title: The study of operating variables in soil washing with EDTA.
abstract: This study discusses the operating variables for removal of metals from soils using EDTA, including the type of EDTA, reaction time, solution pH, dose, temperature, agitation, ultrasound and number of extractions. For As, Cd, Cu, Pb and Zn, the removal efficiency order was: H(4)-EDTA > Na(2)EDTA > (NH(4))(2)EDTA. At low EDTA concentrations the removal increased progressively with increasing dose while above 0.4 mmol/g only small increases in extraction efficiency were observed. EDTA induced a two-step process including a rapid desorption within the first hour, and a gradual release in the following hours. The extraction efficiency of metals decreased with increasing pH in the range of 2-10. Consecutive extractions using low concentrations were more effective than a single extraction with concentrated EDTA if the same dose of EDTA was used.
authors.affiliation: School of Environmental Science and Engineering, Sun Yat-sen University, 135 Xin Gang Xi Road, Guangzhou 510275, China.
authors.forename: Zeli
authors.initials: Z
authors.lastname: Zou
authors.forename: Rongliang
authors.initials: R
authors.lastname: Qiu
authors.forename: Weihua
authors.initials: W
authors.lastname: Zhang
authors.forename: Hanying
authors.initials: H
authors.lastname: Dong
authors.forename: Zhihao
authors.initials: Z
authors.lastname: Zhao
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.forename: Xiange
authors.initials: X
authors.lastname: Wei
authors.forename: Xinde
authors.initials: X
authors.lastname: Cai
mesh_terms: D000327:Adsorption; D001151:Arsenic; D002104:Cadmium; D002614:Chelating Agents / Q000494:pharmacology*; D003300:Copper; D004492:Edetic Acid / Q000494:pharmacology*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007854:Lead; D019216:Metals, Heavy; D012989:Soil Pollutants; D013997:Time Factors; D015032:Zinc
chemical_list: D002614:Chelating Agents; D019216:Metals, Heavy; D012989:Soil Pollutants; D002104:Cadmium; D007854:Lead; D003300:Copper; D004492:Edetic Acid; D015032:Zinc; D001151:Arsenic