Updated: July 2002

1. Overview and Advantages

This system comprises an acid fermentation tank that generates an organic acid, and a UASB (Upflow Anaerobic Sludge Blanket) tank which is responsible for methane fermentation. Depending on the quality of intended wastewater type, a small-scale aeration tank may be provided as an after-stage. In the acid fermentation tank, BOD and COD sources are converted into an organic acid, and in the UASB tank, the resultant organic acid is subjected to methane fermentation.
It is a well known fact that UASB system has been often successfully used to treat wastewater of high pollution load, such as food processing wastewater. By our unique technology, our UASB system is also capable of processing low-load wastewater. The photo below shows the granules (colonies of microorganisms responsible for methane fermentation) present in the UASB tank that is presently treating low-load wastewater.
The amount of sludge occurrence is much decreased by treating wastewater with our UASB system instead of a conventional active sludge system. In addition, being a low power consumption system, our UASB system contributes to a lower running cost. Also, it helps reduce the necessary floor space for wastewater treatment.
A small-scale active sludge tank as an after-stage makes it possible to decompose substances that are not decomposed by an anaerobic or aerobic treatment alone.

2. Performance and Applications

Our UASB system can treat not only heavily polluted wastewater such as food processing wastewater but also low-load wastewater (previously, not considered to be the subject of conventional UASB process) such as sewage water, wastewater from chemical plants and dye waste. The treatment efficiency for low-concentration wastewaters with our system is comparable to conventional active sludge techniques. Furthermore, our system can treat many of hard-to-treat substances for active sludge process.
Its power and its floor space requirement is less than half that of conventional systems. It treats wastewaters at a lower running cost.
It positively decomposes colorants released from dyeing plants to decrease the chromaticity of treated effluent.

3. Miscellaneous

Kurabo UASB system allows the generated methane gas to be utilized as energy source, helping promote utilization of waste. It also inhibits occurrence of carbon dioxide and dinitrogen monoxide (each known as greenhouse gas), thereby it can be regarded as an"ecologically friendly product".