Search NASA⌕ Search

Engineering topics

Wolverton, B. C.

Publications and source records attributed to Wolverton, B. C..

At least 19 records

Plants and their microbial assistants: Nature's answer to Earth's environmental pollution problems

The utilization of higher plants and their associated microorganisms to solve environmental pollution problems on Earth and in future space applications is briefly reviewed. If man is sealed inside closed facilities, he becomes a polluter of the environment. It is also common knowledge to most people that man cannot survive on Earth without green photosynthesizing plants and microorganisms. Therefore, it is vitally important to have a better understanding of the interactions of man with plants and microorganisms. Biosphere 2 and other related studies presently being conducted or planned, hopefully, will supply data that will help save planet Earth from impending environmental disaster. The development of means to utilize both air and water pollution as a nutrient source for growing green plants is examined.

Wolverton, B. C.↗

Interior Landscape Plants for Indoor Air Pollution Abatement

In this study, the leaves, roots, soil, and associated microorganisms of plants have been evaluated as a possible means of reducing indoor air pollutants. Additionally, a novel approach of using plant systems for removing high concentrations of indoor air pollutants such as cigarette smoke, organic solvents, and possibly radon has been designed from this work. This air filter design combines plants with an activated carbon filter. The rationale for this design, which evolved from wastewater treatment studies, is based on moving large volumes of contaminated air through an activated carbon bed where smoke, organic chemicals, pathogenic microorganisms (if present), and possibly radon are absorbed by the carbon filter. Plant roots and their associated microorganisms then destroy the pathogenic viruses, bacteria, and the organic chemicals, eventually converting all of these air pollutants into new plant tissue. It is believed that the decayed radon products would be taken up the plant roots and retained in the plant tissue.

Wolverton, B. C.↗

A Study of Interior Landscape Plants for Indoor Air Pollution Abatement

Previously, preliminary data on the ability of a group of common indoor plants to remove organic chemical from indoor air was presented. The group of plants chosen for this study was determined by joint agreement between NASA and the Associated Landscape Contractors of America. The chemicals chosen for study were benzene, trichloroethylene, and formaldehyde. The results show that plants can play a major role in removal of organic chemicals from indoor air.

Wolverton, B. C.↗

Bioregenerative space and terrestrial habitat

For 15 years, NASA has been involved in bioregerative component development for air, water, and waste treatment. The results of this work have been integrated in the completion of a novel facility called BioHome which incorporates all of the developed bioregenerative components for air, water, and nutrient recovery into a single habitat. The evaluation and refinement of BioHome's integrated component efficiencies will provide a test-bed for future systems to be used in long-term space travel.

Wolverton, B. C.↗

Foliage Plants for Improving Indoor Air Quality

NASA's research with foliage houseplants during the past 10 years has produced a new concept in indoor air quality improvement. This new and exciting technology is quite simple. Both plant leaves and roots are utilized in removing trace levels of toxic vapors from inside tightly sealed buildings. Low levels of chemicals such as carbon monoxide and formaldehyde can be removed from indoor environments by plant leaves alone, while higher concentrations of numerous toxic chemicals can be removed by filtering indoor air through the plant roots surrounded by activated carbon. The activated carbon absorbs large quantities of the toxic chemicals and retains them until the plant roots and associated microorganisms degrade and assimilate these chemicals.

Wolverton, B. C.↗

Aquatic Plant/microbial Filters for Treating Septic Tank Effluent

The use of natural biological processes for treating many types of wastewater have been developed by NASA at the John C. Stennis Space Center, NSTL, Mississippi, during the past 15 years. The simplest form of this technology involves the use of aquatic plant/marsh filters for treatment of septic tank effluent. Septic tank effluent from single home units can be treated to advanced secondary levels and beyond by using a 37.2 sq m (400 sq ft) surface area washed gravel filter. This filter is generally 0.3 m (1 ft) deep with a surface cover of approximately 0.15 m (6 in.) of gravel. The plants in this filter are usually aesthetic or ornamental such as calla lily (Zantedeschia aethiopica), canna lily (Canna flaccida), elephant ear (Colocasia esculenta), and water iris (Iris pseudacorus).

Wolverton, B. C.↗

Aquatic Plants and Wastewater Treatment (an Overview)

The technology for using water hyacinth to upgrade domestic sewage effluent from lagoons and other wastewater treatment facilities to secondary and advanced secondary standards has been sufficiently developed to be used where the climate is warm year round. The technology of using emergent plants such as bulrush combined with duckweed is also sufficiently developed to make this a viable wastewater treatment alternative. This system is suited for both temperate and semi-tropical areas found throughout most of the U.S. The newest technology in artificial marsh wastewater treatment involves the use of emergent plant roots in conjunction with high surface area rock filters. Smaller land areas are required for these systems because of the increased concentration of microorganisms associated with the rock and plant root surfaces. Approximately 75 percent less land area is required for the plant-rock system than is required for a strict artificial wetland to achieve the same level of treatment.

Wolverton, B. C.↗

Space bio-technology in housing

Gas chromatography and mass spectrometry data obtained from monitoring atmospheric pollutants in Skylab spurred studies of indoor pollutants in terrestrial buildings. Subsequent studies of techniques for removing the pollutants from space habitats have led to building concepts which achieve the same purpose on earth. The Skylab data indicated that the synthesized organic materials used in many modern buildings, furnishings, personal clothing and aerosols add significant amounts of chemicals to the indoor atmosphere. Lowered circulation and ventilation rates to conserve energy have caused trapping of these substances in buildings. Studies of methods for space modules which will use plants and microbes to absorb airborne and wastewater pollutants have defined biotechnology designs which can be applied to remove pollutants from air and wastewater organically. Plant roots trap pollutants from wastewater and leaves readily absorb air pollutants, as well as improve the overall energy efficiency of buildings. Several designs which incorporate biotechnology to enhance both the aesthetics and efficiency of homes and office buildings are illustrated.

