(PDF) WASTEWATER TREATMENT USING MEMBRANE BIOREACTOR

WASTEWATER TREATMENT USING MEMBRANE

BIOREACTOR

BY

SHENDE TAKSHAK BHIMRAO

Department of Civil Engineering

Submitted

In partial fulfillment of the requirement of the degree of

MASTER OF TECHNOLOGY

TO

Department of Civil Engineering

Indian Institute of Technology Delhi

MAY 2009

WASTEWATER TREATMENT USING MEMBRANE

BIOREACTOR

MASTER OF TECHNOLOGY

in

ENVIRONMENTAL ENGINEERING

AND MANAGEMENT

by

Shende Takshak Bhimrao

2007CEV2760

Under the Guidance of

Dr. A K Mittal

Department of Civil Engineering

Indian Institute of Technology

May, 2009

CERTIFICATE

This is to certify that the thesis titled “WASTEWATER TREATMENT USING

MEMBRANE BIOREACTOR” is a bonafide record of work done by Mr. SHENDE

TAKSHAK BHIMRAO for fulfillment of the requirement for the degree of Master of

Technology, Environmental Engineering & Management, Department of Civil Engineering,

Indian Institute of Technology Delhi, New Delhi, India. He has fulfilled the requirements for

the submission of this thesis, which to the best of my knowledge has reached the required

standard.

This thesis was carried out under my supervision and guidance and has not been

submitted elsewhere for the award of any other degree.

New Delhi Dr. A. K. Mittal

MAY 2009 Associate Professor, Department of Civil Engineering

Indian Institute of Technology Delhi, New Delhi.

ACKNOWLEDGEMENT

I feel immense pleasure and privilege to express my deep sense of gratitude,

indebtedness and thankfulness towards my supervisor, Dr. A. K. Mittal, Associate Professor,

Department of Civil Engineering, Indian Institute of Technology, New Delhi, for his

invaluable guidance, constant supervision, continuous encouragement and support throughout

this work. His suggestions and critical views have greatly helped me in successful completion

of this work.

I extend my sincere thanks to Prof. Dr. Mukesh Khare, Dr. A K Nema, Dr. B. J.

Alappat, for their time and expert suggestion and comment which contributed a lot towards

my work.

I would also like to thank all the staff members Mr. Sanjay Gupta and Mr. Ishwar

Singh of the Environmental Engineering lab for their cooperation and help they provided

during the study.

I would also like to thanks Mr. Santosh Kolte, Research scholar, Dept of Civil

Engineering, IIT Delhi for their suggestions and help in carrying out this work.

I am also thankful to all those who helped directly or indirectly in completion of this

work.

New Delhi (SHENDE TAKSHAK BHIMRAO)

MAY 2009 (2007CEV2760)

i

ABSTRACT

India is widely using UASB for wastewater treatment. Due to some disadvantages of UASB

for Indian scenario like effluent of brown colour, less production of Energy, upgradetion of

UASB is required. Present study is with the objective of Upgradetion of UASB technology

using Membrane Bioreactor. A laboratory scale upflow anaerobic bioreactor coupled with a

ultra filtration membrane was investigated for treating synthetic wastewater at different

Organic Loading rate and Temperature. The system was capable of achieving over 75% of

Chemical Oxygen Demand (COD) removal with effluent of COD less than 250mg/L, on the

average at volumetric loadings ranging from 1.0799 to 7.1994 kg/m

3

.d. Very low COD

removal efficiency was observed during starting period due less temperature and low upflow

velocity. COD removal efficiency was increased after increase in the atmospheric

temperature and upflow velocity and reaches to 76% at OLR of 1.727 Kg/m

3

d. HRT of the

reactor was increased due to reduction in flux due to fouling of membrane. Irreversible

fouling of membrane was more compare to the reversible fouling of membrane in the reactor.

Membrane permeability was largely affected by intermittent suction mode and backwashing

mode. Backwashing of membrane with thrice the suction flow rate for 4 min found efficient

for minimizing fouling of membrane. A stable operation could be maintained continuously

with membrane flux less than 3 L/m

3

h. Critical flux of 3 L/m

2

h was observed after flux step

method.

ii

CONTENTS

Page No.

Acknowledgements i

Abstract ii

List of figures iii

List of plates iv

List of Table v

Notation vi

Chapter I: Introduction and Objectives

1.1 Objectives of present study 2

1.2 Scope of present study 2

1.3 Methodology 3

1.4 organization of report 3

Chapter II: Membrane Bioreactor – An Overview

2.1 Membrane Bioreactor 4

2.2 Membrane fouling and Flux Reduction in AnMBR 5

2.2.1 Membrane Material and pore size 6

2.2.2 Suspension properties 7

2.2.3 Operation condition 7

2.3 Critical flux 8

2.4 Some studies on Anaerobic Membrane bioreactor 8

Chapter III: Design of Anaerobic Membrane Bioreactor

3.1 Design of AnMBR 14

Chapter IV: Material and method

4.1 Experimental setup

4.1.1 Peristaltic pump 16

4.1.2 Diaphragm vacuum pump 16

4.1.3 Water level sensor and controller 16

4.1.4 Electric valve 17

4.1.5 Electronics circuit 17

4.1.6 Manometer 17

4.1.7 Rotameter 17

4.1.8 Biogas measurement using Water displacement Method 17

4.1.9 Membrane module 17

4.2 Methodology

4.2.1 Reactor Start up 23

4.2.2 Preparation of Synthetic wastewater 23

4.2.3 Preparation of Flat sheet membrane cartridge 24

4.2.4 Experimental Methodology 25

4.2.4.1 Membrane Performance characterization 25

4.2.4.2 Critical Flux Determination 26

Chapter V: Result and discussion

5.1 Anaerobic Inoculums Composition 27

5.2 Reactor Performance 29

5.2.1 Operation Mode 1 (0 – 18 days) 29

5.2.1 Operation Mode 2 (18 – 34 days) 29

5.2.1 Operation Mode 3 (34 – 39 days) 30

5.2.1 Operation Mode 4 (40 – 55 days) 30

5.2.1 Operation Mode 5 (55 – 65 days) 31

5.2.1 Operation Mode 6 (65 – 79 days) 31

5.2.1 Operation Mode 7 (80 – 18 days) 32

5.2.1 Operation Mode 8 (95 – 105 days) 32

5.3 Membrane Performance 35

Chapter VI: Conclusion 44

References 45

Appendix - A 50

Table of Experimental and calculated value 50

LIST OF FIGURES

Fig No. Name Page No.

2.1 Membrane bioreactor for wastewater treatment according to membrane 5

Position

2.2 Partial filtration resistance during Membrane filtration 6

(Jaison D., 2007)

4.1 Experimental set up of Anaerobic Membrane Bioreactor 18

4.2 Membrane Cartridge 24

5.1 Variation of COD of Influent and Effluent with Time 33

5.2 Variation of COD removal with respect to Organic Loading rate 33

5.3 Variation of Alkalinity and pH with Time 34

5.4 Variation of VFA and α value with Time 34

5.5 Variation of TMP and flux with Time 36

5.6 Variation of TMP and flux with Time on 15

th

day of operation 36

5.7 Variation of TMP and flux with Time on 16

th

day of operation 37

5.8 Variation of TMP and flux with Time on 17

th

day of operation 38

5.9 Variation of TMP and flux with Time on 18

th

day of operation 39

5.10 Variation of TMP and flux with Time on 19

th

day of Operation 39

5.11 Variation of TMP and flux with Time on 20

th

day of Operation 40

5.12 Variation of TMP and flux with Time on 22

nd

day of Operation 40

5.13 Variation of TMP and flux with Time after 47

th

day of Operation 41

5.14 Variation of TMP and flux with Time after 48

th

day of Operation 42

5.15 Critical flux determination using flux step method on 70

th

day of operation 43

iii

LIST OF PLATES

Plate No. Name Page No.

Plate 1 AnMBR experimental setup 19

Plate 2 Peristaltic Pump Assembly 19

Plate 3 Water level sensor and controller 20

Plate 4 Electronic Circuit for Automatic control of Pump and solenoid 20

Plate 5 Biogas measurement using Water displacement method 20

Plate 6 Rota meter and pressure gauge 21

Plate 7 Solenoid connected with Electronic circuit 21

Plate 8 Membrane bioreactor for wastewater treatment and Manometer 22

Plate 9 Input and output point in the reactor 22

Plate 10 Diffuser in the reactor 23

iv

LIST OF TABLE

Table No. Name Page No.

2.1 Biological and Membrane performance in past Anaerobic MBR research 10

3.1 Specification of Anaerobic Membrane bioreactor 15

4.1 Chemical Composition of Synthetic Wastewater 23

4.2 Trace Element for synthetic wastewater 24

4.3 Methods for analytical study of different parameter of AnMBR 25

5.1 Composition of Anaerobic Inoculums 27

5.2 Reactor operation 28

A1 Experimental Results for Concentration of alkalinity, COD and OLR. 50

A2 Experimental Result for VFA and Bicarbonate Alkalinity and calculated

α value 54

A3 Experimental Result for Variation of TMP with time after submergence of

Membrane in the reactor 56

A4 Experimental results for TMP and Flux on 15

th

day of operation 58

A5 Experimental results of TMP and Flux on 16

th

day of operation 61

A6 Experimental results of TMP and Flux on 17

th

day of operation 63

A7 Experimental results of TMP and flux on 18

th

day of operation 66

A8 Experimental results of TMP and flux on 20

th

day of operation 69

A9 Experimental results of TMP and flux on 22

nd

day of operation 71

A10 Experimental results of TMP and flux on 47

th

day of operation 72

A11 Experimental results of TMP and flux on 48

th

day of operation 73

A12 Experimental results of Flux Step Method 75

v

NOTATIONS

R

T

Membrane Resistance

R

C

Resistance due to cake layer formation over the membrane

R

F

Resistance due to membrane fouling linked to pore blocking and adsorption

R

CP

Resistance originated from the formation of the condensation polarization layer.

J Applied flux

.

Fig. Figure

m Meter

l litter

Q Flow rate, lit/day

A

c

Cross section Area of reactor, m²

A

m

Membrane area required, m

2

W

m

Width of Membrane, m

v Upflow velocity, m/hr

L

r

Length of Reactor, m

W

r

Width of Reactor, m

Greek letters

η Permeate viscosity

Abbreviations

AnMBR Anaerobic Membrane Bioreactor

MBR Membrane Bioreactor.

AnSMBR Anaerobic Submerged Membrane Bioreactor

UASB Upflow anaerobic sludge blanket

HRT Hydraulic Retention time

TMP Trans Membrane Pressure

VFA Volatile Fatty Acid

MLSS Mixed liquor suspended solid

OLR Organic Loading Rate

COD Chemical Oxygen Demand

TSS Total Suspended Solid

Temp. Temperature

VSS Volatile Suspended Solid

1

Chapter I

INTRODUCTION AND OBJECTIVES

Biological waste treatment processes play a central role in the way societies manage their

wastewaters. It is based on the activity of a wide range of micro-organisms, converting

the organic pollutants present in the wastewater. The treatment capacity is directly related

to the amount of micro-organisms that can be effectively retained in the treatment

system

.

The traditional way to achieve a high biomass concentration in wastewater

treatment systems is by post-reactor sludge settling, followed by recirculation of the

settled sludge to the biological reactor.

Low biomass yields and low growth rates represent one of the important advantages of

anaerobic biotechnology, since they translate into the generation of low amounts of waste

sludge, up to ten times less than during aerobic treatment. Installation of the first full

scale upflow anaerobic sludge blanket (UASB) reactor, three decades ago (Lettinga et al.,

1980), anaerobic process has been successfully used for the treatment of many kinds of

industrial wastewaters as well as sewage. Nowadays, it can be considered an established

technology that offers the possibility of an efficient treatment with low capital and

operational costs.

At present close to 80% of all full-scale anaerobic installations are sludge bed reactors in

which biomass retention is attained by the formation of sludge granules.

