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11.
Trivedi N  Gupta V  Kumar M  Kumari P  Reddy CR  Jha B 《Chemosphere》2011,83(5):706-712
The organic solvent tolerant bacteria with their physiological abilities to decontaminate the organic pollutants have potentials to secrete extracellular enzymes of commercial importance. Of the 19 marine bacterial isolates examined for their solvent tolerance at 10 vol.% concentration, one had the significant tolerance and showed a relative growth yield of 86% for acetone, 71% for methanol, 52% for benzene, 35% for heptane, 24% for toluene and 19% for ethylacetate. The phylogenetic analysis of this strain using 16S rDNA sequence revealed 99% homology with Bacillus aquimaris. The cellulase enzyme secreted by this strain under normal conditions showed an optimum activity at pH 11 and 45 °C. The enzyme did show functional stability even at higher pH (12) and temperature (75 °C) with residual activity of 85% and 95% respectively. The enzyme activity in the presence of different additives were in the following order: Co+2 > Fe+2 > NaOCl2 > CuSO4 > KCl > NaCl. The enzyme stability in the presence of solvents at 20 vol.% concentration was highest in benzene with 122% followed by methanol (85%), acetone (75%), toluene (73%) and heptane (42%). The pre-incubation of enzyme in ionic liquids such as 1-ethyl-3-methylimidazolium methanesulfonate and 1-ethyl-3-methylimidazolium bromide increased its activity to 150% and 155% respectively. The change in fatty acid profile with different solvents further elucidated the physiological adaptations of the strain to tolerate such extreme conditions.  相似文献   
12.
ESR increased at all concentrations and exposures to LAS. However, increases were more pronounced at LC50 for 24 h and minimum at the end of 96 h.  相似文献   
13.
14.
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   
15.
The work highlights the utilization of an agricultural waste mustard plant ash (MPA) as a soil additive and an adsorbent. MPA was characterized by X-ray fluorescence (XRF), energy-dispersive X-ray spectroscopy (EDX), proximate analysis, CHNS analysis, Brunauer–Emmett–Teller (BET) surface area analysis, zeta potential measurements, Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). XRF analysis confirmed the presence of CaO (31.35 %), K2O (18.55 %), and P2O5 (6.99 %), all of which act as micronutrients to plants. EDX also confirms high amount of elemental O, Ca, K, and P. The adsorptive ability of MPA was investigated using a commonly used herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), as a representative chemical. Batch adsorption experiments were conducted to study the effect of different operational parameters such as adsorbent dose, initial 2,4-D concentration, contact time, and temperature on the adsorption process. Data from experiments were fitted to various kinetic and isothermal models. The pseudo-second-order kinetic model was found to show the best fit (R 2?>?0.99), with the highest k 2 value of the order 105. Based on the study results, dosage of MPA/hectare for different crops has been recommended for effective removal of 2,4-D. To our knowledge, this is the first study in which MPA has been characterized in detail and investigated for dual applications (as an adsorbent and as a soil additive).  相似文献   
16.
In India, farming is the primary source of income for many families. Following each harvest, a huge amount of biomass is generated. These are generally discarded as “agrowaste,” but recent reports have indicated several beneficial uses for these biomasses and their ashes. However, before the utilization of biomass ashes (BMAs), their chemical and physical properties need to be investigated (characterized) so as to utilize their potential benefit to the fullest. In this paper, eight different biomass ashes (soybean plant ash, mustard plant ash, maize ash, groundnut plant ash, cotton plant ash, wheat plant ash, pigeon peas ash, and groundnut shell ash) were characterized, and their chemical properties are discussed. Surface chemical composition analysis, proximate analysis, and ultimate analysis were performed on all BMA samples, and properties such as porosity, particle density, bulk density, point of zero charge, BET surface area, water-absorption capacity, and bulk parameters such as surface pH and surface charges were determined. BMAs were characterized by SEM and FTIR. The surface areas of biomass ashes vary from 1.9 to 46 m2/g, and point of zero charge for all BMAs exceed 9.8, which confirmed the alkaline nature of these samples. Based on the chemical composition, BMAs are categorized into four types (S, C, K, and CK), and their utilization is proposed based on the type. BMAs find applications in agriculture and construction industries; glass, rubber, and zeolite manufacturing; and in adsorption (as a source of silica/zeolites). The paper also discusses the research challenges and opportunities in utilization of BMAs.  相似文献   
17.
