Effect of carbohydrates to protein in EPS on sludge settling characteristics |
| |
Authors: | Hang-Sik Shin Seok-Tae Kang Se-Yong Nam |
| |
Institution: | (1) Environmental Technology Research Laboratory, Department of Civil Engineering, KAIST, 373-1 Kusong-dong, Yusong-gu, 305-701 Taejon, Korea |
| |
Abstract: | Extracellular polymeric substances (EPS) are believed to play a role in the binding and formation of microbial flocs. However,
the precise role is not well known Sludge settling characteristics and the carbohydrate to protein ratio in EPS were tested
with various airflow rates in this study. Sludge, was collected from three modified sequencing batch reactors (SBRs), which
were operated at 16°C with an airflow rate of 0.8 L/min, 3L/min and 6 L/min, respectively. During the operation, the reactor
operated at an airflow rate of 0.8 L/min showed sludge volume index (SVI) of 80 to 90 mL/g and a constant ratio of carbohydrate
to protein in the EPS, while a significant increase in the SVI was seen in the other reactors. Sludge bulking increased the
amount of carbohydrate in the EPS, while kept protein almost constant in the airflow rate of 3 L/min and 6 L/min. Surface
charge also increased with increases in the carbohydrate to protein ratio in the EPS, which weakens the attraction between
the EPS and multivalent cations. The ratio of carbohydrate to protein in the EPS was inferred to be essential for bioflocculation. |
| |
Keywords: | extracellular polymeric substance SVI sludge bulking surface charge sequencing batch reactors |
本文献已被 SpringerLink 等数据库收录! |
|