Nano-Enabled Polymers: A New Era in Water Purification

Land use/land cover (LULC) changes impact the structure and functioning of ecosystems, which consequently influences the provisioning of a range of ecosystem services (ES). There is a growing consensus regarding the merit of integrating the evaluation of ES into regional policy planning. The Yangtze River is the world's third longest and supports more than 6% of its population. However, assessing the potential impacts of different resource management policies upon ES is complicated in the Yangtze basin. To remedy this, here we designed a scenario analysis-based approach that used remotely sensed data and GIS (geographic information system) to analyze the relationships between ES (i.e., water flow regulation, water purification) and policies envisioned to improve human welfare in the Chongqing municipality, in the upper reaches of the Three Gorges Reservoir Area (TGRA) in the Yangtze basin. This watershed area has high population density and suffers from severe flood hazard and critical pollution issues. The GEOMOD modeling technique was used to predict LULC changes according to policy planning alternatives, producing scenarios by 2050 for the TGRA watershed. The GIS-based ES model (InVEST model) was developed as a tool to inform the decision-making process with the intention of aligning conservation measures with economic development. We examine policy effectiveness by comparing three scenarios for 2050: scenario-1 maintains the current policy, with no considerations of ES; scenario-2 integrates ES into policy planning; and scenario-3 integrates ES into policy planning considering the needs of local people. Our scenario-based LULC change analysis showed thatthe land with large increases in water flow regulation (i.e., values ≤-3000 × 103 m3 km-2) were scattered over the entire study area, while phosphorus reduction (i.e., values ≤ -30 kg km-2) were located mainly along rivers in all scenarios. Scenario-2 and scenario-3 are based on policies aiming at enhancing ES provisioning; for these, the projected ecological risks of water pollution are significantly reduced (39.97% and 37.58%, respectively). Total net changes of the investigated ES under scenario-2 or scenario-3 were almost double that occurring under scenario-1. Although scenario-2 and scenario-3 showed a near-equal total net change, water purification under scenario-2 was the greatest relative to forest expansion. However, scenario-3 offered the best future environmental development scenario, as it accounted for the demand and supply characteristics of water yield and purification in different regions. The water purification service made the greatest contribution to positive and negative effects (26%-47% and -7%, respectively) on ES provisioning. Linking water purification service to policy planning would effectively improve the overall ES. These scenario forecasting results will help the Three Gorges Dam to gain more ecological benefits via improvements to water flow regulation and the effective alleviation of degraded water quality in heavily populated regions in the Yangtze basin.

The LUWEX project (Validation of Lunar Water Extraction and Purification Technologies for In-Situ Propellant and Consumables Production) aims to enable sustainable lunar exploration by developing and validating systems for water extraction and purification directly from lunar regolith. This study presents findings from the laboratory campaign dedicated to the testing of the Water Purification subsystem, conducted under laboratory conditions to evaluate system efficacy and reliability. Within the LUWEX framework, the Water Purification subsystem is critical for converting extracted raw water into potable water for crewed missions as well as for deionized water for electrolysis. The purification unit was tested for performance parameters including filtration efficiency, contaminant removal, and adaptability to variable raw water input contamination rates, simulating the dynamic extraction conditions expected on the lunar surface. Preliminary results indicate that the purification subsystem meets key benchmarks in removing impurities, achieving product water standards, and effectively integrating with the broader LUWEX system architecture. Key findings demonstrate not only the subsystem's capability to support water quality requirements for human consumption but also its potential scalability for long-term lunar operations. The outcomes of this test campaign highlight advancements in In-Situ Resource Utilization (ISRU) and the readiness of water purification technologies for future lunar bases.

According to the existing statistical data at the country level, over 65% of the wastewater (rural from agricultural livestock farms) is discharged without purification, 61% are insufficiently purified and only 10-15% are properly purified. The pollution effect of wastewater not purified or insufficiently purified on surface waters, is mainly manifested by the content of suspended matter, of organic matter, in nutritional salts, ammonium and in pathogenic microorganisms. It is well-known that the nutritional salts of nitrogen and phosphorus cause the eutrophication of surface waters, with the effect of consuming the dissolved oxygen needed to sustain the aquatic life. Ammonia is particularly toxic to aquatic life. Unsaturated or insufficiently purified wastewater pollutes groundwater, among others with nitrates, ammonium and bacteriologically. From the presented results, the purification of waste water is an essential requirement of the development of human civilization. Being a necessity with special social and ecological implications, the unitary regulation and the general provision of the necessary infrastructure is a priority, in this sense an article will be presented in an experimental treatment station that performs the collection of waste water from an agrozootechnical farm. The purification of water within this experimental model of treatment plant will be done autonomously from an energy point of view (electricity supply is carried out through a hybrid system based on photovoltaic panels and wind turbine), and the recovery. The use of purified water is done in a greenhouse, using a mixed irrigation system (dripping / spray irrigation).

