Water quality assessment of cau river flows through thai nguyen province for the period 2012 2019

THAI NGUYEN UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY LE THI THU THAO WATER QUALITY ASSESSMENT OF CAU RIVER FLOWS THROUGH THAI NGUYEN PROVINCE FOR THE PERIOD 2012 – 2019 BACH

THAI NGUYEN UNIVERSITY

UNIVERSITY OF AGRICULTURE AND FORESTRY

LE THI THU THAO

WATER QUALITY ASSESSMENT OF CAU RIVER FLOWS

THROUGH THAI NGUYEN PROVINCE FOR THE PERIOD 2012 – 2019

BACHELOR THESIS

Study mode : Full-time

Major : Environmental Science and Management Faculty : International Program Office

Batch : 2015 – 2019

Thai Nguyen, 2019

DOCUMENTATION PAGE WITH ABSTRACT

Thai Nguyen University of Agriculture and Forestry Degree Program Bachelor of Environmental Science and Management Student name Le Thi Thu Thao

Student ID DTN1554110066

Thesis Title Water quality assessment of Cau river flows through Thai

Nguyen province for the period 2012-2019 Supervisors Dr Tho Huu Nguyen

of upstream monitoring points, especially after the 300m Cam Gia stream discharge point Because this area receives a number of wastewater sources of factories, industrial zones, urban areas, and craft villages In which totally suspended solids (TSS) pollution at the monitoring points in the years was still high, surpassing QCVN 08: 2008 / BTNMT level B1 Moreover, WQI in the rainy season at Cau River was much lower than in the dry season In the downstream areas after the discharge point of 300m Cam Gia stream and Pho Huong stream, the WQI index in the rainy season is 43 and 53, respectively, the dry season is 76 and 56, the water quality is the only used for irrigation The upstream zone always has a higher WQI index from 86 to 92 in the dry season and from 64 to 72 in the rainy season

Currently, Thai Nguyen Province has started to build and improve water treatment systems for Cau River After assessing the current state of Cau River water quality, the necessary measures are proposed In management, perfecting the legal policies and regulations in water environment protection and combine the implementation of many solutions for better control, of which the most important thing is to create a link between management agencies, scientists, and community participation In wastewater treatment, it is necessary to build wastewater treatment areas in industrial and urban areas In addition, it is necessary to focus on examining factory areas, urban areas, and craft villages to reduce illegal discharge

In general, the water quality of Cau River in recent years has been improved, monitoring indicators mostly meet the permitted standard according to QCVN 08: 2008 / BTNMT level A2 It is shown that the management measures,

as well as the treatment of water quality on the Cau River, have been taken seriously

