Underestimated risks of conjugated estrogens in wastewater: New insights into transformation products and mass balance.

Cascaded nanozyme-based Fe3O4-GOx@ZIF-8/Ag Janus nanomotors with pH-responsive for photo-Fenton degradation of tetracycline hydrochloride.

Potential impact of Eucalyptus plantations on water quality and the formation of toxic disinfection byproducts during drinking water treatment.

The majority of research on microplastic (MP) characterization and removal has focused on municipal wastewater treatment plants (WWTPs). Hence, this study was performed at an industrial zone WWTP with sectors of textile, plastic recycling, furniture, etc. Three monthly sampling campaigns were conducted to analyze the MPs (abundance, shape, color, size, polymer type), and to investigate their fate and removal rate in the WWTP. Furthermore, the environmental risk assessment using EPI Suite™ modeling was conducted for common MP polymer types. The results indicated that the highest MP concentration was detected in the sludge sample (3,734 MP/L), while the lowest one was observed in the effluent sample (52 MP/L). While large MPs (5 mm - 425 µm) were removed by primary treatment processes, smaller MPs (250-125 µm) showed a tendency for accumulation in the sludge. The most dominant MP shapes were fiber and fragment in both wastewater and sludge samples, while the most dominant polymer types were polypropylene (38%), polyethylene (24%), and polyethylene terephthalate (11%). The environmental risk assessment reveals that polyvinyl chloride, polyethylene terephthalate, and polystyrene, present in minimal quantities in this study, are more likely to impact the growth of living organisms significantly compared to more common polymer types like polypropylene and polyethylene. Although the overall MP removal efficiency of the industrial zone WWTP was 88%, a significant quantity of MPs (1.5x109 MP/day) was still discharged into the Kızılırmak river that is mostly used for irrigation. Effective control/reduction of MP discharge necessitates the implementation of tertiary treatment processes in industrial zone WWTPs to prevent soil pollution.

Abstract Respirometry is a widely used tool for analyzing and optimizing of biological wastewater treatment processes. However, existing respirometers are often complex and expensive, which limits their applicability in settings with limited resources. This study presents a simple and cost-effective respirometer based on standard laboratory equipment that can be used to monitor and evaluate microbial activity in wastewater treatment plants. The proposed methodology involves constructing a respirometer with a beaker and a magnetic stirrer. The device has two operating modes: intermittent and continuous aeration. It is suitable for open-vessel experiments. A mathematical model was adapted to estimate microbial respiration rates from oxygen consumption data while accounting for passive oxygen transfer. The intermittent aeration mode demonstrated good reproducibility. However, the continuous aeration mode resulted in a lower error rate, suggesting that it may be more effective for detecting subtle changes in respiration activity. The respirometer described in this study is simple, cost-effective and provides a practical solution for evaluating microbial respiration in wastewater treatment plants. The methodology is highly accessible, requiring only equipment that is widely available, and it can be used for routine monitoring and model calibration. Intermittent and continuous aeration modes offer different advantages and limitations that should be considered depending on the desired application. Overall, this study underscores the importance of simplifying respirometry techniques to enhance their accessibility to researchers and practitioners in wastewater treatment.

ABSTRACT The assessment of energy efficiency in water facilities is receiving increasing attention as a key strategy in the transition toward an energy‐neutral urban water cycle. This study evaluates the energy efficiency of 146 drinking water treatment plants (DWTPs) in Chile by applying a latent class stochastic frontier analysis (LCSFA) to account for both observable and unobservable sources of heterogeneity. Unlike traditional models that assume homogeneity across units, the LCSFA approach identified two distinct groups of DWTPs with significantly different operational characteristics, pollutant loads, and efficiency profiles. Group 1 exhibited an average energy efficiency score of 0.534, while Group 2 showed a significantly higher average of 0.737. In Group 1, efficiency scores estimated under the pooled frontier are higher than those obtained from the latent class model for 73% of DWTPs, whereas in Group 2 the pooled frontier yields lower efficiency scores for 58% of plants. The analysis also revealed substantial energy‐saving opportunities. Group 1 facilities could reduce energy use by an average of 0.112 kWh/m 3 , compared to 0.044 kWh/m 3 in Group 2. These findings demonstrate the importance of adopting heterogeneity‐aware methods for fair and accurate benchmarking. The study offers methodological innovation and practical insights for regulators and utility managers aiming to design targeted energy efficiency interventions and performance‐based incentives in the water sector.

