Search Results (177)

The article presents the results of the development of multicomponent adsorption materials based on industrial waste sludge from the water treatment plant of a thermal power plant. Activation of the sludge at 1000 °C makes it possible to obtain a porous matrix. It has been experimentally established that compositions with 50% activated sludge content in combination with oxides of Zn, Fe, Mn, Cu and NaOH have an optimal sorption capacity with respect to hydrogen sulfide. Kinetic studies have shown that the optimal contact time of the adsorbent with the adsorbate is 15–20 min, and the operating temperature should not exceed 300 K. The calculated thermodynamic parameters confirm the exothermic chemical mechanism of sorption. The materials have the ability to regenerate and display a color change upon contact with hydrogen sulfide. With respect to mercaptan sulfur, the maximum capacity was achieved for the sorption composition with 74.7% ZnO content. The logarithmic dependence of the mercaptan sulfur capacity on the percentage of zinc oxide in the composition has also been established. The environmental significance of the work lies in the utilization of large-tonnage waste and the absence of liquid effluents during regeneration. The proposed materials show promise as potentially cost-effective alternatives for gas purification, though comprehensive economic analysis remains the subject of future work. Full article

This study produced and analyzed composite membranes composed of polysulfone (PSf), polyvinylpyrrolidone (PVP) and Metal–Organic Framework (ZIF-8) for treating effluent generated by the Batik industry. The incorporation of ZIF-8 was performed to enhance membrane efficiency. The findings indicated that ZIF-8 markedly enhanced hydrophilicity and pure water flux of membranes. The M-0.5 membrane containing 0.5 g of ZIF-8 demonstrated superior performance, with a water contact angle of 49.4° and a porosity of 83.5%. In contrast, the ZIF-8-free membrane (M-0) displayed a water contact angle and porosity of 66.3° and 76.7%, respectively. These combined characteristics enabled the M-0.5 membrane to achieve the highest pure water flux of 197.1 L m⁻² h⁻¹ at 5 bar. All membranes attained complete total suspended solids (TSS) rejection at 100% efficiency. Turbidity rejection rates ranged from 75% to 92%, whilst color rejection rates ranged from 65.7% to 87.6%. The maximum chemical oxygen demand (COD) rejection observed was 57.9%, achieved by the M-0.25 membrane (0.25 g of ZIF-8) at an operational pressure of 4 bar. Meanwhile, for permeability and hydrophilicity, the ideal loading is 0.5 g of ZIF-8 (M-0.5). This concentration yielded the optimal equilibrium of porosity (83.5%), the minimal water contact angle (49.4°), and the maximal pure water flux (197.1 L m⁻² h⁻¹). Nonetheless, the TDS rejection rate was rather low at 8.0–21.1%. The membrane effectively preserved effluent pH stability between 7.9 and 8.3. The aggregation of ZIF-8 at elevated concentrations diminished mechanical strength and selectivity. Additional optimization is required to equilibrate these performance indicators. Full article

Ultraviolet (UV) disinfection is widely used in municipal wastewater and reuse systems, yet its full-scale outcomes depend strongly on how fluence is delivered under real-water conditions rather than on nominal lamp output. This review consolidates the photochemical basis and plant-relevant limitations of UV disinfection, with emphasis on key factors such as matrix optics (e.g., UVT254, color, and turbidity/suspended solids) and particle shielding. Building from these constraints, UV-enhanced disinfection is examined as an engineering strategy that couples UV with oxidants or catalytic/physical processes to expand inactivation pathways and improve robustness in challenging effluents. Representative configurations have been reported (e.g., UV/free chlorine, UV/monochloramine) and are compared in terms of dominant reactive species and reaction networks, matrix dependence and scavenging effects, disinfection performance trends across microbial targets, and process-specific trade-offs including transformation products/disinfection byproducts, energy and chemical demands, and materials durability. Finally, practical considerations for implementation are summarized, including monitoring and control variables, validation approaches (e.g., biodosimetry, challenge testing), and operating windows that balance inactivation with risk and resource inputs, to support more reliable selection and operation of UV and UV-hybrid disinfection for water reuse. Full article

