JI Caiye1, LIU Yuyan1, FU Bo1, WU Dan1, WANG Lin1, ZHANG Lan1, SHEN Mengchen1, FU Qianqian1, HE Linsheng1
1. College of Geography and Environmental Science, Hainan Normal University, Hainan 571158, China；
2. Analysis and Testing Center, Capital Normal University, Beijing 100083, China
Abstract: Palladium (Pd), a member of the platinum group elements (PGEs), is widely used as the catalyst in automobile exhaust catalytic converters (VECs). The concentration of Pd in the environment worldwide increases rapidly and its potential threat is increasing by entering the food chain. In this paper, the mangrove wetland in the Dongzhai Harbor, Hainan Province, was taken as the research area to collect samples of mangrove plants. The Pd content was determined by the method of microwave digestion and ICP-MS. The results showed that Pd contents of mangrove leaves decreased horizontally from the estuary to the offshore, indicating that Pd in mangrove leaves came mainly from terrestrial origins, from the mudflat to the mangrove, showed the characteristics of interior forest > mudflat > forest margin. The vertical concentrations of Pd in mangrove leaves decreased from bottom to top. Compared with the stem, the concentrations of Pd in leaves of mangrove plants were significantly lower, indicating that mangrove plants absorbed and accumulated Pd from sediments mainly through roots. For mangrove plants of different ages, concentrations of Pd in stems and leaves followed the trend of mature > young > old and the trend of old > mature > young, respectively. The seasonal variation of Pd contents in mangrove leaves was significant, higher in the dry season than in the wet season. Compared with domestic and foreign plants, the concentrations of Pd in mangrove plants in the Dongzhai Harbor were lower. This study elucidated the accumulation characteristics of Pd in mangrove wetlands, and had important scientific significance in the environmental protection of mangrove wetlands.
Key words: mangrove wetland; Pd; mangrove plant; accumulation; characteristics
EARTH AND ENVIRONMENT Vol.48, No.2, Tot No.334, 2020, Page 190-196
