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431.
Raj Kumar Singh Manoj Datta Arvind Kumar Nema 《Environmental Modeling and Assessment》2010,15(6):549-567
In developing countries, several old municipal solid waste dumps (unlined landfills) exist adjacent to large cities, releasing
contaminants to the underlying aquifer, thus posing the hazard of groundwater contamination. These uncontrolled waste dumps
need to be prioritized in terms of the groundwater contamination hazard posed by them, so that necessary control and remedial
measures can be undertaken in a phased manner. This paper presents a time-dependent system for evaluating groundwater contamination
hazard rating of municipal solid waste dumps. The system is based on source–pathway–receptor relationships and evaluates the
relative value of hazard posed by a site over its entire leaching life, on a scale of 0–1,000. The system parameters have
been selected based on literature and expert opinions. The Delphi technique is used to derive the relative importance weights
of the system parameters. The proposed system is compared with six selected existing hazard rating systems. The comparison,
made by way of score range analysis, shows that the proposed system exhibits a much wider range of hazard scores for various
scenarios of site conditions, and hence the proposed system is more sensitive to varied site conditions. The application of
different systems to six municipal solid waste dumps located in four cities of India shows that, whereas the existing systems
individually produce clustered scores and return the same rank to more than one site, the proposed system produces significantly
varying scores and return different ranks to different sites. This demonstrates that the proposed system improves decision
making and makes a better basis for prioritization of municipal solid waste dumps for adopting control and remedial measures. 相似文献
432.
Santosh Ranjan Mohanty Parul Rajput Bharati Kollah Dipanti Chourasiya Archana Tiwari Muneshwar Singh A Subba Rao 《Environmental monitoring and assessment》2014,186(6):3743-3753
There is worldwide concern over the increase use of nanoparticles (NPs) and their ecotoxicological effect. It is not known if the annual production of tons of industrial nanoparticles (NPs) has the potential to impact terrestrial microbial communities, which are so necessary for ecosystem functioning. Here, we have examined the consequences of adding the NPs particularly the metal oxide (CuO, ZnO) on CH4 oxidation activity in vertisol and the abundance of heterotrophs, methane oxidizers, and ammonium oxidizers. Soil samples collected from the agricultural field located at Madhya Pradesh, India, were incubated with either CuO and ZnO NPs or ionic heavy metals (CuCl2, ZnCl2) separately at 0, 10, and 20 μg g?1 soil. CH4 oxidation activity in the soil samples was estimated at 60 and 100 % moisture holding capacity (MHC) in order to link soil moisture regime with impact of NPs. NPs amended to soil were highly toxic for the microbial-mediated CH4 oxidation, compared with the ionic form. The trend of inhibition was Zn 20?>?Zn 10?>?Cu 20?>?Cu 10. NPs delayed the lag phase of CH4 oxidation to a maximum of 4-fold and also decreased the apparent rate constant k up to 50 % over control. ANOVA and Pearson correlation analysis (α?=?0.01) revealed significant impact of NPs on the CH4 oxidation activity and microbial abundance (p?<?0.0001, and high F statistics). Principal component analysis (PCA) revealed that PC1 (metal concentration) rendered 76.06 % of the total variance, while 18.17 % of variance accounted by second component (MHC). Biplot indicated negative impact of NPs on CH4 oxidation and microbial abundance. Our result also confirmed that higher soil moisture regime alleviates toxicity of NPs and opens new avenues of research to manage ecotoxicity and environmental hazard of NPs. 相似文献
433.
Removal of hexavalent chromium from contaminated ground water using zero-valent iron nanoparticles 总被引:1,自引:0,他引:1
Ritu Singh Virendra Misra Rana Pratap Singh 《Environmental monitoring and assessment》2012,184(6):3643-3651
Batch experiments were conducted on ground water samples collected from a site contaminated with Cr(VI) to evaluate the redox
potential of zero-valent iron (Fe0) nanoparticles for remediation of Cr(VI)-contaminated ground water. For this, various samples of contaminated ground water
were allowed to react with various loadings of Fe0 nanoparticles for a reaction period of 60 min. Data showed 100% reduction of Cr(VI) in all the contaminated ground water
samples after treatment with 0.20 gL−1 of Fe0 nanoparticles. An increase in the reduction of Cr(VI) from 45% to 100% was noticed with the increase in the loading of Fe0 nanoparticles from 0.05 to 0.20 gL−1. Reaction kinetics of Cr(VI) reduction showed pseudo first-order kinetics with rate constant in the range of 1.1 × 10−3 to 3.9 × 10−3 min−1. This work demonstrates the potential utility of Fe0 nanoparticles in treatment and remediation of Cr(VI)-contaminated water source. 相似文献
434.
