Search Results (1,185)

Nitrous oxide (N₂O), a potent greenhouse gas, is an important environmental concern associated with biological nitrogen removal in wastewater treatment plants. Anaerobic ammonium oxidation (anammox), recognized as an advanced carbon-neutral nitrogen removal technology, requires a continuous supply of nitrite, which also serves as a key precursor for N₂O generation. However, the regulation of the carbon-to-nitrogen (C/N) ratio to minimize N₂O emission in mainstream anammox systems remains insufficiently understood. In this study, we evaluated the long-term nitrogen removal performance and N₂O emission potential of an oxygen-limited anammox biofilm reactor treating synthetic municipal wastewater with a typical C/N range of 4.0–6.0. Experimental results demonstrated that the highest nitrogen removal efficiency (95.3%), achieved through coupled anammox and denitrification, and the lowest N₂O emission factor (0.73%) occurred at a C/N ratio of 5.0. As the C/N ratio increased from 4.0 to 5.0, N₂O emissions decreased progressively, but rose slightly when the ratio was further increased to 6.0. High-throughput sequencing revealed that microbial community composition and the abundance of key functional taxa were significantly influenced by the C/N ratio. At a C/N ratio of 5.0, proliferation of anammox bacteria and the disappearance of Acinetobacter populations appeared to contribute to the significant reduction in N₂O emission. Furthermore, gene annotation analysis indicated higher abundances of anammox-associated genes (hzs, hdh) and N₂O reductase gene (nosZ) at this ratio compared with others. Overall, this study identifies a C/N-dependent strategy for mitigating N₂O emissions in mainstream anammox systems and provides new insights into advancing carbon-neutral wastewater treatment. Full article

Y₂O₃ nanoparticles were used in a polyethersulfone (PES) as additives to increase the permeation properties of the polymeric membranes. Membranes were manufactured by diffusion-induced phase inversion in N-methyl-pyrrolidone (NMP) using a different concentration of nanoparticles. Y₂O₃ is used in polymeric membranes to enhance their functional properties, especially in wastewater treatment processes. Incorporating Y₂O₃ nanoparticles into the polymer matrix improves the membrane’s hydrophilicity, permeability, and mechanical strength. Additionally, Y₂O₃ provides better properties and reduces fouling. Recent studies highlight its potential as a modifying agent for advanced composite membranes. This paper investigated challenges in the synthesis of Y₂O₃-enhanced membranes and links synthesis with performance. It was observed that the composite membranes have better permeation properties by adding a small amount of Y₂O₃. For membranes at 21 wt.% PES permeability increase from 107 to 112 L/m²h/bar. Fouling performance increases by adding nanoparticles, relative flux decreases by 30% for membranes without nanoparticles and by 10% for membranes with nanoparticles, both at a concentration of 25% PES. Rejection increases for membranes at 21%Pes from 21% for membranes without nanoparticles to 39% for membranes with nanoparticles. The influence of Y₂O₃ nanoparticles on the membranes' performance was determined by filtration experiments to establish the permeability, fouling, retention, and the water flux; by contact angle to establish the surface hydrophilicity; and by SEM to investigate the membranes' structures. Full article

Electronic nose (e-nose) systems have emerged as transformative tools for odor and gas analysis, leveraging advances in nanomaterials, sensor arrays, and machine learning (ML) to mimic biological olfaction. This review synthesizes recent developments in e-nose technology, focusing on innovations in sensor design (e.g., graphene-based nanomaterials, MEMS, and optical sensors), drift compensation techniques, and AI-driven data processing. We highlight key applications across healthcare (e.g., non-invasive disease diagnostics via breath analysis), food quality monitoring (e.g., spoilage detection and authenticity verification), and environmental management (e.g., pollution tracking and wastewater treatment). Despite progress, challenges such as sensor selectivity, long-term stability, and standardization persist. The paper underscores the potential of e-noses to replace conventional analytical methods, offering portability, real-time operation, and cost-effectiveness. Future directions include scalable fabrication, robust ML models, and IoT integration to expand their practical adoption. Full article

