Anaerobic Effluent Treatment

Due to the high levels of organic pollutants in wastewater, its treatment is often energy-intensive and costly. We use specific microorganisms to convert these organic pollutants efficiently into biogas, resulting in sustainable energy generation and energy-positive wastewater treatment.



We combine UASB (Upflow Anaerobic Sludge Blanket) technology with our proprietary gas hoods to optimise the process. This technology is used for water flows produced by the food industry (including potato processors, abattoirs and breweries, and the dairy, sugar, alcohol and starch industries). It is also applied in the paper and textile industries and, in specific cases, to municipal wastewater.


Wastewater is fed in at the bottom of a UASB reactor, bringing the granular sludge in suspension. The wastewater flows through the bed of granular sludge, converting organic pollutants into biogas, which consists mainly of CO2 and CH4. Gas hoods, also known as three-phase separators, are installed at the top of the reactor to capture the formed biogas and treated water, and ensure that the sludge stays in the reactor.


UASB technology is a robust, reliable method to significantly reduce the operational costs of water treatment. The biogas produced by this method can be used locally as a sustainable energy source for the production of heat and electricity, or it can be upgraded to green gas. Colsen can advise and consult on biogas applications and purification.