AI SearchBiodegradation of cellulose in Upflow Anaerobic Sludge Blanket (UASB) reactor treating domestic wastewaters
Call Number: AIT RSPR no. EV-91-03 Material type:
SeriesSeries: Asian Institute of Technology. Research studies project report ; no. EV-91-3Publication details: Bangkok : Asian Institute of Technology, 1991Description: 88 p. + 1 online resourceSubject(s): Online resources: Dissertation note: Research Studies Project Report (M.Eng.) - Asian Institute of Technology, 1991 Summary: Biodegradation of cellulose was investigated in a 4 meter high 126 liter working volume Upflow Anaerobic Sludge Blanket (UASB) Reactor treating domestic wastewaters of about 500 mg/l COD concentration. The reactor is passing through its fourth phase of operation with theoretical organic loading rate of 3.0 kg COD/cum reactor volume per day at HRT of 4 hours. Cellulose (avicel) has been contributing to about 20 % of the imposed organic loadings at all phases. Granulation of biomass in the reactor was observed in this phase after about 230 days of operation, started on 11 September, 1990. This investigation was conducted after about 45 days of observed granulation. The study indicates that the insoluble cellulose particles initially act as inert support media for the bioflocculation. Hydrolytic bacteria might be the dominant species. These cellulose-bearing micro-flocs, due to decrease in specific gravity and upward fluid velocity, show a tendency of flotation and accumulation in the upper region of the reactor with a cellulose build-up of about 80 % of MLSS (w/w) and a wash-out (physical removal) of about 9. 7 g cellulose per day from the reactor against an average input of 62.58 g/day (about 15.51 %). An almost static accumulation of about 1.9 gm of cellulose per liter reactor volume was observed at the present phase of its operation, which is only around 50 % of the concentration of 4 g/l (or more) as observed to be optimum from the batch study and as suggested in recent research literature. The micro-flocs grow in size in the upper region and settle downwards with simultaneous conversion of cellulose, thereby bringing down the build-up to about 5 % of MLSS (w/w) at the lower regions of the reactor, with overall conversion of about 84.48 % as observed. This shows alternative for that the UASB reactor cellulose biomethanation.
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A Research Study Report submitted in partial fulfillment of the requirements for the degree of Master of Engineering
Research Studies Project Report (M.Eng.) - Asian Institute of Technology, 1991
Biodegradation of cellulose was investigated in a 4 meter high 126 liter working volume Upflow Anaerobic Sludge Blanket (UASB) Reactor treating domestic wastewaters of about 500 mg/l COD concentration. The reactor is passing through its fourth phase of operation with theoretical organic loading rate of 3.0 kg COD/cum reactor volume per day at HRT of 4 hours. Cellulose (avicel) has been contributing to about 20 % of the imposed organic loadings at all phases. Granulation of biomass in the reactor was observed in this phase after about 230 days of operation, started on 11 September, 1990. This investigation was conducted after about 45 days of observed granulation. The study indicates that the insoluble cellulose particles initially act as inert support media for the bioflocculation. Hydrolytic bacteria might be the dominant species. These cellulose-bearing micro-flocs, due to decrease in specific gravity and upward fluid velocity, show a tendency of flotation and accumulation in the upper region of the reactor with a cellulose build-up of about 80 % of MLSS (w/w) and a wash-out (physical removal) of about 9. 7 g cellulose per day from the reactor against an average input of 62.58 g/day (about 15.51 %). An almost static accumulation of about 1.9 gm of cellulose per liter reactor volume was observed at the present phase of its operation, which is only around 50 % of the concentration of 4 g/l (or more) as observed to be optimum from the batch study and as suggested in recent research literature. The micro-flocs grow in size in the upper region and settle downwards with simultaneous conversion of cellulose, thereby bringing down the build-up to about 5 % of MLSS (w/w) at the lower regions of the reactor, with overall conversion of about 84.48 % as observed. This shows alternative for that the UASB reactor cellulose biomethanation.
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