Terrestrial environment

Effect of pH on transport of Pb2+, Mn2+, Zn2+ and Ni2+ through lateritic soil:Column experiments and transport modeling


Srilert Chotpantarat , Say Kee Ong , Chakkaphan Sutthirat , Khemarath Osathaphan

DOI:

Received March 09, 2010,Revised August 25, 2010, Accepted , Available online

Volume 23,2011,Pages 640-648

  • Summary
  • References
  • Related Articles
This study investigated the e ects of pH on the transport of Pb2+, Mn2+, Zn2+ and Ni2+ through lateritic soil columns. Model results by fitting the symmetric breakthrough curves (BTCs) of bromide (Br??) with CXTFIT model suggested that physical non-equilibrium processes were absent in the columns. The heavy metal BTCs were, however, asymmetrical and exhibited a tailing phenomenon, indicating the presence of chemical non-equilibrium processes in the columns. The retardation factors of Pb2+ were the largest of the four metal ions at both pH 4.0 (33.3) and pH 5.0 (35.4). The use of Langmuir isotherm parameters from batch studies with HYDRUS-1D did not predict the BTCs well. Rather the two-site model (TSM) described the heavy metal BTCs better than the equilibrium linear/nonlinear Langmuir model. The fraction of instantaneous sorption sites ( f ) of all four metal ions on the lateritic soil was consistently about 30%–44% of the total sorption sites.

Copyright © Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.京ICP备05002858号-3