International Journal of Environmental Science and Technology最新文献

In this study, the efficacy of three important adsorbents- pure sand, a sucrose-derived graphene sand composite, and an innovative 3D sucrose-derived graphene composite using silica and carbonate sands for transforming the field of copper (II) ion removal was meticulously explored. Coating the surfaces of silica and porous carbonate sands with sucrose and subjecting them to heat treatment resulted in the formation of layered graphene on the sands. Converting these materials into 3D structures creates a cost-effective and efficient 3D graphene adsorbent with nano-porous channels. The graphene silica sand composite, boasting a thickness of 9 cm, achieved an impressive 82.4% removal rate, while the carbonate sand composite with 9 cm thick achieved an astonishing 99% removal rate due to its high specific surface area and porous structure. Among the utilized adsorbents, the 3D graphene carbonate sand composite, boasting a lower thickness of 4.5 cm and featuring an ingenious multilayered graphene coating and nanoporous channels, displayed a high efficiency of 96.4% in removing copper (II) ions, making it the most effective among all the studied adsorbents. The significant results pave the way for the development of economically viable, highly efficient, and environmentally friendly adsorbents, representing a major stride in combating copper contamination.

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A process showing potential for slowing down the quick recombination of photogenerated electron-holes and enhancing the dispersion of charges produced by photocatalytic reaction during photodegradation processes is coupling of semiconductor photocatalysts. In the current study, tungsten oxide embellished graphitic carbon nitride (WCN) nanocomposites have been prepared. Three different photocatalytic composites of tungsten oxide and gCN in the mass ratios of 1:1, 2:1, and 3:1, denoted WCN1, WCN2, and WCN3, were created for the methylene blue (MB) and methyl orange (MO) photodegradation. Thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were adapted to characterize the morphological, structural and optical features of the treated photocatalyst. Graphitic carbon nitride (gCN), a metal-free photocatalyst, has drawn considerable interest because of its possible use in photocatalytic environmental pollution treatment. The findings show that, rather than changing the sample crystalline structure, this extensively disperses gCN to increase its surface area. The combined photocatalytic degradation rate of MB after 150 min in visible light (500–800 nm) was 52.46% for gCN, 86.4% for WCN1, 98.8% for WCN2, and 91.2% for WCN3. For methyl orange, the generated materials' photocatalytic activity was examined. The analysis outcome reveals astonishing deterioration values for WCN1 (72.9%), WCN2 (89.7%), and WCN3 (83.6%), respectively. For five cycles, the hybrid photocatalyst yielded consistent photodegradation results and check their Total organic carbon reduction in the wastewater after treatment. It has been observed that W₂O₆/gCN is promising photocatalyst for dye industrial wastewater remediation using visible light.

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Apart from nitrogen fertilizer management, improving nitrogen fertilizer formulations is known as a promising strategy for improving nitrogen uptake efficiency. The present study was aimed to synthetize a nitrogenous fertilizer with low ammonia volatilization potential. Pruning wastes of mature pistachio trees were converted to biochar, enriched with urea, and encapsulated with five different biodegradable polymer and solution compounds, namely Fert.1, Fert.2, Fert.3, Fert.4 and Fert.5. Our objective was to investigate the ammonia volatilization potential of these five products compared to urea in two soils with distinct electrical conductivities of 5.3 and 13.79 dS m⁻¹. The results showed that total volatilized nitrogen from soil with electrical conductivity of 5.3 dS m⁻¹ was 85%, 80%, 72%, 66%, 36% and 50% of applied nitrogen for urea, Fert.1, Fert.2, Fert.3, Fert.4, and Fert.5, respectively. While total volatilized nitrogen from urea, Fert.1, Fert.2, and Fert.3 was not impacted by increased soil salinity, it significantly increased by 49% and decreased by 22% for Fert.4 and Fert.5, respectively. Hence, Fert.4 and Fert.5 with 57% and 52% reduction in total volatilized ammonia compared to urea are recommended for non-saline and saline conditions, respectively. Overall, it can be concluded that encapsulation of nitrogen fertilizer can decrease ammonia volatilization potential by up to 50%.

