Sustained degradation of phenol under extreme conditions by polyurethane-based Bacillus sp. ZWB3

Abstract

Phenol is a serious pollutant to the environment, therefore, it is urgent to find a rapid and effective method for its removal. In this study, Bacillus cereus ZWB3 immobilized on a polyurethane (PUF) carrier was studied. The PUF-ZWB3 required only 20 h for the degradation of 1,500 mg L−1 of phenol, shortened by 8 h than the free bacteria. In addition, the PUF-ZWB3 could increase the degradation concentration of phenol from 1,500 to 2,000 mg L−1, and the complete degradation of 2,000 mg L−1 phenol only used 44 h. In addition, the PUF-ZWB3 showed much higher removal of phenol than the free bacteria at different pH values, salt concentrations, and heavy metal ions. Particularly, the PUF-ZWB3 could still completely remove phenol in a strongly alkaline environment, such as pH 10 and 11. In addition, the removal efficiency of phenol by PUF-ZWB3 was still 100% after 10 cycles. This study showed that the PUF immobilization system had great potential in the field of remediation of organic pollution. HIGHLIGHTS PUF can increase the degradation rate and concentration of phenol by ZWB3.; The PUF-ZWB3 system can effectively degrade high concentrations of phenol at a higher pH.; The PUF-ZWB3 system has an excellent cyclic degradation performance.;

Keywords

• biodegradation
• immobilization
• phenol
• polyurethane