Search Results (1,184)

This study explores the effectiveness of ultraviolet (UV) irradiation, ozonation (O₃), granular activated carbon (GAC) adsorption, and their combinations (UV/GAC, O₃/GAC) in removing selected pharmaceuticals and common wastewater micropollutants under controlled laboratory-scale conditions. Eight target compounds—candesartan, irbesartan, valsartan, metoprolol, diclofenac, metformin, sucralose, and caffeine—were identified and quantified in real wastewater samples collected from a municipal wastewater treatment plant. Ozonation proved to be the most effective standalone method, achieving complete removal (100%) of five pharmaceuticals and partial removal of sucralose (~60%) and metformin (~17%). The combined O₃/GAC treatment further enhanced overall removal efficiency. In contrast, UV irradiation alone showed limited effectiveness. Importantly, all substances except metformin were fully removed by at least one of the tested methods. These findings underscore the potential of advanced and hybrid treatment technologies—validated here at the laboratory scale—for improving pharmaceutical removal from wastewater and mitigating their environmental impact. Full article

There is an urgent need to evaluate the toxicity of xenobiotics and environmental mixtures for preventing loss in water qualityfor the sustainability ofof aquatic ecosystems. A simple prebiotic chemical pathway based on malate formation from pyruvate (pyr) and glyoxalate (glyox) pathway is proposed as a quick and cheap screening tool for toxicity assessment. The assay is based on the pyr and glyox (aldol) condensation reactions, leading to biologically relevant precursors such as oxaloacetate and malate. Incubation of pyr and glyox at 40–70 °C in the presence of reduced iron Fe(II) led to malate formation following the first 3 h of incubation. The addition of various xenobiotics/contaminants (silver, copper, zinc, cerium IV, samarium III, dibytlphthalate, 1,3-diphenylguanidine, carbon-walled nanotube, nanoFe₂O₃ and polystyrene nanoparticles) led to inhibitions in malate synthesis at various degrees. Based on the concentration inhibiting malate concentrations by 20% (IC20), the following potencies were observed: silver < copper ~ 1.3-diphenylguanidine ~ carbon-walled nanotube < zinc ~ samarium < dibutylphthalate ~ samarium < Ce(IV) < nFeO₃ < polystyrene nanoplastics. The IC20 values were also significantly correlated with the reported trout acute lethality data, suggesting its potential as an alternative toxicity test. The pyr-glyox pathway was also tested on surface water extracts (C18), identifying the most contaminated sites from large cities and municipal wastewater effluents dispersion plume. The inhibition potencies of the selected test compounds revealed that not only pro-oxidants but also chemicals hindering enolate formation, nucleophilic attack of carbonyls and dehydration involved in aldol-condensation reactions were associated with toxicity. The pyr-glyox pathway is based on prebiotic chemical reactions during the emergence of life and represents a unique tool for identifying toxic compounds individually and in complex mixtures. Full article

This article deals with the design of a technically, legislatively, and economically balanced sewerage system for the municipality of Ropice, which has long lacked a central sanitary sewer system. On the basis of the analysis of the territorial conditions, hydro-technical calculations, and legislative requirements, two potential solutions are compared—a decentralized domestic WWTP and a central separate sewerage system with a treatment plant. The final concept favors the central solution in order to ensure operational reliability, sustainability, and the possibility of using grants. This study provides a model example of an applicable solution for rural settlements with similar wastewater management problems. Full article

Accurate estimation of individual tree aboveground biomass (AGB) is essential for understanding forest carbon dynamics, optimizing resource management, and addressing climate change. Conventional methods rely on destructive sampling, whereas unmanned aerial vehicle (UAV) remote sensing provides a non-destructive alternative. In this study, spectral indices, textural features, and canopy height attributes were extracted from high-resolution UAV optical imagery and Light Detection And Ranging (LiDAR) point clouds. We developed an improved YOLOv8 model (NB-YOLOv8), incorporating Neural Architecture Manipulation (NAM) attention and a Bidirectional Feature Pyramid Network (BiFPN), for individual tree detection. Combined with a random forest algorithm, this hybrid framework enabled accurate biomass estimation of Chinese fir, Chinese pine, and larch plantations. NB-YOLOv8 achieved superior detection performance, with 92.3% precision and 90.6% recall, outperforming the original YOLOv8 by 4.8% and 4.2%, and the watershed algorithm by 12.4% and 11.7%, respectively. The integrated model produced reliable tree-level AGB predictions (R² = 0.65–0.76). SHapley Additive exPlanation (SHAP) analysis further revealed that local feature contributions often diverged from global rankings, underscoring the importance of interpretable modeling. These results demonstrate the effectiveness of combining deep learning and machine learning for tree-level AGB estimation, and highlight the potential of multi-source UAV remote sensing to support large-scale, fine-resolution forest carbon monitoring and management. Full article

