Boylan Helen M, Cain Randy D, Kingston H M
Department of Chemistry, Westminster College, New Wilmington, Pennsylvania 16172, USA.
J Air Waste Manag Assoc. 2003 Nov;53(11):1318-25. doi: 10.1080/10473289.2003.10466300.
U.S. Environmental Protection Agency (EPA) Method 7473 for the analysis of mercury (Hg) by thermal decomposition, amalgamation, and atomic absorption spectroscopy has proved successful for use in Hg assessment at coal-fired power stations. In an analysis time of approximately 5 min per sample, this instrumental methodology can directly analyze total Hg--with no discrete sample preparation--in the solid matrices associated with a coal-fired power plant, including coal, fly ash, bottom ash, and flue gas desulfurization (FGD) material. This analysis technique was used to investigate Hg capture by coal combustion byproducts (CCBs) in three different coal-fired power plant configurations. Hg capture and associated emissions were estimated by partial mass balance. The station equipped with an FGD system demonstrated 68% capture on FGD material and an emissions estimate of 18% (11 kg/yr) of total Hg input. The power plant equipped with low oxides of nitrogen burners and an electrostatic precipitator (ESP) retained 43% on the fly ash and emitted 57% (51 kg/yr). The station equipped with conventional burners and an ESP retained less than 1% on the fly ash, emitting an estimated 99% (88 kg/yr) of Hg. Estimated Hg emissions demonstrate good agreement with EPA data for the power stations investigated.
美国环境保护局（EPA）的方法7473，即通过热分解、汞齐化和原子吸收光谱法分析汞（Hg），已被证明成功用于燃煤发电站的汞评估。每个样品的分析时间约为5分钟，这种仪器方法可以直接分析总汞——无需进行离散的样品制备——在与燃煤发电厂相关的固体基质中，包括煤、飞灰、底灰和烟气脱硫（FGD）材料。该分析技术用于研究三种不同燃煤电厂配置中煤燃烧副产品（CCB）对汞的捕获情况。通过部分质量平衡估算汞的捕获量和相关排放量。配备FGD系统的电站在FGD材料上的捕获率为68%，总汞输入量的排放量估计为18%（11千克/年）。配备低氮氧化物燃烧器和静电除尘器（ESP）的发电厂在飞灰上保留了43%，排放了57%（51千克/年）。配备传统燃烧器和ESP的电站在飞灰上的保留率不到1%，估计汞排放量为99%（88千克/年）。所调查电站的汞排放估计值与EPA数据显示出良好的一致性。
