Solubility and Potential Mobility of Heavy Metals in Two Contaminated Urban Soils from Stockholm,Sweden

The solubility and potential mobility of heavy metals (Cd, Cu,Hg, Pb and Zn) in two urban soils were studied by sequential andleaching extractions (rainwater). Compared to rural (arable) soils on similar parent material, the urban soils were highlycontaminated with Hg and Pb and to a lesser extent also with Cd,Cu and Zn. Metal concentrations in rainwater leachates were related to sequential extractions and metal levels reported fromStockholm groundwater. Cadmium and Zn in the soils were mainly recovered in easily extractable fractions, whereas Cu and Pb were complex bound. Concentrations of Pb in the residual fractionwere between two- and eightfold those in arable soils, indicatingthat the sequential extraction scheme did not reflect the solidphases affected by anthropogenic inputs. Cadmium and Zn conc. inthe rainwater leachates were within the range detected in Stockholm groundwater, while Cu and Pb conc. were higher, whichsuggests that Cu and Pb released from the surface soil were immobilised in deeper soil layers. In a soil highly contaminatedwith Hg, the Hg conc. in the leachate was above the median concentration, but still 50 times lower than the max concentration found in groundwater, indicating the possibilityof other sources. In conclusion, it proved difficult to quantitatively predict the mobility of metals in soils by sequential extractions.     

冬季降雪过程对城市大气气态汞污染的影响

2009年降雪和非降雪期间对北京西北城区的气态总汞浓度进行了连续采样,比较了降雪期间、非降雪期间的气态总汞浓度日变化过程;降雪期间气态总汞浓度的降低和恢复过程。结果表明,降雪和非降雪期间大气气态总汞浓度的日均值有显著差异,降雪期间气态总汞的平均浓度为5．64ng·m^-3,非降雪期间的平均浓度为7．43ng·m^-3,前者约为后者的70％。降雪后约7h气态总汞浓度恢复到降雪前水平。研究中分析了气象因素（气压、风速、阵风速度、气温和相对湿度）对于气态总汞浓度的影响,结果表明：降雪期间主要受到风速（r=-0．527）和阵风速度（r=-0．574）的影响;非降雪期间主要受到风速（r=-0．691）,阵风速度（r=-0．726）和相对湿度（r=0．692）的影响,并且相对湿度的影响与风速的影响相近。降雪和非降雪期间气态总汞的日变化有所差异：非降雪期间气态总汞浓度在午夜和清晨较高,日变化趋势与相对湿度一致;降雪期间气态总汞的日变化没有明显规律。     

松花江沉积物汞的新变化:分布、演化与现状及潜在生态风险评估

分析了第二松花江中下游和松花江干流表层沉积物中总汞的含量水平和分布规律,同期采集了牡丹江、黑龙江沉积物作为对照,并采用地累积指数法以及潜在生态风险指数法,初步评价了松花江沉积物中汞的污染状况和潜在的生态风险.结果表明,松花江10个断面沉积物总汞含量范围0.029~1.317 mg·kg~(-1),均值0.183 mg·kg~(-1).第二松花江3个典型断面沉积物总汞含量均显著高于松花江干流的7个典型断面(P0.05).地累积指数(Igeo)及潜在生态风险指数(Er)表明第二松花江3个典型断面沉积物汞污染程度为偏中度至重度污染,存在高度生态风险;松花江干流7个典型断面为轻度污染,具有较高生态风险.近10年松花江沉积物汞含量变化及空间分布结果显示,现阶段第二松花江沉积物汞含量有所下降,但松花江干流个别江段沉积物汞含量有所上升,应引起重视.     

混汞法采金地区的汞污染研究进展

混汞法是一种设备简单、操作简便且应用历史悠久的提金方法 ,在世界范围内得到了普遍使用 ,同时也导致了严重的汞污染。本文介绍了混汞法的流程以及汞的释放过程和释放因子 ;综述了应用混汞法提金的不同国家和地区 ,对由此引发的大气、水体、生物 (包括人体 )和土壤汞污染的研究现状 ,并讨论了采金地区的环境管理政策     

How does eliminating mercury from artisanal and small-scale gold mining lead to achieving sustainable development goals?

Artisanal and small-scale gold mining (ASGM) is the principal anthropogenic activity that globally contributes to overloading our environment with mercury. Although the Minamata Convention, led by the United Nations, is a crucial instrument to eliminate its use progressively, novel approaches to accelerate this difficult transition are welcome. This article proposes a framework for policy-making or improvement, fostering the enforcement of mercury elimination through the lens of the 17 Sustainable Development Goals (SDGs), focusing on the excluded artisanal and small-scale gold miners and their dependents. We move forward with a literature review of the Artisanal and Small Mining topic, taking each SDG as a unit of analysis. Understanding the problem as a puzzle of four sets of pieces, namely: (1) social, (2) environmental, (3) economic, and (4) institutional, the paper offers potential opportunities for the decision-makers and practitioners to accelerate the substitution of this heavy metal and develop sustainable futures for the ASGM communities. We conclude by proposing a pragmatic framework that synthesizes the means, actions, and ends to accelerate a sustainable transition.     

