Search Results (1,341)

Tetracycline (TC) is a widely used antibiotic that is frequently detected in rivers, lakes and wastewater. Because TC is poorly removed by conventional biological treatment, its residues can harm aquatic organisms and promote the spread of antibiotic resistance; efficient and low-cost technologies for removing TC from water are therefore needed. In this study, copper smelting slag (CSS), an abundant industrial solid waste, was converted into a catalyst composed of Fe₃O₄ particles loaded on mesoporous silica (denoted Fe₃O₄@MS) via an alkali fusion–hydrothermal method. The catalyst was used to activate peroxymonosulfate (PMS), forming the Fe₃O₄@MS/PMS treatment system for the degradation of TC in aqueous solution. The effects of the main operating parameters (catalyst dosage, PMS concentration, initial pH and reaction temperature) on TC degradation were systematically evaluated. Under the optimized conditions (catalyst 0.5 g/L, PMS 1.0 mmol/L, initial pH 6.5, 25 °C), the Fe₃O₄@MS/PMS system removed 98.70% of 50 mg/L TC within 60 min. Radical quenching experiments and electron paramagnetic resonance (EPR) analysis revealed that TC was degraded through both radical pathways (hydroxyl •OH, sulfate SO₄^•− and superoxide O₂^•− radicals) and a non-radical pathway involving singlet oxygen (¹O₂), with •OH being the dominant reactive species. Nine degradation intermediates were identified by liquid chromatography–mass spectrometry (LC-MS), based on which three degradation pathways were proposed. Toxicity estimation indicated that ring-opening and deamination reactions are the key steps for detoxification. In addition, a life cycle assessment (LCA) across five selected impact categories identified the main environmental burdens associated with catalyst production. Overall, this work demonstrates that CSS-derived Fe₃O₄@MS is an efficient, low-cost and sustainable catalyst for PMS-based antibiotic removal from water, offering a circular-economy approach that couples solid-waste valorization with clean water production. Full article

Owing to advantageous properties such as high mechanical strength and wear and hydrolysis resistance, polyvinylidene fluoride (PVDF)-based materials have been widely used to fabricate membranes utilizing in anaerobic membrane bioreactors (AnMBRs) for wastewater treatment. Though AnMBRs can be regarded as high-rate bioreactors, membrane fouling caused by organic, inorganic, and biological contaminants remains an inevitable challenge. In order to alleviate this issue, this review systematically summarizes modification methods including crosslinking, surface coating, and assembly for the loading of functional materials and inorganic nanoparticles onto the membrane surface. Additionally, this review indicates that modified PVDF-based membranes with enhanced conductive or antifouling properties can be effectively applied in AnMBRs, and better chemical oxygen demand (COD) removal efficiency can be achieved compared with those utilizing pristine PVDF membranes. Different from previous reviews, this review proposes technology intensification strategies utilizing pristine PVDF membranes including electrochemical AnMBR (electro-AnMBR) and anaerobic fluidized bed membrane bioreactor (AFMBR). Both of them have demonstrated enormous potential for mitigating membrane fouling relative to conventional AnMBR configurations. Spontaneously, this review underscores the critical need to integrate these intensification strategies with modified PVDF-based membranes as relative studies in this combined area. Therefore, this review provides comprehensive guidance on modification methods of PVDF membranes and technology intensification strategies utilizing modified PVDF-based membranes. Full article

Anthropogenic pollution of aquatic ecosystems presents a significant global challenge, underscoring the urgent need for resilient, biologically mediated remediation strategies. In this context, microalgae have emerged as a compelling solution, owing to their inherent adaptability to diverse environments and their capacity for efficient contaminant mitigation through bioremediation. These organisms possess the potential to sequester and remove a broad spectrum of pollutants from wastewater streams, including excess nutrients, organic substrates, heavy metals, and various emerging contaminants. Specifically, their metabolic versatility allows these microorganisms to tolerate and degrade complex substances such as recalcitrant micropollutants and hydrocarbons even under fluctuating environmental conditions. This review evaluates extremophilic microalgae as specialized biological agents capable of functioning under harsh anthropogenic stressors that may constrain the performance of microalgal strains commonly investigated for wastewater treatment. Their distinctive stress tolerance may provide advantages for treating wastewater characterized by extreme physicochemical conditions. By examining the unique metabolic pathways of these extremophiles, this analysis addresses critical gaps in the current bioremediation literature regarding the practical scalability and economic viability of integrating such specialized biomass into large-scale treatment infrastructure. Full article

