Fixed-bed column adsorption of olive mill wastewater using clinker: Optimization via response surface methodology

Abstract

Using a continuous-flow adsorption system with a clinker -filled column is a novel method to remove phenolic compounds and lower chemical oxygen demand (COD) from olive mill wastewater (OMWW). The aim of this method is to improve treatment of these effluents by exploiting adsorbent properties of clinker in order to attenuate their pollutant potential. Analysis of clinker before and after treatment was carried out using scanning electron microscopy (SEM), X-ray diffractometry (EDX), and Fourier transform infrared spectroscopy (FTIR). The adsorption rate in the column is significantly influenced by a few parameters, including height of the adsorbent bed, withdrawal rate, and size of the material's particles. parameters optimized by response surface method were set at 70 μm for particle size, 28.5 ml/min for flow rate, and 9 cm for bed height. The results obtained showed the effectiveness of this treatment in reducing the pollutant load of olive mill wastewater, with an output concentration of around 273 mg/L of COD. Also, high-performance liquid chromatography (HPLC) analyses revealed a significant reduction in the concentration of polyphenolic molecules. These results in accordance with Moroccan discharge standards. Our study is the first to suggest an economical and effective method to treat OMWW.

Keywords

• Adsorption
• HPLC
• FTIR/MEB/EDX
• Olive mill wastewater
• Box- Behnken