碱性过硫酸钾消解-离子色谱法测定印染废水中总氮含量

Determination of total nitrogen in dyeing effluents using alkaline potassium persulfate digestion-ion chromatography

采用国标HJ636-2012《水质总氮的测定碱性过硫酸钾消解紫外分光光度法》测定印染废水总氮含量时,发现含醇及醇瞇类无氨氮促染剂ST373和ST373A替代尿素用于活性染料印花,醇及醇醋类物质对总氮测试结果有干扰。为了规避其影响,研究了碱性过硫酸钾消解-离子色谱法测定活性染料印花废水总氮的可行性。通过对比碱性过硫酸钾消解-紫外分光光度法和碱性过硫酸钾消解-离子色谱法两种方法的测试结果发现,用碱性过硫酸钾消解后再采用离子色谱法测定废水中总氮含量,总氮校准曲线线性关系良好,线性相关系数r达0.9997,相对标准偏差小于5%,加标回收率在101%~108%之间。该方法的精密度和准确度满足要求,适用于印染废水中总氮含量的测定。

When standard HJ 636?012 is used to determine the total nitrogen in printing wastewater, the alcohol and glycol ethers within non ammonia and nitrogen accelerants ST373 and ST373A are found to have in terfere nee in ultraviolet absorbency. To avoid this influe nee, the feasibility of determi nation of total nitrogen in reactive dye printing wastewater with alkaline potassium persulfate digestion-ion chromatography is explored. The results show that the calibration curve of total nitrogen has a good linear re-lati on ship using alkaline potassium persulfate digestion and ion chromatography method. The lin ear correlation coefficient r is 0.9997, the relative standard deviation is less than 5%, and the recovery of standard addition is 101%-108%. The precision and accuracy of the method can meet the requirements and can be applied to the determination of total nitrogen in printing wastewater.