通过对表层沉积物及柱状沉积物的分析,研究漳江口红树林湿地沉积物重金属Cu、Zn、Cr的变化规律.结果表明:表层沉积物中Cu、Zn、Cr的含量范围分别为:46.98~63.21 mg/kg,241.21~301.76 mg/kg,40.55~83.42 mg/kg,平均值分别为56.93,259.09和61.82 mg/kg.与台湾海峡南部海区背景值相比,该区沉积物Cu、Zn含量较高、污染较重,但样地间波动范围小、没有明显变化,表明保护区周边的生活污水和养殖污水没有对红树林沉积物重金属污染产生明显影响.随着深度增加,Cu含量呈现不规则递增的趋势,Cr呈现不规则变化,Zn在33 cm以上含量急剧减小,说明近年与Zn有关的重要污染源被关闭.利用欧共体标准物质局的BCR三步分级提取法分析沉积物中重金属形态,结果显示Cu、Zn、Cr的残渣态含量都较高,可提取态分别为总量的9.31%~35.90%,10.14%~17.21%,9.32%~35.70%.在可提取态中B1态在总量中所占比例较小,B2态含量最低,B3态较高,这可能与红树林沉积物高硫,高有机质和相对还原的特点有关.The contents of Cu,Zn and Cr in surface sediments and profile sediments from the Zhangjiang estuary mangrove area were analyzed.The results showed that the ranges of contents in surface sediments were Cu 46.98～63.21 mg/kg,Zn 241.21～301.76 mg/kg and Cr 40.55～83.42 mg/kg respectively.The average containing values of these three metals were 56.93,259.09,61.82 mg/kg respectively.Compared with the average value of heavy metals in sediments of Taiwan Strait,the contents of Cu,Zn were much higher.On the other hand,the heavy metal contents fluctuated in a small scope among sampling spots.In vertical profile,copper level enhanced irregularly with increasing of depth.But chromium level changed irregularly.Zinc level increased dramatically since depth of 33 cm.It perhaps demonstrated that some important Zn contamination sources were closed in recent years.BCR three stage sequential extraction procedure was applied to examine the speciation of heavy metals.Only small proportion of heavy metals can be extracted from these samples.And most Cu,Zn,Cr exists in the residual form.Contents of extractive speciation of Cu,Zn,Cr increase in the order of B2 < B1 <B3.It might be related with abundant sulfur,high organic and reductive condition in mangrove sediments.国家自然科学基金(30530150);; 厦门大学中央行动计划联合资