Stricter requirements on nutrient removal in wastewater treatment are being imposed by rapid urbanization and tightening water-quality standards. Despite their excellent solid–liquid separation and effective biological treatment, MBRs in conventional operation remain hindered by membrane fouling, limited robustness to influent variability, and elevated energy consumption. In recent years, precise process control and resource-oriented operation have been enabled by the integration of artificial intelligence (AI) with MBRs. Advances in four areas are synthesized in this review: optimization of MBR control architectures, intelligent adaptation to multi-source wastewater, regulation of membrane operating parameters, and enhancement of nitrogen and phosphorus removal. According to reported studies, increases in total nitrogen and total phosphorus removal have been achieved by AI-driven strategies while energy use and operating costs have been reduced; under heterogeneous influent and dynamic operating conditions, stronger generalization and more effective real-time regulation have been demonstrated relative to traditional approaches. For large-scale deployment, key challenges are identified as improvements in model interpretability and applicability, the overcoming of data silos, and the realization of multi-objective collaborative optimization. Addressing these challenges is regarded as central to the realization of robust, scalable, and low-carbon intelligent wastewater treatment. Full article

Chromium (Cr), a toxic heavy metal, poses significant environmental and health risks when industrial effluents containing Cr are discharged untreated. Addressing this challenge, this study developed a selective chromium removal strategy using IRA-900 resin in a sulfuric acid system with sodium phosphite (NaH₂PO₃) as a complexing agent. In the NaH₂PO₃-H₂SO₄ system, IRA-900 resin exhibited exceptional selectivity for Cr³⁺ with minimal co-adsorption of competing ions. The adsorption process followed the Langmuir isotherm model (R² > 0.99), indicating monolayer chemisorption dominated by homogeneous active sites, and achieved a maximum capacity of 103.56 mg·g⁻¹. Characterization via XPS, FT-IR, and SEM-EDS revealed a two-step mechanism: Cr³⁺ reacts with H₂PO₃⁻ to form an anionic complex, and then the complex undergoes electrostatic interaction and ion exchange with chloride ions (Cl⁻) on the quaternary ammonium groups of the resin. The chromium-loaded resin demonstrated remarkable structural stability, resisting Cr³⁺ desorption under conventional elution conditions. This property provides a novel pathway for chromium solidification in industrial wastewater, effectively minimizing secondary pollution risks. This work advances the design of ligand-assisted ion-exchange systems for targeted heavy metal removal, offering both high selectivity and environmental compatibility in wastewater treatment. Full article

Antibiotic resistance remains one of the most formidable challenges to modern medicine, threatening to outpace therapeutic innovation and undermine decades of clinical progress. While resistance was once viewed narrowly as a clinical phenomenon, it is now understood as the outcome of complex ecological and molecular interactions that span soil, water, agriculture, animals, and humans. Environmental reservoirs act as silent incubators of resistance genes, with horizontal gene transfer and stress-induced mutagenesis fueling their evolution and dissemination. At the molecular level, advances in genomics, structural biology, and systems microbiology have revealed intricate networks involving plasmid-mediated resistance, efflux pump regulation, integron dynamics, and CRISPR-Cas interactions, providing new insights into the adaptability of pathogens. Simultaneously, the environmental dimensions of resistance, from wastewater treatment plants and aquaculture to airborne dissemination, highlight the urgency of adopting a One Health framework. Yet, alongside this growing threat, novel therapeutic avenues are emerging. Innovative β-lactamase inhibitors, bacteriophage-based therapies, engineered lysins, antimicrobial peptides, and CRISPR-driven antimicrobials are redefining what constitutes an “antibiotic” in the twenty-first century. Furthermore, artificial intelligence and machine learning now accelerate drug discovery and resistance prediction, raising the possibility of precision-guided antimicrobial stewardship. This review synthesizes molecular insights, environmental drivers, and therapeutic innovations to present a comprehensive landscape of antibiotic resistance. By bridging ecological microbiology, molecular biology, and translational medicine, it outlines a roadmap for surveillance, prevention, and drug development while emphasizing the need for integrative policies to safeguard global health. Full article

Nitrogen eutrophication represents a significant environmental challenge in Chinese aquatic ecosystems, exacerbated by rapid agricultural intensification, industrial expansion, and urban development. This review consolidates existing knowledge on the drivers and impacts of nitrogen pollution in Chinese aquatic ecosystems, with a focus on environments such as lakes, rivers, and coastal waters. The primary sources of nitrogen enrichment are excessive fertilizer application, livestock manure discharge, industrial emissions, and untreated industrial and municipal wastewater. These inputs have led to severe ecological consequences, including harmful algal blooms, hypoxia, loss of biodiversity, and deteriorating water quality, threatening ecosystem health and human well-being. The review also examines mitigation strategies implemented in China, encompassing regulatory policies such as the “Zero Growth” fertilizer initiative, as well as technological advancements in wastewater treatment and sustainable farming practices. Case studies highlighting successful interventions, such as lake restoration projects and integrated watershed management, demonstrate the potential for effective nitrogen control. However, persistent challenges remain, including uneven policy enforcement, insufficient public awareness, and gaps in scientific understanding of nitrogen cycling dynamics. This review aims to inform future efforts toward achieving sustainable nitrogen management in China by synthesizing current research and identifying key knowledge gaps. Addressing these issues is crucial for safeguarding China’s aquatic ecosystems and promoting global nutrient stewardship. Full article

