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Rare earth element enrichment in sedimentary phosphorites formed during the Precambrian-Cambrian transition,Southwest China

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Geoscience Frontiers 2024年第2期15卷 334-348页

作者： Jieqi Xing Yuhang Jiang Haiyang Xian Wubin Yang Yiping Yang Hecai Niu Hongping He jianxi zhu CAS Key Laboratory of Mineralogy and Metallogeny Guangdong Provincial Key Laboratory of Mineral Physics and MaterialsGuangzhou Institute of GeochemistryChinese Academy of Sciences(CAS)Guangzhou 510640China CAS Center for Excellence in Deep Earth Science Guangzhou 510640China University of Chinese Academy of Sciences Beijing 100049China

Numerous sedimentary phosphorites in Southwest China were formed around the Precambrian–Cambrian transition(PC–C),including the upper Ediacaran Doushantuo Formation and lower Cambrian Gezhongwu Formation.The Gezhongwu phosphorites in Zhijin exhibit marked rare earth element(REE)enrichment(>1000 ppm),and may represent new REE resources.Although the main characteristics of the Gezhongwu phosphorites have been well constrained,the REE enrichment mechanisms remain unclear.We undertook a comparative study of three typical sedimentary phosphorites with variable REE contents formed at the PC–C transition in central Guizhou Province,Southwest China.These include sections A and B of the Doushantuo phosphorites(560±8 Ma)from the Weng’an area(i.e.,WA-A and WA-B),and the Gezhongwu phosphorites(527±24 Ma)from the Zhijin area(ZJ).The phosphorites were investigated with state-of-the-art macroscale to nanoscale analytical techniques.In contrast to the extraordinary REE enrichment in the ZJ phosphorites(average RREE=1157 ppm),the phosphorites in WA-A(average RREE=234 ppm)and WA-B(average RREE=114 ppm)are REE-poor.Elemental mapping by laser ablation–inductively coupled plasma–mass spectrometry,along with transmission electron microscopy analyses,showed the REEs in the studied phosphorites are hosted in nanoscale francolites.The 87Sr/86Sr and Y/Ho ratios of the francolite grains indicate that greater terrigenous input may have led to more REE enrichment in the WA-A than WA-B phosphorites,but this cannot explain the extraordinary REE enrichment in the ZJ phosphorites.The F/P_(2)O_(5)values of the francolite grains in the ZJ phosphorites(~0.097)are higher than those in the WA-A(~0.084)and WA-B(~0.084)phosphorites,and the grain size of the francolite in the ZJ phosphorites(~89.9 nm)is larger than those in the WA-A(~56.6 nm)and WA-B(~57.4 nm)phosphorites,indicative of more intense reworking of the ZJ than WA phosphorites during early diagenesis.A plot of Nd concentration versus Ce/Ce^(*)reveals that lower sedimentation rates characteri

关键词： REE enrichment Francolite,phosphorites Sedimentary reworking Rate of sedimentary

Interaction of polyhydroxy fullerenes with ferrihydrite：adsorption and aggregation

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Journal of Environmental Sciences 2018年第2期30卷 1-9页

作者： Jing Liu Runliang zhu Tianyuan Xu Mingwang Laipan Yanping zhu Qing Zhou jianxi zhu Hongping He Key Laboratory of Mineralogy and Metallogeny Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangdong Provincial Key Laboratory of Mineral Physics and Material Research & Development Guangzhou 510640 China University of Chinese Academy of Sciences Beijing 100049 China

