Quick detecting method for needed oxygen COD cr of mercuryless salt high-chlorine waste water chemical

Abstract

The invention discloses a quick measuring method for mercury salt less high chlorine waste water chemical oxygen demond quantity CODcr. Its character lies in: the method uses standard potassium dichromate method, uses MnSO4 and NiSO4 to replace Ag2SO4, and checks the CODcr in water sample. The method is reliable, the energy consumption and reagent cost are saved; and because of using AgNO3 and CrK (SO4)2 to replace severe toxici HgSO4 as combined masking agent, solves the secondary contamination to environment.

Description

technical field [0001] The invention relates to monitoring of water quality environment, in particular to high chlorine wastewater chemical oxygen demand (COD) Cr rapid determination. Background technique [0002] Chemical oxygen demand (COD) refers to the amount of oxidant consumed when a certain oxidant is used to treat water samples under certain conditions, expressed in mg / L of oxygen. COD reflects the degree of water pollution by reducing substances, and can be used as a comprehensive indicator of the relative content of organic matter. As human beings pay more and more attention to environmental problems, the research on COD measurement methods is also deepening. [0003] Standard COD Cr The method of determination is to accurately add excess potassium dichromate standard solution to the strong acid solution and heat it to reflux to oxidize the reducing substances (mainly organic matter) in the water sample, and use ferrous iron as indicator for the excess potassium...

AI Technical Summary

Problems solved by technology

[0014] The method has a short reflux time and replaces the toxic HgSO with silver nitrate and chromium potassium sulfate 4 As a combined masking agent for chloride ions, but with expensive Ag 2 SO 4 As a catalyst, the determination process requires a large amount of silver salt, and the reagent cost is relatively large

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