ENVIRONMENTALSCIENCEANDENGINEERING(BCE101)

RequirmentofHumanBeing:

Energy Water Quantitative&Qualitative Food

EnvironmentEngineersWorkToprovidegoodqualityofwater

(Watertreatmentplant)

WastewatertreatmentControlonAirPollutiontoMaintaintheAirQuality

(Temperature,Pressure,Wind,Moisture)

ControlonWaterPollutionSolidWasteManagement

(Storage,Separation&Transportation)

1BookEnvironmentEngineeringByGerardKiely2H.S.PeavyD.R.RoweG.TechnobanogLous3WaterSupplyEngineeringbyS.K.Garg

1.1 EcologicalPerspective:

The environmental engineer is interested to use the varies physicalresourcessuchasnaturalenergy (waves,wind,minerals,hydroelectric)andwaterfordomestic&livingpurpose.

Therefore, It has tounderstand the functioningwith the living systemanditsinteractionwiththeenvironment.

Environment(orEcosystem)Itconsistsoffourmajorelementsuchas(i) Land(ii) Water(iii) Airand(iv) LivingOrganism(Plant&Animals)

Environment(Ecosystem)

PhysicalEnvironment BiologicalEnvironment(Abiotic) (Biotic)

LivingOrganisms(Planteanimals,Viruses,Bacteria,Fungi)

Hydrosphere Lithosphere Atmosphere(Waterovertheearth (Solidearth&soils) (airuptoadistance&insidetheearth) of700km.)

Livingorganismsaredependentoneachother&dependson thephysicalenvironment.

Ex. Plansgrowonland&inwater.Herbivorousanimalsusetheplantasfood.Carnivorousanimalseatherbivorousanimals.

1.2 ValueofEnvironment:orResources

NaturalResources

Renewable Nonrenewable(Energyfromsun,water (Fossil,Fuel,Mineralsetc)andBiologicalcycles)Itisrecycled&reused. Theyarenot

Replaced.ForestPlantation Amountarefinite.

Abstract(Animal,plantandnaturalsightusedfortourism)

1.3 EnvironmentAuditing:Listingofalltheresourcesofanarea

Differenttypesofdevelopmentalworkgoaheadinanareadependsontheeconomicalconsideration.

Ithastorestricttheeconomy(money)cased.

Therefore,Wehavetoauditormakealistofalltheresourcesofthearea.(Environmentalauditing)

Auditing

Nosofspecies(Livingorganisms)exist

Usesofthelivingenvironment.

Directuses Indirectuses

Food,Industrial&Commercialproducts,tourism,medicinesetc.

1.3.1 DirectuseFoodPlantsordomesticatedanimalproducts

Industrial & commercial products: Mineral, fossil, fuel, wools, cotton,jute,rubberetc.

Medicines

1.3.2

IndirectUses

9 Biodiversityisthebiologicalprocessesthemselvesthatprovidethevalue.Itisregardingaboutindirectusesofenvironments.

9 Environmentconsistsofpopulationsofspecieswithair,water,land.

Populationofonespecies(Environment)

Biological mixedtogetherwithother

Processhelps species

Theentiresystem. Communities

Manycommunitiesare

Combined

Landscape

9 Therefore, biodiversity is a basic resourcewhich acts as a human lifesupportsystem.

9Biodiversity

Sail formation,wastedegradation,air&waterpurification,solarenergyabsorption,andmaintenanceofhydrologicalcyclesetc.

LossofBiologicalresources

Reductionofonecommonspecies. 1Depletionofaoncecommonspecies

2Localorglobalspeciesextinction

3 Ecosystemdisruption

Environment may be changed due to habitat destructionextinction means the potential of the particular species to beappearedinfuture.

1.4.0 CostBenefitAnalysis:

Afterenvironmentalauditing,wehavetocalculatethecostfor

thedevelopmentalwork.

Someof the environmental process or services are excluded fromthecalculationsuchas:

9 Pollutionabsorptionbybioticsystem9 Ecosystemstability9 Recreationalvalue

9 Historicimportance.

Environmental parameters to be incorporated is based on WorldConservationStrategy(IUCN,1980).

1.5 BioticComponent:

Everythingintheglobalenvironmentisinonecomponentcanaffectmanyothersoverspace&time.

Sixmajorlevelsofecologicalorganizationarerecognized

9 Individual(Physiologicalfunctions)Singlespecies

9 Population(Birth,death,populationgrowthrate)9 Community(Interactionbetweendifferentspecies)

Bothplants&animals

9 Ecosystem(Interactionbetweenliving&(biotic)

Nonlivingcomponent.)

Abiotic

Biotic

CommunityofLiving

Hydrosphere

(Water)

Lithosphere

(earth,soil)

Atmosphere

(Air)

ABiotic

Fig1Interactionsbetweenvariouscomponent

EnergyflowoccursatthelevelofEcosystem

9 Biomes: Environmental conditions are similar indifferentpartsofcountry.

Exclimate.Vegetationtype.

9 Biosphere: Part of earth & atmosphere in which lifeexists.(Lithosphere, Atmosphere & Hydrosphere comes intocontactinBiosphere)

1.6 EcosystemProcess:

Ecosystemistheinteractionbetweenbiotic&abioticcomponents(Fig1).

Processoccurredatecologicallevelare

9 Energyflow9 Nutrientcycling

1.6.1 EnergyFlow

Interactions between living organism & environment is because ofrequirementoffoodwhichsupplyenergytosurvive

Italsohelpstoconstructbodytissues&gamesforreproductionofspecies. (child/nextgeneration)

Energysources

converted1Lightenergychemicalenergy

(storedinlivingorganism)

SolarenergySun(ultimatesourcesofenergy)

2EnergyinEnvironment

AutotrophicHeterotrophic(Energyoriginated

Fromprimaryproductioninotherecosystem.)

twoways1Productionofenergybygreenplantsinpresenceoflightthroughtheprocessof

photosynthesis.2Bysulphuroxidizingbacteriaindeepseaecosystems.

PhotosynthesisGranplantscreatetheirownfoodthroughaseriesofchemicalreactions.12H2O+6CO2+LightChlorophyII+enzymes

Water709kcalC6H12O6+6O2+6H2OCarbohydrate(toair)(Glucose)+Sugarmolecules.

Photosynthesisiscarriedoutindaylightinleaves&instemsofsomegreenplants.

Plantrequireinorganicsubstancelike

9 Nitrogen9 Phosphorusobtainedfromsoils.9 Magnesium9 Iron

Glucose+chemicalreactionFat,Proteins&Nucleicacid(usedtoformbodytissues)PrimaryproductionProductionoforganicmatterbyplants.

Whenanyorganismrequiresenergy,thereversereactiontophotosynthesisoccurs,celledrespiration.C6H12O6+6O2metabolicenzymes

CO2+H2O+EnergyforworkPrimaryProductionTheproductionoforganicmatterbyplantsiscalledprimaryproduction.

The rate of photosynthesis & primary production plays a vital role in theecosystem.Therefore,Ithastoconsidertheamountofprimaryproductionindifferentecosystem.Netprimaryproduction=GrossPrimaryproductionrespirationGrossprimaryproduction is thetotalamountofchemicalenergystoredbyplantsperunitareaperunittime.Theprimaryproductionisaffectedbytheenvironmentalfactors,

9 Water9 Light9 Soilnutrients9 Temperature.

Foodchain

Autotrophs(plants)cancreatetheirownfood,butheterotrophscannot.

(animals)

Heterotrophdirectlyorindirectlydependsonprimarysourceoffood.

Primaryproductionplant

(chemicalenergy)

+Organicmatter

(GrossProduction)

1.6.2 Decomposition&NutrientRecycling

Nutrient:aminoacids,minerals,sugar,salts&vitamins.

With flowof energy through food chain, nutrients arepassed fromone organismtoanotherduringfeeding.

AutotrophOrganicmatter

Photosynthesis

respiratory Netproduction

to

Herbivores

Carnivores

SunlightPhotosynthesis Respiratory

Sunsenergy

R

R

R

R

Fig4Energyflow

Plant

Primaryproducer

Decomposer Primaryconsumer

Secondaryconsumer

Soil Rain

Primaryproduct

DecomposerPrimaryconsumer

Herbivores

Carnivores

Fig5Nutrientcycle

1.7EnvironmentalGradients&Tolerance:

Eachspeciesisnotfoundineverytypeofhabitat(area)Unevendistributionoforganism

Thisisbecauseofseveralfactors

9 Light9 Temperature9 PH9 Food9 Water9 Shelter9 Predictor&competitorsinteraction.

Theaboveenvironmentalfactorsvariesfromtheequatortowardsnorthorsouth;iscalledenvironmentalgradient.

Theplotbetweenenvironmental&populationsizeiscalledtolerancecarve.

++++++++++++

A=Speciesabsent

B=Lowpopulation

Secondaryconsumer

Rangeofoptimum:Areaofgreatestnumbers.

ConceptofHydrology2.1Hydrologicalcycle:

Water evaporates from oceans & other water bodies, and from landsurfaces. The evaporated water rises into the atmosphere until the watervapour condness. Then the condensed water vapour condenses. Then thecondensedwatervapourintheformofrain&sometimesassnow.

++++++++++++++++

Fig2.1Hydrologicalcycle.2.2Waterbalance:

Theaccountingofwaterforaparticularcatchment,regionorearthiscalledwaterbalance.

Therefore,waterbalanceistheaccountofhydrologicalcycle.Moreover,theinputtothehydrologicalcycleisduetoprecipitation.

theequaforwaterbalanceis

P=Precipitation,mm/day

R=Streamrunoff

E=Evaporation

S=Changeinsoilmoisturestatus

G=Changeingroundwaterstatus

2.3 Energybudget/balance:

P=R+E SG

Thesourceofenergyissolarradiation.Earthsurfaceabsorbssolarradiation.

Theenergyabsorbedbyearthsurfaceisreflectedbacktotheatmosphere& some enters into the earth. Furthermore, the earth also reradiates somesolarenergy.

The energy balance is the accounting of distribution of the solar radiationthrough atmosphere and onto the earths surface of land and ocean.Moreover, It accounts for the outgoing terrestrial radiation from the earthssurface.

