Search Results (334)

Wastewater treatment plants (WWTPs) are key nodes in the environmental dissemination of antimicrobial resistance (AMR), although their net role as sources or barriers of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARG) under full-scale conditions remains insufficiently understood. This study evaluated the occurrence and dynamics of ARB and ARG in a full-scale urban WWTP and its receiving river over a two-year monitoring campaign. Samples were collected from the WWTP influent and effluent, and from river water upstream and downstream of the discharge point, enabling an integrated assessment of treatment performance and potential environmental dissemination. Wastewater treatment markedly reduced AMR indicators, with ARG concentrations decreasing by at least 90% from influent to effluent. No consistent increase in ARB or ARG levels was observed downstream compared with upstream, indicating no measurable dissemination attributable to the WWTP discharge. Multidrug-resistant bacteria were prevalent across all compartments, highlighting widespread background resistance in the urban water cycle. Temporal analysis revealed higher ARG abundances in 2021 and 2022 than 2020, consistent with possible changes in antibiotic consumption during the COVID-19 pandemic. Overall, the investigated WWTP did not act as a net AMR source, highlighting its potential role as a control point and the value of integrated monitoring for assessing AMR dynamics and environmental risk. Full article

The textile dyeing and printing (TDP) industry in Zhejiang Province faces significant pressure to reduce conventional pollutants and carbon emissions. Dyeing and finishing (DF) are key links in energy consumption and pollutant emissions in the TDP industry. However, the trade-offs between pollution reduction and carbon mitigation remain poorly understood. This study evaluated five synergistic technology pathways using a hybrid life cycle assessment (LCA) approach. The pathways included low-carbon energy substitution, waste heat recovery, advanced wastewater treatment, intelligent process control, and integrated application. The IMPACT 2002+ method was used to quantify 7 environmental impact categories. The results showed that no single technology pathway achieved optimal performance across all categories. Scenario 3 (advanced wastewater treatment) reduced eutrophication potential by 54.97% but increased global warming potential by 18.00%. Scenario 5 (integrated application) achieved the best overall performance. It reduced non-renewable energy consumption by 30.90%, global warming potential by 32.69%, acidification potential by 26.08%, and eutrophication potential by 40.00%. The synergy coefficient of Scenario 5 was 1.08, indicating strong pollution-reduction synergy. Extrapolation to the provincial level showed reductions of 40% for COD, 39.76% for ammonia nitrogen, 40.78% for SO₂, 10.67% for NOx, and 14% for VOCs. These findings demonstrate that systematic technology integration can resolve the trade-offs inherent in individual pollution control measures under the conditions evaluated in this Zhejiang-based case study. This study provides scientific guidance for technology selection and policy formulation in the DF industry. Full article

Microplastics have emerged as a persistent and prevalent threat to human health and the marine environment due to their widespread use and poor management, including low recycling rates, inadequate waste management, improper disposal, and inadequate control of plastic leakage into the environment. Plastic pollution is transported to the marine ecosystem through both ocean-based and land-based pathways and can be fragmented into microplastics (<5 mm) and nanoplastics (<1 µm). The study explains the sources, distribution, mechanisms of degradation, and transport pathways to the marine environment. Land-based activities are recognized as the dominant source, causing approximately 70–80% of marine plastic pollution. Domestic greywater is highlighted as a significant and common source of microplastics due to the release of microbeads and synthetic fibers from different sources, such as laundry, washbasins, and personal care products (PCPs). Similarly, greywater release from maritime vessels and cruise ships significantly contributes to marine microplastic pollution. The study discusses the biotic and abiotic degradation mechanisms. The health and environmental effects of microplastics are measured across different trophic levels. Ingestion and bioaccumulation of microplastics can cause physiological and reproductive disturbances. Human exposure through seafood consumption and inhalation may result in skin infections, cardiovascular complications, gastrointestinal disorders, and respiratory problems. The mitigation and control measures include improvements in wastewater treatment, public awareness, policy regulations, and biodegradable alternatives to support sustainable protection of the marine environment. Full article

