UASB Reactor

Compiled by:
Eawag (Swiss Federal Institute of Aquatic Science and Technology), Dorothee Spuhler (seecon international gmbh)
Adapted from:
TILLEY, E.; ULRICH, L.; LUETHI, C.; REYMOND, P.; ZURBRUEGG, C. (2014)

Executive Summary

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.

In Out

Blackwater, Faecal Sludge, Brownwater, Faeces, Excreta

Digested Faecal Sludge, Fertigation Water

Introduction

In countries with a warm climate throughout the whole year, high wastewater allow and favour an anaerobic treatment of the entire sewage flow, not only the sludge portion (TBW 2001b). Anaerobic treatment systems such as UASB (see also anaerobic digestion general) do not require an energy consuming aeration system and can be constructed much simpler than aerobic treatments. They convert the organic matter into biogas, which can be recovered. The nutrient-rich effluent can be used for agricultural irrigation (ROSE 1997). Sludge, even is partily stabilised (mineralised) and can be used as an organic soil fertiliser after composting or drying (see also planted and unplanted drying bed).

UASB reactors can treat all type of hyigh-strenght wastewater. It can be used at large-scale (e.g. agro-industrail wastes) or as decentralised treatment systems for domestic wastewaters; yet domestic treatment is still relatively new and not always successful as domestic wastewater generally lower strength.

Treatment Process

UASB Reactors are constructed out of concrete or another watertight material and can be designed in a circular or rectangular way. Wastewater is pumped from the bottom into the reactor where influent suspended solids and bacterial activity and growth lead to the formation of 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 upflow. The microorganisms in the sludge layer degrade organic compounds. As a result, gases (methane and carbon dioxide i.e. biogas) are released. The rising bubbles mix the sludge without the assistance of any mechanical parts. Upstream velocity and settling speed of the sludge is in equilibrium and forms a locally rather stable, but suspended sludge blanket (SASSE 1998). 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. A gas-liquid-solids separator (GLSS) separates the gas from the treated wastewater and the sludge (ROSE 1997, SANIMAS 2005).

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 upflow regime, granule-forming organisms are preferentially accumulated as the others are washed out. Fortunately, these bacteria are also more efficient for biogas production than flocculated biomass (WENDLAND 2008).

Design Considerations

 TILLEY et al. (2014)

Cross-section of an Upflow Anaerobic Sludge Blanket (UASB) reactor. Source: TILLEY et al. (2008)

UASB Reactors are constructed out of concrete or another watertight material and can be designed in a circular or rectangular way. Critical elements for the design of UASB reactors are the influent distribution system, the gas-solids separator, and the effluent withdrawal design. The gas that rises to the top is collected in a gas collection dome and can be used as energy (see also use of biogas) for cooking, heating or other, but scrubbing before use is required (UNEP 2004). If the biogas is converted to electricity, the heat produced as a by-product can be reused to heat the reactor, favouring anaerobic digestion.

 

 TBW (2001b)

UASB reactors are separated in three phases: granules, liquid and gas (left). They can be constructed circular or rectangular (right). Source: TBW (2001b)

To maintain the reactor well-mixed and allowing the formation of granules and a good contact of the active sludge blanket and the influent sewage, it is critical that the influent is equally distributed in the bottom before moving upwards (see Figure 1). Besides these design requirements, the main influencing parameters are pH, temperature, chemical oxygen demand (COD), volumetric COD loads, HRT and flow, upflow velocity, concentration of ammonia and start-up phase (TBW 2001b). 

pH Value

The pH-value needs to be between 6.3 and 7.85 (TBW 2001b) to allow bacteria responsible for anaerobic digestion to grow. The pH-value is also important because at high pH-values, ammoniac (NH4+) dissociates to NH3 which inhibits the growth of the methane producing bacteria

Temperature

For an optimal growth of these bacteria and thus a optimal anaerobic digestion, the temperature should lie between 35 to 38°C. Below this range, the digestion rate decreases by about 11% for each 1°C temperature decrease and below 15°C the process is no longer efficient (ALAERTS et al. 1990 in TBW 2001b), although bacterial activity can still be noticed at temperatures less than 10°C (TBW 2001b). 

COD Loads

Influents should have concentrations of above 250 mg COD/Lm, as for lower rates, anaerobic digestion is not beneficial. Optimum influent concentrations are above 400 mg COD/L and an upper limit is not known (TBW 2001b). 

