Chemical Engineering in Daily Life – Question 21: Are those methods for removing formaldehyde from indoor air really effective? Standard answer already exists
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This post was last edited by yjqin1 on 2015-8-29 07:17. The real estate industry is highly developed, and it’s a characteristic of us Chinese – without our own home, we feel as if we don’t have a home. But if I do the math, there are no fewer than 15 properties I rented for periods over 3 months, and I wasn’t able to get a mortgage to buy my own house until I was 42. A 370-square-meter mansion for just over 1 million, a used home, near New York. There was a huge explosion in the Binhai New Area this time; I’ve received countless calls and text messages. Thank you to my relatives and friends for their concern! ! ! In the end, I drafted a standard reply: Everything is fine; this location is farther from the explosion site than the epicenter of the 1976 Tangshan earthquake, and also farther than the site where the Twin Towers collapsed in 2001. Am I fortunate or unfortunate? Just waiting for the good fortune to come. Why buy a second-hand house? Back to the main topic: new houses, new floors and ceilings, new furniture – all of which contain formaldehyde, and formaldehyde is toxic. People in China everywhere say this and remind one another of it. On some of the plants in the flower shop, large letters read: Absorbs formaldehyde (potassium aldehyde, formaldehyde, methanamine – there are many spelling mistakes in any case). There are numerous legends about how to deal with formaldehyde, circulating in TV commercials, on the Internet, in forums, and throughout streets and neighborhoods. Which of the following methods is most effective in removing formaldehyde from indoor air? 1. Fill the room with a large amount of water to absorb it ； 2. Add adsorbents such as activated carbon ； 3. Specialized formaldehyde removal equipment equipped with catalytic oxidation functionality ； 4. Open windows regularly for ventilation. 5. Once the house is decorated and the furniture is installed, move in after a year ； 6. Practice qigong, yoga, etc. to boost resistance. Please consider it from the perspective of chemical engineering.
2 and 4 have better practicality................
Teacher, I have a suggestion: don’t just create questions without checking the homework. More involvement leads to more interaction. --------------------------- I think everything except 45 is just a placebo
The house is finished decorating, the furniture is purchased and placed in place, and it’s ready for occupancy after a year
Only 4 and 5 are valid; use 2 based on that
I think it’s enough to wipe the furniture with water several times; formaldehyde seems to dissolve in water, and I think all other methods are just gimmicks
Unless you keep wiping it all the time. It takes time for formaldehyde inside the furniture to spread out; step 1 is the diffusion within the furniture itself, step 2 is the diffusion within the concentration boundary layer on the outside of the furniture, and only then does it spread into the air in the main room. If there are two processes in series for formaldehyde removal, wiping only reduces the smaller of the mass transfer resistances. Please analyze it using the basic knowledge and principles of chemical engineering. How do you say that sentence? It is necessary to focus on the main contradictions and the key aspects of those contradictions.
Ventilation, move in after one year. All that talk about adsorption and professional removal is just nonsense. Formaldehyde is released slowly; it gets absorbed today and then released again the next day.
4. Open windows regularly for ventilation. 5. Once the house is decorated and the furniture is installed, move in after a year； Everything else is just merchants tricking people; it doesn’t have much real effect.
This post was last edited by yjqin1 on 2015-8-29 07:16. Standard answer: I’m on the 10th floor; the 9 floors above are the standard answer. Formaldehyde is indeed highly soluble in water; it hydrolyzes in water to form \"methylene glycol\", which then dimerizes or even dodemerizes to form larger molecules. However, the boiling point of formaldehyde itself is minus 20 degrees Celsius. These two factors make formaldehyde a very special substance. In chemical terms, in an extremely dilute aqueous formaldehyde solution, the relative volatility of formaldehyde/water lies between 0.3 and 0.6. Therefore, it is possible to dilute formaldehyde with water. However, the gas and liquid must be in full contact. In that case, your home will either become a chemical plant equipped with absorption towers or a cave with water curtains. As for using activated carbon for adsorption, it is feasible, especially when the air humidity in the room is not very low. However, this also requires a large solid-gas contact area to be effective. Some people keep activated carbon at home or in their offices. I said you need to put a lot, lots of them, spread them out, and also replace them regularly. As for the other methods that rely on the chemical reactivity of formaldehyde, it is theoretically possible, but this is not a qualitative matter; quantitative considerations are necessary: is the catalytic activity sufficient, and is the air circulation rate adequate? Let’s just say that buying ten of them to keep at home will definitely work. So, for a new house, new renovations, and new furniture, it’s better to wait for a long time before moving in. But which family is that luxurious? Open the windows often. This is simple and easy to do. But isn’t it overcast everywhere in our motherland? I’m currently staying at the Beijing Xiyuan Hotel, writing this post. Looking up, I see the outlines of the Western Hills with remarkable clarity; I experience that legendary \"parade blue\" hue, but I can’t help thinking: It’s really hard for us Chinese people to live!
The original poster is interesting; where is the answer? Those in the chemical industry who can solve the problem of formaldehyde will have many business opportunities. Of course, this isn’t some trickery to deceive people.