Search Results (973)

TiO₂/activated carbon (TiO₂/AC) was coated on mesh using the dip-coating method employing polyvinyl pyrrolidone (PVP) as a copolymer via a simple mixing method. The obtained catalyst was used to treat real wastewater from a building discharge with a horizontal photoreactor with a continuous flow system. The synthesis of 20%wt TiO₂/AC-coated mesh was performed with a fixed TiO₂:AC ratio of 1:0.05 wt/wt, as confirmed by employing various characterization techniques, which resulted in a composite TiO₂/AC characterized by XRD, FE-SEM, and EDS, confirming the uniform distribution of TiO₂/AC nanoparticles coated on mesh substrates. The influence of vital parameters on the best conditions of the photoreactor design, including flow rate (8.0 L/min), light intensity position (5.0 cm), and the number of mesh layers (20 mesh layers), was systematically examined during photocatalytic oxidation. The treatment efficiency of domestic building wastewater was evaluated using a TiO₂/AC coated on mesh under visible light irradiation for 120 min. The recirculating batch photoreactor was operated at a continuous flow rate of 8.0 L/min, corresponding to a total treated wastewater volume of 960 L. In real wastewater treatment, the optimized TiO₂/AC-coated mesh exhibited the highest activity, achieving approximately 68% BOD removal and 65% COD removal. This study indicates that TiO₂/AC-coated mesh can be a good candidate for building wastewater treatment systems using photocatalytic activity under visible light irradiation. However, the TiO₂/AC coating exhibited limited reusability, with BOD degradation decreasing to 53% after three cycles. Future work must develop a more stable binder to improve its durability and reusability. Full article

Eutrophication remains a persistent water-quality problem in shallow lakes, where external inputs interact with internal loading and biogeochemical cycling. Although floating treatment wetlands (FTWs) are increasingly promoted as nature-based solutions for water remediation, their field-scale interpretation in hydrologically complex eutrophic lakes remains challenging. This study examined the spatial organization of water quality during the operation of a floating-island system in a eutrophic urban lake affected by polluted tributary inflow. The study was not designed to quantify isolated FTW removal efficiency, but to evaluate spatial water quality organization during FTW operation under real-use field conditions. Water quality was monitored over two growing seasons across six functionally defined zones, and spatial and temporal patterns were analyzed using descriptive statistics and linear mixed-effects models. The results showed parameter-specific spatial structuring rather than a uniform treatment response. The clearest inlet-lake contrasts were observed for electrical conductivity (EC), suspended matter (SM), and nitrate nitrogen (NO₃-N), whereas biochemical oxygen demand (BOD₅), ammonium nitrogen (NH₄-N), and total organic carbon (TOC) showed lower values at the inlet and higher values in downstream zones. Dissolved oxygen (DO), oxygen saturation (SO), chemical oxygen demand (COD), nitrite nitrogen (NO_2-N), and orthophosphate phosphorus (PO₄-P) showed moderate or non-robust zonal effects. These findings indicate that FTWs in shallow eutrophic lakes should be evaluated through functional zoning and parameter-specific interpretation rather than as isolated units with uniform removal responses. Full article

This study investigates the degradation and mineralization of sulfamethazine (SMT) by an electrochemically assisted Fe³⁺/persulfate (electro/Fe³⁺/PDS) process. Experiments were conducted in a single-compartment electrochemical cell equipped with a carbon felt anode and a stainless steel cathode under constant current conditions. Compared with PDS alone and Fe³⁺/PDS, the combined electro/Fe³⁺/PDS system exhibited a strong synergistic effect, achieving up to 89.4% SMT removal within 90 min at a current intensity of 1.6 A. The enhanced performance was attributed to electrochemical Fe²⁺ regeneration enabling continuous activation of persulfate and generation of sulfate radicals (SO₄^•−). Operational parameters significantly influenced process efficiency. Increasing current intensity accelerated SMT degradation but reduced mineralization efficiency due to parasitic reactions. Under optimized conditions (I = 3 A and [Fe³⁺] = 1 mM), SMT degradation reached 96.83% after 60 min, while the mineralization yield attained 72.05%. Excess iron promoted radical scavenging. Similarly, a PDS concentration of 5 mM was sufficient, with higher dosages leading to self-scavenging effects. Kinetic analysis followed a pseudo first order model, with apparent rate constants decreasing at higher SMT concentrations due to radical competition. Biodegradability assays revealed a substantial increase in the BOD₅/COD ratio from initially low values to 0.34 after 300 min of pretreatment, indicating improved suitability for biological post-treatment. Overall, the electro/Fe³⁺/PDS process represents an efficient pre-oxidation strategy for the removal of refractory antibiotics from aqueous media. Full article

