Anaerobic treatment of domestic sewage: established technologies and perspectives

2002 ◽  
Vol 45 (10) ◽  
pp. 181-186 ◽  
Author(s):  
E. Foresti
Keyword(s):  
Sewage Treatment ◽  
Anaerobic Treatment ◽  
Domestic Sewage ◽  
Anaerobic Reactors ◽  
Resources Conservation ◽  
In The Beginning ◽  
Conventional Systems ◽  
Further Development ◽  
Uasb Reactors ◽  
Research Centres

The use of anaerobic reactors for domestic sewage treatment has increased significantly since the UASB configuration started to be efficiently applied for this purpose in the beginning of the 1980s. Nowadays, hundreds of UASB reactors, or similar anaerobic units, are used in domestic sewage treatment systems, particularly in developing countries. These units have been operated at ambient temperature, normally higher than 20°C, at hydraulic detention time in the range of 6 to 10 hours, and organic loading rates lower than 3.0 kg COD.m−3.d−1. They have presented COD removal efficiencies in the range of 65% to 80%. Besides, new configurations have been developed and assayed in research centres, aiming to amplify the range of application and to improve process performance. At the same time, research is being conducted on the post-treatment of anaerobic effluents attempting to offer alternatives to the existing conventional systems. It takes into consideration not only sanitation and environmental protection, but also considers resources conservation at lower construction and running costs as the main supporting concepts for further development. This text presents some aspects of the consolidated technologies and suggests on further developments in the conception of domestic sewage treatment systems having the anaerobic process as their core.

scholarly journals Constraints, performance and perspectives of anaerobic sewage treatment: lessons from full-scale sewage treatment plants in Brazil

2019 ◽  
Vol 80 (3) ◽  
pp. 418-425 ◽  
Author(s):  
T. Bressani-Ribeiro ◽  
L. A. Chamhum-Silva ◽  
C. A. L. Chernicharo
Keyword(s):  
Sewage Treatment ◽  
Full Scale ◽  
Upflow Anaerobic Sludge Blanket ◽  
Operational Performance ◽  
Anaerobic Sludge ◽  
Anaerobic Reactors ◽  
Anaerobic Sludge Blanket ◽  
Operational Constraints ◽  
Uasb Reactors ◽  
Design Construction

Abstract There are hundreds of full-scale upflow anaerobic sludge blanket (UASB) reactors in operation in various parts of the tropical world, notably in India and Latin America, Brazil being the holder of the largest park of anaerobic reactors for sewage treatment in the world. Despite the recognized advantages of UASB reactors, there are problems that have prevented their maximum operational performance. Neglecting the existence and delaying the solution of these challenges can jeopardize the important advances made to date, impacting the future of anaerobic technology in Brazil and in other countries. This work aims to evaluate the operational performance of five full-scale UASB reactors in Brazil, taking into account a monitoring period ranging between two and six years. The main observed design, construction, and operational constraints are discussed. Some outlooks for important upcoming developments are also provided, considering that most of the observed drawbacks can be tackled without significant increases on reactor costs.

scholarly journals ANÁLISE DA EFICIÊNCIA DO TRATAMENTO ANAERÓBIO DA MANIPUEIRA

2021 ◽  
Vol 12 (4) ◽  
pp. 30-37
Author(s):  
Danielle Florindo Pereira ◽  
Debora Yukie Pereira Ishida ◽  
Júlio Kazuya Itimura Omori ◽  
Alexandre Teixeira de Souza
Keyword(s):  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Anaerobic Treatment ◽  
Domestic Sewage ◽  
Effluent Treatment ◽  
Total Volatile ◽  
Anaerobic Reactor ◽  
Total Solids ◽  
Volatile Solids

In the processes of industrialization of cassava flour (Minihot esculenta), there is the generation of an effluent called manipueira, which requires treatment before being released into the water body. The objective of this work was to evaluate the efficiency of effluent degradation by an anaerobic reactor, using as substrate, manipueira of a flour producing industry, and, as inoculum, two distinct sludges, one from an anaerobic reactor of ascending flow (RAFA) of domestic sewage treatment plant, and another from the activated sludge system of effluent treatment of a grain producing industry. The efficiency of the process was evaluated by the physicochemical parameters: COD, BOD, total solids (TS), total volatile solids (STV), fixed total solids (STF), pH, turbidity and cyanide. Throughout the treatment there was a significant removal of Cyanide in the effluent, that is, one of the major problems of the effluent can be solved effectively via anaerobic treatment.

