Supergene processes on ore deposits—a source of heavy metals

The study of supergene processes (i.e., secondary processes running in ore deposits and driven by thermodynamic nonequilibrium between ore-and rock-forming minerals and natural waters, gasses, etc.) is important in order to understand the migration of heavy metals from ore into their adjacent surroundings. The contamination of the local environment can be characterized by the composition of pore waters. The Pb-Zn-Cu ore deposits of Zlaté Hory (Czech Republic) have been chosen for a detailed study of pore solutions. A simple model has been created to describe the evolution of supergene processes in the ore deposits. This model is based on the determination of chemical composition of pore solutions. The dilution of pore solutions of such mineral deposits results in acid mine drainage. Pore solutions can have, during specific stages of their evolution, relatively high concentrations of Cu (0.09 mol/kg), Zn (0.1 mol/kg), SO₄ (0.8 mol/kg) and an extremely low pH (1.38). The supergene alteration of pyrite is the most important process determining the character of pore water. This reaction causes significant acidification and is a leading source of acid mine drainage. The leached zone originates from the interaction of pyrite and limonite. Increased concentrations of heavy metals and sulfates occur in pore waters. The dynamic composition of pore waters within ore deposits undergoing the supergene process can be used to distinguish: (1) three main zoneslimonite, transition, and primary zone and (2) two areas—an area with the highest intensity of weathering processes and an area of weathering initiation. In these areas the rate of sulfide oxidation is higher as a result of low pH. From the study of these zones and areas we can further our knowledge of ore body, pore solution, acid mine drainage, and contamination of the local environment.     

重金属高背景区水稻镉积累与健康安全风险评价：以云南省会泽县娜姑镇为例

调查发现,重金属高背景区存在土壤中的镉含量超标,而农作物中的镉含量并未超标的现象,但对其原因知之甚少。开展区内农作物镉积累研究并探寻制约农作物镉吸收的因素,对土壤环境质量评价和污染土地生态修复都具有重要意义。以云南省会泽县娜姑镇娜姑坝子为研究区,采集了水稻籽实和配套土壤样品各41件,采用ICP-MS方法检测了Cd含量。通过偏相关、R型聚类、逐步线性回归等分析了水稻镉与土壤元素（指标）之间的相关关系。结果显示,水田土壤镉（Cd）含量为 0.467~1.87 mg/kg,平均为 0.78 mg/kg,是全国土壤背景值的 5.69 倍,58.5% 的样品超过农用地土壤污染风险筛选值。水稻（糙米）镉含量为 0.007~0.062 mg/kg,平均 0.016 mg/kg,均低于食品安全国家标准限值。水稻镉与土壤铀（U）、钼（Mo）等呈显著正相关,与土壤有机碳（TOC）、硫（S）等呈显著负相关,与土壤 Cd 总量和酸碱度（pH）无显著相关性。土壤镉超标而水稻镉不超标的现象可能与土壤富含有机碳有关,该地区土壤有机碳（TOC）含量达全国背景值的5.57倍。当 TOC > 3% 时,水稻镉含量迅速下降。据此提出土壤镉环境等级的有机碳修正方法,将研究区3.42 km2（5129 亩）Ⅱ等水田修正为Ⅰ等。此外,还提出了一些土壤养护和修复的建议。     

金属成矿省等级体制成矿

基于成矿“时间维”造就“空间维”的活动论新思维，提出了金属成矿省等级体制成矿概念，即成矿构造背“景”、成矿构造聚敛“场”、金属成矿“相”和矿“床”4个成矿等级在1个金属成矿省内的成矿作用，及其随着地质历史演化进程，通过在一定地质时期的一定地质事件，促发4个不同等级的成矿组成以一定规律发生耦合。不耦合者不成矿，一般耦合仅成一般规模矿床，最佳耦合导致巨量金属堆积，形成特大型矿床。文章以华北板块北缘及其北侧金属成矿省为例，通过成矿等级体制的有序耦合、耦合程度及其巨量金属堆积机制的研究，发现巨量金属的堆积是在一定的地质历史时期内，由一定的地质事件激发常规成矿作用发生异常“引潮共振”的结果。     

Distribution and population structure of deep‐dwelling red coral in the Northwest Mediterranean

