炼焦过程及周边环境颗粒物中水溶性无机离子特征

Characterization of Water-Soluble Inorganic Ions in Particles from Coking Process and the Plant Area

为明确炼焦过程排放颗粒物及周边环境颗粒物中水溶性无机离子的污染特征,于2012年5月利用改良的标准大体积总悬浮颗粒采样器采集燃烧室废气烟囱排放、焦炉顶无组织排放及焦炉周边环境空气TSP(total suspended particulates,总悬浮颗粒物)样品,使用Staplex234大流量采样器采集焦炉顶无组织排放及焦炉周边环境空气PM 1.4样品,采用ICS-90离子色谱仪测试样品中SO4^2-、NH4^+、Ca ^2+、Cl^-、NO3^-、F^-、Mg^2+、K^+、Na^+共9种水溶性无机离子.结果表明:SO4^2-为炼焦过程排放的特征离子.炼焦过程燃烧室废气烟囱排放的TSP中总水溶性无机离子质量浓度最高,为(5493±901)μg m^3;其次为焦炉顶无组织排放的TSP,其总水溶性无机离子质量浓度为(902±222)μg m^3;焦炉周边环境空气的TSP中总水溶性无机离子质量浓度最低,为(712±288)μg m^3.SO 4^2-为燃烧室废气烟囱排放TSP与燃煤锅炉烟气排放颗粒物中共有的主要特征离子,但与燃煤锅炉烟气相比,燃烧室废气烟囱排放的w(SO4^2-)略低,w(F^-)则相反.NH 4+较易富集于焦炉顶无组织排放的细颗粒物中,而SO4^2-则较易富集于粗颗粒物中.研究显示,炼焦过程及焦炉周边环境空气颗粒物中9种水溶性无机离子分布特征不同,SO 4^2-是燃烧室废气烟囱排放、焦炉顶无组织排放的TSP中质量浓度最高的水溶性无机离子.

In order to investigate the characteristics of water-soluble inorganic ions in the particles from coking process and in the plant area,the total suspended particulates(TSP)from combustion chamber exhaust chimney,the coke oven top as well as the ambient air surrounding the coke oven were collected using high-volume total suspended particulate samplers(TH-1000F,China).The PM 1.4 samples from the coke oven top and the ambient air surrounding the coke oven were also collected using Staplex234 cascade impactor in May 2012.Nine ions(SO4^2-,NH4^+,Ca^2+,Cl^-,NO3^-,F^-,Mg^2+,K^+,Na^+)in the samples were analyzed by ICS-90 ion chromatograph.The results showed that SO4^2-was the characteristic water-soluble ion during coking process.The total concentration of water-soluble inorganic ions in TSP was the highest in the exhaust gas of the combustion chamber,which was(5493±901)μg m^3,followed by TSP on the coke oven top,which was(902±222)μg m^3,and TSP in the ambient air surrounding the coke oven was the lowest,which was(712±288)μg m^3.SO4^2-was the main common ion in the particles from coke oven combustion chamber exhaust,coal-fired boiler flue gas and coal-fired power plant flue gas.The ratio of SO4^2-to total inorganic ions from the coke oven combustion chamber exhaust was higher than that from the flue gas of coal-fired boiler,while the opposite was true for F^-.NH 4^+tended to concentrate in fine particles,while SO4^2-was concentrated in coarse particles from fugitive emissions on the coke oven top.The study showed that the distribution characteristics of water-soluble inorganic ions in the particles from the coking process and in the ambient air surrounding coke oven were different.SO4^2-was the water soluble ion with the highest mass concentration in TSP from the exhaust gas chimney of combustion chamber as well as the coke oven top.