Water, Air, & Soil Pollution最新文献

A novel biochar-chitosan cryogel derived from shrimp shells and tea residues was prepared for tetracycline (TC) antibiotic elimination from water in batch experiments with the advantages of high adsorption capacity, environmental friendliness, sustainability and non-toxicity. The fabricated adsorbents were characterized by Brunauer–Emmett–Teller (BET), Scanning electron microscopy (SEM–EDX, X-ray diffraction (XRD), Fourier-transform infrared (FTIR) and Zeta potential. The main factors governing the adsorption performance such as pH, adsorbent dosage, contact time, initial TC concentration and solution temperature were studied in the batch adsorption experiments. The kinetic and isotherms studies were performed and showed that the pseudo-first-order (PFO), pseudo-second-order (PSO), Freundlich and Langmuir models were well described the experimental results, indicating that the adsorption process on the surface followed a combined physicochemical mechanism. The adsorption process of chitosan – tea residues biochar- Fe cryogel (CTB-Fe) was spontaneous and exothermic the Qmax value reached 64.10 mg/g at pH 6, dose of 2 g/L and room temperature (25℃). The adsorption mechanism of TC involves multiple processes, including physical adsorption (mainly surface diffusion and van der Waals interactions), hydrogen bonding, π–π electron interactions, and metal–ligand complexation.

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This study investigates particulate matter (PM) associated with aquatic moss as a monitor of the transfer of artificial radionuclides in the Yenisei River, which receives authorized releases of liquid radioactive wastes. Samples of aquatic moss and bottom sediments (BS) were collected in the Yenisei in September 2019–2023 close to the radioactive discharge site. PM associated with moss was recovered from samples of fresh moss in laboratory. Samples of unwashed moss, washed moss, PM retained by the moss, and BS were analyzed for contents of radionuclides using HPGe-gamma-spectrometry and alpha-spectrometry; for mineral composition – by X-ray diffraction analysis; for elemental composition – by SEM–EDS analyses. PM retained by aquatic moss constituted 13.5–43% of dry biomass of moss samples. Mineral matter constituted 89.4 ± 5.5% of the dry mass of that PM and consisted mainly of rock-forming minerals and a considerable proportion, up to 25%, of X-ray amorphous phase, represented mainly by frustules of epiphytic diatoms. Considerable proportions of artificial radionuclides were associated with PM of moss: 12–67% for ⁶⁰Co; 38–81% for ¹³⁷Cs; 20–66% for ²⁴¹Am; 25–78% for ¹⁵²Eu; 55% for ¹⁵⁴Eu; 2.5–48% for ²³⁸Pu; and 3.8–41% for ^239,240Pu. Principal Component Analysis revealed the greatest similarity between PM retained by aquatic moss and BS in contents of radionuclides, minerals, and organic matter. The results allowed us to conclude that PM associated with aquatic moss could be considered as a representative component of the ecosystem that makes it possible to monitor the transfer of artificial radionuclides in water current of the Yenisei River.

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The present study evaluates the amoxicillin adsorption from aqueous solutions using biochar derived from sugar beet pulp (SBC), in batch conditions. The biomass improved by phosphoric acid pretreatment followed by pyrolysis. Adsorption variables were optimized by the response surface methodology (RSM). In this regards, initial amoxicillin concentration (7.5 to 77.5 (text{mg }{text{L}}^{-1})), solution pH (2.5 to 10.5), sorbent dosages (0.05 and 1.85 (text{g }{text{L}}^{-1})), and adsorption time (5 to 105 min) were considered. Furthermore, the effect of temperature at 293 to 323 K were considered in optimized conditions. According to the obtained results, the specific surface area and total pore volume of the phosphoric acid-modified SBC (MSBC) exhibited significant enhancement, increasing from 4.46 to 564.25 ({text{m}}^{2} {text{g}}^{-1}) and from 0.004 to 0.350 ({text{m}}^{3} {text{g}}^{-1}), respectively. The equilibrium data were well represented by the Sips and Redlich-Peterson isotherm models. The maximum adsorption capacity for amoxicillin, as determined by the Sips and Langmuir isotherms, were found to be 110.63 and 66.87 (text{mg }{text{g}}^{-1}), respectively, at 298 K. Kinetic analysis revealed that the adsorption process followed to the pseudo-second-order kinetics model. Furthermore, thermodynamic analyses indicated that the adsorption process is spontaneous, exothermic, and primarily physical. The introduction of 0.1 M sodium, calcium, and magnesium chloride salts resulted in a 21–34% reduction in amoxicillin removal efficiency. Additionally, this research assessed the effectiveness of non-linear least squares modeling in estimating the parameters of pseudo-order equations, comparing its efficacy to that of linear modeling. The findings advocate for the adoption of non-linear optimization methods in the estimation of parameters for kinetic models to enhance accuracy and reduce potential errors.

