Evaluating water quality characteristics of red river in cam khe distrct, phu tho province

1 ABSTRACT In evaluate the water quality of Red river in Cam Khe district, I conducted the survey in 13 locations correspond with 13 commune located near Red riverside in Cam Khe.. This

I am grateful to my supervisor, Dr Bui Xuan Dung, whose expertise, understanding, generous guidance and continuous support made it possible for me to work on a topic that I chose It was my pleasure being his student

I am hugely indebted to the staff of Center for Environmental Analysis & Application

of Geospatial Technology for spending time and consideration to analyze the samples I collected

Besides, I would like to thank my family, acquaintances for their encouragement, support during the period of conducting this study Without their support, I would not have been able to complete this thesis

Despite spending the best efforts in the thesis conducting process, this research still has many shortcomings due to the limitations of time, finance and my ability I am looking forward to receiving comments from teachers, friends to a better thesis completion

Thank you!

Hanoi, 15 th September 2019

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TABLE OF CONTENTS

ACKNOWLEDGEMENT i

TABLE OF CONTENTS ii

LIST OF TABLES iv

LIST OF FIGURES v

LIST OF ABBREVIATIONS vi

ABSTRACT 1

I INTRODUCTION 2

1.1 Introduction 2

1.2 Literature review 3

II GOALS AND OBJECTIVES 7

2.1 Goal 7

2.2 Objectives 7

III STUDY SITE AND METHOD 8

3.1 Study site 8

3.1.1 Some characteristics of Cam Khe district 8

3.1.2 Some characteristics of Red river 11

3.2 Determining the potential factors 13

3.2.1 Methods of collecting, synthesizing and analyzing data 13

3.2.2 Specialized software 13

3.3 Method for collecting samples and samples preservation 13

3.4 Laboratory analysis 17

3.5 Data analysis 18

3.5.1 QCVN 18

3.5.2 WQI calculation 19

IV RESUTLS AND DISCUSSION 24

4.1 Potential factors impact on water quality of Red river 24

4.2 Evaluating water quality of Red river 26

4.2.1 Water quality of Red river according to QCVN 08:2015/MONRE 26

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4.2 Water quality of Red river according to WQI 35

4.3 Suggesting solutions 38

V CONCLUSION – LIMITATION - SUGGESTIONS 39

5.1 Conclusion 39

5.2 Limitation 39

5.3 Suggestions for future researches 39 REFERENCES

APPENDIX 1

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LIST OF TABLES

Table 3.1 Characteristics of 13 sample sites 14

Table 3.2 Measuring methods for each parameter 17

Table 3.3 Specific value for surface water quality parameters 18

Table 3.4 Specifying qi and BPi values 20

Table 3.5 Specifying BPi and qi values based on % DOsaturation value 21

Table 3.6 Specified BPi and qi values in accordance with pH parameter 22

Table 3.7 Water quality index and status of water quality 23

Table 4.1: Turbidity measured at the study sites 34

Table 4.2 Temperature of water measured at the study sites 34

Table 4.3 Evacuation of water quality of Red river according to WQI 35

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LIST OF FIGURES

Fig 3.1: Map of study site 8

Fig 3.2 Map of survey points at 13 villages in Cam Khe district 15

Fig 3.3 (a) Quick measuring; (b) taking water samples; (c) laboratory analysis 16

Fig 4.1: Map of land use types along Red river 24

Fig 4.2 Percentage of land use types along Red river 25

Fig 4.3: Characteristics of pH in two times at the sample sites 26

Fig 4.4: BOD5 measured at the sample sites 27

Fig 4.5 COD measured at the study sites 28

Fig 4.6 DO measured at the study sites 29

Fig 4.7 N-NH4 measured at the study sites 30

Fig 4.8 P-PO4 measured at the study sites 31

Fig 4.9 TSS measured at the study sites 32

Fig 4.10 Coliform measured at study sites 33

Fig 4.11 Water quality of Red river according to WQI 36

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LIST OF ABBREVIATIONS

BOD5 Biochemical Oxygen Demand

COD Chemical Oxygen Demand

TSS Total Suspended Solid

WQI Water uality Index

1

ABSTRACT

In evaluate the water quality of Red river in Cam Khe district, I conducted the survey

