Interfacial solar energy evaporation is an effective measure to alleviate the current global shortage of clean water resources. However, many solar evaporators are two-dimensional (2D) structured devices developed by coating light-absorbing materials on the surface of host materials, and the efficiency of solar steam generation is limited. For this reason, the present study reports a facile and environment-friendly method to construct a conical three-dimensional (3D) wooden evaporator, which uses flexible wood as the substrate and tannic acid complex as the light-absorbing material and is formed by further convolution. Reasonable structural design and material combination enable the evaporator to show excellent mildew resistance and highly efficient evaporation performance. The black decoration considerably improves the wood light absorption, resulting in high absorbance (>90%) of DW-TA-Fe3+ in the wavelength range of 200–800 nm. The water evaporation rate of the wooden cone evaporator can reach up to 1.79 kg m−2 h−1, about 1.6 times higher than that of the 2D evaporator. Moreover, the evaporator exhibits outstanding biological stability and effective desalination performance. This work is expected to offer a new direction in designing a 3D wooden evaporator for effective solar water desalination.

Coagulation is a simple and cost-effective water treatment method that does not work well in removing multiple cationic and anionic heavy metals simultaneously from drinking water. Titanium potassium oxalate (K2TiO(C2O4)2), a fur tanning reagent, was found to be able to efficiently remove arsenite (As(III)), arsenate (As(V)), and Cd simultaneously. A dose of 120 µmol/L K2TiO(C2O4)2 could remove more than 90% of As and Cd to meet the drinking water standards when their initial concentrations were 10 times their maximum concentration limits, whereas traditional coagulants, such as Fe2(SO4)3 and Al2(SO4)3, failed to meet the drinking water standards. Additionally, K2TiO(C2O4)2 coagulation consumes natural water hardness (Ca2+/Mg2+) to produce softer water and releases healthy K+ as a by-product. The mechanism study indicated that K2TiO(C2O4)2 reacted with natural calcium ions in drinking water to form calcium oxalate, while residual titanium was hydrolyzed with water to form hydrous titanium oxide. Arsenic was removed primarily via complexation with hydrous titanium oxide, while Cd was removed via the combined effect of adsorption by hydrous titanium oxide and mixed-crystal formation by calcium oxalate. This study provides an efficient coagulant for removing multiple heavy metals simultaneously, which can be applied in water treatment to provide safe and healthy drinking water.

The Artificial water channels (AWCs) encapsulate water wires or clusters, analogous to natural porins, and offer iterative and continuous hydrogen bonding that plays an essential role in their stabilization. During the last few years, significant progress has been made in AWCs characterization and synthesis, and bridging these advancements to practical development remains a unique challenge. In this study, the possibility of high water selectivity and permeability, as well as the stability of the AWCs channel, is examined via classical molecular dynamic (MD) simulations and well-tempered metadynamics (Wt-metaD) simulations. The results of MD simulations demonstrated that AWCs could provide paths for rapid and selective water permeation via the formation of water-wire networks. Moreover, our findings revealed that the AWC is stable during the simulation time and non-bonded interactions, especially hydrogen bonding, have an essential role in forming a stable OH channel for transporting water molecules. However, the obtained water fluxes (L m−2 h−1) using nanofiltration AWC give us a high flux value, 19.08 (L m−2 h−1), 17.96, and 20.2 (L m−2 h−1), for AWC/ NO3−, AWC/Mg2+, and AWC/Ca2+, respectively. Well-tempered metadynamics simulations of water transport in the OH channel also report similar activation energy values and provide molecular-scale details of the mechanism for water entry into these channels. The free energy values for the AWC/water complexes at their global minima are about ~−241.912, ~−223.479, and ~−255.98 kJ mol−1 in systems AWC/NO3−, AWC/Mg2+, and AWC/Ca2+, respectively.

To address the efficient resourcefulness of papermaking wastewater, this study designed a super-efficient gel material (SGPQG/SGPQ) that could remove over-10-times masses of lignins from wastewater, and subsequently realized the highly-efficient reuse of wastes. The mass of lignin removed by per unit mass of SGPQG/SGPQ was 10,157.71 mg•g-1, i.e., the mass of lignin removed was 10.16 times that of the mass of SGPQG/SGPQ itself, which was 1.23-50.55 times better than the existing similar materials, showing a super-efficient lignin removal ability. Meanwhile, the average lignin removal rate of SGPQG/SGPQ was 1.85-3.34 times higher than those of the pre-products. Moreover, the extended application of SGPQG/SGPQ in the purification of a complex wastewater and a real papermaking wastewater had been also successfully carried out. The mechanism investigations confirmed an integrated skeleton-space effect mechanism, which is the key factor for SGPQG/SGPQ to achieve the super-efficient lignin removal in the purification of papermaking wastewater. In addition, the SGPQG/SGPQ wastes after treating lignins, could be directly used for adsorption treatment of dyeing wastewater, and had 443.9 times adsorption capacity compared to the widely-used activated carbon, demonstrating an efficient resourcefulness reuse.

