作　　者： ; ; ; ;

机构地区： 浙江大学机械与能源工程学院热能工程研究所

出　　处： 《环境科学》 2012年第11期3999-4005,共7页

摘　　要： 以医疗垃圾焚烧炉布袋除尘器前管道内飞灰(BG)及布袋除尘器后飞灰(AG)为对象,研究不同温度及时间段下其在管式炉中的热脱附特性.结果表明,在低温氮气气氛下,热脱附作用较为明显,2种飞灰中的二噁英都有了不同程度的脱除,其中布袋前飞灰中二噁英的脱除率为82.9%～99.9%之间,毒性当量脱除率为77.3%～99.8%,布袋后飞灰中二噁英的脱除率为66.8%～99.8%之间,毒性当量脱除率为43.5%～99.6%.检测收集到的实验尾气,发现了二噁英的存在,且在300～350℃这个温度段生成量最多,且生成的有毒二噁英同系物中以OCDD为主.通过比较发现,当温度为400℃,加热时间为45 min时2种飞灰中的二噁英脱除效率最高.鉴于惰性气氛下的热脱附对处理飞灰中的二噁英具有较好的作用,可将其大规模应用于实际工程中. Two kinds of fly ash（AG and BG） from hazardous waste rotary kiln were investigated as the targets of thermal treatment.AG was sampled after fabric filter with activated carbon spray and BG was sampled in pipe before fabric filter.The effects of temperature and time on PCDD/Fs degradation rate in fly ash were investigated in quartz tubular.Under nitrogen atmosphere,low-temperature thermal treatment for dioxin degradation had obvious effect.For sample BG,the degradation rate of dioxin in solid phase was 82.8%-99.9%,and the degradation rate of I-TEQ was 77.3%-99.8%.For sample AG,the degradation rate was 66.8%-99.8%,and the degradation rate of I-TEQ was 43.5%-99.6%.Although dioxin in solid phase was reduced,it was generated in gas phase,and among all the different temperatures tested,dioxin was generated at highest amounts at 300℃-350℃,and among all the toxic congeners,OCDD was detected as the most abundant in this experiment.The best conditions of thermal treatment were： heating time 60 min,temperature 400℃,under nitrogen atmosphere.The results indicate that low-temperature thermal treatment under inert atmosphere has good effect on treating dioxin present in medical fly ash,it can be applied in practical projects in large scales.

关 键 词： 医疗垃圾飞灰 二噁英 低温热脱附 脱除率 气氛

领　　域： [环境科学与工程]