Novel FeMgO/CNT nano composite as efficient catalyst for phenol removal in ozonation process

Abstract

A novel FeMgO/carbon nanotube composite (FeMgO/CNT) was synthesised using a chemical vapor deposition (CVD) method and applied to catalytic ozonation for phenol degradation. The degradation performance and mineralisation of phenol in the FeMgO/CNT catalytic ozonation process (COP) were compared with a sole ozonation process (SOP), and various parameters (e.g. presence of radical scavengers, solution pH, ozone dosage, and FeMgO/CNT dosage) were investigated. Phenol degradation during ozonation improved in the presence of the catalyst due to the ability of FeMgO/CNT to decompose ozone and generate hydroxyl radicals. The results indicated that the FeMgO/CNT catalyst promoted the degradation of phenol, Total organic carbon (TOC), higher than 22 and 9% if compared to the SOP (at pH 7, O3: 0.304 g L−1 h−1, 1 g L−1 catalyst) and the catalyst had a high efficiency over a wide pH range. We established an predictive kinetic model of phenol degradation, in which the main factors (i.e. catalyst dosage, ozone concentration, and initial pH) had important effects. Finally, the decrease in phenol removal efficiency of only 8.7% after reusing the catalyst four times illustrates that this catalyst has high stability and can be re-used.