A sustainable and cyclic metal organic framework-driven Fenton process for efficient removal of methylene blue

Textile industries being one of the largest consumers of water generate humongous quantities of textile effluents. Textile wastewater constitutes around 28% of the total untreated Indian industrial effluents (6200 million liters per day (MLD)). About 1750 MLD of textile effluent goes untreated causing major environmental concern. Several physical, chemical, and biological methods of textile effluent treatment exist. However, one of the key reasons for such untreated or improperly treated effluents contaminating existing freshwater resources is the inefficiency of conventional treatment technologies in removing complex textile contaminants. The focus of this study is to investigate the role of an iron-based metal organic framework, PCN-250 in driving sustainable degradation of methylene blue via Fenton's process in the presence of hydrogen peroxide. The effect of hydroxylamine as a reducing agent for recycling the Fenton catalyst to have sustained methylene blue degradation is also investigated. Hydrogen peroxide, hydroxyamine and PCN-250 proved to be a synergistic combination for the possible generation of oxidants and in turn methylene blue degradation without the need for electricity as in most other treatment processes. Owing to this nature of the MOF-based water treatment system developed herein, it proves to be suitable for water treatment even under situations of scarce resources and poor economic conditions.