Birnessite is regarded as an efficient oxidizing agent that would significantly influence the environmental fate of elements such as arsenic. This study compared the chemical and photocatalytic oxidation of As(III) over birnessite. During the chemical oxidation, As(III) was oxidized to As(V), while Mn(IV) was reduced to Mn(II), subsequently forming MnOOH. The coverage of the reactive sites by MnOOH inhibited the chemical oxidation of residual As(III). At pH 5.0, after 360 min of reaction, 61% of As(III) was oxidized to As(V), and the oxidation of As(III) decreased with an increase in pH. The photocatalytic oxidation of As(III), where almost all As(III) could be oxidized to As(V) over a pH range of 5.0–8.0 and 360 min, was much more efficient compared to chemical oxidation. In contrast to chemical oxidation, the formation of MnOOH slightly affected the photocatalytic performance of birnessite. It was demonstrated that •O2− radicals and holes (hvb+) played an important role in the photocatalytic oxidation of As(III) over birnessite. Our findings confirmed that light dramatically promoted the oxidation of As(III) by birnessite, broadening the understanding of the environmental behaviors of arsenic.

Due to the limitations of conventional ultrafiltration/microfiltration-based membrane bioreactors (UF/MF-MBRs) in removing trace organic compounds (TrOCs), the concept of high-retention membrane bioreactors (HR-MBRs) was introduced. Despite the benefits, HR-MBRs still suffer several drawbacks. Therefore, this paper critically reviews the effectiveness and feasibility of the proposed strategies to alleviate fouling, salinity build-up and incomplete biodegradation of TrOCs during wastewater treatment by HR-MBRs. The severity of each challenge is compared amongst the various configurations together with the associated capital and operational expenditure to determine the most cost-effective set-up. Guidance is provided on strategies and/or lessons that could be adopted from well-established processes used at municipal scale. Chemical cleaning as mitigation for fouling degrades membranes leading to poor TrOCs removal, while pre-treatment and membrane surface modification increase operational expenditure (OpEX). However, there are other environmentally-friendly pretreatment and cleaning options which hold great potential for future application. These options such as advanced oxidation processes (AOPs) are critically discussed in this work. Further, in-depth discussion is made on the pros and cons of the various approaches (such as frequent sludge withdrawal, intermittent UF/MF filtration and using organic salts) to alleviate salt build-up. Finally, incomplete biodegradation of rejected TrOCs in the bioreactor transfers problems of toxic pollutants from wastewater treatment to sludge management. Herein mitigation strategies including using stronger biological agents and coupling HR-MBRs with other techniques are debated. Despite the challenges, HR-MBRs are a promising solution for clean water production from TrOCs impaired wastewater. Therefore, more research is needed to improve the performance of HR-MBRs.

Both piezoelectricity and self-Fenton catalysis are effective ways to degrade water pollution, but little research has combined them to construct a more efficient water pollution treatment method. Here, a Fe-doped SnS2 (Sn1-xFexS2) piezoelectric self-Fenton system was constructed, which shows superior water treatment performance. The best piezoelectric properties of the Sn0.97Fe0.03S2 system were verified by degrading rhodamine B (RhB). The toxicity analysis of degradation intermediates and solutions confirmed that the toxicity of RhB decreased after degradation. In addition, Kelvin probe force microscopy and photoelectrochemical analysis confirmed the better piezoelectric properties of Sn0.97Fe0.03S2. It has demonstrated the enhancement of systematic piezoelectricity by Fe lattice defects and the formation of self-Fenton by Fe as an active center in the degradation of RhB. In this work, an efficient piezoelectric and self-Fenton technology is constructed to remove organic pollutants from water, which is significant for developing water treatment technology.

The treatment of azo dye effluent from the dyeing process, as well as the sustainable development of the environment, can all be achieved through the use of green mycoremediation. In this in vitro study, Trichothecium roseum was isolated by the sedimentation technique from the environment of an unplasticized polyvinyl chloride pipe manufacturing plant and used to decolourize and optimise the biosorption percentage of Azo Lanasyn Navy M-DNL dye. T. roseum was also used to test the decolourization percentage of the dyes Lanasyn Navy M-DNL, Isolan Black 2S-LDN, and Isolan Yellow 2S-GLN. The outcomes showed that Lanasyn Navy M-DNL dye has the highest decolourization percentage (94%). Lanasyn Navy M-DNL dye was also found to be adsorbed onto the surface of T. roseum using scan electron microscopy and Fourier-transform infrared spectroscopy investigations. Under ideal optimisation parameters, the biosorption percentage of Lanasyn Navy M-DNL dye by beads of immobilised T. roseum cells was 96%, 97%, 96%, 97%, and 96%, respectively, for beads number 60, fresh weight 1 g, incubation temperature 25 °C, pH 6, dye concentrations 10 mg/l, and sucrose concentrations 10 g/l. Langmuir and Freundlich adsorption isotherms show good agreement between the Freundlich adsorption isotherm model and the adsorption process. Also, the elution cycle was found to be effective enough to be employed for five cycles using sixty beads of immobilised T. roseum cells. The current study suggests that T. roseum is an influencer of Lanasyn Navy M-DNL dye biosorption to create a successful green strategy for handling Lanasyn Navy M-DNL dye-contaminated effluents.

