悬浮物对生活污水中总氮与氨氮浓度检测的影响

Study on the Effect of Suspended Solids on the Detection of Total Nitrogen and Ammonia Nitrogen Concentration in Domestic Sewage

关键词:  悬浮物  总氮  氨氮  标准方法  改进方法

Key words:  suspended solids  total nitrogen  ammonia nitrogen  standard method  improved method

摘要:

针对标准方法检测实际生活污水水样时经常会出现氨氮(NH₃-N)浓度大于总氮(TN)浓度的不合理现象，本研究探讨了生活污水水样中悬浮物(SS)浓度及过滤处理方式对检测结果的影响。结果表明，SS浓度与标准方法测定偏差呈正比，原水样和0.45 μm膜过滤处理的水样TN浓度测定结果与实际偏差高达11.1%，滤纸与0.45 μm膜过滤处理的水样NH₃-N浓度测定结果与实际偏差高达31.4%。此外，标准方法和改进方法的测定偏差与SS浓度的线性关系良好，经验校正方程的提出减少了SS带来的测定误差。因此，采用标准方法检测生活污水水样TN和NH₃-N浓度前建议使用0.45 μm滤膜过滤预处理，或采用本研究提出的经验校正方程进行校正，以提高标准方法检测的准确性。

Abstract:

In view of the unreasonable phenomenon that the concentration of ammonia nitrogen (NH₃-N) is often greater than the concentration of total nitrogen (TN) when the standard method is used to detect the actual domestic sewage water samples,the effects of suspended solids (SS) concentration and filtration treatment on the detection results of domestic sewage samples were studied in this study.The results showed that the concentration of SS was proportional to the determination deviation of the standard method.The deviation of TN concentration between raw water samples and water samples treated by 0.45 μm membrane filtration was as high as 11.1%.The deviation of NH₃-N concentration in water samples treated with filter paper and 0.45 μm membrane filtration was as high as 31.4%.In addition,the measurement deviation of the standard method and the improved method has a good linear relationship with the SS concentration,and the proposal of the empirical correction equation reduces the measurement error caused by SS.Therefore,before using the standard method to detect the TN and NH₃-N concentrations in domestic sewage water samples,it is recommended to use 0.45 μm filter membrane filtration pretreatment,or use the empirical correction equation proposed in this study to improve the detection accuracy of the standard method.