全球汞污染回顾与分析

回顾全球所经历的主要汞污染事件,引述国外科研工作者对全球汞污染与汞排放的调查和研究成果,重点介绍金矿开采对环境的污染与危害,揭示造成亚马逊流域汞污染的深层根源。分析今后全球防止汞污染的主要措施：一是主要工业化国家将进一步研究和改善工业领域相关行业的工艺技术水平,趋向无汞产品和无汞工艺,以减少自身的汞污染与排放;其二,发达国家陆续立法禁止汞的自由贸易和出口。发达国家对汞的出口限制将促使发展中国家相关行业（特别是小金矿）采取汞的替代工艺,从而减少全球性汞污染与排放。     

Clean artisanal gold mining: a utopian approach?

Artisanal and small-scale mining (ASM) provides an important source of livelihood for rural communities throughout the world. These activities are frequently accompanied by extensive environmental degradation and deplorable socio-economic conditions, both during operations and well after mining activities have ceased. As gold is easily sold and not influenced by the instability of local governments, it is the main mineral extracted by artisanal miners. Mercury (Hg) amalgamation is the preferred gold recovery method employed by artisanal gold miners and its misuse can result in serious health hazards for miners involved in gold extraction, as well as for surrounding community inhabitants, who may be exposed to mercury via the food chain. The rudimentary techniques characteristic of ASM result in a number of occupational hazards, other although most risks are primarily attributed to machinery accidents and ground failure, such as landslides and shaft collapses.Several technologies and methods commonly utilized by large-scale mining operations can be downsized to smaller scale operations. However, the likelihood that miners will adopt these large-scale methods, or those developed specifically for ASM, depends upon some key factors. For an artisanal miner, these factors include: (1) increased or comparable simplicity, (2) quick recovery of the economic mineral, and (3) demonstrated financial gain. Other practical aspects, such as the availability of materials (chemicals, steel rods, piping, generators, etc), capital and operating cost requirements and access to technical support, also influence acceptance of new techniques.This article will review four inter-related areas: first, the limitations and benefits, for ASM, of a number of specific technologies; second, the role of Processing Centers in education, information dissemination and provision of “clean” services; third, benefits and challenges associated with formalization of ASM activities; and fourth, the contribution of ASM to the development of sustainability of communities, primarily through diversification of livelihoods. The appropriate application of technologies, particularly given the diversity of ASM communities around the world, will also be explored.     

陕西潼关冶金污染土壤的修复评价及应用潜力

为了科学评估客土法、石灰和磷酸钙作为重金属钝化剂的原位稳定化修复技术在实际重金属污染土壤改良中的应用潜力,以潼关县安乐乡土壤重金属污染修复示范工程为例,从"三小"冶金土壤污染现状、工程修复技术的筛选、稳定化的修复效果以及修复后土壤农业生产安全性评价等角度进行了系统分析.结果表明"三小"冶炼行为对于周边土壤造成了严重的污染,主要污染物为Cd、Pb和Hg,矿渣是主要的污染源.采用潜在生态危害指数法进行评价,该区域潜在生态危害指数(RI)范围为668~10 969,具有很强的生态危害.通过对重度污染和轻度污染土壤分别采用客土法及原位固化的修复方法,土壤中重金属的总量以及有效态含量均有了显著的下降.除Cd外,土壤中重金属的总量均低于土壤二级标准中的限值.尽管土壤稳定化修复取得了一定的效果,但部分农作物中重金属的累积量高于国家食品安全标准中规定的限值,继续种植存在一定的风险.因此,在重金属污染修复后的土壤上不建议立刻进行粮食生产,应改变原有生产模式同时持续监测,在确保粮食安全后再进行生产.     

Recent improvements in oily wastewater treatment: Progress, challenges, and future opportunities

Oily wastewater poses significant threats to the soil, water, air and human beings because of the hazardous nature of its oil contents. The objective of this review paper is to highlight the current and recently developed methods for oily wastewater treatment through which contaminants such as oil, fats, grease, and inorganics can be removed for safe applications. These include electrochemical treatment, membrane filtration, biological treatment, hybrid technologies, use of biosurfactants, treatment via vacuum ultraviolet radiation, and destabilization of emulsions through the use of zeolites and other natural minerals. This review encompasses innovative and novel approaches to oily wastewater treatment and provides scientific background for future work that will be aimed at reducing the adverse impact of the discharge of oily wastewater into the environment. The current challenges affecting the optimal performance of oily wastewater treatment methods and opportunities for future research development in this field are also discussed.     

