American Society of Civil Engineers


Application of Downflow-Upflow Biological Aerated Filter in the Pretreatment of Raw Water Containing High Ammonia Nitrogen


by Shaoming Lu, (Professor, School of Environmental Science & Engineering, South China Univ. of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, China.), Xiaojun Niu, (corresponding author), (School of Environmental Science & Engineering, South China Univ. of Technology, Guangzhou 510006, China. E-mail: xjniu@scut.edu.cn), Yuanyuan Ren, (School of Environmental Science & Engineering, South China Univ. of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, China.), and Deye Chen, (School of Environmental Science & Engineering, South China Univ. of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, China.)

Journal of Environmental Engineering, Vol. 137, No. 12, December 2011, pp. 1193-1198, (doi:  http://dx.doi.org/10.1061/(ASCE)EE.1943-7870.0000447)

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Document type: Case Studies
Abstract: In a subtropical area, a downflow-upflow biological aerated filter (D-UBAF) was used in the pretreatment of raw water containing seasonal high levels of ammonia nitrogen ( NH3- N) and organic pollutants. Operating parameters for low-flow periods were as follows: filtration rate of 8 m/ h and gas-water ratio of 0.5√1.5. In terms of water quality, the average concentrations of NH3- N and permanganate index ( COD Mn) and the turbidity of the raw water were 5.02–9.45 mg/ L, 5.79–10.1 mg/ L, and 19.7–63.1 NTU, respectively. The corresponding indexes of the D-UBAF effluent were 0.30–0.96 mg/ L, 3.24–5.85 mg/ L, and 3.83–19.9 NTU, respectively. The removal efficiencies were 90.3%, 42.7%, and 66.3%, respectively. Operating parameters for high-flow periods were as follows: filtration rate of 12 m/ h and gas-water ratio of 0.3√0.5. In terms of water quality, the average concentrations of NH3- N and COD Mn and the turbidity of the raw water were 2.19–3.41 mg/ L, 5.30–7.56 mg/ L, and 27.3–40.1 NTU, respectively. The corresponding indexes of the D-UBAF effluent were 0.18–0.41 mg/ L, 2.87–4.50 mg/ L, and 5.43–16.8 NTU, respectively. The removal efficiencies were 89.3%, 40.2%, and 65.0%, respectively. The D-UBAF with one DBAF and two UBAFs constituted a "<artwork id="g1"><graphic file="d1"/></artwork>"-shaped structure. The space among these three components was used as a common tube gallery. The UBAF is the principal component of the biological pretreatment process. The DBAF runs before the UBAF; it can ensure that the head loss in the UBAF does not exceed 0.2 m H2 O after filtration for 24 h. This also satisfies the head loss control requirement for numerous UBAFs, which share a centralized aeration system to achieve uniform aeration.


ASCE Subject Headings:
Turbidity
Nitrogen
Ammonia
Water treatment
Filters

Author Keywords:
D-UBAF
Water pretreatment
Turbidity
Ammonia nitrogen