Obviously, the

granulation process represents a key factor in the operation of these high-rate anaerobic

reactors. Several conditions have been identified to play an important role in the

formation and stability of anaerobic granules. Both, wastewater characteristics and

operational conditions have been shown to be of determinative importance (Jeison,

2007). Granule formation is a complex process involving physical-chemical as well as

biological interactions. The success of anaerobic wastewater treatment can be attributed

to an efficient uncoupling of the solids residence time from the hydraulic residence time

through biomass retention, which is usually accomplished through biofilm or granule

formation. With this strategy, a high concentration of biocatalyst is obtained, leading to

high volumetric treatment capacities.

2

Biofilm or granule formation is severely affected in UASB and Granular sludge bed

reactor, membrane assisted physical separations can be used to achieve the essential

sludge retention. Membrane bioreactors (MBR) ensure biomass retention by the

application of micro or ultra filtration processes. This allows operation at high sludge

concentrations (Stephenson et al., 2000). Since biomass is physically retained inside the

reactor, there is no risk of cells washout and the conversion capacity is apparently non-

dependent on the formation of biofilms or granules. In addition, membrane bioreactors

offer the possibility to retain specific micro-organisms that, in the generally applied

upflow reactors, would wash out (Vallero et al., 2005). Furthermore, since the permeate

is free of solids or cells, water would eventually require less post-treatment steps if reuse

or recycle is of interest, in comparison with sludge bed technologies.

So far, the main drawback of MBR systems is related with membrane costs, energy

requirements and membrane fouling (Choo and Fane., 2002). However, important

advances have been made in the development of new types of membranes, of which the

costs have been significantly, reduced (Judd, 2006).

1.1 OBJECTIVES

Development in UASB using Membrane based Technology for efficient wastewater

treatment.

• To design and Install a transparent Anaerobic submerged Membrane Bioreactor.

• To study removal efficiency of COD.

• To study influence of various HRT and organic loading rate on pollutant removal.

• To study the effect of backwashing of membrane for flux recovery and fouling

mechanism in ultrafiltration membrane.

1.2 SCOPE

The scope of the work to access the efficiency of the AnMBR for synthetic wastewater

treatment under cyclic operation of suction and backwash. Backwashing was the only

physical cleaning method used for minimizing fouling.

3

1.3 METHODOLOGY

The following methodology was adopted to achieve the set objective.

• Experimentation works were conducted on AnMBR experimental set up at

different flow rate and organic loading rate from mid January to May.

• Synthetic wastewater was used for experimentation work.

• Electronics circuit was developed for continuous cyclic operation of Suction and

Backwashing of membrane.

• Following parameter were measured during experimentation work.

COD, pH, Alkalinity, were measured as per standard methods. TMP was

measured with the help of manometer; VFA was measured using Distillation Method

described in Standard Methods. Biogas produced was measured with the help of

water displacement method.

1.4 ORGANIZATION OF THE REPORT

The current report is organized into six chapters. The second chapter includes the

literature search wherein the salient features of the literature collected are discussed and

overview of Membrane Bioreactor has been given. In the third chapter the design of

Anaerobic Membrane Bioreactor an upgradetion of UASB is presented. Fourth chapter

consists of details of experimental setup and method used for experimentation wok. In

Chapter five results obtained so far have been discussed. The sixth chapter is giving

concluding remark.

4

Chapter II

MEMBRANE BIOREACTOR – AN OVERVIEW

2.1 MEMBRANE BIOREACTOR

Research on membrane bioreactor started 30 years ago. The technology first entered in

the Japanese market through a license agreement between Dorr-Oliver and Sanki

Engineering Co Ltd. And today they are commonly used in Japan. Today over 500

Membrane bioreactors are being used in processed for treating and reuse of domestic

wastewater and industrial wastewater. (Stephensen et al., 2000)

Membrane bioreactor (MBR) technologies are, as the name suggests, those technologies

that provide biological treatment with membrane separation. According to how the

membrane is integrated with the bioreactor, two MBR process configurations can be

identified: side-stream and submerged (Figure 2.1). In side-stream MBRs membrane

modules are placed outside the reactor, and the reactor mixed liquor circulates over a

recirculation loop that contains the membrane. In submerged MBRs, the membranes are

placed inside the reactor, submerged in the mixed liquor. Side-stream MBRs involve

much higher energy requirements, due to higher operational trans-membrane pressures

(TMP) and the elevated volumetric flow required to achieve the desired cross-flow

velocity. Indeed, pumping requirements for side-stream aerobic MBRs account for 60 to

80 % of the total energy consumption, aeration being only 20 to 40% (Gander et al.,

2000). However, side-stream reactors have the advantage that the cleaning operation of

membrane modules can be performed more easily in comparison with submerged

technology, since membrane extraction from the reactor is needed in the later case.

Submerged MBRs involve lower energy needs, but they operate at lower permeate fluxes,

since they provide lower levels of membrane surface shear. The latter means higher

membrane surface requirements. The selection between submerged and side-stream

configurations for aerobic MBRs seems somehow settled, in favour of submerged MBRs.

In fact, nowadays, most of the commercial applications are based on the submerged

configuration, due to lower associated energy requirements (Judd, 2006).

5

Fig.2.1 Membrane Bioreactor for wastewater treatment according to membrane

Position

Most of the reported research done with anaerobic membrane bioreactors (AnMBR) has

been performed with the side-stream configuration (Liao et al., 2006). However, the

potential negative effect of the circulation of digester broth through the membrane unit,

pumps and valves has raised some concern. Anaerobic degradation of organic matter

involves the participation of different micro-organisms, with complex metabolic

interactions (Jeison, 2007).

2.2 MEMBRANE FOULING AND FLUX REDUCTION IN AnMBR

Membrane fouling is definitively the main drawback of the application of MBRs for

wastewater treatment (Flemming et al., 1997). Membrane cleaning activities directly

affect reactor operation due to the need for process interruptions. The flux reduction

phenomenon is usually analysed in terms of filtration resistances. The flux through the

membrane is a function of the TMP, the permeate viscosity (η) and the total resistance

(R

T

) (Judd, 2006).

in which J represents the applied flux

.

The total resistance can be divided in several

partial resistances (Mulder, 1996):

6

Where R

T

is the membrane resistance, R

C

is the resistance due to cake layer formation

over the membrane, R

F

is the resistance due to membrane fouling linked to pore blocking

and adsorption and R

CP

is the resistance originated from the formation of the

condensation polarization layer.

Fig 2.2 Partial filtration resistance during Membrane filtration (Jeison D., 2007)

Applied flux is affected by following factor: membrane material and pore size,

suspension properties, and operational conditions.

2.2.1 Membrane Material and Pore Size

Selection of type of membrane should be basis on the material of membrane and pore

size. Membrane materials used for wastewater treatment are typically made of

polypropene cellulose acetate, aromatic polyamides or thin-film composite (Metcalf &

Eddy, 2003). Several type of configuration of membranes has been used for MBR

applications. This includes tubular hollow fibre membrane, Flat plate and frame

membrane, rotary disk. Mainly polymeric membranes have been used in MBR systems

for wastewater treatment, based on their lower costs. Membrane hydrophobicity has

shown in some studies to play a significant role (Chang and Lee, 1998; Stephenson et al.,

2000; Jeison, 2007). Hydrophobic protein residues can form strong attachments to

hydrophobic membranes resulting in strong fouling (Jaison, 2007).

7

Membrane pore sizes used in wastewater treatment applications are in the range of 0.02-

0.5 µm (Stephenson et al., 2000). Higher pore sizes may foul more rapidly as a result of

blocking by macro colloids or cells, while those smaller are expected to foul more readily

as a result of clogging by micro-colloids that can adsorb to the internal surface of the

pores. It should also be considered that membrane rejection properties are not only

defined by membrane pore size but also by the formation of a gel or cake layer, which

acts as a secondary dynamic membrane. This phenomenon has been observed in both

anaerobic and aerobic MBRs (Choi et al., 2005; Jeison, 2007).

2.2.2 Suspension Properties

Suspension properties can also affect the filtration performance of the membrane.

Increasing the suspended solids concentration usually produces a decrease in the

attainable flux (Beaubien et al., 1996). Indeed, convective flow of particles towards the

membrane surface is directly related with the suspended solids concentration. Particle

size distribution can also strongly determine solids deposition over the membrane

surface. Complex systems like AnMBRs, filtration flux may be determined by a fraction

of the total sludge. Not only suspended solids, such as biomass, can affect membrane

permeability, but also many other agents like colloids (Choo and Fane., 2000), soluble

organic matter, inorganic precipitates (Choo and Lee, 1996) and extracellular polymers

(Chang and Lee, 1998). The relative contribution of all these fouling agents to the overall

performance is, of course, determined by the conditions of each particular application

.

2.2.3 Operation Condition

Operational conditions are the third key factor determining flux reduction. Membrane

fouling is usually prevented applying shear over the membrane surface. An increase in

the cross-flow velocity usually results in an increase of the applicable flux (Beaubien et

al., 1996). However high cross-flow velocities can induce a decrease in particle size

distribution, increasing the chances for particle deposition (Choo and Lee, 1996). Gas

sparging is the most common way to provide high shear conditions in submerged MBRs.

Air sparging is widely used in aerobic MBRs, where it carries out a double function:

provide oxygen transfer to the liquid phase, and promote scouring of the membrane

surface (Cui et al., 2003). In AnSMBRs biogas can be recirculated in order to achieve a

8

similar effect. At increasing gas flow rates bubbles tend to collide and coalesce, which

leads to large bubbles referred to as gas slugs or Taylor bubbles. Bubbles motion

generates secondary liquid flows that enhance the liquid-membrane surface mass transfer,

especially in the liquid falling film region and the bubble wake (Taha and Cui, 2002).

2.3 CRITICAL FLUX

The critical flux concept was introduced over 10 year ago, and has proven useful to

characterize membrane fouling in membrane applications, especially in MBRs (Bacchin

et al., 2006). The critical flux was originally defined as the flux below which no fouling

occurs. So, the critical flux is the value at which TMP starts to deviate from the pure

water behaviour

.

Different methods have been used to determine the critical flux, such as direct membrane

observation (Lee et al., 2007), mass balances (Kwon and vigneswaran., 1998) and TMP

observation in flux step or cycling experiments (Chen et al., 1997). Mass balances and

microscopic observations are unlikely to be used in full-scale installations or in

submerged MBRs. However, pressure increase at constant flux operation can be easily

applied for critical flux determination in any type of membrane process, both at lab and

full scale

.

2.4 SOME STUDIES ON ANAEROBIC MEMBRANE BIORECTOR

Table 2.1 represent several research reports about application of AnMBR for Wastewater

treatment. Table 2.1 represents biological performance as well as membrane

performances attained during the past researches. These reports show that the application

of AnMBRs has been studied so far for a wide variety of wastewaters: sewage, food

processing wastewaters, industrial wastewaters, high solids wastewaters. However, the

application of membrane filtration to anaerobic digestion processes is still in its

developing stage.

9

Liao et al. (2006) refer to the potential applications of AnMBRs. According to them,

minimal opportunities for AnMBR application exists for the treatment of high-strength

soluble wastewaters, since granular technologies already provide a reliable treatment of

these wastes. On the contrary, high-strength particulate wastewaters offer extensive

opportunities for the application of AnMBRs, due to its complete solids retention. The

authors also consider the application of membrane technology to low strength

wastewaters as a future opportunity. However, it must be realised that during the

treatment of dilute wastewaters, hydraulic retention time will be low, requiring a high

permeate flow, and thus a high permeate flux or a high membrane area.

10

Table 2.1: Biological and Membrane performance in past Anaerobic MBR research

Type of

wastewater

Configurati

on

Volume

M

3

Temp.

o

C

MLSS

g

TSS/L

OLR

kgCOD/m

3

d.