The production of lithium (Li) increased by 256% in recent years due to unprecedented demands from technological industries. Intensive harvesting poses serious impacts on the sustainability of Li production. Herein, we address the global Li cycle and predict the peak production to reach 740000 million tons in 2041. Global Li accumulation in water bodies is mapped, and the consequences on human health of a wide range (20 mg L−1) of Li concentrations in drinking water are explored. The implications to human health of Li exposure remains unresolved and needs further investigation. There are still no recommendations on safe limits of Li in drinking water for humankind. In conclusion, there is an emergency call to health governing bodies, environmental protection agencies and scientific communities for urgent efforts on sustainable production of Li and identify their thresholds levels in drinking water to minimize the emerging consequences of Li on humans.

Combining electrocoagulation with another process is a potential strategy for increasing the efficiency of water and wastewater pollutant removal. The integration of advanced oxidation processes (AOPs) and electrocoagulation (EC) demonstrates improved performance. The mechanism of the EC combined with ozone (O3), hydrogen peroxide (H2O2), sulfate radicals, electrooxidation (EO), Fenton/electro-Fenton, and UV is discussed. This review sheds light on EC-AOP hybrid processes in terms of their mechanisms, development, challenges, and their potential application for the removal of contaminants of emerging concern (CECs). The majority of the articles claimed improved performance of the EC process when combined with AOP as a pre-treatment, especially in terms of removing recalcitrant contaminants. For instance, the integrated EC-Fenton/photo-Fenton processes have been shown to be a promising treatment to virtually complete removal of the phenolic compounds in oil refinery wastewater. In EC-EO process, boron doped diamond (BDD) anode, despite being costly electrode, has the highest oxidation potential and is therefore the most suitable type for the mineralization of organic pollutants. PFASs are more effective at being removed from water through zinc and Ti4O7 electrodes in EC-EO treatment. Furthermore, the peroxone and synergistic effects between O3 and coagulants played almost equal dominant role to removal of ibuprofen using hybrid EC-O3. However, enough data for conducting these integrated processes at industrial scale or with real wastewaters do not exist, and so there is a lack for comprehensive and systematic approaches to address complexity of such systems. Although a great number of papers were focused on the degradation of effluents from different industries, viruses, and pharmaceuticals, there is not sufficient research in terms of the removal of herbicides, pesticides, microplastics, and micropollutants.

Achieving a thorough understanding of the determinants of household water consumption is crucial to support demand management strategies. Yet, existing research on household water consumption determinants is often limited to specific case studies, with findings that are difficult to generalize and not conclusive. Here, we first contribute an updated framework for review, classification, and analysis of the literature on the determinants of household water consumption. Our framework allows trade-off analysis of different criteria that account for the representation of a potential water consumption determinant in the literature, its impact across heterogeneous case studies, and the effort required to collect information on it. We then review a comprehensive set of 48 publications with our proposed framework. The results of our trade-off analysis show that distinct groups of determinants exist, allowing for the formulation of recommendations for practitioners and researchers on which determinants to consider in practice and prioritize in future research.

The lack of electron donors in oxygen-rich aquatic environments limits the ability of natural denitrification to remove excess nitrate, leading to eutrophication of aquatic ecosystems. Herein, we demonstrate that electron-rich substances in river or lake sediments could participate in long-distance electron rebalancing to reduce nitrate in the overlying water. A microstructure containing Dechloromonas and consisting of an inner layer of green rust and an outer layer of lepidocrocite forms in the sediment-water system through synergetic evolution and self-assembly. The microstructure enables long-distance electron transfer from the sediment to dilute nitrate in the overlying water. Specifically, the inner green rust adsorbs nitrate and reduces the kinetic barrier for denitrification via an Fe(II)/Fe(III) redox mediator. Our study reveals the mechanism of spontaneous electron transfer between distant and dilute electron donors and acceptors to achieve denitrification in electron-deficient aquatic systems.

This paper demonstrates a stainless-steel (SS) nano-pyramid structure (diameter of ~20–50 nm and pore size of 156.1 nm) sputter-coated on mixed cellulose ester (MCE) membrane for the use in separation of oil/water emulsions. SS-coated MCE membrane presented a superhydrophilic, antifouling surface as well as underwater superoleophobicity. The coated membrane achieved excellent separation efficiency of >99% when applied to light oil-water emulsions with a range of viscosities and densities. The highest permeation flux measured was 1,555 L m−2 h−1 when applied to toluene-in-water emulsions. The membrane also presented outstanding recyclability, as evidenced by oil rejection rate retaining at >99% through four separation cycles. The coated membrane was also shown to work well under harsh conditions including salty water, extreme pH values (1–14), and high temperatures (60 °C). In addition, our fabrication route of SS-coated MCE employs low process temperature while being highly scalable, which is favorable for industrial-scale applications.

