生活垃圾焚烧飞灰矿物学特性及重金属分布

生活垃圾焚烧飞灰的矿物学特性是飞灰中重金属赋存环境的直观反映,与重金属在处置环境中的释放和迁移行为密切相关.为掌握重金属在生活垃圾焚烧飞灰中的分布规律,结合X射线衍射、扫描电镜等常规矿物学研究工具及矿物解离分析系统对飞灰的矿物学宏观属性和微观属性进行全面测试.结果表明,飞灰是由矿物相和非矿物相组成,两者之间紧密连生,主要矿物相包括氯盐和方解石、氢氧钙石等多种含钙矿物.重金属元素在飞灰中主要以3种形式存在:均匀分布在无定形的非矿物组分中,以同晶置换赋存在方解石等矿物中以及吸附在特殊矿物如石英、赤铁矿等表面.难挥发性重金属Cu和Cr绝大部分分布在非矿物相中;半挥发性重金属Zn和Cd各有43.92%和60.61%的含量分布在矿物相中,其中,方解石对Cd、赤铁矿对Cr及硅酸盐对Zn存在较强的富集作用.     

Application of radiometric analysis in the study of provenance and transport processes of Brazilian coastal sediments

Natural gamma radiation of beach sand deposits was measured along the south coast of Rio de Janeiro State, Brazil, with the aim of studying the provenance and transport processes of sediments in this area. Concentrations of thorium, uranium and potassium were evaluated using γ-ray spectrometry and a behavioral study of eTh/eU and eTh/K cross plots was performed, reflecting the mineralogical properties of beach sands, as well as their history of transport and sorting processes. The results show that such technique can be efficiently used to map heavy mineral distributions and to distinguish the different origins of coastal sediments disclosing the influence of nearby rivers.     

Influence of Suspended Clay Minerals and Humic Matter on the Solid Phase Extraction Efficiency of Selected Pesticides from Water

The purpose of this investigation was to determine the influence of humic acids (HA) and Ca-montmorillonite (CaM) on the solid-phase extraction (SPE) efficiency of atrazine, alachlor and α-cypermethrin from water samples at various pH-values. The nature and intensity of binding of the studied pesticides to CaM were determined by X-ray diffraction analysis and termogravimetric analysis (TGA) test. The studied pesticides eluted from discs were analysed by thin-layer chromatography (TLC). The effects of CaM and humic acid were generally pH-dependent and acted independently in extraction efficiency influence. Lower recovery of pesticides was observed at higher pH values when CaM was ≥0.1 g and was attributed to greater dispersion of clay, increased surface area and subsequent adsorption. Concentrations of dissolved organic carbon (DOC) in humic acid had less effect on the extraction efficiency when water was at pH 8 compared to water at pH 2, which was probably due to greater nonpolar interactions of the pesticides to the charge-neutralized humic acid molecule.     

The possible association between selected sediment characteristics and the occurrence of benthic macroinvertebrates in a minimally affected river in South Africa

Forty-two families of which the vast majority associated with particles >2000?µm were found. Sediment particle sizes <2000?µm had a detrimental effect on biodiversity. The highest biodiversity was recorded at sites characterised by riffle and run habitats. Although relatively high concentrations of selected metals were present in the sediment, it was largely from geological origin and most probably not bioavailable. No significant correlation was demonstrated between variation in temperature, pH, and electrical conductivity and diversity and abundance of macroinvertebrates. Therefore, it can be concluded that, under these conditions, sediment particle size and biotope availability played a decisive role on the distribution and abundance of macroinvertebrate taxa.     

有色金属国际价格波动的影响因素研究

有色金属作为国际上流通量较大的大宗产品,近年来其价格的频繁剧烈波动受到学界和业界的高度关注。从有色金属国际贸易的交易量数据看,中国、美国、巴西等20个国家是有色金属国际贸易的主体,贸易量较大的是铜、铝、铅、锌四种有色金属。本文选取了国际贸易中铜、铝、铅、锌四种有色金属的主要进口国和出口国,在已有研究的基础上,从供需、实体经济和货币金融三个维度选取变量,运用国家之间构成的面板数据,建立PVAR模型,分析四种有色金属价格的波动及其影响因素;通过铜、铝、铅、锌四种有色金属价格的脉冲响应函数,比较分析铜、铝、铅、锌四种有色金属价格波动影响因素的不同。研究发现:(1)铜、铝、铅、锌四种有色金属价格波动均受国内生产总值和货币供应量的影响,供需因素对有色金属价格产生长期的影响,货币供给量对有色金属价格的影响短暂而剧烈;(2)国内生产总值和贸易量与铜价的波动密切相关,货币供应量和消费者价格指数与铝、铅、锌价格的波动密切相关;(3)有色金属主要贸易国的各个变量对铜、铝、铅、锌价格波动的贡献程度不同。铜贸易国的贸易量对铜价波动的贡献度要高于其他有色金属贸易国家;铝、铅、锌贸易国家的金融因素对铝、铅、锌价格的影响要强于铜贸易国家。最后,本文从进口国角度对中国有色金属进口提出了建议:中国是铜、铝、铅、锌四种有色金属的最大进口国,应密切关注有色金属价格走势,建立健全有色金属价格的实时监测和预警机制,加快对有色金属价格波动的反应速度,利用金融手段避险趋利。     