Beauty salon wastewater is an emerging commercial greywater characterized by high chemical oxygen demand (COD), intense color, and low biodegradability due to the presence of surfactants and oxidative dye precursors. This study evaluated a solar-assisted photo-Fenton process using waste-derived iron sludge as a heterogeneous catalyst for treating real beauty salon effluent. Operational parameters, including pH, H₂O₂ concentration, iron sludge dosage, reaction time, and temperature, were optimized based on dye removal and COD reduction. Under optimal conditions (pH = 3, H₂O₂ = 400 mg L⁻¹, iron sludge = 40 mg L⁻¹), the system achieved approximately 98% dye removal and 95% COD reduction within 50 min of irradiation. Additionally, maximum performance was observed at 40 °C, while higher temperatures reduced efficiency due to non-productive H₂O₂ decomposition. Kinetic analysis was performed, and the results indicated predominant second-order behavior. Thermodynamic evaluation confirmed an endothermic process with moderate activation energy (Eₐ = 21.8 kJ mol⁻¹). Response surface methodology confirmed strong parameter interactions and high predictive accuracy. The integration of solar irradiation with iron sludge valorization provides a sustainable and decentralized solution for treating dye-loaded beauty salon wastewater. Full article

The widespread release of microplastics (MPs), especially fibrous microplastics (FMPs) originating from synthetic textiles, poses a growing threat to environmental systems due to their persistence, mobility, and potential for bioaccumulation in aquatic and terrestrial ecosystems. Conventional gravimetric methods (GMs) remain the primary approach for assessing FMP shedding, yet they are hindered by moisture-sensitive filters, false positives from detergents and minerals, environmental contamination, and the labor-intensive manual measurement of individual fibers. To address these limitations, we developed an automated image analysis (AIA) framework that integrates an attention-based U-Net architecture with meta-learning modules to quantify FMP number, length, diameter, and mass from stitched microscopic images of entire filter membranes. This approach enables detection of fibers down to 28 μm in diameter with the spatial resolution of 2.17 µm/pixel, supports both target-color and multi-color analysis, and eliminates the need for manual characterization or extrapolation from partial membrane segments. The method achieved the highest accuracy of approximately 98% in color-specific fiber detection, correctly identifying 257 of 263 white fibers, and demonstrated similarly robust performance for black, red, and green fibers, while minimizing interference from non-target colors, even when their fibers overlapped. Multi-color detection was further validated using effluent water samples containing mixed-color fibers. Overall, the developed system enhances the accuracy, efficiency, and reproducibility of FMP analysis, offering a standardized and scalable approach for environmental monitoring of MP pollution. Full article

The pulping and paper-making (P&P) industry is one of the world’s largest manufacturing sectors, yet it is plagued by high water/energy consumption and massive discharge of highly polluted wastewater. The effluents from pulping, bleaching and papermaking processes are characterized by high chemical oxygen demand (COD), intense color, toxic adsorbable organohalides (AOX) and abundant refractory lignin, which pose significant threats to aquatic ecology and human health. Although conventional physical, chemical and biological treatments have been widely applied, they are constrained by insufficient degradation efficiency toward recalcitrant organics, high cost and potential secondary pollution. In recent years, electrocatalytic technologies including electrocatalytic oxidation, electroreduction and their integrated processes, have demonstrated superior efficacy in specific scenarios of P&P wastewater treatment, such as lignin degradation, toxic side-streams treatment, pretreatment for enhancing biodegradability, and polishing steps in integrated treatment systems, which are not universally applicable solutions for P&P wastewater remediation. Meanwhile, biomass fuel cells typified by direct biomass fuel cells (DBFC) and microbial fuel cells (MFC) provide promising pathways for synchronous pollutant removal, energy production and resource recovery. Representative studies have reported COD removal efficiencies of 60–100% for electrochemical and advanced oxidation processes, while integrated electro-Fenton–biological treatment increased the BOD/COD ratio from 0.34 to 0.52 and achieved an overall COD removal of 94%. It should be noted that these advanced electrochemical technologies are still confronted with challenges in industrial scale-up, high energy and electrode material costs, and stable continuous operation. This review systematically elaborates on the physicochemical properties, generation mechanisms and environmental impacts of P&P wastewater, comprehensively summarizes the mainstream treatment technologies including physicochemical, biological, electrochemical and integrated processes, and analyzes their reaction mechanisms, efficiencies and applicable conditions. Particular emphasis is placed on electrocatalytic treatment and bio-electrochemical valorization strategies. This review is anticipated to provide a valuable reference for the efficient and targeted treatment as well as sustainable utilization of P&P wastewater, thereby supporting the green and low-carbon development of the P&P industry. Full article

