Removal of phenolic compounds from olive mill wastewater (OMW) by tailoring the surface of activated carbon under acidic and basic conditions
Abeer Al Bawab, Muna Abu‐Dalo, Hussein Kanaan, Nathir A. F. Al‐Rawashdeh, Fadwa Odeh
Abstract
Olive mill wastewater (OMW), a by-product of olive oil production, poses significant environmental risks due to its acidity and high polyphenol content, particularly in water-scarce regions like Jordan. This study developed a cost-effective approach to reduce the phenolic content in OMW using modified granular-activated carbon (GAC). Commercial GAC, chosen for its high surface area and adsorption capacity, was modified via oxidative treatment with concentrated nitric acid and reductive treatment using 10 wt.% ammonia solution. The modified GAC samples were tested for phenolic compound (PC) adsorption from OMW under varying surfactant types, concentrations, and pH levels using a batch method. The optimized conditions revealed that reduced GAC at pH 9 achieved the highest removal efficiency, reducing the phenolic content by 88% after 48 h. Surfactants had no significant effect on the performance of reduced GAC. Desorption tests after 7 and 32 days indicated a minimal release of PCs, confirming strong binding to the GAC surface. These findings demonstrate the potential of reduced GAC as a sustainable and cost-efficient solution for treating OMW, addressing the critical challenges in water resource management and environmental pollution in regions like Jordan.