Improved nitrogen removal in upflow anaerobic sludge blanket (UASB) reactors by incorporation of Anammox bacteria into the granular sludge

2004 ◽  
Vol 49 (11-12) ◽  
pp. 69-76 ◽  
Author(s):  
J.E. Schmidt ◽  
D.J. Batstone ◽  
I. Angelidaki
Keyword(s):  
In Situ Hybridisation ◽  
Granular Sludge ◽  
Ammonia Removal ◽  
Appropriate Technology ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
The Third ◽  
Anammox Activity ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

Upflow anaerobic sludge blanket reactors may offer a number of advantages over conventional mixed-tank, SBR, and biofilm reactors, including high space-loading, low footprint, and resistance to shocks and toxins. In this study, we assessed the use of upflow anaerobic sludge blanket (UASB) reactor technology as applied to anaerobic ammonia removal, or Anammox. Four 200 ml UASB reactors were inoculated with 50% (by volume) anaerobic granular sludge and 50% flocular sludge from different sources (all with the potential for containing Anammox organisms). Tools used to assess the reactors included basic analyses, fluorescent in-situ hybridisation, and mathematical modelling, with statistical non-linear parameter estimation. Two of the reactors showed statistically identical Anammox activity (i.e., identical kinetic parameters), with good ammonia and nitrite removal (0.14 kgNHx m-3 reactor day-1, with 99% ammonia removal). The third reactor also demonstrated significant Anammox activity, but with poor identifiability of parameters. The fourth reactor had no statistical Anammox activity. Modelling indicated that poor identifiability and performance in the third and fourth reactors were related to an excess of reduced carbon, probably originating in the inoculum. Accumulation of Anammox organisms was confirmed both by a volume loading much lower than the growth rate, and response to a probe specific for organisms previously reported to mediate Anammox processes. Overall, the UASB reactors were effective as Anammox systems, and identifiability of the systems was good, and repeatable (even compared to a previous study in a rotating biological contactor). This indicates that operation, design, and analysis of Anammox UASB reactors specifically, and Anammox systems in general, are reliable and portable, and that UASB systems are an appropriate technology for this process.

Degradation of chlorinated aromatic compounds in UASB reactors

1995 ◽  
Vol 31 (1) ◽  
pp. 249-259 ◽  
Author(s):  
Nina Christiansen ◽  
Hanne V. Hendriksen ◽  
Kimmo T. Järvinen ◽  
Birgitte K. Ahring
Keyword(s):  
Metabolic Pathways ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Ring Cleavage ◽  
Anaerobic Sludge ◽  
Chlorinated Phenols ◽  
Desulfomonile Tiedjei ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

Data on anaerobic degradation of chloroaromatic compounds in Upflow Anaerobic Sludge Blanket Reactors (UASB-reactor) are presented and compared. Special attention is given to the metabolic pathways for degradation of chlorinated phenols by granular sludge. Results indicate that PCP can be degraded in UASB-reactors via stepwise dechlorination to phenol. Phenol will subsequently be converted to benzoate before ring cleavage. Dechlorination proceeds via different pathways dependent upon the inocula used. Results are further presented on the design of special metabolic pathways in granules which do not possess this activity using the dechlorinating organism, Desulfomonile tiedjei. Additionally, it is shown that it is possible to immobilize Dechlorosporium hafniense, a newly isolated dechlorinating anaerobe, into granular sludge, thereby introducing an ability not previously present in the granules.

Organic and ammonium nitrogen and oxygen in relation to granular sludge growth in lab-scale UASB reactors

1994 ◽  
Vol 30 (12) ◽  
pp. 43-53 ◽  
Author(s):  
J. Thaveesri ◽  
K. Gernaey ◽  
B. Kaonga ◽  
G. Boucneau ◽  
W. Verstraete
Keyword(s):  
Environmental Parameters ◽  
Granular Sludge ◽  
Ammonium Nitrogen ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Negative Effects ◽  
A Minor ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors ◽  
Oxygen Ratio

Laboratory studies of in-reactor granular-sludge yield (Ygran) were carried out to investigate the effect of substrates rich in proteins. Both lab-scale upflow anaerobic sludge blanket (UASB) and shake-flask systems were used to monitor the behaviour of the sludge. Influent based on molasses with a COD to N ratio of 100:2.5-3.0 gave good Ygran; increasing substitution of the carbohydrate COD by protein COD resulted in a deterioration of the sludge characteristics. The negative effects appear to be related to the protein rather than to the NH4+ formed. Of the various environmental parameters examined, the surface tension of the mixed liquor was the main deviating factor. At a proper range of oxygenation i.e., by means of monitoring of both the input COD to oxygen ratio (gCOD gO2−1) and the daily oxygen loading rate (mgO2 gVSS−1.d−1), the UASB reactors treating the nitrogen-rich wastewater showed enhanced Ygran with only a minor reduction in methanogenesis. A range of working conditions in which this principle can be applied to decrease fluffy growth to the advantage of granular increase is proposed.

