Water, Air, & Soil Pollution最新文献

H₂S treatment is a potential method to remove As from smelting wastewater. However, it was difficult to achieve the high concentration As containing wastewater to standard through H₂S one-step treatment. Meanwhile, the sulfide-abundant conditions after H₂S treatment changed the As species and the pH condition, which put forward challenges for removing As deeply. In this study, we developed an H₂S-modification method to prepare sulfide nanoscale zero-valent iron (S-nZVI) to improve the acid resistance and the adsorption performance of adsorbents for As in sulfide-abundant conditions. The results showed that the H₂S-modification method expanded the pH windows with excellent As(III) removal efficiency from 3 to 7, and at pH value of 3, the As(III) removal efficiency reached 99%. Under pH = 3, the concentration of iron released from nanomaterials decreased from 200 to 20 mg/L, which is attributed to the protection of the surface by the FeS_x layer. Moreover, through H₂S-sulfidation, H₃AsO₃ (As-O species) transformed to As-S species, which were more challenging to remove than As-O species. In As(III)-S(-II) solution, S-nZVI adsorbed 95% of As(III) in the range of pH 1–5, and the excessive S(-II) could react with Fe(III) to accelerate the cycle of Fe(III)/Fe(II). This improved the efficiency of the Fenton reaction to enhance the oxidation of As(III). Furthermore, consumption of the S(-II) could promote the transformation from As-S species to As-O species. Thus, excellent acid resistance and the synergy with S(-II) made S-nZVI holds great potential to be applied in As(III) removal.

This study assessed the spatial variations of water quality and trophic state of the ex-mining lakes converted into man-made wetlands in Paya Indah Wetlands, Selangor, Malaysia. The variations of the parameters were referred to the National Water Quality Standard (NWQS) to determine the water quality index (WQI) and Carlson's Trophic State Index (CTSI), guided by the National Lake Water Quality Standard (NLWQS) to assess the quality and trophic state of lake water. Water sampling was carried out at 13 stations within the Main Lake, Sendayan Lake and Teratai Lake through the DotS sampling method. The potential pollution sources affecting water quality were quantified using a statistical approach, including Pearson's correlation and principal component analysis/factor analysis (PCA/FA). The results show that the water quality parameters in some stations exceeded the NLWQS. Pearson analysis shows that nutrients flow with the organic and inorganic matter in the lake. Average WQI values ranged from 62 to 77, indicating slightly polluted to clean water quality in Paya Indah Wetlands. Two factors were found to account for over 82% of the total variation in the dataset when PCA was used to compare the compositional patterns among the samples that were analysed. This suggests that the point source (open areas for development) and non-point source (agriculture-oil palm estate) as well as the natural processes are the main causes of fluctuations in the concentration of the water components. Organic matter and nutrient regimes mainly affect water quality. Even though the lakes at the studied stations are currently hypertrophic, the overall water quality assessment categorises Paya Indah Wetlands as Class III. Hence, Paya Indah Wetlands has great potential to be an alternative water source supplying water to surrounding areas which require extensive water treatment.

A growing number of scientific studies have shown that particulate matter harms the environment and endangers human health. Thus, making timely predictions about airborne particulate matter (PM) concentrations could help the general public to be better organized and avoid excessive exposure to harmful pollutants. This study analyzes the possibility of making accurate predictions about PM_2.5 concentrations in ambient air. The proposed methodology is tested using the data from citizen-installed PM_2.5 sensors from three locations (Serbia, North Macedonia, and Pakistan) that are relatively different in size, population (density), geographic, economic, social, and other relevant means. The data (study sample) were collected through the NASA data access viewer online platform and citizen-installed devices that sample PM_2.5 concentrations (non-referent methods). Four predictive algorithms – Random Forest, XGBoost, CatBoost, and LightGBM – were employed to achieve this goal. The Sequential-Forward-Selection algorithm was used to simplify model building, contributing to the generalization of the methodology. Among the selected algorithms, CatBoost exhibited the best performance in Serbia and North Macedonia, while Random Forest performed best in Pakistan. The study conclusion is that here presented methodology is universally applicable for forecasting PM_2.5 airborne concentration in the areas that are covered by citizen-installed PM_2.5 sensors and are not necessarily covered by official referent sampling stations.