The Yellow River Basin is an important ecological security barrier and agricultural production area in China. Using panel data for nine sprovincial-level regions from 2010 to 2022, this study constructs a multidimensional development index of rural industrial integration and examines its association with regional environmental pollution. Regional pollution pressure is measured from total wastewater discharge, sulfur dioxide emissions, and general industrial solid-waste generation; the measure therefore captures broad regional pollution linked to agricultural and related industrial chains rather than agricultural non-point-source pollution alone. Two-way fixed-effects estimates show that higher integration scores are significantly associated with lower pollution levels. This association is statistically evident in the upper reaches, whereas the middle- and lower-reach estimates are not statistically significant and are interpreted as exploratory because each subsample contains only two provinces. Exploratory channel regressions suggest that agricultural technological progress, rural labor mobility, and agricultural industrial scale may help explain the observed association, but the regressions do not establish causal mediation. The findings indicate potential synergies between rural industrial integration and environmental governance, while also requiring caution regarding causal interpretation, composite-index boundaries, and small-sample regional comparisons. Full article

Improving the low-carbon operational performance of wastewater treatment facilities (WWTFs) is important for coordinated pollution reduction and carbon mitigation in China. The interprovincial carbon emission efficiency (CEE) of WWTFs reflects both the low-carbon performance of regional wastewater governance systems and cross-regional linkages shaped by technology diffusion, governance experience, and spatial adjacency. Using operational data from WWTFs in 30 provincial-level regions of China from 2010 to 2023, this study first measures provincial CEE with a super-efficiency slack-based measure (SBM) model incorporating undesirable outputs. It then integrates a modified gravity model, social network analysis, and the quadratic assignment procedure (QAP) to examine the evolution, structure, and formation mechanisms of the association network. The results show that the CEE of provincial WWTFs remained below the efficiency frontier overall, with periodic fluctuations and persistent structural differences. The model-inferred association network first contracted and then expanded, showing dense connections in eastern and central China and sparse connections in the northwest. Its node structure evolved from a dispersed multicore pattern to hub-centered concentration and then back toward a multicore configuration, while inter-block linkages showed a hierarchical transmission structure involving core spillovers, absorptive transmission, and peripheral reception. The QAP results indicate that interprovincial adjacency is the most stable correlate of network formation, whereas differences in technological innovation and capacity utilization show only stage-specific associations. These findings suggest that the CEE of WWTFs is not only a local performance outcome, but also a relational outcome shaped by regional linkages and structural positions. Therefore, low-carbon governance of WWTFs should move beyond single-region efficiency improvement and place greater emphasis on cross-regional collaboration, role-specific policy design, and leadership by core regions. Full article

The detection of organic carbon in wastewater is essential for process monitoring and regulatory assessment. Yet conventional chemical oxygen demand (COD) and total organic carbon (TOC) methods remain reagent-dependent, slow, and unsuitable for inline operation. Photoelectrochemical (PEC) sensing based on TiO₂ offers a reagent-free alternative, but its response to wastewater-relevant dissolved organic matter (DOM) and real effluent matrices is still poorly understood. In this study, a TiO₂-based PEC system was systematically evaluated using four representative model compounds—glucose, potassium hydrogen phthalate, L-tryptophan, and urea—covering major fractions typically present in municipal wastewater. For the first time, representative wastewater-associated organic compound classes, conductivity effects, and the transferability of the PEC response to real wastewater effluent were systematically investigated. The photocurrent response showed distinct, highly linear concentration–signal relationships for each substance, suggesting a dominant contribution of surface-associated electronic effects. Conductivity variations across a relevant range had no measurable influence on sensitivity or photocurrent magnitude, indicating that the PEC response is not governed by bulk ionic transport but primarily is an interfacial process at the site of TiO₂. When applied to real wastewater effluent, the sensor exhibited an excellent linear correlation with dilution level (R² = 0.9954), demonstrating a linear response within a defined matrix and an LOD of 1.12 mg L⁻¹ COD. For the investigated model compounds, LOD values ranged from 1.06 to 3.00 mg L⁻¹ COD, while a linear response was maintained up to approximately 80–100 mg L⁻¹ COD. These findings establish TiO₂-based PEC sensing as a promising platform for the reagent-free, online monitoring of organic loads in wastewater treatment. Full article