Startup of thermophilic (55°C) UASB reactors using different mesophilic seed sludges

1996 ◽  
Vol 34 (5-6) ◽  
pp. 445-452 ◽  
Author(s):  
Herbert H. P. Fang ◽  
Ivan W. C. Lau
Keyword(s):  
Oxygen Demand ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Methanogenic Activity ◽  
The Third ◽  
Uasb Granules ◽  
Thermophilic Condition ◽  
Anaerobic Sludge Blanket ◽  
The Impact ◽  
Uasb Reactors

Performances during startup of three 2.8-litre UASB (upflow anaerobic sludge blanket) reactors operated under thermophilic condition were investigated. All reactors were seeded with mesophilic sludges: one with flocculent digester sludge (Reactor-F), another with UASB granules (Reactor-G), and the third with disintegrated granules (Reactor-D). The reactors were operated in parallel at 55°C and 24 hours of retention time, using sucrose and milk as substrate at COD (chemical oxygen demand) loadings up to 10 g-COD/l·day. Immediately after temperature was step-increased from 37°C to 55°C, all reactors encountered sludge washout and deterioration of COD removal efficiency; however, the impact of temperature increase was more severe on Reactor-F. Sludge granulation took place in all reactors; first granules became noticeable after 45 days in Reactor-D, and after 90 days in Reactor-F. Reactor-G and Reactor-D were capable of removing 95% of soluble COD after 75 days, while Reactor-F after 110 days. Throughout this study, there was little difference in performance between Reactors G and D. The thermophilic granule were estimated to have a yield of 0.099 g-VSS/g-COD, and a methanogenic activity of 0.71-1.55 g-methane-COD/g-VSS·day, comparable to that of mesophilic granules.

scholarly journals Degradation and Fate of Carbon Tetrachloride in Unadapted Methanogenic Granular Sludge

1998 ◽  
Vol 64 (7) ◽  
pp. 2350-2356 ◽  
Author(s):  
Miriam H. A. Van Eekert ◽  
Thomas J. Schröder ◽  
Alfons J. M. Stams ◽  
Gosse Schraa ◽  
Jim A. Field
Keyword(s):  
Carbon Tetrachloride ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Reductive Dehalogenation ◽  
Acid Mixture ◽  
Anaerobic Sludge ◽  
End Products ◽  
A Minor ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

ABSTRACT The potential of granular sludge from upflow anaerobic sludge blanket (UASB) reactors for bioremediation of chlorinated pollutants was evaluated by using carbon tetrachloride (CT) as a model compound. Granular sludges cultivated in UASB reactors on methanol, a volatile fatty acid mixture, or sucrose readily degraded CT supplied at a concentration of 1,500 nmol/batch (approximately 10 μM) without any prior exposure to organohalogens. The maximum degradation rate was 1.9 μmol of CT g of volatile suspended solids−1day−1. The main end products of CT degradation were CO2 and Cl−, and the yields of these end products were 44 and 68%, respectively, of the initial amounts of [14C]CT and CT-Cl. Lower chlorinated methanes accumulated in minor amounts temporarily. Autoclaved (dead) sludges were capable of degrading CT at rates two- to threefold lower than those for living sludges, indicating that abiotic processes (mediated by cofactors or other sludge components) played an important role in the degradation observed. Reduced components in the autoclaved sludge were vital for CT degradation. A major part (51%) of the CT was converted abiotically to CS2. The amount of CO2 produced (23%) was lower and the amount of Cl− produced (86%) was slightly higher with autoclaved sludge than with living sludge. Both living and autoclaved sludges could degrade chloroform. However, only living sludge degraded dichloromethane and methylchloride. These results indicate that reductive dehalogenation, which was mediated better by living sludge than by autoclaved sludge, is only a minor pathway for CT degradation. The main pathway involves substitutive and oxidative dechlorination reactions that lead to the formation of CO2. Granular sludge, therefore, has outstanding potential for gratuitous dechlorination of CT to safe end products.

Acclimation of Anaerobic Granular Sludge and 2,6-DNP Removal in the Upflow Anaerobic Sludge Blanket (UASB) Reactors

2011 ◽  
Vol 183-185 ◽  
pp. 352-361
Author(s):  
Zong Lian She ◽  
En Shi ◽  
Xiao Hui Fu ◽  
Jian Wu ◽  
Li Na Jiang ◽  
...  
Keyword(s):  
Anaerobic Degradation ◽  
Hydraulic Retention Time ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Substrate Removal ◽  
Before And After ◽  
Removal Efficiencies ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

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.

Introduction of Bioremediation Ability into Granular Sludge

1994 ◽  
Vol 29 (5-6) ◽  
pp. 189-193 ◽  
Author(s):  
N. Christiansen ◽  
B. K. Ahring
Keyword(s):  
Waste Treatment ◽  
Granular Sludge ◽  
Bottom Layer ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Treatment Processes ◽  
Significant Difference ◽  
Desulfomonile Tiedjei ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

Three 200 ml upflow anaerobic sludge blanket (UASB)-reactors were inoculated with sugar degrading granules. To impart 3-chlorobenzoate degrading ability to the reactors, one was inoculated with the 3-chlorobenzoate (3-CB) dechlorinating Desulfomonile tiedjei, and the second received a 3-CB dechlorinating consortium, consisting of D.tiedjei and a benzoate degrading coculture of Syntrophus buswellii with Methanospirillum sp. No degradation of 3-CB was observed in the third reactor only inoculated with granules. After several months operation at a hydraulic retention time at 0.5 day, shorter than the reported generation time of D. tiedjei, the reactors showed increasing dechlorinating abilities. Activity tests done with granules from the control and the consortium-inoculated reactor showed no activity in the control reactor and no significant difference in the specific dechlorination rate with granules from the top, middle or bottom layer of the active reactor sludge bed, with or without carbon source added. This indicated that the added bacteria were immobilized in the granules and they were responsible for the dechlorinating activity. These results have important implications for the use of pure anaerobic culture or defined microbial mixtures in viable waste treatment processes.

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