Malodorous gases from the odor-removal structures are collected and sent together with the main odor conveyance pipeline to the upper section of the biological washing stage. Atomizing nozzles fully atomize water, which then mixes with the air flow, quickly reaching a saturated humidity state in the gas to be treated. Additionally, some of the malodorous molecules in the gas are absorbed by the washing liquid, creating favorable conditions for the stable operation of the biological filtration process.Favorable terms.
The gas treated through the biological washing stage enters the biological filtration stage from bottom to top. As the gas moves upwards, odor molecules within the gas pass through the filling layer and are thoroughly contacted with the biofilm formed on the surface of the filling material. The odor molecules are then oxidized and decomposed by microorganisms, converting them into carbon dioxide, water, minerals, etc., achieving the goal of odor purification.
The treated gas passes through a 15-meter exhaust pipeline after being processed by a biological filter unit, meeting emission standards.
Process Principle and Features:Odor control devices using biological methods are widely researched, technically mature, and commonly used for treating malodorous gases. The process involves the gas containing malodorous substances being pre-treated with dust removal, humidification, or cooling, then passing through the filter bed from bottom to top. As it passes through the filter layer, the malodorous substances transfer from the gas phase to the water-microorganism mixed phase (biological layer), where they are decomposed by the metabolic actions of microorganisms attached to the filter material. This method primarily utilizes the biochemical actions of microorganisms to decompose pollutants into harmless substances. Microorganisms use organic matter as a substrate for their growth and reproduction, converting large or complex organic molecules through heterotrophic processes into simple inorganic substances like water and carbon dioxide. Simultaneously, through assimilatory processes and utilizing the energy produced during heterotrophic processes, the microorganisms grow and reproduce, creating favorable conditions for enhancing their ability to process organic matter. The essence of pollutant 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 processes, which can be simplified to the following expression:
The composition of malodorous gases varies, leading to different decomposition products. Different types of microorganisms yield different metabolic by-products. For nitrogen-free organic substances like carboxylic acids and formaldehyde, the final products are carbon dioxide and water. Sulfur-containing malodorous components are oxidized and decomposed into sulfate ions and sulfur under aerobic conditions. For nitrogen-containing malodorous substances like amines, they release NH3 through ammonification, which can then be oxidized by nitrite bacteria into nitrite ions and further oxidized by nitrate bacteria into nitrate ions.