Water scarcity and increasing environmental pressures have intensified the need for sustainable water management, including the reuse of treated wastewater. This study evaluated the continuous up-flow sand filter as a tertiary treatment process for secondary wastewater effluent. A pilot-scale filtration unit was installed downstream of the secondary treatment at Qaha Wastewater Treatment Plant (QWWTP), Egypt and operated at influent flow rates of 3.9–8.5 m³/h. Performance was assisted for removing turbidity, total suspended solids (TSS), biochemical oxygen demand (BOD₅), E. coli, total nitrogen (TN), and total phosphorus (TP), under three phases: baseline operation, variable influent quality produced by mixing secondary effluent with raw wastewater, and coagulant-assisted filtration using alum or ferric chloride. During baseline and variable influent conditions, the maximum removal efficiencies were 67.0%, 62.1% and 37.3% for turbidity, TSS and BOD₅, respectively. Alum improved the corresponding removals to 94.5%, 71.7% and 55.5%, while ferric chloride achieved 81.4%, 83.8%, and 87.5%, respectively. Overall, the results demonstrate that coagulant-assisted continuous up-flow sand filtration is a robust and practical tertiary treatment approach for upgrading secondary effluents to meet stringent wastewater reuse standards. Full article

This study explores the case of the Wuhan East Lake National Independent Innovation Demonstration Zone (East Lake High-Tech Zone), investigating an advanced-scale stormwater and sewage co-treatment system alongside a “low-position, differentiated, vacuum” sewage collection approach. These systems operate within the framework of the “five-builds-one-management” model, which covers sewage collection, treatment, sludge disposal, reclaimed water utilization, tailwater discharge, and operation and maintenance management. The proposed system was associated with measurable before–after improvements: the sewage collection rate increased by 17%, the influent BOD₅ concentration at the sewage treatment plant rose from approximately 92 mg/L to 112 mg/L (~+22%), and water level fluctuations in the tailwater receiving area were reduced by 75%. This planning framework offers a valuable reference for similar urban areas, though calibration based on local hydrological conditions, industrial structure, and population size is essential. Full article

In sustainability and environmental performance assessment, as in many other multidimensional policy contexts, Benefit of the Doubt (BoD) composite indicators are widely used to compare units across multiple dimensions. However, their interpretation remains limited when panel data are available. In these settings, observed changes over time may reflect two distinct sources: a unit may move closer to cumulative best practices, thereby generating a catch-up effect, or the best-practice frontier itself may evolve, generating a benchmark shift effect. The present paper proposes a dynamic decomposition framework that separates these two components. Building on the reference technology approach pioneered by Tulkens and Vanden Eeckaut, the BoD setting is adapted to include contemporaneous, sequential, and intertemporal frontiers. This yields three indices that satisfy an exact multiplicative decomposition at the unit level. The framework is fully non-parametric, producing unit-specific measures of catch-up alongside a cross-sectional summary measure of benchmark shift. The results of simulation experiments conducted under pure benchmark shift, pure catch-up, and mixed dynamics demonstrate the efficacy of the method in accurately recovering the underlying data-generating processes. As an empirical illustration, the framework is applied to renewable energy performance across European Union countries over the period 2015–2024, using Eurostat SHARES (Short assessment of renewable energy sources) data. The empirical results indicate an average annual benchmark expansion of approximately 3.3%, together with heterogeneous catch-up dynamics across country groups. Full article

Today, the reuse of treated wastewater is considered an important and strategic key driver of integrated and sustainable water and soil management in extremely arid desert regions, where significant constraints due to water scarcity, soil salinization, and the fragility of agricultural ecosystems within palm oases place a strain on all sustainable development policies. Through this study, we conducted a comprehensive evaluation of the performance of the treatment, as well as the constraints related to salinity and the implications for land management of the activated sludge wastewater treatment plant located in the Timimoun desert oasis in southern Algeria. Through monthly monitoring over a 12-month period, we conducted an analysis of physicochemical, nutritional, and microbiological parameters, as well as a seasonal analysis, in addition to calculating irrigation suitability indicators using first-order kinetic modeling of COD degradation. The results showed high reduction rates for COD (90%), BOD₅ (90.5%), and TSS (93.8%), confirming the resilience and effectiveness of biological treatment under very difficult and hostile climatic conditions. Furthermore, the ultraviolet disinfection process ensures microbiological quality that enables the reuse of treated water for agriculture. Despite this, the treated wastewater exhibited moderate salinity and sodicity levels, reflected by EC values ranging from 2.4 to 2.8 dS/m and an SAR value of 6.2, which remain important limiting factors for the long-term sustainability of wastewater reuse. Therefore, this study provides valuable scientific data for developing sound and sustainable water and land management policies in the harsh climate of Saharan oases. Full article

