Factors influencing the accumulation of Pd in mangrove wetland sediments in Dongzhai Harbor, Hainan, China

摘要

The mangrove wetland in Dongzhai Harbor, Hainan Province was taken as a research area for the collection of samples of sediments and other media. The Pd content was determined by microwave digestion and inductively coupled plasma mass spectrometry (ICP-MS), and the factors influencing the accumulation of the platinum group element (PGE) Pd in mangrove wetland sediments were discussed. The results showed that the average concentrations of Pd in the surface sediments, plants and water of mangrove wetlands were 4.81 ng/g (1.51 similar to 8.15 ng/g), 0.94 ng/g (ND similar to 4.34 ng/g), and 0.11 ng/mL (ND similar to 0.27 ng/mL), respectively. Pd was mainly concentrated in the sediments, which absorb most of the Pd in the mangrove wetland environment. From the wetland estuary to offshore, the sediment Pd showed a decreasing trend. The land origin of Pd in mangrove wetland was explained. Extending from the mudflat to the mangrove, the "V" shape becomes the main distribution pattern of sediment Pd, which is higher in the mudflat and forest, and lowest in the forest edge. In the vertical direction, the average concentrations of Pd were the highest at the surface (10-20 cm) and decreased with increasing depth. Pd concentrations in the sediment in the dry season was higher than that in the wet season. Pd was significantly correlated with pH and Eh. This study can help clarify the environmental geochemical process of PGEs in mangrove wetlands and has important scientific significance and practical value for the environmental protection and utilization of mangrove wetlands.