scholarly journals Anaerobic-aerobic treatment of swine wastewater in uasb and batch reactors in series

2014 ◽  
Vol 34 (1) ◽  
pp. 124-142 ◽  
Author(s):  
Estevão Urbinati ◽  
Roberto Alves de Oliveira
Keyword(s):  
Batch Reactor ◽  
Anaerobic Treatment ◽  
Post Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Swine Wastewater ◽  
Organic Load ◽  
Anaerobic Sludge ◽  
Batch Reactors ◽  
Removal Efficiencies ◽  
Uasb Reactors

In this work it was evaluated the performance of two systems of swine wastewater treatment consisting of two-stage upflow anaerobic sludge blanket (UASB) reactors, with and without post-treatment in sequencing batch reactor (SBR), fed continuously, with aerobic phase. The UASB reactors in the first stage had 908 L in the sets I and II, and in the second stage 350 and 188 L, respectively. In the set II the post-treatment was performed in a SBR of 3,000 L. The hydraulic detention times in the anaerobic treatment systems were 100, 75 and 58 h in the set I; 87, 65 and 51 h in the set II; and 240 and 180 h in the SBR. The volumetric organic load applied in the first stage UASB reactors ranged from 6.9 to 12.6 g total COD (L d)-1 in the set I and 7.5 to 9.8 g total COD (L d)-1 in the set II. The average removal efficiencies of total COD, total phosphorus (Ptotal), and Kjeldahl and organic nitrogen (KN and Norg) in the anaerobic treatment systems were similar and reached maximum values of 97%, 64%, 68%, and 98%. In the SBR, the removal efficiencies of total COD and thermotolerant coliforms were up to 62 and 92% resulting, respectively, in effluent concentrations of 135 mg L-1 and 2x10(4)MPN (100 mL)-1. For Ptotal, total nitrogen (TN) and Norg, the average removal efficiencies in the SBR were up to 58, 25 and 73%, respectively.

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.

Anaerobic treatment of natural tannin extracts in UASB reactors

2003 ◽  
Vol 48 (6) ◽  
pp. 157-163 ◽  
Author(s):  
J. López-Fiuza ◽  
F. Omil ◽  
R. Méndez
Keyword(s):  
Volatile Fatty Acids ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Tannin Extract ◽  
Aqueous Environments ◽  
Removal Efficiencies ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

Tannin extracts are substances commonly used in leather production processes. Since most of the steps of tannery manufacturing processes are carried out in aqueous environments, the presence of these compounds in the wastewaters is important. The aim of this work is to study the feasibility of the anaerobic degradation of three natural tannin extracts in three Upflow Anaerobic Sludge Blanket (UASB) reactors, which were fed with increasing concentrations of two condensed (quebracho and wattle) and one hydrolysable tannin extract (chestnut). Concentrations of applied extracts were 100, 200, 400, 800 and 1,000 mg/l, and 5 g/l of glucose was used as cosubstrate. Reactors were operated during 210 days and their performance was evaluated from the values of total and soluble COD, total and intermediate alkalinity, volatile fatty acids, pH and UV absorption at 280 nm. COD removal efficiencies higher than 85% were achieved in all cases. However, tannin extract removal efficiencies (based on UV-280 nm absorption measurements) were significantly lower, around 20% for condensed extracts and 60% for the hydrolysable one, when the reactors operated with the highest tannin extract concentration. The operation of the reactors was stable, commonly with alkalinity ratios below 0.30. Mass balances carried out indicate that most of the COD removal efficiencies are due to the removal of the readily biodegradable organic matter (glucose), whereas the tannin extracts are hardly anaerobically biodegradable, especially condensed extracts (wattle and quebracho).

scholarly journals Performance of UASB reactors in two stages followed by post-treatment with activated sludge in wastewater batch of wet-processed coffee

2013 ◽  
Vol 33 (4) ◽  
pp. 808-819 ◽  
Author(s):  
Marcelo Bruno ◽  
Roberto A. de Oliveira
Keyword(s):  
Activated Sludge ◽  
Post Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Nitrogen And Phosphorus ◽  
Removal Efficiencies ◽  
Two Stages ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

