Cost-effective Water Purification Research Articles

Dual-crosslinked and dual-networked hydrogels with high mechanical properties for cost-effective solar water desalination and purification

Dual-crosslinked and dual-networked hydrogels with high mechanical properties for cost-effective solar water desalination and purification

Fe3O4/ZnO/L-lysine functionalized graphene oxide a promising nanocomposite with double Z-scheme visible photocatalytic and dark catalytic activity for water remediation

Developing multifunctional catalysts for efficient pollutant degradation in dark and visible light conditions represents a significant advancement in water remediation technology. This study reports the synthesis of a novel Fe3O4/ZnO/Lys-rGO nanocomposite via environmentally friendly methods that exhibit catalytic-photocatalytic activity for efficient degradation of organic pollutants. The synergistic effect of compositing Lys-rGO, a bio-organic component with a narrow band gap (1.08 eV), into the Fe3O4/ZnO inorganic composite induces a double Z-scheme mechanism by providing two pathways for effective charge separation in the visible photocatalytic activity of the nanocomposite. Additionally, the stored electrons in the very conductive Lys-rGO layers offer active sites for the catalytic activity of the nanocomposite in the dark. Meanwhile, ZnO generates reactive oxygen species (ROS) through surface oxygen vacancies, further contributing to the nanocomposite’s dark catalytic activity. The degradation of various organic pollutants (Methylene Blue, Tetracycline, Ciprofloxacin, Rhodamine B, and their mixture), as well as Congo Red, with low catalyst dosage and visible light irradiation time, demonstrates the high performance and versatility of this nanocomposite. This research highlights the potential of Lys-rGO in compositing with semiconductors to design multifunctional catalysts for cost-effective sustainable water purification technologies.

Photocatalytic TiO2-Based Nanostructures as a Promising Material for Diverse Environmental Applications: A Review

Contemporary technological and industrial advancements have led to increased reliance on chemicals for product innovation, leading to heightened contamination of water sources by traditional pollutants (organic dyes, heavy metals) and disease-causing microorganisms. Wastewater treatment processes now reveal “emerging pollutants”, including pharmaceuticals, endocrine disruptors, and agricultural chemicals. While some are benign, certain emerging pollutants can harm diverse organisms. Researchers seek cost-effective water purification methods that completely degrade pollutants without generating harmful by-products. Semiconductor-based photocatalytic degradation, particularly using titanium dioxide (TiO2), is popular for addressing water pollution. This study focuses on recent applications of TiO2 nanostructures in photocatalysis for eliminating various water pollutants. Structural modifications, like doping and nanocomposite formation, enhance photocatalyst performance. The study emphasizes photocatalytic elimination mechanisms and comprehensively discusses factors impacting both the mechanism and performance of nano-TiO2-based photocatalysts. Characteristics of TiO2, such as crystal structure and energy band-gap, along with its photocatalytic activity mechanism, are presented. The review covers the advantages and limitations of different TiO2 nanostructure production approaches and addresses potential toxicity to human health and the environment. In summary, this review provides a holistic perspective on applying nano-TiO2 materials to mitigate water pollution.

Cormorant-inspired macro-porous hydrogel thin film evaporators for boosting cost-effective solar water purification

We develop a macro-porous hydrogel film strategy for solar water purification inspired by the structure of cormorant wings. The evaporation rate can reach 4.14 kg m−2 h−1 and the energy efficiency can reach 98% under one sun.

Emerging environmentally friendly bio-based nanocomposites for the efficient removal of dyes and micropollutants from wastewater by adsorption: a comprehensive review.

Water scarcity will worsen due to population growth, urbanization, and climate change. Addressing this issue requires developing energy-efficient and cost-effective water purification technologies. One approach is to use biomass to make bio-based materials (BBMs) with valuable attributes. This aligns with the goal of environmental conservation and waste management. Furthermore, the use of biomass is advantageous because it is readily available, economical, and has minimal secondary environmental impact. Biomass materials are ideal for water purification because they are abundant and contain important functional groups like hydroxyl, carboxyl, and amino groups. Functional groups are important for modifying and absorbing contaminants in water. Single-sourced biomass has limitations such as weak mechanical strength, limited adsorption capacity, and chemical instability. Investing in research and development is crucial for the development of efficient methods to produce BBMs and establish suitable water purification application models. This review covers BBM production, modification, functionalization, and their applications in wastewater treatment. These applications include oil-water separation, membrane filtration, micropollutant removal, and organic pollutant elimination. This review explores the production processes and properties of BBMs from biopolymers, highlighting their potential for water treatment applications. Furthermore, this review discusses the future prospects and challenges of developing BBMs for water treatment and usage. Finally, this review highlights the importance of BBMs in solving water purification challenges and encourages innovative solutions in this field.

