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Ranjan RK Ramanathan A Singh G Chidambaram S 《Environmental monitoring and assessment》2008,147(1-3):389-411
The 26 December 2004-Tsunami has deposited sediments in the Pichavaram mangrove ecosystem, east coast of India. Ten surface and three core sediment samples were collected within thirty days of the event. High concentrations of Cd, Cu, Cr, Pb, and Ni were observed in the tsunamigenic sediments. With respect to Fe, Zn, and Mn, there was little variation as compared to pre-tsunami values. The geo-accumulation index was calculated in order to assess the contamination of heavy metals in the sediments. The sediments were extremely contaminated with respect to Cd and they showed moderate to strong contamination with respect to Cr, Pb and Ni. The study highlighted the future risk of enhanced metal pollution in near future in this mangrove ecosystem. 相似文献
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Appraisal of salinity and fluoride in a semi-arid region of India using statistical and multivariate techniques 总被引:1,自引:0,他引:1
Suman Mor Surender Singh Poonam Yadav Versha Rani Pushpa Rani Monika Sheoran Gurmeet Singh Khaiwal Ravindra 《Environmental geochemistry and health》2009,31(6):643-655
Various physico-chemical parameters, including fluoride (F−), were analyzed to understand the hydro-geochemistry of an aquifer in a semi-arid region of India. Furthermore, the quality
of the shallow and deep aquifer (using tube well and hand pumps) was also investigated for their best ecological use including
drinking, domestic, agricultural and other activities. Different multivariate techniques were applied to understand the groundwater
chemistry of the aquifer. Findings of the correlation matrix were strengthened by the factor analysis, and this shows that
salinity is mainly caused by magnesium salts as compared to calcium salts in the aquifer. The problem of salinization seems
mainly compounded by the contamination of the shallow aquifers by the recharging water. High factor loading of total alkalinity
and bicarbonates indicates that total alkalinity was mainly due to carbonates and bicarbonates of sodium. The concentration
of F− was found more in the deep aquifer than the shallow aquifer. Further, only a few groundwater samples lie below the permissible
limit of F−, and this indicates a risk of dental caries in the populace of the study area. The present study indicates that regular monitoring
of groundwater is an important step to avoid human health risks and to assess its quality for various ecological purposes. 相似文献
3.
Reddy Yudhistir Ganguly Dipnarayan Singh Gurmeet Prasad Mamidala Harikrishna Arumughan Paneer Selvam Banerjee Kakolee Kathirvel Arumugam Ramachandran Purvaja Ramachandran Ramesh 《Environmental science and pollution research international》2021,28(31):42051-42069
Environmental Science and Pollution Research - Efficient nutrient cycling and adequate sediment bioavailable nutrient supply are considered to be the two most important factors regulating the high... 相似文献
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Kumar A Ramanathan AL Prabha S Ranjan RK Ranjan S Singh G 《Environmental monitoring and assessment》2012,184(5):3027-3042
The pollution of aquifer sediments by heavy metals has assumed serious concern due to their toxicity and accumulative behavior.
Changes in environmental conditions can strongly influence the behavior of both essential and toxic elements by altering the
forms in which they occur and therefore quantification of the different forms of metal is more meaningful than total metal
concentrations. In this study, fractionation of metal ions in aquifer sediments of Semria Ojhapatti area, Bhojpur district,
Bihar has been studied to determine the ecotoxic potential of metal ions. The investigations suggest that iron, copper, and
arsenic have a tendency to remain associated in the following order residual > reducible > acid-soluble > oxidizable; manganese
and zinc have tendency to be associated as residual > acid-soluble > reducible > oxidizable. The risk assessment code reveals
that manganese and zinc occur in significant concentration in acid-soluble fraction and therefore comes under the high risk
category and can easily enter the food chain. Most of the iron, copper, and arsenic occur as immobile fraction (i.e. residual)
followed by its presence in reducible fraction and would pose threat to the water quality due to changing redox conditions.
The metal enrichment factor in the study area shows moderate to significant metal enrichment in the aquifer sediments which
may pose a real threat in near future. The geo-accumulation index of metals also shows that the metals lie in the range of
strongly contaminated (for iron at shallow depths) to moderately contaminated to uncontaminated values. 相似文献
5.
Dipnarayan Ganguly Gurmeet Singh Purvaja Ramachandran Arumughan Paneer Selvam Kakolee Banerjee Ramesh Ramachandran 《Ambio》2017,46(6):667-679
Net ecosystem metabolism and subsequent changes in environmental variables were studied seasonally in the seagrass-dominated Palk Bay, located along the southeast coast of India. The results showed that although the water column was typically net heterotrophic, the ecosystem as a whole displayed autotrophic characteristics. The mean net community production from the seagrass meadows was 99.31 ± 45.13 mM C m?2 d?1, while the P/R ratio varied between 1.49 and 1.56. Oxygen produced through in situ photosynthesis, exhibited higher dependence over dissolved CO2 and available light. Apportionment of carbon stores in biomass indicated that nearly three-fourths were available belowground compared to aboveground. However, the sediment horizon accumulated nearly 40 times more carbon than live biomass. The carbon storage capacities of the sediments and seagrass biomass were comparable with the global mean for seagrass meadows. The results of this study highlight the major role of seagrass meadows in modification of seawater chemistry. Though the seagrass meadows of Palk Bay are increasingly subject to human impacts, with coupled regulatory and management efforts focused on improved water quality and habitat conservation, these key coastal ecosystems will continue to be valuable for climate change mitigation, considering their vital role in C dynamics and interactions with the overlying water column. 相似文献
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Rajesh Kumar Ranjan Gurmeet Singh Joyanto Routh Al Ramanathan 《Environmental monitoring and assessment》2013,185(10):8197-8213
The geochemistry of coastal sediments of southern India was altered after the tsunami in 2004. A five-step sequential extraction procedure was applied to assess the effects of tsunami on mobility and redistribution of selected elements (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn). Ten surface sediments and three cores were analyzed for different metal fractions (exchangeable, carbonate, reduced, oxidized, and residual). Total metal concentrations increased in mangrove sediments after the tsunami, but their spatial distribution did not show significant variation (except Mn). The sediments were mixed by the tsunami, and there was lack of variation in metal concentrations in different fractions with depth (except Pb and Mn). High concentrations of Pb and Zn occurred in the oxide fractions, whereas Cu, Cr, Cd, and Ni were high in the organic and sulfide-rich fractions. Metals in the residual fraction (lattice bound) had the highest concentration suggesting their non-availability and limited biological uptake in the system. Most of the metals (except Mn) do not constitute a risk based on the different geochemical indices. 相似文献
7.
Reddy Yudhistir Ganguly Dipnarayan Singh Gurmeet Prasad Mamidala Harikrishna Arumughan Paneer Selvam Banerjee Kakolee Kathirvel Arumugam Ramachandran Purvaja Ramachandran Ramesh 《Environmental science and pollution research international》2021,28(31):42070-42070
Environmental Science and Pollution Research - A Correction to this paper has been published: https://doi.org/10.1007/s11356-021-14155-3 相似文献
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