The rapid development of nanoscience and nanotechnology, with thousands types of nanomaterials being produced, will lead to various environmental impacts. Thus,understanding the behaviors and fate of these nanomaterials is essential. This study focused on the interaction between polyhydroxy fullerenes（PHF） and ferrihydrite（Fh）, a widespread iron（oxyhydr）oxide nanomineral and geosorbent. Our results showed that PHF were effectively adsorbed by Fh. The adsorption isotherm fitted the D-R model well, with an adsorption capacity of 67.1 mg/g. The adsorption mean free energy of 10.72 k J/mol suggested that PHF were chemisorbed on Fh. An increase in the solution p H and a decrease of the Fh surface zeta potential were observed after the adsorption of PHF on Fh; moreover, increasing initial solution p H led to a reduction of adsorption. The Fourier transform infrared spectra detected a red shift of C–O stretching from 1075 to 1062 cm-1 and a decrease of Fe–O bending, implying the interaction between PHF oxygenic functional groups and Fh surface hydroxyls. On the other hand, PHF affected the aggregation and reactivity of Fh by changing its surface physicochemical properties. Aggregation of PHF and Fh with individual particle sizes increasing from 2 nm to larger than 5 nm was measured by atomic force microscopy. The uniform distribution of C and Fe suggested that the aggregates of Fh were possibly bridged by PHF. Our results indicated that the interaction between PHF and Fh could evidently influence the migration of PHF, as well as the aggregation and reactivity of Fh.

关键词： Nanoparticles Polyhydroxy fullerenes Ferrihydrite Adsorption Aggregation

TiO_2/Schwertmannite nanocomposites as superior co-catalysts in heterogeneous photo-Fenton process

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Journal of Environmental Sciences 2019年第6期31卷 208-217页

作者： Yanping zhu Chun Zeng Runliang zhu Yin Xu Xingyan Wang Huijun Zhou jianxi zhu Hongping He CAS Key Laboratory of Mineralogy and Metallogeny Guangdong Provincial Key Laboratory of Mineral Physics and Material Research and Development Guangzhou Institute of Geochemistry Chinese Academy of Sciences University of Chinese Academy of Sciences School of Environmental Science and Technology Xiangtan University

The heterogeneous photo-Fenton reaction is an effective technique in combating organic contaminants for both soil and water remediation,and extensive studies have focused on enhancing its efficiency and reducing its costs.In this work,we developed novel photoFenton catalysts by simply milling commercially available TiO_2(P25)with Schwertmannite(Sh),a natural iron-oxyhydroxysulfate nanomineral.We expect that the photo-generated electrons from TiO_2could continuously migrate to Sh,which then could enhance the separation of electron-hole pairs on TiO_2and accelerate the reduction of Fe(III)to Fe(II)on Sh,leading to high degradation efficiency of the target organic contaminants.SEM and TEM results showed the distribution of TiO_2on Sh surface for the nanocomposites(TiO_2/Sh).Under simulated sunlight irradiation,the much higher content of Fe(II)was determined on TiO_2/Sh than on Sh via a common method in the iron ore,and the consumption of H_2O_2and the production of·OH were more significant in the TiO_2/Sh system than those in the TiO_2and Sh systems.These results well support our hypothesis that the photo-generated electrons could migrate from TiO_2to Sh on the composites,and can also explain the much higher degradation efficiency of Rhodamine B(RhB)in the TiO_2/Sh system.Besides,TiO_2/Sh had lower Fe dissolution as compared with Sh,and retained high catalytic stability after four repeated cycles.Above merits of the TiO_2/Sh composites,in combining with their simple synthesis method and low-cost property,indicated that they should have promising applications as heterogeneous photo-Fenton catalysts.

关键词： Photo-Fenton reaction Semiconductor Schwertmannite Advanced oxidation

有机蒙脱石/壳聚糖气凝胶的制备及有机污染控制应用

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地球化学 2024年第1期53卷 142-152页

作者：刘相君陈情泽朱润良朱建喜中国科学院广州地球化学研究所矿物学与成矿学重点实验室/广东省矿物物理与材料研究开发重点实验室广东广州510640 中国科学院大学北京100049

以蒙脱石(Mnt)为主要原料,十六烷基三甲基溴化铵(C16)为疏水改性剂,壳聚糖(CS)为交联剂,通过超声法、溶胶凝胶法和冷冻干燥制得有机蒙脱石/壳聚糖气凝胶(CS-C16Mnt)。采用扫描电子显微镜(SEM)、X射线衍射(XRD)、傅里叶红外光谱(FT-IR)... 详细信息

