Influence of effluent-recirculation condition on the process performance of expanded granular sludge bed reactor for treating low strength wastewater

W. Yoochatchaval, K. Nishiyama, M. Okawara, A. Ohashi, H. Harada, K. Syutsubo

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

A 2.0 L volume of EGSB reactor was operated at 20°C for more than 500 days with 0.3-0.4 g COD/L of sucrose base wastewater to investigate the influence of effluent-recirculation on the process performance. At the start up period, the reactor was operated in EGSB mode with 5 m/h upflow velocity by continuous effluent recirculation. The COD loading was set to 7.2-9.6 kg COD/m3 day with HRT of 1 hour. However, in this mode, EGSB reactor exhibited insufficient COD removal efficiency, i.e., 50-60%. Therefore, UASB mode (without recirculation, 0.7 m/h upflow velocity) was used for 30 minutes in every 40 minutes cycle to increase the COD concentration in the sludge bed. As a result, an excellent process performance was shown. The COD removal efficiency increased from 65% to 91% and the reactor could maintain a good physical property of retained sludge (sludge concentration: 33.4 g VSS/L and SVI: 25 mL/g VSS). Furthermore, retained sludge possessed sufficient level of methanogenic activity at 20°C.

Original languageEnglish
Pages (from-to)869-873
Number of pages5
JournalWater Science and Technology
Volume57
Issue number6
DOIs
Publication statusPublished - 2008 May 26

Keywords

  • Anaerobic treatment
  • EGSB
  • Low strength wastewater
  • Methane fermentation
  • Moderated temperature

ASJC Scopus subject areas

  • Environmental Engineering
  • Water Science and Technology

Fingerprint Dive into the research topics of 'Influence of effluent-recirculation condition on the process performance of expanded granular sludge bed reactor for treating low strength wastewater'. Together they form a unique fingerprint.

  • Cite this