The formaldehyde in the finely decorated house is mainly used in the customized cabinets of the whole house, especially the formaldehyde content of particle board and MDF is the highest, and the wall paint may also have.
Although we use formaldehyde removers, such as photocatalysts, activated carbon paints, etc., after operating according to the requirements, we can indeed remove formaldehyde, and the test with a measuring instrument has reached a safe value, but after a few days, the formaldehyde level has returned to the original level that exceeded the standard. This is because the formaldehyde in the board is sealed by the foreskin on the surface, like an itch in the boot, and we cannot remove it. So, what do we do?
It's actually very simple, wipe the surface of the board with a damp rag, and then open the window for ventilation and turn on the fan to accelerate the convection. After a few days of repeated operation, I bought two large industrial fans and an air purifier that degrades formaldehyde. When you go out during the day, turn on the fan and window for strong ventilation, and when you sleep at night, turn on the air purifier to purify formaldehyde. 
Summary: The key to dealing with formaldehyde is to use a large fan to accelerate air convection, open windows for ventilation, and finally use an air purifier to sleep at night. After a few months, when the formaldehyde content in the board becomes very low, the formaldehyde released will naturally be very small, do not think about completely removing formaldehyde in the short term, as long as the indoor formaldehyde content is kept in a safe range, this is a long-term process.