臭氧与超声耦合提高垃圾渗滤液的降解效率

Coupling of Ozone and Ultrasound to Improve the DegradationEfficiency of Landfill Leachate

分别采用单独臭氧(O_(3))、单独超声(US)和臭氧与超声耦合(O_(3)&US)的方法对垃圾渗滤液进行降解,考察垃圾渗滤液浓度、酸碱环境、电导率、阴阳离子对方法O_(3)&US降解垃圾渗滤液的影响。结果表明:相同条件下,方法O_(3)&US对垃圾渗滤液的降解能力高于方法O_(3)和方法US。随垃圾渗滤液浓度的增大,方法O_(3)&US的降解效果呈现趋势是先增强后降低。在垃圾渗滤液初始COD为300 mg/L时,方法O_(3)&US降解效果最优,其COD、氨氮、总氮去除率分别是46.8%、38.8%、44.3%。碱性条件能提高方法O_(3)&US降解能力,酸性条件则会起抑制作用。垃圾渗滤液电导率提高,方法O_(3)&US对垃圾渗滤液降解能力降低。阴离子HCO_(3)^-和CO_(3)^(2-)会抑制方法O_(3)&US中羟基自由基的生产,降低降解能力,且CO_(3)^(2-)的抑制作用大于HCO_(3)^-的。

Ozone alone(O3),ultrasound alone(US)and ozone combined with ultrasound(O3&US)were used to degrade landfill leachate respectively.The effects of landfill leachate concentration,acid-base environment,electrical conductivity,cation and anion on the degradation of landfill leachate by O3&US were investigated.Experimental results indicated that under the same conditions,the degradation ability of O3&US was higher than that of O3 and US.With the increase of landfill leachate concentration,the degradation effect of O3&US showed a trend,which was increase ascended at first and descended.When the initial COD of landfill leachate was 300 mg/L,the degradation effect of O3&US was the best,and the removal rates of COD,ammonia nitrogen and total nitrogen were 46.8%,38.8%and 44.3%respectively.While basic condition can improve the degradation ability of O3&US,acidic condition can inhibit it.With the increase of electrical conductivity of landfill leachate,the ability of O3&US to degrade landfill leachate is reduced.Bicarbonate and carbonate can inhibit the production of hydroxyl radicals in O3&US,thus reducing the degradation ability of O3&US,and the inhibition effect of carbonate is greater than that of bicarbonate.