This study presents a screening-level conceptual, stoichiometric, and scenario assessment of a pathway linking sulfur dioxide (SO₂) capture from coal-fired flue gas to sulfuric acid production and the downstream reaction of sulfuric acid with pretreated scrap aluminum. A regenerable sodium sulfite (Wellman–Lord) capture route, followed by gas polishing and drying, catalytic SO₂ oxidation, controlled SO₃ absorption, acid conditioning, and an Al–H₂SO₄ reactor, is used as the reference configuration. The sulfur balance distinguishes sulfur in coal, ash retention, gaseous SO_x, SO₃/acid mist, absorber inlet and stack slip, captured sulfur, regenerated sulfur, and sulfate purge. Under the central assumptions, 1 t of sulfur in coal yields 0.849 t of recovered sulfur equivalent, 2.599 t of H₂SO₄, 0.477 t of aluminum feed, 2.419 t of anhydrous-equivalent Al₂(SO₄)₃, 4.240 t of commercial aluminum sulfate on a 17 wt% Al₂O₃ basis, and 42.4 kg of H₂ at 80% aluminum conversion. The upstream base-energy screen is 3.3–7.2 GJth and 0.18–0.45 MWhe per tonne of sulfur in coal. Diluting the acid to the selected 0.5–1.0 M aluminum-reaction window and subsequently producing a 17 wt% Al₂O₃ product creates a minimum water-removal load of 21.6–47.6 t and a latent-heat floor of approximately 49–108 GJth/t S. Retail prices are replaced by 2024 customs unit values, and internal-acid-production and sulfuric-acid-opportunity-cost boundaries are evaluated separately. In the central opportunity-cost case, the H₂ value must reach approximately 6.9 USD/kg merely to balance material values before CAPEX, OPEX, energy, purification, transport, and environmental-compliance costs. The Afşin–Elbistan A case is treated as a full-design-throughput illustration based on an historical 18 Mt/y coal requirement, not as a measured current operating average; coal sulfur is tested over 1.0–2.5 wt%. The aluminum step is restricted to cooled and diluted 0.5–1.0 M H₂SO₄ at 40–60 °C, and direct H₂ production from 96 to 98 wt% acid is not assumed. Plant-specific capacity factor, time-matched coal assays, flue-gas flow, oxygen-corrected stack data, reaction kinetics, gas purity, and product quality remain to be verified. The integrated sustainability screening indicates conditional circular-economy potential rather than a demonstrated sustainability advantage: sulfur recovery must be weighed against energy and water demand, sulfate purge and wastewater, diversion of recyclable aluminum from remelting, hydrogen purification, and market-scale product offtake. The pathway therefore remains a research hypothesis requiring experimental validation, process simulation, techno-economic assessment, comparative life-cycle assessment, safety analysis, and market verification. Full article

Potentially toxic element (PTE) contamination of food systems has emerged as an important environmental and public health concern in many developing countries, including Uganda, owing to rapid urbanization, industrialization, mining activities, wastewater reuse, informal waste disposal, and expanding urban agriculture. This review synthesizes evidence from peer-reviewed and selected grey literature on the occurrence of cadmium (Cd), chromium (Cr), nickel (Ni), lead (Pb), and arsenic (As) in cereals, vegetables, tubers, livestock products, fish, fruits, and processed foods consumed in Uganda. A structured literature synthesis and screening-level dietary risk assessment using estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), carcinogenic risk (CR), and total carcinogenic risk (TCR) were conducted to identify contamination hotspots, priority exposure pathways, and potential public health implications. The available evidence revealed substantial spatial variability, with contamination consistently concentrated in mining-influenced agricultural areas, wastewater-irrigated farms, municipal dumpsites, industrial corridors, and urban food markets. Vegetables, cereals, livestock products, fish, and street-vended foods exhibited the greatest contamination burdens, while Pb and Cd were the PTEs most frequently reported exceeding WHO/FAO, Codex Alimentarius, and Ugandan food safety limits. Screening-level risk estimates indicated that Pb, Cd, and Cr contributed most to cumulative dietary exposure, with children consistently exhibiting higher EDI, THQ, HI, and TCR values than adults because of greater food intake relative to body weight. Although cumulative HI and TCR values exceeded recommended screening thresholds in several hotspot regions, these estimates should be interpreted as conservative screening-level indicators derived from heterogeneous published datasets rather than nationally representative measures of dietary exposure. Overall, the evidence indicates that PTE contamination in Ugandan food systems is predominantly hotspot-driven and highlights the need for targeted surveillance, standardized monitoring and reporting, improved pollution control, and strengthened food safety management to reduce chronic dietary exposure and protect public health. Full article

