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Dr. Uday G. Kelkar, P.E., BCEE

Director India Operations

NJS Consultants Co. Ltd., Japan

Energy footprints of Wastewater / Energy footprints of Wastewater / reuse and recycle:reuse and recycle:

Challenges and OptionsChallenges and Options

Regional WorkshopEnergy and Resource Efficiency in Urban Water

Management20th December 2013

Unit Operations in Wastewater TreatmentUnit Operations in Wastewater TreatmentBiological

Aerobic Process

Anaerobic Process

Suspended Growth

Attached Growth

Activated

Sludge

(ASP)

CSTR, Plug flow, Sequencing Batch reactor,

oxidation ditch, Orbal, Biolac, Cyclic ASP,

Extended Aeration, aerobic/aerated lagoons

Trickling Filter and Trickling

filter with solids contact

system

Submerged Attached Growth

Rotating Biological

Contactors (RBC)

ASP with fixed film packing

Down flow attached growth process, upflow

submerged attached growth, fluidized bed

bioreactor, membrane separation aerobic process

Suspended Growth

Attached Growth

Anaerobic contact process, anaerobic sludge

blanket process-UASB, anaerobic baffled

reactor system,

Up-flow packed bed attached growth, and

expended bed reactors, anaerobic fluidized

bed reactors, anaerobic lagoons, membrane

separation anaerobic process

Combination of aerobic and anaerobic process are used in tertiary treatment for the removal of nitrogen and phosphorus from the wastewater

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Conventional Activated Sludge

ActivatedActivatedSludgeSludge

SecondarySecondaryClarifier Clarifier

SandSandFilter Filter

PrimaryPrimaryClarifierClarifier

SludgeSludgeDigestionDigestion To SludgeTo Sludge

Dewatering Dewatering

ActivatedActivated

SludgeSludge

To Sludge Dewatering To Sludge Dewatering

Membrane Bioreactor Process

Technologies and ConfigurationsTechnologies and Configurations

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� Implementation of more stringent effluent requirements, including enhanced removal of nutrients and other emerging contaminants of concern that may, in some cases, lead to the use of more energy intensive technologies.

� Enhanced treatment of bio-solids including drying/pelletizing.

� Aging wastewater collection systems that result in additional inflow and infiltration, leading to higher pumping and treatment costs.

� Increase in electricity rates.

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Integrated Processes forIntegrated Processes forNutrient RemovalNutrient Removal

Integrated Processes forIntegrated Processes forNutrient RemovalNutrient Removal

NitrogenRemoval

Nitrogen & Phosphorus

Removal

PhosphorusRemoval

SuspendedGrowth

Attached GrowthSingle Sludge

Suspended Growth

Single Sludge(Multi-Phased)

Multiple Sludge(Multi-Zoned)

Multiple Sludge

AlternatingAeration

SBR

BiodenitroTM

Single Sludge(Multi-Staged)

Two-Stage Four-Stage

ModifiedWuhrman

ModifiedLudzackEttinger

BardenphoTM

CarrouselTM

SchreiberTM

OrbalTM

Dual Sludge

TripleSludge

ImmobilizedCells Fluidized

Bed StationaryBed

MovingBed

Single Sludge(Multi-Phased)

Single Sludge(Multi-Staged)

Single Sludge(Sidestream)

SBR

PhaseIsolationDitches

Three Stage Five-StageBardenphoTM

A2/OTM

UCT

VIP

OrbalTM

Phostrip IITM

SBR PhostripTM

A/OTMChemical

Precipitation

OWASA

Biological treatmentBiological treatment

An

A2O process• Simple & proven

• NO3 in RAS

reduces

P removal

• Only one internal

recycle

UCT process• Proven

• No NO3 to

anaerobic

zone, better P

removal

• Two internal

recycles

OxAx

An OxAxPumped

Pumped Pumped

Pumped

Pumped

An?

Ax?

Ox?

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Nutrient removal is:Nutrient removal is:ENVIRONMENTAL ENVIRONMENTAL MANIPULATION OF THE MANIPULATION OF THE BIOMASSBIOMASS

ZONE DISSOLVED

OXYGEN

NITRATE

OXYGEN

Aerobic Yes Possibly

Anoxic No Yes

Anaerobic No No

What is anaerobic, anoxic and oxic?What is anaerobic, anoxic and oxic?

