Biological degradation of nitrophenol mixture in a continuous aerobic reactor

摘要

This study is focused on the biodegradation of mononitrophenols (MNP) from a simulated wastewater in a continuously and long-term operated packed bed reactor with immobilized cells (microbial consortium). At a hydraulic retention time of 45 min, the bench scale reactor was able to remove 2 g of the MNP mixture per liter per day (q_w) with the removal efficiency (RE_W) of 99.5%. The position of the nitro group on the benzene ring strongly affected the rate and efficiency of the individual MNP isomers removal, when they were present in a mixture. Analyzing nitrite, nitrate and ammonium ions in the outflow water enabled us to predict the metabolic pathways of the individual MNP degradations. Monitoring of the microbial composition showed enrichment in Gram-negative strains with some fungal contamination.