Heavy metal concentration in soil and woody plants in a quarry

This study determined the concentration of three heavy metals zinc (Zn), lead (Pb), and cadmium (Cd) in soil and in a woody plant species, Milicia excelsa, at Ishiagu quarry, Nigeria. The highest soil concentrations of Zn, Pb, and Cd in soil were obtained at 1?m from the quarry site. In M. excelsa, the highest concentrations of Zn, Pb, and Cd were 3.12–9.1, 3.9–6.01, and 0.51–1.12?mg?kg^?1, respectively. There were significant positive correlations between Cd and Zn (r?=?0.963) and Cd and Pb (r?=?0.974) in plants as well as between Cd and Pb (r?=?9.84) in soil. The level of Cd in soil reflected significant pollution compared to average global concentrations in soils.     

露天采石场边坡稳定因素浅析

忽视对露天采石场边坡稳定问题的分析研究,放松管理必然导致重大事故的发生。通过对1984—2001年河南省露天采矿场重、特大事故分析得出如下结论:18年间重特大事故共发生27起。分为两类,一类是放炮事故,一类是边坡坍塌事故。放炮事故3起、死亡13人,事故起数和死亡人数分别占11.11%和10.08%;坍塌事故24起、死亡116人,事故起数和死亡人数分别占88.89%和89.92%。统计分析和经验告诫:深入了解露天采石场边坡稳定因素,加强边坡管理是实现露天采石场安全生产的重中之重。     

闽江下游水环境问题浅析

分析闽江下游的水环境问题是：南、北港分流比变化造成北港冲刷，南港淤积，并带来严重后果；河道采砂过量使河床下切严重，破坏水工建筑物；水质存在一些问题，影响生活及工业用水；湿地遭到破坏，导致湿地动植物数量与种类大量减少。针对这些问题，提出解决闽江下游水环境问题需要设计南、北港水量科学合理分配方案；设计合理的河道采沙方案；加强污水管理体制；对闽江河口湿地分区保护和管理；加强河道的监测工作；加强公众环境保护教育。要使专家研究、政府管理和提高公众环保意识相结合。     

采石场大气污染物源强分析研究

采石场环境影响评价的关键在于生产过程中产生的大气污染。TSP、PM10的影响，而TSP、PM10的影响又取决于其产生的源强的大小及扩散模式。以襄樊市襄阳城南岘山两处采石场为例，采用模拟实验、实测法对采石场大气污染物扩散模式、扩散参数及源强的确定进行分析研究。结果表明：在通常气象(平均风速)条件下，各类稳定度的TSP小时平均浓度在下风向距离800m以上均较低。基本上与实测值的。TSP值相吻合。在D类稳定度情况下，距离污染源800～900mTSP最大小时平均浓度为0．13～0．11mg／hm^3。     

Environmental and socioeconomic impacts of cobblestone quarries in Addis Ababa and implication for resource use efficiency,environmental quality,and sustainability of land after‐use

The extraction of construction material in Addis Ababa has been a source of public conflict for many years, especially in terms of quarry operation, displacement of people, rehabilitation of quarry sites, and land after‐use. One of the main reasons for the conflict has been the extraction sector's inability to adjust to the existing laws. This paper reports the findings of a study undertaken to assess the environmental and socioeconomic impacts of quarry mining in Addis Ababa, Ethiopia, and it prescribes interventions that can assist in mitigating the negative impacts of mining. Marked operational, environmental, and socioeconomic impacts have occurred as a result of cobblestone quarrying in Addis Ababa. Improvements in the mitigation of these impacts can be achieved if quarrying operations are planned prior to commencement; resource‐efficient and sustainable mining techniques are employed; stakeholder participation is enhanced; the government provides institutional, organizational, and technical support to the operators; regulations are improved and regulatory implementations receive strict follow‐up; and the provision of the Ethiopian constitution's regarding “rights to development” is respected.     

采石场生态重建的有关问题

综述了采石场生态重建的相关问题,包括采石场生态重建的重要性,生态重建研究的历史,生态重建的基础理论,采石场的水土流失治理,采石场植被恢复及植物品种的选择与配置等。无论是国内还是国外,采石场的生态重建只是到了最近二十多年才受到相当的重视。我国特别是东南沿海地区采石场已经引起了严重的生态问题,其重建也取得了很大进展,但仍然存在着许多需要改进的地方,如植被恢复效果不理想,植物品种选择的任意性,复绿方式的单一性等。文章提出了目前采石场生态重建存在问题及改进方法。     

中国茶叶中的氟近十年来的研究进展

主要对茶叶中氟的来源,氟含量,氟浸出率以及茶叶降氟措施研究作了详细的综述。大量的研究资料表明,土壤中的氟直接影响到茶叶中氟的含量,茶树吸收氟与土壤的pH值、有机质含量、粘粒含量、成土母质及土壤中的阳离子有关。大气污染影响茶叶氟含量主要是氟通过叶片气孔进入细胞,进而在茶树体内积累。水环境中氟的含量主要受土壤与大气环境的影响。茶叶中的氟含量随着叶片成熟度的增加而增加;茶叶等级越差,氟含量越高;原料粗老的茶类氟含量要比原料较嫩的茶类氟含量高;不同季节、茶树品种对氟吸收也存在差异性;茶树各部位氟累积强度依次为:叶>花蕾>籽>皮>细枝>骨干枝>细根>茎(主轴)>茎(主干)>主根>侧根;茶叶中氟浸出率与冲泡水温、冲泡时间、冲泡次数等有关。在茶叶加工过程中可以通过热水处理,添加化学试剂,改进生产工艺等措施来降低茶叶中的氟含量。此外,尚可以培育含氟量低的茶树品种。