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PubMed1998

Wetland systems for bioregenerative reclamation of wastewater: from closed systems to developing countries.

Results are presented from constructed wetland systems designed to treat wastewater in Akumal, Quintana Roo, Mexico, which was developed after prior experience with the Biosphere 2 closed ecological system wetland systems. These systems illustrate the congruity of needs in advanced life support systems and in solving social and environmental problems in developing countries. For sustainable food production for life support, closed ecological systems need to bioregenerate and recycle nutrient-rich wastewater. Developing countries need low-tech ecologically engineered systems that minimize requirements for capital, nonrenewable energy, and technical expertise. Biosphere 2's surface flow wetlands covered 41 m2 and treated the wastewater from eight inhabitants, laboratories, and domestic animals during the 1991-1993 closure experiment. The Mexican wetlands are subsurface flow wetlands using limestone gravel as substrate. Two wetland systems treat sewage from 40 people and cover 131 m2. During the initial year of operation, the wetlands in Akumal reduced BOD 86%, TSS 39%, total P 80%, total N 75%, and coliform bacteria 99.85%. Phosphorus uptake in the limestone gravel was around 6 mg/kg. High biodiversity, with 70 plant species, was maintained in the Akumal constructed wetlands 1.5 years after planting. The Shannon diversity index was 4.7 (base 2). Plant diversity was slightly less than tropical forest ecosystems of the region, but far greater than biodiversity in natural mangrove wetlands.

Arizona↗
PubMed1994

Considerations of human's long stay in closed systems.

Conditions for long stay of human in closed systems with material circulation, such as space stations and lunar bases, are discussed compared with the current human's life style on earth in the light of human cultural history. Impact on the life-style in the closed ecological system lies on meals and hygiene systems. A key to resolve problems in a new life-style in a closed system lies on mental aspects relating to a new life culture. Necessary items to be developed are shown in order to realize comfortable life in the closed system.

Cultural Evolution↗
PubMed1998

Mineral recovery system for a Closed Ecology Experiment Facility (CEEF).

A unique recovery system, which consists of electrodialysis (ED) and crystallization processes, is proposed for NaCl (salt) from waste water after oxidation of urine. NaCl recovery characteristics from the oxidized urine, which contains KCl and NO3- impurities, were experimentally evaluated. Concentrated NaCl/KCl mixed solution was obtained using the ED process from simulated oxidized urine and sweat. Large amounts of NO3- were contained in the concentrated solution. After the crystallization process, NaCl salt of 90% purity, containing less than 5% NO3-, could be recovered by crystallization from the solution at 90 degrees C because NaNO3 or KNO3 salt has high solubility in water at that temperature. The results show that the proposed mineral recovery system can recover NaCl from waste water in the CEEF.

Chemical Precipitation↗
PubMed1994

"SYMBIOSE" SYstem for Microgravity BIOregenerative Support of Experiments.

SYMBIOSE is an ESA supported research and development program which aims at establishing a first pilot model of a closed ecological system, compatible with operation in weightlessness conditions, and dedicated to scientific investigations in the microgravity environment. It integrates microalgal photosynthesis within an artificial ecosystem featuring a symbiotic strain of Chlorella (241 .80, Gottingen), which synthesizes and excretes substantial amounts of maltose, and is further looped on a consumer compartment. A technological concept has been developed. It is presently being integrated in order to gain knowledge on the system dynamics, and ultimately demonstrate the feasibility of such a biotechnology. Preliminary work on the photosynthetic metabolism of this microalga is being undertaken in order 1) to support later a mathematical formalisation of the dynamics of this artificial ecosystem, and, on this basis, 2) to compensate for its lack of stability with model-based external control. The most recent results are presented, along with a new design of the photobioreactor which integrates efficient light energy capture, microgravity compatible gas transfer and reduced shear stress.

Bioreactors↗
PubMed2003

Development and research program for a soil-based bioregenerative agriculture system to feed a four person crew at a Mars base.

