Sustainable Water Purification Research Articles

Manipulating 2D Membrane Interlayer Channels with Accelerated Mass-Transfer Behavior to Boost Solar Desalination.

The scarcity of fresh water necessitates sustainable and efficient water desalination strategies. Solar-driven steam generation (SSG), which employs solar energy for water evaporation, has emerged as a promising approach. Graphene oxide (GO)-based membranes possess advantages like capillary action and Marangoni effect, but their stacking defects and dead zones of flexible flakes hinders efficient water transportation, thus the evaporation rate lag behind unobstructed-porous 3D evaporators. Therefore, fundamental mass-transfer approach for optimizing SSG evaporators offers new horizons. Herein, a universal multi-force-fields-based method is presented to regularize membrane channels, which can mechanically eliminate inherent interlayer stackings and defects. Both characterization and simulation demonstrate the effectiveness of this approach across different scales and explain the intrinsic mechanism of mass-transfer enhancement. When combined with a structurally optimized substrate, the 4Laponite@GO-1 achieves evaporation rate of 2.782kg m-2 h-1 with 94.48% evaporation efficiency, which is comparable with most 3D evaporators. Moreover, the optimized membrane exhibits excellent cycling stability (10 days) and tolerance to extreme conditions (pH 1-14, salinity 1%-15%), verifies the robust structural stability of regularized channels. This optimization strategy provides simple but efficient way to enhance the SSG performance of GO-based membranes, facilitating their extensive application in sustainable water purification technologies.

Confinement effect of FeMOFs glass enhances the proton coupled electron transfer reaction for the organic pollutants polymerization toward sustainable water purification

Polymerization-driven removal of pollutants in advanced oxidation processes (AOPs) offers a sustainable way for the simultaneous achievement of contamination abatement and resource recovery, supporting a low-carbon water purification approach. In this work, metal–organic frameworks (MOFs) glass complexes (g-ZIF-62@8) were used as a platform to enhance proton transfer through the confinement effect of nanopores, modulating proton coupled electron transfer (PCET) reaction to promote organic pollutant polymerization. The results show that the confinement effect of nanopores in ZIF-62 glass can significantly improve the proton and electron transfer behavior, the proton diffusion coefficient is increased by 4.9 times (2.91*10−3 to 1.43*10−2), the energy barrier of the PCET reaction can be reduced by 1.9 eV, and the reaction kinetic rate constant is increased from 0.0198 min−1 to 0.20118 min−1. Photogenerated holes and Fe(IV = O), as the main reactive oxygen species (ROS), undergo PCET reaction with Bisphenol A (BPA) to convert them into phenoxy radicals, which are then polymerized into macromolecular organic compounds. PCET with proton-electron synergy was identified as a key driver of pollutant polymerization. This enables low-carbon purification and organic carbon recovery in wastewater. Our work provides new insights into the application of confinement effects to enhance proton and electron behavior to regulate pollutant polymerization toward sustainable water purification.

Spongy and anti-pollution MXene/Ag2S/cellulose acetate membrane for sustainable solar-driven interfacial evaporation and water purification

Solar-driven interfacial evaporation (SIE) technology stands out as a promising approach for seawater desalination, leveraging solar energy efficiently in an environmentally friendly manner. However, the enrichment of organic pollutants on the interfacial evaporator has posed significant obstacles to the sustained implementation of SIE. Herein, a spongy, anti-pollution cellulose acetate membrane consisting of Ag2S-doping MXene nanosheets (MT-Ag2S/CAM) is proposed for sustainable desalination. The MT-Ag2S/CAM exhibited ultralow water vaporization enthalpy of 1.50 kJ g−1. Meanwhile, the MT-Ag2S/CAM, featured by high porosity (75.25 %), excellent light absorption and salt resistance, demonstrated a notable solar-driven evaporation rate of 1.8 kg m−2h−1 and a remarkable photothermal conversation efficiency of 91.6 % under one sun irradiation. Meanwhile, MT-Ag2S/CAM can realize a removal efficiency of 93.3 % for methylene blue, exhibiting outstanding anti-pollution and self-cleaning capabilities as well as long-term stability due to its strong mechanical properties. Finally, a device for sustainable desalination, water purification and clean water collection is designed and implemented in a practical SIE process.

