大宝山矿水外排的环境影响:Ⅲ.综合治理对策

大宝山外排酸性矿水对下游水生生态系统及周边农村地区农业生态系统带来严重影响，并可能已危及当地人民的健康。文章根据大宝山矿所在地区的实际情况，对大宝山矿区及周围地区生态退化和环境污染的综合治理途径进行探讨，提出：(1)必须走系统整治的路径才能做到既治标又治本；(2)治理污染源是整个治理方案的关键环节；(3)为了使深受污染之害的矿区周边人民尽快脱离危险，近期最迫切的治理地段是受矿水严重污染的农田，尤其是重污染区一上坝村；(4)在治理方法上，必须将化学治理、生物治理与工程治理相结合；(5)为了更好地实施各项治理工程，可考虑运用经济杠杆，以便有效地筹集足够的矿山治理资金；(6)着眼于未来更严格的环境质量标准，建立水质的生物预警系统；(7)目前制约大宝山矿地区生态环境治理的主要瓶颈之一是缺乏适合中国国情的高效低投入治理技术，政府应考虑提供研究经费支持相关的应用基础研究和技术开发，以便能加快治理的步伐。     

Lead, Zinc, Copper, and Cadmium in Fish and Sediments from the Big River and Flat River Creek of Missouri's Old Lead Belt

The Old Lead Belt of Missouri was a major lead-producing region for over a century. Several large tailings piles and other industrial wastes remain behind, though mining operations in the region ceased in 1972. Samples of stream sediments and fish were collected from established sites on the Big River and Flat River Creek over a 3-year period from 1998 to 2000 to evaluate ongoing remediation efforts and determine the current impact of residual mining wastes. Benthic sediments and fish taken in the vicinity of inactive industrial sites were found to contain elevated concentrations of Pb, Zn, Cu, and Cd. Concentrations of Pb and Zn in fillets of suckers and sunfish, as well as in whole bodies of sunfish, correlate well with metal concentrations observed in surficial sediments. The results of analyses provide valuable quantitative information regarding specific sources, current levels of contamination, potential risk to public health, and will allow more accurate assessment of continuing remediation efforts.     

Mapping Soil Lead and Remediation Needs in Contaminated Soils

For the past two decades, the Taiwan Environmental Protection Administration has made a systematic investigation of As, Cd, Cr, Cu, Pb, Hg, Ni and Zn in agricultural soils to identify soil pollution from industrial production. The EPA has cooperated with local governmental agencies to establish a soil quality monitoring system that would upgrade the land recovery ability and prohibit polluted lands from being cultivated or turned over to other uses. Based on an island-wide soil survey, more than 1,000 hectares of arable soils in Taiwan were found to be considerably contaminated by heavy metals. One of the heavy metal contaminated sites, located near a ceramic product manufacturing factory in Nantou County, was identified as lead contaminated. According to the Nantou Environmental Protection Bureau, the lead content in contaminated sites showed a great variation of several mg Pbkg^–1 soil to several thousands mg Pbkg^–1 soil. Therefore, it is appropriate to estimate the lead spatial distribution through geostatistics such as Kriging. The soil lead concentration contour maps obtained by Kriging can help us to identify the pollution patterns and delineate the range of contaminated sites. The purpose of this study is to determine the Pb concentrations at each location by performing detailed soil sampling on those Pb contaminated sites and estimating the lead spatial distributions by Kriging. A total of 70 soils were sampled from different locations at two experiment sites. Lead contents were determined with 0.1M HCl extractable lead content of the soils. The results obtained by investigating the lead contents in each 15cm segment down to a 60cm depth, revealed that lead contents were greater in arable land near the ceramic products manufacturing factory, and lead concentrations decreased with depth. In addition, Pb concentrations in heavily contaminated soils showed heavy concentrations of Pb in specific locations. Results from Pb content spatial distributions indicated that the Kriging model is a useful tool and can provide decision-makers with critical information for delineating hazardous areas in heavy metal contaminated sites.     

