二氧化鈦對泥漿溫泉水中大腸桿菌（ETEC O4）的光催化殺菌作用

Disinfection of E. Coli (ETEC O4) by Photocatalysis of Titanium Oxide in Mud Hot Spring

泡湯已成為國人主要休閒活動，為達溫泉資源保育目的，溫泉水需考慮採用循環及回收再利用，此時溫泉水需做殺菌處理。本研究使用紫外燈（UVA、UVC）、日光燈、及暗室等不同的光照射條件，配合添加無臭、無毒性之二氧化鈦光觸媒，比較各種光催化條件對關仔嶺泥漿溫泉水中大腸桿菌enterotoxigeic E.coli （ETEC O4）的殺菌效果。研究結果顯示，對富含碳酸氫鈉及氯化物之泥漿溫泉水中大腸桿菌做殺菌處理，不同的光輻射條件、光強度、輻照時間和二氧化鈦添加量都會影響光催化殺菌的效率。在暗室與日光燈條件下，並無殺菌效果，反而時間愈長，大腸桿菌愈增多；而在UVA及UVC不同光強度下之殺菌效果則有明顯差異，而輻照時間愈長，殺菌效果愈佳。此外，也發現在UVA照射下，添加0.12 g/L 二氧化鈦對泥漿溫泉中大腸桿菌的光催化殺菌效果最佳，但是添加太多二氧化鈦殺菌效果反而不好；而在UVC照射下，則添加0.2 g/L 二氧化鈦對泥漿溫泉中大腸桿菌的光催化殺菌效果最佳。綜合本研究結果，在各種光催化條件下，對離心過後的溫泉水殺菌效果比未經離心過的溫泉水要好，推測原因為泥漿溫泉水中含有許多泥沙，使光穿透性受阻，導致殺菌效果受到影響。

Taking a hot spring bath is an important leisure and entertainment in Taiwan. For resource conservation of hot spring, hot springs circulation and recycling need to be done with sterilization.The aim of this study is to explore the sterilization effect of both different photo-irradiation （UVA, UVC, solar irradiation, fluorescent lamp and darkroom） and dosing with odorless and non-toxic photocatalyst on E coli. （ETEC O4） in the mud hot spring of Guanziling under batch tests.Results show that the sterilization of E coli. （ETEC O4） in the mud hot spring of sodium bicarbonate chloride type was affected by intensity of photo-irradiation, photo-irradiation time, doage of titanium oxide. Results show that there was no disinfection effect on ETEC O4 under fluorescent lamp and darkroom conditions, and more E coli. found after longer reaction time. However, there were different effects on ETEC O4 under UVA and UVC, and better effects accompanying with duration time.Results also reveal that the effect of UVA photocatalysis was the best by dosing with 0.12 g/L titanium oxide, however, more than this dosage, the more dosage led to the worse sterilization effect. The effect of UVC photocatalysis was the best by dosing with 0.2 g/L titanium oxide.The disinfection effects on centrifugal hot spring better than without centrifugation might be caused by muds, which scattering possibly the penetrating of light, leading to worse effects on the disinfection of ETEC O4.