Low temperature treatment of domestic sewage in upflow anaerobic sludge blanket and anaerobic hybrid reactors

1999 ◽  
Vol 39 (5) ◽  
pp. 177-185 ◽  
Author(s):  
Tarek A. Elmitwalli ◽  
Marcel H. Zandvoort ◽  
Grietje Zeeman ◽  
Harry Bruning ◽  
Gatze Lettinga
Keyword(s):  
Low Temperature ◽  
Sewage Treatment ◽  
Average Diameter ◽  
Anaerobic Treatment ◽  
Domestic Sewage ◽  
Cod Removal ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Removal Efficiencies

The treatment of sewage at a temperature of 13°C was investigated in three reactors (each 3.84 litre) a UASB and two anaerobic hybrid (AH) reactors with small sludge granules with an average diameter of 0.73 mm. The media used in the AH reactors were vertical polyurethane foam sheets. The reactors were operated at a HRT of 8 h. The use of small sludge granules and operating the reactors at low upflow velocity (1.8 m/d) improved suspended COD removal efficiencies for the UASB reactor. Moreover, the use of sheets in the AH reactors significantly increased suspended COD removal efficiencies as compared to the UASB and reached to 87% for pre-settled sewage treatment. The treatment of pre-settled sewage instead of raw sewage in AH reactors significantly increased colloidal and dissolved COD removal efficiencies with 13% and 12% respectively and colloidal COD removal efficiency for the UASB reactor with 13%. At ‘steady state’ for pre-settled sewage treatment, the AH reactors removed 64% of the total COD which is significantly higher by 4% than the UASB reactor. Therefore, the anaerobic treatment of domestic sewage at low temperature can be improved by treating pre-settled sewage in shallow AH reactors containing small sludge granules.

EFICIÊNCIA DO REUSO DE ÁGUAS RESIDUÁRIAS NA IRRIGAÇÃO DA CULTURA DO MILHO.

Irriga ◽  
2010 ◽  
Vol 15 (3) ◽  
pp. 231-247
Author(s):  
Antonio Javarez Júnior ◽  
Túlio Assunção Pires Ribeiro ◽  
Durval Rodrigues De Paula Júnior
Keyword(s):  
Sewage Treatment ◽  
Wastewater Reuse ◽  
Domestic Sewage ◽  
Production Costs ◽  
Uasb Reactor ◽  
Small Communities ◽  
Wastewater Disposal ◽  
Modular Systems ◽  
Anaerobic Reactors ◽  
Lower Production

Este trabalho apresenta uma alternativa para o tratamento de esgotos domésticos de pequenas comunidades, com a aplicação do efluente no solo para a cultura do milho. O experimento é constituído de sistemas modulares, que são compostos por dois reatores anaeróbios, um reator UASB e outro reator anaeróbio compartimentado (RAC), ambos combinados com quatro filtros anaeróbios. Os sistemas funcionaram, utilizando-se os seus efluentes como fonte de nutrientes para a cultura do milho. Foram feitos dois tratamentos testemunhas, sendo um em sequeiro (sem irrigação) e outro com suplementação hídrica, através de um sistema de irrigação por sulcos. Avaliou-se o desenvolvimento da cultura e sua respectiva produtividade em dois ciclos. Utilizaram-se sistemas modulares por ser uma maneira adequada e viável de promover o tratamento sanitário do esgoto de pequenas comunidades com o objetivo de maior e melhor preservação do meio ambiente. O emprego desta técnica propicia a vantagem de diminuição nos custos de produção e aumento na produtividade do milho, obtendo-se valores de 6307 e 6593 kg ha-1 na safrinha com efluente do UASB e RAC respectivamente, e na entressafra de 6323 e 5424 kg ha-1.   Palavras-chave: tratamento de esgoto, sistemas modulares, reatores anaeróbios, disposição no solo, reuso. Efficiency of wastewater reuse for irrigation of corn.   Abstract This paper presents an alternative for the treatment of domestic sewage from small communities, with the application of effluent in the soil for growing corn. The experiment consists of modular systems, which are composed of two anaerobic reactors, one UASB reactor and another a compartmented anaerobic reactor (CAR) both combined with four anaerobic filters. The systems were operated, using the effluent as a source of nutrients for the corn crop. Two control treatments were operated, one being rainfed (no irrigation) and another with water supply, through a system of furrow irrigation. We evaluated the development of culture and its productivity in two cycles. The use of modular systems are an appropriate and viable way to promote the sanitary treatment of wastewater from small communities with the goal of greater and better preservation of the environment. The use of this technique provides the advantage of lower production costs and increased productivity of maize, and the values of 6307 and 6593 kg ha-1 for second season with the effluent of UASB and CAR, respectively, and in dry season of 6323 and 5424 kg ha-1. Keywords: sewage treatment, modular systems, anaerobic reactors, wastewater disposal, reuse.

