Physiological Response Of Alpinia Oxyphylla Seedlings To Chromium And Speciation Changes Of Heavy Metals In Planting Soil

In order to study the effects of different stress concentrations on antioxidant enzyme system,malondialdehyde(MDA)and osmotic adjustment substance content of Alpinia oxyphylla seedlings,the simulated experiment of chromium(CR)pollution was carried out.In order to explore the relationship between the variation of different forms of heavy metal Cr and soil p H value in the soil of Alpinia oxyphylla seedlings,the appropriate passivator and dosage were selected and added to the soil of Alpinia oxyphylla seedlings.The results of the study were as follows:(1)Effects of different concentrations of heavy metal stress on the growth of Alpinia oxyphylla seedlings were studied.The results showed that the antioxidant system of Alpinia oxyphylla seedlings had higher activity when the content of Cr was50 mg / kg-75 mg / kg in soil,while the activities of SOD and cat were inhibited when the concentration of Cr was 75 mg / kg-150 mg / kg.The content of MDA and pro increased with the increase of heavy metal stress concentration.The contents of soluble reducing sugar and soluble protein increased first and then decreased.(2)It can be concluded from the experiment of Cr passivation and remediation by lime and biochar.The best choice for the passivation of available Cr content in soil is the combined application of biochar and lime,followed by the application of lime alone,and the most effective is biochar.The efficiency of stabilizing heavy metal Cr in soil by biochar is 23%-46%,lime can reach 30%-54%,and the combined application of biochar and lime can reach 38%-60%.Biochar passivation mainly improves the p H value of heavy metal Cr,and the removal efficiency is high It has a good adsorption effect on the surface,so it has a good passivation effect.Lime also increases the p H value,enhances the ability of soil to absorb heavy metal Cr,and reduces the availability of chromium in soil,so as to reduce the pollution degree of heavy metal to soil.(3)The results showed that when 0.2% lime was added to the soil,the p H value increased first and then decreased.The content of water-soluble heavy metal chromium and weak acid extracted heavy metal chromium in the soil was affected by the change of p H,and changed into the form which was not easy to be absorbed by the seedlings,The toxicity of heavy metal pollution on Alpinia oxyphylla seedlings can be reduced by adjusting the p H value of planting soil...