表面活性剂增效修复土壤有机污染研究进展

系统评述了表面活性剂增效修复土壤有机污染的原理、研究现状及存在的问题。     

Efficacy of in-situ for the remediation of PAH contaminated soils

Polycyclic aromatic hydrocarbons (PAHs) are of environmental concern because many PAHs are either carcinogens or potential carcinogens. Petroleum products are a major source of PAHs. The occurrence of PAH contamination is widespread and novel treatment technologies for the remediation of contaminated soils are necessary.Ozone has been found to be extremely useful for the degradation of PAHs in soils. For these compounds, the reaction with molecular ozone appears to be the more important degradation pathway. Greater than 95% removal of phenanthrene was achieved with an ozonation time of 2.3 h at an ozone flux of 250 mg h⁻¹. After 4.0 h of treatment at an ozone flux of 600 mg h⁻¹, 91 % of the pyrene was removed. We have also found that the more hydrophobic PAHs (e.g. chrysene) react more slowly than would be expected on the basis of their reactivity with ozone, suggesting that partitioning of the contaminant into soil organic matter may reduce the reactivity of the compound. Even so, after 4 h of exposure to ozone, the chrysene concentration in a contaminated Metea soil was reduced from 100 to 50 mg kg⁻¹ .Ozone has been found to be readily transported through columns packed with a number of geological materials, including Ottawa sand, Metea soil, Borden aquifer material and Wurtsmith aquifer material. All of these geological materials exerted a limited (finite) ozone demand, i.e. the rate of ozone degradation in soil columns is very slow after the ozone demand is met. Moisture content was found to increase the ozone demand, most likely owing to the dissolution of gaseous ozone into the pore water. As once the initial ozone demand is met, little degradation of ozone is observed, it should be possible to achieve ozone penetration to a considerable distance away from the injection well, suggesting that in-situ ozonation is a feasible means of treating uncontaminated unsaturated soils. This is substantiated by two field studies where in-situ ozonation was apparently successful at remediating the sites.     

原位化学氧化法在土壤和地下水修复中的研究进展

综述了原位化学氧化法修复污染土壤及地下水的最新进展 ,着重介绍了几种氧化剂 ,如二氧化氯、双氧水及Fenton试剂、高锰酸钾和臭氧在土壤修复中的应用、不足及改进 ,并对化学氧化修复技术的发展前景进行了展望     

SEAR技术修复土壤和地下水中NAPL污染的研究进展

就SEAR技术修复土壤及地下水中NAPL污染的原理及发展现状进行了综述.SEAR技术可以快速有效地去除土壤和地下水中的NAPL污染源,适于多种污染物.该技术通过增溶和增流2种途径提高NAPL污染物的去除率.表面活性剂的选择和微乳液体系的调配是SEAR技术实施的关键环节.将SEAR技术用于高浓度NAPL污染源的治理,并与生物修复和自然降解相结合,是经济高效的治理方案.     

Kinetics of soil ozonation: an experimental and numerical investigation

This study investigates the use of ozone for soil remediation. Batch experiments, in which ozone-containing gas was continuously recycled through a soil bed, were conducted to quantify the rate of ozone self-decomposition and the rates of ozone interaction with soil organic and inorganic matter. Column experiments were conducted to measure ozone breakthrough from a soil column. Parameters such as ozone flow rate, soil mass, and ozonation time were varied in these experiments. After ozone concentration had reached steady state, the total organic carbon concentration was measured for all soil samples. The ozonation efficiency, represented by the ratio of soil organic matter consumed to the total ozone input, was quantified for each experiment. Numerical simulations were conducted to simulate experimentally obtained column breakthrough curves. Experimentally obtained kinetic rate constants were used in these simulations, and the results were in good agreement with experimental data. In contrast to previous studies in which soil inorganic matter was completely ignored, our experiments indicate that soil inorganic matter may also promote depletion of ozone, thus reducing the overall ozonation efficiency. Three-dimensional numerical simulations were conducted to predict the efficacy of ozonation for soil remediation in the field. These simulations indicate that such ozonation can be very effective, provided that effective circulation of ozone is achieved through appropriately placed wells.     

重金属污染土壤的电动原位修复技术研究

电动力学修复技术作为一种新型的修复技术,由于其处理土壤污染的高效性,近几年来受到了越来越多的关注。综述了电动力学修复技术原理及近几年来其在重金属修复中的最新研究进展,阐述了电动力学修复技术相对于其它修复技术的优势,并指出了电动修复技术中需要克服的技术障碍,探讨了其大规模商业应用的可行性。电动技术能够强化土壤物质的传质过程,能够高效、快速定向迁移土壤中重金属离子达到去除的目的;同时电动技术可以与其它修复技术结合发展出系列组合修复技术,具有广泛的应用前景。从单一电动到复合电动是今后电动力学技术发展的重要方向。目前对污染物质复合电动力学效应下的迁移机理及模型、不同土壤性质(组分、酸碱性等)对于污染物质去除效率及其调控措施的研究仍需进一步深入。     

固定化藻膜去除水中氮磷的模拟研究

针对富营养化水体生物修复和污水深度处理氮磷的去除,将细颤藻、水绵、水网藻、栅裂藻固定在纤维填料上,形成固定化藻膜。用固定化藻膜处理模拟富营养化湖水、实际富营养化湖水、城市污水二级出水、低质量浓度生活污水,考察固定化藻膜去除氮磷的效果。实验结果表明,固定化藻膜具有良好的去除磷、氨氮能力,对水中有机物去除也有一定的促进作用。对TP质量浓度小于5.0mg·L-1,NH4 -N质量浓度小于34.0mg·L-1的污染水体,四种藻膜都有良好的去除氮磷能力,其中栅裂藻去除TP、NH4 -N的能力最强。综合除污能力和藻细胞的可固定性,水绵应是最佳的备选藻种。研究结果显示,固定化藻膜具有良好的除污性能,预示了悬浮载体将在水体生物修复、氧化塘污水处理方面具有重要的潜在应用价值。