10. anaerobic reactor technologies

1

CIE4485

Wastewater Treatment

Prof.dr.ir. Jules van Lier

10. Anaerobic Reactor Technologies

1

6 December 2012

Challenge the future

DelftUniversity ofTechnology

CT4485 Wastewater Treatment

Lecture 4c: Anaerobic Reactor TechnologiesProf.dr.ir. Jules van Lier

2Anaerobic Wastewater Treatment

Sludge digestion

1.septic tank

a.height of liquidb.> 7.5 cmc.> 30 cmd.40% of liquid heighte.2/3 of Lf. 1/3 of L

sludge

scum layer

Donald Cameron, 1895 (UK)

2


Sludge digestion

2. Imhoff tank

A. effluentB. sludge feedC. settlingD. settled sludgeE. sludge digestingF. sludge discharge pipe

Karl Imhoff, 1905 (Germany)


Sludge digestion & Wastewater treatment

3. Clarigester

A. sludge feedB. effluentC. scum dischargeD. scum break offE. bottom scraperF. sludge discharge pipe

Stander, 1950 (South Africa)

3


1930’s

Buswell

IndustrialWastes



1955, Shroepfer, USA

Schroepfer

Contact process


4


methanereactor

Flocculator or degasifier Clarifier

influent effluent

recycle sludgeexcess sludge

Contact Process (CP)


basic principles:

• complete mixing in the digester in order to achieve good contact

between sludge and wastewater

• sludge recycling (flow rate generally 80-100 % of the influent flow

rate) in order to maintain a high sludge content in the digester

=> high organic removal efficiency stable operation

The Anaerobic Contact Process

5


type of waste water

sludge loading(kg COD ·

kg-1 VSS · d-1)

load(kg COD ·

m-3 · d-1)

reactor volume(m3)

COD removal

efficiency (%)

sugar factory

distillery

citric acid

yeast factory

dairy

green vegetable cannery

pectin factory

starch factory

meat processing works

1.3 - 2.0

0.17 - 0.24

0.16 - 0.29

0.24 - 0.37

0.13

0.11 - 0.28

0.03 - 0.22

1.4

0.5 - 1.1

0.6 - 12.9

1.5 - 2.5

1.3 - 4.0

2.8 - 3.9

0.88

2.0 - 4.2

1.7 - 5.3

3.6

0.8 - 4.8

2100 - 16000

300 - 1890

10000

1900

84

5000

3000 - 3618

900

2670 - 7117

90 - 95

90 - 98

75 - 83

77 - 82

-

90 - 95

88 - 93

65

88 - 95

The anaerobic contact process


1970s, Gatze Lettinga, The Netherlands

Lettinga

UASB

Wastewater Treatment: UASB

6


Development of “high-rate” anaerobic treatment systems

Completely mixed

(Bio)gas

influent effluent

Relative capacity: 1

Physical retention


Immobilised biomass



Early full-scale UASB for sugar mill effluent (CSM,1976)

7


Anaerobic Granular Sludge

Sorry guys.., I only appear when Dutch

men are around…!


Expanded Granular Sludge Bed (EGSB) Reactors

Main Features- High upflow velocities (> 8 m/h)- High concentration of bio-catalyst- Extreme loading rates (20-40 kg/m3.d) - Virtually no mass transfer limitation - Very small footprint

Application:- cost effective alternative for UASB (2-3 times

higher load)- Cold wastewaters (< 20°C)- Dilute wastewaters ( < 1 g COD/l)- Presence of degradable toxic compounds- LCFA containing wastewaters- Wastewaters with foaming problems in UASB

Biogas

Effluent

Influent

Granularsludge

Effective use of granular sludge !!

8


Completely mixed

(Bio)gas

influent effluent


Physical retention


Immobilised biomass


Enhanced contact


Development of “high-rate” anaerobic treatment systems


Influent

Sludge bed

Settler

EffluentBiogas

Sludge blanket

2 2

1 1

3 32

1. Sludge/biomass inlet2. Gas baffle plates3. Return settled sludge

From UASB to EGSB

Sludge bed

Influent

Effluent

Biogas

2

1

1. Sludge/water mixture2. Settled sludge

Re

cycle

Biothane Systems International

9


Application of Multi-layer settling system

Polypropylene settlers

Less PP per m2/ No tropical hardwood


Developments – Technical/Technological

Biopaq® - UASBBiopaq® - IC

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Increasing diameter of Biopaq® - IC



2008 : 15 m

1987 : 2,8 m

100 tpd CODper reactor

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1989 : 6 x Ø 3,2 m

1996 : 1 x Ø 8 m


Full scale AWWT at beer brewery

Beer, NL Heineken, Den BoschUASB

IC

Paper, China

12


Chemical Wastewater TreatmentCOD: 40 kg/m3, of which: - Formaldehyde 20 kg/m3

- Methanol 10 kg/m3

Possible to treat with a UASB??


Fe + micro

Flare

5 m3/h

Conditioning

tank20 m3

Buffertank150 m3

Biobed®

reactor275 m3

5 m3/h 150 m3/h

145 m3/h

120 m3/d

Caustic

Yeast extr.

