| 摘要: |
| 根据沉积物中无机碳的结合强度,运用连续浸取的方法将沉积物中的无机碳分成5种不同的形态:NaCl相、氨水相、NaOH相、盐酸羟胺相、HCl相。并以渤海辽东湾柱状沉积物为例,探讨了各形态无机碳的含量特征及其控制因素。研究表明,辽东湾不同层次沉积物中各形态无机碳的含量特征比较明显:氨水相>盐酸羟胺相≈盐酸相>NaOH相>NaCl相。氨水相、盐酸羟胺相和盐酸相无机碳占沉积物中总无机碳的绝大部分,大于80%;NaCl相和NaOH相无机碳只占总无机碳的一小部分。沉积物中各形态无机碳含量的变化受沉积环境如pH、Eh、Es、含水率、Fe3+/Fe2+、有机碳含量等因素的影响。其中NaCl相无机碳受pH、Eh影响较大;氨水相无机碳主要由含水率、Fe3+/Fe2+、pH、Eh控制;NaOH相无机碳主要由含水率、Eh和pH控制;盐酸羟胺相无机碳主要受含水率、Eh、有机碳的影响;HCl相无机碳的控制因素和盐酸羟胺相的相似,但它受pH和Eh的影响更显著。虽然有机碳和各个形态的无机碳都呈负相关关系,但它对每一形态的影响都不相同,其作用受其它环境因素的制约。环境的氧化能力越强,pH值越小,越不利于盐酸羟胺相和盐酸相无机碳的保存,而有利于NaCl相、氨水相和NaOH相无机碳的形成;环境的还原能力越强,pH值越大,越有利于盐酸羟胺相和盐酸相无机碳的保存,而不利于NaCl相、氨水相和NaOH相无机碳的形成。辽东湾沉积物的弱氧化-还原环境有利于盐酸羟胺相和盐酸相无机碳的保存。 |
| 关键词: 无机碳形态 影响因素 沉积物 辽东湾 |
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| 基金项目:中国科学院创新工程重要方向性项目(KZCX3-SW-214);青岛市科技将才专项计划项目(04-3-JJ-03);中国科学院“百人计划”项目(科人2003-202);中国科学院创新重大项目(KZCX1-SW-01-08) |
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| Forms of inorganic carbon in Liaodong Bay core sediments |
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| Abstract: |
| According to combined strength of inorganic carbon(IC) in sediments, inorganic carbon was divided into five forms by sequential extractions: NaCl form, NH3·H2O form, NaOH form, NH2OH·HCl form and HCl form. As a case of Liaodong Bay sediment, the contents of various IC forms and their influencing factors were discussed. The results showed that NH3·H2O form > HCl form ≈ NH2OH·HCl form > NaOH form > NaCl form. NH3·H2O form, NH2OH·HCl form and HCl form account for more than 80% of total inorganic carbon, NaCl form and NaOH form only account for the minority. The changes of their content and distribution were influenced by many environmental factors, such as pH, Eh, Es, water content,organic carbon, Fe3+/Fe2+ and so on. NaCl form was influenced mainly by Eh and pH; NH3·H2O form was controlled mainly by water content, Fe3+/Fe2+, pH and Eh; NaOH form was influenced mainly by water content, Eh and pH; NH2OH·HCl form was controlled mainly by water content, Eh, organic carbon; the influencing factor of HCl form was similar to that of NH2OH·HCl form but the influences of pH and Eh were more stronger. Although the correlation between organic carbon and each IC form was negative, but the influences of organic carbon on every IC form is different and the influence was restricted by other environmental factors. In general, the environment which has higher oxidation capacity and lower pH will make against the preservation of NH2OH·HCl form and HCl form, but was suitable for the formings of NaCl form, NH3·H2O form and NaOH form. However, the environment which has higher reductive capacity and higher pH was suitable for the preservation of NH2OH·HCl form and HCl form, but will make against the formings of NaCl form, NH3·H2O form and NaOH form. Weak oxidation-reductive environment was suitable for the preservations of NH2OH·HCl form and HCl form in Liaodong Bay sediments. |
| Key words: forms of inorganic carbon influencing factors sediment Liaodong Bay |
