The device is an underground plant which adopts the advanced Biological technology and the company’s scientific research and engineering practice result, it can effectively remove BOD₅,COD and NH₃-N. The device is characterized by the stable performance, effective treatment, economical investment, automatic operation, convenience of maintenance and small occupying space. There is no need for plant construction, neither heating and heat preservation. The surface can be used as green land or square land.

As the most efficient sewage treatment device, it is widely used in treating the sewage in the area of senior hotels, villa districts and residential districts, etc. The water after treatment would meet the national emission standards.