Sewage anaerobic treatment technology uses the metabolic process of anaerobic microorganisms to decompose and convert macromolecular organic pollutants in sewage into small molecular substances without oxygen supply, and at the same time generate a certain amount of clean energy biogas. Among them, the internal circulation anaerobic reactor (Internal Circulation, IC) is the third-generation high-efficiency anaerobic reactor successfully developed by the Company Paque from Holland in the 1980s. It is developed on the basis of UASB (Up-flow Anaerobic Sludge Blanket Reactor). Compared with UASB, IC has the advantages of high organic loading rate, small footprint, and strong impact load resistance, so it has been more and more used in the field of high-concentration wastewater treatment all over the world.

However, the existing IC reactor has its shortcomings, which are embodied in the following two aspects: one is that the water inlet flow rate of the water distribution system at the bottom of the reactor is too small, and the disturbance intensity is not enough, so that the inlet wastewater cannot react fully with the biomass in the wastewater distribution system located at the bottom of the reactor. The sludge at the bottom of the device and the return active sludge of the internal circulation downer are not fully mixed, and so the COD removal rate of the system is restricted; the second is the slow start-up speed of the system. In the early stage of commissioning, due to the small gas production, the gas lift phenomenon cannot be formed in the riser, so there is no real internal circulation.

Biojet IC® (Anaerobic Reactor with Enhanced Internal Circulation) adopts a unique jet tangential water distribution system. The high-speed water distribution flow rate through the jet enhances the disturbance intensity of the inlet, thereby improving the mass transfer efficiency; in addition, through the negative pressure suction effect generated by the jet, the inner circulation is formed immediately at the beginning of commissioning, and continuously enhanced. Compared with conventional IC, the startup speed is faster and the pollutant removal rate is higher.