in 13 locations correspond with 13 commune located near Red riverside in Cam Khe Water samples are collected on August 15th and September 15th There were 9 indicators analyzed:

pH, DO, COD, BOD5, TSS, PO43-, NH4+, turbidity and coliform The principle of sampling and testing water was in form of QCVN 08:2008/MONRE and Water Quality Index (WQI) There are 3 main potential factors affecting to water quality of Red river are resident, agriculture and other infrastructure such as roads, highway, factories 4 indicators such as pH, DO, PO43-, and Coliform satisfy with the column B1 in QCVN 08:2008/MONRE08:2015/MONRE for irrigation

or other uses that require similar water quality or uses such as B2 Whereas, TSS, BOD5, NH4, COD are significant higher the limit in column B1 in QCVN WQI value is range of 1 -

N-72 Most of water samples such as are heavily polluted and need treatment measures in the future This study provides an overview of status of water quality of Red river and suggests some solution to reduce and manage the influences of human activities on water quality of Red river

Red river is a large river flowing through the Northern Delta in Vietnam The river originates from Yunnan Province, China at an altitude of 1,776m on the Weishan Range The section on Chinese territory is named Nguyen Giang The river is about 1,183 km length, the section flowing through Vietnam is 650 km, through the provinces of Lao Cai, Yen Bai, Phu Tho, Vinh Phuc, Hanoi, Hung Yen, Nam Dinh, Ha Nam and Thai Binh Red river plays an important role on not only human activities such as irrigation, transportation and fisheries but also lots of cultural values

However, accompany with strong development of industry, services, population growth and increase in chemical fertilizers, pesticides in agriculture (Tuan, 2013) Residential activities significantly affect to water quality of Red river People live near at two banks of Red river discharges directly domestic waste into the river without any treatment or classifications As a result, there are lot of waste which appears at channel of Red river in dry seasons Besides, industrial and agricultural activities also impact on water quality of Red river by several ways such as point source pollution and non-point source pollution Water quality of Red river now faces with risk of pollution which directly affects to human health, aquatic organism and quality of ground water In order to deal with this issue, the evaluation

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of water quality is essential for people to treat and control discharge point and determine appropriate and suitable water use Therefore, this project “EVALUATING WATER QUALITY CHARACTERISTICS OF RED RIVER IN CAM KHE DISTRCT, PHU THO PROVINCE” has been conducted to assess the quality of water, determine which factors affect to water quality and propose suggestions for a sustainable management of the river

1.2 Literature review

Water is abundant resources on the planet, but fresh water for human activities and organism is limited and not equally distributed on the world Water quality refers to the physical, chemical and biological characteristics of water It is a measure of the condition of water relative to the requirements of one or more biotic species and or to any human need or purpose The most common standards used to assess water quality relate to health of ecosystems, safety of human contact and drinking water Environmental water quality, also called ambient water quality, relates to water bodies such as lakes, rivers, and oceans Rivers are vital and vulnerable freshwater ecosystems that are critical for the sustenance of all life Rivers are waterways of strategic importance across the world, providing main water resources for domestic, industrial and agricultural purposes (Rhythm Aggarwal, Dr Shakti Arora, 2012) Therefore, there are many scientific researches about water quality, especially water quality of rivers

In 2007, Alam, and Muyen have been collected water samples from a part of Surma River along different points Effects of industrial wastes, municipal sewage, and agricultural runoff on river water quality have been investigated The study was conducted within the Chattak to Sunamganj portion of Surma River, which is significant due to the presence of two major industries-a paper mill and a cement factory The study involved determination of physical, biological and chemical parameters of surface water at different points Standard methods were adapted for the analysis of various water quality parameters APHA-

