The Selective Reaction of Lead and Amorphous Iron with EDTA in Lead Sulfate-contaminated Soil System

Kim, Chulsung; Ong, Say Kee

Environmental Engineering Research 1998;3(3): 167-174.

Chulsung Kim^†, and Say Kee Ong

Department of Civil Engineering, Iowa State University, USA

Corresponding Author: Chulsung Kim ,

Received: June 10, 1998; Accepted: September 5, 1998.

ABSTRACT

Amorphous iron in soil may compete with lead for EDTA (Ethylenediaminetetraacetic acid) ligand sites in the extraction of lead from lead sulfate-contaminated soil. Experiments conducted with varying amounts of amorphous iron content indicated that the extraction efficiency of lead with EDTA from lead sulfate-contaminated soil was effected especially for pH values less than 6.0. The percent extraction of lead from the contaminated soil depends on the lead: EDTA stoichiometric ratio, pH, and amorphous iron concentration. The effect of amorphous iron on lead extraction appeared to be dominant at pH less than 6 for lead: EDTA stoichiometric ratio of less than 1 : 2. The theoretically calculated model using thermodynamic data approxi¬mately matched with the results experimentally conducted.