Organic degradation and extracellular products of pure oxygen aerated activated sludge under different F/M conditions

• DOI: 10.1016/j.biortech.2019.01.130
• Publication Date: 2019-01-30T09:31:27Z
• Authors: Hong-Ling Zhang; Wei-Li Jiang; Rong Liu; Ying Zhou; Yong Zhang
• Keywords: Oxygen; Bioreactors; Sewage; Food; 11. Sustainability; Food Microbiology; 0211 other engineering and technologies; 02 engineering and technology; Extracellular Space; 6. Clean water

This study aimed to investigate the effect of food to microorganisms rate (F/M) on organic removal, extracellular polymeric substances (EPS) and soluble microbial products (SMP) of the pure oxygen aerated activated sludge running in batch mode. The F/M rates were controlled by adjusting the MLSS concentrations (2000, 5000, 8000 mg/L) and/or the initial TOC concentrations (100, 500 mg/L). Results showed that at high F/M rate (0.25 kg TOC/kg MLSS), the substrate degradation rate in the oxygen aerated reactor could reach 1.347 mg TOC/(L·min)), much higher than that in the air aerated reactor (0.640 mg TOC/(L·min)). The SMP concentrations with oxygen aeration were also higher than those with air aeration under high F/M conditions. The total EPS contents in the pure oxygen aerated sludge were significantly lower regardless of the different F/M rates. High F/M condition would lead to more amount of polysaccharides synthesis rather than proteins synthesis in EPS.