4种稻田土壤对铵的矿物固定的动力学研究

Studies on Kinetics Properties of Fixed Ammonium in Several Paddy Soils

采用振荡平衡法研究了紫泥田、河沙泥、灰泥田及红黄泥4种稻田土壤对铵的矿物固定的动力学及热力学特性。结果表明:供试土壤对添加铵的矿物固定速度很快,随着固铵量增多,固铵速度下降,反应后24 h固定基本上达到平衡,不因土壤种类而异。数学拟合结果表明,以一级动力学方程和Elovich方程描述供试土壤固定铵的动力学特性最优,抛物扩散方程也能较好地描述实验结果,以零级方程的拟合效果最差。

By the method of batch equilibrium,kinetics properties of NH4^＋ fixation was studied in purple clayey soil,alluvial sandy soil,grey clayey soil and reddish yellow clayey soil.The results showed that the fixing rate for added NH4^＋ in the tested soils was quick,but velocity of NH4^＋-fixation grew slow with the increase of fixed ammonium,and the reaction reached euquilibrium after 24 hour.Both first order equation and Elovich equation were the most adaptable to descrbing the NH4^＋-fixation kinetics.The parabolic diffusion euqation was also adaptable to describing NH4^＋-fixation kinetics properties.The parabolic diffusion equatoion could also describe the experimental data satisfactorily.Zero-level equation was not adaptable to descrbing the NH4^＋-fixation kinetics properties.