Low-glutamic-acid monosodium glutamate wastewater (L-MSGW), characterized by high (NH₄)₂SO₄ concentrations, presents significant challenges for conventional treatment. γ-Polyglutamic acid (γ-PGA) production using industrial wastewater is an economical and environmentally friendly strategy. In the current study, we isolated and identified Bacillus subtilis GB, which exhibited exceptional tolerance to (NH₄)₂SO₄, and capability for the high-efficiency biosynthesis of γ-PGA using untreated L-MSGW. Fermentation conditions were optimized using single-factor experiments coupled with response surface methodology, followed by scale-up validation in a 5 L fermenter. Under optimal conditions, the maximum γ-PGA yield reached 16.57 g/L with a minimal glutamate consumption of only 4.9 g/L. The study validated the feasibility of efficient γ-PGA production from L-MSGW by B. subtilis GB, providing a novel technical approach and theoretical basis for low-cost treatment and high-value resource utilization of L-MSGW. This study not only demonstrates the low-cost L-MSGW can be used for the high-value γ-PGA by B. subtilis GB but also provides a sustainable and economically viable solution for industrial wastewater treatment. Full article

The complex composition of landfill leachate, characterized by high concentrations of refractory organic matter, ammonium nitrogen, and heavy metals, requires efficient and sustainable treatment technologies. Recently, sludge-based adsorbents (SBAs) obtained from wastewater treatment plants (WWTPs) sludge have emerged as promising alternatives to the conventional activated carbon materials for landfill leachate. This review critically evaluates the recent literature related to the transformation of sludge waste and municipal solid waste-based adsorbents into high-efficiency SBAs as a circular economy strategy for leachate remediation. The correlation of the physicochemical characteristics of landfill leachate with the properties of SBAs to enhance the removal of specific contaminants is discussed. The treatment strategies for landfill leachate including physicochemical, biological, and integration of those are summarized. By correlating adsorption performance with SBAs’s properties and circular economy principles, this review identifies the key knowledge gaps and provides guidance for the development and large-scale implementation of sustainable leachate treatment technologies. Furthermore, the prospects for the application of SBAs in the closed-loop landfill leachate treatment system are addressed. Full article

Electrochemical treatment can provide contaminant destruction, phase separation, ionic polishing, and resource recovery; however, performance cannot be judged by removal efficiency alone. This structured critical review compares electro-oxidation (EO), electrocoagulation (EC), electro-Fenton (EF), electrodialysis (ED), electrodeionization (EDI), capacitive deionization (CDI), flow-electrode CDI (FCDI), and bioelectrochemical systems (BES) in municipal wastewater, industrial effluents, sludge-related applications, and treatment side-streams. Searches of Scopus, Web of Science Core Collection, and PubMed were updated to 22 July 2026, and the evidence was assessed according to treatment function, wastewater realism, operating mode, durability, residual fate, energy and cost boundaries, resource recovery, and life cycle implications. Recent advances include porous flow-through anodes, oxygen-efficient cathodes, selective ion separation materials, and pilot BES configurations. However, scale-up remains constrained by electrode aging, by-products, sludge and concentrate management, oxygen transfer, fouling, competing ions, internal resistance, biological instability, and incomplete long-term economic and environmental evidence. The quantitative results show that the energy, cost, and carbon outcomes depend strongly on the treatment function and system boundary. The evidence for sludge and biosolids is less mature than that for liquid wastewater. Therefore, electrochemical technologies are best positioned as function-specific units within hybrid treatment trains rather than as universal replacements for conventional treatments. Full article

Background: Carbamazepine (CBZ) and aripiprazole (ARI), frequently detected in medical facility effluents, are resistant to conventional wastewater treatment. However, a systematic comparison of their electrolytic degradation product profiles under different electrode conditions using an identical operating platform has not been previously reported. Methods: CBZ and ARI in NaCl solutions were subjected to electrolytic oxidation using the Eleca^® system with either a boron-doped diamond (BDD) or a metal electrode. Residual drugs were quantified by LC-MS/MS and pseudo-first-order degradation kinetics were calculated. Transformation products were characterized by LC/PDA/HRMS/MS based on accurate mass measurements, MS/MS fragmentation, chromatographic behavior, and UV absorption. Radical scavenger experiments using methanol and tert-butanol were conducted to investigate reactive species’ contributions to degradation. Results: Both drugs were rapidly degraded under all conditions, with the metal electrode consistently exhibiting higher apparent pseudo-first-order rate constants than the BDD electrode. The metal electrode generated hydrophobic intermediates apparently retaining aromatic skeletons (consistent with partial oxidation), whereas the BDD electrode yielded more polar, low-molecular-weight products consistent with more extensive skeletal fragmentation (deep oxidation). Scavenger experiments suggested a greater relative contribution of hydroxyl radicals (•OH) under BDD electrode conditions. Transformation products were transiently detected but eliminated by prolonged electrolysis. Conclusions: Electrode material critically determines the degradation pathway, reactive species distribution, and product profile. Structural analysis of the tentatively identified transformation products suggests loss of pharmacophore integrity in several intermediates; however, residual pharmacological risk has not been experimentally validated and requires biological sassays for confirmation. Furthermore, the observed disappearance of the parent compounds does not demonstrate complete mineralization, detoxification, or environmental safety, as total organic carbon measurements and ecotoxicological assays were not performed. This study provides the first comparative characterization of transformation products of recalcitrant psychotropic drugs under metal vs. BDD electrode electrolysis, offering mechanistic insights for pharmaceutical wastewater treatment optimization. Full article

