低聚合羟基铁离子-蒙脱石复合体吸附磷和氟的实验研究

将提纯的钙蒙脱石与羟基铁离子溶液作用，制备了低聚合羟基铁-蒙脱石复合体。在实际土壤的酸度(pH=4～8)和温度(t=34～50℃)条件下，进行了低聚合羟基铁-蒙脱石复合体吸附P和F的实验，探讨了复合体的P和F吸附能力与pH值、温度、吸附时间、P和F的初始浓度、离子强度间的关系，并与蒙脱石和含水氧化铁的P和F吸附行为进行了对比。研究表明，在实验条件下，低聚合羟基铁-蒙脱石复合体对磷具有明显的亲合力，对氟的亲合力较低，只略高于蒙脱石原样。低聚合羟基铁-蒙脱石复合体对P和F的吸附，特别是对磷的吸附行为对该元素在土壤中的迁移过程有重要影响，成果对土壤学和环境学研究有参考价值。     

低聚合羟基铁-蒙脱石复合体吸附铬酸根的实验研究

摘要：在模拟的酸性土壤条件下，利用制备的低聚合羟基铁蒙脱石复合体对铬酸根进行吸附实验。重点研究了吸附条件对复合体铬吸附能力的影响，对比了蒙脱石和含水氧化铁。结果表明，实验条件下复合体有较强的铬吸附能力，其铬吸附量低于铁沉积物而明显高于蒙脱石。铬初始质量浓度是影响复合体铬吸附量的最主要因素，离子强度次之。吸附时间(12h以上)、温度、pH值对复合体铬吸附量的影响很小；说明在酸性土壤条件下，复合体有强且稳定的铬吸附能力。     

低聚合羟基铁离子-蛭石复合体吸附铬的实验研究

将提纯的镁型蛭石与羟基铁离子溶液作用,制备低聚合羟基铁一蛭石复合体。用化学分析、电子探针分析、粉晶X射线衍射分析、差热分析等手段对蛭石原样、低聚合羟基铁一蛭石复合体进行表征。在模拟实际土壤酸度（pH=4～7）和温度（20℃～40℃）条件下,进行低聚合羟基铁蛭石复合体吸附有害元素铬的实验,探讨复合体的铬吸附能力与pH值、温度、吸附时间、铬初始质量浓度、离子强度间的关系,并与蛭石的铬吸附行为进行对比。研究表明,在实验条件下,低聚合羟基铁一蛭石复合体对铬具有明显的亲和力,低聚合羟基铁蛭石复合体吸附铬的过程有可能是地表岩石和土壤中重要的地球化学过程,是影响铬在地表,特别是土壤中迁移、富集的重要因素．     

磷酸根、铬酸根离子在低聚合羟基铁离子-蒙脱石复合体系中竞争吸附行为的实验研究

在模拟的氧化、酸性土壤条件下，用制备的低聚合羟基铁离子-蒙脱石复合体对磷酸根、铬酸根离子的竞争吸附进行实验研究发现：磷酸根离子和铬酸根离子的不同用量、不同添加顺序对竞争吸附的影响。并与蒙脱石和含水氧化铁对磷酸根离子、铬酸根离子的竞争吸附行为进行了对比。研究表明：在实验条件下，磷酸根离子、铬酸根离子在低聚合羟基铁离子蒙脱石复合体表面存在弱的竞争吸附现象。由于低聚合羟基铁离子蒙脱石复合体具有对磷酸根稍强的亲和性，在竞争吸附中，磷酸根离子处于稍有利的位置。     

