摘要
研究了酸性条件下,利用恒电流直接还原模拟废水中的Cr(Ⅵ)。结果表明,低浓度Cr(Ⅵ)在350 nm处符合郎伯-比尔定律,且Cr(Ⅵ)还原降解曲线均呈较强线性关系,由此建立模型得到反应速率与60 m in时的还原降解率的对应关系,并用模型导出的速率/电流效率系数Γ代替瞬时电流效率和平均电流效率进行分析。Cr(Ⅵ)反应控制条件分为3个区间,从0.2 mA/cm2到1.0 mA/cm2控制条件为电流因素,模型ICE=1,Γ相对最大且较为恒定。1.0 mA/cm2到2.0 mA/cm2,ICE<1,控制条件转为体相对流传质,Γ/i呈双曲线形。2.0 mA/cm2到15.0 mA/cm2,ICE<1,控制条件为电解产生气泡间接加强对流传质,Γ/i变化平稳且存在极限。
Reduction hexavalent chromium Cr（ Ⅵ ） in simulated wastewater was studied by direct constant - current electrolysis. The results showed that at low concentration Cr（Ⅵ） u. v -absorbency at 350nm accorded with Lambert -Beer Law, and the profile of Cr（ Ⅵ） degradation was almost linearity, so a relation between degradation rate and ratio in 60min, rate/ratio efficiency coefficient F, deduced from experiment could replace instantaneous current effleieney and average current efficiency for analysis. Cr（Ⅵ ） ＇ s reaction control condition could be divided into three intervals. From 0.2 mA/cm^2 to 1.0 mA/cm^2 current controlled reaction model ICE = 1 and P was maximum and constant corresponding. From 1.0 mA/cm^2 to 2.0 mA/cm^2 ICE 〈 1, the condition changed to convective mass transfer and Γ/i was hyperbola. From 2.0 mA/cm^2 to 15.0 mA/cm^2, ICE 〈 1, current predueed microbubble strengthened convection, synchronously Γ/i changed smoothly and had limit value.
出处
《辽宁化工》
CAS
2008年第12期815-818,共4页
Liaoning Chemical Industry
关键词
恒电流电解
含铬废水
电流控制
对流传质控制
瞬时电流效率
Constant current electrolysis
Wastewater containing chromium
Current control
Convective mass transfer control
ICE