It includes evaporation flux, sensible heat flux & net radiant emission bysurface.

Ourinterestisfindthenetincomingradiationattheearthssurface.

Quantityofradiantenergyremainingattheearthssurface.

WhereRn=Specificfluxofnetincomingradiation,W/m2

L=Latentheatofvaporization(Doesntincreasethetemperature)

E=specificfluxenergyofsensibleheatintotheatmosphere(watt/m2)

G=Specificfluxofheatintooroutofthesoil

PS=Photosyntheticenergyfixedbyplants

M=Energyforrespiration&heatstorageinacropcanopy.

NeglectingPS&M,wehave

2.4Precipitation:

Rn=LE+H+G+PS+M

Rn=LE+H+G

Preciptionisintheformofrain,hailorsnow.Weareinterestedtodeterminetheamount,rate&durationofprecipitation.

Themagnitudeofrainfallisdeterminedbythreewayssuchas:

9 Precipitationgauges9 RaderInstruments9 Satelliteremotesensing

Precipitationcanbecalculatedfromdifferentmethodanalysisresultsi.e.

9 Areaprecipitation9 Deptareadurationanalysis9 Precipitationdurationfrequencyanalysis.9 Intensitydurationfrequencyanalysis.9 Extremevaluesofprecipitation.

Areaprecipitation

P1=.dx

MeanareaTotalaccumulationPrecipitationofprecipitationatallpointx1inthecatchment

Timeaveragedmainareaprecipitation

MP2=

I=1AATotalprecipitationatx&timeti.Where

A=CatchmentareaT=Totalstormperiod.

Depthareadurationanalysis.Generally,astheareaofacatchmentincreases,thedepthofprecipitation

decreases.Therefore,anareareductionfactor(ARF)Isusedforprecipitationinthisanalysis.

Precipitationfrequency

Rainfallrecordoveraperiodoftimewithaspecificmagnitude.(No.oftimes)

+++++++++++++++++Fig2.3DepthareadurationcurveIntensitydurationfrequencyanalysis(IDF)

FromIDFcurves,asrainfallintensityincreases,itsdurationdecreasesi.e.

Runoff(Q)=CIA

Catchmentarea(km2)

Localityconstants.

2.5 Infiltration:

Itisthemovementofwaterfromsoilsurfaceintothesoil.About76%ofprecipitationinfiltrateintothesoil.

I

1 Thepropertiesofsoilwhichresponsibleforinfiltrationare

9 Bulkdensity9 Particledensity9 Porosity9 Volumetricwatercontent9 DegreeofSaturation.

Bulkdensityofasoilis:

(b)

Md=Drymassofasoilvolume

Vt=totalvolume(Undriedcondn)

Particledensity(m)=

Vd=dryvolume

Typicalvalueformostsailsis2.65kg/m

Porosity()==1

Va=volumeofair

Va=volumeofwater

Vs=volumeofsolids

b=()

VolumetricWatercontent()==

Degree of saturation (S) is the proportion of water containing pores. of the

measureofwetness.

S==

SoilhorizonsandHydraulicconductivityHydraulicconductivityistherateof

movementofwaterintothesoil.

Deadleavesvegetation(Grass,tree)

UnsaturatedzoneAHorizon

BHorizon

CHorizon

3Soilmoisturecontentorsoilwatercontent

Eachsoilhasamaximummoisturemagnitude/capacity,whenitissaturated.

+++++++++++++++

Aerationzone:istheupperzonewheretheporesareoccupiedbyair.

Capacityzone:isthezonethroughwhichwaterwillrisethroughthesoilpores

bycapillaryaction.

Groundwaterzone:existsbelowthewatertable.

2.6Evaporation&Evapotranspiration:

Soil

Subsoil

Saturatedsoil

BedRock

Evaporation is the process by which water is returned to the

atmosphere,fromliquid&soildintothevapourstate.

Evaporationintotheatmosphereoccursthroughthetranspirationofleaf

partsofplants.Theprocessistermedasevapotranspiration.

30% of rainfall flows in the form of runoff. Therefore, on the ocean

surfaceofearththereismoreevaporationthanprecipitation.

Thetypeofevaporation/evaporatranspirationare:

9Evaporationfromlakesurface(Eo)9Actualevapotranspiation,(ET)9Potentialevapotranspiration(PE)

Evaporationfromlakeoropenwaterbodysurface.

Itincludestheevaporation&transpirationfromalandsurface,&vegetated.It

willvarydependingonthepresentsoilmoisturestatus.

Potential evapotranspioration is determined for catchment research

projects,whenradiation&heatbalanceareconsidered.

Factors causing evaporation from any surface are: 1 Latent heat of

vapourization&(2)wind

2.7Groundwater:

Groundwaterisdefinedasthewaterbelowthewatertable.

The levelof soilbelowwhich theporespace is100%occupiedby

water.

2.7.1Aquifers

Watertable

+++++++++++++++

An aquifier is a water bearing rock formation that contains sufficient

amountsofwatertobeexploited&broughttothesurfacebywells.

Aquifersaretwotypesinnature:

9 Contined9 Uncontined

Upperaquiferisunconfined&ithasanaturalwatertableline.

Freetomoveup&down

The impermeable strata between unconfined aquifer& confined aquifer is

calledaquaclude.

Whenwellsaredrilledintoconfinedaquiferwaterwillrise&attainitsown

watertableline.

2.8Groundwaterchemistry:

(quality/properties)

Thequality of groundwaterdependson the subsoil& rocks that it passes

through.

Ex:hardness,iron,manganese

1 Hardness

WhenGroundwaterpassthroughthelimestone,itdissolves/mixedwith

calcium & magnesium compounds; which cause hardness. (200 to 400

mg/litr)

2 Iron&Manganese

Excessamountofironsdontcausehealthproblem(Tasteproblems)

Itwillgiveametabolictastetowater.

Manganesecauseablackdiscolorationofwater.

Iron&manganesearegoodindicatorofwaterpollution.

3 Hydrogensulphide(gas)

H2Sispresentinwaterfromrockslikelimestonesorshales.

ItcreatethesameproblemasinthecaseofIron.

4 Sulphate(800mg/lit)

5 SodiumChloride(Nacl)

Thisproblemoccursinareaswhererocksarehighlypermeable.

2.9 Ground water contamination: internet Make impure which will

becomeharmful

TheindicatorsofthesourceofcontaminationareE.coli,nitrate,ammonia,

potassium,chloride,iron,manganeseetc.

1 Bacteria&Viruses.

E. coli is the parameter which indicates the presence of bacteria &

viruses.

Presence of bacteria in ground water causes typhoid fever, diarrhea,

gastrointestinalinfectionetc.

EcoliBacteriaFromseptictankeffluent,landfillsites&birdsetc.

2 Nitrate

Nitraterichwatercausemathaemoglobinaemia(bluebabysyndrome)to

youngchildren.

3 Ammonia

Ithasalowmobilityinsoil&subsoil.

4 Potassium(K)

Itisimmobileinsoil.

5 Chloride(Cl)

6 Iron&Manganese

2.10Groundwaterpollutioncontrol/prevention:

WaterQualityRequirement:

3.1InStreamStandards:

Waterqualityrequirements&waterqualitystandard.

Manyfactorsaffectstream

Qualityex:Wastewaterdischarge&humanactivities

3.2Portablewaterstandard:

+++++++++++++

3.3Wastewatereffluentstandards:

Decomposition:Theprocessofdecaycausedbybacteria&fungi

:WaterQualityinRivers:

4.1OrganiccontentparameterDO&BODinstreams

DODissolvedoxygen.

Waterbodiessupportavarietyoffishandanimals.Theyrequire

oxygen&astream/rivermusthaveaminimumdissolvedoxygenabout

2mg/litr.

Whenanorganicwasteisdischargedtoastream,theorganiccontent

undergoesbiochemicalreaction.Thisreactionaconsumesoxygenfrom

waterbodies.

Organiccontent+O2microorganism

New+Co2+H2O+stableproducts

Biomass

Theamountofdissolvedoxygenusedupfromwatersamplebymicro

organismforthebiochemicalreactionistermedasBOD.

TherelationbetweenDO&BODisdevelopedbyStricter&Phelps

model.

Follow=K1LtK2DO

otherbook=

Lo=Oxygendemandatt=to

Lt=CBOD(mg/Litr)

=Carbonaceousbiochemicaloxygendemand

amountofoxygen

Remainingattimet

ConstantsK1dexygenationrate(1/day)

K2reactionrate(day1)

(LoLt)Oxygenconsumed.

K1L0eK1tK2DO

Thedissolvedoxygen(Do)decreasesinariver/streambydegradationof

BOD.ThevariationofDOinthestream/riverw.r.tBODwasderivedby

Streeter&helpsmodel.

Seededwater

Deoxygenation

ChemicalOxygenDemand(COD):Aquickchemicaltesttomeasurethe

oxygenequivalentoftheorganicmattercontentofwastewaterthatis

susceptibletooxidationbyastrongchemical.(organic&inorganic)

(both)

OrCODisameasureofthetotalorganiccarbonwiththeexceptionof

certainaromaticsuchasbenzenewhicharenotcompletelyoxidizedin

thereaction.

Organicmaterialssuchascellulose,phenolsetc.resistbiodegrationalong

withpesticides&thesematerialsareoxidizedintheCODtest.

*Theorganiccontentofawastewaterstreamisdeterminedbyfollowing

tests.

BOD5:conc.OfDoatday5

COD

TOC:Totalorganiccarbon,

atdayOatday5

BOD5=P(DOiDos)

Dilationfactor.

4.2Transformationprocessinwaterbodies:

TheconstituentsinwaterbodiesareDO,BOD,temperature,salinity,

nitrogen(asorganic,ammonia&nitrateetc),phosphursetc,(considering

waterquality).