This study investigated dioxins and dioxin-like polychlorinated biphenyls in gasses emitted from waste incinerators and thermal processes in central and western parts of India. The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/DFs) ranged from 0.0070 to 26.8140 ng toxicity equivalent (TEQ)/Nm3, and those of dioxin-like polychlorinated biphenyls (PCBs) ranged from 0.0001?×?10?1 to 0.0295 ng TEQ/Nm3. The characteristics of mean PCDD/F I-TEQ concentration and congener profiles were studied over all the samples of air. In particular, a pattern consisting of a low proportion of dioxin-like PCBs and high proportion of PCDDs/DFs was common for all the samples from incinerators and high-temperature processes.  相似文献   
18.
Environmental Science and Pollution Research - Urbanization is a rapidly growing phenomenon that affects wildlife. Laboratory studies show the effects of night light on the physiology of the...  相似文献   
19.
The study was conducted on 20 vegetables including leafy, root, modified stem, and fruity vegetables like bitter gourd, jack fruit, french-bean, onion, colocassia, pointed gourd, capsicum, spinach, potato, fenugreek seeds, carrot, radish, cucumber, beetroot, brinjal, cauliflower, cabbage, tomato, okra, and bottle gourd. Forty-eight pesticides including 13 organochlorines (OCs), 17 organophosphates (OPs), 10 synthetic pyrethriods (SPs), and eight herbicides (H) pesticides were analyzed. A total number of 60 samples, each in triplicates, were analyzed using Quick, Easy, Cheap, Effective, Rugged, and Safe method. The quantification was done by GC-ECD/NPD. The recovery varies from 70.22% to 96.32% with relative standard deviation (RSD) of 15%. However the limit of detection ranged from 0.001?C0.009 mg kg???1 for OCs, SPs, OPs, and H, respectively. Twenty-three pesticides were detected from total 48 analyzed pesticides in the samples with the range of 0.005?C12.35 mg kg???1. The detected pesticides were: ??-HCH, Dicofol, ??-Endosulfan, Fenpropathrin, Permethrin-II, ??-cyfluthrin-II, Fenvalerate-I, Dichlorvos, Dimethoate, Diazinon, Malathion, Chlorofenvinfos, Anilophos, and Dimethachlor. In some vegetables like radish, cucumber, cauliflower, cabbage, and okra, the detected pesticides (??-HCH, Permethrin-II, Dichlorvos, and Chlorofenvinfos) were above maximum residues limit (MRL) (PFA 1954). However, in other vegetables the level of pesticide residues was either below detection limit or MRL.  相似文献   
20.
The present study was to evaluate heavy metal toxicity stress symptoms in fish blood during long-term exposure of sublethal concentration of copper sulphate (CuSO4). The effects of copper on various heamatological parameters were evaluated exposing Indian fresh water fish, Channa punctatus to a sub-lethal concentration of copper sulphate (0.36 mg l(-1)) for different periods. Exposure of fish to copper showed a significant decrease in the haemoglobin (Hb) content from 10.73 to 6.60%, red blood cells (RBC) from 2.86 to 1.84 x 10(6)/mm3 and packed cell volume (PCV) from 31.00 to 23.33% at the end of 45th day as compared to control. Whereas the white blood cells (WBC) increased from 60.00 to 92.48 x10(3)/mm3, clotting time (CT) from 27.66 to 43.00 second, erythrocyte sedimentation rate from 5.0 to 13.66 mm/hr and mean corpuscular volume from 108.11 to 126.85 cmu, significantly, with increase in exposure periods. Although mean corpuscular haemoglobin concentration (MCHC) and mean corpuscular haemoglobin (MCH) values showed significant increase during 15 and 30 days exposures, both the values were found significantly increased at the end of the experimental period. The differential leucocytes count (DLC) showed a significant increase in the populations of lymphocytes and eosinophils, whereas neutrophils, monocytes and basophiles were found decreased after exposure to copper.  相似文献   
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