DGT-based Measurement of Phosphorus in Sediment Microzones and Rhizospheres

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 of P 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.