高效除磷渗滤床填料筛选及连续流动态运行特性

磷是造成水体富营养化的重要因素之一，深度去除污染水体中的磷，具有重要的环保意义.为此，本研究比较了多种填料包括海绵铁及其改性填料、钢渣、活性氧化铝、活性炭的吸附除磷特性及动力学，探究了除磷机理，构建了高效除磷渗滤床，考察了动态连续流运行条件下的除磷特性.结果表明酸改性海绵铁具有最高的饱和磷吸附容量，为19.45 mg·g^-1，碱改性海绵铁、活性氧化铝、钢渣、未改性海绵铁及活性炭的饱和磷吸附容量分别为10.91、8.70、7.73、3.39和1.34 mg·g^-1.在此基础上，利用高效除磷填料酸改性海绵铁和钢渣构建了除磷渗滤床，开展了连续240 d的连续流实验，在磷容积负荷为6 g·d^-1·m^-3条件下，渗滤床累积磷吸附量达到10215 mg，单位容积吸附量达到1.62 kg·m^-3.总之，利用酸改性海绵铁和钢渣构建的除磷渗滤床具有较高的除磷效率和性能，可以作为除磷单元与现有的水污染治理及净化工艺耦合，提高或拓展系统除磷功能.

Removal of phosphate in a high-efficiency infiltration bed: adsorptive filler screening and performance during continuous operation

Phosphorus (P) is one of the key factors causing water eutrophication. From the respect of environmental protection, it is of great significance to remove phosphate from polluted water. This study first compared the adsorption characteristics and kinetics of phosphate removal by various fillers including pristine and modified sponge iron, steel slag, activated alumina, and activated carbon. The mechanism of phosphate removal was also investigated. Furthermore, an infiltration bed was constructed based on the selected adsorptive carriers of sponge iron and steel slag, and its long-term performance on P removal was explored through dynamic and continuous flow experiment. The results showed that acid-modified sponge iron exhibited the highest saturation P adsorption capacity of 19.45 mg·g^-1, followed by alkali-modified sponge iron (10.91 mg·g^-1), activated alumina (8.70 mg·g^-1), steel slag (7.73 mg·g^-1), pristine sponge iron (3.39 mg·g^-1), and activated carbon (1.34 mg·g^-1). The infiltration bed demonstrated P removal property during 240-day continuous operation under the volume loading of 6 g·d^-1·m^-3. The cumulative amount of adsorbed P by the infiltration bed reached up to 10215 mg, and the per-volume P removal capacity attained 1.62 kg·m^-3. On the whole, the infiltration bed constructed on the supports of acid-modified sponge iron and steel slag exhibited a good P removal capacity and it may be coupled with other water treatment unit to upgrade P removal capacity.