Effective removal of phenol from polluted water via bio-based rigid polyurethane foams in collaboration with Alcaligenes faecalis

Abstract

In this study, the removal efficiencies of bio-based rigid polyurethane foams (“RPUFs” group), Alcaligenes faecalis subsp. faecalis NBRC 13111T (“strain” group), and the combined use of RPUFs and A. faecalis subsp. faecalis NBRC 13111T (“RPUFs + strain” group) were investigated. The concentration of NaCl, number of RPUFs, initial pH and initial phenol concentration were sequentially examined. The results showed the adsorption of phenol in “RPUFs” group and “RPUFs + strain” group was improved with the increased number of RPUFs, and the highest adsorption was about 200 mg/L when 40 pieces of RPUFs were used. Under all conditions, the phenol removal efficiency of “RPUFs + strain” group was higher than that of the “strain” group. With the increased concentration of NaCl, the complete removal time of phenol in “strain” group and “RPUFs + strain” group was correspondingly prolonged. In neutral and weakly alkaline conditions, the phenol removal efficiency of “strain” group and “RPUFs + strain” group was much improved, and the phenol-removed time of 500 mg/L of “RPUFs + strain” group was only 30 h at the pH of 7. With the increase of initial phenol concentration, the complete removal time in “strain” group and “RPUFs + strain” group was delayed, especially at the high concentration of 1100 mg/L, the “strain” group had nearly no ability to remove phenol, while the “RPUFs + strain” group could still completely removed phenol at 78 h. The phenol removal mechanism of the “RPUFs + strain” group was attributed to “physical adsorption - biodegradation”.