石门砷污染农田修复项目经验介绍

文章介绍了石门县雄黄矿区土壤污染治理项目的开展情况及取得的效果,该项目作为运用蜈蚣草萃取技术修复砷污染土壤的示范项目,为我国砷污染土壤修复工作的开展提供了借鉴。     

生物炭对土壤中复合重金属的固化/稳定化研究

土壤重金属污染逐渐变成全球关注的环境问题。而固化/稳定化技术是修复重金属污染土壤快速、有效及经济的方式。概括土壤中重金属的来源和危害、固化/稳定化技术的机理,探讨了以独特物化性质的生物炭作为治理土壤中重金属的固化/稳定化剂时对重金属和砷的处理研究。最后,对未来生物炭的安全性和长期稳定性的研究作出了展望。     

重金属污染土壤的修复方法及其在几类典型土壤修复中的应用

文中首先阐述了重金属污染土壤的途径与特点。介绍了当前几类主要的重金属污染土壤修复方法:物理化学方法、植物修复法、微生物修复法、动物修复法等的技术要点,详述了各自的技术特点及机理,并对它们的修复效能、环境友好性等进行了比较。从土壤的特性出发,区分出了3种典型的遭受重金属污染的土壤:农业土壤、城市土壤、矿区土壤,并从国内外最新的重金属污染修复实践中选取了适合各自土壤类型的修复方法进行了重金属污染土壤的治理探讨。最后,对土壤重金属污染修复技术的发展进行了展望。     

土壤污染的生物修复技术及其研究进展

近年来土壤污染呈现加重的趋势,有关污染土壤的修复研究正日益受到重视.生物修复技术是一项用于污染土壤治理的新技术.介绍了污染土壤生物修复技术,综述了近年来国内外土壤生物修复技术的研究和应用现状,并评述了土壤生物修复技术存在的问题以及污染土壤生物修复的发展方向.     

土壤-植物系统中磷和砷相互作用关系的研究进展

砷元素导致的环境污染问题日益突出,施磷已成为植物修复砷污染土壤过程中必要强化措施之一。土壤-植物系统中磷和砷的相互作用关系是非常复杂的,研究表明：磷和砷在土壤中往往是共生的,但又存在竞争吸附关系;磷和砷在不同植物中的相互作用关系主要有拮抗效应和协同效应;有必要通过分子生物学手段对磷和砷表达基理进行深入研究,获得对砷具有超积累能力的植株。     

浅析生物修复技术在石油污染治理中的应用

生物修复技术是目前人们比较关注的一种新型石油污染治理技术。文章简要介绍了生物修复技术在石油污染的土壤、河流、湖泊、地下水、海洋领域的应用,阐述了该技术的研究将大力推进生物高科技的发展,对环保科技的发展具有重大意义。     

污染土壤与地下水修复工程环境监理实践探讨——以某修复工程为例

为解决土壤与地下水污染问题,近几年开展污染土壤与地下水修复的地块越来越多。土壤与地下水修复工程属于生态环境工程,隐蔽性和复杂性是其突出特点,极易引发二次污染问题。环境监理是土壤与地下水修复工程中的关键环节,对控制土壤与地下水修复工程效果、二次污染防控起到关键作用。以某地块污染土壤与地下水修复工程环境监理实践经验为例,阐述土壤修复工程环境监理要点、技术方法,以期对类似修复工程开展环境监理工作有所帮助。     

石油污染土壤修复技术研究进展

概述了目前国内外石油污染土壤常用的修复技术及其研究进展,综述了物理修复、化学修复,特别是生物修复技术的优越性,并针对国内外石油污染土壤修复技术研发和实际应用过程中存在的问题,提出加强研发污染土壤综合修复技术、完善修复工程设计、加大新型功能材料的开发和应用力度、加强分子生态学技术在污染土壤修复中的应用4项建议。     

植物修复PAHs污染土壤的强化技术研究进展

PAHs是具有"三致"作用且严重威胁生态环境和人类健康的危险污染物.植物修复作为一种绿色经济的修复技术,被广泛应用于PAHs污染土壤的治理中.综述了植物修复PAHs污染土壤的效能、机制及有关强化技术的研究现状,为提高植物修复PAHs污染土壤的有效性提供思路.     

