What are the 11 methods to remove formaldehyde?

Formaldehyde is a colorless gas that is extremely harmful to humans. Especially when decorating a house, many decoration materials will contain formaldehyde. So here we remind everyone that you would rather spend more money to buy healthy and environmentally friendly decoration materials. In addition, you must master the correct decoration methods to avoid the production of formaldehyde as much as possible. In addition, you must also learn the following methods to remove formaldehyde.

11 ways to remove formaldehyde:

1. Ventilation method

There is no need to explain the ventilation method in detail. It is to discharge harmful gases to the outside through the flow of air. This is a simple and effective method. The only drawback is that the formaldehyde release cycle is long, generally three to fifteen years. It is obviously unrealistic to leave the new house vacant for more than three years after decoration. Therefore, ventilation alone cannot meet the requirements.

2. Plant-derived air purifier

AQ air purifier spray plant-based biological agents use biotechnology to refine and extract the effective ingredients of sesquiterpenoids and alcohol compounds from plants such as Italian black poplar, mountain locust, and pink-flowered chinaberry, and formulate them into a plant-based compound purification liquid with an exclusive patented formula. It has a significant and long-lasting bactericidal effect. Tested by authoritative departments such as the Hong Kong Polytechnic University, it has a killing rate of up to 99.9% within 60 minutes for various common bacteria, fungi and viruses such as Salmonella, Shigella, pathogenic Escherichia coli, Vibrio cholerae, Staphylococcus aureus, Legionella, SARS coronavirus, human influenza virus, avian influenza virus, etc. And it can effectively decompose toxic gases such as formaldehyde, benzene, TVOC, etc. Decomposes instantly without secondary pollution. It is edible and pleasing to the eyes.

3. Formaldehyde scavenger or formaldehyde dissolving enzyme

Formaldehyde removers "remove" formaldehyde through chemical reactions. The essence of this method is to reduce the toxicity of the target substance or convert it into a non-toxic substance. Formaldehyde can be oxidized into formic acid or reduced into methanol. Although the toxicity and irritation of these two substances are lower than that of formaldehyde, their toxicity still exists. For example, some highly oxidizing formaldehyde removers can oxidize formaldehyde, but they are easy to decompose. Spraying them on wooden boards will not only damage the wood, but will also lose their effectiveness within a few hours, making it impossible to achieve "one spray and forever." Moreover, high concentrations of cleaners sprayed into the air will create new pollution hazards to humans. Other oxidants and reducing agents cannot effectively remove formaldehyde and may introduce similar new pollution.

4. Activated carbon adsorption

Mr. Li, who specializes in activated carbon at Nankai University, told reporters that activated carbon is indeed effective in the initial stage of use because the pores have adsorption potential, which is formed by the attraction between carbon molecules and adsorbed molecules. The smaller the pore size, the stronger the adsorption potential. In addition, according to the theory of molecular motion, all objects are composed of molecules or atoms. There are gaps between them, and at the same time they are in a state of endless and irregular thermal motion, and molecules collide with each other frequently. According to relevant data, under standard conditions, the free movement speed of formaldehyde molecules is about 450 meters per second, and one formaldehyde molecule collides with other molecules 109 times per second. At this time, if the diameter of the colliding molecule matches the pores of the activated carbon, it will be adsorbed. Whether it is traditional activated carbon or the more popular modified activated carbon, their adsorption capacity is limited due to their large pores.

The highest temperature of sunlight is only about 50 degrees Celsius, which can only evaporate water. The pollutants adsorbed in activated carbon cannot be completely volatilized, and the adsorption function of the carbon cannot be completely restored. Therefore, exposure to the sun is more about removing moisture from the activated carbon. Its adsorption properties cannot be restored.

Activated carbon generally has a certain adsorption effect on benzene, but the adsorption effect on formaldehyde is not obvious. Generally, the adsorption capacity of activated carbon will weaken after one month.

5. Use water, vinegar, or black tea to remove formaldehyde

Many people on the Internet have said that since formaldehyde is soluble in water, you can place several basins of water at home to absorb the formaldehyde, or use vinegar or black tea to soak in water. It is a fact that formaldehyde is easily soluble in water, alcohol and ether. Free formaldehyde in the air will dissolve into water when it encounters water during movement, which is similar to the adsorption principle of activated carbon. The contact area between a basin of water and the air is only the size of the basin, while the specific surface area of ​​the pores inside 1 gram of activated carbon can reach as large as a football field. Even if you place a hundred basins of water in the room, the adsorption effect will not be much stronger than a small bag of activated carbon. Therefore, it is obviously unrealistic to use water, black tea, vinegar and other methods to absorb formaldehyde. The release of formaldehyde is closely related to the indoor temperature and humidity. When the humidity in the air increases, the release of formaldehyde will increase greatly. Experimental results show that if the relative temperature in the air increases by 10%, the indoor formaldehyde emission will increase by about 5%.

