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。     

美国蒙大拿州Butte、Berkeley矿坑的水文地球化学

蒙大拿州Butte、Berkeley矿坑自1982年停止开采以来,水位每年以近于22m的速度上升。预测表明:如果不及时采取补救措施,到2009年水位可能达到海拔1G82m。另外,在矿区水位连续上升的同时,具有污染水潜在侵入到冲积含水层中的危险及金属元素连续运移而进入Sihver Bow Creek。1987年10月期间的地球化学研究及其水样分析结果表明:Berkely矿坑水属中氧化条件(30米之下Eh为460mv),酸性(pH=3.0)SO_4-Ca-Fe水溶液,主要离子为Al、As、Ca、Cd、Cu、Fe、K、Mg、Mn、Na、SO_4和Zu,这些离子浓度从矿坑表面到底部其浓度明显增大。As主要为As(v),总金属浓度达到1mg/l,在上部3米层中,Fe则为Fe(Ⅲ),3m层之下为Fe(Ⅱ),浓度高达1000mg/l,在130m深处的含水层中,水中的硫酸浓度高达mg/L。而在此深度上,铜和锌的总浓度分别为202和512mg/L。为了检验野外测定的Eh值,根据Fe(Ⅱ)/Fe(Ⅲ)电偶利用MINTEQ求得理论Eh值。计算结果表明:当Fe(Ⅱ)和Fe(Ⅲ)浓度大于0.25mg/L及其低浓度物种的最低浓度至少占总浓度的5％时,Fe(Ⅱ):Fe(Ⅲ)比值代表体系的Eh值。把数据代入地球化学计算模型PHREEQE,进而评价把选矿厂所排出的碱性尾矿溶液加入酸性水体而补救酸性水体的可能性。本文评价了五种情况,两种封闭体系(P_(co_2~-)不固定),三种为开放体系(P_(co_2)=10~(-3·5))。可能的固体矿物包括Fe(OH)_3,石膏(CaSO_4·2H_2O)、斜铝矾(AlOHSO_4)和黄钾铁矾(KFe_3(SO_4)_2(OH)_6]。按碱性溶液与酸性溶液3:1的体积比把碱性溶液加入到酸性溶液而使混合后的溶液pH值达到5.0,根据现在硷性溶液的生产速度,(43.9ml/d),这一选择可能要花费7年时间,此时,液面可能位于冲积层与基岩接触面以上20m左右之处。     

柠檬酸对石灰岩溶蚀动力模拟及岩溶意义

柠檬酸对未清洗的石灰岩颗粒(直径0.15～0.25mm)的溶蚀模拟试验表明,石灰岩溶蚀释放的钙离子量呈对数式增加。随柠檬酸浓度(10mg /l, 50mg /l,100mg /l)的增加,溶液的初始pH依次降低,而石灰岩颗粒溶出的钙离子依次升高,它们分别是去离子水溶出量的1.77、4.25、5.03倍。100mg /l柠檬酸, 10×10- 2atmCO2 和50mg /l柠檬酸+5×10-2atm CO2 对石灰岩微颗粒的溶蚀释放的钙离子量大致相当。这表明有机酸亦是岩溶动力系统重要的驱动力。      

As(Ⅴ)对嗜酸性氧化亚铁硫杆菌混合培养物氧化性能的影响

通过对pH、Eh、溶液中Fe2+浓度的定期监测以及对实验结束时生成沉淀的XRD、SEM和元素能谱扫描等手段,对比研究了不同初始浓度的As(Ⅴ)对Fe2+的化学氧化和嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans)氧化的影响, 同时就As(Ⅴ)在实验体系中固液相之间的分配行为进行了分析.结果表明,Fe2+的化学氧化速率极低,最终氧化率低于8%,As(Ⅴ)的浓度对Fe2+的化学氧化没有影响.有A. ferrooxidans的实验体系,100 mg/L As(Ⅴ)对Fe2+的氧化具有一定的促进作用.当As(Ⅴ)浓度为500 mg～1 g/L时,Fe2+的氧化率在约60 h左右即可达到100%;但4g/L的As(Ⅴ)则会明显抑制Fe2+的氧化,Fe2+的完全氧化大约需要106 h.体系中初始的100 As/(As+S)(摩尔比)会对沉淀物的物相及结晶程度造成一定影响.As(Ⅴ)浓度为0 g/L时,微生物体系中生成的固体沉淀物黄钾铁矾的特征峰明显,随着As(Ⅴ)浓度的提高,沉淀物的结晶程度逐步下降,至4 g/L时沉淀物全部为无定形.元素能谱扫描检测到有大量的As(Ⅴ)存在于固体沉淀物中,表明在Fe2+的氧化过程中,As(Ⅴ)可能会以吸附或共沉淀的形式被固定在固相沉淀物中,这为酸性矿坑水(AMD)地区As(Ⅴ)污染的治理提供了重要的参考.     

