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Feed spacers improve mixing and mass transfer in membrane modules. However, they also lead to foulant deposition in the vicinity of the spacer surface. In this paper, two hydrophilic monomers, namely, acrylic acid (AA) and 2‐hydroxyethyl methacrylate (HEMA), are respectively coated on the surface of a commercial feed spacer via a plasma‐enhanced chemical vapor deposition (PECVD) method. The resulting modified spacers are then evaluated alongside with a reverse osmosis (RO) membrane for its solute rejection, water permeability, and antifouling properties. Results show that the surface hydrophilicity of feed spacers has been enhanced upon the AA and HEMA deposition. During filtration test, the HEMA‐modified spacer demonstrates higher flux recovery rate (94.17%) and salt rejection (95.78%) for the RO membrane. In contrast, the membrane with the unmodified spacer only shows 89.44% and 92.46%, respectively. Additionally, the membrane with the HEMA‐modified spacer has a thinner fouling layer (200 nm) compared to the unmodified spacer (700 nm). The HEMA‐coated spacer outperforms all the tested spacers, demonstrating that feed spacer modification with a hydrophilic monomer via the PECVD method can effectively reduce membrane fouling. [ABSTRACT FROM AUTHOR]

The coexistence of different foulant compositions in the feed water of reverse osmosis (RO) systems causes serious complications in the fouling process of the membranes. Hence, in this technical research, the phenomenon of combined inorganic (gypsum)-colloidal (silica particles) fouling (inorganic-colloidal fouling) of brackish water RO (BWRO) process was studied in the lab-scale experiments. Moreover, the effect of the presence of air micro–nano bubbles (AMNBs) in the feed water; as a new practical method for control of membrane fouling, was investigated on this phenomenon. For this purpose, a suspension with the potential of inorganic scaling [calcium sulfate, Saturation index (SI)=0.96 ] and colloidal fouling (colloidal silica, 50 mg/L) was used to form the inorganic and colloidal foulings (simultaneously) on the membrane surface during the inorganic-colloidal fouling process. All experiments were performed twice, once in the absence and once in the presence of AMNBs. Finally, the results of this research were compared with the results of the inorganic and colloidal fouling studies. Based on the results, the inorganic-colloidal fouling formed a dense and compact fouling layer on the membrane surface, which severely reduced the permeate flux (76.3%) and salt rejection (4%). The amount of decrease of these two parameters in inorganic-colloidal fouling was much higher than each of individual inorganic and colloidal foulings. In the presence of AMNBs, both types of inorganic and colloidal foulings greatly reduced and the major portion of inorganic-colloidal fouling was related to the colloidal fouling. Thus, a significant decline was observed in adverse effects of inorganic-colloidal fouling on the membrane performance and the permeate flux and salt rejection decreased by 18.5% and about 1%, respectively. The results of this study could introduce the micro–nano bubbles (MNBs) technology as an effective method to inhibit the inorganic-colloidal fouling in RO systems. Practical Applications: Today, reverse osmosis processes are known as efficient technologies for supplying drinking water from brackish and sea water resources due to their high ability to remove various compounds. The separated compounds from the water accumulate near the membrane surface and consequently deposit on it and/or inside its pores. This phenomenon is called membrane fouling and has adverse effects on the performance of reverse osmosis processes. Water resources usually have different types of pollutants that simultaneous presence of them can intensify the membrane fouling process. Gypsum scaling and colloidal silica fouling are two major common types of reverse osmosis membrane fouling. Therefore, in this research, the effects of the inorganic-colloidal fouling were studied on the performance of a commercial brackish water reverse osmosis membrane, in presence and absence of air micro–nano bubbles. The results showed that the combined fouling formed a complex fouling layer on the membrane surface in absence of air micro–nano bubbles. In real-scale reverse osmosis process, this layer can severely reduce the membrane permeate flux and salt rejection which result to increase in the operational and maintenance costs. Alternatively, the presence of air micro–nano bubbles in the reverse osmosis feed flow could limit both inorganic and colloidal foulings and their synergetic effects on each other. [ABSTRACT FROM AUTHOR]

Feed water temperature has a role in controlling the specific energy consumption (SEC) of reverse osmosis (RO) desalination plants. Higher feed water temperatures result in lower SEC values, making management of temperature a key consideration for optimum energy efficiency in RO desalination. This paper introduces an Axial Flux Eddy Current Heating (AFECH) device to increase the temperature of feed water with the help of eddy currents. A 3D model of AFECH is designed and developed in ANSYS to analyze the magnetic characteristics, heat flux, and temperature on the aluminum plate. A hardware setup is designed to prove the concept of AFECH. Different observations are tabled for different rotor speeds. The design of AFECH is extended into a more practical approach, and this paper proposes a novel design of a multilevel disk-type AFMECH device. Based on the observations, multilevel disk-type AFMECH has raised the temperature of feed water from 29 to 60 °C. Based on the comparison between normal RO desalination and RO with a multilevel disk-type AFMECH system, the specific energy consumption has observed to be decrease from 1.16 to 0.6213 kWh/m3. [ABSTRACT FROM AUTHOR]

The article investigates the purification and remediation of reverse osmosis concentrate (ROC) using the microalgae Chlorella vulgaris. The study examines the efficacy of Chlorella vulgaris in eliminating heavy metals, nutrients and other substances from ROC. It analyzes the physico-chemical characteristics of wastewater, including alkalinity, dissolved oxygen, potential of hydrogen (pH), total solids and concentrations of heavy metals, before and after treatment with Chlorella vulgaris.

Decreasing groundwater levels, increasing world population, and pollution of water resources by industries lead to the use of new technologies for augmenting the fresh water supply such as its desalination. Chitosan-modified zinc oxide (C-ZnO) nanoparticles were synthesized and used for surface modification of polysulfone (PSf) in water desalination. PSf /C-ZnO membrane was fabricated through the phase inversion method and characterized by Fourier transfer infrared (FTIR), X-Ray diffraction (XRD), field emission scanning electron microscope (FESEM), atomic force microscope (AFM), energy dispersive X-ray (EDX), Braunauer-Emmett-Teller (BET), and contact angle. The nanoparticle effect on the membrane properties was investigated by measuring the pure water flux and solute rejection under two constant pressures, at 6 and 10 bar, and the salts concentration of MgSO4, MgCl2, NaCl, and CaCl2 at 1 gL−1. The results showed that nanoparticles increased the hydrophilicity of the pristine PSf membrane while slightly decreasing the water permeability. Moreover, the salt rejection increased with the nanoparticle addition up to 0.2 wt.% while it decreased with 0.5 wt.% nanoparticle due to changing the membrane finger-like pores sublayer structure. [ABSTRACT FROM AUTHOR]