Hydraulic Retention Time (HRT)

The hydraulic retention time (HRT) should not be less than 2 hours. Anaerobic microorganisms, especially methane producing bacteria, have a slow growth rate. At lower HRTs, the possibility of washout of biomass is more prominent (BAL & DHAGAT 2001). The optimal HRT generally lies within 2 to 20 hours (TBW 2001b).

Upflow Velocity

//www.entec-biogas.com/de/leistungen/technik-system-uasb.php

Large-scale UASB reactor followed by a post-treatment in trickling filters. Source: ENTEC BIOGAS GMBH (2014)

The upflow velocity in UASB is an important design parameter as the process plays with the balance of sedimentation and upflow (SASSE 1998). On one hand, sludge should not be washed out the reactor, and on the other hand, a minimum speed needs to be maintained to keep the blanket in suspension, and also for mixing (TBW 2001b). An upflow velocity of 0.7 to 1 m/h must be maintained to keep the sludge blanket in suspension. Primary settling is usually not required before the UASB.

Health Aspects/Acceptance

The operators should take proper health and safety measures while working in the plant, such as adequate protective clothing. Effluent and sludge still pose a health risk and should not be directly handled. 

However as nitrogen and phosphorous are not effectively reduced in anaerobic technologies, this primary treatment approach is particularly apt when used in parallel with agriculture or aquaculture (ROSE 1997). As in all anaerobic treatment processes, sludge is stabilised and if not used in agriculture, has good dewatering characteristics and can be treated in thickening ponds and drying beds or by composting before safe reuse or disposal (ROSE 1997; WSP 2008). The effluent can be used in fertigation but as it pathogen removal is only low the WHO 2006 guidelines must be considered for agricultural application. To meet higher effluent standards, the effluent may be post-treated in pond systems (e.g. wastewater stabilisation ponds), constructed wetlands or anaerobic treatment units (e.g. trickling filter). The most common post-treatment alternatives for effluents are maturation ponds (see also waste stabilisation ponds where nutrients are further reduced, their primary function however being pathogen removal (TBW 2001b).

Cost Consideration

The significantly lower level of technology required by the UASB process in comparison with conventional advanced aerobic processes means that they are also cheaper in construction and maintenance. Capital costs for construction can be estimated as low to medium and comparable to baffled reactors (SANIMAS 2005). Operation costs are low, as usually no costs arise other than desludging costs and the operation of feeding pump (SANIMAS 2005).

Operation & Maintenance

The UASB is a Centralized Treatment technology that must be constructed, operated and maintained by professionals. A skilled operator is required to monitor the reactor and repair parts, e.g., pumps, in case of problems. 

UASB reactors require several months to start up. The sludge not only needs to form but also needs to adapt to the characteristics of the specific wastewater (TBW 2001b). As domestic or municipal wastewater already contains the composition of nutrients and micronutrients required for bacterial activity and growth, they are generally less problematic than industrial wastewaters. High organic loading in connection with lower hydraulic loading rates quicken the granulation process in the starting phase (SASSE 1998).

To keep the blanket in proper position, the hydraulic load must correspond to the upstream velocity and must correspond to the organic load. The latter is responsible for development of new sludge (SASSE 1998). This means that the flow rate must be controlled and properly geared in accordance with fluctuation of the organic load.

Sludge production is relatively low (WSP 2008). Desludging is infrequent and only excess sludge is removed every 2 to 3 years (TILLEY et al. 2014). 

At a Glance

Working Principle

Industrial wastewater or blackwater flows into the bottom of an anaerobic upflow tank. Accumulated sludge forms granules. Microorganisms living in the granules degrade organic pollutants by anaerobic digestion. The sludge blanket is kept in suspension by the flow regime and formed gas bubbles. A separator at the top of the reactor allows to recover biogas for energy production, nutrient effluent for agriculture and to retain the sludge in the reactor. Sludge accumulation is low (emptying is only required every few years) and the sludge is stabilised and can be used as soil fertiliser.

Capacity/Adequacy

Centralised or decentralised at community level, for industrial wastewater or blackwater. The system requires a continuous and stable water flow and energy.