聚合羟基铁铝蒙脱石复合体对磷的吸附行为及其动力学

在一定条件下利用钠基化蒙脱石合成了聚合羟基铝-蒙脱石复合体(HyA1-Mt)、2个不同铁含量的聚合羟基铁-蒙脱石复合体(HyFe-Mt)和3个不同Fe:Al摩尔比的聚合羟基铁铝-蒙脱石复合体(HyFeAl-Mt),研究了酸性和弱酸性条件下(pH=3.0～6.5)以上蒙脱石复合体对磷的吸附行为和动力学特征。结果表明,HyFeAl-Mt对磷的吸附容量大于HyA1-Mt和HyFe-Mt复合体,且随着Fe:Al摩尔比的增大,对磷的吸附容量依次增加。随pH升高,蒙脱石复合体对磷的吸附量容量变小。但随Fe:Al摩尔比增大,HyFeAl-Mt复合体零电荷点(pHZPC)升高,pH对磷的吸附的影响越来越小,HyFe-Mt对磷的吸附几乎不受pH的影响。随Fe:A1摩尔比的增大,HyFeAl-Mt对磷的吸附能力增强,铁含量是磷吸附量的重要控制因素。磷在各蒙脱石复合体上的吸附实验数据可很好地用Langmuir吸附等温方程拟合。磷在各蒙脱石复合体上的吸附动力学过程可分为快速和慢速两个过程,快速过程中的动力学受铁含量影响明显。动力学数据可同时用准二级动力学方程和Elovich方程拟合。     

铬酸根离子在羟基铁离子一蒙脱石体系中的吸附行为研究

采矿，电镀，制革等行业废物排放及含Cr矿物风化可造成一些地区土壤和地下水的Cr污染，Cr主要以三价和六价形式存在，其中Cr(Ⅵ）有强的迁移能力，对动植物均有很强的毒害性。研究了在氧化，酸性条件下，土壤及土壤溶液中的蒙脱石和羟基铁离子共存时对铬酸根离子（主要以HCrO4^2-)和CrO4^2-等Cr(Ⅵ）形式存在）的吸附行为，进行了蒙脱石，羟基铁离子，Cr(Ⅵ）离子添加顺序不同的3个系列的实验，重点研究了Cr的初始质量浓度，溶液pH值，环境温度，吸附时间，溶液离子强度对3个系列Cr吸附行为的影响，并与羟基铁离子体系进行了对比。结果表明，蒙脱石－羟基铁离子体系的Cr吸附能力明显强于蒙脱石而低于羟基铁离子，其Cr吸附率随Cr初始质量浓度，温度的升高和吸附时间的延长而降低，随离子强度的升高而升高，而pH值对不同系列的Cr吸附率有不尽相同的影响。     

低分子有机酸对聚合羟基铁铝-蒙脱石复合体吸附磷的影响

在一定条件下,利用钠基化蒙脱石(Na-Mt)合成聚合羟基铁铝-蒙脱石复合体(HyFeAl-Mt),M3+/Mt比为10mmol/g,Fe3+/Al3+摩尔比分别为0.1、0.2和0.5。研究了酸性和弱酸性条件下低分子有机酸(以柠檬酸、草酸和苹果酸为代表)及其添加顺序对HyFeAl-Mt复合体吸附磷的影响。结果表明,低分子有机酸对HyFeAl-Mt复合体吸附磷有抑制作用,且随着低分子有机酸浓度的增加愈加明显,酸性条件下的抑制作用比弱酸性条件下明显;低分子有机酸羧基个数越多、分子结构越大,对HyFeAl-Mt对吸附磷的影响越大;酸性环境中低分子有机酸与磷共存时,磷吸附曲线较好地符合Freundlich方程,且其对磷在HyFeAl-Mt0.2上的最大吸附量影响较小;磷与低分子有机酸的添加顺序不同也影响HyFeAl-Mt复合体对磷的吸附。     

氟与聚合羟基铝-蒙脱石复合体相互作用机理及土壤环境意义

在一定条件下利用钠基蒙脱石 (Na- Mt)合成了 OH/Al比为 1.6的聚合羟基铝-蒙脱石 (HyAl- Mt)复合体,并研究了弱酸性和强酸化条件下 HyAl- Mt与氟之间的相互作用及土壤环境意义.结果表明, pH在 5.0～ 9.0之间时, HyAl- Mt对氟的吸附受 pH影响小;当 pH < 4.5时,吸附能力随 pH减小迅速增大. pH 6.62时, HyAl- Mt对氟的吸附主要是络合交换机制,而 pH 3.02及高氟浓度条件下是表面吸附、矿物溶解及共沉淀-卷扫等协同作用机制,并使 HyAl- Mt具有异常高的氟去除能力.与蒙脱石粘土相比, HyAl- Mt的氟吸附能力明显提高,土壤中的 HyAl- Mt组分可有效地降低氟污染土壤中氟的迁移性并减少其生物有效性.在酸性氟污染的土壤中,氟与 HyAl- Mt相互作用还可一定程度抑制土壤的酸化.土壤酸度越大,这种抑制作用越明显.施用合成的 HyAl- Mt 可作为酸性氟污染土壤修复并控制土壤酸化的有效途经之一.     

