I focused on a practical treatment of animal liquid manure for land application using some materials in an aerated reactor. After solid-liquid separation of animal manure in a barn, liquid manure is moved to four tanks sequentially. At each tank a reactor is suspended and aerated with air pump. The reactor consists of pumice, granite, and soil pellet, not only promoting biological digestion of the manure but also providing some minerals in it. The soil pellet is sometimes alternated by the powdery soil, spread at the bottom of the tanks. The aerated reactor system is called “BMW”, meaning bacteria, mineral, and wastewater. After qualified for three week to a month in the sequential tanks, the wastewater, low in organic materials and rich in minerals, is used for plant cultivation as an activated fertilizer. In this study, we investigated the wastewater quality of the BMW plant using soil, granite, and pumice as main materials, installed at a large-scale swine farm. A land application of the treated wastewater from the BMW plant was examined to yam potato production. In addition, at lab scale model plants we investigated the purification and mineral dissolution mechanisms of the materials used in the BMW combined with Shell plant, the BMW combined with Zeolite plant, and the Non-Material plant that using nothing in an aerated reactor.

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Akkeshi-cho is located in the southeast in Hokkaido. The population is 12,300. The main industries are agriculture, forestry and fishery as the primary industry. Akkeshi-cho is challenging to construct a sustainable system based on agriculture, forestry and fishery with using natural and recycling resources. Akkeshi-cho has established “The Organic Waste Compost Center” which enables to convert organic wastes discharged from homes and industries to useful resources and “The Oyster Seedlings Production Center” which enables to produce high-quality oyster seedlings efficiently. We report the present situation of the challenge for constructing the sustainable agriculture, forestry and fishery system, and the future prospect for promoting the challenge with community activities.

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I survey the importance and influence on environment of aquaculture. Although aquaculture is an important fishery enterprise, its influence on environment cannot be disregarded, and must be improved considering maintenance of fishery environment. The closed recirculating aquaculture system is expected to solve this problem. I am evaluating the possibilities of the system to breed the high-class fish and to research for production increase of a fish to control environment, but I am apprehensive about the efficiency to the environmental problem of this system. I make, therefore, a semi-closed recirculating system proposal to flounder aquaculture.
When Japanese flounder are bred in a culture tank on the ground, breeding water is usually kept pouring all the time. In my proposing system, only when load from the tank is larger, the breeding water is recirculated and treated. It is thought that introduction of this system is easy compared with the closed recirculating system, and will contribute to the improvement of fishery environment.

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Fish production in closed recirculating systems, which makes reduced discharge of organic and inorganic wastes possible, is considered to be one of the promising approaches for sustainable development of aquaculture. The system also has advantages in preventing natural disaster such as red tide from damaging fish culture, in accelerating fish growth, and in producing safe fish as food. A pilot scale culture system of 10 m³ in total water volume was developed, and rearing experiment of Japanese flounder Paralichthys olivaceus was carried out. The system consists of a fish tank, settling tank, drum screen filter, submerged biological filter, heating-cooling unit, oxygen generator, blower, and UV-irradiator. In the rearing experiment, 1015 fish of 2 g in body weight were reared for 259 days with pellet diet. Fish grew to 456 g in mean body weight with good survival rate (85%) and feed efficiency (97%). Maturation and spawning of Japanese flounder were also successfully demonstrated in closed recirculating system with considerably small volume of culture water. Fish production with the system will become popular by improving its economical efficiency.

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Although reusable biomass resources are expected for preventing global warming or substitution of petroleum resources as a carbon free energy, compared with the conventional energy resources, introduction is not progressing for the lowness of energy density and the omnipresent nature, and high cost quantity. Therefore, Japanese government decided upon “biomass Nippon general strategy” for a setup of the introductory target as promoting use of alternative energy or its effective use. It can be said that a biomass boom emerged in our country recently. Under the circumstance, the development of energy onversion efficiency such as thermal gasification technology, which related to processing the biomass, has been examined. Considering cost of the collecting biomass waste, however, there are many difficulties and problems in constructing large-scale institution. Considering the situation mentioned above, introducing a small-distributed power generation system can be one of the appropriate solutions in effective use of waste as local resources. From an eco-engineering standpoint as one measure of the environmental load reduction and energy recycling in primary industry which deeply related with biomass production, this paper illustrates present situation of development of low calorie gas co-firing diesel engine for small-scale distributed power generation that enables to create electricity and thermal energy from waste with thermal gasification technology.

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The concept for stabilizing the environmental factors using material recirculation technologies as shown in the Mini-Earth is important for solving the energy crisis and environmental problems. The Eco-Town is one of the Mini-Earth applications, which aim for reducing energy requirement and realizing Zero emission. This paper presents the result of studies on energy balance of the Eco-Town. The result shows, the resident can alive without external energy by saving energy and using solar and wind power energy.

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The eco-engineering system combining the industrialization of agriculture, forestry and fisheries to create the [1+2] industry with the hybrid utilization of renewables with fossil fuels will reduce the natural eco-system degradation and promote the development of the renewables. The hybrid utilization technology of biomass and coal is one of the eco-engineering process which can contribute to construction of sustainable society and prevention of the natural eco-system degradation in South East Asia. The development solar energy in sunbelt by means of hybrid utilization technology such as solar-hybrid fuel production system can be considered as one of the eco-engineering process, which will contribute to construction of sustainable society without destroying the natural eco-system. The creation of green market for utilization of the hybrid fuels will facilitate to solve the problem on the cost higher compared with that of fossil fules.

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Ecosystems in nature are closed systems except an incidence of light and radiations of heat. Microcosm treated here is a minimal ecosystem containing three classes of organisms; chlorella as a producer, bacteria as a decomposer, and rotifer as a consumer. Especially, it is known that ecological structures, i.e. colonies, are generated at their mature stage. It is thought that the formation of colony is important for effective material circulation and stability of the system. Therefore, the formation of colonies in a simulation model is critically important. Then, we have proposed Individual-Based-Model which is based on Cellular Automaton method. It gives local rules of food chain and interaction between organisms including predator-prey relationship, production, suppression, and self-suppression. It enables an emergence of the overall system only by these local rules, and it was possible to reproduce colony generation. Also, a time transition of population of each microorganism corresponded to the experimental results very well. In this study, it was shown that the Individual-Based-Model was very effective to reveal the nature of the ecosystem.

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In this paper, conditions of forming colonies and stability and thermodynamic efficiency of microcosm system are discussed by using the mathematical model of microcosm (Individual-Based-Model) reported in the first report. To examine these matters, behaviors of the system were observed after changing characteristics of microorganisms at its mature stage. As the properties of organisms to be changed, we chose the maximum growth rate coefficients of rotifer and chlorella. Changing the parameters means to perturb the ecosystem. In order to change the maximum growth rate coefficients in the model, it is necessary to vary the division active index (energy for multiplication) or the maximum nutrition intake rate. The simulation resulting from a change of these parameters shows that (1) there are two stable phases of the system, (2) the microcosm with colonies is more efficient than the one without colonies, and (3) the strength of the interaction and its frequency among three organisms are important for the colony formation and the stability of the microcosm system.

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