土壤重金属污染研究回顾与展望Ⅱ——基于三大学科的研究热点与前沿分析

文章基于三大学科——环境科学、土壤科学、环境工程,采用内容分析法对Web of Science引文数据库和中国知网(CNKI)期刊数据库检索出的土壤重金属污染相关文献进行了研究,从土壤重金属污染来源、危害、治理方法及生物修复技术等方面,重点分析了目前国内外学者在土壤重金属污染治理和修复技术问题的研究前沿和重点:生物修复技术是土壤污染治理的环境友好技术,微生物修复和植物修复技术结合使用,并加以化学与工程、农艺等其他措施来强化能较好地提高重金属污染修复的效率。并从重金属富集植物、组合修复技术及基因工程技术三方面对未来的研究热点进行了展望。     

板材成形新技术及其发展趋势(Ⅰ)

近些年来,面对全球化的竞争,越来越需要小批量、多样化、周期短的新的成形技术.薄板成形技术在成形工艺中占有很重要的地位,其多样化趋势已经变得越来越明显,出现了多种加工方法,它对将来的工业结构和产品的生产技术将是一场革命.文中介绍了变压边力技术、成对液压成形技术、粘介质成形技术、无模分层成形技术等几种柔性化程度高的板材成形技术及其发展趋势.     

Trends in the small-scale mining of precious minerals in Ghana: a perspective on its environmental impact

Small-scale mining in Ghana is defined to include both the exploitation of mineral deposits (1) using fairly rudimentary implements and/or (2) at low levels of production with minimal capital investment. While the large-scale mining—of particularly gold—has become predominant, small-scale mining, which predates such operations, has continued to be an important economic activity, particularly within the remote and poorer areas of the country. The environmental impacts of such small operations have, however, varied, depending on methods and the scale of operation. The factors that have contributed to aggravating these environmental impacts are economic, technical, legal, and operational in nature. Although mitigation efforts have had a limited impact, it is expected that the measures now being considered for adoption will improve the efficacy of the Government of Ghana’s drive towards improving environmental management in resident small-scale precious metal mining operations.This paper examines the environmental impacts of small-scale mining in Ghana—with particular emphasis on precious minerals and metals extraction—and outlines a series of initiatives for improving environmental performance in the industry.     

逐级提取(SEE)技术及其在沉积物和土壤元素形态研究中的应用

概述了元素形态的研究方法,介绍了SEE技术及其在沉积物、土壤元素形态研究中的应用,并就该技术在元素形态研究中的作用、实现标准化的可能性及难度、未来发展趋势等问题进行了探讨,得出了以下三点认识:(1)SEE技术是目前沉积物、土壤元素形态研究的必要手段,但其在未来元素形态研究中的作用,在很大程度上取决于技术本身的标准化和新发展以及其它形态分析方法的发展;(2)根据研究目的,系统研究不同样品的采集和预处理方法、试剂种类和浓度以及操作条件等元素形态影响因素,对现有流程进行改进或提出新的更合理的流程,作为SEE技术的标准流程,是必要且可能的,但其任务也是艰巨的;(3)SEE技术可能向两个趋势发展,分别形成微波加热-连续流-逐级提取(MCSE)技术以及微波加热-超声波震荡-动力学-平行提取(MUKPE)技术。     

堆肥在土壤修复与质量提升的应用现状与展望

堆肥作为一种经济有效、环境友好的技术手段,通过生物强化将垃圾有机质转变为富含多种功能基团的大分子胡敏酸类的产品,可修复和改善土壤质量,将垃圾中的有效资源最大程度循环固定回土壤中,有效解决我国耕地超负荷种植、有机质持续下降等突出矛盾。对目前国内外利用堆肥在土壤修复与质量提升方面的研究进行了综述,对常见土壤污染类型如重金属污染、盐污染和有机氯农药污染的修复以及土壤碳库质量的提升和全球碳循环进行了详细讨论,并展望堆肥应用的未来,以期对今后有机垃圾处理—胡敏酸类物质工程应用—土壤修复与质量提升全链条深入研究,土壤修复与质量提升技术的理论依据和促进实际应用的发展提供参考。     

金尾矿综合利用技术研究与应用进展

黄金矿石的品位低,经选冶后产生比其他金属矿石更多的尾矿。黄金矿山每天尾矿的大量排放,造成了黄金及其他有价金属的流失,同时大量的尾矿堆积,对环境带来极大的危害。为了进一步回收有价金属,保护矿区的生态环境,本文介绍了尾矿的综合利用技术,其中重点介绍了尾矿中有价元素的综合回收技术,进一步变废为宝,开发宝贵的二次资源。     

Gold mining in Australia: linking historical trends and environmental and resource sustainability

