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301.
J. Jai Devi Tarun Gupta Rajmal Jat S. N. Tripathi 《Environmental science and pollution research international》2013,20(3):1632-1648
Personal exposure measurement can serve as an effective tool to understand the effect of exposure to air pollutants. Alternatively, exposure assessment using pollutant concentrations in different microenvironments and accurate time–activity information for the subjects can provide good information regarding human integrated exposure. A panel of 18 healthy students of Indian Institute of Technology (IIT) Kanpur in the age group of 18 to 30 years participated in the personal exposure measurements for particulate matter, CO, NO2 and VOC during post-monsoon and pre-monsoon seasons. Overall, 432 h person exposure data was collected in this study. The major sources of particulate and gaseous co-pollutants were identified. These directly obtained personal exposure values were then compared to the indirectly estimated integrated exposure values. Personal and integrated exposures gave statistically similar results. Through this study, we have shown that integrated exposure values could closely estimate the personal exposure values for particulate matter that can significantly reduce time and cost involved in personal exposure studies. The lung parameters for all the subjects measured during the pre-monsoon and post-monsoon seasons showed statistically significant reduction during pre-monsoon. This was attributed to the high levels of coarse particles during pre-monsoon. 相似文献
302.
Tarun Gupta Anil Mandariya 《Environmental science and pollution research international》2013,20(8):5615-5629
The main objective of this atmospheric study was to determine the major sources of PM1 (particles having aerodynamic diameter <1.0 μm) within and near the city of Kanpur, in the Indo-Gangetic Plain. Day and night, 10 h long each, filter-based aerosol samples were collected for 4 months (November 2009 to February 2010) throughout the winter season. These samples were subjected to gravimetric and quantitative chemical analyses for determining water-soluble ions (NH4 +, F?, Cl?, NO3 ?, and SO4 2?) using an ion chromatograph and trace elements using an inductively coupled plasma–optical emission spectrometer. The mean PM1 mass concentrations were recorded as 114?±?71 μg/m3 (day) and 143?±?86 μg/m3 (night), respectively. A significantly higher diurnal contribution of ions (NH4 +, F?, Cl?, NO3 ?, and SO4 2?) in PM1 mass was observed during the fog-affected days and nights throughout the winter season, for which the average values were recorded as 38.09?±?13.39 % (day) and 34.98?±?12.59 % (night), respectively, of the total PM1 mass. This chemical dataset was then used in a source-receptor model, UNMIX, and the model results are described in detail. UNMIX provided a maximum number of five source factors, including crustal material, composite vehicle, secondary aerosol, coal combustion, and iron/steel production and metallurgical industries, as the dominant air pollution sources for this study. 相似文献
303.
Increasing population levels, rapid economic growth and rise in community living standard accelerates the generation rate of municipal solid waste (MSW) in Indian cities. Improper management of MSW causes hazards to inhabitants. The objectives of the study are to determine the quantitative and qualitative characteristics of MSW along with basic information and to create GIS maps for Allahabad city. The samples have been randomly collected from various locations and analyzed to determine the characteristics of MSW. A questionnaire survey has been carried out to collect data from inhabitants including MSW quantity, collection frequency, satisfaction level, etc. The Geographic Information System (GIS) has been used to analyze existing maps and data, to digitize the existing sanitary ward boundaries and to enter the data about the wards and disposal sites. The total quantity of MSW has been reported as 500 ton/day, and the average generation rate of MSW has been estimated at 0.39 kg/capita/day. The generated ArcGis maps give efficient information concerning static and dynamic parameters of the municipal solid waste management (MSWM) problem such as the generation rate of MSW in different wards, collection point locations, MSW transport means and their routes, and the number of disposal sites and their attributes. 相似文献
304.
Sharma KK Dubey JK Deka SC Chandrasekaran S Kalpana Gupta P Kumar A Vandana Devi MJ Singh B Baruah AA Kennedy JS Sharma ID Patyal SK Nath A 《Chemosphere》2007,68(4):790-796
Spiromesifen (Oberon) is a new insecticide and miticide of chemical class ketoenol active against white flies (Bemisia spp., Trialeuroides spp.) and spider mites (Tetranychus and Panonychus spp.). Due to its potential significance in insect resistance management, it is important to establish its behaviour on crop and environment. In the present study, the degradation/dissipation of spiromesifen on tea crop under tropical environmental conditions was studied and its DT(50) (t(1/2)), and DT(90) (time to reduce to 90% of the initial value) were estimated. Spiromesifen was sprayed on tea crop after first rain flush at four different locations @ 96 and 192ga.i.ha(-1). Samples of tea leaves were drawn at 0, 1, 3, 5, 7, 10, 15, 21 and 30 days after treatment and that of soil at 10 days after treatment and at harvest from 0 to 15 and 15 to 30cm layers. After crude extraction of tea leaves for spiromesifen residues with acetone:water, the contents were partitioned with cyclohexane:ethyl acetate and cleaned up on Florosil column. Soil residues were also extracted similarly. Quantification of residues was done on GC-MS in Selected Ion Monitoring (SIM) mode in mass range 271-274m/z. The LOQ of this method was found to be 0.05microgg(-1) while LOD being 0.015microgg(-1). The DT(50) of spiromesifen when applied at recommended doses in tea leaves was found to be 5.0-8.5 days. Ninety-nine percent degradation was found to occur within 33-57 days after application. In soil, no residues of spiromesifen were detectable 10 days after treatment. 相似文献
305.
