工业废水中总氮测定主要误差消除方法的探究

An Investigation on How to Eliminate the Main Deviation in the Determination of Total Nitrogen in the Industrial Wastewater

工业废水中污染物成分复杂,采用过硫酸钾蒸汽消解紫外比色法测定总氮受影响因素多,实验结果误差大。采用过硫酸钾微波消解的方法可以提高实验成功率和稳定性,消除了由于蒸汽压力、碱性腐蚀等导致的漏气现象;当消解体积增大至25 mL和消解时间为30 min时可以提高测量结果的准确度。消解后利用气相分子吸收光谱仪测定,稳定性和准确度均比紫外比色法有所提高,同时避免了有机物和浑浊度对吸光度的影响。

Because of the c omplicated ingredients in industrial wastewater pollutants, the determination of total nitrogen was affected by a multitude of factors when using the potassium persulfate steam digestion-UV colorimetric method. Potassium sulfate microwave digestion method could improve the experimental success rate and stability, eliminate the gas leak caused by the steam pressure and the alkaline corrosion; when the digestion volume increased to 25 mL and digestion time was 30 min, the accuracy of the results was improved. After digestion, the sample was determined by gas phase molecular absorption spectrometer, which improved the stability and accuracy, and the influences of organic matter on absorbance and turbidity were avoided.