以秸秆为微生物碳源的尾矿原位修复:动态实验的初步分析

对铜陵相思谷尾矿砂中的重金属在生物和非生物条件下的淋滤行为进行了研究。设置两个动态反应柱进行实验(实验柱填充尾矿砂+污泥+秸秆,对照柱仅填充尾矿砂,进水SO42-1000 mg/L,pH 7.5)。结果表明,实验初期(0~20 d)实验柱出水重金属浓度明显高于对照柱,归因于柱内微生物加速了矿物分解和重金属的淋滤;此后实验柱出水SO42-浓度逐渐降低,同时Cu2+、Cd2+、Zn2+、总Fe浓度分别降至0.1 mg/L、0.1 mg/L0、.4 mg/L和1 mg/L以下。据此推测,实验柱中出现了微生物作用下的硫酸盐还原作用,生成了可以吸持重金属的硫化物沉淀。研究结果表明,以稻草为碳源、污泥为微生物接种源构建尾矿砂-微生物体系,能够有效还原硫酸盐并去除重金属,该方法可以用于矿山尾矿的原位修复。     

含方解石铜矿石微生物氧化作用的实验研究

矿山固体废物中硫化物经微生物作用形成的酸性矿山排水及其引起的重金属污染是备受关注的环境问题,而岩石和矿石中的方解石能够影响酸性矿山排水的生成和迁移。为了考察方解石对硫化物-微生物氧化作用的影响,开展了系统的模拟实验,利用ICP-AES、XRD、XRF等分析手段,测定了实验溶液的pH值、Eh值、离子浓度和次生沉淀成分。结果表明,在无方解石或方解石含量低时,黄铜矿的微生物氧化过程中,pH值下降、Eh值上升,有多种重金属离子进入溶液,并生成大量黄钾铁矾、自然硫等次生沉淀。添加过量方解石能有效中和氧化过程产生的酸并能显著抑制氧化菌的活动。因此通过添加碳酸盐矿物的方法可使溶液pH调节至微碱性,降低微生物的活性、阻滞铜矿石的氧化,能够有效降低重金属的释放。     

典型岩溶区硫化物矿床——广西贵港锡基坑铅锌矿开采的生态效应

硫化物矿床开采的环境污染效应与围岩性质有密切关系,碳酸盐岩类围岩能在一定程度上中和硫化物矿床开采形成的酸性矿山废水(AMD),从而降低酸性废水及重金属的污染危害。以广西贵港锡基坑硫化物矿床为研究区,系统采集了矿石、尾矿、废水、地表水、悬浮物、底积物及地下水样品,测定了重金属含量及pH值等理化指标,研究了岩溶区硫化物矿床开采的生态效应,以期为类似碳酸盐岩地区硫化物矿床开采的环境污染与生态危害评价、矿山环境保护提供科学依据。研究取得结论如下:(1)尾矿及废水样品中Cd、Pb等重金属含量较高,对矿区地表水及地下水质量构成一定的潜在风险;(2)硫化物矿床开采过程释放的重金属元素对矿区地表水有较显著影响,由于碳酸盐岩的中和作用,流出矿区后地表水、悬浮物及底积物中重金属含量迅速降低,重金属潜在风险处于轻微等级;(3)富含Cd、Pb等重金属的矿坑酸性积水,下渗过程中与碳酸盐岩中的Ca~(2+)、CO_3~(2-)、HCO~-_3发生中和反应而沉淀,矿区地下水环境质量良好,除了尾矿库、矿坑水周边存在少量超标样品外,矿区周边村镇地下水质均未受到明显的采矿污染影响。可见,碳酸盐岩类围岩是重金属元素迁移的天然地球化学障,能有效降低硫化物矿床开采的环境污染风险。     

氧化还原生物对石门雄黄矿区尾矿砷释放行为研究

对石门4处典型不同种类的含砷尾矿进行样品采集,并采用1种氧化菌(氧化亚铁硫杆菌,Thiobacillus ferrooxidans,简称T.f)和2种还原菌(硫酸盐还原菌,sulfate reducing bacteria,简称SR;嗜酸铁还原菌,Acidiphilium cryptum JF-5,简称JF-5)分别对其进行作用,据此研究生物还原和氧化条件下原生和次生含砷矿物的释砷情况,进而确定潜在的释砷风险。ICP-OES定量分析显示,3种细菌作用后,雄黄矿和雌黄矿的砷释出浓度都不断升高。168 h氧化菌T.f作用后的砷释出顺序为雌黄矿>淋滤液次生含砷矿物>雄黄矿>含砷夹矸尾矿。LC-AFS原子荧光分析释出液砷形态结果表明:①T.f作用后,雄黄矿和雌黄矿表现出非常明显的差异;1.5 h作用后4种含砷矿物释放As(Ⅴ)的顺序为含砷夹矸尾矿>雄黄矿>淋滤液次生含砷矿物>雌黄矿;②2种还原菌作用后,SR更能促进雌黄矿释放的As(Ⅲ),其释放量是JF-5的2倍;雌黄矿释出As(Ⅲ)在168 h达到20.64 mg/L(SR)和9.54 mg/L(JF-5)。96 h SR作用后4种含砷矿物释放As(Ⅲ)的顺序为雌黄矿>淋滤液次生含砷矿物>含砷夹矸尾矿>雄黄矿。96 h JF-5作用后4种含砷矿物释放As(Ⅲ)的顺序为雄黄矿>雌黄矿>含砷夹矸尾矿>淋滤液次生含砷矿物。     