Spiropyran molecular aggregates implanted photo-responsive graphene oxide membrane with self-cleaning ability for enhanced water purification

Stimuli-responsive separation membranes with adjustable interfacial properties are highly desired for energy-efficient and sustainable water purification, owing to their exceptional antifouling capability and separation selectivity. However, the construction of highly efficient responsive membranes continues to present a substantial challenge. Herein, photo-responsive spiropyran (SP) molecular aggregates obtained via a "good-poor" solvent self-assembly strategy were implanted into lamellar graphene oxide (GO) membrane. The obtained GO/SP membrane with enriched water transport channels and enhanced hydrophilicity demonstrated superior water permeability (95.0 L h−1 m−2 bar−1). Benefiting from the reversible photoisomerization of SP molecules between the hydrophobic SP upon light irradiation and the hydrophilic zwitterionic merocyanine (MC) in dark conditions, the GO/SP membrane possessed captivating photo-response property verified by tunable water permeability and molecular rejection. Theoretical calculation revealed that the thermodynamic interface energy between bovine serum albumin (BSA) and membrane surface changed from attraction in dark conditions to repulsion under light conditions. Consequently, the water permeability of BSA-fouled membranes could recover to 96.2 % of its initial level after light irradiation, exhibiting fascinating photo-driven self-cleaning capability. The designed photo-responsive membrane with feasible membrane fouling control holds great promise for efficient water purification.

Carbon redirection via tunable Fenton-like reactions under nanoconfinement toward sustainable water treatment

The ongoing pattern shift in water treatment from pollution control to energy recovery challenges the energy-intensive chemical oxidation processes that have been developed for over a century. Redirecting the pathways of carbon evolution from molecular fragmentation to polymerization is critical for energy harvesting during chemical oxidation, yet the regulation means remain to be exploited. Herein, by confining the widely-studied oxidation system—Mn3O4 catalytic activation of peroxymonosulfate—inside amorphous carbon nanotubes (ACNTs), we demonstrate that the pathways of contaminant conversion can be readily modulated by spatial nanoconfinement. Reducing the pore size of ACNTs from 120 to 20 nm monotonously improves the pathway selectivity toward oligomers, with the yield one order of magnitude higher under 20-nm nanoconfinement than in bulk. The interactions of Mn3O4 with ACNTs, reactant enrichment, and pH lowering under nanoconfinement are evidenced to collectively account for the enhanced selectivity toward polymerization. This work provides an adaptive paradigm for carbon redirection in a variety of catalytic oxidation processes toward energy harvesting and sustainable water purification.

Sustainable and eco-friendly membranes from sugarcane bagasse: An upcycling approach for wastewater treatment and energy storage

Developing eco-friendly alternatives to synthetic membranes is crucial in advancing modern membrane technology for water purification. In a pioneering effort, sustainable free-standing Forward Osmosis (FO) membranes composed of cellulose-derived from waste agricultural sugarcane bagasse (SBC) and PVA were developed. These membranes represent a novel upcycling approach, offering both biodegradability and sustainability while ensuring the production of high-quality water. Various analytical techniques were employed to characterize the SBC and membranes. The SBC exhibited a surface area of 1.9 m2 g−1, as determined by BET analysis and was rich in various functionalities. Membrane contact angle measurements revealed their hydrophilic nature. The optimized membrane, SBC-15-DS, demonstrated remarkable performance with an osmotic water flux (OWF) of 9.5 ± 0.2 L m−2h−1, reverse solute flux (RSF) of 0.23 ± 0.01 mol m−2h−1, and specific solute flux (SSF) of approximately 0.009 mol L−1, achieving > 99 % retention for all pollutants. Notably, flux rates of 11 to 14 L m−2h−1 with 99 % rejection were attained for various real industry wastewaters. The SBC-15-DS membrane exhibited excellent stability over 216 h without backwashing, and its biodegradability was confirmed through mulching. Furthermore, fouled membranes were recycled through pyrolyzing at 900 °C, yielding carbon for fabricating supercapacitor electrodes. These electrodes exhibited a specific capacitance of 115 F g−1 at a current density of 0.1 A g−1. Thus, these membranes hold promise for the advancement of sustainable and eco-friendly water purification methods in FO processes.

