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Biojarosite as a replacement for commercial iron catalyst in the oxidative degradation a dye Rhodamine B was confirmed and established. Investigation on the oxidative degradation by Fenton's oxidation and UV – Fenton's oxidation with EDTA at neutral pH were conducted and degradation of target compound was evaluated. UV – Fenton's oxidation was shown to be efficient over Fenton's oxidation in the degradation of Rhodamine B with removal efficiency of 90.0%. Design of Experiments was performed with Box – Behnken design. Investigation was conducted for the predicted values separately for both Fenton's oxidation and UV – Fenton's oxidation and the Rhodamine B removal was taken as response. Variable parameters biojarosite, H2O2 dosage and EDTA were optimized in the range of 0.1 g/L – 1 g/L, 2.94 mM – 29.4 mM and 10–100 mM respectively. A quadratic regression model is fitted for both Fenton's and UV – Fenton's oxidation. ANOVA is performed and model fit is discussed.

Novel cost-effective catalyst granular activated carbon (GAC)-based zinc ferro nanocomposites for the heterogeneous Fenton's oxidation of dye were synthesized using bioleached laterite iron (BLFe) as a precursor and Psidium gujava leaf extract. Synthesized nanocomposites were characterized using SEM, EDS, XRD and BET surface area analysis. The degradation of Rhodamine dye was carried out with nanocomposites using adsorption–Fenton's oxidation process. The catalytic role of nanocomposites in Fenton's oxidation of Rhodamine B (RhB) was investigated and reported. The maximum dye removal of 96.2% was observed with 64.2% COD removal within 200 min of treatment. An increase in nanocomposite dosage has a positive effect on dye removal marking 5 g/L as an optimum dosage. Adsorption studies reveal that RhB removal using BLFe-based GAC/zinc ferro composites fits the Freundlich Adsorption Isotherm model with an adsorption capacity of 47.81 mg/g. A combination of adsorption and Fenton's oxidation has resulted in higher removal efficiency with nanocomposite material. Reusability studies confirm that the spent catalyst can be reused for five cycles.

Laterite based nano iron particles were synthesized using natural laterite extract as a precursor and Psidium guajava plant extract for its application as Fenton's catalyst in the degradation of triclosan. Chemical digestion method was used for the extraction of iron from laterite soil. Synthesized nano iron catalyst was characterized using SEM – EDS, XRD and FTIR and evaluated for its catalytic application in the Fenton oxidation of triclosan. Maximum triclosan degradation of 69.5 % was observed with nano iron catalyst dosage of 0.1 g/L and hydrogen peroxide dosage of 200 mg/L at acidic pH of 3. Hydrogen peroxide influence on the process was observed with Fenton's oxidation. Role of iron in the process has been accessed by control experiment with no nano catalyst addition in which degradation is considerable low. Fenton's oxidation was compared with conventional Fenton's oxidation driven by a green nano iron catalyst. Study claims the usage of natural laterite iron as a replacement for commercial iron in Fenton's degradation of triclosan. Regeneration and Reusability studies on catalyst were studied and synthesized catalyst was observed to be reusable in three consecutive cycles. Degradation of triclosan in Fenton's oxidation follows pseudo-second order reaction with linear fit.