Search Results (31,007)

Anaerobic digestion (AD) is widely used for organic waste stabilization and bio-energy recovery, but its performance is often constrained by process instability, slow syntrophic metabolism, and sensitivity to acidification, ammonia, organic overloading, and inhibitory contaminants. Biochar has emerged as a promising strategy to enhance AD, with benefits extending beyond increased methane yield. This review examines how biochar properties, including pore structure, surface functional groups, alkalinity, and electrical conductivity, regulate different AD stages and improve process stability. Biochar provides microbial habitats, buffers pH, adsorbs inhibitors, accelerates volatile fatty acid conversion, and facilitates interspecies electron transfer. The effects of biochar dosage, feedstock type, reactor configuration, and operational conditions on digestion performance and resource recovery are critically evaluated. Broader contributions to organic waste valorization are also discussed. Future research should prioritize tailored biochar design, standardized characterization, long-term validation in continuous reactors, techno-economic analysis, and life-cycle assessment. These efforts are essential for translating laboratory findings into reliable and sustainable applications for organic solid waste treatment and resource recovery. Full article

Approximately 5–33% of the dates growing in Saudi Arabia are downgraded to low-quality fruit that either goes to waste or is used to make animal feed, which is considered a potential feedstock abundant in sugar. By a thorough comparative study, this study evaluated the up-cycling of low-quality Saudi dates (Wannana, Shagra, Sabbaka, Barhi, Saqai, Khalas and Sukkari) as fermentation substrates for xanthan gum production by Xanthomonas campestris. Pure glucose, pure sucrose, and a commercial standard were used as a baseline. The sole carbon source was date juice (≈12.5–17 °Brix) in a batch aerobic fermentation conducted at the standard conditions of temperature (30 °C), speed 180 rpm, and time (120 h). The xanthan gum was quantified and tested for its properties like functional groups (FTIR), color, thermal behavior (TGA and DSC), and rheology in the form of both steady- and dynamic-shear rheology. Xanthan gum was produced in the range 5.60–7.77 g L⁻¹ by the date-based substrates with Barhi (7.77 g L⁻¹) and Saqai (7.58 g L⁻¹) surpassing those of the glucose (6.68 g L⁻¹) and sucrose (6.23 g L⁻¹) controls. FTIR spectra of date-derived gums were almost identical to that of the commercial standard, indicating that their functional groups and the primary structure were very similar. In addition, the date-derived powders were darker and yellower (L* 61.09, 71.00; whiteness index 54.92, 63.34) than the commercial gum (L* 84.71; whiteness index 78.19). This is likely attributed to the presence of residue date pigmentation and products of Maillard and caramelization. Thermogravimetric analyses revealed that the breakdown of materials occurred in two stages, of which the char residue of the date-derived gums was much higher for those degraded at 500 °C (48.93, 54.05%) versus that of the commercial reference (33.49%), which is to be interpreted as a better ability of the former to resist thermal degradation. All solutions acted as pseudoplastic, shear-thinning liquids (flow behavior index n < 1); the consistency coefficient (K) rose with concentration and fell with temperature. The activation energy varied between 9.98 kJ mol⁻¹ (commercial) and 29.39 kJ mol⁻¹ (Saqai). Overall, low-quality Saudi dates can be considered a technically and economically viable, sustainable, and low-cost carbon substrate suitable for upcycling to produce xanthan gum, which is safe for use as a food additive. Full article

Waste polystyrene is a burden for the economy, especially when it spreads in environment due to incorrect waste management. In addition, there are toxic pollutants which should not end up in the natural environment. A good way to tackle these problems is to consider recycling polystyrene, through chemical transformation, into an adsorbent for pollutants. This study considers waste polystyrene (PS) and the materials synthetized from it as adsorbents for removal of the pollutant phenol. Dichloroethane polystyrene (DCEPS) and tetrachloromethane polystyrene (TCMPS) were synthesized in the laboratory by crosslinking polystyrene with dichloroethane and tetrachloromethane, using a Friedel–Crafts reaction. The materials were characterized by FTIR to observe the structural modifications induced by crosslinking. Then, the materials were compared for their adsorption capacity at 300 K. The experimental data proved that, for an initial concentration of phenol in water of 517 mg/L, the adsorption capacity is moderate and increases in the following order: PS (13.4 mg phenol/g) < TCMPS (15.7 mg phenol/g) < DCEPS (19.1 mg phenol/g). The adsorption isotherms at 300 K were determined for a large range of concentrations, and the parameters of Freundlich and Langmuir models were calculated, concluding that the Langmuir model fits better. The kinetics were studied and are represented by a pseudo-first order equation, confirmed by high coefficients of determination for all three materials. The adsorption of phenol from an industrial wastewater flux was performed in continuous flow over a laboratory column. PS and DCEPS were tested, with good results. For example, 1.595 L water containing 22 mg phenol/L was adsorbed on 3.76 g DCEPS; the bed capacity in equilibrium with the wastewater is 10 mg/g adsorbent, the removal efficiency was 95% for a treated volume of 1.595 mL, the breakthrough time was 240 min, and the exhaustion time was 270 min. The novelty of the work consists in demonstrating the possibility of applying polystyrene-based materials as adsorbents for the treatment of phenolic wastewater proceeding from oil refineries. Full article

