沉积物中硫的形态分析及其应用

发布时间：2018-04-23 04:16

  本文选题：沉积物 + 硫　； 参考：《华东师范大学》2016年硕士论文

【摘要】：沉积物作为物质迁移转化的蓄积库,记录了成岩作用时硫的生物地球化学过程,包括硫酸盐还原和硫化物形成等信息。研究沉积物中硫循环,可为全球碳和铁循环、古气候变化以及地质历史演化等提供重要的资源。本论文详细讨论了沉积物样品中主要基体组分对硫测定的影响,并比较了不同的定量校正方法消除基体效应的效果,建立了简便有效的沉积物样品前处理技术和准确快速的测定方法。利用搭建的热蒸馏装置,建立了一套连续提取沉积物中可溶性硫和可交换态硫(H2O-S+A-S)、酸挥发性硫(AVS)、盐酸溶解性硫(HCl-S)、元素硫(S0)、黄铁矿硫(Spy)、有机硫(Sorg)六种形态的分离方法：应用建立的连续提取技术,研究了东海内陆架区沉积物中各形态硫和硫同位素比值的分布特征。主要研究结果如下：1. 在中分辨率模式下,采用双聚焦电感耦合等离子体质谱仪结合微波消解技术,建立了准确测定沉积物中硫含量的分析方法。针对基体组份对硫测定的影响,以Rh做内标,比较了常规标准曲线法(SCM)和标准加入法(SAM)对基体效应的校正效果。结果显示,SCM法无法消除基体组分对硫测定的影响,而SAM法能有效消除基体效应,但样品分析通量低。基于此,又进一步创新性提出了标准加入校正曲线法(SACM),且当实际样品与SACM标准系列溶液中的基体浓度匹配在士50%范围内时,可简单有效地消除同类沉积物样品的基体效应。2. 采用搭建的装置,分别对H2O-S+A-S、AVS、HCl-S.S0、Spy、Sorg提取时提取剂的浓度和用量、提取温度与时间等参数进行了系统优化,建立了连续提取沉积物中硫形态的分析技术。选用表层沉积物样品进行多次重复提取实验,方法的全程平均回收率为94.1±2.3%,准确度较优。3. 将建立的连续提取沉积物中硫形态方法应用于东海内陆架区A和B站位的柱状沉积物样品分析,探讨了沉积物样品中硫形态及硫同位素比值的分布特征。结果表明：H2O-S+A-S和Spy是A、B站位沉积物中硫形态的主要存在形式,分别占总硫比重的83.6%和90.0%,两站位中AVS和S0的含量总体比重低于2.0%；A、B站位沉积物样品中SEM(同步浸提的酸溶性金属)/AVS比值均1, SEM-AVS差值均在0-5范围内,表明两站位沉积物样品存在一定的毒性效应。两站位AVS/Spy比值均小于0.3,表明AVS能有效地转化成Spy；B站位δ34SH2O-S+A-S(‰)变化范围为12.13‰～18.92‰,δ34SHCl-S(‰)变化范围为2.41‰～16.439‰,而δ34SAVS(‰)、δ34SS0 (‰）、δ34Spy(‰)、δ34Sorg(‰)比值均为负值,变化范围为-13.09‰～-46.51‰,且δ34SAVS(‰)和δ34Ss0(‰)变化趋势(先不断增大后保持稳定)与δ34Spy(‰)较为一致,Spy的形成与AVS和S0具有较好的相关性。
[Abstract]:As a reservoir of material migration and transformation, sediments record the biogeochemical processes of sulfur during diagenesis, including sulfate reduction and sulphide formation. The study of sulfur cycle in sediments can provide important resources for the global carbon and iron cycle, paleoclimate change and geological history evolution. In this paper, the effects of the main matrix components in sediment samples on the determination of sulfur are discussed in detail, and the effectiveness of different quantitative correction methods in eliminating the matrix effect is compared. A simple and effective pretreatment technique and an accurate and rapid method for the determination of sediment samples were established. Using the built thermal distillation unit, A set of methods for the continuous extraction of six forms of soluble sulfur and exchangeable sulfur H _ 2O -S _ (A-S), acid volatile sulfur (AVS), hydrochloric acid dissolved sulfur (HCl-S), elemental sulfur (S _ 0), pyrite sulfur (Spyn), organic sulfur (Sorg) have been established. The distribution characteristics of sulfur and sulfur isotopic ratios in sediments of continental shelf in the East China Sea are studied. The main results are as follows: 1. An accurate analytical method for the determination of sulfur in sediments was established by using a dual-focus inductively coupled plasma mass spectrometer and microwave digestion technique in the medium resolution mode. In view of the effect of matrix composition on the determination of sulfur, the correction effect of conventional standard curve method (SCM) and standard addition method (SAM) on the matrix effect was compared with Rh as internal standard. The results showed that the effect of matrix composition on sulfur determination could not be eliminated by SAM method, while the matrix effect could be effectively eliminated by SAM method, but the sample analysis flux was low. Based on this, the standard addition correction curve method is further innovated, and the matrix effect of similar sediment samples can be eliminated simply and effectively when the actual sample is matched with the matrix concentration of SACM standard series solution in the range of 50%. The concentration and dosage of the extractant, the extraction temperature and the time were optimized by using the set up apparatus, and the analytical technique of sulfur form in the continuous extraction of sediment was established by using the set up apparatus. The parameters such as the concentration and dosage of the extractant, the extraction temperature and the time of the extraction of H2O-S A-SV AVSU HCl-S.S0S0Sorg were systematically optimized. Surface sediment samples were selected for repeated extraction experiments. The average recovery of the method was 94.1 卤2.3, and the accuracy was better. 3. The method of continuous extraction of sulfur forms in sediments was applied to the analysis of columnar sediment samples at stations A and B in the continental shelf of the East China Sea. The distribution characteristics of sulfur forms and sulfur isotope ratios in sediment samples were discussed. The results showed that the main forms of sulfur forms in the sediments of the Agna B station were H _ 2O -S A-S and Spy. The total specific gravity of AVS and S0 in the two stations was lower than that in the sediment samples at the station 2.0 and the ratio of acid-soluble metal / / AVS was 1, and the difference of SEM-AVS was in the range of 0-5, respectively, which accounted for 83.6% and 90.0% of the total sulfur specific gravity, respectively, and the total specific gravity of AVS and S0 in the two stations were lower than those in the sediment samples at the station 2.0. The results indicate that the two station sediment samples have some toxic effects. The ratio of AVS/Spy in the two stations was less than 0.3, which indicated that the range of 未 34SH2O-S A-S (鈥，

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