Macro nut.

Waste water To Carrousel®

Amended process design to prevent toxicity in anaerobic stage

Chemical Wastewater Treatment

98% efficiency17 kg COD/m3.day

Influent : recycle ratio = 1 : 30 !!

Total COD: 40 g/lFormaldehyde: 20 g/l

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Influent

Effluent

BiogasUpflow Anaerobic Attached Fixed Film Expanded Bed (EB)

Attached Growth Anaerobic Fluidised Bed (FB)

Fluidized Bed Systems


FB reactors rebuilt to EGSB reactors at DSM-yeast factory, Delft

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Anaerobic Attached Growth Processes


Upflow Anaerobic Filters (UAF)

Downflow Stationary Fixed Film (DSFF)

Influent

Effluent

Recycle

Biogas

Influent

Effluent

Recycle

Biogas

Anaerobic Filter Systems (1)

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Upflow Anaerobic Filter (UAF)

based on:- attachment of a biofilm to a solid (stationary) carrier material- sedimentation and entrapment of sludge particles between the

interstices of the packing material- formation of well settling sludge aggregates

Major disadvantage- difficult to realise required contact between sludge and wastewater- applicable loads are relatively low, I.e. generally below 10 kgCOD/m3.day



Downflow Stationary Fixed Film (DSFF)Attached Anaerobic Film (AFF)

Sludge retention based on:Attachment of biomass to the packing.(sludge retention is relatively low, because hardly any suspended material retained)

- generally no channelling problems- low loading potentials


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Historically applied anaerobic processes(1981 – 2007 (Jan.) N= 2266)

(Granular) sludge bed based: 77%

IC15%

UASB50%

* 1%FB 2%

HYBR 3%

LAG 4%

CSTR 7%

AF 6%

EGSB 12%

* References with incomplete data (1%)Source: Worldref. 04-2007


Currently Applied Anaerobic Processes(2002 – 2007 (Jan.), N= 610)

* References with incomplete data (1%)Source: Worldref. 04-2007

(Granular) sludge bed based: 89%

Expanded Bed Reactors: 55%

IC33%

* 1%FB 2%

HYBR 2%

LAG 1%CSTR 4%

AF 1%

EGSB 22%

UASB34%

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Full Scale Expanded Bed versus UASB Systems

UASB

Expanded Bed (EGSB, IC, FB)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

1980 1985 1990 1995 2000 2005 2010

Year

Per

cen

tag

e o

f ye

arly

pro

ject

s

UASB

HIGH RATE (EGSB+FB+IC)


Gas

Permeate

Gas

Permeate

Gas

Permeate

Novel development: Aerobic MBR applications / potential Anaerobic homologues

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permeate

biogas injection

wastewater

over-flowpump

P

pressuresensor pump

gas flow-meter

biogasAD under Extreme Conditions

David Jeison (2005)

AD under Extreme Conditions

David Jeison (2005)

Anaerobic Membrane Bioreactor (AMBR)

Fouling control: back-flushing, flow stoppage, biogas recirculation (also for mixing).


Operational performance submerged AnMBR

0

10

20

30

40

50

0 100 200 300

Time (d)

OL

R (

kgC

OD

/m3d

)

0

20

40

60

80

100

CO

D r

emo

val (

%)

OLR COD Removal

0

10

20

30

40

50

0 100 200 300

Time (d)

So

lids

(g/L

)

TSS VSS

Mesophilic conditions, VFA-fed reactor

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0

5

10

15

20

25

0 50 100 150 200 250

Time (d)

Cri

tica

l flu

x (L

/m2h

)

R1: thermophiliccompletely acidifiedR3: mesophiliccompletely acidified

Thermophilic

Mesophilic

Mesophilic Thermophilic

Flux determining factors in anaerobic MBRs

Smaller particle size

Particledeposition

High shear rate

The shear rate dilemma…

(Jeison and van Lier, 2008)


• high retention of viable sludge in the reactor

• sufficient contact between viable biomass and waste water

• high reaction rates and absence of serious transport limitations of

substrate and metabolic end products

• sufficiently adapted and/or acclimatised viable biomass

• prevalence of favourable environmental conditions for all required

organisms inside the reactor under all imposed operational

conditions

High Rate Anaerobic Reactor Systems

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Bacterial attachment on non-fixed carriers

e.g. FB (Fluidised Bed) reactors

Bacterial attachment on fixed support materials

e.g. Anaerobic filters

Auto immobilisation / granulation

e.g. UASB (Upflow Anaerobic Sludge Bed) reactors

Sludge settling and membrane filtratione.g. CP (Contact Process) reactors

AMBR (Anaerobic membrane bioreactors)

AttachedFilm

Principles of Sludge Retention in High-Rate Reactors

Sludge Bed

Separation

10. anaerobic reactor technologies

Documents

cie4485 wastewater treatment

sludge feedc

sludge digestingf

sludge feedb

high sludge content

anaerobic reactor technologies

sludge discharge pipestander

wastewaters wastewaters