Effluent Treatment Plant it is industrys

İt is about ETP and about industrial pollution

1. Industrial Pollution Control
Lecture : (ETP) Effluent Treatment Plant
Industrial water treatment
Submitted by
Mr. Kawar Abid

2. WhatisanETP?
INFLUENT
ETP
•ETP(EffluentTreatmentPlant)isaprocessdesignfortreatingthe
industrialwastewaterforitsreuseorsafedisposaltothe
environment.
•Influent:Untreatedindustrialwastewater.
•Effluent:Treatedindustrialwastewater.
•Sludge:Solidpartseparatedfrom wastewaterbyETP.
TREATMENT
EFFLUENT
SLUDGE

3. NeedofETP
•Toclean industryeffluentandrecycleitforfurtheruse.
•Toreducetheusageoffresh/potablewaterinIndustries.
•Tocutexpenditureonwaterprocurement.
•TomeettheStandardsforemissionordischarge
ofenvironmentalpollutantsfromvariousIndustriessetby
theGovernmentandavoidheftypenalties.
•Tosafeguardenvironmentagainstpollutionandcontributein
sustainabledevelopment.

4. DesignofETP
The design andsizeofthe ETPdependsupon:
•Quantity andquality oftheindustriesdischargeeffluent.
•Landavailability.
•Monetaryconsiderationsforconstruction,operation&maintenance.
•Areadimensiondependson:
Qualityof wastewatertobetreated,
Flowrate
Typeof biologicaltreatmenttobe used.
•Incaseoflessavailableland,CETP(CommonEffluentTreatment
Plant)is preferredover ETP

5. TreatmentLevels&MechanismsofETP
•Treatmentlevels:
Preliminary
Primary
Secondary
Tertiary(oradvanced)
•Treatmentmechanisms:
Physical
Chemical
Biological

6. PreliminaryTreatmentlevel
Purpose:Physicalseparationofbigsized impuritieslikecloth,
plastics,wood logs,paper,etc.
CommonphysicalunitoperationsatPreliminarylevelare:
Screening:Ascreenwithopeningsofuniformsizeisusedtoremove
largesolidssuchasplastics,clothetc.Generallymaximum10mmis
used.
Sedimentation:Physicalwatertreatmentprocessusinggravityto
removesuspendedsolidsfromwater.
Clarification:Used forseparationofsolidsfromfluids.

7. PrimaryTreatmentLevel
Purpose:Removaloffloatingandsettleablematerialssuchassuspended
solidsandorganicmatter.
•Methods:Bothphysicalandchemicalmethodsareusedinthis
treatmentlevel.
•Chemicalunit processes:
Chemicalunitprocessesarealwaysusedwithphysicaloperationsand
mayalsobeusedwithbiologicaltreatmentprocesses.
Chemicalprocessesusetheadditionofchemicalstothewastewaterto
bringaboutchangesin itsquality.
Example:pHcontrol,coagulation,chemicalprecipitationandoxidation.

8. pHControl:
ToadjustthepHinthetreatmentprocesstomakewastewaterpHneutral.
Foracidicwastes(lowpH):NaOH,Na
2CO
3,CaCO
3orCa(OH)
2.
Foralkaliwastes(highpH):H
2SO
4,HCl.
ChemicalcoagulationandFlocculation:
•Coagulationreferstocollectingtheminutesolidparticlesdispersedina liquid
intoalargermass.
•ChemicalcoagulantslikeAl
2(SO4)
3{alsocalledalum}orFe
2(SO4)
3areadded
to wastewater to improve the attraction among fine particles so that they come
togetherandformlargerparticlescalledflocs.
•A chemical flocculent(usually a polyelectrolyte) enhances the flocculation
processbybringingtogether particlestoformlargerflocs,whichsettle out
morequickly.
•Flocculationisaidedbygentlemixingwhichcausestheparticlestocollide.
PrimaryTreatmentLevel(cont…)

9. SecondaryTreatmentLevel
Methods:Biologicalandchemicalprocessesareinvolvedinthislevel.
Biologicalunitprocess
Toremove,orreducetheconcentrationoforganicandinorganiccompounds.
Biologicaltreatmentprocesscantakemanyformsbutallarebasedaround
microorganisms,mainlybacteria.
AerobicProcesses
Aerobictreatmentprocessestakeplaceinthepresenceofair(oxygen).
Utilizesthosemicroorganisms(aerobes),whichusemolecular/freeoxygento
assimilateorganicimpuritiesi.e.convertthemintocarbondioxide,waterand
biomass.
AnaerobicProcesses
Theanaerobictreatmentprocessestakeplace in theabsenceofair(oxygen).
Utilizesmicroorganisms(anaerobes)whichdonotrequireair(molecular/free
oxygen)to assimilateorganic impurities.
The finalproductsaremethaneandbiomass.

