Evaluation of monobasic calcium phosphate for the immobilization of heavy metals in contaminated soils from Lavrion.
The objective of this work was to evaluate the efficiency of monobasic calcium phosphate for the stabilization of heavy metals in contaminated soils. The treatment was applied on a soil sample from the Lavrion mining area, Greece, heavily contaminated with Pb, Zn, Cd and As and characterized as toxic in respect to Pb according to the US EPA toxicity characteristics leaching procedure (TCLP). The efficiency of stabilization was evaluated based on two criteria: (a) the reduction of metals mobility below the TCLP regulatory limits; (b) the reduction of phytoaccumulation. Phytoaccumulation was evaluated both indirectly by applying leaching tests using EDTA, DTPA and NaHCO(3) solutions and directly by carrying out pot experiments with Phaseolus vulgaris as plant indicator. This treatment was found to immobilize Pb and Cd, whereas As and Zn were slightly mobilized. No effect on phytoaccumulation was observed. Moreover, the treatment had a negative effect on plants growth, which was combined with a strong deficiency of Ca in the tissue of leaves.
Theodoratos
Panagiotis
P
Laboratory of Metallurgy, National Technical University of Athens, GR-157 80 Zografos, Greece.
Papassiopi
Nymphodora
N
Xenidis
Anthimos
A
D001673:Biodegradation, Environmental; D001682:Biological Availability; D002130:Calcium Phosphates / Q000737:chemistry*; D004787:Environmental Pollution / Q000517:prevention & control*; D019216:Metals, Heavy / Q000032:analysis*; D027805:Phaseolus / Q000502:physiology; D012989:Soil Pollutants / Q000032:analysis*; D014018:Tissue Distribution
D002130:Calcium Phosphates; D019216:Metals, Heavy; D012989:Soil Pollutants; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous