Behnajady M A, Modirshahla N, Fathi H
Research Laboratory, Department of Applied Chemistry, Islamic Azad University, Tabriz Branch, Tabriz, IR, Iran.
J Hazard Mater. 2006 Aug 25;136(3):816-21. doi: 10.1016/j.jhazmat.2006.01.017. Epub 2006 Feb 28.
The decolorization of C.I. Acid Red 27 (AR27), a monoazo anionic dye, was studied in the ultraviolet radiation (UV) alone and UV plus hydrogen peroxide (UV/H(2)O(2)) processes. The experimental results indicated that the kinetics of both oxidation processes fit well by pseudo-first order kinetics. The reaction rate was sensitive to the operational parameters and increased with increasing H(2)O(2) concentration and light intensity. The reaction orders of H(2)O(2) concentration and light intensity in both processes were obtained with linear regression method. A regression model was developed for pseudo-first order rate constant (k(ap,UV/H(2)O(2))) as a function of the Cconcentration and UV light intensity. (k(ap,UV/H(2)O(2)))=(2 x 10(-4)I(0.75)(0) + k(3)I(1.38)(0)H(2)O(2)(0))phi(AR27). As a result of two opposing effects of H(2)O(2) concentration at low and high concentrations, n has a value of 0.49 and -0.39 and k(3) has a value of 3 x 10(-4) and 0.1 for the regions of 0 mg l(-1) < H(2)O(2) < 650 mg l(-1) and 650 mg l(-1) < H(2)O(2) < 1500 mg l(-1)1, respectively. PhiAR27 is the initial dye concentration correlation index for developing of model for different initial concentrations of AR27. This rate expression can be used for predicting k(ap,UV/H(2)O(2) at different conditions in UV alone and UV/H2O2 processes. The results show that UV alone cannot be an efficient method for decolorization of AR27 in comparison with UV/H(2)O(2) process, therefore the first term of the model can be neglected.
研究了单偶氮阴离子染料酸性红27（AR27）在单独紫外线辐射（UV）以及紫外线加过氧化氢（UV/H₂O₂）过程中的脱色情况。实验结果表明，两种氧化过程的动力学均符合准一级动力学。反应速率对操作参数敏感，且随H₂O₂浓度和光强的增加而增大。采用线性回归法得到了两种过程中H₂O₂浓度和光强的反应级数。建立了一个回归模型，用于描述准一级速率常数（k(ap,UV/H₂O₂)）与初始浓度和紫外光强的函数关系。（k(ap,UV/H₂O₂)）=(2×10⁻⁴I₀⁰·⁷⁵ + k₃I₀¹·³⁸[H₂O₂]₀ⁿ)φ(AR27)。由于H₂O₂在低浓度和高浓度时存在两种相反的影响，在0 mg L⁻¹ < [H₂O₂]₀ < 650 mg L⁻¹和650 mg L⁻¹ < [H₂O₂]₀ < 1500 mg L⁻¹区域，n的值分别为0.49和 -0.39，k₃的值分别为3×10⁻⁴和0.1。φ(AR27)是针对不同初始浓度的AR27建立模型时的初始染料浓度相关指数。该速率表达式可用于预测单独UV和UV/H₂O₂过程中不同条件下的k(ap,UV/H₂O₂)。结果表明，与UV/H₂O₂过程相比，单独UV不能作为AR27脱色的有效方法，因此模型的第一项可以忽略。