This study presents a comprehensive and integrated characterization of solid and liquid residues generated during industrial glass-cutting operations, highlighting the novelty of treating glass-cutting sludge and process wastewater as compositionally linked outputs of the same industrial comminution process. The research examined the morphology, elemental composition, and selected physicochemical properties of sludge and wastewater-derived particulates to assess material-recovery potential and provide a basis for further evaluation of water reuse. Samples were analyzed using particle morphology assessment, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS), Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR), dynamic light scattering (DLS), and pH measurements. The results showed that the solid fraction consisted predominantly of soda–lime–silica glass constituents, with oxygen, silicon, sodium, calcium, and magnesium as the main components, while potentially problematic contaminants remained at low levels. Although isolated particles enriched in Fe, Cu, Ni, Sn, La, or Ce were detected, their occurrence was limited and did not significantly affect the average particulate composition observed within the SEM-EDS dataset. This is particularly important for coated glass, where functional coatings contribute negligibly to the bulk glass matrix. From a material-recovery perspective, the sludge should be regarded as a promising glass-derived mineral residue requiring further route-specific qualification rather than as waste intended solely for disposal. However, this study does not demonstrate suitability for any specific reuse route, and additional validation is needed regarding compositional consistency, variability, moisture and organic content, leaching behavior, and route-specific acceptance criteria. For process wastewater, contamination was governed mainly by suspended glass-derived solids, indicating that solid–liquid separation is the key treatment step. However, the present dataset is insufficient to confirm the suitability of treated water for direct industrial recirculation, and the results should therefore be interpreted as indicating potential for further evaluation after appropriate clarification. This work establishes an empirical multi-scale characterization framework that links glass-cutting sludge and process wastewater as compositionally related outputs of the same comminution process, thereby supporting circular-economy strategies by jointly informing sludge valorization and water-clarification pathways. Overall, this work establishes a multiscale characterization framework for integrated residue management, jointly supporting sludge valorization and wastewater clarification assessment within a circular-economy perspective. Full article

Smart wastewater treatment plants are increasingly essential for improving the resilience of water infrastructure under climate-related disturbances and operational variability. Despite significant advances in sensing technologies and data analytics, full-scale automation remains limited. One of the primary barriers is that monitoring strategies remain primarily designed for regulatory compliance, prioritizing absolute analytical accuracy often at relatively high cost, thereby limiting their widespread use for real-time decision-making. This perspective proposes a shift from compliance-oriented monitoring to purpose-oriented monitoring, in which monitoring systems are designed according to the operational purpose they support. To support this shift, we introduce a framework recognizing that different operational applications require different levels of measurement performance. Accordingly, compliance assessment, early warning, process troubleshooting, real-time control, and asset management each require different combinations of accuracy, precision, temporal resolution, and tolerance to measurement error. Within this framework, high-frequency multi-source data streams from conventional, spectral, visual, and virtual sensors can provide complementary information on process dynamics, effectively supporting operational decisions, even when individual measurements do not achieve laboratory-level analytical performance. When combined with hybrid models that integrate mechanistic and data-driven approaches, this purpose-oriented monitoring framework can enable predictive process management and accelerate the transition toward autonomous wastewater treatment systems. Full article

