農業部水產試驗所全球資訊網

氨是水產動物的主要代謝產物，具有很強之毒性，因此在養殖系統中必須去除。本報告即設計以氣體曝氣的方法使二氧化鈦光觸媒懸浮，並以PL型之UV-A光源來激發二氧化鈦，使產生電子與電洞，以試驗探討不同氣體 (空氣、純氧及臭氧) 在不同水中 (純水、自來水及海水) 對懸浮二氧化鈦氧化總氨氮之影響。在4.0 L的壓克力反應槽內裝3.5 L含總氨氮3.5 TAN mg/l 之純水中，以1 g/l二氧化鈦及Philips 36W PL型UV-A燈管處理之，其試驗結果如下：在純水中，當打入空氣、氧氣及臭氧不同氣體時，其對總氨氮的氧化速率分別是0.04 ± 0.02、0.07 ± 0.01及0.24 ± 0.02 TAN mg/hr。在自來水中，當打入三種不同氣體時，其對總氨氮的氧化速率分別是0.59 ± 0.14、0.67 ± 0.15及0.71 ± 0.18 TAN mg/hr。而在海水中，當打入三種不同氣體時，其對總氨氮的氧化速率分別是1.22 ± 0.26、1.45 ± 0.18及1.81 ± 0.34 TAN mg/hr。由以上結果可知，二氧化鈦光觸媒對總氨氮之氧化速率，除受水中的離子影響外，亦受水中存在的氣體分子影響。其中以臭氧在二氧化鈦光觸媒反應系統中對總氨氮之氧化速率影響最大，其次是純氧，最後是空氣。

摘要abstract(英) Ammonia is a major metabolic product of aquatic organisms. It is highly toxic to aquatic organisms, and therefore must be removed from aquatic ecosystem. A new photocatalytic system was designed to remove total ammonia nitrogen in water in this study. Titanium dioxide was suspended by disc air diffuser stone and activated by PL type UV-A lamp light to produce free electron and electron hole. The photocatalytic oxidation of total ammonia nitrogen was measured in different water (deionized water, tap water and seawater) that was aerated with different gases (air, oxygen and ozone). In deionized water, the photocatalytic oxidation rate of total ammonia nitrogen aerating with different gases were 0.04 ± 0.02, 0.07 ± 0.01, and 0.24 ± 0.02 TAN mg/hr, respectively. In tap water, the photocatalytic oxidation rate of total ammonia nitrogen aeration with different gases were 0.59 ± 0.14, 0.67 ± 0.15, and 0.71 ± 0.18 TAN mg/hr, respectively. In seawater, the photocatalytic oxidation rate of total ammonia nitrogen aerating with different gases were 1.22 ± 0.26, 1.45 ± 0.18, and 1.81 ± 0.34 TAN mg/hr, respectively. It indicated that the photocatalytic oxidation rate of total ammonia nitrogen was affected not only by ion in water, but also by the gases types of aerating. Ozone aeration was the best to enhance the photocatalytic oxidation rate of ammonia by titanium dioxide. Oxygen aeration was the follower and air aeration was the last.