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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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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