Degradation of isothiazolinone biocides in reverse osmosis concentrate by GO/Fe3O4/MgO nanocomposite

The presence of biocide, significant risks for humans, animals, and the environment. Isothiazolinone biocides are the most commonly used non-oxidizing biocides in RO systems, and they have commonly been detected in RO concentrates. In this work, GO/Fe3O4/MgO nanocomposite was synthesized and fully characterized. The effect of pertinent factors (pH, the amount of catalyst, and organophosphate concentration) in the synthesis process was studied using a central composite design by response surface methodology. The band gap of the synthesized GO/Fe3O4/MgO nanocomposite appropriate for visible light photocatalytic activity. According to the obtained results, GO/Fe3O4/MgO photocatalyst showed more than 95% degradation efficiency for isothiazolinone as biocide. The magnetic characteristic of the synthesized photocatalyst helped its recovery from the solution after the reaction. According to the obtained data, GO/Fe3O4/MgO nanocomposite could degrade isothiazolinone (efficiency more than 90%) even after five consecutive runs. The GO/Fe3O4/MgO nanocomposite shows promising performance for catalytic degradation of isothiazolinone with the possibility to expand its application for other toxic chemicals removal.