ABSTRACT

In this study anodic oxidation of Cr₂(SO₄)₃ was carried out in an air-sparged divided parallel plate cell. Variables studied were current density, Cr₂(SO₄)₃ concentration, and superficial air velocity. The rate constant of Cr₂(SO₄)₃ oxidation was found to increase with increasing current density and Cr₂(SO₄)₃ concentration. The effect of air sparging was found to depend on Cr₂(SO₄)₃ concentrations, at high Cr₂(SO₄)₃ concentration (> 0.1 M) air sparging does not affect the rate constant of the reaction denoting that the reaction is charge transfer controlled. As Cr₂(SO₄)₃ concentration decreases below 0.1 M the reaction becomes under mixed diffusion and chemical control and the rate constant increases with increasing air superficial velocity, the lower Cr₂(SO₄)₃ concentration the higher the contribution of diffusion to the reaction rate. The current efficiency of the process ranged from 20 to 85% depending on current density and Cr₂(SO₄)₃ concentration. Electrical energy consumption which ranged from 1.8 to 14.4 kW h/kg of Cr⁶⁺ was found to increase with increasing current density and decreases with increasing Cr₂(SO₄)₃ concentration. Air sparging was found to decrease electrical energy consumption in the case of dilute solutions << 0.1 M Cr₂(SO₄)₃.

摘要

_{在这项研究中，Cr 2} (SO ₄ ) ₃的阳极氧化是在空气喷射的分隔平行板电池中进行的。研究的变量是电流密度、Cr ₂ (SO ₄ ) ₃浓度和表观空气速度。_{发现Cr 2} (SO ₄ ) ₃氧化的速率常数随着电流密度和Cr ₂ (SO ₄ ) ₃浓度的增加而增加。发现空气喷射的效果取决于 Cr ₂ (SO ₄ ) ₃浓度，在高 Cr ₂ (SO ₄) ₃浓度 (> 0.1 M) 空气喷射不影响反应的速率常数，表明反应受电荷转移控制。当 Cr ₂ (SO ₄ ) ₃浓度降低到 0.1 M 以下时，反应变为混合扩散和化学控制，并且速率常数随着空气表观速度的增加而增加，Cr ₂ (SO ₄ ) ₃浓度越低，扩散对扩散的贡献越大。反应速率。根据电流密度和 Cr ₂ (SO ₄ ) _{3的不同，该工艺的电流效率在 20% 到 85% 之间}专注。发现从 1.8 到 14.4 kW h/kg Cr ⁶⁺的电能消耗随着电流密度的增加而增加，随着 Cr ₂ (SO ₄ ) ₃浓度的增加而减少。_{在稀释溶液 << 0.1 M Cr 2} (SO ₄ ) ₃的情况下，发现空气喷射可降低电能消耗。