In this work, a dual-pronged approach– (i) novel thin-film nanocomposite polyether sulfone (PES) membrane with MIL-101 (Fe) and (ii) 3D printed spacers were explored to enhance water recovery by forward osmosis. The concentration of PES, pore former, draw solution, and MIL-101(Fe) was optimised for maximum pure water flux (PWF) and minimum specific reverse solute flux (SRSF). The best membrane exhibited a PWF of 7.52 Lm−2 h−1 and an SRSF of 0.33 ± 0.03 gL−1 using 1.5 M NaCl and DI water feed. The M22 membrane with the diamond-type spacer demonstrated a PWF of 2.53 Lm−2 h−1 and SRSF of 0.75 gL−1 for emulsified oily wastewater feed. The novel spacer design imparted significant turbulence to the feed flow and a lower foulant resistance of 1.3 m−1 as compared to the ladder type (1.5 m−1) or commercial spacer (1.7 m−1). This arrangement could recover 19% pure water within 12 h of operation (98% oil rejection) with a ∼ 94% flux recovery after hydraulic wash. [ABSTRACT FROM AUTHOR]

The purification of water is not only essential for human consumption but is becoming a necessity considering the limited freshwater reserves of the planet. Over the last few decades advancements in material sciences and technology have paved the way for the development of novel purification techniques. Amongst these techniques membrane-based filtration is considered as the least expensive and most effective. These membrane-based filtration techniques can be broadly categorized into reverse osmosis (RO), ultrafiltration, microfiltration and activated carbon filters (ACF). The mode of operation, research evolution and practical applications of each technique are compared in this holistic analysis. Although RO is the oldest and most established membrane-based filtration technique in the literature, it is ACF that is ranked as the most promising new technique with much simplicity and effectiveness. [ABSTRACT FROM AUTHOR]

The challenge of global water scarcity, exacerbated by population growth, pollution, and uneven resource distribution, demands innovative solutions. Seawater desalination, particularly Reverse Osmosis (RO) desalination technology, offers a promising remedy due to its efficiency, economic attractiveness, and enduring durability. This study explores the potential of solar-powered desalination to replace grid-imported electricity as a cost-effective solution to water scarcity, emphasizing economic and environmental aspects. We delve into the economic viability of desalination by developing a model that considers desalination capacity, input electricity prices, and specific energy consumption. Applying this model to case studies in Portugal (Porto Santo Island in the Madeira Archipelago and Algarve in the southern mainland) demonstrates that integrating photovoltaic (PV) solar energy systems to supply the electricity required in the desalination process can reduce the unit production costs of desalinated water by about 33%. The obtained unit production cost of desalinated water using solar PV input is lower than current water tariffs, underscoring the economic feasibility of this approach. The proposed solution is in line with the United Nations Sustainable Development Goals (SDGs), contributing to Goal 6 (Clean Water and Sanitation), Goal 7 (Affordable and Clean Energy), and Goal 8 (Decent Work and Economic Growth). [ABSTRACT FROM AUTHOR]

Reverse osmosis (RO) membranes have been widely applied in the advanced treatment of chemical mechanical polishing (CMP) wastewater. However, membrane fouling persists in practical treatment processes. Herein, a hybrid coagulation-ultrafiltration (UF)-RO (CUR) system was used to control the fouling of the RO membrane, and a novel composite coagulant was developed to enhance the coagulation efficacy for CMP wastewater. Compared to traditional processes, the improved Coagulation-UF process exhibited a remarkable capacity, removing 98.62% of total silica and achieving complete turbidity removal in CMP wastewater. Furthermore, the aluminum residual was reduced by 76.47%, and the normalized flux of the RO membrane increased from 0.87 to 0.95. Moreover, the new coagulant achieved remarkable coagulation effectiveness, with silica and turbidity removal rates reaching 97.29% and 99.87%, respectively, while reducing residual aluminum to 15.50%. Notably, dissolved silica in CMP wastewater emerged as the primary contaminant on the surface of the RO membrane. The net sweep was the primary coagulation mechanism of the new coagulant, proving good performance in reducing the burden on both UF and RO membranes. These results exhibit significant implications for designing efficient pretreatment schemes for CMP wastewater and optimizing the longevity of RO membranes in semiconductor plants. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This review explores the advancements and remaining challenges in inorganic membrane science, particularly focusing on their potential for industrial applications. It delves into the fundamental principles of inorganic membrane design, fabrication, and characterization techniques. The review also critically analyzes key challenges faced by inorganic membranes, such as physical aging, plasticization, defective formation, and fouling. Strategies for overcoming the limitations to enhance permeability and long-term stability are discussed. Specific examples are provided to illustrate the applications of inorganic membranes in gas separation and wastewater treatment, emphasizing their high chemical stability, as compared to conventional polymeric membranes. The energy efficiency of inorganic membranes for volatile organic compound (VOC) removal at ambient temperatures is highlighted with PDMS (polydimethylsiloxane) serving as an example for removing toluene, xylene, and acetone from gas streams. Finally, the review assesses future research directions to further enhance the engineering applicability of inorganic membranes for wastewater treatment and gas separation, solidifying their position as a promising technology for diverse industrial processes. [ABSTRACT FROM AUTHOR]

The accumulation of organic micropollutants (OMP) in aquatic systems is a major societal problem that can be addressed by approaches including nanofiltration, flocculation, reverse osmosis and adsorptive methods using insoluble materials (e.g. activated carbon, MOFs, nanocomposites). More recently, polymeric versions of supramolecular hosts (e.g. cyclodextrins, calixarenes, pillararenes) have been investigated as OMP sequestrants. Herein, we report our study of the use of water insoluble dimethylcatechol walled acyclic cucurbit[n]uril (CB[n]) hosts as solid state sequestrants for a panel of five OMPs. A series of hosts (H1–H4) were synthesized by reaction of glycoluril oligomer (monomer–tetramer) with 3,6‐dimethylcatechol and fully characterized by spectroscopic means and x‐ray crystallography. The solid hosts sequester OMPs from water with removal efficiencies exceeding 90 % in some cases. The removal efficiencies of the new hosts parallel the known molecular recognition properties of analogous water soluble acyclic CB[n]. OMP uptake by solid host occurs rapidly (≈120 seconds). Head‐to‐head comparison with CB[6] in batch‐mode separation and DARCO activated carbon in flow‐through separation mode show that tetramer derived host (H4) performs very well under identical conditions. The work establishes insoluble acyclic CB[n]‐type receptors as a promising new platform for OMP sequestration. [ABSTRACT FROM AUTHOR]

