使用含铁基质的水平潜流人工湿地间隙水亚铁离子及理化环境的动态变化

使用富含铁基质的水平潜流人工湿地,运行过程中,由于内部氧化还原和p H条件的变化,可能会导致基质中铁溶出,致使间隙水中亚铁离子增加,进而影响污水去除效率.本研究以使用富含铁基质的香蒲人工湿地系统为研究对象,分析了其处理富含有机物污水时,内部间隙水的亚铁离子、氧化还原电位(ORP)和p H时空变化特点.研究结果表明,各位点间隙水都含有较高浓度亚铁离子,范围为8.23~462.86 mg·L-1,远远高于进水中亚铁含量,表明运行过程中,基质铁大量溶出;内部各位点ORP在-236~40 m V之间,变化范围较大,多数位点ORP均为负值,表明整个湿地内部大部分区域处于厌氧状态,是污水中较高浓度有机物降解导致;ORP在水深方向逐渐下降,污水沿程方向是逐渐升高的,夏季ORP整体较高,春秋季较低.亚铁离子变化特点与ORP相反,ORP高的情况下,亚铁离子浓度较低,表明亚铁离子浓度受ORP影响.湿地内部各位点处的p H空间变化范围不大,在6.44~7.97之间,仍维持在中性范围.结合p H和ORP的分布特征可以得知,间隙水中亚铁离子应是基质中铁氧化物特别是三价铁氧物,络合和还原解离共同的产物.     

Effect of Earthworm（Pheretima sp.） Density on Revegetation of Lead/zinc Metal Mine Tailings Amended with Soil

The objective of this study was to investigate the effects of earthworm density on the availability of nutrients and heavy metals in metal contaminated soils. Pb/Zn mine tailings were mixed throughly with a red yellow podzolic soil at the ratio （w/w） of 75：25. Earthworms （Pheretima sp.） were introduced to the mixture at four different densities, zero, three, six and nine individuals per pot planted with ryegrass （Loliun multiflorum）. The results indicated that earthworm activity significantly enhanced ryegrass shoot biomass. However, as denser earthworm population was introduced, shoot biomass tended to decrease. Earthworm activity significantly increased soil pH and availability of N, P and K in the tailings and soil mixture. There was a general tendency that uptake of Zn by ryegrass increased after earthworm inoculation, although the increase in extractable Zn in tailings and soil mixture was not significant. On the contrary, there seemed to be a lower uptake of Pb by ryegrass under earthworm inoclation, despite the fact that higher extractable Pb concentrations were observed. The present project indicated that the improved growth of ryegrass was due to improved nutrient availability and other soil conditions, by inoculation of earthworms at an appropriate rate. Further studies are needed to illustrate the relationship between metal availability and earthworm activity in the field.     

基于可拓学的尾矿库安全评价

为综合评价尾矿库的安全状态,基于尾矿库灾变机理和大量工程实践构建了一套包括3级指标、22个因素的评价指标体系,并确定了评价指标的等级量值区间。采用EAHP和熵权法结合的方式确定指标权重,基于可拓理论评价尾矿库的安全等级。以湖南黄金集团责任有限公司旗下的7座尾矿库为案例,评价其安全状态,根据蒙特卡洛模拟基本理论,基于Crystal Ball对案例进行敏感性分析,找出具体敏感因素,为后期尾矿库安全管理提供简单有效的控制方法。     

论多自然型河流治理法对河流生态环境的影响

本文首先介绍了成都府河望江公园段多自然型护岸工程的由来,然后通过简述国外多自然型河川治理常用方法论述了对河流生态环境的改善作用,最后在对府河多自然型护岸设计介绍的基础上提出了试验工程的深远意义及其对今后工作的启迪     

Mining pollution: The case of the Baguio mining district,the philippines

Environmental problems caused by improper mine tailings disposal in the Baguio district include pollution of the Lower Agno River system and its watershed and siltation of irrigation canals in the Pangasinan plains. Direct economic losses are from reduced agricultural production due to siltation of irrigation works and farmlands. To check the adverse ecological effects of improper mine tailings disposal, government regulations have been imposed on mining firms. Several disposal schemes have been proposed, including the use of the reservoir of a multipurpose project to be sited in the watershed where the mines are located. Because of siltation problems, however, trapping the tailings in the reservoir will diminish the economic benefits that can be derived from the project.     

