Air pollution is a global problem. More and more people pay attention to indoor pollution. According to the World Health Organization, every year, more than 4 million people die prematurely from diseases caused by indoor air pollution. The following for you to share a method of indoor air pollution control knowledge.
Physical method of formaldehyde removal
The most effective way to avoid formaldehyde is source control, that is, decoration and furniture purchase should start from style and materials, such as using log nailing or metal furniture and decoration as much as possible, reducing wood products in glue form, especially cheap plywood products. At the same time, when paint and wood cannot be avoided, low formaldehyde inspection materials should be selected.
It is the best plan to reduce the stock of formaldehyde in the house from the source.
Formaldehyde removal by strong ventilation
Strong ventilation is a powerful and effective method to reduce formaldehyde concentration, which surpasses other methods. However, it can only be carried out when the outdoor temperature and humidity, air quality and noise are acceptable. It does not necessarily reduce the formaldehyde to a safe level. Once the ventilation is stopped, the formaldehyde concentration will start to increase. If the noise or the use of air conditioning cause the windows unable to be opened for a long time, an all heat exchanger should be installed With the use of air conditioning is a compromise approach, and has a similar effect with the window.
Formaldehyde removal by activated carbon adsorption
Indoor activated carbon bags can adsorb formaldehyde, and there are many holes on the surface of carbon surface to lock formaldehyde molecules. However, there is no other mechanism, so it will be ineffective when the adsorption is full, so it is necessary to change the package frequently, and even the adsorbed formaldehyde will be released again when the temperature rises. Exposing the carbon package in the sun can release the gas it has locked and reuse it. However, it can only be repeated several times. The advantage is that there is less ultraviolet light in the drawer or deep room, and the photocatalyst can be used in the place where the photocatalyst fails.
Formaldehyde removal by ozone unit
The effective concentration of ozone is also toxic, but ozone can be decomposed in a short time. If it is determined that there is no human and livestock in a certain period of time, and the human and livestock can be shut down for a period of time, the ozone generator can be turned on to reduce the accumulation of formaldehyde.
Formaldehyde removal from indoor potted plants
Indoor plants to reduce formaldehyde is a long-term research topic. Not all plants have the ability to effectively reduce indoor VOCs (volatile organic compounds). Taiwan's environmental protection department has issued a special open manual for the public to refer to the relevant plants and dispel some folk rumors. However, if considering the cultivation ease and comprehensive reduction of indoor VOCs capacity, the white crane taro is undoubtedly one of the priority considerations. According to the research report written by Wolverton in 1993, a 46 cm tall white crane taro can degrade 939 micrograms of formaldehyde per hour under strong light irradiation. Assuming 12 hours of daily light, a 46 cm tall plant can degrade 11268 micrograms (11 mg) of formaldehyde.
According to a report published by Hong Kong Baptist University in 2010, it was found that the efficiency of formaldehyde degradation by plants was not high. The formaldehyde removal efficiency per square meter of leaves per hour was only 0.1 mg. If we want to achieve the results mentioned in the literature in 1993, the total leaf area of the plant should reach 10 square meters. This means that previous studies may have overestimated the efficiency of formaldehyde degradation by plants.
If it is a room with a practical area of 80 square meters and a floor height of 3 meters, the formaldehyde concentration is 0.5 mg per cubic meter. Indoor air is 120 mg of formaldehyde in total. To reach the safety standard (0.1 mg / m3), it is necessary to remove at least 96 mg formaldehyde. Even without considering the formaldehyde volatilized from the decorative materials, it takes 240 days to rely on a medium-sized plant (with a total leaf area of 0.3 square meters). Or if you want to clear it in a week, you need 34 trees. Considering the continuous release of new formaldehyde from household materials, I believe that plant formaldehyde removal is not feasible.
Fruit and so on formaldehyde removal
There are many fallacies about the method of removing formaldehyde. For example, pineapple, onion, tea and other indoor environment, claimed to be able to adsorb or even decompose formaldehyde. All these methods were proved to be false. Even if there is no smell, formaldehyde doesn't disappear, it's just covered up by the smell. This will put down the guard, ignore the importance of ventilation, so that indoor air formaldehyde content is higher.
Governance misunderstanding
1. Orange, pineapple and other fruits can not adsorb formaldehyde
This is a method used by many people in the past. It can be said to be a folk method. Many folk soil methods are the summary of long-term experience and the truth tested by time and practice. But this method is totally absurd. CCTV financial channel "is it true" column once broadcast a program, pomelo peel, pineapple to remove formaldehyde, is it true. Experiments were specially made in the program. The experimental results show that in the same sealed warehouse, the formaldehyde content in the experimental warehouse with pomelo peel is 10 times higher than that in the blank warehouse. Because after putting pomelo peel, the temperature of the experimental chamber increases and the formaldehyde emission increases greatly. Pomelo peel, pineapple and so on can not only remove formaldehyde, but also increase indoor formaldehyde content.
In the past, many people thought that the interior decoration smell was less after using grapefruit peel and pineapple, because the smell of fruit covered up the smell of formaldehyde. Inside these plants, there are "assembly lines" that remove formaldehyde, which react with specific chemicals to produce amino acids (such as serine). Or it turns directly into carbonic acid and carbon dioxide, which goes into the material cycle and is used to make new sugars, fats or proteins. In this way, this process undoubtedly reduces the damage of formaldehyde to plant cells, on the other hand, it also increases the "nutrients" of plants. After all, there is no difference between carbon from formaldehyde and carbon dioxide. It's a good way to kill two birds with one stone.
The main reason is that formaldehyde will combine with superoxide dismutase (SOD) in plant cells to inactivate these key proteins, further destroy the cell membrane structure, and finally pull down the wall. That's a key part of the strict control of nutrients, water and waste in and out. At this point, the fate of plants can be imagined.
2. Water, vinegar, black tea to remove formaldehyde
Many people on amethyst.com said that because formaldehyde is soluble in water, you can put several more basins at home to absorb formaldehyde, or use vinegar or black tea to make water. It is a fact that formaldehyde is easily soluble in water, water, alcohol and ether. Free formaldehyde in the air will dissolve into water when it meets water during its movement, which is similar to the adsorption principle of activated carbon. The contact area of a basin of water and air is only the size of a water basin, and the specific surface area of pores in 1g activated carbon can reach the size of a football field.
Even if you put 100 pots of water in the room, the adsorption effect will not be much stronger than a small bag of activated carbon. Therefore, using water, black tea, vinegar and other methods to adsorb formaldehyde is obviously unrealistic. The release of formaldehyde is closely related to the indoor temperature and humidity. With the increase of air temperature, the emission of formaldehyde will be greatly increased. The results show that the indoor formaldehyde emission will increase by 5% when the relative humidity in the air increases by 10%.
3. Limited air purification by plants
But we have to be aware that this is just an outbreak of plant resistance. It is a last resort for plants to remove formaldehyde. It is far less effective than photosynthesis to absorb carbon dioxide.
And in this process, plants themselves will also be injured, many plants in the high concentration of formaldehyde environment will be injured, serious and even death. Among them, Oxalis Carthami is particularly sensitive. As long as it is put in the environment with formaldehyde concentration of 0.1 mg / m3 for 3 hours, 95% of the leaves will be injured (calculated by area ratio). Moreover, when the concentration of formaldehyde increases, the speed of injury is faster. They can only persist in the environment of formaldehyde concentration of 0.4 mg / m3 for 3 hours, and then the whole leaves turn yellow brown and wilt due to water loss and become withered grass.
