International Journal of Environmental Science and Technology最新文献

The study was focused on analyzing the land use and land cover status, change patterns, and future scenarios in the Mayurakshi basin in Jharkhand and West Bengal state of eastern India. The dataset collected for image classification included Landsat 5 (TM) (1991–2008) and Landsat 8 (OLI) (2020). Various sequential preprocessing steps such as atmospheric correction, image enhancement, mosaicking, masking, and clipping were performed using QGIS 3.16 and ArcGIS 10.8 software. The land use and land cover classes found in the study area were water, vegetation, bare land, agriculture, and built-up, and classification was executed by using the Random Forest machine learning algorithm. The accuracy of the classified land use and land cover was validated and accepted with Kappa agreements of 0.89, 0.85, and 0.88 for the years 1991, 2005, and 2020, respectively. Throughout the study period, agriculture emerged as the dominant land use class, followed by vegetation and bare land. The area under the land use and land cover categories of water, vegetation, and bare land continuously decreased between the years 1991–2005 and 2005–2020, while agriculture and built-up areas recorded an increase of 4.49%, 0.76%, 17.81%, and 2.04%, respectively. To project future land use and land cover status, the popular Cellular Automata Markov Chain Model was employed. The projected results indicate that agriculture will remain the dominant land cover with a share of 70.24%, followed by vegetation at 17.72% and built-up areas at 5.09%. However, a marginal decline is expected in both the agriculture and built-up classes.

Novel polymer composites with unique characteristics as new materials are essentially needed to meet future demands. Terpoly(anthranilic acid, m-aminobenzoic acid, and o-nitroaniline) emeraldine base (EB)/macro-microcomposites were generated from equimolar ratios of the corresponding molecules and different ratios of bentonite via in situ oxidative terpolymerization. Their spectral properties upon joining the m-aminobenzoic acid and the o-nitroaniline moieties in the skeleton of polyanthranilic acid were inspected. The spectral analyses were utilized to emphasize the results of both terpoly(o, m-aminobenzoic acid, and o-nitroaniline) (EB) and poly(o, m-aminobenzoic acid, and o-nitroaniline)/bentonite composites. The TGA analyses of the purified terpolymer with and without bentonite in the N₂ atmosphere were investigated. Furthermore, the terpolymer composite morphology was investigated by the SEM technique with the micro-macrometric particle sizes 0.470–2.780 μm at different magnifications.

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Plastic pollution and microplastic (MP, 1 µm to 5 mm) generation are growing problems affecting the global community and a wide range of natural and disturbed environments. Urban and suburban waterways are directly impacted by plastic pollution due to their proximity to population centers and many different types single use plastic waste sources. In this study, plastic waste accumulation and fragmentation was investigated along the Cooper River in Camden County, NJ. Polymer composition was identified for individual plastic waste particles collected along the Cooper River using Fourier transform infrared (FTIR) spectrometry. Multiple human-built structures (Wallworth Lake, Evans Pond and Hopkins Pond dams) along the Cooper River were found to accumulate different types of plastic waste. The accumulation of plastic waste along these structures resulted in the initial stages of plastic fragmentation and the identification of large MP particles (1 to 5 mm). Quantitative analysis revealed that fragmented polystyrene (PS) particles constituted 82.8% of the total plastic fragments identified, most of which were identified at the Wallworth Lake dam. Many other types of fragmented plastic litter, including polyethylene and polypropylene, were identified at the Wallworth Lake dam, as well. This research demonstrates that engineered structures within urban and suburban aquatic ecosystems serve as significant aggregators of plastic debris, thereby catalyzing its breakdown into microplastics. Considering the escalating ecological and human health ramifications of microplastic proliferation, the fragmentation of plastic waste in an urban and suburban waterway observed in this study can also result in potentially toxic smaller MP particles, and increased exposure to aquatic organisms and humans.

This paper simulated hexavalent chromium (Cr(VI)) adsorption using cocoa pod husk biosorbent in a fixed bed column using Aspen Adsorption. This study was designed to show the effectiveness of computational methods in designing, optimising and evaluating the scaled-up adsorption process using low-cost adsorbents. To the best of our knowledge, the economic analysis of Cr(VI) removal using biosorbent adsorption columns with the assistance of Aspen Adsorption and response-surface methodology (RSM) has not been performed previously. Design Expert and RSM were used to optimise and describe the effect of flow rate and initial concentration on breakthrough and saturation times. The breakthrough time was improved by a higher bed height (2.0 m), a wider diameter (2.0 m), and lowering the flow rate (0.010 L/s). The initial concentration had no effect (1.00 mol/L). The predicted breakthrough and saturation time were 29,360 s and 313,351 s, respectively. Two scenarios were economically compared over 20 years. Scenario 1 (1-day breakthrough time) costs $746,585 and Scenario 2 (4-week breakthrough time) costs $1,538,319. This is because Scenario 2 used a taller, wider column which required a greater amount of adsorbent, and 387,873 m³ of water were processed, respectively. Processed water was dependent on the flow rate and breakthrough time. It was concluded that cocoa pod husk could be an efficient adsorbent and the adsorption process can be successfully simulated and optimised. The use of alternative low-cost adsorbents should be encouraged. The economic study showed that simulation and RSM data could successfully be used for economic analysis.

