Product details:

1、 Working principle:

Wastewater flows from bottom to top through UASB. There is a high concentration and high activity sludge bed at the bottom of the reactor, where most of the organic pollutants in the sewage are anaerobically fermented and degraded into methane and carbon dioxide.Due to the agitation of water flow and bubbles, there is a sludge suspension layer above the sludge bed.

2、 Process characteristics:

UASB has a high load capacity and is suitable for the treatment of high concentration organic wastewater. A well functioning UASB has a high organic pollutant removal rate, does not require stirring, and can adapt to significant load shocks, temperature, and pH changes.

The anaerobic reaction process in UASB reactor is the same as other anaerobic biological treatment processes, including hydrolysis, acidification, acetic acid production, and methane production. By involving different microorganisms in the process of substrate conversion, the substrate is transformed into the final product - inorganic substances such as biogas and water.

3. The anaerobic microorganisms involved in the anaerobic digestion process mainly include the following:

① Hydrolysis fermentation (acidification) bacteria, which hydrolyze and ferment complex substrates into various organic acids, ethanol, sugars, hydrogen, and carbon dioxide;

② Acetobacter, which converts the products of the first step of hydrolysis fermentation into hydrogen, acetic acid, and carbon dioxide;

③ Methanogenic bacteria convert simple substrates such as acetic acid, methanol, carbon dioxide, hydrogen, etc. into methane

3、 Structural composition:

UASB consists of three parts: sludge reaction zone, gas-liquid solid three-phase separator (including sedimentation zone), and gas chamber.

There is a large amount of anaerobic sludge stored in the bottom reaction zone, and sludge with good sedimentation and coagulation properties forms a sludge layer in the lower part. The sewage to be treated flows from the bottom of the anaerobic sludge bed and mixes with the sludge in the sludge layer. The microorganisms in the sludge decompose the organic matter in the sewage and convert it into biogas. Biogas is continuously released in the form of tiny bubbles, which merge and gradually form larger bubbles during their ascent. In the upper part of the sludge bed, due to the agitation of biogas, a sludge with a relatively thin concentration rises together with water and enters the three-phase separator. When biogas encounters the reflection plate at the lower part of the separator, it bends around the reflection plate and then enters the gas chamber through the water layer. It is concentrated in the gas chamber and discharged through a conduit. The solid-liquid mixture is reflected and enters the sedimentation zone of the three-phase separator. The sludge in the sewage undergoes flocculation, and the particles gradually increase and settle under the action of gravity. The sludge settled on the inclined wall slides back into the anaerobic reaction zone along the inclined wall, causing a large amount of sludge to accumulate in the reaction zone. The treated effluent separated from the sludge overflows from the upper part of the sedimentation area overflow weir and is then discharged from the sludge bed.