Removal

%

Pore

size

µm

TMP

bar

Cross

flow

velocity

m/s

Final or

Mean

Flux

L/m

2

.h

Reference

Leachate submerged 29 L 35 - 0.7–4.9 95 0.1

µm

- - - Bohdziewicza et al.,

2007

synthetic Submerged 24 L - - - 93 0.2 1 - 10 Yuan et al., 2008

synthetic submerged 3.7 L 30 - 2.0 - 0.2 0.4 - 20 Jeison D, 2007

sewage submerged 0.018 m

3

24-25 16-22 0.4-11 60-95 0.03 0.6 - 5-10 Wen et al., 1999

synthetic submerged 3 L 35 - 1.6 98 0.4 0.25 - 5 Akram and stuckey.,

2008

Acetate,

ethanol,

sulphate

(sulphate

reduction)

submerged 6L 33 Upto

1.8

-

- 0.2 0.1-

0.4

- 17 Vallero et al., 2005

Synthetic

(hydrogen

recirculation)

Submerged 10.1 L 25-30 --

-

- 0.04 0.2bar -- -- Rezania et al., 2007

11

Type of

wastewater

Configurati

on

Volume

M

3

Temp.

o

C

MLSS

g

TSS/L

OLR

Removal

%

Pore

size

µm

TMP

bar

Cross

flow

velocity

m/s

Final or

Mean

Flux

L/m

2

.h

Reference

Domestic

wastewater

Side stream 50 L 37 43 - 49 0.23 - 2 90 - 1 - 2 3 m/s 9 Saddoud et al., 2007

Acetic acid Side stream

0.007 m

3

30 20 -25 20 90 0.2

µm

- 2-3 5-10 Fuchs et al., 2003

Sauerkraut

brine

40- 60 8 >95

Slaughterhou

se

20 - 28 4 >95

Alcohol

fermentation

Side stream 0.005 m

3

55 2 3 - 3.5 90-95 0.2 0.6 3 115 Kang et al (2002)

Slaughterhou

se

50L 37 - 4.37 93.7 o.14 75 Saddoud et al (2007)

Kraft pulp

mill

Side Stream 5 L 53 9 10.7 - - 1 3 20 Minami et al (1991)

12

Type of

wastewater

Configurati

on

Volume

M

3

Temp.

o

C

MLSS

g

TSS/L

OLR

Removal

%

Pore

size

µm

TMP

bar

Cross

flow

velocity

m/s

Final or

Mean

Flux

L/m

2

.h

Reference

synthetic Side stream 1 L 35 - - - 2000k

Da

- - - Lee et al 2007

Acetate Side stream 9 L 35 5-20 0.8 - 0.9 95 0.2 - - - Beaubien et al 1996

synthetic Side stream 25 L - 2.3 g/L 0.46 – 1.44 85 0.2 0.35 2 25 Sui et al. 2008

synthetic Side stream 4.5L 54-56 - - - 0.4 - 0.75 24 Choo and fane, 2002

Food

industry

Side stream 0.4 m

3

37 6-8 4.5 81-94 o.14 0.6-2 0.5-3 - He et al., 2005

Swine

manure

Side stream 6 L 37 20-40

1-3

- 20- 70

kDa

2 1-1.1 10-30 Zhang et al., 2007

13

Type of

wastewater

Configurati

on

Volume

M

3

Temp.

o

C

MLSS

g

TSS/L

OLR

Removal

%

Pore

size

µm

TMP

bar

Cross

flow

velocity

m/s

Final or

Mean

Flux

L/m

2

.h

Reference

Alcohol

distillery

Side stream 4 L 53-55 0.5 1.5 - 2 97 20

kDa

0.3-

0.7

1-2 5-10 Zhang et al., 2007

municipal Side stream 50 L 35 - - 98.1 20

kDa

1-2 0.24 -

0.95

3-10 Choo & lee., 1996

Municipal Side stream - - - - - 0.2 0.2 -

1.2

3.5-10 45 Kocadagistan and

topcu, 2007

14

Chapter III

DESIGN OF A ANAEROBIC MEMBRANE BIOREACTOR

Design of the Anaerobic Membrane bioreactor is based on flow rate of the wastewater,

desired flux through membrane, and upflow velocity of the wastewater. Design of reactor

is done on the principle of UASB reactor. Various parameters in the design are

considered according to literature and previous studies.

3.2 DESIGN OF ANEROBIC REACTOR “B”

Assume

Flow rate Q = 25 lit/day

Flux through membrane (J) = 12 L/m

2

h

Upflow velocity (v) = 0.2 m/hr

Now,

Cross section area of rector (A

r

) = Q/v

= 5.208 x 10

-3

m

2

If Width (W

r

) = 0.03 m

Length (L

r

) = 0.1736 m

Adopt length (L

r

) = 17 cm

Now,

Membrane area required (A

m

) = Q/J

= 0.0868 m

2

If,

Width of membrane (W

m

) = 0.14 m

Height of Membrane = A

m

/W

m

= 0.62 m

2

If, working height of reactor = 0.8 m

Volume of reactor = 4.1667 x 10

-3

m

3

Total Height of Reactor = working height + height for collection of Gas

= 0.8+ 0.1 = 0.9 m

Hydraulic retention time (HRT) = 4 hr

15

Specification of the Anaerobic membrane bioreactor are as given in table 3.1

Table 3.1: Specification of Anaerobic Membrane bioreactor

Sr.

No.

Parameter MBR Reactor

1 Type of membrane Flat sheet membrane

2 Flow rate (Q) 25 lit /day

3 Flux (J) 12 lit/m

2

.h

4 Upflow velocity 0.2 m/s

5 Size of

Reactor

Width 0.03 m

Length 0.17 m

Height 0.9 m

6 Size of membrane 0.14 m x 0.62 m

7 Membrane Area Required

0.0868 m

2

Provided

0.054 m

2

8 Pore size of membrane 0.03µm

16

Chapter IV

MATERIAL AND METHODS

4.1 EXPERIMENTAL SETUP

A schematic diagram of the experimental system consisting of an anaerobic bioreactor, in

which a membrane module is submerged, is as shown in Fig.4.1. The system included a

storage tank, an anaerobic reactor, membrane modules and a membrane cleaning system

The Reactor was fabricated using transparent Perspex sheet. A 4.167 L useful volume

AnSMBR was used to conduct this study. Reactor was fitted with Flat sheet ultrafiltration

membranes fabricated in Environmental Engineering Lab of IIT Delhi; with a nominal

mean pore size of 0.03µm. Reactor was operated under different Temperature condition.

Membrane module was of 14 cm of width and 62 cm of height respectively with

membrane area of 0.054 m

2

. Permeate was collected by mean of peristaltic pump that

provide the required trans-membrane pressure (TMP). TMPs was measured using

manometer located in the permeate line. Synthetic Wastewater was pumped in the reactor

using Peristaltic pump which was controlled through level sensor and level controller

system. Fine bubble diffuse are used for gas sparging. Measurement of biogas was done

with the help of Water displacement method. Electronic circuit was developed for control

of permeate, biogas flow during suction and backwashing operation. The various

instrument were used are as follows

4.1.1 Peristaltic pumps

Three number of Peristaltic pump were used for experimental setup as shown in plate no.

2. Peristaltic pump used for feeding wastewater was controlled by level sensor and

controller for avoiding over flow of wastewater. Peristaltic pump used for permeate

suction and Peristaltic pump used for backwash was in continuos automatic cyclic

operation of different suction and backwashing time using specially designed electronics

circuit.

4.1.2 Water level sensor and controller:

Water level sensor and controller was used for maintaining appropriate and desired

wastewater level in the reactor for restricting excessive water entry in the reactor as

17

shown in plate 3. The Peristaltic pumps were automatically operated by level sensors,

accordingly they used to be switched off and switched on after attending the desired

maximum and minimum water level respectively.

4.1.4 Electric valve (solenoid)

4 numbers of Electric valve/solenoids were used for controlled entry of wastewater and

biogas in the reactor so that AnMBR work properly for the objective which has been set.

Solenoid was controlled by Electronic circuit for different cyclic on/off operation and

vice versa. Solenoid is as shown in plate 7.

4.1.5 Electronics circuit

Electronic circuit were developed for automatic controlled operation of the peristaltic

pumps, solenoids for continuos cyclic operation of different suction and backwash.

Electronic circuit was with time adjustment facility by which operation of suction and

backwash can be controlled for different timing. Electronic circuit is as shown in plate 4.

4.1.6 Manometer

Manometer was used along permeate line for measurement of transmembrane pressure in

membrane (Plate 8).

4.1.7 Rotameter

Rotameter were used for measurement of biogas flow rate in the reactor during

recirculation of the biogas as shown in plate 6. Rotameter used was specially designed for

methane gas mixture.

4.1.8 Biogas measurement using water displacement method

Biogas generated in the reactor during anaerobic process was collected in the sealed

packed bottled and measured using water displacement method as shown in plate 5.

4.1.9 Membrane module

Flat sheet Membrane of pore size 0.03 µm was fabricated and used for filtration of

wastewater in the reactor. Membrane sheet was procured from chemical department,

Indian Institute of Technology Delhi.

18

Bioreactor is as shown in plate 8. Input and out point in the reactor are as shown in plate

9 and diffuser in the reactor for sparging of biogas are as shown in plate 10.

Fig 4.1: Experimental set up of Anaerobic Membrane Bioreactor

19

Plate 1: AnMBR Experimental Setup

Plate 2: Peristaltic pump Assembly

20

Plate 3: Water Level controller and sensors

Plate 4: Electronic circuit for automatic control of pump and solenoid

Plate 5: Biogas

measurement using water displacement method

21

Plate 6: Rotameter and Pressure gauge

Plate 7: Solenoid connected to Electronic Circuit

22

Plate 8: Membrane Bioreactor for wastewater treatment and Manometer

Plate 9: Input and output points in Reactor

Plate 10: diffuser in the reactor

23

4.2 METHODOLOGY

4.2.1 Reactor starts up:

The reactor was fed with synthetic wastewater based on sucrose as source of COD under

anaerobic condition. Anaerobic inoculum was brought from Faridabad Treatment Plant

(UASB), which treat municipal wastewater was fed in the reactor. The Reactor was

started up increasing OLR, by reducing Hydraulic retention time, up to an OLR close to

7.194 kg/m

3.

d. During start up, the COD inlet concentration was 5g/L for one month

with upflow velocity and HRT of 0.073m/hr, 10hr respectively. Once the start-up was

finished the inlet COD concentration was set to 1.2g COD/L. start up period lasted for

40days. Membrane was submerged in the reactor on 40

th

day from day of start-up of

reactor.

4.2.2 Preparation of Synthetic Wastewater:

The Experiments were conducted using a synthetic wastewater to avoid any fluctuation in

the feed concentration and provide continuous source of biodegradable organic Pollutant

such as Sucrose, Ammonium Chloride and Sodium Hydrogen carbonate. Synthetic

Wastewater used for this study contain chemical as given in table 4.1 for per gram of

COD. The feed composition was selected to provide soluble and highly biodegradable

substrate, with essential macro and micro nutrient for optimal bacterial growth. 0.1 ml of

nutrient/trace element was added to each litter of synthetic wastewater. Calcium chloride

was added to synthetic feed as it promotes granule formation by allowing aggregates to

form earlier and to achieve large size, resulting in faster granulation (YU, 2001) Trace

element added in the Synthetic wastewater are as given in Table 4.2. Reactor fed with

Synthetic wastewater based on Sucrose as COD source.

Table 4.1: Chemical Composition of Synthetic Wastewater

Sr. no Chemical Amount (gm/gm COD)

1 Sucrose 0.89 gm

2 NaHCO

3

1.5 gm

3 NH

4

Cl 0.318 gm

4 MgSO

4

0.0624 gm

5 K

2

HPO

4

0.035 gm

6 KH

2

PO

4

0.009 gm

24

Table 4.2: Trace Element for Synthetic wastewater

Sr. No Chemical Amount

1 CaCl

2

. 2H

2

O 125 mg/L

2 FeSO

4.

