Mangrove sediments were sampled form 14 main mangrove reserves of China. Concentrations of Cu, Pb, Zn, Cr and Cd were analyzed with a PE ICP-MS, and physical and physicochemical factors such as particle size distribut...Mangrove sediments were sampled form 14 main mangrove reserves of China. Concentrations of Cu, Pb, Zn, Cr and Cd were analyzed with a PE ICP-MS, and physical and physicochemical factors such as particle size distribution, pH, salinity and Total Organic Matter （TOM） were also determined. In the mangrove sediments of China, the average contents of heavy metals decreased in the order ofZn 〉 Pb 〉 Cu 〉 Cr 〉 Cd. The average contents of heavy metals were： Cu = 22.8 4- 16.46 mg/kg, Pb = 76.1 4- 52.33 mg/kg, Zn = 86.3 4- 42.65 mg/kg, Cr = 18.4 4- 5.83 mg/kg and Cd = 0.21 4- 0.25 mg/kg. Compared with previous studies, levels of heavy metals increased greatly. Contents of Cd, Cu, Pb and Zn were higher than the Background Values （BV）. However, the contents of Cr was under the BV. The results revealed that levels of heavy metals changes significantly with anthropogenic input, physical and physicochemical factors. Significant correlations were found between concentrations of Cu, Ph and pH, TOM.展开更多
Phosphorus fractions and adsorption-release characteristics of sediments in the Zhujiang （Pearl） River estuary wetland were investigated. Results showed that the total phosphorus （TP） content in surface sediments ...Phosphorus fractions and adsorption-release characteristics of sediments in the Zhujiang （Pearl） River estuary wetland were investigated. Results showed that the total phosphorus （TP） content in surface sediments ranged from 648.9 mg/kg to 1064.0 mg/kg; inorganic phosphorus （IP） was the major fraction of TP and ranged from 422.5 mg/kg to 643.9 mg/kg. Among the inorganic phosphorus, the main fractions were phosphorus bound to A1 and Fe （Fe/A1-P）, and calcium-bound phosphorus （Ca-P）, accounting for 23%-42% and 21%-67% of IP, respectively. The vertical distribution of TP contents were significantly positive correlated with organic phosphorus （Org-P） and Fe/A1-P contents. The bio-available phosphorus contents in vertical sediments varied from 128.6 mg/kg to 442.9 mg/kg, mainly existed in Fe-AI/P fraction, and increased from the bottom to top sediments. The transport of phosphorus in sediment-water in- terface was controlled by the soil characteristics. The active Fe and A1 content was considered as the main factor that determines adsorp- tion capacity in vegetated marsh wetland. The P buffering capacity of the sediments in vegetated marsh wetland was greater than that in mudflat wetland. The potential risk of eutrophication in the study area is high. Reducing terrestrial phosphorus discharge and preventing the sediment Fe/A1-P release to the interstitial water are the possible solutions to reduce the risk of eutrophication in estuary wetlands, and planting vegetation in estuary wetland can also reduce the release of phosphorus in surface sediment.展开更多
基金This project is supported by National Natural Science Foundation of China （No. 41176090）.
文摘Mangrove sediments were sampled form 14 main mangrove reserves of China. Concentrations of Cu, Pb, Zn, Cr and Cd were analyzed with a PE ICP-MS, and physical and physicochemical factors such as particle size distribution, pH, salinity and Total Organic Matter （TOM） were also determined. In the mangrove sediments of China, the average contents of heavy metals decreased in the order ofZn 〉 Pb 〉 Cu 〉 Cr 〉 Cd. The average contents of heavy metals were： Cu = 22.8 4- 16.46 mg/kg, Pb = 76.1 4- 52.33 mg/kg, Zn = 86.3 4- 42.65 mg/kg, Cr = 18.4 4- 5.83 mg/kg and Cd = 0.21 4- 0.25 mg/kg. Compared with previous studies, levels of heavy metals increased greatly. Contents of Cd, Cu, Pb and Zn were higher than the Background Values （BV）. However, the contents of Cr was under the BV. The results revealed that levels of heavy metals changes significantly with anthropogenic input, physical and physicochemical factors. Significant correlations were found between concentrations of Cu, Ph and pH, TOM.
基金Under the auspices of National Natural Science Foundation of China(No.U0833002)National Science and Technology Support Program of China(No.2012BAC07B05)
文摘Phosphorus fractions and adsorption-release characteristics of sediments in the Zhujiang （Pearl） River estuary wetland were investigated. Results showed that the total phosphorus （TP） content in surface sediments ranged from 648.9 mg/kg to 1064.0 mg/kg; inorganic phosphorus （IP） was the major fraction of TP and ranged from 422.5 mg/kg to 643.9 mg/kg. Among the inorganic phosphorus, the main fractions were phosphorus bound to A1 and Fe （Fe/A1-P）, and calcium-bound phosphorus （Ca-P）, accounting for 23%-42% and 21%-67% of IP, respectively. The vertical distribution of TP contents were significantly positive correlated with organic phosphorus （Org-P） and Fe/A1-P contents. The bio-available phosphorus contents in vertical sediments varied from 128.6 mg/kg to 442.9 mg/kg, mainly existed in Fe-AI/P fraction, and increased from the bottom to top sediments. The transport of phosphorus in sediment-water in- terface was controlled by the soil characteristics. The active Fe and A1 content was considered as the main factor that determines adsorp- tion capacity in vegetated marsh wetland. The P buffering capacity of the sediments in vegetated marsh wetland was greater than that in mudflat wetland. The potential risk of eutrophication in the study area is high. Reducing terrestrial phosphorus discharge and preventing the sediment Fe/A1-P release to the interstitial water are the possible solutions to reduce the risk of eutrophication in estuary wetlands, and planting vegetation in estuary wetland can also reduce the release of phosphorus in surface sediment.
