Ammonium thiosulphate assisted phytoextraction of mercury and arsenic in multi-polluted industrial soil

The possibility of using ammonium thiosulphate in assisted phytoextraction was evaluated on a greenhouse scale (mesocosm) for the simultaneous removal of mercury and arsenic from multi-polluted industrial soil. The addition of thiosulphate to the soil greatly promoted the uptake and translocation of both contaminants in the aerial parts of Brassica juncea and Lupinus albus. Thiosulphate showed great potential since it is a common fertilizer used to promote plant growth and is able to promote plant uptake of both Hg and As. Hg concentration in the aerial part of the plants reached 867 mg kg-1 in B. juncea and 114 mg kg-1 in L. albus. In the aerial parts, As concentration was about 9 mg kg-1 in B. juncea and 20 mg kg-1 in L. albus. This thus increases the applicability of phytoextraction in terms of cost and time especially if the remedial targets are based on bioavailable metal concentrations.