Performance

60 to 90 % BOD; 60 to 80 % COD and 60 to 85 % TSS; low pathogen reduction minimal removal of nutrient (N and P)

HRT: minimal 2 hours, generally 4 to 20 hours

Costs

Investment is comparable to baffled reactors. For operation usually no costs arise beneath desludging costs and operation of feeding pump.

Self-help Compatibility

Can be constructed with locally available material but requires skilled staff for construction, maintenance and operation.

O&M

Desludging is not frequent but feeder pump and control of organic loads requires skilled staff for operation and maintenance.

Reliability

Not resistant to shock loading and sensitive to organic load fluctuations.

Main strength

High removal of organics and solids (BOD and TSS) with low production of sludge and the possibility to recover biogas; only little land required.

Main weakness

Requires skilled staff, electricity and is sensitive to variable flows.

Applicability

A UASB is not appropriate for small or rural communities without a constant water supply or electricity and skilled labour. It is particularly adapted for densely populated urban areas as it has low land requirements. The technology is relatively simple to design and build, but developing the granulated sludge may take several months. The UASB reactor has the potential to produce higher quality effluent than Septic Tanks, and can do so in a smaller reactor volume. Although it is a well-established process for large-scale industrial wastewater treatment and high organic loading rates up to 10 kg BOD/m3/d, its application to domestic sewage is still relatively new. It is often used for brewery, distillery, food processing and pulp and paper waste (TARE & NEMA n.y.) since the process typically removes 80 to 90% of COD. Where the influent is low-strength or where it contains too many solids, proteins or fats, the reactor may not work properly. Temperature is also a key factor affecting the performance. UASB reach high treatment levels regarding organics and the produced biogas can be used for energy conversion. Pathogens, however, as well as nutrients are not removed. Due to the low nutrient removal, the effluent is adapted for reuse in agriculture after further treatment or considering some special health protection measures.
UASB are not adapted for colder climates.

Advantages

  • High reduction of BOD
  • Can withstand high organic and hydraulic loading rates
  • Low sludge production (and, thus, infrequent desludging required)
  • Biogas can be used for energy (but usually first requires scrubbing)
  • No aeration system required (thus little energy consumption)
  • Effluent is rich in nutrients and can be used for agricultural irrigation
  • Low land demand, can be constructed underground and with locally available material
  • Reduction of CH4 and CO2 emissions

Disadvantages

  • Treatment may be unstable with variable hydraulic and organic loads
  • Requires operation and maintenance by skilled personnel; difficult to maintain proper hydraulic conditions (upflow and settling rates must be balanced)
  • Long start-up time to work at full capacity
  • A constant source of electricity is required
  • Not all parts and materials may be locally available
  • Requires expert design and construction
  • Effluent and sludge require further treatment and/or appropriate discharge
  • Not adapted for cold regions

References Library

ALAERTS, G. J.; VEENSTRA, S.; BENTVELSEN, M.; DUIJL, L. A. van (1990): Feasibility of Anaerobic Sewage Treatment in Sanitation Strategies in Developing Countries. (= IHE Report Series 20). Delft: The Netherlands.

BAL, A.S.; DHAGAT, N.N. (2001): Upflow anaerobic sludge blanket reactor- a review. Indian Journal of Environmental Health . URL [Accessed: 16.02.2011]. PDF

ENTEC BIOGAS GMBH (Editor) (2014): SYSTEM UASB. Fussach: entec biogas gmbh. URL [Accessed: 09.07.2014].

GUTTERER, B.; SASSE, L.; PANZERBIETER, T.; RECKERZÜGEL, T.; ULRICH, A. (Editor); REUTER, S. (Editor); GUTTERER, B. (Editor) (2009): Decentralised Wastewater Treatment Systems (DEWATS) and Sanitation in Developing Countries. Loughborough University (UK): Water Engineering and Deveopment Centre (WEDC). URL [Accessed: 20.03.2014]. PDF

LETTINGA, G.; ROERSMA, R.; GRIN, P. (1983): Anaerobic Treatment of Raw Domestic Sewage at Ambient Temperatures Using a Granular Bed UASB Reactor. In: Biotechnology and Bioengineering 25, 1701-1723.John Wiley & Sons.