For humans to survive during long-term missions on the Martian surface, bioregenerative life support systems including food production will decrease requirements for launch of Earth supplies, and increase mission safety. It is proposed that the development of "modular biospheres"--closed system units that can be air-locked together and which contain soil-based bioregenerative agriculture, horticulture, with a wetland wastewater treatment system is an approach for Mars habitation scenarios. Based on previous work done in long-term life support at Biosphere 2 and other closed ecological systems, this consortium proposes a research and development program called Mars On Earth(TM) which will simulate a life support system designed for a four person crew. The structure will consist of 6 x 110 square meter modular agricultural units designed to produce a nutritionally adequate diet for 4 people, recycling all air, water and waste, while utilizing a soil created by the organic enrichment and modification of Mars simulant soils. Further research needs are discussed, such as determining optimal light levels for growth of the necessary range of crops, energy trade-offs for agriculture (e.g. light intensity vs. required area), capabilities of Martian soils and their need for enrichment and elimination of oxides, strategies for use of human waste products, and maintaining atmospheric balance between people, plants and soils.

Air Conditioning↗
PubMed1994

Biospherics: a new science

The experience of human existence in the last few decades shows clearly that developed civilizations come into greater and greater antagonism with nature. Modern technology cannot on its own coexist easily with the biosphere without destroying key biological components. The necessity of comprehending the laws of development of the biosphere as a single whole is becoming more and more obvious and urgent. Because it is so precious and fragile, the biosphere cannot be subjected to any direct study which may harm it. Therefore this science depends on the study of analogs and small models such as artificial ecological systems with differing degrees of complexity and closure. On such model ecosystems we can (and must) study both the particular laws of development of individual elements and components of the ecosystems, and the general principles of turnover of the entire biospheric system. As this new science is being formed, it is necessary to develop the scientific basis of harmonizing the relationship of humanity and nature, to open the path to the next phase, termed the noosphere by Vernadsky. The principal objects of study are closed ecological systems, from simple microsystems to more sophisticated human life-support systems under extreme conditions on the Earth and in space. Biospherics by its very nature knows no political boundaries, and is by necessity an international effort. As such, it is deserving of support both intellectually and economically from all peoples.

Earth, Planet↗
PubMed1998

Concluding remarks of Autonomous Biological Systems (ABS) experiments.

Team efforts for analysis on the Autonomous Biological Systems (ABS) space experiments are summarized here to conclude scientific findings, and to scope the extended studies in future. From the three experiments on Space Shuttle and Space Station Mir, a closed ecological system modeled by the ABS was verified to be capable of sustaining its members of animals and plants under space environment for a period of several months. The animals successfully completed their life cycle in space during the course of these experiments, this was the first time that the life cycle of higher organisms had been completed in space and ecological system. Importance of gravity for ecology was proven at the same time. Gravity is a dominant factor for ecology by formulating spatial patterns and distribution of members of ecological system. Under microgravity, the fate of ecological system was found highly sensitive against the variation of environmental factor, such as light illumination cycle.

Amino Acids↗
PubMed1985

Dehydrohalogenation of atmospheric contaminants in the space cabin.

A total of nine chlorinated ethanes and ethenes were circulated over lithium hydroxide in a laboratory scale closed system simulator. System volume and lithium hydroxide temperature were varied from that intended to maximize possible reactions to conditions approximating those of a space cabin environment. Of the nine compounds tested, seven were found to be dehydrohalogenated (viz., loss of hydrogen chloride) in the course of one or more experimental treatments. Of particular significance was the conversion of 1,2-dichloroethane to chloroethene, a known carcinogen, and of trichloroethene to dichloroethyne, a highly toxic substance. It is therefore concluded that a potentially hazardous situation exists for the inhabitants of closed ecological systems such as spacecraft, one for which precautions must continue to be taken.

Air Pollution↗
PubMed1983

Changes in symbiotic and associative interrelations in a higher plant-bacterial system during space flight.

The miniature cenosis consisting of the water fern Azolla with its associated symbiotic nitrogen-fixing cyanobacterium Anabaena and the concomitant bacteria was investigated. Ecological closure was shown to produce sharp quantitative and qualitative changes in the number and type of concomitant bacteria. Changes in the distribution of bacterial types grown on beef-extract broth after space flight were recorded. Anabaena azollae underwent the most significant changes under spaceflight conditions. Its cell number per Azolla biomass unit increased substantially. Thus closure of cenosis resulted in a weakening of control over microbial development by Azolla. This tendency was augmented by spaceflight factors. Reduction in control exerted by macro-organisms over development of associated micro-organisms must be taken into account in constructing closed ecological systems in the state of weightlessness.

