These investigations present qualitative and quantitative assessments of the 222Rn contributing potential of the technologically modified sources, e.g. mine exhausts and tailings piles, arising due to the mining and processing of uraniferous minerals at Jaduguda, India. The overall geometric mean of the 222Rn flux from low-grade uranium (U) mill tailings being 1.19 Bq m-2 s-1, requisite attenuation of 37.8% to the recommended limit of 0.74 Bq m-2 s-1 can be attained by a typical clay coverage of 20 cm. Theoretically, feasible options for selection of overburden materials for stabilisation of the tailings piles are examined. Extrapolation studies with a turbulent diffusion model yield an atmospheric dispersion pattern of 222Rn in reasonable correspondence with the prevailing concentrations, especially for locations beyond a 4 km radius. The overall 222Rn contribution of the U complex to the ambient air is the same as that contributed by the adjoining land mass of 2.75 km radius in this mineralised terrain. 相似文献
There is a demand for the development of environmental friendly methods for the synthesis of graphene composites. Reduced graphene oxide/silver (RGO/Ag) nanocomposites are very good catalysts. Here, we propose a simple, green method for the synthesis of RGO/Ag nanocomposite using the amino acid tyrosine as bioreductant and stabilizing agent. RGO/Ag nanocomposite was characterized by using various analytical techniques and studied for its catalytic degradation of 4-nitrophenol. Results of attenuated total reflectance Fourier transform infrared spectroscopy and Zeta potential at ?55 mV reveal the surface capping of tyrosine onto the reduced graphene oxide nanosheets. RGO/Ag nanocomposites show excellent catalytic reduction of 4-nitrophenol with NaBH4, when compared to actual individual silver nanoparticles. 相似文献
Environment, Development and Sustainability - Groundwater is the major primary source of drinking and irrigation water for nearly 500 million inhabitants in both rural and urban areas of the Ganga... 相似文献
The concentrations of heavy metals such as Cd, Cr, Cu, Mn, Ni, Pb and Zn were investigated in drinking water sources (surface and groundwater) collected from Swat valley, Khyber Pakhtunkhwa, Pakistan. The potential health risks of heavy metals to the local population and their possible source apportionment were also studied. Heavy metal concentrations were analysed using atomic absorption spectrometer and compared with permissible limits set by Pakistan Environmental Protection Agency and World Health Organization. The concentrations of Cd, Cr, Ni and Pb were higher than their respective permissible limits, while Cu, Mn and Zn concentrations were observed within their respective limits. Health risk indicators such as chronic daily intake (CDI) and health risk index (HRI) were calculated for adults and children separately. CDIs and HRIs of heavy metals were found in the order of Cr 〉 Mn 〉 Ni 〉 Zn 〉 Cd 〉 Cu 〉 Pb and Cd 〉 Ni 〉 Mn 〉 Cr 〉 Cu 〉 Pb 〉 Zn, respectively. HRIs of selected heavy metals in the drinking water were less than 1, indicating no health risk to the local people. Multivariate and univariate statistical analyses showed that geologic and anthropogenic activities were the possible sources of water contamination with heavy metals in the study area. 相似文献
Environmental Science and Pollution Research - This study aims to contribute to the literature and examine the causal relationship between Pakistan’s agricultural products export,... 相似文献
Environmental Science and Pollution Research - Recent attention has been focused on reproductive toxicity of nanoscale materials in combination with pre-existing environmental pollutants. Due to... 相似文献
This research examines the influence of intellectual capital on financial and environmental performance with a mediating role of green supply chain management and a moderating role of financial resources. Structural model estimation was conducted on the data set of 324 Pakistani manufacturing SMEs and showed that intellectual capital significantly encourages green supply chain management as well as significantly contributes to financial and environmental performance. Green supply chain management partially mediates the relationship between intellectual capital and performance both the financial and environmental. Financial resources significantly strengthen the relationship between intellectual capital and green supply chain management. In light of the results, we suggest that firms should encourage intellectuality among their managers and employees to adopt green practices that can improve their financial and environmental performance. In addition, it is also suggested for managers and CEOs to effectively manage financial resources that are necessary for green practices.
Environmental Science and Pollution Research - Electrocoagulation (EC) is one of the emerging technologies in groundwater and wastewater treatment as it combines the benefits of coagulation,... 相似文献
Environmental Science and Pollution Research - To understand the nexus between economic growth and energy sources, in this study, we have selected Pakistan and collected data over the period... 相似文献
Environmental Science and Pollution Research - In developing countries like Pakistan, agriculture constitutes the primary source of support for the majority of rural and the adjacent urban... 相似文献