Artificial intelligence (AI), when integrated with photocatalysis, has demonstrated high predictive accuracy in optimizing photocatalytic processes for wastewater treatment using a variety of catalysts such as TiO₂, ZnO, CdS, Zr, WO₂, and CeO₂. The progress of research in this area is greatly enhanced by advancements in data science and AI, which enable rapid analysis of large datasets in materials chemistry. This article presents a comprehensive review and critical assessment of AI-based supervised learning models, including support vector machines (SVMs), artificial neural networks (ANNs), and tree-based algorithms. Their predictive capabilities have been evaluated using statistical metrics such as the coefficient of determination (R²), root mean square error (RMSE), and mean absolute error (MAE), with numerous investigations documenting R² values greater than 0.95 and RMSE values as low as 0.02 in forecasting pollutant degradation. To enhance model interpretability, Shapley Additive Explanations (SHAP) have been employed to prioritize the relative significance of input variables, illustrating, for example, that pH and light intensity frequently exert the most substantial influence on photocatalytic performance. These AI frameworks not only attain dependable predictions of degradation efficiency for dyes, pharmaceuticals, and heavy metals, but also contribute to economically viable optimization strategies and the identification of novel photocatalysts. Overall, this review provides evidence-based guidance for researchers and practitioners seeking to advance wastewater treatment technologies by integrating supervised machine learning with photocatalysis. Full article

Plasma has become an up-and-coming advanced oxidation technology for wastewater treatment. However, its efficiency is often limited due to the lack of high-performance catalytic materials. In this study, one-dimensional carbon nanofiber precursors were first fabricated via electrospinning, followed by the in situ growth of the Zn/Fe-MOF on their surfaces. After pyrolysis at different temperatures, a series of carbon-based catalysts (FeNFC) were obtained. This new type of catalyst possesses advantages such as high porosity, a large specific surface area, and mechanical stability. Using tetracycline (TTCH) as the target pollutant, the performance of the catalyst was evaluated in the dielectric barrier discharge (DBD) system. The study showed that the addition of FeNFC significantly increased the degradation rate of TTCH in the system. Comparing different pyrolysis temperatures, at 900 °C, the comprehensive performance of the catalyst (FeNFC-900) was the best (the kinetic constant was k_obs = 0.126 min⁻¹, and the removal rate of TTCH was 91.8% within 30 min). The catalytic performance was influenced by factors such as the dosage of the catalyst, the concentration of TTCH, the power of DBD, and the initial pH. The catalytic effect of the material increased within a certain range with the increase in the catalyst dosage. The increase in TTCH concentration led to a decrease in the catalytic performance. The higher the power of the DBD, the higher the removal rate of TTCH. Moreover, when the initial pH was strongly alkaline, the catalytic effect of the catalyst was the best (k_obs = 0.275 min⁻¹, and the removal rate of TTCH was 98.7% within 30 min). Ionic interference tests demonstrated the strong resistance of FeNFC to common water matrix components, while radical quenching experiments revealed that multiple reactive species contributed to TTCH degradation. This work has broad application prospects for enhancing the efficiency of DBD systems in the removal of TTCH. Full article

