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以幕阜山5个海拔高度的土壤粘粒复合体为对象,用等温平衡吸附法研究了磷吸附量随加入磷浓度和平衡时间改变的变化规律。结果表明;①随着海拔高度增加,土壤粘粒的最大吸磷量由2.48 mg·g~(-1)依次增大到9.38 mg·g~(-1),达到饱和吸附所需加入的磷浓度增高,最大解吸磷量却逐渐降低,磷的解吸率减小。②根据土壤粘粒吸附磷速率的不同可将供试样品的吸磷过程划分为3个阶段,在24小时内的吸磷量占480小时吸磷量的72%～85%。海拔越高的土壤粘粒,快反应速率越高,缓慢吸附的时间越长。同一样品经不同时间吸附的磷解吸率变幅不大。③供试粘粒吸磷量随平衡液浓度和平衡时间的变化特征可用Langmuir,Temkin,Freundlich,Elovich等方程描述,相关系数在0.94～0.99之间,达极显著水准。④不同海拔土壤在磷吸附量、吸附速率和吸附强度等方面的不同,主要与土壤粘粒复合体中吸磷载体的含量差异有关。
In this study, the changes of phosphorus adsorption amount with phosphorus concentration and equilibrium time were studied by isothermal equilibrium adsorption method. The results showed that: ① As the altitude increased, the maximum P uptake from soil clay increased from 2.48 mg · g ~ (-1) to 9.38 mg · g ~ (-1), reaching the required phosphorus Concentration increased, the maximum desorption of phosphorus was gradually reduced, desorption of phosphorus decreased. ② According to the different adsorption rates of soil clay, the process of phosphorus uptake can be divided into three stages, and the phosphorus uptake within 72 hours accounted for 72% -85% of the phosphorus uptake in 480 hours. The higher the elevation of soil clay, the faster the reaction rate, the slower the time of adsorption. The desorption rate of phosphorus adsorbed by the same sample at different times changed slightly. ③ The change characteristics of phosphorus uptake quantity of the test slurries with equilibrium solution concentration and equilibrium time can be described by the Langmuir, Temkin, Freundlich and Elovich equations, and the correlation coefficient is between 0.94 and 0.99, reaching a significant level. ④ The difference of phosphorus uptake rate, adsorption rate and adsorption strength between different altitude soils mainly related to the content of phosphate uptake carriers in soil clay complex.