Description of Bioreactors used in the fermentation industry.

1. Industrial Microbiology
MRC-511
Dr. Debajyoti Bose, PhD
School of Biotechnology
Research Web Page: https://sustainabilityresearchcentre.wordpress.com/
Contact: debajyoti@shooliniuniversity.com
Cell: +91-98317-80513

2. Effluent Treatment

3. Concept ofETP
Effluent treatment Plant covers the mechanisms and processes used to treat such waters that have been
contaminated in some way by anthropogenic industrial or commercial activities prior to its release into the
environment or its re-use.
This effluent contains several pollutants, which can be removed with the help of an effluent treatmentplant.
ETP treat water and make free from all objectionable impurities present in suspension, colloidal or
dissolvedform.

4. Why do we need to treat Effluent?
Toprevent groundwater pollution
Toprotect soil
Toprotect marine life
Protection of public health
Toreuse the treated effluent
For agriculture
For groundwater recharge
For industrial recycle
Solving social problems caused by the accumulation of wastewater

5. Need of ETP in Industry
Manufacturers face strict regulations on discharge and waste.Non-compliance can lead to expensive fees and
operationsinterference.
A wastewater treatment help themto:
Stay in compliance
Reduce transportation and off-site treatmentcosts
Reduce supply costs by recovering production materials out ofthe waste-stream for re-use
Eliminate municipalfees
Eliminate unnecessary water usage during processing

6. MajorTreatmentunitsinETP
• Preliminary Treatment
Screens
Detritor/scrapers
Grit Chamber
Skimming Tanks
Aeration
• Primary Treatment
Sedimentation/ Settlingtank
Clarifloculator
Equalization Tank
Neutralization Tank
Secondary Treatment
Activated Sludge Process (ASP)
Trickling Filter
Aerated Lagoons
UASB
Multiple Evaporator (ME)Plant
Rotating Biological Contactors(RBC)
Tertiary Treatment
Sand/ Membrane Filters
Activated Carbon Filters
Disinfection
Ion-exchange/ESP
Nutrient Removal

7. PreliminaryTreatment
Preliminary treatment removes gross solids and materials that can be easily collected from the effluent
and can damage or clog the pumpsand skimmers of primary treatmentclarifiers.
These are in-organic materials and insoluble organic pollutants (i.e. large floating and suspended solid
matter, grit, oil & grease) which are inert and cause problems to further chemical and biologicaltreatments.
The presence and sequence of preliminary treatment units aretotally depend upon the characteristic
of effluent that is to betreated.
All preliminary treatment consist of physical separation techniquesby controlling flow rate of effluent.

8. Preliminary Treatment-Screens
Screens are used for removal of large floating and sub-mergedmaterial such as plastic, paper pieces, rubber,
etc. from effluent.
Major objectivesare:
They prevent clogging in pump, pipes and valves, etc.
Prevent to interfere large material in primary and secondarytreatment
units.
Screens are classified in number of ways as follows:
Based on the size of opening- such as coarse, medium and finescreens.
Depending upon shape- such as disc, drum, band,etc.
Based on method of cleaning- such as mechanical ormanual.

9. Mechanical mediumscreen Fine screen
Course bar screen

10. Preliminary Treatment- Detritors/Scrappers
Detritors are shallow circular ponds used in pre-treatment plants withthe
purpose of grit removal.
Chain or blade type Detritors/scrappers are utilised in anadjacent channel into which the collected
grit is transferred.
Used when the soft and sticky substance, sticks on fixed bars and cannot get through the screen. Grits with
a 6 m diameter are removed in the detritor.

11. Preliminary Treatment- Gritchamber
 Grit Chamber is used for removal of inert inorganic material consist of sand, ash, cinder, silt, clay, glass
pieces, etc.
 It provides safeguard against ant damage to pumps, pipes and other equipments by avoiding
settling in pipe bends and channels.
 The eliminated material is collected from chamber and used for land-filling, road making and on sludge
dryingbeds.
Major objectives:
Protection of pumps, valves, piping,etc.
Minimizing chances of pipe chocking with in-organic inertmaterial.
Preventing grit from occupying volume in primary and biologicaltreatment units.

12. Preliminary Treatment- Skimmingtank
 Skimming Tank is used for removal of oil and grease consist of fats, waxes, fatty acids, soaps, mineral oils,
etc. present in emulsified condition in effluent.
 These materials have low solubility in water, therefore not readily available for biological treatment and
often accumulate on surface inform of scum causing foulodors.
 The efficiency can be improve by aeration, chlorination or vacuum floatation.
Objectives:
Removal of scum (oil & grease) which can otherwise create problemin biological treatment units.
Increases DO content and remove undesirable gases.
Enhances flocculation of suspended particles.

