title: Element remobilization, "internal P-loading," and sediment-P reactivity researched by DGT (diffusive gradients in thin films) technique.
abstract: Labile P, Fe, and sulfide with the high spatial resolution in sediment porewater of five sites (A-E) of Dianchi Lake (China) were measured at same locations using AgI/Chelex-100, Chelex-100, and ferrihydrite DGT (diffusive gradients in thin films) probes. DGT derived P/Fe/S concentrations in sediment porewater on millimeter or sub-millimeter scale in order to reveal the element remobilization process and the mechanism of "internal P-loading" of sediments in Dianchi Lake. Decomposition of alga biomass in the uppermost sediment layer and the reductive dissolution of Fe-bound P in the anoxic sediment were the two main processes causing P release. A dynamic numerical model-DIFS (DGT-induced flux in sediments) was used to assess sediment-P reactivity (capacity of solid pool and rate of transfer) and P release risk by kinetic parameter-T C (1089∼20,450 s), distribution coefficient-K d (167.09∼502.0 cm(3) g(-1)), resupply parameter-R (from 0.242 to 0.518), and changes of dissolved/sorbed concentration, R and M at the microzone of DGT/porewater/sediment.
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, People's Republic of China. wzh7185@mail.bnu.edu.cn.|State Environmental Protection Key Laboratory for Lake Pollution Control, Research Center of Lake Eco-environment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, People's Republic of China. wzh7185@mail.bnu.edu.cn.|Dongtinghu Lake Ecological Observation and Research Station (DEORS), Yueyang, Hunan Province, 41400, People's Republic of China. wzh7185@mail.bnu.edu.cn.
authors.forename: Zhihao
authors.initials: Z
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, People's Republic of China. wangsr@craes.org.cn.|State Environmental Protection Key Laboratory for Lake Pollution Control, Research Center of Lake Eco-environment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, People's Republic of China. wangsr@craes.org.cn.|Dongtinghu Lake Ecological Observation and Research Station (DEORS), Yueyang, Hunan Province, 41400, People's Republic of China. wangsr@craes.org.cn.
authors.forename: Shengrui
authors.initials: S
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, People's Republic of China.
authors.forename: Mengchang
authors.initials: M
authors.lastname: He
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, People's Republic of China.|State Environmental Protection Key Laboratory for Lake Pollution Control, Research Center of Lake Eco-environment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, People's Republic of China.|Dongtinghu Lake Ecological Observation and Research Station (DEORS), Yueyang, Hunan Province, 41400, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, People's Republic of China.|State Environmental Protection Key Laboratory for Lake Pollution Control, Research Center of Lake Eco-environment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, People's Republic of China.|Dongtinghu Lake Ecological Observation and Research Station (DEORS), Yueyang, Hunan Province, 41400, People's Republic of China.
authors.forename: Lixin
authors.initials: L
authors.lastname: Jiao
mesh_terms: D002681:China; D004784:Environmental Monitoring / Q000379:methods*; D019015:Geologic Sediments / Q000032:analysis*; D007501:Iron / Q000032:analysis*; D007700:Kinetics; D060106:Lakes; D008962:Models, Theoretical; D010758:Phosphorus / Q000032:analysis*; D012106:Research; D012117:Resins, Synthetic; D013440:Sulfides / Q000032:analysis*
chemical_list: D012117:Resins, Synthetic; D013440:Sulfides; C024997:Chelex 100; D010758:Phosphorus; D007501:Iron
keywords: DGT (diffusive gradients in thin films); DIFS (DGT-induced fluxes in sediments); Sediment-P reactivity; “Internal P-loading”