VIETNAM NATIONAL UNIVERSITY, HANOI
VIETNAM JAPAN UNIVERSITY
NGUYEN THU HOAI
DEVELOPMENT OF A NOVEL
URBAN-RURAL RELATIONSHIP FOR
SUSTAINABLE NITROGEN CYCLE:
CASE-STUDY IN HAI PHONG CITY
MASTER’S THESIS
VIETNAM NATIONAL UNIVERSITY, HANOI
VIETNAM JAPAN UNIVERSITY
NGUYEN THU HOAI
DEVELOPMENT OF A NOVEL
URBAN-RURAL RELATIONSHIP FOR
SUSTAINABLE NITROGEN CYCLE:
CASE-STUDY IN HAI PHONG CITY
MAJOR: ENVIRONMENTAL ENGINEERING
CODE: 8520320.01
RESEARCH SUPERVISOR:
Prof. Dr. KENSUKE FUKUSHI
Associate Prof. Dr. TRAN THI VIET NGA
Hanoi, 2020
ACKNOWLEDGEMENT
First and foremost, I would like to deepest appreciation to my supervisor, Prof. Dr.
Kensuke Fukushi for his patience, motivation, enthusiasm, and immense knowledge.
It was my honor to broaden and deepen my knowledge in the field of Environment
and Sustainability Science under his constant instructions and encouragement. I
would like to send my thanks to my boss and my co-supervisor, Assoc. Prof. Tran
Thi Viet Nga for her support and valuable advice to my fieldwork in Vietnam. It is
certain that without their sympathy and support, I could not able to complete this
thesis.
My gratitude is extended to all my teachers in the Master’s Programme in
Environmental Engineering, Vietnam Japan University for their enlightening lectures
and instructions in many fields of Environment and Sustainability Science. I would
like to thank all of the staffs working in VJU for their wonderful assistant during my
study and their support for field exercises. Under VJU sponsorship, I would able to
learn from the field and to exchange knowledge with other scholars working for the
sake of sustainable development. My thank is extended to all the friends in VJU, we
have been working hard for our own project but also working as a team in each
subjects and field exercises, and we enjoy the good times as well as overcome
hardships.
Last but not least, I would like to thank my family for their encouragement and trust.
Their constant love and caring enable me to complete this research.
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TABLE OF CONTENTS
TABLE OF CONTENTS ............................................................................................1
LIST OF TABLES ......................................................................................................6
LIST OF FIGURES.....................................................................................................8
LIST OF ABBREVIATIONS ...................................................................................10
INTRODUCTION .....................................................................................................11
1.1
Background ..................................................................................................11
1.1.1
Problem statement.................................................................................11
1.1.2
Wastewater management in Vietnam ...................................................12
1.1.3
Organic fertilizers in Vietnam ..............................................................14
1.2
Research objective .......................................................................................18
1.3
Scope of study .............................................................................................18
1.4
Thesis structure ............................................................................................18
CHAPTER 1 LITERATURE REVIEW ...................................................................20
1.1
Nitrogen in the environment ........................................................................20
1.1.1
The essential of Nitrogen and its cycle .................................................20
1.1.2
Sources of nitrogen ...............................................................................22
1.2
Waste sludge and its recovery and reuse .....................................................30
1.2.1
Definition and classification of sludge .................................................30
1.2.2
Characteristics .......................................................................................32
2
1.2.3
Impacts of sludge to environment and human health ...........................34
1.2.4
Technical of reusing sludge ..................................................................37
1.3
Nitrogen in Hai Phong city ..........................................................................40
CHAPTER 2 MATERIAL AND METHODS ..........................................................43
2.1
Hai Phong city .............................................................................................43
2.1.1
Natural and Socio-Economic features ..................................................43
2.1.2
Social-economic features ......................................................................44
2.2
Methodologies .............................................................................................44
2.2.1
Data collection method .........................................................................44
2.2.2
Feasibility assessment ...........................................................................47
CHAPTER 3 ESTIMATION OF THE PRODUCTION AND CONSUMPTION OF
NITROGEN ..............................................................................................................49
3.1
The production of nitrogen ..........................................................................49
3.1.1
Septage sludge ......................................................................................49
3.1.2