Key words water quality, WQI, Cau River

Number of pages 67

Date of submission 23/09/2019

ACKNOWLEDGEMENT

With deep respect and gratitude, I am extremely grateful to my supervisor

Dr Nguyen Huu Tho for his invaluable useful advice, discussions, and

comments which brought an added value to this research work

I sincerely thank the Headmaster, International Training and Development

Center Office and all teachers of Thai Nguyen University of Agriculture and

Forestry for enthusiastically teaching and imparting valuable knowledge to me,

creating good conditions to help me during my studies at the university

Finally, I would like to express my gratitude to my family, relatives, and

friends who have cared, supported and encouraged me during the process of

studying, researching as well as completing this thesis

TABLE OF CONTENT

LIST OF TABLES 1

LIST OF FIGURES 2

LIST OF ABBREVIATIONS 3

PART I INTRODUCTION 4

1.1 Research rationale 4

1.2 Research‘s objectives 5

1.3 Research questions and hypothesis 6

1.3.1 Research questions 6

1.3.2 Hypothesis 6

1.4 Limitations 6

1.5 Defination 6

PART II LITERATURE REVIEW 9

2.1 Study area background 9

2.1.1 Geographical location 9

2.1.2 Geographical features 9

2.1.3 Climate conditions and Hydrologic features 10

2.1.4 Socio-economic conditions 11

2.2 Scientific background 11

2.3 Theoretical background 14

2.4 Surface water quality assessment method 15

2.4.1 Traditional method 15

2.4.2 Water quality index 17

PART III MATERIALS AND METHODS 22

3.1 Equipment and Materials 22

3.1.1 Equipment 22

3.1.2 Materials 22

3.2 Methods 23

3.2.1 Secondary data collection 23

3.2.2 Methods of collecting, storing and analyzing samples 23

3.2.4 Synthesizing, analyzing and processing data methods 31

3.2.5 Statistical and comparison methods 31

PART IV RESULTS 32

4.1 Assessing the situation and development of water quality of Cau river flowing through Thai Nguyen province 32

4.2 The result of calculating the WQI of Cau river flows through Thai Nguyen province 46

4.3 Solutions to improve water quality 52

4.3.1 Overall solution 52

4.3.2 Specific solution 53

PART V DISCUSSION AND CONCLUSION 56

5.1 Discussion 56

5.1.1 Status of water quality in Cau river from 2012 to 2019 56

5.1.2 Status of water quality in Cau river through WQI in 2018 and 2019 59

5.1.3 Solution for water quality of Cau river 59

5.2 Conclusion 60

REFERENCES 63

LIST OF TABLES

Table 1.1: List of selected studies carried out worldwide using Water Quality

Indices 19

Table 3.1: Table specifying qi and BPi values 28

Table 3.2: Table specifies BPi and qi values for saturated DO% 29

Table 3.3: Table specifies BPi and qi values for pH 29

Table 3.4: Compare WQI values 31

Table 4.1: Water quality development in the dry season of Cau river 33

Table 4.2 Water quality development in the rainy season of Cau river 36

Table 4.3: Results of calculation of WQI of Cau River in rainy season 2018 47

Table 4.4 Results of calculation of WQI of Cau River in dry season 2019 48

LIST OF FIGURES

Figure 4.1: Evolutions of DO content on the sections of Cau River flowing

through Thai Nguyen province by dry season from 2012-2019 39 Figure 4.2: Evolutions of DO content on the sections of Cau River flowing

through Thai Nguyen province by rainy season from 2012-2018 39 Figure 4.3 Evolutions of BOD5 content on the sections of Cau River flowing

through Thai Nguyen province by dry season from 2012-2019 40 Figure 4.4 Evolutions of BOD5 content on the sections of Cau River flowing

through Thai Nguyen province by rainy season from 2012-2018 40 Figure 4.5 Evolutions of COD content on the sections of Cau River flowing

through Thai Nguyen province by dry season from 2012-2019 41 Figure 4.6 Evolutions of COD content on the sections of Cau River flowing

through Thai Nguyen province by rainy season from 2012-2018 42 Figure 4.7 Evolutions of TSS content on the sections of Cau River flowing

through Thai Nguyen province by dry season from 2012-2019 43 Figure 4.8 Evolutions of TSS content on the sections of Cau River flowing

through Thai Nguyen province by rainy season from 2012-2018 43 Figure 4.9 Evolutions of Coliform content on the sections of Cau River flowing

through Thai Nguyen province by dry season from 2012-2019 44 Figure 4.10 Evolutions of Coliform content on the sections of Cau River flowing

through Thai Nguyen province by rainy season from 2012-2018 44 Figure 4.11 Monitoring points map for water quality of Cau river flowing

through Thai Nguyen province 46 Figure 4.12 Compare WQI in dry season and rainy season of Cau river 49 Figure 4.13 Water quality zoning map of Cau river in Thai Nguyen province

according to WQI – rainy season 2018 50 Figure 4.14 Water quality zoning map of Cau river in Thai Nguyen province

according to WQI – dry season 2019 51

LIST OF ABBREVIATIONS

BOD COD CWQI

DO DNRE

GDP GMES

NSFWQI

QCVN

T TCVN TSS WQI

WQ

Biochemical Oxygen Demand Chemical Oxygen Demand Canadian Water Quality Index Dissolved oxygen

Department of Natural Resources and Environment

Gross domestic products The standards of the global environmental monitoring system

National Sanitation Foundation Water Quality Index

National Technical Regulations of Vietnam

Temperature Viet Nam standard Total Suspended Solids Water quality index Water quality

PART I INTRODUCTION

Water is vital to Earth's existence Changes in water availability, both in

terms of water quantity and water quality, can impact people's lives and other

living things as the main resource for human and ecological life (Stantec and

Northcliff, 2013) Rivers are man's most significant resource of fresh water In

the past, social, economic and political growth was mainly linked to the

accessibility and allocation of freshwaters in riverine systems (M Meybeck, G

Friedrich, R Thomas and D Chapman, 1996) Cau river (also known as Nhu

Nguyet River, Thi Cau River, Nguyet Duc River or My Quan River) is the

mainstream of the Thai Binh river system This is a place to store abundant

natural resources and supply water for industrial, agricultural and daily-life

activities in 6 provinces of Bac Kan, Thai Nguyen, Bac Giang, Bac Ninh, Vinh

Phuc, and Hai Duong Nowadays, when the social development faster and higher

demand of human, leading to series of unreasonable exploitation from industrial

zone and trade villages such as massive mining, deforestation of watershed

protection forests, beside wastewater treatment is still unregarded Therefore, the

water sources, landscapes, and ecosystems of Cau River, as well as the river

basin, were degraded and at risk of depletion, adversely affecting production and

life, ecological environment, natural landscape

Thai Nguyen province, where has the long flows of the Cau River and it is a

province with strong industrial development in the North of Vietnam According to

annual monitoring data, the section of Cau River flowing through Thai Nguyen

province has been heavily polluted, due to receiving industrial wastewater, domestic

