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At first ‘sustainable mining’ could be perceived as a paradox—minerals are widely held to be finite resources with rising consumption causing pressure on known resources. The true sustainability of mineral resources, however, is a much more complex picture and involves exploration, technology, economics, social and environmental issues, and advancing scientific knowledge—predicting future sustainability is therefore not a simple task. This paper presents the results from a landmark study on historical trends in Australian mining, including ore milled, ore grades, open cut versus underground mining, overburden/waste rock and economic resources. When complete data sets are compiled for specific metals, particular issues stand out with respect to sustainability—technological breakthroughs (e.g. flotation, carbon-in-pulp), new discoveries (e.g. uranium or U), price changes (e.g. Au, boom/bust cycles), social issues (e.g. strikes), etc. All of these issues are of prime importance in moving towards a semi-quantitative sustainability model of mineral resources and the mining industry. For the future, critical issues will continue to be declining ore grades (also ore quality and impurities), increased waste rock and associated liabilities, known economic resources, potential breakthrough technologies, and broader environmental constraints (e.g. carbon costs, water). For this latter area, many companies now report annually on sustainability performance—facilitating analysis of environmental sustainability with respect to production performance. By linking these two commonly disparate aspects—mining production and environmental/sustainability data—it becomes possible to better understand environmental sustainability and predict future constraints such as water requirements, greenhouse emissions, energy and reagent inputs, and the like. This paper will therefore present a range of fundamental data and issues which help towards quantifying the resource and environmental sustainability of mining—with critical implications for the mining industry and society as a whole. 相似文献
573.
Over the last two decades, mining and mineral exploration companies have adopted various environmental management practices in response to society’s pressure for better environmental protection. The literature highlights a number of benefits and challenges for companies adopting environmental management practices with the Greek Mining and Mineral Industry (GMMI) facing similar issues. In order to analyze the challenges faced by the GMMI, a Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis was conducted, which examined the strengths, weaknesses, opportunities and threats faced by the industry when adopting environmental management practices. The analysis prescribes policy recommendations both for the government and industry which, if adopted, could facilitate improved environmental performance. 相似文献
574.
This study was conducted to investigate the effect of external iron status and arsenic species on chelant-enhanced iron bioavailability and arsenic uptake. Rice seedlings (Oryza sativa L.) were used as model plant, and were grown in artificially contaminated sandy soils irrigated with Murashige and Skoog (MS) culture solution. Arsenate uptake in roots and shoots of rice seedlings were affected significantly (p > 0.05) while dimethylarsinic acid (DMAA) was not by the additional iron and chelating ligand treatments. Regardless of iron concentrations in the soil solution, HIDS increased arsenic uptake for roots more than EDTA and EDDS. Chelating ligands and arsenic species also influenced iron uptake in rice roots. Irrespective of arsenic species, HIDS was found to be more effective in the increase of iron bioavailability and uptake in rice roots compared to other chelants. There was a significant positive correlation (r = 0.78, p < 0.05) between arsenate and iron concentrations in the roots of rice seedlings grown with or without additional iron indicating that arsenate inhibit iron uptake. In contrast, there was no correlation between iron and DMAA uptake in roots. Poor correlation between iron and arsenic in shoots indicated that iron uptake in shoots was neither affected by additional iron nor by arsenic species. Compared to the control, chelating ligands increased iron uptake in shoots of rice seedlings significantly (p < 0.05). Regardless of additional iron and arsenic species, iron uptake in rice shoots did not differed among EDTA, EDDS, and HIDS treatments. 相似文献
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578.
槐树组织培养中超度含水态苗发生与防止的研究 总被引:5,自引:0,他引:5
对槐树(Sophorajaponica)花药愈伤组织在培养条件下形成超度含水态苗的条件研究表明:短期培养的愈伤组织及在含有较低ρ(BA)的培养基上多形成正常苗,而经长期培养的愈伤组织及在含有较高ρ(BA)的培养基上产生了大量的超度含水态苗;在MS附加ρ(IAA)0.2mg/L、ρ(BA)5.0mg/L的培养基上,愈伤组织经连续1.5a以上的继代培养后,其表面产生的芽均为超度含水态芽;将这种愈伤组织和超度含水态芽转人含不同浓度和种类植物激素及生长调节剂的培养基后发现:BA和高ρ(KT)明显促进了超度含水态苗的形成;而一定ρ(NAA)和ρ(2,4-D)则显著地促进了正常苗的形成.对培养过程的观察显示:在各种培养基上形成的正常菌中,有一部分是由超度含水态的芽和苗转化而来,即由其顶端或腋生分生组织进一步发育转化而来,而另一些则由愈伤组织上重新产生. 相似文献
579.
酸性土壤中Cd2+的吸附与运移特性 总被引:2,自引:1,他引:1
采用平衡吸附和室内土柱淋溶实验研究Cd2 在酸性土壤中的吸附和运移规律.结果表明:红壤和砖红壤中Cd2 的吸附,在其低浓度范围内符合线性等温方程,Cd2 在砖红壤上的分配系数是红壤上的8倍,能较好地用一级动力学方程的两点和一点模型拟合Cd2 的吸附.红壤快反应的比例约为50%-60%,砖红壤快反应的比例约为90%-95%.采用两点位非平衡模型,红壤β值范围为0.50-0.70,f值的范围是0.40-0.60,仅有40%-60%的吸附点位是瞬间完成,还有一部分吸附点位受速率限制,用非平衡两点模型比用平衡模型能更好地描述Cd2 的运移规律;而砖红壤β值在0.93-0.99,f>0.92,有大于 90%的吸附点位是瞬间完成,不到10%受速率限制,很容易达到局部平衡,运用平衡模型可能更适合,这与动力学方程的结果基本一致. 相似文献
580.
低温对高产杂交稻抽穗期剑叶光合色素含量和抗氧化酶活性的影响 总被引:8,自引:0,他引:8
以高产杂交稻“两优培九”和常规杂交稻“汕优63”为试验材料,采用15和20℃处理2和4 d,比较低温对水稻抽穗期剑叶光合色素含量和抗氧化酶活性的影响。结果表明:低温下抽穗期水稻剑叶光合色素(叶绿素、类胡萝卜素)含量随处理时间延长而下降,抗氧化酶CAT活性下降,SOD、POD活性变化存在品种间差异。低温处理4 d后,“两优培九”SOD活性上升,POD活性降低,“汕优63”变化则相反。抗氧化酶之间活性变化的不平衡,使活性氧的产生与清除失衡,O2-迅速积累,膜脂过氧化加剧,MDA含量上升。这些变化导致水稻剑叶净光合速率在低温下降低。试验结果表明,高产杂交稻“两优培九”比常规杂交稻“汕优63”对低温的适应能力更强。 相似文献