脉冲放电降解垃圾焚烧飞灰PAHs和二恶英的研究

Study on Simultaneous Decomposition of PAHs and Dioxins in Municipal Solid Waste Fly Ashes by Pulse Corona Discharge

焚烧炉处理城市垃圾后排放的粉尘中含有严重危害人类身体健康,甚至危害生命安全的有机污染物多环芳烃(PAHs)和二恶英。该文采用高压正脉冲电晕放电低温等离子体对垃圾焚烧炉布袋除尘器中飞灰进行处理,并对处理后飞灰的孔隙结构、微观表面形态及其PAHs和二恶英含量进行了观察分析。结果发现高压正脉冲电晕放电可以使颗粒表面产生物理脆性变化,从而改变其原有的孔隙结构。含量分析结果表明放电后粉尘中PAHs和二恶英含量明显降低,而且随着放电峰值电压升高,降解效率逐渐增加。随着粉尘中PAHs和二恶英初始浓度的增加,降解效率有所减小,峰值电压为30kV时对高浓度二恶英的降解效率为5%～15%,对低浓度二恶英的降解效率可以高达50%。随着放电时间的增加,PAHs的降解效率逐渐增加,放电时间3min对其降解效率可达80%。

The fly ashes emitted from municipal solid waste （MSW） burning consist of polycyclic aromatic hydrocarbons （PAils） and dioxins, which are dangerous to human health and even their life. The MSW fly ashes from baghouses were detoxified using non-thermal plasma generated by pulse corona discharge.After the decomposition, the analysis of the pore structure, the surface morphology and the compositions of PAHs and dioxins were made. The pore structure analysis shows that high-voltage pulse corona discharge effectively causes mechanical fracture of the samples, which resulted in the pore structure change. The composition analysis shows that the positive pulse corona discharge reduces the amount of PAHs and dioxins in the samples, while the decomposition efficiencies of PAils and dioxins increase with the increase of the peak voltage. With the increase of the initial concentrations of PAHs and dioxins in the samples, the decomposition efficiency decrease; with the peak voltage of 30kV, the decomposition efficiency is about 50% and 5%-15% for low and high concentrations, respectively. The decomposition efficiency of PAHs also increases as the pulse corona discharge time increases, which reaches up to 80% with the discharge time of 3min.