air pollution is a global problem, more and more people turn the attention of outdoor pollution to indoor pollution. According to the World Health Organization, every year, more than 4 million people die prematurely due to diseases caused by indoor air pollution. In this issue, we will share with you a knowledge about the methods of indoor air pollution control. Let’s go into the dry goods class together!
Physical formaldehyde removal method
the most effective way to avoid formaldehyde is source control, that is, decoration and furniture purchase should start from style and materials, such as log nailing or metal furniture and decoration, Reduce the adhesive form of woodworking products, especially avoid cheap plywood products, at the same time paint and wood can not avoid the use of low formaldehyde inspection qualified materials.
it is the best plan to reduce the formaldehyde stock in the house from the source.
removal of formaldehyde by strong ventilation
strong ventilation is a powerful and effective method to reduce formaldehyde concentration, which surpasses other methods. However, it can only be implemented when the outdoor temperature and humidity, air quality and noise are acceptable. It does not necessarily reduce the formaldehyde to a safe level, and once the ventilation is stopped, the formaldehyde concentration will start to increase, If the windows cannot be opened for a long time due to noise or the use of air conditioning, it is a compromise to install an all heat exchanger to cooperate with the use of air conditioning, which is close to the effect of opening windows.
activated carbon adsorption in addition to formaldehyde
indoor activated carbon package can adsorb formaldehyde. There are many small holes on the carbon surface that can lock formaldehyde molecules, but there is no other mechanism, so it is invalid after the adsorption is full, and the package needs to be changed frequently. Even the adsorbed formaldehyde will be released when the temperature rises. If the carbon package is exposed to the sun outdoors, the locked gas can be released and reused, but it can only be repeated several times. The advantage is that there is less ultraviolet light in the drawer or deep room, and the place where the photocatalyst fails can be used.
ozone device in addition to formaldehyde
effective concentration of ozone is also toxic, but ozone can be decomposed in a short period of time, in the case of confirming that there is no human and animal existence for a period of time, human and animal can be closed before entering for a period of time, the ozone generator can be turned on to reduce the accumulation of formaldehyde.
Formaldehyde removal by indoor potted plants is a long-term research topic. Not all plants have the ability to effectively reduce indoor VOCs (volatile organic compounds). The environmental protection department of Taiwan Province has issued a special open manual for the public to consult relevant plants and dispel some folk rumors. However, considering the ease of breeding and the comprehensive ability to reduce indoor VOCs, white crane taro is undoubtedly one of the priorities. According to Wolverton’s Research Report in 1993, a 46 cm tall white taro can degrade 939 micrograms of formaldehyde per hour under strong light. Assuming 12 hours of light per day, a 46 cm tall white crane taro can degrade 11268 micrograms (11 mg) of formaldehyde.
the report published by Hong Kong Baptist University in 2010 found that the efficiency of formaldehyde degradation by plants is not high. The efficiency of formaldehyde purification per square meter of leaves per hour is only 0.1 mg. If we want to achieve the results mentioned in the literature in 1993, the total leaf area of this plant should reach 10 square meters. This means that previous studies may overestimate the efficiency of formaldehyde degradation by plants.
if the practical area is 80 square meters and the floor height is 3 meters, the formaldehyde concentration is 0.5 mg per cubic meter. There is 120 mg of formaldehyde in the indoor air. To reach the safety standard (0.1 mg / m3), at least 96 mg of formaldehyde should be removed. Even if we don’t consider the formaldehyde volatilized from the decoration materials, if we rely on a medium plant (with a total leaf area of 0.3 square meters), we have to work 240 days. Or if you want to clear it in a week, you need 34 trees. Considering that new formaldehyde is constantly released from household materials, it is not feasible to remove formaldehyde from plants.
fruits and so on to remove formaldehyde
there are many ways to remove formaldehyde there are quite a big fallacy. For example, pineapple, onion, tea and other indoor environment, claimed to be able to absorb or even decompose formaldehyde. In the end, these methods were proved to be absurd. Even if there is no smell, formaldehyde does not disappear, but is covered by the fragrance. On the contrary, it will put down the vigilance, ignore the importance of ventilation, and make the formaldehyde content of indoor air higher.
In the past, many people like to use this method, which can be said to be a folk method. Many folk methods have been used for a long time, but we must note that this is just an outbreak of plant resistance. Formaldehyde removal is a must for plants. There are many detours to deal with it harmlessly, which is far less effective than the absorption of carbon dioxide by photosynthesis.
and in this process, the plant itself will be injured, many plants in the high concentration of formaldehyde environment will also be injured, serious or even die. Oxalis Carthami is particularly sensitive. As long as it is thrown into the environment with formaldehyde concentration of 0.1 mg / m3 for 3 hours, 95% of the leaves will be injured (calculated according to the area ratio). Moreover, when the concentration of formaldehyde increases, the rate of injury is faster. They can only persist in the environment with formaldehyde concentration of 0.4 mg / m3 for 3 hours, and then the whole leaves turn yellow brown and wilt with water loss, and become withered grass.