Si. Wada et Y. Umegaki, Major ion and electrical potential distribution in soil under electrokinetic remediation, ENV SCI TEC, 35(11), 2001, pp. 2151-2155
Citations number
26
Categorie Soggetti
Environment/Ecology,"Environmental Engineering & Energy
To assess the effect of pore water chemistry on the contaminant removal rat
e, we monitored major ion concentrations in the pore water and the electric
al potential distribution of a soil during electrokinetic remediation treat
ment. On application of the voltage, the soil near the anode became acidic
due to the electrolytic generation of Hf, and the acid region gradually spr
ead toward the cathode. The major cation in the acid region was, however, n
ot Hf but Al3+ that arose from the acid-induced dissolution of soil mineral
s, and it migrated very slowly toward the cathode. The measured pH and acco
mpanying ion concentrations indicated that the anomalously slow migration o
f Al3+ was due to its precipitation-dissolution reaction at the acid front.
The stagnancy of Al3+ increased the ionic concentration, flattened the ele
ctrical potential profile, and in turn, diminished electromigration in the
acid region. This seems to be one of the causes of the relatively low remov
al rate of cationic and anionic contaminants in electrokinetic treatments.