Although sewage sludge in agriculture can promote circular economy goals, concerns remain about the transfer of contaminants of emerging concern (CECs) into crops and soils. This study evaluated the uptake and risk of 27 CECs in tomatoes cultivated in peat substrate amended with stabilised anaerobically digested (dried) sludge from a local municipal wastewater treatment plant at two rates corresponding to nitrogen and nitrogen/potassium requirements. Peat substrate served as the control. Additional treatments included CEC-spiked media and peat amended with non-dried sludge. Analysis was performed with LC–MS/MS. In tomato fruits, ibuprofen (15.8 ng/g) and triclosan (17.9 ng/g) were quantified at the low amendment rate, while caffeine (381 ng/g), carbamazepine (18.1 ng/g), ciprofloxacin (306 ng/g) and ibuprofen (5.3 ng/g) were quantified at the high amendment rate. Dietary exposure estimates were below the health-based reference values for most compounds; however, a potential risk was identified for bisphenol S when non-dried anaerobically digested sludge was applied. Soil risk quotients (RQ > 1) for several CECs at the end of the experiment indicate possible ecological concern. These findings emphasise that monitoring CECs in sludge-amended soil remains essential to ensure the safety of sludge reuse in agriculture. Full article

Aromatic amines such as 3-chloroaniline (3-CA) are toxic, persistent, and environmentally relevant water contaminants. Their reliable determination in aqueous systems has therefore become increasingly important. The monitoring of trace levels of these pollutants in complex water matrices typically necessitates a preconcentration step, most achieved via solid-phase extraction (SPE). However, conventional SPE sorbents often suffer from limited surface reactivity and slow adsorption kinetics, which compromise their performance at ultra-low concentrations. In contrast, nanomaterials offer a promising upgrade due to their high surface area, tunable chemistry, and rapid mass transfer behavior. In this work, mesoporous silica nanoparticles (MSNs) were synthesized via a green sol–gel route from sodium silicate precursor using polyethylene glycol template and then chemically functionalized with bisphenol A (BPA) to produce BPA-MSNs with π-rich and hydrogen-bonding active sites. Characterization using XRD, BET, FTIR, SEM/EDX, and TGA confirmed the successful synthesis and surface modification of the nanosorbent. BPA-MSNs achieved a maximum adsorption capacity of 30.2 mg/g toward 3-CA, fitting Langmuir and Jovanovic isotherm models. Kinetic analysis followed a pseudo-first-order model, indicating physisorption enhanced by π–π stacking and hydrogen bonding. The optimized dispersive SPE (D-SPE) method allowed a low detection limit (LOD = 0.016 mg/L), recovery of 73–85%, and precision below 5.3% RSD in tap, bottled, synthetic municipal wastewater and groundwater samples. The sorbent retained >90% efficiency over five reuse cycles, demonstrating strong potential as a reusable nanosorbent for preconcentration and remediation of aromatic amines in and treatment water analysis. Full article

