Anaerobic COD removal

In anaerobic treatment, bacteria convert organic compounds (COD) to biogas in an environment without oxygen. Not only do the bacteria remove contaminating compounds from the effluent, thereby reducing discharge costs, they produce green energy at the same time.

Organic components (COD) are converted to CH4 + CO2 + BIOMASS

The generation of biogas from agricultural waste, municipal slurries and wastewater has been gaining interest from scientists, industry and municipalities interest is rapidly growing now, since renewable energy sources are favoured to limit global warming. Biogas consists mainly of methane and some carbon dioxide. It can be utilized as a fuel for power generation, steam production and drying processes.

New technologies

Paques started the design and supply of installations for COD conversion into biogas in the early nineteen eighties with the application of the BIOPAQ®UASB (Upflow Anaerobic Sludge Blanket) reactor. This was an invention of Professor Gatze Lettinga from Wageningen Agricultural University in the Netherlands. The reactor was scaled up from pilot to full scale and deployed for many types of wastewater.

Paques quickly became global market leader in this field of anaerobic treatment. Its position was further strengthened by the development of a new type of anaerobic reactor called the BIOPAQ®IC (Internal Circulation) reactor. Both the BIOPAQ®UASB reactor and the BIOPAQ®IC reactor are used for wastewater treatment with a wide range of carbohydrate concentrations, i.e. from 1,000 to 20,000 mg COD/l.

Within this range the bacteria form compact granules with very good settling characteristics. Above this range the bacteria tend to grow in a more flocky structure and for this Paques developed the BIOPAQ®UASBplus reactor. For more concentrated wastewaters containing fine organic particles and/or fat and proteins, Paques designed the BIOPAQ®AFR (Anaerobic Flotation Reactor).

For decentralised sewage treatment in warmer climates, Paques has developed the very compact BIOPAQ®UBOX, which combines a first stage anaerobic treatment with a second stage aerobic treatment.

Paques’ reactors are found in all kind of industries and applications, such as Food, Pulp and Paper, Beer and Beverages, Distilleries and Chemical and Pharmaceutical.

Anaerobic COD removal cases