Journal of Chemical Engineering & Process Technology
Open Access

Abstract

Removal of Methyl Orange in Aquaculture Water by Spray-Coated TiO₂ Photocatalysis

Wen Zhao, Yangyang Zhang, Laura C. Rodriguez-Gonzalez, Fei Zhong, Sarina J Ergas and Norma A Alcantar

A major challenge for aquaculturists using recirculating aquaculture systems is the accumulation of off-flavor compounds, such as geosmin and 2-methylisoborneol (MIB), in the farmed fish. This work investigates the removal of off-flavor compounds in aquaculture systems using titanium dioxide (TiO2) photocatalysis. Due to concerns of TiO2 nanoparticles on fish, TiO2 was immobilized onto glass plates. A photodegradation reactor that incorporated the TiO2 coated plates was designed and operated as a recirculating system. Methyl orange was used as a surrogate compound for geosmin and MIB. In parameter optimization experiments, a flow rate of 2.5 mL/s, a water depth of 2 mm and a TiO2 dosage of 0.25 mg/cm3 were found to provide a high methyl orange removal rate constant of 0.77/h, when the compound was supplied in a solution made in deionized (DI) water. Due to the presence of natural organic matter (NOM) in the RAS water, the methyl orange removal rate constant decreased to 0.44/h. The results indicate that although NOM interferes with the photocatalysis process, if an extended reaction time is applied acceptable removal efficiencies can be achieved. This work is currently being applied in a photocatalysis study on removal of off-flavor compounds in RAS.