Microplastics (MPs) are increasingly recognized as emerging contaminants in aquatic environments; however, their occurrence and fate in tropical wastewater treatment systems remain poorly understood. This study provides the first inland–island comparison of MP removal in wastewater treatment plants (WWTPs) across Thailand’s Eastern Economic Corridor. Influent and effluent samples were collected from six WWTPs, encompassing five treatment types: oxidation ditch, aerated lagoon, stabilization pond, aerated tank, and sand filtration combined with reverse osmosis. Polymeric composition and size distribution were examined in parallel with conventional water quality indicators. Across all sites, polyethylene (PE) and polypropylene dominated influent MPs, together accounting for 57–92% of total abundance. Inland plants received heterogeneous municipal wastewater, including domestic inputs and agricultural runoff. In contrast, island facilities consistently showed PE-enriched influents (45–60%) in site F, reflecting tourism-driven reliance on single-use plastics and personal care products. In addition, several minor polymers were identified, including poly (vinyl stearate) (up to 26%), polyamide, polytetrafluoroethylene and ethylene–butyl acrylate, highlighting overlooked pathways of MP entry into WWTPs. Fine MPs (100–300 μm) comprised over two-thirds of influent particles, with stabilization ponds reaching 16,000 MP m⁻³. Removal efficiency ranged from 86.0% to 98.5%. Spearman’s correlation and multiple linear regression analyses revealed strong positive relationships between MPs and both total suspended solids (TSS) and turbidity. Suspended solids parameters emerged as the most reliable predictor of MP abundance (adjusted R² = 0.91, p = 0.001). This finding highlights TSS coupled with turbidity as a practical, cost-effective indicator for monitoring MPs in tropical WWTPs. To achieve greater accuracy, a larger dataset should be built and further analyzed. Full article

Wastewater treatment plants are municipal facilities established by governments to process wastewater from local communities. Aeration is a crucial stage of wastewater cleaning. In this paper authors present the concept of an airflow controller based on measures obtained from installation in Kraków/Płaszów. The model of the blowers’ station, which is based on measured values from this plant, is used as a reference. The development of such a numerical model enables tests of more efficient control strategies of blowers, leading to cost savings. From a technical standpoint, such a model can be systematically integrated into the management framework of wastewater treatment plants through the implementation of model predictive control (MPC) strategies. We decided to apply the control strategy presented in this paper to demonstrate the modeling approach by using only SCADA data measurements. The authors present two independent tests introduced to reduce momentary power consumption that is considered as the final indicator of system performance. The first test analyses two approaches to start-up inactive blower. The first algorithm selects the blower that has been inactive the longest. In the second one, the decision to activate the blower is based on its actual characteristics. The results of simulations clearly show that choosing the blower based on its characteristics is non-significantly more effective. The second test presented a strategy that delays blower activation to achieve operation at more favorable working points. A comparison of the simulation shows that delaying their activation leads to an improvement in the operating point, lowering average power consumption. Full article

With the continuous improvement of wastewater treatment standards, advanced nitrogen removal from municipal wastewater treatment plant effluents faces severe challenges. This paper systematically analyzes the application potential of sulfur-based autotrophic denitrification (SAD) technology in advanced wastewater treatment, focusing on its denitrification efficiency, operational costs, and carbon reduction benefits. Compared to conventional heterotrophic denitrification (HD), SAD technology demonstrates significant advantages, including high denitrification efficiency, low operational costs, low sludge production, and low CO₂ emission, through the reduction of external organic carbon source addition and energy consumption. Among the autotrophic denitrification processes, SAD has the highest denitrification rate with low cost and low safety risk. Through sulfur source selection and process optimization, the denitrification rate could reach 1.2 kg N/m³·d, and the accumulation of byproducts can be effectively controlled. As calculated, SAD can reduce over 55% sludge production, reduce 50–80% operational costs, and reduce over 80% greenhouse gas (GHG) emissions. Despite challenges such as long start-up periods, SAD technology shows promising application prospects for advanced treatment of low C/N ratio wastewater. Future research should focus on process optimization and scale-up engineering applications to promote the large-scale implementation of this technology. Full article

Anaerobic co-digestion of agro-industrial and municipal biowastes can enhance methane production, but the optimal mixture depends on nonlinear interactions among substrates. This study evaluated swine wastewater (SW), cheese whey (CW), and the organic fraction of municipal solid waste (OFMSW) under mesophilic batch conditions to quantify composition–response relationships and identify a robust operating window. A restricted simplex-centroid mixture design was tested; linear, quadratic, and special cubic models were fitted and evaluated using ANOVA, diagnostic plots, and optimization with desirability mapping. Cumulative methane yield (CMY) ranged between 251 and 295 NmL CH₄ g VS⁻¹ in the mixtures, outperforming SW as single component. All mixtures maintained neutral pH and moderate alkalinity ratios. The special cubic model provided the best performance (high R² and R²pred) and revealed significant ternary interaction. The optimization indicated a composition near 63% SW, 10% CW, and 27% OFMSW with a predicted CMY of 300 NmL CH₄ g VS⁻¹; a high-performance band (desirability 0.90–1.00; corresponding to CMY ≥ 294.8) defined a robust window of ~60–66% SW, 6–20% CW, and 20–31% OFMSW. Overall, balanced ternary co-digestion showed synergistic effects beyond additive expectations, and the response surface model based on mixture design proved effective in capturing interactions and providing flexible guidance for practical implementation. Full article

