TITLE:
High-Resolution Profiles of Dissolved Reactive Phosphorus in the Porewaters of Lake Sediments Assessed by DGT Technique
AUTHORS:
Jian Wang, Jingtian Zhang, Qiong Xie, Fengyu Zan, Shengpeng Zuo, Shouliang Huo
KEYWORDS:
Dissolved Reactive Phosphorus (DRP), Diffusive Gradients in Thin Films (DGT) Technique, Porewaters, Sediments
JOURNAL NAME:
Journal of Environmental Protection,
Vol.5 No.8,
June
16,
2014
ABSTRACT:
The
technique of DGT (diffusive gradients in thin films) was applied to obtain high-resolution
vertical profiles of dissolved reactive phosphorus (DRP) in sediment porewater
of Lake Chaohu, a shallow eutrophication lake. Three kinds of DGT probes (with
three thicknesses of diffusive gel: 0.38 mm, 0.78 mm and 1.18 mm) measured
vertical concentration and induced flux from solid to solution phase which had
intricate variations with depth. The results indicated that higher
concentrations and induced fluxes of DRP were achieved by using DGT probe with
thicker diffusion layer (CDGT1.18 > CDGT0.78 > CDGT0.38)
and relatively stable DRP concentration profiles using DGT probes with 0.78 mm
diffusive gel were obtained in each sediment core. The DRP concentrations displayed
a clear gradient from Core C1 to Core C3 in sediment porewaters due to different sources and exchange degrees of reactive
phosphorus. Compared to the concentrations obtained by the centrifugation
technique, the concentrations of DRP resulting from the DGT technique were
higher because some dissolved reactive phosphorus compounds have always been
neglected using conventional centrifugation method.