10. Tertiary/AdvancedTreatment
Purpose:Finalcleaningprocessthatimproveswastewaterqualitybefore
itisreused,recycledordischargedtotheenvironment.
Mechanism:Removesremaininginorganiccompounds,andsubstances,
suchasthenitrogenandphosphorus.Bacteria,virusesandparasites,
whichareharmfultopublichealth,arealsoremovedatthisstage.
Methods:
Alum:Usedtohelpremoveadditionalphosphorusparticlesandgroup
theremainingsolidstogether foreasy removalinthe filters.
Chlorinecontacttankdisinfectsthetertiarytreatedwastewaterby
removingmicroorganismsintreatedwastewaterincludingbacteria,
virusesandparasites.
Remainingchlorineisremovedbyaddingsodiumbisulphatejustbefore
it'sdischarged.
OzonationbyusingO
3astodisinfectmicroorganisms.
PhysicaloptionsbyusingultravioletUV,Heating,Gammaray.
Ultraadvancedtreatmentlikeultrafiltrationwithreverseosmosis,
carbonadsorption,ionexchange,denitrificationandNH3strippingand
others.

11. Possible Choice For
WastewaterTreatment
AndTheirSequence
with details

12. ETPPlantOperation
1.Screenchamber:
Removerelativelylargesolidstoavoidabrasionofmechanicalequipmentsand
cloggingofhydraulicsystem.
2.Collectiontank:
Thecollection tankcollectstheeffluent waterfromthescreeningchamber,
storesand thenpumpsittotheequalizationtank.
3.Equalizationtank:
Theeffluentsdonothavesimilarconcentrations atallthetime;thepHwillvary
timetotime.
Effluentsarestoredfrom8to 12 hoursintheequalizationtankresultingina
homogenousmixing ofeffluentsandhelpingin neutralization.
Iteliminatesshockloadingonthesubsequenttreatmentsystem.
Continuousmixingalsoeliminatessettlingofsolidswithin the equalizationtank.
ReducesSS,TSS.
•

13. ETPPlantOperation
4.Flashmixer:
Coagulantswereaddedtotheeffluents:
1.Lime:(800-1000ppm)TocorrectthepHupto8-9
2.Alum:(200-300ppm)Toremovecolour
3.Polyelectrolyte: (0.2ppm)Tosettlethesuspendedmatters&reduceSS,TSS.
The additionoftheabovechemicalsbyefficientrapidmixingfacilitates
homogeneouscombination of flocculatestoproduce microflocs.
5.Clarriflocculator:
Intheclarriflocculatorthewateriscirculatedcontinuouslybythestirrer.
Overflowedwateristakenouttothe aerationtank.
Thesolidparticlesaresettleddown,and collectedseparatelyanddried;this
reducesSS,TSS.
Flocculationprovidesslowmixing thatleadstotheformationof macroflocs,
whichthensettlesoutin the clarifierzone.
Thesettledsolidsi.e. primarysludge arepumpedintosludgedryingbeds.

14. ETPPlantOperation
6.Aerationtank:
Thewaterispassedlikeathinfilmoverthedifferentarrangementslike
staircaseshape.
DosingofUrea andDAP isdone.
Watergetsdirectcontactwiththeairtodissolvethe oxygenintowater.
BOD& CODvaluesof waterisreducedup to 90%.
7.Clarifier:
Theclarifiercollectsthebiologicalsludge.
Theoverflowedwateriscalledastreatedeffluentand disposedout.
The outletwaterquality ischeckedtobewithin theacceptedlimitas
delineatedin the normsofthegeneral world standards.
Throughpipelines,thetreatedwaterisdisposedintotheenvironmentriver
water,barrenland,etc.