Industrial effluent is a liquid waste product used for diverse purposes. It has a significant impact on the surrounding environment when discharged without treatment or moderately treated. The poor management of industrial waste from lead-acid manufacturing battery plants leads to the release of untreated effluent. The purpose of this study was to develop competent technique for the appraisal of the effluent treatment plant (ETP) efficiency of the effluent of lead-acid battery plant by optimizing key parameters using response surface methodology. This study focused on appraising the impact of pH, Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solid (TSS), and Total Dissolved Solid (TDS) as independent variables on ETP efficiency. A quadratic model was proposed to establish the relationship between these variables and attain maximum efficiency under optimal process conditions using the Box-Behnken design (BBD). This study shows that pH and TSS are the most operative parameters for the efficiency of Effluent Treatment Plant (ETP) in contrast with BOD, COD and TDS. This is possibly due to the high values of F-statistics for pH and TSS, which greatly impact the efficiency of the ETP. The depictions of the influent and effluent were assessed using a highly calibrated analytical instrument. The F-value of model (18.35) shows the importance of the model, while P-values less than 0.05 propose that the model terms are significant. The ANOVA results confirmed the agreement between the forecasted and actual experimental data. This study revealed that plants require improvement in the system.

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Globally, on-site sanitation systems such as soak pits and cesspits are widely used in regions lacking centralized sewer networks, particularly in low- and middle-income countries. While these systems provide low-cost wastewater disposal solutions, numerous studies have reported their association with groundwater contamination, public health concerns, and recurring household expenditures. In Jordan, the reliance on soak pits has increased markedly in rural and peri-urban areas due to limited sewer coverage. This study evaluates the environmental, economic, and health implications of soak pit use across different residential contexts. A structured survey was conducted with 157 respondents representing diverse regions and housing types. Environmental and health impacts were assessed using a five-point Likert scale, complemented by a SWOT analysis to examine perceived system strengths and limitations. An Analytic Hierarchy Process (AHP) was applied to prioritize sanitation-related risks based on expert judgment across residence types. The results indicate that 66.5% of respondents agreed or strongly agreed that soak pits contribute to groundwater contamination, while over 70% associated them with increased health risks and economic burdens related to frequent desludging and pumping costs. Environmental criteria ranked highest in the AHP model, particularly groundwater contamination, followed by cost and health-related factors. These findings highlight the need for context-specific sanitation interventions and policy measures to improve wastewater management in arid regions with limited sewer infrastructure.

Low-carbon green stabilization/solidification (S/S) has attracted much attention in hazardous waste treatment. In this study, environmentally friendly Fe–Mn modified biochar (FMBC), which was synthesized by loading Fe–Mn oxides (FMO) onto biochar (BC) using a hydrothermal co-precipitation method, was used as an additive in cement-based S/S of arsenic (As) contaminated soil. Pristine BC, FMO, and FMBC were included for comparison. Results showed that BC effectively reduced the agglomeration of Fe/Mn oxide and endowed more interfacial active sites. FMBC treating significantly promoted the As immobilization efficiency (94.2–97.3%) and satisfied the regulated leaching limit. Simultaneously, the addition of FMBC facilitated the conversion of exchangeable As to Fe/Mn oxide and residual states. Spectroscopic and microstructural analysis showed that FMBC-surface manganese oxides oxidized As(III) to lower-toxicity, reduced-mobility As(V), while iron oxides/hydroxides efficiently immobilized As through adsorption and co-precipitation. Meanwhile, FMBC facilitated the cement hydration reaction via retaining water and promoting internal curing effect, and hence promoted the encapsulation of As by calcium silicate hydrate and the ion exchange of As by ettringite. This study expands the emerging application of BC and demonstrates the potential application of FMBC as additives in S/S of As-contaminated soil.

Machine learning (ML) techniques have shown significant potential in individual optimization of electrocoagulation (EC) and electrooxidation (EO) processes, but their application to combined EC and EO processes represents a significant research gap. The hybrid EC-EO process is recognized as a highly complex electrochemical process, exhibiting nonlinear relationships between operating parameters. Hence, this study investigates the implementation of data-driven models comprising artificial neural networks (ANN), adaptive neuro-fuzzy inference system (ANFIS), and support vector regression (SVR) to predict chemical oxygen demand (COD) removal efficiency from real domestic sewage water in hybrid EC-EO process. Five input variables were employed: initial pH, current intensity, electrocoagulation time, electrooxidation time, and electrode type. The ANN performance was measured using Levenberg–Marquardt (trainlm) algorithm, whereas ANFIS modelling was accomplished using Takagi–Sugeno type FIS. For SVR, an advanced Bayesian algorithm was adopted to optimize the model. The experimental datasets were segregated into 70% for training and 30% for testing. The statistical metrics, Coefficient of determination (R²), mean absolute error (MAE), mean squared error (MSE), root mean squared error (RMSE), and sum of squared error (SSE) were utilized to compare the efficiency of model with measured COD removal values. The comparative evaluation revealed model performance in the following order: ANN > ANFIS > SVR. During testing, the R², MAE, MSE, RMSE, and SSE values for ANN obtained were 0.9157, 0.0736, 0.0082, 0.0906, and 0.4265, respectively. Additionally, sensitivity analysis utilizing Garson’s algorithm and Partial derivatives was conducted on the superior model, establishing current intensity and electrode type as the most impactful parameters affecting COD removal efficiency in hybrid EC-EO process. This study confirms the effective implementation of data-driven techniques in hybrid electrochemical process.

