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81.
This paper provides baseline information about the total annual dust fall, and its constituents and seasonal variation, from a sub-tropical opencast coalmine area in Bina, India. Dust samples were collected monthly for 2 years (June 2002-May 2004) from five sampling sites in the region and analyzed in the laboratory for water-soluble and -insoluble matter. Water-insoluble components constituted the major fraction of the total annual dust fall. Two-way ANOVA indicated significant variations in dust fall at different sites, over the months and in their interactions. The dust deposition rate was highest during summer (March-June), followed by winter (November-February) and lowest in the rainy season (July-October). Maximum dust fall was observed near the coal handling plant (at site 2) followed by the receiving pit of the coal handling plant (site 3), near the main sub-station (site 4), Jawahar colony (site 1) and Gharasari village (site 5). An inverse and significant relation was observed between dust fall and precipitation. Our studies have shown that the main residential areas are experiencing higher levels of dust fall which makes them unsuitable for living. We suggest that residential areas should be moved farther away from the mining area in the opposite direction of prevalent winds. 相似文献
82.
Hydrolytic depolymerization of polyamide waste in water was studied using 0.5 L high pressure autoclave at temperatures of
235, 240, 245, 250 °C and at autogenious pressure 480, 500, 520, and 600 psi (pound per square inch).The reaction rate constant,
energy of activation, enthalpy of activation, entropy of activation and equilibrium constant were calculated from the experimental
data obtained. The maximum depolymerization (59.2%) of polyamide waste into monomer caprolactum was obtained at 250 °C and
600 psi pressure. The reaction rate constant was obtained on basis of measurement of amine value and residual weight. The
depolymerization reaction was found to be pseudo first order with reaction rate constant of the order of 10−3 min−1. The enthalpy, entropy and free energy of activation were recorded as 85.75, −0.1354 and 156.59 kJ mol−1 respectively at the experimental conditions for maximum depolymerization of polyamide waste. The thermodynamic equilibrium
constant for this hydrolysis reaction was found to be 2.3 × 10−16. 相似文献
83.
K. Rajeev K. Parameswaran Bijoy V. Thampi Manoj Kumar Mishra Anish Kumar M. Nair S. Meenu 《Atmospheric environment (Oxford, England : 1994)》2010,44(21-22):2597-2604
Every year, during the pre-monsoon period (March–May), a pronounced increase in aerosol optical depth (AOD) is observed over the eastern Arabian Sea, which is attributed to the transport of continental aerosols. This paper presents the altitude distribution of tropospheric aerosols, characteristics of elevated aerosol layers and aerosol radiative heating of the atmosphere during the pre-monsoon season over Trivandrum (8.5°N, 77°E), a station located at the southwest coast of Indian peninsula which is covered by the eastern Arabian Sea plume. Altitude profiles of aerosol backscatter coefficient (βa) and linear depolarization ratio (LDR) reveal two distinct aerosol layers persisting between 0–2 km and 2–4 km. The layer at 2–4 km, which contributes about 25% of the AOD during polluted conditions, contains significant amount of non-spherical aerosols. This layer is prominent only when the advection of dry airmass occurs from the northern parts of the Indian subcontinent and northern Arabian Sea. Role of long-range transport in the development of this aerosol layer is further confirmed using latitude–altitude cross-section of βa observed by CALIPSO. Aerosol content in the layer below 2 km is large when advection of air occurs from the north and east Arabian Sea and is significantly small when it occurs from the southwest Arabian Sea or Indian Ocean. During the highly polluted conditions, aerosols tend to increase the diurnal mean atmospheric radiative heating rate by ~0.8 K day?1 at 500 m and 0.3 K day?1 at 3 km, which are about 80% and 30% of the respective radiative heating in the aerosol-free atmosphere. 相似文献
84.
