Study On Design Of Photocatalytic Degradation Reactor And Its Application In Drinking Water Treatment

In this paper, the photocatalytic degradation reactor was designed for treatment of drinking water on removing pollutants (such as phenol, chloroform and sodium nitrite) and bacteria.The reactor was mainly made up of 20w ultraviolet lamp and nano TiO2 attached on the active carbon and rock wool.Through the static and dynamic experiments, the photocatalytic reactivity of nano powder TiO2 and coated TiO2 was studied.The adsorption of active carbon and rock wool on phenol could accelerate its degradation. The amount of catalyst, initial concentration of phenol and flow rate in the reactor have the effect on the degradation rate. Dissolved O2 and H2O2 are benefit for the degradation. The qualified drinking water can be got when two kinds of water were treated by the reactor in different flow speeds, one was 1.0mg/L phenol solution ( including H2O2 150mg/L) in 5mL/min and the other was 0.02mg/L phenol solution in 100mL/min.According to the decrease of chloroform and increase of chloride, it was showed that chloroform could be thoroughly degradated into inorganics. The property of coated TiO2 is better than pure TiO2 and little H2O2 can accelerate the reaction rate. The content of chloroform was less than 0.06mg/L when the concentration of chloroform was 0.44mg/L and the flow speed of water was 100mL/min.During its decomposition, nitrite was converted into nitrate and ammonium , while the amount of compounded nitrogen was less than initial amount because of the liberation of N2. Urea is benefit for the degradation of sodium nitrite. The treatment result of l.Omg/L sodium nitrite solution (including urea 4.4 u g/L) by the reactor was that qualified water can be got when the flow rate was 100mL/min.By the synergism of adsorption and filtration provided by rock wool, disinfection by ultraviolet and photocatalysis by TiO2, the disinfection resultof drinking water which included bacteria was that qualified water(the colony were 86 per milliliter and the colibacillus were 3 per liter) can be got by the reactor when the flow rate was 1 OOmL/min.The treatment result of low concentration pollutants (0.02mg/L phenol, 0.44mg/L chloroform and l.Omg/L sodium nitrite) in drinking water by the reactor was that qualified water can be got when flow rate was 1 OOmL/min.