Water, Air, & Soil Pollution最新文献

A solvothermal route was used to synthesize manganese ferrite/multi-wall carbon nanotubes (MnFe₂O₄/MWCNT) composite catalyst, which was firstly employed to activate peroxymonosulfate (PMS) to eliminate rhodamine B (RhB) from water. The catalytic activity of the as-obtained MnFe₂O₄/MWCNT for PMS activation and RhB degradation was higher than that of MnFe₂O₄ and MWCNT. The optimal MnFe₂O₄/MWCNT-10 catalyst (0.3 g/L) can remove 98.1% of RhB (20 mg/L) from water by activating PMS (1.0 g/L) after 100 min of reaction, and this catalyst remained stable in the oxidation process. Quenching experiments, X-ray photoelectron spectroscopy (XPS) and electrochemical analysis demonstrated that RhB elimination in the MnFe₂O₄/MWCNT-PMS system was accomplished by the non-radical (¹O₂ and electron transfer) and free radical (O₂^•−, SO₄^•‒ and •OH) oxidation pathways, and ¹O₂ played a leading role. The influence of operational factors (PMS dosage, initial solution pH, catalyst dosage, reaction temperature, common inorganic anions and water matrix) on RhB removal by MnFe₂O₄/MWCNT-10 activated PMS was investigated in detail. The presence of Cl^‒ ions significantly boosted RhB degradation due to the production of more ¹O₂.

The potential risks associated with steroid estrogens (SEs) on both water and human health are significant. Through the utilization of bibliometric analysis methods and visual network graph analysis, this study revealed several key findings: (1) There is a growing interest in research on SEs pollution in water, as evidenced by the increasing annual and cumulative number of publications. Scholars worldwide are particularly focused on studying the environmental behavior, toxicological effects, removal methods, and detection technologies related to SEs in water. (2) Upon entering the environmental medium, free estrogens (FEs) undergo processes such as adsorption, migration, transformation, and degradation. Conjugated estrogens (CEs) can serve as precursors to FEs under specific conditions, with interconversion between the two types of estrogens also observed. (3) The toxic effects of SEs on aquatic animals primarily manifest in reduced fertilized egg and offspring survival rates. In terms of plant growth, SEs exhibit stimulatory effects at low concentrations and inhibitory effects at high concentrations. Furthermore, SEs can impact human health by modulating the expression of genes essential for reproductive and immune functions through epigenetic mechanisms. (4) Currently, various pretreatment technologies for water samples are utilized, such as solid phase extraction, liquid–liquid extraction, and other methods. The removal methods for SEs can be categorized into physical, chemical, and biological techniques. Moving forward, it is crucial to focus on developing efficient and sensitive target sensors, as well as establishing more sensitive, convenient, and accurate detection technologies to support decision-making in managing, controlling, and restoring SEs pollution risks in water.

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Microplastic (MP) pollution has become a pressing environmental issue globally, prompting extensive research into its prevalence, distribution, and composition in diverse ecosystems. This study offers a comprehensive analysis of MP contamination in Indian lakes, rivers, and coastal environments, synthesizing recent investigations across the country. Significant MP abundance and distribution were observed in lakes, particularly in high-altitude and remote areas like Kashmir, Ladakh, and Himachal Pradesh. Notable findings include high MP concentrations in lakes such as Anchar Lake, Pangong Lake, and Tsomoriri Lake, with tourism, textile disposal, and industrial emissions identified as major pollution sources. Lonar Lake and Kanke Lake showed MP contamination in both surface water and sediments, highlighting the need for urgent mitigation measures. Studies on Indian rivers revealed diverse MP characteristics, with fragments, fibers, pellets, and foams being dominant. Chemical analysis identified common polymer components originating from industrial waste, plastic debris, and synthetic textiles. Seasonal and geographical factors influenced MP distribution in rivers, emphasizing plastic pollution's pervasive presence. Coastal regions of Southern India exhibited high concentrations of plastic debris, primarily fibres from synthetic textiles, with prevalent polymers derived from urban runoff, marine activities, and industrial discharges. The present study offers insightful information about the widespread and varied characteristics of MP contamination in Indian aquatic ecosystems, emphasizing the urgent need for comprehensive mitigation strategies to safeguard biodiversity and ecosystem health. Further research is necessary to understand MP sources, impacts, and distribution, informing evidence-based management strategies to reduce the potential risks concerning people’s health and the environment related to plastic contamination.

