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A study was conducted to evaluate the leaching potential of unpaved road materials (URM) mixed with lime activated high carbon fly ashes and to evaluate groundwater impacts of barium, boron, copper, and zinc leaching. This objective was met by a combination of batch water leach tests, column leach tests, and computer modeling. The laboratory tests were conducted on soil alone, fly ash alone, and URM-fly ash-lime kiln dust mixtures. The results indicated that an increase in fly ash and lime content has significant effects on leaching behavior of heavy metals from URM-fly ash mixture. An increase in fly ash content and a decrease in lime content promoted leaching of Ba, B and Cu whereas Zn leaching was primarily affected by the fly ash content. Numerically predicted field metal concentrations were significantly lower than the peak metal concentrations obtained in laboratory column leach tests, and field concentrations decreased with time and distance due to dispersion in soil vadose zone. 相似文献
878.
Along with the rapid increase in both production and use of TV sets in China, there is an increasing awareness of the environmental impacts related to the accelerating mass production, electricity use, and waste management of these sets. This paper aims to describe the application of life cycle assessment (LCA) to investigate the environmental performance of Chinese TV sets. An assessment of the TV set device (focusing on the Cathode Ray Tube (CRT) monitor) was carried out using a detailed modular LCA based on the international standards of the ISO 14040 series. The LCA was constructed using SimaPro software version 7.2 and expressed with the Eco-indicator' 99 life cycle impact assessment method. For a sensitivity analysis of the overall LCA results, the CML method was used in order to estimate the influence of the choice of the assessment method on the results. Life cycle inventory information was compiled by Ecoinvent 2.2 databases, combined with literature and field investigations on the current Chinese situation. The established LCA study shows that the use stage of such devices has the highest environmental impact, followed by the manufacturing stage. In the manufacturing stage, the CRT and the Printed Circuit Board (PCB) are those components contributing the most environmental impacts. During the use phase, the environmental impacts are due entirely to the methods of electricity generation used to run them, since no other aspects were taken into account for this phase. The final processing step-the end-of-life stage-can lead to a clear environmental benefit when the TV sets are processed through the formal dismantling enterprises in China. 相似文献
879.
研究了以β-环糊精(β-CD)和环氧氯丙烷为原料,采用反相悬浮聚合法合成的β-CD微球对对苯二酚单甲基醚( HQMME)的静态吸附行为,分析了吸附热力学性质和动力学特征.实验结果表明:β-CD微球对HQMME的吸附过程同时符合Lagergren一级吸附动力学方程和McKay二级吸附动力学方程;β-CD微球对HQMME的吸附等温线可同时用Langmuir等温吸附方程和Freundlich等温吸附方程描述;在不同温度下,β-CD微球吸附HQMME的吸附焓变、吸附熵变、吸附吉布斯自由能变均为负值,说明吸附是一个自发、放热的过程. 相似文献
880.
以不同的含钛化合物作为原料,在无模板条件下经一步溶剂热法合成了两种TiO2介孔球——TiO2-1和TiO2-2。对两种TiO2介孔球的形貌进行了表征,结果表明:TiO2-1和TiO2-2粒径分别为5.7 nm和8.0 nm;比表面积分别为159.4 m2/g和128.3 m2/g;孔径约为4.0 nm和5.0 nm。采用P25型TiO2、TiO2-1和TiO2-2对双酚A溶液进行光催化降解反应。在催化剂加入量为0.5 mg/L的条件下降解60 min,双酚A去除率分别为76.3%,99.7%,98.5%。TiO2-1和TiO2-2的光催化效果优于P25型TiO2,且TiO2-1的光催化效果更好。 相似文献