dynamic behavior of the optimal architecture is designed by considering the real meteorological data of Djerba Island. In terms of productivity, the maximum photovoltaic and wind energy production reached 11.31 GWh in July and 0.51 GWh in April, respectively. The findings demonstrate the technical and economic feasibility of powering large-scale desalination plants with hybrid renewable energy systems, reducing their environmental impact and energy costs. The optimal system proposed in this study can serve as a model for future desalination projects in Tunisia and other water-scarce regions.

Performance evaluation of solar-assisted humidification dehumidification system for seawater desalination: An experimental approach

Humidification/dehumidification desalination presents a promising method for small-scale water production due to its ability to utilize solar energy and minimal technological requirements. This research examines the performance of solar-assisted humidification/dehumidification (SA-HDH) desalination system, which is designed to treat seawater from Dumas Beach in Surat city of India. The system integrates a solar air heater, a packed humidifier, and a dehumidifier with an indirect evaporative cooler. Through comprehensive energy, exergy, sustainability, and economic assessments, the study aims to assess system efficiency and viability. Results demonstrate that increasing airflow rates significantly enhances heat transfer efficiency within the humidifier and dehumidifier, boosting system performance and increasing yield by 5.4–7.7 %. The average energy efficiency of 35.5 % is observed at an airflow rate of 125 kg/h. The system effectively removed 99.7 % of total dissolved solids, total hardness, and chloride from the seawater, producing high-quality freshwater. The cost of water production ranging from 0.025 to 0.028 $/L, with a sustainability index ranging from 1.052 to 1.064. These findings underscore the SA-HDH system’s potential as an efficient, sustainable, and cost-effective solution for mitigating water scarcity.

Optimization of vacuum membrane distillation and advanced design of compact solar water heaters with heat recovery

With the escalating global population, freshwater scarcity has become a pressing challenge. To address this issue, this paper presents a novel compact solar water heater (CSWHT) system incorporating heat recovery and submerged-membrane filtration. The research aims to develop an efficient desalination method that reduces water production costs and maximizes output. The system comprises a feed storage tank, a vacuum membrane distillation (VMD) system positioned atop the submerged CSWHT, a liquid ring vacuum pump (LRVP) utilizing waste heat from the outlet to preheat the feed, and hollow fiber membranes.Three critical parameters, namely the mass of the feed in the storage tank, the number of hollow fiber membrane rows, and the feed volumetric flow rate, were optimized using a multi-objective non-dominated sorting genetic algorithm II (NSGA II) to minimize water production cost (WPC) while maximizing water production. Subsequently, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) was employed to identify the optimal scenario from among the selected best solutions.For Mediterranean seawater and a 6 m2 solar collector area, the multi-objective NSGA II algorithm identified 20 membrane rows per collector, 334.4 kg feed mass in the storage tank, and 0.027 kg.s−1 feed mass flow rate as the optimal system parameters. Under these optimized conditions, the system exhibited a daily production capacity of 92.5 kg water, 4.6 kg chloride, and 0.03 g bromide, while achieving a production cost of 12.2 USD.m−3 and a gain output ratio (GOR) of 1.6. These results highlight the system's remarkable potential for desalination with high efficiency and low cost. Future research should focus on scaling up the system and exploring its applicability in various geographical locations.

Exergo and enviro-economic analysis of thermal energy storage assisted finned solar still

The current investigation focuses on improving the performance of a single slope solar still integrated with Phase Change Material as energy storage media. The problem of low thermal conductivity of PCM which hinders the energy storage capability has been addressed by incorporating fins with different profiles into the energy storage unit. Initially, an experimental investigation was conducted and analyzed to assess the effective performance of a Conventional Single Slope Solar Still (CSS) using various water depth levels: 1–4 cm. The optimal basin water depth for testing solar still with energy storage material along with fins was identified as 2 cm. Subsequently, the CSS was subjected to performance enhancement investigation under three different conditions: Case 1 – Solar Still (SS) with PCM storage unit, Case 2 – SS with fins at the PCM storage unit, and Case 3 – SS with fins at the storage unit and a parallel plate attached to the other end of the fins. The experimental results demonstrated the production of fresh water and efficiency improvements are as follows 26.95%, 55.86%, 69.14% and 24.34%, 52.83%, 68.83% for cases I, II, and III, respectively. Further, it was observed that Case III exhibited a lower cost of water production and a shorter payback period compared to CSS. The enviro-economic analysis revealed that the net CO2 emissions (NCEM) and Carbon Credits Earned (CCE) for Case III were 15.60 tons and 312.07 USD respectively against 9.22 tons and 184.31 USD for CSS.