The growing urbanisation of India is a major contributor to the production of 72,368 million litres of wastewater daily. Unfortunately, not even 28 to 31% of the generated wastewater receives proper treatment before disposal, putting public health, water quality, and ecological conditions at risk. Traditional wastewater treatment technologies have been proven effective, but they cannot be applied in decentralised settings due to excessive initial investment costs, continuous power needs, and the need for expert supervision. Constructed wetlands (CWs) provide an efficient and environmentally friendly option for decentralised treatment, but these systems suffer from a gradual loss of effectiveness associated with the problem of media-clogging in traditional setups. This research investigates the functioning and efficiency of the Modified Towery Bio-rack Constructed Wetland (MTBRCW) technology designed specifically to mitigate media-clogging issues. The MTBRCW is tested on the basis of its performance under continuous operating conditions for thirteen months (January 2025 to January 2026), as well as on the effectiveness of the treatment at eight different hydraulic retention times (days 1 to 8). A pilot-scale MTBRCW system was monitored through two periodic sampling events (S1 and S2) conducted during each month of operation. The pilot-scale MTBRCW unit is made up of an inlet storage tank (volume 0.099 m³) followed by two wetland containers (volume 0.034 m³ each) planted with Typha angustifolia and Chrysopogon zizanioides (vetiver grass). In continuous testing mode, influent–effluent paired samples are collected for eight days at each HRT (totalling eighty samples), and samples are analysed according to APHA Standard Methods for pH, BOD, COD, TN, and TP. In continuous testing mode, the MTBRCW exhibits high removal efficiencies at the levels of 89.8% for BOD, 87.5% for COD, 78.2% for TN, and 74.4% for TP. The BOD/COD of the effluent was within the prescribed CPCB discharge limits for all thirteen months of the study, and the TN levels were adhered to in 12 out of 13 months, with one non-compliance event recorded only in July 2025 (effluent TN = 10.8 mg/L), coinciding with the peak monsoon hydraulic loading rate of 0.28 m³/m²·d. TP remained within CPCB limits in all thirteen months. In batch testing mode, removal efficiencies are 94.9% for BOD and 89.9% for COD by day 8. In addition, there were no indications of clogging or any reduction in hydraulic performance during the entire period of the tests through the use of visual inspections and measurement of the outlet flows, but this can only be seen as an observation in a field operation, and not as proof of the hydraulic performance of the system, since no tracer test or measurement of hydraulic conductivity was conducted. Full article

Reliable accounting information is increasingly important for fiscal transparency and the assessment of sustainability-related public-finance issues. This study examines how harmonised Environmental Protection Expenditure Accounts (EPEAss) can support comparative analysis and preliminary risk screening in the EU public sector. Using EurostatEPEAsA, GDP and population data, the study applies a descriptive comparative design to analyse EU-level trends for 2018–2022, 2022 public-sector expenditure per capita across all 27 Member States, institutional-sector composition and CEPA-based functional allocation. Nominal EU environmental protection expenditure increased by 17.5% between 2018 and 2022, while its share of GDP remained close to 1.9%. Public-sector expenditure per capita varied substantially across Member States, with a median of EUR 314 and a coefficient of variation of 72.8%. Wastewater and waste management accounted for 69.7% of EU environmental protection investment. These patterns should be interpreted in light of accounting scope, institutional arrangements and infrastructure needs rather than as measures of environmental performance or fiscal risk. EPEA can enhance comparability, auditability and functional interpretation, but direct risk assessment requires additional evidence on liabilities, debt, asset condition, regulatory obligations and environmental outcomes. Full article

Slaughterhouse wastewater introduces potentially toxic elements into aquatic ecosystems, yet bioaccumulation patterns in commercial fish species and associated human health risks remain underexplored in West Africa. This study quantified zinc (Zn), lead (Pb), iron (Fe), magnesium (Mg), chromium (Cr), and cadmium (Cd) in three ecologically distinct fish species—Oreochromis niloticus (Nile tilapia), Clarias gariepinus (African sharptooth catfish), and Mugil cephalus (Flathead grey mullet)—from two slaughterhouse-impacted rivers (Transamadi and Mgbuosimini) and a control site (Iwofe) in Rivers State, Nigeria. Metal concentrations were measured using atomic absorption spectrophotometry. Two-way ANOVA assessed species and location effects. Principal component analysis (PCA) was performed, with Mg used as a potential geogenic tracer, as its loading pattern was independent of Pb and Cd and consistent with the natural background. A Water Quality Index (WQI) classified Mgboshimini and Iwofe as having poor water quality (WQI > 75), while Transamadi had medium quality. Health risks were evaluated using estimated daily intake (EDI), target hazard quotients (THQ), and hazard indices (HI) following USEPA guidelines. Metal levels varied significantly by species and location (p < 0.001). Flathead grey mullet from Mgbuosimini had the highest Pb (1.50 ± 0.05 mg/kg) and Cd (0.41 ± 0.02 mg/kg), exceeding EU maximum levels for fish muscle (Pb 0.30 mg/kg, Cd 0.05 mg/kg) by 500% and 800%, respectively. PCA explained 77.5% of the variance, with Pb and Cd clustering as anthropogenic sources, while Mg loaded independently. THQ for Pb approached unity in Flathead grey mullet (0.88), and THQ for Cd reached 0.97. HI exceeded 1.0 in all species from Mgbuosimini, peaking at 2.07 in Flathead grey mullet. Uncertainty analysis (using ±SD) gave a HI range of 1.89–2.25 for this species, all above the safety threshold. Carcinogenic risk for Flathead grey mullet (3.97 × 10⁻⁴) approached the upper acceptable limit. Slaughterhouse effluent appears to elevate Pb and Cd burdens in fish, with detritivorous Flathead grey mullet posing the highest health risk. Exceedance of safety thresholds and HI > 1.0 indicate potential non-carcinogenic and carcinogenic risks. We recommend improved wastewater treatment and species-specific consumption advisories. Full article

