随着珠江河口地区经济的快速发展,红树林生态环境受人类的影响日益严重.红树林湿地内的重金属污染物具有不能被生物降解、残留时间长、容易通过食物链富集等特征而受到越来越多的关注.选取深圳福田红树林和宝安红树林湿地,采集0~30 cm深度的表层沉积物,并以沉积物的基本理化指标(TOC、TN、pH)以及重金属(Cd、Cu,、Zn和Pb)为研究对象,探讨深圳典型红树林湿地的重金属积累和历史污染特征.结果表明:(1)与宝安红树林湿地相比,福田红树林湿地沉积物存在较高的TOC含量(福田TOC 4.52%~7.74%>宝安TOC 2.14%~3.21%)和较低的TN含量(福田TN 0.35‰~0.55‰<宝安TN 0.77‰~1.44‰);(2)福田红树林湿地沉积物中Cd、Cu、Zn和Pb的质量分数分别为5.10~6.65μg·g-1、75.38~92.37μg·g-1、303.05~429.93μg·g-1和303.05~429.93μg·g-1,低于宝安红树林湿地,体现出保护区管理模式对污染管控的优势;(3)聚类分析和主成分分析表明,福田红树林重金属污染主要受工业和生活污水污染共同影响,宝安红树林主要为工业污染;(4)宝安红树林湿地沉积物重金属的地质累积指数(Igeo)值和潜在生态危害指数(RI)值均高于福田红树林湿地,表明宝安红树林湿地的重金属的生态风险高于福田红树林.福田红树林湿地中Cd的Igeo和Eir分别为4.09~4.47和765.00~997.50,存在严重的生态风险.宝安红树林湿地中的Cd和Cu均存在严重的生态风险,其中Cd的Igeo和Eir分别为4.66~4.95和1000.00~1392.50,Cu的Igeo和Eir分别为6.71~6.85和784.20~862.43.因此,深圳福田和宝安红树林湿地由于受到不同的人类活动的影响而具有不同的重金属污染特征.研究结果可为深圳红树林湿地重金属污染控制和修复提供科学支撑.%Concomitant with rapid economic development in the Pearl River Estuary Region is the mounting impact that industrial and domestic sewage discharge is having upon mangrove wetlands. Due to heavy metal pollution's characteristic non-biodegradability, long residual time and enrichment through the food chain, related research within mangrove sediments is surging. In this study, surface sediments with depths of 30 cm were collected in the Futian and Baoan mangrove wetlands. Physical-chemical properties (TOC, TN and pH) and heavy metal content (Cd, Cu, Zn and Pb) of sediments were determined. Also investigated were the particular ecological risks of heavy metal sediment in these mangrove wetlands. Results indicated that: (1) Compared with the Baoan mangrove, the sediment of the Futian mangrove wetland had a higher TOC level (Futian TOC level 4.52%~7.74%>Baoan TOC level 2.14%~3.21%) and a lower TN level (Futian TN level 0.35‰~0.55‰展开▼
