Biodegradation of catechol (2-hydroxy phenol) bearing wastewater in an UASB reactor

The present study deals with the biodegradation of catechol through co-metabolism with glucose in aqueous solution as primary substrate in an upflow anaerobic sludge blanket (UASB) reactor. Batch studies indicated that the 1000 mg 1(-1) glucose concentration was sufficient to cometabolize and degrade catechol in an aqueous solution up to a concentration of 1000 mg 1(-1). The reactor operated at 35 +/- 2 degrees C, and at a constant hydraulic retention time of 8 h with a gradual stepwise increase in catechol concentration from 100 to 1000 mg 1(-1) along with glucose as a cosubstrate. The results showed that the catechol was successfully mineralized in an UASB reactor in which microbial granulation was achieved with only glucose as the substrate. The reactor showed >= 95% COD removal efficiency with 500-1000 mg 1(-1) catechol concentration in the feed and a glucose concentration of 1500 mg 1(-1) as a cosubstrate. Similar efficiency was obtained at a constant catechol concentration of 1000 mg 1(-1) with 500-1000 mg 1(-1) glucose concentration. Once the reactor got acclimatized with catechol, higher concentrations of catechol can be mineralized with a minimum amount of glucose as the cosubstrate without affecting the performance of the UASB reactor. (C) 2007 Published by Elsevier Ltd.