红壤对三氮吸附-解吸性能实验研究

Study on the Capabilities of Three-nitrogen Adsorption and Sorption in Red Soil

以厦门市农田土壤为研究对象,通过室内吸附实验,分析了土壤对三氮的吸附性能,并探讨了氯离子对吸附行为的影响.实验结果表明:红壤对氨态氮具有明显的吸附作用,吸附等温线符合Henry线性等温吸附模型;对亚硝态氮以解吸为主;对硝态氮明显表现为解吸作用;在氯离子作用下,水土体系中有亚硝化作用发生,而硝化作用则明显受到了抑制.在氮素数学模型中,在不考虑亚硝态氮的前提下,对氨态氮需考虑吸附常数,而对硝态氮则需考虑解吸常数.对盐渍化或滨海土壤中三氮迁移转化进行研究时,还要考虑氯离子对三氮迁移转化的影响.

Characteristics of soil adsorption and impact of chloride on adsorption of three-nitrogen were studied by experiments in laboratory in the agricultural soils of Xiamen as an example. The results indicated that red soil had obvious adsorption to ammonia, and ammonia adsorption in red soil accorded with Henry isothermal adsorption pattern; red soil had mainly desorption to nitrite and had obvious desorption to nitrate; when adding chloride, nitrosation happened but nitrification was obviously restrained in the water-soil system. Therefore, in the nitrogen mathematical model, adsorption constant of ammonia and desorption constant of nitrate needed to be considered, disregarding the nitrite. Impact of chloride should be considered when transform and transfer of three-nitrogen were studied in the salinization or marine soil.