Decolorization and Biodegradation of Amido Black using Activated Sludge under Aerobic and Aerobic Denitrifying Conditions

Abstract

In the present study, decolorization and biodegradation of amido black at 0.1, 1.0, 5.0 and 10.0 mM using activated sludge under aerobic and aerobic denitrifying conditions were investigated for 10 days. At day 5 and 7 of the experiment, methanol was added for 0.1 and 0.2 mL, respectively. Results showed that activated sludges under aerobic and aerobic denitrifying conditions were capable of decolorizing 0.1 mM amido black only. They could reduce the color intensity from 10 to 1 and from 10 to 3, respectively. Methanol was used as carbon source for co-metabolism process. However, the activated sludges under both conditions were unable to decolorize amido black at 1.0 – 10.0 mM. For ability of amodo black biodegradation assessed by measurement of total gas production, aerobic activated sludge degrade partial amido black at all tested concentrations (0.1, 1.0, 5.0 and 10.0 mM) with gas production for 0.2, 0.150, 0.1and 0.1 mL, respectively. Moreover, activated sludges under aerobic and aerobic denitrifying conditions were capable of continuously removing 0.1 mM amido black due to detection of gas production at day 6 and 7 of the experiment. In case of higher concentration of amido black, no detection of gas was observed again. Therefore, this study could be concluded that activated sludges under both conditions had potential for decolorization and biodegradation of 0.1 mM amido black only by using methanol as another carbon source for co-metabolism process. Aerobic activated sludge showed a higher effectiveness for decolorization, compared to that of aerobic denitrifying sludge.