Concentration of heavy metals (Cd, Ni, Zn, Fe, Cu, Mn, Pb, Cr, Hg and As) in the waters of River Yamuna and in the soil of
agricultural fields along its course in Delhi are reported from 13 sites, spread through the Delhi stretch of Yamuna, starting
from the Wazirabad barrage till the Okhla barrage. Varying concentration of heavy metals was found. Peaks were observed in
samples collected downstream of Wazirabad and Okhla barrage, indicating the anthropogenic nature of the contamination. The
Wazirabad section of the river receives wastewater from Najafgarh and its supplementary drains, whereas the Shahdara drain
releases its pollution load upstream of the Okhla barrage. Average heavy metal concentration at different locations in the
river water varied in the order of Fe>Cr>Mn>Zn>Pb>Cu>Ni>Hg>As>Cd. The river basin soil shows higher level of contamination
with lesser variation than the water samples among sampling locations, thereby suggesting deposition over long periods of
time through the processes of adsorption and absorption. The average heavy metal concentration at different locations in soil
varied in the order of Fe>Mn>Zn>Cr>Pb>Ni>Hg>Cu>As>Cd. 相似文献
Environmental Science and Pollution Research - The energy sector of Argentina is predominantly reliant on fossil fuels. Consequently, such fossil fuel dependency within the nation’s power... 相似文献
Environmental Science and Pollution Research - Energy consumption for sustainable development has become a crucial issue in recent years. The anthropogenic effects of traditional energy sources... 相似文献
Environmental Science and Pollution Research - Environmental sustainability concerns are increasing worldwide; both developing and developed countries face environmental degradation. Literature has... 相似文献
Environmental Science and Pollution Research - Environmental sustainability has become a major concern for policymakers across the globe. In this regard, understanding the factors responsible for... 相似文献
Environmental Science and Pollution Research - The study inspects the inverted U shape of the environmental Kuznets curve (EKC) hypothesis following the influence of economic growth on CO2... 相似文献
Methanogens, the members of domain Archaea are potent contributors in global warming. Being confined to the strict anaerobic environment, their direct cultivation as
pure culture is quite difficult. Therefore, a range of culture-independent methods have been developed to investigate their
numbers, substrate uptake patterns, and identification in complex microbial communities. Unlike other approaches, fluorescence
in situ hybridization (FISH) is not only used for faster quantification and accurate identification but also to reveal the
physiological properties and spatiotemporal dynamics of methanogens in their natural environment. Aside from the methodological
aspects and application of FISH, this review also focuses on culture-dependent and -independent techniques employed in enumerating
methanogens along with associated problems. In addition, the combination of FISH with micro-autoradiography that could also
be an important tool in investigating the activities of methanogens is also discussed. 相似文献
Delhi is one of the many megacities struggling with punishing levels of pollution from industrial, residential, and transportation
sources. Over the years, pollution abatement in Delhi has become an important constituent of state policies. In the past one
decade a lot of policies and regulations have been implemented which have had a noticeable effect on pollution levels. In
this context, air quality models provide a powerful tool to study the impact of development plans on the expected air pollution
levels and thus aid the regulating and planning authorities in decision-making process. In air quality modeling, emissions
in the modeling domain at regular interval are one of the most important inputs. From the annual emission data of over a decade
(1990–2000), emission inventory is prepared for the megacity Delhi. Four criteria pollutants namely, CO, SO2, PM, and NOx are considered and a gridded emission inventory over Delhi has been prepared taking into account land use pattern, population
density, traffic density, industrial areas, etc. A top down approach is used for this purpose. Emission isopleths are drawn
and annual emission patterns are discussed mainly for the years 1990, 1996 and 2000. Primary and secondary areas of emission
hotspots are identified and emission variations discussed during the study period. Validation of estimated values is desired
from the available data. There is a direct relationship of pollution levels and emission strength in a given area. Hence,
an attempt has been made to validate the emission inventory for all criteria pollutants by analyzing emissions in various
sampling zones with the ambient pollution levels. For validation purpose, the geographical region encompassing the study area
(Delhi) has been divided into seven emission zones as per the air quality monitoring stations using Voronoi polygon concept.
Dispersion modeling is also used for continuous elevated sources to have the contributing emissions at the ground level to
facilitate validation. A good correlation between emission estimates and concentration has been found. Correlation coefficient
of 0.82, 0.77, 0.58 and 0.68 for CO, SO2, PM and NOx respectively shows a reasonably satisfactory performance of the present estimates. 相似文献
Latin America experiences an increasing urban primacy index and a rapid expansion of the financial system, putting direct pressure on the demand for resources to satisfy the consumption of large cities. We investigate the convergence of per capita biocapacity in 16 Latin America countries and evaluate the factors that influence its evolution over time. Specifically, we analyze the impact of the urban primacy index, economic progress, and the financial globalization index on the convergence of per capita biocapacity. We use the methodological framework developed by Phillips and Sul Econometrica 75:1771-1855, (2007) to analyze the convergence and the formation of convergence clubs of biocapacity during 1970–2017. The findings indicate that the countries of the region do not share a common trend of biocapacity, although they are grouped into five converging clubs. Biocapacity transition analysis reveals that countries have heterogeneous transition pathways between them. Using marginal effects, we find that the urban primacy index and economic progress reduce the biocapacity. The effect of the financial globalization index on biocapacity is not conclusive. The quantile regressions reveal that quantiles’ impact of the urban primacy index and financial globalization on per capita biocapacity is heterogeneous. However, the effect of economic progress on biocapacity that predominates among quantiles is positive. The adoption of common policies among the countries that form the converging clubs could improve the effectiveness of pro-environmental policies and promote the achievement of the Sustainable Development Goals related to environmental quality.