喀斯特地区煤矿酸性废水(AMD)综合治理研究

贵州重安江流域皮陇河源头区采矿形成的煤矿酸性废水(AMD)对地表及地下水造成严重污染。由于地处碳酸盐岩发育区,岩溶作用极其发育大大增加了AMD治理难度。基于喀斯特地区煤矿AMD治理项目实践,根据AMD产生和污染机理,结合区内地质环境条件和先进生态修复理念,采用生态修复综合技术对区内一系列生态环境问题进行系统治理：源头区采用“主动治理”技术,使用生石灰对AMD进行中和,对煤矸石等尾矿进行无害化封存填埋的同时修复相对隔水层杜绝源头AMD产生;末端采用“被动治理”技术综合应用,使用石灰石修筑可渗透反应墙、沉淀反应池、可渗透反应岸和生态湿地等工程,对AMD系统收集、逐级净化;同时在人工湿地中利用微生物、植物和水生动物联合作用对水体重金属离子逐级去除并恢复水生生态系统功能。治理后水体pH值由2.54～3.90提升至7.10～8.19,多呈弱碱性,Fe离子浓度由137.51mg/L下降至0.24mg/L,净化率达97.76%,重金属离子Hg、Zn、As等均得到净化。目前治理工程运行稳定且寿命随时间推移而延长,这一实践经验对喀斯特地区煤矿AMD治理具有重要推广应用价值。     

绿泥石包壳对碎屑岩储层物性的影响及其形成环境--以鄂尔多斯盆地大牛地气田上古生界为例

以大牛地气田含绿泥石胶结物样品为研究对象,结合国内外研究现状,研究绿泥石包壳的成因及其对储层物性的影响,并探讨其环境指示意义.大牛地气田的绿泥石包壳形成于成岩作用早期,厚10~20 μm,由原生粒间孔的边缘向中心晶形渐好,颗粒渐大.据铁质来源绿泥石包壳可分为原地和异地成因,原地成因由先体黏土矿物和岩屑溶解未排出的富铁流体生成,一般以混层黏土和晶体较小的包壳形式存在;异地成因是富铁矿物及岩屑溶蚀、溶解形成的富铁流体通过河流异地絮凝沉淀生成,结晶充分、晶形好.绿泥石包壳的储层保护机理为:①抑制石英次生加大;②增加矿物颗粒间抗压实强度,抑制压溶作用;③抑制碳酸盐胶结,促进溶蚀作用.大牛地气田的绿泥石包壳主要发育于盒一段(63%)和山二段,当其含量在15%以下时,孔隙度随绿泥石含量的增高呈线性递增.绿泥石包壳可作为三角洲(辫状河三角洲)前缘水下分流河道(水下辫状河道)等强水动力条件的微观相标志.     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

NONMETALS DEPOSITS

正20141520 Bo Ying(Key Laboratory of Metallogeny and Mineral Assessment,MLR,Beijing 100037,China);Liu Chenglin Saline Spring Hydrochemical Characteristics and Indicators for Potassium Exploration in Southwestern and Northern Tarim Basin,Xinjiang(Acta Geoscientica Sinica,ISSN1006-3021,CN11-3474/P,34(5),2013,p.594-602,5 illus.,3 tables,28 refs.)     

MATHEMATICAL GEOLOGY

正20141243Chen Ge(Hangzhou Research Institute of Petroleum Geology,PetroChina,Hangzhou 310023,China);Si Chunsong Study on Sedimentary Numerical Simulation Method of Fan Delta Sand Body(Journal of Geology,     

PROSPECTING EXPLORATION

正20142599Chen Sanming(Guangxi Key Laboratory of Concealed Deposits Exploration,Guilin University of Technology,Guilin541004,China);He Yuzhou Block Model and Reserves Estimation of Panzhihua Iron Deposit Based on 3D Geological Modeling(Journal of Guilin University of Technology,ISSN1674-9057,CN45-1375/N,33(4),2013,p.610-615,9illus.,1table,15refs.)     

STRUCTURAL GEOLOGY

正20140594 Bai Daoyuan(Hunan Institute of Geology Survey,Changsha 410016,China);Zhong Xiang Faults in the Jingzhou Basin and Their Tectonic Settings(Geotectonica et Metallogenia,ISSN1001-1552,CN44-1595/P,37(2),2013,p.173-183,6illus.,59refs.)Key words:basin evolution,tectonic setting,South China In the Upper Paleozoic and Jurassic se-     

STRUCTURAL GEOLOGY

正20141912Cao Hui(State Key Laboratory for Continental Tectonics and Dynamics,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China)Gravitational Collapse and Folding during Orogenesis:A Comparative Study of FIA Trends and Fold Axial Plane Traces(Geology in China,ISSN1000-3657,CN11-1167/P,40(6),2013,p.1818-1828,9illus.,35refs.,with