To achieve more stable combustion control in municipal solid waste incinerators (MSWI), it is necessary to monitor in real time changes in lower heating value (LHV) of the MSW fed into the furnace, and to control precisely the combustion air and stoker speed. In this study, we formulated the compaction and movement of MSW in hoppers and chutes, and developed a calculation model for the status of MSW that is fed into a hopper and furnace by considering its volume and weight in the hopper, its compaction characteristics, and the formula of the relationship between density and LHV. Then, we applied this calculation model in some experiments with artificial waste at a pilot plant to ensure the accuracy and validity of the model. Since the calculated volumes were well matched with real movement volumes in the chute and discharged volumes, this model makes it possible to estimate the volume just fed to a furnace by measuring the change of volume in its hopper. As for the quality of the supplied MSW, the calculated weight was slightly heavier than the real weight, but the high correlation coefficient indicated good reliability. As a result, we concluded that this model is acceptable for estimating the compaction and movement of MSW in a hopper and a chute.

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This study presents the key elements of recent waste management policy and strategy by the Chinese government, currently advocating : (1) Planning and assignment of waste management in consideration of the surrounding social environment, (2) Release of necessary information to the public, (3) Energy consumption using natural gas or petroleum replaced by coal gas energy, (4) Encouragement of the three “D's” (de-toxification, de-duction, and de-use or deuter-use) for solid waste, (5) Promotion of a basic law concerning circular economics or a recycle-oriented economy and the promotion of Green Mark Procurement, and (6) Business- or market-driven waste treatment by corporations, industries, and companies. The government is facing the realities of waste disposal implementation by focusing on the Private Finance Initiative (PFI), which has recently been introduced in China.

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We have proposed a new processing technology for fire retarding substances kept in the nuclear power plants, etc., which contain low level radioactive wastes. The purpose of this research is to develop a furnace with less combustion air and smaller off-gas system. In this technology, the fire retarding substances are placed on molten slag. The volatile material and fixed carbon are them gasified. Ash at the surface of burning substances melts into the molten slag. This technology is hereafter referred to as the slag fluidized bed process. We compared this new technology to the conventional one. The weight loss of different kinds of substances with different sizes (φ2-5mm) was measured at 1100 deg. C. and in the air. The main results are as follows.
(1) The processing time was greatly dependent on ash contents and the sizes of substances.
(2) In the case of consentional air combustion technology, the processing time of fire retarding substances which had a high ash ratio became longer. This result is due to the surface combustion of fixed carbon. On the other hand, in the case of the slag fluidized bed technology, the processing time was comparatively shorter.
(3) The reason is attributed to the continuous removal of ash along with the molten slag, being followed by the contact of its bare surface with the air.
(4) In this new technology, no evaporation of ash was observed because it was almost all resolved in the molten slag.

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In Japan, stabilization with chemical agents is the prevalent method for controlling the release of heavy metals from fly ash generated at municipal solid waste (MSW) incinerators and MSW melting furnaces. The objective of this study was to investigate the functional capability of chemical agents for long-time release control of metals. Three types of chelating agents were used for the stabilization of fly ash from a MSW incinerator. The stabilized fly ash was aged in 5 kinds of ageing conditions, varying the combination of dehydration and atmosphere, for a maximum of 68 days. Release of metals was evaluated by the Leaching Test proscribed in the Japanese Environmental Agency Notification No. 13, 1973 (JLT-13) .
The experiment proved that only in the wet condition with less than 2% of oxygen gas kept the released concentration of Pb in less than 0.1 mg/L. On the other hand, all of the other conditions overreached the criterien of 0.3 mg/L. Fixed heavy metals might be released after some time periods if the stabilized fly ash is placed in an ineligible condition. At the same time, another behaviour of heavy metals was observed. Independent of chelating agent and atmospheric gas conditions, Pb, Zn and Ca were moderately insolubilized in the wet condition.

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Advances are being made in the gasification and melting processes for domestic waste. Still, more research is needed to achieve further energy recovery, effective resource utilization, and operating condition optimization. To date, we have established a pyrolysis reaction model using typical chemical substances that constitute municipal solid waste (MSW) .
In the present study, we examined the effects of pyrolysis conditions and MSW composition on the amount of residue and the residue calorific value after pyrolysis using a new fixed temperature pyrolysis model. As a result, we were able to estimate the MSW calorific values from a composition sample using a model with calorific values of typical substances in MSW.
Furthermore, we compared pyrolysis residue amounts and calorific values calculated in the pyrolysis model with those obtained experimentally using a tubular electric furnace. The results suggest that it is possible to estimate the amount of pyrolysis residue and the residue calorific value with this model and that it is effective in establishing efficient pyrolysis process operating conditions.

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This study aims to clarify both the concerns of residents regarding solid waste management (SWM) facilities, and to introduce what factors determine their opposition to the construction of such facilities. Data was obtained by conducting three different kinds of questionnaire surveys. Residents living in the vicinity of an SWM facility showed stronger opposition than non-neighbor residents, even though groups held similar concerns regarding the environmental effects of the facility. Reasons for their opposition seem to be triggered by the construction itself, and not by the physical or emotional impact caused by the running of the facility. In general, non-neighbor residents hold a more negative image of landfills than incinerators. The intensity of this negativity is well correlated to their opposition, and a grim image seems to strengthen the negative image of landfills. Visiting an SWM facility could be one of the most efficient ways to handle public education, with an aim to lessen the concerns and opposition of the residents involved.

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