A new type of seawater desalination plants using solar energy

An integral and multidimensional review on multi-layer perceptron as an emerging tool in the field of water treatment and desalination processes

Design of plants for solar desalination using the multi-stag heating/humidifying technique

New parent for Schenk Filterbau

Utilization of graphene and its derivatives for air & water filtration: A review

Water desalination is a promising technological solution for assuring water security in many parts of the world. Although conventional desalination techniques, such as thermal desalination, reverse osmosis (RO), and electrodialysis (ED), are currently in use for supplying freshwater, it may not be a sustainable solution in the long term due to the heavy reliance on fossil fuels to power the process. The desalination driven by sunlight could be a potential, energy-conserving alternative to the existing techniques. Here, we demonstrated the use of redox-active photoanode to power the water desalination. We have used a dye-sensitized photoanode (of the Grätzel cell) as one of the electrodes of a water desalination cell, in which a redox couple (I−/I3 −) mediates light-to-energy conversion and sustains ion transport and ion separation in the cell. The cell consisted of electrode channels recirculating the redox couple and feed channels fed with 50 mM NaCl, which were divided by an alternative array of anion and cation exchange membranes. The short-circuit current (J sc) achieved in the integrated solar desalination cell was 2.75 mA/cm2 using a Xenon lamp (100 mW/m2), which was significantly higher than previously reported DSSC-based solar desalination (J sc = ~ 0.1 mA/cm2 [1]). This improved current density allowed for a reduction in NaCl concentration from 50 mM in the feed to 38 mM in the effluent, indicating that integrating photon-to-electron conversion and water desalination processes within a single device is a viable approach for solar-powered water desalination.[1] Chen et al., Exploration of a photo-redox desalination generator, J. Mater. Chem. A, 2019, 7, 20169

Hybrid systems in seawater desalination-practical design aspects, status and development perspectives

Case studies on environmental impact of seawater desalination

Water scarcity is a critical global issue, necessitating efficient water purification and desalination methods. Membrane separation methods are environmentally friendly and consume less energy, making them more economical compared to other desalination and purification methods. This survey explores the application of artificial intelligence (AI) to predict membrane behaviour in water purification and desalination processes. Various AI platforms, including machine learning (ML) and artificial neural networks (ANNs), were utilised to model water flux, predict fouling behaviour, simulate micropollutant dynamics and optimise operational parameters. Specifically, models such as convolutional neural networks (CNNs), recurrent neural networks (RNNs) and support vector machines (SVMs) have demonstrated superior predictive capabilities in these applications. This review studies recent advancements, emphasising the superior predictive capabilities of AI models compared to traditional methods. Key findings include the development of AI models for various membrane separation techniques and the integration of AI concepts such as ML and ANNs to simulate membrane fouling, water flux and micropollutant behaviour, aiming to enhance wastewater treatment and optimise treatment and desalination processes. In conclusion, this review summarised the applications of AI in predicting the behaviour of membranes as well as their strengths, weaknesses and future directions of AI in membranes for water purification and desalination processes.

CONCEPT FOR WATER, HEAT AND FOOD SUPPLY FROM A CLOSED GREENHOUSE - THE WATERGY PROJECT

Water desalination system via ion immobilization on iron corrosion-based colloids and filtration by kevlar support

Chapter 4 - Solar-driven water treatment: generation II technologies

A feasibility study of a small-scale photovoltaic-powered reverse osmosis desalination plant for potable water and salt production in Madura Island: A techno-economic evaluation

The aim of this work is to design and analyze solar humidification and dehumidification desalination plant that is integrated with an energy tower. The proposed integrated water production plant (IWPP) utilizes the waste humid air of the energy tower for the production of potable water as an added benefit in bonus apart from the power production through energy tower. The layout of the proposed desalination plant has been presented which is configured with 100 solar humidification dehumidification desalination units and capable to fulfill potable water demand of 800 liters per day that may be sufficient for a small community of remote area. The seasonal and annual performance of the plant has been analyzed in the climatic condition of Jamnagar which is hot and humid city in western Indian state, Gujarat. The optimum values of air and water mass flow rate have been identified with the help of mathematical simulations in summer, rainy and winter season. The results showed that air mass flow rate 118–120 kg/hr through solar air heater is suitable for water production throughout the year. The water mass flow rate of 125–130 kg/hr in humidifier and 120 kg/hr−122 kg/hr in dehumidifier has been found optimum for potable water production. The seasonal variation in gain output ratio is 0.32−0.45 however it can be increased to 0.62 at optimized operating condition. Finally, the economic and environmental analysis of the proposed plant resulted Rs 0.93/kg (US $ 0.011/kg) cost of potable water, payback period of 0.49 year and 146.8 t/annum reduction in CO2 emission, respectively.

