Removal of alkylphenols from industrial wastewater by means of ozone-based processes and fenton reaction

Alkylphenols belong to the group of synthetic specific substances and their effective removal requires non-traditional processes, novel approach and technologies. Advanced oxidation processes are effective for degradation of most organic substances, toxic and persistent pollutants. They produce highly reactive and nonselective radical intermediates, such as hydroxyl radical. The Fenton reaction is the most widely studied and used. In this paper, ozonation and selected ozone-based advanced oxidation processes including ozonation combined with granular activated carbon, Fe-modified zeolite and Mn-modified zeolite were studied for alkylphenols and their ethoxylates removal from a pre-treated industrial wastewater. Fenton reaction was also studied. Ozonation with subsequent adsorption on granulated activated carbon was used as reference processes. It was observed that the 4-octylphenol was completely removed by all ozone-based advanced oxidation processes during applied reaction time. The removal efficiencies of 4-nonylphenol and nonylphenol ethoxylates were gradually increased by the application of ozonation combined with the Fe-modified zeolite and Mn-modified zeolite.