High Rate Thermophilic Anaerobic Membrane

Bioreactor for Wastewater Treatment

by

Kaushalya C. WijekoonMaster Student (st107821)

EEM/SERD

Wastewater Ξ Biogas Ξ Green

Energy

1/22

Content

Study Background

Aerobic Wastewater Treatment

Anaerobic Wastewater Treatment

Anaerobic Membrane Bioreactor

Potential Application Areas

Achievements of the Study

Conclusions

2/22

Wastewater Treatment Options

3/22

Aerobic Biodegradation

Biomass

Organic Matters + O2 + CO2 + H2O

Anaerobic Biodegradation

Organic Matters + CO2 + H2O

Biomass

Aerobic Process: High Energy Demand

Sludge Treatment

50 % of Wastewater Treatment Plant’s

Energy Requirement

3/22

30 - 40 % of Wastewater Treatment

Plant’s Energy Requirement

Aeration Tank

Anaerobic Process

Why Anaerobic Process

Lessnutrient removal

Low biomass production

Low energy requirement

Energy recovery through biogas

Low sludge production

Opportunity for nutrient recovery

Low Cost & Less Energy

Requirement

5/22

Why Thermophilic Anaerobic Process

Increased Microbial activity

Promote higher loading rates,

Higher Biogas Production

Effluent disinfection :

Promote Wastewater Reuse

6/22

Thermophilic Anaerobic Process: Problems Encounter

Biomass retention is crucial

Membrane Bioreactor

7/20

Restrained thermophilic

application of high rate

anaerobic wastewater treatment

Dispersed sludge production

Increased biomass washout

100 % Biomass Retention

Ideal Solution to Biomass Washout

Anaerobic Membrane Bioreactor (AnMBR)

Recirculation Pump

Treated water

Feed

Biogas

Membrane ModuleConcentrate

Biomass Waste

8/20

Membrane

Membrane Filtration : Biomass & Treated

Wastewater Separation

Why Two Stage Anaerobic Membrane Bioreactor ?

PermeateBiogas

Methanogenic Reactor

MembraneModule

Concentrate Recirculation

Feed

Biogas

Hydrolytic Reactor

9/22

Advantages : Easy to Control Optimum Conditions of Both Reactors Increased Biogas Production Increased Process Stability Higher Organic Loading Higher Organic Matter Removal Efficiency

Potential Applications of Thermophilic Anaerobic Membrane Bioreactor Palm Oil Industry Wastewater Pulp and Paper Industry Food Processing Industry Sea Food Industry Tanneries Sugar Manufacturing Textile Industry

10/22

Hot wastewater from

Industries

Palm Oil

Palm Oil Processing Flow Chart

FFBTransportation of FFBSterilization

Cooking (Digestion and Pressing)

Clarifier

All Wastewater Streams are at High Temperature

Treshing

EFB

Wastewater

11/22

Wastewater from Plant

Palm Oil Industry Wastewater Treatment

12/22

Loss of Energy GHG Emission Inefficient Treatment Massive Land Requirement

Step-Aeration

Anaerobic Pond System

Palm Oil Industry : Wastewater Characteristics

Parameter Value

BOD (mg/L) 16,000

COD (mg/L) 41,000

Oil & Grease (mg/L)

3,700

Total Nitrogen (mg/L)

32.9

pH 3.9

Temperature (oC) (Before cooling) 78.0

Temperature (oC)(After cooling) 40.0

Energy Loss

High Organic Loading

13/22

0 5000

Biogas Production (m3/d)

