Evaluation of contaminants retention in soils from Viamão District, Rio Grande do Sul State, Brazil     

Ronaldo Herlinger Jr  Antonio Pedro Viero 《Environmental Geology》2006,50(1):47-54

Adsorption is one of the most significant processes in the mobility of soluble pollutants in soils. The aim of this work is to characterize and evaluate the adsorption capacity of soils from Viamão District, Brazil. The studied ions were lead_total, copper_total, sulfate, phosphate, and potassium. The soils were mapped by remote sensing and characterized by granulometrical and mineralogical techniques. The adsorption tests were made by the contact of soil samples with aqueous solutions. The soils adsorption capacity presented the following trend: Pb_total>Cu_total≈PO ₄ ³⁻ >K⁺ ≈SO ₄ ²⁺ . Adsorption in the soils is strongly influenced by clay content. The adsorption of phosphate, copper, and lead was accentuated by the presence of organic matter. Phosphate adsorption was controlled by oxides and organic matter. Both potassium and sulfate showed insignificant adsorption in the studied soils.  相似文献   

硅酸盐体系的化学平衡:(3)反应动力学     

马鸿文  戚洪彬  王蕾  聂轶苗  靳昕  王英滨  苏双青 《现代地质》2006,20(4):647-656

通过具体实例,简要介绍了矿物材料学研究中有关反应动力学研究的基本原理,给出了对硅酸盐体系若干典型过程的反应动力学研究结果,包括:(1)高铝粉煤灰-Na2CO3体系的中温烧结反应和钾长石-石膏-碳酸钙体系钾长石的热分解反应;(2)KA lS i3O8-Ca(OH)2-H2O体系钾长石水热分解-雪硅钙石晶化反应;(3)S iO2-A l2O3-CaO体系微晶玻璃的β硅灰石晶化反应;(4)13X微孔分子筛和MCM-41介孔分子筛对Hg2+的吸附反应。反应动力学研究成果可望对矿物材料制备实验方案优化、工业生产过程的条件控制以及改进矿物材料性能提供理论指导。  相似文献   

生烃动力学、同位素动力学方法在烃源岩研究中的应用     

刘大永彭平安  林会喜林玉祥 刘华 《地质通报》2006,25(9):1201-1204

生烃动力学、同位素动力学常用于烃源岩评价、油气源对比研究中.生烃动力学参数结合盆地热史,可恢复烃源岩在任一时代的生烃史,对构造复杂盆地的二次生烃研究具有独特的优势.利用生烃动力学方法可以实现有机质总量的恢复,在此基础上对高-过成熟样品原始有机质丰度是否有必要恢复进行了讨论;而基于生烃动力学的油气源对比综合考虑热史、成藏期次、成藏过程等各种地质参数对烃源岩生烃的影响,是一种动态的研究方法.  相似文献   

Biosorption of mercury(II), cadmium(II) and lead(II) ions from aqueous system by microalgae Chlamydomonas reinhardtii immobilized in alginate beads     

Gülay Bayramoğlu  Ilhami Tuzun  Gokce Celik  Meltem Yilmaz  M. Yakup Arica 《International Journal of Mineral Processing》2006

The potential use of the immobilized microalgae (in Ca-alginate) of Chlamydomonas reinhardtii to remove Hg(II), Cd(II) and Pb(II) ions from aqueous solutions was evaluated using bare Ca-alginate bead as a control system. Ca-alginate beads containing immobilized microalgae were incubated for the uniform growth at 22 °C for 5 days. Effects of pH, temperature, initial concentration of metal ions and biosorbent dosages on the adsorption of Hg(II), Cd(II) and Pb(II) ions were studied. Adsorption of Hg(II), Cd(II) and Pb(II) ions on the immobilized microalgae showed highest values at around pH 5.0 to 6.0. The adsorption equilibrium was represented with Langmuir and Freundlich adsorption isotherms. The adsorption of these ions on the immobilized microalgae followed second-order kinetics and equilibrium was established in about 60 min. The temperature change in the range of 5–40 °C did not affect the adsorption capacities of the immobilized microalgae. The immobilized-algal systems can be regenerated using 2 M NaCl for Hg(II), Cd(II) and Pb(II) ions.  相似文献   