土壤重金属污染、生态效应及植物修复技术

探讨了土壤中重金属的来源、特点以及生态效应,综述了土壤重金属污染的植物修复技术,展望了重金属污染土壤的植物修复研究发展趋势。     

On the potential of biological treatment for arsenic contaminated soils and groundwater

Bioremediation of arsenic contaminated soils and groundwater shows a great potential for future development due to its environmental compatibility and possible cost-effectiveness. It relies on microbial activity to remove, mobilize, and contain arsenic through sorption, biomethylation–demethylation, complexation, coprecipitation, and oxidation–reduction processes. This paper gives an evaluation on the feasibility of using biological methods for the remediation of arsenic contaminated soils and groundwater. Ex-situ bioleaching can effectively remove bulk arsenic from contaminated soils. Biostimulation such as addition of carbon sources and mineral nutrients can be applied to promote the leaching rate. Biosorption can be used either ex-situ or in-situ to remove arsenic from groundwater by sorption to biomass and/or coprecipitation with biogenic solids or sulfides. Introduction of proper biosorbents or microorganisms to produce active biosorbents in-situ is the key to the success of this method. Phytoremediation depends on arsenic-hyperaccumulating plants to remove arsenic from soils and shallow groundwater by translocating it into plant tissues. Engineering genetic strategies can be employed to increase the arsenic-hyperaccumulating capacity of the plants. Biovolatilization may be developed potentially as an ex-situ treatment technology. Further efforts are needed to focus on increasing the volatilization rate and the post-treatment of volatilization products.     

Arsenic distribution in Florida urban soils: comparison between Gainesville and Miami

Arsenic contamination is of concern due to its effect as a carcinogen. Understanding the distribution of arsenic in urban soils is important for establishing baseline concentrations from which anthropogenic effects can be measured. The soil cleanup target level (SCTL) for arsenic in Florida (0.8 and 3.7 mg kg(-1) in residential and commercial areas, respectively) is lower than in most states and is near the arsenic background concentrations in Florida soils. The objective of this study was to characterize the distribution of arsenic in the soils of two Florida cities, Gainesville and Miami. More than 200 soil samples were collected from three land-use classes in each city (residential, commercial, and public land), digested with USEPA Method 3051a, and analyzed with graphite furnace atomic absorption spectrophotometry. Arsenic concentrations varied greatly in Gainesville, ranging from 0.21 to approximately 660 mg kg(-1) with a geometric mean (GM) of 0.40 mg kg(-1) (after discarding outliers), which was significantly lower than the GM of 2.81 mg kg(-1) in Miami, although Miami samples ranged only from 0.32 to approximately 110 mg kg(-1). Arsenic concentrations in 29 and 4% of the Gainesville soil samples and 95 and 33% of the Miami samples exceeded the Florida residential and commercial SCTL, respectively. This study is the first to provide information on arsenic distribution in urban soils of Florida, and the data are useful for assessing arsenic contamination and determining the need for remediation.     

Potential anthropogenic mobilisation of mercury and arsenic from soils on mineralised rocks, Northland, New Zealand

Eroded roots of hot spring systems in Northland, New Zealand consist of mineralised rocks containing sulfide minerals. Marcasite and cinnabar are the dominant sulfides with subordinate pyrite. Deep weathering and leached soil formation has occurred in a warm temperate to subtropical climate with up to 3 m/year rainfall. Decomposition of the iron sulfides in natural and anthropogenic rock exposures yields acid rock drainage with pH typically between 2 and 4, and locally down to pH 1. Soils and weathered rocks developed on basement greywacke have negligible acid neutralisation capacity. Natural rainforest soils have pH between 4 and 5 on unmineralised greywacke, and pH is as low as 3.5 in soils on mineralised rocks. Roads with aggregate made from mineralised rocks have pH near 3, and quarries from which the rock was extracted can have pH down to 1. Mineralised rocks are enriched in arsenic and mercury, both of which are environmentally available as solid solution impurities in iron sulfides and phosphate minerals. Base metals (Cu, Pb, Zn) are present at low levels in soils, at or below typical basement rock background. Decomposition of the iron sulfides releases the solid solution arsenic and mercury into the acid rock drainage solutions. Phosphate minerals release their impurities only under strongly acid conditions (pH<1). Arsenic and mercury are adsorbed on to iron oxyhydroxides in soils, concentrated in the C horizon, with up to 4000 ppm arsenic and 100 ppm mercury. Waters emanating from acid rock drainage areas have arsenic and mercury below drinking water limits. Leaching experiments and theoretical predictions indicate that both arsenic and mercury are least mobile in acid soils, at pH of c. 3-4. This optimum pH range for fixation of arsenic and mercury on iron oxyhydroxides in soils is similar to natural pH at the field site of this study. However, neutralisation of acid soils developed on mineralised rocks is likely to decrease adsorption and enhance mobility of arsenic and mercury. Hence, development of farmland by clearing forest and adding agricultural lime may mobilise arsenic and mercury from underlying soils on mineralised rocks. In addition, arsenic and mercury release into runoff water will be enhanced where sediment is washed off mineralised road aggregate (pH 3) on to farm land (pH>6). The naturally acid forest soils, or even lower pH of natural acid rock drainage, are the most desirable environmental conditions to restrict dissolution of arsenic and mercury from soils. This approach is only valid where mineralised soils have low base metal concentrations.     