Introduction Water scarcity threatens global rice production, necessitating identification of genotypes with improved water use efficiency (WUE) whilst maintaining productivity. Previous drought studies typically imposed severe stress conditions that compromised yield and quality, creating a knowledge gap regarding rice responses to moderate water limitation during vegetative growth. Here we show that 18 temperate japonica and 2 indica rice genotypes employ two distinct water conservation strategies under controlled limited water conditions (60–65% field capacity): inherent physiological tolerance versus adaptive phenotypic plasticity. Methods We evaluated rice varieties under ponded and limited water treatments, integrating stomatal traits, chlorophyll fluorescence parameters, leaf carbon isotope composition (δ 13 C), and surface properties quantified via scanning electron microscopy and ATR-FTIR spectroscopy. Results Inherently tolerant genotypes maintained stable photosynthetic performance through constitutively lower stomatal conductance and enhanced cuticular wax deposition. Conversely, adaptive genotypes exhibited pronounced physiological plasticity under water limitation. Notably, LW treatment induced significant enlargement of leaf surface papillae positioned over stomatal complexes, suggesting a potential structural mechanism contributing to reduced transpirational water loss. This represents a previously under-recognised adaptation in smooth-leaf Australian germplasm lacking protective trichomes. Mixed-effects modelling confirmed that photochemical traits and water-use traits responded most strongly to treatment, while reproductive and yield-related measurements indicated no major penalty under limited water. Carbon isotope discrimination (δ 13 C) validated superior intrinsic WUE in top-performing varieties. Discussion/conclusion These complementary strategies provide multiple pathways for breeding water-efficient rice adapted to Australian temperate production systems under moderate water limitation without substantial yield loss.

The growing expansion of industrial operations, particularly within the oil and gas sector, has led to a substantial increase in produced water generation, an effluent rich in recalcitrant organic and inorganic contaminants. Conventional membrane based separations remain limited by low permeability and severe fouling, necessitating the development of more robust and multifunctional treatment systems. In this study, a durable photocatalytic hybrid membrane composed of polyvinylidene fluoride integrated with tungsten based polyoxometalate was fabricated via phase inversion. The incorporation of 2 wt% tungsten based polyoxometalate notably enhanced both permeability and contaminant rejection through improved interfacial compatibility and photocatalytic activity. Controlled ultraviolet irradiation for five minutes further optimized surface hydrophilicity and pore structure, achieving an outstanding water flux of 158.83 L/(m2 h), while excessive exposure induced pore densification and reduced flux. A synergistic adsorption–ozonation pretreatment for three hours was integrated prior to photofiltration, resulting in 89% chemical oxygen demand removal and 85% ammonia nitrogen removal, effectively minimizing fouling and enhancing overall system stability. Under optimized conditions the membrane exhibited a steady permeate flux of 145 L/(m2 h) over 600 minutes and achieved removal efficiencies of 99.0% chemical oxygen demand, 99.5% ammonia nitrogen, 20.5% total dissolved solids, and 6.87% phenol. These results demonstrate the combined effects of tungsten based polyoxometalate incorporation and pretreatment integration in improving both separation performance and operational durability. This work provides a scalable and sustainable strategy toward next-generation hybrid photocatalytic membranes for advanced produced water purification.

This study calculates the carbon footprint of chemical coagulants and operational energy for residential and industrial (whey digestion) wastewater treatment using ReCiPe 2016 methodology within a clearly defined system boundary from cradle to gate. Data from water treatment facilities have been analyzed to quantify environmental impacts and identify sensitive design parameters. The estimated emission of treating 1 m3 of wastewater from whey digestion (7.1195 kg CO2 eq) is over 50 times higher than that of a residential one (0.1349 kg CO2 eq). Life cycle impact assessment (LCIA) reveals that iron (III) chloride (40% in H2O) and operational electricity consumption have higher impact categories compared to other design components. The uncertainty analysis indicates that electricity consumption (r = 0.4) is the dominant contributor to emissions, with a mean value of 4.22 kg CO2-eq per m3 of wastewater treated. In contrast, iron (III) chloride emerges as the most sensitive parameter (r = 0.88) with small variations in dosing causing a disproportionately large impact on overall emissions. Therefore, the optimized use of an iron-based coagulant, the adoption of membrane electrolysis, and the integration of renewable electricity into the process supply chains have been identified as effective strategies for reducing emissions.

