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Wani K.,Pandit Ravishankar Shukla University | Nirmal M.,Pandit Ravishankar Shukla University | Patel V.,Pandit Ravishankar Shukla University | Khatoon R.,Pandit Ravishankar Shukla University | And 2 more authors.
Asian Journal of Chemistry | Year: 2017

A simple, rapid and selective spectrophotometric method was developed for the determination of carbendazim in environmental samples. The developed method is based on the oxidation followed by the formation of orange coloured chromogen complex by the reaction of carbendazim with ferric chloride and 1,10-phenanthroline which absorbs maximally at 470 nm. The analytical parameters and their effects on the reported method are investigated. Beer's law was obeyed in the range 5.0-70 μg mL-1 with correlation coefficient (r) 0.979. The molar absorptivity, Sandell's sensitivity, detection and quantification limits were also calculated. Interference study was carried for other pesticides and pollutants. The results of the analysis were validated statistically and the method was applied to the determination of carbendazim in various environmental samples. © 2017, Chemical Publishing Co. All rights reserved.


Bhambri R.,Wadia Institute of Himalayan Geology | Bolch T.,University of Zürich | Bolch T.,TU Dresden | Kawishwar P.,Chhattisgarh Council of Science and Technology | And 3 more authors.
Cryosphere | Year: 2013

Glaciers in the Karakoram show long-term irregular behaviour with comparatively frequent and sudden advances. A glacier inventory of the upper Shyok valley situated in northeast Karakoram has been generated for the year 2002 using Landsat ETM+ and SRTM3 DEM as baseline data for the investigations and subsequent change analysis. The upper Shyok valley contained 2123 glaciers (larger than 0.02 km2 in size) with an area of 2977.9 ± 95.3 km2 in 2002. Out of these, 18 glaciers with an area of 1004.1 ± 32.1 km2 showed surge-type behaviour. Change analysis based on Hexagon KH-9 (years 1973 and 1974) and Landsat TM/ETM+ (years 1989, 2002 and 2011) images had to be restricted to a subset of 136 glaciers (covering an area of 1609.7 ± 51.5 km2 in 2002) due to adverse snow conditions. The area of the investigated glaciers, including the 18 surge-type glaciers identified, showed no significant changes during all studied periods. However, the analysis provides a hint that the overall glacier area slightly decreased until about 1989 (area 1973: 1613.6 ± 43.6 km2; area 1989: 1602.0 ± 33.6 km2) followed by an increase (area 2002: 1609.7 ± 51.5; area 2011: 1615.8 ± 35.5 km2). Although the overall change in area is insignificant, advances in glacier tongues since the end of the 1980s are clearly visible. Detailed estimations of length changes for individual glaciers since the 1970s and for Central Rimo Glacier since the 1930s confirm the irregular retreat and advance. © 2013 Author(s).


Srivastava P.,Wadia Institute of Himalayan Geology | Srivastava P.,University of Pune | Bhambri R.,Wadia Institute of Himalayan Geology | Kawishwar P.,Chhattisgarh Council of Science and Technology | Dobhal D.P.,Wadia Institute of Himalayan Geology
Journal of Earth System Science | Year: 2013

Himalaya-Karakoram (H-K) region hosts large number of high altitude lakes but are poorly gauged by in-situ water level monitoring method due to tough terrain conditions and poor accessibility. After the campaigns of ICESat during 2003-2009, now it is possible to achieve lake levels at decimetre accuracy. Therefore, in present study, high altitude lake levels were observed using ICESat/GLAS altimetry in H-K between 2003 and 2009 to generate baseline information. The study reveals that out of 13 lakes, 10 lakes show increasing trend of water levels at different rate (mean rate 0.173 m/y) whereas three lakes unveiled decreasing trend (mean rate -0.056 m/y). Out of five freshwater lakes, four lakes show an increasing trend of their level (mean rate 0.084 m/y) whereas comparatively six salt lakes (out of seven salt lakes) exhibited ~3 times higher mean rate of lake level increase (0.233 m/y). These observed lake level rise can be attributed to the increased melt runoffs (i.e., seasonal snow and glacier melts) owing to the enhanced mean annual and seasonal air temperature during past decade in north-western (NW) Himalaya. Further, varied behaviours of lake level rises in inter- and intra-basins suggest that the local climatic fluctuations play prominent role along with regional and global climate in complex geographical system of NW Himalaya. © Indian Academy of Sciences.


Prajapati A.K.,National Institute of Technology Raipur | Choudhary R.,National Institute of Technology Raipur | Verma K.,National Institute of Technology Raipur | Chaudhari P.K.,National Institute of Technology Raipur | Dubey A.,Chhattisgarh Council of Science and Technology
Desalination and Water Treatment | Year: 2015

The removal of COD and color from biodigester effluent (BDE) of rice grain–based distillery was studied using inorganic coagulants such as CuSO4·5H2O, Alum, FeCl3, AlCl3, and FeSO4·7H2O. The CuSO4·5H2O was found to be the best among all coagulants provided maximum 91% COD reduction and 85% color reduction with 60 mM Cu2++ at a optimum initial pH (pHi) 6. The pH of the effluent/coagulant mixture showed significant role in the removal of harmful substances from the BDE. Settling and filterability characteristics of the treated BDE slurry were found to be dependent on coagulant type and treatment conditions. High COD and color reductions of the BDE in the coagulation process show a better alternative to the conventional bio-aerobic treatment process applied for the treatment of wastewater. © 2013, Balaban Desalination Publications. All rights reserved.


