粉煤灰中残留氨检测方法的影响因素分析

Methods of Measuring Residual Ammonia in Fly Ash:Influence Factors and Comparison

为了准确地检测出粉煤灰中残留的氨含量,分析了纳氏分光光度法、中和滴定法和氨气敏电极法检测粉煤灰中残留氨含量的主要影响因素,探讨了这3种检测方法的主要影响因素的最佳值选取,研究了3种方法结果的相关性。结果表明:影响纳氏分光光度法的主要因素为浸提剂、浸提固液比和浸提时间,最佳值选取分别为0.05 mol/L H 2 SO 4、1∶10和30 min;影响中和滴定法的主要因素为吸收溶液、氢氧化钠加入量和蒸馏时间,最佳值选取分别为0.05 mol/L H 2 SO 4、0.2 g和30 min;影响氨气敏电极法的主要因素为提取液和搅拌时间,最佳值选取分别为去离子水和[10,25]min。同时,这3种方法检测结果的相关性较好。研究成果探究了适用于有效定量检测粉煤灰中残留氨的方法,为控制和限定粉煤灰中残留氨提供检测基础。

The residual ammonia in fly ash was measured by Nessler’s reagent spectrophotometry method,neutralization titration method,and ammonia-sensitive electrode method respectively in this paper.The main influence factors and their values were determined and the correlation among results of these three methods were investigated in detail.Results showed that the main influence factors of Nessler’s reagent spectrophotometry method were extraction solvent(best as 0.05 mol/L H 2 SO 4),liquid ratio(optimum as 1∶10),and extraction time(optimum as 30 min);the main influence factors of neutralization titration method were absorption solution(best as 0.05mol/L H 2 SO 4),sodium hydroxide content(optimum as 0.2 g)and distillation time(optimum as 30 min);the main influence factors of ammonia-sensitive electrode method were extracting solution(best as deionized water)and stirring time(optimum as[10,25]min).In addition,the results of the three methods are of good correlation.