全球主要森林系统中植被汞分布特征及其影响因素

基于过去20a全球森林植被中汞循环过程的相关研究,本文通过荟萃分析法阐明全球主要森林类型中植被汞分布特征及其影响因素.结果表明,汞在植被中浓度排序特征(以中值计)依次为凋落物(38.9ng/g)>叶片(24.1ng/g)>树根(18.5ng/g)>树皮(13.2ng/g)>树枝(12.0ng/g)>树干(3.1ng/g...     

基于T-Hg2+-T结构的Hg2+生物传感器研究进展

Hg²⁺不仅污染环境,还会引发多种疾病,危害人体健康.因此,实现对Hg²⁺的快速灵敏检测十分必要.传统的Hg²⁺检测方法存在一定的局限性,而基于T-Hg²⁺-T结构的汞离子生物传感器具有高特异性、高稳定性的优势,近些年得到广泛研究和应用.本文简要介绍了T-Hg²⁺-T结构的概念和特点,并从荧光型、比色型和电化学型3个方面综述了基于T-Hg²⁺-T结构的汞离子生物传感器的研究进展,对未来的发展前景进行了展望.     

巢湖杭埠-丰乐河汞的污染特征及生态风险

通过对水样、沉积物和背角无齿蚌中汞含量的测定,研究杭埠-丰乐河汞的污染特征,并利用单项污染指数法、地累积指数法评估了汞的生态风险.结果表明：水样总汞的浓度为0.04～0.20μg/L（均值为0.10μg/L）,H5、H9、F2、S4和S5处水样中汞含量超过地表水Ⅲ类限值.沉积物中汞、甲基汞含量分别为29.13～251.49μg/kg（均值为65.42μg/kg）和0.22～3.31μg/kg（均值为0.68μg/kg）,H5、H9和F2处沉积物中汞为轻度污染,S4、S5为偏中度污染,工业排污是主要污染来源.背角无齿蚌中汞、甲基汞含量分别为101.34～171.15μg/kg（干重）和54.22～89.63μg/kg（干重）,均符合GB18406.4-2001中汞的限量要求.背角无齿蚌对汞和甲基汞均有明显的富集,其组织对汞的积累也具有明显选择性（浓度高低依次为：外套膜 > 内脏 > 腮和肌肉）.背角无齿蚌中汞含量与水和沉积物中汞含量相关性良好,表明背角无齿蚌作为指示生物其生物监测结果可进一步验证水和沉积物中的汞污染水平.     

Removal of elemental mercury by KI-impregnated clay

This study described the use of clay impregnated by KI in gas phase elemental mercury (Hg^o) removal in flue gas. The effects of KI loading, temperature, O₂, SO₂ and H₂O on Hg^o removal were investigated using a fixed bed reactor. The Hg^o removal efficiency of KI-clay with 3% KI loading could maintain at a high level (approximately 80 %) after 3 h. The KI-clay demonstrated to be a potential adsorbent for Hg^o removal when compared with activated carbon based adsorbent. O₂ was found to be an important factor in improving the Hg^o removal. O₂ was demonstrated to assist the transfer of KI to I₂ on the surface of KI-clay, which could react with Hg^o directly. NO and SO₂ could slightly improve Hg^o removal, while H₂O inhibited it greatly. The results indicated that after adsorption, most of the mercury escaped from the surface again. Some of the mercury may have been oxidized as it left the surface. The results demonstrated that the chemical reaction primarily occurred between KI and mercury on the surface of the KI-clay.     

溴添加对燃煤烟气汞形态转化的影响

在一维管式沉降炉燃烧试验装置上,以汞的氧化率为评价指标,进行了溴化物种类、添加浓度、添加方式等因素对燃煤烟气汞形态转化影响的实验研究.结果表明: 溴对汞的氧化起促进作用,汞氧化率在一定的范围快速增加,超过此范围缓慢增加.不同的煤质,不同的溴添加物,这个范围是不同的;综合考虑添加成本,操作难易程度以及汞的氧化率,添加同浓度的溴化物时,汞的氧化率由低到高的排列顺序依次是:HBr炉后< HBr炉前< CaBr2< NaBr.在本实验条件下,汞的氧化效果最佳的条件是,褐煤中添加200mg/kg溴化钠,汞的氧化率约72%;亚烟煤添加1000mg/kg溴化钠,汞的氧化率约83%.