wwmt-d2s3.2 modern trends with integrated aspects on wastewater treatment (liquid phase ) and ...

8/3/2019 WWMT-D2S3.2 Modern Trends with Integrated Aspects on Wastewater Treatment (Liquid Phase ) and Associated Sludge Treatment Optimisation by Alain Meunier

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WASTEWATER MANAGEMENT TECHNOLOGIES

MODERN TRENDSw ith Integrated Aspectson Wastewater treatment (liquid phase)

and Associated Sludge Treatment Optimization

ADB – MANILA – November 18th, 2011Alain MEUNIER - Degrémont



TWO Main Aspects in a WASTEWATER TREATMENT PLANT

•

for the Environmental ProtectionGenerally rejected to the receiving body

River Lake Ocean

It is very Surface consuming

very Energy consuming

Modern trends: to reduce SURFACE

to reduce ENERGY

ADB - MANILA – November 18th, 2011 2



TWO Main Aspects in a WASTEWATER TREATMENT PLANT

•

Huge quantities of Dry Solids to be processed1 Million Inhabitants = approx. 40 T/day of dry solids after digestion

60 T/da if not

or 160 T/day of cake at 25% drynessi.e. 60,000 T per year

How to manage such big quantities of solids, highly organic?

oLOCAL STRATEGY




DESIGN of WWTPs TWO DIFFERENT WAYS

VALENTON (City of Paris) – Stage 1 NICE (French Riviera)


220,000 m3/d300,000 m3/d




LA FARFANA – Santiago de Chile1 million m3/d

PARIS – Colombes (France)DWF 240 000 m3/d – WWF 1 million m3/d





CAIRO (Gabal El Asfar) EGYPT600,000 m3/d

BUSAN KOREA126 000 m3/d





60,000 m3/d

Panama City – 1 million inhabitants

240,000 m /




MODERN TRENDS for WASTEWATER (Liquid Phase) TREATMENT

COMPACTNESS with all associated benefits starting from impactson t e a n nterceptors

A revolution in the concept of the Network/Wastewater Treatment Plant (WWTP)

Optimization

REUSE of Treated Wastewater for Irrigation, Industries …

Ultrafiltration Membranes A new Driver for Reuse Applications(UF)

but very Site Specific Local water needs, public acceptance,environmental strategy




Conclusions on COMPACTNESS

CONSIDER All significant benefits linked to compactness

“nuisances zero” WWTP in concentrated urban areasHuge savings concerning INTERCEPTORS

COMPACTNESSIt is in the Histor DirectionENCOURAGE To consume few land and to protect future.Encourage the direction by introducing bonuses in therules of the game (Tender specifications)

xamp e ase on cos o an :Bonus of X millions $ per hectar saved




COMPACTNESS is a FANTASTIC DRIVER for DESIGN OPTIMIZATION

Requirements

& Associated Costs

PossibleConstruction of

Reduction of Nuisances(Noise, Odours)

COMPACTNESS WWTPsin

City Centers

Arc i tecturaIntegration

Significant

savingsin Main

Compact WWTPs require 2 to 5 times

Interceptors




Overview of COMPACT TECHNOLOGIES & PROCESSES

• HIGH RATE SETTLING TANKS Inte ration of Lamellar Modules

with activated sludge (Suspended Growth Biomass)

with attached Growth Biomass




Overview of COMPACT TECHNOLOGIES & PROCESSES

HIGH RATE SETTLING TANKS Use of Lamellar Modules

Conventional Primary

Sedimentation Tanks

Primary

Sedimentation

Tanks (PSTs) with

Lamellar Modules

(PSTs)

Hydraulic loading at Peak Flow = 3 to 5 m3/m2.h 20 m3/m2.h(1) No coagulant/flocculant30 to 70 m3/m2.h (1) with coagulant / flocculant


(1) m² of horizontal surface



HIGH RATE PRIMARY SEDIMENTATIONDENSADEG

Flocculation:mixing tank: mixing of the polymerplug tank: the flocs become heavier

