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701.
Breakthrough adsorption study of migratory nickel in fine-grained soil.   总被引:1,自引:0,他引:1  
The present study was conducted to evaluate the breakthrough curve for nickel adsorption in fine-grained soil from a nearby ash pond site of a thermal power plant. Nickel was found to be the major polluting solute in the ash sluicing wastewater. The adsorption of nickel by vertical soil column batch test and horizontal migration test was carried out in the laboratory. Field investigation was conducted also, by installing test wells around the ash pond site. Experimental results showed a good adsorptive capacity of soil for nickel ions. The breakthrough curves showed a reasonable fitting with a one-dimensional mathematical model. The breakthrough curves yielded from field test results showed good agreement with a two-dimensional mathematical model.  相似文献   
702.
Alloxan-induced diabetic rats were treated with multiple herbal preparation besides a control group receiving distilled water. The levels of glucose and alkaline phosphatase (ALP) increased abnormally in the alloxan treated group and the same were normalized upon treatment with the herbal preparation. The levels of blood urea nitrogen (BUN), alanine aminotransferase (ALT), protein and albumin in all groups remained unaltered. However, weekly body weight gain which got significantly altered in the alloxan-treated group was normalized by treatment with the herbal preparation. On the whole, a profound hypoglycemic effect was observed by the multiple herbal treatment in the diabetic rats.  相似文献   
703.
Different dilution levels of tannery treated effluent and their corresponding concentration of chromium (Cr6+) were studied in a petridish culture experiment on seed germination and seedling growth in radish (Raphanus sativus L). The different concentrations of Cr6+ (2, 5 and 10 ppm) and treated tannery effluent (10, 25 and 50%) showed reduction in seedling growth and related enzymatic activities with increase in concentration of Cr6+ in treatments and effluent both. The low concentration of chromium (2 ppm) and effluent dilution (10%) showed significant growth reduction separately. At this concentration of chromium and effluent dilution chlorophyll content, amylase, catalase and protein contents remained unchanged while with increase in Cr6+ concentration (>2ppm) and effluent dilution (> 10%) in treatments showed growth inhibitory effects.  相似文献   
704.
By combining the concepts of environmental stress, state susceptibility and environmental crisis, “Security Diagram” (SD) provides a quantitative approach to assessing environmental change and human security. The SD is a tool that clearly presents in a diagram the security situation of a population or region affected by a particular environmental crisis. Its underlying concept emphasises that the higher the level of environmental stress and socio-economic susceptibility, the higher the probability of the occurrence of crisis. Focusing on drought, this study analyses the susceptibility of case study regions in India, Portugal, and Russia from a socio-economic perspective. A conceptual framework of socio-economic susceptibility is developed based on the economic development theories of modernisation and dependency. Fuzzy set theory is used to generate susceptibility indices from a range of national and sub-national indicators, including financial resources, agricultural dependency and infrastructure development (for economic susceptibility), and health condition, educational attainment and gender inequality (for social susceptibility). Results indicate that socio-economic susceptibility over the period 1980–1995 was highest in India, followed by Russia and (since 1989) lowest in Portugal. Globalisation is likely to contribute to changes in the level of socio-economic susceptibility over time. Moreover, specific social and economic structures unique in each country (e.g., the role of women in society in India, the socialist legacy in Russia) may explain differences in susceptibility between the case study regions.
Sabine CampeEmail:
  相似文献   
705.
长江三角洲地区大气污染过程分析   总被引:1,自引:0,他引:1  
针对2015年和2016年12月2个月的4次污染过程,利用中分辨率成像光谱仪(MODIS)Terra卫星的气溶胶光学厚度(AOD),Angstrom波长指数(AE)气溶胶数据,并结合PM2.5和PM10的浓度以及比值变化分析,发现以PM2.5为代表的人为因素产生的细颗粒物是造成研究地区污染发生的重要因素.并且利用MODIS火点数据以及美国海军气溶胶分析与预测系统(NAAPS)模拟分析污染物成分,发现2015年12月12~16日和19~27日2次污染都以人为因素产生的细粒子污染物为主,沙尘以及生物质燃烧产生的烟粒对研究地区影响较小.2016年12月6~10日和15~18日2次污染过程产生的原因不同,利用潜在源贡献因子分析法(PSCF)分析发现6~10日污染天气的产生主要是由西北方向含有大量沙尘粒子气流以及南方生物质燃烧产生的大量烟粒共同输送到研究地区,加之研究地区大量人为污染细粒子的产生,导致了此次混合型污染天气发生.15~18日污染过程与2015年2次污染过程相似,主要原因都在于人为因素产生的细颗粒污染物的影响,沙尘以及烟粒对污染过程起到了加剧的作用.  相似文献   
706.