Anaerobic digestion (AD) is a green biotechnology feed with various materials, including wastewater sludge and organic fraction of municipal solid waste (OFMSW). Even if a viral contamination of the organic materials is present, the persistence of the viruses in the effluent after the anaerobic treatment is not yet well known. This study aims to assess viral contamination in the influents and effluents of AD process combining innovative methods—digital polymerase chain reaction (ddPCR) and transmission electron microscope (TEM) observations—in a real-scale context. The research activity involved 2 wastewater treatment plants (WWTP) and 2 OFMSW treatment plants with an anaerobic digestion (AD) step. After a screening on 12 viral targets, including known pathogens and indicators, the 7 most present—adenovirus, norovirus genotype II (GII), SARS-CoV-2 and GII-GIII coliphages, pepper mild mottle virus (PMMoV), tomato mosaic virus (ToMV)—were investigated in 72 samples. Adenoviruses and the viral indicators were present in higher concentrations (> 5 log gene copies/kg sludge), lower values were observed forthe other viruses. SARS-CoV-2 RNA positivity was detected with a different prevalence in the samples (84% WWTP vs 36% OFMSW; p < 0.01). AD produced limited viral decrease (≤ 1 Log) especially in WWTP sludges. ToMV was always observed when at least one viral pathogen was noted in the samples, supporting that it may be a promising viral marker. The innovative methods applied have produced useful evidence on the persistence of viruses in the sludges, valuable for the management and improvement of current waste treatments.

Hydrocarbon extraction from underground reservoirs is often associated by water or salt-water, known as produced water. As the reservoir matures, the amount of water increases and often exceeds the relative hydrocarbons before the reservoir is depleted, especially when secondary or tertiary production processes are used to enhance production. Membrane technology in literature have been applied as water treatment technique and it has been associated to with fouling; but in this study, inorganic fillers such as titanium dioxide (TiO₂) have been added to improve its performance due to the limitation of conventional membranes. This study examines the application of permeable thin film TiO₂ nanocomposite membrane in the treatment of produced wastewater from a hydrocarbon-brown field. TiO₂ is the most common material in our daily life and its use in this study is due to the high degree of commercialization and excellent hydrophilic and photocatalytic properties which are of interest in environmental purification application. In this paper, cellulose acetate membrane was synthesized and further doped with TiO₂ nanoparticles of different weight-percent (10, 20, and 30 wt %). The synthesized TiO₂ nanoparticles were examined using Fourier Transform Infrared Spectroscopy, while the morphology of the synthesized membrane was analyzed using scanning electron microscopy. The results obtained from the experiments at constant pressure, shows that adding TiO₂ nanoparticles to the cellulose acetate membrane structure enhanced the permeability and pore size of the membranes. The free surface energy of the nanocomposite membranes ranged from 58 ± 0.9 to 73 ± 0.9 mJ/m², while that of the cellulose acetate membrane was about 73 ± 0.9 mJ/m². The pure water flux ranged from 18 L/m²h for the cellulose acetate membrane to 35 L/m²h for the TiO₂ nanocomposite membrane. The trend shows that at constant pressure, permeate flux through the nanocomposite membrane will decrease with time. For the percentage retention analysis, adsorption is responsible for the higher retention, however, we found that retention decreased with increasing membrane saturation over time.