In this study it was evaluated the efficiency of the treatment of wet-processed coffee wastewater in upflow anaerobic sludge blanket (UASB) reactors in two stages, in bench scale, followed by post-treatment with activated sludge in batch. The first UASB reactor was submitted to an hydraulic retention time (HRT) of 6.2 d and organic loading rates (OLR) of 2.3 and 4.5g CODtotal (L d)-1, and the second UASB reactor to HRT of 3.1 d with OLR of 0.4 and 1.4g CODtotal (L d)-1. The average values of the affluent CODtotal increased from 13,891 to 27,926mg L-1 and the average efficiencies of removal of the CODtotal decreased from 95 to 91%, respectively, in the UASB reactors in two stages. The volumetric methane production increased from 0.274 to 0.323L CH4 (L reactor d)-1 with increment in the OLR. The average concentrations of total phenols in the affluent were of 48 and 163mg L-1, and the removal efficiencies in the UASB reactors in two stages of 92 and 90%, respectively, and increased to 97% with post-treatment. The average values of the removal efficiencies of total nitrogen and phosphorus were of 57 to 80% and 44 to 60%, respectively, in the UASB reactors in two stages and increased to 91 and 84% with the post-treatment.

scholarly journals COD, TSS, nutrients and coliforms removals in UASB reactors in two stages treating swine wastewater

2014 ◽  
Vol 34 (6) ◽  
pp. 1256-1269 ◽  
Author(s):  
Roseane Del'Arco Ramires ◽  
Roberto Alves de Oliveira
Keyword(s):  
Pilot Scale ◽  
Upflow Anaerobic Sludge Blanket ◽  
Swine Wastewater ◽  
Anaerobic Sludge ◽  
Two Stage ◽  
In Series ◽  
Removal Efficiencies ◽  
Two Stages ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

The performance of two upflow anaerobic sludge blanket (UASB) reactors was evaluated in pilot scale (908 and 188 L), installed in series (R1 and R2), fed with swine wastewater with TSS around 5 and 13 g L-1. The UASB reactors were submitted to HDT of 36 and 18 h with VOL of 5.5 to 34.4 g COD (L d)-1 in the R1 and HDT of 7.5 e 3.7 h with VOL from 5.1 to 45.2 g COD (L d)-1 in the R2. The average removal efficiencies of COD ranged from 55 to 85% in the R1 and from 43 to 57% in the R2, resulting in values from 82 to 93% in the UASB reactors in two stage. Methane concentrations in the biogas were 69 to 74% with specific production from 0.05 to 0.27 L CH4 (g removedCOD)-1 in the R1 and of 0.10 to 0.12 L CH4 (g removedCOD)-1 in the R2. The average removal efficiencies were 61 to 75% for totalP, 39 to 69% for KN, 82 to 93% for orgN and 20 to 94% for Fe, Zn, Cu and Mn. The amN concentration were not reduced indicating the need to post-treatment for effluent disposal into water bodies. There were reductions of total coliforms from 99.8123 to 99.9989% and of thermotolerant coliforms from 99.9725 to 99.9999%. The conditions imposed to the UASB reactors in two stage provided high conversions of removedCOD into methane (up to 77%) and reductions of organic an inorganic pollution loads from swine wastewater.

Impact of microaeration bioreactor on dissolved sulfide and methane removal from real UASB effluent for sewage treatment

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
Keyword(s):  
Sewage Treatment ◽  
Oxygen Demand ◽  
Post Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Sulfide Removal ◽  
Dissolved Sulfide ◽  
Removal Efficiencies ◽  
Anaerobic Sludge Blanket

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.

New Technologies for Anaerobic Wastewater Treatment

1986 ◽  
Vol 18 (12) ◽  
pp. 41-53 ◽  
Author(s):  
Look Hulshoff Pol ◽  
Gatze Lettinga
Keyword(s):  
Wastewater Treatment ◽  
New Technologies ◽  
Anaerobic Treatment ◽  
Full Scale ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Anaerobic Wastewater Treatment ◽  
Start Up ◽  
Uasb Reactors ◽  
Sludge Granulation

Presently anaerobic wastewater treatment is becoming an accepted simple technology for the treatment of a variety of wastewaters. Of the different treatment systems that have been developed the UASB process (Upflow Anaerobic Sludge Blanket) has found the widest application. Almost all of the more than 60 full scale UASB reactors in operation now, are running satisfactorily. The excellent sludge retention generally found in UASB-reactors is obtained by sludge granulation, which can be seen as a sludge immobilization process. The presently available insight into the sludge granulation process is briefly presented, together with the strategy to be applied for performing a proper first start-up and secondary start-up of UASB reactors, viz. using granular seed sludge. The effect of the presence of SS with regard to the loading potentials of anaerobic treatment systems will be discussed. The experiences obtained with some full scale applications of the UASB-process are presented.

