Up Flow Anaerobic Sludge Process: The upflow anaerobic sludge blanket reactor (UASB) is a single tank process in an anaerobic centralised or decentralised industrial wastewater or blackwater treatment system achieving high removal of organic pollutants. 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. Bacteria living in the sludge break down organic matter by anaerobic digestion, transforming it into biogas. Solids are also retained by a filtration effect of the blanket. The upflow regime and the motion of the gas bubbles allow mixing without mechanical assistance. Baffles at the top of the reactor allow gases to escape and prevent an outflow of the sludge blanket. As all aerobic treatments, UASB require a post-treatment to remove pathogens, but due to a low removal of nutrients, the effluent water as well as the stabilised sludge can be used in agriculture.

Advantages of UASB

  • Low/minimum power consumption for biological treatment of wastewater
  • Less sludge production
  • Produces stabilized sludge which can be used as manure
  • Produces useful byproduct- BIOGAS- can be used to produce electricity
  • Low nutrient requirements for biological treatment of wastewater
  • Very much suitable for high organic load (BOD/COD) wastewater
  • Less foot print required compared to footprint required for aerobic biological treatment of wastewater
  • Less mechanical Equipments, hence Low maintenance plant