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11.
Thompson ID 《Environmental monitoring and assessment》2006,116(1-3):263-273
A pilot scale study was conducted to find out the different forms of metals if fly ash (FA) and bioaccumulation of these metals
in the naturally growing vegetation on FA dumps. The total, acid extractable, bioavailable and water soluble fraction of metals
of Fe, Cu, Mn, Zn, Ni, Co and Pb, and their bioaccumulation coefficients (BAC) on naturally growing vegetation were determined.
FA samples had a neutral pH, low electrical conductivity, low organic C and trace amounts of N and P. The relative abundance
of total metals in FA were found in the order Fe ≤ ≤ Zn ≤ Ni ≤ Co ≤ Cu. The concentration of bioavailable (DTPA) metals depend
on the type and nature of coal used in thermal power stations. In the water the extract solution, only Fe and Zn were found
above detection limits. After one year only four species of naturally occurring herbaceous vegetation were found growing and
Cynodon dactylon (grass) covered almost entire surface of the FA. Iron accumulated to the greatest extent in vegetation followed by Mn, Zn,
Cu, Pb, Ni and Co. The sequence of BAC for different metals were Fe (202) ≤ Mn (90) ≤ Zn (63) ≤ Pb (49) ≤ Ni (41) ≤ Cu (24).
The experimental study revealed that Cynodon grass could be used for remediation of fly ash without any amendments, as this grass species act as metal excluder type. 相似文献
12.
Recognition of the social costs associated with traditional practices of urban waste management in India led to the formulation of Municipal Waste Management and Handling rules (2000). However, compliance with the proposed collection and disposal involves higher commitment in terms of both time and money on the part of the residents, local bodies as well as the state and central government. In this context, information about the value of the environmental improvements conferred upon the city dwellers would be important from the planner’s perspective. Given the non-market characteristic of waste disposal services, we infer about beneficiaries’ perceived demand for the proposed service by means of Double-Bounded Dichotomous Choice Contingent Valuation Survey conducted in the Bally Municipality in the district of Howrah, West Bengal. We estimate the average WTP by controlling for anchoring bias and use the annualized value of cost to examine the feasibility of the proposed system. 相似文献
13.
Subham Mookerjee Abhishek Jaiswal Prasenjit Batabyal Marc H. Einsporn Ruben J. Lara Banwarilal Sarkar Sucharit Basu Neogi Anup Palit 《Environmental monitoring and assessment》2014,186(10):6241-6250
The Gangetic delta is a century-old cholera endemic belt where the role of riverine–estuarine ecosystem in cholera transmission has never been elucidated. Seasonality, distribution, and abundance of environmental Vibrio cholerae O1/O139 and vibriophage in Hooghly riverine–estuarine environment and their correlation with cholera incidence pattern in West Bengal, India, have been analyzed for the first time across summer, monsoon, and winter months. A total of 146 water samples collected from two sites of the Hooghly River (Howrah and Diamond Harbour) were analyzed physicochemically along with cultivable Vibrio count (CVC), V. cholerae O1/O139, and vibriophages. V. cholerae O1 was detected in 56 (38.3 %) samples, while 66 (45.2 %) were positive for V. cholerae O1 phages. Flood tide, water temperature (31?±?1.6 °C), and turbidity (≥250 nephelometric turbidity unit (NTU)) significantly stimulated V. cholerae and vibriophage abundance in riverine ecosystem. Solitary existence of V. cholerae O1 and phages (p?0.0001) in aquatic environment divulges the dominance of either of the entity (V. cholerae O1 or V. cholerae O1 Φ) on the other. Significant association (p?0.05) between Kolkata cholera cases and V. cholerae O1 in aquatic environment implies the role of riverine–estuarine ecosystem in cholera transmission. A “biomonitoring tool” of physicochemical stimulants, tidal, and climatic variants has been proposed collating V. cholerae and phage dynamics that can forewarn any impending cholera outbreak. 相似文献
14.
This study provides a methodology for evaluation and monitoring of recurring hazards in underground coal mining. An important measure in this regard may be the ‘time between occurrences’ (TBO) of hazards that can be modeled in the similar fashion of ‘time between failures’ (TBF) data modeling which is practiced in reliability study. Typically, time between accidents is modeled in safety study. This study is therefore new in two counts: (i) statistically modeling hazard occurrences based on inspection reports and (ii) monitoring of safety status based on control charting of hazard occurrences. The methodology includes Weibull-distribution based hazard rate functions, Poisson-distribution based cumulative risk functions, and Weibull-distribution based control charts. The new methodology is applied to an underground coal mining worksystem and the results are discussed. The case study results show that hazards related to machinery, ground-fall, housekeeping, roadways, and materials are more frequently occurring. It is recommended that in addition to planned inspections for identification of hazards, a control chart based hazard mitigation scheme should be employed at the mine sections for better monitoring and control of hazards. 相似文献
15.
