辉光放电等离子体处理阳离子染料结晶紫废水

用辉光放电等离子体技术对结晶紫进行了降解脱色处理,考察了多种因素对结晶紫降解效果的影响。实验发现,提高电解质浓度和增加电压均可提高结晶紫的脱色效果,考虑到电极损耗,辉光放电最佳条件为:电解质浓度为2 g/L Na2SO4,电压为600 V。当改变溶液的初始pH值时,结晶紫的脱色率随溶液的初始pH值升高而增加,加入一定量H2O2能明显地提高结晶紫的脱色效率;若加入0.4 mmol/L Fe2 ,5 min时结晶紫的脱色率由原来的13.64%增加到91.36%。结果表明,辉光放电产生的.OH对结晶紫的降解起重要作用。最佳条件下,40 min内的脱色率达到93%,降解率为74%。

Degradation of Cationic Dye Crystal Violet In Wastewater using Glow Discharge Plasma

The plasma degradation of crystal violet by glow discharge electrolysis is presented.The factors for the degradation and/or decoloration processes were studied.The decoloration efficiency of crystal violet could be increased considerably by increasing electrolyte concentration and voltage applied.After considering the service life of the Pt electrode used,an electrolyte concentration of 2 g/L Na2SO4 and an applied voltage of 600 V were chosen as the optimum experimental conditions.Increasing the initial pH of the solution could accelerate the decoloration of crystal violet.Addition of H2O2 can increase the rate of decoloration,too.Furthermore,the presence of 0.4 mmol/L Fe2 can improve the decoloration rate of crystal violet from 13.64% to 91.36% within 5 minutes.The addition of a radical scavenger n-butanol decreases the decoloration efficiency of crystal violet,which shows that hydroxyl radicals play an important role in the degradation process.Based on ultraviolet(UV) absorption spectra obtained during the degradation process,more than 93% crystal violet was decolorized,and 74% crystal violet was degraded after oxidation for 40 minutes.The possible degradation pathway for crystal violet is proposed.The results show that the combination of glow discharge plasma,H2O2 and/or Fe2 can accelerate the degradation of crystal violet considerably.