Fe-based Metal–Organic Frameworks (MOFs) show promise as heterogeneous Fenton-like catalysts; however, in the removal of hydrophobic VOCs, traditional wet Fenton systems suffer from slow Fe³⁺/Fe²⁺ cycling and high gas–liquid mass transfer resistance, severely limiting their industrial application. To address these challenges, this study proposes a dual optimization strategy. Specifically, a gas-phase H₂O₂ Fenton-like system was constructed to overcome mass transfer limits, and multivalent Mn was introduced into the MIL-100(Fe) to accelerate the Fe²⁺/Fe³⁺ cycle. Among the synthesized catalysts, MIL-100(Fe₄Mn₁) (4FM) exhibited superior catalytic performance, achieving 85% toluene degradation efficiency and a capacity of 87.17 μg C₇H₈/(g·min)) under optimized conditions, significantly outperforming its monometallic counterparts. Characterization results reveal that 4FM retains an ordered crystalline structure with highly dispersed active sites and an optimized pore architecture. Mechanistic studies indicate that Fe–Mn synergy induces an “electron pump” effect, utilizing the thermodynamic potential differences to accelerate the reduction of Fe³⁺ to Fe²⁺. Concurrently, the system establishes dual reaction centers (Fe and Mn), where efficient Mn²⁺/Mn³⁺/Mn⁴⁺ and Fe²⁺/Fe³⁺ redox cycles facilitate sustained gaseous H₂O₂ activation into hydroxyl radicals (·OH), promoting efficient toluene degradation. This study provides a promising strategy utilizing gas-phase Fenton-like catalytic technology to overcome kinetic and mass transfer bottlenecks in degrading of hydrophobic VOCs.

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A Gram positive strain of Alkalihalobacillus clausii ABF28, indigenous to environment contaminated by Cr(VI) was identified by applying molecular imaging and de novo genomic profiling. This study investigates the potential of Alkalihalobacillus clausii ABF28 for the bioremediation of hexavalent chromium in a batch column reactor. We assess both immobilized and free bacterial cell systems to evaluate their efficiency in reducing chromium contamination. Bacterial strain grew well in marine broth media despite being stressed with 700 mg/l and 1500 mg/l chromate. Furthermore, the MIC found was 2500 mg/l. The XPS confirmed that the bacterial strain reduced Cr(VI) to a + 3 oxidation state. The strain was grown in free and immobilized state and later was analyzed with SEM, STEM, XPS and FTIR. A similar observation was made in elemental mapping of EDX. In addition, we conduct whole genome profiling of the bacterial strain to uncover the underlying genetic mechanisms that facilitate chromium detoxification. The chromate transporter ChrA is acknowledged as a crucial component in the expulsion of chromium, which aids in maintaining low intracellular levels. A collection of reductive enzymes, including MdaB (NADPH-dependent quinone reductase), Fpr (ferredoxin-NADP⁺ reductase), Qor (quinone oxidoreductase), and CypX (cytochrome P450 oxidoreductase), collaborate within complementary pathways to channel electrons from NADPH and ferredoxin for the reduction of Cr(VI), simultaneously contributing to the alleviation of oxidative stress. These genes collaborate with antioxidant mechanisms such as superoxide dismutase and catalase, establishing a dual strategy that integrates efflux and enzymatic reduction. Collectively, these findings underscore A. clausii ABF28 as a remarkably versatile bacterium proficient in detoxifying Cr(VI), indicating its potential role in the remediation of chromium-contaminated marine ecosystems.

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The dependence on the indiscriminate use of plastics has had a negative impact on the environment. Despite studies on macro- and microplastics in coastal areas, empirical evidence in urban inland and high-altitude regions remains scarce, especially in Latin American cities, where atmospheric dynamics differ from those of coastal regions. In light of this scenario, there is an urgent need for research focused on the presence, concentration, and behaviour of airborne microplastics in urban outdoor environments. The objective of this research, which was conducted in Zonal Planning Unit 99 in Bogotá, Colombia, was to determine the presence, concentration, and characteristics of microplastics and evaluate their relationship with physicochemical and environmental variables using a high-volume air sampler. The filters were processed by chemical digestion with HCl and H₂O₂ in order to remove organic matter. Subsequently, the microplastics were dried and visually analysed under a stereoscope, classified by shape, colour, and size. They were then confirmed as plastics using morphological criteria and the hot needle test. A total of 211 microplastic were found across two monitoring points, with differences observed in both the quantity and colour of the fibres. These findings emphasize the importance of addressing microplastic contamination in urban environments and underscore the necessity of implementing measures to reduce plastic pollution. Although no statistically defined hotspots were identified at this scale, the constant presence of microplastics in all samples indicates widespread contamination, highlighting the need for continuous monitoring of this emerging pollutant, particularly in high-altitude urban settings where data are still limited.