The Degradation of Natural Organic Matter in Surface Water by a Nano-TiO2/Diatomite Photocatalytic Reactor

A new nano-TiO2/diatomite (NTD) composite was employed in a photocatalytic reactor to assess the removal of natural organic matter (NOM) at fluxes ranging from 0.6 to 1.8L/h. Various analytical methods, such as scanning electron microscopy, Fourier transform infrared spectrometry, X-ray diffraction, and high performance size exclusion chromatography-UV/Vis detector-total organic carbon (TOC), were adopted. The experimental results found that the NTD photocatalytic reactor was effective in removing NOM from raw water. The flux had a significant effect on the degradation of TOC, and the UV absorbance at 254nm (UV254) increased as the decreasing flux and the prolonged photocatalytic operation. According to the analysis of the NOM fractionation results, the absorption and photocatalysis by the NTD particles removed different NOM fractions, and the very hydrophobic acids and neutral hydrophilic acids of lager molecular weight could be strongly degraded by the NTD photocatalytic reactor.