摘要
利用硝酸银与氯化钠在水溶液中形成胶体氯化银 ,在近紫外条件下 ,光催化胶体氯化银 ,产生高活性自由基 ,对染料色素、环境荷尔蒙 1 7β estradiol等有机污染物进行降解 ,对环境污染微生物进行消毒和杀菌 .结果表明 ,胶体氯化银在近紫外条件下 ,能够产生大量的高活性自由基 ,对环境荷尔蒙 1 7β estradiol,样品浓度在 2 2mg/L时 ,3min能够降解 99%以上 ,6min时由HPLC 荧光检出器已几乎不能检出 ;对染料色素甲基橙 ,浓度在 1 1mg/L ,2min就能够完全分解 ;与同样条件下的氧化钛相比 ,降解速率有了很大的提高 ;对环境微生物 ,由于银离子和羟基自由基等方面的多重作用 ,近紫外条件下 ,具有非常强的杀菌作用 ,对大肠杆菌和青霉菌在光照条件下不能检出时间分别为 2min、1 0min ,比利用氧化钛的杀菌效果提高 1 0 0倍以上 .
In the aqueous solution, AgNO 3 reacted with NaCl to produce AgCl colloid. Under near UV illumination, AgCl colloid was then photocatalyzed to generate hydroxyl radical, which can not only degrade organic pollutants such as dye pigment and environmental hormone 17β estradial, but also kill and decompose environmental baneful microorganisms of bacteria, fungi. The results show that, under near UV illumination, AgCl colloid could yield a great amount of hydroxyl radicals, and decomposed environmental hormone 17β estradiol so rapidly that the degradation rate reached over 99% in 3 minutes in 22ppm, and 17β estradiol was hardly detectable in 6 minutes on the HPLC fluorescence analyzer. Furthermore, it could completely degrade dye pigment methyl orange in 2 minutes in 11ppm. Comparing with TiO 2 under the same conditions as mentioned above, AgCl colloid had a much higher degradation speed. Due to the dual effect of both Ag + ion and hydroxyl radicals, it had an excellent sterilization ability, for which E. coli, penicillium were not detectable in 2, 5 and 10 minutes respectively, under light irradiation, over 100 times the sterilization effect of TiO 2 did.
基金
安徽省自然科学基金 (0 10 4 5 30 3)资助项目
