Investigation of nitrite accumulation by hydrogenotrophic denitrification in a moving bed biofilm reactor for partial denitrification and anammox process
The partial denitrification and anammox (PDA) process has received attention for its ability to optimize treatment of wastewater containing a low -N concentration. This study investigated the suitable operational conditions for -N accumulation by hydrogenotrophic denitrification (HD) in operation of...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
IWA Publishing
2022-06-01
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| Series: | Water Science and Technology |
| Subjects: | |
| Online Access: | http://wst.iwaponline.com/content/85/12/3396 |
| Summary: | The partial denitrification and anammox (PDA) process has received attention for its ability to optimize treatment of wastewater containing a low -N concentration. This study investigated the suitable operational conditions for -N accumulation by hydrogenotrophic denitrification (HD) in operation of a laboratory-scale moving bed biofilm reactor, for future application in the PDA process. -N accumulation was achieved by minimizing the H2 flow rate under optimized conditions (i.e., 15 mL/min H2 flow rate, 40 mg-N/L influent -N, 7.0 h hydraulic retention time, and 2 L working volume). Hydrogenophaga comprised 39.2% of the bacterial abundance after -N accumulated, indicating its contribution to the -N accumulation. In addition, an intermittent H2 supply maintained the -N accumulation rate (NAR) and maximized the nitrite accumulation efficiency (NAE). A H2 supply ratio of 0.7 (i.e., ON: 7 min, OFF: 3 min) was optimal, which induced increases in NAR, NAE, and the -N removal efficiency that reached 0.07±0.01 kg-N/m3/d, 64.4±14.5%, and 89.2±8.9%, respectively. The ratio of H2 supply rate to the -N loading rate was calculated as 4.3 in this experiment, which may represent the optimal balance for maximization of -N accumulation by HD. HIGHLIGHTS
This study demonstrated suitable operational conditions for -N accumulation through the hydrogenotrophic denitrification process.;
-N accumlation after its maximization maintained for 60 days.;
A suitable input ratio of H2 and -N for maximizing -N accumulation was 4.3.;
Hydrogen gas oxidizing bacterial genus Hydrogenophaga was the most dominant bacteria with 39.2% of relative abundance.; |
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| ISSN: | 0273-1223 1996-9732 |