Patent ID: 6908548

Claim:
In a prefabricated biological purification system for treatment of residential wastewater, the system having two main units including a primary purification unit including a prefabricated biological depurator and a secondary purification unit containing a filling material having a grain size distribution of about 2 cm to about 4 cm in diameter, the primary purification unit having modular elements of an elongated octagonal shape and assembled one on top of the other, wherein the modular elements form a container which varies in height depending on a number of the modular elements assembled, internal elements having an inflow tube, an internal separation panel with fluid passage duct, a trapezoidal diaphragm, and a device for controlling liquid outflow and the container with an octagonal cover, the primary purification unit comprising: (a) the internal separation panel defining a first internal sector and a second internal sector; (b) a second diaphragm in a form of an octagonal modular element positioned within the container; (c) a horizontal fluid passage duct formed as a horizontal opening of 5 cm between a bottom end portion of the internal separation panel and the second diaphragm; and (d) a flow control element forming an intake space between a bottom end portion of an outlet pipe and the trapezoidal diaphragm.