Flocculation, Anaerobic and Microaerobic Treatment Process of Normal Temperature Low Concentration Domestic Sewage

2012 ◽  
Vol 518-523 ◽  
pp. 2530-2534
Author(s):  
Li Jun Nie ◽  
Hua Wen Zhong ◽  
Mei Huang ◽  
Xu Dong Yin
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Removal Rate ◽  
Sewage Treatment ◽  
Anaerobic Treatment ◽  
Domestic Sewage ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Low Concentration ◽  
Cod Removal Rate

Domestic sewage was treated by adopting flocculation, anaerobic and microaerobic combined process under normal temperature. The result demonstrates: total hydraulic retention time is 5.5h (chemical flocculation 1.0h, UASB reactor 2.0h and MUSB reactor 2.5h). UASB reactor can achieve anaerobic sludge granulation under normal temperature and is fairly feasible for low concentration domestic sewage treatment. Compared with single stage UASB reactor, hydraulic retention time of flocculation-UASB combined technique reduces from 4h to 2h. COD removal rate rises from 45% to 50%-60% and suspended COD is mainly removed. DO of microaerobic MUSB technique after anaerobic treatment is 0.2mg/L-0.5mg/L with air and water ratio of 1:1. Effluent quality is stable, in accordance with first standard of Synthetical Draining Standard of Sewage, GB8978—1996.

Feasibility of Anaerobic Sewage Treatment in Sanitation Strategies in Developing Countries

1993 ◽  
Vol 27 (1) ◽  
pp. 179-186 ◽  
Author(s):  
G. J. Alaerts ◽  
S. Veenstra ◽  
M. Bentvelsen ◽  
L. A. van Duijl
Keyword(s):  
Biogas Production ◽  
Low Cost ◽  
Sewage Treatment ◽  
Shallow Groundwater ◽  
Anaerobic Treatment ◽  
Site Management ◽  
Anaerobic Reactors ◽  
Total Treatment ◽  
A Minor ◽  
Public Health Protection

Sanitation strategies in the growing cities may aim at protection of shallow groundwater, public health protection, removal of oxygen-consuming substances andre moval of nutrients. It is shown that anaerobic treatment of municipal waste waterin UASB type reactors has become afeasible treatmentoption in those strategies. This study investigates the merits of the technology for on-site management of black and grey waste water, and for off-site centralised treatment. At on-site scale where effluent is leached into the ground, anaerobic reactors offer no advantage over cheaper leaching pits. At larger centralised scale, anaerobic reactors have performed well and reliably over longer periods. Post-treatment may be required, but the total treatment is financially advantageous in warm climates; if land cost is low long-retention ponds may be more attractive, however. In addition, the technology's characteristics open the possibility to develop “intermediate” solutions at township-level based on low-cost (shallow and small-bore) sewerage and reactors for communities of typically 100 up to 1000 households. Sludge, produced in lower quantity, dries easily. Pathogen removal is limited, and biogas production only a minor asset.

scholarly journals Influence of temperature on the performance of anaerobic treatment systems of municipal wastewater

Water SA ◽  
2018 ◽  
Vol 44 (2 April) ◽  
Author(s):  
Silvânia Lucas Dos Santos ◽  
Sílvia Raphaele Morais Chaves ◽  
Adrianus Van Haandel
Keyword(s):  
Experimental Investigation ◽  
Municipal Wastewater ◽  
Sewage Treatment ◽  
Poor Performance ◽  
Pilot Scale ◽  
Anaerobic Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Organic Load ◽  
Anaerobic Sludge ◽  
Uasb Reactors

Anaerobic sewage treatment systems, especially upflow anaerobic sludge blanket (UASB) reactors, have found wide application over the past decades, particularly in regions with a warm climate. A low sewage temperature is generally considered as a factor contributing to poor performance, characterized by an increase of the COD fractions in the effluent and the generated sludge, and decreasing the fraction that is transformed into methane. An experimental investigation was carried out at pilot scale to establish the values of the three COD fractions for different values of temperature and the applied organic load. The sludge age of the anaerobic treatment, together with temperature, was identified as the main operational variable that affects the efficiency of anaerobic treatment. An empirical expression was derived for the values of the three factions as a function of these two variables. From the results of the experimental investigation it was apparent that there is no point in applying a sludge age of more than 100 d, when the reactor is near its best performance. An expression was derived to establish the hydraulic retention time for maximum digestion efficiency as a function of temperature, concentration and composition of organic material and sludge mass. It was established that the main limit to the sludge hold-up in UASB reactors treating sewage is not the sludge settleability, but rather the break-up of flocs leading to loss of small, poorly-settling particles.

