[Study on oxidant strengthening photocatalytic degradation of DMF over TiO2 fiber catalyst].

Oxidant strengthening the degradation of DMF aqueous solution was investigated when TiO2 fiber is used as the photocatalyst. When the UV light was absent, ozone per se could not make DMF degrade, which proves that DMF is a stable substance. But ozone could increase obviously photocatalytic degradation rate of DMF in O3/TiO2 (F). Under the same reaction condition, photocatalytic degradation rate and speed of DMF in O3/TiO2 (F) was almost 1.5 times and 2 times higher than that in air/ TiO2 (F) and H2O2/TiO2 (F) respectively. COD analysis showed DMF was almost mineralized completely when the reaction was carried out for 120 min. Through Hinsberg test secondary amine was proved as one of intermediates in the process of DMF photocatalytic degradation. Rise of pH value of reaction solution also showed that amine was produced in the photocatalytic reaction process. Degradation speed of DMA in O3/TiO2 (F) was higher than that in air/TiO2 (F). The increasing degradation rate and speed of DMF was mainly caused by fast degradation of secondary amine in the process of DMF photocatalytic degradation in O3/TiO2 (F).