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西安作为汾渭平原地区最大的城市,大气颗粒物污染形势严峻.2017年夏季期间,在西安市浐灞生态园区运用气溶胶化学组分监测仪,对大气亚微米颗粒物中的非难挥发性组分(NR-PM1)进行了在线监测.观测期间NR-PM1的平均质量浓度为(30.1?±?15.4)μg???m?3.其中有机物含量最高,占NR-PM1总质量浓度的63...  相似文献   
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Feasibility of an irrigation project is evaluated by two criteria viz., reservoir capacity to irrigate its command area and economic returns by incremental crop production versus capital investment for dam construction. The annual water requirement of different crops in the command area is estimated and compared with the availability of water from the dam for irrigation purpose. The annual crop water requirement is estimated as the sum of evapotranspiration for crops and transmission and other losses. Evapotranspiration is estimated by modified Penman formula. Economics of crop production is analyzed by first estimating the monetary value of existing crop production under current rain fed conditions and then estimating the incremental production of irrigated command area for the proposed crop pattern. The proposed cropping pattern is prepared so as to maximize the benefit of crop production and fodder requirement while maintaining a better crop rotation to improve and maintain physical, chemical, and biological conditions of the soil. The dam is to be used for irrigation and water supply only. Command area served by this reservoir will be 76,500 ha. The existing annual agricultural return is Rs. 2995.56 lakhs and with the proposed irrigation scheme, it is estimated as Rs. 1,77,91.90 lakhs. The incremental annual return would be Rs. 1,47,96.35 lakhs i.e., 642.68% increase in annual return.  相似文献   
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The air pollution due to anthropogenic activities seriously affected human life, vegetation, and heritage as well. The vegetation cover in and around the city mitigates the air pollution by acting as a sink for pollution. An attempt was made to evaluate biochemical changes occurred in four selected plant species, namely Azadirachta indica, Mangifera indica, Delonix regia, and Cassia fistula of residential, commercial, and industrial areas of Nagpur city in India. It was observed that the correlated values of air pollutants and plant leaves characteristics alter foliar biochemical features (i.e., chlorophyll and ascorbic acid content, pH and relative water content) of plants due to air pollution. The changes in air pollution tolerance index of plants was also estimated which revealed that these plants can be used as a biomarker of air pollution.  相似文献   
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The Paraiba do Sul (PSR) and Guandu Rivers (GR) water diversion system (120 km long) is located in the main industrial pole of Brazil and supplies drinking water for 9.4 million people in the metropolitan region of Rio de Janeiro. This study aims to discern the trace metals dynamics in this complex aquatic system. We used a combined approach of geochemical tools such as geochemical partitioning, Zn isotopes signatures, and multivariate statistics. Zinc and Pb concentrations in Suspended Particulate Matter (SPM) and sediments were considerably higher in some sites. The sediment partition of As, Cr, and Cu revealed the residual fraction (F4) as the main fraction for these elements, indicating low mobility. Zinc and Pb were mostly associated with the exchangeable/carbonate (F1) and the reducible (F2) fractions, respectively, implying a higher susceptibility of these elements to being released from sediments. Zinc isotopic compositions of sediments and SPM fell in a binary mixing source process between lithogenic (δ66/64ZnJMC ≈ + 0.30‰) and anthropogenic (δ66/64ZnJMC ≈ + 0.15‰) end members. The lighter δ66/64ZnJMC values accompanied by high Zn concentrations in exchangeable/carbonate fraction (ZnF1) enable the tracking of Zn anthropogenic sources in the studied rivers. Overall, the results indicated that Hg, Pb, and Zn had a dominant anthropogenic origin linked to the industrial activities, while As, Cr, and Cu were mainly associated with lithogenic sources. This work demonstrates how integrating geochemical tools is valuable for assessing geochemical processes and mixing source effects in anthropized river watersheds.  相似文献   
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An important goal of ecological rehabilitation is to accelerate natural successional processes to increase biological productivity, soil fertility and biotic control over biogeochemical fluxes within the recovering ecosystems. A new approach called Microbe Assisted Green Technology (MAGT) is an integrated biotechnological approach developed at National Environmental Engineering Research Institute (NEERI) through exhaustive laboratory as well as field studies and serve as a model for land reclamation and development of lush green vegetation on mine overburdens. One year old seedlings of native tree species were planted on 6.3 ha area of manganese mine overburden at Gumgaon under Manganese Ore India Ltd., Maharashtra, India. Continuous efforts resulted in nutrient rich soil with high N, P, K and organic carbon; well developed biodiversity, including bacteria, fungi, higher plants (more than 350 species) and different classes of animals. Planted trees accumulated 698 t ha( - 1) above ground biomass and 143 t ha( - 1) below ground mass. This was achieved in 18 years by MAGT, which otherwise takes hundreds of years.  相似文献   
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