Enhanced water production in pyramid solar stills: Utilizing suspended trays, fogging system, and forced condensation

This work investigated how to improve the thermal efficiency of pyramid distiller (PSD). A modified PSD (MPSD) was constructed with suspended trays (4-cm width) on three vertical walls. The performance of the MPSD with and without a fogging system was evaluated. Additionally, the MPSD was integrated with an external condensation unit using a withdrawing fan operating at various speeds (1, 1.5, 2, 2.5, 3, & 3.5 rpm). The MPSD with suspended trays exhibited a significant improvement, achieving a 35 % increase in distillate yield compared to the PSD. The MPSD with a fogging system demonstrated a 160 % yield increase. The highest thermal performance for the MPSD with trays, fogger, and external condenser was attained at a fan speed of 2 rpm. At this setting, the MPSD's productivity increased by 194 % with a thermal efficiency of 62.4 %. Notably, the cost of water production decreased from 0.24$/L for the PSD to 0.18$/L for the MPSD. These findings suggest that the MPSD with suspended trays, fogging system, and external condenser offers a promising approach to enhance both the yield and efficiency of solar desalination.

Simulation of vacuum membrane desalination within an enhanced design of compact solar water heaters

Vacuum Membrane Distillation stands out as a solar desalination method utilizing membrane pressure differentials to evaporate seawater and collect it as fresh water. On the other hand, the new design of compact (or integrated) solar water heaters can be very suitable for Vacuum Membrane Distillation use. In the new design of solar system, its upper part, which is under buoyancy pressure, can have a very suitable space for installing the Vacuum Membrane Distillation system. The purpose of this research is to simulate the proposed design and a dynamic time-domain model was developed for comprehensive simulation, encompassing absorber plate characteristics, collector dimensions, mass flow rate, vacuum pressure reduction, the influence of increasing membrane rows, and seawater concentration. Simulation results showcase the system’s potential, yielding 57.12kg/m2/day of freshwater daily with an average gain output ratio exceeding 1.1. The estimated water production cost is 0.039USD.L-1, along with the generation of 4.3kg.kg/m2/day of chlorine and 0.037g.kg/m2/day of bromine from Mediterranean seawater. For super saline water, the projections indicate a daily production of 104.46kg.kg/m2/day of freshwater with a production cost of less than 0.01 USD/L, a GOR of 1.7, and a daily production of 37.8kg.kg/m2/day of chlorine for a collector area of 6 m2. These outcomes underscore the efficiency and economic viability of the proposed design, positioning it as a promising solution for seawater desalination challenges.

Solar thermal hot water system in hospitals: Robust design methodology considering uncertainties

The energy yield of solar thermal installations is influenced by local climatic conditions, heating demand, and the efficiency of the system. These factors are affected by uncertainties arising from natural variations and a lack of knowledge. Designers typically address these uncertainties by oversizing the collector area. However, this practice usually leads to high costs, low efficiency, and short service lifetimes of the system. This paper proposes a robust sizing methodology for the solar thermal system used for service hot water preparation in a case-study hospital with a daily average hot water consumption of 8.69 m3. This novel approach incorporates uncertainties through probabilistic simulations, assessing the system’s reliability in achieving a 70% solar fraction design goal. The simulations reveal a mere 22% confidence in the initial deterministic design concerning the solar target and emphasize the importance of thermal insulation, temperature control, and collector cleaning as key factors to reduce performance variability. Although the final revised design outcome requires a 15% increase in the collector area compared to the initial scenario and stricter specifications for control components, pipe insulation, and valve maintenance, it achieves a 90% reliability. In addition, annual carbon emissions and levelized costs of hot water production can be reduced by 18% and 13%, respectively.

