USBF Technology (Upflow Sludge Blanket Filtration) - WWTS, CAMIX Vietnam



Background: A new biological domestic wastewater treatment process, which has been presented these days in activated sludge modification, is Upflow Sludge Blanket Filtration (USBF). This process is aerobic and acts by using a sludge blanket in the separator of sedimentation tank. All biological flocs and suspended solids, which are presented in the aeration basin, pas through this blanket. The performance of a single stage USBF process for treatment of domestic wastewater was studied in laboratory scale. Methods: The pilot of USBF has been made from fiberglass and the main electromechanical equipments consisted of an air compressor, a mixing device and two pumps for sludge return and wastewater injection. The wastewater samples used for the experiments were prepared synthetically to have qualitative characteristics similar to a typical domestic wastewater (COD= 277 mg/l, BOD5= 250 mg/l and TSS= 1 mg/l). Results: On the average, the treatment system was capable to remove 82.2% of the BOD5 and 85.7% of COD in 6 h hydraulic retention time (HRT). At 2 h HRT BOD and COD removal efficiencies dramatically reduced to 50% and 46.5%, respectively. Conclusion: Even by increasing the concentrations of pollutants to as high as 50%, the removal rates of all pollutants were remained similar to the HRT of 6 h.


Scheme of wastewater treatment

Operation of a USBF plant is simple and self-regulating. Wastewater enters the anoxic – denitrification compartment of the bioreactor (A) where it mixes with activated sludge recycled from the bottom of the last saparation compartment (C). Agitated and moved in a controlled manner, the mixed liquor flows from the denitrification compartment into the bioreactor’s aerobic compartment (B). From the aerobic compartment the mixture enters the sludge filter at the bottom and then the separation compartment(D). Filtered effluent overflows into the anoxic compartment (A).

USBF technology is a new innovated solution of biological wastewater treatment. Being flexible, USBF reactors enable using this technology for a wide range of wasterwater treatment plants from one-family houses (with 4 inhabitants) up to large cities with several million inhabitants.

USBF technology is the top innovation. The clarified water reaches high quality including elimination of eutrophication elements of phosphorus and nitrogen. Both phosphorus and nitrogen support i.a. growing of algae and cyanobacteria.


Advantages of USBF:

  Significant short terms of refurbishments
  No new land area required
  Gradual refurbishment of USBF possible without land area requirement
  Cost saving
  Technological parts of wasterwater plants to be built in are made of stainless steel with 30 years guarantee.