The mining of gold has been and continues to be an important aspect of Australian industry. Gold mining moved quickly from fossicking and alluvial sources in the 1850's to hard rock mining. This paper presents, arguably for the first time, a detailed historical compilation of Australian gold mining production data. This data is then analysed in the context of sustainability, focussing particularly on mineral resource sustainability and the broader aspects of environmental impacts now commonly reported by some mining companies in annual sustainability performance reports. The key trends which are demonstrated by the data include a long-term decline in ore grade, increased open cut mining, substantive increases in tailings and waste rock production, as well as showing the impact of new technologies and economics on available gold resources. The available environmental data on material and energy inputs to and pollutant emissions from gold production is also presented, showing a clear sensitivity to ore grade. In terms of sustainability, these relationships raise significant issues such as increasing greenhouse footprint per unit gold produced, potential impacts on energy and water consumption, as well as overall gold resource sustainability. The paper presents a unique case study of the resource and environmental sustainability of the Australian gold mining sector with major implications for sustainability policy and reporting.     

金属/有机涂层体系环境失效的电化学研究方法

简要介绍了金属/有机涂层体系环境失效的现代电化学研究和评价方法,包括交流阻抗技术、局部交流阻抗技术、扫描Kelvin探头技术、电化学噪声技术等.综述了这些技术的特点和应用,使用原位无损评价方法,多种技术综合研究,将有助于进行涂层性能的评价和金属/有机涂层体系环境失效机理的研究.     

金属矿山土壤重金属污染生物修复研究进展

金属矿区及周边土壤重金属污染已成为严重的环境问题之一。重金属污染使土壤质量下降,生态系统退化,同时污染农作物,威胁到人类的健康。目前,修复重金属污染土壤的方法很多,包括物理、化学、生物等方法。其中生物修复法近年来得到了特别的重视,并取得了显著进展。文章全面介绍了目前各种生物修复技术:植物修复、微生物修复以及微生物-植物联合修复,包括修复原理、进展、优缺点等。矿山固体废物和酸性废水导致矿区土壤中富集大量重金属,结合目前生物修复技术及其应用,对金属矿山重金属污染土壤的整体修复提出设想,并进一步指出发展方向:将基因工程引入植物的重金属修复;构建菌根-植物-微生物修复体系,促进土壤重金属污染的生物修复。     

中国西南地区金属矿开采对矿区土壤重金属影响的Meta分析

金属矿开采是土壤重金属的最主要来源之一.以往针对单个或少数几个金属矿区的研究尚不足以有效支撑大尺度特别是跨省域尺度内矿区土壤重金属污染的治理.本研究针对我国金属矿产资源丰富的西南地区（云南省、四川省、贵州省、重庆市和西藏自治区）,搜集了有关金属矿开采对土壤重金属影响的文献,采用Meta分析量化了不同情景模式（即不同子区域、矿种和土地利用类型）下金属矿开采对周边土壤As、Cd、Cr、Cu、Hg、Ni、Pb和Zn的影响,最后利用失安全系数与漏斗图检验了研究数据的发表性偏倚.结果表明,我国西南地区金属矿开采整体上显著增加了表层土壤中重金属含量［ES₊（weight effect size）=1.53］,重金属增加量由高到低顺序为：Cd （4109.80%）>Pb （741.49%）>Hg （452.90%）>Zn （420.70%）>As （278.10%）>Cu （138.69%）>Ni （16.18%）,Cr无显著影响;四川和云南采矿对土壤Cd （ES_+四川=4.16;ES_+云南=3.20）和Pb （ES_+四川=3.47;ES_+云南=2.54）的影响较高,贵州采矿对土壤Hg （ES₊=2.80）的影响最高;金属矿开采对耕地土壤（ES₊=1.42）的影响较高;铅锌矿和锡矿开采显著增加了土壤中Cd、Pb和Zn的含量,铜矿开采显著增加了土壤Cu、Cd和Pb的含量;以上重金属中,Pb和Zn的研究结果受发表性偏倚的影响（P<0.05）.本研究结果可为西南金属矿区土壤环境保护提供更多的有效信息.     

汞矿山废弃地土壤汞污染研究

中国是世界上第3大产汞国,而主要的供应源是汞开采,尽管多数矿山开采活动已经关闭,但大规模遗留下来的矿山废弃地会引发许多生态环境问题,尤其是矿山废弃地土壤中汞污染已经成为严重的环境问题之一.文章通过对矿山废弃地的环境污染特征、土壤汞污染途径、迁移方式进行系统综述,介绍了土壤汞污染修复技术,并在此基础上提出了存在的问题以及有待进一步研究的方向.     