A proposed methodology to evaluate the influence of climate change on drinking water treatments and costs

Drinking water (DW) production treatments can be affected by climate change, in particular intense rainfall events, having an impact on the availability and quality of the water source. The current study proposes a methodology for the evaluation of the costs of the different treatment steps for surface water (SW) and groundwater (GW), through the analysis and quantification of the main cost items. It provides the details to count for strong variations in the key quality parameters of inlet water following severe rainfalls (namely turbidity, iron, manganese, and E. coli). This methodology is then applied to a large drinking water treatment plant (DWTP) in Italy, which treats both SW, around 70 %, and GW, around 30%. It discusses the overall DW production costs (from 7.60 c€/m3 to 10.43 c€/m3) during the period 2019–2021 and analyzes the contributions of the different treatment steps in water and sludge trains. Then it focuses on the effects on the treatments of significant variations in SW turbidity (up to 1863 NTU) due to intense rainfalls, and on the daily costs of DW with respect to the average (baseline) costs evaluated on the annual basis. It emerges that, when SW has low turbidity levels, the energy-based steps have the biggest contribution on the costs (final pumping 22 % for SW and 10 % for GW, withdrawal 15 % and 14 %, respectively), whereas at very high turbidity levels, sludge greatly increases, and its treatment and disposal costs become significant (up to 14 % and 50 %). Efforts are being made to adopt the best strategies for the management of DWTPs in these adverse conditions, with the aim to guarantee potable water and optimize water production costs. A mitigation measure consists of increasing GW withdrawal up to the authorized flow rate, thus reducing SW withdrawal. In this context, the study is completed by discussing the potential upgrading of the DWTP by only treating GW withdrawn from riverbank filtration. The DW production cost would be 7.76 c€/m3, which is lower than that seen for the same year (2021) with the current plant configuration (8.32 c€/m3).

Performance, economic, and statistical analysis assessment for the hybrid solar dish concentrator with turbine, generator, and reverse osmosis desalination unit

The development of a thermodynamically modeled hybrid commercial solar dish with reverse osmosis is conducted in this study with a rated concentrate thermal and a receiver temperature of 853 °C. To simulate and assess the performance characteristics of the suggested TJ-SDC/RO hybrid system in the city of Tianjin-republic of China, a theoretical model was created and built with MATLAB application. A daily and yearly performance study of the TJ-SDC/RO system under investigation is accomplished. Furthermore, energy analysis viability is achieved in order to evaluate the TJ-SDC/RO system’s life cycle. According to the findings, the suggested TJ-SDC/RO system can produce enough desalinated water to meet daily changes in solar radiation. In June of Tianjin-China’s climate, the superior efficiency of the Rankine cycle was 33.92 %, while the SDC-RO system maximum cycle efficiency peaked at 24.95 % with minimum production costs per unit of electricity of 0.0902 $/kW.h and average water production costs yearly 7.09 $/m3. A mathematical model by Minitab commercial software of the nonlinear regression technique is used with an adjusted R2 of 0.99999485, which indicates the accuracy and reliability of the prediction correlation.

Experimental study on the scaling law of the heat exchange tube surface in the process of low-temperature single-effect distillation of high-mineralized mine water

