Chlorine dioxide - a powerful tool for removing formaldehyde

Formaldehyde is a class of carcinogen announced by the WHO, and its harm to the human body has been scientifically verified. When the formaldehyde content in indoor air is 0.1mg/m³, it will make people feel uncomfortable; when it reaches 0.3mg/m³, respiratory discomfort will occur; when it reaches 0.5mg/m³, it will cause nausea and vomiting symptoms; if the concentration is higher, , and even cause damage to the human lungs and central nervous system.

According to the "National Standard for Indoor Air Quality" - GB/T18883-2002, the indoor air quality standard formaldehyde content is below 0.1 mg/m3; in the "Code for Indoor Environmental Pollution Control of Civil Construction Engineering" - GB50325-2010, the indoor air quality standard formaldehyde The content is less than 0.08mg/m3.

However, in newly renovated houses, the formaldehyde content often exceeds the above concentration, and formaldehyde may last for several years, ten years or even longer. Therefore, if there are children, pregnant women, the elderly and other people with poor health at home, you must pay more attention to the indoor formaldehyde concentration (even healthy adults are irreversibly damaged by high concentrations of formaldehyde).

There are various methods for removing formaldehyde. Common examples include: maintaining ventilation for a long time, finding a cleaning company to seal and treat, using adsorbent materials to absorb, etc.; in recent years, there have also been some novel and more practical new products, among which the most noteworthy category is It is a chlorine dioxide space formaldehyde removal product.

Chlorine dioxide can react with formaldehyde, which is a two-step reaction:

2ClO2 + 5HCHO + H2O →5HCOOH + 2Cl- + 2H+2ClO2 + 5HCOOH → 5CO2↑ + 2Cl- + 2H+ + 4H2O

Chlorine dioxide reacts with formaldehyde to form formic acid. Chlorine dioxide can react with formic acid to form carbon dioxide and water. The chlorine dioxide is reduced to chloride ions.

The overall reaction equation is as follows:

In practical applications, is chlorine dioxide solid sustained-release agent really effective in removing formaldehyde? Next, let us take a look at the research results of Guangdong University of Technology "Research on Sustained-release Chlorine Dioxide for Purifying Indoor Formaldehyde Pollution" , original text from: https://www.cnki.net/.

This paper uses the formaldehyde content in the "Code for Control of Indoor Environmental Pollution in Civil Construction Engineering" as a benchmark to study the use of chlorine dioxide to remove formaldehyde when formaldehyde exceeds the standard by 2 times, 4 times and 6 times. The details are as follows.

As can be seen from the figure above, when formaldehyde exceeds the standard by about 2 times and the concentration of chlorine dioxide is around 0.23-0.66mg/m3, the formaldehyde concentration can be reduced to less than 0.08mg/m3.

As can be seen from the figure above, when formaldehyde exceeds the standard by about 4 times and the concentration of chlorine dioxide is around 0.42-0.90mg/m3, the formaldehyde concentration can be reduced to less than 0.08mg/m3.

As can be seen from the above figure, when formaldehyde exceeds the standard by about 6 times and the concentration of chlorine dioxide is around 0.77-0.90mg/m3, the formaldehyde concentration can be reduced to less than 0.08mg/m3.

It can be seen that chlorine dioxide at low concentration (less than 0.9 mg/m3) has excellent formaldehyde removal effect in environments where formaldehyde exceeds the standard.