Shape-transformable long-lasting superhydrophilic carbon cloth for sustainable solar vapor generation

Global water scarcity has spurred the quest for eco-friendly, cost-effective solar-based water desalination and purification methods. However, creating an efficient and durable solar evaporator still remains a formidable challenge. Here, we demonstrated that a rapid and straightforward air plasma activation process can transform a commercially available hydrophobic carbon cloth into a shape-transformable superhydrophilic solar evaporator enriched with nitrogen and oxygen dopants. The activated carbon cloth preserved the merits of the original material and exhibited long-term wettability and salt-rejection properties which are critical for the realization of stable solar vapor generation. Notably, the resulting activated carbon cloth achieved a remarkable vapor evaporation rate of 1.78 kg m-2 h-1 under one-sun irradiation, likely thanks to the abundance of surface intermediate waters that reduce the enthalpy required for evaporation. Furthermore, the constructed column-like solar evaporator with a 5-cm height exhibited an impressive evaporation rate of 3.82 kg m-2 h-1 under one-sun irradiation.

Gas foaming guided fabrication of hydrogel beads with controlled phase and porous structure for durable and highly efficient solar-powered water purification

Solar-powered interfacial evaporation has emerged as a reliable and sustainable strategy for clean water production, and accordingly, the rational fabrication of hydrogel-based evaporators has received special attention. The systems with anti-salt accumulation, scalable fabrication and facile use in large areas of water are in urgent need. Herein, MoS2-embedded foam hydrogel beads having hybrid open- and closed-cell structures are constructed via a self-assembly spinning-foaming-crosslinking method. Taking advantage of the internal hierarchical pore structure and spherical surface geometry of hydrogel beads, the assembled “indirect contact” architecture possess efficient in-situ energy utilization strategy, and could induce sufficient Marangoni effect to accelerate water transport and salt ions backflow, leading to prominent salt resistance. Gratifyingly, the improved system achieves an impressive evaporation rate of 3.58 kg m−2 h−1 and photothermal conversion efficiency of 94.7% under one sun illumination, as well as maintain over 3.3 kg m−2 h−1 for 8 cycles (12 h/cycle) even in the 25 wt% brine. As demonstrated by portable solar still prototype, high quality freshwater with production rate of ∼22 L/m−2 day−1 was collected. This study offers a viable strategy for developing the ease of scale, flexible of use, cost-effective and sustainable solar water purification system in real-world applications to mitigate clean water shortages.

Schottky-like photo/electro-catalytic carbon nanotube composite ultrafiltration membrane reactors

Stimuli-responsive membrane reactors offer advanced strategies towards simultaneous separation and degradation of persistent organic contaminants, allowing for triggered response through photo or electro stimuli. However, the scalable fabrication of stimuli-responsive nanoporous membranes with high selectivity and catalytic reactivity is still challenging in practical application. Here, photo-electro responsive membranes were designed by assembling carbon nanotubes (CNT) scaffolds decorated with conformal nanoscale SnO2 coatings. The membranes, built from spinnable CNT materials supported the generation of a unique class of ultrathin and flexible ultrafiltration membranes with thicknesses down to 25 nm and pore size as narrow as ∼20 nm. The CNTs were used as effective conductive photosensitizers to promote charge transfer from the graphitic to the SnO2 layer, supporting synergistic effects arising from generated Schottky-like diodes to improve the photo/electro-catalytic activity of nanocomposite membranes. The SnO2-CNT membranes exhibited high water permeance of 2.24 × 103 L m−2 h−1.bar−1, and faster reaction kinetics of 77.6 × 10−3 for acetaminophen degradation, which was 2–10 times higher than the kinetics achieved by currently available catalytic membrane reactors. The structural stability and outstanding performance of SnO2-CNT membranes were maintained over 8 reuse cycles with ∼99% degradation efficiency against acetaminophen in 60 min. The unique solid-state fabrication method of uniformly coated catalytic metal oxide on well aligned CNTs provides a scalable feasible approach to produce high-performance ultrafiltration photo/electro-catalytic membrane reactors towards cost-effective water purification at a competent reaction rate.

