Optimization of photocatalytic process with SnO2 catalyst for COD reduction from petroleum refinery wastewater using a slurry bubble photoreactor

• DOI: 10.1016/j.cscee.2024.100687
• Publication Date: 2024-03-12T08:18:39Z
• Authors: Husham M. Al-Tameemi; Khalid A. Sukkar; Ali H. Abbar; Zaidoun K. Kuraimid
• Keywords: Petroleum industry; Anodic oxidation; Environmental engineering; AOPs; 02 engineering and technology; Wastewater; TA170-171; Chemical engineering; Hybrid process; TP155-156; Photocatalysis; 0210 nano-technology

Heterogeneous multiphase reactors with nano photocatalysts are characterized by their high mass transfer rate due to the efficient hydrodynamic specifications. In the present work, a slurry bubble photoreactor with an external circulation of SnO2 nanoparticles was successfully used to remove the chemical oxygen demand (COD) from petroleum refinery wastewater. The influence of main effective variables such as SnO2 dosage, pH, and time on the removal efficiency (RE%) of COD was investigated and optimized using a response surface methodology (RSM). Results showed that pH has the most substantial impact on RE% with a contribution of 41.16%, followed by the time with a contribution of 28.68%, and finally by the dosage of SnO2 with a contribution of 18.21%. The optimum results of the treatment process were 0.1g/L SnO2, pH = 3, and time = 99 min which given COD removal of 73.16% combined with an electrical energy consumption of 25.5 kWh/m3. Moreover, the results of the kinetics showed that the degradation of COD using UV/SnO2 follows a pseudo first order with a correlation coefficient of 0.989. The reusability results showed that a slight decrease in the activity of SnO2 was observed at the end of 5 cycles where RE% decreased from 73.16% (in the first cycle) to 68.1% (at the five cycle) confirming the good reusability of SnO2 catalyst during the treatment of petroleum refinery wastewater. Finally, the adopting of a slurry bubble photoreactor with SnO2 photocatalyst proved to be an efficient system to degrade COD at low cost of energy.