High-mineralized mine water, due to its characteristics such as high mineralization degree, will have scaling phenomena on the surface of the heat exchange tube during the desalination treatment process, resulting in a reduction in the water production efficiency of the equipment and affecting the normal operation. To reduce the cost of water production and improve the service life of distillation equipment, this paper independently designs and builds a low-temperature single-effect distillation high-mineralized mine water experimental system to study the influence of operating parameters (temperature, spray density, concentration ratio, and system pressure) on the scaling law on the surface of the heat exchange tube. The distribution and characteristics of scale deposits on the surface of the heat exchange tube are analyzed through the growth rate and microscopic morphology of the scale deposit. The results indicate that the scaling on the surface of the titanium plate is mainly in the needle-like and rod-like morphology of CaCO3 aragonite, and a small amount of CaSO4 and calcite are generated with the increase of temperature. It was found that within the range of spray density from 0.0509 kg/(m·s) to 0.0625 kg/(m·s), concentration ratio from 2.3 to 2.7, and system pressure at 36.3 kPa, it is beneficial to the evaporation heat transfer of the heat exchange tube and the reduction of scaling generation. At the same time, it is found that the scaling of the first row of heat exchange tubes is mainly within the range of circumferential angle from 0 to 100 degrees, and the scaling of the second row and the third row of heat exchange tubes is mainly within the range of circumferential angle from 110 to 170 degrees. The research results of this paper provide support for the design and operation of the low-temperature multi-effect treatment system for mine water in engineering, promote the process of zero discharge of high-mineralized mine water in Xinjiang, China, and improve the resource utilization rate of high-mineralized mine water.

A novel mathematical model for simultaneous optimization of desalination plant location and water distribution network; A case study

In recent decades, water scarcity has turned into a serious problem spanning many countries, now even capable of causing or inflaming ethnic and national conflicts. While our planet has very limited freshwater resources, it has huge amounts of saltwater in seas and oceans. There is a very limited number of ways that can make saltwater drinkable, the most important of them is desalination. This study aimed to provide a method for the simultaneous optimization of desalination plant location and its water distribution network based on mathematical modeling. For this purpose, the authors formulated a non-linear mathematical model with the objective of minimizing the costs of water production and transmission. A genetic algorithm was also developed for solving the proposed nonlinear model. The method was used in a case study of Sistan and Baluchestan, which is one of Iran's most water stressed provinces. The proposed genetic algorithm managed to provide an acceptable solution for this problem in 3.74 s. The best solution was found to be constructing a desalination facility with a capacity of 394,052 cubic meters per day in a single location, that is, the city of Chabahar. The water transmission lines needed for transporting water to other parts of the province and their capacities were also determined.

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.

MnFe layered double hydroxides confined MnOx for peroxymonosulfate activation: A novel manner for the selective production of singlet oxygen

Singlet oxygen (1O2) is a reactive species for the selective degradation of stubborn organic pollutants. Given its resistance to harsh water environment, the effective and exclusive generation of 1O2 is acknowledged as a key strategy to mitigate water production costs and ensure water supply safety. Herein, we synthesized MnOx intercalated MnFe layered double hydroxides (MF-MnOx) to selectively produce 1O2 through the activation of PMS. The distinctive confined structure endowed MF-MnOx with a special pathway for the PMS activation. The direct oxidation of BPA on the intercalated MnOx induced the charge imbalance in the MnFe-LDH layer, resulting in the selective generation of 1O2. Moreover, acceptable activity deterioration of MF-MnOx was observed in a 10 h continuous degradation test in actual water, substantiating the application potential of MF-MnOx. This work presents a novel catalyst for the selective production of 1O2, and evaluates its prospects in the remediation of micro-polluted water.

Simulation of landfill leachate treatment systems involving self-designed disk tube reverse osmosis (DTRO) model integrated with mechanical vapor recompression (MVR)

Four landfill leachate treatment systems involving self-designed disk tube reverse osmosis (DTRO) module integrated with mechanical vapor recompression (MVR) were established in Aspen Plus. To assess the treatment efficiency and the economic feasibility of landfill leachate treatment techniques, simulation of leachate treatment by four systems were conducted, and the corresponding recovery rate Y, removal rate Rt, energy consumption and operating cost were obtained. Results indicate that for the two-stage DTRO system, the optimal operational pressures in compliance with emission standards are 5.6 MPa in the first stage and 3.5 MPa in the second stage. Adding an MVR system to further treat the membrane concentrate (MC) can greatly reduce the pollutant recharge and the energy consumption of the DTRO system. When Y in MVR is not strictly required, the single-stage MVR system is the most energy-saving one. When a high Y (≥80 %) is required, the series double-stage MVR system affords the highest energy-efficiency, offering a 3.14 % lower operating cost, a 3.27 % lower unit COD removal cost, and a 7.29 % lower unit water production cost as compared to the single-stage MVR system.

