Diversity and degradation mechanism of an anaerobic bacterial community treating phenolic wastewater with sulfate as an electron acceptor

Abstract

Petrochemical wastewater often contains high concentrations of phenol and sulfate that must be properly treated to meet discharge standards. This study acclimated anaerobic-activated sludge to treat saline phenolic wastewater with sulfate reduction and clarified the diversity and degradation mechanism of the microbial community. The active sludge in an upflow anaerobic sludge blanket (UASB) reactor could remove 90 % of phenol and maintain the effluent concentration of SO4 (2-) below 400 mg/L. Cloning and sequencing showed that Clostridium spp. and Desulfotomaculum spp. were major phenol-degrading bacteria. Phenol was probably degraded through the carboxylation pathway and sulfate reduction catalyzed by adenosine-5'-phosphosulfate (APS) reductase and dissimilatory sulfite reductase (DSR). A real-time polymerase chain reaction (RT-PCR) showed that as phenol concentration increased, the quantities of 16S rRNA gene, dsrB, and mcrA in the sludge all decreased. The relative abundance of dsrB dropped to 12.46 %, while that of mcrA increased to 56.18 %. The change in the electron flow ratio suggested that the chemical oxygen demand (COD) was removed mainly by sulfate-reducing bacteria under a phenol concentration of 420 mg/L, whereas it was removed mainly by methanogens above 630 mg/L.

Performance and microbial community composition in a long-term sequential anaerobic-aerobic bioreactor operation treating coking wastewater

“…Though Ottowia has been isolated from activated sludge treating CWW wastewater (Felfoldi et al 2011;Cao et al 2014;Geng et al 2014), its presence at such a high abundance in anaerobic sludge was not reported previously. The presence of Ottowia together with Advenella Ghosh et al 2011), Corynebacterium (Dalal et al 2012;Guo et al 2015), and Sphingobium (Kertesz and Kawasaki 2010) might be associated with the removal of phenols, NHCs as well as PAHs under the anaerobic conditions (Table S8). Soehngenia, the second most abundant anaerobic bacterium in this study, was previously reported to degrade benzaldehyde (Parshina et al 2003), an intermediate in anaerobic phenol degradation (Sharma and Philip 2015).…”

Two-stage conversion of syngas and pyrolysis aqueous condensate into L-malate

“…Syngas accounted for over 90% of the total e-mol for the first 40 days of the fermentation. Although no significant correlation was identified between Clostridium sensu stricto 12 and aromatics removal in this work, prior research indicated that Clostridium sensu stricto participated in the anaerobic digestion of aromatics-rich wastewaters [73][74][75][76]. Examples include also the enrichment of Clostridium sensu stricto (up to 17.5%) during the degradation of tars from rice husk gasification, where biochar facilitated syntrophic relations with Methanosaeta [26].…”

Recent Advances in Biotechnologies for the Treatment of Environmental Pollutants Based on Reactive Sulfur Species

“…Anaerobic treatment of phenol-containing wastewater is mostly performed in UASB (up-flow anaerobic sludge blanket) reactors [ 41 ]. Guo et al achieved up to 90% phenol removal using a UASB reactor based on sulfate reduction [ 42 ]. Sequencing 16s DNA showed that Clostridium spp.…”