This study emphasizes on identification of source and accessing the spatial variation of dissolved heavy metals (Cu, Cd, Fe, Ni, Pb and Zn) in the rivers of Sundarban Biosphere Reserve India, the UNESCO world heritage site. ANOVA (Analysis of Variance), PCA (Principal Component Analysis) as well as FA (Factor Analysis) are used for assessing the significant difference in means of metals concentration among the sites and understanding the sources of these pollutants. Three principal components with cumulative variance of 32, 55, and 73 %, show that Pb, Ni and Cd are closely associated with each other indicating an anthropogenic origin of these metals. Heavy metal evaluation index (HEI) values indicate that areas close to densely populated sites are affected by elevated metals concentration due to anthropogenic activities. The ratio between the concentration of Cd, Ni and Pb in sites and the maximum respective permissible limit for these metals for conserved habitat is Log10 normalized to understand the threats of these pollutants over the distributaries of Sundarbans. Pb pollution is prevalent in the areas that rely on the fossil fuel-operated boats, for transport, whereas higher Cd concentration is found in the areas dependent on rechargeable batteries to meet their energy demand. So these anthropogenic activities and mal-practices may be responsible for the heavy metal pollution in this region. The study concludes that gradual increase in metal pollution in river water due to anthropogenic activities, particularly Pb and Cd, could have a negative impact on the conserved flora and fauna of this ecosystem. 相似文献
16.
This research paper aims at establishing baseline PM10 and PM2.5 concentration levels, which could be effectively used to develop and upgrade the standards in air pollution in developing countries. The relative contribution of fine fractions (PM2.5) and coarser fractions (PM10-2.5) to PM10 fractions were investigates in a megacity which is overcrowded and congested due to lack of road network and deteriorated air quality because of vehicular pollution. The present study was carried out during the winter of 2002. The average 24h PM10 concentration was 304 μg/m3, which is 3 times more than the Indian National Ambient Air Quality Standards (NAAQS) and higher PM10 concentration was due to fine fraction (PM2.5) released by vehicular exhaust. The 24h average PM2.5 concentration was found 179 μg/m3, which is exceeded USEPA and EU standards of 65 and 50 μg/m3 respectively for the winter. India does not have any PM2.5 standards. The 24 h average PM10-2.5 concentrations were found 126 μg/m3. The PM2.5 constituted more than 59% of PM10 and whereas PM10-PM2.5 fractions constituted 41% of PM10. The correlation between PM10 and PM2.5 was found higher as PM2.5 comprised major proportion of PM10 fractions contributed by vehicular emissions. 相似文献
17.
Ecological Restoration of Coal Mine‐Degraded Lands in Dry Tropical Climate: What Has Been Done and What Needs to Be Done?
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In developed countries, ecological restoration is a widely accepted practice to restore the productivity of degraded coal mine spoils and prevent mine‐degraded sites from acting as sources of pollution. During the past decade, ecologists realized the global need for ecological restoration, and the benefit of restoration is now assessed on the basis of ecosystem services that the restored lands can provide. In this article, the knowledge gap between crude reclamation and ecological restoration is examined, the steps crucial to ecological restoration in tropical conditions are identified, and simple guidelines are given for easy understanding. Restoration issues, such as modification of the forestry restoration approach, reestablishment of biodiversity, removal and reuse of topsoil during progressive and final stages of ecological restoration, drainage, promotion of a plant‐succession‐based approach, use of a grass–legume mixture as an initial colonizer, stabilization of steep slopes, and soil blanketing, are discussed. Those attributes of a degraded ecosystem that are responsible for the success of any restoration project are critically examined, and the opportunities provided by ecological restoration are explored. 相似文献
18.