Anaerobic ammonia oxidation (Anammox) technology has emerged as a highly promising biological nitrogen removal approach, exhibiting remarkable technical and economic advantages in treating wastewater with high ammonia nitrogen content and a low carbon-to-nitrogen ratio. However, with the escalating global plastic pollution, microplastics (MPs) have become ubiquitous in wastewater treatment systems. This review systematically collates the research status regarding the sources and classification of microplastics in wastewater treatment plants, and the impacts of MPs on anammox systems. Based on their degradation characteristics, MPs are categorized into two major types: degradable microplastics and non-degradable microplastics. The critical factors influencing anammox processes in the presence of microplastics are comprehensively summarized and analyzed. The impacts exerted by MPs on anammox systems are closely correlated with key factors such as polymer type, particle size distribution, concentration-dependent effects, and exposure duration-dependent responses. Low concentrations of microplastics can act as biofilm carriers or provide carbon sources, thereby facilitating microbial adhesion and growth, and enhancing the nitrogen removal efficiency of the system. In contrast, high concentrations of microplastics usually inhibit anammox activity through pathways including physical clogging, toxic effects, and oxidative stress, which in turn leads to the decline of nitrogen removal performance, damage to sludge structure and alterations of microbial community structure in the system. The underlying mechanisms involve three aspects: shifts in microbial community structure, regulation of functional gene expression, and disturbance of metabolic processes. Finally, this review proposes potential future research directions. This study aims to provide comprehensive theoretical support for the stable operation of anammox systems and environmental risk management against the backdrop of microplastic pollution.

The contamination of water resources by pathogenic microorganisms remains a critical global challenge, predominantly in low- and middle-income countries. Conventional water treatment technologies, such as chlorination and filtration, often face drawbacks, including the formation of harmful byproducts and high operational costs. The increasing demand for efficient, sustainable, and scalable solutions necessitates the exploration of advanced materials for water disinfection. This study investigates the potential of silver-iron (Ag-Fe)-modified biochar as a photocatalyst under visible light to achieve high microbial inactivation. The material demonstrates dual functionality through the antibacterial effects of Ag and the photocatalytic activity of Fe, integrated within a renewable biochar. Elemental composition analysis shows that a composition of 4.3 wt% Ag and 30.0 wt% Fe enhances antimicrobial performance. Experimental results indicate bacterial inactivation under visible light conditions. Ag-Fe-modified biochar presents a potential alternative to conventional disinfection methods.

A bimetallic CoMnOx catalyst supported on carbon nanofibers has been constructed for peroxymonosulfate (PMS) activation.

The activated sludge process (ASP) is a widely used biological wastewater treatment method. The present patent landscape analysis examined the patent published on ‘Activated Sludge’ from Patentscope (World Intellectual Property Organisation database), Scopus Patents, Google Patents, and Lens. This analysis included around 355 patent records of International Patent Classification C02F class that related to ASP for water treatments from year 1916 to 2024. The legal status of patent application shows 56% of Patent Application in Process, 43% of Granted Patent, and 1% of Amended Application. The jurisdictional structure revealed that the Patent Office of USA was the top office where the highest number of patents were published, that is, 146, which was around 40% of total application published globally. The patent no. US 4056465 A identified as a largest patent family belonged to Air Prod & Chem which was based on non-bulking ASP. The potential inventor was identified as Fujino Kiyoharu who had eight patent records related to ASP. Furthermore, this article has listed key features of patent application at national and multi-national phase via Patent Cooperative Treaty. As per the authors’ knowledge, this is the first article that provides patent insight on ASP for industrial wastewater treatment.

Naproxen (NPX) is a widely occurring, refractory organic contaminant that cannot be removed by conventional water treatment processes. In response to the growing environmental pollution caused by NPX, an innovative and highly efficient green degradation method has been developed, designed on the principles of sustainability to promote long-term ecosystem health and advance a circular economy. In this study, using zero-valent molybdenum as a catalyst in combination with trivalent iron (Fe3+) and hydrogen peroxide (H2O2), we constructed a Mo/Fe3+/H2O2 system to treat NPX-contaminated water. The effects of solution pH, H2O2 concentration, Fe3+ concentration, Mo dosage, and co-existing water-matrix constituents (Cl−, HCO3−, PO43−, NO3−, and humic acid (HA)) on NPX removal were investigated; reactive species were identified; and the reusability of Mo as well as its performance under the continuous-flow condition were evaluated. The results showed that the optimal pH was 3 and the appropriate Fe3+ dosage is 100 µM. With 500 µM H2O2, 87.9% of NPX was removed within 7 min, and a moderate increase in Fe3+ concentration, together with a suitable H2O2 level, enhanced the removal efficiency. HCO3−, Cl−, and HA exerted slight inhibition, whereas PO43− markedly suppressed NPX degradation. Recycling tests and the 6 h continuous-flow treatment demonstrated excellent reusability and stability of Mo. Quenching experiments revealed that HO• and Fe(IV) were the dominant reactive species responsible for NPX degradation.