ASSESSMENT OF GROUND WATER QUALITY AND ITS IMPACT ON HUMAN HEALTH (A CASE STUDY OF SHORKOT CITY), (JHANG) PUNJAB, PAKISTAN


 
 
 Achieving resourceful, beneficial and cost-effective water purification techniques for the public is the important to human existence and growth, because the management of water at present is a global issue. Water is the main resource vital for supporting all human actions, so its provision in preferred quantity and quality is of highest significance. Water contamination effects drinking water quality which subsequently damages health of humans. The current research mainly focuses on evaluating the drinking water quality in Shorkot City of Jhang district and its potential effects on human health. The objective of the research was to find out the spatial distribution of water contaminants and their concentration in the ground water quality and analyze the impact of drinking water on the health of humans of study area besides to identify the main waterborne diseases. Different analyses comprising of physical, chemical and microbiological examinations were performed on the water samples collected from 45 areas of the study area. Locations of these samples were noted with the help of Global Positing System (GPS). Data was presented by Geo Statistical Analysis technique in ArcGIS10x. The interpolation of the consequences of drinking water sample points was observed by Inverse Distance Weighted (IDW) methods. The concentration of TDS 62%, Alkalinity 12%, turbidity 6%, calcium 62%, magnesium 6%, hardness 44% and chloride 28% values exceeds as compared to WHO proposed standard limit. Similarly, the value of PH 100% remains under the permissible limit and Electrical conductivity 100% values exceed as compared to WHO proposed standard limit values. Survey results showed that higher concentration of calcium, TDS, chloride, magnesium, turbidity, Alkalinity, Electrical conductivity and hardness cause Dysentery, Typhoid, Cholera, Diarrhea, Gastroenteritis, Hepatitis, Scabies, Kidney stone, Asthma, Cancer, Heart diseases. Quality of water becomes worse due to agricultural substances, untreated industrial discharge and urban effluent that effect on their health. It is hoped that, results of this research will provide worthwhile perceptions for safe water provision for the people of the study area and justifiable management of resources of drinking water to decrease the human health risks.
 
 

Titan Yellow and Congo Red Removal with Superparamagnetic Iron-Oxide-Based Nanoparticles Doped with Zinc

In this work, we present magnetic nanoparticles based on iron oxide doped with zinc synthesized using the wet co-precipitation method for environmental application. The morphology of the samples was revealed by SEM and TEM, which showed particles of granular shape and size of about 15 nm. The specific surface areas of the materials using the BET method were within the range of 85.7 to 101.5 m2 g−1 depending on the zinc content in the superparamagnetic iron oxide nanoparticles (SPIONs). Magnetometry was performed to determine the magnetic properties of the particles, indicating superparamagnetism. Synthesized magnetic nanoparticles with different amounts of zinc dopant were used as an adsorbent to remove model pollutant Titan yellow (TY) from the aqueous solutions. Adsorption was determined by investigating the effects of sorbent amount, dye concentration, and contact time. The synthesized material removed Titan yellow quickly and efficiently within the physical adsorption. The adsorption isotherms were consistent with the models proposed by Langmuir and Redlich-Peterson. The monolayer adsorption capacities were 30 and 43 mg g−1 for Fe3O4 and Fe3O4@10%Zn, respectively, for the removal of TY. However, that of Congo red is 59 mg g−1 by Fe3O4@10%Zn. The proposed nanoparticles offer fast and cost-effective water purification, and they can be separated from solution using magnets.

