Dear Mehta,

Please take a look this article:

"Integrated application of upflow anaerobic sludge blanket reactor for the treatment of wastewaters" Muhammad Asif Lati fRumana Ghufran Zularisam AbdulWahid Anwar Ahmad, Water Research Volume 45, Issue 16, 15 October 2011, Pages 4683-4699.

It exhibits performance of upflow anaerobic sludge blanket reactors for various wastewaters.

Good luck.

An anaerobic granular bed technology refer to a special kind of reactor concept for the high rate anaerobic treatment of wastewater. sludge The sludge blanket is comprised of microbial granules (1 to 3 mm in diameter), i.e., small agglomerations of microorganisms that, because of their weight, resist being washed out in the up flow. The microorganisms in the sludge layer degrade organic compounds. As a result, gases (methane and carbon dioxide) are released. The rising bubbles mix the sludge without the assistance of any mechanical parts. Sloped walls deflect material that reaches the top of the tank downwards. The clarified effluent is extracted from the top of the tank in an area above the sloped walls.

OBJECTIVES- The major objectives of the UASB process is:

• Pre sedimentation anaerobic wastewater treatment and final sedimentation including sludge stabilization are essentially combined in one reactor making it most attractive high-rate wastewater treatment option.

• To produce by products like Methane enriched biogas and nutrient rich sludge.

After several weeks of use, larger granules of sludge form which, in turn, act as filters for smaller particles as the effluent rises through the cushion of sludge. Because of the up flow regime, granule-forming organisms are preferentially accumulated as the others are washed out.

The upflow anaerobic sludge blanket reactor, developed by Prof Gatze Lettinga, has been applied for treatment of a wide range of municipal and industrial wastewaters. The UASB is best suited for more concentrated waste (high organic matter) and at higher temperatures. However, the UASB has also been tested for sewage with low BOD and at low T (but then methane yields are rather low, while organic matter removal may largely be attributed to sedimentation under these circumstances).Please note that the UASB only removes organic matter (conversion to biogas), and does not reduce other contaminants such as nitrogen or pathogens. Therefore the application of a combination of technologies would be advisable (e.g. UASB followed by waste stabilisation ponds). see also following references:

Gijzen, H.J. (2001). Anaerobes, aerobes and phototrophs – A winning team for wastewater management. Water Science and Technology 44:8, 1213-132.

El-Shafai S.A., El-Gohary F.A., Nasr F.A., van der Steen N.P. and Gijzen H.J. (2007) Nutrient recovery from domestic wastewater using a UASB-duckweed ponds system. Bioresource Technology 98, 4, 798-807.

Gijzen HJ (2006) The role of natural systems in urban water management in the city of the future – a 3-step strategic approach. Ecohydrology Hydrobiology 6:115-122

Sharing link:

https://www.sswm.info/water-nutrient-cycle/wastewater-treatment/hardwares/semi-centralised-wastewater-treatments/upflow-anaerobic-sludge-blanket-reactor-%28uasb%29

Regards!

Where should we employ UASB process ? Why?

The answer is as under:

Under following circumstances Up-flow Anaerobic Sludge Blanket process is primarily dictated by:

1. the amount of viable sludge which can be retained in the anaerobic reactor and

2. the contact that can be achieved between the incoming wastewater and the sludge

Here the in this process unlike aerobic treatment processes, the loading potentials of the process are not limited by the supply of any required agent/ingredient. If more sludge can be retained higher loads can be applied however sufficient contact between sludge and wastewater can be maintained.

Thus the UASB reactor is high loading capacity type. It differs from other processes due to its simplicity in design and it is low cost high rate anaerobic treatment processes.

Thank you Sir Wonderful answer Dr Sheth.