直接恒电流降解Cr(Ⅵ)模拟废水的控制条件模型讨论  

Discussion on Control Condition Model of Reduction Cr(Ⅵ) in Simulated Wastewater by Direct Constent-current Treatment

作　　者：于永海[1] 王栋[1] 房小红[1] 边朝政[1] 

机构地区：[1]大连理工大学环境与生命学院,辽宁大连116023

出　　处：《辽宁化工》2008年第12期815-818,共4页Liaoning Chemical Industry

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.

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 

分 类 号：X703[环境科学与工程—环境工程]