Wastewater Treatment: The Emergence of Cobalt Ferrite and Its Composites in Sulfate Radical-Based Advanced Oxidation Processes

Water pollution is affecting every aspect of our life. Over the few previous decades, various new practices have been developed to counter the increasing amount of wastewater, but conventional methods fall short when dealing with highly stable organic pollutants such as dyes and antibiotics. In comparison to modern techniques, advanced oxidation processes (AOP) have demonstrated their superior benefits such as high efficiency, cheap cost, rapid reaction rate, etc. There are different types of advanced oxidation processes that are being utilized for treating industrial discharge, although the AOP which shows the highest potential for wastewater treatment is sulfate radical-based advanced oxidation process (Sr-AOP). The Sr-AOP demonstrate good degradation in a broader pH range and, the sulfate radicals for Sr-AOP are generated either by help of peroxymonosulfate (PMS) or by persulfate (PS). There are numerous activators that may be used to activate the PMS, which is necessary for it to be employed in AOP. Cobalt ferrite and their composites can act as an excellent activator for PMS-based Sr-AOP. Therefore, in the present review work, we discussed numerous useful qualities of cobalt ferrite (CF) which makes it a better heterogeneous catalyst than available options. We also explained the basis of Sr-AOP along with an emphasis on the mechanism for cobalt ferrite-activated Sr-AOP. To counter various shortcomings of using cobalt ferrite, various cobalt ferrite-based composites were also addressed. Lastly, the various challenges and future directions for utilizing cobalt ferrite and their composites (CFC) for activating PMS-based AOP were discussed.