Nanomaterials (NMs) have shown broad application potential in wastewater deep treatment, but the actual application is constrained by some issues such as nanoparticle (NP) aggregation and poor recyclability. Different from previous comprehensive reviews, this article systematically synthesizes data from over 100 peer-reviewed studies (2012 to 2026) to review the preparation methods, purification mechanisms, and removal efficiencies for various pollutants, and the technical and economic feasibility of NMs, with an emphasis on carrier-assisted immobilization and NM–microbial aggregate interactions. To start with, the methods of preparation were roughly distinguished into two categories which were “top-down” and “bottom-up” methods. The advantages, disadvantages, and utilities of the physical, chemical, and eco-friendly methods of biosynthesis were investigated while paying particular attention to the function of the loading technique in preventing NP aggregation and improving recyclability. By using the technique of loading in the carrier, the growth of NPs could be restricted up to 2–50 nm. Secondly, seven basic mechanisms that underlie the process of removing pollutants by using NPs were explained: adsorption, catalytic degradation, ion exchange, surface complexation, antibacterial action, redox transformation, and waste recycling. Particular focus was placed on understanding the interactions between NMs, microbial aggregates, and extracellular polymeric substances in wastewater treatment systems. Extracellular polymeric substances (EPS) could capture >90% NMs and mitigate their toxicity. Once again, the removal efficiency and main influencing factors associated with different types of NMs, for the treatment of heavy metals, dyes, antibiotics, and pathogenic microorganisms were summarized. Removal efficiencies of the pollutants ranged from 70% to over 99%, but these values were strongly influenced by pH and matrix and often decreased substantially in real wastewater. The existing literature was used to classify the experimental substrates (single-solute systems, multi-solute synthetic systems, municipal wastewater, industrial wastewater, secondary effluent). The performance of NMs in different categories was compared, revealing the huge performance gap between ideal laboratory conditions and practical applications. Lastly, the economic viability of the methods based on the use of NMs for purifying water was assessed taking into consideration various factors such as raw materials’ prices, energy costs of the process of making materials, recyclability of the materials, and the possibility of introducing the use of NMs on a larger scale. Unlike existing reviews, this article aims to provide a quantitative mechanistic framework bridging the rational design, safe application, and engineering promotion of NMs in deep wastewater treatment. Full article

This work reports the development of sustainable composites based on waste polystyrene (WPS) reinforced with natural calcium carbonate (CaCO₃), aiming at both plastic waste valorization and performance enhancement. The composites were fabricated via a solvent casting approach using recycled polystyrene cutlery and varying CaCO₃ loadings. Structural analyses performed by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and photoluminescence (PL) spectroscopy confirmed the effective incorporation of calcite within the polymer matrix, as evidenced by characteristic peak shifts and intensity variations indicative of interfacial interactions. PL spectra exhibited two emission bands centered around 365 and 400 nm for all samples, with enhanced emission intensity at low filler contents (2 and 6 wt%), followed by pronounced quenching at 10 wt%, highlighting a concentration-dependent interaction and uniform filler dispersion at lower loadings. Thermal analyses (DSC, TGA, and DTA) demonstrated a systematic improvement in thermal stability upon CaCO₃ addition, with decomposition temperatures increasing up to 432 °C compared to 429 °C for neat WPS, attributed to the barrier effect of the inorganic filler and restricted polymer chain mobility. Overall, these results demonstrate that natural calcite is an efficient, low-cost, and locally available reinforcing agent for recycled polystyrene, providing a viable and scalable strategy for the upcycling of plastic waste into value-added, thermally stable composite materials. Full article

