Ecological engineering remediation of heavy metal polluted soil

Remediation of Cu and Zn from a contaminated soil by Herba Elsholtziae and Papermulberry and impacts of Cu and Zn pollutant in soil on physiological characteristics of the plants were analyzed. Results show that heavy metal concentrations in the plant tissue increase with the increase of heavy metals in the soil in pot experiment. For Herba Elsholtziae, concentration of Cu is the aboveground part < the underground part while concentration of Zn is the aboveground part > the underground part. However, for Papermulberry, concentrations of both Cu and Zn are as follows: root>leave>stem. In general, the accumulation coefficient in the Papermulberry is more than 1, especially the greatest accumulation coefficient is 2.42 for Cu. Although the accumulation coefficient for Papermulberry is less than 0.5, the biomass in the aboveground part is huge, therefore, the content of heavy metals removed from the soil is considerable. In addition, the Papermulberry has good economic value. Combined the Herba Elsholtziae with the Papermulberry form, a three-dimensional model of ecological engineering remediation is established. The model would be able to remove heavy metals from the contaminated soil, to restore ecological environment and microorganism environment of soil and to bring economic and environmental benefit.