Heterogeneous activation of peroxymonosulphate by supported ruthenium catalysts for phenol degradation in water

Abstract

Activated carbon (AC) and Zeolite Socony Mobil-5 (ZSM5) supported ruthenium oxide catalysts were prepared and tested to degrade aqueous phenol in the presence of peroxymonosulphate. The physicochemical properties of ruthenium oxide based catalysts were characterised by several techniques such as XRD (X-ray diffraction), SEM-EDS (scanning electron microscopy-energy dispersive X-ray spectroscopy), and N(2) adsorption. It was found that RuO(2)/AC was highly effective in heterogeneous activation of peroxymonosulphate to produce sulphate radicals, presenting higher reaction rate in phenol degradation compared with RuO(2)/ZSM-5. Degradation efficiency of phenol could be achieved at 100% of phenol decomposition and 60% of total organic carbon (TOC) removal in 1h at the conditions of 50ppm phenol, 0.2g catalyst, 1g Oxone(®) in 500mL solution at 25°C using the two catalysts. It was also found that phenol degradation was strongly influenced by catalyst loading, phenol concentration, Oxone(®) concentration and temperature. Kinetic studies proved that a pseudo first order kinetics would fit to phenol decomposition and the activation energies for RuO(2)/AC and RuO(2)/ZSM5 were obtained to be 61.4 and 42.2kJ/mol, respectively.