Electrokinetic Restoration of Sulfate-Accumulated Saline Greenhouse Soil

Abstract

Electrokinetic (EK) process was performed to restore sulfate-originated saline soil and to evaluate the effect of treatment duration. Sulfate and potassium were the major ionic salts in the saline soil used in this study. A constant voltage gradient of 1?V/cm was applied for 8, 12, and 16 days. After EK treatment, anions and cations were transported toward anode and cathode, respectively, by electromigration. Chloride was completely removed, and 85.6% of nitrate was removed after 8 days of treatment. The increase of treatment period from 8 to 12 days had a negligible effect on the enhancement in the rate of sulfate removal; however, over 70% was removed after16 days. At the end of experiment, the electrical conductivity (EC) of the soil, an indicator of soil salinity, decreased to 1.93?dS/m from an initial value of 5.3?dS/m, and the distribution of sulfate was similar to that of EC. The operation time of 16 days was sufficient to restore the sulfate-originated saline soil using the EK process.