High-pressure soil column experiments were constructed to simulate the process of NH4+-N migration in the aquitard under different pH conditions, and to discuss the potential influencing factors and migration mechanism.The experimental results indicate that in a short experimental period (168h) and a relatively hypoxic environment, as the lowconcentration NH4+ -N solution permeates the aquitard, the vast majority of ammonia is removed mainly by adsorption and partly by biological reaction.When the pH value is greater than 7, NH4+ -N in the aquitard is easier to be adsorbed and cause biological reactions, which helps remove NH4+ -N.The pH conditions is likely to affect the competitive adsorption of NH4+ oN in calcium and magnesium ions.%通过高压土柱实验模拟不同pH条件下地下水中NH4+-N透过弱透水层越流迁移的过程,并对其可能的影响因素及迁移机理进行讨论分析.结果表明:在较短的实验周期内(168 h)及相对缺氧的环境中,低浓度的NH4+-N溶液通过弱透水层后绝大部分被去除,其主要作用是吸附,生物作用只占很小一部分;pH大于7时弱透水层中的NH4+-N较易被吸附和发生生物作用,利于NH4+-N的去除;pH条件易影响钙镁离子对NH4+-N竞争吸附.
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