4种稻田土壤对铵的矿物固定的动力学研究

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。

Studies on Kinetics Properties of Fixed Ammonium in Several Paddy Soils

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.