Photocatalytic degradation of methyl orange by a multi-layer rotating disk reactor
Journal
Environmental Science and Pollution Research
Journal Volume
19
Journal Issue
9
Pages
3743-3750
Date Issued
2012
Author(s)
Abstract
Introduction: Solar wastewater treatment based on photocatalytic reactions is a green process that utilizes renewable energy resources and minimizes secondary pollution. Reactor design plays an important role in promoting treatment efficiency and throughput density (based on unit volume of the reactor). Experimental: A rotating disk reactor that significantly increases the process efficiency has been designed and evaluated for application to photocatalytic decomposition of dye pollutants in aqueous solutions. In this process, a novel multi-layer rotating disk reactor (MLRDR) was presented. Photocatalyst (TiO2) particles are immobilized on the surfaces of disks. Within each layer of the reactor, methyl orange aqueous solution is allowed to flow from the center of the disk in a radial direction along the surface of the disk, which is rotating at high speed and is irradiated with UV lamps. The effluent is then directed to the center of another layer that lies underneath. Up to four stacked layers have been tested in this study, and the effects due to the number of the layers and volumetric flow rate on reaction conversion are investigated. Results and discussion: The efficiency of this photocatalytic reactor exhibits complex dependence on these parameters. With selected operating conditions, conversions greater than 95% can be achieved within seconds of residence time. Design equations of the reactor have been derived based on fluid dynamics and kinetic models, and the simulation results show promising scale-up potential of the reactor. © 2012 Springer-Verlag.
Subjects
Fluid dynamics modeling; Kinetics modeling; Photocatalysis; Rotating disk reactor; Scale-up; Simulation; Wastewater
Other Subjects
azo compound; methyl orange; titanium; titanium dioxide; aqueous solution; catalysis; decomposition; dye; flow velocity; fluid dynamics; numerical model; photodegradation; pollution control; reaction rate; renewable resource; solar radiation; wastewater; article; catalysis; chemical model; chemistry; kinetics; methodology; photochemical smog; photolysis; sewage; waste water; water pollutant; Azo Compounds; Catalysis; Kinetics; Models, Chemical; Oxidants, Photochemical; Photolysis; Titanium; Waste Disposal, Fluid; Waste Water; Water Pollutants, Chemical
Type
journal article