Integrated photocatalytic-biological reactor for accelerated phenol mineralization
- 401 Downloads
An integrated photocatalytic-biological reactor (IPBR) was developed for accelerated phenol degradation and mineralization. In the IPBR, photodegradation and biodegradation occurred simultaneously, but in two separated zones: a piece of mat-glass plate coated with TiO2 film and illuminated by UV light was connected by internal circulation to a honeycomb ceramic that was the biofilm carrier for biodegradation. This arrangement was designed to give intimate coupling of photocatalysis and biodegradation. Phenol degradation was investigated by following three protocols: photocatlysis with TiO2 film under ultraviolet light, but no biofilm (photodegradation); biofilm biodegradation with no UV light (biodegradation); and simultaneous photodegradation and biodegradation (intimately coupled photobiodegradation). Photodegradation alone could partly degrade phenol, but was not able to achieve significant mineralization, even with an HRT of 10 h. Biodegradation alone could completely degrade phenol, but it did not mineralize the COD by more than 74%. Photobiodegradation allowed continuous rapid degradation of phenol, but it also led to more complete mineralization of phenol (up to 92%) than the other protocols. The results demonstrate that intimate coupling was achieved by protecting the biofilm from UV and free-radical inhibition. With phenol as the target compound, the main advantage of intimate coupling in the IPBR was increased mineralization, presumably because photocatalysis made soluble microbial products more rapidly biodegradable.
KeywordsBiofilm Photocatalysis Bioreactor Wastewater treatment Phenol
The authors acknowledge the financial support by the National Natural Science Foundation of China (50678102), the Special Foundation of Chinese Colleges and Universities Doctoral Discipline (20070270003), the Shanghai Leading Academic Discipline Project (S30406), the Leading Academic Discipline Project of Shanghai Normal University (DZL711), and the US National Science Foundation (0651794). Precious Biyela provided valuable comments on the manuscript.
- Balcioglu IA, Cecen F (1999) Treatability of kraft pulp bleaching wastewater by biochemical and photocatalytic oxidation. Water Sci Technol 40:281–288Google Scholar
- Huang G, Yang Y, Zhang L, Liu Y (2009) Effect of Hydraulic Retention Time on the Formation of Soluble Microbial Products in Aerobic Completely Stirred Tank Reactor. Journal of East China University of Science and Technology (Natural Science Edition) 35(1):66–70Google Scholar
- Jianmin W, Gowei G, Chonghua Z (1993) Anaerobic biodegradation of phenol:bacterial accumulation and system performance. Water Sci Technol 28:17–22Google Scholar
- Li XZ, Zhao YG (1999) Advanced treatment of dyeing wastewater for reuse. Water Sci Technol 39(10–11):249–255Google Scholar
- Reddy MP, Srinivas B, Kumari VD, Subrahmanyam M, Sharma PN (2004) An integrated approach of solar photocatalytic and biological treatment of N-containing organic compounds in wastewater. Toxicol Environ Chem 86(1–4):125–138Google Scholar
- Wei F (2002) Monitoring and analytic methods of water and wastewater, 4th edn. Environmental Science Press of China, BeijingGoogle Scholar
- Yan J, Jianping W, Bai J, Daoquan W, Zongding H (2006) Phenol biodegradation by the yeast Candida tropicalis in the presence of m-cresol. Biochem Eng J 29:227–23Google Scholar
- Yuan L, Jiang L, Peng Z, Ruan Q (2009) Breeding of the high phenol-degraded bacterium JY01 and study on phenolic biodegradation. Microbiology Bulletin 36:587–592Google Scholar
- Zhang Y, Han L, Wang J, Yu J, Shi H, Qian Y (2002) An internal airlift loop bioreactor with Burkholderia pickttii immobilized onto ceramic honeycomb support for degradation of quinoline. Biochem Eng J 11(2–3):149–157Google Scholar
- Zhang Y, Quan X, Rittmann BE, Wang J, Shi H, Qian Y, Yu J (2004) IAL-CHS (internal airlift loop—ceramic honeycomb supports) reactor used for biodegradation of 2, 4-dichlorophenol and phenol. Water Sci Technol 49(11–12):247–254Google Scholar