High-Rate Sulfate Reduction at High Salinity (up to 90 mS.cm-1) in Mesophilic UASB Reactors

M.V.G. Vallero, J. Sipma, G. Lettinga, P.N.L. Lens

Research output: Contribution to journalArticleAcademicpeer-review

36 Citations (Scopus)


Sulfate reduction in salt-rich wastewaters using unadapted granular sludge was investigated in 0.9 L UASB reactors (pH 7.0 ± 0.2; hydraulic retention time from 8-14 h) fed with acetate, propionate, or ethanol at organic loading rates up to 10 gCOD.L-1.day-1 and in excess sulfate (COD/SO of 0.5). High-rate sulfate reduction rates (up to 3.7 gSO42-.L-1.day-1) were achieved at salinities exceeding 50 gNaCl.L-1 and 1 gMgCl2.L-1. Sulfate reduction proceeded at a salinity of up to 70 gNaCl.L-1 and 1 gMgCl2.L-1 (corresponding to a conductivity of about 85-90 mS.cm-1), although at lower rates compared to a conductivity of 60-70 mS.cm-1. Ethanol as well as propionate were suitable substrates for sulfate reduction, with acetate and sulfide as the end products. The successful high-rate treatment was due to the proliferation of a halotolerant incomplete oxidizing SRB population present in the unadapted inoculum sludge. Bioaugmentation of this sludge with the acetate oxidizing halotolerant SRB Desulfobacter halotolerans was unsuccessful, as the strain washed out from the UASB reactor without colonizing the UASB granules. © 2004 Wiley Periodicals, Inc.
Original languageEnglish
Pages (from-to)226-235
JournalBiotechnology and Bioengineering
Issue number2
Publication statusPublished - 2004


  • sulfate
  • reduction
  • chemical reactions
  • salinity
  • activated sludge
  • biodegradation
  • acetates
  • propionates
  • ethanol
  • water treatment
  • desulfitobacterium-frappieri pcp-1
  • anaerobic granular sludge
  • long-term competition
  • waste-water
  • methanogenic bacteria
  • biological treatment
  • reducing reactors
  • bed reactor
  • wastewaters
  • ammonia


Dive into the research topics of 'High-Rate Sulfate Reduction at High Salinity (up to 90 mS.cm-1) in Mesophilic UASB Reactors'. Together they form a unique fingerprint.

Cite this