Environmental Chemistry and Engineering

Olive stones are an agricultural waste from the olive oil industry and represent one of the most abundant renewable resources in Mediterranean areas. In addition, much attention is paid to water quality and removal of persistent organic pollutants as the well-known endocrine disruptor bisphenol A (BPA) or the herbicides such as Diuron. So, the aim of this study was to explore the possibility of using this biomass for the preparation of activated carbon (AC) for BPA and Diuron adsorption from polluted waters. The AC was prepared according to the method of chemical activation and pyrolysis. To optimize the performances of the obtained materials (expressed in terms of adsorption capacity), the effect of main preparation parameters was studied, such as pyrolysis temperature, activating agent and mass ratio. The prepared AC were characterized by DRX, FTIR, SEM, N2 adsorption-desorption and CHNS. Simultaneously, a study was performed on the effects of temperature, pH solution, and initial concentration on the removal efficiency for our targeted pollutants. Further, simplified kinetic models (pseudo-First-order and pseudo-Second-order) were tested to investigate the adsorption behaviors and Freundlich and Langmuir models to analyze the adsorption equilibrium. Promising performances were pointed out as 70% of Diuron and 92% of BPA can be removed from aqueous solution for an initial concentration respectively 35 mg/L and 20 mg/L, when the usual concentrations of BPA in environmental waters are in the range of 10 ng/L to 400 μg/L and Diuron is around 1600 ng/L. Adsorption on AC has many advantages because it converts agricultural waste to useful added-value adsorbent and proposes a low operating cost, easy use, simple design but efficient technique. To achieve a complete process of remediation, we check the possibility to desorb pollutants from AC and to oxidize them through VOC’s catalytic treatment