Fe_2O_3/UV/H_2O_2光催化法降解造纸废水的研究

Photocatalytic degradation of paper-making sewage with Fe_2O_3/UV/H_2O_2

以Fe2O3为催化剂,高压汞灯为光源,对造纸废水进行光催化法降解实验研究,初步分析了光催化法处理废水的基本原理,对不同反应体系的处理效果进行比较并讨论了Fe2O3用量、H2O2用量、pH值、反应时间等影响处理效果的主要因素。研究结果表明,Fe2O3/UV/H2O2体系能有效、快速地降低造纸废水的COD。实验考察了Fe2O3用量、H2O2用量、pH值、反应时间等因素对降解效果的影响,得出的最佳的降解条件及效果为:室温下Fe2O3用量为1.0g/L,H2O2用量为0.5%(体积比),pH值为3.0,300W高压汞灯照射下反应3h后废水的CODCr去除率达到93.3%,出水CODCr降到54mg/L。光催化反应体系中,Fe2O3的光催化氧化在有机物的降解反应中起着主要作用。由于Fe2O3和H2O2能发生协同作用,因此在反应体系中加入适量H2O2可以提高光催化反应效率和反应速度,大大提高了对造纸废水的处理效果。反应体系中的催化剂可回收处理后重复使用多次,对处理效果没有明显影响。

The present article has given the author＇s renovated study results on using photocatalytic degradation of sewage from paper-making plant with Fe2O3 as photocatalyst and high-voltage mercury lamp as a light source. For the introductory purpose, first of all, the paper has analyzed the basic principle of photocatalytic degradation. Then, it has compared the results of using his renovated method to show its distinctiveness from others and main affecting factors such as the amount of F32O3 and H2O2 added, pH value with irradiation time carefully investigated. The experiment results of his suggested method indicate that a heterogeneous photocatalyst system of Fe2O3/UV/H2O2 could help to bring down effectively the content of CODCr in wastewater and achieve the optimal condition for degradation. Experimentally speaking, the optimal condition of ours helps to reach 93.3 % , and, when the ideal amount of Fe2O3 is made to be equal to 1.0 g/L, the H2O2 would be 0.5% （VH2O2/Vsewage）, with pH value being 3.0 along with the radiation time of 3 h and the removal rate of CODCr. However, in the photocatalytic system, the photocatalytic oxidation should be Fe2O3 mainly for the need to degrade the organic pollutants. In addition, under the optimum condition, the H2O2 added is expected to bring remarkable improvement to the reaction efficiency along with Fe2O3. and in turn, to increase the efficiency and rate of photocatalytic degradation greatly. Furthermore, since the catalyst can be recycled for many times with no harm of the effect, the suggested photocatalytic degradation method can be made wider and more effective in the future because of its own outstanding features of low cost in operation with no secondary pollution.