wastewater as well as waste from activities along the two banks

To assess water quality, many countries in the world have used the Water

Quality Index (WQI) WQI is a way of using aggregate data rather than

evaluating each parameter From many values of different parameters, by

appropriate calculations, the results obtained a unique index that is used to

quantify the water quality and usability of that water source; expressed through a

scale of 0 to 100

It is not easy to assess water quality for huge samples containing

concentrations formany parameters (Almeida C., Quintar S., González P and

Mallea M., 2008) Therefore, the advantage of WQI is simple, easy to understand

and highly generalized, moreover, it can be used for the purpose of evaluating

water quality development in space and time, so that WQI is a good source of

information for the community and for managers With these advantages, WQI is

now considered an effective tool to manage water resources

Derived from the reality, through the agreement of my supervisor Dr Tho

Huu Nguyen and International Training and Development Center - Thai Nguyen

University of Agriculture and Forestry, the study researched on the subject:

“Water quality assessment of Cau river flows through Thai Nguyen province for the period 2012-2019”

1.2 Research’s objectives

 Assessing the status development of water quality of Cau river in Thai Nguyen province on the 2012 – 2019 periods

 Assessing the status development of water quality of Cau river in Thai Nguyen province through WQI

 Propose solutions to manage Cau river environment regarding area running in Thai Nguyen province

1.3 Research questions and hypothesis

1.3.1 Research questions

 What is the status development of water quality of Cau river in Thai Nguyen province on the 2012 – 2019 period?

 How is the water quality of Cau River through the WQI value in 2018 - 2019?

 What can human and government do to reduce water pollution of Cau river?

1.3.2 Hypothesis

The hypothesis is the water quality of the Cau River will be better in

recent years The upstream water quality is better than the downstream area

1.4 Limitations

Due to the limitation of time and resources, this study mainly focuses on

the water pollution in Cau River through flows Thai Nguyen province The

survey is examined is relatively small, the findings cannot be generalized to the

broader community The water data is only taken from a source; it would not

achieve absolute accuracy for all area

1.5 Defination

- Environment

According to term 1, article 3 of the Law on Environmental Protection

(The National Assembly of Vietnam, 2014), the environment is defined as:

―Environment is a system of natural and artificial physical factors affecting the existence and development of human beings and creatures‖

- Water resources

According to Stantec and Northcliff (2013): ―Water Resources are defined herein as the groundwater and surface water resources that are available for

human use Water Resources has been identified as a valued environmental

component (VEC) because of the importance of this resource in providing

potable water to users in the area surrounding the Project Water Resources are

closely linked to other VECs, including the Aquatic Environment (as a resource

for fish and aquatic life), Terrestrial Environment (as a resource for wildlife),

Vegetated Environment (as a resource for plants), Wetland Environment (as

habitat for plants, animals and communities, and for hydrological function), and

Land and Resource Use (as a resource for humans), and the potential environmental effects of changes to water resources on these VECs‖

- Surface water

According to M G Khublaryan (2009): ―Surface waters could be regarded as including all inland waters permanently or intermittently occurring

on the Earth surface in either liquid (rivers, temporary streams, lakes, reservoirs,

bogs) or solid (glaciers, snow cover) condition All types of liquid surface waters

are considered—rivers, reservoirs, lakes, bogs.‖

- Environmental pollution

According to term 8, article 3 of the Law on Environmental Protection

(The National Assembly of Vietnam, 2014), Environmental pollution refers to

―the change in the environmental components in breach of technical regulations

on environment and environmental standards, which can result in adverse impacts on human beings and creatures‖

According to in term 6 – Article 3 of the Law on Environmental protection

(The National Assembly of Vietnam, 2014) Environmental standards referred as

―a set of parameters relating to the environmental quality in surrounding areas, amount of contaminants that remain in wastes, technical and managerial

requirements which are issued by a competent regulatory authority in the form of

a written document that entities involved may choose to follow at their discretion

to serve the purpose of environmental protection‖

PART II LITERATURE REVIEW

2.1.1 Geographical location

Cau River Basin is one of the major river basins in Vietnam which lies in

coordinates from 21° 07' to 22° 18' N and 105° 28' to 106° 08' E The basin area is 6.030 km2, accounting for 47% of the total area of 6 provinces: Bac Can, Thai

Nguyen, Vinh Phuc, Bac Giang, Bac Ninh, and Hai Duong It has a length of about

290 km, the average height of the basin: 190 m, average slope of 16.1%, average basin width: 31 km, river network density of 0.95 km / km² and bending coefficient section 2.02 (People's Committee of 6 provinces in Cau River basin, 2005)

2.1.2 Geographical features

The river basin has a long stretch from north to south The upper and

middle valleys lie between two anticlines of the Gam river and the Ngan

Son-Yen Lac The upper part of Cau River flows in the North-South direction, the

average height reaches 300 - 400m while the riverbed is narrow and very steep,

with many rapids and a sizeable meandering coefficient (> 0.2), the average

width in the dry season about 50 - 60m, 80 - 100m in the flood season and the

slope is about > 0.1%

The middle part from Moi market, Cau River flows in the

Northwest-Southeast direction on a rather long section, then returns to the old direction to