Animal manure .....................................................................................51
3.1.3
Aquaculture ...........................................................................................53
3.1.4
Industry .................................................................................................54
3.1.5
Total loading of nitrogen in sludge .......................................................56
3.2
The consumption of Nitrogen through fertilizer .........................................57
3.2.1
3.3
The nitrogen fertilizer consumption .....................................................58
Nitrogen consumption and production ........................................................58
3
CHAPTER 4 ASSESSMENT OF CITIZENS AND FARMERS FOR WASTEBASED FERTILIZER ..............................................................................................60
4.1
Urban area ....................................................................................................60
4.1.1
Drainage system ....................................................................................62
4.1.2
Septage management ............................................................................63
4.1.3
Assessment of citizens for three type of fertilizer ................................66
4.2
Rural area .....................................................................................................69
4.2.1
Paddy farm ............................................................................................70
4.2.2
Animal farm ..........................................................................................72
4.2.3
Aquaculture ...........................................................................................72
4.2.4
Assessment of farmers for three type of fertilizer ................................73
CHAPTER 5 SUSTAINABLE AND INTEGRATED WASTE-BASED NITROGEN
MANAGEMENT IN HAI PHONG CITY ...............................................................76
5.1
Sustainable and integrated waste-based nitrogen management ..................76
5.1.1
Scenario 1 (Baseline scenario) ..............................................................76
5.1.2
Scenario 2 (Government contribution) .................................................78
5.1.3
Scenario 3 (Public Private Partnership) ................................................79
5.2
Feasibility assessment..................................................................................80
5.2.1
Financial analysis ..................................................................................80
5.2.2
Feasibility assessment ...........................................................................83
CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS .............................91
4
6.1
Research significance ..................................................................................91
6.2
Recommendations .......................................................................................92
REFERENCES ..........................................................................................................94
APPENDIX .............................................................................................................101
5
LIST OF TABLES
Table 1-1 The production and consumption of nitrogen in fertilizer around the world
from 2016 to 2022 (thousand tons) [20] ...................................................................24
Table 1-2 The concentration of nitrogen in precipitation across United Kingdom from
2000 to 2002 ..............................................................................................................27
Table 1-3 Waste management and treated in selected cities [32] .............................28
Table 1-4 Selected technologies for resources recovery in waste sludge [49] .........37
Table 2-1 General information of Hai Phong city ....................................................43
Table 2-2 General information of surveyors living in urban area of Hai Phong ......45
Table 2-3 General information of surveyors in Ang Duong hamlet .........................46
Table 2-4 Agriculture land and total number of selected animal in Hai Phong city [4]
...................................................................................................................................46
Table 2-5 Agriculture land and total number of selected animal in Ang Duong hamlet
...................................................................................................................................47
Table 3-1 The total nitrogen generated from human excreta in Hai Phong city and
Ang Duong hamlet ....................................................................................................51
Table 3-2 Daily manure production and characteristics (per head per day) [56] .....51
Table 3-3 The loading of nitrogen generated by animal manure in Hai Phong city
and Ang Duong Hamlet ............................................................................................52
Table 3-4 The total number of animal farms in Ang Duong hamlet ........................52
Table 3-5 The loading of nitrogen generated in aquaculture in Hai Phong city and
Ang Duong Hamlet ...................................................................................................54
Table 3-6 List of industrial parks and its wastewater facility [59] ...........................55
6
Table 3-7 Total loading of Nitrogen from different sources of excreta in Hai Phong
city and Ang Duong Hamlet .....................................................................................56
