The New Jersey Institute of Technology's
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Title:	Catalytic ozone/ultraviolet light oxidation of organics in water : integrated charcoal/ozonation/UV radiation
Author:	Wang, Dawei
View Online:	njit-etd1992-115 (ix, 69 pages ~ 1.7 MB pdf)
Department:	Department of Civil and Environmental Engineering
Degree:	Master of Science
Program:	Environmental Engineering
Document Type:	Thesis
Advisory Committee:	Bozzelli, Joseph W. (Committee chair) Liskowitz, John W. (Committee member) Cheng, Su Ling (Committee member)
Date:	1992-10
Keywords:	Water -- Purification -- Organic compounds removal Water -- Purification -- Ozonization Water -- Purification -- Oxidation Water -- Purification -- Ultraviolet treatment Organic compounds -- Environmental aspects Organic compounds -- Absorption and adsorption
Availability:	Unrestricted
Abstract:	A novel heterogeneous catalytic-oxidation technology where activated carbon is used as a catalyst-adsorbent, ozone serves as the oxidant and UV light as activation agent, is developed in a lab scale study. We demonstrate this process for destruction of recalcitrant organics in water i.e: combined oxidation by ozone, UV light plus activated carbon. The investigation includes evalution of various operating conditions: ozone levels, activated carbon levels; time for complete destruction of the individual target pollutants, plus evalution of activity of the continuously recativated carbon surface in-situ. All experiments were performed at room temperature in a semi-batch reactor. Seven representative chemicals was used as target pollutants: Phenol, N,N-dimethyl Formamide, O-cresol, Aniline, Pyridine, Trichloroethlene, Dioxane. The experiments indicate that activated carbon may function as effective catalyst besides being an adsorbent. This new process can achieve more complete and rapid oxidation to recalcitrant compounds when compared to either photocatalytic-ozonation or adsorption operations as seperate treatment processes. It is observed that in adsorption only experiment, 8% of phenol removal was obtained after 10.5 min, while photolytic-ozonation process decomposed 50% of the phenol in this time. However, in the new process, 66% of phenol removal was obtained. we also found that carbon adsorption capacities were significantly increased and activity regenerated by continuously activating the carbon with UV light and in-situ reaction. Rate constants, characteristic constants of carbon uptake test for this C/O3/UV process compared to O3/UV process are: Table 1: Rate constants Compound Rate Ratio* Aniline 1.17 Pyridine 1.80 N,N-dimethyl Formamide 1.98 O-cresol 1.63 Trichloroethylene 1.50 Dioxane 1.38 Phenol 1.50 * Ratio of rate for this process to photolytic ozonation (no carbon present ) Table 2: Characteristic constants of carbon Uptake Test For equation: q(mg/mg)=Kf*Ce(1/n)   (1): C/O3/UV process:     Kf=10(-7*03); n=0.519.   (2): Carbon only process:     Kf=10(-20.03); n=0.169.       (Phenol as Adsorbate) We also describe and characterize on increased rate of ozone mass transfer from the gas to the liquid phase with the UV/carbon present.