Evaluation of cyclonic ash, commercial Na-silicates, lime and phosphoric acid for metal immobilisation purposes in contaminated soils in Flanders (Belgium).
In order to reduce the health risks associated with historically enriched metal smelting sites in Flanders (Belgium), the capacities of a non-beringite cyclonic ash and commercial Na-silicates to fix metals and create conditions to restore vegetation cover were evaluated and compared to lime and H(3)PO(4). All tested amendments reduced Ca(NO(3))(2)-extractable soil metal concentrations and reduced metal uptake in Agrostis capillaris seedlings. Sodium released by Na-silicates was possibly toxic to bean plants while an isotopic dilution technique revealed that metals were only weakly sorbed by silicates (i.e. reversible sorption). Cyclonic ash appeared more efficient than lime in both reducing oxidative stress in beans and Zn, Cu and Pb uptake in grasses. The metal fixing mechanism for both amendments appeared similar (i.e. irreversible fixation at constant pH), in contrast to H(3)PO(4) where at least part of the immobilised Cd was irreversibly fixed across a range of pH.
Geebelen
Wouter
W
Hasselt University, Centre for Environmental Sciences, Environmental Biology, Agoralaan--Gebouw D, B-3590 Diepenbeek, Belgium. wouter.geebelen@uhasselt.be <wouter.geebelen@uhasselt.be>
Sappin-Didier
Valérie
V
Ruttens
Ann
A
Carleer
Robert
R
Yperman
Jan
J
Bongué-Boma
Kwèlè
K
Mench
Michel
M
van der Lelie
Niels
N
Vangronsveld
Jaco
J
D000327:Adsorption; D031703:Agrostis / Q000737:chemistry / Q000378:metabolism; D001530:Belgium; D001673:Biodegradation, Environmental; D002106:Cadmium Radioisotopes / Q000737:chemistry; D017610:Calcium Compounds; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D008669:Metallurgy; D019216:Metals, Heavy / Q000032:analysis; D010087:Oxides; D027805:Phaseolus / Q000378:metabolism; D010756:Phosphoric Acids; D017640:Silicates; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000032:analysis; D018675:Toxicity Tests
D002106:Cadmium Radioisotopes; D017610:Calcium Compounds; D007220:Industrial Waste; D019216:Metals, Heavy; D010087:Oxides; D010756:Phosphoric Acids; D017640:Silicates; D012987:Soil; D012989:Soil Pollutants; C016538:lime; C030242:phosphoric acid; C005691:sodium silicate