6H

2

O 10 mg/L

3 NiSO

4

0.5 mg/L

4 MnSO

4

0.5 mg/L

5 ZnSO

4

0.1 mg/L

6 H

3

BO

3

0.1 mg/L

7 COCl

2

50 µg/L

8 CuSO

4

5 µg/L

9 (NH

4

)

6

Mo

7

O

24

50 µg/L

4.2.3 Preparation of Flat sheet Membrane Cartridge:

Membrane sheet of 0.03µm was brought from Chemical

Department of IIT Delhi. Membrane cartridge was

constructed by sealing sheet of thin Polymeric Membrane

to the back and front of Plastic net support panel. Between

the Support panel & membrane material is Plastic spacer

material that distributes water to a series of grooves that

channel flirted water to the top of Cartridge as shown in fig

4.1. Sealing of Membrane is done by applying Silica gas

maker and Araldite on the boundary of Membrane and

applying thin rubber sheet on it. Output point is provided at

the top of membrane for suction of water. Total Membrane

surface area was 0.054 m

2.

Fig 4.1: Membrane cartridge

25

4.2.4 Experimental Methodology

COD measurement was based on the ‘‘Closed reflux, colorimetric method’’ described in

section 5220-D of Standard Methods. Total suspended solids (TSS) and volatile

suspended solids (VSS) were measured in triplicate according to the modified procedure

described in section 2540-B and 2540-E of Standard Methods where centrifugation

instead of filtration was used. pH was measured in triplicate using a pH meter ( pH538

Model WTW, Germany) calibrated with buffer solutions of pH 4 and 7. VFA was

measured using distillation Method prescribed in Standard Methods. Bicarbonate

alkalinity was measured using simple titration method. The Parameter α, defined as ratio

of VFA concentration over bicarbonate alkalinity was also calculated. This parameter has

been found useful to monitor upset and or failure (zang et.al 2007). SVI measured as per

Standard Methods. Method for Measurement of different parameter during study are as

given in table 4.3.

Table 4.3: Methods for analytical study of different parameter of AnMBR

Sr

No.

Parameter Method

1 COD Standard Method

2 TS, TSS, TVS, VSS, Alkalinity Standard Method

3 pH pH Meter

5 VFA Distillation Method

7 Amount of biogas Water displacement method

8 TMP Manometer

9 Gas flow rate measurement Rotameter

10 Sludge Volume Index (SVI) Standard Method

4.2.4.1 Membrane performance characterization:

To characterize membrane fouling, the initial water flux of clean membrane was

measured. The permeate flux (J) through the membrane was measured under different

value of TMP. Permeate flow rate was measured manually by measuring volume of water

collected in the volumetric jar per min.

26

Water flux was measured at each step of cleaning procedure. In order to minimize the

fouling, backwashing was adopted in AnSMBR. The operational mode selected depends

on the TMP attended. Different backwash time and flow rate were adopted to optimize

the flux and TMP of permeate. Separate Peristaltic pump was used for backwashing of

membrane along permeate line. Membrane fouling and cleaning were evaluated based on

flux measurement during normal reactor operation. Cleaning of membrane was checked

for different flow rate and time.

4.2.4.2 Critical Flux determination:

In this work, the flux-step method was used to determine the critical flux value. The flux

was stepwise increased for a fixed duration (10 min) for each increment (2 Lm

-2

h

-1

),

giving a relatively stable TMP at low flux but an ever-increasing rate of TMP increase at

higher fluxes. This flux-step method yielded the highest flux for which TMP increase

remains stable as the critical flux. The TMP value was measured in the each 1 min. The

critical flux determination was carried out with a suspension in the anaerobic reactor.

27

Chapter V

RESULT AND DISCUSSION

5.1 Anaerobic Inoculum Composition

On 12

th

Jan 2009 Anaerobic Inoculum was brought from Faridabad wastewater

Treatment plant (UASB), Faridabad, Hariyana, India which treat Municipal Wastewater.

This Anaerobic Inoculum has following organic composition as given in Table 5.1

Table 5.1 Composition of Anaerobic Inoculum

Sr. No Parameter Value

1 Sludge volume Index (SVI) 4.67 ml/g

2 COD 1728 mg/L

3 Total Solids (TS) 66711 mg/L

4 Total Suspended Solids (TSS) 23510 mg/L

5 Total Volatile Solids (TVS) 17567 mg/L

6 Volatile Suspended Solids (VSS) 12001 mg/L

7 Temperature 19

o

C

8 pH 8.71

9 Alkalinity 3000 mg/L

Sludge volume index of the Anaerobic Inoculum was 4.67 ml/g SVI should be in the

range of 50 ml/g. Less SVI shows poor Settling characteristic of the Anaerobic Inoculum.

pH of 8.71 shows sufficient level of Alkalinity in the inoculum, required for

development of good anaerobic condition. VSS of 12001 mg l

-1

was sufficient for good

anaerobic bacterial development in the reactor. Temperature of 19

0

C was due to winter

season. As Anaerobic Inoculum is brought from bottom port of UASB Reactor of

Faridabad Wastewater Treatment plant it has high COD Concentration in the range of

1728 mg/L.

28

Table 5.2: Reactor Operation during AnMBR study

Parameters Operation 1 Operation 2 Operation 3 Operation 4 Operation 5 Operation 6 Operation 7 Operation 8

days 0-19 20-33 33-40 41-52 53-65 65-79 80 - 95 95- 108

HRT, hr 10hr 7hr 7 hr 7 hr 4hr 16 hr 16 hr 16 hr

Flow rate, (L/d) 9 13 13 13 25 6 6 6

OLR,

Kg/m

3

.d

1.0799 1.0799 to

3.743

3.743 3.743 7.1994 1.727 1.727 1.727

Upflow Velocity

m/s

0.073 0.103 0.103 0.103 0.204 0.204 0.204 0.204

Reactor

operation

- - Recirculation

of Permeate

in reactor

Membrane

submerged

- - - -

Membrane

operation

- -- - Suction : 3.45

min

Backwash:

30 sec

Checked for

different

suction and

backwash

time

Suction :12

hr

Backwash :

30 min

Suction : 5

min,

Backwash : 1

min

Suction: 7 min

Backwash: 2

min

29

5.2: Reactor Performance:

The effect of operating conditions, including pH, HRT, influent COD concentration,

OLR and temperature, on the performance of the AnMBR was studied. As the UF

membranes could not reject alkalinity, CO

3

/HCO

3

ions crossed through the membranes

with permeate. HRT and OLR were important parameters in the AnMBR operation to

ensure system efficiency. Due to the decline of membrane flux, average HRT of the

anaerobic reactor increased gradually and tended to be stabilized. The effect of HRT on

the AMBR performance was evaluated in the average HRT range of 4h to 16 h, and the

OLR was kept at 1.0799 to 7.194 kg/m

3

d. The COD removal rate depended upon upflow

velocity and Temperature, increasing approximately linearly with Temperature, and

remaining above 76 % at HRT of 16 h (Fig 5.2). Reactor was operated under different

operation mode are as given in table 5.2.

5.2.1 Operation mode 1 (0- 18 day):

The AnMBR was started by feeding Anaerobic Inoculum in the reactor. Reactor stated

with Organic Loading rate of 1.007 kg/m

3

d and SLR of 0.3749 gm COD/gm VSS.d.

Different Operation condition maintained in the reactor were as given in table 5.2. Fig

5.3 Illiterate the stable pH (7- 8) and alkalinity (1050-1200 mg/L) of permeates for good

Methanogenic activity. Very less COD removal was observed during start-up of the

reactor, due to development of aerobic condition in the reactor due to leakage which got

confirmed on 9

th

day. It took 7 days for correcting leakage of the reactor.

5.2.2 Operation mode 2 (18 – 34 day):

Reactor was again restarted on 18

th

day by feeding Synthetic feed with OLR 1.529

Kg/m

3

d. Different Operation conditions maintained during this operation were as given in

table 5.2. Increase in the COD removal up to 30 % was observed due to Increase in the

OLR from 1.079 kg/m

3

d to 3.743 kg/m

3

d and upflow velocity to 0.103 m/h.

Methanogenic Activity in the reactor was very less due less temperature in the range of

(15

o

C – 24

o

C). Fig 5.4 illustrates the very less average total VFA concentration of 140

mg/L as acetic acid) of the effluent which may be due to less acid fermentation in the

reactor. For successful digestion in the anaerobic reactor α value of less than 0.4 is

30

required. Avg α value during operation was 0.075.

The optimum VFA for better

operation of anaerobic system should be below 250 mg/l and alkalinity should be in the

range of 1000 mg/L - 5000 mg/L. Even though pH was in beyond the recommended

values, VFA and alkalinity values are well agreed with optimum values indicating the

system was operated well. The VFA and alkalinity, separately, is not a good indicator for

evaluating the process stability of the anaerobic reactor since total alkalinity reflect both

levels of VFA and bicarbonate, and under unstable conditions increased VFA reduce the

bicarbonate resulting in constant total alkalinity. So, it is well reported that the ratio of

VFA to alkalinity is the best option to monitor process stability in anaerobic systems to

overcome above mentioned misunderstandings (Zang et. al., 2007). The ratio of VFA to

alkalinity exceeds 0.8, the inhibition of methanogens occurs and process failure is

apparent and increase above 0.3-0.4 indicate the system instability and need immediate

correction actions. A proper ratio is between 0.1 and 0.2 (Zang et. al., 2007). On contrary,

optimum ratio of VFA to alkalinity should be less than 0.3 or 0.4. Acid fermentation and

Methanogenic activity was slow in the reactor due very less upflow velocity and less

temperature. Surface area available for anaerobic microbes in the reactor was very less

due to compressed sludge bed as upflow velocity was not sufficient to provide

appropriate sludge bed height.

5.2.3 Operation mode 3 (34 -39 days):

For increasing the Sludge bed height recirculation of Permeate with flow rate of 35 L/d

was maintained in the reactor. Sludge bed height changes from 18 cm to 40 cm. Filter of

pore size 0.5 mm diameter were fixed at the permeate output for minimizing biomass

loss. Different operation parameters during run were as given in table 5.3. Average COD

removal during this run observed was 30%. Fig 5.4 shows average VFA concentration

and Avg α were 150 mg/L and 0.1 respectively (Fig 5.4). Performance of the reactor was

poor due to less atmospheric temperature in the range of 15

0

C - 20

o

C.

5.2.4 Operation mode 4 (40- 55 day) :

On 40

th

day Membrane was submerged in the reactor. Different operating parameters of

the reactor during this run were as given in the table 5.2. Temperature of the reactor was

maintained at 29

o

C in constant temperature room. OLR was maintained between 3.743

31

kg/m

3

d and 4.44 kg/m

3

d. Performance of the reactor started increasing. After 53

rd

day

52% of COD removal was observed. Fig 5.3 Illustrate the accumulation of the VFA in

the reactor (227 - 477 mg/l as acetic acid), indicating successful acidogenic activity in the

reactor. Avg α value of 0.25 was observed, which is less than desirable 0.4 shows stable

anaerobic digestion in the reactor. pH of the reactor was above 7.5 (Fig 5.3). Alkalinity of

the effluent was in the range 1800-2100 mg/L required for stable performance of the

reactor. Methane production in the reactor was not able to measure due to fluctuation in

the water level in the reactor.

5.2.5 Operation mode 5 (55 – 65 day):

Different operating parameters during operation mode 5 were as given in table 5.2.

Temperature in the reactor was maintained at 29

o

C in the constant temperature room.

