Kinetics of nitrification and acrylamide biodegradation by <i>Enterobacter aerogenes</i> and mixed culture bacteria in sequencing batch reactor wastewater treatment systems

Abstract

This study evaluated the kinetics of acrylamide (AM) biodegradation by mixed culture bacteria and Enterobacter aerogenes (E. aerogenes) in sequencing batch reactor (SBR) systems with AQUASIM and linear regression. The zero-order, first-order, and Monod kinetic models were used to evaluate the kinetic parameters of both autotrophic and heterotrophic nitrifications and both AM and chemical oxygen demand (COD) removals at different AM concentrations of 100, 200, 300, and 400 mg AM/L. The results revealed that both autotrophic and heterotrophic nitrifications and both AM and COD removals followed the Monod kinetics. High AM loadings resulted in the transformation of Monod kinetics to the first-order reaction for AM and COD removals as the results of the compositions of mixed substrates and the inhibition of the free ammonia nitrogen (FAN). The kinetic parameters indicated that E. aerogenes degraded AM and COD at higher rates than mixed culture bacteria. The FAN from the AM biodegradation increased both heterotrophic and autotrophic nitrification rates at the AM concentrations of 100-300 mg AM/L. At higher AM concentrations, the FAN accumulated in the SBR system inhibited the autotrophic nitrification of mixed culture bacteria. The accumulation of intracellular polyphosphate caused the heterotrophic nitrification of E. aerogenes to follow the first-order approximation.

Klebsiella aerogenes and Comamonas testosteroni as bioremoval agents on graffiti-coated concrete and granite: Impact assessment through surface analysis

“…ATCC have shown a promising profile for biocleaning of black and silver graffiti paints. Previously, different strains of Enterobacter aerogenes, a common flora found in the human gastrointestinal tract (Sanders and Sanders, 1997) have been reported to degrade xenobiotic compounds, such as pyrethriodspesticide residues (Liao et al, 2009), anionic surfactants like alkylbenzene sulfonate compounds (Fathi et al, 2016), and acrylamides (Buranasilp and Charoenpanich, 2011;Jangkorn et al, 2018;Madmanang et al, 2019). An E. aerogenes strain isolated from domestic wastewater in Thailand proved to be an acrylamide-degrading bacterium, degrading acrylamide to acrylic acid and further to lower polarity compounds.…”