Table 3-8. The fertilizer consumption and the percentage of nitrogen fertilizer [60],
[61] ............................................................................................................................57
Table 3-9 The total fertilizer consumption and nitrogen fertilizer consumption in Hai
Phong city..................................................................................................................58
Table 3-10 The nitrogen in fertilizer consumption and nitrogen in waste sludge of Hai
Phong city and Ang Duong hamlet ...........................................................................59
Table 4-1 Emptying septage sludge activity of SADCO (unit:m3)...........................61
Table 4-2 The number of survey questionnaires by districts ....................................61
Table 4-3 Occupation percentage of the interviewer ................................................61
Table 4-4 The number of farmers in Ang Duong hamlet .........................................69
Table 4-5 The amount of fertilizer which farmers use in different types .................70
Table 5-1 Inflow-out flow financial of three scenarios.............................................80
Table 5-2 Financial analysis of three scenarios (VND/year) ....................................82
Table 5-3 Feasibility assessment of 3 scenarios .......................................................83
Table 5-4 Summary the feasibility assessment for three scenarios ..........................89
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LIST OF FIGURES
Figure 1-1 Sources of Nitrogen .................................................................................22
Figure 1-2 The meat production by meat type (2028 vs 2016-18) ...........................25
Figure 1-3 The process of manure-N production [28] ..............................................26
Figure 1-4 Nitrogen cycle in Hai Phong city ............................................................41
Figure 2-1 Administrative map of Hai Phong ...........................................................43
Figure 2-2 Location of households surveyed in urban area of Hai Phong................45
Figure 3-1 Percentage of different type of factories in the industrial parks of Hai
Phong .........................................................................................................................55
Figure 3-2 Fertilizer consumption and the percentage of nitrogen in fertilizer in
Vietnam [60], [61] .....................................................................................................57
Figure 4-1 Process Flow diagram of sludge treatment in Trang Cat plant ..............60
Figure 4-2 Response of citizens in the on-site and off-site drainage system ............62
Figure 4-3 The connection of indoor and outdoor drainage system .........................62
Figure 4-4 Assessment of citizens for the emptying septic tank activity .................64
Figure 4-5 Unit in charge in emptying septic tank activity.......................................64
Figure 4-6 The emptying septic tank cost .................................................................65
Figure 4-7 Location discharging septage sludge.......................................................65
Figure 4-8 Trang Cat sludge treatment plant ............................................................66
Figure 4-9 The assessment for chemical and organic fertilizers by citizens ............67
Figure 4-10 The assessment of citizens for waste-based fertilizers ..........................68
8
Figure 4-11 Fertilizer cost per year ...........................................................................71
Figure 4-12 Fertilizer distribution places ..................................................................71
Figure 4-13 Paddy field in Ang Duong hamlet .........................................................72
Figure 4-14 The assessment for chemical and organic fertilizers by farmers ..........73
Figure 4-15. The assessment of farmer for waste-based fertilizers ..........................74
Figure 5-1 Four main step of waste treatment and disposal .....................................76
Figure 5-2 Scenario 1 (Baseline scenario) ................................................................77
Figure 5-3 Scenario 2 (Government contribution) ....................................................78
Figure 5-4 Scenario 3 (Public Private Partnership) ..................................................79
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LIST OF ABBREVIATIONS
SDG
Sustainable development goals
WWTP
Wastewater treatment plant
MARD
Ministry of Agriculture and Rural Development
RRR
Resources recovery and reuse
PPP
Public private partnership
FAO
Food and Agriculture Organization
NPV
Net present value
IRR
Internal rate of return
RoI
Return on Investment
SADCO
Sewage and Drainage Company
GLOBAL GAP
Global Good Agricultural Practice
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INTRODUCTION
1.1 Background
1.1.1 Problem statement
Vietnam is becoming one of the 15 largest agricultural exporters in the world with
the total export countries of more than 180 countries and territories around the world.
The annual export turnover of Vietnam is very high, but the quality of the product is
unstable. Central Chairman of Vietnam Farmers Association mentioned that exported
goods only achieved 5% of the international quality. Most of the products contain
high levels of chemical substances that come from chemical fertilizers and pesticides.