The non-oxidizing antimicrobial 2-Methyl-4-Isothiazolin-3-one (MIT) poses a significant environmental risk given its frequent detection in municipal wastewater. This study showed that the combination of Vacuum UV/UV (VUV/UV) and persulfate (PDS) efficiently achieved the rapid transformation and removal of 10 μM MIT within 90 s, which is much faster than UV, UV/PDS, and VUV/UV. Increasing the PDS dosage improved MIT degradation, whereas changes in pH between 4 and 10 had little effect. Radical quenching experiments showed that 93% of the MIT oxidation was attributable to the hydroxyl radical (•OH) and the sulfate radical (SO₄•⁻). SO₄•⁻ and •OH at concentrations of 8.6 × 10⁻¹² M and 1.5 × 10⁻¹² M accounted for 32% and 61% of the MIT degradation, respectively, and the greater contribution of •OH was attributed to its higher reaction rate constant with MIT compared to SO₄•⁻. Sulfate had a negligible impact on the radical concentrations. Chloride (1 mM) reduced the SO₄•⁻ and •OH concentrations by 61% and 27%, respectively. And the SO₄•⁻ contribution to MIT degradation fell to 19%. Nitrate (5 mM) readily quenched •OH but minimally affected SO₄•⁻. The •OH concentration decreased by 79%, reducing its contribution to 27%. Bicarbonate/carbonate (5 mM) simultaneously reduced the SO₄•⁻ and •OH by 26–30% and had little effect on their contributions. Because of the quenching effect of organic matter and inorganic anions on radicals, secondary effluent inhibited the degradation of MIT. After a 120 s treatment, the total organic carbon, UV₂₅₄, and fluorescence regional integration were reduced by 5%, 8%, and 17–24%, respectively. This study provides a quantitative analysis of how inorganic ions alter the concentrations and contributions of •OH and SO₄•⁻, elucidating the MIT removal mechanisms in VUV/UV/PDS for sustainable wastewater reclamation. Full article

Wastewater treatment plants (WWTPs) play a key role in the protection of the environment and public health by reducing the levels of pollutants released into the water. Here, we evaluate the quality of water obtained from two key points of the treatment process of a municipal WWTP (León, Spain) using zebrafish (Danio rerio) embryos and larvae as sentinels. Three experimental groups were established: (1) “Control” (CTRL) maintained in embryo medium, (2) “Influent” (I) exposed to influent water before the secondary (biological) treatment (concentrations: I-100% and I-75%), and (3) “Effluent” (E) exposed to effluent water from the secondary treatment (concentrations: E-100% and E-75%). Our results confirmed that survival was subtly affected in I-100% and E-100%, as well as the hatching rate in the effluent. Larvae exposed to both experimental conditions also presented a higher rate of malformations, affecting biometry and showing reduced embryo motility, with the exception of E-75%. The I-100% condition also caused reduced heartbeat, reduced fin regeneration, and a higher number of delocalized primordial germ cells. I-100%-exposed larvae showed dysregulation of four genes (foxm1l, cenpf3b, hoxc6a, and ddit3) out of the 19 studied. Effluent dilution mitigated the observed effects, and the model proved to be an effective additional test for wastewater treatment plants. Full article

