Optimization of the synthesis of UiO-66-NH2 catalyst and its application for removing organophosphorus pesticides from wastewater

Abstract

The present research focuses on optimizing the laboratory synthesis of a metal-organic framework for decomposing organophosphorus pollutants in aquatic environments (caused by pesticides). In the first stage, by defining and scoring five screening criteria, such as the price of raw materials, the complexity of the synthesis reaction, the efficiency of the catalyst, the possibility of industrial production (scalability), as well as the cost of the necessary equipment, the metal-organic framework 2-aminoterephthalate;oxygen(2-);zirconium(4+);tetrahydroxide was selected as the target catalyst. By considering the catalyst production yield as an objective function, the optimization of the most important variables affecting catalyst synthesis (reaction time, reaction temperature, amount of reaction solvent, type and amount of acid catalyst required, type and quantity of secondary solvent, and rotation speed of centrifuges) was discussed. The synthetic framework’s structure has been confirmed by infrared spectroscopy and powder X-ray diffraction analyses. According to Brunauer-Emmett-Teller surface area analysis, the resulting catalyst has a specific area of 825 m2/g and a mean pore diameter of 2.25 nm. This catalyst performed well in the laboratory in decomposing the selected organophosphorus pollutant (dimethyl nitrophenyl phosphate compound) with a half-life of 9 minutes.

Keywords

• organophosphate pesticide
• hydrolysis
• catalyst synthesis
• optimization
• metal-organic framework