A loose and inconsistent structure of Vietnam’s management system can be one of
the reasons when 90% of fertilizer products used in Vietnam are chemical products,
and farmers in Vietnam mostly overuse the fertilizer amount. The sustainable
development goals 2 (SDG 2) for the End hunger, ensure food security, improve
nutrition and promote sustainable agriculture development has implemented many
Decisions and projects towards sustainable agriculture, though very few results
recorded at this time. The trendy production in the world and in Vietnam is organic
products in which organic fertilizers substitute for chemical fertilizers. Nowadays,
Vietnam has many projects and models of production and use of organic fertilizers in
crops but they are small and prone to failure. Nutrient resources management has not
paid much attention in Vietnam, and the concept of resource recovery and reuse has
been currently unpopular.
In the other hand, there are many sources that can exceed nutrient like nitrogen in our
environment such as human waste, animal manure, industry waste while most of these
sources in Vietnam are having discharged into the environment without the treatment.
According to SDG 6 (Ensure availability and sustainable management of water and
sanitation for all), The Ministry of construction mentioned that Vietnam currently has
37 concentrated WWTPs in urban areas with a total capacity of about 890,000m³/day,
it is estimated that around 80% of the generated wastewater discharged directly into
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the water bodies without any collection and treatment or partially treated by simple
on-site treatment facilities such as septic tanks, and moreover most of sludge
generated from wastewater have not paid much attention. The management of sludge
has only been noticed in recent years, and it has been mentioned with wastewater
management in Vietnam's legal system. In waste sludge, nitrogen exists mostly in the
form of organic nitrogen, which can be recovered and reused for organic fertilizer.
However, the recovery and reuse of sludge in Vietnam have just stopped at the
research step and has not been put into actual operation. Most studies only focus on
analyzing the properties, characteristics of sludge, and the ability of waste-based
fertilizer in the laboratory. Therefore, it is certain that research for sludge waste
management with the purpose of waste-based fertilizer production is necessary.
1.1.2 Wastewater management in Vietnam
1.1.2.1 Wastewater management in urban areas of Vietnam
In major cities in Vietnam, most of the drainage network has been built centuries ago
and is now degraded. Most of the wastewater system in Vietnam is a centralized
system, collecting both wastewater and rainwater, only a few new urban areas have
the separated drainage systems.
Major cities such as Hanoi, Quang Ninh, Da Nang have drainage network and
wastewater treatment system in the city area. However, there is still a complete
construction of a WWTP but no drainage network has been built yet. Therefore, some
WWTPs (WWTPs) do not operate at full capacity because there is not enough input
wastewater [1]. According to the report, by 2018, Vietnam has about 37 centralized
WWTPs with a total design capacity of 890,000 m3/day. It is expected that by 2020
there will be more 50 WWTPs with a total capacity of about 2 million m3/day and
operation, and the rate of collected and treated wastewater will increase to about 20%.
Although the number of urban WWTPs have increased over the years, however, this
number is still very small compared to the actual requirements to be treated.
Wastewater collection and treatment services are still quite low compared to water
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supply systems, so in many places, wastewater and rainwater are still discharged
directly into rivers and lakes [2].
1.1.2.2 Wastewater management in rural areas of Vietnam
According to Center for Rural Water Supply and Sanitation (CERWASS), only 50%
of households have typical latrines when compared to the national target of 60% of
rural areas, and only 25% of households are able to equipped with standard meeting
facilities [3].
The infrastructures in remote areas are mostly funded by the Ministry of Agriculture
and Rural Development (MARD) in decentralized level under the responsibilities of
provincial or commune People’s Committee [2]. The sanitation coverage in rural
areas is still low because the main focus now is on the provision of drinking water.
According to statistics, in the period of 2010-2016, the percentage of households
using hygienic toilets increased from 75.7% to 83.3% [4].
1.1.2.3 Legal framework
Vietnam has issued and implemented many policies related to SDG 6, in which proper
management, conservation and utilization of water resources have been emphasized
in laws and policies such as: Environmental Protection Law, Construction Law,
Biodiversity Law, Law on Water Resources; Resolution 24-NQ/TW of the Central
Committee on proactive response to climate change, strengthening resource
management and environmental protection.
