Biological cleaning of waste gas from contamination by organic substances is a simulation and intensification of processes running in natural conditions, summarily called self-cleaning. Biological cleaning is economically more advantageous compared to physically-chemical and chemical processes with the same efficiency, and it does not bring into the environment contaminating substances (full degradation of contamination in a certain concentration range), for example, ash, inorganic salts, etc.
Biofilters operate on the principle of biofilm, which covers the particles of the material used and the filling of equipment. Volatile pollutants are dissolved together with oxygen in the moistened biofilm and are metabolised by micro organisms under aerobic conditions. Such metabolites (CO2) diffuse by a biological layer, are converted into the gas phase and are collected from the device.
It is necessary to ensure a supply of mineral nutrition for micro organisms in the biofilter (in particular, phosphor and nitrogen), moisture and oxygen air. It is also necessary to ensure the proper pH, temperature and permeability of the filter medium for the achievement of maximum efficiency of the process. Biological filters for cleaning of air are designed for volumes within the range of flow from 100 to 10,000 m3/hour, in the case of cleaning of water 1-100 m3/hour.
Biodegradation in the biofilm on the surface of the particle of the filter medium.
Areas of use: