椒江河口沉积物As、Hg黄铁矿矿化程度及其生物有效性  

Pyritization of As and Hg and Their Bioavailability in Sediments from the Jiaojiang Estuary, Zhejiang

作　　者：叶思源[1] 钟少军[2] 丁喜桂[1] 袁红明[3] 

机构地区：[1]青岛海洋地质研究所,山东青岛266071 [2]中国科学院海洋研究所,山东青岛266071 [3]中国海洋大学,海洋地球科学学院,山东青岛266100

出　　处：《地质论评》2007年第4期499-505,共7页Geological Review

基　　金：国家自然科学基金资助项目(编号40642009)的成果

摘　　要：本文利用取自浙江椒江河口3个未扰动柱状沉积物样,进行了孔隙水化学测试、固相沉积物的活性分量与黄铁矿分量的分级提取和测试,结果表明:Hg主要以黄铁矿态形式存在于沉积物中。As在有机碳较高的河口区潮上带和沉积速率较慢的潮下带主要以黄铁矿形态存在[DTMP(degree of trace metal pyritization,痕量元素黄铁矿矿化程度)>50%)],而在中潮带As的黄铁矿矿化程度略低(DTMP均值为40.99%),研究区DOP(Fe的黄铁矿矿化程度)值普遍较低(<35%),Mn-DTMP低于3.32%。从而揭示了浙江椒江河口沉积物在数厘米以下,毒性痕量元素Hg和As被高度黄铁矿矿化的规律性,并指出在遇有海事活动或风暴潮事件对海底沉积物进行扰动时,河口沉积物与充氧的海水反应,高度黄铁矿矿化的痕量元素会转变成活性态,从而导致近海生态系统的毒性事件。To determine the reactive and pyrite fractions of elements, 3 undisturbed cores were obtained from the Jiaojiang estuary. The reactive and pyrite fractions of the trace elements have been performed by modified sequential extraction procedures, meanwhile, the pore waters were extracted for chemical analysis. Results indicated that Hg underwent more significant pyritization with average degree of trace metal pyritization （DTMP） 〉78% ,while the average of As-DTMP was higher than 50% at both low and high tide lands and with 40. 99% at TZ02, and Mn-DTMP was less than 3.32%. The degree of pyritization （DOP） was generally less than 35%. Finally, the authors pointed out that As and Hg were highly bonded in pyrite fraction even at several centimeters depth in estuary, which were potentially bioavailable. Dredging and maritime transport activities as well as episodic submarine slumping events （resuspension of anoxic sediments） in the estuary could lead to the oxidation of pyrite, and the release mercury and arsenic to the water column.

关 键 词：沉积物 痕量元素 活性态 黄铁矿态 生物有效性 椒江河口 

分 类 号：P512.22[天文地球—地质学] P575