Commercially harvested since ancient times, the highly valuable red coral Corallium rubrum (Linnaeus, 1758) is an octocoral endemic to the Mediterranean Sea and adjacent Eastern Atlantic Ocean, where it occurs on rocky bottoms over a wide bathymetric range. Current knowledge is restricted to its shallow populations (15–50 m depth), with comparably little attention given to the deeper populations (50–200 m) that are nowadays the main target of exploitation. In this study, red coral distribution and population structure were assessed in three historically exploited areas (Amalfi, Ischia Island and Elba Island) in the Tyrrhenian Sea (Western Mediterranean Sea) between 50 and 130 m depth by means of ROV during a cruise carried out in the summer of 2010. Red coral populations showed a maximum patch frequency of 0.20 ± 0.04 SD patches·m^?1 and a density ranging between 28 and 204 colonies·m^?2, with a fairly continuous bathymetric distribution. The highest red coral densities in the investigated areas were found on cliffs and boulders mainly exposed to the east, at the greatest depth, and characterized by medium percentage sediment cover. The study populations contained a high percentage (46% on average) of harvestable colonies (>7 mm basal diameter). Moreover, some colonies with fifth‐order branches were also observed, highlighting the probable older age of some components of these populations. The Ischia population showed the highest colony occupancy, density and size, suggesting a better conservation status than the populations at the other study locations. These results indicate that deep dwelling red coral populations in non‐stressed or less‐harvested areas may diverge from the inverse size‐density relationship previously observed in red coral populations with increasing depth.     

刮痧配合针刺治疗神经根型颈椎病30例临床观察

目的：观察刮痧配合针刺治疗神经根型颈椎病的临床疗效。方法：将60例神经根型颈椎病患者随机分为2组,每组各30例。对照组采用针刺治疗,治疗组在对照组基础上结合刮痧治疗。结果：总有效率治疗组为93.3%,对照组为70.0%,组间比较,差异有统计学意义（P＜0.05）;2组VAS评分治疗前后组内比较及治疗后组间比较,差异均有统计学意义（P＜0.01）。结论：刮痧结合针刺治疗神经根型颈椎病有较好疗效。     

云母:花岗岩-伟晶岩稀有金属成矿作用的重要标志矿物

云母是花岗岩、伟晶岩中的重要造岩矿物,不仅是整个岩浆阶段的结晶产物,而且也是热液过程的参与者。作为层状硅酸盐矿物,层间或八面体位置上可容纳锂、铷铯、锡、铌钽等稀有金属。本文结合前人研究积累和作者近年来的研究成果,阐述了云母作为一个重要的稀有金属成矿标志矿物的矿物学特征。铁锂云母-锂云母是稀有金属成矿作用中重要的锂矿物,同时云母中锂含量可以反映花岗岩的分异程度。铷、铯可以置换云母层间钾,在高演化花岗岩、伟晶岩中可以形成铷、铯为主的云母(既可以是锂云母系列,也可以是黑云母系列)。黑云母是稀有金属花岗岩中一个特殊的矿物。准铝质含锡花岗岩中黑云母锡含量可达100×10~(-6),其锡含量可以指示其锡成矿能力。稀有金属花岗岩中,常见的是铌钽氧化物矿物。但是最近研究发现,黑云母中铌可以超常富集(超过1000×10~(-6)),成为稀有金属花岗岩中最重要、甚至唯一的铌矿物,形成一种以富铌黑云母为特色的新类型稀有金属花岗岩,并可能代表了一种新型的潜在铌资源。基于云母在花岗岩中的重要性和结构的特殊性,今后要利用微区成分和结构分析技术,加强对云母中稀有金属晶体化学的研究,以及进一步揭示云母对稀有金属成矿的特殊重要意义。     

鄱阳湖流域乐安河重金属污染水平

乐安河是鄱阳湖五大入湖水系中重金属污染最严重的水域.为研究其污染现状,于2003-2004年度对乐安河水体、底泥及水生生物的重金属污染进行了调查与分析.结果表明,乐安河水体中的重金属除Cu的含量超出地表水环境质量标准Ⅲ类标准外,其它各项监测指标均能达到地表水环境质量Ⅲ类标准.乐安河底泥的重金属含量平均值与国家土壤环境质量相比,Cu的平均值超出了三级标准,而Pb和Zn的含量指标均符合三级标准;通过地质累积指数评价结果表明,乐安河底泥中Cu为严重污染,Pb为偏中度污染,Zn为中度污染.乐安河水生植物对Cu,Pb,Zn都有不同程度的富集,根据富集系数评价表明,植物对Cu的平均富集能力相对较强,其次是Pb和Zn.浮游动物、植物和底栖动物也受到不同程度的污染,其分布和数量因河段水质变化的影响也出现类似的波动.     

