Self-adaptive titration method for potassium permanganate index

Abstract

The invention provides a self-adaptive titration method for a potassium permanganate index. The self-adaptive titration method comprises the following steps of: (A1) dropwise adding a potassium permanganate solution with the volume of V0 into a water sample, and stirring at the stirring speed of omega and the temperature of the water sample of T; acquiring the time t required by dropping the potassium permanganate solution into the water sample until the color of the water sample is dissipated; (A2) acquiring a predicted total titration volume V by using a mapping relation V=f(V0, T, t, omega); if the total titration volume V exceeds a threshold value Vm, entering the step (A3); if the total titration volume V does not exceed the threshold value Vm, entering the step (A4); (A3) dropwise adding the potassium permanganate solution with the volume of (V-A) into the water sample at a first speed v1, stirring, and entering step (A4), and (A4) dropwise adding the potassium permanganate solution into the water sample at a second speed v2 (v2 is less than v1) until the titration end point. The self-adaptive titration method has the advantages of high efficiency, automation and the like.

Description

technical field [0001] The invention relates to water sample detection, in particular to an adaptive titration method for potassium permanganate index. Background technique [0002] Manual titration and automatic titration of water quality permanganate index (IMN) need to judge whether the titration end point is reached while dripping, and the detection takes a long time. [0003] According to the national standard GB11892-1989, the existing detection method of permanganate index adopts the method of heating the water sample in a water bath and titrating with potassium permanganate. This method requires manual operation, including quantitative addition of 100ml water sample to the Erlenmeyer flask, quantitative addition of various chemical reagents, water bath timing for 30min±2min, manual potassium permanganate titration, and visual judgment of titration results. During the titration, the temperature of the water sample should be kept at 60-80°C, and the titration with pot...

AI Technical Summary

Problems solved by technology

[0006] 1. Since the constant rate titration is adopted, that is, the titration is carried out drop by drop in the form of dropping one drop at a fixed interval, which consumes a long time and the analysis efficiency is low

[0007] 2. Because it adopts the heating plate heat preservation method, the temperature of the water sample is not directly monitored. Under different temperature, humidity and ventilation environments, the temperature of the water sample may exceed the temperature range required by the national standard, which will affect the accuracy of the measurement results.

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