Membrane technology has turned out to be a cornerstone in water treatment, providing advanced solutions that significantly enhance the efficiency of the purification process. The conventional reverse osmosis processes have shortcomings like large volume of rejects and fouling, which have been addressed largely using membrane distillation (MD). The ability of MD to treat a wide array of brines and hypersaline water sources, ranging from seawater to industrial wastewater, has made it a leading desalination technology. This review explores the role of silane chemistry in developing hydrophobic membranes, fundamental classification of silanes, grafting intricacies, critical pretreatment procedures, and techniques for silane functionalization. It further sheds light on the methods for evaluating hydrophobicity and performance metrics, highlighting the advantages of stable flux, enhanced solute rejection, and resistance to fouling. The paper particularly highlights the emergence of silanes as the preferred agents for enhancing membrane hydrophobicity that exhibit anti-wetting properties, concluding with a call for further research aimed at large-scale production of these membranes for global water treatment. [ABSTRACT FROM AUTHOR]

Biogas-fueled decentralized energy systems featuring gas turbines emerge as pivotal players in the quest for more adaptable and eco-friendly energy solutions. This study presents the design of a cutting-edge multigeneration system that harnesses the potential of a gas turbine coupled with ejector-driven dual-loop bi-evaporator technology, reverse osmosis desalination, proton exchange membrane electrolysis, and an organic Rankine cycle. The research encompasses an extensive sensitivity analysis and deploys a genetic algorithm-based optimization technique. Through meticulous Optimization, the system achieves remarkable outcomes, including electricity generation, cooling capacity, heating capacity, desalinated water production, and hydrogen yield, measured at 957.3 kW, 231.4 kW, 272.3 kW, 7.336 kg/s, and 0.99 kg/h, respectively. Notably, this performance surpasses the base case by 2% and 8.9%, yielding exergy efficiency and total unit cost improvements of 33.3% and 16.4 $/GJ. Among the critical decisions made was selecting an organic working fluid for the organic Rankine cycle. Through rigorous evaluation, isobutene emerged as the optimal choice, demonstrating significantly improved output power compared to alternatives. Isobutane as the working fluid led to a substantial increase in overall exergy efficiency and a resultant total unit cost of 18.06 $/GJ, accompanied by an impressive 23.48% exergy efficiency. [Display omitted] • Proposing a novel multi heat recovery for a biogas-fed Brayton cycle in five stages. • Using an ejector-based bi-evaporator cycle in integration with a dual-loop ORC. • Comprehensive energy/exergy/cost study and multi-objective optimization. • Comparing different organic fluids in the MCCP leading to selecting isobutene. • Optimum exergy efficiency and total unit products' cost are 33.33% and 16.44 $/GJ. [ABSTRACT FROM AUTHOR]

The osmotically assisted reverse osmosis (OARO) process is gaining attention for cost‐effective aqueous solution concentration. However, there is a lack of pilot‐scale studies. This research used two spiral‐wound modules in a pilot‐scale plant. The first one, an adapted commercial reverse osmosis module, showed no positive results, likely due to excessive membrane thickness and high internal concentration polarization. In contrast, the second one consisting of a novel forward osmosis prototype demonstrated promising outcomes, achieving water fluxes exceeding 2 L m−2 h−1 even at high salt concentrations (50 g L−1) and relatively low applied pressures (above 12 bar). The study highlights OARO potential, underscores limitations, and emphasizes the need for dedicated module design. [ABSTRACT FROM AUTHOR]

In the current research, an ocean thermal energy conversion (OTEC) assisted multi-generation process with a transcritical Rankine cycle (tRC) working with carbon dioxide is proposed for green hydrogen, oxygen, and distilled water production. The suggested utilizes thermal energy from the ocean to drive tRC, where the liquefied natural gas (LNG) subsystem acts as the heat sink. The process also comprises an LNG turbine to take advantage of LNG cold energy, a proton exchange membrane electrolyzer (PEM-El) unit for hydrogen and oxygen production, photovoltaic/thermal (PV/T) collectors, and reverse osmosis (RO) desalination unit with a recovery turbine. For the thermodynamic evaluation, a numerical model is engineered for the system, and the evaluation of the system's performance in terms of energy and exergy is conducted. According to the analysis, the total net power obtained from the hybrid system is calculated as 1734 kW, while the overall energy efficiency of the system is found to be 26.3%. In addition, the total exergy destruction is determined as 4859 kW with an exergy efficiency of 35.5%. Furthermore, H 2 and distilled water production rates are estimated as 1.349 kg/h and 10.31 m3/h, respectively. • A novel design for an ocean thermal energy conversion-based combined plant is proposed. • Energetic and exergetic performance of the hybrid system is analyzed. • The overall energy and exergy efficiencies are 26.3% and 35.5%, respectively. • The highest contributor to the irreversibility rate is found to be the condenser with 3265 kW. [ABSTRACT FROM AUTHOR]

Oily wastewater treatment is a major problem for a large variety of industrial sectors. Membrane filtration is quite promising for oil-in-water emulsion treatment by virtue of numerous eminent advantages. Here, microfiltration carbon membranes (MCMs) were prepared by the blends of phenolic resin (PR)/coal as precursor materials for efficient removal of emulsified oil from oily wastewater. The functional groups, porous structure, microstructure, morphology and hydrophilicity of the MCMs were analysed by Fourier transform infrared spectroscopy, bubble-pressure method, X-ray diffraction, scanning electron microscope and water contact angle, respectively. The effect of coal amount in precursor materials on the structure and properties of MCMs was mainly investigated. Under operation at 0.02 MPa for trans-membrane pressure and 6 mL min−1 for feed flowrate, the optimal oil rejection and water permeation flux are correspondingly attained to 99.1% and 21,388.5 kg m−2 h−1 MPa−1 for MCMs made by the precursor containing 25% coal. Besides, the anti-fouling ability of the as-prepared MCMs is greatly improved in comparison with the one merely made by PR. In summary, the result indicates that the as-prepared MCMs are very promising for oily wastewater treatment. [ABSTRACT FROM AUTHOR]

We compare the performance of photovoltaic (PV), flat-plate and evacuated-tube solar-thermal (ST), and hybrid photovoltaic-thermal (PV-T) collectors to meet the energy demands of multi-effect distillation (MED) desalination plants across four locations. We consider three scales: 1700 m3day−1, 120 m3day−1 and 3 m3day−1. We find a strong dependence of the capacity and configuration of the solar collectors on both the cost of sourcing electricity from the grid and the specific collector employed. We find specific costs as low as 7.8, 3.4 and 3.7 USDm−3 for the three plant capacities. We find that solar-driven systems optimised for the lowest specific cost result in CO2eq emissions equal to, or higher than, those from grid-driven reverse osmosis (RO) and in line with PV-RO. This highlights the need to consider the environmental footprint of these systems to ensure that desalination is in line with the United Nations' Sustainable Development Goal 6. [ABSTRACT FROM AUTHOR]

