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41.
Atmospheric deposition studies of heavy metals in Arctic by comparative analysis of lichens and cryoconite 总被引:1,自引:0,他引:1
Shiv Mohan Singh Jagdev Sharma Puja Gawas-Sakhalkar Ajay K. Upadhyay Simantini Naik Shailesh M. Pedneker Rasik Ravindra 《Environmental monitoring and assessment》2013,185(2):1367-1376
Lichens and cryoconite (rounded or granular, brownish-black debris occurring in holes on the glacier surface) from Ny-Ålesund were used for understanding the elemental deposition pattern in the area. Lichen samples collected from low-lying coastal region and cryoconite samples from high altitudinal glacier area were processed and analysed for elements such as aluminium (Al), arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), cesium (Cs), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), vanadium (V) and zinc (Zn) through inductively coupled plasma mass spectrometry. Results showed that heavy metals, Al and Fe, are present in high concentration in the cryoconite samples. Al was also present in high amounts in seven of the eight lichen samples studied. The general scheme of elements in the decreasing order of their concentrations for most of the cryoconite samples was Al?>?Fe?>?Mn?>?Zn?>?V?>?Pb?>?Cr?>?Ni?>?Cu?>?Co?>?As?>?Cs?>?Cd while that for the lichen samples was Al?>?Fe?>?Zn?>?Mn?>?Pb?>?Cu?>?Cs?>?Cr?>?Ni?>?V?>?Co?>?As?>?Cd. Similarity in trends in the two sample types confirms that the environment indeed contains these elements in that order of concentration which overtime got accumulated in the samples. Overall comparison showed most elements to be present in high concentrations in the cryoconite samples as compared to the lichen samples. Within the lichens, elemental accumulation data suggests that the low-lying site (L-2) from where Cladonia mediterranea sample was collected was the most polluted accumulating a number of elements at high concentrations. The probable reasons for such deposition patterns in the region could be natural (crustal contribution and sea salt spray) and anthropogenic (local and long-distance transmission of dust particles). In the future, this data can form a baseline for monitoring quantum of atmospheric heavy metal deposition in lichens and cryoconite of Svalbard, Arctic. 相似文献
42.
Ravindra Soni Anil Kapri M. G. H. Zaidi Reeta Goel 《Journal of Polymers and the Environment》2009,17(4):233-239
Seventeen bacterial isolates were screened for the utilization of low density polyethylene (LDPE) as the sole carbon source,
out of which five potential strains were selected for the development of a consortium. In vitro biodegradation efficiency
of the consortium was studied for two differently textured forms of LDPE viz. non-poronized and poronized. Although, both the forms were acted-upon well by the consortium, but the degradation was found
to be better in the poronized form. This was substantiated by λ-max shift, FTIR spectra and simultaneous TG-DTG-DTA. The analysis
revealed the breakage and formation of chemical bonds in the polymer backbone, as a result of microbial activity. The biodegraded
samples of non-poronized and poronized LDPE exhibited similar weight losses at 400 °C (24.12% and 24.48%, respectively) as
compared to their controls (4% and 4.5% respectively), but the latter could achieve it with greater ease as reveled by its
lower heat of reactions (ΔH values). The study signifies the influence of poronization of polyethylene on its rate of biodegradation. 相似文献
43.
Aminul Islam Yun Hin Taufiq-Yap Chi-Ming Chu Eng-Seng Chan Pogaku Ravindra 《Process Safety and Environmental Protection》2013,91(1-2):131-144
The production of biodiesel is gaining momentum with the ever increasing demand of the fuel. Presently, limited literature is available with respect to well designed solid heterogeneous catalyst for biodiesel production considering all the characteristics, process and operation parameters. Hence, a study was conducted to design effective heterogeneous catalyst for biodiesel production. Further, the significant impact of different catalysts, different feed stock, various reaction conditions such as temperature, methanol oil molar ratio, catalyst concentrations and stability/inactivation of the catalysts, are detailed out for transesterification process of biodiesel production. Based on the studies it can be concluded that well designed heterogeneous catalyst can yield high throughput of biodiesel. 相似文献
44.
Leachate Characterization and Assessment of Groundwater Pollution Near Municipal Solid Waste Landfill Site 总被引:6,自引:0,他引:6
Leachate and groundwater samples were collected from Gazipur landfill-site and its adjacent area to study the possible impact
of leachate percolation on groundwater quality. Concentration of various physico-chemical parameters including heavy metal
(Cd, Cr, Cu, Fe, Ni, Pb and Zn) and microbiological parameters (total coliform (TC) and faecal coliform (FC)) were determined
in groundwater and leachate samples. The moderately high concentrations of Cl−, NO−
3, SO2−
4, NH+
4, Phenol, Fe, Zn and COD in groundwater, likely indicate that groundwater quality is being significantly affected by leachate
percolation. Further they proved to be as tracers for groundwater contamination. The effect of depth and distance of the well
from the pollution source was also investigated. The presence of TC and FC in groundwater warns for the groundwater quality
and thus renders the associated aquifer unreliable for domestic water supply and other uses. Although some remedial measures
are suggested to reduce further groundwater contamination via leachate percolation, the present study demand for the proper
management of waste in Delhi. 相似文献
45.
