Effluent treatment.

摘要

The invention provides a biological aerated filter comprising an upstanding hollow column (10), the column being packed with support media (14) for microbial biomass, and a portion of the interior of the column at the lower end (12) being free of support media and housing an air diffuser (15), whereby in use liquid effluent is contained in the column and surrounds microbial biomass on the support matrix, and air is diffused through the effluent by the air diffuser.