Oxidative degradation of phenol via heterogeneous fenton-like reaction over Fe-ZSM5 catalyst using sodium perborate and sodium percarbonate as oxidants

Date of Award

2017

Document Type

Thesis

Degree Name

Master of Science in Chemistry

Department

Chemistry

First Advisor

Fabicon, Ronaldo M., Ph.D

Abstract

This study focused on the investigation on the efficiency of sodium percarbonate (SPC) and sodium perborate (SPB) as sources of hydrogen peroxide in the degradation of phenol in water via heterogeneous Fenton-like reaction over a laboratory synthesized Fe-ZSM5 catalyst across varying temperature, pH and oxidant to phenol ratio. Experiment results showed that both SPC and SPB could be used as oxidants in phenol degradation over Fe-ZSM5. The use of SPC gave better phenol degradation profiles compared to that of SPB. Results of the catalytic and blank catalytic runs for both SPC and SPB showed that both of the hydrogen peroxide from the oxidants and the propagated hydroxyl radicals contributed in the oxidation of phenol. The systems in the presence of catalyst Fe-ZSM5 had higher rates of phenol degradation compared to those without catalyst due to the higher oxidative property of the hydroxyl radicals activated by the Fe-ZSM5. Kinetic studies showed that both of the SPC/Fe-ZSM5 and SPB/Fe-ZSM5 systems followed zero or first order kinetics depending on the operating conditions of the phenol oxidation system. Based on the screening tests conducted, the SPC/Fe-ZSM5 system was greatly affected by the interaction of operating temperature and operating pH while SPB/Fe-ZSM5 was mostly governed independently by the operating temperature and the operating pH. Prior to the catalytic experiments, Fe-ZSM5 zeolite was synthesized in the laboratory using a modified method of hydrothermal synthesis of a non-continuous 12-12-12-hr duration under a fluctuating synthesis temperature of 160C to 190C. The synthesized crystals were characterized using XRD, XRF, FTIR and SEM. The synthesized crystals were identified to be zeolite ZSM5 of orthorhombic structure and of 89% crystallinity. The 0.30% by weight iron was successfully incorporated to the zeolitic framework. The sponge-like crystals formed from the aggregation of smaller crystals were to have an average mean diameter of 630nm.

Comments

The C4.L324 2017

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