为有效解决人工湿地基质除磷普遍存在的去除率不断下降问题和基质结构优化设计与维护问题，需针对不同介质掌握其对具体含磷污水的吸附特性及实际去磷效果的演变趋势与规律。选取人工湿地可选用的除磷性能较好的沸石、麦饭石和磁铁矿3种基质，首先通过静态实验研究它们对磷的吸附动力学过程和等温吸附特征，并考察不同基质和粒径对磷吸附的影响。进而选取其中磷吸附性能最好的沸石进行去除磷的砂箱渗流模拟试验，获取潜流湿地的基质除磷净化效果。通过磷吸附静态实验和磷去除砂箱渗流模拟试验综合研究，查明不同粒径的沸石基质实际去磷效果的主要机制与演变趋势和规律。研究结果表明：3种基质对磷的吸附过程都包括快速吸附、缓慢吸附和逐渐平衡3个过程，Langmuir方程准确地描述基质吸附磷的等温吸附过程。当含磷水在砂箱基质中呈渗流状态时，不同粒径的沸石吸附除磷及总体除磷效率呈现较大差异，各粒径沸石基质的除磷效率具有波动现象，且总体呈先上升再明显下降趋势。分析表明，除明显的吸附除磷机制，微生物除磷作用也产生相当的去磷效果。
In order to solve the problem of decreasing for the removal rate of phosphorus and consider the optimal design and maintenance of the substrate structure in constructed wetlands, it is necessary to understand the phosphorus adsorption characteristics for different substrates and obtain the evolution trend and law regarding the actual dephosphorization effect for specific phosphorus-containing wastewater. In this study, three substrates including zeolite, medical stone, and magnetite, were selected, which are commonly used in constructed wetlands with good phosphorus removal performance, to study their adsorption kinetics and isothermal adsorption characteristics of phosphorus and to investigate the effects of different substrates and particle sizes on phosphorus adsorption. Further, zeolite with the best phosphorus adsorption performance among the three substrates was selected to carry out the seepage sand tank test for phosphorus removal, so as to simulate and obtain the phosphorus removal and purification effects of the subsurface flow wetland. By integrating the static experiment with seepage sand tank test for the phosphorus removal, the mechanisms of dephosphorization and the evolution trend and law of actual dephosphorization effects of the zeolite substrates with different particle sizes were identified. The results show that the adsorption process of phosphorus on the three substrates consists of the fast adsorption, slow adsorption, and gradual equilibrium. Furthermore, the Langmuir equation can accurately describes the isothermal process of phosphorus adsorption on the substrates. The adsorption phosphorus removal efficiency and the overall phosphorus removal efficiency of the zeolite substrate with different particle sizes are significantly different. Additionally, the phosphorus removal efficiency of the zeolite substrates fluctuates with the particle size, and the overall phosphorus removal efficiency initially increases and then decreases considerably. The analysis of the achieved data sets indicates that, in addition to the significant mechanism of phosphorus adsorption removal, the microbial effect is also considerable on the phosphorus removal. Based on this type of integrated investigations, the phosphorus removal mechanisms with their relative importance and the overall phosphorus removal efficiency can be identified.
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