��An: Anaerobic : DO < 0, NO3 absentAn: Anaerobic : DO < 0, NO3 absent

�� P accumulation organisms (PAOs) grow P accumulation organisms (PAOs) grow only under strictly anaerobic conditiononly under strictly anaerobic condition

�� NO3 removal prior to anaerobic tank NO3 removal prior to anaerobic tank improves P removal as improves P removal as rbCODrbCOD is made is made available to available to PAOsPAOs

��Ax: Anoxic : DO between 0 to 0.2, max Ax: Anoxic : DO between 0 to 0.2, max 0.50.5

�� High DO inhibits growth of High DO inhibits growth of denitrifyersdenitrifyers

��Ox: DO > 0.5Ox: DO > 0.5

�� DO > 1 recommended for nitrificationDO > 1 recommended for nitrification

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Optimization ChallengeOptimization Challenge

Solids

Volume

Reduction

Process

Optimization

Resource

Recovery

Energy

Management

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�� Energy Conservation measures for PumpingEnergy Conservation measures for Pumping

�� Pumping designs, VFD application, motors and Pumping designs, VFD application, motors and efficient pumpsefficient pumps

�� Design and Control of Aeration SystemDesign and Control of Aeration System

�� design of aeration systems and automated aeration design of aeration systems and automated aeration control, control, conventional conventional control based on dissolved control based on dissolved oxygen (DO) measurements and emerging oxygen (DO) measurements and emerging control control strategiesstrategies. Innovative and emerging technologies for . Innovative and emerging technologies for automated control of biological automated control of biological nitrogennitrogen

�� Blower and Diffuser TechnologyBlower and Diffuser Technology

�� blower and diffuser blower and diffuser equipment, blower equipment, blower types such types such as as singlesingle‐‐stage stage centrifugal, highcentrifugal, high‐‐speed turbo, and screw speed turbo, and screw compressors, new diffuser compressors, new diffuser technology, material of technology, material of cover, strip v/s disc vs tubular cover, strip v/s disc vs tubular –– retrievable v/s nonretrievable v/s non--retrievableretrievable

�� Adaption of new disinfectants Adaption of new disinfectants

�� Chlorine v/s UV Chlorine v/s UV disinfeactiondisinfeaction

�� Adapt an innovative energy management system Adapt an innovative energy management system

�� Develop energy management Develop energy management –– conduct routine conduct routine energy optimization exercise energy optimization exercise

nnPlanPlan-- Do Do –– Check Check -- ActAct

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WERF 2012

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Energy Efficiency and Energy Efficiency and ConservationConservation

AnammoxAnammox –– the next the next BIGBIG thing!!thing!!

Carbon

N2

NO2-

Carbon

NO3-

O2

NO2-

O2

NH4+ NH4

+

NO2-

O2

N2

� 63% reduction in oxygen

� No supplemental carbon for denitrification

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12

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Electricity through Microbial Fuel Cell Electricity through Microbial Fuel Cell

�� AllAll biologicalbiological sludgesludge producedproduced inin wastewaterwastewater treatmenttreatmentshouldshould bebe anaerobicallyanaerobically digesteddigested forfor methanemethaneproductionproduction..

�� TheThe optionoption ofof thermophilicthermophilic digestiondigestion shouldshould bebe triedtried ononthethe pilotpilot scalescale inin IndiaIndia.. IfIf thethe pilotpilot programprogram isis successful,successful,fullfull scalescale plantsplants ofof thisthis typetype maymay bebe consideredconsidered..

�� TheThe methanemethane gasgas generatedgenerated fromfrom sludgesludge digestiondigestionshouldshould bebe convertedconverted toto electricityelectricity usingusing gasgas enginesengines..UseUse ofof dualdual--fuelfuel enginesengines isis discourageddiscouraged asas suchsuch unitsunitshavehave beenbeen provenproven toto bebe uneconomicaluneconomical..

Sludge Management Sludge Management

Conceptual Plan for Integrated Sludge Management

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Fuel Materials Generated in Fuel Materials Generated in BiosolidsBiosolidsGasificationGasification

Summary of Energy Recovery Summary of Energy Recovery Potential using Established Potential using Established TechnologiesTechnologies

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Wastewater Treatment Industry Wastewater Treatment Industry ––Main TrendsMain Trends

Environmental

awareness

Regulation

(Nutrients & odors)

Energy costs

Sludge disposal costs

Chemicals costs

Fresh water price

Fresh water availability

Available land for wastewater treatment plants

Infrastructure quality (aging)

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Resource SustainabilityResource Sustainability