Clarification:heaviest flocs settlelightest flocs are retained in the lamellae

Coagulation:formation ofthesmall flocs

TreatedwaterRaw

Sludge recirculation:it improves the flocculation

Thickened sludgeextraction




The Most SURFACE CONSUMING Stage

The biolo ical treatment : 60 to 70% of the total area

Possibilities of Surface reduction with Processes based on ACTIVATED SLUDGE BIOMASS

uspen e row

- Using rectangular works mainly for

final sedimentation tanks and

- Cancelling the final sedimentationtanks and replacing it with UFMembranes (MBR)




The Sequential Batch Reactors (SBRs)

Biological Reactors operating with Activated Sludge

combinin Aeration and Sedimentation b Sequencing the different phases

A Cycle:

- Complete Biological Treatement ofCarbon-Nitrogen / Phosphorus ifrequired

• Fill-Aeration

» carbon removal

» nitrification» denitrification

- Possible rectangular “Boxes”

• Settling

» clarification

» denitrification

• Draw off

- It can e eas y p e upBangkok, Dublin,Le Havre (France) …

»

» denitrification

TreatedWater

ExcessSludge




Example of a 4 Periods Cycle with a CYCLOR*

4 periods cycle

Cell 1 FA DSFA

er o er o er o er o

Cell 2 DS FAFA

e

Cell 4

FAFA

FA FA

S

S D

D

FA: Fill, Aeration 1h05x2=2h10S: Settling 1h05D: Draw off 1h05


* Degrémont Process



It requires a Treated water discharge reliable device

,

Float and discharge pipe Operation

FILL / AERATION / SETTLINGSEQUENCES

No Incoming Flocs

DRAW OFF

No Floating Scum incoming the outlet

No Suction of the Activated Sludge Bed




The MEMBRANE BIOREACTORS

Activated sludge is separated from interstitial treated water by

Fibres areassembled in

elements

- No final sedimentationvery significant surface gain

Elementsare grouped

- qua y o rea e wa erin SS, Turbidity, Faecal Coliforms,Phosphorus, SDI

in

cassettes - Ideal for Reuse Applications inIrrigation or Combined with DownstreamReverse Osmosis (R.O.) if TDS reductionrequested




The MEMBRANE BIOREACTORS

y enon e rocess

Outside – inhollow fibre

Pollens Yeasts

Bacteria Virus

Colloids

Dissolved salts

Organic macro Molecules

Wastewater

. …

... …..Screening

Biological Reactor withconventional Activated Sludge*

100 µm 10 1 0,1 0,01 0,0010,0001

Hair Redglobulae

Smallestmicro-organism

Reverse osmosis

Nanofiltration

UltrafiltrationSand filter

.. . ..

..

. .. .

..

.. . ..

..

. .. .

..

Membrane

Treated

water for

backwash

Nominal pores diameter: 0.035 µm

Microfiltration

Sludgetreatment

s aeration

* But with h igh MLSS 7 -8 g/L

Many other Manufacturers: Puron – Koch – Siemens


and other Membrane types: Plate Membranes ofKubota, Toray



Some CASES

Paris North / La Morée60,000 m3/d




Some CASES

– renc v era : , n a an s

- Membrane BIOREACTORs

-Thermal drying for Sludge Treatment: Granulates to cement plant


- Buildings with positive Carbon print: 4,000 m² solar panels



The BIOLOGICAL TREATMENT

Surface reduction with Processes based on attached growthfilms

Recent Trends:

• Biofiltrationa biological reactor with an aerobic / or anoxic biomass

attached to a fine granular media 3-5 mmacting as a filter

no final clarification

• Moving bed Bioreactor MBBR- a biological reactor with a moving bed consisting of a plastic

biofilm carrier

- a final solids / liquid separation is necessarynew trends are a high rate dissolved air

FLOTATION – 25 m3 /m².hor MICROSCREENING




BIOFILTRATION

e mos compac poss y a e momenDegrémont’s BIOFOR

Carbon Removal or Nitrification


emova o car on an n trogen + p osp orus requ re n t e pre m nary stage

A lot of combinations with various treatment steps: physico-chemical and biological



BIOFILTRATION – References in the world are very numerous

– ,

DALIAN – China / 120,000 m3/d




BIOFILTRATION: OSLO (Norway)–Built in rock caverns

,




Another Example: PARIS (Colombes) - France

1,000,000 m3 / d in stormconditions

•32,400 m² underground

•13,000 m² above ground

BOD5 pollution equivalent to 2.2 millioninhabitants in storm conditions.




