In the BIOPAQ®IC bioreactor, organic compounds are converted to biogas by bacteria in the absence of air. In this way, effluent discharge costs are reduced and at the same time green energy is produced.

BIOPAQ IC - anaerobic COD removal - biogas from wastewater by Paques - 2

With the development of high rate Internal Circulation (IC) bioreactors, Paques made a break-through in anaerobic wastewater treatment. The internal circulation provides excellent mixing of the biomass with the influent is self-regulating with the incoming COD-load. It can therefore deal with high loading rates in a very compact reactor. In addition, both noise and odour issues have been addressed.

BIOPAQ®IC bioreactors have become a proven technology, with hundreds of examples worldwide in various industrial sectors. A complete range of BIOPAQ®IC models is available through a worldwide network of licensees.

Advantages of BIOPAQ®IC

  • Very efficient COD removal, through intensely mixed biomass at bottom of reactor
  • Production of green energy
  • High reliability: self regulating through the internal circulation
  • Good capability of handling influent fluctuations
  • Optimal biomass retention by the use of the 3 phase separators
  • Compact, small footprint
Typical influent characteristics
Characteristic Influent specification
COD level 1,000 to 20,000 mg COD/l
Loading rate 20 - 30 kg COD/m3/day

Working principle

The influent is pumped into the bottom of the reactor using an efficient distribution system, and is mixed with the granular anaerobic biomass (1).

In the lower reactor compartment (2) most of the organic components are converted into methane and carbon dioxide. This biogas is collected in the lower level phase separator (3). This generates a gas lift that forces the water upwards through the riser (4) into the liquid/gas separator on the top of the reactor (5). The biogas leaves the reactor through this separator, and the water returns through the downer (6) back to the bottom of the system: hence the name, Internal Circulation.

In the second, upper compartment the effluent is polished (7). The biogas formed here is collected in the upper phase separator (8) while the cleaned effluent leaves the reactor from the top.

The BIOPAQ®IC bioreactor is a vertical tank 16-28 meters high and 1,5 - 15 meters wide.