不同含磷化合物对中国芥菜(Brassica Oleracea)铅吸收特性的影响

Effects of different phosphorus-compounds on Pb uptake by Brassica Oleracea 

研究了不同含磷化合物(羟基磷灰石HA、磷矿粉PR、磷酸氢钙SSP)对污染土壤中铅的植物有效性及形态变化影响.结果表明:高磷水平(5000mg·kg-1)对降低植物茎叶和根中铅的含量有明显作用.其中HA对降低土壤中铅的植物有效性的效果最明显,HA5000处理对植物茎叶和根组织中铅的含量分别降低52 2%和73 1%,在5000mg·kg-1的施磷水平下,上述含磷化合物对降低植物吸收铅的影响顺序为:HA>(HA+SSP)>SSP>PR.连续提取法试验结果表明:土壤中加入不同的含磷化合物对形成土壤中残留态铅、降低有效态铅的含量有明显效果,其影响顺序为HA>PR>HA+SSP>SSP.以上结果表明,HA对降低土壤中铅的生物有效性、增加污染土壤中铅的化学稳定性具有明显的效果.

Effects of different phosphoruscompounds (hydroxylapatite, HA; phosphate rock, PR; and single superphosphate, SSP) on the phytoavailibility and speciation of Pb in a contaminated soil were examined. Results showed that the Pb concentrations in both shoots and roots of the vegetable plants (Brassica Oleracea, BO) decreased with increasing quantities of added P compounds, and the HA treatment had the best effect at the level of 5000 mg(P).kg-1 compared with other treatments, in which Pb concentrations in shoots and roots of BO plants decreased by 522% and 731% respectively compared with the control treatment. At the level of 5000 mg(P). kg-1 the effect of treatments followed this order: HA> PR >HA+SSP>SSP. Sequential extraction results indicated that the addition of different P compounds transformed soil Pb from nonresidual fractions to the residual fraction substantially. The effect of treatments followed this order at the equivalent level of added P: HA> PR >HA+SSP>SSP. The results suggested that HA amendment could lower the bioavailability and increase the geochemical stability of soil Pb, it therefore has the potential for insitu remediation of Pb contaminated soils.