Knowledge of climate change vulnerability and impacts is a prerequisite for formulating locally relevant climate change adaptation policies. A participatory approach has been used in this study to determine climate change vulnerability, impacts and adaptation aspects for the Kangsabati River basin, India. The study approach involved engaging with stakeholders representing state (sub-national), district and community levels, through an interactive brainstorming method, to understand stakeholder perceptions regarding (a) local characteristics which influence vulnerability, (b) climate change impacts and (c) relevant adaptation options. The study reveals that vulnerability varies across upstream, midstream and downstream sections of the river basin. Suggested adaptation options, in this predominantly agricultural basin, are found to be applicable across spatial scales. Stakeholder perceptions, regarding vulnerability and impacts, vary with the level of interaction, academic background and type of experience. Interaction confirms the notion that stakeholders have inherent knowledge regarding adaptation, reveals their preferences and ability to think unconventionally. We discuss limitations of the approach while demonstrating its ability to deliver locally relevant and acceptable adaptation options, which could facilitate implementation. We conclude that engaging stakeholders at multiple levels was highly effective in assessing locally relevant aspects of climate change vulnerability, impacts and applicable adaptation options in the Kangsabati River basin. Based on this assessment, a sub-basin scale is recommended for evaluating these aspects, especially for water resources and agricultural systems, through multi-level stakeholder input. 相似文献
85.
Mishra Jyotirmoy Nanda Bharadwaj Patro Sanjaya K. Das Shaswat K. Mustakim Syed M. 《Journal of Material Cycles and Waste Management》2022,24(3):1095-1108
Journal of Material Cycles and Waste Management - Earlier studies indicated that the reactive MgO reduces shrinkage crack and porosity, and accelerates the hydration and strength development.... 相似文献
86.
Coontail (Ceratophyllum demersum L.) plants when exposed to various concentrations of Pb (1-100microM) for 1-7days, exhibited both phytotoxic and tolerance responses. The specific responses were function of concentration and duration. Plants accumulated 1748mugPbg(-1) dw after 7d which reflected its metal accumulation ability, however most of the metal (1222microgg(-1) dw, 70%) was accumulated after 1d exposure only. The toxic effect and oxidative stress caused by Pb were evident by the reduction in biomass and photosynthetic pigments and increase in malondialddehyde (MDA) content and electrical conductivity with increase in metal concentration and exposure duration. Morphological symptoms of senescence phenomena such as chlorosis and fragmentation of leaves were observed after 7d. The metal tolerance and detoxification strategy adopted by the plant was investigated with reference to antioxidant system and synthesis of phytochelatins. Protein and antioxidant enzymes viz., superoxide dismutase (SOD, EC 1.15.1.1), guaiacol peroxidase (GPX, EC 1.11.1.7) ascorbate peroxidase (APX, EC 1.11.1.11), catalase (CAT, EC 1.11.1.6) and glutathione reductase (GR, EC 1.6.4.2) showed induction at lower concentration and duration followed by decline. All enzymes except GPX showed maximum activity after 1d. An increase in cysteine, non-protein thiols (NP-SH) and glutathione (GSH) content was observed at moderate exposure conditions followed by decline. Phytochelatins (PC(2) and PC(3)) were synthesized to significant levels at 10 and 50microM Pb with concomitant decrease in GSH levels. Thus production of PCs seems important for the detoxification of metal, however it may lead to depletion of GSH and consequently oxidative stress. Results suggest that plants responded positively to moderate Pb concentrations and accumulated high amount of metal. Due to metal accumulation coupled with detoxification potential, the plant appears to have potential for its use as phytoremediator species in aquatic environments having moderate pollution of Pb. 相似文献
87.
Mishra VK Upadhyay AR Pandey SK Tripathi BD 《Environmental monitoring and assessment》2008,141(1-3):49-58
Five heavy metals Cu, Cd, Mn, Pb and Hg were found in high concentration from three sampling sites located in Asia’s largest
anthropogenic lake Govind Ballabh Pant GBP Sagar. Concentrations of these heavy metals were measured in Water, bottom sediment
and in different parts of the aquatic macrophytes collected from the reservoir. Plants collected from the lake were Eichhornia crassipes, Azolla pinnata, Lemna minor, Spirodela polyrrhiza, Potamogeton pectinatus, Marsilea quadrifolia, Pistia stratiotes, Ipomea aquqtica, Potamogeton crispus, Hydrilla verticillata and Aponogeton natans. These plants have shown the high concentrations of Cu, Cd, Mn, Pb and Hg in their different parts due to bioaccumulation.