Synthetic azo dyes are the largest class of industrial colorants having widespread application in textile, food, cosmetic, and pharmaceutical industries. Moreover, they are persistent and toxic, threatening aquatic environments as well as human health. Disperse red 1 (DR1), a mono-azo dye belonging to the disperse dye group and widely used in polyester dyeing, cosmetics, and other applications, is of particular concern due to its mutagenic potential and resistance to conventional treatment processes. The present study investigated an integrated DR1 removal strategy using thermotolerant Bacillus licheniformis Tol1 as well as its EPS-stabilized biogenic silver nanoparticles (AgNPs). With a maximum tolerable concentration of 0.5 g L⁻¹, B. licheniformis Tol1 showed a maximum decolorization of 70.86% (0.2 g L⁻¹, 55 °C). However, response surface methodology (RSM) based on the Box–Behnken design showed an actual decolorization efficiency of 73.13%. The artificial neural network (ANN) model predicted an accuracy of R² = 0.9933, confirming the robustness and reliability of the experimental findings. To enhance dye removal efficiency, Tol1 EPS-stabilized AgNPs were synthesized via a green method and characterized using UV-Vis, SEM-EDAX, TEM, AFM, FTIR, DLS and zeta potential. Characterization of AgNP confirmed the formation of spherical stable AgNPs with an average size of 19.99 ± 0.38 nm, indicating polydisperse colloids nature with moderate electrostatic stability. A sunlight/H₂O₂-assisted process (photocatalytic experiments) demonstrated DR1 decolorization (80.72 ± 1.72% within 5 h under sunlight) following pseudo-first-order kinetics (k = 0.271 h⁻¹). Furthermore, FTIR analysis confirmed the degradation of the chemical structure of DR1 through the disappearance of the characteristic azo (–N=N–) bond, indicating cleavage of the dye molecule. Overall, the present study provides a dual biological–nanotechnological approach for DR1 decolorization using single bacteria as well as its polysaccharide-stabilized AgNP, a sustainable eco-friendly future approach. However, further studies on complete mineralization, transformation products, toxicity evaluation, detailed catalyst reusability, and silver (Ag) leaching are needed to facilitate the practical implementation for wastewater treatment. Full article

Microplastics have emerged as one of the most widespread and significant environmental pollutants, occurring in aquatic and terrestrial ecosystems, the atmosphere, food, and living organisms. Given the rapid expansion of research in this field, a comprehensive synthesis of the current state of knowledge is warranted. The aim of this study was to map the available literature on microplastics, with particular emphasis on advanced identification and characterisation techniques, environmental transport and transformation processes, life cycle assessment, and remediation strategies. This scoping review was conducted in accordance with the PRISMA-ScR guidelines using publications retrieved from the PubMed, Scopus, Web of Science, and Google Scholar databases. The analysis demonstrated substantial advances in analytical methodologies, particularly spectroscopic and microscopic techniques, enabling the accurate characterisation of micro- and nanoplastic particles. It also highlighted the complex mechanisms governing the transport and transformation of microplastics across environmental compartments, as well as their important role as vectors of chemical contaminants. From a systems perspective, life cycle assessment of plastics was identified as an essential tool for evaluating their environmental impacts. Current mitigation approaches, including filtration technologies, wastewater treatment processes, and biological remediation strategies, were also reviewed, along with their limitations and potential for future development. This review identifies the lack of standardised analytical methodologies and the limited capability for nanoplastics detection as two major challenges hindering the global harmonisation of microplastics research. The findings emphasise the need for further interdisciplinary studies and the implementation of integrated strategies encompassing the entire life cycle of plastics to effectively reduce microplastics emissions and mitigate their environmental impacts. Full article

