Chromium and nickel mobilization from a contaminated soil using chelants.
The mobilization of chromium and nickel from an industrial soil was investigated using two biodegradable chelants (citric acid and histidine), compared with a persistent one (ethylenediaminetetraacetic acid). Successive metal mobilizations were carried out in batch experiments. The main reactions involved were estimated by modeling the system with MINEQL+. For a single mobilization, citric acid was the most effective for Cr mobilization and EDTA for Ni. Their effectiveness could be explained by their ability to solubilize the mineral matrix and by the competition for the surfaces sites to desorb Cr(VI). Before and after the mobilizations, the distribution of metals was determined by a sequential extraction procedure. Only slight modifications were observed due to the low percentage of solubilized metal. A concentration of 0.05 mol L(-1) (citric acid and EDTA) allows a good compromise between metal mobilization and preservation of the soil mineral integrity.
Jean
Liliane
L
Laboratoire des Sciences de l'Eau et de l'Environnement, Université de Limoges, 123 avenue Albert Thomas, Limoges, France.
Bordas
François
F
Bollinger
Jean-Claude
JC
D001673:Biodegradation, Environmental; D002614:Chelating Agents / Q000737:chemistry*; D002857:Chromium / Q000032:analysis / Q000737:chemistry*; D019343:Citric Acid / Q000737:chemistry; D004492:Edetic Acid / Q000737:chemistry; D006639:Histidine / Q000737:chemistry; D007220:Industrial Waste; D007700:Kinetics; D009532:Nickel / Q000032:analysis / Q000737:chemistry*; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000737:chemistry*; D012995:Solubility
D002614:Chelating Agents; D007220:Industrial Waste; D012987:Soil; D012989:Soil Pollutants; D002857:Chromium; D019343:Citric Acid; D006639:Histidine; D009532:Nickel; D004492:Edetic Acid