Malodorous gases are collected from the odor-elimination structures and sent together with the main odor conveying pipeline to the upper section of the bio-washing stage. The atomizing nozzles fully atomize the water, mixing it with the air flow to quickly achieve a saturated humidity state in the gas to be treated. Some of the malodorous molecules in the gas are absorbed by the washing liquid, creating favorable conditions for the stable operation of the bio-filtration process.
After passing through the biological washing stage, the gas enters the biological filtration section from bottom to top. As the gas moves upwards, odor molecules in the gas pass through the packed bed and come into full contact with the biofilm formed on the surface of the packing. These odor molecules are then oxidized and decomposed by microorganisms, converting them into carbon dioxide, water, minerals, and other substances, thereby achieving the goal of odor purification.
Gases processed through the biological filtration unit are discharged through a 15-meter exhaust pipeline, meeting emission standards.
Process Principle and Features: The biological deodorization device is a widely researched, mature technology, and commonly used method for treating malodorous gases in practice. Its process involves the gas containing malodorous substances being pre-treated with dust removal, humidification, or cooling, and then passing through the filter bed from bottom to top. During this passage, the malodorous substances are transferred from the gas phase to the water-microorganism mixed phase (biolayer) in the filter layer, where they are decomposed by the metabolic actions of microorganisms attached to the filter material. This method primarily utilizes the biochemical action of microorganisms to decompose pollutants and convert them into harmless substances. Microorganisms use organic matter as the matrix for their growth and reproduction, converting large or complex organic molecules through heterotrophic actions into simple inorganic substances like water and carbon dioxide, and by utilizing the energy produced during heterotrophic actions, they promote their own growth and reproduction, creating favorable conditions for further processing of organic matter. The essence of pollution removal is the absorption, metabolism, and utilization of organic matter as nutrients by microorganisms. This process is a complex combination of physical, chemical, physicochemical, and biochemical actions. It can be simplified into the following expression:
Volatile organic compounds vary in composition, resulting in different breakdown products. Different types of microorganisms produce distinct metabolic byproducts. For nitrogen-free organic substances like carboxylic acids and formaldehyde, the final products are carbon dioxide and water. For sulfur-containing malodorous components, under aerobic conditions, they are oxidized and decomposed into sulfate ions and sulfur. For nitrogen-containing malodorous substances like amines, they release NH3 through ammonification, which can be oxidized by nitrosating bacteria into nitrite ions, and further oxidized by nitrifying bacteria into nitrate ions.