Phosphogypsum (PG) governance is a persistent challenge in industrial solid waste management, particularly in regions where large-scale stockpiling, uneven resource-utilization capacity, and policy implementation pressures coexist. Existing studies have paid considerable attention to regulatory instruments and recycling technologies, but less is known about how governments, waste-generating enterprises, and waste-utilizing enterprises adjust their strategies under bounded rationality. This study develops a tripartite evolutionary game model incorporating prospect theory. The technology–organization–environment (TOE) perspective is used as a parameter-identification lens to capture three external conditions: policy incentive intensity, enterprise governance input, and resource-utilization technology maturity. Based on case-informed parameter calibration from Guizhou and related policy-industrial evidence, numerical simulations are conducted to examine evolutionary paths, equilibrium conditions, and parameter sensitivity. The results show that PG governance may evolve from systemic inaction to policy-driven transformation and then to market-oriented sustainability. Technological maturity plays a threshold role, while excessive loss aversion can destabilize cooperative evolution. The interaction analysis further indicates that policy incentives are effective only when they are aligned with enterprise treatment behavior and viable market-entry conditions. These findings suggest that PG governance should move beyond short-term administrative intervention toward staged policy support, technical standardization, and market cultivation. Full article

Aflatoxin B1 (AFB1) contamination of feed used in poultry farming is an important issue in food safety since it compromises animal productivity and leads to the transfer of toxic waste to the food chain. In this sense, as an alternative to conventional mineral adsorbents, in the present study, two sustainable and low-cost biochars were obtained from agro-industrial waste of orange peel (B-OP) and guava leaves (B-GL) to evaluate their efficiency in the removal of AFB1 in an in vitro avian model. Biochars were obtained from pyrolysis and characterized in terms of particle size, surface area, morphology, surface charge, surface chemistry, and pore size. Furthermore, their adsorption capacity was evaluated in an avian in vitro model. The results showed that B-OP had a smaller particle size (55.30 µm), a larger specific surface area (31.50 m²/g), and a smaller pore size (2.38 nm) than B-GL (82.88 µm, 9.74 m²/g, and 6.24 nm). Furthermore, the biochars presented different morphologies, FTIR spectra, and zeta potentials. In the avian in vitro model, the feed matrix reduced the effectiveness of AFB1 removal compared to the in vitro model using only buffer solutions. However, B-OP (27.4%) significantly outperformed B-GL (22.7%) in the intestinal segment. The valorization of these agro-industrial wastes into biochar represents an economical and sustainable strategy for removing AFB1 and strengthening food security. Full article

In this research, the catalytic pyrolysis properties, kinetics, thermodynamic characteristics, and composition of the vapor evolved from the thermal decomposition of copper-incorporated nylon fishing net (CuFN) waste were investigated. The analysis was performed on CuFN composed mainly of nylon and copper (3 wt.%) as an anti-corrosion element. A comparative catalytic study was conducted using two types of zeolite catalysts, ZSM-5 (CuFNz) and Y-type (CuFNy). Reaction complexity in the presence of both catalysts was investigated through linear and nonlinear kinetic approaches, along with estimation of the relevant thermodynamic parameters. In addition, a well-trained artificial neural network was used to predict the catalytic thermal decomposition properties of both batches under untested heating conditions. Thermogravimetric results indicated that the catalyst type moderately influenced the decomposition profiles, with CuFNz achieving complete decomposition at 495 °C (44 wt.%), compared to 475 °C (52 wt.%) for CuFNy. Also, the type of catalyst did not affect the functional groups in TG-FTIR, which showed two main peaks at 1712 cm⁻¹ (Carbonyl group) and 2933 cm⁻¹ (C-H stretching band), but the alkyl C-H band was dominant in the case of CuFNy. Meanwhile, gas-chromatography–mass-spectrometry results indicated that caprolactam (88.21%) was a major GC compound in the CuFNz sample and 5-Cyano-1-pentene (70.43%) was dominant in the vapor of the CuFNy sample. However, the presence of the catalyst increases the complexity of the reaction, reflected by higher pyrolytic activation energies of 244.8 kJ/mol (CuFNz) and 296.3 kJ/mol (CuFNy). Moreover, the mysterious catalytic thermal decomposition of CuFN was fully recognized by the optimized ANN algorithm with R = 1. The study demonstrates that catalytic pyrolysis can convert CuFN into valuable products, including caprolactam using a ZSM-5 catalyst and 5-Cyano-1-pentene using a Y-type catalyst, potentially leading to significant environmental and economic benefits. Full article

