Carolyn N. Kinder
The build up of trace gases could kill the inhabitants of Biosphere 2. Even in nonlethal doses, carbon monoxide, nitrogen oxides, and other such gases affect health; gases such as methane are flammable. A structure the size of Biosphere 2 will have numerous sources of trace gases. Plastics, paints, sealers, and other materials used to build the structure of Biosphere 2 will slowly release various hydrocarbons. Hot lubricants will produce carbon monoxide. Electrical sparks will generate nitrogen oxide and ozone. Livestock produces methane and other gases. Plants will produce ethylene, a hormone affecting flowering, fruit maturation, senescence, and wound response. If ethylene were not cleaned from the air, it would prematurely stimulate plants into life cycle changes. Composting of cabbage, turnips, kale, and other crucifer vegetables will also produce sulfur dioxide. This might give rise to actual acid rain.
Some trace gases, such as methane, break down naturally, high in Earth’s atmosphere but this is not expected on Biosphere 2.
The principle that was worked out on Biosphere 2 is simple. Soil properly aerated, contains vast surface area coverted by a living carpet of bacteria and fungi. By pumping air through the soil beds microbes would consume trace gases quicker, digest them, and release carbon dioxide and water. In Biosphere 2, this could be accomplished by pulling air with fans and blowing it through it. By using the soil in the agricultural area, that is giving it a dual purpose, the Biosphere 2 wouldn’t have to increase in size. The air would pass up through the soil, rejoining the Biosphere 2 atmosphere among the potatoes, beans greens, and cucumbers. As the air passed through the soil, the microbes’ insatiable appetites would ensure clean air.
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