二氧化钛光催化降解活性红24模拟染料废水

Photocatalytic Degradation of C.I. Reactive Red 24 Solution with Titanium Dioxide

在紫外光和阳光下,研究了二氧化钛(TiO2)对活性红24(RR24)模拟染料废水的光催化脱色降解效果.研究表明,TiO2投加量、RR24溶液的初始浓度以及光照时间对其脱色降解均有影响.当RR24溶液初始浓度为10 mg/L,TiO2加入量为0.75 g/L,溶液初始pH为6,对200 mL RR24溶液光催化反应1 h,其脱色率可达88.69%,CODCr和TOC的去除率分别达到47.2%和17.78%.空穴清除剂碘化钾和自由基清除剂异丙醇对TiO2光催化RR24溶液脱色降解影响研究表明,TiO2光催化RR24溶液降解机理是光致空穴h+和.OH共同参与的过程.TiO2光催化RR24溶液脱色降解遵循一级动力学反应.

Titanium dioxide（TiO2） photocatalytic decomposition of C.I.Reactive Red 24 solution（abbreviated as RR24） with the UV-lamp（253.7 nm,20 W） and sun light was investigated.The results show that the photocatalytic degradation efficiency of the RR24 with TiO2 was affected by the initial concentration of the RR24 solution,the amount of TiO2 and photolysis time.When the initial pH of RR24 solution is 6 and the initial concentration of that（200 mL） is 10 mg/L with 0.75 g/L of TiO2.and irradiated for 1h under UV-lamp,the decoloration rate is 88.69% with the CODCr and TOC removal rates of 47.2% and 17.78%.The effect of holes scavenger（potassium iodide） and free radical scavenger（isopropanol） on the photocatalytic degradation RR24 solution were also studied.It demonstrates that the process of photodegradation of RR24 solution with TiO2 is a pesudo first-order reaction which can be described by Langmuir-Hinshelwood equation.Hydroxyl radicals and holes are both the main oxidants in the photocatalytic reaction of RR24 solution with TiO2.