Anabaena↗
PubMed2003

Naturally deducing estimate for the coefficient of CELSS closure.

The term Closed Ecological System (CES) is in wide use. However there is no generally accepted measure of the closure of ecological systems. In order to obtain reproducibility of experiments with natural and man-made CES (with respect to degree of closure) some universal estimate needs to be developed. Understanding ecological systems as a network and closure as the degree of matter recycling allows the use of matrix graphs. Graphs are very natural forms for the presentation of the network of matter flows in ecosystems. An estimate equal to the sum of products of weights of oriented edges that constitute contour is suggested as a measure of the degree of closure in ecosystems. It is shown that this estimate can be uniformly applied to ecosystems of arbitrary size and configuration of flows.

Biomass↗
PubMed2003

Embryogenesis and swimming behavior of Medaka fish in JUSTSAP STARS Program (STS-107).

JUSTSAP (Japan-US Science, Technology and Space Application Program) Medaka fish experiment was carried out as a part of STARS (Space Technology and Research for Student) experiment, a space shuttle mission, STS-107 in January 2003. Four eggs laid on earth under artificially controlled environment were put in a closed ecological system, AHAB (Aquatic Habitat), and launched by Space Shuttle Columbia. For the control experiment, four eggs were put in the AHAB and remained on the ground. There was no remarkable difference in the time course of the development. In ground experiment embryos were observed to rotate in the egg membrane, whereas in flight unit they did not rotate. One egg hatched out on L (Launch) +8 days in flight unit. Four eggs hatched out in ground unit. Fry in flight unit was observed to face its back usually to the camera with little swimming movement. Fry in ground unit were observed to move actively and also to control their posture with respect to gravity vector.

Animals↗
PubMedDate not supplied

[Formation of microbial biocenosis of wheat in a manned spacecraft].

Mutual effects of microbial complexes of biological objects, men and their environment are of crucial importance for manned space missions. The present experiment to study wheat microflora flown in a manned spacecraft was a continuation of investigations the purpose of which was to identify the pattern of formation of microbial cenosis of higher plants in a closed ecological system. It was found that the microbial cenosis of plants grown during an early period of vegetation in space was formed under the influence of the anthropogenic factor. It was characterized by a high bacterial and fungal concentration of their phyllosphere and, to a lesser extent rhizosphere, occurrence of Escherichia coli representatives, and increased amount of cellulose-lytic bacteria.

Aerospace Medicine↗
PubMed1992

Biosphere 2 Test Module: a ground-based sunlight-driven prototype of a closed ecological life support system.

Constructed in 1986, the Biosphere 2 Test Module has been used since the end of that year for closed ecological systems experiments. It is the largest closed ecological facility ever built, with a sealed variable volume of some 480 cubic meters. It is built with a skin of steel spaceframes with double-laminated glass panels admitting about 65 percent Photosynthetically Active Radiation (PAR). The floor is of welded steel and there is an underground atmospheric connection via an air duct to a variable volume chamber ("lung") permitting expansion and contraction of the Test Module's air volume caused by changes in temperature and barometric pressure, which causes a slight positive pressure from inside the closed system to the outside thereby insuring that the very small leakage rate is outward. Several series of closed ecological system investigations have been carried out in this facility. One series of experiments investigated the dynamics of higher plants and associated soils with the atmosphere under varying light and temperature conditions. Another series of experiments included one human in the closed system for three, five and twenty-one days. During these experiments the Test Module had subsystems which completely recycled its water and atmosphere; all the human dietary needs were produced within the facility, and all wastes were recycled using a marsh plant/microbe system. Other experiments have examined the capability of individual component systems used, such as the soil bed reactors, to eliminate experimentally introduced trace gases. Analytic systems developed for these experiments include continuous monitors of eleven atmospheric gases in addition to the complete gas chromatography mass spectrometry (GCMS) examinations of potable, waste system and irrigation water quality.

Air Conditioning↗
PubMed1988

Carbon recycling in materially closed ecological life support systems.

Materially closed microbial ecosystems represent model life support systems for the future human habitation of space. These ecosystems when subjected to a constant energy flux seem to be reliable and self-sufficient systems for recycling of biologically produced carbon compounds.

Bacteria↗
PubMed1984

Algal culture studies related to a closed ecological life support system.

