Assisted phytostabilisation of As, Pb and Sb-contaminated Technosols with mineral and organic amendments using Douglas fir (Pseudotsuga menziesii (Mirb.) Franco).

Phytoremediation of metal(loid)s by conifers is not widely studied, although conifers may be interesting, particularly in temperate-cold areas and/or on acidic soils. In this study, seeds of Douglas fir were sown in greenhouse and cultivated for 3 months on two Technosols highly contaminated with different concentrations of Pb, As and Sb and collected in two French old former mines located in massif Central or close to it: a mine of gold at La Petite Faye and a mine of lead and silver at Pontgibaud. Two amendments, a nutrient solution (NS) and composted sewage sludge (CSS), were tested in order to stimulate Douglas fir growth and to reduce the metal(loid)s mobility and phytoavailability.