Influence of Bio-Filter Bed on Treatment of Domestic Sewage in Purifying Tank

The influence of bio-filter on domestic sewage treatment in purifying tank was studied in this paper. The result shows that when all the three zones were added bio-filter the mean values of effluent COD and NH3-N were 37.8mg/L and 9.64mg/L respectively, which shows that the bio-filter bed is a key technology and plays important roles for solid-liquid separation, bio-sorption and bio-degradation, to raise the effluent quality in the sewage treatment process.