Textile wastewater remains one of the most challenging industrial effluents to remediate due to its intense and persistent coloration, high organic load, elevated salinity, and fluctuating pH and the presence of recalcitrant dye structures and auxiliary chemicals. Conventional physicochemical and biological treatments frequently achieve incomplete removal, generate secondary wastes, or fail under high-salt and toxic dye matrices. Advanced oxidation processes (AOPs) provide molecular-level degradation via reactive oxygen species (ROS), yet their deployment is often constrained by narrow operating windows, catalyst instability, chemical/energy demand, and scale-up limitations. In this context, metal–organic frameworks (MOFs) have emerged as tunable porous catalytic platforms that integrate adsorption and oxidation within a single architecture through controllable metal nodes, functional linkers, and engineered pore environments. This critical review reimagines textile effluent treatment through the lens of MOF-based hybrid catalysts, synthesizing progress across Fenton/photo-Fenton catalysis, photocatalytic MOFs, persulfate activation, and MOF-derived/composite systems. Mechanistic pathways are discussed by linking pollutant enrichment, cyclic redox reactions, charge-transfer processes, and ROS-driven degradation toward mineralization, with emphasis on the distinction between rapid decolorization and true organic removal. A critical comparison highlights how hybridization improves charge transport, stability, and catalyst recovery, while persistent gaps remain in hydrolytic robustness, metal leaching control, intermediate toxicity assessment, real-wastewater validation, continuous-flow reactor integration, and techno-economic feasibility. Finally, the review outlines actionable research directions, including water-stable and defect-engineered MOFs, immobilized and structured catalysts, solar-driven operation, standardized performance metrics, and life-cycle-informed design, to accelerate translation toward scalable and sustainable textile wastewater remediation. By bridging material chemistry with reactor-level feasibility and sustainability assessment, this review provides an implementation-oriented perspective for next-generation textile wastewater treatment. Full article

Olive mill wastewater (OMWW) is a highly polluting agro-industrial effluent characterized by elevated organic load, low pH, and high concentrations of phenolic compounds responsible for its phytotoxicity and dark coloration. In this study, 41 non-conventional yeast strains belonging to the University of Basilicata Yeast Collection (UBYC), were tested for both the oleaginous potential traits and OMWW detoxification capacity in comparison to two commercial oleaginous controls, Yarrowia lipolytica ATCC 46483 and Lipomyces tetrasporus Li-0407. Primary screening in synthetic medium under nitrogen-limited conditions revealed widespread intracellular lipid accumulation. Quantitative analysis showed lipid contents above 20% (w/w) in some strains, with Candida tropicalis AII122 (33.3%) and Pichia manshurica ML-3 (29.4%) exhibiting the highest values in synthetic medium. The cultivation of eight selected strains in synthetic medium supplemented with 15% (v/v) of OMWW reduced intracellular lipid accumulation, with the highest value of 6.48% for the 2R1 strain. Levels of phenol reduction and color removal were highly different among all the analyzed strains, and C. tropicalis AII122 achieved the highest phenolic reduction and decolorization ability. These findings demonstrate that indigenous non-conventional yeasts represent a source of natural biodiversity, supporting sustainable waste valorization strategies based on the use of selected microorganisms within a circular bioeconomy framework. Full article

