Degradation of model olive mill contaminants of OMW catalysed by zero-valent iron enhanced with a chelant

► Oxidation of OMW models catalysed by Fe(0) and nitrilotriacetic acid was effective. ► p-hydroxyphenylacetic, vanillic and caffeic acids were totally removed in isolation. ► Coumaric acid, tyrosol and cinnamic acid attained a lower removal, less than 90%. ► Order of reactivity was modified in the mixtures. ► Removal of some acids was highly enhanced by the presence of other compounds.