To cite this article: Sam, S. P., Ng, S. L. & Rohana, A. (2018). Kinetics of biodegradation of phenol and p-nitrophenol by acclimated activated sludge. J. Phys. Sci., 29(Supp. 1), 107–113, https://doi.org/10.21315/jps2018.29.s1.14
The removal of highly toxic phenolic compounds, such as phenol and p-nitrophenol (PNP) from wastewater through biological approach provides a good cleanup strategy in wastewater treatment. It is recognised as an efficient green treatment with relatively low cost in comparison to conventional physicochemical processes. In this present study, activated sludge was acclimated to phenol and PNP, respectively, using sequencing batch reactor (SBR) system. The growth kinetics of both phenol- and PNP acclimated activated sludge were well described by Haldane model. The values of the Haldane kinetic parameters, namely, maximum specific growth rate, μmax, saturation constant, Ks, and inhibition constant, Ki, were found to be 0.4039 and 0.1346 h−1, 5.393 and 110.3 mg l−1, and 550.8 and 63.58 mg l−1, respectively. The smaller ratio of Ks/Ki for phenol degradation compared to that of PNP biodegradation indicates the higher resistance of phenol-acclimated activated sludge to inhibition by its substrate. The pseudo zeroth-order equation was able to describe the phenol degradation kinetics at different initial concentrations. However, the equation was inadequate for the PNP degradation which was attributed to its higher toxicity compared to phenol.