Sustainable multilayer biomass carbon and polymer hybrid column as potential antibacterial water filter

Stipulation of fresh water for domestic use without any microbial, organic and inorganic contaminants is of high need. Sustainable, efficient, cost-effective and robust water purification technologies is of high need and it can be achieved using nanomaterials and their composite. Nanostructured graphene has unique properties like high surface to volume ratio, higher absorbability, reusability with minimal chemical alterations, and low cytotoxicity. From the validation of these properties, we have developed PLLA-Ag@graphene sandwich structures as an effective adsorbate for water purification application. As the real water bodies have lot of bacterial contaminants, the material is also designed as efficient adsorbate with antibacterial efficacy. In view of achieving these objectives, we have synthesized PLLA fibre mats by electrospinning method, followed by PLLA-Graphene and Ag decorated PLLA-graphene mats. The crystallite size for graphite and Ag@graphene was calculated as 30.82 nm and 43.79 nm, respectively. Furthermore, the UV analysis of Ag@graphene shows two peaks corresponding to graphene and Ag NP at 285 nm and 407 nm respectively. The layers were assembled in the order of polymeric fibre, as-fired biomass graphite, Ag@graphene for methodical filtration process. The filtration efficacy of the filtrate was tested using sewage water and the results shows higher contamination removal percentage of 87 % with TDS values in the drinking water standards after filtration. The antibacterial efficacy results also evidence of the potentialities of the hybrid system towards water purification application.

A novel bioreactor system to purify contaminated runoff water

Water scarcity has become a global crisis and an economic burden. Environmental challenges in climate change, population growth, and urbanization have raised serious concerns for safe drinking water, food security, social stability, and public health. Current physicochemical purification techniques are costly, chemically-invasive, or ineffective. The aim of this study was to engineer an eco-friendly and cost-effective water purification system using an ex-situ bioremediation approach. The main objective was to use limestone, denitrifying bacteria, and sulfate-reducing bacteria present in the soil as natural resources. Organic compost was added as a carbon source to enhance activities of intrinsic soil bacteria. All samples were collected from mining and industrial sites in Eastern Pennsylvania. We evaluated and verified the feasibility of a novel modular bioreactor system for the effective removal of nitrate, sulfate, and heavy metals from runoff water while increasing its alkalinity. The impacts of pH and temperature on the bioremediation efficiency were evaluated, revealing ideal temperatures to be above 16°C and pH above 7. Nitrate levels dropped from 80 ppm to 0 ppm, and pH increased from 4 to above 7 consistently. Combining neutralization with bacterial bioremediation proved to have synergistic benefits within 30 minutes of treatment. Results showed a successful removal of nitrate (NO3-), sulfate (SO42-), sulfite (SO32-), Zinc (Zn), Copper (Cu), Aluminum (Al), and Lead (Pb) from contaminated wastewater. This system is a cost-effective, energy-efficient, and practical tool that opens numerous avenues for generating sustainable, portable, and fast water purification options for low-income communities. A large-scale system could be adapted for commercial or industrial purposes.

Solution combustion synthesized TiO2/Bi2O3/CuO nano-composites and their photocatalytic activity using visible LEDs assisted photoreactor

In this work we have synthesized a series of binary TiO2/Bi2O3 and ternary TiO2/Bi2O3/CuO composites having different amount of Bi2O3 and CuO using the facile solution combustion approach. The characteristics of samples were identified using the X-ray diffraction (XRD), X- ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), photoluminescence (PL) spectroscopy and UV–vis diffuse reflectance spectroscopy (UVDRS) techniques. The Rhodamine B was taken as the organic pollutant to determine the photocatalytic efficiency of the materials under ultra-low power consumption visible LEDs as the source of light. The results demonstrate that the synthesized compounds possess good crystallinity and improved optical characteristics after introduction of Bi2O3 and CuO. The ternary sample having 10% of Bi2O3 and 10% of CuO showed the highest photoremoval of RhB which might be due of the formation of heterojunctions and improved optical characteristics towards the visible region. The beauty of the synthesized samples is their fast rate of removal of pollutant under visible LEDs which is beneficial for development of cost-effective water purification technique.

