Treatment and disposal of bio-hazardous sludge accounts for 50-60% of the operational costs at a wastewater treatment plant. To treat this sludge, it undergoes a process involving thickening, conditioning, and dewatering, followed by transport to a landfill or incinerator. In addition to high costs, landfilling and incineration are detrimental from a sustainability standpoint.
In this patented invention, a closed, anaerobic, completely stirred tank side stream reactor is added after the outlet of the settling tank at the wastewater treatment plant. Solids retention time in the reactor is short (< 4 days), keeping its size and cost down. The acidic and anaerobic environment of the reactor causes biomass to deflocculate and sludge to hydrolyze, ultimately reducing sludge by 60%. The invention also has the added benefit of producing hydrogen and methane fuel.
