Biodegradation of Phenol–Polluted Air in Aerobic Granular Reactors

Abstract

As one kind of toxic volatile organic compound (VOC), phenol-polluted air was degraded by aerobic granules. Aerobic granulation is a novel biotechnology, which has a strong ability to tolerate toxicity and to handle high phenol loading rates. The objective of this work is to evaluate the possibility of phenol elimination by aerobic granules and the characteristics of the aerobic granules. In this experiment, phenol was added to the reactor at loading rates of 0.5, 1.0, 1.5 and 2.0 kg/m 3 ·d. Aerobic granules showed good degrading ability at different phenol loading rates. At a steady state, the phenol removal rate was higher than 96% while the COD removal rate was higher than 95%. The phenol loading rate exerted a profound influence on the activity, morphology, and structure of the aerobic granules. The specific oxygen utility rate of the aerobic granules changed from 91 to 32 mg O 2 /gVSS·h when the reactor was fed with phenol-polluted air. Then it increased to 74 mg O 2 /gVSS·h at phenol loading rate of 1.5 kg/m 3 ·d. Extracellular polymers, as well as protein, polysaccharides increased with the increasing of phenol loading rates. The sludge volume Index (SVI) and settling velocity were 42.5-44 ml/g and 72.6-80.0 m/h, respectively. The compact structure of the aerobic granules was maintained after fed with phenol waste gas. This study confirmed the application of aerobic granule technology on VOCs elimination.