Periodate-assisted pulsed sonocatalysis of real textile wastewater in the presence of MgO nanoparticles: Response surface methodological optimization

• Sonocatalysis of real textile wastewater over as-synthesized MgO nanoparticles.
• Effect of pulsed mode of sonication and chemical enhancers on the sonocatalysis.
• Optimization of operational conditions for the maximum COD removal efficiency.
• Reasonable survey of mineralization rate by way of TOC analysis.

The improvement of sonocatalytic treatment of real textile wastewater in the presence of MgO nanoparticles was the main goal of the present study. According to our preliminary results, the application of pulse mode of sonication, together with the addition of periodate ions, produced the greatest sonocatalytic activity and consequently, the highest chemical oxygen demand (COD) removal efficiency (73.95%) among all the assessed options. In the following, pulsed sonocatalysis of real textile wastewater in the presence of periodate ions was evaluated response surface methodologically on the basis of central composite design. Accordingly, a high correlation coefficient of 0.95 was attained for the applied statistical strategy to optimize the process. As results, a pulsed sonication time of 141 min, MgO dosage of 2.4 g/L, solution temperature of 314 K and periodate concentration of 0.11 M gave the maximum COD removal of about 85%. Under aforementioned operational conditions, the removal of total organic carbon (TOC) was obtained to be 63.34% with the reaction rate constant of 7.1 × 10−3 min−1 based on the pseudo-first order kinetic model (R2 = 0.99). Overall, periodate-assisted pulsed sonocatalysis over MgO nanoparticles can be applied as an efficient alternative process for treating and mineralizing real textile wastewater with good reusability potential.