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Different environment of deposition along with microplastic

This study investigated the preparation and modification of MOF-5 for the removal of acid violet 7 (AV7) dye. One type of waste-derived siliceous material, i.e., rice husk ash (RHA), was used in different ratios to create modified MOF-5 adsorbents. From preliminary studies, it appears that MOF-5, modified with RHA-1000, has significant potential for the removal of the AV7 dye. Using Taguchi optimization approach, the optimum adsorbent for the removal of AV7 dye from aqueous solutions was found to be MOF-5/RHA-1000/(2:2:2). The study also investigated the factors influencing the removal of AV7 dye by the modified MOF-5 adsorbent. The optimum initial dye concentration, shaking rate, temperature, pH, amount of adsorbent and contact time for effective AV7 dye adsorption were 85 mg/L, 250 rpm, 50 °C, 9, 0.4 g and 4 h, respectively. The results showed that the Temkin isotherm model and the pseudo-first order model gave excellent agreement with the experimental conditions. The study further demonstrated that the adsorption of AV7 dye onto modified MOF-5 is a non-spontaneous and endothermic process. The results of the SEM micrographs revealed a consistent and nearly uniform arrangement of pristine MOF-5, with cubic particles of similar size. The BET study indicated that the specific surface area was a factor influencing the effectiveness of AV7 dye adsorption. The FTIR analysis confirmed the successful formation of the pristine and modified MOF-5 framework and the presence of new peaks in the FTIR spectra of spent adsorbents indicates the successful adsorption of AV7 dye onto the MOF-5 adsorbents. The results demonstrate that modified MOF-5 adsorbents are effective for removing AV7 dye.

The concentration of ambient ammonia gas (NH₃(g)) in Kitakyushu, Japan was determined by a passive method for four years, with a mean value of 4.7 ppb. On a weekly basis, the NH₃(g) concentration fluctuated greatly; however, by applying a low-pass filter of 1 Hz/yr, a common feature in seasonal variation, a relative maximum for one year appeared in late spring to summer, and a relative minimum appeared in late autumn to winter. The two outliers with high NH₃(g) concentrations (16.5, 10.5 ppb) were observed in July and September in the second year, 2019. By using the backward trajectory analysis as well as comparing with other air pollutants from the viewpoint of time series and correlation coefficient, the high NH₃(g) concentration was considered to be due mainly to local meteorology and emissions. Five cases in which the NH₃(g) concentration was N.D. (not detected) reflected the low level in actual atmospheric condition; the PM_2.5 concentration also decreased synchronously during corresponding period. Comprehensively taking into account not only the large fluctuation but also the evaluation of high and low NH₃(g) concentrations, a statistically significant increasing trend of ca. 0.24 ppb/yr, providing an increasing rate of ca. 5.1%/yr during the study period which was comparable to the studies by satellite data analyses, was clarified. Wavelet analysis further showed three oscillation periods in NH₃(g) concentration on the scales of 30–50 weeks (w), 60–80 w, and 85–128 w. Moreover, the strongest oscillation occurred at 111 w with the variance of 3990, and three down-up conversions for the real part of wavelet coefficients were found, providing an overall cognition of NH₃(g) concentration variation to predict further changes.