Ravindra K Wauters E Tyagi SK Mor S Van Grieken R 《Environmental monitoring and assessment》2006,115(1-3):405-417
Public transport in Delhi was amended by the Supreme Court of India to use Compressed Natural Gas (CNG) instead of diesel or petrol. After the implementation of CNG since April 2001, Delhi has the highest fraction of CNG-run public vehicles in the world and most of them were introduced within 20 months. In the present study, the concentrations of various criteria air pollutants (SPM, PM10, CO, SO2 and NOx) and organic pollutants such as benzene, toluene, xylene (BTX) and polycyclic aromatic hydrocarbons (PAHs) were assessed before and after the implementation of CNG. A decreasing trend was found for PAHs, SO2 and CO concentrations, while the NOx level was increased in comparison to those before the implementation of CNG. Further, SPM, PM10, and BTX concentrations showed no significant change after the implementation of CNG. However, the BTX concentration demonstrated a clear relation with the benzene content of gasoline. In addition to the impact of the introduction of CNG the daily variation in PAHs levels was also studied and the PAHs concentrations were observed to be relatively high between 10 pm to 6 am, which gives a proof of a relation with the limited day entry and movement of heavy vehicles in Delhi. 相似文献
46.
Jitendra K. Sharma Ravindra K. Gautam Sneha V. Nanekar Roland Weber Brajesh K. Singh Sanjeev K. Singh Asha A. Juwarkar 《Environmental science and pollution research international》2018,25(17):16355-16375
In recent years, microbial degradation and bioremediation approaches of polychlorinated biphenyls (PCBs) have been studied extensively considering their toxicity, carcinogenicity and persistency potential in the environment. In this direction, different catabolic enzymes have been identified and reported for biodegradation of different PCB congeners along with optimization of biological processes. A genome analysis of PCB-degrading bacteria has led in an improved understanding of their metabolic potential and adaptation to stressful conditions. However, many stones in this area are left unturned. For example, the role and diversity of uncultivable microbes in PCB degradation are still not fully understood. Improved knowledge and understanding on this front will open up new avenues for improved bioremediation technologies which will bring economic, environmental and societal benefits. This article highlights on recent advances in bioremediation of PCBs in soil. It is demonstrated that bioremediation is the most effective and innovative technology which includes biostimulation, bioaugmentation, phytoremediation and rhizoremediation and acts as a model solution for pollution abatement. More recently, transgenic plants and genetically modified microorganisms have proved to be revolutionary in the bioremediation of PCBs. Additionally, other important aspects such as pretreatment using chemical/physical agents for enhanced biodegradation are also addressed. Efforts have been made to identify challenges, research gaps and necessary approaches which in future, can be harnessed for successful use of bioremediation under field conditions. Emphases have been given on the quality/efficiency of bioremediation technology and its related cost which determines its ultimate acceptability. 相似文献
47.
Guvvala Pushpa Rani Sellappan Selvaraju Parameswaraiah Ravindra Janivara 《Environmental science and pollution research international》2016,23(18):18200-18210
Environmental Science and Pollution Research - The arsenic (As) is a multi system effector including reproduction. The present study examined the association of graded doses of As(V) on testicular... 相似文献
48.
Hydro-chemical Survey of Groundwater of Hisar City and Assessment of Defluoridation Methods Used in India 总被引:1,自引:0,他引:1
Ground water quality of Hisar city was assessed for its suitability for drinking purposes. Samples collected from the Bore-wells
(forms a part of municipal water supply) and handpumps (direct consumption) were analyzed for the various physico-chemical
parameters including pH, electrical conductivity, total dissolved salts, total hardness, total alkalinity, sodium, potassium,
calcium, magnesium, carbonate, bicarbonate, chloride and sulfate. The concentrations of magnesium, sodium, potassium, sulfate
and especially of chloride were found moderately higher than the WHO standards for the drinking water. Further a comparison
of fluoride (F−) levels in groundwater of various cities and towns of Haryana state was performed. The relatively higher concentrations of
F− in groundwater of Haryana raise the risk of fluorosis and hence groundwater must be used with proper treatment. Promising
defluoridation methods using locally available materials and technologies are discussed for the prevention and control of
fluorosis. Data were assessed statistically to find the suitable markers of ground water quality as an aid to monitoring groundwater
quality. 相似文献
49.
Murtaza G Haynes RJ Kim KR Zia MH Naidu R Belyaeva ON 《Environmental science and pollution research international》2012,19(3):636-645
Purpose
The study examines if a short period of reaction after addition of biosolids to soils can reduce the solubility and potential phytotoxicity of biosolid-borne Zn and Cu. 相似文献50.
Mor Suman Negi Pooja Ravindra Khaiwal 《Environmental science and pollution research international》2019,26(24):24516-24531
Environmental Science and Pollution Research - Ammoniacal nitrogen is considered as one of the major pollutants of the leachate generated from the landfill site and has the potential to deteriorate... 相似文献