NATURGERECHTE TECHNOLOGIEN, BAU- UND WIRTSCHAFTSBERATUNG (TBW) GmbH (Editor) (2001): Anaerobic Treatment of Municipal Wastewater in UASB-reactors. (= Technical Information W6e). GTZ and GATE . URL [Accessed: 11.03.2010]. PDF

ROSE, D.G. (1999): Community-Based Technologies for Domestic Wastewater Treatment and Reuse- options for urban agriculture. (= Cities Feeding People (CFP) Report Series., 27). Ottawa: International Development Research Center Canada (IDRC). PDF

SANIMAS (Editor) (2005): Informed Choice Catalogue. pdf presentation. BORDA and USAID. PDF

SASSE, L. ; BORDA (Editor) (1998): DEWATS. Decentralised Wastewater Treatment in Developing Countries. Bremen: Bremen Overseas Research and Development Association (BORDA). PDF

SCHELLINGKOUT, A.; COLLAZOS, C. J. (1999): Full-scale Application of the UASB Technology for Sewage Treatment. Water Science and Technology. URL [Accessed: 18.01.2011].

SPERLING, M. von; LEMOS CHERNICHARO, C.A. de (2005): Biological Wastewater Treatment in Warm Climate Regions Volume 1. London: International Water Association (IWA) Publishing. URL [Accessed: 01.11.2013]. PDF

TARE, V.; NEMA, A. (n.y.): UASB Technology-expectations and reality. United Nations Asian and Pacific Centre for Agricultural Engineering and Machinery. URL [Accessed: 29.04.2010]. PDF

TCHOBANOGLOUS, G.; BURTON, F. L.; STENSEL, H. D.; METCALF & EDDY Inc. (Editor) (2003): Wastewater Engineering, Treatment and Reuse. (= Fourth Edition). New York: McGraw-Hill Companies, Inc..

TILLEY, E.; ULRICH, L.; LUETHI, C.; REYMOND, P.; ZURBRUEGG, C. (2014): Compendium of Sanitation Systems and Technologies. 2nd Revised Edition. Duebendorf, Switzerland: Swiss Federal Institute of Aquatic Science and Technology (Eawag). URL [Accessed: 28.07.2014]. PDF

TILLEY, E.; LUETHI, C.; MOREL, A.; ZURBRUEGG, C.; SCHERTENLEIB, R. (2008): Compendium of Sanitation Systems and Technologies. Duebendorf, Switzerland: Swiss Federal Institute of Aquatic Science and Technology (EAWAG) and. URL [Accessed: 15.02.2010]. PDF

See document in FRENCH

UNEP (Editor) (2004): Chapter 4. Wastewater Technologies. In: UNEP (Editor) (2004): A Directory of Environmentally Sound Technologies for the Integrated Management of Solid, Liquid and Hazardous Waste for SIDS in the Caribbean Region. Nairobi, 63-125. PDF

VIGNESWARAN, S.; BALASURIYA, B. L. N.; VIRARAGHAVAN, T. (1986): Environmental Sanitation Reviews. Anaerobic Wastewater Treatment – Attached Growth and Sludge Blanket Process. Bangkok: Environmental Sanitation Information Center (ENSIC).

WENDLAND, C. (2008): Anaerobic Digestion of Blackwater and Kitchen Refuse. (PhD Thesis). (= Hamburger Berichte zur Siedlungswasserwirtschaft). Hamburg: Institut fuer Abwasserwirtschaft und Gewaesserschutz (AWW), Technische Universitaet Hamburg-Hamburg (TUHH). URL [Accessed: 11.03.2010]. PDF

WHO (Editor) (2006): Guidelines for the safe use of wastewater excreta and greywater. Volume IV. Excreta and Greywater Use in Agriculture. Geneva: World Health Organisation. URL [Accessed: 26.02.2010]. PDF

WSP (Editor) (2008): Technology Options for Urban Sanitation in India. A Guide to Decision-Making. pdf presentation. Washington: Water and Sanitation Program. URL [Accessed: 26.03.2010]. PDF

Further Readings Library

Reference icon

GUTTERER, B.; SASSE, L.; PANZERBIETER, T.; RECKERZÜGEL, T.; ULRICH, A. (Editor); REUTER, S. (Editor); GUTTERER, B. (Editor) (2009): Decentralised Wastewater Treatment Systems (DEWATS) and Sanitation in Developing Countries. Loughborough University (UK): Water Engineering and Deveopment Centre (WEDC). URL [Accessed: 20.03.2014]. PDF

This document speaks about waste water and sanitation strategies in the developing countries. It also advocates the use of DEWATS as sustainable treatment of waste water at a local level backing it up with case studies from different countries. It describes various options available for sanitation and waste water treatment. It gives an idea of planning and executing CBS programs.