Carbon Nanoparticles as Sources for a Cost-Effective Water Purification Method: A Comprehensive Review

As the global population grows, the demand for cost-effective and eco-friendly water purification methods is increasing, which presently is at its peak due to the increase of impurities in water and the increasing awareness of waterborne disease. Carbon-based materials, which includes activated carbon, carbon nanotubes (CNTs), graphene, graphene oxide (GO), reduced graphene oxide (rGO), fullerene, and carbon dots, are observed as potential candidates for water treatment. In the present review, developments related to water purification methods using carbon nanomaterials over the last decade are critically summarized, with an emphasis on their thermophysical properties. The fabrication techniques for activated carbon, CNTs, graphene, and graphene oxide are presented, with an emphasis on the properties of carbon materials that allow their usage for water purification. Then, an extensive review of 71 patents dedicated to water purification using carbon materials such as activated carbon and cotton fibers is performed. Subsequently, the more important research studies on water purification using carbon nanomaterials are discussed, showing that CNTs, GO, and rGO are widely used in water treatment processes. The present review critically discusses the recent developments and provides important information on water purification using carbon materials.

Asymmetrically superwetting Janus Double-layer fabric for synchronous oil removal and catalytic reduction of aromatic dyes

Effective synchronized removal of oils and aromatic dyes from wastewater is of great significance for environmental and water rehabilitation. Herein, cotton fabric was first grafted with polyaniline (PANI) nanofibers via a dilute solution polymerization to obtain Fabric@PANI. Utilizing the reversible oxidation-reduction property of PANI, the Fabric@PANI was in-situ oxidized to form superhydrophilic Fabric@PANI@Ag. Afterwards, the Fabric@PANI@Ag was post-modified with octadecanethiol (Thiol) to obtain the superhydrophobic/superoleophilic Fabric@PANI@Ag@Thiol. Notably, the PANI nanofibers as the activated anchored sites could uniformly and robustly immobilize Ag nanoparticles on the fabric. Moreover, a functional superwetting double-layer fabric (DL-Fabric) with asymmetric wettability that consisted of a top Fabric@PANI@Ag layer and a bottom Fabric@PANI@Ag@Thiol layer was prepared, on which immiscible oils can pass through both layers of the DL-Fabric and the water with soluble organic dyes can only wet the top layer. In addition, the water-soluble organic dyes can be reductive degradation using NaBH4 with the assistance of Ag catalysis, achieving simultaneous oil-removal (flux > 2.7 L m−2 s−1, oil rejection > 95%) and in situ catalytic reduction of aromatic dyes (0.01–0.02 M, efficiency > 99.2%). Thus, the versatile functionality of the fabric combined with its facile preparation strategy showed great potential applications in cost-effective water purification.

Biomass-Derived Hybrid Hydrogel Evaporators for Cost-Effective Solar Water Purification.

Solar vapor generation has presented great potential for wastewater treatment and seawater desalination with high energy conversion and utilization efficiency. However, technology gaps still exist for achieving a fast evaporation rate and high quality of water combined with low-cost deployment to provide a sustainable solar-driven water purification system. In this study, a naturally abundant biomass, konjac glucomannan, together with simple-to-fabricate iron-based metal-organic framework-derived photothermal nanoparticles is introduced into the polyvinyl alcohol networks, building hybrid hydrogel evaporators in a cost-effective fashion ($14.9 m-2 of total materials cost). With advantageous features of adequate water transport, effective water activation, and anti-salt-fouling function, the hybrid hydrogel evaporators achieve a high evaporation rate under one sun (1 kW m-2 ) at 3.2 kg m-2 h-1 out of wastewater with wide degrees of acidity and alkalinity (pH 2-14) and high-salinity seawater (up to 330 g kg-1 ). More notably, heavy metal ions are removed effectively by forming hydrogen and chelating bonds with excess hydroxyl groups in the hydrogel. It is anticipated that this study offers new possibilities for a deployable, cost-effective solar water purification system with assured water quality, especially for economically stressed communities.