Maiti SK 《Environmental monitoring and assessment》2007,125(1-3):111-122
Major environmental impacts of opencast mining are degradation of landscape and aesthetics of the area by creating huge overburden
dumps and deep voids at the mining sites. These overburden dumps are characterised by high rock fragment contents, low moisture
retention capacity, higher bulk density, low nutrients, lower pH and elevated metal concentrations. Overburden dumps are reclaimed
by tree species for stabilising as well as pollution control and overall improvement of the visual aesthetics. A field study
was carried out in the old reclaimed coal mine overburden dumps at KD Heslong project, Central Coalfields, India to study
the physico-chemical changes in the reclaimed overburden dumps and determines the magnitude of trace elements accumulation
in the planted tree species. Total, bioavailable and acid extractable trace metals concentration in minesoils of overburden
dump and topsoil in the mining areas was compared with undisturbed soil. The study showed that tree plantation improves the
moisture contents, bulk density, pH and overall nutrient contents of minesoils. The study revealed that lower pH in the minesoils
increases the bioavailabity of metals but concentration were found within toxic limits. However, ratio between total and bioavailable
metals was found lower in overburden dumps than topsoil due to low pH and lack of organic matter. Out of six tree species
studied, Bambusa shows highest accumulation of Fe and Cr. Bioaccumulation coefficient for Cr and Zn was found 74 times in Bambusa and 83 times in Dalbergia sissoo. The results of the study underscore the need for close monitoring of trace elements in reclaimed overburden dumps. Tree
species like Dalbergia sissoo, Eucalyptus, Cassia seamea, Acaccia mangium and Peltaphorum were found to be the best species for bioreclamation of overburden dumps. 相似文献
19.
Madhumanti Halder Subham Mookerjee Prasenjit Batabyal Anup Palit 《Environmental monitoring and assessment》2018,190(3):172
Diarrhoea remains a global public health enigma raising deep concerns for the health planners since contaminated potable water often spoils the community health structure. We hereby report a 6-year odd continuing outbreak surveillance report based on potable water indices, during which 264 water samples were screened from different districts of West Bengal, India. Samples were analysed for the presence of different enteropathogenic bacterial species by conventional molecular tools and their sensitivity to antibiotics. 78.03% samples were positive for enteropathogenic bacterial organisms and 75% samples harbored Coliform. 45.45, 12.12, and 4.16% samples were positive for E.coli, V. cholerae, and V. mimicus, respectively. Diarrhoeagenic E.coli 7 EPEC, 10 ETEC, and 2 EIEC were isolated along with 2 V. cholerae O1 Ogawa (ctxA and tcpA ElTor positive), one each from tube well and pond. Interestingly, 4 V.cholerae non-O1/non-O139 also harbored hlyA gene. The detection of toxin genes among this bacterial pool of sampled water indicates the fallout of the potable water sources, thus enabling us to establish that it is none other than the contaminated potable water system which often wreaks havoc in the south Bengal diarrhoeal menace. The consequences are further complicated by the presence of drug-resistant pathogenic bacterial pool to fluoroquinolone, beta-lactams, and cephalosporins, in the accessible potable water, with threats of outbreaks exploding into an epidemic, given suitable environment, poor sanitation, and unhygienic practices. Therefore, we strongly recommend re-modelling of ‘point-of-use water disinfection’ measures and adequate personal hygiene for healthier community life. 相似文献
20.
A field study was conducted in the fly ash lagoons of Santandih Thermal Power Plant located in West Bengal (India) to find
out total, EDTA and DTPA extractable metals in fly ash and their bioaccumulation in root and shoot portion of the naturally
growing vegetation. Fly ash sample has alkaline pH and low conductivity. The concentration of total Cu, Zn, Pb and Ni were
found higher than weathered fly ash and natural soil, where as Co, Cd and Cr were found traces. Five dominant vegetation namely,
Typha latifolia, Fimbristylis dichotoma, Amaranthus defluxes, Saccharum spontaenum and Cynodon dactylon were collected in the winter months (November–December). Bioaccumulation of metals in root and shoot portions were found
varied significantly among the species, but all concentration were found within toxic limits. Correlation between total, DTPA
and EDTA extractable metals viz. root and shoot metals concentration were studied. Translocation factor (TF) for Cu, Zn and
Ni were found less than unity, indicates that these metals are immobilized in the root part of the plants. Metals like Mn
have TF greater than unity. The study infers that natural vegetation removed Mn by phytoextraction mechanisms (TF > 1), while
other metals like Zn, Cu, Pb and Ni were removed by rhizofiltration mechanisms (TF < 1). The field study revealed that T. latifolia and S. spontaenum plants could be used for bioremediation of fly ash lagoon. 相似文献