灌溉对非饱和带中砷迁移转化过程的影响

通过场地灌溉试验,探讨了灌溉活动对非饱和带中砷迁移转化过程的影响机理。结果表明:灌溉过程中非饱和带中砷的迁移转化受多个地球化学过程共同控制,非饱和带pH值、Ec值、SO_4~(2-)和HCO_3~-与As的竞争吸附以及氧化还原条件的波动都会影响土壤孔隙水中砷的质量浓度。灌溉活动导致土壤处于相对还原环境,铁氧化物矿物还原溶解,被吸附或与之共沉淀的砷被释放进入水相,灌溉结束后,土壤逐渐恢复相对氧化环境,重新生成铁氧化物矿物,土壤孔隙水中砷以吸附/共沉淀形式被其固定。因此,通过改变非饱和带氧化还原条件导致铁氧化物矿物的沉淀/溶解是灌溉作用下非饱和带水体中砷迁移转化的主要原因。     

灌溉活动对大同盆地表层土壤中砷迁移的影响

大同盆地是我国原生高砷地下水典型分布区。高砷地下水常被用作灌溉水源,灌溉回流对表层土壤中砷迁移和富集有着重要影响,但具体机制尚不清晰。通过场地灌溉模拟试验,并结合室内分析,探讨了灌溉活动对表层土壤中砷迁移转化的影响机制。结果表明,灌溉回流不仅导致地表土壤载砷量显著增加,而且引起潜水位快速上升。近地表还原性环境的强化使得含砷铁氧化物还原溶解增强,从而导致了砷的释放。此外,土壤孔隙水离子强度增加促进了离子交换态砷的迁移。灌溉停止后,伴随潜水位回落,氧化环境的增强有利于结晶态铁氧化物的形成,水砷通过吸附和共沉淀作用重新被铁氧化物固定。因此,高砷地下水灌溉通过改变近地表氧化还原环境可促进砷的迁移,砷和铁的输入最终导致表层土壤总砷和铁含量增加。     

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.     

Late Wuchiapingian (Late Dzhulfian,early Late Permian) limestone olistolites within the Tertiary flysch of Glypia Unit (Mount Parnon,central–eastern Peloponnesus,Greece)

Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931.     

PALEONTOLOGY

正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.)     

GEOCHEMICAL EXPLORATION

正20141719 Chen Zhijun(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China);Chen Jianguo Automated Batch Mapping Solution for Serial Maps:A Case Study of Exploration Geochemistry Maps(Journal of Geology,ISSN1674-3636,CN32-1796/P,37(3),2013,p.456-464,2 illus.,2 tables,10 refs.)     

MICROPALAEONTOLOGY

正20140962 Chen Fenning(Xi’an Institute of Geology and Mineral Resources,Xi’an710054,China);Chen Ruiming Late Miocene-Early Pleistocene Ostracoda Fauna of Gyirong Basin,Southern Tibet(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,87(6),2013,p.872-886,6illus.,56refs.)     

PETROLOGY

正1.IGNEOUS PETROLOGY20142008Cai Jinhui(Wuhan Center,China Geological Survey,Wuhan 430205,China);Liu Wei Zircon U-Pb Geochronology and Mineralization Significance of Granodiorites from Fuzichong Pb-Zn Deposit,Guangxi,South China(Geology and Mineral Resources of South China,ISSN1007-3701,CN42-1417/P,29(4),2013,p.271-281,7illus.,     

ENVIRONMENTAL GEOLOGY

正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an