The clean water crisis in Indonesia has recently increased due to wastewater pollution in groundwater. As an alternative, the use of seawater for clean water needs to be developed, considering that Indonesia has a very abundant area of sea water which is an alternative as a raw material for clean water resources. In this study, we fabricated TiO₂ nanoparticles (NPs) embedded in CA/PEG/Chitosan membranes for seawater desalination. The effect of TiO₂ NPs for high-performance of developed membranes was evaluated by reverse osmosis (RO) method to determine the unique characteristics and performance of membranes material for evaluating seawater desalination process. Preparation of CA/PEG/Chitosan membrane-embedded TiO₂ NPs was evenly dispersed into the CA/PEG/Chitosan membrane interlayer by blending method and printed on a glass surface to obtain a thin film developed membranes. The characterization and performance over developed membranes were evaluated to observe unique characteristic by adding TiO₂ NPs and its high-performance to reject salt content in seawater. Based on these results, the developed membranes were interestingly characterized by using FTIR spectrophotometer shows the presence of functional groups for organic and inorganic bonds such as C = O, -CH₃, NH₂, C-O, -OH, C-H, and Ti–O-Ti. The presence of TiO₂ NPs indicates the attachment of TiO₂ NPs in the membranes. In addition, a scanning electron microscope (SEM) was also confirmed to evaluate the morphological structure of without and CA/PEG/Chitosan-modified TiO₂ type (I) and (II), in which the pore size of CA/PEG/Chitosan is larger than membrane-embedded TiO₂ NPs. Moreover, XRD analysis also confirmed that TiO₂ NPs has shown amorphously structures formed on CA/PEG/Chitosan membrane, in which the TiO₂ NPs crystal size with 0.25 g of 2.87 nm and 0.5 g of 3.05 nm. Determination of seawater desalination and water flux has shown Ca/PEG/Chitosan membrane-modified TiO₂ NPs can increase salt rejection value but reduce membrane water flux value. The highest flux value is 29.4 L/m indicates by CA/PEG/Chitosan membrane, while the salt rejection value is 61.76% from CA/PEG/Chitosan membrane-embedded 0.5 g TiO₂ NPs. This study provides a new idea for preparing highly permeable and seawater desalination membranes of CA/PEG/Chitosan membrane-embedded TiO₂ NPs under the reverse osmosis method for producing clean water resources.

Aluminium-based coagulants are extensively used in water treatment, producing significant quantities of waste sludge (WTS), that poses challenges for landfill disposal. Eutrophication, mainly driven by phosphorus (P) enrichment from wastewater, remains a critical environmental concern in aquatic ecosystems. WTS contains substantial amounts of aluminium (Al), which exhibits a high affinity for phosphate. This study aimed to assess the phosphorus adsorption capacity (qmax) of WTS and its potential for agricultural use. The WTS samples were characterized using various analytical techniques. Kinetic and isothermal experiments were conducted using dried (105 °C) and calcined (650 °C) WTS samples. Characterization revealed crystallinity differences between dried WTS and calcined WTS Kinetic tests, indicating equilibrium times of 16 h for dried WTS and 1 h for calcined WTS. Isothermal tests showed maximum adsorption capacity values at pH 7 of 13.81 mgP g⁻¹ for dried WTS and 52.03 mgP g⁻¹ for calcined WTS, highlighting the enhanced phosphorus removal efficiency of calcined WTS. Phytotoxicity assessments demonstrated that dried and calcined WTS promoted enhancements in germination and root elongation of Lactuca sativa of 20 and 10%, respectively, suggesting its potential agricultural benefit. Therefore, WTS demonstrates promise for tertiary wastewater treatment, contributing to a circular economy by potentially reclaiming phosphorus-rich compounds for agricultural reuse.