This study synthesized three MoS₂ morphologies—nanospheres, nanoplatelets, and nanosheets—under varied conditions and incorporated them into chitosan membranes. TEM confirmed unique morphologies and crystallinity. Clean water flux showed that the nanoplatelet (P-CM) membrane had the highest flux due to higher porosity. The P-CM membrane excelled in removing Mn²⁺ and Zn²⁺ ions, achieving 93.0 ± 0.5% and 90.4 ± 1.5% removal, outperforming membranes with nanospheres (S-CM) and nanosheets (T-CM). Its superior performance is attributed to thicker nanoplatelets forming more water channels. The MoS₂'s tri-layered structure generated reactive oxygen species (ROS) via H₂O₂ catalysis, contributing to enhanced heavy metal removal. These adsorptive-catalytic membranes combine adsorption with catalytic decomposition of heavy metals, highlighting the work's novelty and superior performance. The membranes demonstrated excellent flux recovery and reusability (96.0 ± 0.5% for P-CM) after chemical cleaning. The findings emphasize the impact of nanomaterial morphologies on membrane performance in water treatment and environmental remediation. [ABSTRACT FROM AUTHOR]

Molecular weight (MW) of organics was one of the important factors influencing membrane fouling propensity. This study identified critical foulants of reverse osmosis (RO) membranes in reclaimed water by MW fractionation. MW > 10 kDa component was identified as the critical fouling contributor (CFC) in secondary effluent (SE), which accounted for only 13 ± 5% of dissolved organic carbon (DOC) but contributed to 86 ± 11% of flux decline. Throughout 12-month monitoring, SE and MW > 10 kDa component showed a similar fouling variation tendency: apparently higher fouling potential in winter and lower in summer, while MW < 10 kDa component presented minor fouling changes. Morphology of membrane fouled by CFC characterized a smooth and thick foulant layer on membrane surface. CFC was mainly composed of proteins and polysaccharides, and a protein-polysaccharide-protein "sandwich" fouling layer structure was preferentially formed on membrane surface. extended Derjaguin–Landau-Verwey–Overbeek (xDLVO) analysis demonstrated that strong attractive interactions between CFC and membrane surface dominated the fouling process. Furthermore, computational fluid dynamics (CFD) simulation revealed strong filtration resistance of CFC, confirming its significant fouling potential. Dual effects including attractive interactions and advantageous ridge-and-valley surface appearance accounted for the significant fouling propensity of MW > 10 kDa component and glean valuable insights into RO fouling mechanisms of reclaimed water in practical application. [ABSTRACT FROM AUTHOR]

The reverse osmosis (RO) technique has been extensively employed in the advanced treatment of industrial water and wastewater. However, this process results in the production of a significant quantity of reverse osmosis concentrate (ROC), which contains high levels of salinity and organic contaminants, thereby posing serious environmental problems. This study reported a two-stage precipitation process utilizing quicklime (CaO) and caustic soda (NaOH) in conjunction with air blowing (carbonation) for the removal of Ca2+ and Mg2+ from real brackish water ROC of factory. In stage I, the CaO precipitation-carbonation process was employed to eliminate the majority of Ca2+ from the ROC, while leaving Mg2+ virtually unaffected, yielding high-purity CaCO3 precipitates. In stage II, the NaOH precipitation method was utilized to eliminate the remaining Ca2+ and Mg2+ from the ROC. It was demonstrated that under optimal conditions, the removal rates of Ca2+ and Mg2+ exceeded 97%. Finally, the characterization of precipitates demonstrated the generation of high-purity CaCO3 precipitates in stage I, as well as the formation of CaCO3 and Mg(OH)2 precipitates in stage II. The results confirmed the feasibility of employing the two-stage precipitation with carbonation process to economically treat ROC and enable its reuse, offering valuable insights for the treatment of industrial wastewater. [ABSTRACT FROM AUTHOR]

In Kazakhstan, the issue of providing the population with quality drinking water remains one of the topical and important issues. Despite significant efforts in the field of infrastructure and water treatment technologies, many regions of Kazakhstan still face problems of pollution and insufficient water resources. In this regard, the development of effective water treatment methods is of particular importance. This study considers the issue of wastewater treatment by the combined method of forward and reverse osmosis, which is a key direction in modern water treatment. The relevance of the work is the use of integration of forward osmosis methods with the process of adsorption by powdered activated carbon in wastewater treatment. The use of powdered activated carbon in the process of wastewater treatment leads to a reduction in the content of organic matter, which are water pollutants. As a result of the experiment with pretreatment of wastewater with powdered activated carbon, a decrease in the level of chemical oxygen demand (COD) in wastewater from 538 mg O/dm3 to 256 mg O/dm3 was observed, as well as a relative decrease in the concentration of other indicators. The draw solution in the form of 1.5 M NaCl gradually drawing water molecules from the feed solution pretreated with activated carbon on the tenth day had a concentration of 0.425 M absorbing 2.529 liters of water entering through the membrane that is 27.6% more than the control version of the experiment. The effectiveness of integrated methods lies in the successful combination of different technologies to improve water treatment processes and ensure the availability of clean water not only in Kazakhstan, but also in different parts of the world. [ABSTRACT FROM AUTHOR]

In complex systems with multiple variables monitored at high‐frequency, variables are not only temporally autocorrelated, but they may also be nonlinearly related or exhibit nonstationarity as the inputs or operation changes. One approach to handling such variables is to detrend them prior to monitoring and then apply control charts that assume independence and stationarity to the residuals. Monitoring controlled systems is even more challenging because the control strategy seeks to maintain variables at prespecified mean levels, and to compensate, correlations among variables may change, making monitoring the covariance essential. In this paper, a vector autoregressive model (VAR) is compared with a multivariate random forest (MRF) and a neural network (NN) for detrending multivariate time series prior to monitoring the covariance of the residuals using a multivariate exponentially weighted moving average (MEWMA) control chart. Machine learning models have an advantage when the data's structure is unknown or may change. We design a novel simulation study with nonlinear, nonstationary, and autocorrelated data to compare the different detrending models and subsequent covariance monitoring. The machine learning models have superior performance for nonlinear and strongly autocorrelated data and similar performance for linear data. An illustration with data from a reverse osmosis process is given. [ABSTRACT FROM AUTHOR]

Water is the utmost essential commodity for the support of life process in animals. In recent decades, rapid industrialization and uncontrolled agricultural practices have led to increased level of toxic pollutants in groundwater, including organic pollutants (dyes, nitroarene compounds, antibiotics, etc.), inorganic pollutants (heavy metals, nanoparticles, etc.), and pesticides, posing a serious threat to human health and the environment. Although various technologies such as adsorption, photocatalysis, reverse osmosis, filtration, sedimentation, flocculation, and precipitation are available for the elimination of toxic pollutants from wastewater, issues such as their cost and efficacy limit their usage. Recently, catalysis has been found to be the most effective approach since it exhibits significant capability to eliminate almost all the pollutants and offers the benefit of simple design and low initial cost. In the present study, ternary zinc–copper–nickel layered double hydroxide (ZnCuNi‐LDH) synthesized using facile acid hydrolysis method was employed as an efficacious heterogeneous catalyst for the reduction of NACs (para‐nitrophenol and para‐nitroaniline) and degradation of organic azo dyes (methyl orange, amaranth, and brilliant black). ZnCuNi‐LDH exhibited superior catalytic activity for the reduction of all five model pollutants with reduction efficiency of more than 95% within a short time span of 5 min. Therefore, keeping in view the layered structure, high specific surface area, and remarkable catalytic performance, ZnCuNi‐LDH holds immense potential for the large‐scale catalytic degradation of refractory pollutants. [ABSTRACT FROM AUTHOR]

