Method for monitoring content of total cadmium in water and device for automatically monitoring content of total cadmium in water on line

Abstract

The invention discloses a method for monitoring content of total cadmium in water. The method comprises the following steps: after pretreating a water sample obtained by water sampling, pumping the water sample into a constant volume container and keeping a constant volume; respectively pumping a tween-80 solution, a titanium yellow solution, a sodium hydroxide solution and a vitamin C solution into a constant volume container and keeping constant volume; sequentially pumping the water sample, the tween-80 solution, the titanium yellow solution, the sodium hydroxide solution and the vitamin C solution with constant volume into an absorption tank to obtain a mixed solution, diluting the mixed solution to a fixed volume with distilled water and injecting gas to the bottom in the absorption tank; performing colorimetric analysis, i.e., after gas injection, discharging all the solutions from the absorption tank into a colorimetric tank and reading by a photometer; sending data read by the photometer to a processor, and displaying a result after computation, thereby accomplishing the monitoring on the content of total cadmium in water. The invention also discloses a device for automatically monitoring content of total cadmium in water on line, which is implemented in match with the method. The application of titanium yellow and tween-80 which respectively serve as a color developing agent of cadmium ions is conductive to the realization of engineering of online monitoring of the content of total cadmium in water.

Description

technical field [0001] The invention relates to a monitoring method and a monitoring device for total cadmium in water quality, in particular to a monitoring method and an automatic online monitoring device for total cadmium in water quality based on a spectrophotometric method. Background technique [0002] At present, cadmium pollution has been paid more and more attention as one of the sources of heavy metal pollution. The detection methods for cadmium pollution include flame atomic absorption spectrometry, graphite furnace atomic absorption spectrometry, low temperature atomic absorption spectrometry, hydride atomic fluorescence spectrometry, and spectrophotometry. method, oscillographic polarography, anodic stripping voltammetry, and biological detection methods. As far as online monitoring of water quality is concerned, spectrophotometry is suitable for automatic online monitoring equipment, and other methods are more suitable for laboratory environment or rapid detect...

AI Technical Summary

Problems solved by technology

[0004] Above-mentioned dithizone spectrophotometric method, detection concentration scope is in (1-50) ug / L, detection limit reaches 1ug / L, because used chloroform in its method as extraction agent, so its popularization is subject to by drug control and safety requirement. The addition of reagents needs to be shaken and oscillated, which requires high automation equipment and cumbersome operations; in addition, potassium cyanide itself is also a highly toxic drug

In addition, the detection concentration range of atomic absorption spectrophotometry is (0.05-1) mg / L, the detector is expensive, and it is generally used as a laboratory scientific research or measurement instrument; the anodic dissolution method is seriously interfered by ions, and the electrode is fragile, so mercury is used More electrodes, easy to cause secondary heavy metal pollution

[0005] In general, the above-mentioned traditional detection methods for cadmium pollution are difficult to meet the engineering needs of automatic online monitoring of total cadmium in water quality and environment

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