封存过程中CO2流体与煤中矿物作用关系研究进展

利用深部煤层封存二氧化碳(CO2),既能减排主要人为温室气体CO2,又能同步开采煤层气(主要成分为甲烷,即CH4)。在适宜CO2封存的含煤储层条件下,CO2属于超临界流体,其易与煤中部分无机矿物发生作用,进而改变煤的理化性质,最终影响煤层的CO2封存效果。为此,归纳了煤中易与CO2发生作用的矿物分布特征,分析了CO2与矿物间的作用规律及其对煤理化性质的影响,并指出了后续研究方向。结果表明,煤中易与CO2流体发生作用的无机矿物主要包括碳酸盐矿物和黏土矿物。上述矿物的分布与煤变质程度和沉积环境有关。在封存过程中,超临界CO2流体与煤中矿物间的作用会改变煤体孔隙结构、煤的CO2吸附能力和含煤储层渗透率。针对CO2与煤中矿物的作用关系,后续需开展以下研究:CO2流体与煤中矿物之间的微观作用机理;CO2流体与煤层顶底板中主要无机矿物的作用规律;实际储层条件(温度、压力和地应力等)对CO2与矿物之间作用关系的影响;CO2与矿物之间的相互作用对同步采收CH4的影响。     

基于3S技术的矿产资源开发景观格局动态变化研究——以木里县梭罗沟金矿改扩建工程为例

本文在阐述3S技术特点的基础上,以四川省木里县梭罗沟金矿改扩建工程所在地的梭罗沟和如米沟为研究区,介绍了3S技术在景观格局信息提取的技术要求、数据收集和工作流程,并对研究区景观格局的提取结果进行了动态变化预测与分析。实例研究证明,3S技术是景观生态学研究的重要技术工具,应用3S技术开展矿产资源开发景观格局动态评价,可以准确、快速地提取景观格局的主要特征指标,掌握景观格局现状、预测其动态变化特征、揭示其变化规律,满足区域景观格局研究的要求。本研究方法适用于生态类建设项目或区域开发规划的景观格局中短期动态预测研究,不宜用于景观格局长期的动态预测。     

碳酸盐-硫酸盐矿物强化垃圾渗滤液厌氧处理研究

厌氧消化通常是垃圾渗滤液生物处理的首要环节,但处理效率不高.本研究尝试通过添加碳酸盐、硫酸盐等矿物来提高垃圾渗滤液的厌氧转化效率.研究共设置5组厌氧生物反应器,包括投加硬石膏、方解石、石膏、白云石的反应器及空白对照,考察添加矿物对垃圾渗滤液厌氧消化的影响.从实验结果可以看出,添加矿物的反应器中COD的去除率可以达到75%左右,而空白对照组去除率尚不足60%,添加矿物反应器甲烷产量显著高于对照.从反应器中的p H变化可以看出,矿物的添加可以提高溶液中的p H.研究结果表明,添加碳酸盐/硫酸盐矿物对垃圾渗滤液中的有机物厌氧消化过程具有重要的促进作用.     

垃圾填埋场甲烷厌氧氧化作用研究进展

垃圾填埋场是温室气体甲烷的重要人为排放源之一,垃圾分解产生的甲烷会发生垂向和侧向迁移,并被氧化固定在垃圾填埋场中。研究显示与硫酸盐还原作用耦合的甲烷厌氧氧化(AOM)作用在垃圾填埋场内及其渗滤液羽状体中均可发生,形成自生碳酸盐和硫化物等沉积。因此,AOM作用是垃圾填埋场甲烷减排的重要途径之一。然而只运用气体地球化学方法与技术难以确定填埋场AOM作用的特征,而填埋场内自生碳酸盐可能保存了AOM作用的信息,但其矿物学、地球化学等特征很少有报导,还有待进一步研究确定。