Domestic sewage treatment in full-scale UASBB plant at Mangueira, Recife, Pernambuco

2001 ◽  
Vol 44 (4) ◽  
pp. 71-77 ◽  
Author(s):  
L. Florencio ◽  
M. Takayuki Kato ◽  
J. Cardoso de Morais
Keyword(s):  
Sewage Treatment ◽  
Domestic Sewage ◽  
Cod Removal ◽  
Metropolitan Region ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Active Biomass ◽  
Methanogenic Activity ◽  
Technology Application ◽  
Uasb Reactors

The anaerobic technology application for domestic sewage treatment in Pernambuco State (Brazil) is relatively recent. Some UASB reactors of less than 250 m3 were built in the Recife Metropolitan Region (RMR) in the 1990s. Mangueira (18,000 inhabitants) was the first neighborhood where the municipality built a plant with a bigger UASB reactor of 810 m3. It was intended to evaluate the performance and verify if such technology would be feasible. The objective would be the possible application of UASB reactors to the RMR, according to the new sewage master-plan under elaboration that would benefit about 3 million inhabitants. The monitoring of the Mangueira UASB reactor over 30 months showed that satisfactory results were obtained. Three distinct operational phases occurred, in which efficiency varied from 60% up to 90% based on COD removal. The results were very dependent on the operation and maintenance, either in the plant or in the sewage collection. Significant amount of inert solids was measured inside the reactor. Despite the operational problems, the UASB was shown to be very robust and stable. Under high fluctuation of influent concentrations (150-750 mg COD/L) during the period, resulting in applied organic loading rate of 0.5 to 2.5 kg COD/m3.d, the average values of COD removal efficiency did not change significantly. An active biomass with specific methanogenic activity varying from 0.18 to 0.25 gCOD/gVSS.d was measured at the end of the period.

Perspectives on anaerobic treatment in developing countries

2001 ◽  
Vol 44 (8) ◽  
pp. 141-148 ◽  
Author(s):  
E. Foresti
Keyword(s):  
Developing Countries ◽  
Latin American ◽  
High Performance ◽  
Sewage Treatment ◽  
Anaerobic Treatment ◽  
Domestic Sewage ◽  
Batch Reactors ◽  
Dissolved Air Flotation ◽  
Ambient Temperatures ◽  
Tropical Areas

Developing countries occupy regions where the climate is warm most of the time. Even in sub-tropical areas, low temperatures do not persist for long periods. This is the main factor that makes the use of anaerobic technology applicable and less expensive, even for the treatment of low-strength industrial wastewaters and domestic sewage. Based mainly on papers presented at the ‘VI Latin-American Workshop and Seminar on Anaerobic Digestion’ held in Recife, Brazil, in November 2000, this text approaches the perspectives of anaerobic treatment of wastewaters in developing countries. Emphasis is given to domestic sewage treatment and to the use of compact systems in which sequential batch reactors (SBR) or dissolved-air flotation (DAF) systems are applied for the post-treatment of anaerobic reactor effluents. Experiments on bench- and pilot-plants have indicated that these systems can achieve high performance in removing organic matter and nutrients during the treatment of domestic sewage at ambient temperatures.

Vacuum Operation for Overloaded Anaerobic Treatment Systems

1989 ◽  
Vol 21 (4-5) ◽  
pp. 87-95
Author(s):  
J. De Santis ◽  
A. A. Friedman
Keyword(s):  
Volatile Fatty Acids ◽  
Loading Rate ◽  
Anaerobic Treatment ◽  
Optimum Operating ◽  
Operating Pressure ◽  
Simple Modification ◽  
Anaerobic Reactors ◽  
Fixed Film ◽  
Solids Retention ◽  
High Concentrations

Overloaded anaerobic treatment systems are characterized by high concentrations of volatile fatty acids and molecular hydrogen and poor conversion of primary substrates to methane. Previous experiments with fixed–film reactors indicated that operation with reduced headspace pressures enhanced anaerobic treatment. For these studies, four suspended culture, anaerobic reactors were operated with headspace pressures maintained between 0.5 and 1.0 atm and a solids retention time of 15 days. For lightly loaded systems (0.4 g SCOD/g VSS-day) vacuum operation provided minor treatment improvements. For shock organic loads, vacuum operation proved to be more stable and to support quicker recovery from upset conditions. Based on these studies and a companion set of bioassay tests, it was concluded that: (a) a loading rate of about 1.0 g SCOD/g VSS-day represents a practical loading limit for successful anaerobic treatment, (b) a headspace pressure of approximately 0.75 atm appears to be an optimum operating pressure for anaerobic systems and (c) simple modification to existing systems may provide relief for organically overloaded systems.

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