OLR was maintained at 7.1994 kg/m

3

d with HRT of 4hr. Fig 5.3 illustrates the 50 % of

COD removal during this Operation mode. As OLR in the reactor was increased, VFA

start acclimating in the reactor and it reaches to 586 mg/L as acetic acid on 59

th

day. It

illustrates the decrease in Methanogenic reaction in the reactor due to increase in the

OLR. After 60

th

day VFA start decreasing reaches to 375 mg/L as acetic acid. α value

during this run was start increasing and reached to 0.4 on 59

th

day and then start

decreasing. α value was below 0.4 and pH in the reactor was above 8, shows stable

performance of the anaerobic reactions (Fig 5.3).

5.2.6 Operation mode 6 (65 - 79 day):

Different Operation parameters during Operation mode 6 were as given in the table 5.2.

OLR was decrease to 1.727 kg/m

3

d on 65

th

day and was constant for rest of the all

operation. 60 % COD removal was observed on 75

th

day but it started decreasing from

76

th

day. Leakage in the reactor was the reason for decreasing in the COD removal.

Leakage in the reactor was confirmed on 77

th

day and was corrected. COD removal

started recovering after 78

th

day and reaches to 48% on 79

th

day. When Chemicals of

Synthetic wastewater come in contact with araldite in presence of Oxygen, it starts

reacting with Araldite and convert Araldite in liquid form. Conversion of Araldite into

liquid from give space for permeates to come outside from the reactor. Alkalinity was in

the range of 2000mg/L and pH was above 8. Average VFA concentration of permeate

32

was 350mg/L as Acetic acid (Fig 5.4) and α value below 0.4, shows stable Methanogenic

activities in the reactor.

5.2.7 Operation mode 7 (80 – 95 day)

Different Operational parameters during operation run 7 were as given in the table 5.3.

OLR was maintained at 1.727 kg/m

3

d and HRT at 16 hr. Increases in the HRT was due to

decreases in the flux, as fouling of the membrane was increased to its critical flux.

Temperature of 33

o

C was maintained in constant temperature room for increasing activity

of Mesophilic bacteria’s. COD Removal was started increasing from 80

th

day and reaches

to 75% on 95

th

day. Average VFA concentration of permeate was 300 mg/L and α value

was below 0.2 shows stable anaerobic performance of the reactor. Upflow velocity of

0.204 has provided the sludge bed height of 30 cm from 20 cm in the reactor which was

main parameter for increasing the COD removal efficiency of the AnMBR. Higher

alkalinity in the permeate indicates Methanogenesis is taking place at the upper portion

of the sludge bed consuming the short chain fatty acid produced during the initial stage of

acidogenesis realising CH

4

and CO

2

.

5.2.8 Operation Mode 8 (95 -108 day)

Different operating parameters during operation mode 8 were as given in table 5.3. OLR

and HRT was 1.727 kg m3/d , 16h respectively. Temperature of 38

o

C was maintained in

the constant temperature room for increasing the Methanogenic activities in the reactor.

Stable performance of anaerobic activities was observed during this run. COD removal of

75 % was observed with VFA concentration decreasing to 180 mg/L. α value of permeate

was below 0.1 and Alkalinity of the permeate in the range of 2000 mg/L, shows stable

performance of the reactor. During the steady state conditions, the short chain fatty acids

produced in the lower portion of the sludge bed are converted to CH

4

and CO

2

in the

upper part of the sludge bed, there by generating the alkalinity, this in turn increase the

pH of the permeate.

33

34

35

5.3 Membrane Performance:

Membrane performance was characterized using membrane transmembrane Pressure

(TMP) and Membrane flux. Fig 5.5 Illustrate the greater TMP during all operation was

0.74 bar, but during reactor operation measured TMPs varied between 0.1 and -0.73 bar.

During continuous operation, the permeation flux dropped sharply by more than 80%

with in less than 7 days and arrived at a low value of 3 L/m

2

.h (Fig 5.5). Changes in TMP

Pressure and fluid viscosity had little effect on the flux improvement, suggestion strong

adhesion of cells/ biomass to the membrane surface and compaction of cake layer. In

order to remove cake layer, backwashing was performed (down to about 0.14 bar), which

brought about transient elevation in the permeation flux (Fig 5.6 - Fig 5.14).

Fig 5.5 shows the extent of flux recovery after attempting backwashing as cleaning

method for a given period of time. However, the Efficiencies of the Physical cleaning

methods were reduced gradually with operating time. It could be hypothesized that under

applied pressure the sticky cake layer forged on the membrane surface become more and

more dense. Beside the simple densification of the biomass cake layer, membrane fouling

from gradual precipitation. Deposition of the sparingly soluble inorganic material is

probably responsible for poor flux recovery. Membrane fouling, which is mainly

attributable to the adsorption of the dissolved and organic matter and the adhesion of the

suspended particles.

Fig5.5 shows in general, all TMP under different intermittent operational modes had a

stable TMP of -0.7 bar and Flux of 4 L/m

2

h with operation period. Membrane

submergence in the reactor considered as first day during this operation.

36

37

Fig 5.6 shows the rapid increase in the TMP to (-0.6 bar) for first 100 min and then TMP

become constant and reaches to (- 0.7 bar) with decrease in at flux from 10 L/m

2

h to 5

L/m

2

h. It shows strong fouling cake layer formation on the membrane surface. To check

flux recovery of Membrane, it was backwash for 6 min after 779 min. Again restarting

suction through membrane, same pattern of flux-TMP change was observed.

Fig 5.7 shows effect of backwashing of membrane with same flow rate as of suction rate

on 16

th

day of operation for optimising time of backwash. It was observed that after

backwashing for 4 min with flow rate of 25L/d, flux return to its original value of 10

L/m

2

h but may be due to irreversible fouling, flux again reaches to 4 L/m

2

h with in 30

min. Illustrate that backwashing with same flow rate is not effective for flux recovery.

Fig 5.8 illustrates the variation of TMP and flux with time on 17

th

day of operation.

Membrane was checked for different backwash time with backwash flowrate of 50L/d.

Fig 5. 8 shows that after 2 min of backwash TMP were changes from -0.7 bar to -0.2 bar

and flux recover to 10 L/m

2

h. after 5 min of backwash TMP changes from -0.7 bar to 0.1

38

bar and flux reduces to 4 L/m

2

h after 30 min. membrane fouling was more due to

Irreversible fouling.

Fig 5.9 Illustrates the Variation of TMP and flux with time on 18

th

operation day with

backwash rate triple of the suction rate. It was observed that membrane backwashing for

4 min is more effective for flux recovery. As with after 2 min of backwash TMP reaches

to -0.6 bar with in 10 min whereas after 4 min of backwash TMP reaches to -0.6 bar after

25 min.

Fig 5.10 illustrates the variation of TMP and flux on 19

th

day of operation for different

suction and backwash time. It was observed that backwashing with 75L/d recovered Flux

with in 4 min compared to 50L/d which took 7 min. but Increase in TMP pattern was

same for all after backwashing shows that more strong cake layer formation on

membrane. Reversible fouling is less than Irreversible fouling. Reversible fouling is

which can be removed by physical cleaning and irreversible fouling is which can be

removed with help of chemical cleaning.

Fig 5.11 shows the variation of TMP and flux with time for suction with flow rate of

25L/d for 10 min and backwash of membrane with 50 L/d for 2 min. It was observed that

39

Membrane performance was better. TMP was increasing gradually and reaches to -0.4

bar after 200 min and flux was reduced to 8

L/m

2

h.

40

41

Fig 5.12 shows the variation of TMP and flux with time on 22

nd

day of operation with

Suction rate of 25L/d for 7 min and backwash rate of 50L/d for 1 min. It was observed

that TMP was increasing gradually and reached to -0.4 bar after 80 min and -0.6 bar after

120 min. Flux was reduced to 5 L/m

2

h after 110 min.

42

Fig 5.13 Illustrate the variation of TMP and flux on 47

th

operational day with suction

flow rate of 25L/d for 15 min and backwash rate of 50L/d for 5 min. It was observed that

TMP was increasing gradually and reaches to -0.4 bar with in 40 min and flux decrease to

4 L/m

2

h after 30 min. after each backwashing Flux was recovered to 10 L/m

2

h and with

in 15 min it was decreased to 4 L/m

2

h. It was due to structure of Membrane. Membrane

was filling with water during Backwashing of membrane and no water was coming

outside of the membrane through pores, means no backwashing was actually occurring.

During suction cycle water in the membrane was coming out for which not much

pressure was required, but as soon as membrane get emptied more pressure was required

for suction of permeate and flux was less as no cleaning was occurred.

43

Fig 5.14 shows the variation of TMP and flux after 48

th

day of operation with cycle of

suction rate of 25L/d for 30 min and backwash rate of 50L/d for 15 min. It was observed

that even after backwash for 15 min with 50L/d flux recovery was not poor. It may be

due to Pore blocking and Irreversible fouling. Cake layer formation on membrane was

acting as secondary membrane and flux of 3 L/m

2

h was observed during all operation.

5.2.1 Critical Flux and TMP increase rate dependence on Flux

No severe increase in the TMP was observed as a function of the stepwise increase of the

flux (up to 12 L/m

2

h). It was also observed that each increase in the flux (2 L/m2h)

produced an increaser in the TMP. According to Chen et al. (1997), the critical flux is

defined as the last flux step at which the TMP remain Constant. A closer examination of

the initial flux step, however, reveals that the TMP never remain absolutely constant at

any point during the test (Fig 5.15). Critical Flux of 3 L/m

2

.h was observed during

operation.

44

45

Chapter VI

CONCLUSION

Stable anaerobic treatment can be achieved in AnMBR with submerged membrane.

AnMBR achieved 76% of COD removal efficiency at loading rate of 1.67 kg/m

3

.d, at

HRT of 16 hr. The combination process of Anaerobic Upflow reactor with Ultrafiltration

membrane has a high ability to tolerate organic loading rate of 1.007 Kg/m

3

.d to 7.95

Kg/m

3

d and temperature varying from 15

o

C to 37

o

C. AnMBR system revealed high

COD removal; this is because the microbial cell moves from the bioreactor to membrane

surface due to high shear stress from the pump. This shift a suspended growth to attached

growth and gave rise to diverse membrane fouling. AnMBR system could be improved

by increasing upflow velocity and mixing in the reactor by recirculation of biogas for best

membrane as well as reactor performance

Membrane fouling in the reactor was mainly due to strong dense cake layer formation on

the membrane surface. Pore blocking and strong dense cake layer formation on

membrane was mainly contributing to the irreversible fouling of the membrane.

Backwashing of membrane is not sufficient for minimizing fouling as amount of

irreversible fouling was more compared to reversible fouling. Critical flux of 3 L/m

2

.d

was observed after flux step method. Membrane performance can be improved by

sparging of biogas in the reactor.

46

References:

-

Akram, A. and Stuckey, D.C. (2008). “Flux and performance improvement in a

submerged anaserobic membrane bioreactor (SAMBR) using powdered activated carbon

(PAC).” Process biochemistry, 43, 93-102.

Bacchin, P., Aimar, P. and Field, R. W., (2006). “Critical and sustainable fluxs: theory,

Experiment and Applications” Journal of Membrane Science, 281, 42-69

Beaubien, A., Baty, M., Jeannot, F., Francoeur, E. and Manem, J. (1996). “Design and

operation of anaerobic Membrane Bioreactors : development of a filtration testing

stratergy.” Journal of Membrane Science, 109, 173- 184

Bohdziewicz, Jolanata., Neczaj, Ewa and Kwarciak, Anna (2007), “Landfill leachate

Treatment by means of Anaerobic Membrane Biorector.” Desalination., 221, 559 – 565

Chang, I.S. and Lee, C.H. (1998). “Membrane filtration characteristics in membrane-

coupled activated sludge system - the effect of physiological states of activated sludge on

membrane fouling.” Desalination 120, (3), 221-233.

Chen, V., Fane, A.G., Madaeni, S. and Wenten, I.G. (1997) Particle deposition during

membrane filtration of colloids: Transition between concentration polarization and cake

formation. Journal of Membrane Science 125(1), 109-122.

Choi, H., Zhang, K., Dionysiou, D. D., Oerther, D. B. and Sorial, G. A., (2005).