Freshwater shallow lakes are vulnerable to global warming, putting entire aquatic ecosystems at risk, but evidence from managed reservoirs remains limited despite the existence of long-term empirical data. Using data from 29 stations on Lake Tisza covering an 18-year period (2007–2024), this study quantifies warming rates, thermal stress patterns and trends in water quality in lacustrine, transitional and riverine zones. Lake areas warmed at a rate of 0.90 °C/decade (p < 0.001), faster than the river/transition areas and even than global averages in shallow lakes. Temperature-critical years now affect 90.4% of lake stations, compared with 59.6% in 2007–2012. A strong negative correlation between temperature and dissolved oxygen was observed along all systems (Spearman’s p; river: −0.83, transition: −0.65, lake: −0.53), indicating thermal-driven deoxygenation risk. At the same time, a water quality index (conductivity, pH, BOD₅, total nitrogen and phosphorus, total coliforms) showed an improvement (lake WQI: 63.7 to 74.3). Principal component analysis explained 85% of its variance, showing spatial gradients of eutrophication and fecal contamination, with lacustrine homogenization suggesting management interventions. Lake Tisza is warming faster than global shallow lake averages, with critical implications for the ecosystem’s function; nonetheless, the coexistence of thermal deterioration with improvements in its WQI reveals the effectiveness of the intermittent discharge system and the need for climate-adapted monitoring frameworks that incorporate thermal vulnerability into water quality assessment for regulated shallow lakes under climate change pressure. Full article

This study evaluates the performance of natural plant-derived coagulants as sustainable alternatives to conventional chemical coagulants in water treatment. Surface water samples were collected from the Meda Ela stream in Karadiyana, Sri Lanka, which is an urban water body impacted by leachate from the Karadiyana dumpsite, industrial discharges, and urban runoff. Grab samples were analyzed for key water quality parameters, including pH, conductivity, turbidity, dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD₅), settleable solids, total solids (TS), total dissolved solids (TDS), total suspended solids (TSS), total nitrogen, and total phosphorus. Several parameters exceeded permissible standards established by the Central Environmental Authority (CEA) of Sri Lanka, including turbidity (35 NTU; limit: 20 NTU), COD (80 mg/L; limit: 15 mg/L), TDS (1000 mg/L; limit: 500 mg/L), and TSS (100 mg/L; limit: 40 mg/L), indicating significant pollution levels. Jar test experiments were conducted to compare the coagulation efficiency of cowpea seeds (75.8%), fenugreek seeds (69.2%), papaya seeds (72.5%), okra pods (84.6%), and Moringa oleifera (drumstick) leaves (87%) with conventional alum (94.2%) at an optimum dosage of 12 mL/L. Among the tested plant-derived coagulants, Moringa oleifera leaves demonstrated the highest turbidity removal efficiency, reducing residual turbidity to 4.54 NTU. A low-cost integrated treatment system incorporating coagulation, flocculation, sedimentation, and filtration using sawdust and cotton wool was developed, achieving average removal efficiencies of 90.13% for turbidity, 88.57% for COD, 83.46% for TDS, and 74.83% for TSS, with all effluent parameters maintained within CEA permissible limits. The results confirm that locally available plant-derived coagulants, particularly Moringa oleifera leaves, offer an effective, environmentally friendly, and economically viable approach for sustainable water treatment, highlighting the potential of nature-based solutions in strengthening climate-resilient water management strategies. Full article

Brevibacillus laterosporus strain B.O.D. is a well-established commercial probiotic and antimicrobial microorganism that finds use in human health and in agriculture as a biofertilizer. On the other hand, while B. laterosporus is a well-known entomopathogenic species, the possible insecticidal potential of strain B.O.D. remains unexplored. To address this knowledge gap, this study combined genome sequencing and comparative analysis with other B. laterospours strains and insect bioassays. The genome of B. laterosporus B.O.D. was found to harbor a wide range of genes related to entomopathogenicity encoding putative proteases, chitinases, collagenase-like proteases, mosquitocidal proteins, bacillolysin, and spore-surface proteins. Antimicrobial compounds such as gramicidin and surfactin were also found. Sequence alignment with other well-characterized B. laterosporus strains and analysis revealed significant differences, which support the corresponding differences in insecticidal activity observed when comparing strain B.O.D. with others against a variety of lepidopteran and dipteran pest species. This study reports for the first time the genome of strain B.O.D., providing a comparative analysis and highlighting its insecticidal properties, which appear more moderate compared to previously characterized entomopathogenic strains of the same species. Everything considered, B. laterosporus strain B.O.D. appears to be remarkably versatile, underscoring wide biotechnological potential. Full article

