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The Closed Ecology Experiment Facilities (CEEF) were installed to collect data for estimation of transfer of radionuclides from atmosphere to humans in the ecosystem. The first target among the radio-nuclides is 14C. In order to validate function of material circulation in an experimental system constructed in the CEEF, circulation of air constituents, water and materials in waste was demonstrated connecting the Closed Plant Experiment Facility (CPEF) and the Closed Animal and Human habitation Experiment Facility (CAHEF) of the CEEF, since 2005 to 2007. The CPEF has a Plant Cultivation Module (PCM), which comprises of three plant chambers illuminated solely by artificial lighting, one plant chamber illuminated by both natural and artificial lighting, a space for preparation, and an airlock, and a physical/chemical material circulation system.

Before a series of overall material circulation in an experimental system including crops, animals and humans, technical examinations for the development of a waste processing system were conducted for incorporating the system to the Closed Ecology Experiment Facilities (CEEF). The examinations are intended to validate the function of the carbonization and incineration processing units which were installed in the CEEF in 2006. Using different mock-up samples, examinations have been carried out to verify the function and capability of the whole system, including the waste carbonization processing unit, incineration processing unit, exhaust gas tank and the exhaust gas processing unit. In an examination using filter paper pulp as a mock-up sample, processing time in each unit was checked. The processing times needed for carbonization and incineration processing were 5.7 and 2.6 hours, respectively.

The Closed Ecology Experiment Facilities (CEEF) were installed to collect data for realistic estimation of radiocarbon transfer in the ecosystem. Two-week experiments were conducted three times from September to November of 2006, in which two human subjects called as eco-nauts were enclosed and worked in an airtight facility, the CEEF. The eco-nauts were changed after a week from beginning of each experiment. In these experiments, a Plant Module (PM) with 23 crops, including rice, soybean, peanut, and sugar beet, was connected to an Animal & Habitation Module (AHM) which included the eco-nauts and two goats. 91.8-94.6% (by weight) of the food consumed by the eco-nauts and 79% of the feed to the goats (straw, leaf and bran of rice, leaf and stem of soybean, and leaf, stem and shell of peanut) were produced from crops in the PM. Amount of oxygen produced by the crops was more than the amount consumed by respiration of human and animals in these experiments.

Closed Ecology Experimental Facilities, CEEF, is designed to regenerate everything required for living, such as air, water, and food. Researchers called “econauts” play a crucial role in maintaining the system in good order. CEEF must involve confinement, which is one of the major factors responsible for deterioration in crew health and performance. Two econauts repeated 7-day habitation in the CEEF 3 times in 2005. Blood cells, hormones and mood status were analyzed. Although clinically no problem, changes of mood status and a stress hormone correlated in an econaut. Characteristic changes were observed in leukocyte ratio. These data are essential in considering the effects of forthcoming long-term habitation in CEEF.

This paper introduces a concept and a design to supply paper products for an earth based Advanced Life Support System (ALSS) test bed and it shows some results of paper production trials on the ALSS using inedible biomass. Rice plants (i.e. straw and roots), and soybean stems were pulped by boiling and/or alkali soaking and a mechanical processing method. Paper could be produced from both and exhibited different characteristics. Paper with quality suitable for hygienic tissue could be obtained and very absorbent paper was also possible. A rapid pulping method without a chemical process was also investigated. A potential for reducing chemical consumption, liquid waste and labor cost of paper production in the ALSS was demonstrated.

Closed habitation experiments are to be carried out using Closed Ecology Experiment Facilities (CEEF) from FY2005 to FY2009. The last target of duration of closed habitation is four months. Preliminary study and testing have been conducted in order to carry out the closed habitation experiments. The CEEF has three closed plantation chambers (PC-A, B and C) with artificial lighting solely having each cultivation area of 30 m2 and a closed plantation chamber (PC-F) with both natural lighting and supplemental artificial lighting having a 60-m2 cultivation area. A ‘stable’ period of sequential crop cultivation was maintained for four weeks in a trial experiment conducted in FY2003 using the Plantation Module (PM), in which rice, soybean and crops including rice sapling, soybean sapling, soybean, peanuts and safflower were cultivated in PC-A, PC-B, PC-C and PC-F, respectively. Amount of total clean water input to PM was 741 L day−1 on the average for the period.

A simulation of an open mode system experiment was run using the same experimental conditions as an integration test conducted from September 1999 to February 2000 using the Closed Plant Experiment Facility at the Institute for Environmental Sciences in order to evaluate the operation of closed mode system to be conducted in future. Operation of the open mode system experiment required a supply of water and carbon dioxide from the outside, and the discharge of nutrient waste water and oxygen. The present simulation verified the feasibility of using non-integrated wet-oxidation processor, nutrient synthesis unit and nutrient waste water processor connected within a closed mode system, and it was confirmed that sufficient material circulation could be achieved when rice and soybeans were divided into six beds with different growing stages to facilitate control of the nutrient solution.