Climate change and urbanization challenge utilities’ pursuit of water security worldwide. While water utilities are directly impacted by climate change, their operations also contribute to greenhouse gas emissions. Digital technologies have proven effective in improving utilities’ operations, leading to a more sustainable urban water cycle. However, the global progress of digital water transformation remains largely understudied. Here, we present the results of an online survey involving 64 utilities from 28 countries investigating the impacts of digital transformation on the water utility sector, its drivers, and key-enabling technologies. We found that the water distribution system is the entry point to further adoption of digital technologies in the whole urban water cycle. Furthermore, technology adoption is driven primarily by economic benefits, followed by government regulation and hydroclimatic factors. Starting from the survey results, we point out avenues for further research targeting a better understanding of the influence of regulation, corporate mindset, and consumer involvement for successful digital transformation.

Degradation of organic contaminants into less toxic substances is the best option to remove these compounds rather than using conventional techniques. The sulfate radical-based-advanced oxidation process is an effective strategy that degrades organic contaminants by activating peroxymonosulfate (PMS). Such a strategy generates singlet oxygen (1O2), hydroxyl (\(^ \bullet \!{{{\mathrm{OH}}}}\)), and sulfate (\({{{\mathrm{SO}}}}_4^{ \bullet\! - }\)) radicals. \({{{\mathrm{SO}}}}_4^{ \bullet \!- }\) is distinguished by its high oxidation selectivity and activity toward the degradation of organic contaminates compared to other radicals. Various catalysts are employed in PMS activation including layered doubled hydroxides (LDHs), which are characterized by their facile synthesis and high catalytic activity. This review article is the first attempt to compile the recent progress in the degradation of common organic pollutants including aromatic compounds, pharmaceutical residues, and dyes via the PMS activation using LDH-based catalysts. The degradation pathways, reaction parameters’ influence, stability of LDHs, and comparisons between different LDH-based catalysts are investigated in this work.

A wide range of chemicals was measured in different types of drinking water and urine samples through target and non-target screening (NTS) to estimate human exposure. Tap water samples collected from 42 locations in Barcelona (August–October/2020, May/2021), tap water filtered with domestic activated carbon filters (AC, N = 6) and reverse osmosis (RO, N = 5), commercial bottled water (N = 10), and urine (N = 39) samples were included. 35 per- and polyfluoroalkyl substances (PFAS), bisphenol A, and nonylphenol were analyzed using LC–MS/MS and GC–MS/MS, and NTS using LC–HRMS. 9 PFAS were detected in unfiltered tap water of first sampling (79% samples, median = 30 ng/L), 6 in the second (69%, median = 9.8 ng/L), and 5 in 13% urine samples. NTS tentatively identified pharmaceuticals and other industrial chemicals in drinking water. PFAS were removed by RO and not by AC filters. Findings provide valuable information for exposure science and water quality monitoring of emerging drinking water contaminants.

The development of technologies for continuous measurement of nitrogen forms in the soil is essential for optimizing the application of fertilizers in agriculture and preventing water-resource pollution. However, there is no effective commercial technology available for continuous monitoring of ammonium species in soil pore water. This work investigates an approach for real-time measurement of ammonium in soil water using near-infrared transmission spectroscopy and partial least squares regression (PLSR) for spectral analysis. The PLSR model was trained using soil pore water collected from various soils spiked with ammonium to achieve a wide concentration range. The monitoring approach was then validated through transport experiments in a soil column. The results demonstrated capabilities for real-time tracking of the temporal variation in soil ammonium concentration and potential utilization in agronomical or environmental sensing.

In 2005, Israel began using desalination to augment limited natural water supplies. While desalination has helped Israel overcome chronic water shortages, high-population growth may test this approach. We examine how three population growth scenarios (low, medium, high) could affect water demand and supply by 2065. Our projections show that Israel will need to desalinate as much as 3.7 billion m3 annually, compared to 0.5 billion m3 in 2020. Meeting this demand could require the construction of 30 new desalination units. The effects of population growth on Israel’s water supply are likely to dwarf those of climate change. Increased desalination would, however, increase electricity demand, requiring over 11 TWh electricity annually. Population growth is also likely to challenge Israel’s wastewater management policies, producing more effluent than farmers will have the capacity to consume. The Israeli experience will provide important lessons for regions facing similar pressures.

