从碳硫污染物(CO_(2)、 H_(2)S)出发合成甲硫醇(CH_(3)SH),再经由甲硫醇资源化催化制低碳烯烃(methyl mercaptan to olefins,M_(2)TO)的工艺技术,不仅实现污染物CO_(2)和H_(2)S协同资源化利用,还为低碳烯烃的多元化来源拓展了新路径.因...从碳硫污染物(CO_(2)、 H_(2)S)出发合成甲硫醇(CH_(3)SH),再经由甲硫醇资源化催化制低碳烯烃(methyl mercaptan to olefins,M_(2)TO)的工艺技术,不仅实现污染物CO_(2)和H_(2)S协同资源化利用,还为低碳烯烃的多元化来源拓展了新路径.因此甲硫醇资源化催化制低碳烯烃具有重要的研究意义和应用前景.我们介绍了甲硫醇资源化催化制低碳烯烃反应的发展历程及研究现状,对比了甲醇制烯烃(MTO)与甲硫醇制烯烃(M_(2)TO)反应机理,分析了M_(2)TO反应较难实现的原因,也探讨了反应温度、酸性位密度、分子筛结构和甲硫醇甲基化能力对M_(2)TO反应的影响,并提出了一些解决方法 .展开更多
Copper(Cu) mine tailings,because of their high content of heavy metals,are usually hostile to plant colonization.A pot experiment was conducted to determine the tolerance of four forage grasses to heavy metals in Cu m...Copper(Cu) mine tailings,because of their high content of heavy metals,are usually hostile to plant colonization.A pot experiment was conducted to determine the tolerance of four forage grasses to heavy metals in Cu mine tailings and to examine the variation in the microbial functional diversity of soils from the tailing sites in southern China.All the four grass species survived on Cu mine tailings and Cu mine tailing-soil mixture.However,on pure mine tailings,the growth was minimal,whereas the growth was maximum for the control without mine tailings.The tolerance of grasses to heavy metals followed the sequence:Paspalum notatum > Festuca arundinacea > Lolium perenne > Cynodon dactylon.The planting of forage grasses enhanced the soil microbial biomass.The Biolog data indicated that the soil microbial metabolic profile values(average well color development,community richness,and Shannon index) of the four forage grasses also followed the sequence:P.notatum > F.arundinacea > L.perenne > C.dactylon.Thus,P.notatum,under the experimental conditions of this study,may be considered as the preferred plant species for revegetation of Cu mine tailing areas.展开更多
A total of 198 agricultural soil samples were collected from Zhangjiagang and Changshu in Southern Jiangsu for analysis of 13 polychlorinated biphenyls （PCBs） in order to assess the levels of pollution, sources, are...A total of 198 agricultural soil samples were collected from Zhangjiagang and Changshu in Southern Jiangsu for analysis of 13 polychlorinated biphenyls （PCBs） in order to assess the levels of pollution, sources, area distribution, and potential risk for the environment. All methods were rigorously tested and an adequate quality control was ensured. Only one site had no PCBs residues, and the highest total PCBs concentration in the surface soils was 32.83 ng/g. The average concentration in all the soil samples was 4.13 ng/g, signaling low-level pollution. Tetra-, penta-, and hexa-chlorinated biphenyls were dominant species in soil samples, accounting for more than 75% of ∑PCBs in the soil samples. PCB118 was the most abundant congener in all the samples. The PCB118 was about 20% of ∑PCBs. The soil organic matter content showed only a weak correlation with the levels of all PCB congeners, in which a better correlation was noted for the more volatile lighter PCB congeners than for the heavier homologues. To a certain extent, the sources and land use seemed to influence the levels of PCBs.展开更多
基金the National Natural Sciences Foundation of China (Nos40171054 and 40125005)the National Key Basic Research Support Foundation of China (No2002CB410809/10)
文摘Copper(Cu) mine tailings,because of their high content of heavy metals,are usually hostile to plant colonization.A pot experiment was conducted to determine the tolerance of four forage grasses to heavy metals in Cu mine tailings and to examine the variation in the microbial functional diversity of soils from the tailing sites in southern China.All the four grass species survived on Cu mine tailings and Cu mine tailing-soil mixture.However,on pure mine tailings,the growth was minimal,whereas the growth was maximum for the control without mine tailings.The tolerance of grasses to heavy metals followed the sequence:Paspalum notatum > Festuca arundinacea > Lolium perenne > Cynodon dactylon.The planting of forage grasses enhanced the soil microbial biomass.The Biolog data indicated that the soil microbial metabolic profile values(average well color development,community richness,and Shannon index) of the four forage grasses also followed the sequence:P.notatum > F.arundinacea > L.perenne > C.dactylon.Thus,P.notatum,under the experimental conditions of this study,may be considered as the preferred plant species for revegetation of Cu mine tailing areas.
基金Project supported by the National Basic Research Program (973) of China(No. 2002CB410810).
文摘A total of 198 agricultural soil samples were collected from Zhangjiagang and Changshu in Southern Jiangsu for analysis of 13 polychlorinated biphenyls （PCBs） in order to assess the levels of pollution, sources, area distribution, and potential risk for the environment. All methods were rigorously tested and an adequate quality control was ensured. Only one site had no PCBs residues, and the highest total PCBs concentration in the surface soils was 32.83 ng/g. The average concentration in all the soil samples was 4.13 ng/g, signaling low-level pollution. Tetra-, penta-, and hexa-chlorinated biphenyls were dominant species in soil samples, accounting for more than 75% of ∑PCBs in the soil samples. PCB118 was the most abundant congener in all the samples. The PCB118 was about 20% of ∑PCBs. The soil organic matter content showed only a weak correlation with the levels of all PCB congeners, in which a better correlation was noted for the more volatile lighter PCB congeners than for the heavier homologues. To a certain extent, the sources and land use seemed to influence the levels of PCBs.
