我国部分矿区矿井水中氨氮（NH₄⁺—N）存在超标问题，且去除矿井水中的NH₄⁺—N要求越来越高，为了实现矿井水中NH₄⁺—N的高效去除，对天然沸石（NZ）进行六偏磷酸钠（SHMP）浸渍改性，增强其对矿井水中NH₄⁺—N的去除效果。结果表明：天然沸石经过0.1 mol/L SHMP溶液浸渍3 h制备出了六偏磷酸钠改性沸石（SHMP−NZ），在初始NH₄⁺—N质量浓度5 mg/L、投加量2 g/L的条件下振荡吸附2 h后NH₄⁺—N去除率可达到95.7%，相较于未改性天然沸石提高了39.9%。扫描电镜和比表面积测定显示改性后沸石孔隙变大，表面变得光滑松散，比表面积增加，微孔体积减小，介孔、大孔和平均孔径增加。X射线衍射和傅里叶红外光谱分析表明改性后沸石的基本骨架无明显变化。弱酸性或中性环境有利于SHMP−NZ吸附去除水中的NH₄⁺—N，共存阳离子的影响由大到小排序为K⁺＞Na⁺＞Ca²⁺＞Mg²⁺。拟一级动力学、拟二级动力学和Elovich动力学非线性拟合表明，天然沸石和SHMP−NZ吸附NH₄⁺—N更加符合拟二级动力学模型，对NH₄⁺—N的吸附属于化学吸附（离子交换）过程，颗粒内扩散模型表明2种材料对NH₄⁺—N的吸附涉及外扩散、内扩散和反应平衡3个阶段；Freundlich等温线模型表明，SHMP−NZ较天然沸石更易于吸附NH₄⁺—N，Langmuir等温线模型可以较好地描述天然沸石及SHMP−NZ吸附NH₄⁺—N的过程，相关系数R²分别为0.963 6和0.982 8，SHMP−NZ最大NH₄⁺—N吸附量为11.03 mg/g，较天然沸石提升了88.23%；吸附热力学表明各试验温度下吉布斯自由能变（ΔG）均小于0，焓变（ΔH）和熵变（ΔS）大于0，是一个熵增反应，有利于NH₄⁺—N的去除。SHMP−NZ吸附−解吸循环5次后，对NH₄⁺—N的去除效率仍有89.7%。实际矿井水中低浓度NH₄⁺—N的处理，改性沸石在投加量1 g/L，25 ℃条件下振荡吸附1 h后，出水满足《地表水环境质量标准》Ⅲ类水质中氨氮的要求。

The ammonium nitrogen (NH₄⁺—N) exceeding standard in mine waters is a widespread issue in certain mining regions of our country. As the demand for its removal escalates, a strategy involving the modification of natural zeolite (NZ) with sodium hexametaphosphate (SHMP) immersion was employed to enhance its removal efficiency. The results demonstrated that after 3 h of immersion in a 0.1 mol/L SHMP solution, SHMP-modified zeolite (SHMP−NZ) was prepared. Under conditions with an initial NH₄⁺—N concentration of 5 mg/L and a dosage of 2 g/L, an oscillatory adsorption of 2 h led to a NH₄⁺—N removal efficiency of 95.7%, representing a 39.9% enhancement compared to the unmodified natural zeolite. Scanning electron microscopy and surface area measurements revealed that upon modification, the zeolite exhibited enlarged pores, a smoother and more loosely structured surface, increased specific surface area, decreased micropore volume, and an augmentation in mesopore, macropore, and average pore diameter. Analyses using X-ray diffraction and Fourier-transform infrared spectroscopy indicated no significant alteration in the fundamental framework of the modified zeolite. The adsorption of NH₄⁺—N by SHMP−NZ was optimal under weakly acidic or neutral conditions. The impact of coexisting cations on the adsorption followed the order K⁺ > Na⁺ > Ca²⁺ > Mg²⁺. Pseudo-first-order, pseudo-second-order, and Elovich kinetic nonlinear fitting suggested that both natural zeolite and SHMP−NZ adsorption of NH₄⁺—N is better aligned with the pseudo-second-order kinetic model. The adsorption process was identified as chemisorption (ion exchange), and particle inner diffusion models revealed that the NH₄⁺—N adsorption by both materials involves three stages: external diffusion, internal diffusion, and reaction equilibrium. The Freundlich isotherm model revealed that SHMP−NZ is more conducive to NH₄⁺—N adsorption compared to NZ. The Langmuir isotherm model aptly described the NH₄⁺—N adsorption process by both natural zeolite and SHMP−NZ, with correlation coefficients R² being 0.9636 and 0.9828, respectively. The maximum NH₄⁺—N adsorption capacity of SHMP−NZ was 11.03 mg/g, an 88.23% improvement compared to NZ. Adsorption thermodynamics showed that the Gibbs free energy (ΔG) values at each test temperature were less than 0, while the enthalpy change (ΔH) and entropy change (ΔS) were greater than 0. This indicates that the adsorption process is constituting an entropy-increasing reaction which is favorable for the removal of NH₄⁺—N. After five regenerations, SHMP−NZ still maintains an ammonia nitrogen removal efficiency of 89.7%. Research on treating low-concentration ammonia nitrogen in actual mine water with SHMP−NZ shows that after 1 h of oscillating adsorption at a dosage of 1 g/L and at 25 °C, the effluent meets the ammonia nitrogen requirements of category III as per the environmental quality standards for surface water.