In the Closed Ecology Experiment Facilities (CEEF), waste materials such as plant inedible parts, feces and urine of animal and human, and garbage are to be decomposed to inorganic materials by a physical and chemical (P/C) process; Wet Oxidation (W/O). It is known that significant part of nitrogen (N) in the waste materials is reduced to gaseous nitrogen (N2) through W/O process. There is also some deposition of minerals such as iron (Fe) and phosphorous (P) through W/O process. Nitrogen Fixation Subsystem (NFS) produces ammonia (NH3) which is one of end products of NFS, from N2 separated from module air and hydrogen (H2) derived from electrolyses of water, and also produces nitrate (HNO3) from a part of the NH3 and oxygen (O2) derived from electrolyses of water. As another end product of NFS, ammonium nitrate (NH4NO3) is produced from the HNO3 and a part of the NH3.

The Nitrogen Fixation System (NFS) which produces ammonia and nitric acid from nitrogen and water has been developed. The NFS is one essential part of material circulation system of the CEEF (Closed Ecological Experiment Facility) the first Japanese CELSS experiment facility. Basically, physico-chemical and some new technologies are utilized as elemental processes in the NFS. Low pressure ammonia synthesis, ammonia enrichment with PSA and water electrolysis with SPE are such new technologies. We designed and installed the NFS as a subsystem of CEEF. The capacity of the NFS is 125g/day as fixed nitrogen. First operation of NFS is expected to be done early fiscal year of 1996 in CEEF.

In order to verify the material circulation design for a Closed Ecology Experiment Facilities, CEEF, the organic element analysis of edible and inedible parts of the major candidate plants (rice, soybean, sesame and komatsuna (Brassica campestris)) has been carried out experimentally and by using food analysis data. In the experiment, rice, soybean and sesame were cultivated by hydroponics and soil culture for this purpose. The organic element analysis data from the food analysis data were made using empirical chemical equations formulated as to major nutriments by Volk and Rummel. The experimental results showed good agreement with those obtained from the food analysis data. Komatsuna has high nitrogen content. Inedible parts of rice, soybean and sesame have almost the same constituent ratio. The edible part of soybean contains five times as much nitrogen as its inedible part. Rice shows no significant difference between the edible and inedible parts.

IES (Institute for Environmental Sciences) is now constructing CEEF at Rokkasho, Aomori, Japan. The simulation for material flow is made based on a system model of CEEF, which includes one person and 7 plant species of Rice, Soybean, Komatsuna, Sesame, Tomato, Potato and Buckwheat. In this simulation software, plants, human and their support systems are mathematically defined and material flows such as O2, N2, CO2, waters, fertilizers and organic matters are computed. This software simulates only material flow and but does not simulate thermal dynamics of the environment. The simulation result showed reasonable material flows in a closed system.

Construction of Closed Ecology Experiment Facilities (CEEF) is started in Rokkasho village of Aomori prefecture, the northern part of Honshu island in Japan. CEEF consist of Closed Plant Experiment Facility (CPEF) and Closed Geo-Hydrosphere Experiment Facility (CGEF) with capability to simulate ecological systems containing plants, animals, human, trees and sea living things. These biospecies are selected according to experimental plans and are maintained their lives in controlled environments. Recyclings of materials circulating in the closed system of CEEF are made mainly utilizing physical chemical treatments. The construction of CEEF will be completed by 1998. This paper mainly describes design of CPEF.

The system design of the Nitrogen Fixation System (NFS) for CEEF has been carried out. The system is a fertilizer production process for plant cultivation from air and water. Newly developed technologies are adopted as key processes of the system. Use of physico-chemical methods made the total system compact, energy efficient and controllable. The NFS is completely self-confined and generating no unnecessary byproducts. The system has a applicability for future lunar or Mars base CELSS system.

We propose a new recovery system for NaCl from human urine. The system has an electrodialysis (ED) part and a crystallization part. Separation and concentration characteristics of the system are discussed for fundamental experiments of the ED and crystallization parts. Concentrated NaCl-KCl mixed solution is obtained using the ED process from simulated oxidized urine and sweat which include Ca2+ and S042- ions. Then, the crystallization process is used to separate about 80% of the NaCl from the ED treated solution. The experimental studies indicate that the mineral recovery system we proposed can recover NaCl from waste water of a CEEF.

Materials circulating in a closed ecological system are classified as metabolic ones and nonmetabolic ones. Nonmetabolic substances relate to environment constituents and cultural activities. Treatment of these materials are discussed from a view point of CELSS concept. The closed system, CEEF, will be constructed in Japan in the near future. CEEF is an experiment facility with processing capacity of two adult persons, consisting of a plant module, an animal module, a habitat module and supporting facilities for the three modules. The supporting facilities are composed of artificial processors of gases, waters and wastes. The plant module has artificial and natural lighting cultivating sections.