Application of artificial neural networks for classification of uranium distribution in the Central Rand goldfield,South Africa

Mine tailings generate significant environmental impacts and contribute to water pollution. The Central Rand goldfield, South Africa is replete with gold mine tailings which have contributed significantly to water pollution as a result of acid mine drainage (AMD). Water quality is affected by mine tailings and spillages, especially from active slimes dams, currently reprocessed tailings, as well as footprints left behind after reprocessing. The release and distribution of uranium from these sites was studied. Correlation matrices show a strong link between different variables as a result of AMD produced. Principal component analysis (PCA) was used to identify very influential variables which account for the pollution trends. Artificial neural networks (ANN) using the Kohonen algorithm were applied to visualise these trends and patterns in the distribution of uranium. High concentrations of this radionuclide were detected in streams in the vicinity of the tailings dumps, active slimes and reprocessing areas. The concentrations are reduced drastically in dams and wetlands as a result of precipitation and dilution effects.     

利用雄黄尾矿制备药用雄黄

在分析比较现有提炼富集雄黄工艺的基础上，提出了利用雄黄尾矿制备药用雄黄的“湿法”工艺流程，并对其中的关键工艺－雄黄除杂工艺进行了试验研究，结果表明，较佳的工艺条件为：盐酸浓度2mol/L，温度45℃，液固比2．5L：1kg，反应时间90min，研磨时间0.5h，在此条件下除杂，可制得符合药典要求和雄黄。     

基于最大Lyapunov指数分析的尾矿坝浸润线控制混沌方法

为了改善尾矿坝浸润线状况，提出了一种控制混沌方法。该方法对时间序列叠加一个周期振动，通过最大Lyapunov指数分析，来判别叠加前后系统混沌特性的变化，进而实现控制混沌。应用这种方法，分析了银山铅锌矿尾矿坝浸润线实测数据。结果表明，叠加周期振动可以降低最大Lyapunov指数。最大Lyapunov指数的降低程度与振动周期成负相关，与振幅成正相关。采用控制混沌方法，即对尾矿排放、库水位调节、排渗、不同尾矿库的使用等措施进行周期性控制，可以提高尾矿坝安全度，实现尾矿坝科学管理。中还以防洪高度为例，具体分析了尾矿坝工程中的控制混沌，表明该方法在应用上是可行的。     

采空场处理与利用

地下采空场既是一种隐患，又是一种资源。介绍了采空场的若干应用；包括水充填、尾砂充填、垃圾充填，对空场处理有借鉴意义。     

酸性淋溶对铅锌尾矿金属行为的影响及植物毒性

露天存放的铅锌尾矿受到自身酸化和酸雨的双重影响,从而加剧尾矿对环境的影响。因此,研究尾矿在酸性条件下的重金属行为及其植物毒性,对植物在铅锌尾矿地的自然定居有非常重要的意义。将铅锌尾矿砂装柱,用pH2～7溶液淋溶50天的结果表明,酸度的提高可以显著地增加尾矿砂中重金属（Pb、Zn、Cu和Cd）的溶出。而随着时间的延长,Zn的溶出量明显增高,Pb和Cu的溶出则逐渐降低。在pH值＜3时,Cd的溶出逐渐升高,pH值＞3时,Cd的溶出也呈下降趋势。酸度对重金属溶出的影响由大至小依次为Zn＞Cd＞Cu＞Pb。渗滤液对植物的毒性随着起始淋溶酸度的提高与时间的推移而加剧