反应器型式对有机废水光催化氧化特性的影响

Influence of Reactor Types on Photocatalytic Oxidation Performance of Organic Wastewater in Slurry Reactors

采用浆态光催化反应器对苯甲酰胺模拟废水光催化氧化特性进行了研究。探讨了催化剂的用量、污染物的初始浓度、反应时间、空气流量等操作参数对鼓泡式、循环式等形式的浆态光催化反应器内苯甲酰胺模拟废水光催化氧化特性和动力学的影响。结果表明,浆态光催化降解过程中污染物的浓度越低效果越好,催化剂的用量存在适当值;不同操作条件对不同形式浆态光催化反应器内苯甲酰胺模拟污染物光催化降解性能的影响不近相同。在所考察的污染物初始浓度、催化剂量和空气流量范围内,反应器中苯甲酰胺光催化氧化速率均符合拟一级动力学方程。与鼓泡式浆态光催化反应器相比,所开发的循环式浆态光催化反应器在空气作用下能更好地改善催化剂与气体和废水的混合效果,进而提高了光催化剂的利用效率,能更有效降解有机污染物;而且空气利用量小,能够大大降低浆态床光催化氧化处理废水的运行成本。

The technique of photocatalytic oxidation was employed in the treatment of the simulated wastewater as a model pollutant. The photocatalytic oxidation performance and kinetic of the simulated organic wastewater were investigated in a circulating slurry photocatalytic reactor and a bubble column slurry reactor. The effect of operation conditions, such as dosage of photocatalyst, illumination time, initial benzamide concentration in wastewater and gas flow rate, on the photocatalytic oxidation performance was discussed. The results showed that the application of photocatalytic oxidation in the treatment of wastewater was feasible and efficient, but it was affected by the operation conditions. The dosage of catalyst and initial benzamide concentration exist an optimum value for the photocatalytic oxidation. The results of kinetic of the photocatalytic oxidation of benzamide with different dosages of photocatalyst, initial concentrations and gas flow rates show that the photocatalytic degradation rate follows pseudo-first order kinetic. Compared with the bubble column slurry reactor, the circulating slurry photocatalytic reactor exploited in our lab provides not only an excellent blend of catalysts and reactants, but also a high efficiency of UV light. It can improve the output of treatment and reduce the dosage of catalyst.