Thetransformationprocessinwaterbodiesare:

1 Influentcleanflows

2 Influentwasteflows

3 Biologicaloxidationofcarbonaceous&nitrogenousorganicmatter.

4 Reparationofsurfacelayer

5 ReductionofBOD(sedimentation)

6 Photosynthesis

7 Respiration

8 Oxygendiffusion

9 COD(Chemicaloxygendemand)

4.3Transportprocessinwaterbodies:

Transportprocessesare

1 Advection(heat,humidity&solidityinocean)

2Difusion:theprocessbywhichmodelsSeeS.K.Garg

intermingleasaresultoftheir&otherBook

extwogasesmixK.E.ofrandommotion.Fordestination

withcostivelyoftheprocess

3Buoyancy:isanupwardforexertedby

fluidthatopposestheweighofimmersedobject.

4.4StricterPhelpsOxygenSagModel:

Therateofdecompositionoforganicmatterisproportionaltotheamountoforganicmatteravailable;i.e.

11

Lt=BODremainingattimet,K1=deoxygeneationratecoefficientperday

Integrateequation1between(Lo)to(Lt)

Wehave2

WhereLo=UltimateBOD

=(BODattintO)=initialBOD

BODconsumedattimet.

(BOD)t=LoLt

=LoLoeK1t

=Lo(1eK1t)

Solve

Ex7.1

=K1Lt

Lt=Loek1t

7.3

Whenbiodegradablewastewasdischargedtoastream/river,Itconsumed

oxygen.

Thedeticienyofdissolvesoxygenismaintainedthroughreaertionfrom

atmosphere.

Hence,eqa1canbewrittenas

=K1LtK2(DO)

=K1Loek1tK2(DO)

3

WhereDO=DOdeficit(oxygendeficit).

=maintainDOactualDO

LtOxygenremainingattimet

K1deoxygenationrateperday

K2=reparationrateperday

Integratingeq,wehave

DO(t)=(ek1tek2t)+

DOek2t

4

WhereLo=Oxygendemandatt=to

Doo=dissolvedoxygendeficitatt=to

Dissolvedoxygensaturationdeficitatanytimet.

Equ4isthestreeterPhelpsoxygensagformula.

Solveex7.5

InitialDODOcDOsagcurve

DeficitminReaertimDO(mg/lit)

deoxygenation

time

FigDissolvedoxygensagcurve

DocMinimumormaximumdissolvedoxygendeficit

differentiateequ4w.r.ttot&setitequaltozero.Wehave

tc=.Ln1

timeofoccurrenceofminimumDOormaximum

dissolvedoxygendeficitDOc

=DO(t)DOo

Dissolvedoxygensaturationdeficitattime.

ChemicalPretreatment:toremoveundesirablepropertiesofwater(excess

colourofalgae)Photosyntheticalghe.(doubt)

Unit(NTU:Nephelonetricturbidityunit)

Prechorinctinfor(Lowturbiditywater)

Activaledcarbon

(Turbidity:Shouldbe

OxygenO2contentisincreasedtorechesthebadtaste(metabolic

taste).

Additionofoxygenhelpstoseparatethesubstance(Iron&

manganses)inasolidform.

Adsorption:theaccumulationofgas,liquidorsolutesonthesurface

asolid/media.

Sedimentationtank(settingtank):(I)dissolveparticiple

=

Flowvelocityinhorizontaldegree.

Vs=settingvelocity

Therearethreezonesinthetank.

1 Inletzone

2 Outletzone

3 Sludgezone

Sedimentationofflocculentparticles:(II)

Settingofflocculentparticles.

V=()xVs

Coagulationisthefirstprocessofaddingthecoagulantwhichchanges

theparticleselectriccharges&thenhelpstoaggregateinmass.

Flocculationisthesecondprocessofgettingthecoagulatedmixto

formlargerflocs.

Beforeflocculationcolloidalparticlesaresuspendedinaliquid&not

dissolvedinthesolution.

Incoagulationprocesscoagulantswithoppositechargetothe

suspendedsolidareweldedtoneutralizethevechargesondispersed

nonsettablesolids.

Ex7.1Asampleofwastewaterisdilutedwithaseededwater&isplaced

inanairtightbottle.MeasuretheconcentrationofDOatignitionday.

1 PretratmentProcess:

9 Screening:Coarseserreemy(25mm100mmsize)9 Storage9 Aeration(ToreleaseexcessH2S,CO2,O2)9 Chemicalpretreatment.(Prechlorination&Activatedcarbon)

Screeny

Coarsesereeny(25mmdiabar&100mmspellingisusedtopreventlargefloatingmaterial)

FixSereen(6mmdiaopening)Aobstructionis

Microscreen(2040Nmopening)madewithwovensteel

Wirenet.

Storagetankareusedforsettlementofsuspendedparticles

(initialsettingtank)

9 Thismaybeusefultoreelncepathogensbyexposuretodaylight.9 Timeofstorageisabout12hr.Aration:issupplyofoxygenfromatmospheretowatertochangequalityofwater.

(PH,hardness,manganese,H2Setcinaspecifiedanomy)

Aerationisusedtorelease(H2S),which

releaseCO2,whichiscorrosiveinnature.

:WaterTreatment:

5.1Watersources&theirquality:

Differentwatersourcesare

9 Rivers9 Lake&reservoir9 GroundwaterQualityofwaterare:

PH,Acidity,Alkalinity,Colour,Turbidity,DO,etc.

Disonfeet

Sedimentation,Coagulation(Fitration)

5.2WaterTreatmentOperation:

5.2.1Sedimentation

Pretreatment Primarytreating Secondarytreatment

Theseparationofsuspendedsolidsfromtheliquidbygravitysetting

processisreferredassedimentation.

Sedimentationofdiscreteparticles(I)

Separatepart

9 Settingtanksarecircular/rectangular.Particlessettleoutindividuality.Thedesignofsuchtanksarebasedonsettingvelocity.

Aparticlewillaccelerateverticallydownwardsuntilthedragforce

(FD)equalstoimpellingforce(F1).Thenparticlewillsettleata

constantvelocity.

Stokesvelocity(V2)

F1=(sw)V

s=densityofsolidparticles(Psg)

w=densityofsolidwater(Pwg)

V=Volumeofparticles

FD=CDAsPw

CD=Dragcolficient

=0.4forspheres.

As=spheresectionarea.

Vs=stokesvelocity

V=kinematicviscosity=

Sedimentationofflocculentparticles(I)

Flocculent:cloudlikeaggregations.

Flocculentparticlesarethoseparticlesthatarechemically(Addthechemical)

assistedtocometogether&producelargeparticle&settle.

5.2.2(Coagulation:

Iftheparticlesizerangeisbetter107to101mm,thenbecauseofsmall

size,thesuspendedmatterhasnegligiblevelocity.Tosettletheseparticles,we

usechemicalcoagulanttocollecttheparticlesinmass.

Coagulant:Aluminumsulphate,ferrous,sulphete&ferricchloride.

Whenalumisaddedtorawwater,thereactionis:

Al2(SO4)3.14H2O+3Ca(HCO3)2

Alumcalciumbicarbonate

PH=PotentialofHydrogen(VariesfromOto14)

=Itisthelogarithmofthereciprocalofhydrogenionconcentrationingram

atomsperlitre.

=7(Basic/alkalining)

FlocGelatinousparticle(Asmalljellyaggregatemassformed.)

Itthereisinsufficientalkalinityinwater,limeisaddedtowater.Thereaction

is:

Al2(SO4).14H2O+3Ca(OH)2

CalciumHydroxide

Then,thesmallparticlesattachedwiththeflockmass&producealarger

mass&itsettlesdown.

Solve.

Ex.11.3,11.4

5.2.3Filtrationistheprocessofpassingwaterthroughaporousmedium.,(ex

sandlayer).

Usuallysandfiltrationhasbeenusedfortheporousmedium.

Classificationoftitrationsystemare

9 Gravityorpressure9 Rapid/slowfiltration9 Depth/cakefiltration

Gravityfiltrationistheprocesswherewatergoesthroughfilteronly

bygravityforce.

PressurefiltersWaterisforcedthroughthefiltermediaunder

pressure.

Slow/rapidfiltration

Slow:filtrationrate(0.1to0.2m/hmeter)

Rapid:filtrationrate(5to20m/h)

Depthfiltrationiswheremostofthedepthofthefiltermediumis

activeinthefiltrationprocess.

SlowSandFilteration

Supernatantwater

Schmutzdecke

Sandfiltered

Inlet

Structure

Systemofunderdrain.

Waterenterthroughinletandflowerontheschmutzdeckelayer.

Thislayeriscomposedofliving&deadmicroorganisms.

TheSupernatantwaterprovidessufficientwatertodrivethrough

thesandfilter.

Thefilterbdisoffinesand(0.15to0.3mm)

Inshowsandfiltration

Totalcoliformbacteriaremoval(99.4%)

Removalofparticlewithsizes1to60r&m

Colourremovalisnotsignificant.

Turbiding(waterwithfineclay/mueldyparticles)removalis25%

Slowsandfiltrationfiltersabout26month.

RapidGravityFilters

InfluentWaterheadcoarsematerialFinesand

+++++++++++++++++++++++++++++++

Rapidgravityfiltersareusedtofilterchemicallycoagulatedwater&

producehighqualitydrinkingwater.

Biologicalactivityoccurinthebreakdownofammoniatonitrateas

innitrification:

NH4+2O2NO3+

AmmoniaBacteriaNitrate

2H++H2O

Filtrationoperateswithaheadofabout1mofwater.

Maintainsamefiltrationrate

Waterorcompressedairfrombottomissentupthroughbackwash.

(BackwashVelocity>0.3melm/min)

Waterisrecycledthroughtheplant.

Filtrationoperatedonhydraulicprinciple.

Vf=Vtxf4.5

Porosity

Terminalvelocitytowashmediumfrombed

5.2.4Disinfection

Itreferstooperationsusedtokillpathogenicmicroorganisms.

Sterilizationistheprocessforthecompletedestructionofallliving

matter.

Disinfectiondoesntindicatetosterilizationprocess.

90%ofbacteria&virusesareremovedbycoagulation&filtration

process.

Therateofdestructionofmicroorganismisalchemicalreaction

(chickslaw)

=kNt

solun

Nt=Nooforganismsattimet

No=

K=rateconstantofthetypeofdisinfectant,microorganism

Thecommonuseddisinfectantsare

9 Chlorinedioxide.9 Chloramines9 Ozone9 Ultravidetradiaction9 Chlorination.

1Makeashortnoteontheuse&effectofdifferentdisinfectants.

