Houseflies, claws, and offensive odors are still the most common problems in any landfill site. To cope with such problems, various types of pesticides have been used. Intensive use of chemicals, however, has brought about a new concern : it has made the target species more resistant to these pesticides. As a result, the range of chemicals effective against the insect pests has been considerably reduced. Meanwhile, the use of daily cover soil has gone into decline because it occupies quite a large portion of the landfill site, and so reduces the life of the latter.
This paper reports on an experiment conducted with two types of foam (non-hardening and hardening types) in two landfill sites in the southern part of Kyushu. Unlike daily cover soil, foam disappears and so does not waste any space in a landfill site. One site was used as a control ; we sprayed the other experimental site with foams for about a month. We then examined the population of houseflies, allowing for meteorological impact on their population density. We used two adhesive ropes as a means of measuring the density of the housefly population. Judging from the results of the experiment, it is suggested that both types of foam are effective for controlling the population of houseflies, and that the foams can replace the daily cover soil.

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Three types of processed waste municipal resource recovery facilities (for incineration, for landfill, and for recycling) were measured for physical composition, ignition loss, etc. The results show that the difference in the characteristics in the residues depend mainly on the input wastes. For example, ignition loss for landfill residue from residential bulky wastes was about 50%, but that of residential incombustible waste was about 20%.
To date there is no research which measures the physical composition of fine particles under 5.6 mm in landfill residue. A new method is proposed for classifying fine particles into five kinds of physical composition : wood, paper, plastics, metals, and other incombustibles. Using this method, it is possible to obtain the mass of the five components in the municipal facilities for size reduction and resources recovery.

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Biodegradability of poly-propiolactone (PPL), one of the biodegradable plastics, under thermophilic composting was examined by using a bench-scaled composting apparatus. Since the PPL can be converted to CO₂ and H₂O when it is completely decomposed by microorganisms, the percentage of biodegradability was obtained by determining the percentage of carbon in the PPL that was converted to CO₂ during composting. Quantity of CO₂ evolution accompanied with PPL decomposition was estimated by the difference of cumulative CO₂ evolution between compostings with and without addition of PPL. The difference in CO₂ evolution became larger with the composting progress suggesting that the degradation of PPL occurred at the late stage. Biodegradation of PPL proceeded faster at around 40-50°C than at 60°C when dog food was used as a composting raw material, and approximately 37% of PPL decomposed to CO₂ no more than 8 days at the 50°C composting. In addition, biodegradability of PPL was found to be dependent on the kind of seeds used for composting.
Furthermore, it was also confirmed that the PPL was degraded ca. 40% for 19 days of thermophilic composting process where garbage was tried to use as a composting raw material instead of dog food.

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The treatment and disposal of the waste excess sludge generated by night-soil treatment has become a serious social problem. The material balance and heat balance during the composting process were examined using a laboratory-scale composting reactor.
The solid matter balance and organic matter balance were difficult to determine using a small-scaled apparatus because of the large loss. When more than 15% of the carbon and nitrogen was collected in the exhaust gas, the composting state was good judging from composting temperature, appearance, touch, and odor of product. The composting state was good after evaporation of 50-70% of sludge moisture.
The generation of carbon dioxide during composting of sludge was about 170-230g C/kg organic matter, and that of ammonia was about 16g N/kg organic matter. The composting state was good when the composting heat was 15% or more of the calorific heat value in the raw material fed or exceeded 880kcal/kg organic matter fed.

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Our basic research was conducted on solid waste of regulated composition for examination of combustion properties. The emission behaviors of Thermal and Fuel NOx was studied using an incinerator under different combustion conditions. The following results were obtained.
(1) The conversion rate of Fuel NOx increased at high combustion temperature and concentration of O₂.
(2) The conversion rate of Fuel NOx, initially present at 1.7 to 9.3%, became less than 1/3 that of boiler burning fossil fuel.
(3) The emission of Fuel and Thermal NOx was inhibited with decrease in O₂ in the burning area. Fuel NOx decreased 2 to 5 times more than that of Thermal NOx.
(4) As for combustion temperature, Thermal NOx was found to be more dependent on temperature than Fuel NOx.

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Sixteen runs of decomposition experiments of recovered chlorofluorocarbons (CFC-11, 12, 113) and hydrochlorofluorocarbon (HCFC-22) were carried out in 3 industrial waste incineration facilities with a rotary kiln, and the necessary conditions of the facilities and their operation for safe and reliable decomposition of CFCs/HCFC were clarified.
At first, a quantitative characterization method for wastes and their incineration conditions was proposed, and the characteristics of the 3 facilities were clarified.
Under conditions of an incineration gas temperature over 850°C, a gas residence time over 2 seconds, an O₂ concentration over 6 vol%, and a molar ratio of hydrogen to halogen over 30, over 99.99% of the CFCs/HCFC decomposed and no volatile organochlorine compounds would be present. Moreover, PCDDs/PCDFs formation could be controlled by quenching of flue gas.
A method to determine the optimum feed rate of CFCs/HCFC for each the facilities was proposed by concerning the produced concentrations of HCl and HF in the flue gas. The alkaline consumption and the costs for HCl and HF treatment were also estimated.

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