MOVING BED BIOREACTORS MBBR

Meteor 660 type *

METEOR

2 possible ways:

• IFASIntegrated fixed filmactivated sludge process

• MBBRMoving bed bioreactor

• Protected surface: 660 m²/m3

• Diameter: 12.2 mm

• Length: 12.0 mm


• ater a :* Two other types existing 450 and 515 m²/ m3



• IFAS Process –

Activated Sludge (reduced nitrification stage)

but much less Compact than MBBRFinal Clarification does subsist

– Adapted to quality expansions: C N / DN

• MBBR – , ,

Associated with very compact final separation stages- high rate dissolved air flotation (DAF)- microstraining




MBBR Configurations for CARBON and NITROGEN REMOVAL

Dissolved Air Flotation

Microscreening – 10 µ

Other type of microscreening – µ




MBBR

or a tertiary stage complementary to a CAS* for BOD5 polishing..,Nitrification, Denitrification w ith methanol

Degrémont is implementing in DHAKA (Bangladesh) – 474 MLD

nitrification plant for drinking w ater plantanalogous w ith a tertiary treatment of domestic sewage.

NH4 inlet concentration: 15 to 20 mg/ L


* Conventional Activated Sludge



The biggest WWTP in Europe > 2 millions m3/day

A FINAL CASE STUDY

GREAT PARIS / ACHERES (North West)70 m3/s in Storm Conditions

Current Status:

A conventional WW TP

various stages

Non integrated in the

region

Odour nuisances

Bad- impact on neighbourhood- c aims

- devaluation of real estatevalues




GREAT PARIS / ACHERES

Approx. 10 Years of Works

Complete rehabilitation of the site

Nuisances ZERO Environmental INTEGRATION

COMPLETE RECOVERY

o t e rea estate va ue n t eneighbourhood

A pretreatment passing 70 m3/s

(Storm peak)

A biological treatment passing up to2,200 MLD with a peak of 51 m3/s

Biological filtration + MBR for 300 MLD




TREATED WASTEWATER REUSE


Doha LUSAIL (Qatar) – 60,000 m3/d – 260,000 P.E.



TREATED WASTEWATER REUSE

Think about Reuse

Easy and Cheap

-All technical tools - Additional costs are generallyare available limited unless Reverse osmosis

is involved for reducing salinity

-Recently UF membranesBrought new prospects

but linked to very regional conditions climate, distance between theWWTP and the enduser, …




A GOOD IDEA

Many European Countries practice an indirect recycling for drinking

Treated waterualit is ada ted

Drinking WaterTP

Town B

RIVER




• The most o ular

Agriculture

Irrigation

Play grounds, publicparks, gardens, lawns,olf courses tree-lined

avenues, recreationalimpoundments

• n us r a coo ng or any n us r a reuse

• Groundwater recharges into potable or non potableaquifers

• Indirect potable reuse (Singapore – PUB)• Direct potable reuse – extremely scarce (Windhoek –




Objectives to be settled

• Reuse olic Local strate

• ualit of Treated water to be obtained

Localregulations

Local Technical &Economical

Conditions• Reduction of salinity to be obtained or NOT

R.O. required or NOT


d l d l



Guidelines, Recommendations, Regulations

Many in the World

Well known – W.H.O. Guidelines for Reuse in Irrigation

(relating to Health only)

– US EPA Environmental Protection Agency

For• BOD5 < 10 mg/lUnrestricted Urban Uses • <• No detectable Fecal

Coliforms / 100 ml• Residual Chlorine > 1 mg/L

oo crops eaten rawrecreationalimpoundments

Groundwater Recharges Site Specificor Industries

For




Main Possibilities:

• Tertiary Treatment dow nstream a SecondaryTreatment

genera y a conventiona activate s u ge

process leading to

» BOD5 < 20 mg/ L

» SS < 20 m L

» TN < 15 mg/ L

• Integrated secondary / tertiary treatment

UF Membrane BIOREACTORS


FLOW DIAGRAMS ith t REVERSE OSMOSIS



FLOW DIAGRAMS without REVERSE OSMOSIS

CONVENTIONALACTIVATED SLUDGE T.P. M3+

PST SSTAT CoagulationSand

FiltrationDisinfection

Ultrafiltration SafetyDisinfection

BOD5 < 20 mg/l

SecondaryTreatment

2

SS < 20 mg/lTN < 15 mg/l

PST MBRSafety

Disinfection

Bioreactor


a case study in AUSTRALIA



a case study in AUSTRALIA

• A WWTP for discharge to the Pimpama River – capacity 17 MLD

• A RWTP (recycled water treatment plant) – capacity 12 MLD’

• Toilets

• Fire hydrants

• External reuse (gardening)

Commissioned in 2008


General FLOW DIAGRAM



General FLOW DIAGRAM


Recycled Water Quality



Recycled Water Quality

Median Values 95%ile Values

. Turbidity (NTU) 2 5

(Bacteria) . E-Coli (cfu/100 mL) 1 10

Parasites)

.

. Viruses (pfu/100 mL) 1 10

. Manganese (as Mn) (mg/L) 0.01 (85%ile) 0.05 (max.)

Specific of Reuse in Toilets to avoid Black Stains


FLOW DIAGRAM



FLOW DIAGRAM

17 MLD TN 2.7 mg/L (50%ile)

Sludge Plant

ChlorinationSand Filters

Sand Filters

Cl2 for Mn Oxidation

PIMPAMA River

12 MLD

UltrafiltrationMEMTECH

(Rack System)

UVUnits

Cl2

Storage Tank10,000 m3

REUSE APPLICATIONS (Housing)


SLUDGE and ENERGY



SLUDGE and ENERGY

Anaerobic Digesters (8 x 15,000 m3)of SANTIAGO de CHILE

oso s ompost ng n e


WATER & SLUDGE TREATMENT



WATER & SLUDGE TREATMENT

• Water Treatment (liquid phase)• High Electrical Energy Consumption of the complete WW TP (80-90% )

• The Biological Treatment itself (35-50%)

• genera es u ge• Highly organic 65-80% from P rimary Sedimentation

+ Biological Treatment Steps

• A huge burden or an opportunity


OPPORTUNITIES



OPPORTUNITIES

• How to pass from a Burden to an opportunity

• To produce energy from Organic matter• Anaerobic Digestion Methane CH4

•

• To valorize Sludge and produce Biosolids

acce table for A ricultureClass A (US EPA for instance)

to upgrade Sludge from a residue to Biosolids


Key Aspects



y p

• More and more constraints – Sludge Production growth more and more WWTPs

– More and more stringent regulations for final disposal:Legislative P ressure

– Sustainable development cri teria: a global concern

• us omer s ncreas ng concerns ar e ressure – Increasing costs

– Public acceptance is decreasing

Farmers acceptance

Uncertainties on the future of disposal ways

• Many site specific aspects

LOCAL OPTIMISATION


International Trends



• Diversification of Disposal Routes

on long term disposal routes may change:

» Full landfills

» Economical conditions variations

» Public acceptance decrease

Multiways processes: Examp e: T erma rying pe ets to agr icu ture or to power

cement plant as a fuel

• Improvement of Agricultural use acceptance

Part 503 Biosolids

• Optimization of Energy Recovery» Biogas production in anaerobic digestion

» Steam production in Incinerators

• Reduction of Odour Nuisances and Air Pollutions


Other International Trends



Generally, parallel to sustainable development criteria

• Reduction of Sludge Production

less transportation cost and less road trafficless CO2 emissions,ess env ronmen a mpac