The growing scarcity of fresh water is a major political and economic challenge in the 21st century. Compared to thermal-based distillation technique of water production, pressure driven membrane-based water purification process, such as ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO), can offer more energy-efficient and environmentally friendly solution to clean water production. Potential applications also include removal of hazardous chemicals (i.e., arsenic, pesticides, organics) from water. Although those membrane-separation technologies have been used to produce drinking water from seawater (desalination) and non-traditional water (i.e., municipal wastewater and brackish groundwater) over the last decades, they still have problems in order to be applied in large-scale operations. Currently, a major huddle of membrane-based water purification technology for large-scale commercialization is membrane fouling and its resulting increases in pressure and energy cost of filtration process. Membrane cleaning methods, which can restore the membrane properties to some degree, usually cause irreversible damage to the membranes. Considering that electricity for creating of pressure constitutes a majority of cost (~50%) in membrane-based water purification process, the development of new nano-porous membranes that are more resistant to degradation and less subject to fouling is highly desired. Styrene-ethylene/butylene-styrene (SEBS) block copolymer is one of the best known block copolymers that induces well defined morphologies. Due to the polarity difference of aromatic styrene unit and saturated ethylene/butylene unit, these two polymer chains self-assemble each other and form different phase-separated morphologies depending on the ratios of two polymer chain lengths. Because the surface of SEBS is hydrophobic which easily causes fouling of membrane, incorporation of ionic group (e,g, sulfonate) to the polymer is necessary to reduces fouling. Recently, sulfonated SEBS became commercially available and has been extensively explored for membrane-mediated water purification technology. The sulfonated block copolymer creates a well developed nano-sale phase-separated morphologies composed of hydrophilic domains (sulfonated polystyrene) and hydrophobic domains (polyethylene/polybutylene). The hydrophilic domains determines transport properties (water transport, salt and/or ion rejection, etc) and the hydrophobic domains provides mechanical stability of the membrane. Unfortunately, a high degree of sulfonation of SEBS induces excessive swelling and deterioration of mechanical stability of the membrane. In an effort to develop robust polymeric membrane materials for water purification technology, phosphonic acid-functionalized SEBS membranes are investigated during this report period. In compare to sulfonated polymers, the corresponding phosphonated polymers are known to swell less because of the formation of extensive hydrogen bonding networks between phosphonates. In addition to the expected better mechanical stability, phosphonated polymers has another advantage over sulfonated polymers for the use water purification membrane; each phosphonate can accommodate two ions while each sulfonate accommodates only one ion. Membrane properties (ion type, ionic density, etc) of new membranes will be studied and their separation performance will be evaluated in water purification and desalination process. Through systematic study of the relationship of chemical structure–surface property–membrane performance, we aim to better understand the nature of membrane fouling and develop more fouling-resistant water purification membranes. The basic understanding of this relationship will lead to the development of advanced membrane materials which can offer a solution to environmentally sustainable production of fresh water.

Despite the importance of the desalination process in removal of water salinity to produce fresh drinking water, it is an energy-consuming process. Therefore, the use of solar energy as an alternative and free energy source has an important role in enhancing the efficiency of the desalination process. This paper presents an experimental investigation using solar chimney to enhance the desalination process, where a modification to the conventional solar stills has been made. A mathematical model describing air flow inside the solar chimney has been constructed using Computational Fluid Dynamics (CFD). The commercial CFD package fluent release 6.3 has been used in this paper to express the air flow and temperature distribution inside solar chimney. Furthermore, the process parameters such as seasonal temperature, salt concentration, water depth and type of solar desalination unit have been examined to find the best operating conditions. The desalination process has been recommended to be carried out under permissible operating conditions in sunny days, with water depths ranging from (1–2 cm) and low salt concentration ranging from (3.5–8%). The modeled data has been verified with experimental data and the verification results have been estimated at 14%. Simulation results showed that water desalination has been improved by 30%.