Here, we describe surface functionalized, superparamagnetic iron oxide nanocrystals (IONCs) for ultra-high PFAS sorption and precise, low energy (magnetic) separation, considering perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). As a function of surface coating, sorption capacities described are considerably higher than previous studies using activated carbon, polymers, and unmodified metal/metal oxides, among others. In particular, positively charged polyethyleneimine (PEI) coated IONCs demonstrate extreme sorption capacities for both PFOA and PFOS due to electrostatic and hydrophobic interactions, along with high polymer grafting densities, while remaining stable in water, thus maintaining available surface area. Further, through a newly developed method using a quart crystal microbalance with dissipation (QCM-D), we present real-time, interfacial observations (e.g., sorption kinetics). Through this method, we explore underpinning mechanism(s) for differential PFAS (PFOA vs PFOS) sorption behavior(s), demonstrating that PFAS functional head group strongly influence molecular orientation on/at the sorbent interface. The effects of water chemistry, including pH, ionic composition of water, and natural organic matter on sorption behavior are also evaluated and along with material (treatment) demonstration via bench-scale column studies.

This study investigates the potential of surface-patterned membranes in replacing the conventional feed spacer-assisted filtration process. Two types of surface patterns, namely diamond (D) and honeycomb (HC), were utilized in the fabrication of the surface-patterned membranes. These membranes showed larger effective membrane area and higher average porosity when compared to the flat PES membrane. The D-Patterned and HC-Patterned membranes achieved pure water flux of 76.6 ± 16.9 and 88.3 ± 17.4 L m−2 h−1, respectively, which was higher than the flat PES membrane with and without the use of feed spacers. Furthermore, the patterned membranes reported lower natural organic matter (NOM) fouling in short and long-term filtration experiments and higher flux recovery ratio (FRR), indicating their superior anti-fouling performance over the PES membrane when using feed spacers. Overall, the simple fabrication technique, higher permeability, and excellent anti-fouling performance of the surface-patterned membranes render them suitable for potentially replacing the current configuration used in spacer-assisted filtration processes.

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.

Heterogeneous photocatalytic systems generally lack thermodynamic dependence on the degradation of organic pollutants in aqueous solution. Therefore, it is important to reveal the reasons for the inhibited surface kinetics but still be neglected. Herein, we reveal the mechanism that BiVO4 can’t degrade organics although it is thermodynamically feasible. The surface solvation and formation of double layer (compact layer and diffuse layer) makes low-polarity organics far away from the surface of BiVO4. We found that the introduction of sulfite can solve this problem. Theory calculation illustrates that sulfite can enter into the compact layer because of its higher adsorption energy on BiVO4 and lower adiabatic ionization potential (AIP). Then, photogenerated holes initiate the chain transformation of sulfite and produce strong oxidizing species which can diffuse out to degrade organics. This paper provides an insight into the understand the effects of solid-liquid interface on heterogeneously photocatalytic degradation of organic pollutants.

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 (<0.06–>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.

The COVID-19 pandemic and associated prevention policies can directly or indirectly alter the sentiment of individuals while registering water pollution complaints, but observational evidence remains limited. Here, we conducted a sentiment analysis on over 10,000 water pollution complaints from residents in Alabama, USA (2012–2021) to better understand how and to what extent COVID-19 has altered emotion (polarity score-based) and attitude (subjectivity) of water pollution complaints. We found that the 2017 state-wise drought significantly increased the percentage of negative water pollution complaints by +35%, with no significant alternation in attitude before the COVID-19 pandemic. Since COVID-19, the percentage of negative and subjective water pollution complaints significantly decreased and increased by −30 and +20%, respectively, and these sentiment alternations were maintained by 2021. This study provides a new direction for environmental governance and management, requiring a timely response to changes in the public’s emotions and attitudes during the next climate extremes and pandemics.