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The research is devoted to solve the problem of elevated dust levels in subway air through the implementation of a proposed dust collection system. A comprehensive experiment to determine the fractional and chemical compositions, as well as dust density, in the existing metro systems of Almaty (Kazakhstan) and Novosibirsk (Russian Federation) was conducted. The experiment results led to hypotheses about the sources of dust emission in subways. An innovative method for de-dusting tunnel air has been developed. The method is based on the use of air flows generated by the piston action of trains and the installation of labyrinth filters in the ventilation joints of stations. The parameters of the computational model of a subway line on the basis of decomposition approach to mathematical modeling of aerodynamic processes methods of computational aerodynamics by transition from a full model of a subway line to an open-ended periodic one have been substantiated. The research also justifies the geometric parameters of the labyrinth filters, determining their effectiveness based on air velocity and the number of filter element rows. Additionally, potential energy savings achievable with the proposed system were assessed. The scope of application of the results of the presented study of air distribution from the piston effect in subway structures and the effectiveness of the proposed air filtration system are limited to subways with single-track tunnels and open-type stations equipped with ventilation joints.

Agrochemicals have become essential to meet the increasing demand for food and other commodities, but they can contaminate the environment, especially water resources, if not properly managed. Advanced Oxidation Processes (AOP), such as Fenton’s process, are a quick alternative to remove these toxic compounds from water and wastewater. Previous studies suggest that carboxylic acids can promote the Fenton reaction by accelerating the degradation rate of H₂O₂ and the formation of hydroxyl radicals. In this study, formic and acetic acids were applied in a heterogeneous Fenton system to degrade imidacloprid (C₉H₁₀N₅ClO₂), a model agrochemical molecule. Activated limonite and steel wool were used as low-cost heterogeneous iron precursors. The activated limonite was produced by reducing limonite’s iron under H₂ flow at 200 and 300 °C. The Fenton process with 300 °C-activated limonite showed a reaction rate approximately 8-fold higher than the test using natural limonite and 2-fold higher than the one with limonite activated at 200 °C. Adding acetic acid to the Fenton process using the 300 °C-activated limonite increased the reaction rate by more than 2-fold. When steel wool was used as the iron precursor, the addition of acetic acid resulted in the complete degradation of imidacloprid within 1 min of reaction. Acetic acid exhibited a higher promoting activity than formic acid, and the degradation rate increased with increasing concentrations of both carboxylic acids. This study indicates that carboxylic acids can serve as Fenton promoters to increase the degradation rate of agrochemicals, such as imidacloprid, present in water and wastewater.

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Soil electrokinetic remediation (SEKR) is considered an effective method for removing pollutants by integrating chemical, physical, and biological treatments. It has multiple applications in fields such as dewatering, consolidation, sedimentation, seed germination, etc. This work builds upon a series of recent publications on SEKR, covering topics like electrode approaches, reverse polarity-based SEK, SEK design modifications, installation of perforated materials, and chemical-based SEK. This review focuses on the role of pulsed electric field (PEF) in enhancing the performance of SEKR. There are several other names for the PEF, including periodic, interval, “ON” and “OFF”, intermittent, and breaking electric fields. PEF is proposed as a solution to overcome certain obstacles in SEKR. The review evaluates PEF's impact on (a) remediating organic and inorganic hazards, anions, and salt, (b) integrating with other processes (reverse polarity, phytoremediation, and bioremediation), and (c) electro-dewatering and consolidation. PEF offers several advantages, such as reducing energy consumption, converting the residual fractions into weakly bound fractions, achieving satisfactory remediation, avoiding the voltage drop in the area across the cation exchange membrane, enhancing desorption and/or migration of charged species, permits the exchange of contaminant from solid to the liquid phase (interstitial fluid), allows contaminant diffusion through the soil pores during the off time, generate high electroosmotic flow, avoiding electrode corrosion, decreasing concentration polarization, etc. However, it may also prolong the remediation period and cause contaminant diffusion through the soil pores, which are considered obstacles for SEKR. This review also describe different techniques related to PEF and highlights the potential use of solar cells as a renewable energy source for SEKR.

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