Chemical treatment with chelating agents is a method of stabilizing heavy metals in Air Pollution Control residue (APC residue) from Municipal Solid Waste (MSW) Incinerators. The aim of this research was to find the appropriate ratio of chelating agent and APC residue to achieve the optimal stabilization of heavy metals. The investigations focused on Pb as a representative and relevant heavy metal in APC residue.
APC residue samples were collected from three MSW incinerators. The samples were mixed with chelating agent and/or pH controlling agent at different ratios. In some conditions Pb, Cu or Zn metal salt were added to determine their influence on Pb release. Then they were inspected according to the Japanese Leaching Test, stated in The Japanese Environmental Agency Notification No. 13 (JLT 13) .
The experiments proved that the sum of the content of Pb and Cu is the deciding factor for the amount of chelating agent that is needed to meet the disposal standard for Pb (0.3 mg/L) . Another important outcome is that it is possible to control the release of Pb by adding pH-controlling agents. In this case, the disposal standard for Pb was met for leachate that was adjusted to a pH of 9 to 10.

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In order to develop a treatment for waste fire retardant plastics which contain bromine flame retardant, conservative gas-fired incineration and wet oxidation tests were conducted, focusing on the behaviour of flame retardant and Antimony trioxide.
In the case of the gas-fired method, decomposition products such as hydrogen bromide and aromatic bromine compound were detected. About 80 wt.% of trioxide Antimony in the sample was discharged to the gas outlet of the incinerator. This result demonstrated the possibility of discharging Antimony compounds into the environment.
On the other hand, antimony compounds were confirmed to be left in the autoclave in wet oxidation. Depending on the molecular structure of the flame retardant, different yields of the decomposition were shown.

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The treatment and disposal on land of waste stillage from shochu distillery (hereafter called waste stillage) is mainly classified into two types : resource recovery, such as fertilization (farmland reduction) and feeding, and incineration plant treatment. Every year, the latter has been more commonly used, in view of the ban in the year 2001, on ocean-dumping.
This research was to attempt to make reborn paper of low or middle quality by adding some amount of old newspaper to waste stillage.
As a result, it is clear that reborn paper is able to be produced under the condition of low pressure (0.55 kPa-2.87 kPa) and mixing ratio (1 %-7 %) of old newspaper. Especially when the pressure is 0.55 kPa and the mixing ratio of old newspaper is 7 %, the reborn paper holds the waste stillage completely. This research was also to clarify the physical and mechanical properties of the reborn paper made from waste stillage and old newspaper under each condition.

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From previous studies, we, the authors collected and arranged the octanol-water partition coefficients (K_ow), water solubilities (S₀), and partition coefficients (K_oc) to dissolved humic matter (DHM) of 94 organic compounds, and presented the correlations between each physical property. To estimae the effect of DHM on sorption and retardation, strong reductions in sorption and retardation factors were obtained resulting from increasing the DHM concentration. The K_oc and K_ow, of PCDDs/ DFs estimated were significantly increased while S₀ was decreased on increasing the chlorine number. Also the solubilities (S_w) of organic compounds in coexistence with DHM increased when increasing their K_oc values. Thus, the ratio of solubility enhancement (S_w/S₀) in high chlorinated PCDDs/DFs such as HpCDDs and OCDD is higher than that in low chlorinated ones. Also the ratio of solubility enhancement (S_w/S₀) in PCDDs are greater than those in PCDFs because of the effect of DHM. The limitation, however, of this research is that the K_ocs used are estimated, not measured values. To more accurately estimate the behavior of PCDDs/DFs, we need accurately measured K_oc and other factors not considered in this paper.

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Many municipalities have been recommending the use of household composting containers to compost kitchen waste. When users apply it, however, they suffer from odor trouble caused by the anaerobic condition in the composting container. Because these odors influence not only the users but also their neighbors, some users have stopped using the container. The authors thought that the odor trouble was caused by high water content in the compost.
The authors therefore devised one case study using 7 aerobic pipes and another case study, again using 7 aerobic pipes but, in this case, ones which were connected to drainage pipes creating semi-aerobic reclamation structure within the container. In the former case study, the water content decreased within about a year. In the latter case study, the water content of the compost decreased within about 4 months and aerobic condition appeared in the compost.

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This is a study of a “Variable Rate Pricing Policy for Waste Management”. In our study, “The Fee System” means that residents should pay the waste management fee in proportion to the amount of waste they discard. In our theoretical analysis, from the point of view of microeconomics, we constructed a three-factor consumer behavior model made up of traditional waste management service, resource recovery service and a compound factor. We derived an ordinary demand curve of traditional waste management service and resource recovery service, by applying utility maximization theory, including a waste generation function. Next we constructed a benefit analysis method with this demand function by applying the method of welfare economics, within the cost of time for residents. As our case study location we used the Hitachi-Ohta district, Ibaraki prefecture, Japan. In the time series analysis, we derived 103 yen per capita per year as a net economic benefit in executing The Fee System in this area, from October 1992. We also showed that residents took notice of the resource recovery service. It was also shown that for the year of introduction, the city became one in which waste was easily reduced.

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