Chlorine transport as conservative matter through unsaturated solid waste landfills was analyzed by experimental work using four large scale simulated lysimeters; a mathematical model on this was formulated and the experimental results were used to calibrate and verify it. The hydraulic properties for moisture flow, and the parameters for solute transport, were determined from additional small scale experiments.
Simulated leachate discharge rate in a moisture flow model, which assumed that unsaturated hydraulic conductivity is dependent on the volume fraction of mobile phase in liquid phase, showed reasonable agreement with the observed one. It was also shown that a Modified Two Phase Flow Model, incoporating hydraulic dispersion of solute in mobile phase, as well as solute exchange occurring between mobile and stagnant phases in the liquid phase, could express solute transport through a solid waste layer successfully. Results from the simulation of chlorine transport through a solid waste layer show that the exchange term has a similar function to the leaching term, working between dissoluble phase and mobile phase.

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The volume of solid waste has recently increased more and more due to economic growth and the diversification of people's life styles in many cities throughout Japan. Therefore, great expectations are placed on accelerated research and development regarding effective waste collection and transportation to create a new waste collection and transportation system that harmonizes with the urban environment in the 21st century.
In order to respond to this situation, high efficiency and streamlining of waste transportation have been selected for this research. In other words, wastes generated will be collected into waste collection centers, packed into capsules and capsule-transported by means of air flow, to waste treatment plants, via dedicated pipelines.
The density of compressed and packed waste, surface pressure during the compression/ packing and discharge of this waste, and also the drag coefficient of vehicles loaded with capsules have been obtained in experiments on the development of elemental technology, in order to solve problems involving waste transportation. Also, a simulation program for the waste transportation system has been developed and the transportation cost of waste has been trial-calculated. The results show that the system is fully viable from a commercial viewpoint.

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Volatile organic chlorinated compounds have been used in large quantities because they have various useful properties industrially. Some of them, however, have been proved to be carcinogenic or ozone depleting substances. Optimal incineration conditions have been investigated for liquid waste containing 1, 1, 1-trichloroethane (C₂H₃Cl₃), carbon tetrachloride (CCl₄) . Incineration tests with varying mean residence time, in which the temperature of incinerator was about 950°C, were carried out in a commercial field plant. In spite of long and short mean residence times (9.1 sec vs. 1.8 sec), there was little difference in DBEs (destruction and removal efficiencies) of C₂H₃Cl₃ and emissions of PICs (products of incomplete combustion) . Additionally, incineration tests with varying temperature of incinerator were carried out in a laboratory-scale incineration plant. In higher temperature conditions, above 800°C, DREs of C2H₃Cl₃ and CC1₄ exceeded 99.999%. But in the lowest temperature condition, about 700°C, DREs decreased and some PICs increased greatly. When experimental DREs were compared with theoretical DREs, which were calculated with gas phase reaction rate as rate-determining step, experimental DREs of C₂H₃Cl₃ were much lower than theoretical DREs. It was thought that these results were due to not considering the evaporation rate of drops formed when liquid waste was fed to the incinerator. Therefore, atomizing conditions were considered to be one of the important factors of C₂H₃Cl₃ thermal destruction. However, DREs of CCl₄ were higher than theoretical DREs. Waste was fed with liquefied petroleum gas to the incinerator, so the atmosphere in the incinerator was hydrogen-rich. Hence, H/Cl the ratio of waste was considered to be one important factor in CCl₄ thermal destruction.

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Lubricating oils, used by industry and motorcars, are usually re-refined by chemical treatment, such as with sulfuric acid. There are many other re-refining methods of these oils, but these are not sufficient from in terms of reclaimed oil quality, processing efficiency and other economic considerations.
In this paper, results of a pilot plant for a new treatment method, composed of (1) high temperature vacuum distillation, (2) gas removal and (3) rapid cooling, are reported and discussed.
In this re-refining method, the first vacuum distillation reclaims the“bottom oil”from the waste oil, then this“bottom oil”is washed with sulfuric acid and contacted with active clay. The oil is again treated with vacuum distillation. The lubricating oil finally reclaimed by this treatment process has better quality than any other re-refined waste oil.

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