Emerging wastewater treatment strategy for efficient nitrogen removal and compact footprint by coupling mainstream nitrogen separation with chemical coagulation and biological aerated filter

摘要

In this study, an ammonia nitrogen (NH4+-N) ion exchange (IE) and regeneration (AIR) was constructed, and the chemical enhanced primary treatment (CEPT), AIR and biological aerated filter (BAF) were coupled in series to construct a novel CEPT-AIR-BAF process for efficient pollutants removal. At total hydraulic retention time of 4.6 h, the pilot-scale CEPT-AIR-BAF system obtained effluent with chemical oxygen demand of 17.9 +/- 6.0 mg/L, NH4+-N of 0.5 +/- 0.3 mg/L, total nitrogen of 2.4 +/- 1.0 mg/L and total phosphorus of 0.08 +/- 0.05 mg/L. AIR module achieved outstanding NH4+-N IE performance with NaClO-NaCl regeneration, and long-term regeneration increased surface area and mesopore of zeolites. Faster-growing heterotrophic bacteria, such as Pseudomonas and Comamonas, were enriched in BAF. The CEPT-AIR-BAF system saved at least 60% of land occupation and upfront investment, and the treatment cost ($ 0.155/m(3)) should be further reduced by investigations on the regeneration of loaded zeolite.