Chrome tanning of fish skins generates hazardous effluents and carcinogenic Cr(VI) residues; chromium-free routes to valorize collagen-rich by-products from aquaculture and coastal fisheries are therefore needed. We report a 12-stage ecological protocol employing acetic acid/NaCl pickling, Acacia mearnsii tannin, A. podalyriifolia retanning, mashed-papaya enzymatic bating, and cinnamon as antimicrobial/odor adjunct, scaled from bench to pilot using exclusively locally sourced inputs, for Nile tilapia (Oreochromis niloticus) and Patagonian flounder (Paralichthys patagonicus). Three trained operators evaluated macroscopic quality against five predefined criteria adapted from SATRA and ISO 3376 grading conventions, providing a structured feasibility baseline that does not substitute for the standardized instrumental testing designated as priority future work. Both species achieved satisfactory grain stability, complete tannin penetration, pliable handle, and cinnamon-dominant odor without residual amines; dark-brown coloration is a recognized practical limitation for fashion applications. In silico molecular docking (GNINA v1.0) was used to explore the mechanistic plausibility of each ecological substitution, generating testable hypotheses rather than definitive mechanistic conclusions: the multidentate polyphenol proxy (PGG) exhibited consistently superior collagen engagement over the flavanol monomer across both collagen constructs and all three scoring metrics (1CAG: Vina affinity −5.51 ± 0.13 vs. −3.54 ± 0.35 kcal/mol; CNNscore 0.874 ± 0.009 vs. 0.771 ± 0.010; 7CWK: Vina affinity −6.98 ± 1.43 vs. −4.37 ± 0.16 kcal/mol; CNNscore 0.858 ± 0.024 vs. 0.635 ± 0.094). Dipeptide probes were reproducibly accommodated in the papain catalytic cleft, with the closest configuration reaching 3.997 Å from the catalytic nucleophile (OCS25-SG). Trans-cinnamaldehyde occupied the quorum-sensing pocket with reproducible placement (CNNscore 0.718 ± 0.034) but without score-based selectivity over structural decoys, a result interpreted as hypothesis-generating for future microbiological validation. The protocol is reproducible from bench to pilot and generalizable across two species with distinct dermal architectures. Quantitative physical-mechanical testing (shrinkage temperature, tensile strength, elongation, tear load), CIELab colorimetric analysis, and effluent characterization (COD, BOD₅, total phenolics) are designated as priorities for future validation. Full article

The development of sustainable ceramic membranes remains a major challenge for advanced wastewater treatment, particularly regarding the trade-off between mechanical durability and the removal of dissolved micropollutants. While bentonite membranes offer high stability, they often lack the selective adsorption sites required for complex effluents, and the recovery of high-capacity powder adsorbents remains technically prohibitive. This paper addresses these gaps by developing an integrated hybrid system that combines eco-friendly bentonite-based tubular membranes with regenerable clam shell-derived adsorbents. The membranes were synthesized using natural plasticizers and binders with optimization at a sintering temperature of 1000 °C yielding an average pore size of 1.7 µm, a high flexural strength of 24.06 MPa, and a permeability of 525 L h⁻¹ m⁻² bar⁻¹. To enhance the performance, clam shell powder was integrated as a functional adsorbent layer. When applied to real textile effluent from a jeans washing plant, this integrated process achieved superior removal efficiencies: 85.6% COD, 86.5% BOD₅, 86.5% TSS, and 96.5% color. A key scientific contribution of this paper is the successful application of a photochemical regeneration approach, which ensures complete adsorbent recovery and maintains membrane flux, directly supporting circular economy objectives. These results demonstrate that combining low-cost ceramic scaffolds with marine waste-derived materials provides a unique, efficient, and green solution for the scalable treatment of industrial wastewater. Full article

The world’s water resources are being deteriorated by the continuous discharge of various contaminants, highlighting the problem of dyes. Many industrial activities (dyeing, food, and medicines) depend on the use of synthetic dyes. Due to their strong color, toxicity, and carcinogenic properties, dye effluents are detrimental to human health and the environment and their treatment is mandatory before discharge. The manuscript intends to present a comprehensive summary of the advantages and drawbacks of using different treatments on the removal of dyes, mainly those based on adsorption. Emphasis is placed on the use of adsorbents from biomass or biomass waste, which are used in their original form or after conversion into biochar or activated carbon (AC). In this review, the use of biomass-based feedstocks to produce biochar and ACs and their application on the removal of various types of dyes from liquid effluents are compiled and critically discussed. This approach positions waste and sub products not as a problem, but as a valuable raw material for producing high value-added materials. The performance of different adsorbents, for the removal of cationic and anionic dyes, is discussed and related to the textural, physical and chemical characteristics of adsorbents and adsorption. It differs from the other revision manuscripts in that it elucidates to the readers the points to ponder before choosing an adsorbent for the removal of a specific dye, mainly for large-scale uses. Full article

