We examined the real running conditions of municipal waste collection vehicles in Tokyo, and established a running pattern for the estimation of exhaust gas from vehicles used in the collection of municipal waste.
The emitted amounts of air pollutants from 3 kinds of low emission vehicles used in municipal waste collection, that used methanol, liquefied petroleum gas, and compressed natural gas as fuel, were investigated according to established running patterns, and were compared with those of a diesel vehicle over a distance of 1 km. It was found that NOx and particulate matter decreased drastically, but CO, total hydrocarbons, and HCHO did not always decrease. Furthermore, the emission units (g / t-waste) of the air pollutants from the municipal waste collection vehicles were obtained. In all of Japan, the emitted amounts of NOx, CO, total hydrocarbons, HCHO, and particulate matter from municipal waste collection vehicles were estimated to be 2.2 × 10³ t/y, 1.1 × 10³t/y, 1.6 × 10² t/y, 9.0 t/y, and 2.6 × 10² t/y respectively, in 1995.

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In the ‘Primary Disassembly Process’, a motor or a compressor is removed and disassembled from the cabinet of a post-use electrical home appliance by automatically cutting the part of the cabinet to which the motor or compressor is fastened. Using the automatic ‘Primary Disassembly Process’ it is necessary to recognize the category of electrical home appliances to which an object belongs, to know the position at which the motor or compressor is attached to the appliance, and to sort the appliance according to its category. We therefore developed a method for automatically recognizing an appliance's category, as well as a method for automatically finding the attachment position of the motor or compressor and also determining where to cut the cabinet in order to remove the motor or compressor.
The former method determines an appliance's category by measuring its cabinet size by using computer vision. The latter method finds the attachment position by measuring the ‘unbalance’ of the appliance's mass.
It took about 40 seconds to perform the automatic recognition and sorting process by using an automatic sorting machine based on these methods.

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Cadmium elimination from the waste products of scallop processing, which are below the regulation content is necessary to reuse these wastes as feed and fertilizer materials.
In this experiment, influences of various factors on cadmium removal efficiency were examined, to decide the most suitable conditions using an electrochemical treatment method. This method consists of a cadmium leaching process from the mid-gut gland by soaking in a sulfuric acid solution, and a cadmium electrodeposition process on the cathode surface by passing an electric current through it.
We have obtained the following results by using this method.
1) The grain size of the mid-gut gland has a great influence on the cadmium leaching rate, as expected. Therefore, drying and crushing the scallop waste is useful for shortening the cadmium removal treatment time, to about half as many hours as when not crushed.
2) Ti plates coated with iridium oxide and coated Pt group oxides are most suitable for anode materials when using this electrolysis method.
3) A minimum electrolytic voltage of 3.2 V is required for deposition of cadmium when using this electrolysis method. Consequently, in cases of electrolysis below this electrolytic voltage, cadmium does not deposit, and conversely remelting of deposited cadmium on the cathode surface is caused.

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In this experiment, the manufactured RDF made from combustible wastes was carbonized to develop new uses of RDF. Carbonization has been applicable to lumber and coal as an important method of making refining fuels.
The following results were obtained.
The weight of the carbonized product changed to 1/3 of the weight of RDF and 1/8-4/6 of that of the original waste that was originally RDF material. Another effect of carbonization was, 61% of chlorine was decreased. While trace elements which are necessary for the growth of plants are contained in the carbonized product, the content and the leaching amount of the toxic substance are so small, the carbonized product can be used as a soil improvement material.
To reduce the chlorine content, the carbonized product was washed. After washing with hot water (80°C) and steam (115°C), more than 90% of the chlorine content in RDF was removed.
From this experiment, it became clear that there are three advantages in the carbonization of RDF. Firstly, an improvement in transport efficiency by a decrease in the weight of waste and RDF. Secondly, a decrease in chlorine content, which is a very important factor when carbonized product are used for fuel. Thirdly the carbonized product can be used as a soil improvement material.

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This study verified the most suitable conditions for static aeration and scooping up time in composting. Garbage was fed to a scoop-type fermentor, which could compost one ton of raw material per day. A first series of experiments was carried out to evaluate the effect of aeration with a constant scooping up time (5 times a day) . The experiments were conducted under the three aeration rates of zero, 370 and 900l/min for one dry-weight ton of garbage and paper, as the composition of the raw material. The experiment with the 900l/min aeration rate showed the fastest rate of increase of temperature, pH and degradability of organic matter. However it was expected that the microorganism activity might be decreased by the excessive decline in moisture content under this condition. Furthermore the rate of increase of temperature and pH at the early stage of composting and the amount of degraded organic matter in the 370l/min aeration experiment were not so different from those of the 900l/min experiment. Hence, if we consider the plant investment and running costs of a practical plant, the most suitable condition for static aeration should be 370l/min. In the next series of experiments, the effect of scooping up time was examined at a regular static aeration rate (370l/min) . The experiments were carried out for six scooping up conditions; one, 3, and 5 times over a day, and 3, 6, and 12 times over a night and day. A faster rate of increase of temperature and pH at the early stage of composting was obtained in the higher scooping up frequency, although there was very little difference in the degradability of organic matter among the experiments. It seemed that the excessive high temperature in the later stage of the experiments depressed the microorganism activities. Since the excessive scooping up at this stage tends to cause temperature decrease, we should choose a suitable scooping up frequency.

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The per-capita waste amount and recycling rate are considered useful indicators to show waste reduction and recycling within municipalities. However, with regards to waste statistics in Japan, household waste and commercial waste are not always counted separately and the recycling rate is calculated only by using amounts collected by municipality. The concept of “waste stream”, waste material flows from separate waste sources, should be commonly understood, then waste indicators should be re-defined.
In this paper, the waste stream of household waste is estimated. Instead of using traditional waste categories according to the type of material, twenty-eight waste components are used to characterize possible waste streams created by new recycling laws. Statistical data from manufacturers and waste statistics in municipalities, including resource recovery, are used to estimate the “waste stream”.

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