Role of microbial electrolysis desalination cell in sustainable water and energy management: Performance assessment of platinum and nickel foam cathodes and simulating integration with reverse osmosis systems

This research introduces the microbial integrated cell (MIC), a bioelectrochemical system that combines microbial electrolysis and desalination for sustainable energy and water purification. Efficiency evaluations of nickel foam and Pt/CC cathodes for hydrogen production and desalination showed nickel foam achieving a 91% desalination efficiency, closely following Pt/CC's 99%, with hydrogen generation rates of 0.96 m3H2/m3/d for Pt/CC cathodes and 0.72 m3H2/m3/d for nickel foam. Despite marginally lower performance, the cost advantages of nickel foam suggest its feasibility for large-scale deployment. Further exploration into MIC integration with reverse osmosis (RO) system aims to enhance the sustainability of the combined system. Simulation outcomes indicate that MIC-RO integration can significantly reduce energy consumption and brine concentration discharged into the sea, highlighting its potential to improve desalination plants' efficiency and environmental impact. This research facilitates the transition of these green technologies to practical applications, optimizing efficiency and environmental benefits.

In-situ lignin regeneration facilitated corn straw-based photothermal evaporator with high cost-effectiveness

Solar evaporators are one of the most efficient and sustainable water purification strategies, but it requires the use of expensive photothermal materials. Herein, the surface of waste corn straw was modified with condensed lignin by means of in-situ lignin regeneration. The resulting material was composited with hydrophilic chitosan and then applied as a sustainable and cost-effective photothermal material to construct a solar evaporator. The non-radiative transport was conferred by π-π stacking between conjugated aromatic rings of lignin, allowing the composites to demonstrate promising photothermal conversion ability. The composites presented a max evaporation rate of ∼1.44 kg m−2 h−1 under 1 sun, plus they consistently produced clean water in aqueous organic dye solutions (100 ppm RhB dye and 100 ppm MB dye) and seawater. Due to the ultra-low cost of raw materials and uncomplicated manufacturing procedure, these composites displayed a cost-effectiveness of ∼475 g h−1 $−1. Thus, this work provides a green and sustainable method for converting agricultural waste into functional photothermal evaporators, which is meaningful for both materials and environmental science.

Enhanced near-infrared absorption of Cs0.32WO3 nanoparticles for efficient interfacial solar steam generation

Solar steam generation has gained significant attention as a promising method for clean and sustainable water purification and desalination. The spectral absorption performance of the photothermal conversion material directly affects its thermal conversion efficiency. This research investigates the enhanced near-infrared absorption of Cs0.32WO3 nanoparticles for efficient interfacial solar steam generation. In this study, Cs0.32WO3 nanoparticles were synthesized using a simple co-precipitation and heat treatment method. The synthetic nanoparticles were then incorporated into a porous membrane to create a photothermal conversion material for solar steam generation and their near-infrared absorption properties were characterized. The experimental results demonstrated that the Cs0.32WO3 nanoparticles effectively converted solar energy into heat, resulting in efficient interfacial steam generation. The membrane showed a high evaporation rate of of ∼ 3.15 kg·m−2·h−1 under one sun illumination. The findings of this study provide valuable insights into the design and development of efficient solar steam generation systems using near-infrared absorption nanomaterials.

Competitive adsorption of copper and zinc ions by Tetradesmus obliquus under autotrophic and mixotrophic cultivation

The competitive adsorption mechanism of Tetradesmus obliquus on copper and zinc ions was explored under varied cultivation conditions. Removal efficiency of Tetradesmus obliquus for these ions was evaluated during autotrophic and mixotrophic cultivation. The results revealed that Tetradesmus obliquus demonstrated achieved removal efficiencies of 74.30 %, 86.48 %, 84.55 %, and 65.33 % for 16 mg/L of Zn2+, Cu2+, and a mixture of Cu2+ and Zn2+, respectively, under autotrophic conditions. Conversely, under mixotrophic conditions, Tetradesmus obliquus demonstrated improved removal efficiencies of 86.90 %, 92.31 %, 92.30 %, and 71.94 % for Zn2+, Cu2+, and a Cu-Zn mixture, along with adsorption capacities of 38.57 mg/g, 43.86 mg/g, 23.15 mg/g, and 15.24 mg/g, respectively. This represents an increase of 46.65 %, 31.16 %, 29.47 %, and 43.50 % compared to the autotrophic group, respectively. The second-order kinetic equation and Langmuir isotherm model, as proposed, successfully fitted the experimental data for kinetics and isotherms of Zn2+ and Cu2+ in the monometallic system. The maximum adsorption capacities were determined to be 43.22 mg/g and 69.41 mg/g, respectively, under mixotrophic cultivation conditions. The Extended Langmuir isotherm model best fit all experimental data in the mixed system. The presence of Cu2+ markedly reduced Zn2+ adsorption, whereas the presence of Zn2+ had no effect on Cu2+ adsorption. The 3D fluorescence results further confirmed that glucose addition stimulates algal cells to produce additional extracellular polymers, consequently enhancing metal adsorption by microalgae. These research findings confirm that culturing Tetradesmus obliquus in a mixed environment enhances heavy metal removal during water treatment, which is of significant importance for environmental remediation and sustainable water purification.

