Environment Technology Behind Food - Innovations in Organic Wastewater Treatment and Related Technologies 1999

Environment Technology Behind Food - Innovations in Organic Wastewater Treatment and Related Technologies 1999

In the 1990s, the Japanese food industry continued to discharge large volumes of organic wastewater while meeting mass production and diversifying consumer needs. Wastewater from brewing, dairy, meat processing, beverage, and other factories contained high concentrations of BOD and COD, which, if discharged into rivers and coastal areas, would cause eutrophication and red tides. Although the conventional activated sludge method was in widespread use, its high maintenance costs and the large amount of sludge generated by large-scale facilities were problematic.

Under these circumstances, a group of new energy-saving and low-pollution treatment technologies attracted attention in the late 1990s. For example, the membrane bioreactor (MBR) method separates treated water through a fine membrane filter, resulting in a high level of water quality and enabling reuse within the plant. In addition, the MBR eliminates the need for a sludge sedimentation tank, thus saving space. Furthermore, the anaerobic treatment (UASB reaction tank, etc.) was innovative in that organic matter can be decomposed by methane fermentation and recovered as biogas, which can be reused as an energy source.

Related technologies that are becoming popular include advanced oxidation treatment (ozone treatment and Fenton reaction) to decompose persistent organic matter, energy-saving biological treatment such as the rotary disc contact method and fluidized bed method, and water recycling technology using reverse osmosis (RO) and nanofiltration membranes. By using these methods in combination rather than independently, an optimal system could be constructed to meet the water quality and cost requirements of each factory.

In addition, recycling technologies that use sludge, a byproduct of treatment, as compost or animal feed were also tried, and these technologies were in line with the trend toward "zero emissions," which aims for zero waste. These technologies are now regarded not only as environmental measures, but also as strategic technologies that affect corporate competitiveness.

In general, the innovation of organic wastewater treatment technology around 1999 was an epoch-making move that opened up the "sustainability of the food industry" through the integration of diverse technologies that simultaneously enabled the reduction of environmental impact and resource recycling.