The study of operating variables in soil washing with EDTA.
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.
Zou
Zeli
Z
School of Environmental Science and Engineering, Sun Yat-sen University, 135 Xin Gang Xi Road, Guangzhou 510275, China.
Qiu
Rongliang
R
Zhang
Weihua
W
Dong
Hanying
H
Zhao
Zhihao
Z
Zhang
Tao
T
Wei
Xiange
X
Cai
Xinde
X
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
D002614:Chelating Agents; D019216:Metals, Heavy; D012989:Soil Pollutants; D002104:Cadmium; D007854:Lead; D003300:Copper; D004492:Edetic Acid; D015032:Zinc; D001151:Arsenic