Introducing Students to Remediation of Polluted Soils: Influence of Waste-Based Amendments on Cd Extractability

A laboratory experiment to study the effect of soil amendments in the bioremediation of polluted soils is described. Students extracted and measured 0.01 M CaCl2- soluble Cd, EDTA-soluble Cd, and DTPA-soluble Cd concentrations in contaminated soils, treated with a liming material (mussel shell), and/or with an organic amendment (pine bark). The results of the laboratory experiment show that it is easy to perform and reproduce, and it gives results that can be interpreted from the point of view of bioremediation and immobilization of Cd, whereas the postlab work by the students shows that the learning objectives of the laboratory phase were met, with students being able to identify the relevance of two of the main parameters affecting metal bioavailability in soils: pH and organic matter content.