重庆市垃圾焚烧厂汞的分布特征与大气汞排放因子研究

Mercury Distribution Characteristics and Atmospheric Mercury Emission Factors of Typical Waste Incineration Plants in Chongqing

垃圾焚烧是大气汞的重要排放源之一.为了解重庆市垃圾焚烧行业大气汞污染水平,研究选取了重庆市典型生活垃圾焚烧厂和医疗垃圾焚烧厂,采用美国环保署的30B标准方法对烟气汞排放进行了现场测试,同时采集垃圾焚烧后的飞灰和炉渣样品进行分析.结果表明,测试得到生活垃圾焚烧厂和医疗垃圾焚烧厂排放的烟气中汞质量浓度分别为(26.4±22.7)μg·m-3和(3.1±0.8)μg·m-3;生活垃圾和医疗垃圾焚烧飞灰中汞含量分别为(5 279.2±798.0)μg·kg-1和(11 709.5±460.5)μg·kg-1.生活垃圾焚烧过程中仅0.7%汞残留在炉渣中,65.3%在飞灰中,烟气排放占34.0%,脱汞效率为66.0%;医疗垃圾焚烧过程中0.2%汞残留在炉渣中,67.5%存在飞灰中,烟气排放占32.3%,脱汞效率为67.7%.实测得到重庆市生活垃圾焚烧和医疗垃圾焚烧厂大气汞排放因子分别为(126.7±109.0)μg·kg-1和(46.5±12.0)μg·kg-1.与国内珠三角地区生活垃圾焚烧厂相比,重庆市生活垃圾焚烧厂的大气汞排放因子较低.

Waste incineration is one of the important atmospheric mercury emission sources. The aim of this article is to explore the atmospheric mercury pollution level of waste incineration industry from Chongqing. This study investigated the mercury emissions from a municipal solid waste incineration plant and a medical waste incineration plant in Chongqing. The exhaust gas samples in these two incineration plants were obtained using USA EPA 30 B method. The mercury concentrations in the fly ash and bottom ash samples were analyzed. The results indicated that the mercury concentrations of the municipal solid waste and medical waste incineration plant in Chongqing were（ 26. 4 ± 22. 7） μg·m- 3and（ 3. 1 ± 0. 8） μg·m- 3in exhaust gas respectively,（ 5 279. 2 ± 798. 0） μg·kg- 1and（ 11 709. 5 ± 460. 5） μg·kg- 1in fly ash respectively. Besides,the distribution proportions of the mercury content from municipal solid waste and medical waste in exhaust gas,fly ash,and bottom ash were 34. 0%,65. 3%,0. 7% and 32. 3%,67. 5%,0. 2%respectively; The mercury removal efficiencies of municipal solid waste and medical waste incineration plants were 66. 0% and67. 7%,respectively. The atmospheric mercury emission factors of municipal solid waste and medical waste incineration plants were（ 126. 7 ± 109. 0） μg·kg- 1and（ 46. 5 ± 12. 0） μg·kg- 1respectively. Compared with domestic municipal solid waste incineration plants in the Pearl River Delta region,the atmospheric mercury emission factor of municipal solid waste incineration plant in Chongqing was lower.