Mesoporous silica-grafted deep eutectic solvent-based mixed matrix membranes for wastewater treatment: Synthesis and emerging pollutant removal performance

Abstract Nano-enhanced membrane technology and deep eutectic solvents (DESs) have demonstrated effectiveness in addressing emerging environmental pollutants. This research centers on purifying water by removing heavy metals employing membranes enhanced with mesoporous silica and DES. Various DESs, including hexanoic acid, octanoic acid, and decanoic acid, were synthesized using tetrabutylammonium bromide (TBABr) as a base. The study combined a polysulfone-based membrane with mesoporous silica, aiming for efficient indigenous crafting to remove heavy metals. Mesoporous silica was blended with the synthesized DES solution, creating diverse membranes for heavy metal separation. The study characterized these membranes using various techniques such as scanning electron microscopy, atomic force microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and contact angle measurements. Surface mapping confirmed the integration of silicon-based DES, reducing the membrane surface roughness from 4 to 1.4 nm. By adjusting the carboxylic acid chain length with TBABr and adding mesoporous silica, leaching ratios were reduced from 4.2 to 2.3%. Silica-grafted DES-based membranes exhibited a progressive increase in flux from 2.6 to 26.67 L/m2 h. The synthesized silicon-based membranes demonstrated outstanding performance, achieving rejection rates exceeding 80% for chromium and arsenic, maintaining an impressive 90% flux recovery ratio even at high flux rates. This study will envision the potential of nano-enhanced membrane technology utilizing DES for sustainable water purification and wastewater treatment applications to achieve the sustainable development goal (SDG) of clean water and sanitation (SDG-6).

Eco-Friendly Fabrication of Silver Nanoparticles for Sustainable Water Purification and Antibacterial Synergy

Eco-Friendly Fabrication of Silver Nanoparticles for Sustainable Water Purification and Antibacterial Synergy

Chitosan-derived carbon aerogel modified with lignin carbon quantum dots for efficient solar evaporation

Solar-powered desalination technology offers outstanding benefits in providing clean, safe water and alleviating global freshwater shortages. However, the low evaporation rate, poor salt resistance and high cost limit the development of solar evaporators. Inspired by plant transpiration, a solar evaporator was fabricated from lignin carbon quantum dots (LCQDs) modified chitosan carbon aerogel (C-LCDCA). The introduced LCQDs and low carbonization temperature (280 °C) ensured hydrophilic properties while maintaining the three-dimensional porous structure, as well as improved light absorption and photothermal conversion properties. The evaporation rate of C-LCDCA under one sun was 1.71 kg m−2h−1. Interestingly, C-LCDCA promoted the local crystallization of salt crystals and realized the collection. The evaporation performance of the evaporator can be adapted to different evaporation situations by making simple layer adjustments. The optimal C-LCDCA evaporator (4-layer integrated) surpassed the limit of the interfacial evaporation system, with evaporation rate and efficiency up to 2.32 kg m−2h−1 and 113.9 % respectively under one sun, and with strong salt-rejecting (no obvious salt crystallization in 20 wt% brine for 8 h) and excellent self-cleaning ability (0.3 g NaCl re-dissolved back to 15 wt% brine in 15 min). With superior evaporation performance, the condensate obtained by the evaporator in simulated seawater evaporation experiments met the World Health Organization’s drinking water standards, and enabled effective treatment of industrial wastewater containing heavy metal ions (Cr3+, Fe3+, Pb2+, and Ni2+), nanoplastics (500 and 50 nm), and dyes (Rhodamine B, Methyl Orange, and Malachite green). These findings provide new ideas for the preparation of efficient, salt-rejecting, self-cleaning, and environmentally friendly solar evaporators and advance the practical application of sustainable water purification technologies.

Innovative Sol-gel functionalized polyurethane foam for sustainable water purification and analytical advances.

