Comparative study of the efficiency of conventional and green-prepared iron nanoparticles for catalytic ozonation

This study aimed at the preparation of green and conventionally prepared iron nanoparticles (Fe-C-NPs), their characterization and application as catalysts of ozonation to remove emerging contaminants and disinfection. It is the first time that a study has compared the chemical and morphological characteristics of Fe-C-NPs and related them to their efficiency as catalysts in ozonation. Green Fe-C-NPs were prepared with eucalyptus and mulberry leaves extract and the conventional Fe-C-NPs prepared using ammonia as reducing agent. The green synthesis routes are low cost and environmental friendly, thereby reducing the risk of harmful effects of toxic chemicals and derivative compounds. The Fe-C-NPs were characterized by FTIR, SEM, XRD, XPS and VSM, and were applied in the degradation of malachite green, methylene blue, sulfamethoxazole, atrazine, and acetaminophen in ultrapure water and secondary effluent as well as in the inactivation of disinfection indicators. As expected, the implementation of Fe-C-NPs in catalytic ozonation resulted in enhanced efficacy compared to ozonation alone. However, the green Fe-C-NPs showed equivalent or better efficiency compared to the conventionally Fe-C-NPs, showing better efficiencies in cleaner water matrices. When applied to remove micropollutants and promote disinfection in secondary effluents, the green Fe-C-NPs showed equivalent efficiencies in comparison with conventional Fe-C-NPs. It highlights that nanomaterials produced by green routes can be an alternative to traditional nanomaterials that use of toxic reagents on its production.