UASB system
Upflow anaerobic reactor. It degrades biodegradable organic matter without continuous mechanical aeration, with low energy demand and less sludge.

Anaerobic biological systemSludge blanket and GLS separator
What is the UASB system?
The UASB (Upflow Anaerobic Sludge Blanket) system is an anaerobic biological treatment technology used to remove biodegradable organic matter from wastewater. The process takes place in an upflow reactor that maintains a high concentration of anaerobic biomass in the form of a sludge blanket and biological granules.
Its configuration brings together in a single unit the contact between wastewater and biomass, the anaerobic degradation of organic matter and the separation of the solid, liquid and gas phases. Because it operates without continuous mechanical aeration, it has a low energy requirement and generates less excess sludge.
- 1UpflowWater enters at the bottom and crosses the sludge blanket.
- 2Anaerobic degradationMicroorganisms convert organic matter into biogas.
- 3GLS separatorCaptures the biogas, retains the biomass and releases the effluent.
Advantages
- Low sludge generation. Reduces excess biomass production.
- Low energy consumption. Operates without continuous mechanical aeration.
- Compact design. Reduces the area required for installation.
- High biomass retention. Maintains a high concentration of active microorganisms.
The process, step by step
Wastewater enters at the bottom of the reactor and flows upward through the sludge blanket. Along the way, the organic matter comes into contact with anaerobic microorganisms, which degrade it through several biological stages and generate mainly biogas and stabilized biomass.
The upward movement of liquid and biogas promotes contact between substrate and biomass. At the top, a gas–liquid–solid (GLS) separator recovers the biogas produced, retains the biological solids inside the reactor and directs the treated effluent to the outlet.


Gas–liquid–solid separation
The UASB system has a three-phase separator in its upper zone, designed to control the streams generated during the anaerobic process. This component separates and directs the gas, liquid and solid phases, helping keep the biomass inside the reactor.
The biogas produced during the degradation of organic matter rises and is captured at the top; the treated effluent continues to the outlet, while the separated solids return to the sludge blanket. This configuration helps preserve the active biomass and the operational stability of the process.
Works well with
Every technology performs better within a well-designed treatment train.
- Anaerobic biologicalEGSB systemExpanded granular sludge bed to treat organic loads in a small footprint and generate biogas.View solution
- Aerobic biologicalMBBR systemBiofilm on moving carriers that degrades organic matter in a compact reactor.View solution
- Biological + membranesMBR systemAerobic biological treatment and membrane filtration in a compact system.View solution
Need a UASB system for your effluent?
Send us your wastewater characterization and the flow to be treated. We will assess your case and propose the right solution, with local installation and technical service.
Contact us
Office in EcuadorDe los Eucaliptos E8-70 y calle E9, Quito 170307
Phone+593 99 871 1330
+593 2 280 8126
Emailinfo@sanitronec.com
Office hoursMonday to Friday
9:00 a.m.–12:00 p.m. and 1:00–6:00 p.m.
Office in the United States9995 NW 9th St. Circle, Suite 3, Miami, FL 33172
+1 786 972 2008
