BioHome - AbsoluteAstronomy.com

BioHome Data
Project Name	BioHome
Construction Dates	1989 (Completion)
Thermal Insulation Value	R-40

BioHome was a small facility created by NASA

NASA

The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

that could support one person in a fully functional habitat. One of the influences of the project being the results from data obtained on the 1973 Skylab 3 (SL-3)

Skylab 3

Skylab 3 was the second manned mission to Skylab. The Skylab 3 mission started July 28, 1973, with the launch of three astronauts on the Saturn IB rocket, and lasted 59 days, 11 hours and 9 minutes...

, where a total of 107 VOCs were offgassed

Outgassing

Outgassing is the release of a gas that was dissolved, trapped, frozen or absorbed in some material. As an example, research has shown how the concentration of carbon dioxide in the Earth's atmosphere has sometimes been linked to ocean outgassing...

by synthetic

Chemical synthesis

In chemistry, chemical synthesis is purposeful execution of chemical reactions to get a product, or several products. This happens by physical and chemical manipulations usually involving one or more reactions...

materials that composed the SL-3. However, the study of indoor air quality

Indoor air quality

Indoor air quality is a term referring to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants....

was not the only focus of the project, as it was a part of research into closed ecological

Ecology

Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...

life support

Life support

Life support, in medicine is a broad term that applies to any therapy used to sustain a patient's life while they are critically ill or injured. There are many therapies and techniques that may be used by clinicians to achieve the goal of sustaining life...

systems.

The facility is still in use as of this writing and has paved inroads into creating self-supporting life support systems.

Construction

Construction of the BioHome concluded in 1989 and construction materials included synthetics which gave off the aforementioned VOCs. The BioHome itself resembles a mobile home

Mobile home

Mobile homes or static caravans are prefabricated homes built in factories, rather than on site, and then taken to the place where they will be occupied...

in size where it contained a living area and treatment facilities for human waste and air.

While not completely air-tight, such as the Biosphere 2

Biosphere 2

Biosphere 2 is a structure originally built to be an artificial, materially-closed ecological system in Oracle, Arizona by Space Biosphere Ventures, a joint venture whose principal officers were John P. Allen, inventor and Executive Director, and Margret Augustine, CEO...

structure, the structure was engineered for maximum air and energy confinement. This was unsurprising, given that the interior walls were composed of molded plastic panels with 30 cm of fiberglass insulation.

The BioHome had living facilities that could support one person and foliage plants were placed throughout the structure, aiding in air purification. In addition to the plants, a prototype fan-assisted plant filter was installed; the filter had the removal capacity of 15 standard potted plants.

The BioHome was equipped with monitoring ports for the detection of VOCs, which were measured using mass spectrometer / gas chromatograph equipment.

In experiments regarding wastewater treatment, the facility was outfitted with PVC

Polyvinyl chloride

Polyvinyl chloride, commonly abbreviated PVC, is a thermoplastic polymer. It is a vinyl polymer constructed of repeating vinyl groups having one hydrogen replaced by chloride. Polyvinyl chloride is the third most widely produced plastic, after polyethylene and polypropylene. PVC is widely used in...

piping and ultraviolet

Ultraviolet

Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...

equipment.

Wastewater treatment

In its nascence, the BioHome focused on alternative, non-chemical sewage treatment

Sewage treatment

Sewage treatment, or domestic wastewater treatment, is the process of removing contaminants from wastewater and household sewage, both runoff and domestic. It includes physical, chemical, and biological processes to remove physical, chemical and biological contaminants...

methods utilizing non-edible plants of aquatic

Aquatic plant

Aquatic plants are plants that have adapted to living in aquatic environments. They are also referred to as hydrophytes or aquatic macrophytes. These plants require special adaptations for living submerged in water, or at the water's surface. Aquatic plants can only grow in water or in soil that is...

disposition. The aquatic and semi-aquatic plants were chosen based on their previously known abilities for waste treatment. Another usage for the plants used in the wastewater treatment included its implementation as compost

Compost

Compost is organic matter that has been decomposed and recycled as a fertilizer and soil amendment. Compost is a key ingredient in organic farming. At its most essential, the process of composting requires simply piling up waste outdoors and waiting for the materials to break down from anywhere...

, which was feasible as the plants grew as more sewage was introduced.

Means

All waste material, such as feces

Feces

Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...

and urine

Urine

Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...

, were routed through PVC pipes, punctured so that the root systems of aquatic / semi-aquatic plants could be inserted. At different points of the flow, the water was studied (although those specific results are unavailable at this writing).

Ensuring total eradication of microorganisms, the processed water was subjected to ultraviolet radiation.

The processed water is subsequently used as toilet and plant water, though not for consumption.

Plants used

Plants, or more accurately, the root systems of aquatic plants found to have a filtering effect include bulrush

Bulrush

-Wetland plants:* Bolboschoenus, a genus in the sedge family * Cyperus, a genus in the sedge family * Scirpus, a genus in the sedge family * Schoenoplectus, a genus in the sedge family...

