Water, Air, & Soil Pollution最新文献

Radioactive wastewater containing high concentrations of radionuclides threatens ecosystems and human health. Developing environmentally friendly adsorbents with high enrichment efficiency and ease of solid–liquid separation is essential for removing europium from wastewater. In this study, three amide podand derivatives with different alkyl chain structures were loaded onto polyacrylonitrile via electrospinning, yielding DODGA@PAN, DPDGA@PAN, and DEHDGA@PAN nanofibers. The presence of two carbonyl oxygens and one ether oxygen in these materials enhances coordination with trivalent metal ions, making them highly efficient in europium removal.In reuse tests, DODGA@PAN and DPDGA@PAN maintained strong performance, with only 3.84% and 3.87% decreases after five adsorption–desorption cycles, respectively. In contrast, DEHDGA@PAN, due to its branched structure, exhibited higher adsorption capacity but lower reusability. This branched structure increased porosity, improving adsorption while also causing deformation, reducing its durability. Europium removal efficiency varied with changes in pH, temperature, time, and initial concentration. The Langmuir isotherm model confirmed effective europium adsorption by all three nanofibers. Kinetics indicated chemisorption, while thermodynamics showed the process was endothermic and spontaneous.

A ternary nanocomposite integrating disodium ethylenediaminetetraacetate (EDTA), cetyltrimethylammonium bromide (CTAB) and illite/smectite (I/S) clay nanoflakes (denoted as C-I/S-E) was prepared by a mechanochemical route in a high energy–density stirred bead mill. The characterizations confirm the exfoliation of clay into nanoflakes and effective EDTA functionalization. The adsorption behavior of Ni (II) ions in aqueous solution was evaluated with respect to the effects of adsorbent dosage, contact time, and initial Ni (II) concentration. Meanwhile, the adsorption mechanism in an atomic scale was analyzed via the first-principles density functional theory (DFT) calculations. The integrated experimental and simulation findings indicate that the enhanced adsorption performance of the EDTA-modified I/S clay nanoflakes is attributed to a synergistic interplay of physical adsorption by the clay substrate and chemical chelation by the EDTA functional groups. The nanocomposite C-I/S-E shows a promising potential as an efficient adsorbent for removal of heavy metal ions from wastewater.

Microplastics (MPs) are emerging contaminants that have garnered widespread global attention owing to their pervasive pollution across various environmental matrices. In this study, pine needles were employed as passive samplers for atmospheric microplastics (AMPs) to systematically investigate the occurrence status of AMPs in five typical counties/cities (Urumqi, Changji, Shihezi, Hutubi and Manasi) within the "Wuchangshi" region of Xinjiang, China. The results indicated that the annual average abundance of AMPs in the study region was 9.63 ± 4.59 n/g. In terms of spatial distribution, Urumqi exhibited the highest AMPs abundance (11.62 ± 7.15 n/g), while the abundance in winter was significantly higher than that in other seasons (16.81 ± 3.87 n/g). Fibrous AMPs accounted for the highest proportion (48.6%), with colorless being the dominant color. Polyethylene (PE) was the predominant polymer type, accounting for 19.7% of the total AMPs. Potential sources of pollution mainly including transportation, commercial activities, and industrial operations. The ecological risk exhibited regional variations, and the Potential Ecological Risk Index (PERI) indicated an overall high-risk status. This study aims to provide a new reference for the application of pine needles as passive samplers and a scientific basis for the formulation of national environmental quality standards for MPs.

Recently, with the proliferating growth of pharmaceutical pollutants as the expiration date passed, household and agricultural poisons, as well as inorganic pollutants, have become a substantial global issue. Photocatalysts represent an efficient, affordable, and safe solution for degrading these contaminants using light. This study aimed to synthesize Ag₃PO₄ (APO) nanoparticles as metallic photocatalyst assistance, Zinc Stannate (Zn₂SnO₄; ZSO) perovskite as main photocatalyst, and BiOCl (BOC) nanosheets as materials non-metallic photocatalyst assistance for efficient photodegradation of 4-chlorophenol (C₆H₄ClOH) antibiotic (CPA), diazinon (C₁₂H₂₁N₂O₃PS) poison (DZP) as organic contaminants, and inorganic contaminants of nitrate (NO₃⁻), and carbon dioxide (CO₂). The photodegradation of diazinon poison, 4-chlorophenol antibiotic, NO₃⁻, and CO₂ contaminants was conducted under experimental conditions with a pH range of 1–9, temperature between 25–65 °C, agitation speed of 100–400 rpm, retention time of 1–6 h, photocatalyst dosage of 0.25–1.5 g/l, polluters concentration of 50–500 ppm, and a distance of 5–20 cm betwixt the visible light and photoreactor. The photocatalytic efficiency of the Ag₃PO₄/Zn₂SnO₄/BiOCl ternary heterojunction photocatalyst was enhanced by examining the impact of solution pH, photoreaction time, photocatalyst dosage, and contaminant concentrations. Notably, the Ag₃PO₄/Zn₂SnO₄/BiOCl (APO/ZSO/BOC) nanocomposite demonstrated the maximum photodegradation of 4-chlorophenol antibiotic (CPA), achieving a value of 80%. Moreover, the maximum photodegradation of diazinon poison (DZP) reached approximately 85% with visible light exposure. Eventually, the highest removal of inorganic pollutants, such as nitrate and carbon dioxide, was achieved with values of 75% and 80%, respectively. Finally, the Ag₃PO₄/Zn₂SnO₄/BiOCl ternary photocatalyst maintained its reactivity even after five experiments of repeated use.

