盐酸萘乙二胺分光光度法测定硝酸生产尾气中氮氧化物的误差分析与校正

ERROR ANALYSIS AND CALIBRATION IN DETERMINING NITROGEN OXIDE CONTENT IN NITRIC ACID TAIL GAS BYN(1-NAPHTY1)-ETHYLENEDIAMINEDIHYDROCHLORIDE SPECTROPHOTOMETRIC METHOD

硝酸生产尾气中氮氧化物监测分析方法有HJ/T 43—1999《固定污染源排气中氮氧化物的测定盐酸萘乙二胺分光光度法》和《空气和废气监测分析方法》(第4版)定电位电解法。上级环保部门定期督查采用定电位电解法,四川泸天化股份有限公司氮氧化物监测采用HJ/T 43—1999标准,两种方法测定结果存在较大差异。对光度法可能产生误差的原因进行分析,同时分别采用光度法与电解法进行对比试验,光度法测定结果单向偏低。进一步将两种方法分析数据进行统计对比分析,测定结果之间呈极强正相关,根据相关性建立了光度校正法测定尾气氮氧化物浓度,该法与电解法测定结果无显著性差异,能确保硝酸生产尾气氮氧化物达标排放。

Nitrogen oxide content in the tail gas of nitric acid production is supervised and analyzed by the standard of JH/T 43—1999 Determination of Nitrogen Oxide Content in the Emission from Stationary Pollution Source-N（1-Naphty1）-Ethylenediamine Dihydrochloride Spectrophotometric Method,and constant potentiometric electrolysis in Air and Waste Gas Supervision and Analysis Method（Rev.4）.The administration of environment protection supervises the nitrogen oxide emission by constant potentiometric electrolysis method periodically.Our company adopts the standard of JH/T 43—1999,however the results from two different methods come to big discrepancy.Errors that might happen in spectrophotometry were analyzed,and comparative test by spectrophotometry and electrolysis was taken respectively at the same time.The result shows that spectrophotometry tend to low value unidirectionally.Further analysis of two kinds of method by statistics shows that the results demonstrate strong positive correlation.According to the correlation,the spectrophotometry calibration method was built up to determine the content of nitrogen oxide,the results come to no significant difference from electrolysis,and can meet the requirement in the standard of nitrogen oxide emission.