In general plant roots exhibited higher concentrations of heavy metals than corresponding sediments. A comparison between
different morphological tissues of the sampled plants reveled the metal concentration in following order roots > leaves. Analyses
of bottom sediment indicated the higher concentrations of Cd, Mn, Cu and Pb. Strong positive correlations were obtained between
the metals in water and in plants as well as between metal in sediment and in plants. Indicating the potential of these plants
for pollution monitoring of these metals. 相似文献
88.
Water availability in arid regions is both sporadic and highly variable in quantity. If the water quality shows large variations
of salinity and concentration of other chemical constituents with depth and time span, it has considerable effect on the entire
hydrological set up of the area. In the Saidabad tahsil area, the deep aquifers that supply water to borewells in the alluvial
plain of the Mathura region, Uttar Pradesh, have higher salinity than those of the dugwells from the shallow aquifers. The
excessive drilling of tubewells and high yield tubewells are resulting in deterioration of water quality of the shallow aquifers.
On the contrary, the chemical constituents such as, Na+, K
+, Cl
-, andHCO
3
- show higher concentration in shallow aquifers than deep aquifers. A study carried out to monitor water quality in this region
reveals that the groundwater quality varies with depth and time span in shallow and deep aquifers. Factors controlling variations
in salinity and concentration of chemical constituents of the water in the two types of aquifers are discussed. The relative
merits of the shallow water for potability are pointed out with respect to salinity concentrations and public health. 相似文献
89.
Bajpai R Mishra GK Mohabe S Upreti DK Nayaka S 《Journal of environmental biology / Academy of Environmental Biology, India》2011,32(2):195-199
A biomonitoring study was conducted to assess the levels of atmospheric heavy metal pollution in Katni and Rewa cities of Madhya Pradesh, state in central India. The Pyxine cocoes and Phaeophyscia hispidula, two epiphytic foliose lichen were used as bioindicators in the present study and seven metals (As, Al, Cd, Cr, Fe, Zn, Pb) were analyzed in naturally growing thallus. The concentrations of these metals was observed to be in higher range as maximum values of Al, Cd, Cr and Zn were reported from the lichen samples from Rewa city which was 561.8 +/- 2.4, 6.8 +/- 0.8, 35.2 +/- 1.4, 214.6 +/- 2.0 microg g(-1) dry weight respectively. Whereas As, Fe and Pb were reported maximum in the lichen samples collected from Katni city areas with 33.4 +/- 0.05, 689.4 +/- 2.6, 13.3 +/- 0.5 microg g(-1) dry weight respectively. However the accumulation of Cd and Pb from both the cities are more or less similar in concentration. The selectivity sequence of metals were Fe>Al>Zn>As>Cr>Pb>Cd in Katni city, and Al>Fe>Zn>Cr>As>Pb>Cd in Rewa city. The findings of this study indicates that extent of heavy metal pollution in the atmosphere of the two cities which may lead to adverse health affects. 相似文献
90.
Chromium accumulation in submerged aquatic plants treated with tannery effluent at Kanpur, India 总被引:1,自引:0,他引:1
Gupta K Gaumat S Mishra K 《Journal of environmental biology / Academy of Environmental Biology, India》2011,32(5):591-597
Aquatic macrophytes have been widely studied because of their capability of absorbing contaminants from water and their subsequent use in biomonitoring. This study presents a comparison of Cr accumulating potential of submerged aquatic plants viz Vallisneria spiralis and Hydrilla verticillata. These plants were treated with various concentrations of treated tannery effluent collected from UASB, Jajmau, Kanpur under repeated exposure in controlled laboratory conditions in order to assess their maximum bioaccumulation potential. The maximum accumulation of 385.6 and 201.6 microg g(-1) dry weight was found in roots of V. spiralis and the whole plants of H. verticillata, respectively at 100% concentration after 9th day of effluent exposure. The chlorophyll and protein content of both species decreased with increase in effluent concentration and duration. At highest concentration and duration a maximum reduction of 67.4 and 62.66% in total chlorophyll content, 9.97 and 4.66% in carotenoid content and 62.66 and 59.36% in protein content was found in V. spiralis and H. verticillata respectively. Anatomical studies in both V. spiralis and H. verticillata was carried out to assess the effects of metal accumulation within the plants. Changes in the anatomical structures of both plants exhibits the capacity of these species to act as indicator of effluent toxicity. The high accumulation potential of Cr by both plants revealed their capability to remove pollutants from effluent. 相似文献