In apartments and buildings, dilution ventilation systems are traditionally used to improve the air quality and reduce dust and pollution. However, this is not feasible without various filter systems if the outdoor air is not clean. Korea’s atmosphere contains ultrafine dust and various gaseous pollutants. Therefore, the use of air cleaners or ventilation systems with dust collection and activated carbon filters to improve indoor air quality has recently increased. However, traditional dust collection and activated carbon filters exhibit limited performance in removing gaseous pollutants in homes. Photocatalysts remove gaseous pollutants; therefore, a model combining a titanium dioxide (TiO₂) photocatalytic reactor and mechanical ventilation system, which is mostly applied in new apartments in Korea, was proposed. The performance of indoor pollutant removal was assessed through mock-up tests, and it was verified that formaldehyde (HCHO) could be reduced by at least 35.48% (with 1ACH (air change per hour) over 150 min) and toluene (C₇H₈) by at least 39.95% (with 1ACH over 300 min). Thus, it is anticipated that if the photocatalytic ventilation system is applied to apartments, it will provide enhanced performance in the removal of various indoor pollutants.

Due to the widespread use of glyphosate in agriculture, remediation techniques have emerged to reduce its impact on the environment. The use of agricultural by-products as soil amendments can enhance microbial proliferation in soil and subsequently reduce glyphosate persistence. Agave by-products possess constituents that can influence on the sorption of phosphorus in soil and displace glyphosate from soil surfaces, which may increase glyphosate availability and, therefore, increase the efficacy of glyphosate remediation. This work describes an initial approach to assess the potential of agave leaf powder to enhance glyphosate bioremediation. Phenolic acids, organic acids, and other constituents were evaluated from Agave attenuata leaf powder. Two experiments were performed under laboratory conditions. A batch equilibrium sorption experiment using three different New Zealand soils showed significant desorption of orthophosphate, aluminium, and iron after the addition of A. attenuata leaf powder to soil solution. Analysis of soil induced respiration showed that agave leaf powder in combination with two glyphosate doses increased the soil induced respiration ratio. Exogenous carbon associated with these treatments was positively correlated with the Carbon: Nitrogen ratio in soil solution, inferring increased microbial activity. These results suggest that Agave leaf powder has potential as a soil amendment to enhance glyphosate biodegradation. Further research is needed to clarify the effect of agave leaf powder on glyphosate biodegradation; and on the desorption of orthophosphate, aluminium, and iron from soils.

In water quality literature, in-situ data collections and their experimental investigations are prevalent; however, numerical modelling of flow of water in waterbodies are rare in literature. The pollutant dispersion affecting water quality must be explored. In the study, a three-dimensional numerical model was developed to analyze water flow and pollutant dispersion in the Upper Ganga Canal (UGC) from the old canal bridge to the Ganeshpur bridge in Roorkee. The model simulated pollutant inflow from five sewage outlets and examined the impact of varying sewage velocities (0.2 m/s, 0.4 m/s, and 0.6 m/s) on pollutant concentrations. Results showed that pollutant concentration is maximum near the canal banks and minimum at the centre of the canal. The study also tracked the movement of solid particles, revealing that particles larger than 80 µm settled quickly, with 100% of particles settling at the base, whereas smaller particles (< 25 µm) remained suspended longer, with only 30% settling. The findings indicate that sewage pollutants predominantly affect water concentration near the canal banks and are proportional to the number of sewage inlets and their velocities. This model provides critical insights into the dispersion of pollutants in canal systems, essential for improving water quality management strategies.

A novel photocatalyst comprising g-C3N4/NiAl-layered double hydroxide (LDH)/CeO2 nanocomposites were synthesized via a straightforward hydrothermal method. Rhodamine B (RB) was employed as a model dye to assess the degradation efficiency of the nanocomposites. The catalytic efficiency of the synthesized ternary nanocomposites was compared with of dual g-C3N4/NiAl-LDH and NiAl-LDH/CeO2 nanocomposites. The pristine photocatalysts were subjected to characterization through X-ray diffraction (for crystallinity), field emission scanning electron microscopy and transmission electron microscopy (for microstructure), thermogravimetry analysis (for thermal stability) and X-ray photoelectron spectroscopy (for composition and chemical bondings). UV–visible diffuse reflectance spectroscopy were used for energy band gap calculations. Results demonstrated the successful formation of g-C3N4/NiAl-LDH/CeO2 3D nanocomposite by bridging g-C3N4 and CeO2. The resultant g- C3N4/NiAl-LDH/CeO2 composite exhibited superior photocatalytic activity compared to bare NiAl-LDH, CeO2, and g-C3N4/NiAl-LDH and LDH/CeO2 nanocomposites, achieving a degradation efficiency of 98% for RB under UV irradiation after 350 min. A broader range of absorption (from UV to visible light) was achieved for ternary nanocomposite. A plausible mechanism was proposed based on the observed results and the kinetic of degradation was studied.