• Either at source less dry solids (DS) produced

ex: Anaerobic digestion 30-40% less DS

• Or by volume reductionDewatering, drying

• Or bothIncineration remaining mineral DS

1,000 kg of DS at 25% approx. 80 kg of ashes(8% of initial weight)


OPTIMIZATION of SLUDGE TREATMENT



• Deeply linked to regional conditions: – egu a ons, c ma e, ava a e an , cos o energy, …

• Starts from Downstream disposal strategy: – Agricultural reuse

– Landfilling

Wet Mechanical

Thickening

SludgeHydrolysis REED

– a er a reuse

Mechanical

dewatering

oxidation

Thermal

dryingLime dosing Composting

dewatering

SOLAR

DRYING

Digestion

Gazification /pyrolysis

Dedicatedincineration

Wasteincineration

Energyproduction


Materialreuse Landfill

Agriculturalreuse

Up To Date Technologies and Trends



• Boosted Anaerobic Digestion, with efficient mixing

• Boosted Dewatering

• Thermal Drying

• On site Incineration

•


Anaerobic Digestion



• Well known Mesophilic (35°C) Anaerobic Digestion has keyadvantages:

Process requires few energy(to the contrary of Aerobic Digestion)

High reduction of Organic Matter

30-35% of dry solids reduction

Biogas (CH4) production w ithpossible energy recovery

Gas network feeding

Long term stabilizationlong term storage


ANAEROBIC DIGESTION BOOSTERS



• Many different research axis

• But all have the same basisLYSIS of

• Different means applied:• Mechanical

Non satisfactor results

• Ultra sounds

• Enzymatic hydrolysis under Development

• Thermal Hydrolysis / A well Proven Process

CAMBI Process


CAMBI PROCESS



• Norwegian company which has developed for morethan 10 years a thermal process of sludge toenhance anaerobic digestion


Cambi Process: general schematics



Liquid sludge

steam

Heat recovery

fumes

water

Pre-dewatering CHP

Biogas

Electricity

ANAEROBIC

hopperPost-

dewatering

water

CAMBIDIGESTER

35°C

Thermal

HydrolysisProcess

at 160-165°C


Dewatered sludgeFiltrate

CAMBI : the principle



waterTo the boilerRecycled

steam

dr ness 14%

P R

°F

T 45°C

dryness 12%

Recycleddigested

sludge

80/100°C5-6 bar

~105°C

Dilution

Reactor160-165°C

steam

water

Pulper steamFlash Tank

30’

hopperPre-dewatering

Dryness 15%To the di ester


CAMBI : NAESTVED WWTP (Denmark)



A typicalcase

Reduction ofSludge

Quantities

and

H ienization

forAgriculturalReuse


CAMBI: Naestved – Cambi + MAD* vs MAD*



Biogas = 600 Nm3/d

4 t TS/d60% VM/TS

TS= 6%63 m3/d

3.1 t TS/d

1600

m3

Conventional desi n=

dryness 18%

* MAD = Mesophilic Anaerobic Digestion Cake Production: 17.2 T/D

Biogas = 900 Nm3/ddilution

38 m3/d

S = 10% SRT = 15 d

4 t TS/d60% VM/TS 2.8 t TS/j

46% VM/TS

600

m3


TS =15%

ryness

Cake Production: 9.3 T/D (- 45%)

Some Main References



CAMBI : Dublin (1.9 millions pe)

SBR files on 2 levels

4 pulpers, 8 reactors,2 flashtanks

3 digesters(4,500 m3 each)


CAMBI ProcessAdvantagesKEY



• Reduction of Anaerobic Direction Volume (2.5 times)

Sludge Class A (US EPA Biosolids Part 503)

instead of Class B

Biogas more Energy to be recovered

for Thermal Drying

• u ge ewa er ng: - on ca e ryness

• Cake to bedisposed of: 20 to 40% reduction

Depending onSludge quality


BOOSTED DEWATERING



Liquid sludge generally dewatered (cake production) before• Transportation to final disposal: landfill for instance

