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Biological nutrient removal in
municipal waste
Clickwater
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INTRODUCTION
 MAIN
PROBLEM IS THE RISING
CONCENTRATION OF NUTRIENTS.
 NITROGEN
AND PHOSPHORUS ARE THE
PRIMARY CAUSES OF EUTROPHICATION.
 MOST
RECOGNIZABLE MANIFESTATIONS ARE
ALGAL BLOOMS.
 SYMPTOMS
ARE LOW DISSOLVED OXYGEN, FISH
KILLS, MURKY WATER AND DEPLETION OF
FLORA AND FAUNA.
EUTROPHICATION BEGINNING IN TOBA LAKE, INDONESIA
BIOLOGICAL NUTRIENT
REMOVAL(bnr)
 BIOLOGICAL
NUTRIENTS ARE ORGANIC
MATERIALS.
 BNR
IS A PROCESS USED TO REMOVE
NITROGEN AND PHOSPHORUS.
 USING
MICRO-ORGANISMS.
BNR PROCESSES
BNR IS COMPRISED OF TWO PROCESSES:
 BIOLOGICAL
NITROGEN REMOVAL
 BIOLOGICAL
PHOSPHORUS REMOVAL
Form
Common Removal
Mechanism
Nitrification
Technology Limit,
mg/L
<0.5
Denitrification
1-2
Particulate Organic-N
Solids separation
<1.0
Soluble Organic-N
None
0.5-1.5
Total Phosphorus
Soluble P
Microbial uptake
and/or
Chemical precipitation
0.1
Particulate P
Solids removal
<0.05
Total Nitrogen
Ammonia-N
Nitrate-N
EFFLUENT TN AND TP COMPONENTS AND ACHIEVABLE LIMITS
BIOLOGICAL NITROGEN
REMOVAL
 AMMONIA,
NITRATE, PARTICULATE ORGANIC
NITROGEN AND SOLUBLE ORGANIC NITROGEN.
 NITRIFICATION
AND DENITRIFICATION.
 AMMONIA
IS OXIDISED TO NITRITE AND
NITRITE IS THEN OXIDISED TO NITRATE.
 REDUCTION
OF NITRATE TO NITRIC OXIDE,
NITROUS OXIDE AND NITROGEN GAS.
BIOLOGICAL PHOSPHORUS
REMOVAL
 SOLUBLE
AND PARTICULATE PHOSPHORUS.
 THE
TREATMENT PROCESS CAN BE DESIGNED
TO PROMOTE THE GROWTH OF PAOs.
 PAOs
CONVERT AVAILABLE ORGANIC MATTER
TO PHAs.
Treatment processes
I.
INTEGRATED FIXED FILM ACTIVATED SLUDGE
PROCESS
II.
SEQUENTIAL BATCH REACTOR PROCESS
III.
STEP FEED PROCESS
IV.
MOVING BED BIOFILM REACTOR PROCESS
V.
MEMBRANE BIOLOGICAL REACTOR PROCESS
VI.
OXIDATION DITCH PROCESS
INTEGRATED FIXED FILM
ACTIVATED SLUDGE PROCESS(ifas)
 COMBINES
FIXED FILM TECHNOLOGY WITH
CONVENTIONAL ACTIVATED SLUDGE.
 IMMERSE
A SOLID SUPPORT MEDIA INTO AN
AERATION BASIN.
 MEDIA
CAN BE FIXED OR FLOATING.
 TEXTILE
MESH MATERIAL, FLOATING SPONGES
OR PLASTIC MEDIA.
 PROVIDES
SURFACE AREA FOR BIOLOGICAL
GROWTH TO ATTACH.
IFAS PROCESS(Cont…)
 CREATES
ADDITIONAL BIOMASS.
 PROVIDES
ADDITIONAL BIOLOGICAL ACTIVITY.
 INCREASES
SOLIDS SETTLING.
 INCREASES
WASTE WATER TREATMENT
FACILITIES.
FIXED MEDIA SYSTEMS
FLOATING MEDIA SYSTEMS
Sequential batch reactor
PROCESS(sbr)
 CONTINUOS
FLOW SYSTEM.
 PRIMARLY
FOR NITROGEN REMOVAL.
 FLEXIBLE,
INEXPENSIVE AND EFFICIENT.
 OPERATIONAL
 THREE
COST IS HIGH.
PHASES
FILL PHASE
REACT PHASE
REACT
FILL
SETTLE/DECANT
SBR PROCESS SEQUENCE
STEP FEED PROCESS
 CONTINUOUS
FLOW PROCESS.
 INFLUENT
FLOW IS SPLIT TO SEVERAL FEED
LOCATIONS.
 RECYCLE
SLUDGE STREAM IS SENT TO THE
BEGINNING.
 HIGHER
SOLIDS RETENTION TIME IS ACHIEVED
PROVIDING ENHANCED TREATMENT.
 PHOSPHORUS
REMOVAL IS LIMITED.
STEP FEED PROCESS
Moving bed biofilm reactor
PROCESS(mbbr)
 DIRECT
DERIVATIVE OF FIXED FILM ACTIVATED
SLUDGE PROCESS.
 HDPE
CARRIER ELEMENTS ARE USED.
 PROVIDE
SITES FOR BACTERIA ATTACHMENT.
