疏水沸石负载纳米TiO2光催化去除水中土霉素

Removal of Oxytetracycline in Water by UV/Hydrophobic Zeolite Loaded with TiO2.

摘要:

通过固体扩散法将纳米TiO2负载在疏水沸石上制成复合光催化剂.研究了不同配比的复合光催化剂在32 W紫外灯照射下对水中土霉素的去除效果,探讨了复合光催化剂投加量、土霉素初始质量浓度、初始pH值对降解效果的影响.结果表明,质量分数为40%的纳米TiO2和质量分数为60%的疏水沸石制成的复合光催化剂在UV(紫外线)照射下对土霉素具有最佳的去除效果,对于初始质量浓度为50 mg·L-1的土霉素水溶液,复合光催化剂投加500 mg·L-1,UV照射150 min即可将土霉素去除99%以上,UV照射6 h,溶液的总有机碳(TOC)可去除86%.土霉素初始质量浓度越低,降解速度越快,随着pH值的提高,其降解速率常数逐渐增大.

Abstract:

The composite photocatalysts were made by solid dispersion method with hydrophobic Zeolite and nanometer titanium dioxide.The removal of oxytetracycline (OTC) in water by UV/ Hydrophobic Zeolite loaded with different ratio of TiO2 was investigated respectively under the irradiation of 32 W lowpressure mercury lamps.The effects of composite photocatalyst quantity,initial OTC concentration and pH were studied.Results show that UV/composite photocatalyst with 40% TiO2 and 60% hydrophobic Zeolite is the best way to remove OTC in water compared to the others.99% of OTC (50 mg·L-1) in ultrapure water mixed with 500 mg·L-1 composite photocatalyst degrades within 150 min under UV irradiation.And after 6 hours,86% TOC of the OTC solution is removed.It is found that the degradation rate is quicker when the OTC initial concentration is lower and initial pH is higher.