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941.
磷酸二氢钾-磷酸氢二钠缓冲溶液调控下白菜对钼矿区重金属污染土壤的修复 总被引:2,自引:0,他引:2
取同质钼矿区土壤放于通风处自然风干,平行A、B两组盆栽实验。A组直接投放不同浓度的磷酸二氢钾-磷酸氢二钠缓冲溶液50 ml,B组做对照,种植白菜,待白菜生长50 d后再投加一次缓冲溶液50 ml,60 d后收割其地上部分及对应土壤进行消解。采用ICP-AES分析土壤及植物体中各种重金属元素的含量,研究了在磷酸二氢钾-磷酸氢二钠缓冲溶液在其不同浓度梯度下投加,白菜地上部分对钼矿区重金属污染土壤的修复潜力。结果表明:在投加磷酸二氢钾-磷酸氢二钠缓冲溶液的条件下均能显著提高白菜的地上部分富集土壤中重金属元素的能力(Cd除外),但缓冲溶液对白菜积累重金属能力的促进作用也存在重金属元素种类及浓度梯度之间的差异;投加pH=7.3磷酸二氢钾-磷酸氢二钠缓冲溶液可以较好地去除钼矿区污染土壤中的Cr、Mo、Ni、Pb;投加pH=7.7磷酸二氢钾-磷酸氢二钠缓冲溶液可以较好地去除钼矿区污染土壤中的As、Cu、Hg、Zn。 相似文献
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Cribb BW Stewart A Huang H Truss R Noller B Rasch R Zalucki MP 《Die Naturwissenschaften》2008,95(1):17-23
A number of arthropod taxa contain metals in their mandibles (jaws), such as zinc, manganese, iron, and calcium. The occurrence of zinc and its co-located halogen chlorine have been studied in relation to the mechanical properties and shown to be linked in a direct fashion with increasing concentration. Hardness along with elastic modulus (stiffness) has also been linked to zinc and halogen concentration in some marine polychaete worms. The metal appears to be incorporated within the biological matrix, possibly bonding with proteins. However, the comparative advantage of metal inclusion has not been tested. It is possible that without metals, alternative mechanisms are used to achieve hardness of equal value in similar 'tools' such as mandibles. This question has direct bearing on the significance of metal hardening. In the present article, we compare across mandibles from six termite species, including samples with major zinc concentration, minor manganese, and no metals. Nanoindentation, electron microscopy, and electron microanalysis are used to assess metal concentration, form, and mechanical properties. The data demonstrate that termite mandibles lacking metals when fully developed have lower values for hardness and elastic modulus. Zinc is linked to a relative 20% increase in hardness when compared with mandibles devoid of metals. The similar transition metal, manganese, found in minor concentrations, is not linked to any significant increase in these mechanical properties. This raises the question of the function of manganese, which is as commonly found in insect mandibles as zinc and often located in the same mandibles. 相似文献
945.
人粪便序批式好氧堆肥热平衡分析 总被引:1,自引:0,他引:1
利用以锯末为载体的Bio—LuxS15型生态卫生设备,进行人粪便连续堆肥试验。在90天的试验周期内,每天定时定量投加1kg粪便,分析了系统的输入热量与输出热量组成和热量平衡。试验结果表明,水蒸发速率随着反应时间而增加,其值在1.1kg/d~5.1kg/d的范围内。反应器温度维持在50℃~60℃时下,输入热量的77.2%-99.5%主要用来进行水分的蒸发,在保证堆肥反应器中含水率维持在50%-60%的前提下,减少多余水分可有效减少热量消耗。整个过程无臭无味,通过外加热源,可以保证高含水率粪便堆肥化顺利的进行。 相似文献
946.
Ming Ge Changsheng Guo Xingwang Zhu Lili Ma Zhenan Han Wei Hu Yuqiu Wang 《Frontiers of Environmental Science & Engineering in China》2009,3(3):271-280
ZnO/TiO2 composites were synthesized by using the solvothermal method and ultrasonic precipitation followed by heat treatment in order
to investigate their photocatalytic degradation of methyl orange (MO) in aqueous suspension under UV irradiation. The composition
and surface structure of the catalyst were characterized by X-ray diffraction (XRD), field emission scanning electron microscope
(FE-SEM), and transmission electron microscopy (TEM). The degradation efficiencies of MO at various pH values were obtained.
The highest degradation efficiencies were obtained before 30 min and after 60 min at pH 11.0 and pH 2.0, respectively. A sample
analysis was conducted using liquid chromatography coupled with electrospray ionization ion-trap mass spectrometry. Six intermediates
were found during the photocatalytic degradation process of quinonoid MO. The degradation pathway of quinonoid MO was also
proposed. 相似文献
947.
Qishe Yan Chang-Bo Zhou Peng Qu Rui-qin Zhang 《Mitigation and Adaptation Strategies for Global Change》2009,14(8):793-804
The clean development mechanism (CDM), one of three flexible mechanisms of the Kyoto Protocol, has received noticeable attention
in cement industry in china. In this paper we will discuss in past the utilization ratios of waste heat generated in cement
industry are at low level in China and at present it is at high level and how the CDM contributes to upgrade cement industry
structure. Making fully use of the opportunity brought by clean development mechanism can help cement enterprises in china
to recover the waste heat generated in the process of cement production. Implementing the development of clean development
mechanism projects in cement industry field, mainly focusing on waste heat for power generation projects, can not only reduce
environmental pollution, but also bring certain economic and social benefit. It is in favor of promoting the upgrade of cement
industrial structure, and will contribute to positive and far-reaching effect toward sustainable development of cement industry
in China. 相似文献
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介绍了大型储油罐一次机械密封结构改造为一次机械镀锌钢板加内隔膜弹性耐腐蚀橡胶软密封后,一次机械密封与二次机械密封之间的可燃气体浓度由原来的80%LEL以上下降至10%LEL以下,大型储油罐防雷击火灾取得了较好的效果。 相似文献