Enhanced biodegradation of quinoline and indole with a novel symbiotic system of Polyurethane-chlorella-bacteria

Abstract Nitrogenous heterocyclic compounds in coal gasification wastewater have a great threat to human health and ecological environment. In recent years, algal-bacterial symbiotic system has been applied to industrial wastewater treatment. The aim of this work was to study an algal-bacteria symbiotic system of Polyurethane(PU)-chlorella-bacteria for strengthening degradation of nitrogen heterocyclic compounds. The results indicated PU-chlorella-bacteria system showed better stability and higher degradation ratio on quinoline and indole. Ammonia nitrogen (NH3-N) was released from the transformation of quinoline and indole in PU-chlorella-bacteria, and the presence of chlorella could decrease the NH3-N concentration. Illumination time of 12 h/24 h was more conducive to the degradation of refractory pollutants. Under the enhancement of PU-chlorella-bacteria, acute toxicity analysis demonstrated that the toxic inhibition on barley seeds decreased effectively. Enriched Chlorobaculum, Aquabacterium, Levilinea, and Longilinea may be responsible for the degradation of quinoline and indole.