The development of advanced photocatalysts that are efficient, recyclable and sustainable represents a significant challenge in the face of the growing presence of persistent organic contaminants in industrial wastewaters. This paper presents a novel approach based on the design of new heterostructures synthesized from BiOI and magnetic materials, using not only synthetic magnetite, but also magnetic compounds extracted from mine tailings, transforming environmental liabilities in active supporting materials through valorization strategies in line with the circular economy. Through precise control of composition, it was established that a proportion of 6% by mass of the magnetic phase allows the formation of a heterostructure that is highly photocatalytically efficient. These compounds were evaluated using caffeic acid, an organic contaminant of agroindustrial origin, as a target compound. Experiments were carried out under simulated solar radiation for 120 min. Among the materials synthesized, the BiOI/MMA heterostructure, derived from industrial tailing A, displayed an outstanding photodegradation efficiency of over 89.4 ± 0.25%, attributed to an effective separation of photoinduced charges, a broad active surface and a synergic interface interaction between its constituent phases. Furthermore, BiOI/MMA exhibited excellent structural stability and magnetic recovery capacity, which allowed for its reuse through two consecutive cycles without any significant losses to its photocatalytic performance. Thus, this study constitutes a significant contribution to the design of functional photocatalysts derived from industrial tailings, thus promoting clean, technological solutions for the treatment of wastewater and reinforcing the link between environmental remediation and circular economy. Full article

The escalating problem of nitrate pollution, coupled with the environmental burden of the Haber-Bosch process, has spurred intense interest in the electrocatalytic nitrate reduction reaction (eNO₃RR) as a sustainable route for simultaneous wastewater treatment and ammonia production. However, the efficiency and selectivity of eNO₃RR are hampered by the multi-step proton-coupled electron transfer process and the competing hydrogen evolution reaction. This review provides a comprehensive and critical overview of recent advances in understanding and designing catalysts for eNO₃RR. We begin by elucidating the fundamental mechanisms and key reaction pathways, followed by a discussion on how critical parameters (e.g., electrolyte microenvironment, applied potential, reactor design) dictate performance. Further discussion of recent advances in catalysts, including single-metal catalysts, alloy catalysts, transition metal compounds, single-atom catalysts, carbon-based non-metal catalysts, and composite catalysts, highlights their significant roles in enhancing both the efficiency and selectivity. A distinctive feature of this review is its consistent critical assessment of catalysts through the dual lenses of practicality and sustainable development. Finally, we outline prevailing challenges and propose future research directions aimed at developing scalable and commercially viable electrocatalytic systems for green nitrogen management. Full article

Laccases, a class of multicopper oxidases found in diverse biological sources, have emerged as key green biocatalysts with significant potential for eco-friendly pollutant degradation. Their ability to drive electron transfer reactions using oxygen, converting pollutants into less harmful products, positions laccases as promising tools for scalable and sustainable treatment of wastewater, soil, and air pollution. This review explores laccase from a translational perspective, tracing its journey from laboratory discovery to real-world applications. Emphasis is placed on recent advances in production optimization, immobilization strategies, and nanotechnology-enabled enhancements that have improved enzyme stability, reusability, and catalytic efficiency under complex field conditions. Applications are critically discussed for both traditional pollutants such as synthetic dyes, phenolics, and pesticides and emerging contaminants, including endocrine-disrupting chemicals, pharmaceuticals, personal care products, microplastic additives, and PFAS. Special attention is given to hybrid systems integrating laccase with advanced oxidation processes, bioelectrochemical systems, and renewable energy-driven reactors to achieve near-complete pollutant mineralization. Challenges such as cost–benefit limitations, limited substrate range without mediators, and regulatory hurdles are evaluated alongside solutions including protein engineering, mediator-free laccase variants, and continuous-flow bioreactors. By consolidating recent mechanistic insights, this study underscores the translational pathways of laccase, highlighting its potential as a cornerstone of next-generation, scalable, and eco-friendly remediation technologies aligned with circular bioeconomy and low-carbon initiatives. Full article

This literature review highlights the latest advances in the use of adsorption materials based on modified chitosan for the purification of aqueous solutions from pharmaceutical residues. Some countries are actively working to detect pharmaceuticals and their metabolites in water samples from natural sources and municipal wastewater, as well as to study their impact on the environment. In this article, adsorbents based on chitosan, a natural, low toxic and biodegradable polymer, are considered as a promising solution to this problem. Due to some disadvantages of pure chitosan (low mechanical strength, small specific surface area), its practical application is limited. One of the ways to overcome them is to create modified materials, such as grafted copolymers, as well as chitosan derivatives and its composites, including those with magnetic nanoparticles and carbon materials. Modification of chitosan makes it possible to achieve an increase in mechanical strength, specific surface area and porosity. The high efficiency of hybrid adsorbents is emphasised, demonstrating high adsorption capacity, reuse ability and selectivity for a wide range of pharmaceutical preparations, including antibiotics. Thus, despite a number of limitations, chitosan-based materials are a promising solution for deep wastewater treatment. Full article