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

Hierarchical retail forecasting requires predictions that are both accurate and coherent across multiple planning levels, from total demand to individual product–store series. Because these forecasts guide inventory, replenishment, storage, and distribution decisions, improving their coherence and reliability can support more efficient resource use, reduce avoidable overstock and product waste, and limit the need for emergency logistics. This study investigates how global deep-learning architectures interact with post hoc reconciliation in point and probabilistic forecasting. Using an M5-derived hierarchical and grouped structure comprising 42,840 series, we compare three MLP-oriented models, MLP, N-BEATS, and N-HiTS, with five transformer-based models, Transformer, Temporal Fusion Transformer, Informer, PatchTST, and Autoformer. All models are evaluated under a common 28-day forecasting horizon, temporal partition, Optuna-based tuning protocol, and three complete seeded runs. Coherence is imposed using Bottom-Up reconciliation and four MinTrace variants, while probabilistic forecasts are generated through residual-block bootstrap reconciliation. Point and probabilistic performance are assessed level-wise and globally using MASE and scaled CRPS, respectively. The results show that the strongest transformer-based combination outperforms the strongest MLP-based combination at every hierarchy level. PatchTST combined with MinTrace-WLS-struct is particularly effective at aggregate and intermediate levels, achieving a Total-level MASE of 0.537 and sCRPS of 0.037. At the Product–Store level, Bottom-Up reconciliation becomes preferable, with the Transformer attaining the lowest MASE of 1.367 and sCRPS of 0.912. Because granular series dominate the hierarchy-wide average, the lowest overall MASE is obtained by TFT with Bottom-Up reconciliation (1.428), whereas the lowest overall sCRPS is shared by the Transformer and Informer with Bottom-Up reconciliation (0.813). These findings demonstrate that neither the forecasting architecture nor the reconciliation method should be selected independently of hierarchy depth and forecasting objective. Strategic and tactical levels benefit primarily from PatchTST with MinTrace reconciliation, whereas highly granular operational forecasting favors Bottom-Up reconciliation with transformer-based models. From a sustainability perspective, this level-aware framework provides a basis for aligning forecasting decisions with resource efficiency, waste reduction, service reliability, and greater resilience across the retail supply chain. Full article

Triazole fungicides (TFs) are widely used in cereal production due to their potent fungicidal activity and broad-spectrum efficacy. Nonetheless, residues of TFs in food products may pose risks to food safety and human health. Therefore, the development of efficient and environmentally friendly sample preparation methods is paramount for the reliable determination of TFs. Herein, a novel green solvent-based dispersive liquid–liquid microextraction method coupled with high-performance liquid chromatography (DLLME-HPLC) was developed for the determination of TFs in cereal samples. The prepared magnetic deep eutectic solvents (MDESs), composed of nonanoic acid and ferric hydroxide, served as green, magnetically responsive extraction solvents, enabling rapid magnetic separation without centrifugation. Four bio-based solvents (BBSs) were investigated as green dispersive solvents to facilitate the dispersion of MDESs and replace conventional toxic organic dispersants, thereby further enhancing the environmental sustainability of the extraction procedure. Owing to the combined effects of hydrophobic interactions, hydrogen-bonding networks, and magnetic responsiveness, the proposed method achieved efficient extraction and rapid phase separation while minimizing solvent consumption and operational complexity. The greenness of the method was evaluated using multiple green analytical chemistry metrics, confirming its low environmental impact, reduced waste generation, and improved operational safety compared with conventional DLLME procedures. Under optimized conditions, the method was successfully applied to determine TFs in rice, wheat, corn, buckwheat, and oat samples, achieving recoveries ranging from 75.0% to 101.9% and relative standard deviations of 1.6–4.8%. The developed DLLME method provides a rapid, sensitive, and environmentally friendly strategy for cereal pesticide residue analysis and expands the application of MDESs and BBSs in green sample preparation. Full article

