Statistical optimization of process parameters for ultrafiltration of olive oil mill wastewaters

Abstract

Ultrafiltration of olive oil mill wastewaters was investigated in this study. The Box–Behnken statistical experiment design and response surface methodology were used to investigate the effects of major operating variables. Flow rate, transmembrane pressure, and operation time were selected as independent variables in Box–Behnken design while chemical oxygen demand (COD) removal and permeate flux were considered as the response function. The predicted values of COD removal and permeate flux obtained using the response function were in good agreement with the experimental data. For the highest COD removal efficiency, the optimum set of flow rate, pressure, and operation time were 100 L/h, 1 bar, and 30 min, respectively, with 86.8% removal efficiency. On the other hand, for the maximum permeate flux, the optimum set was 200 L/h, 3 bar, and 30 min with 32.9 L/m² h flux value.

Keywords:

• Box–Behnken design
• Olive oil mill wastewater
• Operating conditions
• Pretreatment
• Ultrafiltration