Study On The Remediation Effect Of Different Ameliorant To The Pb Polluted In Granitic Latosol

Through the methods of adding the heavy metal Pb into unpolluted Granitic latosol in Hainan ,after 2 fortnight's equilibrium, adding lime, calcium magnesium phosphate, cow dung, calcium magnesium phosphate and the cow dung mixture match executes, taking Brassica chinensis as instruction crops, according to its different quality of physics and chemistry such as growth dynamic change and the biomass of the harvest, the absorbing capacity of the heavy metal, the soil pH, the content of heavy metal in the soil, we had appraised the improvement effects of each kind of modifiers to the Pb polluted in Granitic latosol. Then we could provide the reference for improving the Pb polluted in Hainan Granitic latosol. The experiment results as follows:1. In the lead polluted soil, the growth of Brassica chinensis in the bonsai was slow, calcium magnesium phosphate,calcium magnesium phosphate and the cow dung mixture improved the soil physics and chemistry character, and enhanced the soil pH, soil alkalized-nitrogen, organic matter and rapidly available phosphor, also effectively alleviated the heavy metal to poison the function, remarkably enhanced Brassica chinensis biomass. The effect of lime treatment was next and the effect of cow dung processing is little. Therefore cow dung is not a kind ideal modifier to the Pb polluted in Granitic latosol.2. Lead pollution soil planter Brassica chinensis, adult plant Pb centre markable increase, also the higher pollution level, the higher Pb content in the Brassica chinensis . After adding lime, calcium magnesium phosphate, calcium magnesium phosphate and cow dung mixture three kind of modifiers processing in to each pollution soil, Pb content in the Brassica chinensis was remarkably reduced comparing to the comparison. The studies showed that three kinds of modifiers could effectively suppress Brassica chinensis to the soil in the Pb absorption. When pollution level was less than 2000mg/kg calcium magnesium phosphate , calcium magnesium phosphate and the cow dung mixture processing suppression Brassica chinensis were the best to the Pb suppression effect and the lime was next. The effect of these three kinds of modifiers were better than cow dung processing.3. Lead pollution soil could remarkably enhance Brassica chinensis Pb absorption coefficient, but exerts the lime, the calcium magnesium phosphate, Calcium magnesium phosphate and the cow dung mixture three kinds modifiers could remarkably reduce the crops Pb absorption coefficient. During different part of Brassica chinensis, the Pb absorption coefficient was different. The root system lead absorption coefficient was remarkably higher than the leaves of absorption coefficient. The results indicated that the crops absorption Pb mainly concentrated in the root system. Brassica chinensis Pb absorption coefficient was reduced with the improved pollution level. This showed that, Brassica chinensis absorption Pb the ability was gradually suppressed with the increase of soil Pb density.4. Adding lime and calcium magnesium phosphate could obviously enhance soil pH, cause the soil OH- increase, form the hydroxide to precipitate, reduce the Pb validity; On the other hand, because between Ca²⁺ and Pb²⁺ exists oppresses the anti-function, thus reduced the crops to the soil in the Pb absorption. In whole processing, lowly pollutes in the level the G₃P₁ processing effect best, the range of fall reaches 38.3%, center pollutes in the level the G₂P₃ processing effect best, the range of fall reaches 39.4%, in the high pollution level the G₃P₃ processing effect is best, the range of fall reaches 47.3%.