Background/Objectives: Environmental dissemination of antimicrobial resistance (AMR) is increasingly driven by wastewater-impacted aquatic systems, yet the key factors controlling multidrug-resistant (MDR) bacterial distribution remain unclear. This study evaluated environmental factors associated with MDR bacteria in the urban Danube River (Novi Sad, Serbia) using a machine learning framework. Methods: Surface-water and wastewater samples were collected during summer and autumn 2024. Bacterial isolates were obtained through membrane filtration onto chromogenic media and identified using MALDI-TOF MS. Physicochemical parameters (including COD, BOD₅, turbidity, pH, and temperature) were used as predictors in seven machine learning models (ANN, RF, SVM, XGB, MARS, TREE, NB). Model performance was assessed using AUC, accuracy, and error metrics. Results: Wastewater samples showed higher bacterial abundance and taxonomic richness than river surface-water samples, with frequent recovery of Klebsiella pneumoniae, Escherichia coli, Aeromonas veronii, and Pseudomonas spp. Tree-based models (RF, XGB) performed best. Organic pollution indicators, turbidity, pH, and water temperature were the most prominent factors. Conclusions: Wastewater-related pollution gradients, reflected by organic load parameters, turbidity, pH, and water temperature, were associated with the occurrence of selected bacterial taxa recovered on selective media. These associations were more pronounced in wastewater samples, while river surface-water samples showed lower abundance and taxonomic richness but still contained selected environmental and opportunistic taxa. Because antimicrobial susceptibility testing and molecular confirmation of resistance determinants were not performed, the findings should be interpreted as culture-based and exploratory. Machine learning approaches may support environmental screening and hypothesis generation for AMR-oriented surveillance, but future studies should include standardized phenotypic and molecular confirmation. Full article

This study evaluated the phytoremediation potential of the halophytic plant Sesuvium portulacastrum (L.) L. for treating industrial wastewater (IWW) in a hydroponic system over a nine-day exposure period. After treatment, the physicochemical analysis of IWW revealed a significant decrease in chemical oxygen demand (COD), biological oxygen demand (BOD), TSs (total solids), total dissolved solids (TDSs), TSSs (total suspended solids), ammonia, phosphate, and nitrate. The COD and BOD were reduced by 90.7% and 82.9%, respectively. The metal analysis indicated a significant decrease in Fe (95%), Mn (87.4%), and Al (93.9%) and complete removal of Ni, Pd, and Zn. The plant stress responses were assessed through the estimation of photosynthetic pigments (Chlorophyll-a, Chlorophyll-b, Total chlorophyll), phenolic and flavonoid contents, and antioxidant activity. Total chlorophyll declined from 1.449 mg/g (control) to 1.20 mg/g on Day 3, followed by partial recovery to 1.25 mg/g by Day 9, indicating physiological acclimatization. Total phenolic content reached 14 mg GAE/g in leaves and 12 mg GAE/g in stems on Day 6, while Total flavonoid content increased from ~70 µg/g (control) to 115 µg/g on in leaves. The metabolic profiling using GC-MS/MS revealed distinct time- and tissue-specific metabolic responses, with 53 metabolites identified in roots and 62 metabolites in leaves. The major differentially accumulated metabolites were sucrose, pinitol, talose and psicose, with peak accumulation at Day 6. A biphasic metabolic response pattern, characterized by early stress perception followed by adaptability, was observed. Phytotoxicity assays using Vigna radiata demonstrated improved germination from 15% (untreated IWW) to 95% after treatment. Overall, the study highlights the strong phytoremediation potential of halophyte S. portulacastrum as an environmentally friendly alternative for industrial wastewater remediation. Full article

