| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 679738 | Bioresource Technology | 2015 | 9 Pages |
•Synergistic pre-denitrification and chemical P precipitation in a BAF system.•Using Fe2+ as the dosed precipitant can significantly enhance P removal.•Dosing sole Fe2+ adversely affects NH4+-N, insoluble COD, and SS removal in BAF.•A combined dosing of Fe2+, PAM, and NaHCO3 has sound COD, N, and P removal results.•The combined dosing of these chemicals leads to less frequent BAF backwashing.
The performance of a BAF system configuring simultaneous chemical phosphorus precipitation in the pre-denitrification stage was examined using a continuously operated setup to treat real domestic wastewater. The effects of using no chemical, dosing sole Fe2+, and dosing combined Fe2+, PAM, and NaHCO3 in the pre-denitrification tank were assessed by monitoring COD, nitrogen, and phosphorus removal and hydraulic headloss development in the BAF column. Though dosing sole Fe2+ significantly enhanced phosphorus removal, it would consume alkalinity through hydrolysis and form smaller-sized sludge flocs in the pre-denitrification tank, and hence resulted in affected NH4+-N, insoluble COD, and SS removal in the BAF. Dosing combined Fe2+, PAM, and NaHCO3 can enhance sludge flocculation to form larger flocs and compensate alkalinity consumption. It exhibited sound performance on COD, nitrogen, and phosphorus removal, and led to less frequent BAF backwashing by slowing clogging development in the BAF filter layer.
