Researcho microoranisms in wet anaerobic fermentation pilot to treat domestic waste :Master's thesis - Major : Sciences and management of the environment

THE JOINT ACADEMIC PROGRAM OF EXECUTIVE MASTER IN

SCIENCES AND MANAGEMENT OF THE ENVIRONMENT BETWEEN

INDUSTRIAL UNIVERSITY OF HO CHI MINH CITY AND LIÈGE

UNIVERSITY

NGUYEN DUY

RESEARCH MICROORGANISMS

IN WET ANAEROBIC FERMENTATION PILOT

TO TREAT DOMESTIC WASTE

Major: EXECUTIVE MASTER IN SCIENCES AND MANAGEMENT OF

THE ENVIRONMENT

MASTER’S THESIS

HO CHI MINH CITY, YEAR 2018

The project was completed at The Industrial University of Ho Chi Minh City

Supervisor’s name: .................................................................................................................

(Write full name and signature)

The thesis was taken at The Industrial University of Ho Chi Minh City date …... month

……. year . . . . .

Committee members (name):

1. ...............................................................................- Committee Chair

2. ...............................................................................- Commissioner

3. ...............................................................................- Secretary

(Write full name and signature)

COMMITTEE CHAIR DEAN OF INSTITUTE OF ENVIRONMENTAL

SCIENCE, ENGINEERING AND MANAGEMENT

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ACKNOWLEDGMENT

First of all, I would like to thank Dr. Trinh Ngoc Nam and Prof. Eppe, who were

give me many useful instructions, suggestions and advices to complete this thesis.

And they were also give me many documentation related to my research, which are

really exciting and provide me many knowledge in my thesis.

Then, I really appreciate the support of Prof. Le Hung Anh and Mr. Thang (a

manager of Nam Binh Duong Domestic Waste Treatment Plant), who gave me

many advices and helped me contact with Nam Binh Duong Domestic Waste

Treatment Plant to installed the wet anaerobic fermentation pilot and implemented

the research.

Third, I would like to thank Industrial University of Ho Chi Minh and University of

Liege gave me opportunity to complete this thesis and the master course.

Finally, sincerely thank my team members (Mr. Rodolfo, Mr. Trung, Mr. Danh, Ms.

Van, Ms. Chau), who were cooperate with me to had this successful research.

Author

Nguyen Duy

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ABSTRACT

Domestic waste is a current worrying situation in Vietnam. Together with the economic

development, population growth and the waste of resources in the living habits of

people, the quantity of waste is increasing, composition increasingly complex and

potentially more risk noxious to the environment and human health.

In fact, most domestic waste only land filled in the normal landfill with many

disadvantages (waste the land, the stench affect to residential areas, could become the

source of disease). The consequences have serious impacts to the environment and does

not save this renewable materials.

One of the methods to recover energy and reuse organic waste with highly effective and

applied in many developed countries is wet anaerobic fermentation system.

Wet anaerobic fermentation system has the opportunity to be an integral part of the

solution to two of the most pressing environmental concerns of urban centers: waste

management and renewable energy. Through wet anaerobic fermentation system,

organics are decomposed by specialized bacteria in an oxygen-depleted environment to

produce biogas and a stable solid. The biogas, which consists of up to 65% methane, can

be combusted in a cogeneration unit and produce green energy.

The most important factor in wet anaerobic fermentation system is anaerobic

microorganisms, so this thesis will focus on:

- Isolated microorganisms in anaerobic sludge after fermentation domestic waste.

- Identify some species of anaerobic microorganisms that predominate during

fermentation.

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TABLE OF CONTENTS

LIST OF FIGURES ............................................................................................................6

LIST OF TABLES..............................................................................................................7

ABBREVIATIONS ............................................................................................................8

INTRODUCTION ..............................................................................................................9

1. The reason for choosing the topic............................................................................9

2. Objectives of the study ..........................................................................................10

3. Subjects and scope of the study.............................................................................11

4. The methodology ...................................................................................................11

CHAPTER 1 LITERATURE REVIEWS ...................................................................12

1.1 Solid waste situation..........................................................................................12

1.1.1 In developed countries...................................................................................12

1.1.2 In Vietnam.....................................................................................................14

1.2 Anaerobic digestion process..............................................................................15

1.2.1 Stages of anaerobic digestion ........................................................................16

1.2.1.1 Hydrolysis.............................................................................................16

1.2.1.2 Acidogenesis.........................................................................................17

1.2.1.3 Acetogenesis .........................................................................................17

1.2.1.4 Methanogenesis.....................................................................................18

1.2.2 Microorganisms in anaerobic digestion ........................................................19

1.2.2.1 Hydrolytic bacteria................................................................................20

1.2.2.2 Acetogenic bacteria...............................................................................23

1.2.2.3 Methanogenic microorganisms.............................................................24

1.2.3 Factors that affect the anaerobic digestion process.......................................25

1.2.3.1 pH..........................................................................................................25

1.2.3.2 Temperature ..........................................................................................26

1.2.3.3 Carbon/Nitrogen ratio ...........................................................................26

1.2.3.4 Retention time .......................................................................................27

1.2.3.5 Loading rate ..........................................................................................27

1.3 Methods to identify microorganisms in Anaerobic Digestion ..........................28

1.3.1 Traditional methods of culture and identification .........................................28

1.3.2 Molecular techniques in ecology of anaerobic microorganisms...................29

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1.4 Conclusion .........................................................................................................30

CHAPTER 2 MATERIAL AND METHODS ............................................................31

2.1 Materials, pilot modeling and equipment..........................................................31

2.1.1 Materials........................................................................................................31

2.1.2 Pilot modeling ...............................................................................................31

2.1.3 Equipment used to analysis samples in laboratory........................................32

2.2 Methods .............................................................................................................33

2.2.1 Coning and quartering method to calculate solid waste composition...........33

2.2.2 COD determined............................................................................................35

2.2.3 Experiments implementation.........................................................................35

2.2.3.1 DNA extraction .....................................................................................35

2.2.3.2 Gel electrophoresis ...............................................................................37

2.2.3.3 Microorganism identify by phylogenetic tree.......................................39

2.2.3.4 Experiments conducting........................................................................40

CHAPTER 3 RESULTS AND DISCUSSION ...........................................................41

3.1 Solid waste composition....................................................................................41

3.2 COD...................................................................................................................41

3.2.1 COD in experiment 1 ....................................................................................41

3.2.2 COD in experiment 2 ....................................................................................42

3.3 Temperature.......................................................................................................43

3.3.1 Temperature in experiment 1 ........................................................................43

3.3.2 Temperature in experiment 2 ........................................................................44

3.4 pH ......................................................................................................................44

3.4.1 pH in experiment 1 ........................................................................................44

3.4.2 pH in experiment 2 ........................................................................................45

3.5 Anaerobic microorganisms................................................................................46

3.5.1 Anaerobic bacteria density ............................................................................46

3.5.2 Anaerobic yeast density.................................................................................46

3.5.3 Anaerobic bacteria density and anaerobic yeast density conclusion ............47

3.6 Anaerobic bacteria isolated ...............................................................................47

3.6.1 K1 bacteria strain...........................................................................................47

3.6.2 K2 bacteria strain...........................................................................................48