Nano zero valent iron and ozonation for selected recalcitrant wastewater: Review

Abstract

Abstract This research reviews application of nano zero valent oxidation and ozone for degradation of selected recalcitrant wastewater. Recalcitrant organics refers to non-biodegradable compounds which are of industrial waste source. It is highly pollutant to the environment due to its non-biodegradable properties which can be caused by various factors including lacking of necessary genetic information on the organisms, compound being too large to enter the cell, or non-existence of transport system across the membrane. Examples of recalcitrant wastewater includes palm oil mill effluent, pesticide wastewater, wastewater from paper production, aromatic organic compounds and polyaromatic hydrocarbon. These are the wastewater being reviewed to inform about the effectiveness of nano zero valent iron oxidation and/or ozonation. The chosen method aims to be an effective alternative from the traditional method, with simple and easy to handle mechanism. In the treatment of recalcitrant organics, several factors affect the process and are normally investigated. These includes the pH value, the contact time, dosage of treating agent as well as amount of competing cations. Recalcitrant wastewater treated with the suggested method are analyzed before and after the treatment. In addition, XRD, FTIR, SEM and BET maybe used to observe produced catalyst morphology and intrinsic elements prior and after treatment. This review provides scientific information from 2010 until 2019, concerning findings of effective and sustainable treatment of recalcitrant wastewater.