Remidiation Of Heavy Metal Contaminated Soil By Intercropping Phyllostachys Pubescens With Sedum Plumbizincicola

The research of heavy metal polluted soil has become a hot spot and the frontier,nowadays,the technology about phytoremediation receives extensive attention of the researchers.According to the trail of the intercropping Phyllostachys pubescens with sedum plumbizincicola,the main conclusions are as follows:(1)Through pot experiments,we started the intercropping experiment of Phyllostachys pubescens seedings and sedum plumbizincicola,to research the influence on growth of plants,the transfer ability of heavy metals(Cu,Cd and Zn)in system of soil and plant and the effect on accumulation of Cu,Cd and Zn in different parts of plant.As the results showed,it isn't suitable for Phyllostachys pubescens to intercrop sedum plumbizincicola in seeding stage,because of the biomass of both and the negative effect on their transfer in soil-root system.However,intercropping has shown the potential of upward transfer by root,and it also has positive impacts on Cu,Cd and Zn accumulation.Therefor it is likely to realize the goal of Phyllostachys pubescens and sedum plumbizincicola interplanting,when Phyllostachys pubescens grow into tree,which also accord with the characteristic of sedum plumbizincicola liking shade.(2)Compare with the fractionation and bio-accessibility of Cu,Cd and Zn,Cd and Zn are the lagest harmness to our health.BCR sequential extraction showed that Cd was mainly in exchangeable fraction form,which was 47.6%~59.8%.The exchangeable Cd contents were improved by monoculture and intercropping.And Zn was mainly in the exchangeable and reducible fraction form,which were 20.2%~27.7% and 54.1~58.5%.The exchangeable and reducible Zn wrer reduced by intercropping,but these proportion of Zn is too much to unabsorb by plants.Moreover,the bioaccessibility of Cd and Zn in stomach clearly higher than those in small intestine.The highest bioaccessibility of Cd is 405% and the biggest totall concentration of Cd is1.5mg/kg.While the highest bioaccessibility of Zn is 29% and the biggest totall concentration of Zn is1433.9mg/kg.(3)In intercropping field experiment,intercropping could accelerate heavy metals concentrations in Phyllostachys pubescens and sedum plumbizicicola to some extent.The accumulation Cd and Zn in aboveground of sedum plumbizincicola was increased greatly by intercropping,the maximum were64.4mg/kg and 3866.1mg/kg.The accumulation of Cu and Zn in leaves and branches of Phyllostachyspubescens was improved,and the accumulation of branches was higher than that of in leaves.While the time of accumulating Cd was advanced about one month by intercropping.And the accumulation of Cd in leaves and branches was adjusted to ensure plants growth.What's more,the change of SPAD and MDA also contributed to growth of Phyllostachys pubescens and sedum plumbizicicola,to improve the tolerance of plants and to live in comtaminated soil.