The mass flow in a soy-sauce production process was analyzed for total mass and four important elements selected from the viewpoints of aqua-environment, that is, organic carbon, nitrogen, phosphorus and chlorine. The soy-sauce lees wasted after filtration of fermented broth was main solid emission and almost all of the liquid emissions were discharged from washing of the apparatus. The dry distillation was investigated to examine its possibility as a method of changing the wasted lees to useful resourceals. It was demonstrated that the gas, liquid and residual solid could be used as an additional fuel of distillation and soil additives for the improvement of vegetable growth.

View full abstract

For the purpose of recovering lead(II) ion from water environments, the adsorption gel was prepared from orange juice residue by saponificating with alkaline solution followed by crosslinking with epichlorohydrin. Adsorption of lead(II) and zinc(II) was tested with the model aqueous solution containing both two metal ions, and it was observed that the gel had high selectivity to lead(II) over zinc(II). In the breakthrough test of lead(II) and zinc(II) by using of the column packed with the adsorption gel, effective removal of lead(II) from the model solution containing lead(II) and zinc(II) was achieved up to about 90 bed volume at solution pH of 2.6. By elution with 1 M nitric acid solution, concentrated lead(II) solution free from zinc was obtained.

View full abstract

Recently, an environmental problem has become a serious problem in a world.Reducing the emission from each industry is impotant . But, it is finite. So, it is necessary to re-use waste products as inputs of another process. In this research, we construct an input-output database system, and by using the database we develop the information system which can search the input-output connection under general frameworks.

View full abstract

Steam explosion of soy sauce cake was carried out to convert it to resources. The effects of cooking temperature, cooking time, the addition of sulfuric acid were studied on the weight loss, elemental analyses and particle size distribution of the residual solids, and TOC and chlorine contents in the waste water. The effects of the addition of sulfuric acid on residual solid weight, and the contents of organic carbon and chlorine ion in the waste water were not evident, but the average diameters of the residual solid decreased. The steam explosion treatment was found effective in terms of short operating time, the amount of the waste water and desalination, as compared with the hot water extraction process.

View full abstract

When the various reuse systems are planned to install, it is important to consider whether the demand for materials reused is enough or not. In this study, the possible supply and demand of compost are estimated for each municipalities in Aichi Prefecture, and the feasibility for installation of compost facilities is investigated. As sources of compost, kitchen garbage from household, sewage sludge and livestock excreta are considered. If compost from excreta of cattle and hens is preferred to use than that from kitchen garbage, and that from kitchen garbage is preferred to use than that from sewage sludge, the compost from sewage sludge is not used in the most of municipalities in the object area.

View full abstract

Nitrogen emission from Nagoya University Farm, where both livestock farming and crop cultivation are carried out and animal feces are recycled through composting, was estimated and scenarios for the reduction of N emission were evaluated. Higher than 80% of nitrogen in feeds and fertilizers were emitted through composting and fertilization. After long-term application of compost, most nitrogen applied as compost became apparently emitted in the same cropping season. In the soil receiving only chemical fertilizers (CF soil), the soil nitrogen concentration decreased, indicating the needs of compost. About 40% of fertilizer nitrogen were absorbed into crops in CF soil, and mulch improved it by several percentages. The absorption rates were lower in the soils receiving compost. Nitrogen loss by denitrification was not observed in CF soil, while about 10% or higher in the soils receiving compost. Nitrate leaching was the major pathway of emission. Higher nitrate concentration in leachate from the soils receiving compost was observed. Reduction of fertilizer nitrogen was effective to reduce emission by 24%. A scenario allowing the highest nitrogen flux by the less nitrogen loss during composting with rice straw and the lowest nitrogen inflow into the Farm achieved to reduce the estimated emission by 40%.