Thai Nguyen In this section, the terrain is significantly reduced, the riverbed is

enlarged, the slope is reduced to only about 0.05% and it's winding is still high

Downstream of Cau River is calculated from Huong Waterfall to Pha Lai,

from which the main flow direction is Northwest-Southeast, the terrain has a high

average of 10 to 20m, the riverbed is opened from 70-150m, and the slope is

significantly reduced only 0.1%

The density of rivers and streams in Cau River basin is high: 0.95-1.2km /

km2, the total length of tributaries is greater than 10km is 1.602km (People's

Committee of 6 provinces in Cau River basin, 2005)

2.1.3 Climate conditions and Hydrologic features

2.1.3.1 Climate conditions

The climate of the Cau River basin has the basic characteristics of the

monsoon tropical climate which is hot and humid

The temperature differentiated strongly in the whole basin Low area (less

than 100m) has the annual average temperature is about 22.5 - 23oC, 500m height

area has the annual average temperature is about 20oC, the area is higher than

1.000m, having 17.5 -18oC of the annual average temperature

Cau River basin is a region with a large amount of rainfall, the annual

average rainfall from 1.500 to 2.700mm In the basin, there is a large rain center

that is Tam Dao, where the annual rainfall can reach 3,000mm

This rainy area extends eastward through Thai Nguyen City, with annual

rainfall exceeding 2.000 mm (Thai Nguyen Department of Natural Resources

and Environment, 2012A)

2.1.3.2 Hydrologic features

The flow of the Cau River basin is fairly uniform in which the Cong River

basin has a flow module of 27-30 l/s.km2, the upper area of Cau River (from

Thac Rieng and up) has a year flow module of 22-24 l/s.km2 of medium type

The least water area belongs to the Du river with annual flow modules of 19.5-23

l/s.km2

The annual flow fluctuates insignificantly, with the gap of years having

more water and the years having less water is by 1.8 to 2.3 times The line

conversion coefficient is about 0.28

The flow regime of the Cau River is distinguished into two distinct

seasons: flood season and dry season The flood season lasts from May or June to

October Flood runoff makes up about 80 - 85% of the annual total with the

highest monthly value in July The low flow season occurs from November to

April or May Runoff in this season contributes only 15-20% of the annual total

The lowest monthly runoff occurs in February (Thai Nguyen Department of

Natural Resources and Environment, 2012A)

2.1.4 Socio-economic conditions

The basin accounts for 47% area of the 6 provinces The total population

of the 6 provinces in the basin in 2018 is 13.857 million people The average

population density is about 427 people / km2 which is 2 times higher than the

national average density

Economic structure based on agriculture, forestry, industry, and fisheries

contribute inconsiderable to this structure GDP grew strongly, doubling in 5

years in most provinces in the basin (Thai Nguyen Provincial People's

Committee, 2006)

2.2 Scientific background

 Water quality assessment

Water quality is assessed based on the following indicators:

* Physical indicators:

- Temperature:

Temperature affects both the chemical and biological characteristics of

surface water It affects dissolve oxygen level in the water, photosynthesis or the

aquatic plants, metabolic rates of aquatic organisms, and the sensitivity of these

organisms to pollution, parasites and disease (Centre for Educational

Technologic, 2015)

- pH:

pH is a measure of the concentration of hydrogen ions in the water or a

measure of how acidic or basic it is on a scale of 0 to 14, with 7 being neutral

(Talling, 2010) Naturally occurring fresh waters have a pH range between 6.5

and 8.5 The pH of the water is important because it affects the solubility and

availability of nutrients, and how they can be utilized by aquatic organisms

(Stone et al., 2013)

- Turbidity:

The concentration and nature of Total Suspended Solids (TSS) determine

turbidity and transparency of water TSS contains soluble organic compounds as

well as fine particles of organic and inorganic matter (Matta, 2014) TSS and

turbidity differs with time based on biological activity in the water system and

type of sediments carried by surface run-off Turbidity highly is influenced by

rainfall at a particular point Turbidity can be related to TSS hence turbidity can

be used as an indirect measurement for TSS (Chapman, 1996)

- Solids concentration:

Solids affect water quality for domestic use and production, hinder or

consume more chemicals in the process Solids in water is caused by inorganic

substances in soluble or insoluble form as emulsified soil and organic matter,

synthetic organic compounds such as micro-organisms, fertilizers and industrial

wastes (Filter and Separation, 2014)

* Chemical indicators

- Biochemical Oxygen Demand (BOD):

