Phytoremediation of heavy metal‐contaminated water and sediment by Eleocharis acicularis

Phytoremediation is an environmental remediation technique that takes advantage of plant physiology and metabolism. The unique property of heavy metal hyperaccumulation by the macrophyte Eleocharis acicularis is of great significance in the phytoremediation of water and sediments contaminated by heavy metals at mine sites. In this study, a field cultivation experiment was performed to examine the applicability of E. acicularis to the remediation of water contaminated by heavy metals. The highest concentrations of heavy metals in the shoots of E. acicularis were 20 200 mg Cu/kg, 14 200 mg Zn/kg, 1740 mg As/kg, 894 mg Pb/kg, and 239 mg Cd/kg. The concentrations of Cu, Zn, As, Cd, and Pb in the shoots correlate with their concentrations in the soil in a log‐linear fashion. The bioconcentration factor for these elements decreases log‐linearly with increasing concentration in the soil. The results indicate the ability of E. acicularis to hyperaccumulate Cu, Zn, As, and Cd under natural conditions, making it a good candidate species for the phytoremediation of water contaminated by heavy metals.     

Distribution and speciation of mercury in soil in the area of an ancient mercury ore roasting site,Frbejžene trate (Idrija area,Slovenia)

In the initial period of mining activities in the Idrija basin (the16^th and the first half of the17^th centuries), Hg ore processing was performed at various small-scale roasting sites in the woods surrounding Idrija, by roasting ore in earthen vessels. The recovery rate of this method was very low; about half of Hg was lost, causing soil contamination and considerable amounts of waste material that could potentially leach Hg into the surrounding environment. The main aims of present geochemical study were to determine the contents, vertical distribution and speciation of Hg in soils at the roasting site at Frbej?ene trate in order to verify the extreme pollution of ancient Hg ore roasting sites in the Idrija area and to establish their significance in the wider spatial contamination of soils and aquatic systems. Soil sampling was performed at the area of the former roasting site. The organic matter-rich surface soil layer (SOM) and underlying mineral soil were sampled at 63 sampling locations. Mercury speciation was performed using Hg thermo-desorption-AAS to distinguish cinnabar from potentially bioavailable forms. The results indicate extremely high Hg concentrations with a maximum of 37,000 mg/kg in SOM and 19,900 mg/kg in mineral soil. The established Hg median in soil was 370 mg/kg and in SOM 96.3 mg/kg. Spatial distributions of Hg in SOM and soil showed very high Hg contents in the central area and decreased rapidly with distance. The results of Hg thermo-desorption measurements indicated the presence of cinnabar (HgS) and Hg bound to organic or mineral soil matter. A significant portion (35–40%) of Hg in the investigated soil and SOM samples was comprised of non-cinnabar compounds, which are potentially bioavailable. It has been shown that soils contain high amounts of potentially transformable non-cinnabar Hg, which is available for surface leaching and runoff into the surrounding environment. Therefore, contaminated soils and roasted residues at the studied area are important for persistent Hg release into the aquatic ecosystem.     

湖南省矿山地质环境监测体系及制度建设

湖南省已开展的矿山地质环境监测工作尚未形成体系,时效性不高,连续性不强.但从法律法规、监管体系、地质环境数据和高新监测技术方面考察,体系建设已经可行.研究按照”简单、实用、高效”的原则,结合实际情况,考察建设该体系的组织结构体系、技术路线、职责与分工、数据汇交制度、质量控制制度及保障措施,提出建立以矿山企业自主监测为主...     

陀螺仪定向纠斜法在中关铁矿区的应用实践

中关铁矿是20世纪60年代中期探明的储量为9300万t的矿区,因地下水位埋藏深,排水难度大,为防止开采成本大和影响生态环境,决定采用帷幕灌浆方法解决治水问题。帷幕灌浆工程的试验孔对钻孔垂直度要求很高,全孔段孔斜不能大于2 m,防斜、纠斜成一大难题,实践中摸索出陀螺仪定向纠斜法并获得成功。     