“Influence of cross-flow velocity on membrane performance during filtration of

biological suspension.” Journal of Membrane Science 248, (1-2), 189-199.

Choo, B. D. and Fane, A. G. (2002). “Fouling transient in nominally sub critical flux

operation of Membrane bioreactor.” Journal of Membrane science 209, 391 -403.

Choo, K. H. and Lee, C.H. (1996). “Membrane fouling mechanisms in the Membrane

coupled with Anaerobic bioreactor.” Water Research ,vol 30 , no 8, pp 117-1780,1996.

47

Clech, P. L., Jefferson, B., Chang, I. S. and Judd, S. J. (2003). “Critical Flux

Determination by the flux-step method in a submerged membrane bioreactor.” Journal of

membrane science 227, 81-93

Cui, Z. F., Chang, S. and Fane, A. G. (2003). “The Use of gas bubbling to enhance

membrane processes.” Journal of Membrane Science, 221, 1-35

Flemming, H., Schaule, G., Griebe, J., Schmmitt, A. and Tamachkiarowa, A., (1997). :

Biofouling – the Achilles heel of Membrane Processes.” Desalination, 113, 215-225.

Fuchs, w., Binder, H., Mavrias, G. and Braun, R. (2003). “ Anaerobic treatment of

wastewater with organic content using a stirred tank reactor coupled with Membrane

filtration unit.” Water research, 37, 902-908

Gander, M., Jefferson, B. and Judd, S. (2000). “Aerobic MBRs for domestic wastewater

treatment: a review with cost considerations.” Separation and Purification Technology,

18, 119-130

He, Y., Xu, P., Li, C. and Zhang B. (2005). “High Concentration food Wastewater

Treatment by an anaerobic Membrane Bioreactor.” Water research 39, 4110-4118.

Jeison David. (2007) Anaerobic membrane bioreactor for wastewater Treatment

Feasibility and potential Application, thesis report Wageningen university page no 43.

Jeison, David and Lier, Jules B. Van. (2007). “ Cake formation and consolidation: main

factors governing the applicable flux in anaerobic submerged membrane bioreactors

treating acidified wastewater.” Separation and purification technology, 56, 71-78

Judd, S. (2006). “The MBR Book.” First Edition, Elsevier, Oxford.

Kang, In-Jong., Yoon, Seong-hoon and Lee, Chung –Hak. (2002). “Comparison of the

filtration characteristics of the organic and inorganic membranes in a membrane- coupled

anaerobic Bioreactor.” Water Research, 36, 1803-1813

48

Kocadagistan, E. and Topcu, N. (2007). “Treatment investigation of Erzurum city

municipal wastewater with anaerobic membrane bioreactor.” Desalination 216, 367- 376

Kwon, D.Y. and Vigneswaran, S. (1998) Influence of particle size and surface charge on

critical flux of cross flow micro filtration. Water Science and Technology 38(4-5), 481-

488.

Lee, k., Lin, ping-jei., Fangchiang, Kai and Chang, Jo-shu. (2007). “Continuous

hydrogen production by anaerobic mixed microflora using a hollow fibre micro filtration

membrane bioreactor.” International Journal of Hydrogen Energy 32, 950- 957

Lettinga, G., Van Velsen, A., Hobma, S. and Zeeuw, W. (1980). “ Feasiblity of

Anaerobic digestion for the direct treatment of and the Enegery recovery from urban

wastes.” Studies in Environmental Science, 9, 97-109

Liao, B.Q., Kraemer, J.T. and Bagley, D.M. (2006), “Anaerobic membrane bioreactors:

Applications and research directions.” Critical Reviews in Environmental Science and

Technology, 36(6), 489-530.

Minami, K., Okamura, Kazuo., Ogawa, Shigemichi and Naritomi, takaaki., (1991).

“Continuous Anaerobic treatment of wastewater from kraft pulp mill.” Journal of

fermentation and Bioengineering, vol 71 no 4, 270- 274, 1991.

Metcalf and Eddy (2003). “ Wastewater Engineering Treatment and Reuse. Tat Mcgraw

Hill Publication.

Mulder, M. (1996) “Basic Principles of Membrane Technology”, Kluwer Academic

Publishers, Dordrecht.

Rezania, B., Oleszkiewicz, J. A. and Cicek, N. (2007). “Hydrogen- dependent

denitrification of waster in an anaserobic submerged membrane bioreactor coupled with a

novel hydrogen delivery system.” Water research 42, 1074 -1080

49

Saddoud, A., Ellouze, M., Dhouib, A. and Sayadi, S. (2007). “Anaerobic Membrane

Bioreactor of Domestic Wastewater in Tunisia.” Desalination, 207, 205 -215

Saddoud, A. and Sayadi, S. (2007). “Application of Acidogenic Fixed-bed reactor prior

to anaerobic membrane bioreactor for sustainable slaughterhouse wastewater treatment.”

Journal of Hazardous Materials, 149, 700 – 706

Stephenson, T., Judd, S., Jefferson, B. and Brindle, K. (2000) “Membrane Bioreactors

for Wastewater Treatment”, IWA Publishing, London, UK.

Sui, P., Wen, X and Huang, X. (2008). “Feasibility of employing ultrasound for online

membrane flouling control in an anaerobic membrane bioreactor.” Desalination 219,

203- 213.

Taha, T. and Cui, Z.F. (2002). “CFD Modeling of gas sparged ultrafiltration in tubular

membranes.” Journal of Membrane Science, 210, 13- 27.

Vallero, M. V., Lettinga, G. and Lens P. N.L. (2005) “High rate sulfate reduction in

submerged anaerobic Membrane bioreactor (SAMBaR) at high salinity.” Journal of

Membrane Science 253, 217 – 232.

Wen, C., Huang, X. and Qian, Y. (1999). “ Domestic wastewater treatment using an

anaerobic Bioreactor coupled with membrane filtration.” Process Biochemistry 35, 335-

340.

Yu, H. and Mu, Y., (2006). “Rheological and fractal Characteristics of granular sludge in

an upflow anaerobic reactor.” Water Research, 40, 3596-3602.

Yuan, Li-mei., Zhang, Chauan-Yi., Zhang, Yan-Qiu., Ding, Yi and Xi, Dan-Li. (2008).

“Biological nutrient Removal using an alternating of anoxic and anaerobic membrane

bioreactor (AAAM) process.” Desalination, 566-575

50

Zang, J., Padmasiri, S.I., Fitch, M., Norddahl, B., Raskin, L. and Morgenroth. E.

(2007). “Influence of cleaning frequency and membrane history on fouling in an

anaerobic membrane bioreactor.” Desalination 207, 153 – 166.

51

APPENDIX - A

Table of Experimental and Calculated Value

Table A1: Experimental Results for Concentration of alkalinity, COD and OLR.

Day

pH of

Effluent

Alkalinity (mg/L as

CaCO

3

) COD

(mg/L) COD

Removal OLR (Kg

COD/m

3

d) Influent Effluent Influent Effluent (%)

1 7.49 - 1100 - 522 - 0

2 7.23 - 1200 - 629 - 0

3 7.38 - 1100 - 660 - 0

5 7.54 - 1200 -

377 - 0

7 7.47 - 1200 - 362 - 0

8 7.65 - 1000 724 598 17. 1.564311

9 7.69 - 1200 398 318 20 0.860537

18

7.84

-

950

701 605 14 2.187677

19 7.86 1100 1050 631 508 20 1.97159

20 7.63 1100 1050 739 570 23 2.308202

21 7.84 1000 1050 631 446 30 1.970976

22 8.01 950 970 645 440 32 2.013956

23

7.85

1500

1600

836 611 27 2.611394

24

7.73

1800

1900

832 576 31 2.595819

25

7.81

1800

1900

804 579 28 2.510956

26 7.67 1800 1900 965 708 27 3.013147

30 7.98 1680 1480 809 563 30 2.525932

32 7.89 1680 1760 804 611 24 2.510956

52

Day

pH of

Effluent

Alkalinity (mg/L as

CaCO

3

) COD

(mg/L) COD

Removal

(%) OLR (Kg

COD/m

3

d) Influent Effluent Influent Effluent

36

8.01

1920

1980

901 611.648 32 2.812271

37 8.05 1620 1940 1030 740 28 3.214024

38

7.98

1760

1840

1191 933 22 3.716215

39 7.68 1720 1820 1376 992 28 4.293086

42

7.65

1800

1920

1128 784 31 3.522327

43

7.82

1760

2000

1160 752 35 3.620169

44 7.86 1800 1900 1136 706 38 3.546288

45

7.83

1800

2260

1013 633 38 3.162906

46

7.74

1860

2120

1140 696 39 3.558269

47 7.81 1880 2080 940 501 47 2.935273

48

8.27

1680

2020

1034 564 45 3.2288

49

8.13

1720

2040

1172 696 41 3.65711

50

8.06

1680

2040

1425 792 44 4.447836

51

8.21

1760

1960

1317 627 52 4.109382

52

8.16

1660

2000

965 579 40 3.013147

53

8.05

1940

2100

1287 740 43 7.726018

55

7.98

1900

2000

1158 643 44 6.953416

56 8.18 1900 2140 1128 533 53 6.773706

57

8.05

1940

2200

1172 570 51 7.032904

53

Day

pH of

Effluent

Alkalinity (mg/L as

CaCO

3

) COD

(mg/L) COD

Removal

(%) OLR (Kg

COD/m

3

d) Influent Effluent Influent Effluent

59

8.16

1760

1940

1160 627 46 6.961864

60

8.03

1780

2000

1223 676 45 7.339717

61

7.84

1920

2060

1158 611 47 6.953416

62 8.05 1820 1960 1062 515 51 6.373965

63 7.98 1860 2000 1158 611 47 6.953416

64 8.08 1900 1980 1128 533 53 6.773706

65 8.14 2020 2140 1172 570 52 7.032904

66 8.02 1860 2000 1191 611 49 1.715176

67 7.85 1880 2000 1160 533 54 1.670847

68 8.06 1960 2160 1223 579 53 1.761532

69 8.13 1900 2120 1158 547 53 1.66882

70 7.99 1780 1940 1128 533 53 1.625689

71 7.91 1800 1920 1140 506 56 1.642278

73 8.02 1800 1900 1160

501 57 1.670847

74 7.82 1880 1960

1172 538 54 1.687897

75 7.95 1940 2000

1191 482 59 1.715176

76 8.08 2120 1840

1223 658 46 1.761164

77 7.45 2020 2220

1191 784 34 1.716005

78 7.92 1900 2200

1105 645 42 1.592512

79 8.3 1640 1800

1160 595 48 1.670847

80 8.5 1600 1900

1128 595 47 1.625689

81 8.32 1920 2020

1075 552 49 1.548276

54

Day

pH of

Effluent

Alkalinity (mg/L as

CaCO

3

) COD

(mg/L) COD

Removal

(%) OLR (Kg

COD/m

3

d) Influent Effluent Influent Effluent

83 8.31 1640 1860

1126 418 63 1.622464

84 8.43 1700 1940

1191 439 63 1.716005

85 8.36 1720 1880

1097 407 63 1.580531

86 8.52 1880 2040

1097 376 66 1.580531

87 8.46 1820 2080

1191 407 66 1.716005

88 8.53 1880 2120

1167 430 64 1.680985

91 8.24 1880 2020

1223 533 57 1.761164

92 8.14 1920 2060

1191 407 66 1.716005

93 8.42 1860 2160

1160 344 70 1.670847

94 8.33 1880 2100

1191 344 71 1.716005

95 8.13 1840 2160

1003 250 75 1.445057

96 8.53 1880 2160

1097 313 71 1.580531

97 8.43 1900 2100

1126 289 74 1.622464

98 8.41 1860 2120

1126 321 71 1.622464

99 8.38 1900 2140

1136 307 73 1.636749

100 8.34 1900 2100

1105 245 78 1.592512

101 8.43 1860 2120

1136 276 76 1.636749

102 8.38 1900 2140

1136 276 76 1.636749

103 8.24 1820 2080

1136 307 74 1.636749

104 8.14 1880 2120

1191 289 76 1.715176

105 8.42 1880 2020

1191 289 76 1.715176

106 8.33 1920 2060

1191 321 73 1.715176

107 8.13 1860 2160

1160 313 73 1.670847

55

Table A2: Experimental Result for VFA and Bicarbonate Alkalinity and calculated

α value

Time

(days)

