title: Integrated photocatalytic-biological reactor for accelerated 2,4,6-trichlorophenol degradation and mineralization.
abstract: An integrated photocatalytic-biological reactor (IPBR) was used for accelerated degradation and mineralization of 2,4,6-trichlorophenol (TCP) through simultaneous, intimate coupling of photocatalysis and biodegradation in one reactor. Intimate coupling was realized by circulating the IPBR's liquid contents between a TiO(2) film on mat glass illuminated by UV light and honeycomb ceramics as biofilm carriers. Three protocols-photocatalysis alone (P), biodegradation alone (B), and integrated photocatalysis and biodegradation (photobiodegradation, P&B)-were used for degradation of different initial TCP concentrations. Intimately coupled P&B also was compared with sequential P and B. TCP removal by intimately coupled P&B was faster than that by P and B alone or sequentially coupled P and B. Because photocatalysis relieved TCP inhibition to biodegradation by decreasing its concentration, TCP biodegradation could become more important over the full batch P&B experiments. When phenol, an easy biodegradable compounds, was added to TCP in order to promote TCP mineralization by means of secondary utilization, P&B was superior to P and B in terms of mineralization of TCP, giving 95% removal of chemical oxygen demand. Cl(-) was only partially released during P experiments (24%), and this corresponded to its poor mineralization in P experiments (32%). Thus, intimately coupled P&B in the IPBR made it possible obtain the best features of each: rapid photocatalytic transformation in parallel with mineralization of photocatalytic products.
authors.affiliation: Department of Environmental Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai, People's Republic of China. zhym@shnu.edu.cn
authors.forename: Yongming
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xia
authors.initials: X
authors.lastname: Sun
authors.forename: Lujun
authors.initials: L
authors.lastname: Chen
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Rittmann
mesh_terms: D001420:Bacteria, Aerobic / Q000502:physiology*; D001673:Biodegradation, Environmental; D018441:Biofilms; D019149:Bioreactors; D002516:Ceramics; D002733:Chlorophenols / Q000378:metabolism*; D055668:Photochemical Processes; D012722:Sewage; D014025:Titanium; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D002733:Chlorophenols; D012722:Sewage; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D014025:Titanium; C024564:2,4,6-trichlorophenol