Modeling and optimization of fixed mode dual effect (photocatalysis and photo-Fenton) assisted Metronidazole...

The study presents the novel concept of application of fixed bed-batch mode in-situ dual effect of degradation of photo-Fenton and photocatalysis using composite material composed of fuller's earth and foundry sand for the removal of antibiotic Metronidazole. The composite material was involved in the subsequent leaching of iron prompting to in-situ photo-Fenton reactions while TiO₂ layer immobilized upon the support involved in photocatalysis. Dual process facilitated the significant reduction in treatment time as 80% of the compound degraded with 30 min of the reaction. Both the processes almost took 180 min for 50% degradation, when applied individually. No doubt, there was an astonishing increase in the rate constant. An artificial neural network model coupled with the genetic algorithm was employed for the optimization of various parameters like H₂O₂ dose, treatment time, number of beads, pH, etc. Various characterizations have been performed to confirm the novelty of the process. Extended recyclability up to 70 recycles of these composite beads really confirmed the feasibility of this technology for field-scale applications.