Long term indiscriminate use of heavy metals (HMs) contaminated wastewater for irrigation purposes leads to build up of higher concentration of HM in soils which will be up taken by food grain crops and ultimately transferred to human body causing bioaccumulation. Biochar, through its high surface area and numerous pores, can be effective in absorbing bioavailable HM, reducing risk of exposure. However, different modification process is used to activate the biochar for better performance and efficiency, in our study we used acid modification using phosphoric acid and a strongly acidic salt iron chloride. Preparation of biochar using invasive weed like parthenium not only reduce weed load of crop field but is economical also due to its easy availability and higher char yield. We used ten treatment combinations of two modified biochar types with unmodified biochar at graded application dose of 5, 7.5 and 10 t ha⁻¹ and one control treatment replicated thrice following completely randomized design. We noticed biochar at the dose of 10 t ha⁻¹ significantly enhanced growth and yield parameters of rice, moreover phosphoric acid and iron chloride modified biochar does this job better even at lower doses of 5 and 7.5 t ha⁻¹ compared to higher dose of (10 t ha⁻¹) unmodified biochar. We noted significant enhancement in soil microbial population after application of biochar and modified biochar, which further enhance different soil enzymes activities related to nutrient cycling as compared to control treatment. Nearly, 1.5 times increment of dehydrogenase, alkaline phosphatase and urease activity in 10 t ha⁻¹ modified biochar treatment was noted as compared to control. Thus, it can be concluded that application of simple and modified biochar was effective in increasing the soil microbial and biochemical parameters in heavy metal contaminated soil.

Due to the rapid development of clothing modernization, dyes have become increasingly necessary. Methylene blue (MB) is among the most widely used dyes, and its environmental persistence after use warrants attention. The combination of Fe₃O₄ composite extracted from iron sand with conductive carbon (C), along with varying proportions of montmorillonite (Mt) from clay (Fe₃O₄/C:Mt with sample ratios of 1:1, 1:2, and 1:3), synthesized using a simple sol–gel method, was selected as a natural material for MB degradation. The proposed photocatalytic degradation process was monitored in real time for 24 h using an IoT-based system as an innovative methodology. It was found that the Fe₃O₄/C:Mt (1:1) composite exhibited 91.97% MB degradation under optimal conditions of pH 8.2, temperature 26.1 °C, photocatalyst dosage of 70 mg, and an initial MB concentration of 400 mg/L. The photocatalytic process was carried out without UV lamps and stirring to mimic environmental conditions. Degradation results were attributed to the small average crystallite size (22.28 ± 2.79 nm) and the consistent narrowing of the (Delta (LO-TO)) (490 cm⁻¹). After three cycles, the catalyst from sample 1 retained high photocatalytic efficiency (77.90%). Based on these findings, the integration of natural materials with an IoT system may represent a novel approach to treating MB-containing wastewater, ready for environmental implementation.

Water pollution caused by the dye industry is a major environmental concern, particularly in regions where textile and dye production are prevalent. Wastewater from dyeing operations is typically characterized by high concentrations of dyes, salts, heavy metals, and other harmful chemicals, making it highly toxic to aquatic ecosystems and human health. Our work deals with the minimization of two commonly used dyes. First is Congo Red, despite its popularity in industrial applications, Congo Red is known for its toxicological and environmental risks, particularly in water pollution. Congo Red (CR) and Rose Bengal (RB) in water bodies can cause significant contamination due to their persistence and difficulty in degradation. These organic contaminants (dye) are carcinogenic and mutagenic, posing potential risks to both aquatic organisms and humans. Also, it has low lipid solubility, which can limit its ability to cross cell membranes and accumulate in tumors. Newly synthesised of ruthenium-doped titanium dioxide nanoparticles have been successfully obtained and demonstrated to be extremely efficient photocatalysts for the photodegradation of dye wastes in water samples. This study employs a sol–gel route, which provides fine control over particle size, dopant dispersion, and material uniformity, all while operating under mild conditions and avoiding the use of harmful substances. A variety of features confirm the production of Ru@TiO₂. Analyses are performed using XRD, FTIR, SEM–EDS, and HR-TEM to understand the composition of the composite. The photocatalytic effectiveness of Ru@TiO₂ photocatalyst is measured using various factors such as pH, contact time, photocatalyst dose, and dye concentration. Ru@TiO₂ is an excellent photocatalyst for dye degradation from wastewater under optimal conditions, with 94 and 96% elimination of CR and RB, respectively, within 100 min of reaction time. In addition, more than 92.0% of total organic carbon was eliminated. Furthermore, the reusability test demonstrated the extraordinary stability of Ru@TiO₂ after five cycles, with just a tiny decrease ( < 16%) in dye degradation efficiency.