2Drawthelayoutofthewatertreatmentplant.

Nt=Noekt

*BrakpointChlorination:Duetothereactivityofchlorine,itreactswitha

multitudeofinorganic&organicmaterialspresentinwater.Insomecases,itis

usedasanoxidizingagentfirsttobreakdownthesematerials.Thistypeof

chlorinationiscalledbreakpointchlorination.Duetohighdosagesofchlorine

normallyemployed,thisprocedureisnolongerperformedinGermany,butstill

widelyusedinUS&othercountries.

:WasteWaterTreatment:

6.1Wastewatercharacteristics:

Wastewatersareeitherfromthesourcofindustrialwastewaterorfrom

municipalwastewater.

Componentsofwastewateraresuspendedsolids,biodegradableorganics,

andpathogens.

Suspendedsolidsareorganicinnature.ExBodywaste,foodwaste,paper&

biologicalcells.

Solubleorganicsinwastewaterareofproteins,carbohydratesandlipids.

Waterbornepathogensmaybefoundindomesticwastewater.

6.2wastewatertreatmentprocesses:

Domestic&industrialwastewatercontainmainlyorganicwaste.

So,themaintreatmentprocessesareusedtowardsorganicremoval.

Processare:

9 Pretreatment9 Primarytreatment9 Secondarytreatment9 Advancedtreatment

6.3Pretreatment:

Thefloatingdebrisdestinationproductofbuildingdebris&grit,&oilydictionaryscumsareremovedfromwaste

Vegetationprolentwater,inthepretreatmentprocess

Sometimes,thepHofwastewaterisinsucharangethatwateriseithertooacidicortooalkalineforoptimumbiologicaldegradation.ItneedpHcorrection.ThePHcorrectionisachievedbytheadditionofsulphuricacid(H2SO4)orlime.

6.3.1Screening

Theobjectiveofscreeningistoremovelargefloatingmaterial&soprotectdownstreammechanicalequipments.

9 Corasescreenwithopening(removelargematerial>6mm)

9 Finescreenswithopening(1.6mmto6mmmaterial)(Foractivatedsludge)

9 Veryfinescreenopening(0.2to1.5mm)9 Microscreenwithopening(0.001to0.3mm)

Fat,oil,greases

6.3.2Gritchannels

Gritisinorganicsandorgravelparticlesdofsizeabout1mm.

Theyarewashedintosewercollectionsystemsfromroad&pavement.

Gritdoesntexistinindustrialprocessofwastewater.

Gritcanabrademechanicalequipments.

Municipalwastewater

screens

Gritfacilities

FOG

flotation

BalancingpH,

Organic,nutrient

Primarytreatment

Gritcollectiondevicesare:

9 Helicalflowaeratedgritchamber9 Horizontalflowgritchannel.

Airentersonesideofchannelnearthebottom&thiscauseaspiralmotionIarto

themainflowdirection.

Airsupply

Grit

FigHelicalflowaerated

gritchannel

Heaviergritparticlessettlewhilethelighterorganicmatter

remaininsuspension.

Aeratedgritchambersaremoreefficientthanhorizontalflow

type.

Thedesignofgritchannelisbasedonsettingofparticle

F1=FD

(sw)V=CDAsfw

Sp=Specificgravityofparticiples

CD=dragcoefficient

=

V=Kinematicviscosity

=

Ex12.4Designahorizontalflowgritchambertoremovegritofsize

greaterthan0.2mmifthethroughflowis10,000M3/d.thespecific

gravityoftheparticlesis1.9.

Solution

Settingvelocity(Vs)=.( p w)d2

=x(1.91)x(0.2)2

=19.6mm/see

=0.02m/see

AssumeDepth(D)=1.5xwidth(w)

Vs=(Sp1)d2

C/sarea=A=WxD

=1.5w2

A===0.39m2

6.3.3 Flotation : Flotation is usedwhen suspended particles have low setting

velocitythattheyarenotsettleableinsedimentationtank.

Sedimentation, in watertreatment chapter, is the gravity unit process of

separatingsolidsfromliquids.

Flotationisthebuoyancyunitprocessofseparatingsolidparticlesfromaliquid

phase.

Inmunicipalwork,solidsarefats,oils&grases(FOG).

Theprocessof separation involves introducing air bubbles at thebottomof a

flotationtank.

+++++++++++++++++++++++++++++++++++

Fig:DissolvedAirFlotation

Airbubbleattacheswithparticulate(composedofdistunitparticles)dictionary)

matter&thecombinedbuoyancyhelpstheparticletorisetothesurface.Then,itis

removedbyskimming.Dictionary.

9 Gravityflotation9 VacuumMakeashortnote9 Electroflotation9 Dissolvedairflotation(DAF)9 Airflotation

6.3.4Equalization:Uniformity/balancing

Wastewater treatment plant receives the waste matter (effluent),

uniformity/balancingisrequiredforthat.

Thisincludes

9 Flowequalization9 Organicequalization9 Nutrientbalancing9 PHbalancing(PHcorrection)

(6.5to8.5)

Flowequalization/balancingoperates&balanced7days.

OverflowRawScreensstructureToprimaryWastewaterGritremovalsedimentation

EqualizationFlowcontrol

1 2 3A

3B 4

6.4PrimaryTreatment:

Primarytreatmentisoftencalledclarification,sedimentationorsetting.

Thewastewater isallowed tosettle foraperiod (about2hr) ina setting tank

andproduceclarifiedliquideffluentinonestream.

Therefore, the objective is to produce a suitable for the secondary biological

treatment&achieveasolidseparation.

Hence,theprimarytreatmentinclude

9 Reductioninsuspendedsolids9 ReductioninBOD9 Reductionintheamountofwasteactivatedsludge(WAS)9 Removaloffloatingmaterial.9 Partialequalizationofflowrates&organicload.

++++++++++++++++

FigC/sofatypicalcircularprimaryclarificationtank.

9 Wastewaterentersthroughthediffusionbox.Thetankissizedso,thattheretentiontime isabout2hr. inthisperiod,thesuspendedparticles

settledownassludge&liftupwardsthroughacentralhopper.

6.4.1Chemicallyenhancedprimarysedimentation

Theadditionofcoagulantchemicals

(iron,salts,lime,alum)

Beforesedimentationmakesthesuspendedfineparticlesintosettleableflocs.

This process increases. The efficiency of suspended solid & BOD removal

rates.

+++++++++++++++++++++++++++++++++++++++++++++++

Surfaceoverflowratem3/d/m2)

Asthesurfaceoverflowrateincreases,theremovalefficiencydecreases.

Themechanismofchemicallyenhancedprimarysedimentationistousean

aerationtank&addcoagulants.

6.4.2Sludgequantitiesfromprimarysetting:

Theamountofsludgeproducedduringprimarysettingwilldependonthe

totalsuspendedsolids&theefficiencyofsolidremoval.

6.5Secondarytreatment:

Inprimary settingprocess.About60%of suspended solids&30%ofBOD

removedfromwestwater.

Thepurposeofsecondarytreatment is toreducetheBODwhichdoesnot

benefitasmuchassuspendedsolidsfromprimarysetting.

Secondarytreatmentprocessproducesnonpollutingandproductsfromthe

(H2O,CO2,Sludge)Biodegradableorganicmatter:

Theendproductshouldntprovideafoodsourceforaerobicbacteria.

(Liquidefficient)

Theremovaloforganicmatterincludestheprocesses:

9 Biodegradation9 Airstripping:removalofcovering9 Adsorption

(accumulation ofmolecules particles to form a thin filmon surface of

water)

9 Activatedsludgesystem9 Attachedgrowthsystem

6.5.1Activatedsludgesystem

Thecommonactivatedsludgesystemsare

9 Completemixreactors.9 Plugflowreactors.9 Oxidationditch9 Contactstabilization9 Sequencingbatchreactors

CompleteMixReactors

Ithasuniformcharacteristicsthroughouttheentirereactor.

Aerationisprovidedbysurfaceaerators.

Dissolved oxygen (DO) levels are maintained throughout the process

(2mg/L).

Thereturnedactivatedsludge(RAS)fromtheclarifier is feddirectlytothe

aerationbasin

bacteriaOrganic+O2CO2+NH3+newbiomassOliodProcess

PlugFlowReactors

Plugflowmeansaplugofsubstrateinfluenttoanaerationbasinismoved

forward, without too much interaction with plug. This means satisfacting

mixingoccursinthelateraldirection,butnoneinlongitudinaldirection.

InfluentEffluent

Thereisahighorganicloadingattheinfluentendofthebasin.

Thereisanexcessoffoodsubstrateattheinfluentendshortageoffood

substrateatthedownstreamend.

Throughtheaerationbasinthefoodsubstrate.Decreaseswhilemicro

organismconcentrationincreases.

OxidationDitch

+++++++++++++

Plug

FigLayoutofanoxidationditchsystem.

ContactStabilization

Aerationiscarriedoutintwophasesintwodifferenttanks.

Influenteffluent

Sludgesludgewasterecycle,Aeratortank Incontact tank the suspendedorganicmatter isadsorbedby themicrobialmassand

thedissolvedorganicmatterisabsorbedbythebiomass.

Sequencingbatchreactors

Itisacomplexmixactivatedsludgesystemwithoutasecondaryclarifier.

Fivedifferentsequencesarefollowedwithinthesingleaerationbasin.

Aeration&clarificationarecarriedoutinonetank.

++++++++++++++++++++

6.5.2Attachedgrowthsystems(Writeashortnote)

Itallowamicrobiallayertogrowonthesurfaceofthemedia(stone,plastic)

Itexposedtotheatmospherefromwhereitdrawsitsoxygen.

Themicrobiallayerissprayedwiththewastewater.

Contacttank Clarifier

Inthisprocess,themicrobiallayerconventsthebiodegradeableorganicwastewaterto

biomass&byproducts.

Microbial:involving/causedbymicrobas

ThemicrobiallayerhelpstoreducetheBODofeffluents.

PercolatingFilters(TrickingFilters)

Thesearegenerallycylindricalorrectangularboxesofconcreteorsteel,containing

stonemedia.

Themediaisangularratherthanrounded(exlimestoneisabetterchoice).