Transforming traditional membrane bioreactors (MBRs) into forward osmosis membrane bioreactors (OMBRs) is a highly challenging yet promising technological upgrade. Although both combine biological treatment and membrane separation, their core driving forces and operating mechanisms are completely different (an MBR is pressure-driven, while an OMBR is osmosis-driven). In this paper, a novel OMBR with an integrated fixed biofilm (BF-OMBR) was tested for the treatment of synthetic rural wastewater using fertilizer potassium chloride (KCl) as the draw solution (DS) and a commercial aquaporin Inside^TM forward osmosis (FO) membrane. A bench-scale investigation was conducted to compare the BF-OMBR with traditional OMBRs and MBRs. The experimental data suggested that the reactor with aquaporin membranes contributed to a higher water flux than traditional TFC membranes, while immobilized biofilms improved the total nitrogen removal rate compared to normal OMBRs. The integration of these two technologies in the BF-OMBR system appears to leverage these individual benefits. Its TOC and ammonia nitrogen removal efficiencies were also better than those of the other two bioreactors. Meanwhile, the BF-OMBR successfully controlled the salinity build-up to a level not exceeding 2.5 mS/cm over 90 days of operation. This novel osmotic bioreactor may represent a possible alternative approach to overcoming the challenges of low-temperature and low-C/N-ratio rural sewage treatment. Full article

In this study, a simple, cost-effective, and eco-friendly approach was developed for the synthesis of AgNPs using white (Muscat Ottonel, WGPE) and red (Cabernet Sauvignon, RGPE) grape pomace extracts. The AgNPs were characterized by SEM, AFM, DLS, UV–Vis, FTIR, and XPS techniques. Their formation was initially indicated by a color change from colorless to dark brown and confirmed by the appearance of an SPR peak at 445 nm. The AgNPs are predominantly spherical with varied sizes. FTIR and XPS analyses indicated the presence of oxygen- and nitrogen-containing functional groups on the nanoparticle surface, suggesting their involvement in the reduction of Ag⁺ ions and the stabilization of the synthesized AgNPs. The biological activity of AgNPs was assessed through wheat (Triticum aestivum L.) seed priming experiments. Treatment with 25 mg/L AgNPs (WGPE) significantly enhanced seedling growth and chlorophyll content, whereas exposure to 100 mg/L AgNPs (RGPE) induced oxidative stress and negatively affected growth parameters. Furthermore, the photocatalytic activity of both AgNPs was evaluated against MB degradation under visible light irradiation. AgNPs (WGPE) showed superior photocatalytic efficiency, achieving up to 77% dye removal within 240 min and a constant rate nearly three times higher than that of AgNPs (RGPE). The photodegradation process was mainly driven by ^•OH radicals. Our results highlight the potential of biosynthesized AgNPs for agricultural applications and wastewater remediation. Full article

Wastewater treatment is undergoing a transition from pollutant removal toward resource recovery, creating opportunities to integrate environmental remediation with circular bioeconomy principles. Filamentous algae have attracted increasing attention as multifunctional biological platforms because their attached growth habit facilitates biomass harvesting while supporting nutrient recovery and biomass valorization. This review synthesizes current knowledge on the roles of filamentous algae in wastewater treatment, with emphasis on nutrient and contaminant removal, biomass production, and the generation of bioenergy, biofertilizers, aquafeeds, and cellulose-based biomaterials. It highlights how filamentous algae differ from conventional suspended microalgae through improved biomass retention, simpler harvesting, and compatibility with attached-growth systems such as algal turf scrubbers and biofilm reactors. The review also examines the ecological interactions between filamentous algae and associated microbial communities that underpin nutrient cycling and treatment performance. Beyond wastewater treatment, it critically evaluates the opportunities and challenges associated with downstream biomass valorization, including biofuel production and the recovery of high-value products within integrated biorefinery frameworks. In addition, the review discusses the principal barriers to large-scale implementation, including limited field-scale validation, variability in biomass quality, contaminant safety, downstream processing requirements, regulatory uncertainty, and the need for comprehensive techno-economic and environmental assessments. Finally, it highlights emerging research directions involving systems biology, advanced process monitoring, artificial intelligence-assisted process control, and integrated biorefinery concepts that may support future development. By integrating biological, engineering, and sustainability perspectives, this review provides a comprehensive framework for understanding the potential of filamentous algae to support resilient wastewater treatment systems and accelerate the transition toward circular resource management. Full article

