Enhanced catalytic complete oxidation of 1,2-dichloroethane over mesoporous transition metal-doped γ-Al2O3

High-surface-area mesoprous powders of γ-Al₂O₃ doped with Cu^2 +, Cr^3 +, and V^3 + ions were prepared via a modified sol–gel method and were investigated as catalysts for the oxidation of chlorinated organic compounds. The composites retained high surface areas and pore volumes comparable with those of undoped γ-Al₂O₃ and the presence of the transition metal ions enhanced their surface acidic properties. The catalytic activity of the prepared catalysts in the oxidation of 1,2-dichloroethane (DCE) was studied in the temperature range of 250–400°C. The catalytic activity and product selectivity were strongly dependent on the presence and the type of dopant ion. While Cu^2 +- and Cr^3 +-containing catalysts showed 100% conversion at 300°C and 350°C, V^3 +-containing catalyst showed considerably lower conversion. Furthermore, while the major products of the reactions over γ-alumina were vinyl chloride (C₂H₃Cl) and hydrogen chloride (HCl) at all temperatures, Cu- and Cr-doped catalysts showed significantly stronger capability for deep oxidation to CO₂.     

Predictive modelling of piezometric head and seepage discharge in earth dam using soft computational models

Environmental Science and Pollution Research - Predictions of pore pressure and seepage discharge are the most important parameters in the design of earth dams and assessing their safety during the...     

The impact trilemma of energy prices,taxation, and population on industrial and residential greenhouse gas emissions in Europe

Environmental Science and Pollution Research - As a major source of pollution and the cause of climate change, greenhouse gas emissions are attracting the attention of scholars, policymakers, and...     

Investigating global surface temperature from the perspectives of environmental,demographic, and economic indicators: current status and future temperature trend

Environmental Science and Pollution Research - Anthropogenic activities have increased atmospheric concentrations of greenhouse gas emissions, which have observably increased global temperature....     

Determination of mercury and arsenic levels in fish caught in the Beheshtabad River,Chaharmahal and Bakhtiari Province,Iran

Mercury and arsenic pollution has been recognized as a potential environmental and public health problem for over 40 years. The major source of exposure to mercury for humans is the ingestion of fish. This study was conducted with the aim of determining the levels of mercury and arsenic in the muscles of four fish species caught in the Beheshtabad River and comparing the results with the maximum tolerance levels for mercury and arsenic. The samples of 90 fish were used for the determination of both the metals by graphite furnace atomic absorption spectrometry. The results showed that the concentrations ranged from 1.5 to 3.8 µg kg^?1 for mercury and from 35 to 70 µg kg^?1 for arsenic, with means of 2.7 ± 0.5 and 57 ± 12 µg kg^?1, respectively. Both mean levels were lower than the threshold limits acceptable by WHO standards.     

Heavy metals assessment and identification of their sources in agricultural soils of Southern Tehran, Iran

A detailed investigation was conducted to evaluate heavy metal sources and their spatial distribution in agricultural fields in the south of Tehran using statistics, geostatistics, and a geographic information system. The content of Cd, Cu, Co, Pb, Zn, Cr, and Ni were determined in 106 samples. The results showed that the primary inputs of Cr, Co, and Ni were due to pedogenic factors, while the inputs of Zn, Pb, and Cu were due to anthropogenic sources. Cd was associated with distinct sources, such as agricultural and industrial pollution. Ordinary kriging was carried out to map the spatial patters of heavy metals, and disjunctive kriging was used to quantify the probability of heavy metal concentrations higher than their recommended threshold values. The results show that Cd, Cu, Ni, and Zn exhibit pollution risk in the study area. The sources of the high pollution levels evaluated were related to the use of urban and industrial wastewater and agricultural practices. These results are useful for the development of proper management strategies for remediation practices in the polluted area.     

Clove bud oil: an efficient, economical and widely available oil for the inhibition of wheat seed germination

Pre-harvest sprouting refers to the precocious germination of the grain in the spike prior to harvest as a result of moist weather conditions at harvest time. From the agricultural viewpoint, it is necessary to impose an exogenous dormancy to wheat seeds in order to improve the resistance of seed to pre-harvest sprouting. In this regard, we found that clove bud essential oil is a strong inhibitor for wheat seed germination. The extract obtained from clove bud by supercritical fluid extraction using CO₂ as solvent minimized the number of extracts to two compounds, eugenol and eugenyl acetate. Eugenol, as the main constituent of the oil, was responsible for its strong inhibitory activity in wheat seeds. The aqueous solution of clove bud oil was submitted to germination assay at various concentrations from 50 to 400 mg/L. Complete inhibition of seed germination was recorded when the concentration was 400 mg/L. Roots and sprouts have similar sensitivity to inhibitory effect. In an empirical study, the synergistic cooperation of eugenol and eugenyl acetate from clove bud oil in the inhibition of seed germination was found to be a 1:1 ratio. The clove bud essential oil is widely available and will broaden the horizon of applications for natural and safe inhibitors in the fields.