Thefloorofthetankhasanunderdrainsystemforcollectingtheunderdrainsystemfor

collectingthetreatedwastewater.

Q.1Operationoftrickingfilterwithdiagram.

Factorsaffectingtheefficiencyofatrickingfilter.

Granularmediafiltration:

Themediamaynatural/syntheticmedia&filtertypeiseitherofpressureorgranting.

Adsorption:(Activatedcarbonadsorption)

OrganiccompoundmayberemovedbyPACorgranulatedactivatedurban(GAC).Powered.Chemicaltreatment:Inthisprocess,thePHofeffluentrisesto10.811.5,sothat

ammonia(wastewater)

Nitrogenconvertedtoammoniagas&itreleasedtoatmosphere.

++++++++++++++

6.6SecondaryClarification:

Theretentiontimeinsecondaryclarificatorisabout2hrssameasinprimaryclarification.Butitisprovidedwithadeepsettingtank.(about4.5m)Theaimisthatnosolidsshouldescapeintheclarifiedeffluent.

Thesolidsarebiologicalinnature.

(Biodegradableorganicmatter)

Itmayrequireoxygendemandfromwaterbodyforthedecomposition.

Theimportantparameterforsecondaryclarificationis

surfaceoverflowrate(SOR)=discharge

AreaofC/S

6.7AdvancedTreatmentProcess(Filtration)

9 Granularmediafiltration:Itcomposedofonetypeofgrains9 Adsorption(Sand/stoneek)9 Chemicaltreatment9 AirstrippingRemovalofammonia;9 Chlorinationwhenammonialevels

arehighineffluent

(wastewater)

6.8WastewaterDisinfection

Theobjectiveofdisinfectionistoeliminatepathogenicorganisms.

Thedisinfectionproducerforwastewaterare?

9 Chlorine9 Ozone

9 Chlorinedioxide9 Ultravidetradiation.

6.9Layoutofwastewatertreatmentplant

+++++++++++++++++++++

Figlayoutofatypicalwastewatersystemincludingfiltration.

:Anaerobicdigestion:

Processofdecomposingtheorganicmatter.

7.1Introduction:

Itisusedforthetreatmentofindustrial,agricultural&municipalwastewater.

Anaerobicdigestionistheuseofmicroorganismsforthestabilizationoforganic

(intheabsenceofoxygen)

matterstotheformofmethaneandotherinorganicproducts.

Organicmatter+H2OmicrobialCH4+CO2+

organism

New+NH3+H2S+HeatBiomassItoccursintheabsenceofoxygen.

Concentratedwastewatersledgesmayreactwithwastewater&hena,canproduce

badproductsorgasestotheenvironment.

Therefore,Ithastomakethesludgesasinertpriortodisposal.ThecommonNoreaction

withwaterorotherelements.Noreactionwithwaterorotherelements.

Processisbiologicaldegradation.Thisprocessconvertthesolidstononcellularend

products.(dictionary)Notdividedintocells

Theprocessiscommonlytermedassludgedigestion.

2 Sludgedigestionreducesthevolumeofthickensludgeaswellasmakesthe

remainingsolidasinert.

Aerobicdigestion

Anaerobicdigestion

Aerobes:Microorganismsrequireoxygenfortheirsurvival,arecalledaerobes.

Anaerobes:Othermicroorganismscantsurviveintheoxygenenvironment,areknown

asanaerobes.

3 Primarysludgecontainslargeamountsofavailableorganicsthatwouldinducearapidgrowthofbiomassiftreatedaerobically.(dictionary)totalmassoflivingmatter

4 Anaerobicdecompositionproduceslessamountofbiomasscomparedtoaerobicprocesses.

The aim of anaerobic digestion process is to convert as much as sludge to end

productssuchasliquids&gases;whileproducingalittleresidualbiomass.

7.2MicrobiologyofAnaerobicdigestion:

Fourdifferentmicrobiologicalgroups(bacteria)arerecognized.

9 Hydrolytic bacteria compound reacts with water & produce othercompound.

9 Acidogenicbacteriaformationofacid.9 AceticlasticMethanogens.9 HydrogenophilicMethanogens.

Proteincarbohydrates.Lipids.HydrolysisProcessHydrologicBacteria.

Acidogenicbacteria

Acidogonesisprocess

Aceticlastic

Complexwaste(sludge)

Aminoacid,sugar Faltyacid,alcohols.

IntermediateProducts.

AcetateH2,CO2

BacteriaHydrogenophilicMethanogens

7.3MethaneProclcetion:

Anaerobicsludgedigestiondividesintotwogroups,theacidformers&methane

formers.

Theinfluentsludgeentersthetankclosetothetopatthesupernatantlayer(purified

liquidlayer)

Thereisaactivitydigestingsludgelayerbelowtosupertentlayer.

Finallythedecomposed(digested)sludgestabilizedatthebottomoftank.

Gasreleased.

InfluentsludgeScam

Supernantreleased.

AActivitydigestingsludge.

Stabilizedsludge

Digestedsludge

ExC6H12O63CO2+3CH4

Methane,CO2

7.4Applicationofanaerobicdigestion:

Agriculturalwastewatertreatment

Industrial

Municipal

:AirPollution:Mancanhardlysurvivefor5minuteswithoutair.

However,hecansurvive5dayswithoutwater&for5weekswithoutfood.

Whenairgetspolluted,itcausesanumberofdiseasesinhumanbody(animals).

Hence,thepollutedairisharmfultoalltypesoflife(plant,animals).

8.1Airpollutants:

Thepollutedairgetscontactwiththenonlivingmaterials(metal,wood,stoneetc)&

corrosiveactionofpollutedairorduetothechemicalattackofairpollutants.

Primarypollutants

Sulphuroxides(SO2),carbonmonoxide(CO),Nitrogenoxides(NO&NO2),Lead(Pb),

hydrocarbons,allergicagents&radioactivesubstances,H2S,H2F,&methyl&ethyl

mercaptans.

Theprimarypollutantsreactwitheachother&withwatervapour&producesnew

pollutants,calledsecondarypollutants.

Secondarypollutantsareproducedfromhechemicalreactionsduetooxidationcaused

byenergyofsun.

Secondarypollutantsaremoreharmfulthantheoriginalprimarypollutants.

Thepollutantsare:

9 H2SO4(Sulpharicacid)

9 Ozone(O3)9 Formaldehydes(HCHO)orCH2O9 Peronyacylnitrate(PAN)(NOz)

1 Sulpherdioxide(SO2)

Itisanirritantgas&wheninhaled,itincreasesthebreathingrate&causesoxygen

deficitinthebody.

exPatientsofasthmaareaffectedbythispollutions.

SO2mayoxidizetoformSO3,whichwheninhaled,maydissolveinbodyfluidtoform

sulphuricacid(H2SO4).H2SO4isaverystrongcorrosiveacid.

SO3causesseverebranchspasm.(dictionary):difficultyinexhalationSO2originatesfromrefineries&chemicalplants,smeltingoperation&burningof

(dictionary):formationmetalsby

heating

fulls.ThermalpowerplantalsoemitsSO2.

ThequantityofSO2inairis0.03ppm

(SpecifiedAirStandard)*

*Contentationofpollutant(Unitofmeasurement)

9 Generallytheconcentrationofpollutantcanbeexpressedasmicrogramspercubismetre(g/m3)atatmospherictemp&pressure.

9 Iftheconcentrationisexpressedincum(m3)permillioncumofair,itiscalledasppm(partspermillion).

9 Therelationbetwnppm&g/m3is:1g/m3=

X103

Liter

Molmolecule

( /mol)VolumeinLiteroccupiedbyonemolecule.

2 Carbonmonoxide.(CO)

COhas200timesaffinitytowardsbloodhemoglobin(Hb)thanoxygen.

Wheninhaled,COreplacesO2fromhaemoglobin&formcarboxyhaemoglobin

(COH6).

Ithasnouseinrespiratoryprocess.Hence,helfofthebloodisused

Carbonmonoxideisresponsibleforheartattack.

SourcesCOoriginatesfromautomobileexhausts&incompletecombinationof

organicmatter.(dictionary):(Processinwhich

substancesreactswithoxygen.)

Incities,theconcentrationofCOis54ppm.

Specifiedstandard(9ppm).

3 OxidesofNitrogen(NO,NO2)

NitricoxideNitrogendioxide.

Eye&NasalirritationsarecausesbyNO2(whenconcentrationis15)

Respiratorydiscomfort(concentrationis25ppm)

Itoriginatesfromautomobileexhausts:(dictionary)Furnacesmokes

SpecifiedstandardforNO2is0.05ppm

4 HydrogenSulphide(H2S)

H2Sisafoulsmellinggaswithaodourofrottenegg.(dictionary)dirty(dictionary):Damaged/useless

Thisgascauseheadaches,sleeplessness&painineyes.

HigherconcentrationofH2Smayblockoxygentransfer&damagetonervetissues.

H2Sisrarelyfoundinatmosphere,therefore,Itisnotincludedintheairquality

standers.(Nospecifiedstandardconcentration)

Itisproducedinindustrieslikeoilrefinibg,rubber,artificial,silketc.

5 Methyl&EthyleMecaptans

Ethylmercaption:C2H3SH

Thesecompoundsarenotharmfultous.

Theyhavestrongodours.

6 HydrogenFluoride&OtherFluorides

Allfluoridecompoundsareextremelyirritantgas&corrosiveinnature.

Theirsmallerconcentrationmayproducesfluorosisincattle&plants

dictionaryapathologicalcondition.

Itisnotharmfultohumanbeings.

SourcesTheyareemittedintoatmospherefromaluminumplant,steelplant,

phosphatefrtiliserplantsetc&byburningofcoal.

Itsconcentrationincityairisveryless(around0.025ppm).Itisnotincludedinair

qualitystandard.

7 Lead(Pb)

SourcesItisejectedintotheatmospherethroughexhaustedofautomobile.(Gasemittedfromtheautomobileengine)Itmaycauseirritationofmucousmucousmembranesofnose,throat&lungs,

when(athinlayerinsideofnose&mouth&outsideofotherpartofbodyinhaledair.