The Prime Minister has signed many important policies with many contents related
to SDG 6 such as: National strategy on water resources to 2020, National
Environmental Protection Strategy to 2020, vision to 2030, National Program to
ensure safe water supply for the period 2016-2025, National Action Plan to improve
the effectiveness of management, protection and use of water resources synthesis in
the period of 2014-2020, National Target Program built new rural construction in the
period 2016-202. With the goal of increasing water use efficiency, in addition to the
13
Law on Water Resources approved in 2012, the Government approved 04 Decrees
52.
Policies and resolutions were issued from the central government and brought to the
ministries and departments, from there to be transferred to the departments of the
localities. In the local areas, appropriate policies will be enforced and brought to the
communities. The main tasks of communities is monitor and protection water
resources; response to water related incidents.
Sewage sludge and hazardous sludge are the only two types of sludge currently
regulated in Vietnam's Environmental Protection Law. In particular, sewage sludge
is identified and managed as solid waste and hazardous sludge is considered as
hazardous waste. The current standard of sewage sludge management in Vietnam is
still in the process of development and drafting, National Technical Regulation
Technical Infrastructure Works Sewerage (QCVN 07: 2009 / BTNMT) is the only set
of standards on limits of hazardous sludge wastes in water treatment facilities. In
addition to the specific regulations on hazardous sludge, the management and
treatment of general sludge in the whole country is currently vacant and has not been
given adequate attention.
1.1.3 Organic fertilizers in Vietnam
According to the Ministry of Agriculture & Rural development, by the end of 2017,
the total amount of organic fertilizers being produced, traded and used was 182
products, accounting for 1.3% of total fertilizer products, the remaining 93.7% were
inorganic fertilizers and 5% is organic fertilizers [5].
The total capacity of organic fertilizer production facilities is 2.5 million tons/year,
accounting for 8.5% of the total domestic fertilizer production capacity (29.5 million
tons/year), and equal to nearly 1/10 of the inorganic fertilizer production capacity
(26.7 million tons/year) [5].
14
Fertilizer utilization efficiency is currently very low due to the imbalance of inorganic
and organic fertilizers. Another issue in using organic fertilizer is that people use
traditional organic fertilizers based on their experience, habits and industrial organic
fertilizer use according to the principal instructions of the seller and label of product.
It is clarified that there is currently no orientation and training for farmers on the
effects of organic fertilizers, how to coordinate the balance between inorganic and
organic fertilizers. Farmers also have very few opportunities to approach and learn
about effective balance of organic fertilizer use.
During 2015-2017, Vietnam exported organic fertilizer to 34 different countries with
a total volume of approximately 76,000 tons. However, the volume of imported
organic fertilizer into Vietnam is nearly three times larger than the export (about
220,000 tons) [5]. The main reason for this big gap is the domestic under-developed
organic fertilizer processing industry. The technology and technique of domestic
fertilizer production is still slower than other countries, leading to high production
costs, making it difficult to compete with foreign fertilizer.
1.1.3.1 The production of organic fertilizers
In Vietnam, organic fertilizer is currently produced domestically in two ways:
traditional composting and industrial production.
The traditional method of composting is mainly used at the farm level based on the
source of waste materials or crop residues collected from livestock and cultivated at
the household level. The organic by-products are mixed well, at the same time can
add mineral elements and microbial preparations then compost in the purpose of
maintaining the temperature to accelerate the decomposition of organic matter,
accelerate the mineralization process and destroy disease-causing organisms for
humans, domestic animals and plants.
Currently, there are many different annealing methods, such as hot annealing, cold
annealing, pre-cooling hot annealing, or advanced annealing methods using EM,
quick annealing, etc. The time and method of composting affects the composition and
15
activity of microorganisms that decompose and convert organic matter into humus,
thereby affecting the quality and volume of composting compost. The centralized and
mechanized livestock production in cultivation has led to a small amount of cattle
raising in households, which has significantly reduced the amount of organic fertilizer
produced by the traditional composting method and instead, the amount of fertilizer
Organic industrial production tends to increase in recent years.