A well known river hydrodynamic model RiverCAD has been used to simulate and visualize flood scenarios for different designated
flood flows under complex riverbed geometry with several man made structures like bridges and barrages. The model applied
successfully for the stretch of 23 km in the Yamuna floodplain of Delhi region from Wazirabad barrage in the upstream to Okhla
barrage. Flood flows for various return periods namely once in 10, 25, 50 and 100 years were estimated based on recorded flow
data for the period of 1963 to 2003 using standard flood frequency analysis techniques. The simulation results were compared
and the model was calibrated with water surface elevation records of the previous floods at various barrage and bridge locations.
Simulation results enabled prediction of maximum water levels, submergence scenarios and land availability under different
designated flood flows for riverbed assessment, development and management. 相似文献
306.
Singh G Gupta SK Kumar R Sunderarajan M 《Environmental monitoring and assessment》2007,130(1-3):173-185
The present study describes the development of empirical models for the prediction of various trace metals i.e., Mn, Cu, Fe,
Zn and Pb found in the leachates generated from the ash ponds of various thermal power plants. The dispersion phenomenon of
these trace metals followed first order reaction rate kinetics. The empirical models for individual trace metals derived from
the lab scale models data correlate well with the real field data with regression coefficients varying from 0.93 to 0.98.
The predicted concentrations of the trace metals varied within ±3% of the observed values in the leachates generated from
the ash ponds of four thermal power plants with standard deviation varying from 0.001 to 0.032. The empirical models derived
from the study can be applied for prediction of trace metals in leachates generated from similar thermal power plants. 相似文献
307.
Sharma KK Rao CS Dubey JK Patyal SK Parihar NS Battu RS Sharma V Gupta P Kumar A Kalpana Jaya M Singh B Sharma ID Nath A Gour TB 《Environmental monitoring and assessment》2007,132(1-3):25-31
In a field study carried out at three different locations, the dissipation of spiromesifen on cotton and chili was studied
and its DT50, and DT99 were estimated at each location. Spiromesifen was sprayed on chili at 96 and 192 g a.i. ha−1 and cotton at 120 and 240 g a.i. ha−1. Samples of chili fruits were drawn at 0, 1, 3, 5, 7, 10, 15, 21, 30 days after treatment and that of cotton seed and lint
at first picking and harvest. Soil samples were drawn 30 days after treatment from 0 to 15 and 15 to 30 cm layer. Quantification
of residues was done on GC–MS in Selected Ion Monitoring (SIM) mode in mass range 271–274 m/z. The LOQ of this method was
found 0.033 μg g−1, LOD being 0.01 μg g−1. The DT50 of spiromesifen when applied at recommended doses in chili fruits was found to be 2.18–2.40 days. Ninety-nine percent degradation
was found to occur within 14.5–16.3 days after application. Residues of spiromesifen were not detected in cotton seed and
lint samples at the first picking. In soil, no residues of spiromesifen were detectable 15 days after treatment. 相似文献
308.
This study assesses the efficiency of various physico-chemical, biological and other tertiary methods for treating leachate.
An evaluation study on the treatability of the leachate from methane phase bed (MPB) reactor indicated that at an optimum
hydraulic retention time of 6 days, the efficiency of the reactor in terms of biological oxygen demand (BOD) and chemical
oxygen demand (COD) removal was 91.29 and 82.69%, respectively. Recycling of the treated leachate through the municipal solid
waste layers in the leachate recycling unit (LRU) resulted in a significant increase in the biodegradation of organics present
in the leachate. Optimum BOD and COD removal efficiencies were achieved at the third recycle; additional recycling of the
leachate did not produce any significant improvement. Physico-chemical treatment of the leachate demonstrated that alum and
lime (Option 2) were more economical than coagulants lime and MgCO3. A cost analysis of the economics of the various treatments revealed that the alternative treatment consisting of a MPB bed
followed by a LRU and aerated lagoon is the most cost-effective treatment. However, the alternative consisting of a MPB followed
by the LRU and a soil column, which is slightly more costly, would be the most appropriate treatment when adequate land is
readily available. 相似文献
309.
There is a paradigm shift from non renewal resources to renewable resources in view of problems of disposal of plastic products
after their life cycle. This paper deals with the approach, preparation and product properties of polymer prepared by using
polysaccharide based biodegradable polymer. Basic material has been prepared by mixing LDPE, LDPE-g-mA (LDPE grafted with
(0.5%) maleic anhydride (1:1)) containing a polar group in the LDPE backbone. Prepared basic material has been compounded
in twin screw extruder with 0, 2.5, 5.0, 7.5, 10.0, 12.5 & 15% of Potato Starch. Thereafter, after conditioning blown film
samples were prepared using extrusion film blowing technique, under temperature profile ranging from 120 to 160 °C. Packaging
films have been prepared with maximum 15% potato starch contents and have been characterized by FTIR, DSC, TGA, and XRD techniques
to ascertain its impact on some structural and thermal properties like thermal stability, flexibility, crystallinity, crystal
size etc. 相似文献
310.
Municipal solid waste generation rate is over-riding the population growth rate in all mega-cities in India. Greenhouse gas emission inventory from landfills of Chennai has been generated by measuring the site specific emission factors in conjunction with relevant activity data as well as using the IPCC methodologies for CH4 inventory preparation. In Chennai, emission flux ranged from 1.0 to 23.5mg CH4m(-2)h(-1), 6 to 460microg N2Om(-2)h(-1) and 39 to 906mg CO2m(2)h(-1) at Kodungaiyur and 0.9 to 433mg CH4m(-2)h(-1), 2.7 to 1200microg N2Om(-2)h(-1) and 12.3 to 964.4mg CO2m(-2)h(-1) at Perungudi. CH4 emission estimates were found to be about 0.12Gg in Chennai from municipal solid waste management for the year 2000 which is lower than the value computed using IPCC, 1996 [IPCC, 1996. Report of the 12th session of the intergovernmental panel of climate change, Mexico City, 1996] methodologies. 相似文献