ItmaydamagetoLiver,kidney&gastrointestinaltracts(systems).(dictionary)system.Specifiedstandardforleadinairqualitystandardis1.5g/m3

8 Hydrocarbons(Alkane,Alkene,Alkynes.)

Alkenesarehighlyreactiveinatmospherethroughphotochemicalrealn.

Itreactswithotherpollutantgases&formsnewpollutants.

SourcesHydrocarbonsreleasedtothetmospherebyautomobileexhausts&by

smokesofincinerators&fromOilrefineries.

Hydrocarbonsarefoundtocausebodycancers.

Formaldehydecauseirritationofeyes,skins&lungs.

Airqualitystandardis160g/m3(0.24ppm)

9 AllergicAgents

Microscopicsubstancesinairmaycauseallergicreactionsinhumanbodies,called

aeroallergens.(Physicalmatterofwhichthing/personconsist)

Sneezing,asthma,skintroublesareduetoallergicagents.

SourcesItOriginatesfromplants&animals.

Finallypoweredindustrialmaterialsmaycauseallergicreacnwithsensitivepersons.

Poweredlikematerialformseasonalplants.

10RadioactiveIsotopesexTitrium(H3) Carbon11,14,18

Radioactive emissions leads to anemia, cancers & shortening of life spans& geneticeffects.(Itsnuclicareunstable&itdisputeenergybyemittingradiationinthefromof,&rays)&accidentialdischargesfromatomic&nuclearreactors.

11Ozone(O3)

The presence of ozone gas in air may cause irritation in the respiratory (dictionary)tract.System.

itmaybeproducedbyphotochemicalprocess

Twopollutantsunittogetherinthepresenceofsunlight,producingathirdpollutant.

In day time, It is also produced by photochemical realn of hydrocarbons & nitrogenoxide.(inhighlymotorizedareas)vehicleused(dictionary)

Theairstandardforozoneis0.12ppm

Environmentprotectionagency

8.2Criteria&Noncriteriapollutants:

Criteriapollutantsare:

9 CO9 NO29 O39 SO29 Lead9 Particlematter(dia

Theratewilldiffer fromplacetoplace&fromtimetotime(daytoday)at thesameplace.

Lapserateataparticularplace&timeisdetermined

bysendingabarbonequippedwithathermometer&

aselfrecordingmechanism.

Ambientlapserate/Environmentallapserate

surrounding.

Whenaparcelofair,whichishotter&lighterthanthesurroundingair,isreleased,the

Emittedgases

ittendstoriseup

Untilitreachestoalevel,whereitsowntemperature&densitybecomesequaltothatofsurroundingair.

Therateofdecreaseoftemperaturemaybedifferentthanambientlapserate.ThisiscalledadiabaticLapserate.

Withouttheadditionoflossofheat

2000

Heightin

meter

500

5101520

To

EnvironmentalLapserate=

Theemittedgasiscalledplume.(Lapseratevsdisperstmot)pollution

EmittedplumeLoppingplumeLoftyplume

BehaveinNeutralplumefumigatingplume

airunderConingplumeTrappingplume

theseconditions.Fanningplume

8.3.2Impactsofwinds

Themovingairisknownaswind.

Themovementinairisduetounequaldistributionofatmospherictemn&pressureovertheearthssurface&alsobecauseofrotationofearth.

Thedirectionofwindisfromhighpressureareastolowpressurearea.

Quickerheating&coolingofearthcomparedtoseamaycauseflowofair.

9 Daytime(fromseatoland)9 Nighttime(fromlandtosea)

Thismayaffecttotheairpollutionproblemwindspeedismeasuredbyanemometer.

Thevelocityofwindatanyheightzis:

U=Uok

WhereU0=windspeedatheightZo

9 K=constforlargelapserate.=(averagevalue)

Thedirection&speedofwindwillinfluencethediffusionofpollutedgases.&emissionofparticulatesfromfactoriesorautomobiles.

unit

8.3.3Impactofpressure

High pressure systems (clear SR/, Light ward condition) cause a bad dispersion ofpollutants.

Lowpressuresystemsleadstogoodmixing&rapiddispersionofpollutions.

8.3.4Impactofmoister

The presence ofmoisture blocks& obstructs the solar radiation reaching to ground,whichaffecttheairquality.

Humidityleadstoformationofdog&increasesthecorrosiveactionofairpollutants.

Excessivemoisture inatmospherewill leadtorain,whichwillbehelpful in improvingthequalityofambientair.

Becauseitwashdownthepollutantstotheearth.

RemovedofatmosphericSO2throughraincauseproblemsduetoreactionofSO2withwater,formingH2SO4.

:Watertreatmentprocess:

Ex.11.3Determinethedailyrequirementofalum,Lime&polyelectrolytetocoagulateaflowof200L/S,ifthejartestindicatesthatqrtimumcoagulationoccurswhen1Litreof

waterisdosedwith3mlof10g/Lalumsolution,1.8mlof5g/Lsuspensionoflime&0.2mg/Lofpolyelectrolyte.

AnsCoagulantsaresometimesassistedwithfurtherchemicals,knownascoagulantaids.

Ex1Polyelectrolyte.

Limealkalinityaddition

PHcorrection:Lime,sulphuric,acid(H2SO4)Theamountofchemicalcoagulantpolyelectrolyterequiredforparticularrawwater

qualitycanbedeterminedusinglaboratoryJartest.

Electrolyte:Asolutionthatconductelectrolyte.

transmissionof

electricity

Polyelectrolyte:Aelectrolyteofhighmolecularweight.

Solution1min1hr

Dailyflowrate=200x60x60x24

=17.28x106L1day

Alumrequirement3mLof10g/L

=30mg/Lx17.28x106L

=518.4kg/day

Linerequirement1.8mLof5g/L

=9mg/Lx17.28x106L

=155.5kg/day

Polyelectrolyte=0.2mg/Lx17.28x106L

=3.46kg/day

Ex9.2S.K.Garg

The maximum daily demand at a water treatment/purification plant has been

estimatedas12millionlitresperday.Designthedimensionsofasuitablesedimentation

tank for the rawwater supplies, assumingadetensionperiodof6hrs& thevelocityof

flowas20cm/minute.(assumebasinwithinis10m)

Solution

GivenQuantityofwatertreatedin24hrs(daily)

=12x106liters

Quantityofwatertreatedduringdetentionperiod

=(x6)

=3x106litres

=3000cu.m(m3)

Thecapacityoftankrequired=3000m3

Givendata(Velocityofflowtobemaintainedthroughoutthetank)=20

=(0.2)

Lengthoftankrequired=(velocityofflow)xt

(Detentiontime(t)=)Lengthoftank

Velocityoftank

=0.2x6x60

=72matres

C/Sareaoftank=

=

=41.7m2

GivenBasinwidth=10m

Waterdepth==4.17

=4.2m

Ex9.6S.K.Garg

In a continuous flow setting tank 3m deep 60m long, what flow velocity of water

wouldyourecommendforeffectiveremovalof0.025mmparticlesat250C.thesp.Gravity

ofparticlesis2.65&kinematicvisocityvforwatermaybetakenas0.01cm2/see

SohtimVs=(Sp1)d2

SettingvelocitydiaofparticlesSp.gravityofparticlesKinematicviscoeity=v = ( s w)d2

So,

Kinematicviscocity

vs=x(2.651)(0.0025)2

vs=0.0562

Settingvelocity

InletAD

Depthof(=H)

water

sludgezone

Vs=(sp1)d2

V=flowvelocityinhorizontaldirect

Vs=settingvelocity

FromthevectordiagramfromAtoC,wecanwrite.

Flowvelocity

V=)xVs

=x0.0562

=1.35cm/see.

Derivationofstokeslaw:

Vs=(Sp1)

Kinematicvisocityofwater(m2/see)

Sp=Sp.Growthofparticle

F1F1=Impellingfor=densityofparticle

FDFD=Dragforcedensityofwater

Dragforceincreaseswithincreaseofvelocity,tillitbecomesequaltoeffectiveweightofparticlei.e.(V=Vs)

Effectiveweightofparticle(F1)

=TotalweightBuoyancy

=)ys)yw

VolumeVolumeofsperialparticle

=r3(VsVa)

Unitwt.ofwater

Unitweightofparticle

=(

Dragforce(FD)

(Areaofparticle)(r2)=CDAs.Pw.

CD=dragcolt.

=

=0.4(forsphericalparticles)

V=dynamicvisocityofwaterdensityinkg/m3(m2/see)

F1=FDVs=Vs=

WhereSp=V=*Dragforcereferstoforcesactingoppositetotherelativemotionofanyobjectmoving

withrespecttothesurroundingfluid.

:NoisePollution:

9.1Introduction:

(Sp1)

Noiseisdefinedasanunwantedsound.Theunwantedsoundproducesseveral

undesirableeffectsonourbodyhealth,therefore,itcanbecalledasapollutant.

Itinterfereswithonesactivitieslikework,rest,sleepetc.&producesundesirable

physiological&psychologicaleffectsinbody.

Itismainlyinhighlyindustrializedcountries,characterizedbyhighvolumeoftraffic;&

sportingactivities&lowflyingaireaftetc.

Itreducesthequalityoflife&causesasignificanthealthhazard.

Ex1)Peoplelivingadjacenttobusyroadtendtohavehigherbloodpressure.

2)Highnoiselevelsofsufficientdurationcanresulttemporary/permanenthearingloss.

3)Irritation,headacheetc.

9.2Physicalpropertiesofsound:

Soundisproducedintheenvironmentbyalternatingpressurechangesintheair

becauseofvibrationsofsolidobjects.orseparationoffluids.

Alternatingpressurevariationproducessoundwaveswhichpropagateintheformof

sinusoidalwavepattern/cosinewavepattern.

T

A

(+ve)

SoundPressure

(ve)T

A=Amplitude

T=Wavelength=Distmabetwntwosuccessivecrests.

Timeperiod:Thetimerequiredforacompleterotationoscillation

Frequency:Thenoofcompletedcyclesperunittime.

Mostsoundsarenotpurelysinusoided.Theyvarybothinfrequency&magnitude.

Soundpressure(Prms)

Rootmeansqure.

=(P2)=1/2

(P=pressureateachinstantoftime.)

