Domestic sewage treatment in an upflow anaerobic sludge blanket ? sequencing batch reactor system

1996 ◽  
Vol 33 (3) ◽  
1996 ◽  
Vol 33 (3) ◽  
pp. 73-84 ◽  
Author(s):  
J. T. de Sousa ◽  
E. Foresti

Domestic sewage treatment in up-flow anaerobic sludge blanket (UASB) reactors has presented significant results in tropical regions. This reactor configuration has proven to be efficient in removing organic matter and total suspended solids as well as in producing smaller amounts of excess sludge than conventional aerobic reactor. On the other hand, its effluent often requires to be post-treated in order to achieve the emission standards. This paper is concerned with the alternative proposed here for treating domestic sewage in a combined anaerobic-aerobic system composed of an UASB reactor followed by sequencing batch aerobic reactors (SBR). In such a system, the UASB reactor removes considerable fraction of the influent organic matter, while the SBRs oxidize part of the remaining organic matter and ammonium nitrogen. A proper system operation would also permit the removal of nutrients (N and P). In order to investigate on the performance of this system for sewage treatment, a bench scale installation fed with synthetic substrate simulating domestic sewage was operated continuously during 38 weeks. The results permit to confirm the hypothesis proposed, since the system has consistently produced high quality effluents (BOD5 and VSS lower than 10 mg.L-1). The results also indicate that such combined anaerobic-aerobic system compete favorably with conventional aerobic systems in three essential cost features: energy consumption, excess sludge production and nutrient removal.


1998 ◽  
Vol 38 (8-9) ◽  
pp. 189-195 ◽  
Author(s):  
Ricardo Franci Gonçalves ◽  
Vera Lúcia de Araújo ◽  
Carlos Augusto L. Chernicharo

This paper presents exploratory results on the association of an Upflow Anaerobic Sludge Blanket - UASB reactor (46 L) and a submerged aerated biofilter – BF (6.3 L) for domestic sewage treatment. The experimental period extended for 322 days, during which the hydraulic and organic loads were gradually increased in both reactors. Having the UASB as a reference, the following hydraulic loads were tested: 0.4 m3/m2.h (θ = 16 h); 0.6m3/m2.h (θ = 10h); 0.8 m3/m2.h (θ = 8 h); 1.0 m3/m2.h (θ = 6 h) and 1.45 m3/m2.h (θ = 4h). During the experiments carried out with the UASB reactor operating at a hydraulic detention time of 6 hours, related to a θ < 11′ in the granular media of the BF, the mean removal efficiency in terms of SS, BOD5 and COD, in both reactors, were respectively 94%, 96% and 91%. The final effluent, related to the BF effluent, presented the following mean characteristics: SS = 10 mg/L, BOD5 = 9 mg/L and COD = 38 mg/L. The results obtained in the last phase of the experiments, when the hydraulic load in the UASB reactor reached 1.45 m3/m2.h (θ = 4h), were similar to those obtained in the previous phase. These results demonstrate that submerged aerated biofilters can be considered a viable alternative for the post-treatment of effluents from UASB reactors treating domestic sewage. These reactors are capable of being operated with very short hydraulic detention times.


2017 ◽  
Vol 75 (7) ◽  
pp. 1659-1666 ◽  
Author(s):  
T. Bressani-Ribeiro ◽  
E. M. F. Brandt ◽  
K. G. Gutierrez ◽  
C. A. Díaz ◽  
G. B. Garcia ◽  
...  

This paper aims to present perspectives for energy (thermal and electric) and nutrient (N and S) recovery in domestic sewage treatment systems comprised of upflow anaerobic sludge blanket (UASB) reactors followed by sponge-bed trickling filters (SBTF) in developing countries. The resource recovery potential was characterized, taking into account 114 countries and a corresponding population of 968.9 million inhabitants living in the tropical world, which were grouped into three desired ranges in terms of cities’ size. For each of these clusters, a technological arrangement flow-sheet was proposed, depending on their technical and economic viability from our best experience. Considering the population living in cities over 100, 000 inhabitants, the potential of energy and nutrient recovery via the sewage treatment scheme would be sufficient to generate electricity for approximately 3.2 million residents, as well as thermal energy for drying purposes that could result in a 24% volume reduction of sludge to be transported and disposed of in landfills. The results show that UASB/SBTF systems can play a very important role in the sanitation and environmental sector towards more sustainable sewage treatment plants.