Degradation of Adsorbed Sarin on Activated Carbons: A 31P‐MAS‐NMR Study     

Doron Kaplan  Liora Shmueli  Ido Nir  Daniel Waysbort  Ishay Columbus 《洁净——土壤、空气、水》2007,35(2):172-177

The fate of the OP nerve agent isopropyl methylphosphonofluoridate (sarin) on granular activated and metal‐impregnated activated carbons that are used in gas‐mask filters was investigated by means of ³¹P magic‐angle‐spinning (MAS) NMR spectroscopy. The results show that most of the adsorbed sarin on extensively dried carbons decomposes with a half‐life of 5–12 days. A MAS‐NMR signal of the degradation product isopropyl methylphosphonic acid (IMPA) appears in the spectra of sarin on non‐impregnated carbons. The IMPA signal is not visible in the spectra from metal‐impregnated carbons, probably due to strong binding of the acid molecule to paramagnetic Cr³⁺ and Cu²⁺ ions. Exposure of BPL and ASC carbons to air of 53% relative humidity shortens the degradation time by approximately an order of magnitude. Wetting shortens the half‐life of sarin on BPL carbon to approximately 2 hours.  相似文献   

重庆万盛炼镁用白云岩分解动力学及影响因素的研究     

刘欢  龙思远  周玉乐  杨怀德  游国强 《岩石矿物学杂志》2013,32(6):1001-1005

对重庆万盛地区的白云岩进行了TG-DTG热分解实验,研究其热分解机理和影响该机理的实验因素。结果表明:该地区白云岩热分解过程遵循三维扩散(球形对称,Jander方程)机理,热分解活化能E=357.4 kJ/mol,基于研究结果,建立了白云岩热分解过程的动力学模型;通过影响因素的对比实验发现,随着试样颗粒粒径的减小和试样重量的增加,白云岩的热分解活化能值会随之升高,而白云岩中SiO₂含量以及保护气体流速的改变对白云岩热分解活化能的影响很小。  相似文献   

Effect of Uncertainty of the Pre-Exponential Factor on Kinetic Parameters of Hydrocarbon Generation from Organic Matter and its Geological Applications     

WANG Min  LU Shuangfang  XUE Haitao  YU Zhanqing 《《地质学报》英文版》2013,87(1):211-218

The source rock sample of the Shahejie Formation（upper Es₄） in Jiyang Sag was pyrolyzed under open system with the Rock-Eval-Ⅱapparatus,and then kinetic model parameters were calibrated for investigating the effect of uncertainty of pre-exponential factors on kinetic parameters and geological applications,where the parallel first-order reaction rate model with an average pre-exponential factor and discrete distribution activity energies was used.The results indicate that when the pre-exponential factor changes from low to high,an extreme value for residual errors occurs.And with the increasing pre-exponential factor,the distribution shape of activation energies are nearly the same,but the values of activation energies move higher integrally,and the average activation energy increases about 12 kJ/mol for every 10-fold of the pre-exponential factors.Extrapolating the geological heating rate of 3.3℃/Ma,the results show that with the increases in pre-exponential factor, the geological temperature corresponding to TR_0.5（transforming ratio of hydrocarbon generation is 50%） increases gradually,and the additional temperature gradually decreases.Combined with geochemical data of source rock,the kinetic parameters with different pre-exponential factors are used to calculate the transformation ratio of hydrocarbon generation,and the result indicates that kinetic parameters corresponding to the better optimized pre-exponential factor are more suitable.It is suggested that the risk assessment of hydrocarbon generation kinetic parameters should be enhanced when using the kinetic method to appraise the oil-gas resources.Meantime,the application result of different kinetic parameters should be verified with geological and geochemical data of source rock in the target area;therefore,the most suitable kinetic parameters for target can be obtained.  相似文献   

