Use this URL to cite or link to this record in EThOS:
Title: Development and applications of the DGT (diffusive gradients in thin-films) technique for the measurement of Mo and W in waters and soils
Author: Fozard , Susan
Awarding Body: Lancaster University
Current Institution: Lancaster University
Date of Award: 2011
Availability of Full Text:
Access from EThOS:
Molybdenum and tungsten are present in the environment as the oxyanions molybdate (MoOl-) and tungstate (WOll Measurements of available Mo and W in soils and waters have been stalled by the lack of a suitable technique. Diffusive gradients in thin films (DGT) is an in situ tool that allows the direct measurement of metal ions accumulated over a given time. This work provides the fIrst systematic investigation on the performance of DGT, containing a binding layer comprising of a single Feoxide reagent, for the measurement of Mo and W in soils and waters. The performance characteristics of DGT, were unaffected by solution conditions likely to be encountered in the environment (PH and ionic strength). DGT effIciently and effectively measured concentrations of labile Mo and W in streams and soils. In laboratory experiments complexation with humic substances was shown to occur with the strongest complexation being observed for HA. Toxicity assays showed that exposure to Mo and W resulted in weight loss, reduced reproduction and bioaccumualtion of Mo within the tissues of earthworms. Collectively these results showed that DGT, using Fe-oxide as the single binding layer, behaves predictably over a wide range of solution conditions and is a suitable and robust passive sampling technique for the measurement of Mo and W in natural environments.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available