AN INTEGRATED STUDY TO EVALUATE PAPER MILL SLUDGE UTILISATION FOR METAL-CONTAMINATED SOIL REMEDIATION

摘要

Metal pollution of soils is a great environmental problem. The major risks due to metal pollution of soil consist of leaching to groundwater and potential toxicity to plants and/or animals. The objective of this study is to evaluate by means of integrated approach (chemical and ecotoxicological tests) the effects on the bioavailable metal fraction of the addition of paper mill sludges on polluted metal soils. The study carried out on soil derived from mining activities and so polluted with heavy metals. The leaching experiments carried out on soil columns with and without adding the sludge showed a decrease of mobile metal form in the presence of sludge. This effect seems to be influenced by the contact time between soil and paper mill sludge. The ecotoxicological studies, based on Microtox? testing, are carried out in both solid phase and leached solution. The results showed a decrease of toxicity with the increasing of the contact time between soil and sludge.