钛-铁双阳极电絮凝法去除电镀废水中的铬(Ⅵ)

Removal of Cr(Ⅵ) from electroplating wastewater by electro-coagulation with titanium-iron double anodes

对采用钛-铁双阳极电絮凝技术去除电镀废水中铬(Ⅵ)进行了研究。以铬(Ⅵ)去除率为考察指标,利用单因素试验和正交试验,详细研究了不同阳极材料及组合方式、电流密度、电解时间、废水pH、电导率、静置时间等因素对其去除废水中铬(Ⅵ)效果的影响,经正交试验的极差分析和方差分析表明:对质量浓度为0.2g/L的含铬(Ⅵ)模拟废水,当电流密度控制在1.5A/dm2,电解时间为1.5h,电解质NaCl质量浓度为1.0g/L及废水pH=9时,铬(Ⅵ)的去除率最高,达96.57%。在此基础上应用于处理实际镀铬废水,获得了满意的结果。同时,初步探讨了钛-铁双阳极电絮凝法除铬(Ⅵ)机理,得出氧化和絮凝作用,是废水中铬(Ⅵ)被有效去除的主要原因。

A new method of removing Cr（Ⅵ） from electroplating wastewater has been studied by using electro-coagulation with titanium-iron double anodes. The effects of influential factors,such as different anodic materials and their combination forms, current density, electrolyzing time, pH of the wastewater,conductance, placing time, etc. on the wastewater treatment efficiency of Cr（ Ⅵ ） have been studied in detail. The orthorhombic test,pole difference analysis and square difference analysis show that when the concentration of the simulated Cr（Ⅵ） containing wastewater is 0.2 g/L,the current density is controlled at 1.5 A/dm^2,electrolyzing time is 1.5 h, electrolyte NaCl concentration is 1.0 g/L and wastewatre pH is 9,the removal rate Cr（Ⅵ） is the highest,up to 96.57%. Based on these conditions,this method is applied to the treatment of Cr（ Ⅵ ） electroplating wastewater. Satisfactory results have been obtained. At the same time,the mechanism of removing Cr（ Ⅵ ） from electroplating wastewater by electro-coagulation with titanium-iron double anodes is discussed. The main reason of removing Cr（ Ⅵ ） from wastewater is that oxidation and are co-existence.