喀斯特深水湖泊富硒沉积物中Se的赋存特征  

Assessment of Selenium Pollution in Sediments from Hongfeng Lake,China

作　　者：胡继伟[1] 刘峰 陈敬安[3] 李存雄[1] 吴迪[1] 章吉萍[1] 罗晋[1] 

机构地区：[1]贵州师范大学贵州省山地环境信息系统与生态环境保护重点实验室,贵阳550001 [2]辽宁省有色地质局一〇四队,营口115007 [3]中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳550002

出　　处：《环境化学》2013年第8期1448-1455,共8页Environmental Chemistry

基　　金：国家自然科学基金资助项目(20967003);贵阳市科学技术局基金项目([2010]5-2)资助

摘　　要：采用硒的循环提取技术,改进后对湖区沉积物中重金属元素硒进行地球化学形态分析.分析结果表明,红枫湖沉积物中Se的硫化物结合态平均含量最高,占总量的45.7%,其含量顺序为硫化物结合态>残渣态>有机结合态>可交换态>酸溶态>水溶态.并采用次生相富集系数法(SPEF)评价红枫湖沉积物中的Se,结果得KSPEF=2.58,即重金属元素Se可能存在某种人为污染.利用配备X射线能谱的电子显微镜进行微形貌的观察,结果表明,沉积物中除去土壤中常见的元素含量外,S的含量较高,约为0.61%(重量比),但并未发现自然Se的存在.应用X射线多晶衍射仪对沉积物中Se的晶型进行分析,红枫湖沉积物中MSe、MSeO4、MSeO3、MSe2O5和含Se的有机化合物是Se元素存在的主要晶型(其中M为金属离子).加之沉积物中有机质及Se的可利用态含量较高,故红枫湖沉积物经植物修复后,可用于富硒农作物的种植.In this paper,it was found that there was a selenium（Se）-rich phenomenon in sediments from Hongfeng Lake located on Guizhou Plateau,and the average Se concentration was up to 13.85 mg.kg-1.A modified sequential extraction procedure was employed to analyze the Se geochemical speciation in the sediments from the lake.The results showed that Se had a high average concentration in sulfide-bound fraction,accounting for 45.7% of the total amount（W / W）.And its average concentration in different fractions follows the order of sulfide-bound residual organic-bound exchangeable carbonate water-soluble.Secondary phase enrichment factor（SPEF） was used to evaluate the Se risks in the sediments from the lake（KSPEF = 2.58）,indicating that there might be a discharge of Se from anthropogenic sources,and that this element might pose a potential risk to the water body.Scanning electron microscope coupled with an energy dispersive spectroscopy（EDX） was also employed to examine a sediment sample from the lake,demonstrating that besides common elements,sulfur had high concentrations in the sediments,accounting for 0.61% of the total weight（W / W）.However,the presence of natural elemental Se was not observed.X-ray powder diffraction analysis of crystalline phases indicated that MSe,MSeO4,MSeO3,MSe2O5（where M is a metal ion） and some Secontaining organic compounds were present in this sediment sample.Further,Se in the sediments from Hongfeng Lake was of relatively high bioavailability.Thus these sediments might be utilized for the cultivation of selenium-rich crops after the removal of other hazardous materials.It is thus expected that this study would provide some useful information for the management of the sediment from Hongfeng Lake.

关 键 词：红枫湖 富硒沉积物 硒 赋存特征 

分 类 号：X832[环境科学与工程—环境工程]