吉林中部黑土区重金属元素生态地球化学特征

基于吉林省中部黑土区地球化学调查数据,分析统计As、Cd、Cr、Cu、Ni、Zn 6种可造成重金属污染的元素在土壤--作物系统中的生态地球化学特征。通过吉林省部分地区土壤样品与玉米籽实样品采样,采用元素有效系数与元素累积系数的方法,计算出采样点的土壤重金属元素全量、有效量和玉米籽实含量特征,从而研究重金属元素生态地球化学特征。结果表明:(1)研究区土壤重金属元素全量虽然较吉林省土壤元素背景值增加明显,但土壤与玉米籽实均未达到污染状态。(2)重金属元素有效系数均值由小到大依次为As Cr Zn Cu Ni Cd,在研究区的空间分布差异性较大;玉米籽实积累系数均值由小到大依次为Cr As Ni Cd Cu Zn,在的空间分布差异性相对较小。(3)吉林省中部黑土区的玉米籽实重金属元素积累程度均较低,在未发生土壤重金属元素污染的清洁土壤中,Cu与Zn对于玉米植株来说,属于必需营养元素范畴;重金属元素中Cd的有效系数大,作物可食部分积累程度较高,应注意其预防与治理工作; As与Cr的有效系数较小,可能是导致其在玉米籽实中积累程度较低的主要影响因素之一; Ni在土壤中有效态转化程度较高,玉米籽实Ni吸收量相对较低。(4)多数重金属元素在玉米籽实中的累积程度与其在土壤中的有效系数呈正相关关系。     

武汉市东湖沉积物的磁性特征与重金属含量之间的关系

对武汉市东湖主湖区的郭郑湖和塘林湖114个沉积物样品的磁化率与代表性样品的频率磁化率系数、磁滞回线参量和重金属元素进行系统分析, 综合区域环境背景, 探讨应用岩石磁性方法技术评价大型城市内陆湖泊沉积物污染程度的可行性及其效果.结果表明, 在主成分中, 郭郑湖沉积物没有一个主成分占绝对优势, 仅有少数重金属元素含量与磁化率相关, 磁化率χ与重金属富集强度的相关性较差; 而塘林湖沉积物有一个“工业源”的主成份占绝对优势, Fe (全铁)、Co、V、Mn、Ti、Ba、Cr、Ni、Cu等元素与饱和等温剩磁SIRM、χ关系密切(相关系数大于0.87).郭郑湖与塘林湖的沉积物的饱和等温剩磁与重金属富集强度的相关程度高于磁化率, 因此, 可以用其(SIRM) 作为环境污染程度的指示参量.      

Regeneration and Reuse of a Seaweed‐Based Biosorbent in Single and Multi‐Metal Systems

A seaweed‐waste material resulting from the processing of Ascophyllum nodosum was previously shown to be very efficient at removing Zn(II), Ni(II) and Al(III) both in single and multi‐metal waste streams. In this study, the regeneration of the biosorbent using an acid wash resulted in the release of high metal concentrations during multiple desorption cycles. Maximum desorption efficiencies (DE) of 183, 122 and 91% were achieved for Zn(II), Ni(II) and Al(III), respectively, for subsequent metal loading cycles, significantly exceeding the desorption rates observed for conventional sorbents. The regeneration of the sorbent was accomplished with very little loss in metal removal efficiency (RE) for both single and multi‐metal systems. Values of 92, 96 and 94% RE were achieved for Zn(II), Ni(II) and Al(III), respectively, for the 5^th sorption cycle in single metal aqueous solutions. A slight decrease was observed for the same metals in multi‐metal systems with maximum REs of 85, 82 and 82% for Zn(II), Ni(II) and Al(III), respectively. This study showed that the novel sorbent derived from a seaweed industrial waste would be suitable for multiple metal sorption cycles without any significant loss in RE.