Aerobic biodegradation of phenol by Immobilized Pseudomonas sp. cells in two different bio-carrier matrices

Abstract

Biotreatment using immobilized cells (IC) technology has proved to be the most promising and most economical approach for the removal of many toxic organic pollutants found in petroleum-refinery wastewater (PRW) such as phenol. This study was undertaken to evaluate the degradation of phenol by Pseudomonas cells individually immobilized in two different bio-carrier matrices including polyvinyl alcohol-guar gum (PVA-GG) and polyvinyl alcohol-agar agar (PVA-AA). Results of batch experiments revealed that complete removal of phenol was attained in the first cycle after 150 min using immobilized cells (IC) in both PVA-GG and PVA-AA. Additional cycles were confirmed to evaluate the validity of recycling beads of immobilized cells for phenol biodegradation. Results revealed that the phenol percentage removals were 95, 92, 86, and 84 % for second, third, fourth, and fifth cycles, respectively using Pseudomonas immobilized in PVA-GG beads. Whereby they were 96, 92, 90, and 84 % using Pseudomonas immobilized in PVA-AA beads for the same sequence of cycles.