Khatoon R.,Pandit Ravishankar Shukla University | Rai M.K.,Pandit Ravishankar Shukla University | Patel V.,Pandit Ravishankar Shukla University | Rai J.,Chhattisgarh Council of Science and Technology
Journal of the Chemical Society of Pakistan | Year: 2014

A new sensitive spectrophotometric method was developed for the determination of widely used herbicide butachlor. The method is based on acidic hydrolysis of butachlor to 2, 6-diethyl amine, followed by coupling with diazotized aniline in acidic medium. The absorption maxima of the orange dye compound formed was measured at 490 nm. Beer's law was obeyed over the concentration range of 10-40 μg (0.1 ppm to 0.4 ppm) in a final solution volume of 10 mL. The molar absorptivity, Sandell's sensitivity and correlation coefficient were found to be 7.07×102 L mol-1 cm-1 , 0.20 μg cm-2 and 0.963 respectively. The standard deviation and relative standard deviation were found to be ±0.009 and 1.98% respectively. The method was simple sensitive and free from interferences of other pesticide and diverse ions. The method was successfully applied to the determination of butachlor in environmental and biological samples.


Patel V.,Pandit Ravishankar Shukla University | Khatoon R.,Pandit Ravishankar Shukla University | Nirmal M.,Pandit Ravishankar Shukla University | Wani K.,Pandit Ravishankar Shukla University | And 2 more authors.
Asian Journal of Chemistry | Year: 2016

A simple and sensitive extractive spectrophotometric determination of organophosphorus insecticide ethion at trace levels based on flotation-dissolution method is presented. A molydophospho complex is formed when ethion is treated with ammonium molybdate in acidic medium. As an ion associate complex with methylene blue, the complex is present in between water and organic layers which is extracted and then dissolved with acetone. The greenish blue complex produced showed an absorption maximum at 660 nm. Beer's law is found to be in the range of 0.5 to 0.16 μg/10 mL for ethion. The molar absorptivity is 6.0 × 105 mol L-1 cm-1 and Sandel's sensitivity is 0.014 μg cm-2. The standard deviation and relative standard deviation were calculated and found to be 0.022 μg mL-1 and 3.5 %, respectively. The method has been applied sucessfully for the determination of ethion in water, soil, vegetables and grains.


Nirmal M.,Pandit Ravishankar Shukla University | Rai M.K.,Pandit Ravishankar Shukla University | Patel V.,Pandit Ravishankar Shukla University | Khatoon R.,Pandit Ravishankar Shukla University | And 2 more authors.
Asian Journal of Chemistry | Year: 2016

A spectrophotometric method for the determination of deltamethrin is reported. The method is based on hydrolysis of deltamethrin to form dibromochrysanthemic acid and phenoxybenzaldehyde cyanohydrin then phenoxybenzaldehyde cyanohydrin on further hydrolysis releases cynide which after bromination form cynogen bromide which reacts with potassium iodide-potassium iodate mixture in the presence of leuco malachite green to form a greenish blue coloured complex which is soluble in 70 % alcohol. The complex shows maximum absorbance at 620 nm. Beer's law obeyed over the concentration range of 10-50 μg in a final solution volume of 10 mL. The molar absorptivity of the coloured system is 7.72 × 104 L mol-1 cm-1 and Sandell's sensitivity is 1.0 × 10-3 μg cm-2. The reproducibility assessed by carrying out seven days replicate analysis of a solution containing 10 μg of deltamethrin in a final solution volume of 10 mL. The standard deviation and relative standard deviation for the absorbance value were found to be 1.53 × 10-3 and 1 %, respectively. The proposed method is free from the interference of other toxicants. The analytical parameters were optimized and the method was applied to the determination of deltamethrin in various environmental samples.


Dewangan S.,Pandit Ravishankar Shukla University | Pervez S.,Pandit Ravishankar Shukla University | Chakrabarty R.,Washington University in St. Louis | Watson J.G.,Desert Research Institute | And 4 more authors.
Building and Environment | Year: 2016

The study was carried out to evaluate the seasonal and annual trend of thermal fractions (organic and elemental carbon) associated to different cultural/ritual-indoor aerosol carbonaceous matter compared to residential-indoors and ambient-outdoors. Thermal speciation of carbonaceous fractions (SCFs: OC1, OC2, OC3, OC4, OP, EC1, EC2, EC3) associated to cultural/ritual-indoors and indoor/outdoor relationship were also taken into account in four different types of cultural/ritual centers: 1) Marriage Places (MP), 2) Muslim Holy Shrines (MHS), 3) Buddhist Temples (BT), and 4) Hindu Temples (HT). Longitudinally measured 360 PM2.5/PM10 samples throughout the year 2012–13, onto quartz fiber filters, were analyzed for organic (OC) and elemental carbon (EC) alongwith eight SCFs using thermal/optical reflectance/transmittance method. SCFs were determined in selected samples, representing all selected cultural/ritual-indoors, to address the source markers associated to biomass burning (BB) emissions; observed during cultural/ritual performances. Results have shown significantly higher levels of BB markers' SCFs in cultural/ritual-indoors compared those reported for residential-indoors and ambient-outdoors. Three to eight-fold higher carbonaceous aerosols was found in cultural/ritual-indoors compared to those determined in residential-indoors and ambient-outdoors. OC/EC ratio was found 2-fold higher in MHS and MP places compared to those found in other selected indoor and outdoor sites. Similarly, higher degree of seasonal variability with higher occurrence of aerosol fractions and associated OC and EC in winter is observed in both MHS and MP due to higher activity pattern. © 2016 Elsevier Ltd

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