| Samples of surficial sediments and vertical profile were collected from Zhangjiang Estuary mangrove wetland (Yunxiao, Fujian) in October 2004. Concentration and speciation of Cu, Zn, Cr and As were examined. The distribution, possible sources and affect factors of Cu, Zn, Cr and As were discussed in this paper. Mangrove Aegiceras corniculatum hypocotyls were cultivated in sand and treated with 10‰seawater for 90 days in a greenhouse. The influence of different arsenic contents and time on ecophysiological properties of Aegiceras corniculatum seedlings was studied. Series of As concentration was composed of 0 mg/L, 0.5 mg/L, 1 mg/L, 2.5 mg/L, 5 mg/L, 15 mg/L, 45 mg/L, 100mg/L, and parameters such as arsenic level, hypocotyls germination, growth, chlorophyll content, soluble protein and antioxidase membrane protection system were determined. The results showed:1. The average contents of Cu, Zn, Cr and As were 56.93 mg/kg, 259.09 mg/kg, 61.82mg/kg and 17.808 mg/kg respectively. Compared with background value, the contents of Cu, Zn were much higher, and Cr, As were close to the content of background. On the other hand, the heavy metal contents fluctuated in a small scope among sampling spots. It showed that cultivate sewage and domestic sewage didn't affect the mangrove Nature Reserve significantly.2. In vertical profile, copper level enhanced irregularly with depth, but chromium level changed irregularly. Zinc level increased dramatically since depth of 33cm. It perhaps demonstrated that some important Zn contamination sources were closed in recent years. Arsenic level changed in a steady range with depth, but the content increased in a big extent since depth of 33cm. It may related with background pollution and the external pollutions.3. Only small proportion of heavy metals can be extracted from these samples, most Cu, Zn, Cr and As exists in the residual form. Contents of extractive speciation of Cu, Zn, Cr increase in the order of B2 < B1 |
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