, reed

Phragmites

Phragmites, the Common reed, is a large perennial grass found in wetlands throughout temperate and tropical regions of the world. Phragmites australis is sometimes regarded as the sole species of the genus Phragmites, though some botanists divide Phragmites australis into three or four species...

, soft rush

Soft rush

Soft Rush is a member of the genus Juncus. Native to most continents and hence also known as Common Rush, this plant is found growing in wet areas, such as the purple moor-grass and rush pastures and fen-meadow plant associations in the United Kingdom.-Description:It grows in large clumps about...

and water iris

Iris (plant)

Iris is a genus of 260-300species of flowering plants with showy flowers. It takes its name from the Greek word for a rainbow, referring to the wide variety of flower colors found among the many species...

. As explained by Wolverton:

"When sewage is slowly filtered through an aquatic plant root filter system, complex biological processes take place during wastewater treatment and purification. The symbiotic relationship that is normally established between the plant roots and microorganisms living on and around these roots is very complex and important in the wastewater treatment process... This process not only removes organic chemicals

Organic compound

An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...

, but is also thought to contribute to the reduction of other polluting substances including pathogenic bacteria

Bacteria

Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

and virus

Virus

A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...

es. It has been shown that roots of aquatic plants such as bulrush, reed, soft rush and water iris excrete substances that can either partially or completely kill pathogenic bacteria while not harming beneficial bacterial. The aerobic zone

Cellular respiration

Cellular respiration is the set of the metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into adenosine triphosphate , and then release waste products. The reactions involved in respiration are catabolic reactions that involve...

around the aquatic root system can also support, in addition to bacteria, the growth of large numbers of protozoa

Protozoa

Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...

which feed on bacteria, viruses and particular organic matter

Organic matter

Organic matter is matter that has come from a once-living organism; is capable of decay, or the product of decay; or is composed of organic compounds...

Harvesting drinking water

Water suitable for human use was extracted from the condensate from three sources: dehumidifier units

Dehumidifier

A dehumidifier is typically a household appliance that reduces the level of humidity in the air, usually for health reasons. Humid air can cause mold and mildew to grow inside homes, which pose various health risks. Very humid climates or air make some people extremely uncomfortable, causing...

, air conditioning

Air conditioning

An air conditioner is a home appliance, system, or mechanism designed to dehumidify and extract heat from an area. The cooling is done using a simple refrigeration cycle...

, and plant leaves. In fact, plant leaves proved to be a major, consistently reliable source of water vapor

Water vapor

Water vapor or water vapour , also aqueous vapor, is the gas phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Under typical atmospheric conditions, water vapor is continuously...

s.

The condensate was run through ultraviolet equipment to ensure its safety.

Crop growth

Crops were grown in the hydroponic sections of the BioHome, comprising edible plants (squash

Squash (fruit)

Squashes generally refer to four species of the genus Cucurbita, also called marrows depending on variety or the nationality of the speaker...

, corn

Maize

Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...

, sorghum

Sorghum

Sorghum is a genus of numerous species of grasses, one of which is raised for grain and many of which are used as fodder plants either cultivated or as part of pasture. The plants are cultivated in warmer climates worldwide. Species are native to tropical and subtropical regions of all continents...

, tomatoes and other organics) and non-edible plants, which were an essential part of the air purification

Air purifier

An air purifier is a device which removes contaminants from the air. These devices are commonly marketed as being beneficial to allergy sufferers and asthmatics, and at reducing or eliminating second-hand tobacco smoke...

process. Compost made from wastewater treatment plants was used effectively as a growth medium

Growth medium

A growth medium or culture medium is a liquid or gel designed to support the growth of microorganisms or cells, or small plants like the moss Physcomitrella patens.There are different types of media for growing different types of cells....

Air purification

The living areas of the BioHome were teeming with plant foliage, the purpose of which was to purify the air of carbon dioxide

Carbon dioxide

Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

. As a result of the experiment, it was also found that the plants purified the air of synthetic offgases, such as those emitted from formaldehyde

Formaldehyde

Formaldehyde is an organic compound with the formula CH2O. It is the simplest aldehyde, hence its systematic name methanal.Formaldehyde is a colorless gas with a characteristic pungent odor. It is an important precursor to many other chemical compounds, especially for polymers...

, benzene

Benzene

Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....

, toluene

Toluene

Toluene, formerly known as toluol, is a clear, water-insoluble liquid with the typical smell of paint thinners. It is a mono-substituted benzene derivative, i.e., one in which a single hydrogen atom from the benzene molecule has been replaced by a univalent group, in this case CH3.It is an aromatic...

and organics. In essence, the plants established and maintained indoor air quality.

Other studies

As a result of the air purification studies, an unspecified student lived in the BioHome for an unspecified period of time. The student made use of the facilities and offered no complaint about the indoor air quality.