低温等离子体处理次甲基蓝染料废水实验

Degradation of Methylene Blue Dye Wastewater by Low-temperature Plasma

为了研究介质阻挡放电产生的低温等离子体对次甲基蓝(C16H18ClN3S.3H2O)染料废水的脱色效果和机理,反应器采用中心进水、周边出水的辐流式沉淀池结构。实验研究了不同初始浓度、不同放电功率及外界因素如Fe2+、Na2CO3等对次甲基蓝染料废水降解效果的影响。结果表明,低温等离子体对次甲基蓝染料有着较好的处理效果。提高放电功率能够有效地提高次甲基蓝的降解率,考虑到电极和能量损耗,介质阻挡放电最佳条件:放电功率150 W,初始浓度50 mg/L,降解处理120 min时,次甲基蓝脱色率达到98%以上;加入10 mg/L Fe2+,80 min时,次甲基蓝染料的脱色率达到98%,但是当添加量过高时,会在一定程度上抑制其降解;添加Na2CO3作为自由基俘获剂则抑制了次甲基蓝染料的降解,表明.OH是反应过程中降解次甲基蓝的主要活性物质。

In order to stu（ly the new technoh）gy of plasma on wastewater treatment, the degradation l）ehavior of methylene Hue dye wastewater was investigated in the low-temperature plasma formed during the dielectric barrier discharge （DBI）） process. The reactor was the radial flow sedimentation tank structure which was centered on the water inlet. The different initial concentrations, different input powers and the effects of different external factors, such as Fe , N a,CO） on methylene ue dye wastewater degradation were studied. The results showed that methylene blue dye ctht be effe＇tiw, ly removed from aqueous solution by the low-temperature plasma. Increasing the input power could in＇rease the degradation efficiency. Cunsidering the service life of electrode and energy consumption, 50 nag/I, methylene Ilue and input power of 150 V were chosen as the optimum conditions, in which the decoloratlon rate was up to 98c/： at 120 rain discharge time; when Fez＋ concentration was 10 nag/L, the decnloration rate was 98% at 80 rain, however, they hindered the degradation at higher oncentrations; The presence of Na2COas hydroxide radical scavenger decreased the decoloralion efficiency to some extent, which showed that hydroxyl radicals played an important role in the degradation process.