This parameter is defined as the amount of oxygen, divided by the volume

of the system, taken up through the respiratory activity of microorganisms

growing on the organic compounds present in the sample (e.g water or sludge)

when incubated at a specified temperature (usually 20ºC) for a fixed period

(usually 5 days, BOD5) It is a measure of that organic pollution of water which

can be degraded biologically In practice, it is usually expressed in milligrams O2

per litre (Nagel et al., 1992)

- Chemical Oxygen Demand (COD):

The chemical oxygen demand (COD) is used to indirectly measure the

amount of organic compounds in water Most applications of COD determine the

amount organic pollutants found in surface water, making COD a useful measure

of water quality (Harrafi et al., 2012) It is expressed in mg/l, which indicates the

mass of oxygen consumed per litre of solution COD is the measurement of the

amount of oxygen in water consumed for chemical oxidation of pollutants COD

determines the quantity of oxygen required to oxidize the organic matter in water

samples, under specific conditions of oxidizing agent, temperature and time

(Boyles, 1997)

- Dissolved oxygen (DO):

Dissolved oxygen (DO) refers to the volume of oxygen that is contained in

water Oxygen enters the water by photosynthesis of aquatic biota and by the

transfer of oxygen across the air– water interface The amount of oxygen that can

be held by the water depends on the water temperature, among other variables as

described in Smith (1990)

* Microbiological indicators

- Escherichia Coli (E Coli)

Escherichia coli, commonly known as E coli or colon bacilli, usually live

in the intestines of humans and some animals E coli always present in feces of

human, animals, and birds in large numbers The exceeded presence of E coli

proves pollution on this indicator That is considered an indicator reflecting the

viability of pathogenic microorganisms in the gut such as diarrhea, dysentery,

etc (Ashbolt et al., 2001)

2.3 Theoretical background

- Vietnam‘s Strategic Environmental Protection Plan towards 2010 and

orientation to 2020

- Environmental Protection Law No 55/2014/ QH13 passed by the 13th

National Assembly on June 23, 2014

- Water Resources Act, June 2012

- Decree No 120/2008 / ND - CP of the Government dated on December

01, 2008 on the management of river basins

- Decision No 16/2008 / QD – BTNMT dated on December 31, 2008 by

the Ministry of Natural Resources and Environment on the National technical

regulations on environment

- National technical regulation QCVN 08:2008/BTNMT on surface

water quality

- Decision No 879 / QD-TCMT dated on July 1, 2013 by the General

Department of Environment issuing the manual for calculating water quality index

- Vietnamese standards (TCVN) and technical regulations of the State of

Vietnam (QCVN) are mandatory

2.4 Surface water quality assessment method

2.4.1 Traditional method

- Water environment monitoring is an important activity in the state

management on environmental protection that has been put into practice by the

agencies under the Ministry of Natural Resources and Environment since 1994

Environmental monitoring activities record information about the current

situation and environmental trends to serve the development of strategies,

planning, and environmental protection programs

Monitoring of water and air quality is the two major environmental

monitoring activities today Environmental monitoring usually includes the

following basic steps:

- Set up a monitoring plan

- Establish a monitoring network

- Sampling and measuring in the field

- Laboratory analysis

- Data processing

- Analysis and evaluation of data

- Writing reports of monitoring results

Monitoring results are often compared with environmental quality criteria

to assess environmental pollution levels Currently, monitoring results have been used in several computational models to build forecasts of environmental developments according to local socio-economic development scenarios

Disadvantages of the WQ assessment method by comparing the WQ monitoring results with the allowable limits of current Vietnamese regulations are:

- When assessing each individual parameter, it will not tell the general quality of the river (or river section), so it is difficult to compare WQ in each region of a river, comparing WQ of this river with other streams, WQ of this time with another time (by month, by season), WQ in a past, present, and future Therefore, it will make it difficult for monitoring and monitoring the developments of WQ, difficult to evaluate investment efficiency to protect water sources and control water pollution

- When assessing WQ through separate parameters, there may be parameters that meet the value; the parameter exceeds the allowed value, it only says the WQ for each individual parameter Consequently, it is difficult to inform the WQ situation to the community, making it difficult for managers to make appropriate decisions on the protection and exploitation of water resources (Thai Nguyen Department of Natural Resources and Environment, 2012)

2.4.2 Water quality index

2.4.2.1 Definition

According to Nives (1999), WQI is a mathematical instrument used to

transform large quantities of water quality data into a single number which

represents the water quality level while eliminating the subjective assessments of

water quality and biases of individual water quality experts

WQI was first seriously proposed and demonstrated beginning in the

1970s but were not widely utilized or accepted by agencies that monitor water

quality (Cude, 2003) WQI, in common with many other index systems, relates to

a group of water quality parameters to a common scale and combines them into a

single number in accordance with a chosen method or model of computations

(Mohsen, 2007)