The urban periphery and the villages around the river Aras are one of the most important agricultural areas in Iran. Against this background, the present study investigated the hydrochemistry of groundwater along the Aras River in Iran to assess the suitability of groundwater quality for agricultural irrigation. Water samples were taken from 34 groundwater sources in 2021 and 2022. The suitability of groundwater for irrigation was assessed using the sodium absorption ratio (SAR), residual sodium carbonate (RSC), magnesium absorption ratio (MAR), Kelly ratio (KR) and Wilcox classification. The Langelier Saturation Index (LSI) and the Ryznar Stability Index (RSI) were used to predict the corrosion and deposition behavior of the groundwater. The optical emission spectrometer with inductively coupled plasma was used to detect the heavy metals. Monte Carlo simulation was used to assess the non-carcinogenic and carcinogenic risks of these waters when used as drinking water. The average concentration of major ions follows for cations Na⁺˃ Ca²⁺˃ Mg²⁺˃ K⁺ and anions in both groups SO₄²⁻ > HCO₃⁻ > Cl⁻. The corrosion in all samples was found to have a low to considerable corrosion potential. The concentrations of the tested metals were within the range recommended by the WHO in most samples. In summary, it can be said that most of the groundwater sources in the area studied are appropriate for irrigation purposes. However, to reduce the risks associated with drinking, it is advisable to monitor water quality by locating sources of pollution and limiting the input of contaminants.

While several studies have employed coagulation-flocculation (CF) for textile wastewater (TW) treatment, conventional process optimization techniques cause insufficient pollution reduction and large sludge volume generation that deteriorate the environmental matrix and elevate the system’s operating cost. To avoid these drawbacks, this study focuses on optimizing an integrated CF/pyrolysis process using artificial intelligence technique and response surface methodology (RSM) for the dual benefit of TW treatment and biochar production. In the CF experiment, water hyacinth (WH) was employed as a bio-coagulant material for TW treatment under different pH, coagulant dosage, mixing speed, and settling time levels. Under the optimum CF conditions yielded by RSM and artificial neural network (ANN) models (initial pH: 5.5 vs. 5.7, WH dosage: 3.76 g/L vs. 3.5 g/L, settling time: 116 min vs. 102 min, and slow mixing speed: 25 rpm vs. 23 rpm), incomparable removal efficiencies for dye (87.3% vs. 91.3%) and turbidity (93.4% vs. 98.2%) were obtained. These removal efficiencies dropped to 83.5% and 87.6%, respectively, for operating the CF process using unoptimized operating factors. The pyrolysis of post-coagulation sludge yielded a carbon-rich biochar material characterized by a porous structure and abundant cationic microelements. The integrated performance of the CF/pyrolysis scheme under ANN-based optimal conditions achieved a shorter payback period of 5.2 years compared to RSM (5.7 years) and unoptimized (7.9 years) conditions. Furthermore, the optimized scheme supported several sustainable development goals that complied with clean water, good health, and climate change mitigation.

Graphical Abstract

In this paper, a novel graphene oxide/β-cyclodextrin composite (GO/β-CD) adsorbent was synthesized for the effective simultaneous removal of dyes. GO and GO/β-CD were characterized using BET, SEM, FT-IR, Raman, and XRD techniques. GO/β-CD has a BET specific surface area of 0.25 m²/g. The surface of GO/β-CD contains a significant number of reactive groups, such as carboxyl groups, which enable the effective adsorption of methylene blue (MB). The adsorption of GO/β-CD on methylene blue (MB) in aqueous solution was also investigated kinetically and thermodynamically. The kinetic and thermodynamic parameters of the reaction were calculated. Based on the experimental results, the adsorption reaction was determined to be a spontaneous endothermic reaction. The adsorption of MB on GO/β-CD best fit the Langmuir model based on the results of the adsorption isotherm model fitting. The maximum adsorption capacity of the composite was 434.78 mg/g. The GO/β-CD adsorbent was highly efficient at adsorbing cationic dyes, and its performance remained consistently high after six cycles. Thus, GO/β-CD offers the advantages of nontoxicity, excellent adsorption and regeneration properties, and great potential for treating real and simulated wastewater from various industries.