Treatment of olive mill wastewater by adsorption of phenolic compounds

Olive-mill wastewater (OMW) is a typical by-product of olive-oil production and an important environmental problem in the Mediterranean region due to the significant amounts of organic matter that resist degradation and the phenolic compounds that have antimicrobial and phytotoxic properties. However, phenols present strong antioxidant activity that can turn olive oil by-products into an inexpensive source of natural antioxidants. Generally, numerous studies on the recovery of polyphenols from OMW have been conducted and several techniques are used individually or in combination. Among them, adsorption is considered to be the best effective and low cost method. So far, few studies have been carried out using sorbents for the removal of OMW phenols. However, the quite high initial cost and the need for a regeneration system make the common sorbent materials less economically viable as adsorbents. Thus, many researchers have focused their efforts on optimizing adsorption process by development of novel, low-cost adsorbents with high adsorptive capacity, such as natural materials originating from food industry byproducts (biosorbents). The objective of this review is to provide a comprehensive summary of the recovery of phenolic compounds from OMW using common adsorbents or biosorbents.

Automated summary

Olive-mill wastewater is a significant environmental issue due to high levels of organic matter and phenolic compounds. Research is focused on recovering phenolic compounds from wastewater using adsorbents and biosorbents. The development of novel, low-cost adsorbents is crucial for optimizing the adsorption process.