Anaerobic Treatment of Domestic Wastewater in Small Scale UASB Reactors

1993 ◽  
Vol 27 (9) ◽  
pp. 75-82 ◽  
Author(s):  
J. J. Bogte ◽  
A. M. Breure ◽  
J. G. van Andel ◽  
G. Lettinga
Keyword(s):  
Organic Matter ◽  
The Netherlands ◽  
Volatile Fatty Acids ◽  
Domestic Wastewater ◽  
Anaerobic Treatment ◽  
Gas Production ◽  
Upflow Anaerobic Sludge Blanket ◽  
Small Scale ◽  
Anaerobic Sludge ◽  
Uasb Reactors

A survey was made on the feasibility of on-site anaerobic treatment of domestic wastewater from small scale emissions in The Netherlands. Three 1.2 m3 UASB-reactors (Upflow Anaerobic Sludge Blanket) were tested in different rural locations. The survey made clear that the efficiency of the process is highly dependent on the reactor temperature. Below 12 °C purification was predominantly based on settling, while above 12 °C microbial degradation of organic matter increased. Efficiencies for the removal of total COD and BOD of two of the reactors ranged between 33 and 60%, equalising well performing septic tanks. In one of the reactors the average production of biogas, with a methane content of 78%, was 67 liters per day. Complete transformation of volatile fatty acids (VFA) into biogas was achieved during 3 to 4 months a year at temperatures above 15 °C. In this period, during the second year of operation, the average efficiencies for COD and BOD removal were 60 and 72% respectively, while the maximum gas production reached 300 liters per day. In the latter period the mineralisation rate exceeded the input rate of organic matter, resulting in a decrease of settled material in the reactor. The possibility of high efficiencies during summertime in The Netherlands and the positive results of similar experiments in Indonesia and Latin America lead to the conclusion that anaerobic digestion is a promising process for the (pre-)treatment of domestic waste water in (sub)tropical countries.

Sequencing batch reactor as a post-treatment of anaerobically treated dairy effluent

2006 ◽  
Vol 54 (2) ◽  
pp. 199-206 ◽  
Author(s):  
A. Benítez ◽  
A. Ferrari ◽  
S. Gutierrez ◽  
R. Canetti ◽  
A. Cabezas ◽  
...  
Keyword(s):  
Batch Reactor ◽  
Anaerobic Treatment ◽  
Post Treatment ◽  
Operating Conditions ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Operational Parameters ◽  
Reactor Operation ◽  
Set Up ◽  
The Stability

Wastewater from dairy industries, characterized by its high COD content and relative high COD/TKN ratio, requires post-treatment after anaerobic treatment to complete the removal of organic matter and nutrients. Due to its simplicity, robustness and low maintenance costs, sequencing batch reactors (SBR) result in an attractive system, especially in case of small dairy industries in order to comply with the emission standards. The goal of this work was to determine the operational parameters, optimize the performance, and study the stability of the microbial population of a SBR system for the post-treatment of an anaerobic pond effluent. High and stable removal of COD and TKN was achieved in the reactor, which can easily be set up in dairy industries. An active nitrifying population was selected during reactor operation and maintained relatively stable, while the heterotrophic (total and denitrifying) communities were more unstable and susceptible to changes in the operating conditions.

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.

Anaerobic digestion of olive oil mill effluents together with swine manure in UASB reactors

2002 ◽  
Vol 45 (10) ◽  
pp. 213-218 ◽  
Author(s):  
I. Angelidaki ◽  
B.K. Ahring ◽  
H. Deng ◽  
J.E. Schmidt
Keyword(s):  
Anaerobic Digestion ◽  
Olive Oil ◽  
Degradation Products ◽  
Swine Manure ◽  
Degradation Process ◽  
Anaerobic Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Uasb Reactors

Combined anaerobic digestion of olive oil mill effluent (OME) with swine manure, was investigated. In batch experiments was shown that for anaerobic degradation of OME alone nitrogen addition was needed. A COD:N ratio in the range of 65:1 to 126:1 was necessary for the optimal degradation process. Furthermore, it was found that methane productions rates during digestion of either swine manure alone or OME alone were much lower than the rates achieved when OME and manure were digested together. Admixing OME with manure at a concentration of 5 to 10% OME resulted in the highest methane production rates. Using upflow anaerobic sludge blanket (UASB) reactors, it was shown that codigestion of OME with swine manure (up to 50% OME) was successful with a COD reduction up to 75%. The process was adapted for degradation of OME with stepwise increase of the OME load to the UASB reactor. The results showed that the high content of ammonia in swine manure, together with content of other nutrients, make it possible to degrade OME without addition of external alkalinity and without addition of external nitrogen source. Anaerobic treatment of OME in UASB reactors resulted in reduction of simple phenolic compounds such as mequinol, phenyl ethyl alcohol and ethyl methyl phenol. After anaerobic treatment the concentration of these compounds was reduced between 75 and 100%. However, the concentration of some degradation products such as methyl phenol and ethyl phenol were detected in significantly higher concentrations after treatment, indicating that the process has to be further optimised to achieve satisfactory removal of all xenobiotic compounds.

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