The synthesis of five chlorinated dibenzofurans and three chlorinated animodibenzofurans from easily available diphenyl ethers is described. Also reported is the preparation of the diphenyl ethers. The 1H-NMR and mass spectra data for the compounds are also reported.  相似文献   
707.
Examining the contribution of fossil fuel CO2to the total CO2changes in the atmosphere is of primary concern due to its alarming levels of fossil fuel emissions over the globe,specifi cally developing countries.Atmospheric radiocarbon represents an important observationa constraint and utilized to trace fossil fuel derived CO2(CO2ff) in the atmosphere.For the firs time,we have presented a detailed analysis on the spatial distribution of fossil fuel der...  相似文献   
708.
Nitrous oxide (N2O) accounts for 5%of the total enhanced greenhouse effect and responsiblefor the destruction of the stratospheric ozone. The rice-wheat cropping system occupying 26 million ha ofproductive land in Asia could be a major source ofN2O as most of the fertilizer N in this region isconsumed by this system. Emission of N2O asinfluenced by application of urea, urea plus farm yardmanure (FYM), and urea plus dicyandiamide (DCD), anitrification inhibitor, was studied in rice-wheatsystems of Indo-Gangetic plains of India. Total emissionof N2O-N from the rice-wheat systems varied between654 g ha-1 in unfertilized plots and 1570 g ha-1 in urea fertilized plots. Application of FYM and DCDreduced emission of N2O-N in rice. The magnitude ofreduction was higher with DCD. In wheat also N2O-Nemission was reduced by DCD. FYM applied in rice had noresidual effect on N2O-N emission in wheat. In riceintermittent wetting and drying condition of soilresulted in higher N2O-N emission than that ofsaturated soil condition. Treatments with 5 irrigationsgave higher emissions in wheat than those with 3irrigations. In rice-wheat system, typical of a farmer'sfield in Indo-Gangetic plains, where 240 kg N isgenerally applied through urea, N2O-N emission is1570 g ha-1 (0.38% of applied N) and application ofFYM and DCD reduced it to 1415 and 1096 g ha-1,respectively.  相似文献   
709.
Electro Thermal Atomic Absorption Spectrophotometry (ET-AAS), is used for the determination of chromium (Cr) in a variety of environmental matrices. The detection limit for the estimation of Cr is 2 pg absolute for a volume injection of 20 l. The precision of the method is established by analysing Cr from a synthetic mixture containing various elements in different qualities (0.5–10 ppm) and is found to be within ± 8%. The reliability of estimation is further assessed through the analysis of Standard Reference Materials (SRMs) of soil, hay, milk powder and lake sediment obtained from IAEA.The total intake of Cr through air, water and food works out to be 54 g/day for the adult population of Mumbai city. The dietary intake through food is the major contributor to the total intake of Cr. The concentration of Cr in atmospheric air and drinking water collected from different suburbs showed geometric mean concentrations of 0.09 g/m3 and 0.3 g/l, respectively. The daily intake of Cr, though lower, is closer to the lower bound of the recommended value of 50–200 g/day.  相似文献   
710.
Peat, ice deposits and aquatic sediments, which have been used as a geochemical monitor of atmospheric heavy metal pollution until now, are open and dynamic systems and can be easily affected by climatic variations. In contrast, bricks, which are more compact, can act as a better geochemical monitor. Analysis of Cu, Cr, Ni, Pb and Zn in scores of soil and brick (baked/unbaked) samples, collected from a large area in and around a rapidly growing Indian city, Agra, reveals approximately similar concentrations in soils and bricks, thereby showing insignificant fractionation of these metals during brick making. Further, metals concentration in the core of bricks remains unaffected by any significant amount of acidic and alkaline rain. Thus, the feasibility of a novel role of bricks as a geochemical monitor of atmospheric heavy metal pollution has been tested. Utilizing this concept, an attempt has also been made to trace the history of atmospheric copper depositions in the soils of Agra during the last 100 years.  相似文献   
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