Soundpower&intensity

Therateatwhichenergyistransmittedbysoundwavesiscalledthesoundpower(W)

measuredinwatt.

Theaveragesoundpowerperunitareanormaltothedirectionofpropagationofa

soundwaveistermedthesoundintensity.

I=Wetts/m2metre.

I=soundintensity/acousticintensityatadistancerfromthesoundwave.

9.3Noisecriteria:

Loudnessofasoundisdeterminedbyitssoundpressurelevel&frequency.

9.4Noisestandard:(x)

Soundpowerisindifferentrange.

Deeibel:Soundpowerlevelismeasuredindecibel(db).Itisthereferencepowerlevel;

1012watts(db).

Soundpower(watts)

Soundpowerlevelindb

9.5 Noisemeasurement:

Soundpowercantbemeasureddirectly,whereassoundintensitycanbemeasured

withmoderninstrumentation.

9 Soundlevelmeter.(Readthe

Lw=10log10

9.6Noisecontrol:

Whennoiselevelisexcessive,thesolutioninvolvesthreesteps.

(a) SourceSourcecouldbemodifiedbythetreatmenttomachinesurfaces.

(b) TransmissionpathCouldbemodifiedbycontainingthesource(machine)insidea

soundinsulatorandbyconstructinganoisebarrio(absorbingmaterial)

(c) ReceiverProtectionofthereceiver(ear)byprovidingearprotection.

Soundprotectioninbuilding

Externalsoundwillenterabuildingthroughtheweakesttransmissionpath.(maybewindow)Whensoundpressurewavemeetawall/buildingsurface,thebuildingvibrates&

soundisradiatedbuckintospace.

Partofsoundenergyisreflected,partisabsorbedbysurface&remainderis

transmitted.

Vibrationwillbelargeratthenaturalfromofelement(will/building).

Naturalfromdependsonweight,surfacearea&rigidityofbuildingelement.

Soundreductionisbetterforhighernaturalfrequency

:10.SolidWasteManagement:

10.1Introduction:

Solidwastesincludepaper,plastics,glass,foodwaste,ashetc.italsoinclude

paints,oldmedicines,etc.liquidwates

Fromhealthpointofview,solidwastesare

9 Humanpathogens(exHandkerchiefs,contaminatedfood&surgicaldressing)

9 Animalpathogens(exWastefrompets)9 Soilpathogens(exGardenwaste)

10.2Sources&classification

Solidwaste/municipalsolidwasteiscollectedfromdomestic,commercial&industrial

sources.

SourceTypesofwaste

Domestic(Singlefamilyhouse,Food,paper,packaging,glass

MultiFamilyhouse.Low,medicinemetal,ashes.

&highriseapartments)otherhouseholdwaste

Commercial(shop,restaurants,Types

Markets,office,Food,paper,

Buildings,hotelsPackaging,glass,

&institutions)metals,ashes.

(sameasdomestic)

Industrial(Fabrication,Types

Manufacturing,refineries,Industrial,process

chemicalplants,miningwastes,oil,metal,plasticsetc.

Construction&demolition.Soil,concrete,

(destruction)timber,steel,

Plastics,glass.

10.3CompositionofMSW:

Municipalsolidwaste.

Thebasicideaistoidentifywasteasbeingorganicornonorganic(Inorganic).

Organic:Food,vegetables,paper,

Cardboard,plastics,

Clothing,gardenwaste,

Wood,bone.

Inorganic:Metals,glassash,

Stone,brick,etc.

WHO(Worldhealthorganization,1991)

Categorytheindustrialwasteintothreetypes:

9 Nonhazardousindustrialwaste.9 Hazardouswaste.9 Hospitalwaste.

10.4PropertiesofMSN:

Wastehandlersneednttoknowthephysical,

Chemical&biologicalpropertiesofsolidwaste.

Forproperwastemanagement(disposal,transformation,reuse&recycling),wehavetoknowthephysical,chemical&biologicalpropertiesofsolidwaste.

Physicalpropertiesare:

9 Density&moisturecontent(kg/m3)9 Particlesizedistribution.(mm)

(LxBxH)9 Fieldcapacity(%)metre9 Hydraulicconductivity(m/day)9 Shearstrength(KN/m2)

Fieldcapacityisthemaximumpercentageofvolumetricsoilmoisturethatasoilsamplewillholdfreelyagainstgravity.

Density&moisturecontentofMSWisabout20040kg/m3&is1sto40%forthecompaction(density)(moisture)

Ofsoildswasteinlandfill.

Hydrauliccontectingistherateofmovementofwaterintosoil.Sludgeresiststhemovementofwarterdownthroughthesolidwaste.

Densewaste:7x106m/s/Loosewaste:15x1015M/S

Filedcapacity=0.60.55

W=Overburdenweightofsolidwasteinlift.

ShearstrengthofsludgeinLandfillisaboutzero.

Hardness:isdefinedastheconcentrationofmultivalentmetalliccationsInsolution.

Organics:Thesearecarboncompoundproducts.

Biodegradableorganic

Nonbiodegradableorganic

Biodegradableorganic:Materialscanbecetilizedforfoodbynaturallyoccurringmicroorganizations.Thesematerialsconsistsofstarches,facts,proteins,alcohols,acidetc.

NonbiodegradableOrganics:Someorganicmaterialshavetheresistanttobiologicaldegradation.

Aeration:Itisaprocessusedinpreparingthepotablewater.

(drinking)

9 ItmaybeusedtoremoveundesirablegasesdissolvedinwaterBiochemicalprocess:Thesechemicalreactionsarenotspontaneousbutrequireexternalsourceofenergyforinitiation.

Turbidity:isameasureoftheextenttowhichLightiseitherabsorbedorscatteredbysuspendedmaterialinwater.

Itisnotaquantitativemeasurementofsuspendedmaterial.

Sp.Gravity:Thedensityofasubstmee/particlerelativetothedensityofwater.

Effluent:Watermixedwithwastematter

Viscocity:Resistanceofliquidtoshearforceinflow.

PH:Potentialofhydrogen(Logarithmofthereciprocalofhydrogenionconcentrationingmatomsperlitre).

Diffusion:themovementofasubstancefromanareaofhighconcentrationofthatsubstancetoanareaoflowerconcentration.Sludge:theprecipateproducedbysewagetreatment.

Sewage:wastemattercarriedawayinsewers

Decant:Causetoflowoutfromacontainer.

.4 PropertiesofMSW:MostoftheMSWwasdumpedsoitnotnecessarytofindthechemicalproperties.Sincerecycle,reuse&transformationtechnologyfollowed,wearedeterminingthechemicalpropertiesof

MSW.ChemicalPropertiesTechnology/Analysisprocessusedtofindthechemicalpropertiesas:

9 Proximateanalysis9 Ultimate9 Energycontent.

Proximateanalysisinclude

(a) Moisturecontentbypercentageweight(b) Voletinematter(c) Fixedcarbon(d) Noncombustiblefraction(ash).

Theenergycontentisbasedinheatvalue.

Heatenergyproduced,itthe

Solidwasteisburnt

(Joule/kg)/orMI/kg

(Hu)=(HawfxB2.445xw)

Easilyburning

B=Flammablefraction.(%)

(Volatilematter+fixedcarbon)

W=moisturecontentfractionbyweight(%)

Ultimateanalysisisfollowedtoknowtheenergyproducedbycombustionorbiologicaltransformationofsolidwaste.

1)

(Dulongequation)

WhereC,

Ultimateanalysisincludethe%oftheaboveelement.

2) Khanetal(1991)

E=0.051

Energycontentin F=%offrombyweightCP=%ofcarboard&paperbyweight.

PLR=%ofplastic&rubberbyweight.

BiologicalpropertiesDuetoaerobic/anerobicdigestion,solidwasteistransformedintoenergy&otherendproducts.

Anerobicdigestionprocessisresponsibleforthedecompositionoffoodwastestoendproductmethane,Thesolidwaterrelatedtobiodegradation.AreOil,fat,proteins,celluloseetc.Therefore,thebiodegradationoffoodfractionofMSWisdeterminedby

Lignincontent(%)Biodegradationfractionexpressedonavolatilesolidbasic.

LCLignincontent(dryweight)ofVolatilesolid.

LigninAcomplexpolymerconstituteofwood

otherthancarbohydrate.

BF=0.830.028LC

VolatileSubstancethatchangesreadilyfromsolid/liquidto

vapouratnormaltemperature.

Dispose:toarrangethings/orpeopleinaparticularway/position.

Disposal:theactofgettingridof5th.

tobefreeofsb/thing

thathasbeenannoyingyou

haulier:aperson/companywhosebusinessistransportinggoodsbyroads/railways.

10.5 Separation:

Separationofdifferentfractionofwastefromthetotalsolidwastecanbedoneatsource(household/orindustry)oratfinaldestination.

Basedonseparation,thetotalMSWisdividedinto:

9 Wastesthataredesirablyseparatedatsource9 Allotherhouseholdwaste.

Wastesthataredesirableseparatedatsource

(sourceseparation)

9 Foodwaste9 Paper&cardboard9 Plasticaverythickpaper9 Metals9 Glass.

Otherhouseholdwastesare

9 Bulkywaste(tyres,furnitureetc)9 Hazardoushouseholdwaste.9 Yardwaste.

Anareaoutsideabuilding(withasurroundingwell)

10.6) Storage&transportofMSW:

Differenttypes&sizesofstoragecontainersareusedforMSW.

Therangeforsizevaryfrom25Lcapacityto40000litre.

Forapartmentbuilding,thesizeofcontainerisfrom600to1000Litre.

Thetypesofstoragedependonthecollectionfacility.

9 Haulierforbulkyitems.aperson/companywhosebusinessistransportinggoodsbyroad/railways.

9 Doorstepcollection(areaveryclosetodoor.)

9 Regularkerbcollection(sideofroad)

9 Vacuumtrucketc.(emptyspace)

Typesofstoragesareplasticbag,wheeled,bin,vaccum,truck,paperbagetc.

(alargecontainerwithacover/aid)

10.7) MSWManagement:

Thetechnologiesusedfortreatment&disposalofMSWare:

9 Wasteminimization9 Reuse&recycling9 Biologicaltreatment9 Thermaltreatment(combination/incineraton)9 Landfiling

10.8) Wasteminimization:

Itfollowsthereductioninamountofsolidwastegeneratedatsources.