Volatile fatty

acid

(mg/L as acetic

acid)

Total

Alkalinity

(mg/L as

CaCO

3

)

Bicarbonate

Alkalinity

(mg/L as CaCO

3

)

α value =

VFA/ Bicarbonate

alkalinity

25

181.9091

1900 1771.199268

0.102704

36

90.88636

1980 1915.64791

0.047444

38

317.8636

1840 1614.936652

0.196827

39

102.2727

1820 1747.585795

0.058522

42

227.0455

1920 1759.240466

0.129059

43

409.0909

2000 1710.343182

0.239186

44

272.8636

1900 1706.798902

0.159869

45

272.7273

2260 2066.895455

0.13195

46

306.8182

2120 1902.757386

0.161249

47

204.5455

2080 1935.171591

0.105699

48

272.7273

2020 1826.895455

0.149285

49

318.3409

2040 1814.598719

0.175433

50

340.9091

2040 1798.619318

0.189539

51

340.9091

1960 1718.619318

0.198362

52

409.0909

2000 1710.343182

0.239186

53

409.0909

2100 1810.343182

0.225974

54

545.4545

2000 1613.790909

0.337996

55

477.2727

2140 1802.067045

0.264847

56

477.2727

2200 1862.067045

0.256313

57

545.3182

2060 1673.887461

0.325779

58

545.4545

1940 1553.790909

0.351048

59

586.3636

2000 1584.825227

0.369986

60

429.5455

2060 1755.860341

0.244635

61

368.1818

1960 1699.308864

0.216666

62

347.7273

2000 1753.791705

0.198272

63

436.3636

1980 1671.032727

0.261134

64

477.2727

2140 1802.067045

0.264847

65

415.9091

2000 1705.515568

0.243861

66

368.1818

2000 1739.308864

0.211683

67

313.6364

2160 1937.929773

0.161841

68

218.1818

2120 1965.516364

0.111005

69

429.5455

1940 1635.860341

0.262581

70

422.7273

1920 1620.687955

0.260832

71

572.7273

1900 1494.480455

0.383228

73

395.4545

1960 1679.998409

0.23539

74

381.8182

2000 1729.653636

0.220748

56

days

Volatile fatty

acid

(mg/L as acetic

acid)

Total

Alkalinity

(mg/L as

CaCO

3

)

Bicarbonate

Alkalinity

(mg/L as CaCO

3

)

α value =

VFA/ Bicarbonate

alkalinity

75

456.8182

1840 1516.549886

0.301222

76

306.8182

2220 2002.757386

0.153198

77

395.4545

2200 1919.998409

0.205966

78

320.4545

1800 1573.102159

0.203709

79

354.5455

1900 1648.964091

0.215011

80

381.8182

2020 1749.653636

0.218225

81

395.4545

1780 1499.998409

0.263637

82

218.1818

1860 1705.516364

0.127927

83

320.4545

1940 1713.102159

0.187061

84

361.3636

1880 1624.136477

0.222496

85

381.8182

2040 1769.653636

0.215759

86

361.3636

2080 1824.136477

0.198101

87

347.7273

2120 1873.791705

0.185574

88

381.8182

2020 1749.653636

0.218225

91

436.3636

2060 1751.032727

0.249204

92

415.9091

2160 1865.515568

0.222946

93

361.3636

2100 1844.136477

0.195953

94

279.5455

2160 1962.067841

0.142475

96

211.3636

2160 2010.343977

0.105138

97

306.8182

2100 1882.757386

0.162962

98

272.7273

2120 1926.895455

0.141537

99

231.8182

2140 1975.861136

0.117325

100

218.1818

2100 1945.516364

0.112146

101

218

2100 1945.6451

0.112045

102

238

2120 1951.4841

0.121958

103

218

2140 1985.6451

0.109788

104

218

2080 1925.6451

0.113209

105

211

2120 1970.60145

0.107074

106

184

2020 1889.7188

0.097369

107

197

2160 2020.51415

0.0975

57

Table A3: Experimental Result for Variation of TMP with time after submergence

of Membrane in the reactor

Sr. no

days

Trans Membrane

Pressure (TMP),

(bar) Flux

(L/m

2

h)

1 1 -0.03996 9.444444

2 2 -0.15318 8.333333

3 3 -0.09857 8.333333

4 4 -0.15984 7.222222

5 5 -0.1998 7.777778

6 6 -0.1998 7.777778

7 7 -0.21046 9.444444

8 8 -0.20912 9.444444

9 9 -0.03996 8.888889

10 10 -0.09324 7.777778

11 11 -0.23576 6.666667

12 12 -0.31835 5

13 13 -0.40093 4.444444

14 14 -0.663 3.333333

15 15 -0.6942 3.333333

16 16 -0.7007 2.777778

17 17 -0.702 2.777778

18 18 -0.7098 3.333333

19 19 -0.663 2.777778

20 20 -0.6942 2.777778

21 21 -0.7007 3.333333

22 22 -0.702 3.333333

23 23 -0.7098 3.333333

24 24 0.013 9.444444

25 25 -0.663 3.333333

26 26 -0.6942 3.333333

27 27 -0.7007 2.777778

28 28 -0.702 2.777778

29 29 -0.7098 3.333333

30 30 -0.7098 2.777778

31 31 -0.7072 2.777778

32 32 -0.7228 3.333333

33 33 -0.728 3.333333

34 34 -0.7176 2.777778

35 35 -0.728 2.777778

36 36 -0.7085 2.5

37 37 -0.7241 2.777778

38 38 -0.7241 2.5

39 39 -0.7293 2.5

40 40 -0.7254 3.333333

58

Sr. no

days

Trans Membrane

Pressure (TMP),

(bar) Flux

(L/m

2

h)

41 41 -0.7241 3.333333

42 42 -0.7267 3.888889

43 43 -0.728 2.777778

44 44 -0.7345 3.333333

45 45 -0.7124 3.055556

46 46 -0.7241 2.777778

47 47 -0.7267 2.777778

48 48 -0.728 2.5

49 49 -0.7345 2.777778

50 50 -0.7124 2.5

51 51 -0.7085 2.5

52 52 -0.7241 3.333333

53 53 -0.7254 2.5

54 54 -0.7241 2.5

55 55 -0.7267 2.5

56 56 -0.728 2.5

57 57 -0.7345 3.333333

58 58 -0.7124 3.333333

59 59 -0.7085 2.5

60 60 -0.7241 3.333333

61 61 -0.7241 3.333333

62 62 -0.7267 2.777778

63 63 -0.728 2.777778

64 64 -0.7345 3.333333

65 65 -0.7124 3.333333

66 66 -0.7085 2.777778

67 67 -0.7241 3.333333

68 68 -0.7228 2.777778

69 69 -0.728 2.777778

70 70 -0.7176 2.777778

59

Table A4: Experimental Result for TMP and Flux on 15

th

day of operation

Time

(min)

Tans Membrane

Pressure (TMP)

Bar Flux

(L/m

2

h)

0 0 9.444444

5 -0.0333 -

6 -0.05994 -

7 -0.08658 -

8 -0.11322 -

9 -0.13986

10 -0.1665 -

11 -0.18914 -

12 -0.20779 -

13 -0.22644 -

14 -0.23576 -

15 -0.26507 -

16 -0.27173 -

17 -0.28638 -

20 -0.31435 -

21 -0.329

22 -0.33833 -

23 -0.34499 -

24 -0.35165 -

26 -0.37562

27 -0.37562 -

28 -0.38095 -

31 -0.3996 -

32 -0.40493 -

33 -0.41026 -

34 -0.41558 -

36 -0.42224 -

37 -0.43024 -

38 -0.4329 -

39 -0.43956 -

40 -0.44356 --

42 -0.45022 -

43 -0.45288 -

44 -0.45554 -

45 -0.4622 -

47 -0.46886 -

48 -0.4702 -

49 -0.47153 -

50 -0.47552 -

51 -0.47819 -

60

Time

(min)

Tans Membrane

Pressure (TMP)

Bar Flux

(L/m

2

h)

52 -0.48218

53 -0.48485 -

54 -0.48751 -

55 -0.49018 -

57 -0.49151 -

58 -0.49817 -

59 -0.4995 -

60 -0.5035 -

61 -0.50616 -

63 -0.51149 -

65 -0.52081 8.611111

67 -0.52481 -

69 -0.53147 -

71 -0.5328 -

73 -0.53946 -

75 -0.54479 7.5

77 -0.55145 -

79 -0.55544 -

85 -0.55678 -

90 -0.56876 -

99 -0.58475 -

101 -0.58741 -

106 -0.58874 7.5

111 -0.5954 -

116 -0.60206 -

121 -0.6034 -

126 -0.61139 -

131 -0.61139 -

136 -0.61672 8.055556

146 -0.62071 -

156 -0.62604 -

166 -0.62338 -

176 -0.63137 -

186 -0.63936 -

196 -0.64069 5.555556

216 -0.62737 -

262 -0.65268 6.666667

279 -0.65135 -

296 -0.65268 -

306 -0.65934 -

316 -0.66067 5.666667

343 -0.66067 -

61

Time

(min)

Tans Membrane

Pressure (TMP)

Bar Flux

(L/m

2

h)

361 -0.666 -

373 -0.67266 -

403 -0.67532 -

436 -0.67666 6.944444

466 -0.67532 -

596 -0.69664 -

646 -0.70463 -

676 -0.70463 -

770 -0.75658 5.555556

776 0 -

777 -0.05328 -

778 -0.1332 -

779 -0.31968 9.611111

780 -0.34632 -

781 -0.43956 -

782 -0.49018 -

783 -0.5288 -

784 -0.56344 -

785 -0.58208 -

796 -0.66067 -

798 -0.66733 -

799 -0.67266 5.555556

816 -0.69664 -

819 -0.7033 5.833333

62

Table A5: Experimental results of TMP and Flux on 16

th

day of Operation

Time

(min)

Tans Membrane

Pressure (TMP)

Bar Flux

(L/m

2

h)

0 -0.70063 -

1 -0.70063 -

2 -0.61805 -

4 -0.66467 5.555556

5 -0.68731 5.555556

6 -0.69797 5

7 -0.6953 5

30 -0.7326 4.444444

31 -0.5994 -

32 -0.51016 -

33 -0.53546 9.611111

34 -0.57276 5.555556

35 -0.5994 5.555556

36 -0.61805 4.444444

37 -0.6287 5

38 -0.64336 5.555556

60 -0.73793 4.444444

61 -0.73793 -

62 -0.6327 -

63 -0.57542 -

64 -0.42358 -

65 -0.42358 9.611111

66 -0.47952 8.333333

67 -0.5288 8.611111

68 -0.57409 8.611111

69 -0.60073 8.333333

70 -0.61538 7.222222

71 -0.63137 6.111111

72 -0.65135 5.555556

73 -0.67 5.555556

74 -0.67 5.555556

75 -0.67532 6.111111

76 -0.68198 5.555556

77 -0.68198 6.666667

80 -0.70063 4.627778

90 -0.72061 4.444444

150 -0.7659 3.333333

244 -0.76057 3.333333

245 -0.76057 -

246 -0.65534 -

63

Time

(min)

Tans Membrane

Pressure (TMP)

Bar Flux

(L/m

2

h)

