Analysis about the immobilization effect of MKPC on Cu, Zn and Ni in soils and the plant availability

In order to evaluate the immobilization effect of Potassium phosphate magnesium cementing(MKPC) materials on the heavy metal contaminated soils and the plant availability after the curing treatment, pot experiment was performed in this study to analyze the effect of MKPC on Cu, Zn and Ni as well as the plant growth status and biological availability. For the simulated soil samples added with heavy metals at the ratio of 5 g/kg, the additive amount of MKPC is set to be 3.34%. After 60 d of curing, the stabilization rate of Cu, Zn and Ni is 62.6%, 49.8% and 47.2% respectively. MKPC achieves a good stabilization effect on these three heavy metals in soils. After the curing process, the germination and growth of plants are affected. Specifically, the germination period is prolonged by 1-3 d and the growth height is decreased by 5.2-24.4 cm; meanwhile, the availability of plants on these three heavy metals is not significantly reduced. Thus, the results suggest that MKPC exhibits a good curing effect on heavy metals. It can be used to conduct in situ immobilization on the heavy metal contaminated soils, but its effect on plant availability is insignificant.