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苏北滨海地区盐碱性土壤通过耕作措施进行了长期改良,探讨铵氮在该类型土壤中的吸附特性对防控盐碱土区域氮素流失风险具有重要意义。选取苏北平原滨海地区典型盐化潮土,开展了铵氮吸附特性室内模拟研究,描述吸附等温过程,探讨初始浓度和p H的影响,揭示铵氮吸附的动力学和热力学特征。结果表明:铵氮平衡吸附变化满足Langmuir吸附等温式,以单分子层电性吸附模式为主;吸附过程符合Elovich方程;溶液初始浓度越大、p H越高、温度越低,铵氮吸附量越大,但吸附速率降低;热力学参数估算显示该吸附是放热过程,初始浓度增加,吸附需克服的能垒越高。
Saline-alkaline soil in the coastal area of northern Jiangsu has been improved through long-term cultivation measures. It is of great importance to study the adsorption characteristics of ammonium nitrogen in this type of soil to prevent and control the risk of nitrogen loss in saline-alkali soil. The typical salinized soils in the coastal areas of the northern Jiangsu Plain were selected to study the adsorption characteristics of ammonium and nitrogen in laboratory. The adsorption isothermal process was described. The effects of initial concentration and p H were discussed. The kinetic and thermodynamic characteristics of ammonium nitrogen adsorption were also revealed. The results showed that the equilibrium adsorption of ammonium nitrogen satisfied the Langmuir adsorption isotherm and the monolayer electron adsorption model was dominant. The adsorption process accorded with Elovich equation. The higher the initial concentration of solution, the higher p H, the lower the temperature, The larger the adsorption rate, the lower the adsorption rate. The thermodynamic parameters show that the adsorption is an exothermic process. The initial concentration is increased, and the energy barrier to be overcome by adsorption is higher.