To scientifically evaluate the health of river aquatic ecosystems in the Qianxinan Buyi and Miao Autonomous Prefecture, southwestern Guizhou, systematic surveys of benthic macroinvertebrate and periphytic algal communities were conducted in representative rivers during October 2024 (autumn) and April 2025 (spring), coupled with concurrent water quality monitoring. Reference sites were selected based on water quality indicators and habitat conditions. Core parameters were identified through correlation analysis, discriminatory ability analysis, and distribution range analysis to construct a Benthic Index of Biotic Integrity (B-IBI) and a Periphytic Algae Index of Biotic Integrity (P-IBI) suitable for the region. These indices were then applied to assess the ecological health of the rivers. Additionally, stepwise regression analysis was employed to investigate the key environmental drivers influencing the two biotic integrity indices. The results indicated that: (1) In terms of species composition, the benthic macroinvertebrate community structure was relatively simple, dominated by arthropods, particularly chironomid larvae. Bacillariophyta and Cyanophyta consistently dominated the periphytic algae community. (2) Assessments using both B-IBI and P-IBI showed that the overall river health in spring was slightly better than in autumn. However, more than half of the sampling sites were rated as “fair” or worse in both seasons. The reference sites (S2, S10) consistently exhibited “excellent” or “good” health, while the impaired sites showed significant spatial heterogeneity. Discrepancies between B-IBI and P-IBI ratings at some sites revealed differential responses of the two biological communities to environmental stressors. (3) Stepwise regression analysis unveiled a seasonal shift in key environmental drivers. The primary factor affecting the B-IBI in autumn was biochemical oxygen demand (BOD₅), which shifted to total phosphorus (TP) and ammonia nitrogen (NH₄⁺-N) in spring. For the P-IBI, the main factor changed from dissolved oxygen (DO) in autumn to chemical oxygen demand (COD) in spring. These findings confirm the applicability of the B-IBI and P-IBI systems in this region, and indicate that multi-assemblage integrated assessments can contribute to understanding the health status of river ecosystems in the Qianxinan Prefecture. This study could serve as a scientific reference for the protection, management, and restoration of local river ecosystems. Full article

This study investigated the efficiency of macrophyte-based phytoremediation systems using Phragmites karka and Typha latifolia for the treatment of poultry–aquaculture wastewater and its suitability for irrigation reuse. Physicochemical parameters, heavy metals, and water quality indices were analysed using correlation analysis and Principal Component Analysis (PCA). Strong positive correlations were observed among turbidity, nutrients, biochemical oxygen demand (BOD₅), and chemical oxygen demand (COD), while dissolved oxygen (DO) showed significant negative relationships, indicating organic pollution-driven oxygen depletion. Heavy metals exhibited strong intercorrelations, suggesting common anthropogenic sources and similar removal pathways. PCA results revealed that the first three principal components (PCs) explained over 95% of the total variance, with positive values recorded from the first PC highlighting organic load, nutrient enrichment, and metal interactions as dominant factors controlling wastewater quality. The negative values of factor loadings obtained in the second and third PCs confirmed the roles of sedimentation, adsorption, microbial activity, and plant uptake in pollutant removal. Water Quality Index (WQI) values decreased drastically from highly polluted levels (>3000) in raw wastewater to <1.0 after 21 days of treatment, indicating excellent water quality. Sodium Absorption Ratio (SAR) also declined significantly, confirming a low sodicity risk. Both macrophytes demonstrated high treatment efficiency, with Typha latifolia showing slightly improved sodium reduction. Overall, the study highlights macrophyte-based systems as sustainable, cost-effective solutions for wastewater treatment and safe agricultural reuse. Full article

Accurate prediction of wastewater influent quality is critical for optimizing treatment plant operations, minimizing environmental impact, and enabling proactive management under dynamic conditions. However, the complex, nonlinear, and temporally dependent nature of influent processes poses significant challenges to traditional modeling approaches. This study introduces a robust stacked ensemble learning framework that integrates Long Short-Term Memory (LSTM), Support Vector Regression (SVR), and Extreme Gradient Boosting (XGBoost) to forecast three key influent quality parameters: biochemical oxygen demand (BOD₅), total phosphorus (TP), and total solids (TS) at a municipal wastewater treatment plant (WWTP) in Canada. Through sequential backward feature selection and SHapley Additive exPlanations (SHAP), the model achieves both high predictive accuracy and interpretability, providing insights into temporal, environmental, and process-based drivers of influent variability. The ensemble consistently outperforms individual models, delivering high generalization performance across all three influent quality targets. This work demonstrates that stacked ensemble models, when coupled with explainable AI techniques, can bridge the gap between black-box performance and operational transparency in wastewater forecasting. The proposed framework lays the groundwork for more resilient, data-driven decision-making in municipal WWTPs. Full article