Achieving Long-Term Stability of Partial Nitrification and Autotrophic Denitrification in an MABR via Sulfide Dosing.
Yu-Lin HanZhen-Chuan WuBruce E RittmannHe-Ping ZhaoPublished in: Environmental science & technology (2024)
While partial nitrification (PN) has the potential to reduce energy for aeration, it has proven to be unstable when treating low-strength wastewater. This study introduces an innovative combined strategy incorporating a low rate of oxygen supply, pH control, and sulfide addition to selectively inhibit nitrite-oxidizing bacteria (NOB). This strategy led to a stable PN in a laboratory-scale membrane aerated biofilm reactor (MABR). Over a period of 260 days, the nitrite accumulation ratio exceeded 60% when treating synthetic sewage containing 50 mg NH 4 + -N/L. Through in situ activity testing and high-throughput sequencing, the combined strategy led to low levels of nitrite-oxidation activity (<5.5 mg N/m 2 h), Nitrospira species (relative abundance <1%), and transcription of nitrite-oxidation genes (undetectable). The addition of sulfide led to simultaneous PN and autotrophic denitrification in the single-stage MABR, resulting in over 60% total inorganic nitrogen removal. Sulfur-based autotrophic denitrification consumed nitrite and inhibited NOB conversion of nitrite to nitrate. The combined strategy has potential to be applied in large-scale sewage treatment and deserves further exploration.
Keyphrases
- nitric oxide
- wastewater treatment
- microbial community
- antibiotic resistance genes
- hydrogen peroxide
- staphylococcus aureus
- high throughput sequencing
- pseudomonas aeruginosa
- transcription factor
- gene expression
- escherichia coli
- anaerobic digestion
- room temperature
- drinking water
- cystic fibrosis
- dna methylation
- biofilm formation
- human health
- combination therapy
- electron transfer