Dry air by volume contains about 78 percent of nitrogen, 21 percent of oxygen, 0.04 percent of carbon dioxide and smaller amounts of other gases. Aside these natural constituents, air may contain others things that may be harmful to our health. Air pollution is the reason why technology has been used to try to solve the problem of air pollution; this has given rise to purification technologies that help to remove the things that make air polluted.

There are a lot of things present in air which may be harmful to us. They include smoke, hair, mites, dust, pollens, and vapors from chemicals, animal dander, odors, bacteria, mold spores and others.

Dust, hairs, pollen and animal dander can cause allergies and increase our susceptibility to asthma. HEPA filters and plasma grid filters are useful in eliminating the presence of things in the air that gives us allergies and asthma.

Smoke, vapors from chemicals and odors from various sources can irritate our respiratory systems and cause stress to our immune systems. Charcoal filters and carbon filters are useful in removing these organisms from air.

Living organisms like mold spores and bacteria can cause infections. They weaken our immune system and make us unable to fight off infections. When our bodies can’t fight off infections, we fall sick. Ultra violet lights, ceramic filters and plasma grids can help remove most of the microorganisms from air.

CHRONOLOGICAL ORDEROF PURIFICATION TECHNOLOGIES AND THEIR FUNCTIONS

1. CHARCOAL FILTER (1854)

It can be used to absorb odors and some gases. It is good for smoke, pet odor and hazardous fumes. It is cheap and easy to use.

2. OZONE (02) (1881)

Ozone is formed when there are electrical discharges in the atmosphere. Its unstable and is present in the atmosphere in low concentrations. It kills odors and have an effect on mold. It can also be used for the removal of chemical odors. The disadvantage of ozone is that it can be lethal at higher concentrations especially when one is exposed to it over a long period of time. This has made many people afraid to use it.

3. HEPA FILTERS (1934)

Hepa filters are effective. They can trap 99.97 percent of dust, pollen, dander etc. they are useful against substances in air that can cause allergies for example pollen, dust and hairs from cats and dogs. They need to be replace after some time and are very expensive.

4. ULTRA VIOLET LIGHT (1936)

Ultra violet light kills lots of microorganisms such as germs, bacteria and mold present in the air. They are effective and can be seen in places like hospitals, laboratories where there is need to have air that is free from disease causing organisms. It’s a very effective way to kill microorganisms. The ultra violet light bulb needs to be replaced at intervals.

5. NEGATIVE ION (1974)

Negative ion can be used to remove pollen, smog and some dust. Ionizers produced early on will always make the walls black because the dirt will adhere to the walls around the unit. Grid plates fixed to the units to take care of this. It’s a very affordable; works well with other technologies but is less effective if used alone.

6. CERAMIC AIR FILTER

This works by using heat present inside a chamber to kill microorganisms present in the air.It is effective but not readily available.

7. WASHABLE PRE-FILTERS

This is used to trap air and large airborne particles. It is very effective and cheap. The filters and be washed and used again.

8. TiO2 PHOTO-CATALYTIC (1991)

This is a very effective way to kill germs, bacteria and mold present in air. As the air passes through a filter, the ultra violet light is boosted to about 4000 percent to enable it kill the microorganisms present in the air.

9. PLAMA DUST (GRID) FILTERS (1989)

When air is passed through it, a charged grid plate floods the incoming air with positive and negative ions. This enables it to remove some microorganisms and some particles present in the air. It is less effective when used alone. Works well when used with other technologies.

10. POLLEN, ODOR AND DUST SENSORS

This is a new technology from Japan which uses sensors that detect pollen, odors and dust in air. It works well and can help prevent allergies that can be caused by pollen, odors and dust. The sensors can be controlled base on the needs of the room..