 ALLOWS
HIGHER CONCENTRATION OF ACTIVE
BIOMASS.
 MORE
TREATMENT CAPACITY.
 PHOSPHORUS
STAGES.
REMOVAL REQUIRES ADDITIONAL
JET AERATION SYSTEM PIPING WITHIN THE MBBR
K1 CARRIER ELEMENT
Membrane Biological Reactor
PROCESS(mbr)
 CONSISTS
OF SEPARATE AERATION TANKS AND
MEMBRANE FILTRATION TANKS.
 THE
MEMBRANE ELEMENTS SEPARATE SOLIDS
FROM THE TREATED EFFLUENT.
 EXCESS
SOLIDS ARE WASTED DIRECTLY FROM
THE AERATION TANKS.
 MEMBRANES
VARY FROM HOLLOW TUBE
FILTERS TO FLAT PANELS.
 REQUIRE
SEVERAL CLEANING CYCLES.
KUBOTA MEMBRANE AND MEMBRANE BIOREACTOR
ZENON MEMBRANE AND MEMBRANE BIOREACTOR
OXIDATION DITCH PROCESS
 OXIDATION
DITCH IS A LARGE CIRCULAR BASIN
WITH AERATORS.
 REMOVES
ORGANIC MATTER AND POLLUTANTS
 ADSORPTION,
OXIDATION AND
DECOMPOSITION.
 ENSURES
STABLE, CONTINUOUS D.O
MEASUREMENT.
 REDUCES
OPERATING COSTS.
 ELIMINATES
CLEANING.
THE NEED FOR MANUAL
OXIDATION DITCH PROCESS
CASE STUDY: SOUTH MIDDLETON
MUNICIPAL AUTHORITY
 EVALUATED
THE TREATMENT PROCESSES.
 MOST
FEASIBLE PROCESS IS THE IFAS PROCESS
INCORPORATING MBBR TECHNOLOGY.
 INCREASED
 IMPROVED
NITRIFICATION
PROCESS STABILITY
 REDUCED
CAPITAL AND CONSTRUCTION COST
 REDUCED
ANNUAL ENRGY COST
Reactor
Anaerobic Zone
Process Train #1
Volume (gallons)
71,800
Process Train #2
Volume (gallons)
71,800
Pre-Anoxic Zone
65,000
65,000
Aerobic IFAS Zone
240,000
240,000
Post-Anoxic Zone
85,400
85,400
Re-Aeration Zone
24,700
24,700
APPROXIMATE TANK VOLUMES
BNR PROCESS MODELLING
 PRACTICAL
IMPLEMENTATION OF BNR
TECHNOLOGY.
 WIDELY
AND SUCCESSFULLY USED.
 TO
IMPROVE UNDERSTANDING OF THE BNR
PROCESSES.
 TO
OPTIMIZE DESIGN AND OPERATION OF THE
BNR PROCESSES.
A
COMPUTER PROGRAMME SIMULATOR IS
REQUIRED.
BNR PROCESS
MODELLING(Cont..)
 TO
IMPLEMENT ALL UNIT PROCESS MODELS
AND LINK THEM.
 TO
SET UP A WWTP WITH PARTICULAR FLOW
SCHEME, INFLUENT CHARACTERISTICS AND
OPERATION CONDITIONS.
 TO
REPRESENT THE BIOLOGICAL
TRANSFORMATIONS.
 THE
MODEL NEEDS TO BE CALIBRATED AND
VALIDATED BEFORE IT IS USED.
REQUIREMENTS TO SET UP A WWTP PROCESS MODEL
CONCLUSION
 BNR
IS AN ESTABLISHED TECHNOLOGY.
 IMPLEMENTATION
AND OPERATION IS A
CHALLENGE.
 COMPLEX
AND HIGH COST.
 REQUIRES
TRAINED DESIGN ENGINEERS AND
OPERATORS.
 BNR
PROCESS MODELLING IS A USEFUL TOOL
FOR DESIGN AND OPERATION OF WWTPs.
references
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biological phosphorus removal in membrane bioreactors.” Water Sci. Technol., 46(4–5),
281–286
2. Ekama, G. A., andWentzel, M. C. (1999). “Difficulties and development in biological
nutrient removal technology and modeling.” Water Sci. Technol., 39(6), 1–11.
3. Appels, L., Baeyens, J., Degrève, J., and Dewil, R. (2008). “Principles and
potential of the anaerobic digestion of waste-activated sludge.” Prog. Energy
Combust. Sci., 34(6), 755–781.
4. Henze, M., van Loosdrecht, M. C. M., Ekama, G. A., and Brdjanovic, D (2008).
Biological wastewater treatment: Principles, design and modelling, IWA, London.
5. Dold, P. L., Hu, Z., and Gan, Y. (2009). “Nutrient removal MBR systems: Factors in
design and operation.” Proc., 5th IWA Specialized Membrane Conference and
Exhibition, IWA, London.
6. Sen, D., Mitta, P., and Randall, C. W. (1994). “Performance of fixed film media
integrated in activated sludge reactors to enhanced nitrogen removal.” Wat. Sci.
Technol., 30(11), 13 24.
7. Randall, C. W., and Sen, D. (1996). “Full-scale evaluation of an integrated fixed
film activated sludge (IFAS) process for enhanced nitrogen removal.” Water Sci.
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