title: Humic substances-enhanced electroremediation of heavy metals contaminated soil.
abstract: The effects of catholyte conditioning and the use of humic acids (HAs) and fulvic acids (FAs) as chelating agents to improve electrokinetic (EK) remediation efficiency were investigated using a real and highly contaminated soil. By applying a constant voltage (2.0V/cm) to the soil, pH and current changes and heavy metals (HMs) concentration were investigated through a range of durations and positions. The observations demonstrated that both catholyte conditioning with 0.1N HNO3 and using humic substances (HSs) enhance remediation efficiency. After 20 days of EK treatment, the removal efficiency of HMs in HS-enhanced EK remediation was about 2.0-3.0 times greater than when unenhanced. The quantity of HMs moving toward the cathode exceeded the anode, from which it could be reasonably inferred that most negatively charged HM-HS complexes were moved by electroosmotic forces. Further, free HM cations and positively charged complexed HMs migrated to the catholyte compartment by electromigration. The results obtained in this study, demonstrate the suitability of HS-enhanced EK remediation in HMs contaminated soil.
authors.affiliation: Department of Soil Science, Faculty of Agricultural Engineering and Technology, University of Tehran, Iran. Electronic address: MBahemmat@ut.ac.ir.
authors.forename: Mahdi
authors.initials: M
authors.lastname: Bahemmat
authors.affiliation: Department of Soil Science, Faculty of Agricultural Engineering and Technology, University of Tehran, Iran. Electronic address: mfbakhsh@ut.ac.ir.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Farahbakhsh
authors.affiliation: Department of Biotechnology, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran. Electronic address: mkianirad2002@yahoo.com.
authors.forename: Mehran
authors.initials: M
authors.lastname: Kianirad
keywords: Electrokinetic remediation; Fulvic acids; Heavy metals; Humic acids