To develop a low-energy nitrogen removal system, a coupled system consisting of a sunlight-enhanced bacteria-algae biological rotor (SBABR) and an anaerobic ammonia oxidation (Anammox) reactor was constructed. This study investigated partial nitrification stability in the SBABR reactor, color and chlorophyll-a removal efficiency in the Anammox reactor, and the coupled system’s nitrogen and carbon removal performance and microbial community structure using high-throughput sequencing. Under significant light intensity fluctuations (300–2400 μmol/(m²·s)), the SBABR reactor maintained nitrite accumulation rates (NAR) of 94.98–98.13% with effluent NO₂⁻-N/NH₄⁺-N ratios between 1.01 and 1.18. The coupled system achieved average total nitrogen (TN) removal efficiency of 81.78% and ammonia nitrogen (NH₄⁺-N) removal efficiency of 87.71%. SBABR effluent color decreased from 42 to 17 Hazen units after the Anammox reactor, and chlorophyll-a concentration dropped from 296.40 μg/L to below detection limits. Microbial community analysis revealed that Nitrosomonas abundance was 0.69%, while Nitrospira abundance was only 0.01% in the SBABR reactor. In the Anammox reactor, Planctomycetota abundance reached 13.30%, and Candidatus Jettenia reached 11.57%. Results indicate that the activity of both AOB and NOB is inhibited by sunlight, but the inhibition of NOB is more significant, enabling stable nitrite accumulation. The Anammox reactor demonstrated favorable nitrogen removal performance and effectively removed color and chlorophyll-a. Full article

The textile dyeing sector is one of the largest industrial consumers of freshwater and a major source of chemically polluted effluents. To address increasing sustainability demands, this study investigates the feasibility of partially replacing process water with membrane bioreactor (MBR)-treated municipal wastewater in the dyeing of polyester and cotton fabrics. Controlled laboratory trials were carried out using water mixtures containing 0–100% MBR-treated wastewater to evaluate their influence on fabric integrity, coloration, and performance. The experimental work included blind dyeing and both monochromatic and trichromatic dyeing tests. Fourier-transform infrared spectroscopy (FTIR) was used to assess potential modifications to fiber structure, while colorimetric measurements (CIELAB L*, a*, b*, ΔE*) quantified visual differences among samples. Fastness to washing and light was evaluated following the corresponding ISO standards. Results showed no detectable alterations in fiber chemical structure for either cotton or polyester, regardless of the water composition. Color differences remained low across all dyeing conditions, and fastness values fell within typical industrial ranges, with polyester showing the highest overall stability. Overall, the study demonstrates that up to 25% of process water can be substituted with MBR-treated municipal wastewater without compromising dyeing quality, supporting the implementation of circular water strategies in textile finishing. Full article

Sugarcane vinasse is a high-strength effluent with a high organic load and intense coloration from melanoidins and phenolic compounds, making conventional biological treatment difficult. This study presents a magnetically recoverable Fe₃O₄@latex-ZnO nanocomposite, synthesized using natural Hevea brasiliensis latex as a green polymeric interlayer. Transmission Electron Microscopy (TEM) shows a core–shell structure that enhances ZnO anchoring and reduces aggregation. X-ray Diffraction (XRD) confirms the coexistence of spinel Fe₃O₄ and wurtzite ZnO without secondary phases, while Fourier Transformed Infrared Spectroscopy (FTIR) verifies the latex layer through characteristic organic bands, indicating a stable organic–inorganic interface. Under 4 h of UV irradiation, the nanocomposite significantly reduced vinasse COD from 23,450 to 12,450–13,150 mg L⁻¹ (≈44–47%) and BOD from 11,600 to 4800–5000 mg L⁻¹ (≈57–59%), demonstrating substantial oxidation of the organic fraction. The magnetic core enables quick separation post-treatment, enhancing the practicality of the process. Overall, this innovative approach positions the ZnO nanocomposite as a promising option for vinasse pre-treatment and integrated agro-industrial effluent treatment. Full article