Enhancement of ion migration in porous media by the use of varying electric fields

Two kinds of varying electric fields, reciprocating field and rotating field, were used in the paper to investigate the feasibility of the efficiency of heavy metals removal increasing by EKR. Compared with a single-oriented electric field, 3-dimensional rotating electric field was proven to sharply enhance mass transport of several heavy metals in kaolin. The frequency of rotating electric field played an important role, for this experiments, the amount of ions migrated increased considerably from 30% at rotation frequency 0.00 rpm to similar to 80% at rotation frequency 1.25 rpm, and then decreased quickly to similar to 60% at rotation frequency 5.00 rpm and similar to 30% at rotation frequency 10.00 rpm. However, the experimental results showed that the 2-dimensional reciprocating electric filed could not improve ions migration in porous media obviously. Removal of nickel and znic were fixed at 36.5 +/- 3% and 49 +/- 3% respectively in all experiments. (C) 2013 Elsevier B.V. All rights reserved.