Electrokinetic remediation of contaminated soil with waste-lubricant oils and zinc.
The feasibility of electrokinetic technology on the remediation of mixed-waste-contaminated railroad soil, contaminated by lubricant oil and zinc, was investigated. To enhance the removal efficiency, catholyte purging with 0.1M HNO(3) and a supply of non-ionic surfactant, secondary alcohol ethoxylate, was applied to the anode to remove Zn and to solubilize the lubricant oil. The catholyte purging maintained the soil pH as acidic and enhanced desorption of zinc from the soil, where the zeta potential of the acidic soil became positive. Thereafter, the direction of electro-osmotic flow was changed from the cathode to anode and the flow rate was reduced. The lesser in magnitude reverse electro-osmotic flow inhibited the migration of zinc and the lubricant oil was removed by the electro-osmotic flow. The removal of zinc and lubricant oil was enhanced with an increase in voltage gradient; however, a higher voltage gradient resulted in higher energy expenditure. After electrokinetic operation over 17 days, the removal efficiency of zinc was 22.1-24.3%, and that of lubricant oil was 45.1-55.0%. Although the removal of lubricant oil was quite high, the residual concentration did not meet Korean regulation levels.
Park
Sung-Woo
SW
Department of Environmental Engineering, Kumoh National Institute of Technology, Gumi, Gyeongbuk 730-701, Republic of Korea.
Lee
Jae-Young
JY
Yang
Jung-Seok
JS
Kim
Kyoung-Jo
KJ
Baek
Kitae
K
D055664:Electrochemical Techniques; D052918:Environmental Restoration and Remediation; D007220:Industrial Waste / Q000331:legislation & jurisprudence / Q000517:prevention & control; D007723:Korea; D054327:Lubricants; D009821:Oils / Q000737:chemistry*; D011890:Railroads; D012989:Soil Pollutants / Q000737:chemistry*; D015032:Zinc
D007220:Industrial Waste; D054327:Lubricants; D009821:Oils; D012989:Soil Pollutants; D015032:Zinc