a pilot anaerobic filter was used to remove cod from babolsar fiberboard production wastewater. the anaerobic filter was packed with ceramic packings and operated at different organic loading rates of 2.4 and 8 kg cod/m3 /day, in 20, 10 and 5 days hydraulic retention time (hrti), respectively. the reactor achieved cod removal of 80.3%, 81% and 79% for hrt 20, 10 and 5 days, respectively. in add...

activated sludge or extended aeration treatment involves a continous system where aerobic biological growths are mixed with waste water and then separated in a gravity clarifier. therefore, waste treatment system such as the activated sludge system depend on the activities of communities of living organism. in this study, an attempt was made on the indentification of the bacterial population in...