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

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).

1993 ◽  
Vol 27 (9) ◽  
pp. 75-82 ◽  
Author(s):  
J. J. Bogte ◽  
A. M. Breure ◽  
J. G. van Andel ◽  
G. Lettinga

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.


1999 ◽  
Vol 39 (5) ◽  
pp. 177-185 ◽  
Author(s):  
Tarek A. Elmitwalli ◽  
Marcel H. Zandvoort ◽  
Grietje Zeeman ◽  
Harry Bruning ◽  
Gatze Lettinga

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.


1991 ◽  
Vol 24 (3-4) ◽  
pp. 149-160 ◽  
Author(s):  
J. Rintala ◽  
J. L. Sanz Martin ◽  
G. Lettinga

Anaerobic treatment of sulfate - rich (COD/SO4 ratio 1.4-2.1) clarified Whitewater from a thermomechanical pulping (TMP) process was studied in three laboratory-scale upflow anaerobic sludge blanket (UASB) reactors at 55°C and in batch digesters at 55° and 65°C. Different seed materials were used in the UASB reactors. The highest COD removal efficiency (effluent sulfide stripped) achieved was approximately 65 % in the UASB reactors. About 55 % COD removal efficiency was obtained at a loading rate of about 41 kgCODm−3d−1 in the UASB reactor seeded with thermophilic sludge cultivated with volatile fatty acids (VFAs). The total sulfide present in the liquid phase after anaerobic treatment accounted for approximately 65-78 % and 15-61 % of the removed COD in the batch digesters and the UASB reactors, respectively. Sulfate reduction was almost complete in the batch digesters, whereas about 24-64 % of sulfate was reduced in the UASB reactors. Acetate utilization for sulfate reduction was apparent in the batch digesters, whereas that could not be demonstrated in the UASB reactors. Sulfate reduction in the UASB reactors was obviously substrate limited. In conclusion, thermophilic anaerobic treatment is an alternative for the treatment of warm sulfate rich TMP process water.


2014 ◽  
Vol 953-954 ◽  
pp. 1105-1108 ◽  
Author(s):  
Seni Karnchanawong ◽  
Kraiwet Kabtum

The objective of this study was to investigate the toxicity of Na+and K+ions on performance of upflow anaerobic sludge blanket (UASB) system. Three laboratory-scale UASB reactors, 15.8 - l working volume, were employed with 1 reactor operated as control. They were loaded at organic loading rate (OLR) of 5 kg COD/(m3-d), treating synthetic wastewater with COD concentration ~ 5000 mg/l. Na+and K+ions were added in the range of 1010 - 7180 and 41 - 7320 mg/l, respectively. No toxicity was observed at influent Na+and K+concentrations up to 3340 and 2750 mg/l, respectively. Slight inhibitions on COD removal were founded at Na+and K+concentrations of 4610 and 3920 mg/l, respectively, but moderate effect on biogas production had occurred. When Na+and K+concentrations were increased to 7180 and 7320 mg/l, respectively, strong inhibitions were observed with COD removal dropped to 45.5 and 48.8 %, respectively. Ratios of biogas productions, as compared to the control reactor, were dropped to 0.31 and 0.32, respectively. Increasing cation concentrations had more detrimental effect on biogas production than COD removal.


1997 ◽  
Vol 35 (2-3) ◽  
pp. 49-56 ◽  
Author(s):  
Sigrun J. Jahren ◽  
Jukka A. Rintala

The suitability of an internal thermophilic anaerobic treatment system for closing the water circuits in thermomechanical pulp (TMP) production was studied. The dissolution of wood organics in the water circuit was simulated by hot disintegration of TMP pulp, while the water system closure was simulated by repeated hot disintegration of TMP pulp with recirculated water. The upflow anaerobic sludge blanket (UASB) reactors were started at 55 and 70°C with mesophilic inoculum, and stable performances were established within 60 days at both temperatures. Closing the water circuits without internal treatment rapidly resulted in increased chemical oxygen demand (COD) in the recirculated water. In the closed, internally treated water circuits, the UASB reactors removed all the COD and ultraviolet absorbance at 280 nm (UV280; estimation for lignin content) dissolved in the recirculated water during the hot disintegration of the TMP pulp (carbohydrates were not dissolved). The results of this study suggest that thermophilic anaerobic treatment could be feasible at least as a part of an internal purification system to close the water circuit in the TMP process.