石油污染土壤的生物修复技术研究及其前景

根据污染土壤的生物修复技术具有高效、无二次污染和操作管理简便的优点，本文介绍谊类技术在石油污染治理领域的应用。在概述石油的组成成分及其对环境造成的污染的基础上，重点论述了微生物和植物修复技术有效去除有机污染物的应用条件，并就目前两种技术的最新研究成果即基因技术的应用作了介绍，同时指出了石油污染土壤生物修复技术的发展趋势和应用前景。     

极值理论在重金属污染土壤修复中的应用

为了准确预测重金属污染地块不同区域内重金属的最大值,以便于后续筛选重金属修复技术、确定重金属修复药剂使用量等提供依据,采用极值理论方法对某重金属砷污染地块三块区域内的重金属砷浓度数据进行极值分布的统计分析,对比不同分布形式对重金属砷浓度数据拟合的效果。结果表明:广义极值分布可以很好地描述重金属砷浓度数据的分布情况,通过K-S检验、作图法和P-P散点图法验证得出广义极值分布形式对重金属砷浓度数据拟合效果最好,通过广义极值分布形式的表达式可以计算得出A、B和C区不同概率下重金属浓度的最大值。     

应用植物重金属超富集机理修复土壤复合污染的研究现状与展望

超积累植物在修复土壤重金属污染中起着重要的作用,但由于重金属复合污染的存在,许多植物并未能完全适用于实际修复中。本文通过阐述土壤重金属复合污染,参考近年来国际上对超积累植物富集机理的研究,从土壤重金属复合污染自身的交互作用,超积累植物根系活化机理,吸收和运输通道机制,金属配位体的运输与解毒作用,以及细胞分室化现象等各个阶段探讨与展望土壤重金属复合污染修复研究问题。     

污染土壤淋洗修复技术研究进展

本文介绍了淋洗修复技术和淋洗装置在污染土壤修复技术中的应用,对有机物、重金属及放射性核素污染土壤淋洗修复技术的应用现状进行了总结和评价,还探讨了淋洗修复技术的发展方向及其应用前景。     

Using Mediterranean shrubs for the phytoremediation of a soil impacted by pyritic wastes in Southern Spain: a field experiment

Re-vegetation is the main aim of ecological restoration projects, and in Mediterranean environments native plants are desirable to achieve successful restoration. In 1998, the burst of a tailings dam flooded the Guadiamar river valley downstream from Aznalcóllar (Southern Spain) with sludges that contained elevated concentrations of metals and metalloids, polluting soils and waters. A phytoremediation experiment to assess the potential use of native shrub species for the restoration of soils affected by the spillage was performed from 2005 to 2007, with soils divided into two groups: pH < 5 and pH > 5. Four native shrubs (Myrtus communis, Retama sphaerocarpa, Rosmarinus officinalis and Tamarix gallica) were planted and left to grow without intervention. Trace element concentrations in soils and plants, their extractability in soils, transfer factors and plant survival were used to identify the most-interesting species for phytoremediation. Total As was higher in soils with pH < 5. Ammonium sulphate-extractable zinc, copper, cadmium and aluminium concentrations were higher in very-acid soils, but arsenic was extracted more efficiently when soil pH was >5. Unlike As, which was either fixed by Fe oxides or retained as sulphide, the extractable metals showed significant relationships with the corresponding total soil metal concentration and inverse relationships with soil pH. T. gallica, R. officinalis and R. sphaerocarpa survived better in soils with pH > 5, while M. communis had better survival at pH < 5. R. sphaerocarpa showed the highest survival (30%) in all soils. Trace element transfer from soil to harvestable parts was low for all species and elements, and some species may have been able to decrease trace element availability in the soil. Our results suggest that R. sphaerocarpa is an adequate plant species for phytostabilising these soils, although more research is needed to address the self-sustainability of this remediation technique and the associated environmental changes.