Current status of industrial waste disposal and recycling technology (1994-2023)

Current status of industrial waste disposal and recycling technology (1994-2023)

Various technological innovations are being promoted in industrial waste treatment to reduce environmental impact and recycle resources. In particular, the reuse of incinerator ash is attracting attention, and companies such as Mitsubishi Materials Corporation and Takuma Corporation are making advanced efforts.

In Japan, approximately 40 million tons of waste is incinerated annually, resulting in the generation of a large amount of incinerator ash. Disposal of this ash, especially in large metropolitan areas, has become an issue, and new recycling technologies are being introduced. Mitsubishi Materials Corporation has developed a technology for melting incinerator ash at 1,400 to 1,600 degrees Celsius and turning it into crystal glass. This technology has made it possible to encapsulate toxic heavy metals such as lead and cadmium and reuse them as safe construction materials. A cleaning plant in Tokyo's 23 wards uses molten crystal glass as pavement material for the Tokyo Metropolitan Expressway. It is also used as building blocks and tiles in Osaka City, contributing to urban development projects.

Meanwhile, in August 1994, Takuma developed a technology for crushing and compacting incinerator ash. By crushing incinerated ash to less than 25 mm and mixing it with cement, it can be reused as road pavement material and building block interlocking blocks. This technology has been introduced by Osaka Gas, Obayashi Corporation, Keihan Concrete Industry, and other companies to handle waste disposal in metropolitan areas.

In the industrial waste treatment field, the existence of "industrial waste Ginza," an area with a high concentration of treatment facilities, has become an issue. In coastal areas such as Koto-ku, Tokyo (Shinkiba and Wakasu), Osaka (Maishima and Nanko), and Kawasaki City, Kanagawa (Ukishima and Higashi Ogishima), industrial waste treatment facilities are concentrated due to the increase in waste since the high economic growth period. However, in these areas, the problem of environmental impact has been pointed out, and there have been movements by local residents to oppose these facilities.

Illegal dumping of industrial waste is also a serious problem. 3,000 tons of industrial waste was illegally exported to the Philippines in Yokohama City in 1999, which became a major social issue; in 2021, a company in Kanagawa Prefecture illegally exported 1,500 tons of hazardous waste to Indonesia; and in 2022, Toshiba Corp. In 2022, Toshiba Corporation was accused of violating the Basel Convention by illegally exporting 2,500 tons of industrial waste to China and Vietnam. Against this backdrop, a waste tracking system will be introduced in Japan in 2023, enabling real-time monitoring of industrial waste from generation to final disposal.

Looking ahead, Mitsubishi Heavy Industries and other companies are expected to develop plasma technology to render hazardous substances harmless. There is also a need to strengthen international cooperation with Asian countries in waste treatment to solve the problem of illegal exports. Furthermore, the further spread of recycling technology in urban areas is expected to reduce landfill disposal and realize a recycling-oriented society. Industrial waste treatment will continue to be a field where technological innovation and international cooperation are indispensable to reduce the environmental burden and create a sustainable society.