滑动弧等离子体降解印染废水的影响研究

在电压为10kV,载气为O2,气体流速为0.4m3/h,废水流量为20mL/min,电极为不锈钢材料,电极间最窄距离处为3.5mm的条件下,采用气液滑动弧等离子体降解印染废水。结果表明:印染废水pH值为偏碱性和碱性时,CO32-分别主要以HCO3-、CO32-的形式存在,使COD的去除率降低,20min后,其值分别为76.42%和64.36%;pH值呈强酸性时,CO32-主要以H2CO3和CO2的形式存在,对COD的去除率不产生影响,20min后,其值达到92%。印染废水pH值为偏碱性和碱性时,HCO3-和CO32-的存在消耗了等离子体放电产生的羟基自由基。pH=3时,研究了印染废水的COD和TOC的降解动力学,降解符合一级动力学规律,其速率方程分别为ln(COD0/COD)=0.13090t,ln(TOC0/TOC)=0.06395t。印染废水的紫外光谱和红外光谱表明,废水中的发色基团被破坏,溶液脱色,吸收峰降低或消失表明废水中芳香环降解。

Degradation of Dyeing Wastewater by Gas-liquid Gliding Arc Discharge

Under the condition of applied voltage 10kV,O2 as carrier gas,gas flow rate fixed at 0.4m3/h,wastewater flow rate 20mL/min,shortest electrode distance 3.5mm,dyeing wastewater was degraded by gas-liquid gliding arc discharge.Experimental results showed that pH of dyeing wastewater was alkaline and subalkalic,HCO3-and CO32-formed in solution mainly,resulting in decreasing COD removal rate.When pH was strong acidic,H2CO3 and CO2 existed in the solution,and the removal rate of COD did not have an impact.HCO3-and CO32-reacted with hydroxyl radical generated by plasma discharge.Without regard to the effect of CO32-,when pH was 3,degradation kinetics of COD and TOC were 0.13090t and 0.06395t separately,and results showed that the kinetics of degradation followed the first order law.Ultraviolet visible(UV-Vis) spectrum and infrared spectroscopy(FTIR) of dyeing wastewater showed that chromophore group was damaged,solution was decolorized,and the reduction or disappearance of absorption peaks indicated the aromatic ring of wastewater was degraded.