Studying the Application and Advances of Diffusive Gradients in-Thin Films Techniques (DGTs) to Constrain Mobility and Bioavailability of Heavy Metals in Soils

The aim of this review is to investigate the application and latest developments of the Diffusive Gradients in-thin films (DGT) with a focus on the mobility and bioavailability of heavy metals in soil. Soil chemical extractions are extensively used to predict nutrients elements in the soil. However, these measurements have their weaknesses and shortcomings. Comparing DGT with conventional extraction methods, DGT is a sampling technique with significant advantages;including speciation capabilities, sensitivity, time-in- tegrated signal, low risk of contamination and time averaged concentrations. These findings have strengthened the usefulness of the DGT technique as a potential monitoring tool for soil with heavy metal contamination. Studies which have used the DGT technique to evaluate processes important to bioavailability have been booming in the last 13 years, especially its application in soils science. Some recent studies have shown a good relationship between the measurement of metals concentrations in soil and plant by DGT, and cohesive results have been obtained from these measurements when they are based on the DGT technique. DGT is a newly established procedure to assess the bioavailability of trace elements in sediments and soils, and its applications are still in the early stage of testing. Therefore, future application of DGT is likely to include the studies of HMs contamination in soil for risk assessment and transfer rates to the food chain, as some studies have indicated the potential of DGT in these areas.