Journal of Hazardous Materials 215–216 (2012) 25–31 Contents lists available at SciVerse ScienceDirect Journal of Hazardous Materials jou rn al h om epage: www.elsevier.com/loc ate/jhazmat CFD modeling of a UV-LED photocatalytic odor abatement process in a continuous reactor Zimeng Wang 1 , Jing Liu, Yuancan Dai, Weiyang Dong, Shicheng Zhang ∗ , Jianmin Chen ∗∗ Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China a r t i c l e i n f o Article history: Received 26 September 2011 Received in revised form 2 January 2012 Accepted 8 February 2012 Available online 16 February 2012 Keywords: Photocatalysis Computational fluid dynamics Radiation field model Kinetics Light-emitting-diodes Deodorization a b s t r a c t This paper presents a model study of a UV light-emitting-diode (UV-LED) based photocatalytic odor abatement process. It integrated computational fluid dynamics (CFD) modeling of the gas flow in the reactor with LED-array radiation field calculation and Langmuir–Hinshelwood reaction kinetics. It was applied to simulate the photocatalytic degradation of dimethyl sulfide (DMS) in a UV-LED reactor based on experimentally determined chemical kinetic parameters. A non-linear power law relating reaction rate to irradiation intensity was adopted. The model could predict the steady state DMS concentration profiles by calculating the advection, diffusion and Langmuir–Hinshelwood reaction kinetics. By affecting the radiation intensity and uniformity, the position of the LED array relative to the catalyst appeared to be a critical parameter determining DMS removal efficiency. Too small distances might yield low quantum efficiency and consequently poor abatement performance. This study provided an example of LED-based photocatalytic process modeling and gave insights into the optimization of light source design for photocatalytic applications. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Odor pollution from wastewater treatment, landfill, livestock and paper production plants has posed serious environmental and health concerns. Many of the odorous pollutants have extremely low odor thresholds (<100 ppb) and are irritant to eyes, skin and respiratory systems. Repeated exposure to odorous pollution can lead to chronic respiratory and cardiovascular diseases. A number of advanced technologies for the abatement of odorous pollution have been developed, such as active carbon adsorption, activated sludge, biofiltration and incineration [1]. However, these technolo- gies are to some extent limited by either removal efficiency or operating cost [2]. Semiconductor-mediated photocatalytic oxidation (PCO) is a promising technology for odor abatement [3,4], which can be car- ried out at ambient temperatures without extra addition of oxidant chemicals [5]. Nevertheless, one of the challenges in the commer- cialization of PCO technology in air purification industry is the ∗ Corresponding author. Tel.: +86 21 65642297; fax: +86 21 65642297. ∗∗ Corresponding author. Tel.: +86 21 65642298; fax: +86 21 65642080. E-mail addresses: zhangsc@fudan.edu.cn (S. Zhang), jmchen@fudan.edu.cn (J. Chen). 1 Department of Energy, Environmental and Chemical Engineering, Washington University, St. Louis, MO 63130, United States. limitation of reliable tools to assist the design, optimization, and scale-up of photocatalytic reactors [6]. Empirical or trail-and-error methods are not able to efficiently provide an understanding of the capability and the limitations of the reactors. Recent reports demonstrated that computational fluid dynamics (CFD) is a pow- erful tool to model the advection, molecular diffusion and chemical reactions in flow through photocatalytic reactors [7–15]. Compared with ordinary chemical reactors, photocatalytic reactors involve particular considerations of the irradiation designs. Therefore, it is crucial to develop models that can help the optimization of the radiation field [16,17]. A number of experimental studies have established the effect of the radiation intensity on the intrinsic reaction kinetics of photocatalytic process [18–20]. However, com- prehensive models, which integrate the transport, heterogeneous reaction kinetics and radiation field that can predict the odor abate- ment as a function of operating parameters in real reactors, are much less common [6]. Most existing photocatalytic studies and applications are using germicidal lamps and fluorescent black-light lamps [3]. How- ever, these traditional UV sources are limited by shortcomings related to sustainability and the environment [21]. Light-emitting- diodes (LEDs) recently became a promising alternative UV source for photocatalytic applications for their high energy efficiency, long lifetime, compact size and DC power supply availability [22,23]. Several recent studies have illustrated that LEDs offer a practical and competitive alternative light source for PCO 0304-3894/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.jhazmat.2012.02.021