13. Skimming Tank with separated oil & grease at top
Collection of separated oil & grease at edge

14. PrimaryTreatment
Primary treatment consists of temporarily holding the sewage in a inert basin where
heavy solids can settle to the bottom while oil, grease and lighter solids float to the
surface.
The settled material go for sludge treatment and floating materials are skimmed off.
The remaining liquid is passed to secondary treatment.
Tanks are usually equipped with mechanically driven scrapers that continually drive the
collected sludge towards a hopper in the base of the tank where it is pumped to sludge
treatmentfacilities.
Primary treatment can be either only physical or can be combined with
chemical methods depending upon the effluentcharacteristics.
At this stage, over 70% of the suspended solids and 40% of the BOD is removed from
effluent.

15. Sedimentation Tank(Clarifier)
 Sedimentation Tank are designed to remove suspended particles that are heavier than water
through gravitational force by reducing water velocity.
 So it’s a solid liquid separation process in which a suspension is separated into two phases –
1. Clarified supernatant leaving the top of the sedimentation tank(underflow).
2. Concentrated sludge leaving the bottom of the sedimentation tank(overflow).
 An efficient sedimentation tank can remove about 90% of SS and 40% organic matter with two
hour of detention time.
Objectives:
To remove coarse dispersed phase.
To remove coagulated and flocculated impurities.
To remove precipitated impurities after chemical treatment.
To settle the sludge (biomass) after activated sludge process / tricking filters.

16. Sedimentation Tank(Clarifier)
Factors affecting sedimentation
Characteristics of solid particles- size, shape, specific gravity,concentration, etc.
Characteristics of liquid- temp., viscosity, specific gravity,etc.
Physical characteristics of clarifiers- detention period, shape and depthof basins, flow rate, etc.
Types of SedimentationTanks:
According to shape- Rectangular tank, circulartank
According to direction of flow- Longitudinal and radial flow, verticalflow.
According to nature of working- Fill and draw, Continuousflow
According to method of sludge collection- flat bottom tank with orwithout
scrapper, hopper bottom tank.
The most common are horizontal flow sedimentation tank andcenter-feed circular clarifiers.

17. Circular Primary Settling Tank Rectangular Settling Tank
Working of Settling Tank

18. Clarifloculator
Clarifloculator consist of coagulation (chemical) andflocculation (mechanical) process.
Employed when finely divided SS and colloidal particles nan not be efficiently removed by simple
sedimentation. In such cases chemical assistance is taken.
The chemical used for coagulation are calledcoagulants.
The most common coagulants are Alum, hydrated lime, ferricchloride, ferrous sulfate and PAC (Poly
aluminum Chloride).

19. Coagulation andFlocculation
Coagulation
Coagulation is the conversion of finely dispersed colloids into a smallfloc
with the addition of coagulates.
Coagulation can either be followed by the process of settling or flotation.
Flocculation
The purpose of flocculation is to bring coagulated particles togetherby mechanically inducing a velocity
gradient within a liquid.
Organic polyelectrolyte flocculation aids are effective in promotingsoluble solids removal.
Flocculation improves the removal of finely divided solids bygravity
settling.

20. Clarifloculator
Clarifloculator

21. EqualizationTank
Some industries produce different types of wastes, having different characteristics at different intervals of
time.
Hence, equalization tank is used to mixed different type of effluent thoroughly to produce homogenous
and equalized effluent foruniform treatment.
This are large holding tanks with aeration or mechanical agitation with paddles manually to give better
mixing of the different unit volumes of effluents.
The effluent is hold and mixed for specified period oftime.

22. Equalization by Surface Motors
Different Inlet in Equalization Tank

23. NeutralizationTank
Neutralization tank is used to provide treatment to highly acidic or highly alkaline effluent trough
neutralizing pH by addition ofchemicals.
Industry require neutralization of discharged effluent when it has as highly acidic and/or highly
alkalineeffluent.
Acidic effluent is usually treated with lime stone or lime-slurry or caustic soda, depending upon the type
and quantity ofeffluent.
Alkaline effluent is neutralized by sulphuric acid or CO2 or wasteboiler flue gas.

24. Secondarytreatment
Secondary treatment is a biological treatment of effluent which is typically performed by indigenous, water-
borne micro-organisms in a managed habitat.
Secondary treatment removes dissolved and suspended organic (bio- degradable) matter by consuming it as
a food and convert it into new cell mass, energy and CO2.
The most common micro-organisms are bacteria (aerobic or anaerobic), protozoa and rotifers; least
common are fungi andalgae.
After secondary treatment almost 70-90% of BOD and 80-90% of dissolved solids are removed from
effluent.

25. TricklingFilter
In trickling filter treatment, wastewater is sprayed through sprinkling rotating arm on circular beds
consist of 3-10 ft deep coarse media(of crushed stones, gravels or synthetic material).
Microorganisms get attach and grows on the media and results in formation of film of micro-
organisms called zoogloealfilm.
This zoogloeal film consist of millions of micro-organisms breakdowns organic material of effluent into
simple and soluble matter. Treated effluent is drain at bottom from where it is collected then undergoes for
sedimentation(SST).
It is simple to operate and give almost 80-90% of BOD removal with high quality effluent.

