Abstract:
The leachability (toxicity characteristic leaching procedure),availability (CaCl
2) and bioaccessibility (simplified bioaccessibility extraction test) of Cu and Cd were evaluated after application of apatite, lime and charcoal for the first year(2010) and fourth year(2013) by chemical extractable methods. Results show that addition of apatite, lime and charcoal increased soil pH and decreased the concentrations of exchangeable acid and aluminum. Moreover, applications of lime and apatite were more effective in reducing the contents of leachable and available Cu and Cd than the charcoal treated soil, but the immobilization effect was reduced over time. Applications of apatite and lime significantly decreased bioaccessibility of Cu by 28.6% and 23.1%, respectively, and bioaccessibility of Cd by 21.7% and 22.8%, respectively, in 2010, but bioaccessibility of Cu and Cd were increased in the 2013 than those in 2010. The health risk coefficient (
QH) of Cu and Cd for people were all lower than 1. Nevertheless, it should be noted that
QH values for the children were higher than those for adults. Compared to lime and charcoal, apatite was the most effective in decreasing leachability, availability and bioaccessability of Cu and Cd.