固定源排放 烟气中汞物种取样和测定的化学吸收法

[中文适用范围]： 本文件描述了一种用于通过烟道或烟囱排放的气体中采样和测定汞物种的方法。汞通常以气态元素、气态氧化物和颗粒结合形式存在。该方法适用于烟道气中气态元素汞（Hg^0）、气态氧化汞（Hg^{2+}）、颗粒结合汞（Hg^P）和总汞（Hg^T）的采样和测定。本方法适用于粉尘含量较高的场所，包括除尘装置上游、飞灰负荷高达120 g/m³的烟道气位置。当采样体积为0.5 m³（在干燥状态下修正到标准条件时），该方法适用于二氧化硫浓度不超过0.25%的位置。检出限和测定下限取决于仪器检测限、试剂空白、现场空白、测量技术以及所采集气体体积。当采样体积为1.5 m³（在干燥状态下修正到标准条件时），预计的Hg^0、Hg^{2+}和Hg^T的检出限分别为0.103 μg/m³、0.011 μg/m³和0.935 μg/m³，测定下限分别为9.029 μg/m³、0.625 μg/m³、0.802 μg/m³和2.0623 μg/m³。 [外文原描述]： This document describes a method for the sampling and determining mercury species in flue gas passing through ducts or chimney stacks. Mercury generally exists in gaseous elemental form, gaseous oxidized form and particulate-bound form. This method applies to the sampling and determination of gaseous elemental mercury (Hg 0 ), gaseous oxidized mercury (Hg 2+ ), particulate-bound mercury (Hg P ) and total mercury (Hg T ) in the flue gas from stationary sources. This method is suitable at locations with high dust content, including locations upstream of the dust removal device with high particulate loadings in flue gas up to 120 g/m 3 . This method is applicable to locations with sulfur dioxide (SO 2 ) concentration up to 0,25 % when the sampling volume is 0,5 m 3 (on a dry basis as corrected to standard conditions). The limit of detection and the limit of determination depend on the instrumental limit of detection, reagent blank, field blank, measurement technique and volume of sampled gas. When the sampling volume is 1,5 m 3 (on a dry basis as corrected to standard conditions), the expected limits of detection for Hg 0 , Hg P , Hg 2+ and Hg T are 0,103 μg/m 3 , 0,011 μg/m 3 , 0,035 μg/m 3 and 0,127 μg/m 3 , respectively. The expected limits of determination for Hg 0 , Hg P , Hg 2+ and Hg T are 0,229 μg/m 3 , 0,025 μg/m 3 , 0,082 μg/m 3 and 0,263 μg/m 3 , respectively.