This study investigated the CO₂ absorption on the functionalized multi-walled carbon nanotubes with 1,8-diaminooctane (aMWCNT) in pure water solution and N-methyl diethanolamine (MDEA). Hexadecyltrimethylammonium bromide (CTAB) was used as a surfactant to disperse the nanofluid solution. The results showed that at a concentration of 0.005 wt% aMWCNT in water at 16 bar, the CO₂ absorption capacity increased by 17.5% compared to pure water. It was found that adding aMWCNT to 15wt% MDEA solution improves the absorption rate. However, the highest absorption was at 0.005wt% aMWCNT in the solvent. The absorption capacity increased to 59% at the highest pressure in 15%wt MDEA solution, including aMWCNT, compared to 15%wt MDEA solution. It can be concluded that adding aMWCNT has advantages such as increasing the absorption capacity and reducing the heat of absorption.

S. Karaj is the fourth largest city upwind of Tehran, Iran’s capital. The complexity of emission sources in and around the city makes the development of targeted mitigation policies more challenging. This study is focused on identifying the mass concentration of PM_2.5, along with its chemical composition and associated sources. Biweekly fine PM samples, started in October 2020 and lasted for one year,were obtained at an air quality monitoring station and analyzed by ion chromatography paired with a mass spectrometer (IC-MS) and thermal-optical analysis (TOA). Annual average concentration of PM_2.5 was 29.61 ± 17.84 µg/m³, ranging from 9.16 µg/m³ (in December 2020) to 99.04 µg/m³ (in November 2020). Based on the chemical mass closure (CMC) results, organic matter (OM) was a principal constituent, accounting for 31% of PM_2.5 mass. The nitrate, dust and non-sea sulfate contributed most significantly to PM mass by accounting for 15%, 13% and 11%, respectively. The diagnostic ratios reflected that, anthropogenic sources (mobile sources and biomass combustion) play a significant role in PM concentration. The study’s findings are significant as they not only influence policy-making for controlling PM in one of the largest cities but also have a broader impact on air pollution in the capital city, located just downwind. The insights provided by this study on primary components in fine particulate matter will be instrumental in leveraging these findings alongside emission inventory and observational data. This integration aims to inform policymaking processes and facilitate the creation of science-based policies, while also furnishing essential data for health impact assessments.

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Recently, concerns have increased regarding the presence of antibiotics in water resources. This increase has been caused by the discharge of untreated or incompletely treated pharmaceutical wastewater into aquatic environments. Metronidazole is a widely used antibiotic for the treatment of infections caused by anaerobic bacteria and protozoa. The present study investigated the efficacy of nano-pumice prepared from pumice mine waste as a low-cost adsorbent for metronidazole removal from aqueous environments. The effects of input variables, including pH, contact time, nano-pumice dose, and metronidazole concentration, were investigated. The experimental design was based on central point’s using the response surface method to study adsorption. After optimizing the input variables, isotherm and kinetic studies were conducted. The properties of the adsorbent were characterized through FESEM, XRD, BET, and FTIR analyses. The results indicated that the adsorption process followed a quadratic polynomial model, with F and p values of 990.936 and less than 0.0001, respectively. Additionally, the R² was 0.9989, and the Adj-R² was 0.9979. The optimal conditions for achieving a removal efficiency of 94.55% and maximum adsorption capacity of 15.313 mg/g were found to be pH = 3, contact time = 60 min, adsorbent dose = 1.5 g/L, and metronidazole concentration = 20 mg/L. Furthermore, the adsorption process aligned with the Langmuir isotherm and pseudo-first-order kinetics, as indicated by R² values of 0.9965 and 0.9859, respectively. Therefore, nano-pumice can be suggested as a natural and environmentally friendly adsorbent with significant potential for the adsorption of metronidazole and similar antibiotics from aqueous media.

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