}}
[[Image:Icon_upflow_anaerobic_sludge_blanket_reactor.png |right|95px]]
'''The Upflow Anaerobic Sludge Blanket Reactor (UASB) is a single tank process. Wastewater enters the reactor from the bottom, and flows upward. A suspended sludge blanket filters and treats the wastewater as the wastewater flows through it.'''