Phenolic Compounds Removal from Olive Mill Wastewater Using the Composite of Activated Carbon and Copper-Based Metal-Organic Framework.

As the industry of olive oil continues to grow, the management of olive mill wastewater (OMW) by-products has become an area of great interest. While many strategies for processing OMW have been established, more studies are still required to find an effective adsorbent for total phenolic content uptake. Here, we present a composite of a Cu 1,4-benzene dicarboxylate metal-organic framework (Cu (BDC) MOF) and granular activated carbon (GAC) as an adsorbent for total phenolic content removal from OMW. Experimental results demonstrated that the maximum adsorption capacity was 20 mg/g of total phenolic content (TPC) after 4 h. using 2% wt/wt of GAC/Cu (BDC) MOF composite to OMW at optimum conditions (pH of 4.0 and 25 °C). The adsorption of phenolic content onto the GAC/Cu (BDC) MOF composite was described by the Freundlich adsorption and pseudo-second-order reaction. The adsorption reaction was found to be spontaneous and endothermic at 298 K where ΔS° and ΔH° were found to be 0.105 KJ/mol and 25.7 kJ/mol, respectively. While ΔGº value was -5.74 (kJ/mol). The results of this study provide a potential solution for the local and worldwide olive oil industry.

Preparation of Activated Carbon Derived from Jordanian Olive Cake and Functionalized with Cu/Cu2O/CuO for Adsorption of Phenolic Compounds from Olive Mill Wastewater.

Olive oil production generates solid and liquid wastes that cause various environmental problems due to their high phenols and polyphenols load. Although many treatment methods were investigated to manage these wastes, more research is still needed to identify simple and cost-effective approaches. In this study, activated carbon (AC) was prepared from olive cake waste and functionalized with Cu/Cu2O/CuO for efficient and selective removal of phenolic content from olive mill wastewater (OMW). AC media were characterized by scanning electron/dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrometry, and Brunauer-Emmett-Teller (BET) surface area analysis. The optimum adsorption parameters were investigated, and the adsorption isotherms, thermodynamics, and kinetics were determined. The adsorption of phenols onto copper oxide AC was best described by the Langmuir adsorption with maximum adsorption capacity of 13.9, 12.7, and 9.9 mg/g at 311, 302, and 293 K, respectively. The adsorption reaction was found to be spontaneous and endothermic where ∆H° and ∆G° were found to be 30.104 kJ/mol and -1.765, -2.839, and -3.723 (kJ/mol) at 311, 302, and 293 K, respectively. In addition, the kinetics data were perfectly fit by the pseudo-second-order model. The activated product derived from recyclable olive cake and enriched with inorganic functionality can offer a cost-effective treatment solution for OMW; thus, reducing both the liquid and solid waste generated from the olive mill industry.