Synergy of adsorption and fenton processes in water decontamination: A review

Abstract

The coexistence of various types of pollutants in water is a major concern worldwide, and it is difficult to remove them simultaneously using conventional or single treatment techniques. The pursuit of effective and sustainable methods for treating wastewater has prompted the development of a combination of technologies for synergy. One of the most common combinations is to integrate adsorption and Fenton-based Advanced Oxidation Processes (AOPs). Their combination can overcome the drawbacks of each technique, leading to synergy in removal efficiency. This is evidenced by the fact that (1) adsorbents can efficiently adsorb some organic and inorganic substances in wastewater, even those hydroxyl radicals that find it difficult to oxidize or whose existence may reduce the efficacy of AOPs; (2) some intermediates of AOPs may be resistant to oxidation, and can be adsorbed for higher total mineralization of these recalcitrant contaminants; (3) some adsorbents, such as carbonaceous materials and transmission metal-based materials, can act as a catalyst for AOPs, enhancing the formation of reactive oxygen species (ROS); (4) the formation of ROS may also increase the adsorption capacity of adsorbents in some cases; and (5) the combination is beneficial to the regeneration of adsorbents by degrading the adsorbed pollutants. This article reviews the principles, mechanisms, recent advancements, and challenges associated with both the single and combined applications of adsorption and Fenton-based AOPs in wastewater treatment. The synergistic effects of combining these approaches have also been investigated. This study aims to provide insights into the potential of these technologies to address emerging challenges in wastewater treatment.