title: Degradation of high concentration 2,4-dichlorophenol by simultaneous photocatalytic-enzymatic process using TiO2/UV and laccase.
abstract: Removal of 2,4-dichlorophenol (2,4-DCP) by TiO2/UV photocatalytic, laccase, and simultaneous photocatalytic-enzymatic treatments were investigated. Coupling of native laccase with TiO2/UV showed a negative synergetic effect due to the rapid inactivation of laccase. Immobilizing laccase covalently to controlled porous glass (CPG) effectively enhanced the stability of laccase against TiO2/UV induced inactivation. By coupling CPG-laccase with the TiO2/UV the degradation efficiency of 2,4-DCP was significantly increased as compared with the results obtained when immobilized laccase or TiO2/UV were separately used. Moreover, the enhancement was more remarkable for the degradation of 2,4-DCP with high concentration, such that for the degradation of 5mM 2,4-DCP, 90% removal percentage was achieved within 2h with the coupled degradation process. While for the TiO2/UV and CPG-laccase process, the removal percentage of 2,4-DCP at 2h were only 26.5% and 78.1%, respectively. The degradation kinetics were analyzed using a intermediate model by taking into account of the intermediates formed during the degradation of 2,4-DCP. The high efficiency of the coupled degradation process therefore provided a novel strategy for degradation of concentrated 2,4-DCP. Furthermore, a thermometric biosensor using the immobilized laccase as biorecognition element was constructed for monitoring the degradation of 2,4-DCP, the result indicated that the biosensor was precise and sensitive.
authors.affiliation: National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China.
authors.forename: Jingbo
authors.initials: J
authors.lastname: Jia
authors.forename: Songping
authors.initials: S
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: Huajun
authors.initials: H
authors.lastname: Wang
mesh_terms: D015374:Biosensing Techniques; D002733:Chlorophenols / Q000737:chemistry* / Q000528:radiation effects; D042845:Laccase / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D010782:Photolysis; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000528:radiation effects; D018508:Water Purification / Q000379:methods
chemical_list: D002733:Chlorophenols; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D014025:Titanium; D042845:Laccase; C004762:2,4-dichlorophenol