The method of evaluating water quality through the WQI index has

overcome the disadvantages of the comparison method with the standard WQI

method is able to classify the pollution level of water source on a scale

2.4.2.2 Situation of research and application of WQI in the world

There are many countries in the world that have applied WQI to practice

United States: WQI is built for every state; most states have access to the

National Sanitation Foundation (NSF) method - WQI-NSF for short WQI-NSF

was built using Rand Group's Delphi technique, which collects and synthesizes

the opinions of a large number of experts across the United States to select

WQ parameters, determining the establish the role of each parameter (the

important role of the parameter - wi) and proceed to construct the conversion

graphs from the measured values of the parameter to the sub-index (qi)

WQI-NSF is built scientifically based on the majority of scientists' opinions on

water quality, having both the role of participating parameters in WQI and

compare the results with the standard value (target of WQ) through the sub

-index calculation (qi) However, the important values (wi) or sub indexing

schema (qi) in WQI-NSF are only suitable for US water quality conditions

(NSF Consumer Information, 2005)

Canada: WQI-CCME is built on a lot of different data using a statistical

process with at least 4 parameters and 3 principal coefficients (F1-range,

F2-frequency, and F3-amplitude, however, the results do not meet the standard

limited WQ targets WQI-CCME is a very quantitative formula, and their

convenient use with their parameters and standard values (the aim of WQ) can

easily be included in CCME for automatic calculation However, in

WQI-CCME, the role of WQ parameters in WQI is considered the same, although, in

fact, WQ components have different functions for water sources such as the

composition of suspended solids is not essential for water quality as dissolved

oxygen content

Europe: European countries are primarily developed from WQINSF (of

the United States); however, each state and locality chooses parameters and

methods for calculating sub-index separately

The countries of Malaysia and India developed from WQI - NSF, but each

country can build a variety of WQI for each purpose (Wilkes University, 2006)

Table 1.1: List of selected studies carried out worldwide using

Water Quality Indices

Workers Year of

Shokuhi et al 2012 Evaluation of Aydughmush Dam

Reservoir Water Quality NSFWQI

Fataei et al 2013 Water Quality Assessment in

Balikhlou River, Iran

WQI and CWQI

Nawaf et al 2014

Application of Water Quality Index to Assess the Environmental Quality of Kuwait Bay

Modified WQI

Soraya

Bouslah et al 2017

Water quality index assessment of Koudiat Medouar Reservoir, northeast Algeria using the weighted arithmetic index method

WQI

2.4.2.3 Situation of research and application of WQI in VietNam

In Vietnam, many researches have been proposed and applied on WQ

indicators such as WQI-2 and WQI-4 used to assess WQ data on Saigon river in

Phu Cuong, Binh Phuoc and Phu An from 2003 to 2007 Some case studies are as

follows:

- Research by Nguyen Thanh Tuyen, using water quality index (WQI) to

assess the status and evolution of water quality Sai Gon river section flowing

through Thu Dau Mot city in 2018 The results of WQI calculation for surface

water of the Saigon River basin running through Thu Dau One of the three

monitoring periods showed that the WQI index ranged from 17 to 87 Due to the

influence of Coliform parameters, the water quality in VT1, VT2, and VT5 was

both heavily contaminated with Coliforms, requiring remedial measures in the

future Comparison with previous years shows that the water quality of the

Saigon River, in general, is showing signs of decline and begins to be lightly

polluted, so it is necessary to take measures to control and handle pollution in a

timely manner (N.T Tuyen et al, 2018)

- WQI index is combined with GIS in water quality zoning for aquaculture

farming in Dam Lagoon, Phu My commune, Phu Vang District, Thua Thien Hue

Province The project used the water quality index of the US National Sanitation

Fund as a basis for assessing and classifying water quality for aquaculture

activities The research results show that the water quality index of Phu My

lagoon had a significant change over time and space with WQI in the dry season

= 78.59; WQI during the rainy season = 67.66 The results of the zoning

indicated that in the dry season, 100% of the area had a water quality of grade II

(the good one meets water quality standards according to the US National

Sanitation Foundation) In the rainy season, 33.38% of the area (53,409ha) was

class II, mainly around PHUMY sites 2,3,3,8,8 and about 66,62% of the area

reached class III (medium type), mainly around the point PHUMY1,5,6,9

(Truong Van Dan et al, 2015)

- Currently, to agree on the calculation of the water quality index, in July

2011, the General Department of Environment officially issued a technical

manual to calculate the water quality index according to Decision No 879 / QD

-The IDU of the Director of the General Department of Environment According

to the Decision of water quality index is applied to continental surface water

monitoring data and applications to environmental management state agencies,

organizations and individuals participating in the network Environmental

monitoring and participation in the publication of environmental quality

information for the community According to the guideline Water Quality Index

(abbreviated as WQI) is an index calculated from water quality monitoring

parameters, used to quantify water quality and usability of that water source;

performed on a scale WQI parameters (abbreviated as WQISI) are calculated

water quality indicators for each parameter (Vietnam Environment

Administration, 2011)

