The Effect Of Heavy Metals Pollution On Soil Enzyme Activity And Enrichment Ability Of Plant

The paper studied the effects of cadium and nickel pollution of the battery factory surrounding soil onthe soil enzyme activity in simulation firstly. The influences of cadium and nickel addition on urease,catalase and sucrase in planted soil of M. pudica and Trifolium pratense L. were studied through outdoorpot experiments. The results showed that M. pudica and Trifolium pratense L. group of urease, catalaseactivity rose by single cadium and nickel pollution at low concentration. At higher concentration, the M.pudica and Trifolium pretense L. groups of urease and catalase activities were restrained. The sucraseactivity was restrained by single cadium and nickel pollution. Under the combined pollution of cadium andnickel, the M. pudica and Trifolium pratense L. group of urease, catalase and sucrase activities wererestrained. Inhibition of single and combined pollution of cadium, nickel on soil enzyme activities of theorder were urease＞sucrase＞catalase. Including soil urease can be used as early warning indicator of thecadium and nickel pollution. The effect of M. pudica on soil enzyme activity was higher than Trifoliumpratense L.. The M. pudica may have a great value in remending cadium and nickel contaminated soil.Through the study on soil enzyme activity of the rhizosphere of Mimosa and Clover, it could provide thetheoretical basis for the remediation technology of heavy metals polluted soil. And it also played animportant role in the quality assessment of the factory surrounding environment and the prevention of thecombined heavy metals pollution in soil.Secondly, it studied the effects of plumbum single pollution, and cadium and plumbum combinedpollution on the rhizosphere soil urease, catalase and sucrase activity in Impatiens balsamina L by addingexternal heavy metals and outdoor pot experiment. The results showed that, in the condition of plumbumsingle pollution, plumbum had inhibitory effect on soil urease activity, and at first it had activated effect onsoil sucrase and catalase activity, then had inhibitory effect on them. In the condition of cadium, plumbumcombined pollution, there was a negative synergistic inhibition effect on soil urease activity, and the effectson soil invertase and catalase activity was similar to plumbum single pollution situation. No matterplumbum single pollution or cadium, plumbum combined pollution; the inhibition rate was the largest. Sothe soil urease activity could be used as a biochemical index of plumbum and cadium, plumbum pollution, and it provided a reasonable basis for the judgment of cadium, plumbum pollution level.Then it studied the effects of cadium and plumbum on Impatiens balsamena. L’s growth condition andaccumulation ability by adding external heavy metals and outdoor pot experiment. The research showedthat, in the cadium treatment concentration, the content of Impatiens balsamena. L’s plant height, biomassand chlorophyll showed a downward trend when increased the concentration. The low concentration ofcadium（5mg·kg-1）had a stimulating effect on Impatiens balsamena. L’s taproot length. When theconcentration of cadium was more than5mg·kg-1, it had an inhibitory effect. In the plumbum treatmentconcentration, Impatiens balsamena. L’s plant height, main root length, biomass and chlorophyll contentincreased firstly and then decreased. The effects of cadium and plumbum on Impatiens balsamena. L were：stem> root. In addition, the content of heavy metal in the parts of underground was higher than theaboveground parts. The transfer factor and bioaccumulation coefficient decreased with the increase ofplumbum and cadium’s concentration. It showed that the Impatiens balsamena. L aboveground parts’transfer ability was poor, so the Impatiens balsamena. L didn’t have the hyperaccumulator potential. TheImpatiens balsamena. L was not suitable for phytoremediation under the condition of plumbum and cadiumpollution.