Abstract: A method combined non-thermal plasma and blow-off was employed to wipe out of stench from landfill leachate.A new type of high pulse voltage source with Blumlein pulse forming network(BPFN)was adopted,and all experiments were conducted at a fixed pulse frequency of 100 Hz.The influences of important factors,such as gas flow rate,peak voltage and humidity,on removal efficiency of odors were studied.The results showed that the combined method could wipe efficiently out of stench from landfill leachate.Ammonia was taken as the experimental object since it was the main component of odors from landfill leachate.Higher peak voltages could promote removal efficiency of ammonia while larger flow rates reduced it.The removal efficiency of ammonia in plasma reactor could reach 92.5% after continuous operating 10 min at conditions of:ammonia concentration 520 mg穖^-3,peak voltage 37 kV and flow rate 1000 ml穖in^-1.A dynamic model was developed to describe quantitatively the relation between ammonia and energy density and initial concentration.A certain level of humidity in flow gas could enhance oxidation of malodorous gas such as ammonia.In plasma chemistry process,ammonia was removed by direct decomposition by high energy electrons or by reaction with intermediates to form NH₄NO₂ and NH₄NO₃.

Key words: dielectric barrier discharge, blow-off, landfill leachate, ammonia, reaction mechanism

摘要： 采用吹脱结合低温等离子体综合技术对垃圾渗滤液进行脱臭处理,考察了吹脱气量、峰值电压、湿度等因素对恶臭效果的影响。实验采用BPFN(Blumlein pulse forming network)型窄脉冲高压电源供电,脉冲频率采用100 Hz。结果表明,吹脱法结合低温等离子体技术可以有效去除渗滤液恶臭。以吹脱气中主要恶臭成分NH₃为实验对象,NH₃去除率随着等离子体反应器中峰值电压增大而提高,随着吹脱气量的增大而降低。当吹脱气量为1000 ml·min^-1、峰值电压为37 kV、吹脱时间为10 min时,吹脱气中NH₃浓度为520 mg·m^-3,出气中NH₃去除率可达92.5%。NH₃去除率和能量密度、初始浓度的关系通过动力学模型进行定量描述。吹脱气中含有一定湿度,可促进NH₃等恶臭气体氧化分解。在等离子体化学反应过程中,NH₃主要通过高能电子直接分解和与中间产物反应生成NH₄NO₂、NH₄NO₃而被去除。

关键词: 介质阻挡放电, 吹脱, 垃圾渗滤液, 氨气, 反应机理