Kinetic study of adsorption of phenolic compounds from olive oil mill wastewater on activated carbon

Abstract

Olive oil Mill Wastewater (OMW) is not degradable due to the presence of substances (phenols, volatile fatty acids, etc.), which pose problems for the environment. In order to protect this environment, currently know various treatment methods of wastewater such as adsorption. We have studied in our work the adsorption capacity of phenolic compounds present in Olive Oil Mill Wastewater on activated carbon (AC). The phenolic compounds are known for their carcinogenicity and their high toxicity and the activated carbon is the most popular and widely used adsorbent material for OMW treatment. The AC was prepared by the valorization of agrifood waste that are olive leaves (calcination followed by chemical activation using phosphoric acid). A range of analyses was carried out for the characterization of the used adsorbent, among them: Infrared (IR) spectroscopy, which showed the main characteristic bands of activated carbons, X-ray diffractometry (XRD), iodine value, moisture content, ash content and pHzpc. The effect of several parameters such as contact time, amount of adsorbent and pH of the solution were studied. The best adsorption conditions are simple to achieve: Ambient temperature, direct use of the olive oil mill wastewater (V = 100 mL, pH = 1.95) with 4 g mass of AC adsorbent. The obtained adsorption kinetics showed that the adsorption of phenolic compounds from OMW on prepared activated carbon is well described by the Pseudo second order. The obtained results indicate the possibility of olive leaves valorization in the form of activated carbon with what all this implies as socio-economic impacts