Effects Of CTAB,LAS And IBA On Phytoremediation Of Cd²⁺ Contaminated Soil By Chinese Sweet Gum (Liquidambar Formosana Hance) Seedlings

By means of absorption-desorption experiments and pot experiments,the author studied the effects of CTAB and LAS on absorption and desorption of Cd2+ in soil,effects of two kinds of surfactants and IBA on biomass of seedlings of Liquidambar formosana Hance, and the uptake, accumulation and translocation of Cd2+ by seedlings. The mean results were described as follows:(1) With the increasing of CTAB concentration, the absorption of Cd2+decreased, but the concentration of Cd2+ that couble be used by plants increased. CTAB caused greater desorption of Cd2+ from soil than LAS did.With the increasing of CTAB concentration, the desorption of Cd2+ increased. When the concentration of CTAB was 200mg/L, the absorption of Cd2+ by soil reached the least value and the desorption of Cd2+ by soil had the highest value.(2) Both CTAB and LAS could markedly increase the biomass of root system and leaf of seedlings. But both the kind and concentration of surfactants did not have effective influence on the biomass of stem of Liquidambar formosana Hance seedlings. The order of different organ biomass was:root>stem>leaf. The C 2 treatment had the best effect to improve the biomass of seedlings by subordinate function method.(3) Moreover, the concentration of Cd2+ in all parts of seedlings increased with the effect of surfactants, the order of the Cd2+ concentration of plant organs was:root>stem>leaf. CTAB could make more Cd2+ accumulate in plants than LAS do, and with the increasing of CTAB concentration, the accumulation of Cd2+increased. In all of treatments, C 2 had the best effect on uptaking of Cd2+ in Liquidambar formosana Hance seedlings. LAS was more effective than CTAB to improved translocation of Cd2+ from root to shoot, at the same time, CTAB could make more Cd2+ accumulate in root system of seedlings.(4) IBA not only improve the biomass of root and leaf of seedlings, but also have significant effects on the accumulation of Cd2+ in plants.600mg/L IBA is more effective than 200 mg/L IBA(5) With the combined effect of surfactants and IBA, IBA 600+C 1 and IBA 600+C 2 treatments were better to improve the biomass of root, stem and leaf of Liquidambar formosana Hance seedlings. IBA 600+C 2 treatment had the strongest effect on the concentration of Cd2+of plants and the bioaccumulation factor,but it's translocation factor was very poor,therefore, IBA 600+C 2 treatment had less effect on phytoremediation of Cd2+ contaminated soil by Liquidambar formosana Hance seedlings than IBA200+L1 treatment did.