为了认识红树林表层沉积物中Hg的生物地球化学行为,采用改进的TESSIEr连续浸取法,对我国主要红树林沉积物中Hg的形态特征进行了研究,并讨论了Hg的生物可利用性和迁移性。结果表明:(1)我国红树林沉积物中的Hg绝大部分以易挥发态为主,具有较高的生物可利用性,易挥发态Hg向大气Hg的转化是红树林湿地中汞迁移的主要方式。只有深圳红树林沉积物中的Hg以残渣态为主,次为可交换离子态和碳酸盐结合态,沉积物中Hg主要通过不可溶的固体颗粒物形式迁移,其生物可利用性较低。(2)总Hg与易挥发态Hg呈极显著正相关(r=0.967,P<0.01),碳酸盐结合态Hg与铁锰氧化物结合态Hg之间存在极显著正相关(r=0.871,P<0.01),有机结合态Hg分别与碳酸盐结合态Hg、铁锰氧化物结合态Hg存在极显著相关(r1=0.618,P1<0.01;r2=0.686,P2<0.01);有机质与总Hg存在显著正相关(r=0.526,P<0.05)。In order to understanding biogeochemical behavior,speciation of mercury in the mangrove sediments from 9 main mangrove wetlands of China were determined with modified Tiesser's method.It shown:(1) Two situations were found.One is that mercury exists mainly in volatile form in most mangrove wetlands.That volatile mercury turns into atmospheric mercury is the main transport form for most mangrove wetlands.The mangrove wetlands are the source of global mercury pollution.The mercury in sediments of mangrove wetlands can be bio-accumulated easily.Another situation is that mercury exists mainly in the form of residue which is hard to bio-accumulate,typically in Shenzhen mangrove wetlands.The mercury transports in the form of insoluble particle.(2) Significant positive correlation was found between volatile Hg and total Hg(r=0.967,p<0.01).Carbonate-bound Hg is strongly correlated with Fe-Mn oxide-bound Hg(r=0.871,p<0.01),and organic matter is significantly correlated with total Hg(r=0.526,p<0.05).Organic-bound Hg is significant correlated with carbonates-bound Hg and Fe-Mn oxide bound mercury(r1=0.618,p1<0.01;r2=0.686,p2<0.01).国家自然科学基金项目(40676064;30530150);东华理工大学核资源与环境教育部重点实验室开放基金(070717
