石墨相氮化碳光催化灭活水中多重耐药菌研究

研究了光辐照和基于石墨相氮化碳（g-C₃N₄）光催化对二级出水中1株四环素和氨苄西林抗性多重耐药菌E.coli CGMCC 1.1595的灭活效果.结果表明，汞灯辐照功率（100/300/500W）和辐照强度越高，其灭活效率相对越高，在500W汞灯60min辐照条件下，紫外长波（UVA）-可见光（300~579nm）对该多重耐药菌的灭活率为0.41log；基于g-C₃N₄的光催化对其灭活率为1.31log.相比未加g-C₃N₄催化剂的光辐照灭菌，在UVA-可见光条件下g-C₃N₄对其灭活率的贡献为61%~69%；在可见光条件下g-C₃N₄对其灭活率的贡献达到60%~79%.在UVA-可见光g-C₃N₄光催化灭活E.coli CGMCC 1.1595反应体系中，活性氧自由基和电子空穴的活跃程度为：·OH > ·O₂^- > H₂O₂ > h⁺ > ¹O₂，·OH为该光催化体系的主要活性物质，其次是·O₂^-和H₂O₂.

Graphite carbon nitride (g-C3N4) photocatalytic disinfection on a multidrug resistant E. coli strain from secondary effluent

The inactivation effects of multi-drug resistant bacterium E. coli CGMCC 1.1595against tetracycline and ampicillin from secondary effluent by light irradiation and photocatalysis with graphite carbon nitride (g-C₃N₄) were studied. The results showed that the higher irradiation power of the mercury lamp (100/300/500W) with higher irradiation intensity could lead to higher inactivation efficiency. Under the inactivation by 500W mercury lamp irradiation of 60min, the inactivation rate of E. coli CGMCC 1.1595was 0.41log by ultraviolet A (UVA)-visible light (300~579nm) irradiation, and the inactivation rate was up to 1.31log by g-C₃N₄ photocatalysis. The contribution of g-C₃N₄ to the UVA-visible light inactivation was 61%~69% compared to that without g-C₃N₄ catalyst, while the contribution of g-C₃N₄ to the visible light inactivation was 60%~79%. The significance of the reactive oxygen species (ROS) and hole (h⁺) for the g-C₃N₄ photocatalytic inactivation of E. coli CGMCC 1.1595were also investigated, with the activity order as·OH >·O₂^- > H₂O₂ > h⁺ > ¹O₂. Hydroxyl radical (·OH) was a leading contributor to the irradiation, followed by·O₂^- and H₂O₂.