Examplesofsourcesare:

1 Productionunitsforfood&householdproducts.(Industry)

2 Productionunitsforcommercialproducts.3 Shoppingoutlets(Businessplace)4 Households5 Office,institutes&commercialproperties.

10.9) Reuse&Recycling:

Aluminiumcansareconsideredforrecyclingpurpose.

(dictionary)container

Paper&cardboardareusedasarecyclingsolidwastematerial.

Glasswaswellrecycled.

Exdifferenttypesofbottles.

Plasticsaremostlynonbiodegradable.

Hence,itisundesirableinlandfilling.

Therefore,plasticsarerecycled.

Yardwaste,organicfoodfractionetc.

10.10)BiologicalTreatment:

9 AerobicorcompostingItisanaerobicprocessWhichdecomposetheorganic

foodwaste.9 AnaerobicorBiogas9 Combinedanaerobivc&aerobic

1 Compostingisanaerobicprocesswheremicroorganismsdecomposetheorganicfoodwasteinanoxygenenvironment.

aerobicbacteria

Organicmatter+O2Newcells+CO2+H2O+NH2+SO4

Thefinalproduct(compost)consistsofminerals&complexorganicmaterial.

Therequiredparametersforthecompostingprocessare:

9 Temperature*9 Moisturecontent(%)9 Oxygen(%ofoxygen)9 (range68)9 Biochemicalcomposition

(Itinfluencestheprocessrate)

2 Anaerobicdigestion(Absenceofoxygen)

Organicmatter+H2ONewcells+CO2+CH4+NH3+H2S

anaerobicbacteria

ThebeneficialendproductistheCH4(methane).

ThisprocessdecomposethefoodwastetoCH4.

3 Combinedanaerobic&aerobicprocess

Anaerobicdigestionfollowedbyinvesselaerobiccomposting.

(1stprocess) (2ndprocess)

10.11)ThermalTreatment:

Thermaldegradationoforganicmaterialcanbecarriedoutwith/withoutoxygen.

Thermaldegradationwithexcessoxygeniscalledcombustion.

Whenthefuelisawaste,thethermaldegradationprocessiscalledincineration.

IncinerationOrganicmaterialisconvertedintoheatenergy,gas,slag.

10.12)Landfill:

*Aschematic(Layout)oflandfillprocess.

:11HazardousWasteTreatment:

11.1) Hazardouswaste&itsgeneration:

Hazardouswastemeans

9 Itcausesfire(Ignitable)9 Itreactswithother(reactive)9 Itdestroy/corrodeother(corrosive)

Tissue/material9 Solidwasteisdangertohealth.(toxic)

Itpollutewater,food&air

Itmaybemedicalhazardouswaste.

orhouseholdhazardouswasteorfromindustry.

Examples

Copper(Cu),Zine(Zn),Lead(Pb)&

Mercury(Hg)etc.

Lubricatingoil,drillingoil,syntheticoil

NO2,Organics,hydrocarbons,etc.

TaskWriteexamplesofhazard/solidwastesfrommedical/household/industry.

11.2 TreatmentforHazardousWaste:

*Incineration

Hazardouswastecanbemanaged/treatedbyincineration/Landfillingprocess.

Intheincinerator,thewasteisoxidizedinanoxygenrichenvironmentatelevatedtemperature.

Themostimportantcriteriaforhazardouswasteincineratorsisthecompletedestructionofthemajorhazardouscompounds.

Thecombustionefficiency(CE)iscalculatedas:

Where

Incinerationisacontrolledhightempratureoxidationofprimarilyorganiccompoundtoproducecarbondioxide&water.

OrganicwasteIncinerationCO2+H2O+Byprotein

Thenetheatvalue(NHV)forwasteinincinerationprocessis

NHV=1.25(T15)x

[1+0.268(NHV+EA)]

WhereT=(therequiredtemperatureforincineration,OC)

=15+

EA=Heatcapacityofexcesssirof1.25KJ/Kg.OC

Duringincineration,heattransferoccurredbyconduction,convection& radiation.(lowtempn)

at(hightempn)

Energyspreadsintheformofwaverays.

Convection:transferofheat Conduction:transmissionofheat

throughfluid(liquid&gas)(transferfromonemediumtoanothermedium.)

Typesofincinerators

Incineratortypedependsonageofstructure&economics.

9 Rotarykiln9 Liquidinjectionfor(liquidorganicwaste)9 Plasmaarcelectricalconductionthroughagas9 Wetairoxidation9 Fluidizedbed.

Theuseofanelectricalarcforwastetreatmentgenerallyitisusedwithinchemical&metallurgicalindustryastooltoprovidehightemperature.(280000C)

Wetoxidationisanaqueousphaseoxidationwhereorganic&inorganicmaterialssuspendedordissolvedinwateeareexposedtooxygen/(gaseoussource).

11.3) Handlingoftreatmentplantresidences:

Residuefromincineratorare:

9 Slagfromrotarykiln9 Dustfromheatboiler9 Reactionendproducts

Residuefrominorganicplantare:

9 Filtercakes9 Wastewater

Theabovewastesrequirefurthertreatment.

*Securelandgfill*Stabilization(solidification)

SecureLandfill

Securelandfillarethedisposalsitesforfiltercakes,slag,dustfromafulltreatmentfacility(treatmentplant).

ThedesignofasecurelandfillissimilartothatMSWlandfill.

9 SiteLocation9 Designoflandfill9 Constructionoflandfill9 Operation

Stabilization(Solidification)

WhenhazardoussolidwasteisnottreatedbyLandfillingprocess,stabilizationisthenextchoiceforfurthertreatment.

Allingredientsaremixedinacontinuousmixter

Wasteacid

Batchreacts

SolidationPlant

11.2 Treatmentforhazardouswaste(Continued)

1 RotaryKiln

Rotarykilnisusedinthecement,lime,clay,iron,coal&phosphateindustry.

Traditionalcementkilnsarenowchoosenashazardouswasteincinerators.

Rotarykilnprovidetheprocessesforincineration

9 Mixingofsolids9 Containmentofheatforheatexchange.(cantspread)/topreventaccidentalrecycle

ofradioactivematerial.

9 Chemicalreaction

Blastfurnaceash

WasteSolid(or)

sladgeCement Water

Contineousmixer

Rotarykilnsarecapabletotreatbulksolids,sledges,liquidsetc.

2 Liquidinjectionincineration

ItisusuallyusedtoidealLiquidwastestreamscontainingminor

concentrationoforganiccontaminants.makesimpure

(substancethatcontaminates)

InLiquidinjectionincinerator,thewastedontcontainthenecessaryheatvaluetosustainitsowncombustion.

10.12MSWLandfill:

ThetraditionalmethodofdisposingofMSWisLandfill.

ThedesignofLandfill&secureLandfillsaresimilarinnature.

ParameterfordesignofLandfilltosatisfyimpermeabilityinmaterial(generallyconcock).

&topreventleahate(PenetrationofLiquidthroughthematerial).

LandfillDesign:

1) Foundationdesign2) Linerdesign(Toavoidseepageofleachete.)

Aprotectingcoverthatconstructsinsideoflandfilltoprotectthesurface.

3) Leachatecollection&gascollection.(Lechate&Landfillgasisreleased)

4) Drainagedesign5) Fillingdesign6) Runoffcollectionsurfacewelfer7) Closuredesign

ReactionsInLandfill

Gascollection

(Liquidwaste)

Leachateisthecontaminatedwaterinlandfill,whichproductsthroughexternalprecipitation.

(makeharmful/impure)

LandfillOperation:

wasteitems,Loads,typeetc.

(solid,liquid)

(organic/inorganic)

Cell/compartmentforhazardouswaste.

Cell/compartmentfornonhazardouswaste.

Landfilltypes:

Landfillsaretwotypes1)Attentuate&dispersesites.

tomake5thweaker.

2)Containmentsites.Attenuate&dispersesites

Leachatedisperses/spreadsthrough

OldPores&fissuresintotheunderlyingsaturatedzone.Type

Newlandfillsarecontainmentsites.Leachate&Landfillgasarecollectedwithspecialdesignprocedure,whichisisolatedfromthesurroundingenvironment.

Leachatecollection

Lechatetreatment

:EnvironmentalImpactAssessment:

12.1Introduction:

EIAisaprocessthatrequiresenvironmental&publicparticipationinthedecisionmakingprocess

ofprojectdevelopment.

EIAincludesthefollowingprocedures:

9 Screening(Todecidewhichprojectshouldbesubjecttoenvironmentassessment.)

9 Scoping(Issuesshouldbeincludedinenvironmentalassessment)9 EISpreparation(Scientific&objectiveanalysisofpreparationof

documentation.)

Environmental1ReviewMethodsdevelopedImpactstatementtoassiststhetask.

Defuissurveyistobetakenbyagovernmentorganization/agency.Thereviewpanelguidesthestudy&thenadvicesthedecisionmakers.

Wetairoxidation:(continuingfrompreviouspages)Air/oxygen

(coolingwater)

Heatexchanger.

Thetemperatureofoperationisfrom150to3250C&operationalpressureisfrom2000

kpato20,000kpa

Theprocessisitcarriesinabatchreactor.

Batchreactor:Itconsistsofatankwithmovingorshakingfacility&auditionedheating&

coolingsystem.Avarietyofoperationsuchasmixing,dissolution.chemicalreach&crystulization

canbedoneinsidethebatchreactor.

Due tohighpressure&high temperature, the constructionmaterial of reactor.Must

havetheresistancetowardscorrosiveactionofhazardoceswaste.

An extentwaterbased cooling system is provided. If thewaste is in suspension, it is

directlypumpedintothereactor.

Duringtreatmentinahorizontalreactor,oxygen/airareinjectedatcertainpositioninto

thereactor.Acontinuousoxidationtakesplace&majorityoftheorganiccompoundsareoxidized.

FluidizedBedCombustion:Consistsof

9 Airfluidizationsystem9 Bedmaterial9 Fluidizedbedvessel9 Wastefeedsystem9 Fluegascleaningequipment.