Long-term cultures of Scenedesmus obliquus were maintained in an annular air-lift column operated as a turbidostat. We observed a linear relationship between the dry weight of the cultured cells, their cell number, and their chlorophyll content over a broad range of cell density at constant illumination. Thus, the cells did not appear to be adapting to differences in growth rate or light intensity during these experiments. Productivity vs dry wt rose linearly until the cell density reached a level at which light became limiting; at this point approximately 89% of the photosynthetically active radiation (PAR) was being absorbed. The maximum dilution rate of the system corresponded to a doubling time of 13.8 hr, about half the maximum growth rate generally observed at this temperature. Productivity at the maximum was approximately 80% of the maximum theoretical productivity. The rather low incident intensities (approximately 10% of full sunlight) were a main contributing factor to the high light utilization efficiencies obtained in this system, since the cells were never driven into light saturation. In many respects, algae would be ideal plant components for a biologically-based closed life support system, since they are eminently suited to the closely coupled functions of food production and atmosphere regeneration. In this communication, we report some findings on the (steady-state) continuous culture of Scenedesmus obliquus, a physiologically well-characterized green alga with good growth characteristics.

Bioreactors↗
PubMed1994

Man as a component of a closed ecological life support system

Material support of all manned space flights so far has been provided from a prestored stock of substances or replenished from the Earth's biosphere. Exploration of space will, however, become real only when man is able to break away from Earth completely, when he will be accompanied by a system providing everything necessary to sustain full-valued life for an unlimited time. The only known system to date meeting this requirement is the Earth's biosphere. To break away from his cradle, as K.E. Tsiolkovsky called Earth, it is necessary to devise a life support system functionally similar to the natural biosphere. This need not be similar in structure to the vast diversity of trophic relationships available on Earth, but requires the solution of a multitude of various problems of an ecological, physiological, engineering and social-psychological nature. Human life-support systems based on biological regeneration of environments in small volumes have been studied at the Institute of Biophysics (Siberian Branch of the Russian Academy of Sciences) over many years. This work has resulted in the design of Bios-3, a biologically-based self-sustained human life support system.

Blood Cell Count↗
PubMed2001

Application of crop gas exchange and transpiration data obtained with CEEF to global change problem.

In order to predict carbon sequestration of vegetation with the future rise in atmospheric CO2 concentration, [CO2] and temperature, long term effects of high [CO2] and high temperature on responses of both photosynthesis and transpiration of plants as a whole community to environmental parameters need to be elucidated. Especially in the last decade, many studies on photosynthetic acclimation to elevated [CO2] at gene, cell, tissue or leaf level for only vegetative growth phase (i.e. before formation of reproductive organs) have been conducted all over the world. However, CO2 acclimation studies at population or community level for a whole growing season are thus far very rare. Data obtained from repeatable experiments at population or community level for a whole growing season are necessary for modeling carbon sequestration of a plant community. On the other hand, in order to stabilize material circulation in the artificial ecological system of Closed Ecology Experiment Facilities (CEEF), it is necessary to predict material exchange rates in the biological systems. In particular, the material exchange rate in higher plant systems is highly variable during growth periods and there is a strong dependence on environmental conditions. For this reason, dependencies of both CO2 exchange rate and transpiration rate of three rice populations grown from seed under differing conditions of [CO2] and day/night air temperature (350 microL CO2 L-1, 24/17 degrees C (population A); 700 microL CO2 L-1, 24/17 degrees C (population B) and 700 microL CO2 L-1, 26/19 degrees C (population C)) upon PPFD, leaf temperature and [CO2] were investigated every two weeks during whole growing season. Growth of leaf lamina, leaf sheath, panicle and root was also compared. From this experiment, it was elucidated that acclimation of instantaneous photosynthetic response of rice population to [CO2] occurs in vegetative phase through changes in ratio of leaf area to whole plant dry weight, LAR. But, in reproductive growth phase (i.e. after initiation of panicle formation), the difference between photosynthetic response to [CO2] of population A and that of population B decreased. Although LAR of population C was almost always less than that of population A, there was no difference between the photosynthetic response to [CO2] of population A at 24 degrees C and that of population C at 26 degrees C for its whole growth period. These results are useful to make a model to predict carbon sequestration of rice community, which is an important type of vegetation especially in Asia in future global environmental change.

Carbon Dioxide↗