水中高压脉冲放电降解硝基苯废水研究

Investigation on the degradation of nitrobenzene by pulsed high voltage discharge in water

以工业废水中常见的难降解有机物硝基苯作为目标污染物,对高压脉冲放电降解高稳定性有机物效能进行了研究,并对试验参数进行了优化,同时采用G值评价了能量利用的效率.随着电压的升高、电极间距的降低和溶液电导率的降低,高压脉冲放电现象得到加强,硝基苯的降解速度得到提高.高压脉冲放电过程中生成的高氧化性物质被认为是降解硝基苯的主要原因.在放电电压为45 kV、电极间距为2.0 cm、溶液电导率为5μs/cm的情况下,放电60 min后,初始浓度为12.0 mg/L硝基苯的去除率为23.1%.对高压脉冲放电过程所消耗能量的评价表明,低放电电压、低放电间距和溶液的低电导率有利于提高能量的利用效率.试验中得到的优化条件为:放电电压25 kV,溶液电导率5.0μs/cm,放电间距2.0 cm.该优化条件下的G值为0.175.

Degradation of nitrobenzene by pulsed high voltage discharge in water using needle - plate electrodes was primarily investigated and energy efficiency was also evaluated at different discharge conditions.With the increase of applied voltage, decrease of discharge gap and conductivity of solution, nitrobenzene degradation rate increases. The nitrobenzene solution with initial concentration of 12 mg·L^-1 can reach a removal rate of 23. 1% after discharged 60 minutes with a gap of 2. 0 cm, an applied voltage of 45 kV and solution conductivity of 5.0 μs · cm^ - 1. Low voltage, low discharge gap and low conductivity are favorable for the energy efficiency of degradation. An optimum G value can reach 0. 175 with the discharge voltage of 25 kV, discharge gap of 2. 0 cm and the solution conductivity of 5.0 μs · cm^-1.