The multi-media environmental behavior of dissolved organic matter (DOM) is closely related to biogeochemistry and water quality. In this study, we characterized the multi-media distribution patterns and sources of DOM in a human-intensive watershed based on fluorescence measurements and fluorescence quotient (FQ) methods. Clay showed higher proportions in urban areas compared with rural areas. The biological index decreased with the increased similarity of DOM between sediment and a wastewater treatment plant (WWTP)/domestic sewage. The similarity of DOM between sediment and aquaculture was negatively related to coarse silt (Pearson, p < 0.05). In the water, C2 was more abundant in urban areas than in rural areas; among all sources, the WWTP exhibited the highest similarity (98.04%) of DOM with water, which was higher than that between sediment and the WWTP. The fluorescence index decreased with the increased similarity of DOM between waters and the WWTP/domestic sewage. The FQs for some amino acid-like materials and microbial byproducts between sediment and water were negative, while those for humic-like and fulvic-like materials between sediment and water were positive. Structure equation model (SEM) results showed that sediment grain size exerted positive effects on the distribution of C1 between sediment and water and negative effects on the distribution of C3 between sediment and water. The results demonstrated that the distribution of DOM between sediment and water, as well as the source contribution to DOM in sediment, was related to the sediment grain size, revealing the impact of sediment on the multi-media environmental behavior of DOM. Full article

The textile industry is one of the largest consumers of synthetic dyes and a significant source of industrial wastewater contamination. More than 7 × 10⁵ tons of synthetic dyes are produced annually worldwide, and it is estimated that 10–15% of these dyes are released into industrial effluents during manufacturing and textile processing, contributing significantly to aquatic contamination. Due to their complex aromatic structures, many synthetic dyes exhibit high chemical stability and resistance to conventional wastewater treatment processes, leading to persistent environmental pollution. This review discusses the main classes of synthetic dyes used in the textile industry, focusing on their chemical classification, environmental impacts, and associated ecological risks. Dye categories are analyzed both according to their application to textile fibers and their molecular structure, highlighting how these characteristics influence their persistence and toxicity in aquatic environments. Unlike previous reviews that primarily emphasize individual treatment technologies, this work provides an integrated perspective linking dye chemistry, environmental behavior, and the mechanisms, advantages, and limitations of physical, chemical, and biological remediation strategies. The environmental impacts of dye-contaminated effluents include reduced light penetration in water bodies, disruption of aquatic ecosystems, and potential toxic and mutagenic effects on living organisms. In addition, the review examines current remediation strategies for dye removal from textile wastewater, including physical, chemical, and biological treatment methods. Particular attention is given to biological degradation, as well as hybrid systems that combine multiple technologies to improve treatment efficiency. Finally, the advantages, limitations, and future perspectives of these remediation strategies are discussed, emphasizing the need for sustainable and efficient approaches to mitigate the environmental impacts of textile dye pollution. Full article

Cosmetic wastewater is increasingly recognized not only as a disposal problem but also as a potential source of recoverable water and formulation-derived compounds. This review critically examines the relationship between cosmetic formulation chemistry, wastewater composition, pollutant removal mechanisms, membrane separation, fouling behaviour, and reuse-oriented treatment design. Cosmetic wastewater shows high compositional variability, with reported COD values ranging from approximately 2400 mg O₂/L to more than 100,000 mg O₂/L, depending on product type, cleaning practices, and raw material losses. Surfactants, emulsifiers, oils, polymeric thickeners, preservatives, fragrances, UV filters, dyes, and microplastics contribute differently to organic load, emulsion stability, toxicity, and treatment resistance. Conventional treatment processes reduce coarse, suspended, emulsified, and biodegradable fractions, but they are limited by low biodegradability, sludge generation, inhibitory compounds, and incomplete removal of persistent micropollutants. Advanced oxidation, adsorption, electrochemical processes, and hybrid systems can improve the transformation, phase transfer, retention, and polishing of recalcitrant compounds, with AOPs typically achieving COD removal of approximately 55–85% and hybrid systems improving overall performance by about 10–25% compared with biological treatment alone. Membrane technologies are evaluated as selective barriers enabling clarification, polishing, water reuse, and resource recovery. MBRs can remove more than 90–95% of COD and BOD₅, while NF/RO polishing may reject more than 90–95% of selected recalcitrant organics and microcontaminants. The novelty of this review lies in shifting the discussion from end-of-pipe wastewater treatment toward source-oriented recovery, integrated treatment trains, and mechanism-based selection of technologies before cosmetic wastewater becomes diluted, mixed, and difficult to reuse. Full article