Performance of single-stage partial nitritation and anammox reactor treating low-phenol/ammonia ratio wastewater and analysis of microbial community structure.

Phenol and ammonia are common pollutants in many industrial wastewaters. The partial nitritation and anammox process is a very promising technology for treating phenol-ammonia wastewater. This study was the first time to rapidly achieve the start-up and operation of the single-stage partial nitritation /anammox reactor treating phenol-ammonia wastewater. The optimized ratio of phenol and nitrogen (phenol/NH -N=0.3) was set to start-up the reactor. After 60 days of operation, the total nitrogen and COD removal efficiencies were around 73.0% and 79.5%, respectively. The activity of ammonium-oxidizing bacteria was291.1 ± 3.0 mg NH -N g MLVSS d and the specific anammox activity was 20.9 ± 1.0 mg NH -N g MLVSS d . The results indicated that the anammox bacteria had adapted to phenol condition and remained stable activity after the 60 days' operation in the reactor. The sequence analysis of 16SrRNA showed that the microbial community structure evolved to a balanced distribution that the removals of phenol and ammonia could be achieved simultaneously. PRACTITIONER POINTS: Phenol/N ratio of 0.3 was set to start up the single-stage partial nitritation/anammox reactor. The single-stage partial nitritation /anammox reactor was rapidly started up when treating the phenol-ammonia wastewater. Total nitrogen removal rate and COD removal efficiencies could achieve to 73.0% and 79.5%, respectively. Microbial community structure evolved to stable distribution of which AOB, anammox bacteria, denitrification bacteria and heterotrophic nitrification bacteria coexisted.