15. ETPPlantOperation
8.Sludgethickener:
Theinletwaterconsistsof60%water+40%solids.
Theeffluentispassedthroughthecentrifuge.
Due to centrifugal action, the solids and liquids are
separated.
The sludge thickener reduces the water content in the
effluentto 40%water+60%solids.
Theeffluentisthenreprocessedandthesludgecollected
atthebottom.
9.Dryingbeds:
Primaryandsecondarysludgeisdriedonthe dryingbeds.

16. FLOWCHARTOFETP
Influent
Screening
Equalization
(Lime+Alum)pH=8.5
SS,TSS removal
Disperseunit
RECYCLE
TANK
Sedimentationtank
{pH=7.5}
Sludgethickeningunit
BiologicalTreatment&Aeration
{Dosing=(Urea+ DAP)for O
2}
BODremoval~90%
CODremoval~90%
Sludge
Sludgedischarge
Fishpond
Effluent
Effluentdischarge
60%water+
40%solids
40% water+60%solids

17. SCREENING
Screeningisthefiltrationprocessfortheseparationofcoarse
particlesfrominfluent.
Stainless steelnetwithvaryingporesizecanbeutilized.
Screensarecleanedregularlytoavoidclogging.

18. EQUALIZATION TANK
EQUALIZATION TANK
Influentfrom
screening
Equalizationmakes thewastewater homogenous.
Retentiontimedependsuponthecapacityoftreatment
plant.(Generally8-16hours)
Sprayofwatercoming
from dyeingunit
Airfor diffusion
Cool
&
Homogenous
influent to
pHcorrection
Tank

19. PHCORRECTION
pHcorrection
Acidoralkali
Influentfrom
equalization
tank Influent of desired
topHdisperseunit
InthistankpHoftheinfluent iscorrectedtomeetthestandard.
Acidoralkali isaddedtothe effluenttoincreaseordecreasethe
pH.

20. DISPERSEUNIT
DISPERSEUNIT
(MIXINGOFSLUDGE&WASTE)
Sludgefrom
recycletank
InfluentfrompH
correctiontank
Mixed
influent&
sludge to
aeration
Dispersetankmixesthesludgecomingfromrecycletank
withwaste waterfortoproperaeration.

21. AERATION TANK
Mixture of
wastewater
&sludge
Aerobicbacteria
Discharge to
sedimentation
tank
ORGANIC MATTER+O
2
O
2
AIR
REACTION INAERATION TANK:
BACTERIA
NUTRIENT
CO
2+HO
2+HEAT
AERATION
Function of aeration is
oxidationbyblowingair.
Aerobicbacteriaisusedto
stabilizeandremoveorganic
materialpresentsinwaste.

22. Aeration in Activated
sludgeprocess

23. SEDIMENTATION
TANK
Wastewaterfrom
sedimentationpack
Sludge to
thickeningunit
Effluent
Effluent
Discharge
Fishpond
FishPondis usedtoseesurvivaloffishestoascertainfitnessofwater fordisposal
Inthis tanksludge is
settleddown.
Effluent is discharged from
plant throughafishpond.
Sludgeispassed tothe
sludgethickeningunit.
SEDIMENTATION TANK

24. SLUDGETHICKENING UNIT
Heresludge isdriedand
discharged.
Partial amount of sludge is
returnedbacktotheaeration
tank from thickening unit
through recycle tank called
returnsludgetankanddisperse
tank.
SLUDGFE
THICKENING UNIT
Sludge from
sedimentationunit
Sludgedischarge
Sludgetorecycle
tank

25. ADVANTAGE OFRECYCLE SLUDGETOAERATION TANK
Sludgeagainoxidizedtominimizethepollutionfromsludge.
Alivebacteria ofsludgeisagainusedinaerationtoutilizethis
bacteria.
SLUDGE
RECYCLE TANK
Sludgefrom
thickening
unit
Mixingofsludge&
water
Sludgetoaeration
tankthrough
disperseunit
RETURN SLUDGETANK
Functionofreturntankorrecycletankistomixwaterwith
sludge
Thismixtureisthenpassedtoaerationtankthroughdisperse
tank.

26. PERMISSIBLE STANDARDS INGeneral
S.No. Parameter Permissiblelimits
(disposaltoinlandsurface
water)
1 pH 5.5to9.0
2 TSS <100mg/l
3 Oil&Grease <10mg/l
4 BOD <30mg/l
5 COD <250mg/l