Sachet water (SW) is an alternative source of drinking water among many households in Nigeria, and water contamination by heavy metals is a public health concern. This study assessed the physicochemical, lead, iron, and zinc contents of SW samples purchased within the Abuja Municipal Area Council (AMAC), Abuja. Ten bags of SW were purchased from 10 SW ventures within AMAC, labelled A-J, and transported to the laboratory. Three SW from each bag were randomly selected for physicochemical and heavy metal content analysis using a standard protocol. The total dissolved solids, total hardness, and electrical conductivity ranged from 10.75-115.7 mg/L, 0.08-0.64 mg/L, and 7.5-236.1 μS/cm respectively, and were lower than the WHO standard, while the values of the biochemical oxygen demand (BOD), chemical oxygen demand (COD), and dissolved oxygen (DO) ranged from 7.4-10.5 mg/L, 32.5-37.5 mg/L, and 8.4-11 mg/L respectively, and exceeded the WHO threshold. The pH values varied across the samples and were below the WHO threshold. The concentrations of Zn (0.0685-0.2677 mg/L), Fe (0.3774-5.942 mg/L), and Pb (0.0572-0.2331 mg/L) varied across all the SW, with Zn content falling below the WHO threshold, while the Fe and Pb contents exceeded the threshold for drinking water. The study suggests SW contamination by heavy metals, especially Pb, and other physicochemical markers (BOD, COD, and DO), thus recommending stricter enforcement of regulatory standards for Pb content, BOD, DO, and COD in SW, improved water treatment technologies, and better maintenance of water distribution infrastructure towards actualizing the SDG No. 6 (clean water and sanitation)

Brown spot, caused by the fungus Bipolaris oryzae, has led to significant yield losses in rice production worldwide. This study hypothesized that azelaic acid (AzA) could reduce brown spot symptoms in rice leaves by potentiating biochemical defense reactions. A 2 × 2 factorial experiment was arranged in a completely randomized design with five replications per sampling time. The factors studied were plants sprayed with water (control) or AzA (10 mM; 7.5 mL per plant), either non-inoculated or inoculated with B. oryzae. In the in vitro assay, conidia exposed to AzA solutions at rates of 2.5, 5, 7.5, and 10 mM and to the fungicide solution did not form germ tubes compared to those in the control (water) treatment. The area of fungal colonies on oat–agar medium was reduced for the fungicide and AzA (rates increasing from 2.5 to 10 mM) treatments compared to the control (water) treatment. The EC50 value was 3.8 mM AzA. Brown spot severity significantly decreased by 57, 48, 52, and 58% at 36, 60, 84, and 108 h after inoculation (hai) for AzA-sprayed plants compared to water-sprayed ones. The area under brown spot progress curve significantly decreased by 53% for AzA-sprayed plants compared to water-sprayed ones. Greatest activities of defense-related enzymes (chitinase at 108 hai, β-1,3-glucanase at 60 hai, phenylalanine ammonia-lyase at 60 and 108 hai, and lipoxygenase at 84 and 108 hai), a higher concentration of lignin at 84 and 108 hai, and a more robust antioxidative metabolism (higher activities of ascorbate peroxidase at 36 hai, catalase at 84 and 108 hai, and superoxide dismutase at 84 hai) were obtained for AzA-sprayed infected plants. The higher concentration of the superoxide anion radical in AzA-sprayed infected leaves helped to intensify the cell defense reactions against fungal infection and had a fungistatic effect against its hyphae and conidia germination. The findings of this study provide valuable insights into using AzA to potentiate foliar defense reactions in rice plants to hamper the infection by B. oryzae.

A significant amount of ferrous scrap resources remain unrecycled, and the abundant iron content gives them potential as environmental catalysts. However, the practical application of ferrous scrap in catalysis remains a significant challenge. Herein, a strategy based on rapid solidification to increase the specific surface area, regulate the microstructure, and introduce high residual stress in ferrous scrap is proposed, leading to enhanced catalytic performance. The introduction of high residual stress and the construction of an amorphous structure significantly enhance performance, enabling a degradation efficiency of 98% within 40 s and a high kobs of 5.866 min-1. Theoretical calculations reveal that progressively optimizing the phase structure-from the α-phase to the ε-phase and then an amorphous phase-promotes persulfate (PS) adsorption, and significantly enhances the electron transfer capability. Furthermore, optimizing the composition of the catalyst improves its stability to 30 cycles and develops a novel catalyst with dual functionality for both pollutant degradation and water electrolysis, exhibiting an oxygen evolution reaction (OER) overpotential η10 of 309mV. These findings provide a new perspective for the recycling of ferrous scrap and offer innovative ideas for developing multifunctional catalytic materials, which are capable of addressing integrated challenges in water treatment and clean energy conversion.

