High-rate sulfate reduction at high salinity (up to 90 mS.cm−1) in mesophilic UASB reactors

• Published in: Biotechnology and bioengineering 2004-04, Vol.86 (2), p.226-235
• Main Authors: Vallero, Marcus V. G., Sipma, Jan, Lettinga, Gatze, Lens, Piet N. L.
• Format: Article
• Language: English
• Subjects: acetate; acetaten; acetates; activated sludge; Afvalwaterbehandeling; ammonia; anaerobic granular sludge; bed reactor; bioaugmentation; biodegradatie; biodegradation; Biodegradation, Environmental; Biological and medical sciences; biological treatment; Biological treatment of waters; Bioreactors - microbiology; Biotechnology; chemical reactions; chemische reacties; desulfitobacterium-frappieri pcp-1; Desulfobacter halotolerans; Environment and pollution; ethanol; Fatty Acids, Volatile - metabolism; Fundamental and applied biological sciences. Psychology; geactiveerd slib; halotolerant SRB; high salinity; Hydrogen-Ion Concentration; Industrial applications and implications. Economical aspects; long-term competition; methanogenic bacteria; Pilot Projects; propionate; propionaten; propionates; Proteobacteria - drug effects; Proteobacteria - metabolism; reducing reactors; reductie; reduction; salinity; Sewage - microbiology; Sodium Chloride - pharmacology; sulfaat; sulfate; sulfate reduction; Sulfates - metabolism; UASB reactor; Waste Water Treatment; waste-water; wastewaters; Water Purification - methods; water treatment; waterzuivering; zoutgehalte
• ISSN: 0006-3592; 1097-0290
• DOI: 10.1002/bit.20040

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 42‐ 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.