- 學位論文
以二氧化鈦光觸媒降解溶液中之納乃得與巴拉松
Degradtion of Methomyl and Parathion in Aqueous Solutions Using Tio2 Photocatalysts
摘要
本實驗採以商用型Degussa P-25 TiO2觸媒，並使用高壓汞燈(400 W)做為光降解納乃得(Methomyl)與巴拉松(Parathion)農藥試驗溶液中之光源，並藉由改變TiO2觸媒添加量 (0 g~1.5 g)、納乃得與巴拉松濃度(10 mg/L~30 mg/L)、pH值 (4~10) 改變等條件進行實驗，以探討納乃得(Methomyl)與巴拉松(Parathion)在TiO2光觸媒降解過程中的降解變化、pH對降解的影響及礦化程度等差異性與效果。 由實驗結果發現在TiO2/UV 系統中，納乃得與巴拉松之濃度會在0.5 h ( t )內會快速降解，其降解趨勢可以擬一階反應描述，而其反應速率常數會隨著納乃得與巴拉松濃度增加而減少、隨著TiO2濃度增加而增加。若添加過多觸媒則會因遮蔽效應，而延長光催化效率的時間與降低降解效率，且由實驗觀察出(0 g~1.5 g)、初始納乃得與巴拉松農藥水溶液，兩者在降解的趨勢非常的相似，其濃度會在30 min (t)內快速降低，而30 min (t)後的降解速率則逐漸趨向線性呈現，並由降解實驗結果可得知，本實驗之TiO2 / 納乃得的最佳濃度0.75 g/L，巴拉松的最佳濃度1 g/L，pH值在pH4(弱酸)、pH10(弱鹼)時，由於有溶液中的電子加入反應機制中、及呈現水解效果，故皆有較高的降解效率。 利用紫外線/可見光分光光譜儀 (UV / Vis)分析，納乃得與巴拉松在TiO2/UV系統中，溶液反應所得之氨氮( NH4十 )及硝酸鹽氮( NO2-)與亞硝酸鹽氮( NO3- )與磷酸鹽 ( PO4- )等分析結果，由於強氧化環境的作用，光催化氧化處理能使它們完全無機化，並且定量生成亞硝酸鹽氮( NO3- )、磷酸鹽 ( PO4- )、二氧化碳(CO2)等無機產物。 雖然到目前為止，運用此方法來降解廢水中之有機污染物質並非普及，而本文將TiO2光降解技術應用到含納乃得與巴拉松廢水的降解，用以解決自然水體中的農藥廢水的淨化處理及有關的環境問題，克服了傳統廢水處理技術淨化不徹底等缺點及可節省高成本的土地、時間與能源消耗，是一種處理效率高且可以避免二次污染的淨化技術。
並列摘要
The experimental mining Commercial Degussa P-25 TiO2 catalyst and as photodegradation Methomyl (Methomyl), and Ba Lasong (Parathion) pesticide test solution, the light source, the use of high-pressure mercury lamp (400 W) by change the TiO2 catalyst loading (0 g to 1.5 g), Methomyl Bala Song concentration (10 mg / L to 30 mg / L), pH values (4 to 10) and changes in condition to conduct experiments to explore satisfied trusted (Methomyl), and Ba Lasong (Parathion) Degradation of TiO2 photocatalytic degradation process of pH on the degradation and mineralization of the differences and effect. Experimental results found in TiO2/UV system, Methomyl concentration and Bala Song of 0.5 h (t) will rapidly degrade, degradation trends can be a first-order reaction is described, and its reaction rate constant with The Methomyl Bala Song concentration is reduced, increasing with the increase in TiO2 concentration. If you add too much catalyst will be due to the shadowing effect, time and extend the photocatalytic efficiency reduce degradation of efficiency, and the experimental observation (0 g to 1.5 g), the initial Methomyl, and Bala Song pesticide aqueous solution, both very similar to the trend of degradation of its concentration at 30 min (t) quickly reduced, while the rate of degradation after 30 min (t) is gradually moving towards linear presented by degradation results show that under the experiment TiO2 / Methomyl optimum concentration of 0.75 g / L, Bala Song the optimal concentration of 1 g / L, and the pH value pH4 (weak acid), pH10 (weak), since the electrons in the solution was added to the reaction mechanism , presented Hydrolysis Both contain a higher degradation efficiency. The use of UV / visible spectrophotometer (UV / Vis) analysis, Methomyl Bala Song TiO2/UV system, the solution obtained by the reaction of ammonia (NH4 +) and nitrate nitrogen (NO2-) and nitrite nitrogen (NO3-) and phosphate (PO4-)analytical results, due to the strong oxidizing environment, photocatalytic oxidation treatment to make them completely inorganic, and quantitative formation of nitrite nitrogen (NO3-), phosphate (PO4-), carbon dioxide (CO2) and other inorganic product. Although so far, the use of this method of degrading organic pollutants in the wastewater is not popular, and the article will TiO2 photodegradation technology applied to a containing methomyl Bala Song wastewater degradation, pesticide wastewater to solve the natural water bodies purification and environmental issues related to overcome the conventional wastewater treatment technologies purification not completely disadvantages and can save the high cost of land, time and energy consumption, a high treatment efficiency and secondary contamination can be avoided purification technology.