2014 ◽  
Vol 34 (1) ◽  
pp. 124-142 ◽  
Author(s):  
Estevão Urbinati ◽  
Roberto Alves de Oliveira

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.


The textile dye wastewater removal in the environment is a greater problem by its harmful reasons. Dyes which obstruct the penetration of light leads to damage the quality and produce the poisonous effect in the aquatic ecosystem. Several studies were proved that the physicochemical methods were employed for treating the textile dye wastewater. Hence the biological processes are employed for treating the textile dye wastewater due to its cost effectiveness and less toxic effects. Bio filter can be an effective solution for producing high quality water and saving water for recirculation. In this article fujino spirals were mainly focusing as media in the reactor and operated at a hydraulic retention time (HRT) of 24h. The purpose of this study to analysis the overall performance of the UASBR which is achieved the maximum COD removal at 24hrs HRT respectively. From this study results, percentage of COD removal is directly related to the HRT. Hence the UASBR is suitable for treating real textile dye wastewater even upto 1000mg/l efficiency


2013 ◽  
Vol 33 (4) ◽  
pp. 808-819 ◽  
Author(s):  
Marcelo Bruno ◽  
Roberto A. de Oliveira

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.


2011 ◽  
Vol 183-185 ◽  
pp. 352-361
Author(s):  
Zong Lian She ◽  
En Shi ◽  
Xiao Hui Fu ◽  
Jian Wu ◽  
Li Na Jiang ◽  
...  

Characteristics of anaerobic granules before and after acclimation were studied using glucose as co-substrate. Removal efficiencies of 2,6-dinitrophenol (2,6-DNP) using two different co-substrates were investigated in two lab-scale UASB reactors. Granular sludge acclimatized to the wastewater containing 2,6-DNP through 3 months. After acclimation, SEM pictures of the granular biomass showed that Filamentous bacteria were the predominant bacteria on the surface of granules. Throughout the study of 2,6-DNP anaerobic degradation with different co-substrates, influent COD concentration was kept constant as about 2500 mg l-1. Maximum 2,6-DNP concentration was 170.0 mg l-1 and 2,6-DNP removal efficiencies were always more than 98.0% using glucose as co-substrate, keeping hydraulic retention time (HRT) as 35 h. When using sodium acetate as co-substrate and keeping HRT as 30 h, maximum 2,6-DNP concentration was up to 189.5 mg l-1 and over 99.2% 2,6-DNP removal efficiencies could be obtained.


1997 ◽  
Vol 36 (2-3) ◽  
pp. 287-294 ◽  
Author(s):  
G. Ubay ◽  
I. Öztürk

The anaerobic treatability of olive mill effluent was investigated using a laboratory scale upflow anaerobic sludge blanket reactor (UASBR) operated for about six months. The effects of various operating conditions including pH, feed strength and hydraulic retention time on the performance of the anaerobic treatment process were determined. In the first part of this study, the reactor was operated with feed COD concentrations from 5000 to 19,000 mg/l and a retention time of 1 day, giving organic loading rates from 5 to 18 kg COD/m3d. Soluble COD removal was around 75% under these conditions. In the second part of the study, feed CODs were varied from 15,000 to 22,600 mg/l while retention times ranged from 0.83 to 2 days; soluble COD removal was around 70%. A methane conversion rate of 0.35 m3 per kg COD removed was achieved during the study. The average volatile solids (VS) concentration in the reactor had increased from 12.75 g l−1 to 60 g l−1 by the end of the study. Sludge volume index (SVI) determinations performed to evaluate the settling characteristics of the anaerobic sludge in the reactor indicated excellent settleability with SVI values of generally less than 20 ml g−1. Sludge granules ranging from 3 to 8 mm in diameter were produced in the reactor. The second order substrate removal kinetics was applied by assuming that hydraulic conditions in the UASBR are approximately completely mixed and the model fitted well to the steady state operating results.


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