Population growth followed by the increase in plastic consumption and excessive production of plastic waste has caused many concerns for mankind. At present, human is taking action to deal with the plastic pollution crisis through mechanical recycling and returning it to the production cycle. Therefore, in the recycling process when plastics are crushed and washed, phthalic acid esters, which are one of their components, are easily separated from plastics due to their weakness and lack of covalent bond in their structure and enter the water and finally through the effluent enters the environment. This study aims to investigate the pollution load of diethyl phthalate (DEP), isobutyl phthalate (IBP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), bis(2-ethylhexyl) phthalate (BEHP), di n-octyl-phthalate (DOP) and Di methyl phthalate (DMP) in the effluent of plastic recycling units. Sampling of the effluent from 32 plastic recycling workshops in the cities of the three southern coastal provinces of the Caspian Sea in Iran was carried out. Laboratory analysis was performed by gas chromatography-mass spectrometer method after phthalates extraction with hexane. According to the specificity of each workshop in terms of the type of plastic they grind and wash, and data analysis using SPSS software, the average total concentration of phthalates as ppb was determined for DMP (0.27), DEP (8.02), IBP (20.97), DBP (3.41), BBP (8.18), BEHP (23.26) and DOP (0.04). The average total concentration of BEHP in all three PET, HDPE and LDPE recycling units was higher than other phthalates and the highest value was 41.94 ppb belonging to the PET recycling unit. LDPEs did not have DMP and except for DEP and DBP which had the highest concentration in HDPE form, other phthalates had the highest concentration in PET form and there was a significant relationship between different types of plastic with the type and amount of phthalates (p < 0.05). Also the risk assessment of phthalates in the effluent of the plastic recycling workshops in the southern coastal areas of the Caspian Sea showed that BEHP has the potential adverse effects in living organisms and has a very high risk and the cumulative risk assessment (CRA) of the measured phthalates showed a serious threat to health (HI > 100).

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Bacteria on photovoltaic (PV) solar panels have adapted to dehydration, temperature fluctuations, and sunlight. In the current study, a bacterial strain, Bacillus velezensis KKWHNGU1, was isolated from a photovoltaic solar panel and characterized. The strain demonstrated resistance to acidic pH (pH 5), salt (1–9% w/v), UV radiation (approximately 8 min), and temperatures of up to 55 °C. Silver nanoparticles (AgNPs) were synthesized using this strain via a green synthesis approach. Tandem mass spectrometry with liquid chromatography (LC–MS) was used to perform metabolomics, which detected substances such as 2-Hydroxy-3-methylhexadecanoyl CoA, Lapachol, Oxytocin, Icosanoyl-CoA, 3-hydroxyisoheptadecanoyl-CoA, etc. in ethyl acetate extracts. AgNPs synthesis was confirmed by UV–visible spectroscopy, which showed wavelength peaks around 430 and 492 nm, and functional groups were identified based on FTIR. XRD analysis revealed three high-intensity peaks at 27.9°, 32.2°, and 46.3°, demonstrating the crystalline form of AgNPs. According to Scanning electron microscopy (SEM), the AgNPs were spherical and had a regular size of 87 nm, whereas EDX examination confirmed that the produced AgNPs contained 84.10 wt.% Ag. Antimicrobial activity testing demonstrated maximum efficacy against Staphylococcus aureus (12 mm zone of inhibition), followed by Serratia marcescens, Priestia megaterium (9 mm each), and Escherichia coli (8 mm) at a concentration of 1 mg. The AgNPs also exhibited antibiotic removal capabilities, with a maximum cephalexin removal efficiency of 80.85% at a 10 ppm concentration over a contact time of 100 min. The removal efficiency decreased at higher concentrations (57.69% at 30 ppm and 12.97% at 50 ppm). These findings suggest potential applications of the synthesized AgNPs in water treatment and biomedical fields.