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AWWAWPCF (1989) They concluded that the water is certainly unfit for drinking purposes without any form of treatment, but for various other surface water usage purposes, it still could be considered quite acceptable The research collected samples in both dry and rainy seasons to show pollution level significantly different between two seasons However, this study did not recommend any solutions for the pollution of this river

In 2010, Masere carried out study of water quality, along Manyame River and on the tributaries (Ruwa, Nyatsime, Mukuvisi and Marimba) before they join the river Thirty-five sites were sampled and categorized into 5 groups (A, B, C, D and E) with group A and E being the upstream and downstream of Manyame The analysis of results was undertaken using a simple one-way ANOVA with group as the only source of variation Then using ZINWA standard to compare and evaluate water quality This study evaluated clearly about the pollution

of the river, but they did not propose any solutions for the issue

In 2018, Matinus conducted a research in Sunter River flowing in the city of Jakarta with the designation of river water for agricultural purposes, and can be utilized for urban business and hydroelectric power industry The study aimed to determine the Sunter River water quality based on physical and chemical parameters Water sampling was conducted 2 times which done in April and May with 5 sampling stations for measuring The samples were analyzed in the laboratory according SNI methods for parameters BOD, COD, PO43-, NO3, Oil & Grease and Detergents Determination of status of water quality using method of pollution index (IP) attached in Decree of Environment Minister Indonesia The quality status

of Sunter River is determined by the Pollutant Index method The results show that the water quality of Sunter River is influenced by organic parameter as dominant pollutant The source

of pollutants generally comes from the urban drainage channels, tributaries, and slaughtering industry The dominant pollutants entering the Sunter River are organic waste that may come from residential, traditional market, and chicken slaughtering house In 2019, Moriken also

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researched on how land use and land cover affect to water quality of river The literature search was conducted in the main scientific databases, including Scopus, Science Direct, Springer, Google Scholar, and EZ proxy from University Putra Malaysia (UPM) In total, 39

of 52 analyzed articles made it possible to extract the needed information In this study, they addressed the relationship between land use and water quality variables by checking how the attribute variables were correlated as extracted from the literatures examined over a 10-year period After quantifying the attribute variables, we chose to use the Spearman correlation coefficient instead of the Pearson correlation coefficient which is the most common for continuous data Two researches proved that land use and land cover extremely affected water bodies However, two researches did not propose solutions, either Moreover, the second study involved no data collection or laboratory water quality analysis which could not evaluate precise and the change of water quality overtime

According to Vietnam economic framework, Viet Nam‟s surface waters face serious pollution, with only 10% of the municipal and industrial wastewater treated Rivers in and around major cities are considered „dead rivers‟ – increasing groundwater dependence and over-extraction Moreover, two important rivers are Red and Mekong river deal with a lot of pollution problems Therefore, there are many studies are carried out to evaluate water quality

In 2016, Le Viet Thang conducted research to evaluate water quality of Gieng and Dinh rivers which are impacted by economic activities of people in Binh Thuan province The study collected samples at 10 locations in both dry and rainy seasons, applied WQI for evaluating quality of river They concluded that the river is quite polluted based on rating of WQI This study evaluated the polluted load rate to assess amount of waste discharge into river Moreover, they also identified sources of pollution affecting to Gieng and Dinh rivers However, the result of water quality of two rivers are so general and there is no rating of WQI

to evaluating polluted level in locations

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Nguyen Thi Kim Lien carried out research on “Evaluating the water quality in mainstream and tributaries of the Hau River”, this study aims to assess the characteristics of water quality of the Hau River Water samples were collected in the rainy season (June, 2013 and September, 2013) and the dry season (December, 2013 and May 2014) at 14 sites on the mainstream and 22 sites on the tributaries to analyze water quality parameters The study shows level of pollution in different seasons Moreover, they also found out the relation between parameters of water However, the study did not focus on sources of pollution which affect to water quality or river