Reference icon

NATURGERECHTE TECHNOLOGIEN, BAU- UND WIRTSCHAFTSBERATUNG (TBW) GmbH (Editor) (2001): Anaerobic Treatment of Municipal Wastewater in UASB-reactors. (= Technical Information W6e). GTZ and GATE . URL [Accessed: 11.03.2010]. PDF

Ten-page description of all important design parameters for UASB reactors based on a large range of references.


Reference icon

FRASSINETTI-FEITOSA-CALVALCANTI, P. (2003): Integrated Application of the UASB Reactor and Ponds for Domestic Sewage Treatment in Tropical Regions. (= Thesis). Wageningen: Wageningen University. URL [Accessed: 29.04.2010]. PDF

Thesis dealing with aspects of design, performance and operation of sewage treatment systems consisting of an UASB reactor followed by a polishing pond. The thesis investigates an experimental pilot plant in order to assess design and operation parameters with respect to the performance of the UASB reactor, followed by post-treatment in different configurations of polishing ponds.


Reference icon

TARE, V.; NEMA, A. (n.y.): UASB Technology-expectations and reality. United Nations Asian and Pacific Centre for Agricultural Engineering and Machinery. URL [Accessed: 29.04.2010]. PDF

This paper highlights some inherent lacunae of UASB technology for sewage treatment based on a set of case studies, effluent data of UASB systems and a long-term monitoring of the performance of pilot plants in Kantapur (India).


Reference icon

SEGHEZZO, L. (2004): Anaerobic treatment of domestic wastewater in subtropical regions. Wageningen: Wageningen University. URL [Accessed: 05.01.2011]. PDF

This document describes the anaerobic treatment of domestic wastewater in subtropical regions.


Reference icon

NATURGERECHTE TECHNOLOGIEN, BAU- UND WIRTSCHAFTSBERATUNG (TBW) GmbH (Editor) (2001): Anaerobic Methods of Municipal Wastewater Treatment. Technical Information W3e. GTZ and GATE. URL [Accessed: 11.03.2010]. PDF

Technical information on the advantages and main technologies of anaerobic digestion treatment for wastewaters in developing countries.


Reference icon

UNEP (Editor) (2004): Chapter 4. Wastewater Technologies. In: UNEP (Editor) (2004): A Directory of Environmentally Sound Technologies for the Integrated Management of Solid, Liquid and Hazardous Waste for SIDS in the Caribbean Region. Nairobi, 63-125. PDF

Comprehensive overview (in form of factsheets) on the different components of wastewater treatment systems (collection, transfer, onsite treatment, centralised and decentralised treatment, reuse, sludge management and disposal) adapted to the Caribbean Region. Industrial wastewater treatment is also discussed.


Reference icon

WENDLAND, C. (2008): Anaerobic Digestion of Blackwater and Kitchen Refuse. (PhD Thesis). (= Hamburger Berichte zur Siedlungswasserwirtschaft). Hamburg: Institut fuer Abwasserwirtschaft und Gewaesserschutz (AWW), Technische Universitaet Hamburg-Hamburg (TUHH). URL [Accessed: 11.03.2010]. PDF

Thesis assessing the anaerobic treatment of blackwater (toilet wastewater) from vacuum toilets without and with kitchen refuse and its potential for reuse and resources management sanitation concepts.


Reference icon

WSP (Editor) (2008): Technology Options for Urban Sanitation in India. A Guide to Decision-Making. pdf presentation. Washington: Water and Sanitation Program. URL [Accessed: 26.03.2010]. PDF

These guidance notes are designed to provide state governments and urban local bodies with additional information on available technologies on sanitation. The notes also aid in making an informed choice and explain the suitability of approaches.


