Solid-Liquid Partitioning Bioreactors Applied to the Removal of Mixtures of Phenolic Compounds

-In this paper we report the results of an investigation on the performance of conventional and two phase partitioning bioreactors (TPPBs) operating in sequencing batch mode applied to the biodegradation of a binary mixture of 2 substituted phenols, 2,4-dimethylphenol and 4-nitrophenol. The TPPB was operated with the DuPont polymer Hytrel 8206 as the partitioning phase, which was demonstrated to be effective in the uptake and release of a variety of phenolic compounds. Partition tests were performed on both compounds, and partition coefficients of 201 and 143 were obtained in distilled water for 2,4-dimethylphenol and 4-nitrophenol, respectively. Parallel kinetic tests were carried out in conventional and TPPB bioreactors under the same operating conditions. The TPPB results showed a reduction in the aqueous phase concentration for both substrates to sub-inhibitory levels in all the tests, and the effect was more evident for 2,4-dimethylphenol as expected by the partition coefficient values. Moreover, the presence of the polymer has a marked effect on the process kinetics that are significantly increased for both substrates in comparison to the values of the conventional reactor.