Poly(methyl methacrylate) (PMMA) is one of the most widely used polymeric biomaterials in prosthodontics and digital dentistry because of their clinical reliability and compatibility with computer-aided design/computer-aided manufacturing (CAD/CAM). Its widespread use raises questions regarding material consumption, manufacturing waste, recyclability, and circularity. A critical narrative review supported by a structured literature search was conducted. PubMed, Scilit, OpenAlex, and ScienceDirect were searched for English-language literature published from January 2000 to June 2026. Targeted Google Scholar searches, cross-referencing, standards, and official technical sources supplemented the search. Evidence was organized according to its directness to dental PMMA and synthesized thematically. Prepolymerized CAD/CAM PMMA provides consistent material quality and generally improved mechanical performance compared with conventionally processed PMMA; however, subtractive manufacturing generates disc remnants, milling particles, and polishing residues. Mechanical recycling and depolymerization demonstrate technical recovery potential, although evidence specific to heterogeneous dental waste streams, environmental performance, and clinical-grade reuse remains limited. Technical recyclability should not be automatically equated with a viable circular economy or a net environmental benefit. Future research should quantify dental PMMA waste, establish effective collection and recovery pathways, and integrate life-cycle assessments with clinical performance and safety standards. Full article

Refuse collection vehicles are essential for urban sanitation. Adverse conditions, including damaged, displaced, or absent maintenance hole covers on roadways, can result in safety incidents—such as equipment jamming or overturning—during operations, consequently impacting the continuity and safety of cleaning activities. To facilitate real-time, precise identification of maintenance hole cover conditions during cleaning operations, this study proposes a detection method using an enhanced YOLO26 model. Through the development of the YOLO26-ABF detection model, which integrates multiscale feature fusion and multidimensional data augmentation techniques, we attained precise identification of five maintenance hole cover conditions—“good,” “broken,” “circle,” “loose,” and “uncovered”—resulting in a moderate rise in parameter count and computational demand. The experimental findings indicate that this method achieves substantial improvements over the baseline model on a custom dataset. It can precisely identify the condition of maintenance hole covers, providing reliable status awareness for waste collection vehicles and ensuring the safe and stable execution of cleaning activities. Full article

Sesame (Sesamum indicum L.) cv. BRS Anahí is a promising crop for agricultural diversification in the Brazilian semi-arid region, although saline irrigation can limit its development and productivity. The objective of this study was to evaluate the physiological and productive responses of sesame irrigated with brackish water under different fertilization treatments. The experiment was conducted in a greenhouse at the Federal University of Ceará, using a completely randomized design in a 4 × 2 factorial scheme, with four replications. These corresponded to four fertilization treatments (F1: HomeBiogas liquid biofertilizer from CAGECE; F2: HomeBiogas from food waste; F3: shrimp biofertilizer; and F4: mineral fertilization—NPK) and two irrigation water salinity levels (0.8 and 3.0 dS m⁻¹). Irrigation with 3.0 dS m⁻¹ significantly reduced the analyzed variables; however, the intensity of these effects varied according to the fertilization treatment. Treatment F1 promoted greater physiological activity under saline conditions, partially mitigating saline stress. At low salinity, treatments F1 and F3 showed productivity performance similar to F4, while at high salinity, F3 was less effective. The results highlight the potential of the selected biofertilizers to improve sesame performance under saline irrigation. Full article

Rainfall-induced seepage instability is a major concern for internal waste dump slopes in cold-region open-pit coal mines, where slope performance is influenced by groundwater conditions, moisture state, and seasonal temperature variations. This study investigates the internal waste dump slope of the Chaoyang open-pit coal mine and evaluates its seepage and stability responses under prescribed moisture and temperature states before and after rainfall, together with the effectiveness of drainage control. Soil specimens with moisture contents of 14%, 17.6% (natural), 23%, and 26% were tested at ambient temperature, −5 °C, and −15 °C by uniaxial compression and direct shear tests. The mechanical parameters measured under the prescribed moisture and temperature states were assigned to a GTS NX seepage–stability model. Twenty-four parametric cases, comprising four moisture contents, three temperature states, and pre- and post-rainfall conditions, were evaluated using the strength-reduction method, and an HDPE perforated drainage scheme was subsequently assessed. Under the ambient-temperature parameter state, increasing specimen moisture content from 14% to 26% reduced the pre-rainfall factor of safety from 1.41 to 1.18 and the post-rainfall value from 1.38 to 1.17. Parameter sets obtained from low-temperature-conditioned specimens produced higher calculated factors of safety; however, these cases represent prescribed mechanical states rather than the actual winter condition of the full-scale slope. Under the idealized drainage boundary, the pre- and post-rainfall factors of safety increased from 1.22 and 1.18 to 1.40 and 1.39, respectively. The results demonstrate the relative effects of laboratory-derived mechanical parameters, rainfall-induced seepage, and idealized drainage under the prescribed scenarios. Full article