以蒙脱石(Mnt)为主要原料,十六烷基三甲基溴化铵(C16)为疏水改性剂,壳聚糖(CS)为交联剂,通过超声法、溶胶凝胶法和冷冻干燥制得有机蒙脱石/壳聚糖气凝胶(CS-C16Mnt)。采用扫描电子显微镜(SEM)、X射线衍射(XRD)、傅里叶红外光谱(FT-IR)、比表面积及孔结构(BET)等手段对材料进行表征。结果表明,超声溶胀使C16Mnt片层扩张、叠层裂开,CS通过静电作用和氢键与C16Mnt结合,且CS-C16Mnt具有气凝胶典型的三维网络结构。吸附和吸收实验表明,CS-C16Mnt具有良好的有机污染控制能力。当C16Mnt与CS的质量比为10∶1、超声时间为10 min时,处理效果最好,在气相环境中对苯的吸附量达720.9 mg/g,在液相环境中对不同油和有机溶剂的吸收量为14.4~29.0 g/g。此外,CS-C16Mnt具有操作简便、易于回收等优势,是具有应用潜力的有机污染治理材料。

关键词：蒙脱石气凝胶有机改性吸附苯油水分离

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离子吸附型稀土矿床的诱导成矿学研究

大地构造与成矿学 2024年第2期48卷 293-301页

作者：李宁波王焰朱建喜杨武斌中国科学院广州地球化学研究所矿物学与成矿学重点实验室/广东省矿物物理与材料研究开发重点实验室广东广州510640 中国科学院深地科学卓越创新中心广东广州510640 中国科学院大学北京100049

诱导成矿学的核心理念是针对低品位矿石、尾矿和具有成矿潜力岩石中的关键金属资源,通过人工干预手段诱导目标金属元素活化和富集,在有限的时间尺度内形成具有经济价值的可利用资源。离子吸附型稀土矿床是全球稀土资源的主要来源之一,... 详细信息

诱导成矿学的核心理念是针对低品位矿石、尾矿和具有成矿潜力岩石中的关键金属资源,通过人工干预手段诱导目标金属元素活化和富集,在有限的时间尺度内形成具有经济价值的可利用资源。离子吸附型稀土矿床是全球稀土资源的主要来源之一,近年来为全球提供了80%以上的中、重稀土资源供给。该类矿床的形成主要受控于内生稀土初始富集和表生风化淋积成矿两个过程,而后者对于成矿极为关键。由于我国华南地区具有适宜形成离子吸附型稀土矿床的气候条件、大量出露的花岗质岩石及风化壳,因此对该地区开展人工诱导成矿技术研发将具有重要应用前景。通过分析离子吸附型稀土矿床形成的控制因素,预计可选择具有成矿潜力的花岗岩、含稀土风化壳和低品位矿床作为主要诱导成矿对象。通过调控地形地貌、生态、水文和风化壳物理化学条件等加速风化进程,促进稀土元素释放,引导稀土元素定向迁移,并在指定位置进行沉淀成矿,形成具有经济价值的富集稀土的矿体。特别是在该过程中可控制轻重稀土元素的分异,促使其形成富集重稀土的矿体,为解决全球重稀土资源紧缺和保障重稀土资源持续供给提供有效实施方案。因此,对离子吸附型矿床开展诱导成矿学研究具有重要的理论意义和应用价值,可作为诱导成矿学的重点研究方向之一。

关键词：诱导成矿学离子吸附型稀土矿床风化过程稀土元素迁移沉淀

土壤-超积累植物体系中稀土元素的空间富集-分异特征与富集机理

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地球化学 2024年第1期53卷 87-101页

作者：何柳青王园园朱润良朱建喜中国科学院广州地球化学研究所矿物学与成矿学重点实验室/广东省矿物物理与材料研究开发重点实验室广东广州510640 中国科学院大学北京100049

离子吸附型稀土矿是我国南方特色的优质稀土资源,但由于落后的采矿方式和无节制的开采,大量稀土元素(稀土元素+Y,简称稀土元素)被带入环境中,导致稀土矿区周边出现许多环境污染和植被退化问题。乌毛蕨是一种对稀土元素具有较强耐受性和... 详细信息