• A further treatment sta e:» Thermal drying

» incineration

always a profit

• Less transportation costs

• Less fuel if thermal drying• Autogenous combustion reached with low er water content if

incineration

Orientation based on economical o timization but trends are:• Increase of Fuel Cost Reduction of transportation costs

• Reduction of greenhouse effects Boosteddewatering


Conventional DEWATERING DEVICES



• Belt Filter Presses

DECADES with chemicalconditioning:

• Polymer

• Lime

• Plate Filter Presses • Ferric ChlorideCentrifuge Plate Filter Press

Belt Filter Press


A NEW EMERGING TECHNOLOGY



The DEHYDRIS TWIST workshop based on theBUCHER P iston Press

A smarttechnology

compe ng w

Centrifuge +predryer

or

automatic pressfilter


How it works




How it works




SOME RESULTS



Cake Dryness

Low Load Activated Sludge Belt Filter Press 17-18%Polymer only

no r mary sett ng entr uge -

Filter Press (conventional) 26-27%

32 %

Polymer + FeCl3

FeCl3 + CaO (35%)

- +40%

3

FeCl3 + Cao (30%)

Mixed Sludge

Primary + Biological Sludge

Belt Filter Press 22-25%Polymer only

Centrifuge 25-28%

Filter Press (conventional) 31-32%

Bucher Piston Press

(70% Primary Sludge)

35%

40%

Polymer

Polymer + FeCl3


To summarize Results with Piston Press are equivalent to Filter Press with MEMBRANES

BUCHER’s REFERENCES



Lot of references in food industries with the sameTechnology (2000 presses in fruit juice production).

Major references for municipal digested sludge:

• in Sweden:

– Käppala 700,000 EH (8,000 T DS/year)

• in Germany:

– Lingen 195,000 EH

Conclusions on advantages:

– Higher dryness obtained than those obtained onconventiona mac ines

– Equivalent to sophisticatedfilter presses withmembranes, but

100% automatic

(no operating staff)


SLUGE DRYING



less humidity (10-15%)

A perfect pivot for all disposal routes

• Long terme storage

• Reuse in Agriculture Reduced volumeSiviculture Pasteurised productHorticulture Valuable Biosolids

which can be supplemented byPotassium, Nitrogen, Phosphorus

• Landfilling

• Co-incineration w ith garbage

• Reuse as a fuel in thermal power plant or cement plant

• Incineration


Two Main Ways



Depending on Climate

Energy costs

SOLAR DRYING DRYING BEDS, LAGOONS

Availability of land

or THERMAL DRYINGPossible Acceleration of SOLAR

Radiation in a Greenhouse

Many types existingon the Market

Solution to be adapted tolocal climate but

generally not adapted to Megacities

Few are reliable


THERMAL DRYING



Or Industrial drying usinga fuel source

Fuel Oil

LNGExternal

Many types of dryers in the world

direct / indirect/ mixeddrum / belt / multiple hearth / fluidized …

Few are safe and reliable for SLUDGE dryingsince they are coming from other applications

chemical industry

and adapted to sludge treatment

SLUDGE VARIABLE RAW MATERIALis a


THERMAL DRYING



A variable raw materialMany type of Dryers

•

• Quality of sludge primarysecondary

any parame ers• Granulation

• Safety -> risk of fire or explosion• Maintenance -> operating time per year

• Industrial waste

• Ability to natural granulation

•• Flexibility type of sludge

dryness 65-90%• Energy consumption

• -• Pollution of water evaporated• Storage conditions• Ability of pellets to be incorporated in soilDegrémont selects the optimized

• Variations of sludge qualities ifcentralized drying facility

drying process according to its

experience in Construction &Operation


THERMAL DRYING



Degrémont has learnt over 30 years

We know how to select the proper dryer for the PROPER

USE.

