Evaluation of o-cresol removal using PVA-cryogel-immobilised biomass enhanced by PAC

Abstract

The degradation of o-cresol using immobilised acclimated biomass in PVA-alginate hydrogel and cryogel beads was investigated. The results show that the PVA-hydrogel-immobilised biomass achieved better o-cresol removal efficiency than the PVA-cryogel-immobilised biomass. However, the cryogel beads showed better bead stability and reusability. Based on o-cresol removal, the optimum dry biomass density in the cryogel beads of 3–4 mm diameter was found to be 0.02 g·cm-3. An enhancement in the performance of PVA-cryogel-immobilised biomass for o-cresol removal was observed when 0.5% (w/v) powdered activated carbon (PAC) was added into the polymeric matrix. In the reusability and stability test, the cryogel beads containing biomass augmented by PAC were able to sustain 9 cycles of use with a removal efficiency of over 82% per cycle, when treating 300 mg·l-1 of o-cresol, without much biomass leakage being detected.

Keywords: cryogel beads, hydrogel beads, o-cresol, immobilised biomass, powdered activated carbon