非均相UV/Fenton光催化降解土霉异味研究

摘要

[目的]探索非均相UV/Fenton光催化降解土霉异味的效果.[方法]利用离子交换方法将Fe2+负载在NaY分子筛载体上,制得催化剂FeY.在不同紫外波长照射下,利用Fenton反应降解2种土霉异味物质2-甲基异莰醇(MIB)和土腥素(Geosmin),优化pH和H2O2等降解条件,并将MIB和Geosmin添加到东湖本底湖水中进行降解.[结果]FeY的负载量为352.8 mg/g,Fe2+脱附率为5.7％.在FeY为28 mg/L,pH 6.5,H2O2 20 mg/L和反应60min的试验条件下,非均相UVB/Fenton体系对MIB和Geosmin的降解率分别为80.2％和84.9％.在UVA、UVB和UVC紫外光(波长分别为365、312和256 nm)条件下Photo-Fenton体系对MIB和Geosmin的降解率,随着紫外波长的降低而增大,且Geosmin降解速率常数高于MIB.湖泊水样中加入MIB和Geosmin降解表明,降解效率明显低于纯水样品.[结论]该研究制得的催化剂应用于非均相光催化体系,不仅可循环使用,而且还可扩大反应体系的pH应用范围.%[Objective] The study aimed to explore the effects of the heterogeneous UV/Fenton photocatalysis on the degradation of the musty-earthy odors. [ Result] By using ion exchange method, the Fe2+ was loaded on the NaY molecular sieve carrier to prepare the catalyst FeY. Under the radiation of different ultraviolet wavelengths, 2 musty-earthy odor materials of 2-Methylisobomeol ( MIB) and trans-1, 10-dimethyl-trans-9-decalol (Geosmin) were degraded by using Fenton reaction, the degradation conditions such as pH and H2O2 were optimized and the MIB and Geosmin were added to the bottom of East Lake for the degradation. [ Conclusion] The FeY loading amount was 352.8 mg/g and the Fe2+ desorption rate was 5. 7%. The heterogeneous UV/Fenton system had the degradation rate of 80. 2% and 84. 9% resp. On MIB and Geosmin under the test conditions as FeY of 28 mg, pH of 6.5, H2O2 of 20 mg/L and reaction time of 60 min. Under the UVA, UVB and UVC wavelengths of 365 ,312 and 256 nm, resp. , the degradation rate of the Photo-Fenton system on MIB and Geosmin were increased with the reduction of the ultraviolet wavelengths and the degradation rate constant of Geosmin was higher than that of MIB. The degradation of MIB and Geosmin added to the natural water of the lake showed that, their degradation rate was obviously lower than that in the pure water sample. [Conclusion] The catalyst prepared in the study, when used in the homogeneous light catalytic system, could not only be recycled, but also expand the application range of pH value in the reaction system.