Human activities and climate change threaten water quality in China’s rivers. We simulated the monthly concentrations of riverine total nitrogen (TN), ammonia-nitrogen (NH3-N), total phosphorus (TP), and chemical oxygen demand (CODMn) in 613 sub-watersheds of the nation’s 10 major river basins during the 1980–2050 period based on a 16-year (2003–2018) monitoring dataset using the stacking machine-learning models. The results showed that water quality improved markedly, except for the TN concentration, which was probably due to the lack of a TN control target and assessment system. Quantitative analysis indicated that anthropogenic factors were the primary controls compared with climatic drivers and geographical drivers for TN, TP, and NH3-N concentrations. On the basis of all 17 sustainable development goals (SDGs) relevant to water quality in China, the water resources, water environment, aquatic ecology and water security should be considered collectively to achieve improvements in the ecological status of China’s rivers.

Antimicrobial resistome in wastewater treatment plants was investigated via shotgun metagenomic analysis over a variety of geographical locations, seasons, and biological treatment configurations. The results revealed that the transition of the antimicrobial resistome occurred at two locations during wastewater treatment, which resulted in a distinctive antimicrobial resistome in influent wastewater, activated sludge, and treated effluent. The antimicrobial resistome in influent wastewater was characterized by a high abundance of antibiotic resistance genes (ARGs) on clinically important drugs, whereas sludge retained a higher abundance of multidrug ARGs associated with efflux pump. Seasonality was the primary factor affecting antimicrobial resistome in influent wastewater, which partially succeeded to the subsequent resistome of activated sludge and treated effluent. Importantly, some ARGs on clinically important drugs in influent wastewater passed through the biological treatment to be discharged in the treated effluent, except in the membrane bioreactor process.

Monochloramine is used to regulate microbial regrowth in drinking water distribution systems (DWDS) but produces carcinogenic disinfection byproducts and constitutes a source of energy for nitrifying bacteria. This study followed biofilm-dispersed microbial communities of a full-scale DWDS distributing ultrafiltered water over three years, before and after removal of monochloramine. Communities were described using flow cytometry and amplicon sequencing, including full-length 16S rRNA gene sequencing. Removal of monochloramine increased total cell counts by up to 440%. Increased abundance of heterotrophic bacteria was followed by emergence of the predatory bacteria Bdellovibrio, and a community potentially metabolizing small organic compounds replaced the nitrifying core community. No increased abundance of Mycobacterium or Legionella was observed. Co-occurrence analysis identified a network of Nitrosomonas, Nitrospira, Sphingomonas and Hyphomicrobium, suggesting that monochloramine supported this biofilm community. While some species expanded into the changed niche, no immediate biological risk to consumers was indicated within the DWDS.

An electro-Fenton-like reaction process relying on peroxymonosulfate activation can stably degrade chloramphenicol (CAP) within 16 min, where the kinetic rate constant can be as high as 0.089 min−1 and the energy consumption value can be as low as 25.1 kWh•m^−3. Evidence indicated that the use of a Na2SO4 solution as the electrolyte can enhance CAP degradation due to rapid electron transfer properties. The generated electrons and active free radicals are responsible for CAP degradation, and the electrons can be transferred from the highest occupied molecular orbital of CAP to the lowest unoccupied molecular orbital of peroxymonosulfate via the PbO2 electrode. Density functional theory calculations based on Fukui index analysis elucidated the key attack sites in CAP; moreover, reaction-free energy calculations shed light on potential CAP degradation pathways. Not only does this study afford an insight into the activation of peroxymonosulfate for organic pollutant degradation but also provides an innovative technology with potential applications in wastewater purification.

In this Perspective, we present evidence that indicates a discrepancy between laboratory and field performance of point of use water treatment (POUWT) techniques, identified via a narrative review process to investigate the origin of the LRV comparison estimates reported by the WHO. We considered only peer-reviewed articles that reported laboratory and field log reduction values (LRVs) for the same POU technology. We will present a summary of explanations that have been offered by the literature regarding such discrepancies; the potential implications of the “laboratory versus field” data discrepancy; and potential risks posed by conflating the two. Finally, in view of this discussion, we propose a strategy to help mitigate the research gap and explore the potential to improve current health risk assessments and ultimately, recommendations by public health entities and manufacturers of POUWT products.

Little is known about the association between surface water quality and cancer incidence, especially in China. Drinking water quality has been linked to the incidence of several cancers in individual-level studies. However, few studies have attempted to examine multiple pollutants and multiple cancers at population level. This study used water monitoring and population-level cancer data from across China to examine spatial associations between water pollutants and types of cancer. We found a “dose–response” relationship between the number of pollutants present at high levels and cancer incidence. These results provide evidence of a nationwide spatial association between water quality and cancer in China. The precise relationship varies with cancers and pollutants. However, the overall consistency of the “dose–response” relationship suggests that surface water quality is an important factor in cancer incidence. Our findings highlight new issues such as the changing effects when different pollutants co-exist and an increasing number of new cancer cases partially attributable to poor water quality. Our work also points to some ways to deal with these challenges.