【作者】 古丽；

【导师】 刘素美；

【作者基本信息】 中国海洋大学 ， 分析化学， 2011， 硕士

【摘要】 硫是生命体的基本元素,硫酸盐的还原是生产力丰富的海岸沉积物矿化的主要途径之一,占有机质矿化的50%。硫化物作为海洋沉积物中硫酸盐还原的最主要成分,受到人们的关注。沉积物中的硫化物包括酸可挥发性硫(AVS)和黄铁矿(CRS),大陆架区域蕴含了硫酸盐的还原和硫化物的形成埋藏信息,黄、渤海和东海是西北太平洋的边缘海,在全球的硫循环中起着重要的作用。本文研究了黄、渤、东海三个海区柱状沉积物中酸可挥发性硫(AVS)和黄铁矿(CRS)的分布特征,因物质供给、沉积速率、沉积类型、埋藏时间等条件的差异,沉积物中硫化物的含量具有明显的时空变化。1)从整个调查区域来看,黄、渤海AVS空间分布特征为:东海最低,南黄海其次,渤海和北黄海较高,长江口最高;在长江口地区,由河流输入、高的沉积速率以及季节性缺氧的影响,AVS含量有较高值;由于强烈的水动力作用带来丰富洋的补充以及沉积物粒径较大,东海北部陆架区域绝大部分站位没有检测到AVS或者AVS含量很低(<2μmol/g dry);与世界其他海域比,黄、渤、东海AVS处于低值区。2)黄、渤海表层沉积物AVS含量普遍表现出春季高,秋季低的趋势,这与有机质的季节变化一致;在长江口区域,AVS与有机质则表现出春季低、秋季高的趋势,这主要是受长江冲淡水的季节变化所致。3)研究了渤、黄、东海典型站位柱状样沉积物中黄铁矿分布特征,表明绝大部分站位黄铁矿含量随深度逐渐增加,AVS:CRS比值也普遍小于0.3,反应了AVS在深处有效转化为黄铁矿的趋势。由于受硫酸盐扩散通量的限制以及高的沉积速率的影响,长江口AVS在深处转化为黄铁矿受到硫酸盐通量限制,黄铁矿含量低。更多还原

【Abstract】 The reduction of sulfate is one of organic matter degradation pathways in coastal sediment with high primary productivity, it can account for 50% of organic matter degradation. Sulfide which is the main component of sulfate reduction draws scientists’attention. Continental shelves have the buried information of sulfate reduction and sulfide formation that plays an important role in the the global sulfur cycle. The Bohai, Yellow and East China Seas are the marginal sea of the northeast Pacific which plays an important role in the global sulfur cycle, but nowadays little references on them were reported. The distribution of sulfide from in investigation region shows obvious spatial and temporal variations for the complexity of marine environment.1)The concentrations of AVS in Bohai, Yellow and East China Seas are in a low level compared to other areas. Concentration of AVS is the minimum in the East China Sea, lower in the South Yellow Sea, the highest in the Changjiang Estuary, the Bohai and the North Yellow Sea between them. In addition, concentration of AVS in the Changjiang Estuary is also higher due to terrestrial materials input from the Changjiang and the estuary has a higher sedimentation rate, and seasonal hypoxia events in the estuary attributes to the formation of AVS. However, AVS is not detected in the north East China Sea or has a low level(<2μmol/g dry)due to silt or sand sediment with sufficient supplement of oxygen through vertical exchange in seawater.2)In generally, the concentrations of AVS in The Yellow and Bohai Seas are higher in spring than in autumn, and in accordance with seasonal change of organic matter content; in the Changjiang estuary, sulfides and organic matter concentrations are lower in spring than in autumn affected by the CDW transport.3)The distribution characteristics of pyrite in the Bohai, Yellow and the East China Seas are also studied. The results show that the concentrations of pyrite at most investigation stations increased with depth, and the AVS: CRS ratio is generally less than 0.3, reflecting the high conversion of AVS to pyrite. The low sulfate and high sedimentation rates limit the conversion of AVS to pyrite in the Changjiang estuary, so the concentration of pyrite is low.更多还原