Solid waste and graphite derived solar steam generator for highly-efficient and cost-effective water purification

Utilizing the clean and renewable solar energy to generate steam for wastewater purification or seawater desalination is a promising solution to the worldwide scarcity of fresh water. Herein, we report a highly-efficient, eco-friendly and cost-effective solar steam generator based on ball-milling graphite and cellulose fiber from waste paper. Ball-milling graphite/cellulose fiber composite aerogels are facilely developed via a freeze casting-drying method, endowing a featured vertically aligned porous structure. The fabrication of composite aerogels and the construction of evaporation systems take full advantages of recycled materials, contributing to the low cost and solid waste reclamation. High porosity, strong solar absorption, hydrophilicity and low thermal conductivity of the composite aerogels collectively contribute to a splendid solar evaporation rate of water as high as 1.61 kg m−2 h−1, with photothermal efficiency of ~90% under one sun illumination (1 kW m−2). Quantitative studies reveal the effects of ball-milling graphite/cellulose fiber ratio, ball-milling graphite concentration and thickness of composite aerogels on the solar evaporation rates, suggesting the optimal design of composite aerogels. Furthermore, the cycling stability and the capability for seawater desalination as well as polluted water purification manifest the potential of the composite aerogels to purify diverse water. Outdoor tests show 8–13 L of fresh water could be produced daily by 1 m2 of composite aerogel.

Porous carbon derived from Artocarpus heterophyllus peels for capacitive deionization electrodes

Sustainable clean water for human use can be attained through cost effective water purification technologies where by capacitive deionization (CDI) technology is among them. To attain high CDI performance porous carbon materials with good electrical conductivity, high surface area, specific capacitance and good chemical stability are essential. In this study high surface area porous carbon has been synthesized through carbonization of agricultural waste jackfruit peels (Artocarpus heterophyllus) followed by KOH activation at 600, 700, and 800 °C for 1 h. It was found that, the activation temperature significantly increased the BET surface area of the synthesized carbon from 607 m2/g to 1955 m2/g. Desalination experiments were carried out with 30–500 mg/L NaCl solution in batch mode at a flow rate of 2.5 ml/min while applying voltage of 1.2, 1.4 and 2.0 V to the cell. The electrosorption capacity and salt-removal efficiency increased with increasing BET Surface area and applied potential. Specifically, ACJF1:1-700 exhibited highest specific capacitance of 307 F/g, high salt removal efficiency and electrosorption capacity of 5.74 mg/g when voltage of 2 V was applied. These results indicated that the Artocarpus heterophyllus can be promising CDI electrode materials for low salinity water desalination.

Decentralized and cost-effective solar water purification system for remote communities

In this study, a modified stepped solar still is proposed for water desalination. The overall objective of this work is to develop and test the proposed still design to identify the productivity enhancement as compared to conventional basin type solar still. The proposed design takes the advantage of its stepped configuration that allows the water stream to maintain a minimum desirable water column height and the water flow through the stages under the force of gravity. A minimum water depth in the still results in a higher rate of evaporation. The still is also incorporated with Fresnel lens to increase the water temperature that eventually increases the rate of water evaporation. Another important aspect of this design is the incorporation of phase-change-material (PCM) to increase the operational hours of the solar still. Consequently, daily productivity of fresh water is increased.

Development of an Electrochemical Ceramic Membrane Filtration System for Efficient Contaminant Removal from Waters.

Inability to remove low-molecular-weight anthropogenic contaminants is a critical issue in low-pressure membrane filtration processes for water treatment. In this work, a novel electrochemical ceramic membrane filtration (ECMF) system using TiO2@SnO2-Sb anode was developed for removing persistent p-chloroaniline (PCA). Results showed that the ECMF system achieved efficient removal of PCA from contaminated waters. At a charging voltage of 3 V, the PCA removal rate of TiO2@SnO2-Sb ECMF system under flow-through mode was 2.4 times that of flow-by mode. The energy consumption for 50% of PCA removal for TiO2@SnO2-Sb ECMF at 3 V under flow-through mode was 0.38 Wh/L, much lower than that of flow-by operation (1.5 Wh/L), which was attributed to the improved utilization of the surface adsorbed HO· and dissociated HO· driven by the enhanced mass transfer of PCA toward the anode surface. Benefiting from the increased production of reactive oxygen species such as O2•-, H2O2, and HO· arising from excitation of anatase TiO2, TiO2@SnO2-Sb ECMF exhibited a superior electrocatalytic activity to the SnO2-Sb ECMF system. The degradation pathways of PCA initiated by OH· attack were further proposed, with the biodegradable short-chain carboxylic acids (mainly formic, acetic, and oxalic acids) identified as the dominant oxidized products. These results highlight the potential of the ECMF system for cost-effective water purification.