天然沸石混合填料参数优化及废水脱氮应用研究

Parameters Optimization for Natural Zeolite as Composite Filler to Remove Nitrogenfrom Wastewater

以天然沸石、水泥、铁粉为主要原料制备天然混合沸石填料(NZCF),经过三因素三水平正交实验优化制备参数,得到具有高比表面积、机械强度、孔容和开放孔隙率的NZCF。氨氮饱和吸附实验表明NZCF具有优异的氨氮吸附性能,可用作氨氮吸附剂和高负载量微生物载体;生物脱氮研究表明NZCF具有优异的脱氮性能,硝化细菌富集后氨氮去除率稳定在98%,SEM结果表明填料内外凹陷的小孔增大了滤料的比表面积,同时可提高填料附着的微生物含量。通过模拟氨氮废水和曝气生物滤池序批三段式处理,测试天然沸石混合填料的氮素去除性能,结果表明,NZCF在不同水力停留时间下均具有较高的氨氮去除率和稳定性,当离子交换吸附阶段水力停留时间为3.2 h时,氨氮综合去除效率最佳(84.3%~90.3%),表明其在废水脱氮方面具有优异的应用潜力。

Natural zeolite-based composite filler(NZCF) was prepared by combining natural zeolite,cement,and iron powder as primary materials.The preparation parameters were systematically optimized based on three-factor and three-level orthogonal experiment,resulting in the development of NZCF characterized by a notably high specific surface area,mechanical strength,pore volume,and porosity.Saturation adsorption experiments indicated the excellent performance of NZCF in adsorbing ammonium nitrogen,thus demonstrating its significant potential as support with high microbial load and adsorbent for ammonium nitrogen.Biological experiments demonstrated the excellent performance of NZCF in nitrogen removal,with the removal rates of ammonia nitrogen were stabilized at 98% after the enrichment of nitrifying bacteria.Scanning Electron Microscope(SEM) images revealed that the presence of small pores in NZCF increased the specific surface area and enhanced the microbial biomass attachment to the filler.The removal performance of nitrogen over NZCF was tested by simulating the treatment of ammonia nitrogen wastewater using three-stage sequencing batch aeration bio-filter.The results showed that NZCF exhibited notable removal efficiency and stability for ammonia nitrogen at different hydraulic residence times(HRT).The optimal removal efficiency of NZCF for ammonia nitrogen,ranging from 84.3% to 90.3%,was achieved at the HRT of 3.2 h during the ion exchange adsorption stage.This result indicated the impressive application potential of NZCF for nitrogen removal processes from wastewater.