Municipal drinking water distribution systems (DWDSs) and associated premise plumbing (PP) systems are vulnerable to proliferation of opportunistic pathogens, even when chemical disinfection residuals are present, thus presenting a public health risk. Monitoring the structure of microbial communities of drinking water is challenging because of limited continuous access to faucets, pipes, and storage tanks. We propose a scalable household sampling method, which uses spent activated carbon and reverse osmosis (RO) membrane point-of-use (POU) filters to evaluate mid- to long-term occurrence of microorganisms in PP systems that are relevant to consumer exposure. As a proof of concept, POU filter microbiomes were collected from four different locations and analyzed with 16S rRNA gene amplicon sequencing. The analyses revealed distinct microbial communities, with occasional detection of potential pathogens. The findings highlight the importance of local, and if possible, continuous monitoring within and across distribution systems. The continuous operation of POU filters offers an advantage in capturing species that may be missed by instantaneous sampling methods. We suggest that water utilities, public institutions, and regulatory agencies take advantage of end-of-life POU filters for microbial monitoring. This approach can be easily implemented to ensure drinking water safety, especially from microbes of emerging concerns; e.g., pathogenic Legionella and Mycobacterium species. [ABSTRACT FROM AUTHOR]

In light of the escalating population growth within Indonesia's coastal regions, there is a corresponding surge in the demand for fresh water and sanitation facilities. Addressing this challenge, the deployment of membrane-based desalination technology emerges as a viable solution to augment the fresh water supply for coastal communities. This study delves into the application of titanium dioxide (TiO2) as a material in membrane-based desalination processes--namely, electrodialysis (ED) and reverse osmosis (RO)--synthesized through an integrated approach that encompasses technological, environmental, social, and economic perspectives. Specifically, this approach is tailored for implementation among the Bajau Tribe in Pasikuta Village, located in the Southeast Sulawesi Province of Indonesia. The methodology encompasses technological research and a systematic literature review, supplemented by membrane design, desalination technology analysis, and a bibliometric study based on Scopus data. The findings reveal that the development of a simplified desalination system, which combines the ED-RO techniques utilizing TiO2-modified membranes, exhibits promising potential for adoption in coastal communities. Moreover, this system is characterized by its minimal impact on the marine ecosystem, thereby facilitating its straightforward and cost-effective application through the integration of photovoltaic (PV) technology for harnessing renewable energy. Crucially, the success of this desalination technology's community-based application hinges on community engagement, educational initiatives, and enhancements in community income levels, thereby establishing a sustainable model for mitigating water scarcity and reducing environmental repercussions. [ABSTRACT FROM AUTHOR]

In the conditions of growing demand for fresh water and the need to minimize the environmental impact, as well as reduce CO2 emissions, it is appropriate to use renewable energy sources for desalination of sea and brackish water. The application of wind energy systems for water desalination is being studied. The aim of the work is to assess the possibilities of integrating wind energy into technological schemes of desalination. The work provides an overview of various desalination methods, including thermal and membrane technologies. Special attention is paid to reverse osmosis, which is considered the most suitable technology for combining with wind energy. Aspects of energy saving and increasing the efficiency of desalination systems through the use of energy recovery devices are considered separately. Different configurations of autonomous wind power water desalination systems, their advantages and disadvantages, as well as the design and management features of these systems are analyzed. A key point is to consider energy and water storage options to ensure the stable operation of desalination plants due to the time variability of renewable energy. It is noted that the combination of wind and photovoltaic installations is a promising solution for desalination in the conditions of the appropriate climate. The importance of optimization of system components to achieve high efficiency and reliability of operation in conditions of wind energy fluctuations is emphasized, as well as the need for further research to overcome technical challenges. [ABSTRACT FROM AUTHOR]

In this research, a renewable energy hybrid system (PV-Wind) is modeled to compare different design options based on their economic and technical features. The energy requirements of a Reversible Osmosis desalination plant located on the island of Tenerife with a water production capacity of up to 20,000 m3/day was considered. The system is connected to the electricity grid. The HOMER software, version 2.75 was used to produce optimum strategies for renewable energy. The assumptions input into the model were: the technical specifications of the devices, electricity demand of the desalination plant, as well as the solar radiation and the wind speed potentials. Numerous arrangements were considered by the software, version 2.75. The optimal results were obtained based on the use of renewable energy. The data used in the study were recorded in Tenerife in the Canary Islands. The experience of this research could be transferred to other Atlantic islands with similar renewable energy sources (specifically the wind) and water scarce conditions. [ABSTRACT FROM AUTHOR]

This article explores the issue of membrane fouling in various industries and discusses strategies to reduce and delay fouling. Researchers are looking to nature for inspiration, using biomimicry and natural materials to develop innovative solutions. Examples include using superhydrophilic surfaces inspired by cell membranes to repel organic foulants, using bacterial cellulose membranes for oil-water separations, and coating membranes with liquids to control pore openings. The article also discusses methods and technologies used in water treatment processes, such as using polydopamine as a connective tissue for a deeper clean and utilizing cell membrane mimetic coatings to separate oil and water mixtures. The findings have practical implications for improving water treatment processes and reducing waste. [Extracted from the article]

Forward osmosis (FO) is a membrane process of water separation and purification. FO uses the osmotic pressure difference across a semipermeable membrane. The effective osmotic pressure at the membrane–solution interface on both the feed and permeate sides of the membrane is the main driving force for the generation of the water flux. The major hindrance to the permeation of the water flux is the prevalence of concentration polarization on both sides of the membrane. Concentration polarization inhibits permeate flux by increasing the osmotic pressure at the membrane active layer interface on the feed side of the membrane. This work focused on the development of a mathematical model for water flux in the FO process. Combined film theory model and diffusion transport through the membrane were utilized. The effect of internal concentration polarization and external concentration polarization on the flux was studied. Both internal and external concentration polarization were taken into consideration in both membrane orientations, i.e., active layer facing the feed solution and active layer facing the draw solution. The obtained explicit expression for water permeation flux in forward osmosis desalination process shows excellent agreement with the literature data. [ABSTRACT FROM AUTHOR]

