氯胺对电化学法测量自来水中余氯的影响

摘要

自制高锰酸钾溶液、磷酸盐溶液和N,N-二乙基-1,4-苯二胺硫酸盐(DPD)溶液分别作为余氯标准液、缓冲液和显色剂,以分光光度法测试结果为余氯值标准,通过余氯仪检测饮用水中的余氯含量.比较传感器分别为隔膜式与恒电压型两种电化学在线余氯仪的测量结果,对检测中的主要影响因素氯胺进行研究.结果表明:水中无氯胺时,两种电化学法都能准确地测定水中余氯含量;存在氯胺时,恒电压型余氯仪的最大相对误差是隔膜式余氯仪的5倍.%Homemade potassium permanganate solution, phosphate solution and N, N-diethyl-1, 4-phenylenediamine sulfate (DPD) solution as residual chlorine standard solution, buffer solution and color reagent respectively, and test results from spectrophotometric method as the residual chlorine standard value, the residual chlorine analyzer is used for measuring residual chlorine content in drinking water.Comparison of the results from both of electrochemical on-line residual chlorine analyzers with diaphragm sensor and constant-voltage respectively is carried out for research on chloramines which is the major influence factor.The results show that the both of electrochemical methods can accurately determine the residual chlorine content in the water, however, when there is chloramines, the maximum relative error of the constant voltage chlorine analyzer is 5 times of that of the diaphragm chlorine analyzer.