Chapter 15 - Application of emerging nanomaterials in water and wastewater treatment

Utilization of plasma in water desalination and purification

Scarcity of clean water, due to population growth, global warming, and depletion of natural freshwater sources, is among the most formidable environmental challenges facing humanity. Accordingly, development of cost-effective and widely applicable technologies for water remediation and purification is extremely important and highly sought. We present a new strategy for water purification using a composite material comprising carbon dots (C-dots) encapsulated within a porous hydrogel. The hydrogel matrix allows significant water uptake, while the embedded C-dots constitute effective photothermal mediators, absorbing solar energy for enhanced water evaporation. The C-dots further bestowed greater thermal and mechanical stability to the hydrogel host. The C-dot/hydrogel composite exhibited good operating parameters, including a water evaporation rate of 1.4 kg m2 h-1 and solar-to-vapor conversion efficiency of 89%. It was applied for diverse water treatment applications, including water desalination and removal of heavy metal ions, detergents, and organic molecules from contaminated water. The C-dot/hydrogel construct is easily synthesized from inexpensive, biocompatible, and environmentally friendly building blocks, is recyclable, and may be employed in varied water purification applications.

13 - Graphene oxide–metal oxide composites, syntheses, and applications in water purification

Solar-driven enhanced chemical adsorption and interfacial evaporation using porous graphene-based spherical composites

This chapter examines the representative technical solutions that target water availability, access, purity, and delivery. In considering solutions to water delivery and purification, marketing managers must weigh and understand the scientific implications inherent in providing more effective, lower-cost methods to deliver, disinfect, and decontaminate waters from source to point-of-use. A supplier for a water purification system was initially located in Denmark. Source water for the Uganda project is drawn from Lake Victoria, Africa's largest lake, with a solar pumping system, treated with filtration and chlorine disinfection. Grundfos LIFELINK is ready to expand and scale up across Africa and Asia. LIFELINK and Sarvajal are the two major ventures that have developed business models based on the use of machine to machine connectivity for their purified water delivery. An initial goal of LIFELINK was to develop solutions to improve living conditions for people in developing countries, primarily covering rural and peri-urban areas in Africa, Asia, and Latin America.

<span class="ShortAbstract"><em><span lang="EN-US">The purpose of service programs was designed for water filter by using kerubung sand. The method of designing the water purification was literature study on the specifics articles that related to the simple water purification process with the slow water filter method. The development of the filter method by the service team using the kerubung sand. The service teams’ considerations in choosing local materials as the main component as water purification because it was easy to get, less price event some things can be obtained for free because they were available in the wild, or it can be made easily. The results of the water purification design by using the slow water method with kerubung sand had been proportion of 15: 4: 4: 1 with the </span></em></span><span class="ShortAbstract"><em><span lang="EN-US">types of materials were kerubung sand, zeolite sand, the palm fiber, and activated</span></em></span><span class="ShortAbstract"><em><span lang="EN-US"> carbon, respectively. It is hoped that the successful creation of the water purification design composition of the slow water method using kerubung sand will make the quality of water produced from the filter process better than before. The addition output of this service program was the publication of copyright certificate of the manual book for slow water purification method. The conclusion that can be concluded from this design process was that the use of kerubung sand as a filter media is alleged to be a solution for filtering well water at the location of PKM partners</span></em></span>