Water scarcity in Tunisia's semi-arid regions necessitates advanced brackish water desalination solutions. This study evaluates the long-term performance and fouling characteristics of the largest brackish water reverse osmosis desalination plant in southern Tunisia over a period of 5026 days. The plant employs two-stage spiral-wound membrane elements to treat groundwater with a salinity of 3.2 g L−1. The pre-treatment process includes oxidation, sand filtration, and cartridge filtration, along with polyphosphonate antiscalant dosing. Membrane performance was assessed through the analysis of operational data, standardization of permeate flow (Qps) and salt passage (SPs), and the calculation of water (A), solute (B), and ionic (Bj) permeability coefficients. Over the operational period, there was an increase in operating pressure, pressure drop, and permeate conductivity, accompanied by a gradual increase in SPs as well as in the solute B and ionic Bj permeability coefficients. The average B increased by 82%, reflecting a decrease in solute rejection over time. Additionally, the ionic permeability coefficients for both SO42− and Cl− ions increased, with Cl− showing an 88% increase and SO42− showing an 87% increase. The produced water's salinity increased by 67%, indicating a significant loss of membrane performance. To identify the cause of these problems, membrane characterization was analyzed using visual inspection, X-ray fluorescence (XRF), and Fourier transform infrared spectroscopy (FTIR). The characterization revealed the complex nature of the foulants, with a predominant presence of calcium sulfate, along with minor quantities of calcite, dolomite, and silica. The extent of CaSO4 deposition suggests poor antiscaling efficiency, highlighting the critical importance of selecting an effective antiscalant to mitigate membrane fouling. [ABSTRACT FROM AUTHOR]

Water scarcity poses significant challenges in arid regions like the Middle East and North Africa (MENA) due to constant population growth, considering the effects of climate change and water management aspects. The desalination technologies face problems like high energy consumption, high investment costs, and significant environmental impacts by brine discharge. This paper researches the relationships among water scarcity, energy-intensive desalination, and the development of renewable energy in MENA, with a particular focus on the Gulf Cooperation Council (GCC) countries. It examines innovations in solar-powered desalination, considering both solar photovoltaic (PV) and solar thermal technologies, in combination with traditional thermal desalination methods such as multi-effect distillation (MED) and multi-stage flash (MSF). The environmental impacts associated with desalination by brine discharge are also discussed, analyzing innovative technological solutions and avoidance strategies. Utilizing bibliometrics, this report provides a comprehensive analysis of scientific literature for the assessment of the research landscape in order to recognize trends in desalination technologies in the MENA region, providing valuable insights into emerging technologies and research priorities. Despite challenges such as high initial investment costs, technical complexities, and limited funding for research and development, the convergence of water scarcity and renewable energy presents significant opportunities for integrated desalination systems in GCC countries. Summarizing, this paper emphasizes the importance of interdisciplinary approaches and international collaboration by addressing the complex challenges of water scarcity and energy sustainability in the MENA region. By leveraging renewable energy sources and advancing desalination technologies, the region can achieve water security while mitigating environmental impacts and promoting economic development. [ABSTRACT FROM AUTHOR]

Clean water is a necessity for many organisms, especially human life. Due to many factors, there is a significant shortage of potable water. This has led to efforts involving recovering water from wastewater or the sea through different technologies. Recently, the desalination of seawater via the reverse osmosis system has shown to be a promising method for drinking water treatment and recovery. Such a technique relies on mathematical models based on many parameters, resulting in special PDEs to model the reverse osmosis system. This paper develops a numerical method to solve a reverse osmosis model. The governing PDE is converted into a Sylvester equation that is proved to be uniquely solvable, stable, consistent, and convergent. The numerical scheme developed is validated with experimental data from the literature, and some numerical simulations. [ABSTRACT FROM AUTHOR]

The aim of this investigation is to assess the feasibility and benefits of integrating a renewable energy system into a seawater reverse osmosis (SWRO) desalination station in Aqaba, Jordan. It has been determined that the optimal SWRO system configuration produce 109,500.00 m³ daily fresh-water output with high rejection rates for various contaminants. The total water cost is 0.85 $/m³, with a specific energy consumption of 2.67 kWh/m³. Furthermore, the economic and environmental assessments of optimum design of the wind-diesel generator-battery. This con- figuration not only offers the lowest cost of energy but also demonstrates a substantial renewable fraction and significant reduction in CO2 emissions. These results underscore the feasibility and benefits of integrating renewable energy into desalination operations, contributing to both economic sustainability and environmental preservation. [ABSTRACT FROM AUTHOR]

The present study focuses on the technique of hardness removal by using a novel reactor performing an electrocoagulation (EC) process. The variation of alkalinity is also recorded. Continuous flow experiments were conducted for Total Hardness (TH) removal using a transparent plastic reactor using aluminum plate electrodes that have holes so that the water flows through the plates in a zigzag way. The influence of various operating parameters such as the number of plates (two and four), flow rate (600, 1000 L/h), and water type (Tigris River & rejected water from Reverse Osmosis system RO) was investigated. The results showed that an increase in the number of electrodes led to an increase in the total hardness removal efficiency. In addition, the increase in the flow rate led to a decrease in the removal efficiency. For the rejected RO water type, the highest hardness removal rate was 16.16% for 4 plates electrodes and 600 L/h flow rate while for the river water was 29% for 4 plates electrodes and 1000 L/h [ABSTRACT FROM AUTHOR]

This paper presents the study on modeling the performance of Textile and Tannery Common Effluent Treatment Plant (CETP) using Artificial Neural Networks (ANN). The process of Reverse Osmosis (RO) Process and Multiple Effect Evaporator (MEE) process of CETP is modelled using ANNs. Two ANN models were developed to predict the performance of CETP dealing with highly saline effluents. Model-I (RO Model) predicts TDS Rejection (%) by taking pH, Electrical Conductivity (EC), Total Dissolved Solids (TDS), Chemical Oxygen Demand (COD) of RO feed as input parameters thus providing estimate of salt concentration. Model-II (MEE Model) predicts Steam Output needed by taking pH, TDS, Feed flow as input parameters. Levenberg-Marquardt backpropagation (trainlm) algorithm was used as training function for creation of both of ANN models and Hyperbolic Tangent Sigmoid (tansig) was used as transfer function. Separate model validation has been performed to test the predictability of the model and at last prediction accuracy were analysed to show its efficiency in prediction. [ABSTRACT FROM AUTHOR]

