TOLERANCE AND ACCUMULATION CHARACTERISTICS OF ORNAMENTAL PLANTS TOWARDS LEAD

Through hydroponic experiments, seven lead (Pb) pollution concentrations ranging from 0 to 1000 mg/L were used to study the ability of three kinds of ornamental plants, Commilina communis (C. communis), Hosta ventricose (H. ventricosa) and Bryophyllum pinnatum (B. pinnatum), to purify Pb-contaminated water with different mass concentrations. The results showed that the biomass of the shoots and roots of the three ornamental plants decreased to different degrees with increasing Pb concentrations, showing an inhibitory effect of Pb on plant growth. Under different Pb pollution concentrations, the distribution trend of Pb content in the tested ornamental plants showed that the roots had more Pb content than the shoots, and the Pb content in the shoots of all three plants exceeded 1000 mg/kg. C. communis was the most tolerant among the three tested ornamental plants. The effective concentration (EC50) value of the shoots of B. pinnatum was the highest at 714.2 mg/kg. The EC50 value of the roots of C. communis was the highest at 563.1 mg/kg. Therefore, both C. communis and B. pinnatum have strong potential to remediate Pb-contaminated water and soil.