【摘要】 <正> 我们曾研究过汞、镉在珠江口海域水体中的存在形态,为进一步弄清汞、镉在本海域水体中的迁移机制,本文又采用逐级浸提法研究了珠江口海域沉积物中汞、镉的化学形态,并把汞的形态分为水溶性汞、盐酸溶汞、碱性溶汞、硝酸溶汞及王水溶汞等五种形态;把镉的形态分为水可溶态、阳离子可交换态、碳酸盐结合态、铁/锰水合氧化物结合态、有机质结合态及残余态等六种形态。现把研究情况报告如下。更多还原

【Abstract】 The present study deals with the chemical forms of Hg and Cd in sediments collected from the waters at the Zhujiang Mouth with the method of submerged extraction in a grade after grade manner.The result shows that according to the comparison between averaged percentages of these forms, the dissolved Hg by HCl>the dissolved Hg by HCl+HNO3>the dissolved Hg by HNO3>the dissolvable Hg in alkali>>the dissolvable Hg in water; and,Cd in residual form>Cd in compound form with carbonates>Cd in compound form with Fe/Mn oxides>Cd in cation exchangable form>Cd in organic compound form>Cd form dissolvable in water.The reason why Hg in sediments from sea waters presents a higher percentage of desorption has been found from the result.The fact that seawater of high salinity can detach the Cd ions from the sediments that have adsorbed them, so as to decrease the level of Cd in cation exchangable form in the sediments has been verified theoretically as well as practically.更多还原