6. Photocatalyst removes formaldehyde

When exposed to light, photocatalysts will produce a photocatalytic reaction similar to photosynthesis, generating free hydroxyl radicals and active oxygen with extremely strong oxidizing ability. They have strong photo-oxidation-reduction function, can oxidize and decompose various organic compounds and some inorganic substances, can destroy bacterial cell membranes and solidify viral proteins, can kill bacteria and decompose organic pollutants, and decompose organic pollutants into pollution-free water (H2O), carbon dioxide (CO2) and other harmless substances. Therefore, they have extremely strong sterilization, deodorization, mildew prevention, anti-fouling self-cleaning and air purification functions.

Theoretically speaking, photocatalyst is the highest quality formaldehyde removal product. However, in order for photocatalyst to work, it needs ultraviolet light to be stimulated. However, ultraviolet light cannot always be present in the room, especially in drawers, the backs of cabinets and other places where formaldehyde is released most seriously and there is no light. This limits the effect of photocatalyst.

7. Oranges, pineapples and other fruits absorb formaldehyde

This is a method that many people liked to use in the past, and it can be said to be a folk remedy. Many folk remedies are the summary of long-term life experience and are truths that have been tested by time and practice. But this approach is completely ridiculous. CCTV Finance Channel "Is it true? 》 column has just aired an episode, Can grapefruit peels and pineapples remove formaldehyde? Is it true? A special experiment was conducted in the program, and the results showed that in the same sealed warehouse, the formaldehyde content in the experimental warehouse where grapefruit peels were placed was ten times that of the blank warehouse. After the grapefruit peel was put in, the temperature of the experimental chamber increased and the amount of formaldehyde released increased greatly. Grapefruit peels, pineapples, etc. not only fail to remove formaldehyde, but also increase the formaldehyde content in the room. In the past, many people felt that the use of grapefruit peels and pineapples made the interior decoration smell less smelly. That was because the smell of the fruit masked the smell of formaldehyde.

8. Air freshener

The principle of air fresheners is the same as that of grapefruit peels, pineapples, etc. They just use a scent to mask the smell of harmful gases and have no removal effect at all. Moreover, air freshener itself is a chemical and can cause certain harm to your health.

9. Plants absorb formaldehyde

Plants can absorb some harmful substances through photosynthesis, but the effect of this method is extremely limited. Here are the reasons:

1) Plants carry out photosynthesis and generally absorb some harmful substances during the day, but they do not have this function at night. People generally live outdoors during the day and indoors at night. When people need air purification the most, plants cannot play a corresponding role.

2) The harmful substances absorbed by plants are extremely limited. The national standard requires that the formaldehyde emission value be less than 0.08 mg/cubic meter. In most newly renovated houses, the formaldehyde level is not less than 0.2 mg/cubic meter. However, the green ivy, which has a higher efficiency in absorbing formaldehyde, absorbs only 20 micrograms of formaldehyde per hour. For a room of 100 square meters, 3 meters high and with a formaldehyde value of 0.2 mg/cubic meter, 1,800 pots of green ivy are needed, almost filling the entire space of the house, to reduce the formaldehyde to 0.08 mg. This is done under sufficient daylight and to ensure that no formaldehyde is released during the absorption process. In fact, formaldehyde is still being released from the furniture after decoration. Therefore, plants can only play an auxiliary role in controlling harmful substances such as formaldehyde and benzene.

10. Vinegar fumigation

Vinegar is an acidic substance and can weakly neutralize ammonia in the air, but it will not react with other harmful components such as formaldehyde.

11. Air purifier removes formaldehyde

All purification efficiency calculations of air purifiers are completed in the laboratory and are measured under the condition of excluding continuous pollution sources. In other words, these data are obtained under specific conditions. Therefore, in actual use, the purification efficiency will be lower than what the manufacturers claim. In essence, air purifiers only play an auxiliary and remedial role. For example, when the indoor air is already polluted, using an air purifier can reduce the degree of pollution to a certain extent, but it does not mean that it can fundamentally eliminate air pollution.

It is difficult to remove harmful gases after decoration by relying on one method alone. It is best to choose several methods based on the actual situation. Try to reduce harmful gases in the room as much as possible. The above methods are all remedial measures after decoration. In fact, the most effective method is to fully consider the hazards of formaldehyde before decoration, and try to use environmentally friendly materials as much as possible during the decoration process to prepare for a rainy day.