247 -0.56477 -

248 -0.44888 -

249 -0.28638 -

251 -0.32634 -9.611111

252 -0.32634 9.611111

253 -0.50483 9.444444

254 -0.55544 9.444444

255 -0.60473 8.888889

256 -0.61538 8.333333

257 -0.63936 8.333333

258 -0.65002 6.944444

259 -0.67 5.555556

260 -0.67266 5.555556

261 -0.68198 5

262 -0.6993 4.166667

263 -0.6993 2.777778

264 -0.70596 5

265 -0.70596 2.222222

266 -0.70996 3.333333

267 -0.71262 2.777778

268 -0.72194 4.444444

269 -0.72328 2.222222

270 -0.72594 -

275 -0.73926 -

64

Table A6: Experimental results of TMP and Flux on 17

th

day of operation

Time

(min)

Tans Membrane

Pressure (TMP)

Bar Flux

(L/m

2

h)

0

-0.67266

-

1

-0.27572

-

2

-0.27572

-

3

-0.29304

9.444444

4

-0.37296

9.166667

5

-0.42224

6.666667

6

-0.47419

3.888889

7

-0.50749

4.166667

8

-0.53546

4.444444

9

-0.57409

5

10

-0.58208

5.555556

11

-0.60206

5.555556

12

-0.61272

6.111111

13

-0.62471

6.666667

14

-0.63137

5.833333

15

-0.63803

5.555556

16

-0.64202

5.666667

17

-0.65268

3.888889

18

-0.662

3.888889

19

-0.66866

5.833333

20

-0.67266

2.222222

21

-0.68332

3.333333

22

-0.68332

3.777778

31

-0.72461

3.333333

32

-0.72461

33

-0.44489

34

-0.21978

35

-0.21978

36

-0.34632

10.38889

37

-0.41292

9.444444

38

-0.45954

8.888889

39

-0.50083

5

40

-0.53546

5

41

-0.55944

4.722222

42

-0.58874

4.444444

43

-0.59674

5.277778

44

-0.61272

5.388889

45

-0.63137

5.555556

65

Time

(min)

Tans Membrane

Pressure (TMP)

Bar Flux

(L/m

2

h)

46

-0.64202

6.111111

47

-0.65002

5.722222

48

-0.65801

5.277778

49

-0.66334

4.444444

50

-0.67532

4.166667

51

-0.68065

2.777778

56

-0.70196

2.777778

57

-0.666

58

-0.63936

59

-0.41692

60

-0.20646

61

0.01332

62

-0.03996

9.444444

63

-0.14652

10

64

-0.23976

9.722222

65

-0.32234

9.444444

66

-0.39028

8.888889

67

-0.4329

6.944444

68

-0.47286

5

69

-0.50882

5

70

-0.5328

5

71

-0.54745

5.555556

72

-0.56743

5.555556

73

-0.58208

5.555556

74

-0.58608

5.555556

75

-0.5994

4.166667

76

-0.60606

3.888889

77

-0.61272

2.222222

78

-0.62204

4.444444

79

-0.63137

2.777778

80

-0.6367

3.333333

81

-0.63936

3.888889

85

-0.65801

2.777778

87

-0.65801

88

-0.35698

89

-0.1332

90

0.01998

91

0.01332

92

0.05328

11.11111

93

-0.01332

10.55556

94

-0.05994

10

95

-0.1332

10

66

Time

(min)

Tans Membrane

Pressure (TMP)

Bar Flux

(L/m

2

h)

96

-0.21978

10

97

-0.28638

10

98

-0.34632

9.444444

99

-0.39694

8.888889

100

-0.46886

7.222222

101

-0.4702

5

102

-0.49284

5.277778

103

-0.51282

5.833333

104

-0.5328

5.833333

105

-0.54878

6.111111

106

-0.5621

5.555556

107

-0.5701

5.555556

108

-0.58741

3.888889

109

-0.58874

4.444444

110

-0.61006

3.055556

111

-0.61672

2.777778

112

-0.61405

3.888889

120

-0.66334

3

121

-0.66334

122

-0.42624

123

-0.21312

124

0

125

0.087912

126

0.10656

127

0.0666

11.11111

128

0.029304

10

129

-0.01865

10

130

-0.05994

10

131

-0.11722

9.722222

132

-0.16783

9.722222

133

-0.23443

9.444444

134

-0.2957

7.222222

135

-0.34232

5

136

-0.38894

5

137

-0.43157

5.555556

138

-0.45421

5.277778

139

-0.48884

5

140

-0.51016

5.555556

141

-0.52614

5

142

-0.56344

5

149

-0.6327

3.611111

67

Table A7: Experimental results of TMP and flux on 18

th

day of operation

Time

(min)

Tans Membrane Pressure

(TMP)

Bar Flux

(L/m

2

h)

0

-0.51282

1

-0.32634

2

-0.37829

9.611111

3

-0.45421

8.888889

4

-0.51415

8.888889

5

-0.55012

8.888889

6

-0.5701

8.888889

7

-0.58608

8.888889

8

-0.5994

7.222222

9

-0.61139

4.444444

10

-0.61805

3.888889

11

-0.63137

2.777778

12

-0.63137

4.444444

13

-0.56344

1.666667

14

-0.65268

3.333333

15

-0.65401

3.888889

16

-0.65668

2.777778

17

-0.65668

4.166667

20

-0.68065

2.777778

24

-0.69664

2.777778

29

-0.69664

2.777778

30

-0.69397

31

-0.41958

32

-0.01998

33

-0.03996

11.11111

34

-0.35964

11.11111

35

-0.51415

10

36

-0.55944

8.888889

37

-0.55944

8.888889

38

-0.57276

8.333333

39

-0.5994

8.333333

45

-0.63936

3.333333

50

-0.66866

2.777778

55

-0.6993

2.777778

60

-0.6993

3.333333

61

-0.68598

62

-0.42757

63

-0.01332

68

Time

(min)

Tans Membrane Pressure

(TMP)

Bar Flux

(L/m

2

h)

64

0.061272

65

0.03996

10.55556

66

0.01332

10.55556

67

-0.08125

10.55556

68

-0.17316

10

69

-0.2664

9.722222

70

-0.39294

9.444444

71

-0.47952

9.444444

72

-0.54212

8.888889

73

-0.57276

8.777778

74

-0.59274

8.444444

75

-0.60872

8.333333

76

-0.61805

8.888889

77

-0.62737

8.333333

78

-0.63137

8.333333

79

-0.63403

8.333333

80

-0.64069

5

81

-0.64202

3.888889

82

-0.65534

2.777778

83

-0.65534

6.111111

84

-0.66334

2.777778

85

-0.66467

2.222222

90

-0.67399

2.777778

91

-0.67399

92

-0.41292

93

0

94

0.05994

95

0.05994

96

0.050616

7.222222

97

0.050616

11.11111

98

0.04662

10.55556

99

0.03996

10.55556

100

0.01332

10

101

-0.02664

10

102

-0.07992

10

103

-0.13054

8.333333

104

-0.19314

6.666667

105

-0.25175

6.666667

106

-0.30769

6.111111

107

-0.35964

5.555556

108

-0.4036

5.555556

109

-0.45022

5

69

Time

(min)

Tans Membrane Pressure

(TMP)

Bar Flux

(L/m

2

h)

110

-0.46354

5

111

-0.51815

5.555556

112

-0.53014

5.555556

113

-0.55278

5.555556

114

-0.5621

5

115

-0.57542

5

116

-0.58208

6.111111

117

-0.59141

5.555556

118

-0.60073

5.555556

119

-0.60739

4.444444

120

-0.62604

2.5

125

-0.662

3.333333

70

Table A8: Experimental results of TMP and flux on 20

th

day of operation

Time

(min)

Tans Membrane

Pressure (TMP)

Bar Flux

(L/m

2

h)

0

-0.351

2.777778

30

0.091

31

0.0572

7.222222

32

0.039

10.55556

35

0.0364

10.55556

54

0.026

10.55556

60

-0.065

61

-0.065

62

0.0585

63

0.0663

65

0.0286

10.55556

74

-0.2106

10

75

-0.2106

76

0.013

77

0.065

78

0.0182

10.27778

79

-0.013

10.55556

87

-0.247

9.166667

88

-0.169

89

0

90

0.065

91

0

10

92

-0.039

10

99

-0.3016

8.888889

100

-0.0585

101

0.052

102

-0.026

10.55556

112

-0.0611

8.333333

113

-0.286

114

-0.052

115

0.052

116

0

10.55556

126

-0.312

7.222222

127

-0.3224

128

-0.039

129

0.0585

139

-0.0195

10

149

-0.3211

8.333333

150

-0.3211

153

0.052

10.55556

71

Time

(min)

Tans Membrane

Pressure (TMP)

Bar Flux

(L/m

2

h)

163

-0.299

8.333333

164

-0.299

166

0.052

167

-0.013

10.55556

177

-0.325

8.888889

178

-0.325

180

0.0585

181

-0.0195

10.55556

191

-0.3315

8.333333

192

-0.3315

194

0.065

195

-0.039

10.55556

205

-0.325

8.333333

72

Table A9: Experimental results of TMP and flux on 22

nd

day of operation

Time

(min)

Tans Membrane

Pressure (TMP)

Bar Flux

(L/m

2

h)

0 -0.65

32 0.065

35 0.052

39 0.052

40 0.0806

41 0.0494 10.55556

48 0.039 10.55556

49 0.0728

50 0.0455 10.55556

57 0.0325 10

58 0.0689

59 0.0416 10.55556

66 -0.0468 10.55556

67 0.0819

68 0.013 10.55556

75 -0.2834 10.27778

76 0.0247

77 -0.0689 10.55556

84 -0.403 8.333333

85 -0.0585

86 -0.143 10.55556

93 -0.455 10

94 -0.117

95 -0.2366 10.55556

102 -0.4615 8.888889

103 -0.2795 10.55556

104 -0.52 8.333333

105 -0.286

106 -0.3458 10.55556

113 -0.5148 5.555556

114 -0.312

115 -0.364 10.55556

122 -0.5122 4.444444

123 -0.3185

124 -0.364 10.55556

131 -0.5135 4.444444

132 -0.3185

134 -0.364 10.55556

141 -0.5239 5.555556

142 -0.325

73

Table A10: Experimental results of TMP and flux on 47

th

day of operation

Time

(min)

Tans Membrane Pressure

(TMP)

Bar Flux

(L/m

2

h)

0

-0.71129

2.777778

20

0.07992

10.55556

25

0.04662

10

30

0.027972

10

35

-0.22644

8.333333

36

0

40

0.10656

41

0.05328

10.55556

45

0.021312

10.55556

50

-0.2038

8.333333

55

-0.42224

4.444444

56

-0.17316

60

0.07992

61

0.04662

10.55556

65

-0.0666

10

70

-0.3663

8.888889

75

-0.4995

4.444444

76

-0.27972

80

0.07992

81

0.04662

10.55556

85

-0.10656

10

90

-0.41958

8.333333

95

-0.50616

4.444444

96

-0.29304

100

0.09324

101

0.04662

10

115

-0.50616

4.444444

116

-0.34632

120

0.07992

121

0.04662

10

135

-0.58208

3.888889

136

-0.31968

140

0.07992

141

0.05328

10

155

-0.53014

4.444444

156

-0.29304

160

0.07992

161

0.05328

10

175

-0.50616

3.888889

74

Table A11: Experimental result of TMP and flux on 48

th

day of operation

Time

(min)

Tans Membrane

Pressure (TMP)

Bar Flux

(L/m

2

h)

0

0.0666

11.11111

1

-0.2957

9.444444

10

-0.34232

5

20

-0.48884

5

30

-0.6327

3.611111

31

-0.6367

35

-0.42624

40

0.087912

45

0.10656

46

0.0666

10

55

-0.2957

8.888889

65

-0.48884

5

75

-0.6327

3.611111

76

-0.61006

80

-0.42624

85

0.087912

90

0.10656

91

0.0666

10.55556

100

-0.2957

8.333333

120

-0.48884

5

130

WASTEWATER TREATMENT USING MEMBRANE BIOREACTOR

Abstract and Figures