Nanomaterial combined polymeric membranes such as polyurethane foams (PUFs) have garnered enormous attention in the field of water purification due to their ease of management and surface modification, cost-effectiveness, and mechanical, chemical, and thermal properties. Thus, this study reports the use of novel Sol-gel impregnated polyurethane foams (Sol-gel/PUFs) as new dispersive solid phase microextractors (d- µ SPME) for the efficient separation and subsequent spectrophotometric detection of Eosin Y (EY) textile dye in an aqueous solution with a pH of 3-3.8. The Sol gel, PUFs, and Sol gel-impregnated PUFs were characterized using scanning electron microscopy (SEM), goniometry measurements, dynamic light scattering (DLS), energy dispersive spectroscopy (EDS), UV-Visible, and FTIR spectra. Batch experiment results displayed a remarkable removal percentage (96% ± 5.4%) of the EY from the aqueous solution, with the total sorption time not exceeding 60min. These data indicate rate-limited sorption via diffusion and/or surface complex ion associate formations after the rapid initial sorption steps. A pseudo-second order kinetic model thoroughly explained the sorption kinetics, providing a sorption capacity (qe) of 37.64mgg-1, a half-life time (t1/2) of 0.8 ± 0.01min, and intrinsic penetration control dye retention. The thermodynamic results revealed a negative value for ΔG⁰ (-78.07kJmol-1 at 293K), clearly signifying that the dye uptake was spontaneous, as well as a negative value for ΔH⁰ (-69.58kJmol-1) and a positive value for ΔS⁰ (147.65Jmol-1 K-1), making clear the exothermic nature of EY adsorption onto the sorbent, with a growth in randomness at the molecular level. A ternary retention mechanism is proposed, involving the "weak base anion exchanger" of {(-CH2-OH+ -CH2-) (Dye anion)-}Sol-gel/PUF and/or {(-NH2 + -COO-) (Dye anion)-}Sol-gel/PUF via solvent extraction and "surface adsorption" of the dye anion on/in the Sol-gel/PUFs membranes in addition to H-bonding, including surface complexation and electrostatic π-π interaction, between the dye and the silicon/zirconium oxide (Si-O-Zr) and siloxane (Si-O-Si) groups on the sorbent. Complete extraction and recovery (93.65 ± 0.2, -102.28 ± 2.01) of EY dye with NaOH (0.5M) as a proper eluting agent was achieved using a sorbent-packed mini column. In addition, the established extractor displayed excellent reusability and does not require organic solvents for EY enrichment in water samples, making it a talented nominee as a novel sorbent for EY sorption from wastewater. This study is of great consequence for expanding the applicatio1n of Sol-gel/PUFs in developing innovative spectrophotometric sensing strategies for dye determination. In view of this, it would also be remarkable to perform future studies to explore the analytical implications of this extractor regarding safety and environmental and public health issues associated to the pollutant.

Sustainable and Rapid Water Purification at the Confined Hydrogel Interface.

Emerging organic contaminants in water matrices have challenged ecosystems and human health safety. Persulfate-based advanced oxidation processes (PS-AOPs) have attracted much attention as they address potential water purification challenges. However, overcoming the mass transfer constraint and the catalyst's inherent site agglomeration in the heterogeneous system remains urgent. Herein, the abundant metal-anchored loading (≈6-8g m-2) of alginate hydrogel membranes coupled with cross-flow mode as an efficient strategy for water purification applications is proposed. The organic flux of the confined hydrogel interfaces sharply enlarges with the reduction of the thickness of the boundary layer via the pressure field. The normalized property of the system displays a remarkable organic (sulfonamides) elimination rate of 4.87 × 104mg min-1 mol-1. Furthermore, due to the fast reaction time (<1min), cross-flow mode only reaches a meager energy cost (≈2.21Wh m-3) under the pressure drive field. It is anticipated that this finding provides insight into the novel design with ultrafast organic removal performance and low techno-economic cost (i.e., energy operation cost, material, and reagent cost) for the field of water purification under various PS-AOPs challenging scenarios.

A bio-based nanofibre hydrogel filter for sustainable water purification

A bio-based nanofibre hydrogel filter for sustainable water purification

Metal sequestration by Microcystis extracellular polymers: a promising path to greener water treatment.

