湛江港湾表层沉积物重金属的分布特征及潜在生态危害评价

Distribution Features and Evaluation on Potential Ecological Risk of Heavy Metals in Submarine Surface Sediments of Zhanjiang Bay

利用双道原子荧光分析仪对湛江港附近海域表层沉积物砷、汞、铅、镉的含量进行了分析．阐明了这几种重金属的分布特征。结果表明．As的质量分数为（8．138～16．749）×10^-6，平均12．745×10^-6；Hg的质量分数为未检出（nd）～0．322×10^-6，平均0．059×10^-6；Pb的质量分数为（14．306～68．904）×10^-6．平均44．258×10^-6；Cd的质量分数为（1．561～6．882）×10^-6，平均3．0874×10^-6；砷、汞、铅从港内往港外有逐渐减少的趋势．镉的分布没有规律性，在整个港湾内的分布较均匀。从单因子污染指数看，砷、汞和铅都属生态危害轻微；镉污染较为严重．属生态危害强；从综合污染指数看．属生态危害中等。

By using the Atomic Fluorescence Spectrometry（AFS） to analyse As, Hg, Pb, Cd in submarine surface sediments of Zhanjiang Bay,the article expounded distribution features of these heavy metals and the mass fraction and its mean value of As were （8. 132-16. 749） × 10^-6 and 12. 745× 10^-6 respectively; Hg were undetection-0. 322× 10^-6 and 0. 059× 10^-6; Pb were （14. 306- 68. 903）× 10^-6 and 44. 258× 10^-6; Cd were （1.561-6.882）× 10^-6 and 3. 087× 10^-6. As, Hg, Pb, and Cd would reduce by degrees from inside to outside of the harbor,and distribution of Cd had no regulation, it was well-distributed in all the harbor. From the index number techniques of single factor, As,Hg and Pb were low in the sediments; Cd pollution was powerful serious and it was ecological risk; from the index number techniques of synthesis, the average was moderate ecological risk.