View full abstract

Biomass is renewable resources for material and energy, which can really achieve sustainable societies. The amount of carbon contained in biomass annually unutilized and emitted into environment in Japan is about 30-40% of carbon consumed to produce a variety of petrochemicals from oil . Also, biobased products can be reused and/or recycled easily as compared to oil-basis plastics. These facts mean in principle that we already have plenty of renewable resources as far as materials concerned. A concept of "Biomass Refinery" has been proposed recently as an alternative of oil refinery, where services can be provided by biochemicals and biobased products. In this work, material conversion technologies developed in the Monbusyo project, "Zero Emissions Oriented Material Cycle Processes" (The Ministry of Education, Science, Sports and Culture; Grant-in-Aid for Scientific Research on Priority Areas 292, 1996-2000), were summarided and organized in comparison with traditional and conventional biomass utilization technologies.

View full abstract

To maintain sustainable development, that is, to create entire human activities for good quality of life, a social system, which minimize emission to be zero, should be established. To actualize such kind of social request, the research project “Zero Emissions Oriented Material Cycle Processes” supported by Monbusho (The Ministry of Education, Science, Sports and Culture; Grant-in-Aid for Scientific Research on Priority Areas have been performed from 1996 to 2000. In this project, group A03, construction of a mathematical model describing material cycle and prediction/evaluation of regional zero emission, has been investigated as a methodology to actualize regional zero emission and evaluation. In order to establish regional zero emission, current material flow and utilization should be cleared, reduction potential of resource/energy consumption and pollution load should be analyzed with maintaining human and manufacturing activities, and zero emission oriented new material cycle process should be evaluated. It is desirable that total quality management of waste, citizen participant system, environmental law and economical effect should be further investigated for sustainable development of our life and societies.

View full abstract

The mass flow and risk evaluation of recycled aggregates on road works were studied, as there are a lot of inputs and outputs of aggregates on road works . The mass flow was surveyed on each road works conducted for 3 years in a local area and the energy requirement for road works based on the mass flow was estimated. The aggregates dug out may be reused in the spot and the reuse of discharged aggregates extremely decreases the energy consumption of road works in comparison with that of the conventional road works because of cutting down a new input of aggregates. Crushed concrete used as roadbeds are scarcely dissolved into water under the circumstance of roadbeds. The effect of eluate on the environmental pollution is little.

View full abstract

In this study we have performed an evaluation on the material flow of plastic from the Zero-Emission perspective, aiming at the rational use of natural resources as well as control of the strain that plastic materials pose to the environment and the ecology. In Japan, surveys related to the state of affairs in this field show that no more than 12% of waste plastic is regenerated, and even when energy recovery processes are taken into account this value amounts to only 44% . The remainder undergoes simple incineration without energy recovery or is buried in disposal facilities. To achieve the goal of ZeroEmiss ion in the production and consumption of plastics, the most rational material flow process must be created by optimal combination of the hitherto existing pathways . Here we discuss about the ideal material flow process to achieve the zero emission objective in our country as part of the zero emission research project.

View full abstract

This account consists mainly of four sections: (1) Analysis on the depletion problem of petroleum resource that is essential to plastic production. (2) Critical evaluation of the current industrial and government policies that consider waste plastics as wastes but not recyclable materials resources. (3) Proposals for the promotion of monomer recycling systems as the innovation of plastic problems illustrated by the efficient depolymerization of polyethylene terephthalate) and poly(carbonate). (4) Manufacturing of plant-originating non-biodigradable plastics and their recycling as chemical resources are proposed for the future society. This study was done on the basis of the Zero-Emission concept.

View full abstract

The feasibility study for the construction of regional zero-emission system of organic solid wastes such as waste food was carried out noticing the usefulness of waste cold heat of -160°C from LNG tank to the production of feed by freeze-drying technique. As the results, the daily energy of waste cold heat from the LNG tank located m a research area was estimated to be 4.8×10⁶ cal/day, and the ability for freeze-drying treatment by the waste cold heat was concluded to be 7.3 ton/day in a case of using waste food of which water content was 72%. Emissions of waste food from ten shopping center and one provision center of school lunch in the research area were 1.9 ton/day and 0.4 ton/day, respectively. Therefore, the potential of the waste cold heat was seemed to be sufficient for the conversion the waste food to feed material by freeze-drying treatment. The dry products from waste food of 2.3 ton was calculated to be 0.52 ton. It suggests that feed of 5.2 ton per day was produced by mixture of the ratio of 10 % to other feed material.

View full abstract