The problem of heavy metal pollution in water bodies poses a significant threat to both the environment and human health, as these toxic substances can persist in aquatic ecosystems and accumulate in the food chain. This study investigates the promising potential of using Microcystis aeruginosa extracellular polymeric substances (EPS) as an environmentally friendly, highly efficient solution for capturing copper (Cu2+) and nickel (Ni2+) ions in water treatment, emphasizing their exceptional ability to promote green technology in heavy metal sequestration. We quantified saccharides, proteins, and amino acids in M. aeruginosa biomass and isolated EPS, highlighting their metal-chelating capabilities. Saccharide content was 36.5mgg-1 in biomass and 21.4mgg-1 in EPS, emphasizing their metal-binding ability. Proteins and amino acids were also prevalent, particularly in EPS. Scanning electron microscopy (SEM) revealed intricate 3D EPS structures, with pronounced porosity and branching configurations enhancing metal sorption. Elemental composition via energy dispersive X-ray analysis (EDAX) identified essential elements in both biomass and EPS. Fourier transform infrared (FTIR) spectroscopy unveiled molecular changes after metal treatment, indicating various binding mechanisms, including oxygen atom coordination, π-electron interactions, and electrostatic forces. Kinetic studies showed EPS expedited and enhanced Cu2+ and Ni2+ sorption compared to biomass. Thermodynamic analysis confirmed exothermic, spontaneous sorption. Equilibrium biosorption studies displayed strong binding and competitive interactions in binary metal systems. Importantly, EPS exhibited impressive maximum sorption capacities of 44.81mgg-1 for Ni2+ and 37.06mgg-1 for Cu2+. These findings underscore the potential of Microcystis EPS as a highly efficient sorbent for heavy metal removal in water treatment, with significant implications for environmental remediation and sustainable water purification.

2D/2D ultrathin polypyrrole heterojunct aerogel with synergistic photocatalytic-photothermal evaporation performance for efficient water purification

Green photocatalysis has played a crucial role in resolving energy shortage and wastewater treatment. However, poor photogenerated electron-hole separation efficiency is still a great challenge. Notably, the thermal energy generated by photothermal materials through photothermal conversion provides a greater concentration of energy for the separation and utilization of the photoexcited electron-hole. Herein, we prepare 2D/2D reduced graphene oxide/polypyrrole (c-GPP) aerogel with both photocatalytic degradation and photothermal evaporation performance via interface-confined synthesis. The broad spectral response of rGO and PPy endows the aerogel excellent light-harvesting capabilities and facilitates the generation of photogenerated carriers. The π-π interaction between rGO and PPy give rise to built-in electric fields and electron delocalization effects, resulting in excellent photogenerated electron-hole separation efficiency. The aerogel shows excellent degradation of dyes and antibiotics under natural sunlight irradiation (up to 97 % degradation of dyes). In addition, the c-GPP exhibits a satisfactory photothermal evaporation rate of 1.59 kg m−2 h−1 and photothermal evaporation efficiency of 92.52 %. This work provides an effective route for solar-driven photocatalysis-photothermal synergy for efficient and sustainable water purification.

Trapping waste metal ions in a hydrogel/coal powder composite for boosting sewage purification via solar-driven interfacial water evaporation with long-term durability

The improper disposal of effluents contaminated with waste metal ions poses significant threats to clean water resources. Recently, solar-driven interfacial water evaporation has gained increasing interests for sustainable water purification, nevertheless, the presence of various hydrated metal ions from industrial effluents makes it challenging for conventional distillers to achieve efficient purification performances. Herein, a waste metal ion trapping strategy based on a novel solar vapor generator (SVG) toward highly efficient solar-driven sewage purification with prolonged durability is reported. This SVG is constructed based on a polyion complex (PIC) hydrogel/coal powder composite (PCC), where the PIC skeleton provides metal ion entrapment capabilities, and the low-cost coal powders act as solar absorbents. PCC enables improved solar-driven sewage purification from two aspects: first, the entrapped multivalent ions help to activate the water molecules inside PCC and lower water evaporation enthalpy, leading to enlarged evaporation rate; second, the strong interactions between the multivalent metal ions and polyelectrolyte chains aid in stabilizing their porous structure and maintaining continuous water transport capabilities. The resultant PCC-based SVG demonstrated high evaporation rate up to 3.6 kg · m−2· h−1 in simulated industrial sewage under one sun illumination, as well as stable and efficient clean water generation in actual coal washery wastewater even for three weeks. We envision that the rational design of SVG with ions trapping capabilities and cost-effective solar absorbers should broaden the practical applications of SVG for harsh wastewater treatment.

Super stable evaporators based on upcycled self-healing adsorbents for wastewater regeneration

Establishing a self-healing platform for the removal and resource recovery of heavy metals, enabling heavy metal-free drinking water.