Batch and Continuous Flow Adsorption of Phenolic Compounds from Olive Mill Wastewater: A Comparison between Nonionic and Ion Exchange Resins

Abstract

The goals of this work were (i) to compare two anion ion exchange resins (IRA958 Cl and IRA67) and a nonionic resin (XAD16) in terms of phenolic compounds adsorption capacity from olive mill wastewater and (ii) to compare the adsorption capacity of the best resin on columns of different length. The ion exchange resins performed worse than nonionic XAD16 in terms of resin utilization efficiency (20% versus 43%) and phenolic compounds/COD enrichment factor (1.0 versus 2.5). The addition of volatile fatty acids did not hinder phenolic compounds adsorption on either resin, suggesting a noncompetitive adsorption mechanism. A pH increase from 4.9 to 7.2 did not affect the result of this comparison. For the best performing resin (XAD16), an increase in column length from 0.5 to 1.8 m determined an increase in resin utilization efficiency (from 12% to 43%), resin productivity (from 3.4 to 7.6 g sorbed phenolics /kg resin ), and phenolics/COD enrichment factor (from 1.2 to 2.5). An axial dispersion model with nonequilibrium adsorption accurately interpreted the phenolic compounds and COD experimental curves.

Activation of Jordanian Bentonite by Hydrochloric Acid and Its Potential for Olive Mill Wastewater Enhanced Treatment

“…In addition, green process based on resins adsorption/ion exchange (strong-base anionic Amberlyst A265, weak-base anionic Dowex 665, and nonionic macroreticular Amberlite XAD45) was also studied [18]. Moreover, batch and continuous flow adsorption of phenolic compounds from OMWW were applied using nonionic and ion exchange resins [19].…”

Continuous flow adsorption of phenolic compounds from olive mill wastewater with resin XAD16N: life cycle assessment, cost–benefit analysis and process optimization

“…Several processes can be applied to recover PCs from OMW: membrane separation processes, solvent extraction, ultrasound treatment and cloud point extraction . Adsorption and ion exchange were successfully studied and implemented for PC recovery from OMW . They are characterized by a simple design and operation, low operating costs and ease of resin regeneration .…”

“…The interaction between PCs, sugars and proteins has never been included in the studies on the modelling of PC adsorption, to the best of the authors' knowledge. A limited number of studies focused on the continuous‐flow adsorption or ion exchange of PC mixtures . Only a few of these studies were based on the use of an actual OMW, whereas numerous studies used synthetic PC mixtures or other PC‐rich wastewaters or natural sources, such as apples, blueberries, grape marcs and artichokes .…”

“…Indeed, the presence of residual sorbed compounds after each desorption step and the gradual deposition of suspended solids on the initial portion of the column could lead to a gradual decrease in process performance. Previous works relative to PC adsorption from OMW led to the following choices regarding the above‐listed points (i), (ii) and (iii): The PC adsorption performances of several neutral and ion exchange resins (XAD16N, XAD4, Optipore SD‐2, FPX66, XAD761, IRA958 OH, XAD7, IRA96; Isolute ENV+) were compared . Bertin et al, in a comparison between XAD16N, XAD7, IRA96 and Isolute ENV+, obtained the best performance with Isolute ENV+, but XAD16N also led to satisfactory performance.…”

“…Frascari et al reported the best performances with XAD16N and IRA958 OH, whereas Optipore SD‐2, FPX66 and XAD761 were less suitable. On the basis of these results, XAD16N was selected for this study, even if other resins present similar PC adsorption performances. Acidified ethanol (0.5% v/v HCl 0.1 mol L −1 ) was identified as an effective solvent for PC desorption from resin XAD16N; An increase in resin bed height from 0.5 to 1.8 m led to a marked improvement in resin operating efficiency; 1.8 m was therefore selected as a suitable resin bed height for a further process optimization in terms of fluid velocity.…”