基于Meta分析的中国工矿业场地土壤重金属污染评价

工矿业活动是土壤重金属污染的重要来源之一.由于早期企业管理体系不完善和环保意识薄弱等原因,我国工矿业土壤环境问题突出.本文对2005—2022年中国知网、万方、Web of Science等数据库发表的关于我国工矿业土壤重金属污染的138篇文献(包含141处场地)进行Meta分析,并通过地累积指数法和潜在生态风险指数法评价我国工矿业地及周边土壤中Cd、Pb、Zn、Cu、As的污染情况、分布特征及行业特征. Meta分析随机效应模型的计算结果表明,与土壤背景值相比,我国工矿业场地及周边土壤中Cd、Pb、Zn、Cu、As的含量分别增加了897.42%、233.34%、232.34%、196.83%和171.29%.重金属污染分布结果显示,东南沿海及长三角等经济发达地区工矿业土壤污染更严重,北方地区污染较轻,Cd是首要污染物.从行业特征看,化石燃料开采场地及周边土壤中Pb、As含量与背景值差异不显著;有色金属矿开采导致土壤重金属含量显著升高,其中Cd污染十分突出,土壤Cd含量的增幅高达964.40%. 49.21%的有色金属矿区土壤存在极强潜在生态风险;化石燃料开采场区土壤污染较轻,潜在生态...     

Mercury-free gold mining technologies: possibilities for adoption in the Guianas

The rudimentary nature of small-scale gold mining activities often generates a legacy of extensive degradation and deplorable social conditions, both during and after activities have ceased. Small-scale mining usually involves the extraction of secondary gold from placer deposits (alluvial, colluvial or elluvial), which can be liberated and treated using gravity methods. In the Guianas, the most popular form of small-scale gold mining is referred to as “land dredging”, a combination of hydraulicking and suction dredging. This method requires application of large volumes of water for both mining and mineral processing; in most cases, there are no containment structures for the waste tailings generated. Mercury, a dangerous pollutant, is the preferred method employed by small-scale miners for gold recovery. Gold extraction using mercury is comprised of the following four stages: (1) amalgamation, (2) separation of amalgamation, (3) removal of excess mercury, and (4) burning of the remaining amalgam to produce a gold sponge. Mercury can be released into the environment at each stage, which makes the promotion of mercury-free alternatives imperative.Technical alternatives for small-scale gold mining, however, must be thoroughly evaluated, pre-tested, modified accordingly and successfully transferred. Moreover, technology must be inexpensive, relatively simple and easy to adapt, while allowing a rapid rate of return. WWF-Guianas is working with the regulatory agencies and other relevant stakeholders of the Guianas to reduce the environmental footprints caused by small-scale mining. The major aspects of this program are to develop the capacity and regulatory mechanisms within the local government, to promote mercury-free technology, and monitor mercury in the environment. This paper reviews the alternative technologies being investigated by the WWF-Guianas for use in the small-scale gold mining industry.     

重金属污染物在土壤中迁移规律及修复技术研究

世界各国都认识到重金属污染的严重性.多数国家开展了污染场地的修复工作,研究和开发出多种土壤重金属污染修复技术,重金属污染土壤修复技术有物理化学修复技术、植物修复、微生物修复技术和电动修复技术.但这些土壤修复技术的成本高,只重视土壤修复,土壤修复技术更重要的部分是地下水系统的修复,不能忽视地下水系统与土壤修复的完整性,否则会造成二次环境污染.本文在分析土壤中重金属污染物迁移规律的同时提出完整的土壤修复新技术CH-PRB工艺.     

影响潜流人工湿地脱氮主要因素及其解决途径

文章综述了潜流人工湿地除氮的各种机理,包括基质吸附、植物吸收、氨挥发、硝化-反硝化等,其中硝化-反硝化是最主要的脱氮过程。在人工湿地脱氮工艺方面,短程硝化反硝化和厌氧氨氧化是今后研究的前沿。此外讨论了影响人工湿地除氮效率的主要影响因素,包括温度、溶解氧、pH、碳源、重金属、水力学因素等,其中碳源、重金属和水力学方面的影响是研究的热点和前沿。最后,进一步综述了提高人工湿地脱氮效率的研究方法,并对今后的相关研究方向进行了展望。     

我国几个工矿与污灌区土壤重金属污染状况及原因探讨

对我国几个重工业区、矿区、开发区以及污灌区土壤重金属污染状况的调查结果表明，土壤重金属含量绝大部分高于土壤背景值，Cd、Zn等明显超标，某些重金属元素含量间还存在着一定的伴生规律。土中浸提态Cd、Zn含量与土壤pH值呈负相关。土壤中的重金属主要来自于污灌、金属矿藏开采、污泥利用以及大气飘尘等。金属冶炼厂附近土壤中Pb、Zn、Cd含量皆与离污染源距离呈密切的指数相关（R^2＞0.9）。