Study On The Effect Of Aspergillus Niger On Situ Remediation Of Cadmium And Zinc Compound Pollution In Soil

The viability of the microbe can influence the biological invalid of heavy metal and reduce the damage of heavy metals in soil-plant system, which holds a large potential in bioremediation. Aiming at the problem that situ immobilization of microbe in soil, taking anthropogenic added Cd and Zn soil as experimental soil, rape as experimental plant, Aspergillus niger as experimental microbe, with orthogonal regression design of two factors (Cd and Zn) in five levels. A pot experiment was carried out to study the effects of different Aspergillus niger volume treatment and different Cd and Zn pollution levels on Cd and Zn uptake by rape, which can provide scientific basis for Aspergillus niger used in microbe situ immobilization. Main results of the experiments were summarized as follows:1. With the increasing in the volume of Aspergillus niger in the soil, average fresh weight and length of rape in 5 volume of treatment were showed a trend from ascent to descent, that reached significant level. The inflection point is 150 ml.2. Under the treatments of different volume of bacterial liquid, the concentrations of Cd and Zn in shoot and root of oilseed rape in each treatments were significantly lower than control. Concentrations of Cd and Zn in shoot of rape decreased highest by 23.03% and 28.70%, while concentrations of Cd and Zn in root of rape in each treatments declined by 35.08% and 25.71%.3. Under different volume of inoculation bacterial liquid treatments, the contents of available Cd and Zn showed a trend of decreasing significantly in soil with the inoculation volume increased. The average of soil pH increases remarkably with increasing the volume. With the volume increasing, the growth trend was slowing down.4. Under different compound contamination of Cd and Zn, Cd and Zn contents in shoot and root of rape not only affected by the added Cd and Zn contents respectively, but also by co-existent heavy metal element in soil. The interaction of Cd and Zn indicates that Zn inhabited Cd uptake of roots. Under the treatments of adding Aspergillus niger, Cd and Zn contents in shoot and root of rape unaffected by co-existent elements and decreased significantly than the control treatments.5.Under different compound contamination of Cd and Zn, the contents of available Cd and Zn showed a trend of decreasing significantly in soil with increasing of Cd and Zn contents in soil. While in the Aspergillus niger treatments group, the contents of available Cd and Zn decreasing significantly. Aspergillus niger showed better in immobilization on low heavy metal concentration in soil. Suitable range of Aspergillus niger on Situ Remediation of Cadmium and Zinc Compound Pollution in soil is mild to moderate pollution levels of heavy metals.