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31.
Krishna Giri J. P. N. Rai Shailesh Pandey Gaurav Mishra Rajesh Kumar Deep Chandra Suyal 《Chemistry and Ecology》2017,33(9):817-825
Isoproturon (IPU)-degrading soil bacteria were isolated from herbicide-applied wheat fields. These isolates were identified using cultural, morphological, biochemical and 16S rRNA sequencing methods. 16S rRNA sequences of both the bacterial isolates were compared with NCBI GenBank data base and identified as Bacillus pumilus and Pseudoxanthomonas sp. A soil microcosm study was carried out for 40 days in six different treatments. Experimental results revealed maximum 95.98% IPU degradation in treatment 6 where bacterial consortia were augmented in natural soil, followed by 91.53% in treatment 5 enriched with organic manure as an additional carbon source. However, only 14.03% IPU was degraded in treatment 1 (control) after 40 days. In treatments (2–4), 75.59%, 70.92% and 77.32% IPU degradation was recorded, respectively. IPU degradation in all the treatments varied significantly over the control. 4-Isopropylaniline was detected as IPU degradation by-product in the medium. The study confirmed that B. pumilus and Pseudoxanthomonas sp. performed effectively in soil microcosms and could be employed profitably for field-scale bioremediation experiments. 相似文献
32.
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
33.
Kaushik Himanshu Ranjan Rashmi Ahmad Rakhshan Kumar Alok Prashant Kumar Nitish Ranjan Rajesh Kumar 《Environmental science and pollution research international》2021,28(15):18686-18701
Environmental Science and Pollution Research - The concentration of trace metals Mn, Pb, Ni, Zn, and Cu in the core sediment from Kabar Tal wetland was analyzed to understand the level of... 相似文献
34.
Kumar Rajesh Kamakshi Kumar Manoj Awasthi Kamlendra 《Environmental science and pollution research international》2021,28(34):46404-46413
Environmental Science and Pollution Research - For hydrogen-based energy systems development, purified hydrogen (H2) is a basic requirement and it can be achieved by using the H2-selective... 相似文献
35.
Jayshri A. Thote Ravikrishna V. Chatti Kartik S. Iyer Vivek Kumar Arti N. Valechh Nitin K. Labhsetwar Rajesh B. Biniwale M. K. N. Yenkie Sadhana S. Rayalu 《环境科学学报(英文版)》2012,24(11):1979-1984
N-doped mesoporous alumina has been synthesized using chitosan as the biopolymer template. The adsorbent has been thoroughly investigated for the adsorption of CO2 from a simulated flue gas stream (15% CO2 balanced with N2) and compared with commercially available mesoporous alumina procured from SASOL, Germany. CO2 adsorption was studied under different conditions of pre-treatment and adsorption temperature, inlet CO2 concentration and in the presence of oxygen and moisture. The adsorption capacity was determined to be 29.4 mg CO2/g of adsorbent at 55℃. This value was observed to be 4 times higher in comparison to that of commercial mesoporous alumina at a temperature of 55℃. Basicity of alumina surface coupled with the presence of nitrogen in template in synthesized sample is responsible for this enhanced CO2 adsorption. Adsorption capacity for CO2 was retained in the presence of oxygen; however moisture had a deteriorating effect on the adsorption capacity reducing it to nearly half the value. 相似文献
36.
Aullybux Aadil Ahmad Puchooa Daneshwar Bahorun Theeshan Jeewon Rajesh Wen Xuesong Matin Poona 《Journal of Polymers and the Environment》2022,30(4):1462-1477
Journal of Polymers and the Environment - Extracellular polysaccharides (EPS) of microbial origin are polymers with great potential for research and industrial applications. In this study, a... 相似文献
37.
K. Devi M. C. Raicy Deshraj Trivedi P. Srinivasan S. G. N. Murthy Ronald J. Goble Rajesh R. Nair 《Journal of Coastal Conservation》2013,17(4):729-742
The East coast of India is subject to continuous changes by high energy events. We sought to assess the depositional conditions along the coast from the geophysical and sedimentological character of the dune sands of the Gopalpur and Paradeep coast of Odisha, and the Sagarnagar coast of North Visakhapatnam. Quartz layers of the heavy mineral-rich zone collected at a depth of ~2 m from the landward foot of the dunes in the Visakhapatnam and Odisha coast, gave the OSL age estimates as 1,050?±?50 and 260?±?10 years respectively, revealing that the age of the dunes in Visakhapatnam are older than those on the Odisha coast. Episodic high energy events have affected the coast. Evidence from ground penetrating radar data consists of three stratigraphic units. The upper unit consists of vague reflections, parallel to the ground in continuous manner, most probably formed by wind action. On the other hand, the middle layer shows high amplitude reflections of heavy mineral-rich massive layers, possibly the result of tsunami activity. The lower massive layer parallel to the ground surface shows a low reflection pattern. The GPR studies showed that the thickness of the heavy mineral layers is greater on the landward foot of the dune as compared to that on the seaward side. According to the grain size analysis, the dune is composed of both wind generated and tsunamigenic sediments. The scanning electron microscope studies revealed that the heavy minerals present in the dunes are mainly sillimanite, ilmenite, garnet, pyroxene, rutile, sphene, biotite, hornblende, zircon, monazite and magnetite. The study demonstrates the origin of sand dunes in different ages along the East Coast of India by the effect of various natural phenomena. 相似文献
38.
