周期换向电凝聚法处理活性嫩黄X-6G模拟染料废水研究

STUDY ON TREATMENT OF SYNTHESIZED REACTIVE BRILLIANT YELLOW X-6G WASTEWATER BY PERIODICAL REVERSE ELECTRO-COAGULATION

分别采用铝和铁板作为两极,通过周期性改变电流方向使电极钝化和极化现象得以减缓或消失,并实现两极均可溶,利用铝、铁系无机絮凝剂共存时可提高处理效果的特点,对活性嫩黄X-6G模拟染料废水进行处理;通过单因素条件实验,获得了该方法的最佳处理条件。利用紫外-可见光分光光度法和飞行质谱等手段对废水处理过程的脱色反应机理进行了分析。研究表明:最佳条件下,采用周期换向电凝聚法处理活性嫩黄X-6G模拟染料废水30 min,可使模拟废水脱色率达到98%以上,COD去除率可达77%以上;处理过程中除大部分染料分子直接被电凝聚气浮或沉降导致脱色外,部分活性嫩黄X-6G染料分子在电解作用下首先断裂成不同结构的中间体,含有双键的中间体再发生加氢或氧化反应,使双键结构遭到破坏而脱色。

Passivation and polarization of electrode surfaces reduce the wastewater treatment efficiency when traditional electrocoagulation method was used with Al or Fe electrodes. In this article,periodical reverse electro-coagulation with Al / Fe electrodes method was applied to treat the synthesized dye wastewater with reactive brilliant yellow X-6G in order to avoid passivation and polarization. Based on the co-existence characteristics of iron and aluminium series flocculating agents,this method can improve the efficiency of decolorization and COD removal rate when periodically reverse current was supplied. The optimum parameters were obtained after single condition experiments. Then the treatment process was characterized using ultraviolet spectrophotometry and TOF spectrometer techniques to analyze the removal mechanism. Almost 98% decolorization rate and more than 77% COD removal rate were obtained after 30 min treatment under the optimal conditions. The results showed that part of reactive light yellow X-6G molecules was broken into different intermediates with double bond after most of the dye molecules removal by electrocoagulation and electric floating,then most of these double bond was changed and decolored by oxidization or hydrogen reduction.