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Effect of COD:SO4 2− Ratio, HRT and Linoleic Acid Concentration on Mesophilic Sulfate Reduction: Reactor Performance and Microbial Population Dynamics
- Source :
- Water, Vol 7, Iss 5, Pp 2275-2292 (2015)
- Publication Year :
- 2015
- Publisher :
- MDPI AG, 2015.
-
Abstract
- Biological sulfate (SO42−) reduction was examined in anaerobic sequential batch reactors (ASBRs) operated under different hydraulic retention times (HRTs) ranging from 12 to 36 h and COD (Chemical Oxygen Demand)/SO42−) ratios of 2.4, 1.6 and 0.8. Competition between SO42− reducing bacteria (SRBs), methane producing archaea (MPAs) and homoacetogens (HACs) was examined in controls and cultures treated with linoleic acid (LA). The ASBR performance was influenced by the COD/SO42− ratio in control cultures with a SO42− reduction of 87% at a COD/SO42− ratio of 0.8. At a 12 h HRT, in both control and LA treated cultures, greater than 75% SO42− removal was observed under all the conditions examined. In control reactors operating at a 36 h HRT, high levels of MPAs belonging to Methanobacteriales and Methanosarcinales were detected; however, in comparison, under low COD/SO42− ratio and with decreasing HRT conditions, a relative increase in SRBs belonging to Desulfovibrio and Desulfatibacillum was observed. Adding 0.5 g·L−1 LA suppressed Methanobacteriales, while increasing the LA concentration to 1 g·L−1 completely suppressed MPAs with a relative increase in SRBs. HACs belonging to Bacteroidetes were observed in the control and in cultures operated at 12 h HRT with a COD/SO42− ratio of 1.6 and fed 0.5 g·L−1 LA; however, with all other LA levels (0.5 and 1.0 g·L−1) and HRTs (12, 24 and 36 h), HACs were not detected.
Details
- Language :
- English
- ISSN :
- 20734441
- Volume :
- 7
- Issue :
- 5
- Database :
- Directory of Open Access Journals
- Journal :
- Water
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.54207990fa847f99cd11979d98bedd4
- Document Type :
- article
- Full Text :
- https://doi.org/10.3390/w7052275