离子吸附型稀土矿是我国南方特色的优质稀土资源,但由于落后的采矿方式和无节制的开采,大量稀土元素(稀土元素+Y,简称稀土元素)被带入环境中,导致稀土矿区周边出现许多环境污染和植被退化问题。乌毛蕨是一种对稀土元素具有较强耐受性和超强富集能力的蕨类超积累植物,能被用于稀土污染土壤或尾矿的生态修复。本研究以离子吸附型矿区表生土壤上生长的稀土超积累植物乌毛蕨及其根际土为研究对象,通过化学消解和ICP-MS方法测定根际土、根表、根部、叶柄、叶片中稀土元素的含量,分析土壤–植物体系中稀土元素的空间分布、富集与分异特征;采用顺序提取法测定土壤中不同化学形态的稀土元素含量,同时利用微区X射线荧光光谱(μ-XRF)与扫描电镜能谱分析技术(SEM-EDS),阐明乌毛蕨对稀土元素的吸收与富集机理。化学测试结果表明,乌毛蕨对稀土元素有较强的富集和地上转运能力,富集系数(BF)和转移系数(TF)分别为2.61和2.85;植物器官富集能力顺序为:叶片(1750μg/g)>根部(512μg/g)>叶柄(56.5μg/g);植株整体稀土元素配分模式具有与根际土相似的富轻土元素和Ce负异常特征,不同的是,植株整体Eu无异常(根际土δEu=0.51);根际土壤中富集离子交换态的轻稀土离子(34%~64%,(La/Yb)N=2.36),与根系表面呈轻微富轻稀土元素((La/Yb)N=1.29)的现象暗示根际大部分轻稀土元素能以离子形式被根系吸收,重稀土元素与有机配体络合而被吸附在根系表面;稀土元素在向上迁移过程中,(La/Yb)N值下降(叶柄=27.63,叶片=17.17),揭示木质部伤流液的重稀土元素可能比轻稀土元素更容易向上迁移;μ-XRF与SEM-EDS结果显示,乌毛蕨地上部的超富集器官(叶片)将稀土元素主要储存在叶缘的表皮层细胞,且能将大部分非生理需要的稀土元素有效区室化。上述认识揭示了在离子吸附型稀土矿区表生环境中,稀土元素从土壤向植物体内迁移并在地上部富集与分异的过程、规律和主要原因,为今后利用稀土超积累植物实现植物采矿或稀土尾矿生态修复提供科学认知基础。

关键词：离子吸附型稀土矿超积累植物乌毛蕨富集轻、重稀土分异地上部

Phosphorylation of PLIN3 by AMPK promotes dispersion of lipid droplets during starvation

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Protein & Cell 2019年第5期10卷 382-387页

作者： jianxi zhu Mingyang Xu Yi Liu Lisha zhuang Kejun Ying Feng Liu Dan Liu Wenbin Ma Zhou Songyang MOE Key Laboratory of Gene Function and Regulation State Key Laboratory for BiocontrolSchool of Life SciencesSun Yat-sen UniversityGuangzhou 510275China Guangzhou Regenerative Medicine and Health-Guangdong Laboratory(GRMH-GDL) Guangzhou 510530China Verna and Marrs McLean Department of Biochemistry and Molecular Biology Baylor College of MedicineOne Baylor PlazaHoustonTX 77030USA

Dear Editor,Lipid droplets(LDs)are dynamic lipid-storage organelles of storage depots and sources of essential substrates for myriad cellular processes and protect cells from lipotoxicity(Ohsaki et al.,2006).Disrupted LD and fat storage homeostasis has been linked to metabolic diseases such as atherosclerosis,obesity,and type II diabetes(Levin et al.,2001).Structurally,the core of neutral lipids in LDs is surroun ded by a phospholipid mono layer and coated with specific proteins(Storey et al.,2011).Perilipin family of proteins are the predominant LD-associated proteins.