Manoj Kumar R. P. Singh S. Panigrahy A. S. Raghubanshi 《Environmental monitoring and assessment》2014,186(8):4971-4985
In agroecosystems, the annual carbon (C) inputs to soil are one of the most promising greenhouse gas mitigation options. Net primary productivity (NPP) provides the inputs of C in ecosystems that can potentially be sequestered in soil organic matter. In this study, we estimates the C density and accumulation rate in rice–wheat agroecosystem at four sites of Indo-Gangetic Plains and Vindhyan highlands through amalgamation of ground truth (GT) and remote sensing (RS) approach. In addition to this, we validated field-measured aboveground net production (ANP) with remotely sensed SPOT-Vegetation data. ANP of the sites ranged from 6.8 to 11.1 and 3.3 to 8.8 t-C ha?1 year?1 for GT and RS, respectively. Both estimates (GT and RS) were linearly and significantly related with each other (y?=?1.33x???5.82, R 2?=?0.93, P?=?0.04; where x?=?GT ANP and y?=?RS ANP). For the whole region, total NPP (rice?+?wheat) was ranged from 7.9 to 12.5 t-C ha?1 year?1. The C accumulation potential of the present agroecosystems was 9.1 and 1.9 t-C ha?1 year?1 in the form of ANP and belowground NPP (BNP), respectively. The aboveground C stock of agroecosystem allocated in foliage (7.8 %), stem (57.6 %), and grain (35.1 %). Survey about the fate of post-harvested materials indicated that aboveground portion of the crop is almost used completely within the year for different purposes including human consumption and cattle feeding. Therefore, only BNP and litter contribute to long-term C sequestration. Since agroecosystem has enormous potential to sequester C, better management of aboveground portion NPP of the crop may enhance C sequestration potential of agroecosystem. 相似文献
435.
Viral G. Akbari Rupal D. Pandya Satya P. Singh 《Environmental monitoring and assessment》2014,186(10):6351-6362
The assessment of the microbial diversity of the entire community of a given habitat requires the extraction of the total environmental DNA. Metagenomic investigations of a petroleum-polluted habitat have its unique challenges. The specific methods were developed for the extraction of high-quality metagenome in good quantity from the petroleum-polluted saline and non-saline sites in Gujarat (India). The soil samples were washed to remove the toxic, hazardous organic pollutants which might interfere with the recovery of the metagenomic DNA. The metagenomic DNA extraction results were encouraging with the mechanical bead beating, soft lysis, and combination of both. The extracted DNA was assessed for its purity and yield followed by its application in the amplification of the 16S rRNA region. The amplicons were used for judging the molecular diversity by the denaturing gradient gel electrophoresis (DGGE). The microbial diversity was also analyzed statistically by calculating various diversity indices and principal component analysis (PCA). The results on the metagenomic diversity of the bacterial population among the three cohorts based on the culture-independent technique exhibited significant difference among the PAH sites and Okha–Madhi and Porbandar Madhavpur habitats. 相似文献
436.
Air samples for PM(10) (dp?10 μm in aerodynamic diameter) were collected from March 2007 to February 2008 near Taj Mahal-a historically sensitive site in Agra. Each sample collected on 20.3?×?25.4-cm Whatman quartz microfiber filter using respirable dust sampler was analyzed gravimetrically for mass concentrations and chemically for elements such as Na, Mg, Al, Si, S, Ca, Sc, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Br, Rb, Cd, Ba, and Pb by inductively coupled plasma atomic emission spectroscopy and inorganic ions such as NH (4) (+) , K(+), SO (4) (2-) , NO (3) (-) , F(-), and Cl(-) by ion chromatograph. Annual average of PM(10) 155.47?±?77.97 μg/m(3) was three times high the annual average NAAQ standard of 50 μg/m(3) for sensitive area. PM(10) as well as K(+), Cl(-), As, and Pb were higher in winter while crust elements and secondary aerosols were higher in summer. The average equivalent ratio of NH (4) (+) to sum up of SO (4) (2-) and NO (3) (-) was greater than unity which indicates high source strength of ammonia and alkaline nature of aerosols in Agra. Source apportionment of PM(10) was carried out by factor analysis using principal component analysis (varimax rotated factor matrix method) of SPSS. Five sources contributing to PM(10) were identified as crust material, vehicular emissions, industrial emissions, coal and biomass burning, and secondary aerosols. 相似文献
437.