SYZX系列绳索取心液动锤在新余梅山煤矿易斜深孔防斜钻进中的应用

为了解决江西新余梅山煤矿深孔勘查中存在的孔斜问题,采用绳索取心液动锤钻进为主的防斜工艺,优化钻具结构组合,合理地选择钻进技术参数和措施,在该矿区取得了明显的减斜防斜效果。总结了SYZX系列绳索取心液动锤在江西新余梅山煤矿勘查深孔施工中的防斜经验。     

坑道钻探中中深斜孔施工技术

从钻探器具选择、钻探硐室设计、钻孔结构、钻具级配、钻进参数、冲洗液、钻头参数等方面总结了江西德兴银山铜铅锌矿山接替资源勘探中在坑道内进行中深斜孔钻探的工艺技术。     

“松子山构造区”滑覆构造特征浅析

本文通过介绍＂松子山构造区＂的构造特征,总结出滑覆构造是其主要表现形式,研究了构造形态。     

广西大厂巴里碳酸盐型尾矿的酸化特征及机理

以一个堆放近20年的碳酸盐型尾矿的垂向剖面作为研究对象,采用综合地质-地球化学分析方法,包括尾矿组构及组分分析、X衍射分析以及Sobek-ABA估算和NAG测试等,探讨这类尾矿酸化的地质-地球化学特征及酸化作用机理,获得如下认识:①该尾矿剖面由下至上,随着氧化程度的增强,其酸化作用也逐步增强,呈现出明显的层带结构,即下部C层(还原带及原生带)为未蚀变松散尾砂,中部B层(次氧化带及碱缓冲带)为蚀变松散尾砂层,上部A层(氧化带及酸化带)呈厚约100～150cm的板结硬化层;在A层与B层之间形成一个酸化-碱缓冲界面;而氧化-还原界面则较低,位于B层底部接近C层顶部位置。②碱缓冲作用发生在B层内,方解石为碱质的主要来源。③该尾矿的酸中和有效率约为80%,这可能归因于尾矿酸化所产生的次生纤铁矿、石膏等包裹残余方解石,阻断了中和反应的进行。因此,即便是富含碱性碳酸盐的金属硫化物矿尾矿仍然存在酸化污染的可能性。     

硅藻土、石英砂和钾离子促进微生物转化酸性矿山废水中亚铁成次生矿物的研究

嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans)能够在低pH值条件下,迅速将Fe2+氧化并产生大量次生羟基硫酸铁沉淀,从而除去水中可溶性Fe2+。这为富含Fe2+的酸性矿山废水(acid mine drainage,AMD)处理提供了新的思路。本文从晶种刺激和阳离子诱导两个方面,分别研究了固定化载体(硅藻土、石英砂)和具有强诱导能力的成矾离子(K+)对微生物转化酸性体系中Fe2+成次生矿物的影响。结果表明,3种材料均有明显促进可溶性Fe2+向次生矿物转化的作用,且总铁(TFe)沉淀率与3种材料的添加量呈正相关关系。在起始Fe2+浓度为160mmol/L,硅藻土、石英砂和钾离子最大添加量分别为10 g、10 g和80 mmol/L时,经过72 h反应后,TFe沉淀率分别比对照增加了8%、24%和20%。矿物中的Fe、K和S元素含量与溶液中的起始K+浓度有非常密切的关系,随着K+浓度的增大,矿物中的K和S含量逐渐增加,而Fe含量则相应减少。     

灰岩含水层中稀土元素在地下水与围岩间的分异:以皖北任楼煤矿太原组灰岩含水层为例

采取了皖北任楼煤矿太原组灰岩和灰岩水样品进行稀土元素测试分析,结果显示灰岩样品稀土总量较低,平均为36.947×10-6,灰岩样品稀土配分模式表现为轻稀土富集、重稀土亏损型;灰岩水样品稀土总量平均为0.052 6×10-6,灰岩水样品轻、重稀土均富集,轻、重稀土之间分异明显。对灰岩含水层水岩相互作用进行研究,结果表明:轻稀土表现稳定,重稀土分异明显,尤其在Y处有一个明显的峰值;Y元素与Ca元素呈正相关关系,相比石灰岩,灰岩水的Y/Ho、Y/Dy分异更为明显。研究认为,灰岩水中Y元素的峰值效应也可作为灰岩水源识别的依据。