Fresh Water Recycled Water

– Source Availability and location – Captive Resource

– Allocation (reservations for

various Applications)

– No issues with Allocations

– Interstate Disputes – No Interstate Disputes

– Increased O&M – Theft,

pipeline management

– Reduced O&M, Short

distances,

– Higher Cost to Industries – Lower Cost to Industries

Trends in Water Cost Trends in Water Cost -- IndiaIndia

0

5

10

15

20

25

30

35

40

45

1995 2000 2005 2010 2015

Year

La

nd

ed

Co

st o

f w

ate

r to

Uti

lity

(R

s p

er

kL

)

Chennai

Delhi

Hyderabad

Bangalore

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Recycle and ReuseRecycle and Reuse-- Balancing ActBalancing Act

Irrigation

Secondary Treatment

Restricted Urban Reuse

Tertiary Filtration

Industrial Non-Potable Reuse

Indirect Potable Reuse

Direct Potable or High Quality Process

Tertiary membrane Filtration

N&P Control

RO & Disinfection

Water Sources for Bangalore City

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� GoK has allocated 600 cusec or 17 Cumecs (1469 Mld) of raw water from Cauvery River to BWSSB, with CWSS Stage IV - Phase I commissioning, raw water drawl is about 929 Mld

� Balance raw water available is about 540 Mld

� Raw Water (Mld) from Cauvery river

Stage I ( 1974) : 150

Stage II ( 1982) : 150

Stage III ( 1994-95) : 314

Stage IV Phase I (2002) : 315

Stage IV Phase II : 500

Total Abstraction 1429

Source Availability

135 MLD Reuse Process Scheme 135 MLD Reuse Process Scheme –– Indirect Potable useIndirect Potable use

STP

Raw

Sewage

TTPUpgraded

Tertiary

Treatment

Plant

Pumping

Station

Wastewater

Treatment Plant

(BNR)

23 Kms, 1300 mm

diameter MS pipe.

70 MLD (150 MLD)

Break

Tank/Cascade

Aerator and

micro-strainer at

Tarverkare

75 MLD

(150 MLD)

UF

Backwash

/reject

Ultrafiltration (UF)

Plant 70 MLD (145

MLD) Break Tank

After UF

Plant

High rate settler/UF

to recover

backwash water

Waste to Lagoon

Granular

Activated

Carbon (GAC)

filters

GAC Backwash

Treated water

sump

Cl2 addition

(for residual

maintenance)

Cl2 addition

(Super

chlorination)

Arkavathy

River

7 Kms

Inlet to T G

Halli Reservoir

Raw Water

UF

Reservoir

Reverse

Osmosis (RO)

Cl2 addition

To BWSSB

Distribution System

(pumping)

V-valley Plant

Premises Tarverkare

Upgraded T G Halli WTP

Dam

Reclaimed water

Kum

udavath

i Riv

er

67.5 MLD

(135 MLD)

45 MLD (85 MLD)

25 MLD (50 MLD)

70 MLD (140 MLD)

67.5 MLD (135 MLD)

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Recycle reuse Vs Krishna water Recycle reuse Vs Krishna water

OptionOption CapacityCapacity Capital Capital

costcost

Annual Annual

O&MO&M

Rs./m3Rs./m3

MLDMLD Rs.Cr.Rs.Cr. Rs.Cr.Rs.Cr. CapitalCapital O&MO&M R&RR&R NRCDNRCD TotalTotal

KrishnaKrishna 820820 21002100 218.16218.16 9.639.63 7.297.29 -- -- 19.819.8

SwapSwap 300300 618618 36.6536.65 6.856.85 3.353.35 11.9611.96 1.161.16 13.1213.12

JiagudaJiaguda 3030 4848 3.903.90 5.165.16 3.563.56 8.728.72 2.592.59 11.3111.31

NMGudaNMGuda 1010 1616 0.880.88 4.974.97 2.412.41 7.387.38 2.412.41 9.799.79

NagoleNagole 7070 186186 7.067.06 8.518.51 2.762.76 11.2711.27 1.511.51 12.7812.78

N.CheruvN.Cheruv

uu

1010 1010 0.610.61 3.343.34 1.681.68 5.025.02 2.412.41 7.437.43

Annual interest rate : 10%, Amortization period : 24 years (till year 2031)

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Sewage

Potable

Water

High Quality

Reuse Water for

All applications

Treatment for Recycle and Reuse

Energy Management – adopted in Water and Wastewater along with Recycle and reuse could

prove exceptionally beneficial