Recently, the recycling of organic by-products and wood wastes has become very important. The development of technology for recycling organic by-products needs to have sustainable development and be helpful to human life. In this study, the techniques for producing carbonaceous adsorbents from a wood waste and iron, and the application to humidity control in the house are described. The amount of water adsorbed onto carbon produced from woods wastes-iron system constructional materials was greater than that adsorbed onto the carbonaceous materials. The carbon produced from woods wastes-iron system constructional materials could be used repeatedly. These results indicated that the carbon produced from woods wastes-iron system constructional materials could be useful for the humidity control.

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To find a new processing technology for microbial treatment of food production waste, experiments were performed to obtain a thermophilic flora derived the bacteria isolated from panda feces and the use of the high temperature-adapted flora for treating waste such as wheat bran and/or tofu residues was investigated. Using commercial waste-treatment devices, a total of 79.7 kg of mixed refuse consisting of tofu-residue and fish was treated for 17 weeks, 67.2 kg of wheat bran and fish refuse was treated for 12 weeks and 100.2 kg of wheat bran, tofu-residue and fish was treated for 17 weeks, resulting in final digestive rates of 95.12%, 95.24% and 97.01%. The internal temperature of the compost mass reached peaks of 73.2°C, 72.8°C and 72.4°C, respectively. These results indicate that the bacterial flora may be useful for waste treatment of food production refuse at a high performance rate at high temperatures.

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This experiment was conducted for 12 weeks with the objective of determining the most effective garbage control method in Saijo Central Park in Higashi Hiroshima. This experiment was conducted on-site by using evenly distributed waste receptacles, the placement pattern which is believed to be the most effective way to prevent littering. The purpose of this experiment was to investigate the effect of the following interventions : placing separated type waste receptacles, placing separated type waste receptacles with explanatory signs, withdrawal of waste receptacles, withdrawal of waste receptacles with public service announcements. Park patrons were surveyed to find the relationship between the rate of separation and separation consciousness.
When separated type waste receptacles with explanatory signs were used, the ratio of littering is greatly decreased, and the ratio of separation improved compared to placing only separated type waste receptacles. When no waste receptacles were used, the amount of litter increased a little. However, when public service announcements were posted, the amount of litter decreased substantially. In the public space managed, it was also observed that when the waste receptacles were removed in conjunction with placing public service announcements, it was an effective way of controlling garbage. The results of survey also show that park patrons' actual garbage separation is not as high as they estimate themselves in any case.

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Disassembly characteristics of electric home appliances for parts and materials were experimentally examined. All of the mono-material or functional UNIT components of FAX machines, fan heaters, gas water heaters, electric heaters, VCRs, PCs, washing machines, air conditionars and TVs were separated by disassembly and sorting. In the case of refrigerator, only 60 wt% of the product was separated as mono-material or functional UNIT components. The fasteners in small electric home appliances were easily released with screwdriver (+), a precision type screwdriver (+), nippers and a spatula and had no corrosion or deformation. Additional tools such as ratchet type wrench and a saw were also required to release the fasteners of 4 major electric home appliances. The release time of the fastener in the 4 major electric home appliances was two to three times longer than that of the small ones, regardless of the fastener type. There were some remarkable relationships between the disassembly characteristics, release times, and reversibility of connections, and fastener types within the group of products with similar structures, such as among 4 major electric home appliances and among the small ones.

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Decomposition characteristics of pentachlorobenzene (P₅CBz) and 1, 2, 3, 4-tetrachlorodibenzo-p-dioxin (1, 2, 3, 4-T₄CDD) with electron irradiation was studied. To confirm the possibility of irradiation as a flue gas treatment, P₅CBz or 1, 2, 3, 4-T₄CDD made to be absorbed in magnesium silicate powder that was used as a model fly ash, and the electrons were irradiated on powder placed in glass laboratory dishes. The highest obtained destruction efficiency of P₅CBz itself is 96% at a dose of 300 kGy. However, that of total chlorobenzenes remained at 62% at the same dose, because the dechlorination reaction produced low-chlorinated benzenes. The results with 1, 2, 3, 4-T₄CDD indicates almost the same efficiency.
Results of the experiment and an ab initio molecular orbital calculation of P₅CBz indicate that 2 (3) position of 1, 2, 3, 4-T₄CDD is more easily dechlorinated than other positions. So, the isomers produced in the electron irradiation are expected to have a low toxic equivalency factor. Also, though the highly chlorinated benzenes and dioxins are dechlorinated, the considerable amount of low-chlorinated molecules might be decomposed by an open-ring reaction, because the detailed analysis indicated that only a few low-chlorinated benzenes and dioxins could be detected in the decomposition products.

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The final goal of this study is to establish an effective recycling system for reclaiming waste materials that are commonly produced in sewage treatment processes. Also excess sludge, which is mass-produced and is difficult to dehydrate, was experimentally utilized as reusable deodorizer. Hence, as a preliminary experiment, the following procedures were taken. First, the components of sludge were transformed by electrolytic treatment, and, second, verification to prove the deodorizing efficacy of dehydrated sludge (moisture contents 80%) on typical odors produced in processes of sewage treatment was conducted by the batch deodorization experiment. As the result, more than 85-95% deodorizing efficiency by this electrolytically treated sludge was obtained in a short period of time. By the continuous deodorization experiment, durability of deodorizing efficacy was examined. As the result, a stable 99% deodorizing efficacy for 400 hours was obtained. Moreover, further durability of deodorizing efficacy could be obtained by maintaining the moisture content of the electrolytically treated sludge. From results of several experiments, the high possibility of recycling electrolytically treated sludge as a deodorizer was found.

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