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This book focuses on the development of DGT (diffusive gradientsin thin films) and the related techniques for measuring and investigating the geochemicalprocess and P transfer across the sediment/water or sediment/root interface inlakes. 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), andmicrochelex gel/LA-ICP-MS (laserablation inductively coupled plasma mass spectrometry) have been developed.
The corresponding chapters on the theory andmethodology of DGT, the "internal P loading" or P transfer across sediment/rootin two lakes, provide insights into the research method and conclusions, includingthe P release mechanism, the quantification of "internal P loading", kinetic Pexchange in DGT/sediment interface, Fe- or S(-II)-microniches at submillimeterscales in sediments for the prediction ofP release, and DGT as a surrogate for the prediction of P uptakeby roots.
It alsooffers new perspectives in the fields of P analysis and P process inmicro-interfaces in lakes using DGT techniques. The P remobilization fromFe-bound P, the coupled Fe-S(-II)-P geochemical reaction and algae biomassbreakdown causing P release, are elucidated using DGT methods in sedimentlayers. DGT parameters and curves for time or distancederived from DIFS can be used to assess kinetic Prelease in the sediment microzone. CID and LA-ICP-MS methods deliver Fe- andS(-II) images at submillimeter scales, which can be used for the quantificationof flux related to microniche peaks and the prediction of P release fromFe-microniche or Fe-S(-II)-P geochemical reactions. DGT measurements in-situ inrhizosphere or rhizonbox cangive CE (effectiveconcentration) and CDGTvalues for the prediction of P accumulated in plant tissues.
This book provides a valuable reference resource for senior graduatestudents, lecturers and researchers in the fields of the geochemical process ofeutrophic elements in lakes, lake eutrophication mechanism and environmental analysis.
List of contents
Section 1: The basic theory and methodology.- The theory of P process at sediment/water interface (SWI).- Problem introduction and studying zones.- The research methodology.- Section 2: "Internal P-loading" at SWI of Dianchi lake.- The "internal P-loading" at SWI of Dianchi lake assessed by DGT technique.- The coupled Fe-S-P biogeochemical process for P release and sulfide microniche in sediments assessed by DGT-CID technique.- The P release risk predicted by chemical image of Fe in sediment porewater measured by DGT/LA-ICP-MS and Fe-microniches.- Section 3: The P behavior at the interface of sediment/the rhizosphere of aquatic plants in Erhai lake.- The uptake and accumulation mechanisms of P predicted by in-situ DGT test at the rhizosphere of aquatic plants in Erhai lake.- The uptake and accumulation mechanisms of P assessed by DGT/rhizonbox method.- Conclusion and Prospect.
Summary
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 ofP 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.
