以奈米TiO2光觸媒懸浮液分解染料之動力學

Decomposition Kinetics of Dye by Suspension of Nanosized TiO2 Photocatalyst

張弘瑋(Hung-Wei Chang)

指導教授 ： 陳嘉明

大同大學/工程學院/化學工程學系所/碩士(2004年)

摘要

染紡工廠所排放出含有多種染料的廢水，是一種對環境影響甚大的水污染。使用傳統的處理方法如物理、化學處理方法或是生物處理程序等處理上述廢水時，往往有著高成本、高耗能以及過程中容易產生二次污染的缺點。運用紫外光照射二氧化鈦半導體的光觸媒處理程序是一已被驗證有許多好處與有效的污水處理技術。本研究主題為使用柰米粒徑二氧化鈦懸浮液在自然pH環境下，經由改變各種操作條件實驗，找出反應的動力學，研究中改變的操作條件為攪拌速度(50-200 rpm)、二氧化鈦懸浮液濃度(0.037-0.26 g/L)、起始染料濃度(0.01-0.05 g/L)、反應溫度(10-50 oC)與紫外光強度(0-36W)。實驗結果顯示，攪拌速率由50 rpm改變至200 rpm的情況下，對於反應速率以及pH變化的影響甚小;染料分解起始反應速率隨著二氧化鈦懸浮液濃度上升而增加，最高增加到二氧化鈦懸浮液濃度為0.15 g/L，之後染料分解反應速率隨著二氧化鈦懸浮液濃度上升而減少;染料分解的起始反應速率會隨著起始染料濃度的上升而增加到一固定的值，這個值因溫度改變而異，超過這個值後，染料分解的起始反應速率隨著染料濃度上升而降低;染料分解的起始反應速率隨著紫外光照射的強度上升而增加，最高的反應速率出現在紫外光照射強度為24 W時，再增加紫外光的強度無法進一步增加染料分解的起始反應速率。根據研究結果可得到一反應動力模式，該模式與實驗所得動力學數據相當符合。

關鍵字

二氧化鈦 ； 懸浮液 ； 動力學 ； 溫度 ； 濃度 ； 起始反應速率 ； 紫外光 ； 動力學模式

並列摘要

Wastewater effluent from textile plants using various dyes is one of the major water pollutants to environment. Traditional chemical, physical methods and biological processes for treating the textile dye wastewaters have disadvantages such as high cost, high energy waste and generating secondary pollution during the treatment processes. The photocatalytic process using TiO2 semiconductor particles under UV light illumination has been shown to be potentially advantageous and applicable in the treatment of wastewater pollutants. In this study, the dye decomposition kinetics by nano-size TiO2 suspension at natural solution pH was experimentally studied by varying the agitation speed (50-200 rpm), TiO2 suspension concentration (0.037-0.26 g/L), initial dye concentration (10-50 ppm), temperature (10-500C), and UV power intensity (0-36 W). The experimental results show the agitation speed, varying from 50 to 200 rpm, has little influence on the dye decomposition rate and pH history; the dye decomposition rate increases with the TiO2 suspension concentration up to 0.15 g/L, then decrease with increasing TiO2 suspension concentration; the initial dye decomposition rate increases with the initial dye concentration up to a certain value depending upon the temperature, then decreases with increasing initial dye concentration; the dye decomposition rate increases with the UV power intensity up to 24 W, then increasing the UV power intensity cannot further increase the dye decomposition rate. A kinetic model has been developed to fit the experimental kinetic data well.

並列關鍵字

concentration ； initial reaction rate ； kinetics ； kinetics model ； suspension solution ； temperature ； titanium dioxide ； UV

參考文獻

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