The archipelagos of Macaronesia (Canary Islands, Azores, Madeira and Cape Verde) have isolated energy systems (IES). This makes the island systems dependent on themselves for energy production. In the case of an island like Gran Canaria, energy production is mainly obtained from: a) Wind and solar energy, 19 % of the total energy produced, b) Energy obtained from the burning of fossil fuels in the energy production equipment of the existing power plants. Thermal power plants, 81 % of the total energy produced. It is necessary to find a solution to the current production system, which is already partially obsolete and must be renewed and/or dismantled, in order to avoid "Zero Energy", which implies a change in the production cycle. In addition, the incorporation of the "Chira-Soria" pumped-storage hydroelectric power plant into the Gran Canaria electricity system represents another, even more important, change in the dynamics followed up to now. Basically, this plant, hydraulically stabilized by means of a seawater desalination plant, incorporates energy storage by storing water at high altitude to be turbined under the right conditions. The new situation with this incorporation will be analysed and the option of integrated operation in the overall energy system of Gran Canaria will be assessed. [ABSTRACT FROM AUTHOR]

Reverse osmosis (RO) is the most common and widely used desalination method in desalination plants. The operation of RO plants is significantly hindered by RO membrane fouling. This study investigated the impact of operational conditions on RO performance at various levels of fouling. Two types of membranes were used: the SW30ULE-440i membrane from Filmtec and the SW-440R membrane from LG. The performance of the Filmtectec membrane was analyzed using reverse osmosis system analysis (ROSA 9.1), while LG Q-V2.3.2 software assessed the LG membrane. Various feed operating parameters, such as temperature, pressure, salinity, and flow rate, varied for plant operations. By varying these operational feed parameters, the optimal productivity flow rate and salinity were determined for each fouling factor value. The results indicated that fouling had a significant effect on permeate flow rate, salinity, and specific energy consumption (SEC). As the feed salinity changes from 30 to 70 g/l, the permeate salinity and SEC increase exponentially, and the permeate flow rate decreases. When the fouling factor falls from 1 to 0.6, the relative permeate salinity rises by 31.5 % for Filmtec and 126.5 % for LG. While the rate of decrease in permeate flow rate is about 29 % for Filmtec and 33 % for LG. The relative increase in SEC reaches 41 % and 50 % for Filmtec and LG, respectively. This means that the fouling factor has a greater effect on the LG than Filmtec. At high fouling levels, RO productivity can be increased to the intended value by adjusting the feed's pressure and temperature. [ABSTRACT FROM AUTHOR]

The operating cost of the desalination process can be decreased by using the membrane distillation (MD) process due to very low operating pressure and mild operating temperature. Attempts to find the proper membrane for application in MD attract the attention of many researchers. In this paper, PVDF powder was employed for assembling membranes via the VIPS method for operating in air-gap membrane distillation (AGMD). The influence of the ethanol concentration in the coagulation bath and VIPS time was studied. PVDF membrane characteristics were analyzed via pore size distribution, volumetric porosity, thickness, scanning electron microscope (SEM), measuring water contact angle, water flux, and salt rejection. A nodular structure was found for the membranes resulting from delayed demixing and solid-liquid phase separation. Moreover, the results indicated a larger membrane pore size was formed and the hydrophobicity was improved. The hydrophobicity and pore size are two important factors for membrane distillation that can affect and enhance membrane permeability. Moreover, studying the influence of nanoparticles showed that SiO2 nanoparticles are more effective than TiO2. The highest water contact angle was obtained when SiO2 nanoparticles were sprayed on the surface resulting in higher permeability and salt rejection in AGMD. The AGMD experiments' results showed that the membrane permeability increased from 0.3 to 2.41 L/m2 .h, and salt rejection over 99.5 % was obtained. [ABSTRACT FROM AUTHOR]

The water reuse system in a petrochemical and polyester integrated industry in Zhejiang, designed to handle industrial circular sewage, had a capacity of 1600 m³ /h. The system employed a process comprising a high-efficiency sedimentation tank, V-shaped filter, aerated biological filter, ultrafiltration, and reverse osmosis. The high-efficiency sedimentation tank's mud water drainage, along with pretreatment through the biological aerated filter (BAF), V-shaped filter, and ultrafiltration system, resulted in an overall system recovery rate of 70 %. Actual operational results indicated removal rates exceeding 70 % for chemical oxygen demand (COD) and 94 % for chloride ions. The effluent water had a COD of ≤ 20 mg/L, chloride ion concentration of ≤ 50 mg/ L, and conductivity of ≤ 20 μS/cm. Given the high recovery rate and the use of domestically produced ultrafiltration membranes, the direct operational cost of the system amounted to a mere 6.28 yuan/m³. This led to a reduction of approximately 9.67 million tons of wastewater discharged annually, fulfilling the objective of recycling industrial sewage for reuse. [ABSTRACT FROM AUTHOR]

The price of coal used by a pineapple processing plant has increased from 3.90 Php/kg in 2018 to 8.60 Php/kg in 2022, thus increasing steam generation costs. This study conducted an energy audit on the two 22-TPH coal-fired boilers of the pineapple processing plant to determine boiler efficiency, quantify sources of heat loss, identify energy conservation measures, and calculate energy and coal savings. The coal-fired boilers investigated were fluidized bed combustion boilers with a reverse osmosis feedwater system. The boiler efficiency was calculated using an indirect method, considering energy losses from sensible heat in refuse and blowdown water. Of the three performance tests conducted, the average boiler efficiency is at 80.655%. The top five sources of heat loss were dry flue gas, hydrogen in coal, moisture in coal, surface radiation and convection, and boiler blowdown. These sources account for 18.322% of the energy input. The identified energy conservation measures include the installation of an automatic oxygen trim control, the installation of an economizer, the installation of a caustic injection system, and the insulation of uninsulated surfaces. These measures have a total potential energy savings of 52,494,974 MJ/yr and coal savings of 2,594,579 kg/yr. While a caustic injection system is not yet installed, setting blowdown TDS to 2,090 ppm can reduce energy consumption by 1,656,496 MJ/yr and coal consumption by 81,873 kg/yr. Using coal with lower hydrogen and moisture content can also reduce energy loss by 6,096,810 MJ/ yr per 0.5% reduction in hydrogen content and 6,816,813 MJ/yr per 5% reduction in moisture content. [ABSTRACT FROM AUTHOR]

The nanocomposite filtration membranes have emerged as potential water purification and separation technologies. However, reliable estimation of foulant rejection and permeate flux remains difficult due to the complicated interaction of many components. Traditional modeling techniques fail to capture the complex dynamics at work. In this paper, we provide a Refined Support Vector Machine (RSVM) strategy to solve this issue and increase the performance of nanocomposite filtration membranes. To normalize the features, the data are pre-processed using min-max normalization. Data features like foulant rejection rates, permeate flux values, membrane features, and experimental setup are displayed. Furthermore, the proposed RSVM to determine the best input factors for the effectiveness of each nanocomposite membrane. Due to the strong resilience of RSVM and the great generalization ability of the ML model, the obtained results demonstrated that the RSVM model's prediction efficiency (R2 = 0.995) outperformed the mathematical model in terms of prediction performance. To conduct training, validation and testing for this work, we employed statistical data including 764 samples of the input variables (five) and output variables (two). The RSVM approach provides a dependable and effective way to forecast membrane fouling and water filtration by predicting foulant rejection and permeate flux. [ABSTRACT FROM AUTHOR]