Wolverton, B. C.↗

Houseplants, Indoor Air Pollutants, and Allergic Reactions

The technology of using houseplant leaves for reducing volatile organics inside closed facilities has been demonstrated with formaldehyde and benzene. Philodendrons are among the most effective plants tested to date. Philodendron domesticum had demonstrated the ability to remove formaldehyde from small experimental chambers at a rate of 4.31 micro-g/sq cm leaf surface area with initial starting concentrations of 22 ppm. At initial starting concentrations of 2.3 ppm a formaldehyde removal rate of 0.57 micro-g/sq cm was achieved during a 24 hour test. Aleo vera demonstrated a much higher formaldehyde efficiency removal rate than Philodendron domesticum at low formaldehyde concentrations. During a 24 hour exposure period 5 ppm of formaldehyde were reduced to 0.5 ppm demonstrating a removal efficiency rate of 3.27 micro-g/sq cm. Removal efficiency rates can be expected to decrease with concentration levels because fewer molecules of chemicals come in contact with the leaf surface area. Several centimeters of small washed gravel should be used to cover the surface of pot plants when large numbers of plants are kept in the home. The reason for this is to reduce the exposed area of damp potting soil which encourages the growth of molds (fungi). The leaves of Philodendron domesticum and golden pothos (Scindapsus aureus) have also demonstrated their ability to remove benzene and carbon monoxide from closed chambers. A combination of activated carbon and plant roots have demonstrated the greatest potential for removing large volumes of volatile organics along with smoke and possible radon from closed systems. Although fewer plants are required for this concept a mechanical blower motor must be used to pull or push the air through the carbon-root filter. NASA studies on motor sizes and bioregeneration rates should be completed by 1988.

Wolverton, B. C.↗

Microbial-Plant Filters (artificial Marshes) for Treating Domestic Sewage and Industrial Wastewater

Wastewater treatment is an integral part of the water crisis that is emerging throughout the world. Even areas of the U.S. and other parts of the world with a plentiful supply of water are facing problems because the water is becoming contaminated with sewage and/or hazardous chemicals. Therefore, one of the most urgent environmental needs in the world today is a simple, low cost means of wastewater treatment and water reuse.

Wolverton, B. C.↗

Aquatic Plants Aid Sewage Filter

Method of wastewater treatment combines micro-organisms and aquatic plant roots in filter bed. Treatment occurs as liquid flows up through system. Micro-organisms, attached themselves to rocky base material of filter, act in several steps to decompose organic matter in wastewater. Vascular aquatic plants (typically, reeds, rushes, cattails, or water hyacinths) absorb nitrogen, phosphorus, other nutrients, and heavy metals from water through finely divided roots.

Wolverton, B. C.↗

Foliage plants for indoor removal of the primary combustion gases carbon monoxide and nitrogen dioxide

Foliage plants were evaluated for their ability to sorb carbon monoxide and nitrogen dioxide, the two primary gases produced during the combustion of fossil fuels and tobacco. The spider plant (Chlorophytum elatum var. vittatum) could sorb 2.86 micrograms CO/sq cm leaf surface in a 6 h photoperiod. The golden pothos (Scindapsus aureus) sorbed 0.98 micrograms CO/sq cm leaf surface in the same time period. In a system with the spider plant, greater than or equal to 99 percent of an initial concentration of 47 ppm NO2 could be removed in 6 h from a void volume of approximately 0.35 cu m. One spider plant potted in a 3.8 liter container can sorb 3300 micrograms CO and effect the removal of 8500 micrograms NO2/hour, recognizing the fact that a significant fraction of NO2 at high concentrations will be lost by surface sorption, dissolving in moisture, etc.

Wolverton, B. C.↗

Method for treating wastewater using microorganisms and vascular aquatic plants

A method for treating wastewater compresses subjecting the wastewater to an anaerobic setting step for at least 6 hours and passing the liquid effluent from the anaerobic settling step through a filter cell in an upflow manner. There the effluent is subjected first to the action of anaerobic and facultative microorganisms, and then to the action of aerobic microorganisms and the roots of at least one vascular aquatic plant.

Wolverton, B. C.↗

Treating domestic wastewater with water hyacinths

Greenhouse system purifies water, extracts fertilizers, and generates fuels. When fully developed, system may supplant septic tanks and central sewage for rural and underdeveloped areas.

Mcdonald, R. C.↗

Energy from aquatic plant wastewater treatment systems

Water hyacinth (Eichhornia crassipes), duckweed (Spirodela sp. and Lemma sp.), water pennywort (Hydrocotyle ranunculoides), and kudzu (Pueraria lobata) were anaerobically fermented using an anaerobic filter technique that reduced the total digestion time from 90 days to an average of 23 days and produced 0.14-0.28 cu m CH4/kg (dry weight) (2.3-4.5 cu ft/lb) from mature filters. The anaerobic filter provided a large surface area for the anaerobic bacteria to establish and maintain an optimum balance of facultative, acid-forming, and methane-producing bacteria. Consequently the efficiency of the process was greatly improved over prior batch fermentations.

Wolverton, B. C.↗

Fuel gas from biodigestion

Biodigestion apparatus produces fuel gas (primarily methane) for domestic consumption, by anaerobic bacterial digestion of organic matter such as aquatic vegetation. System includes 3,786-1 cylindrical container, mechanical agitator, and simple safe gas collector for short term storage.

Mcdonald, R. C.↗