ABSTRACT
Substrates for aerated Eco-engineered bioreactors (EEBs) such as BREW Bioreactors (BBRs) and submerged attached growth reactor Bioreactors are made up of aggregate materials such as quartz gravel, crushed rock, shale or limestone and dolomite gravels. The substrate surfaces of BBRs are covered over with a layer of insulating material from 0.1 to 0.5 m thick. As with aerobic EEBs, in addition to the substrates, passive treatment anaerobic bioreactors such as some biochemical reactors may contain separator layers, bedding layers for piping, and, in some cases, separate layers of reactive materials such as limestone gravel or cobbles. Biosolids from pulp and paper plant and paper recycling plant wastewater treatment plants are particularly good active media for passive treatment anaerobic bioreactors. Inorganic material will only clog EEB beds if it is not first removed to low levels upstream of the bioreactor cells and the prevention of such situations is a matter of judicious design.
