Synthesis, application and evaluation of non-sintered zeolite porous filter (ZPF) as novel filter media in biological aerated filters (BAFs)

Abstract

A zeolite porous filter (ZPF) was prepared using mixed raw zeolite, cement, and aluminum powder through steam curing and used as a novel filter medium in biological aerated filter (BAF). The performances of ZPF and commercially available ceramsite (CAC) in two laboratory scale upflow BAFs were compared. Results showed that the interconnected porous structure of ZPF was conducive to microbial biofilm growth. ZPF featured a total porosity of 29.55%, a compressive strength of 41–47N, and a specific surface area of 59.53m2/g. BAF containing ZPF showed more effectively the removal of organic carbon, ammonia nitrogen, nitrogen, and phosphorus compared to BAF containing CAC. The hydraulic retention time (HRT) was 7h at an air/water (A/W) ratio of 3:1. The amounts of total nitrogen removed were 59.89% with ZPF and 35.96% with CAC. Moreover, the amount of phosphorus removed was 83.80% with ZPF, whereas that of CAC was only 31.50%. ZPF was more suitable for the attached growth of heterobacteria and nitrobacteria to attain simultaneous nitrification and denitrification performance in the BAF. Therefore, ZPF is a novel suitable filter medium for simultaneous removal of nitrogen and phosphorus in BAFs.