The discharge of dye residues from the textile industry is a major contributor to water pollution, highlighting the urgent need for effective wastewater treatment solutions. This study investigates the synthesis of ZnO and Bi₂O₃ nanoparticles using ionic liquid-assisted methods for enhanced photocatalytic degradation of methylene blue. Three ionic liquids were employed: 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]-BF₄), 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]-PF₆), and 1-butyl-3-methylimidazolium chloride ([BMIM]-Cl). The synthesized nanoparticles were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and photoluminescence (PL) spectroscopy. Results showed that ionic liquid incorporation led to improved crystallinity, uniform morphology, and reduced particle sizes. ZnO-[BMIM]-BF₄ (1%) and Bi₂O₃-[BMIM]-BF₄ (1%) exhibited the lowest band gap energies of 2.50 eV and 2.20 eV respectively, indicating enhanced light absorption. These catalysts also demonstrated superior photocatalytic activity, achieving complete degradation of methylene blue within 40 and 35 min under UV-B irradiation, and 60 min under sunlight. The enhanced performance was attributed to improved light absorption, reduced electron–hole recombination, and efficient charge transfer facilitated by the ionic liquids. The catalysts showed excellent stability over multiple degradation cycles. This study highlights the potential of ionic liquid-assisted synthesis in developing highly efficient and stable photocatalysts for environmental remediation applications.

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Water, a vital resource for life, is increasingly threatened by industrial activities that contribute significantly to water pollution. Industrial wastewater, rich in organic substances, heavy metals, and toxic chemicals from sectors like manufacturing, mining, and petrochemicals, poses significant health and environmental risks. Understanding its physicochemical and microbial properties is essential for effective treatment. Technological advances in wastewater treatment, including membrane filtration, advanced oxidation processes, biological treatments, electrochemical treatments, adsorption, and hybrid systems, have enhanced the effectiveness and efficiency of contaminant removal while ensuring treated water complies with regulatory standards. Large-scale implementation of innovative solutions, such as zero liquid discharge systems and integrated treatment approaches, has demonstrated the potential for significant water savings and pollutant reduction, particularly in high-demand industries. These technologies also promote sustainability through resource recovery, such as nutrient recycling and energy generation, fostering circular economy practices. Beyond environmental benefits, effective wastewater treatment contributes to socio-economic development by ensuring water security, improving public health, creating employment opportunities, and reducing the costs associated with water scarcity and pollution. Smart monitoring and control systems optimize treatment processes through real-time data and predictive analytics. Addressing the environmental impact of industrial wastewater requires robust regulatory frameworks, public awareness, and collaborative efforts to ensure the preservation of water quality, the protection of ecosystems, and the safeguarding of public health for future generations.

The process of electrooxidation of the active substances Paracetamol (PCT), benzoquinone (BQ) and hydroquinone (HQ) was studied using a set of different dimensionally stable anode (DSA) and Boron doped diamond (BDD) electrodes. Comparison of the efficiency of electrocatalytic anodes was assessed using percent total organic carbon (%TOC) removal and PCT amount removal values. The removal of %TOC in synthetically prepared waters for the BDD anode reached 96%, for DSA electrodes Ti/PbO₂-IrO₂-RuO₂ 57%, Ti/IrO₂-RuO₂-TiO₂ 35%, Ti/IrO₂-RuO₂-SnO₂ 31%, Ti/RuO₂-SnO₂ 30% and Pt 24%. BDD effectively degrades PCT and almost completely mineralizes BQ and HQ. A DSA-Ti/PbO₂-IrO₂-RuO₂ electrode and a BDD electrode were used in the electrooxidation process of real industrial wastewater containing PCT. The BDD electrode had a TOC removal efficiency of 58%, while the DSA-Ti/PbO₂-IrO₂-RuO₂ electrode achieved 52%. Despite similar values ​​of PCT removal by both electrodes, the Ti/PbO₂-IrO₂-RuO₂ anode showed low mineralization of organic matter. The originality of this paper lies in the study of the electrooxidation of real PCT wastewater and the use of a Ti/PbO₂-IrO₂-RuO₂ electrode.

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