Some case studies:

– CORK (2nd town of I reland)

– -




CORK (2nd Town of Ireland)

450,000 Inhabitants

• 2 dryers of 1,700 kg H2O/hr each

Drying in 2 steps:• 1st step 45-50%

• 2nd step 70-95%

1st step : indirect drum dryer




First stageoutlet

The Spaghettis extruded by the Chopper

Sludge(45/50 % Dryness)

Sludge crushing

Interchangeable screen(perforated 8 mm sheet iron)Fibers/Tows scraper

Snail(eccentric)

Sludge spaghettis

Swiveling belt(inlet band dryer)


CHOPPER (Spaghettis Machine)

The second STEP: Band Dryer




The 2-STEP DRYERhas major advantages

INNODRY CONCEPT



• Total granulation withoutPellet-Mill

• No dust max. safetyexplosions are coming from dust

• Reduced thermal energy due torecovery from 1st stage to 2nd stage700-750 kWh/T evaporated water

Other processes are consuming upto 60% more (direct dryers)

• Flexibility to adjust the final product

• , , ,

no pellet millThe key advantage Safety Operation


Low air temperature on belt dryer – 105°C



PARIS – South East VALENTON WasteWaterTreatment Plant

Drying Facility


General view of the Plant




TRANSPORT of SILOS




NUTRIENTS adding to DRIED SLUDGE

Technical Data :

Hourly capacity : 40 T/hr



Hourly capacity : 40 T/hr

-Discontinuous cycles

-Yearly capacity : 5000 T/year

-Added nutrients (2 max.) :

oPotassium Chloride : KCl

sludgehopper

Hopper

Hopper

oPotassium Sulphate: K2SO4

oUrea

oOligo elements

-Nutrients conditioned in big bags

Fertilizers for 5% Nitro en

Additiveproduct

Inlet

10% Phosphorus

Typical agricultural use 10% Potassium

Hopper Outlet

Pneumatic transporttowards trucks or trains

Operation withdiscontinuous cycles


NUTRIENTS ADDING




INCINERATION of DEWATERED SLUDGE



egr mon as s ow n ec no ogy

the HIGH TEMPERATURE FLUIDIZED BED

and a REAL EXPERIENCEabout many plants in operation in NORTH AMERICA

80% of sludge incineration systems in

e as years100% since 2000

when no reuse as biosolids is possible




The high temperature fluidized bedAn internationally accepted standard process

A simple reliable system: a big stove

But: – Flue gas has to be highly purifed according to local legislation

– Public acceptance has to be obtained

– Thermal balance has to be optimized

(no additional Fuel)

high cake dryness at inlet (boosted dewatering)

optimization of thermal loops

– Mineral ashes have to be disposed of.


The Thermylis furnace – A big Stove



The fume passes through a flue

-

Water spray

roof dome

reactor

Flared shell lined

with refractories

Sand bed

Upkeep burner Freeboard

Sand feed nozzle

Fluidization grid fitted

with tuyeres

-

Fluidized

bedSludge feed

nozzle Injection pipe for

make-up fuel2 versions :

• “Hot” windbox refractorized

refractory arch

Windbox

Fluidization

for hot temperatures

(Tmax = 650°C)• “Cold” windbox

(Tmax = 400– 450°C)Preheating

burner

Sand extraction

nozzle


The sludge Incineration



Purpose: Using the inner energy of sludge to removefrom it completely the organic matter and the water

1000 kg of

sludge

Dryness = 25%

Puridied

flue gas

Dryness 25%VS/DS = 70%

• 750 kg H2O

Volatile Solids 175 kg

ThermylisFluidized Bed

Incinerator

Dry ashes

74 kg 81 kg

Approx.

8%• Volatile Solids 175 kg

• Mineral Solids 75 kg

IncineratorPurification

residues7 kg

of initial

weight


Thermal Balance



AIRCOMBUSTION

850°C

SLUDGEOrganic matter (LHV)Mineral matterWater

n a py

Steam-generating heat

(Enthalpy)

HEAT LOSSMAKE-UP FUEL ?