Economic and Performance Analysis of Modified Solar Distillation System Coupling Different Integrations Using Carbon Quantum Dot Nanoparticles: Generalized Thermal Model

Abstract Clean drinking water and electricity production utilizing non-conventional sources of energy is the global demand for sustainable development. Ultrafast heat transfer fluids have delivered impressive results in photovoltaic (PV)-integrated solar thermal systems, in recent times. Efforts have been made for the productivity and electricity augmentation of solar still equipped with helically coilled heat exchanger and coupled with different integrations, viz., (a) partially covered N-photovoltaic thermal compound parabolic concentrator (N-PVT-CPC), (b) partially covered N-photovoltaic thermal flat plate collector (N-PVT-FPC), (c) N-FPC-CPC, and (d) N-flat plate collector (N-FPC). System design has also been modified by adding a roof-top semi-transparent PV module and built-in passive copper condenser (circulation mode), and effect of carbon quantum dots (CQDs) water-based nanofluids, nanoparticles volume concentration, and packing factor (βc) of the PV module has been studied by developing generalized thermal modeling of the system (special cases). Overall, 41.1%, 21.52%, 22.01%, and 10.01% rise in evaporative HTCs is observed in FPC-CPC, PVT-CPC, FPC, and PVT-FPC integrations, respectively. Thermal exergy is found to be higher for FPC-CPC integration, and it follows the enhancement order as FPC-CPC (max-0.147 kW) > PVT-CPC (0.088 kW) > FPC (0.038 kW) > PVT-FPC (0.028 kW). In reference to the base fluid, significant enhancement in the daily productivity is observed for FPC-CPC (10.9%) and PVT-CPC (5.16%) integrations using CQD-NPs. The production cost of potable water has also been estimated for all the cases for n = 30 and n = 50 years life span and i = 4% and 8% interest rates, and it is found to be the lowest (0.014 $/L) for FPC-CPC integration using CQD-NPs (n = 30 years, i = 4%).

Enhancing water recovery through integrated graphene oxide-modified forward osmosis and membrane distillation for real textile wastewater treatment

The textile industry is a highly water-intensive sector, emphasizing the increasing importance of reclaiming clean water from textile wastewater and advancing water recovery towards zero liquid discharge. This study proposes and assesses an integrated forward osmosis and membrane distillation (FO-MD) process for treating real textile wastewater, aiming for enhanced water recovery and ensure robustness towards zero liquid discharge. Firstly, a newly developed graphene oxide (GO)-enhanced FO membrane (GFO) was fabricated by adding GO into the polyamide layer during the interfacial polymerization process. Furthermore, the real textile wastewater treatment performance of the FO-MD process based on the GFO membrane was compared to that of a commercial FO membrane (CFO). The results indicated the GFO-based FO-MD process outperformed due to enhanced antifouling properties and stable water flux. Remarkably, the GFO membrane-based FO-MD system achieved over 80% water recovery and nearly 100% rejections for COD, Na+, K+, Cl-, and S2- during continuous 24-hour filtration. The findings highlighted FO-MD as a viable solution, surpassing the individual FO and MD processes by overcoming the limitations of FO draw solution dilution and MD membrane wetting challenges. Moreover, a preliminary techno-economic study for a 200 m3 day−1 textile wastewater estimated water production costs of $6.48 m−3 and $5.73 m−3 for CFO-MD and GFO-MD systems. The analysis highlighted maintaining the water flux above 10 L m−2 h−1 is crucial for economic viability. This work demonstrates the potential of the FO-MD system as a sustainable solution to address the textile wastewater treatment challenges, providing insights for FO-MD system design and optimization.