全自动化仪器滴定水中COD的研究

Study on Automatic Digestion-photometric Titration COD Measuring Instrument

研究了将重铬酸盐法步骤与光度滴定法原理相结合滴定水中的COD,从而验证了全自动消解-光度滴定COD仪器研发的可行性。实验结果分析:实验测定滴定终点红褐色溶液的最佳吸光度波长在510 nm处;在510 nm处不同浓度的待测液在到达滴定终点时均有明显的吸光度突变;通过误差分析,验证了光度滴定判断COD终点的方法可行;结合消解器与光度滴定,全自动消解与滴定操作验证了自动消解-光度滴定COD仪器的研发是可行的。

The concentration of COD in the water combined the dichromate method with photometric titration method was determined,and the feasibility of research and development of automatic digestion-photometric titration COD measuring instrument was verified. According to the results of research,the conclusions can be made as follows: when the solution got brown which meant that it arrived end-point during titration,the wave length of optimum absorbance of the brown solution was 510 nm. There were obvious increases during titration with different concentration of the samples. It was feasible to use photometric titration method to measure COD in the water after error analysis. This examination demonstrated that it was feasible to combine automatic digestion instrument with photometric titration instrument to be an integrated instrument-automatic digestion-photometric titration COD measuring instrument.