The heat recovery

O ibilit



Preheatin of fluidization air

One possibility

Preheated air 400–650°C

SludgeFLUE GAS

PURIFICATIONFURNACE with

hot windbox

850°C Heatexchanger

500–

600°C

Dryness

180– 600°CAdditional

equipment

Cold air

Initial cakedryness

2nd exchanger

Saving of energy is achieved on part of the heat that would°

Boiler for pre-drying


The autogenous combustion



Autogenous combustion for 1 ton of DS of sludge+ 51 k of fats, FS/DS = 85%, Dr ness = 30%

30%

35%

40%

e

A cheap investment forA cheap investment for

an efficient energyan efficient energy

20%

25%

s o f s l u d g

10%

15%

D r y n e

Preheating of air at 650°C

Preheatin of air at 400°C

Preliminary drying could be

efficient solution if energy is

0%45% 50% 55% 60% 65% 70% 75% 80% 85%

Preliminary drying of sludge


/

From small units ELBEUF - FRANCE

100,000 inhabitants



HTFB INCINERATOR dia. 2.34 mGeneral view at the end of erection


To giant units PUERTO RICO dia. 4.68 m




Composite Solutions



• I f the reuse in agriculture is the basic driver

• But if the production capacity of granulates may exceed the

market needs permanently or periodically (seasonal variations)

A composite solution combining Thermal Drying andIncineration may be optimized.

Dewatered Thermal Drying GranulatesPellets at 90 %

20-40% dryness

Incineration

Ashes to

Landfillingor Reuse(Cement Plant..)


ENERGY RECOVERY from ANAEROBIC DIGESTION BIOGAS

Bi f Di ti 60 65% f CH4 M th



• Biogas from Digestion 60-65% of CH4 Methane+ CO 2 + traces (H2S, … )

• High calorific value 6-7 kWh / S m3

• Direct production of THERMAL HEAT through Boilers – Heating sludge before digestion

– Heating o o ices – Feeding a thermal drying

• Direct injection in a gas network

after a pretreatment (: sulphide reduction,pressure and humidity Control)

80,000 m3 / day


COGENERATION on GAS ENGINES, MICROTURBINES, TURBINES

> 20 200 kWe



> 20-200 kWe

> 20 kWe

> 1,2 MWe

- Thermal efficiency 45%

Most of Applications (95%)

Electrical efficiency 35-40%Thermal efficiency 45%

Electrical efficiency 29%Thermal efficiency 56%


CONCLUSIONS on Overall Optimization of SLUDGE and ENERGY

To find the best Sludge and Energy management strategy



To find the best Sludge and Energy management strategyadapted to local conditions

• reduction of mass: digestion + energy

(dry solids) production

To what extent? • reduction of volume: drying

•

In Relationship with Potential final disposals

Production and cost of energy


To launch tenders which consider Comparison of Overall Costs

–(= NPV)



(= NPV)

Taking into account “Proactive”“Ambitious”

for Electrical Energy (example of Green Energy in

Unit costs

for Sludge Transportation

o crea e a v r uous c rc e n avor o ec n ca so u ons a ng n oaccount:

• sustainable development concept

• Cost of energy limitation of consumption

• Limitation of greenhouse gas emissions


•

Example



• Producing electrical energy from Anaerobic Digestionhas an additional CAPEX (gas engines + auxiliaries)

compare solutions (w ith and w ithout gas engines)

w ith high electrical kWh unit costgreen energy in Germany


SELECTION of a CONTRACTOR



May we suggest a w in/ w in procurement process

• Design / Build / Operate (DBO) Contractswith erformance based s ecifications

w ith general & particular specifications

• Operation Period 2 years

– -

– To leave time to Client to control – Treatment guarantees – Operation costs application of penalties if failures


SELECTION of a CONTRACTOR

S l ti f C tit t t l



• Selection of Competitor on a total

+ years or more + on years

of OPEX costs w ith unit costs on consumablesanticipating increases on energy costs

Proactive action on unit costsof :» kWh (green energy)

Includin Bonuses

»

Virtuous circle

for the FUTURE

on Land Savings


wwmt-d2s3.2 modern trends with integrated aspects on wastewater treatment (liquid phase ) and ...

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