Due to human activities, large quantities of dyes, represented by methylene blue, have been discharged into aquatic ecosystems, posing a global threat. The lignite residue (Lig) produced during humic acid extraction requires appropriate valorization or treatment to prevent potential environmental impacts. To develop a modified material with enhanced uptake performance for the effective removal of methylene blue (MB), Lig was functionalized with Fe₃O₄ to form Lig-Fe. The underlying adsorption mechanisms were systematically investigated through comprehensive characterization. Results revealed that Lig was transformed into a mesoporous composite with enhanced surface functionality. The maximum uptake amount and removal effciency of Lig-Fe was 189.91 mg/g and 98.05%. Kinetic analysis indicated that the adsorption process followed a pseudo-second-order model, suggesting chemisorption as the dominant mechanism. Adsorption equilibrium was reached within 150 min for Lig-Fe, compared to 180 min for unmodified Lig. Isotherm modeling revealed hybrid mechanisms that vary with temperature, involving both Langmuir-type monolayer adsorption and Freundlich-type multilayer physisorption. Analyses confirmed chemisorption pathways involving Fe–O coordination, π-π interactions, and actions with oxygen functionalities. The outstanding adsorption performance of Lig-Fe provides insights for further optimizing its modification parameters. This work also provides a technical pathway for simultaneous lignite residue valorization and industrial wastewater remediation, supporting China's dual carbon strategy through circular economy implementation.

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Industrial wastewater from oil refining processes poses significant environmental challenges due to the high concentration of petroleum hydrocarbons and increased chemical oxygen demand (COD), where conventional treatment methods fail due to severe membrane fouling in treatment systems. This study introduces a novel and stable green catalyst (GC) derived from calcium oxide (CaO) prepared from tomato sepal biomass, which is integrated as an efficient visible light photocatalyst with a polyacrylonitrile (PAN) membrane in a photocatalytic membrane reactor (PMR). The main objective was to optimize the PMR to maximize oil and COD removal while minimizing permeate flux (PF) reduction using synthetic wastewater simulated from industrial petroleum effluents. For this purpose, PAN membrane was fabricated via phase inversion and both GC and PAN were characterized using several techniques. Performance evaluation was performed under visible LED light irradiation with 14 W intensity, neutral pH and flow rate of 0.6 L/min, at membrane pressure of 2 bar, with different parameters through central composite design (CCD) in response surface methodology (RSM). The results of the experiments showed the outstanding performance of the PMR membrane with a one-hour treatment, which produced a wastewater flux of 74.34 L/m²h. At a concentration of 100 ppm, the oil and COD removal efficiencies were determined to be 99.20% and 97.15%, respectively. In addition, the PAN membrane showed remarkable self-cleaning performance, achieving a flux recovery ratio (FRR) of 96.24% when operating with industrial wastewater. The results showed the high potential of the PMR system in advancing industrial wastewater treatment by significantly reducing membrane fouling and increasing effluent quality, and achieving compliance with World Health Organization (WHO) standards through residual oil and COD concentrations of 5 and 100 ppm, respectively.

It is important for snowmelt runoff pollution management to recognize the snow pollution characteristics from different underlying surfaces. The underlying surfaces are categorized into five main groups in this study: residential communities, parks, squares, urban roads, and snow dump sites, sampling process was followed a five-point sampling method, to investigate the natural and deposited snow pollution characteristics, the results showed that the land type has an important effect on snow pollution, the deposited snow in urban road and snow dump sites were polluted more seriously. Significant correlation among different pollutants was also founded: chloride ions (Cl⁻) serve as a biomarker for the use of deicing agents, and their peak concentration are significantly positively correlated with total phosphorus (TP), chemical oxygen demand (COD), total nitrogen (TN), as well as various pollutants such as copper (Cu), iron (Fe), and zinc (Zn), indicating the synergistic input mechanism of snow melting activity with nutrients, oxygen consuming substances, and some heavy metal pollution. The dissolved organic matter (DOM) is influenced by both endogenous and terrestrial inputs, with endogenous contributions being more prominent. This provides a new perspective for understanding the biogeochemical processes of organic pollutants in urban environments, and also provides important basis for accurately identifying pollution sources and developing collaborative control strategies.

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