The contamination of ground and surface waters with micropollutants like estrogenic compounds and genotoxins is a major public health concern. Conventional wastewater treatment plants are currently not capable of completely removing those contaminants. In this study, we applied planar bioassays to investigate the genotoxicity and estrogenic activity of hospital and municipal wastewater from an Austrian treatment plant. Using the open-source 2LabsToGo platform in combination with the HPTLC-SOS-UmuC and HPTLC-YES assays, both genotoxic and estrogenic compound zones were detected in untreated wastewater. Genotoxic activity was found in sewage sludge filtrate and hospital wastewater, with bioanalytical concentrations ranging from 1.6 to 21.8 µg 4-NQO-EQ L⁻¹. Estrogenic responses were observed in the influent and hospital wastewater samples, with BEQ values between 3.5 and 16.0 µg E2-EQ L⁻¹. No activity was detected in the treated effluent, indicating efficient removal of these compounds during wastewater treatment. These results confirm the presence of biologically active micropollutants in hospitals and raw wastewater and demonstrate the suitability of planar bioassays for sensitive, spatially resolved detection. The use of portable equipment like the 2LabsToGo system suggests that on-site monitoring of estrogenic and genotoxic activities in wastewater is feasible and could support routine surveillance of treatment efficiency. Full article

Municipal solid waste incineration (MSWI) fly ash, classified as hazardous waste (HW18) due to the presence of heavy metals and dioxins, necessitates both harmless treatment and resource utilization. In this study, a Na-P1 zeolite adsorbent was synthesised from MSW incineration fly ash using its intrinsic Si and Al sources, supplemented by silica sol and sodium aluminate solution. The synthesised zeolite was employed for the adsorption removal of tetracycline hydrochloride (TCH) from wastewater. Under the optimised conditions (initial TCH concentration of 10 mg·L⁻¹, adsorbent dosage of 0.4 g·L⁻¹, pH 5.0, temperature 45 °C, and contact time 60 min), a maximum adsorption capacity of 14.8 mg·g⁻¹ and a removal efficiency of 59.1% were achieved. Kinetic analysis revealed that the adsorption process followed the pseudo-first-order model (R² = 0.975). The Langmuir isotherm provided a better fit than the Freundlich model (R² = 0.988), indicating monolayer adsorption on homogeneous sites. Thermodynamic parameters (ΔG < 0, ΔH > 0) confirmed that the adsorption was spontaneous and endothermic, with higher temperatures favoring enhanced TCH adsorption. This work demonstrates the feasibility of converting hazardous MSW incineration fly ash into a value-added Na-P1 zeolite adsorbent with excellent performance for antibiotic wastewater treatment, thereby offering a sustainable strategy for fly ash resource recovery and environmental remediation. Full article

To address the challenge of treating reverse osmosis concentrate (ROC) in municipal wastewater reclamation processes, this study systematically investigated changes in ozone demand, organic compound molecular weight distribution, UV/fluorescence characteristics, and microalgal growth potential during ozone treatment of ROC. The ROC contained fast-reacting substances and had an instantaneous ozone demand of 6.3 mg/L. The chemical oxygen demand (COD) and total organic carbon were partially removed, and the COD/five-day biochemical oxygen demand ratio increased slightly during the ozonation process. The molecular weight components shifted considerably during ozonation: the 300 Da–1000 Da components became dominant (51.6–72.3%), while the 1000 Da–4000 Da and <300 Da components were partially or completely removed. The maximum absorbance of the ROC peaked at 270 nm. At an ozone dosage of 84 mg/L, the UV₂₅₄ and UV₂₇₀ removal rates reached 76.9% and 86.5%, respectively. The three-dimensional fluorescence spectra showed that ozone effectively removed tryptophan-type aromatic proteins, fulvic acid-type substances, aromatic proteins, soluble microbial metabolites, and humic acid-type substances from the concentrate (84.6–88.9%), but only removed a minimal amount of the tyrosine-type aromatic protein (7.4%). The UV₂₅₄ at different molecular weights and the fluorescence area integrals across regions declined rapidly initially, then slowed gradually, correlating with the rapid reaction of UV/fluorescence chromophore-containing substances in ROC. Studies on microalgal growth potential indicate that ozonation increased the maximum algal density (K) in ROC (48.9–91.7%), while ozone/coagulation effectively reduced K (35.1–76.6%). This occurs because ozone converts organic phosphonate antiscalants in ROC into more readily absorbable inorganic phosphorus, whereas ozone/coagulation effectively removes total phosphorus from water. These results can guide the safe disposal of ROC and facilitate sustainable reclamation of municipal wastewater. Full article