Box-Behnken design-based biodiesel wastewater treatment using sequential acid cracking and electrochemical peroxidation process: Focus on COD, oil-grease and volatile fatty acids removals


YAZICI GÜVENÇ S. , Cebi A., CAN GÜVEN E. , DEMİR A. , Ghanbari F., VARANK G.

KOREAN JOURNAL OF CHEMICAL ENGINEERING, 2022 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Publication Date: 2022
  • Doi Number: 10.1007/s11814-022-1118-z
  • Title of Journal : KOREAN JOURNAL OF CHEMICAL ENGINEERING
  • Keywords: Advanced Oxidation Processes, Oil-grease, Optimization, Total Cost, Volatile Fatty Acids, RESPONSE-SURFACE METHODOLOGY, MILL EFFLUENT, ELECTROCOAGULATION PROCESS, PROCESS OPTIMIZATION, FENTON TREATMENT, COAGULATION, DEGRADATION, PURIFICATION, PARAMETERS, EFFICIENCY

Abstract

The treatability of biodiesel wastewater by the electrochemical peroxidation process following acidification pretreatment was investigated. Box-Behnken design, one of the experimental designs of response surface methodology, was applied to optimize the process parameters for chemical oxygen demand (COD), oil-grease, and volatile fatty acids (VFAs) removal from biodiesel wastewater. The process parameters, i.e., applied current, H2O2/COD ratio, and reaction time, were optimized and the total cost of the process was determined. After the acidification process as a pretreatment, the COD, oil-grease, and VFAs removal efficiencies were 25.4%, 68.7%, and 50%, respectively Optimum conditions determined by the developed model for maximum oil-grease removal (98.2%) were applied: current 1.0 A, H2O2/COD ratio 0.4, and reaction time 32.8 minutes. This devised Box-Behnken model predicted removal efficiencies of 45.5%, 98.2%, and 49.5% for COD, oil-grease, and VFAs, respectively. The total cost of the process determined by the model and obtained from the validation experiments was 2.03 euro/m(3) and 1.97 euro/m(3), respectively. The results of the study showed that the applied process was efficient in pollutant removal from acidified biodiesel wastewater and the Box-Behnken design can be applied to explain the mechanism of the process and optimize the process parameters.