逆向涡流等离子体降解飞灰中二恶英的研究

Removal of PCDD/Fs from fly ash using reverse vortex plasma

利用氮气逆向涡流非平衡等离子体反应器,进行医疗垃圾焚烧飞灰中二恶英的降解.考察氮气逆向涡流非平衡等离子体放电特性,从而获得反应器稳定的工作条件.在实验过程中分别测量处理后飞灰中和尾气中的二恶英质量分数,分析利用氮气逆向涡流非平衡等离子体反应器降解飞灰中二恶英的效果,初步探索二恶英的降解机理.结果表明,切向进气体积流量是影响放电电弧特性的关键因素,增大切向进气体积流量,可以提高电弧放电的稳定性;逆向涡流等离子体对飞灰中二恶英有明确的降解作用,单位质量飞灰中PCDD/Fs总质量的平均降解率为49.6%,总毒性当量I-TEQ平均降解率为62.3%,飞灰中PCDFs比PCDDs更容易降解.

The plasma-induced destruction of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans（PCDD/Fs） in medical waste incinerator fly ash was analyzed using a nitrogen reverse vortex non-equilibrium plasma reactor.The characteristics of the nitrogen reverse vortex discharge were analyzed in order to obtain a stable working condition.The mass fractions of PCDD/Fs in the flue gas and treated fly ash were measured and the degradation efficiency of PCDD/Fs was investigated.The destruction process of dioxin in medical waste incineration fly ash was studied.Results showed that the stability of discharge was depended on the tangential gas flow rate into the reactor,and it can be improved by increasing tangential gas flow rate.The discharge characteristics can be optimized with adding axial gas flow into the reactor.The dioxin contained in fly ash was destructed effectively by the reverse vortex discharge.The average decomposition efficiency of dioxin based on total mass fraction and I-TEQ concentration was achieved up to 49.6% and 62.3%,respectively.The PCDFs were more easily decomposed than the PCDDs in the plasma reactor.