specialized bioreactor
TRANSCRIPT
SPECIALIZED BIOREACTOR - DESIGN & THEIR FUNCTION
-AIR LIFT BIOREACTOR -TOWER BIOREACTOR -MEMBRANE BIOREACTOR
ANITHA.Y 14KUST4002
AIR-LIFT BIO-REACTOR •Has promising role than stirred tank bioreactor – aerobic digestion.
• It is a typical “motionless” bioreactor where internal circulation & mixing – bubbling air.
• Employs pressurized air/force to circulate the nutrient medium & cells.
• Used to culture cells - sensitive to shear.
•They usually employ gas-liquid or gas-slurry contact process.
•Technically & Economically feasible – production of beer, citric acid, vinegar, biomass of yeast , bacteria & fungi
DESIGN OF AIR-LIFT BIOREACTOR•AL Bio-Reactor Consists of a liquid pool divided into 2 distinct zones
• Entire bioreactor is divided into 2 halves by a draft tube : -inner (gassed)region - riser -outer(ungassed)region-downcomer
• RISER- has a gas injection- air moves forward
• DOWNCOMER- has a degassed media & cells
• Mean density gradient b/w riser & down comer
•Difference of density- continuous circulation
• Oscillators(spargers)with nozzle - produce gas
• Headspace or vent – release of gas,foam,flocculation
Draft tube
CHARACTERISTICS OF ALR Liquid mixing Mass transfer Rate of gas transfer Energy dissipation
USES OF ALR1. Mammalian cell culture
2. Waste water treatment
3. Biological processes involving biocatalysts as solids
4. To produce bio-pharma proteins from fragile cells
TYPES OF AIR-LIFT
MODIFICATIONS OF ALR
ADVANTAGES Homogenous mixing & distribution of gas. Simple design, with no moving parts or agitator Less maintenance, less risk of defects Easier Sterilization (no agitator/shaft) Low energy requirement ,low shear force
DIS-ADVANTAGES Greater pressure & air throughout Too much of Foaming No bubble breaker
TOWER BIO-REACTORMainly it’s of the height: diameter 10:1 ratio (over all) but tubular section is 6:1.
Elongated, non-mechanically stirred fermentor, uni-directinal flow of gases.
Production of yeast, beer, citric acid, & tetracyclin.
Flow of substrate & air is concurrent-from bottom to top
They are of 3 types :
Bubble column tower fermentorVertical tower beer fermentorMultistage tower fermentor
DESIGN OF TOWER REACTOR
The tower consists of four to eight compartments separated by sieve plates.
High amount of air is passed from bottom
Baffles at the base – uniform mixing of liquid
Heating & cooling jackets
Settling zone- microbes
Outlet for retrieving products
Flow controller- products are lite
ADVANTAGES shorter fermentation time. no yeast lag phase very consistent product fewer beer losses due to reduced yeast growth
less scope for different products less scope to respond to seasonal and short term variations in
demand must use a highly-flocculent pure yeast culture difficult to maintain microbiological purity different flavour profile from batch process(BRAND) risk of yeast culture changing overtime is greater has to operate seven days a week
DIS ADVANTAGES
MEMBRANE BIO-REACTOR Alternative to activated sluge process
It is the combination of membrane technology(Microfilteration&ultrafilteration) in suspended bioreactor
Used now in municipal & waste water treatment
Size of the plant-48,000 ltrs/day
Membrane size- 0.003-0.01 It is of 2 types :External- Mixed liqour filtered under pressure in a specific membrane module
Internal –Filtered in aerated basin by suction to remove effluents
Screening
Clarification
Disinfection OR Desalination
DESIGN OF MBR It largely relates to: the configuration of the
membrane(Geometry & direction of water flow)
(flat sheet,hollow fibre, multi-channel/tube) the membrane separation process,
and(placement of membrane module)(External-side stream & internal-
submerged) the biotreatment process(biochemistry
of pollutant)(oxygen oxyanions carbon co2 ammonia nitrates phosphate in-org phosphate Ancillary equipement (screening,
membrane controll)
CHARACTERISTICS OF MBR Membrane pore size surface charge hydrophillicity surface roughness Sludge biomass conc particle size.structure colloidal conc solluble microbial product
Operation biology (HRT,SRT,TEMPERATURE) condition memebrane (TRANSMEMBRANE
PRESSURE,TOCIXITY,AERATION)
ADVANTAGES No settlement problems No further polishing required for disinfection/clarification No equalisation of hydraulic and organic loadings required
DISADVANTAGES Membrane surface fouling Membrane channel clogging Process complexity High capital cost High running costs
REFERENCES SLIDE SHARE YOU TUBE https://www.researchgate.net Diederik Rousseau & Tineke Hooijmans, Membrane bioreactors
(MBRs) for wastewater treatment-PPT onlinelibrary.wiley.com pharmacologyonline.silae.it/files/newsletter
Thank you one & all !!