Photocatalytic Properties Of TiO 2 In White Ink Wastewater

Pollutants of white ink wastewater (WIW) is very complex, besides high concentration of organic pollutions, it also contains a large amount of TiO2 pigment. In the field of photocatalytic, TiO2 has good catalytic performance and often used as catalyst. The purposes of this paper are to study the photocatalysis properties of TiO2 in WIW and to explore the feasibility of return utilization of TiO2.Firstly, testing content of TiO2 in WIW by ultraviolet spectrophotometry. Secondly, detacting photocatalytic activity of TiO2 in WIW by the experiment of catalytic degradation of Rhodamine B dye wastewater. Lastly, using TiO2 in WIW as photocatalyst to photocatalytic degradation of actual printing and dyeing wastewater (PDW). And on this basis, coagulation-catalytic oxidation process was used for advanced treatment of exit water. The experimental results were shown below.(1) The experimental results showed that the concentration of TiO2 in WIW is 1002mg/L. According to the related research of TiO2 photocatalytic treatment industrial wastewater, the content of TiO2 in WIW is enough and meet the experimental conditions as photocatalyst.(2) The experimental results of TiO2 in WIW as catalyst photocatalytic degradation of Rhodamine B showed that the initial pH was 7, the WIW dosage was 14mL in 30mL of Rhodamine B wastewater which concentrations of 20mg/L, UV-lighting was 15min under the condition as magnetic stirring, the degradation rate of Rhodamine B was 93.2%. The photocatalytic degradation can be analyzed by Langmuir-Hinshelwood kinetic model, the corresponding degradation rate constant was 0.8159mg/(L·min), and adsorption equilibrium constant was 0.1390L/mg.(3) The experimental results of WIW as catalyst photocatalytic degradation of PDW showed that the removal rate of CODCr and Chroma was 67.3% and 50% during the mixing ratio of WIW and PDW was 1 to 1, pH was 1, UV-lighting time was 60min. The experimental results of advanced treatment showed that the CODcr of the final effluent water was 193mg/L, the chroma dropped to 50, and up to the indirect emission standard of BG 4287-2012.(4) According to the result of TiO2 pigment in WIW photocatalytic degradation of PDW, it was found that TiO2 pigments in WIW has very good photocatalytic properties and realizes the reuse of waste. It can achieve the purpose of utilizing waste treats waste under appropriate conditions.