This book focuses on the development of DGT (diffusive gradients
in thin films) and the related techniques for measuring and investigating the geochemical
process and P transfer across the sediment/water or sediment/root interface in
lakes. A series of DGT techniques such as new types of probes, test methods in sediment or the rhizosphere,
DIFS (DGT induced fluxes in sediments and soils)
model for kinetic P exchange, CID (computer imaging densitometry) for S(-II), and
microchelex gel/LA-ICP-MS (laser
ablation inductively coupled plasma mass spectrometry) have been developed.

The corresponding chapters on the theory and
methodology of DGT, the "internal P loading" or P transfer across sediment/root
in two lakes, provide insights into the research method and conclusions, including
the P release mechanism, the quantification of "internal P loading", kinetic P
exchange in DGT/sediment interface, Fe- or S(-II)-microniches at submillimeter
scales in sediments for the prediction of P release, and DGT as a surrogate for the prediction of P uptake
by roots.

It also
offers new perspectives in the fields of P analysis and P process in
micro-interfaces in lakes using DGT techniques. The P remobilization from
Fe-bound P, the coupled Fe-S(-II)-P geochemical reaction and algae biomass
breakdown causing P release, are elucidated using DGT methods in sediment
layers. DGT parameters and curves for time or distance
derived from DIFS can be used to assess kinetic P
release in the sediment microzone. CID and LA-ICP-MS methods deliver Fe- and
S(-II) images at submillimeter scales, which can be used for the quantification
of flux related to microniche peaks and the prediction of P release from
Fe-microniche or Fe-S(-II)-P geochemical reactions. DGT measurements in-situ in
rhizosphere or rhizonbox can
give CE (effective
concentration) and CDGT
values for the prediction of P accumulated in plant tissues.

This book provides a valuable reference resource for senior graduate
students, lecturers and researchers in the fields of the geochemical process of
eutrophic elements in lakes, lake eutrophication mechanism and environmental analysis.