医疗垃圾焚烧过程中重金属污染物分布特征研究

Distribution Characteristics of Heavy Metal Pollution during Medical Waste Incineration

分别选取回转窑窑尾、布袋除尘器灰斗、洗涤塔塔底和烟囱口采集炉渣、飞灰、淋洗液和烟气样品,探究医疗垃圾焚烧时重金属污染物在整个回转窑焚烧系统中的空间分布特征。结果显示:医疗垃圾样品中Zn占36%、Fe占29%、Pb占19%、Cd占10%、Cu占4%、Mn占2%。炉渣、飞灰、淋洗液和烟气中重金属含量分布差异较大,分别占总量的10%、60%、30%、不到万分之一。像Cd、Zn、Pb和Cu等低沸点重金属随着烟气在焚烧系统中的迁移,其分布规律基本相同,主要集中在飞灰中;而对Fe这类熔沸点相对较高的重金属来说,在炉渣、飞灰和淋洗液中的分布相对比较平均,其中淋洗液中Fe的含量最高。

The end of rotary kiln,ash bucket of bag filter,bottom of scrubbing tower,and stack nozzle were selected to sample slag,fly ash,eluent and flue gas.The spatial distribution characteristics of heavy metal pollutants during medical waste incineration in rotary kiln were explored.The results showed that Zn,Fe,Pb,Cd,Cu,Mn accounted for 36%,29%,19%,10%,4%,and 2% respectively in medical waste samples.Distribution of heavy metals that in slag,fly ash,eluent and flue gas were greatly different,respectively accounted for about 10%,60%,30% of the total,and the heavy metal content in flue gas was less than 1/10 000.The heavy metals,like Cd,Zn,Pb and Cu with low boiling point,had the same distribution law and mainly concentrated in fly ash.While Fe with relatively high boiling point and melting point distributed averagely in slag,fly ash and eluent,and the content of Fe in eluent was the highest.