2017 ◽  
Vol 12 (1) ◽  
pp. 202-210 ◽  
Author(s):  
A. P. Rosa ◽  
A. V. Santos ◽  
A. D. U. C. Schmidt ◽  
J. M. Borges ◽  
C. A. L. Chernicharo

This paper aimed to evaluate the effectiveness of a device to remove scum from the inner part of gas-liquid-solid separators of a full-scale upflow anaerobic sludge blanket reactor treating domestic sewage, as well as determining the scum yield coefficient for different reactors’ operating conditions. The experiments were carried out at the Laboreaux sewage treatment plant (Itabira, Minas Gerais, Brazil) and the effectiveness of the scum removal device was fully demonstrated, with median efficiencies ranging from 65 to 90%. The average scum yield varied from 6.8 to 14.6 mL of scum formed per kg COD applied.


2017 ◽  
Vol 76 (8) ◽  
pp. 2003-2014 ◽  
Author(s):  
Pollyane Diniz Saliba ◽  
Marcos von Sperling

The objective of this study was to evaluate the behaviour of a system comprising an upflow anaerobic sludge blanket reactor followed by activated sludge to treat domestic sewage. The Betim Central sewage treatment plant, Brazil, was designed to treat a mean influent flow of 514 L/s. The study consisted of statistical treatment of monitoring data from the treatment plant covering a period of 4 years. This work presents the concentrations and removal efficiencies of the main constituents in each stage of the treatment process, and a mass balance of chemical oxygen demand (COD) and nitrogen. The results highlight the good overall performance of the system, with high mean removal efficiencies: BOD (biochemical oxygen demand) (94%), COD (91%), ammonia (72%) and total suspended solids (92%). As expected, this system was not effective for the removal of nutrients, since it was not designed for this purpose. The removal of Escherichia coli (99.83%) was higher than expected. There was no apparent influence of operational and design parameters on the effluent quality in terms of organic matter removal, with the exceptions of the BOD load upstream of the aeration tank and the sludge age in the unit. Results suggest that this system is well suited for the treatment of domestic sewage.


2020 ◽  
Vol 81 (9) ◽  
pp. 1951-1960 ◽  
Author(s):  
C. S. Cabral ◽  
A. L. Sanson ◽  
R. J. C. F. Afonso ◽  
C. A. L. Chernicharo ◽  
J. C. Araújo

Abstract Two bioreactors were investigated as an alternative for the post-treatment of effluent from an upflow anaerobic sludge blanket (UASB) reactor treating domestic sewage, aiming at dissolved sulfide and methane removal. The bioreactors (R-control and R-air) were operated at different hydraulic retention times (HRT; 6 and 3 h) with or without aeration. Large sulfide and methane removal efficiencies were achieved by the microaerated reactor at HRT of 6 h. At this HRT, sulfide removal efficiencies were equal to 61% and 79%, and methane removal efficiencies were 31% and 55% for R-control and R-air, respectively. At an HRT of 3 h, sulfide removal efficiencies were 22% (R-control) and 33% (R-air) and methane removal did not occur. The complete oxidation of sulfide, with sulfate formation, prevailed in both phases and bioreactors. However, elemental sulfur formation was more predominant at an HRT of 6 h than at an HRT of 3 h. Taken together, the results show that post-treatment improved the anaerobic effluent quality in terms of chemical oxygen demand and solids removal. However, ammoniacal nitrogen was not removed due to either the low concentration of air provided or the absence of microorganisms involved in the nitrogen cycle.


2019 ◽  
Vol 80 (3) ◽  
pp. 418-425 ◽  
Author(s):  
T. Bressani-Ribeiro ◽  
L. A. Chamhum-Silva ◽  
C. A. L. Chernicharo

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.


2021 ◽  
Vol 7 (1) ◽  
pp. 156-171
Author(s):  
Evangelos Petropoulos ◽  
Burhan Shamurad ◽  
Shamas Tabraiz ◽  
Yongjie Yu ◽  
Russell Davenport ◽  
...  

In this study, we investigated the feasibility of anaerobic sewage treatment at extremely low temperatures (4 °C) using two reactor setups: Upflow anaerobic sludge blanket reactors (UASB) without and with (AnMBRUASB(UF)) a membrane.


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