Material cycles and waste management

Background to the study

Huge amount of domestic waste is discharged during daily life and another huge amount of industrial waste is also generated through industrial activities, while the remaining capacity of the final disposal sites is steadily diminishing. Furthermore, construction of new final disposal sites is very difficult. Thus, it is necessary to reduce the amount of waste through intermediate treatment and try to recycle as much as possible through recovery and reclamation.

Under such circumstances, comprehensive measures are taken in the following study areas to support the waste management system, from the generation of waste to its final disposal and recycling.

1. Studies on waste information management
2. Studies on hazardous and toxic waste management
3. Studies on intermediate treatment
4. Studies on final disposal engineering
5. Studies on waste recycling 

Current research topics

Study on incineration

Recently, quality change of waste for incineration has been  occured by promotion of intermedeate treatment of waste, transition to aging society, and so on. Furthermore, greenhouse gas reduction from waste incineration is needed for establishment of low-carbon society. We study about an analysis of operation management data, an evaluation of electrical generating capability of incineration facilities. In addition, we study out a future direction of incineration treatment by understanding the current conditions and problems of general waste treatment.

Studies on reduction of organic contents in residual soil discharged from crushing/separating facilities

The amount of construction waste in the Kanto area is enormous. In particular, Saitama prefecture is the base for distributing waste and the number of intermediate treatment facilities that handle such construction waste is the most in Japan.

Construction waste is crushed and separated, and classified into two categories, namely recyclable items and construction residue in intermediate treatment facilities. Normally, such residue is transferred to the final disposal sites, but they have caused significant environmental damage at the final disposal sites for stable wastes, as some of it contained large amounts of organic substances. Thus, treatment methods that do not rely on incineration are developed to reduce the amount of organic substances amongst construction residue that is discharged from the crushing/separating facilities.

Studies on recycling of kitchen waste

Measures for recycling and reusing of kitchen waste have gradually been promoted, but expansion of the demand of products is difficult under the current situation. Thus, we seek to establish a recycling system as well as studying the stability and safety of recycling materials and products, and also study their marketability.

Long term performance evaluation on the ability for pollutant capture by using a horizontal permeable reactive barrier

Long term operation and maintenance for treatment of leachate emitted from landfill site is needed. Development of the horizontal permeable reactive barrier (HPRB), that has abilities of pollutant capture, used for the intermediate cover soil has been studied. In this study, we constructed a big lysimeter as a simulated landfill for evaluation of HPRB ability, and long term analysis of leachate has been continued.

Others

a) Measures to prevent illegal waste disposal

Investigation of illegal waste disposal sites is carried out and advice given for environmental restoration of polluted areas.

b) Monitoring of final disposal sites

Leachates from industrial waste disposal sites in the prefecture are monitored and instruction given on the proper handling of landfill sites and disposal methods based on such data.

c) Monitoring/instruction of final disposal sites and incinerators

Inspections into toxic chemicals that may be contained in the ash from incinerators and the leachate from landfill sites for general waste in the prefecture are carried out, and whether or not they are appropriately handled and disposed of is monitored.