Effect of iron oxide on phosphate sorption by calcite and calcareous soils
Effect of iron oxide on phosphate sorption by calcite and calcareous soils
复制标题
氧化铁对方解石和钙质土壤吸附磷的影响
DOI：
10.1111/j.1365-2389.1992.tb00135.x
复制
发表时间：
1992
期刊：
影响因子：
--
通讯作者：
J. Syers
中科院分区：
文献类型：
--
作者：
M. E. Hamad;D. Rimmer;J. Syers
总结
用高氯酸亚铁溶液处理纯方解石（AR级CaCO 3），得到氧化铁（Fe）表面涂层。当涂层量从0.00 g Fe 2 O3，kg−1 CaCO 3增加到16.0 g Fe 2 O3，kg−1 CaCO 3时，方解石对磷酸盐（P）的最大吸附量（xm）从18.2 mg P kg−1增加到160 mg P kg−1。通过光学显微镜和电子探针微区分析，获得了两种苏丹土壤中碳酸盐矿物氧化铁涂层的证据。碳酸盐和铁氧化物矿物，和铁氧化物涂层在这些土壤中的磷吸附的相对贡献进行了计算，根据一个假设的氧化物分布模型。分离相氧化铁是土壤中磷吸附的主要贡献者（30-40%）;碳酸盐矿物上的氧化铁涂层仅是次要贡献者（< 6%），未涂层碳酸盐矿物的贡献被发现可以忽略不计（<1%）。这些结果表明，碳酸盐矿物的作用很小，即使涂有氧化铁，在这些石灰质，苏丹土壤的吸附P。
SUMMARY
Pure calcite (AR grade CaCO3) was treated with ferrous perchlorate solution to give a surface coating of iron (Fe) oxide. Maximum sorption (xm) of phosphate (P) by the calcite increased from 18.2 to 160 mg P kg−1 as the amount of coating increased from 0.00 to 16.0 g Fe2O3, kg−1 CaCO3. Evidence for Fe oxide coatings on carbonate minerals in two Sudanese soils was obtained by optical microscopy and electron-probe microanalysis. The relative contributions of carbonate and Fe oxide minerals, and Fe oxide coatings to P sorption in these soils were calculated, based on an assumed model of oxide distribution. Separate-phase Fe oxide was the major contributor (30–40%) to P sorption in the soils; the Fe oxide coatings on carbonate minerals were only minor contributors (< 6%), and the contribution of uncoated carbonate minerals was found to be negligible (<1 %). These results suggest a very minor role for carbonate minerals, even when coated with Fe oxide, in the sorption of P by these calcareous, Sudanese soils.