PART III MATERIALS AND METHODS

3.1.1 Equipment

- 1500 ml polyethylene plastic bottles

- 1500 ml dark brown glass bottles

- Water from Cau river through Thai Nguyen province

* Reagents and Chemicals

- Chloroform

- Millipore water

3.2 Methods

3.2.1 Secondary data collection

- Secondary data were collected through the reports and statistical data in

Sustainable Development in 2018 of Thai Nguyen People's Committee, Ministry

of Natural Resources and Environment, Department of Natural Resources and

Environment of Thai Nguyen and departments have provided document related

to the economics, natural conditions, climate, land, and results of the previous

analysis on water samples in 2012 to 2018

- The Statistical Yearbook: Statistical Yearbook of Thai Nguyen in 2018 -

2019 To collect the data of population, GDP of Thai Nguyen province

- Additionally, data in scientific reports, conferences, books, newspapers,

on the internet and other materials were also exploiting

3.2.2 Methods of collecting, storing and analyzing samples

- Current status of river water quality Cau river running through Thai

Nguyen province was assessed through water samples taken along the river and

at locations on the river after receiving water from streams Specifically,

monitored 5 points from upstream to downstream in 2 seasons: rainy season

(annual 4th) and dry season (first phase) and compared with Vietnam Standards

(TCVN), National Technical Regulations of Vietnam (QCVN) and the standards

of the global environmental monitoring system (GMES) or Standard methods for

the examination of Water and Wastewater if TCVN is not available

- Based on the inheritance of the monitoring data from 2012 to 2018 of the

Centre for Natural Resources and Environment Monitoring of Thai Nguyen

province, I joined the environment monitoring group of Thai Nguyen province to

conduct sampling at 05 points on the Cau River in April (dry season) 2019 to review

of changes in Cau River water quality in the study from 2012 to 2019 period

* Sample getting methods

+ NM1 (coordinates: 105 ° 50 '19.77 "N, 21 ° 48' 5.33" E) Current status

of watershed water quality of Cau River flows through Thai Nguyen province,

assessing fashionable due to natural conditions, due to activities in Bac Kan

province Provide "background" information for the ages of Thai Nguyen region

+ NM2 (coordinates: 105 ° 48 '20.81 "N, 21 ° 37' 37.22" E) Status of

water quality of Cau River from Van Lang commune to Son Cam commune,

after the confluence with the Du river, the area is affected by agricultural

activities, mining, water quality control when entering the city Thai Nguyen

+ NM3 (coordinates: 105 ° 50 '14.49 "N, 21 ° 35' 51.64" E) Status and evolution of Cau River water quality from Son Cam commune to Gia Bay bridge,

impacts due to urban activities and industrial activities in the northeast of Thai

Nguyen city

+ NM4 (coordinates: 105° 53' 9.48"N, 21° 33' 4.17"E) Assess the quality

of Song Cau water from Son Cam commune to the point of 300m Cam Gia

stream discharge water Wastewater receiving area of Thai Nguyen iron and steel

industry and operating in the southern region of the city

+ NM5 (coordinates: 105° 55' 58.16 "N, 21 ° 28' 41.94"E) Assess the

quality of Song Cau water after receiving the water of Pho Huong stream

Wastewater receiving area operates in the southwest and part of the city south

- Time: 2 times in 2012, 2013, 2014, 2015, 2016, 2017, 2018 and 1 times

in 17/04/2019

* Method of sampling

- Steps for water sampling followed:

 Step 1: Use a long-handled ladle to scoop water at a depth of 0.1m

 Step 2: Pour water into the bucket

 Step 3: Put water into glass and PET plastic bottles

 Step 4: Put the bottles in a cooler for storage and bring to the lab

After taking the products, they will be stored in a refrigerator to analysis

in the laboratory

- Physical and chemical indicators (DO, pH, temperature) were

determined at the scene by fast, high-precision measuring equipment The

remaining parameters were determined by sampling and laboratory analysis

- Water samples was taken according to the standards: TCVN 6663-1: 2011

- Water quality - Sampling - Part 1: Instructions for making sampling programs and

sampling techniques; TCVN 6663-6: 2008 - Water quality - Sampling - Guidance on

sampling in rivers and streams; TCVN 6663-3: 2008 - Water quality - sampling -

Part 3: Instructions for preservation and handling of samples

* Preserving and analyzing samples methods

- Follow current standards, specifically:

+ TCVN 6663-3: 2008 (ISO 5667-3: 2003) - Water quality - Sampling

- Instructions for preservation and handling of samples

+ TCVN 6663-6: 2008: Water quality - Sampling - Guidance on sampling

in rivers and streams

+ TCVN 6492: 2011 (ISO 10523: 2008) - Water quality - Determination

of pH

+ TCVN 6491: 1999 (ISO 6060: 1989) - Water quality - Determination of

chemical oxygen demand (COD)

