CFD modeling of a UV-A LED baffled flat-plate photoreactor for environment applications: a mining wastewater case

Abstract

The use of ultraviolet light in photoreactors for wastewater treatment has become popular as an alternative of known chemical oxidative substances. UV LED light represents cheaper, robust, and versatile alternative to traditional UV lamps. In this study, it was designed and evaluated a photoreactor with an approach of chemical fluid dynamics (CFD) and experimental validation. The evaluation consisted of (1) CFD velocity profile analysis, (2) characterization of the average light distribution with potassium ferrioxalate actinometry, (3) degradation of a typical recalcitrant metallic cyanocomplex Fe(CN), and (4) scavenger effect analysis in the photodegradation using potassium persulfate. Actinometrical essay concluded that the system was able to receive 1.93 μE/s. The reactor operated under turbulent regime and best result for Fe(CN) degradation was obtained at 4 h of operation, using 5-W UV-A LEDs, with pH ~ 7 and 10 mM de SO. Baffled photoreactor demonstrated to be useful for this type of illumination and wastewater treatment.

New approach for the dimensionless analysis of a unidirectional flow solar reactor based on Damköhler's number profiles

“…Therefore, all the researchers who work in the area of photocatalysis from different specific fields are directly working to improve the , either from the synthesis of catalysts [30] , modification of catalysts, broadening the spectrum of absorption [31] , reactor geometry [32] , [33] , hydrodynamics of reactors and CFD [3] , design of new reactors such as microreactors [34] , development of new applications, or evaluation of other contaminants and mixtures. This parameter ( ) becomes a key element in the development of technology.…”

“…Simulation has been widely used to describe complex systems, such as reactors, in order to design new geometries, determine the volume of new reactors, analyze different scenarios, determine the conversion and optimize operating variables [1] , [2] , [3] . Solar reactors are used in water treatment research to degrade pollutants by advanced oxidation process.…”

The Influence of Photocatalytic Reactors Design and Operating Parameters on the Wastewater Organic Pollutants Removal—A Mini-Review

“…UV-A radiation was used to remove hexacyanocobaltate [103] and potassium hexacyanoferrate [104] pollutants. A stirring reactor with 1.5 L volume was employed for the removal of 32 mg/L hexacyanocobaltate in the presence of 0.2 g of TiO 2 .…”

Recent Developments in the Photocatalytic Treatment of Cyanide Wastewater: An Approach to Remediation and Recovery of Metals

“…The ratio Cu:CN influences photocatalytic degradation. A 10:1 ratio was the best for the process [82] 2005 Configuration resulted useful for light harvesting, but it is required more UV Power since the complex was not complete degraded [89] Generally, the main characteristic of these photocatalytic treatments is the use of UV lamps with a high irradiation capacity (about 150, 400 or 700 W) and in some cases metals are recovered by reducing them to their zero valence state [37][38][39][40][41][46][47][48]50,54,59,62,63,66,[81][82][83][84][85][86]90]. Nevertheless, photocatalytic processes for stable metallic cyano-complexes destruction are not yet fully effective for the treatment of mining wastewater, due to the presence of metal re-oxidation-redissolution and photocatalyst poisoning by deposition.…”

“…Demonstrated the utilization of a baffled plat plate photoreactor is useful for UV-LED light harvesting [89]. Iron cyanocomplexes degraded in anoxic conditions using a mini-CPC UV LED photoreactor Achieved the photoreduction of iron and free cyanide liberation as a strategy of recovery instead remediation for this iron cyanocomplex [88].…”