26. Trickling Filter with rotating arm
Working of Trickling Filter
Media bed of gravels and stones

27. Activated Sludge Process(ASP)
This is most versatile biological oxidation method employed for the treatment of effluent containing of
dissolved solids, coarse andcolloidal organic matter.
In this method, effluent is aerated in a reaction tank consist of microbial population in suspension form.
Aerobic bacteria degrades effluent into CO2 and H2O for which oxygen is supplied through mechanical
aeration or by diffused aeration system.
The bacterial flora grows and remains suspended in the form of a floc called activated sludge. A part of
sludge is recycled for the same tank to provide an effective microbial population for a fresh treatmentcycle.
Industrial ww require 6 to 24 hours of aeration though which almost90- 95% of BOD can be removed.

29. UP-flowAnaerobicSludgeBlanketReactor(UASB)
UASB system is a three phase settler which separates sludge, liquidand biogas in same tank under high
turbulence without occupying largespace.
Organic matter is degraded under anaerobic conditions by microbes producing methane and CO2.
More effective than conventional aerobic process, produces only 5-10% of sludge. Hence, more popular in
anaerobic treatmentmethods.

30. Raw effluent is introduce from bottom of the reactor flow upward
through a sludge blanket composed of biologically formed granulesor
particles. Treatment occurs as the waste comes in contact with this
granules.
Treated effluent rises to the top along with generated biogas in form of
small bubbles. Treated effluent is collected though overflow weirs and
biogas is collected through a gas collection domes fromtop.
The separated solids falls back through the baffle system on topwhich
allow to settle down SS in the sludgeblanket.
UP-flow Anaerobic Sludge Blanket
Reactor (UASB)

32. UASB working Mechanism
UASB Tank with gas holder doom

33. TertiaryTreatment
Tertiary treatment is the final treatment, meant for ‘polishing’ theeffluent
and removal of pollutants not removed in primary and secondary
treatment.
These pollutants may include soluble inorganic compounds such as
phosphorous or nitrogen which may support algal growth inreceiving
waters.
Also removes organic materials contributing BOD, COD, color, taste, odor;
bacteria, viruses, colloidal solids contributing turbidity; or soluble
minerals which may interfere with subsequent re-use of the wastewater.
Preferred when treated water is need to be reuse or discharge is intoa
highly sensitive or fragile ecosystem (estuaries, low-flow rivers, coral
reefs, etc).

34. TertiaryTreatment
Tertiary treatment add additional cost to the treatment process but
produce high quality effluent which can be reuse further forcommercial
and industrial applications.
Treated water can be reuse for the irrigation of a golf course, green way
or park, construction work, industrial process, etc. If it is sufficiently
clean, it can also be used for groundwaterrecharge.
Treated water is sometimes disinfected chemically or physically
depending upon the discharging location.

35. Filtration
Filtration is process of removing particulates and bacterial impurities that
could not be removed in earlier treatment, from water by passing it through
a porous medium.
It is used to remove colloidal and other impurities which impart turbidityto
water. Also for disinfection of water by reducing 90% of bacterialload.
It is also used to reduce odor and color by arresting them in filtermedia.
There are various type of filter available to treat certain type of wastewater.
Selection is totally depend upon characteristics of ww, efficiency of
absorbent, flow rate and pollutant to be removed fromww.

36. Sand Filters
Based on Filtration
Rate
Pressure
Filters
Gravity
Filters
Rapid Sand
Filter
SlowSand
Filter
Based on Filter
media Material
Based on Depth of
Filter media
Types of Filters
Anthracite
Filters
Metal Fabric
Filters
Diatomaceous
Earth Filters
Deep Granular
Filters
Pre-coat
Filters

37. Activated Carbon
Filters
ACF consist of activated carbon granules supported by very fine quartz
filter media. Various grades of carbon are available for specialized
treatment of wastewater.
ACF are used to remove free chlorine, organic residues, toxicheavy
metal ions and color fromww.
Most common adsorbents used are activated carbon, peat moss, brown
coal and other cellulosematerials.
This treatment not only improves taste of water but also protectsother
water treatment units such as reverse osmosis membranes and ion
exchange resins from possible damage due to oxidation or organic
fouling.

38. Different media used for ACF
ACF Tubes or channels

39. Ion-
exchange
This treatment is used for removal of toxic materials and recoveryof
valuable materials from effluent.
Ion-exchange is only economical when recovered material is reused. So
not economical when objective is only removal of pollutants.
Majorly used for recovery of Cr,Ni, Phosphate and H2SO4, Cu, Pb, Hg and
removal of cyanides from wastewater after Crrecovery.

40. Tata Motors, Pune

42. Petrochemical Industry ETP

43. ETP Plant with Advance Treatment

44. THE END