Remediation of Cu2+ contaminated soil with Na-bentonite

The adsorption of copper ions in Na-modified bentonite has been studied by isothermal adsorption method, and the pot experiments were carried out to study the effect of Na-bentonite on remediation of copper contaminated soils. The results show that Na-bentonite has a high affinity for copper ions. The Langmuir model is found to describe the sorption processes. According to XRD the adsorption form of Na-modified bentonite for cooper contamited soil is that of ion exchange based on XRD test. The pot experiment show that the dry weight of whole plant could be significantly increased by 16.44%, copper concentration in shoot and in root was decreased by 25.95% and 33.02% respectively, and the effect of phosphorus concentration is not significant in shoot when 5 g Na-bentonite was applied to soil. Na-bentonite is an excellent remediation material for Cu contaminated soils. So it can be used to remedy heavy metal contaminated soils.