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| The extensive use of phenol compounds and the inability to remove these compounds during wastewater treatment have resulted in the widespread occurrence of phenols in the natural environment. Phenols have been linked to serious risks to human and environmental health. Hence the need to develop methods for the removal of phenols from wastewater and source waters is a pressing challenge for our time. In this study, light ceramic particles were immersed in activated sludge acclimated to degrade phenol, and microorganisms were allowed to attach to the particles surface to form biofilm, then the ceramic particles with biofilm were moved into the photolytic circulating-bed biofilm reactor (PCBBR) made of quartz glass, which was used for degradation of phenol by three protocols: photolysis with UV light alone (P), biodegradation alone (B), and the two mechanisms operating simultaneously (photobiodegradation, P&B). The experimental results indicated that phenol removal rate was quickest by B experiment. However, P&B experiment gave more complete mineralization of phenol than that by other protocols. During P&B experiment, the microorganisms grown on porous ceramic carrier still kept the bioactivity degrading phenol, even under UV light irradiation. But the dominant members of the bacterial community changed dramatically after the intimately coupled photo-biodegradation, according to molecular biological analysis to the biofilm. Whereas Beijerinckia sp. was the dominant strain in the inoculum, it was replaced by Thauera sp. MZ1T that played a main role on degrading phenol during P&B experiment. |
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| Keywords:ultra violet irradiation; biofilm; phenol; photolytic circulating-bed biofilm reactor; molecular analysis |
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