The graphene oxide (GO) membrane displays promising potential in efficiently filtering ions from water. However, the precise mechanism behind its effectiveness remains elusive, particularly due to the lack of direct experimental evidence at the atomic scale. To shed light on this matter, state‐of‐the‐art techniques are employed such as integrated differential phase contrast‐scanning transmission electron microscopy and electron energy loss spectroscopy, combined with reverse osmosis (RO) filtration experiments using GO membranes. The atomic‐scale observations after the RO experiments directly reveal the binding of various ions including Na+, K+, Ca2+, and Fe3+ to the defects, edges, and functional groups of GO. The remarkable ion‐sieving capabilities of GO membranes are confirmed, which can be attributed to a synergistic interplay of size exclusion, electrostatic interactions, cation–π, and other non‐covalent interactions. Moreover, GO membranes modified by external pressure and cation also demonstrated further enhanced filtration performance for filtration. This study significantly contributes by uncovering the atomic‐scale mechanism responsible for ion sieving in GO membranes. These findings not only enhance the fundamental understanding but also hold substantial potential for the advancement of GO membranes in reverse osmosis (RO) filtration. [ABSTRACT FROM AUTHOR]

Membrane distillation is an emerging wastewater treatment technology that harnesses low-grade heat as an energy source and exhibits potential for complete desalination. Nonetheless, two notable challenges hinder the practical application of this technology: membrane wetting and fouling. To counter these challenges, an innovative anti-fouling Janus membrane with asymmetric wettability was developed through electrospinning. The hydrophobic layer was formed using tetraethyl orthosilicate/polysulfone (PSF), and the superhydrophilic layer was created using polyvinylpyrrolidone (PVP)/PSF. A sensitive adhesion probe was used to assess the anti-fouling performance of the Janus membrane against oil. Molecular dynamics simulation suggested that PVP reduced the adsorption tendency of the membrane for humic acid (HA). Under experimental conditions involving saline water with HA and a saline oil–water emulsion, the non-Janus membrane suffered severe fouling, resulting in rapid water permeate flux decline. However, the Janus membrane demonstrated consistent permeate flux (26.84 LMH and 24.92 LMH) and an impressive salt rejection rate (> 99.99%). This study suggests that the Janus membrane, with its high permeate fluxes and remarkable resistance to fouling and wetting, could be an effective solution for wastewater treatment, with considerable potential for future application. [ABSTRACT FROM AUTHOR]

Recently, research results on PC-based or alkali-activated slag cement (AASC) using seawater as mixing water have been reported. Unlike seawater, reverse osmosis brine (brine) is waste discharged into the ocean from seawater desalination plants. There is a need to develop new and effective methods of disposing or utilizing brine to reduce marine pollution, protect marine ecosystems, and increase marine plant construction. However, research on cement or concrete using brine as a mixing water is very limited. Brine has almost the same composition as seawater, and the ion concentration is 2–4 times higher. Therefore, it is believed that new methods of using brine can be investigated and developed based on existing research and experimental results on seawater. The effects of brine and aluminum oxide (AO) on activated slag with calcium hydroxide (CH) were investigated for hydration and mechanical properties. 5% and 10% of CH were used, and samples using fresh water (FC) were prepared at the same time for comparison with brine. The slag sample without CH has a low initial (1 and 3d) strength of about 10 MPa for both FC and brine, but increases rapidly from 7d. Incorporation of CH was effective in improving the mechanical performance of FC and brine samples. In addition, the brine sample exhibited higher strength than the FC sample because it formed fewer C3AH6 phases that cause volume instability than the FC sample and affected the hydration promotion of slag particles. And more calcite phases were observed in the brine samples than in the FC samples. Through this study, the possibility of using brine as a building material was confirmed. In addition, the effect of chloride ion adsorption of slag mixed with AO and CH on the physical properties and mechanical performance of the hydration reaction was confirmed. [ABSTRACT FROM AUTHOR]

In Chile, there is an increasing demand for freshwater supply for human consumption, agriculture, and industrial activities. In this sense, the country is highly threatened by climate change, which is drastically affecting the availability of water resources in the north-central region due to desertification processes. Therefore, seawater reverse osmosis (SWRO) desalination is becoming one of the most feasible alternatives to address current and future challenges regarding water scarcity in the country. This investigation aims to evaluate potential locations for a sustainable and cost-effective installation of desalination projects; the latter, under a multi-criteria and geographic information system (GIS)-model. The model was tested in the highly water scarcity-threatened Valparaiso Region, Chile, as a case study. The model was developed integrating economic and socio-environmental criteria involved in the development and/or construction of desalination projects. The results of the multi-criteria analysis show that the Valparaıso Region presents optimal areas for developing SWRO projects. Both the northern and central areas of the Region show appropriate locations for installing SWRO plants and their freshwater distribution lines, ensuring short- and long-term water supply, especially for agriculture and population consumption. The results obtained in this study could be extrapolated as a tool to assess the desalination projects development in other world regions to make future desalination projects more viable and sustainable for addressing global water demands. [ABSTRACT FROM AUTHOR]

This study investigated the potential application of geopolymeric material for the separation of oil-in-water emulsions in wastewater treatment. For the first time, an asymmetric membrane made of geopolymers was developed for this specific separation process. The performances of the geopolymeric membrane in oil separation were compared with those obtained by a commercial ceramic membrane. The study also aimed at exploring the effects of emulsion formulation and emulsion properties (surfactant type and concentration, pH, and zeta potential) and membrane parameters (surface charge and material) on permeate volumetric flux and chemical oxygen demand (COD) rejection. Emulsions were prepared using 3% (w/v) dodecane oil in distilled water, with surfactant concentrations of 1x and 10x critical micelle concentration (CMC) and three surfactants of different nature (Oleth-10, Brij 76, and CTAB) at pH values of 2, 5, and 8. Results showed that for the best operating conditions of the geopolymeric membrane, initial and final permeate flux values of 42 and 26 L h−1 m−2, respectively, were achieved. COD rejection values ranged from 95.0 to 99.4% using the geopolymeric membrane thus indicating a very similar behavior between geopolymeric and ceramic membranes. These findings suggest that geopolymers are promising to produce membranes for oil-in-water emulsion microfiltration, promoting an interesting alternative for the treatment of industrial wastewater more sustainable in terms of environmental effects and costs compared to ceramic membranes. • Novel geopolymeric asymmetric membrane was synthetized. • Geopolymer selective layer was successfully deposited on pressed geopolymer support. • The geopolymeric membrane showed excellent fluxes and removal efficiencies. • Flux and rejection properties vary with surfactant concentration and emulsion pH. • Geopolymer membrane performs similarly to a commercial microfiltration ceramic one. [ABSTRACT FROM AUTHOR]