Anaerobic wastewater treatment of concentrated sewage using a two-stage upflow anaerobic sludge blanket- anaerobic filter system

Maha M. Halalsheh, Zainab M. Abu Rumman, Jim A. Field

Research output: Contribution to journalArticle

7 Scopus citations


A two-stage pilot-scale upflow anaerobic sludge blanket - anaerobic filter (UASB-AF) reactors system treating concentrated domestic sewage was operated at 23°C and at hydraulic retention times (HRT) of 15 and 4 h, respectively. Excess sludge from the downstream AF stage was returned to the upstream UASB reactor. The aim was to obtain higher sludge retention time (SRT) in the UASB reactor for better methanization of suspended COD. The UASB-AF system removed 55% and 65% of the total COD (CODtot) and suspended COD (COD ss), respectively. The calculated SRT in the UASB reactor ranged from 20-35 days. The AF reactor removed the washed out sludge from the first stage reactor with average CODss removal efficiency of 55%. The volatile fatty acids concentration in the effluent of the AF was 39 mg COD/L compared with 78 mg COD/L measured for the influent. The slightly higher CODtot removal efficiency obtained in this study compared with a single stage UASB reactor was achieved at 17% reduction in the total volume.

Original languageEnglish (US)
Pages (from-to)383-388
Number of pages6
JournalJournal of Environmental Science and Health - Part A Toxic/Hazardous Substances and Environmental Engineering
Issue number3
StatePublished - Jan 1 2010



  • Anaerobic filter
  • Concentrated sewage
  • Domestic wastewater
  • HRT
  • Two-stage system
  • UASB reactor

ASJC Scopus subject areas

  • Environmental Engineering

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