Enhanced anaerobic degradation of nitrogen heterocyclic compounds with methanol, sodium citrate, chlorella, spirulina, and carboxymethylcellulose as co-metabolic substances

Abstract

The aim of the study was to explore the feasibility of methanol, sodium citrate, chlorella, spirulina, and carboxymethylcellulose (CMC) as co-metabolic substances in strengthening the anaerobic degradation of selected nitrogen heterocyclic compounds (NHCs). Chlorella, spirulina, and CMC as co-metabolic substances were first introduced into the enhanced anaerobic treatment of refractory compounds. With the addition of 300 μg/L sodium citrate, chlorella, spirulina, and CMC, reactor 3, reactor 4, reactor 5, and reactor 6 had higher degradation ratios than reactor 2 with methanol as co-metabolic substance. The addition of sodium citrate, chlorella, spirulina, and CMC increased the number of bacterial sequences, promoted the richness and diversity of the bacterial community structure, and enriched the functional genera (Levilinea and Longilinea) responsible for the degradation of quinoline and indole.

Keywords: Carboxymethylcellulose; Chlorella; Enhanced anaerobic degradation; Nitrogen heterocyclic compounds; Spirulina.