Reference icon

MES, T.Z.D. de; STAMS, A.J.M. ; ZEEMAN, G. (2003): Chapter 4. Methane production by anaerobic digestion of wastewater and solid wastes. In: REITH, J.H. (Editor); WIJFFELS, R.H. (Editor); BARTEN, H. (Editor) (2003): Biomethane and Biohydrogen. Status and perspectives of biological methane and hydrogen production. , 58-94. PDF

This chapter is part of a publication, commissioned by the Netherlands Agency for Energy and the Environment (Novem) on the status and perspectives of research and development in the field of high-tech biological production of methane and hydrogen. Chapter 4 gives a short but precise introduction the technological aspects of waste treatment by anaerobic digestion and the reuse of the produced biogas.


Reference icon

MONVOIS, J.; GABERT, J.; FRENOUX, C.; GUILLAUME, M. (2010): How to Select Appropriate Technical Solutions for Sanitation. (= Six Methodological Guides for a Water and Sanitation Services' Development Strategy, 4). Cotonou and Paris: Partenariat pour le Développement Municipal (PDM) and Programme Solidarité Eau (pS-Eau). URL [Accessed: 19.10.2011]. PDF

The purpose of this guide is to assist local contracting authorities and their partners in identifying those sanitation technologies best suited to the different contexts that exist within their town. The first part of the guide contains a planning process and a set of criteria to be completed; these assist you in characterizing each area of intervention so that you are then in a position to identify the most appropriate technical solutions. The second part of the guide consists of technical factsheets which give a practical overview of the technical and economic characteristics, the operating principle and the pros and cons of the 29 sanitation technology options most commonly used in sub-Saharan Africa.

See document in FRENCH


Reference icon

LEMOS CHERNICHARO, C.A. de (2007): Anaerobic Reactors. (= Biological Wastewater Treatment Series, 4). London: International Water Association (IWA) Publishing. URL [Accessed: 01.11.2013]. PDF

Anaerobic Reactors is the forth volume in the series Biological Wastewater Treatment. The fundamentals of anaerobic treatment are presented in detail, including its applicability, microbiology, biochemistry and main reactor configurations. Two reactor types are analysed in more detail, namely anaerobic filters and especially UASB (upflow anaerobic sludge blanket) reactors. Particular attention is also devoted to the post-treatment of the effluents from the anaerobic reactors. The book presents in a clear and informative way the main concepts, working principles, expected removal efficiencies, design criteria, design examples, construction aspects and operational guidelines for anaerobic reactors.


Reference icon

SPERLING, M. von; LEMOS CHERNICHARO, C.A. de (2005): Biological Wastewater Treatment in Warm Climate Regions Volume 1. London: International Water Association (IWA) Publishing. URL [Accessed: 01.11.2013]. PDF

Biological Wastewater Treatment in Warm Climate Regions gives a state-of-the-art presentation of the science and technology of biological wastewater treatment, particularly domestic sewage. The book covers the main treatment processes used worldwide with wastewater treatment in warm climate regions given a particular emphasis where simple, affordable and sustainable solutions are required. The 55 chapters are divided into 7 parts over two volumes: Volume One: (1) Introduction to wastewater characteristics, treatment and disposal; (2) Basic principles of wastewater treatment; (3) Stabilisation ponds; (4) Anaerobic reactors; Volume Two (also available in the SSWM library): (5) Activated sludge; (6) Aerobic biofilm reactors; (7) Sludge treatment and disposal.


Case Studies Library

Reference icon

AL-JUAIDY, A.; MIMI, Z.; AL-SA'ED. R. (2003): Palestinian experience with enhanced pre-treatment of black wastewater from Birzeit University using a UASB septic tank system. In: Proceedings of the 2nd international symposium E 2, 563-566. PDF

This study demonstrates the successful implementation of a UASB (Anaerobic upflow sludge blanket) as a pre-treatment for black- and domestic wastewaters at pilot (400L) and full scale. Organic pollutants were removed quite efficiently due to biological and physical processes (sedimentation and microbial degradation), facilitating a natural post- treatment (waste stabilization ponds).


Reference icon

KHALIL, N.; SINHA, R.; RAGHAV, A.K.; MITTAL, A.K. (2008): UASB Technology For Sewage Treatment In India: Experience, Economic Evaluation And Its Potential In Other Developing Countries. URL [Accessed: 05.01.2011]. PDF

This paper reviews the overall implications of UASB (Upflow Anaerobic Sludge Blanket) technology in India. Institutional and technical aspects with special reference to the Yamuna Action Plan (YAP) are presented. It also presents the potential of UASB technology in other developing countries with its future within India as well based on the evaluation of life cycle cost.