+ TCVN 6001-2: 2008 (ISO 5815-2: 2003) - Water quality -

Determination of biochemical oxygen demand after n days (BOD5) - Part 2:

Methods for undiluted samples

+ TCVN 6625: 2000 (ISO 11923: 1997) - Water quality - Determination

of suspended solids by filtration through glass fiber filters

+ TCVN 5988: 1995 (ISO 5664: 1984) - Water quality - Determination of

ammonium - Distillation and titration method

+ TCVN 6202: 2008 (ISO 6878: 2004) - Water quality - Determination of

phosphorus - Spectrometric method using ammonium molipdat

+ TCVN 6638: 2000 Water quality - Determination of nitrogen - Catalytic

digestion after reduction with Devarda alloy

+ TCVN 6187-2: 1996 (ISO 9308 -2: 1990 (E)) Water quality - Detecting

and counting coliform bacteria, heat-resistant coliform bacteria, and presumptive

escherichia coli

* Analysis method:

Water samples was sent to a laboratory that met the standards of the

Resource and Environment Monitoring Center for analysis Procedures for

sampling, preservation, and analysis of samples were followed current technical

standards for sampling, preservation, and analysis

Analysis methods of determining surface water quality parameters

complied with national standards or corresponding analytical standards of

international organizations

The criteria for analysis and analysis included temperature, turbidity, TSS,

pH, DO, COD, BOD5, NH4

+

, PO4 3-

, total Coliform

3.2.3 Calculation method, using WQI

Application of WQI Construction Process issued by the General

Department of Environment

 Calculation of WQI:

The method of calculating the water quality index was used according to:

‗Water Quality Index Handbook‘ by the General Department of Environment

Step 1: Calculation WQI for each parameter

Surface water quality index was calculated as follows:

* WQI parameters (WQISI) was calculated for BOD5, COD parameters, N

-NH4 +, P-PO4-, TSS, Turbidity, Total Coliform according to the following

formula:

WQI SI =

( Bp i+1 – C p ) +q i+1 ( Fomula 1)

Where:

- BPi: The lower limit concentration of the monitoring parameter values

specified in Table 2.2 corresponds to the level i

- BPi + 1: The upper limit concentration of the observed parameter values

- qi: WQI value at level i given in the table corresponding to BPi value

- qi + 1: WQI value at level i is given in the table corresponding to BPi + 1 value

- Cp: The value of the monitoring parameter is taken into account

Table 3.1: Table specifying q i and BP i values

TSS (mg/l)

Coliform (MPN/100ml)

Note: In case the Cp value of the parameter is the same as the BPi value

given in the table, then the WQI of the main parameter can be determined by the

corresponding qi value

Calculate the WQI parameter for the DO parameter (WQIDO) calculated

through saturation DO% value

(1): Calculate saturation DO value

DOsaturation = 14.652 – 0.41022 T + 0.009910 T 2 – 0.000077774 T 3

T: water temperature at the time of monitoring (0C)

Calculate saturation DO% value:

DO% saturation = (DOdissolve / DOsaturate) 100

(2): Calculate the value of WQIDO

WQI SI =

(C p – Bp i+1 ) +q i (Fomula 2)

Where:

CP: saturated DO% value

BPi, BP i + 1, qi, qi + 1: is the value corresponding to i, i + 1 in table 3.1

Table 3.2: Table specifies BPi and qi values for saturated DO%

Bp i ≤20 20 50 75 88 112 125 150 200 ≥200

If DO% saturation value ≤ 20 then WQIDO = 1

If 20 < DO% saturation <80, then WQIDO is calculated according to formula

2 and using table 3.2

If 88 ≤ DO% saturation ≤ 112 then WQIDO = 100

If 112 < DO% saturation <200 then WQIDO is calculated according to

formula 1 and use table 3.1

If DO% saturation value ≥ 200, WQIDO = 1

Calculate the WQI value for the pH parameter

Table 3.3: Table specifies BPi and qi values for pH

If 5.5 < pH < 6, WQIpH is calculated according to formula 2 and using

table 3.3

If 6 ≤ pH ≤ 8.5, WQIpH = 100

If 8.5 < pH < 9 then WQIpH is calculated according to formula 1 and using

table 3.1

If the value of pH ≥ 9 then WQIpH = 1

Step 2: Calculate WQI

After calculated WQI for each of the above parameters, the calculation of

WQI was applied according to the following formula

WQI =

∑

∑

WQIa: WQI value calculated with 5 parameters BOD5, COD, N - NH4, P

- PO4, Total Coliform

WQIb: WQI value calculated for 2 parameters: TSS, turbidity

WQIc: WQI value calculated with Total Coliform parameter

WQIpH: WQI value calculated with pH parameter

Note: The WQI value after calculation will be rounded to an integer

Step 3: Compare calculated water quality indicators with assessment tables

After calculated WQI, use the WQI value determination table

corresponding to the WQI assessment level to compare and evaluate, specifically

as follows: