Investigation of the assessment and remediation of land contaminated with heavy metals
The investigation and remediation of land contaminated with metals (copper, nickel, lead and zinc) was investigated. Calcium, iron and manganesele vels within the soils studied were also investigated. Several soils were used to assessth e three-stageB CR sequential extraction procedure and recent recommended modifications to this procedure. In general the modifications to the procedure were found to increase levels of copper, lead and iron extracted by the reductant used in the procedure. The modified BCR sequential extraction procedure was then used to assess the success of remediation strategies. Column leaching experiments, with EDTA, were set up to simulate soil-flushing technologies. Soil was extracted using the BCR procedure both before and after treatment. The experiments highlighted the need to consider the soil characteristics when determining a remediation strategy. The technique was shown to be successful for the leaching of the more mobile forms of copper, lead and zinc from the soils studied. Phytoremediation and chelate assisted phytoremediation were also investigated using the BCR sequential extraction procedure. Taraxacum officianale (dandelion) was grown in soil contaminated with zinc. The experiment was designed to study the ability of the plant to accumulate metals and also to study the effect of the addition of the chelator EDTA and the effect of the addition of a fertiliser. These methods were shown to remove significant proportions of zinc, copper and lead from the soil studied, however the time frame for remediation based on such techniques may be considerably longer than that for conventional methods.