1. School of Metallurgy and Environment; Central South University; Changsha 410083 PR China
2. Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution; Central South University; Changsha 410083 PR China
3. Crop and Environment Sciences Department; Harper Adams University; Newport TF10 8NB UK
4. SMI, Centre for Mined Land Rehabilitation; The University of Queensland; Brisbane 4072 Qld Australia