Environment Innovations Behind Food - Advances in Organic Wastewater Treatment Technology 1999

Environment Innovations Behind Food - Advances in Organic Wastewater Treatment Technology 1999

In Japan in the 1990s, as the food industry expanded, organic wastewater discharged from factories became a serious environmental issue. Fermented food factories such as beer, soft drinks, dairy products, soy sauce, miso, etc. generated wastewater containing high concentrations of BOD (biochemical oxygen demand) and COD (chemical oxygen demand), causing eutrophication, odors, and red tides in rivers and coastal areas. Although the activated sludge method, which had been the mainstream method in the past, had achieved certain results, the large amount of sludge generated and high maintenance and management costs placed a heavy economic burden on companies.

A new treatment technology that is energy efficient, highly effective, and low-polluting has been attracting attention as a solution to this situation. The membrane bioreactor (MBR) method uses fine membranes for solid-liquid separation to achieve more stable water quality than conventional methods, and enables a circulation system in which treated water is reused within the plant. Anaerobic treatment (UASB reactor, etc.) generates methane gas in the process of decomposing organic matter, which can be recovered as energy, and is considered an epoch-making technology that simultaneously realizes waste treatment and energy utilization.

In addition, advanced oxidation treatment technologies such as ozone oxidation and Fenton reaction, water reuse systems using reverse osmosis (RO) membranes, and energy-saving biological treatment technologies such as the rotating disk contact method were also studied and introduced. These technologies were not used in isolation, but were combined according to the wastewater characteristics and cost conditions of each plant to create an optimal treatment process.

In 1997, following the adoption of the Kyoto Protocol, Japan's policy agenda included the reduction of greenhouse gases and the promotion of resource recycling, and this was a time when support for the development of environmental technologies and tighter regulations were being implemented. These technological innovations in 1999 were the first step in laying the foundation for today's water resource-recycling society.