Olive mill wastewater treatment: an experimental study

Area of Science:

• Environmental Science
• Biotechnology
• Chemical Engineering

Background:

• Olive mill wastewater (OMW) is a major byproduct of Mediterranean agro-industry.
• OMWs present significant environmental hazards due to high organic load, acidity, and toxic phenolic/lipidic compounds.
• Current disposal methods, like soil application in Italy, are insufficient for managing OMW pollution.

Purpose of the Study:

• To investigate the efficiency and feasibility of advanced oxidation processes (AOPs) and biological treatments for OMW.
• To assess the removal of phenolic compounds from OMW using ozone, Fenton's reagents, and aerobic biodegradation.
• To evaluate the impact of oxidation pretreatment on the biological treatability of OMW.

Main Methods:

• Experimental trials conducted on real OMW from a large Italian mill and synthetic solutions.
• Application of ozone and Fenton's reagents for oxidation treatments.
• Aerobic biological treatment in a batch reactor using OMW without initial biomass inoculum.

Main Results:

• Ozone and Fenton's reagents achieved up to 95% removal of polyphenols from OMW and synthetic solutions.
• An indigenous fungal biomass developed in raw OMW, achieving 70% biodegradation of phenolic compounds.
• Oxidative pretreatment significantly enhanced the subsequent biological treatability of OMW.

Conclusions:

• AOPs are highly effective for rapid polyphenol removal from OMW.
• Fungal biodegradation offers a sustainable biological approach for OMW treatment, particularly for phenolic compounds.
• Combining oxidation pretreatment with biological treatment presents a promising strategy for efficient OMW management.