污染源废气中二噁英监测采样应注意的几个问题

解析废气中二噁英监测采样的现状及不足,针对生活垃圾焚烧炉(炉排炉)、蓄热式焚烧炉(RTO)和危险废物焚烧炉(回转窑)3种不同类型焚烧炉,考察了采样过程中烟道类型、采样时间和采样时间间隔不同对二噁英监测的影响。结果表明,在水平烟道和垂直烟道采样测得二噁英排放浓度水平相当,有垂直烟道时,优先在垂直烟道采样;间隔采样和连续采样二噁英测定结果基本一致,为了便于操作,建议均采用连续采样方式;采样时间上,生活垃圾焚烧炉应保证超过1 h,蓄热式焚烧炉以2 h左右为宜;间歇投料危险废物焚烧炉应尽量满足2 h以上,条件不许可时,可通过增加采样流量缩短采样时间保证采样量,并在危险废物完全燃烧前结束采样工作。

Problems Laid Emphasis on Sampling of Dioxin in Waste Gas

Based on the interpretation and practical operation of dioxin monitoring in domestic pollution sources of incineration enterprises, the currentdeficiency of dioxin monitoring and sampling is recognized in this paper. Different flues, sampling time and sampling period were studied in dioxin monitoring and sampling for three different types of incinerators respectively. The results showed that the concentrations of dioxin measured in the horizontal flue were quite the same as in vertical flue. Vertical flue should be preferred when there is a vertical flue; the results of interval sampling and continuous sampling of dioxin are basically the same, so the continuous sampling method is recommended to facilitate the operation. The sampling time of municipal solid waste incinerator should be guaranteed more than 1 h, and the sampling time of regenerative incinerator should be about 2 h; for the batch type hazardous waste incinerator, the sampling time should be sustained for more than 2 h,when the condition is not permitted, the sampling time can be shortened and the sampling amount can be guaranteed by increasing the sampling flow,the sampling process must be finished beforethe complete combustion of hazardous waste.