苯并[a]芘在脊尾白虾（Exopalaemon carinicauda）体内富集的动力学研究     

李磊  蒋玫  沈新强  吴庆元  牛俊翔  许高鹏 《台湾海峡》2014,(4):481-485

通过室内实验模拟了脊尾白虾（Exopalaemon carinicauda）对苯并[a]芘（benzo[a]pyrene,Ba P）的生物富集,通过非线性曲线拟合获得脊尾白虾对Ba P的富集动力学参数（吸收速率常数k1、释放速率常数k2、生物富集因子BCF、平衡状态下脊尾白虾体内Ba P含量CAmax、生物学半衰期B1/2）.各动力学参数分别为：k1范围为12.34～24.96,平均值为18.80,k2范围为0.06～0.10,平均值为0.08,BCF范围为208.41～248.03,平均值为228.02、CAmax范围为12.40～93.79 ng/g,平均值为46.78 ng/g,B1/2范围为6.89～11.71 d,平均为8.95 d.脊尾白虾对Ba P的吸收速率常数k1、释放速率常数k2、BCF均随外部水体中Ba P浓度的增大而减少,CAmax、B1/2随外部水体中Ba P浓度的增大而增大.  相似文献   

鄂尔多斯盆地苏里格大气田天然气成藏地球化学研究   总被引：3，自引：0，他引：3  

李贤庆  冯松宝  李剑  王萌  黄孝波  王康东  孔龙玺 《岩石学报》2012,28(3):836-846

苏里格大气田位于鄂尔多斯盆地伊陕斜坡西北部,属于典型的低渗砂岩气田。对天然气组分和同位素组成研究表明,苏里格大气田上古生界天然气以干气为主、湿气为辅,甲烷含量为82.729%~98.407%,干燥系数为84.7%~98.8%,δ¹³C₁值为-36‰~-30‰,δ¹³C₂值为-26‰~-21‰,属于高成熟度的煤成气;气田范围内各井区天然气组分和碳同位素组成变化较小,暗示其来源和成藏过程的一致性。根据储层流体包裹体镜下观察、包裹体均一温度、含烃包裹体丰度、颗粒荧光定量(QGF)、包裹体激光拉曼分析,苏里格大气田上古生界储层发育盐水包裹体、气体包裹体、液态烃包裹体、CO₂包裹体等不同类型流体包裹体,主要产于石英次生加大边、微裂隙及胶结物中;包裹体均一温度分布呈连续的单峰态,分布范围为80~180℃,主峰温度为100~145℃;上古生界砂岩储层样品的含烃包裹体丰度不高(多为1%~5%),QGF强度较低(1~10pc)。研究认为,苏里格大气田天然气充注可能是一个连续的过程,主要经历了一期成藏,其主要成藏期为晚侏罗世-早白垩世。通过生气动力学与碳同位素动力学的研究表明,苏里格大气田天然气主要来源于苏里格地区及周缘的石炭-二叠系煤系烃源岩,为近源充注、累积聚气成藏。  相似文献   

长江沉积物稀土元素的粒度效应研究          下载免费PDF全文

宫传东  戴慧敏  杨作升 《江苏地质》2012,36(4):349-354

依据Stokes定律,将小于63μm的长江沉积物分成小于2、2～4、4～8、8～16、16～32、32～63μm6个粒级,采用ICP-MS法分别测试了分粒级沉积物的REE含量,结果显示:长江沉积物REE的丰度遵循元素的"粒度控制律",即随粒度变细,∑REE含量依次增高;北美页岩标准化分布曲线均呈右倾的近"W"型,轻、重稀土分馏明显,相对富集LREE,明显的Ce负异常和弱Eu亏损。对长江沉积物不同粒级样品进行X射线衍射分析和体视镜下观测,结果表明:长江沉积物随粒度增大石英和长石含量逐步增加,碳酸盐和重矿物在各个粒级中含量甚微并且随粒级变化不大;长江沉积物REE随粒度变细逐渐增加的特征主要受控于沉积物随粒度变化而变化的矿物成分,黏土粒级及细粉砂中较高的∑REE主要是黏土矿物吸附作用的结果,粗粉砂中较低的∑REE主要为长石和石英的稀释作用结果,而碳酸盐和重矿物因其较低的含量对稀土元素含量影响较小。  相似文献