Keynote Speaker

Prof. Chengyuan Su, School of Environment and Resources, Guangxi Normal University, China

Title: Performance and microbial community of CIC anaerobic reactor treating food waste under different grease and ammonia nitrogen contents

Abstract: The stability of the process and microbial responses in the controlling internal circulation (CIC) reactor used for treating food waste were investigated under different grease and ammonia nitrogen contents. At the grease content of 1 g/L, the removal rates of 94% and 86%-93% were achieved for COD and NH3-N, respectively. In contrast, when the grease content increased to 7 g/L, removal rates for COD and NH3-N significantly decreased to 42.8% and 10%, respectively. In the three-dimensional excitation and emission matrix (3D-EEM) spectra of LB-EPS, the fluorescence intensity of coenzyme F420 was weakened in the granular sludge. However, when the inner cycle ratio was increased to 4, the removal rate of COD and NH3-N increased to about 70% and 76%, respectively. When the grease content increased from 1 g/L to 7g/L, the abundance of Methanofollis increased from 9.93% to 46.41%, while Methanothrix abundance was reduced from 18.4% to 3.07%. It could indicate that Methanothrix was sensitive to high grease content. When ammonia nitrogen concentration in the influent increased to 1500 mg/L, COD removal efficiency was reduced to 76%. The band intensity at 1635 cm-1, attributed to the C=O stretching vibrations, reduced, and the broad band values of 3400 cm-1 implied a sharp peak of the amino group in the fourier transform infrared (FTIR) spectra of TB-EPS. In the CIC reactor, COD removal efficiency reached to about 90% with biochar.