Optimization of photo-catalytic degradation of oil refinery wastewater using Box-Behnken design

Tetteh, Emmanuel Kweinor; Bisetty Naidoo, Dushen; Rathilal, Sudesh

doi:.0..0

DOI: https://doi.org/10.4491/eer.2018.216

Optimization of photo-catalytic degradation of oil refinery wastewater using Box-Behnken design

Emmanuel Kweinor Tetteh, Dushen Bisetty Naidoo, and Sudesh Rathilal^†

Faculty of Engineering and the Built Environment, Department of Chemical Engineering, Durban University of Technology, Steve Biko Campus Block S4 Level 1, Box 1334, Durban 4000, South Africa.

Corresponding Author: Sudesh Rathilal ,Tel: +27-313732123 , Fax: +27-866741148, Email: ektetteh34@gmail.com

Received: June 26, 2018; Accepted: January 17, 2019.

ABSTRACT

The application of advanced oxidation for the treatment of oil refinery wastewater under UV radiation by using nanoparticles of titanium dioxide (TiO2) was investigated. Synthetic wastewater prepared from phenol crystals; Power Glide SAE40 motor vehicle oil and water was used. Response surface methodology (RSM) based on the Box Behnken design was employed to design the experimental runs, optimize and study the interaction effects of the operating parameters including catalyst concentration, run time and airflow rate to maximize the degradation of oil (SOG) and phenol. The analysis of variance (ANOVA) and the response models developed were used to evaluate the data obtained at a 95% confidence level. The use of the RSM demonstrated the graphical relationship that exists between individual factors and their interactive effects on the response, as compared to the one factor at time approach. The obtained optimum conditions of photocatalytic degradation are the catalyst concentration of 2 g/L, the run time of 30 min and the airflow rate of 1.04 L/min. Under the optimum conditions, a 68% desirability performance was obtained, representing 81% and 66% of SOG and phenol degradability respectively. Thus, the hydrocarbon oils were readily degradable, while the phenols were more resistant to photocatalytic degradation.

Keywords: Box Behnken | Oil refinery | Photocatalytic degradation | Response surface methodology | TiO2