ADSORPTION OF POLYPHENOLS FROM OLIVE MILLS WASTEWATER USING PEANUT HUSK

Abstract

Olive Mills Wastewater (OMWW) represents a global and also local environmental problem. A large amount of high organic loaded effluent seasonally produced yearly, the treatment of this effluent is a serious problem since the biological treatment and other treatments methods for this effluent are interrupted by the high content of polyphenols which are substances with highly antioxidant and antimicrobial abilities beside the other negative impacts of polyphenols on different environmental aspects. The batch processes using peanut husk achieved the optimum removal conditions at pH value equal 6 for OMWW, initial polyphenols concentration 11920 mg/lit, adsorbent adsorbate ratio equal 3g/100ml, 500 micron particles size and 100 rpm agitation speed, at these conditions adsorption capacity (Qmax) reaches 180mg/g. Adsorption equilibrium isotherm for peanut husk- OMWW system fits to Freundlich isotherm model, and adsorption kinetics fits to pseudo-second order rate model. Different activation methods were used and activation by H3PO4 was chosen as it gives a highly porous activated carbon with BET 987.463 m2/g surface area. The batch processes using peanut husk activated carbon achieved the optimum removal conditions at pH value equal 2 for OMWW, initial polyphenols concentration 480 mg/lit, adsorbent adsorbate ratio equal 2.4g/100ml, 500 micron particles size and 300 rpm agitation speed, at these conditions adsorption capacity (Qmax) reaches 240 mg/g. adsorption process equilibrium isotherm for PHBAC- OMWW system fits to Freundlich isotherm model, and adsorption kinetics fits to pseudo-second order rate model. In continuous fixed bed process using activated carbon produced from peanut husk, Yoon-Nelson model predicts the breakthrough curve of polyphenols adsorption on peanut husk activated carbon with adsorption capacity 262.122 mg/g.