Date

2017

Author

Rahmani, Amir

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The current study aims to investigate removal of a triarylmethane dye called Acid Blue 5 (AB5) via heterogeneous Fenton-like process and compare it with its homogeneous counterpart. The heterogeneous and homogeneous catalysts used were martite and FeCl3.6H2O, respectively. The unmilled martite microparticles were processed with high energy planetary ball mill to form nanosized catalyst for heterogeneous Fentonlike process. Characterization was performed by SEM, EDX, X-ray dot mapping, BET, XRD, FT-IR, petrography and point of zero charge analyses. Among the three batches of martite nanoparticles formed with milling time of 1 h, 3 h and 5 h at the milling speed of 300 rpm, the catalytic performance of 5h milled nano-sized martite (19.23 m2/g of surface area) was the highest. The influence of initial pH, catalyst dosage, H2O2, initial dye concentration and scavengers on the AB5 degradation was investigated comparatively for heterogeneous and homogeneous processes. AB5 removal efficiency in heterogeneous system was either higher or the same as the homogeneous system in each case. AB5 degradation followed pseudo-first order kinetic for both processes, where 0.096 min-1 and 0.0622 min-1 were calculated as the highest rates for heterogeneous and homogeneous processes, respectively. Various degradation intermediates from heterogeneous process were identified by GC-MS. Reuse of martite in five consecutive cycles did not significantly affect performance. Environment-friendly production of martite nanoparticles, high performance, reusability and low leaching of iron present important advantages of the martite nanocatalyst. Finally, an artificial neural network was expanded to estimate AB5 degradation efficiency with satisfactory results.

Subject Keywords

Oxidation, Environmental chemistry, Factory and trade waste, Organic compounds

URI

http://etd.lib.metu.edu.tr/upload/12620751/index.pdf
https://hdl.handle.net/11511/26263

Collections

Graduate School of Natural and Applied Sciences, Thesis