Shanta Satyanarayan Rajesh S. Bejankiwar P.R. Chaudhari J.P.Kotangale Ahana Satyanarayan 《环境科学学报(英文版)》2004,16(4):631-634
The effects of pesticides on blood characteristics and histological changes in erythrocytes of the fish species Cyprinus carpio and Puntius ticto were studied. The fishes were exposed to sub lethal concentrations of different chlorinated pesticides namely aldrin, dieldrin, DDT, BHC and chlordane for 10, 20 and 30 d in continuous flow-through test. The LCso values were calculated based on acute toxicity tests and the sublethal doses were arrived at for chronic bioassay studies. Results showed an increase in haemoglobin content of both Cyprinus carpio and Puntius ticto in case of aldrin and dieldrin. Haemoglobin content reduced from an initial 13 g/100 ml to 8.07 and 10.15 g/100 ml in case of Cyprinus at the end of ten days exposure to aldrin and dieldrin respectively, and gradually increased to 8.7 g/100 ml and 10.15 g/100 ml after 20 d of exposure. The haemoglobin content after 30 d exposure to aldrin and dieldrin was 10.15 g/100 ml and 11.6 g/100 ml respectively. In case of Puntius ticto, the haemoglobin content in control fishes recorded was 12.8 g/100 ml while in case of fish exposed to aldrin, the haemoglobin content reduced initially on ten days exposure to 10.15 g/100 ml and increased to 11.6 g/100 ml and 13.0 g/100 ml during twenty days and thirty days exposure respectively. This trend was also observed with dieldrin in both the fishes studied. Red blood cells were also counted in case of all the pesticides and exposure periods with respect to Cyprinus carpio and Puntius ticto. Irrespective of the species and pesticide, the RBC counts uniformly showed decreasing trend with the increase in exposure period, while packed cell volume, PCV(%) showed increasing trend with respect to increase in exposure period in case of aldrin and dieldrin in both the fishes. But DDT, BHC and chlordane showed decreasing trend in PCV(%) values with increasing periods of exposure. 相似文献
39.
Muthukkumar Thillainayagam Krishnamoorthy Venkatesan Rana Dipak Saravanan Subramani Balaji Sethuramasamyraja Rajesh Kumar Babu 《Environmental science and pollution research international》2017,24(20):16725-16734
In the Indian agricultural sector, millions of diesel-driven pump-sets were used for irrigation purposes. These engines produce carcinogenic diesel particulates, toxic nitrogen oxides (NOx), and carbon monoxide (CO) emissions which threaten the livelihood of large population of farmers in India. The present study investigates the use of n-propanol, a less-explored high carbon bio-alcohol that can be produced by sustainable pathways from industrial and crop wastes that has an attractive opportunity for powering stationary diesel engines meant for irrigation and rural electrification. This study evaluates the use of n-propanol addition in fossil diesel by up to 30% by vol. and concurrently reports the effects of exhaust gas recirculation (EGR) on emissions of an agricultural DI diesel engine. Three blends PR10, PR20, and PR30 were prepared by mixing 10, 20, and 30% by vol. of n-propanol with fossil diesel. Results when compared to baseline diesel case indicated that smoke density reduced with increasing n-propanol fraction in the blends. PR10, PR20, and PR30 reduced smoke density by 13.33, 33.33, and 60%, respectively. NOx emissions increased with increasing n-propanol fraction in the blends. Later, three EGR rates (10, 20, and 30%) were employed. At any particular EGR rate, smoke density remained lower with increasing n-propanol content in the blends under increasing EGR rates. NOx reduced gradually with EGR. At 30% EGR, the blends PR10, PR20, and PR30 reduced NOx emissions by 43.04, 37.98, and 34.86%, respectively when compared to baseline diesel. CO emissions remained low but hydrocarbon (HC) emissions were high for n-propanol/diesel blends under EGR. Study confirmed that n-propanol could be used by up to 30% by vol. with diesel and the blends delivered lower soot density, NOx, and CO emissions under EGR. 相似文献
40.
Rajesh Kumar 《Environment, Development and Sustainability》2016,18(1):187-196
Distillery effluents, a major by-product of distilleries are a major environmental hazard as they are rich in organic matter, micro- and macroelements. Management of this enormous amount of nutrient-rich effluent and its effective utilization is a major challenge. These effluents can be used as a source of nutrient by C4 crops like sugarcane and subsequent ratoon crops under fertigation system. Impact of fertigation in sugarcane-ratoon cropping system on soil microbial biomass is important as the microbial population plays an important role in the nutrient and biogeochemical recycling. Keeping this in mind, a field experiment was carried out in the sandy loam soil of semi-arid to humid sub-tropical climate of Gajraula (28.85°N, 78.23°E) region, India with different doses of diluted and undiluted effluent for fertigation of sugarcane crop in presence and absence of 50 % recommended dose of fertilizers with suitable replicates. Two post-sown irrigations with four times diluted effluent gave the maximum yield in case of sugarcane crop. Taking into consideration the yield and the culturable microbial population sizes, it can be concluded that one to two post-sown irrigations with diluted effluent can be used to enhance soil fertility in terms of microbial population and to enhance sugarcane and ratoon crop productivity. This package is economically viable and can also take care of distillery waste management and reduction in consumption of chemical fertilizers by 50 %, a key for sustainable agricultural development. 相似文献