The mode of industrial production applied at fertilizer production establishments is
invested in infrastructure, chains of equipment and machines with different sizes of
large and small capacities (from 20,000 to 500,000 tons). Currently, Vietnam has 180
enterprises that have been granted licenses to produce organic fertilizers, accounting
for 24.5% of the total production permits granted by the MARD and the Ministry of
Industry and Trade (735 License). The total capacity of organic fertilizer production
facilities is 2.5 million tons/year, accounting for 8.5% of the total domestic fertilizer
production capacity (29.5 million tons/year) and nearly 1/10 of the inorganic fertilizer
production capacity (26.7 million tons/year). [5]
1.1.3.2 Legal framework
By the end of 2016, 24 Vietnamese standards (TCVN) were issued related to organic
fertilizers, which focused primarily on testing methods to determine the density and
activity of microorganisms and content of limiting factors in compost. In addition,
there are a number of standards that mention the technical requirements for organic
fertilizers such as TCVN 7185: 2002 on microbial organic fertilizer.
Basically, the standard system of fertilizers in general and organic fertilizers in
particular has been developed since the 1990s of the last century until now, but there
is still a shortage of quantity, quality and no response. The application is actually
required. Some biological supplements added to fertilizers, especially foliar fertilizers
such as amino acids, vitamins, growth regulators, etc., do not have standards for
testing and controlling the quality of fertilizers. For microorganisms in
microbiological fertilizers/probiotics, only methods for testing groups of
16
microorganisms such as nitrogen fixation, cellulosolysis, phosphate solubility, the
test method for each strain/species of microorganism still have not been available yet.
The number of standards, especially those related to microorganisms, have not been
reviewed, updated or revised to suit the reality and the development of science and
technology of production and use of organic fertilizers.
The use of useful strains/species of microorganisms to decompose agricultural byproducts and waste in the production of organic fertilizer are becoming an urgent
trend nowadays. This is one of the important factors contributing to the development
of organic fertilizer in particular and organic agricultural production in general. State
management agencies need to make certain investments in the development of testing
methods and techniques to check the quality of organic fertilizers/probiotics using
these microorganisms. In addition to density testing, attention should also be paid to
checking the activity of these microorganisms.
The Department of Food Protection, MARD has reviewed and planned the
development of test method standards for nutrition, limited and microbiological
criteria in faeces. Fertilizers, of which special attention is given to groups of organic
fertilizers, probiotics, microorganisms, etc. The goal is to basically improve standards
on testing methods to check fertilizer quality by 2019.
Recently, the development of technical standards for fertilizers in general and organic
fertilizers in particular is entirely dependent on the state budget. In future, it is
necessary to promote the socialization of technical standards to improve efficiency in
terms of quality, quantity and progress.
No technical standards in the field of fertilizers have been developed at that time.
Plant Protection Department, Ministry of Agriculture and Rural Development is
urgently developing and perfecting technical standards on fertilizer quality, including
specific regulations on quality of organic fertilizers and biological products and
probiotics products.
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1.2 Research objective
The research goal is to propose the integrated mechanism of sludge waste
management to build a novel urban-rural relationship for sustainable nitrogen cycle.
The proposed mechanism is expected to recovery and reuse the nitrogen component
in the sludge generated by various sources in the urban and rural area of Hai Phong
city.
The objective of this study has been three-fold. First, to explore the nitrogen cycle in
Hai Phong city. Second, to determine the potential of nitrogen fertilizer production in
waste sludge. Finally, to propose the sustainable and integrated waste-based nitrogen
management in Hai Phong city.
1.3 Scope of study
This study investigates the potential for recovering and reusing nitrogen in various
waste sludge sources to produce waste-based fertilizer. Sludge management system
from source to distribution is mentioned and evaluated in the study. Various
assessment factors for the three perspectives of Economic-Environment-Social were
assessed through the management system to examine the feasibility of implementing
the waste-sludge management.
1.4 Thesis structure
The remainder of master thesis is structured into six chapters as described below:
- Chapter one highlights the literature review, where the origin of nitrogen in
ecosystem, the definition of waste sludge and the sludge recovery systems were
introduced.
- Chapter two highlights the general information of Hai Phong city and the
methodology of the research that explains detail the data collection and analyzing
process.
- Chapter three highlights the potential of recovery and reuse nitrogen to produce
waste-based fertilizer.
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