Effects of Soil Amendments on the Extractability and Speciation of Cadmium, Lead, and Copper in a Contaminated Soil

The effects of chemical amendments including zeolite, compost and mesoporous molecular sieves (MCM-41) on the extractability and speciation of heavy metals (Cd, Pb and Cu) in a contaminated soil were investigated. Results showed that the application of soil amendments decreased Cd, Pb and Cu uptake by the shoots of pakchoi, up to 44.2–53.2%, 30.2–42.7% and 16.9–22.1%, respectively, compared with the control. Among the three amendments, zeolite and MCM-41 were more efficient in reducing Cd and Cu uptake, while compost was more efficient in reducing Pb uptake by the plants. The growth of pakchoi was improved in amended soils due to the action of chemical amendments.