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
438.
Anthony Imoudu Oyeogbe T. K. Das Arti Bhatia Shashi Bala Singh 《Environmental monitoring and assessment》2017,189(4):198
Increasing nitrogen (N) immobilization and weed interference in the early phase of implementation of conservation agriculture (CA) affects crop yields. Yet, higher fertilizer and herbicide use to improve productivity influences greenhouse gase emissions and herbicide residues. These tradeoffs precipitated a need for adaptive N and integrated weed management in CA-based maize (Zea mays L.)—wheat [Triticum aestivum (L.) emend Fiori & Paol] cropping system in the Indo-Gangetic Plains (IGP) to optimize N availability and reduce weed proliferation. Adaptive N fertilization was based on soil test value and normalized difference vegetation index measurement (NDVM) by GreenSeeker? technology, while integrated weed management included brown manuring (Sesbania aculeata L. co-culture, killed at 25 days after sowing), herbicide mixture, and weedy check (control, i.e., without weed management). Results indicated that the ‘best-adaptive N rate’ (i.e., 50% basal + 25% broadcast at 25 days after sowing + supplementary N guided by NDVM) increased maize and wheat grain yields by 20 and 14% (averaged for 2 years), respectively, compared with whole recommended N applied at sowing. Weed management by brown manuring (during maize) and herbicide mixture (during wheat) resulted in 10 and 21% higher grain yields (averaged for 2 years), respectively, over the weedy check. The NDVM in-season N fertilization and brown manuring affected N2O and CO2 emissions, but resulted in improved carbon storage efficiency, while herbicide residuals in soil were significantly lower in the maize season than in wheat cropping. This study concludes that adaptive N and integrated weed management enhance synergy between agronomic productivity, fertilizer and herbicide efficiency, and greenhouse gas mitigation. 相似文献
439.
Thawale P Ghosh T Kumar Singh S Singh S Kulkarni A 《Environmental monitoring and assessment》2012,184(4):2575-2591
Feasibility of an irrigation project is evaluated by two criteria viz., reservoir capacity to irrigate its command area and
economic returns by incremental crop production versus capital investment for dam construction. The annual water requirement
of different crops in the command area is estimated and compared with the availability of water from the dam for irrigation
purpose. The annual crop water requirement is estimated as the sum of evapotranspiration for crops and transmission and other
losses. Evapotranspiration is estimated by modified Penman formula. Economics of crop production is analyzed by first estimating
the monetary value of existing crop production under current rain fed conditions and then estimating the incremental production
of irrigated command area for the proposed crop pattern. The proposed cropping pattern is prepared so as to maximize the benefit
of crop production and fodder requirement while maintaining a better crop rotation to improve and maintain physical, chemical,
and biological conditions of the soil. The dam is to be used for irrigation and water supply only. Command area served by
this reservoir will be 76,500 ha. The existing annual agricultural return is Rs. 2995.56 lakhs and with the proposed irrigation
scheme, it is estimated as Rs. 1,77,91.90 lakhs. The incremental annual return would be Rs. 1,47,96.35 lakhs i.e., 642.68%
increase in annual return. 相似文献
440.
Asha A. Juwarkar K. L. Mehrotraa Rajani Nair Tushar Wanjari S. K. Singh T. Chakrabarti 《Environmental monitoring and assessment》2010,160(1-4):457-464
Carbon emission is supposed to be the strongest factor for global warming. Removing atmospheric carbon and storing it in the terrestrial biosphere is one of the cost-effective options, to compensate greenhouse gas emission. Millions of acres of abandoned mine land throughout the world, if restored and converted into vegetative land, would solve two major problems of global warming and generation of degraded wasteland. In this study, a manganese spoil dump at Gumgaon, Nagpur in India was reclaimed, using an integrated biotechnological approach (IBA). The physicochemical and microbiological status of the mine land improved after reclamation. Soil organic carbon (SOC) pool increased from 0.104% to 0.69% after 20 years of reclamation in 0–15 cm spoil depth. Soil organic carbon level of reclaimed site was also compared with a native forestland and agricultural land. Forest soil showed highest SOC level of 1.11% followed by reclaimed land and agriculture land of 0.70% and 0.40%, respectively. Soil profile studies of all three sites showed that SOC pool decreased from 0–15, 15–30, and 30–45 cm depths. Although reclaimed land showed less carbon than forestland, it showed better SOC accumulation rate. Reclamation of mine lands by using IBA is an effective method for mitigating CO2 emissions. 相似文献