Anaerobic Filters calculation depends of various parameters like void ratio of media and height ratio of different type of material. but there i have provided with some calculation steps. you can calculate the AF design if you have information about various parameters.
Anaerobic Filter Standards HRT = 8 hrs (Decentralized waste water treatment systems ) OLR = 6 kg BOD/m3/d (Sasse, 1998) OLR = 4 – 5 kg COD/m3/d Filter Material = Cinder, PVC Pipe Pieces, Crushed Glass Length of a chamber < Depth Design Depth allowed = 1.8 m Filter media depth = 1.2 m (Cinder 0.3 m, PVC Pipe Pieces 0.6 m, Crushed Glass 0.3 m) Bottom sludge zone = 0.3 m Top water zone = 0.3 m Free board = 0.5 m (Total Depth = 2.3 m) HRT = 12 hrs Wastewater Volume = 6.67 * 12 = 80 m3 Void Ratio of media = 0.5 Media Volume = 0.5 * 80 = 40 m3 Total wetted volume required = 120 m3 Wetted Width = Width of ABR = 8 m (For both units) Wetted Depth = 1.2 m (excluding top water zone and bottom sludge zone) Wetted Length = Wetted Volume / (Depth * Width) = 120 / (1.2*8) = 12.5 m Total units = 3 Length of each unit = 12.5/3 = 4.2 m ≈ 4 m Upflow velocity: 3.335/(4 * 4) = 0.2 m/hr < 2 m/hr Total Volume of each AF including Freeboard = Length of chamber x No. of Chambers x Width x Depth = 4 * 3 * 4 * 2.3 = 110.4 m3 (Freeboard from top to facilitate inspection) Use 2 AFs for two trains each having 3 compartments. Volume of each AF per train = 110.4 m3