Review article

The results of studies of laboratory tray models of biofilters with different materials of loading at different modes of wastewater supply are presented.It has been found that with an increase in the hydraulic load, as well as with a decrease in the breaks between irrigation of the biofilter loading, the growth rate and the amount of biofilm fixed at the loading decreases in all tested modes of wastewater supply. Episodically, at certain intervals (15-25 days), there was an intensive flushing from the load of the attached biofilm, associated with its age and loss of attachment functions. The amplitude of fluctuations in the amount of biofilm during the process (as a result of its growth and periodic flushing) decreases with an increase in fluid flow, as well as with a reduction in the interval between irrigation of the loading.. At the loads made of hydrophobic and rough materials, the biofilm growth rate was higher only at the beginning of the purification process, when a certain thickness of the biofilm was reached, its further growth was the same at all loads and was determined by the properties of the biofilm.In order to prevent siltation of the media and increase the efficiency of biofilters, it is recommended tochange the mode of wastewater supply depending on the rate of biofilm growth, its amount at the load and age.