5.3.2 Anaerobic Treatment SystemsThe following treatment processes fall under the classification of anaerobic treatment.a) Up flow Anaerobic Sludge Blanket - UASBb) Anaerobic filter - AFc) Anaerobic fluidized bedThese are mainly needed in case where bio-methanation is possible to recover the energy.Instances are the Up Flow Anaerobic Reactor and sludge digesters and the schematic of theseare shown in Figure 5.9, Figure 5.10, and Figure 5.11. The principle of anaerobic treatment isalready shown in Figure 5.2.