Corrosion of pipelines by flue gas desulfurization (FGD) wastewater compromises the normal operation of the desulfurization tower, and corrosion under high-chloride conditions in particular severely damages the tower’s internal structure. To further elucidate the corrosion mechanism at elevated Cl⁻ concentrations, the corrosion behavior of 20 steel exposed to high-chloride FGD wastewater at different Cl⁻ concentrations was investigated through weight-loss measurements, electrochemical tests, immersion corrosion experiments, composition analysis, and microscopic morphology characterization. The results revealed that higher Cl⁻ concentrations corresponded to lower corrosion rates: the corrosion rate reached 0.1964 mm/y in the absence of Cl⁻, but decreased to 0.1537 mm/y at a Cl⁻ concentration of 100,000 mg/L. XPS analysis showed that as the Cl⁻ concentration increased, the corrosion film gradually transformed from porous FeOOH into dense Fe₃O₄. Localized pitting analysis indicated a positive correlation between Cl⁻ concentration and pitting susceptibility. At Cl⁻ concentrations of 0 and 100,000 mg/L, the corrosion current density decreased from 32.44 μA/cm² to 6.43 μA/cm² after 72 h, decreasing by a factor of approximately 5.05. This behavior is attributed to the fact that Cl⁻ increases solution conductivity in high-chloride environments, thereby promoting the formation rate of the corrosion film. Additionally, high Cl⁻ levels reduce dissolved oxygen in the solution, causing the corrosion film to progressively react and form denser Fe₃O₄. Nevertheless, the high penetrability of Cl⁻ continues to aggravate pitting corrosion of 20 steel. Full article

This study evaluates the impact of long-term mining activities on stream surface waters in the Danube Basin in eastern Serbia. Seasonal variations in water chemistry were investigated during three hydrological periods to assess current contamination levels and temporal changes following recent environmental protection measures. The highest element concentrations were recorded during the autumn low-flow period. In contrast, the lowest concentrations occurred during the snowmelt season, indicating a strong influence of seasonal hydrological conditions on contaminant distribution. In streams located downstream of mining facilities, element concentrations were additionally controlled by anthropogenic inputs associated with mining activities. Elevated concentrations of SO₄²⁻ (1054 mg/L), Cu (393 µg/L), and Mn (2064 µg/L) were detected compared with background values characteristic of non-contaminated streams (e.g., SO₄²⁻~100 mg/L, Cu~20 µg/L, and Mn~20 µg/L). Recent environmental protection measures, including the neutralization of mining wastewater before discharge into rivers, have substantially reduced contamination levels. Compared with historical periods when untreated wastewater was directly discharged into river systems, concentrations of Fe, As, Cu, and Mn decreased by approximately 2650-, 900-, 740-, and 6-fold, respectively. In contrast, sulfate concentrations remained relatively unchanged, indicating persistent mining-related pollution and suggesting sulfate as a reliable indicator of contamination in similar mining environments. Overall, the results demonstrate partial recovery of the aquatic system and improved water quality over time; however, elevated concentrations of SO₄²⁻, Mn, and Cu indicate ongoing environmental impacts of mining activities and highlight the need for long-term environmental monitoring and management. Full article