Accumulation Ability of Cd in Water for Phragmites australis,Acorus calamus and Scirpus tabernaemontani

The hydroponic experiments for Phragmites australis,Acorus calamus,Scirpus tabernaemontani were carried out to measure and establish the Cd accumulation ability of these three wetland plants under 6 Cd treatments(0.5,1.0,5.0,15.0,30.0,60.0 mg.L-1)in hydro-ponic solution.The results suggested that the Cd accumulation ability was varied depending on the plant species,growing parts of plants and the Cd concentration in treatments,and there were significant difference among 3 plant species and among different Cd treatments.There were significant correlation relationships between the Cd accumulation contents and Cd concentrations for the overground and underground growing parts of each plant species,and the Cd accumulation contents in plant bodies always increased with the addition of Cd concentrations in proportion.Among these 3 wetland plants,Acorus calamus always performed the strongest Cd accumulation ability,and Phragmites aus-tralis had the lowest Cd accumulation ability.Comparing with the control,the lower concentration Cd treatments did not affected the Cd accu-mulation of three wetland plants,but the higher concentration Cd treatments promoted the accumulation of Cd for three plants.The Cd accu-mulation ability of the underground parts of three wetland plants was greater than the overground parts significantly,and the Cd accumulation contents of the underground parts was to more than double of the overground parts.The Cd accumulation contents in bodies of three plants could arrive to 10 074.17,14 759.33,4 620.00 mg.kg-1 for Phragmites australis,Acorus calamus,Scirpus tabernaemontani respectively.These three wetland plant species all were suitable to use as the plants for controlling the Cd pollution in waste water.