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951.
Severe restrictions imposed by the pollution control authorities on the disposal of chromium, total dissolved solids and chlorides in tannery effluents have forced the tanners to look for low-waste, high exhaust chrome tanning salts. An improved chrome syntan with more than 90% uptake of chrome has been developed. The new product serves both as tanning and retanning agent and can be applied directly to delimed pelts thus eliminating the conventional pickling stage in the leather processing. This modified process helps to reduce the chemical oxygen demand (COD), total dissolved solids (TDS) and chlorides in the spent tan liquor by 51, 81 and 99%, respectively. The product offers full, soft leathers having shrinkage temperature comparable to conventional chrome tanned skins. Since the developed product is highly reactive, it saves time and reduces the water requirement when compared to the conventional chrome tanning method. Thus the novel product/process developed not only has advantages in reducing pollution loads but also seems to be techno-economically viable.  相似文献   
952.
Cadmium is an important contaminant of superphosphate. Market samples of superphosphate revealed a concentration of cadmium in the range of 18.2–28.5 mg/kg. Application of periodic excess doses of superphosphate in vineyards 5–35 years old has led to elevated concentrations of cadmium in the ground water in the vineyards. Ground water samples from different vineyards analysed for cadmium by atomic absorption spectrophotometry revealed concentrations of cadmium in the range of 3.2–99.2 µg/I. These concentrations of cadmium in the ground water can be regarded as significant, since ground water serves as the only source of water for the vineyards.  相似文献   
953.
Distribution of heavy metals in plants and fish of the Yamuna river (India)   总被引:2,自引:0,他引:2  
The distribution of cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn) in the plants and fish of Yamuna river from Delhi to Allahabad, a distance of about 840 km, at five sampling stations was determined in the year 1981. The results have shown wide variations in the heavy metal levels from one sampling station to the other. The concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn in the plants (Eicchornia crassipes) were found to be 0.02–0.12, 2.7–21.3, 4.6–64.8, 9.8–114.0, 193.0–1835.0, 380.0–1443.0, 4.4–83.0, 4.8–30.2, and 22.1–356.5 g g-1 respectively whereas in the fish (Heteropnuestes fossilis) were found to be ND-0.40, 2.3–13.7, 3.7–26.9, 8.33–58.1, 278.3–1108.0, 81.3–213.8, 2.8–32.7, 1.4–12.8 and 101.8–364.8 gg-1 respectively on dry weight basis.  相似文献   
954.
Pakistan is one of the few countries in Asia thatcontinues to use only leaded-petrol as vehicular fuel. Theconcentration of Pb in its petrol reported in 1991 was thehighest (1.5 – 2.0 g Pb L-1) of all produced by the various Asiancountries and far exceeded the WHOs guideline of 0.15 g Pb L-1. We have undertaken a study to trace and quantify this toxicelement in the environs of Karachi, Pakistans major metropolis,having more than 30% of the nations total number of vehicles.In this article we report the Pb contents of petrol and dieselcurrently manufactured and marketed in the city. Samples of`Regular petrol collected in 1999 was found to contain 0.363 gPb L-1 (range: 0.335 – 0.390 g Pb L-1), a factor of 5 lower than thatmarketed prior to 1991. Its concentration in diesel fuel was muchlower (0.017 g Pb L-1). Based on the available statistical data onthe type and volume of vehicular traffic, we assessed that thecurrent lead emission from vehicular traffic into the atmosphereis 391 metric tons a year, which is a factor of 2.7 lower thanthat estimated for 1989.  相似文献   
955.
A procedure has been developed for the determination of ziram, zineb and ferbam dithiocarbamate pesticides by converting ziram and zineb into a zinc-phenylfluorone complex and ferbam into an iron phenylfluorone complex, which are then dissolved in water in the presence of cetylpyridinium bromide and pyridine as a surfactant. The method is sensitive, highly selective and can be used for the determination of ziram, zineb and ferbam in commercial samples and in foodstuffs.  相似文献   
956.
One of the many problems researchers and managers face is to try and interpret data collected from various river studies. There is an underlying awareness of the incompleteness of most data bases due to a variety of problems outside of those concerning sample processing.In this study we have attempted, by using the battery of tests approach (12 tests) and the examination of different types of samples such as water, Milli-Q water extracted sediments, and organic solvent extracted sediments, to explore the implication of spacial and temporal sampling programmes.The results obtained were not unexpected: there were spatial and temporal influences, sometimes so great that it would appear that you were examining samples from different parts of the country. However, data arising from solvent extracted sediments were found to be much less influenced by temporal sampling than by spatial variation. Another interesting and important observation was that sediment composition appeared to have no relationship to toxicant content.In this study, the first field application of the Mutatox test (genotoxicity) was carried out and it was found to be a very responsive test in all three types of samples. This test shows great promise as laboratory studies indicate it is sensitive to many of the chemicals which trigger the Ames test.  相似文献   
957.
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959.
Jordan faces stringent energy challenges mainly in the form of import dependence and escalating demand. The building sector accounts for 58% of total national electricity consumption and therefore plays an important role in addressing these challenges. This article investigates how energy efficiency in green buildings certified by the Leadership in Energy and Environmental Design (LEED) rating system contribute towards achieving United Nations (UN) Sustainable Development Goals (SDGs) in Jordan. Furthermore, this paper proposes a new Comprehensive Contribution to Sustainable Development Index (CCSDI) to assess the contributions of implementation of the LEED 2009 prerequisites and credits in the Energy and Atmosphere (EA) category to achieve UN SDGs in Jordan. Questionnaire surveys were conducted to obtain data. Relative Importance Index (RII) method was used to evaluate the contributions of LEED 2009 prerequisites and credits in the EA category. Results indicate a positive relationship between the LEED 2009 prerequisites and credits in category and UN SDGs 7?9 and 12?13. We conclude that our proposed CCSDI is a robust tool for assessing the contribution of energy efficiency in LEED 2009 certified green buildings towards achieving UN SDGs in Jordan.  相似文献   
960.
Environment, Development and Sustainability - There has been great concern about producing, converting, or disposing of the waste obtained from different sources. Waste production is a continuous...  相似文献   
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