Org

anic

Lo

ad (

kg/d

)5000

Organic Load and Biogas Production

10,000 15,000 20,000 25,000 30,000

10,000

25,000

20,000

15,000

Palm Oil Processing : Energy Recovery from Anaerobic Membrane bioreactor

Sterilization

Digestion and Pressing

Treshing

EFB

Wastewater

Biogas

Anaerobic Membrane Bioreactor 14/22

Energy Back to the Plant

Suction Pump

Retentate recirculation

Methanogenic Reactor

Hydralitic Reactor

Feed Tank

Membrane

Biogas

U tube

Biogas Bag

Level Controller

SV1

SV2

Time Controller

P

Water Bath

Temperature Controller

Biogas Bag

Biogas

Experimental Setup : Two Stage AnMBR

Treated Water

15/22

Retentate recirculation

Methanogenic Reactor

Hydralitic Reactor

Feed Tank

Membrane

Biogas

U tube

Biogas Bag

SV2

Time Controller

Biogas Bag

Biogas

Experimental Setup : Two Stage Anaerobic Membrane

Bioreactor

16/22

BiogasBiogas BiogasBiogas

Treated Water

Biogas

Gravity flow to the

membrane

Ceramic Microfilter membrane with 0.1 µm

nominal pore size Membrane Operation in

Partial Sedimentation

Mode

Membrane : Mode of Operation

17/22

Gravity Flow to Membrane

Low Energy Requirement

Experimental Setup

18/22

Hydrolytic Rector Methanogenic

Rector

External Membrane

Two Stage Thermophilic Anaerobic Membrane Bioreactor

Organic Matter Removal Efficiency

Higher Removal Efficiency

Can Treat high concentration wastewater effectively :

(used wastewater concentration = 10,000- 24,000 mg/L)

Have the Potential to work in high loading rates. 19/22

Major Achievement s

50

60

70

80

90

100

Organic Loading Rate (kg COD / m3.d)

Org

anic

Mat

ter

Rem

oval

E

ffic

ien

cy (

%)

5 8 12

Almost all Organics Removed

Organic Matter Removal : 96 %

Biogas Generation & Methane Composition

Methane Composition = 60 % : similar or higher than other reactors

High Gas Production = 5 times of reactor volume : Very Good

20/22

Days

Biog

as C

ompo

sitio

n (%

)

Biog

as G

ener

ation

(L/d

)

0

5

10

15

20

25

30

35

1 11 21 31 41 51 61 71 81 91 101 111 121 131

Days

Bio

gas

Gen

erat

ion

(L

/d)

0

20

40

60

80

Biogas Generation Rate CH4 %

60 % of Methane

Methane Yield of Two Stage AnMBR

High Methane yield Good Performances over Single Stage/ mesophilic Anaerobic

Membrane Bioreactors and over other Anaerobic Reactors

21/22

0.0

0.1

0.2

0.3

0.4

0.5

1 11 21 31 41 51 61 71 81 91 101 111 121 131

Days

Met

han

e Y

eild

(m

3 CH

4 / k

g C

OD

rem

oved

.d)

Methane Yield = 0.3 – 0.4 m3 CH4/kg COD removed .d

Conclusions

22/22

High Temperature & High Concentration

Wastewater

Two Stage Anaerobic Membrane Bioreactor

Efficient removal of Organic Matter

Energy Generation : Green Energy( 1.5 kWh/m3)

Thank You for Your Attention

Conclusion

Two Stage AnMBR

Energy Requirement

0.9 kWh/m3

Energy Generation

1.5 kWh/m3

A Net Energy Generation

22/22

Organic Matters (Carbohydrate, Protein, Fats)

Simple Organic Matters(Glucose, Amino Acid, etc)

Hydrolysis

Volatile Fatty Acids(Acetic, Butyric, Propionic)

Acidogenesis

H2 , CO2 Acetate

CH4 + CO2

Anaerobic wastewater Treatment Process

Methanogenesis

Acetogenesis

2/20

Wastewater a Green Energy

Fresh Fruit Bunch sterilization Digestion

Wastewater from the Industry

Cooling Pond

Palm Oil Industry Wastewater Generation : Outlook

11/22

Existing Treatment Method Loss of Energy GHG Emission Inefficient Treatment Massive Land Requirement

Anaerobic Pond System

13/22

0

2000

4000

6000

8000

1 11 21 31 41 51 61 71 81 91 101 111 121 131

Days

Tot

al V

FA

Gen

erat

ion

(m

g/L

)

4

5

6

pH

pH &Volatile Fatty Acids (VFA)

Higher Volatile Fatty Acid Generation : 3000-7000 mg/L

Higher Reactor Stability : Constant pH regardless increasing volatile

fatty acid concentration

19/22

Hydrolytic Reactor Major Achievement

Other Reactors2500 - 3000 mg/LVFA =2500 mg/L

pH = stable 5.5

VFA =4700 mg/L

VFA =7000 mg/L