关键词： Phosphorylation PLIN3 AMPK

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光照作用对水铁矿去除Cr(Ⅵ)的影响

地球化学 2024年第1期53卷 153-162页

作者：吕瑛陈情泽朱润良朱建喜何宏平中国科学院广州地球化学研究所矿物学与成矿学重点实验室/广东省矿物物理与材料研究开发重点实验室广东广州510640 中国科学院深地科学卓越创新中心广东广州510640 中国科学院大学北京100049

Cr在环境中释放易导致重金属污染,其所造成的环境危害与Cr存在形态紧密相关。Cr(Ⅵ)多以Cr_(O)_(4)^(2–)或Cr_(2)O_(7)^(2−)形式存在,在水体中具有较高溶解度和迁移性,且具有较大的毒性。水铁矿具有大比表面积和高反应活性,是环境中Cr(... 详细信息

Cr在环境中释放易导致重金属污染,其所造成的环境危害与Cr存在形态紧密相关。Cr(Ⅵ)多以Cr_(O)_(4)^(2–)或Cr_(2)O_(7)^(2−)形式存在,在水体中具有较高溶解度和迁移性,且具有较大的毒性。水铁矿具有大比表面积和高反应活性,是环境中Cr(Ⅵ)的重要吸附剂;同时,水铁矿也是一种天然半导体矿物,在光照诱导作用下可产生光电子并转移电子。然而,水铁矿表面的光化学反应对Cr(Ⅵ)地球化学行为的影响尚不清楚。因此,本研究探讨了光照对水铁矿去除Cr(Ⅵ)的影响。结果表明:在黑暗条件下,水铁矿通过吸附作用去除了57%的Cr(Ⅵ);在光照有氧条件下,水铁矿对Cr(Ⅵ)的去除率上升到67%;在厌氧条件下,光照效应的增强作用更加明显,水溶液中Cr(Ⅵ)几乎完全被去除。结合傅里叶变换衰减全反射红外光谱(ATR-FTIR)和X射线光电子能谱(XPS)分析发现,水铁矿能够快速吸附Cr(Ⅵ),其中有62%的Cr在水铁矿表面被还原,占总去除率的41.5%。因此,光照能够通过还原作用增强水铁矿对Cr(Ⅵ)的去除,从而降低Cr(Ⅵ)的迁移性和环境毒性。本研究为深入认识地表环境中铁(氢)氧化物对氧化还原敏感元素地球化学行为的制约机理提供了新信息。

关键词：光照水铁矿六价铬吸附氧化还原反应

稀土La^(3+)离子在高岭石表面吸附的原位AFM研究

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大地构造与成矿学 2024年第2期48卷 283-292页

作者：冉凌瑜王高锋王迎亚梁晓亮朱润良朱建喜何宏平中国科学院广州地球化学研究所矿物学与成矿学重点实验室/广东省矿物物理与材料研究开发重点实验室广东广州510640 中国科学院深地科学卓越创新中心广东广州510640 中国科学院大学北京100049

离子吸附型稀土矿是我国优势矿产资源,该类型矿床中,稀土元素主要是以离子的形式吸附在高岭石、埃洛石和铁锰氧化物等次生矿物上。本文主要通过原子力显微镜(AFM)的微观区域的力学测量功能,结合DLVO理论,研究原位水环境下稀土La^(3+)对... 详细信息

离子吸附型稀土矿是我国优势矿产资源,该类型矿床中,稀土元素主要是以离子的形式吸附在高岭石、埃洛石和铁锰氧化物等次生矿物上。本文主要通过原子力显微镜(AFM)的微观区域的力学测量功能,结合DLVO理论,研究原位水环境下稀土La^(3+)对高岭石不同表面(Si面和Al面)Stern电位的影响,揭示高岭石对La^(3+)的吸附能力随Si面和Al面表面性质不同而变化。实验结果表明:当La^(3+)浓度从0增加至1.0 mmol/L时,高岭石Si面的Stern电位由−46 mV转变为4 mV,表明高岭石Si面对La^(3+)有吸附作用;而Al面的Stern电位(在28~31 mV之间波动)几乎没有变化,表明高岭石Al面对La^(3+)的吸附作用不强。该研究表明在pH=4~6的风化壳条件下,高岭石Si面对La^(3+)的吸附可能占主导作用,Al面的贡献相对较小。本研究从微观角度揭示了稀土元素在高岭石不同表面的吸附特征,明确了高岭石不同表面对稀土元素吸附的贡献,为阐明风化壳中稀土的富集机制提供信息。

关键词：黏土矿物高岭石稀土吸附 AFM 离子吸附型稀土