Plasmonic hybrids are regarded as promising candidates for water purification due to their structure-dependent photocatalysis and photothermal performance. It remains a challenge to develop materials that possess these two characteristics for efficient water purification. Herein, plasmonic Ti3C2Tx/Bi2S3 two-dimensional (2D)/2D hybrids were prepared for efficient solar-driven water purification via the combination of photothermal conversion and photocatalysis. Benefitting from broad light absorption, large 2D/2D interfaces, and efficient charge transfer, the binary hybrids showed high-efficiency photothermal conversion and photothermal-assisted photocatalytic activity. By depositing these 2D/2D hybrids on a hydrophilic and porous cotton piece, the Ti3C2Tx/Bi2S3 membrane displayed a high water evaporation rate and solar-to-vapor efficiency under one-sun irradiation. The solar-driven evaporation of seawater, heavy metal ion solution, and dye solution jointly indicated that the plasmonic membrane shows great potential for drinkable water generation and industrial wastewater treatment. Most importantly, the synergistic effect of photothermal evaporation and photocatalysis of the Ti3C2Tx/Bi2S3 membrane on water purification was demonstrated. The polluted water can not only be treated by evaporation, but also be degraded via photocatalysis under solar light irradiation. This work provides new insight into designing functional materials for water purification based on the combination of photothermal conversion and photocatalysis.

Water scarcity is one of the significant issues many countries face due to the increased demand for freshwater and exhaustion of water resources. Therefore, developing efficient technologies for water purification is anticipated. Nowadays, nanofiltration (NF) separation processes are gaining importance in water purification and pre-treatment for desalination due to their capability in eliminating hardness, salts, and multivalent ions. In addition, NF can be operated under relatively lower pressure than reverse osmosis (RO), where its membrane pore size lies between ultrafiltration (UF) and RO membrane. Polymeric membranes such as polyamide, cellulose acetate, and polyethersulfone are generally used in NF. Many polymeric membranes offer flexibility in the fabrication process and are relatively inexpensive. However, the application of ceramic membranes in water purification has increased hastily due to their beneficial characteristics such as longer life span, fouling resistance, high stability towards corrosive media, and greater mechanical strength. Hence, this chapter discusses the recent signs of progress in ceramic NF membranes for water purification. Various kinds of composite ceramic NF membranes were elaborated in detail, including ceramic-ceramic, ceramic membranes incorporated with nanoparticles and metal–organic frameworks, and ceramic-polymeric membranes. In addition, the implementation of ceramic NF membranes for various water purification methods such as desalination, heavy metal ion removal, removal of dyes, etc., were discussed.

The tubular ceramic membranes of clay minerals were modified with pyrocarbon, which was obtained by carbonizing of polymer precursors at 750 ° С in an argon flow. The precursor to carbonization of membrane II was polyurethane, obtained from laprol and polyisocyanate. A precursor to carbonization of the membrane III was a mixture of polymers formed by the reaction of components of an aqueous solution of a dry solution with NCO-groups of polyisocyanate. As a result of the modification, the membranes became black with a metallic luster. The composition and structure of the membranes were studied by XRF and SEM. The modifier of the membrane II is located in the pore space in the form of sintered agglomerates. The modifier of the membrane III is represented not only by the same agglomerates, but also envelops the structural elements of the membrane material. The apparent density and open porosity for the unmodified membrane are 1.80 g/cm3 and 44.9 %, for membrane II - 1.67 g/cm3 and 39.9 %, for membrane III - 1.68 g/cm3 and 38.3 %. Testing of modified membranes was carried out by water purification from Ca2 + and Fe3 + using the baromembrane method. The concentration of Ca2 + and Fe3 + in aqueous solutions of CaCl2 and FeCl3 was 100 mg/dm3. The period of time until the establishment of dynamic equilibrium in systems during water purification is (1–3 h). After reaching equilibrium the retention factor (R) of Ca2 + during water purification with membrane II is 30% at a pressure of 0.6 MPa, and at a pressure of 1.1 MPa – 18 %. The specific productivity increases with increasing pressure from 10 to 18 dm3/(m2×h). The R of Ca2 + in water purification with membrane III is 22 % at a pressure of 0.4 MPa, and the specific productivity is 47 dm3/(m2×h). The unmodified membrane does not inhibit Ca2 + at all, and its specific productivity at a working pressure of 0.7 MPa decreases from 755 to 500 dm3/(m2×h) in 2-3 hours. The coefficient of retention of Fe3 + by membrane III after 5 hours at a working pressure of 0.4 MPa is 98 % The specific productivity in this case is 8 dm3/(m2×h).

Dynamics of Topology-dependent Water Purification by Siliceous Zeolite Membranes

"My first experiment was, when I was only 8 years old, studying particles suspended in water exposed to the centrifuge force. When I was eight I already wanted to be a scientist …" Find out more about Raffaele Mezzenga in his Author Profile.