碘量法测定烟气中二氧化硫的影响因素探讨

Study on the Influence Factors of the Determination of Sulfur Dioxide in Flue Gas by Iodometry

结合烟气中二氧化硫含量测量的影响因素，讨论吸收温度、采样量及淀粉滴加时间对测量结果的影响，得出碘量法对固定污染源中二氧化硫的含量进行测定时，吸收温度对烟气的吸收率产生较大影响，吸收温度控制在O-10℃，保证吸收率大于90％；二氧化硫吸收速率控制在300～500mL／min。太快造成吸收时气液接触时间短，吸收效果差；太慢则会造成吸收时间长二氧化硫吸收液对测定结果有影响：滴定过程中，应在快临近滴定终点时再滴加淀粉指示剂。

The effects of absorption temperature, sampling amount and starch dropping time on the measurement of the concentration of sulfur dioxide in flue gas are studied. The results show that for the determination of sulfur dioxide content in stationary pollution sources, and the absorption temperature of the iodometry is of great influence on the absorption rate of flue gas, the absorption tem- perature should be controlled in 0 - 10 %, which can ensure the absorption rate of flue gas more than 90%; the sulfur dioxide ab- sorption rate should be controlled in 300 - 500 mL/min, too high absorption rate will lead to poor absorption effect due to the short contact time of vapor with liquid, and too slow absorption rate will cause the influence of absorption liquid on the determination result due to the long contact time of vapor with liquid; dropping starch indicator should be at near end point of titration.