Photocatalytic digestion of total phosphorus in the presence of H2O2 utilizing nano-TiO2 photocatalyst

In this work, an ultra-violet (UV) photocatalysis method in the presence of H2O2 utilizing nano-TiO2 photocatalyst is presented for the digestion of total phosphorus (TP) in water. The UV digestion of 4 mg/L of sodium glycerophosphate solutions (by weight of P) were conducted at different digestion time and concentrations of H2O2. The H2O2 added to the water samples could increase the formation rate of strong oxidant hydroxyl radicals (center dot OH), but excess H2O2 will consume center dot OH and reduce the conversation rate. The optimum concentration of H2O2 obtained in this work was 740mg/L. At the condition of 60min and 740 mg/L of H2O2, the conversion rate of sodium glycerophosphate reached about 90%, and the maximum value of rate constant k was 0.0306 min(-1). Compared with the traditional thermal oxidation method for TP digestion, this UV/H2O2 photocatalysis digestion method enables the digestion process work at normal pressure. Compared with the individual UV photocatalysis process, UV/H2O2 digestion method decreases the digestion time from two hours to about an hour.