Hydrogen peroxide is widely used in water and wastewater treatment, particularly in advanced oxidation processes that aid in the degradation of compounds and microbial disinfection. Despite concerns about potential environmental contamination, its impact on freshwater ecosystems remains inadequately studied. Evaluating the ecotoxicity of aquatic organisms is crucial for establishing safe environmental concentrations. This study focuses on assessing the impact of hydrogen peroxide on the freshwater planarian Girardia tigrina, a regenerative invertebrate serving as an ecotoxicological model. Both acute and chronic effects were evaluated, including locomotion, regeneration, and reproduction. The LC50 for 48 h was determined to be 123.55 mg/L. Sublethal exposure had minimal effects on locomotion, blastema regeneration, and fertility. Regeneration delays were observed at 3 mg/L, while fecundity was significantly affected at 1.52 mg/L. The planarians exhibited morphological abnormalities at the maximum quantity tested in the reproduction experiment (12.86 mg/L), which may have been the result of hydrogen peroxide-induced mutations. In order to protect ecological health, this study advises keeping hydrogen peroxide levels below 1.52 mg/L and draws attention to the potential risks it poses to aquatic habitats. To guarantee complete environmental protection and a better knowledge of its effects, further research is needed.

This work presents an innovative concept of a mobile micro-water turbine for energy recovery from flood-threatened rivers, combining environmental protection with renewable energy production. In response to the increasing frequency and intensity of floods caused by climate change, the authors propose active utilisation of the kinetic energy of water masses during these events through the installation of mobile water turbines along rivers. Rather than merely mitigating the consequences of floods, the energy from flowing water can be converted into electrical current, and the water can be purified and used for other purposes. The article analyses various solutions for water turbines, including the Kaplan turbine, Banki–Michell turbine, and screw turbine, taking into account their efficiency and ability to adapt to changing flow conditions. For the Biała Lądecka river, it was demonstrated that a mobile micro turbine operating for three days can generate a significant amount of energy for on-site consumption or storage. The key challenge is the development of effective water filtration and treatment systems to remove pollutants brought by floods, as well as mobile platforms enabling rapid assembly and disassembly of turbines at threatened sites. The comparative analysis of turbines conducted makes it possible to determine the optimal choice for mobile systems due to operation at low heads, simple construction facilitating installation, and tolerance for contaminants.

The increasing use of reclaimed water for agricultural irrigation raises concerns about the environmental accumulation of persistent contaminants, including gadolinium-based contrast agents (GBCAs). These compounds, widely used in medical imaging, are excreted unmetabolized and poorly removed by conventional wastewater treatment plants, leading to their release into aquatic environments and potential accumulation in soils and crops. In this study, a method was developed, validated, and applied-for the first time-for the determination of three commonly used GBCAs-gadoteric acid, gadoteridol, and gadobutrol-in clay soil. Quantification was achieved by ion chromatography coupled to inductively coupled plasma mass spectrometry (IC-ICP-MS). Suitable separation was accurately optimized using a mobile phase containing 30mM EDTA and 20mM NH4NO3 at pH 9.8. Elution of all target species was achieved within 7.5min. The method was evaluated using real clay soil samples from an agricultural field in Castelló (Spain) fortified with selected GBCAs at various concentrations. Mild extraction with NH4NO3 yielded recoveries below 50%, which allows assessment of the bioavailable fraction. To achieve quantitative recovery, a more severe alkaline extraction protocol using KOH was subsequently developed. The optimized procedure demonstrated excellent analytical performance, with LOD and LOQ below 2 and 5ngg-1, respectively. This methodology enabled the first quantitative determination of GBCAs in soil samples collected from municipal parks irrigated with reclaimed water. Furthermore, the KOH-based extraction was extended to the quantification of gadoteric acid in peat substrates from greenhouse-scale cultivation trials, yielding a mean recovery of 80% with a relative standard deviation (RSD) of 12%. The application of this method confirmed the accumulation of the contrast agent in peat irrigated with fortified tap water. These findings underscore the necessity for robust, matrix-specific analytical workflows to monitor the environmental fate of GBCAs and to accurately assess their potential transfer into the food chain.