Reference icon

JORDAO, P.; P. SOBRINHO, P.A. (2004): Investigacion y Experiencia con el Post-Tratamiento para Reactores UASB en Brasil. In: Agua Latinoamerica, noviembre/diciembre 3, 17-20. PDF

Case study on UASB reactors in Brasil.

Language: Spanish


Reference icon

HALALSHEH M.M. (2002): Anaerobic Pre-Treatment of Strong Sewage: A proper solution for Jordan. (= PhD Thesis). Wageningen: Wageningen University. URL [Accessed: 11.01.2011]. PDF

The main objective of this research was to assess the feasibility of applying low cost anaerobic technology for the treatment of relatively high strength sewage of Jordan usin two-stage and one-stage UASB (Upflow Anaerobic Sludge Blanket) reactors operated at ambient temperatures.


Reference icon

BROWN, J. (2003): Wastewater Treatment: The Experiences Of The Scientific Research Council In Jamaica. Kingston: Scientific Research Council (SRC). URL [Accessed: 06.01.2011]. PDF

The availability of local water resources in Jamaica is threatened by environmental pollution caused by domestic, agricultural and industrial interference. The Scientific Research Council (SRC) of Jamaica has over the ten years focused on providing appropriate technological and economic alternatives to the agricultural, municipal and industrial sectors, in order to avoid, reduce and treat wastewater. This paper will present experiences of the SRC in providing cost effective solutions to waste producers in Jamaica enabling delivery of “green” products and services to satisfy local and international environmental standards.


Reference icon

THIENGBURANATHUM, P. (n.y.): Utilization Of Biogas From Pig Farms For Energy Production And Environmental Amelioration. Chiang Mai: Biogas Technology Center, Chiang Mai University. PDF

The waste from pig farms in Thailand polluting natural streams and generates odours and fly nuisance. This presentation shows how this problem can be solved in an ecological and sustainable way.


Reference icon

WONGSAPAI, W.; THIENBURANATHUM, P.; RERKKRIENGKRAI, P. (n.y.): Biogas Situation and Development in Thai Swine Farms. URL [Accessed: 05.05.2010]. PDF


Awareness Raising Material Library

Reference icon

SANIMAS (Editor) (2005): Informed Choice Catalogue. pdf presentation. BORDA and USAID. PDF

This informed choice catalogue for community based wastewater treatment technologies helps to identify suitable sanitation options and facilitates the assessment of different sanitation system components with regard to stakeholder preferences. A powerful tool for technical bottom-up planning giving overall information about technical options at a "glance".


Training Material Library

Reference icon

NATURGERECHTE TECHNOLOGIEN, BAU- UND WIRTSCHAFTSBERATUNG (TBW) GmbH (Editor) (2001): Anaerobic Treatment of Municipal Wastewater in UASB-reactors. (= Technical Information W6e). GTZ and GATE . URL [Accessed: 11.03.2010]. PDF

Ten-page description of all important design parameters for UASB reactors based on a large range of references.


Reference icon

MANG, H.-P.; LI, Z. (2010): Technology Review of Biogas Sanitation. (= Technology Review ). Eschborn: Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH. URL [Accessed: 17.06.2013]. PDF

This document provides an overview and introduction on biogas sanitation (anaerobic digestion) for blackwater or for brown water, or excreta treatment for reuse in developing countries. The main technologies discussed are biogas settlers (BSs), biogas septic tanks, anaerobic baffled reactor (ABRs), anaerobic filter (AFs) and upflow anaerobic sludge blanket reactors (UASBs).


Reference icon

WAFLER, M. (2008): Training Material on Anaerobic Wastewater Treatment. (= Ecosan Expert Training Course). Aarau: Seecon GmbH. PDF

This training manual emphasizes basics of biogas technology as well as design principles and technical considerations. A sample design exercise and some technical drawings and sketches are also given.


Reference icon

ELMITVALLI, T. (2005): Treatment of Municipal Wastewater in Upflow Anaerobic Sludge Blanket (UASB) Reactor. Hamburg: Technical University Hamburg-Harburg (TUHH). PDF

This presentation discusses the technical aspect of UASB (Upflow Anaerobic Sludge Blanket) reactors to treat municipal wastewater.


Important Weblinks