EFFECTS OF IONIC STRENGTH ON CHEMISORPTION AND POTENTIAL‐DETERMINING SORPTION OF PHOSPHATE BY SOILS
EFFECTS OF IONIC STRENGTH ON CHEMISORPTION AND POTENTIAL‐DETERMINING SORPTION OF PHOSPHATE BY SOILS
复制标题
离子强度对土壤化学吸附和磷酸盐潜在吸附的影响
DOI：
10.1111/j.1365-2389.1977.tb02296.x
复制
发表时间：
1977
影响因子：
4.2
通讯作者：
J. R. Mclaughlin
中科院分区：
文献类型：
--
作者：
J. Rydén;J. Syers;J. R. Mclaughlin
总结
无机磷（P）吸附量由两个未施肥的土壤，在小于所需的时间达到平衡，受离子强度和阳离子种类的基质溶液。对于非平衡条件下，吸附的P的量随着离子强度的增加而增加，并与Ca 2+比Na+更大。对于较高的磷添加量，导致平衡溶液磷浓度大于30至40μ mol 1 - 1，基质溶液对磷吸附的影响保持平衡，而在较低的磷添加量，吸附对基质溶液组成的依赖性在平衡时被消除。
平衡吸附等温线为每一个土壤和基质的解决方案，由三个朗缪尔方程，这对应于不同的浓度范围或区域（I，II和III）的整体等温线。各区域的吸附自由能（ΔG）基本上与土壤基质溶液无关。对于一个特定的土壤的等温线的区域I和II的吸附最大值也几乎是独立的所使用的基质溶液。然而，区域III的吸附最大值明显依赖于基质溶液，这意味着潜在的决定（p.d.）吸附机理
Summary
Amounts of inorganic phosphate (P) sorbed by two unfertilized soils, during times less than required to reach equilibrium, were affected by the ionic strength and cation species of the matrix solution. For non-equilibrium conditions the amounts of P sorbed increased with increasing ionic strength and were greater with Ca2+ than Na+. For higher P additions, resulting in equilibrium solution P concentrations greater than 30 to 40μrnole 1−1, the effects of the matrix solution on P sorption were maintained at equilibrium, whereas at lower P additions the dependence of sorption on matrix solution composition was eliminated at equilibrium.
Equilibrium sorption isotherms for each soil and matrix solution were described by three Langmuir equations, which corresponded to distinct concentration ranges or regions (I, II, and III) on the overall isotherm. The free energies of sorption (ΔG) for each region, were essentially independent of the soil matrix solution. The sorption maxima for regions I and II of the isotherm for a particular soil were also virtually independent of the matrix solution used. The sorption maximum for region III, however, was markedly dependent on the matrix solution, implying a potential-determining (p.d.) sorption mechanism.