There are a few researches about quality of Red river in the past In 2014, Nguyen Thi Bich Ngoc conducted research on „Evaluating total coliform and fecal coliform in water of Red river, section of Yen Bai to Ha Noi‟ They collected samples at 4 monitoring stations and used QCVN 08:2008/MONRE for evaluation The results show that, most of samples are permissible in QCVN column B1, but in some periods, total coliform and fecal coliforms value are 2 – 2.3 times higher than QCVN column B1 After 1 year, she conducted

“Determining content of heavy metal of Red river” They collected samples at the same locations in previous research All samples are analyzed and compared with QCVN 08:2008/MONRE The results showed that, the content of heavy metal has change unclearly from rainy to dry seasons Heavy metal was acceptable according to QCVN 08:2008/MONRE Two researches just collected samples at monitoring stations while coliform and content of heavy metal comes mainly from industrial factory and domestic waste which are near resident areas Besides, the study just focused only 1 indicator of water, it is not accuracy enough to evaluate water quality of Red river Therefore, I conduct research on

„Evaluating water quality of Red river in Cam Khe district, Phu Tho province” are really necessary

This study has 3 main objectives:

 Determining potential factors impacting on water quality of Red river in Cam Khe district

 Evaluating the water quality of Red river, section of Cam Khe district

 Suggesting some solutions to manage and improve water quality of Red river for sustainable use

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III STUDY SITE AND METHOD

3.1 Study site

3.1.1 Some characteristics of Cam Khe district

Cam Khe district is located in the northwest of Phu Tho province, is one of 13 administrative units of Phu Tho province There are 30 communes, 1 Town (Song Thao Town) It is adjacent to Thanh Ba district in the East; the West borders Yen Lap district; the South borders Tam Nong district; The North borders Ha Hoa district

Fig 3.1: Map of study site

With a total natural area of 23,425ha, the length of the district is 45km, the average width of 4 km, Cam Khe borders Thanh Ba district to the east with the boundary of Thao river all; bordering Yen Lap district to the West, the boundary is an arc of mountainous range of Hoang Lien Son running from northwest to southeast; bordering Tam Nong district to the

River system in Cam Khe was formed due to the process of natural fluctuations thousands of years ago, created Bua River in the South; Gia Ngàng in the North; With hundreds of lagoons, ponds and lakes The climate in Cam Khe is relatively homogeneous, but due to the terrain features of many lowland areas, swamps, ponds and lakes, previously flooded occurred and lasted long, making transportation and production and life of the people have many advantages but also many disadvantages

Hills and mounds have flat, round, sloping peaks, the absolute height (compared to sea level) is mostly below 40 m, the relative height is below 20m, especially, the new peak is over 100m (The mound is 118m high) On the hill planted many palms which grows in forest Cam Khe used to be the district of palm trees in Vietnam In the past, palm leaves were a significant source of income Today, palm forests still exist, but only in the palm forests, the

of life for the people of Cam Khe Up to now, over 80% of the land in Cam Khe has been applied technology in the production instead of the traditional technique Moreover, the productivity is becoming more and more effective "50-60 million VND / ha" fields in the district with increasing ability of multi-cultivation Although the area of land for rice production is increasingly shrinking to make room for industrial production establishments, the total rice output in the district still ensures firmly the food demand in the area

The main agricultural products are rice, maize, cassava, tea The main forestry product is palm leaves There are also fisheries, industry, small industry, services and trading

A part of people has many handicrafts that have been maintained for a long time Typically, such as carpentry, hat making, rattan and bamboo weaving, forging, brick and tile making, lime production, construction workers, etc The handicrafts are mostly formed in Cam Khe from four hundred to five hundred year

Industry, especially handicraft is developing There is a fruit factory which are under construction and tea factory Many traditional handicraft villages, such as making handicrafts and making bamboo and rattan products for export, are the leading localities in the province

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in developing handicrafts In 2004, Phu Tho province was recognized with 5 small-scale handicraft villages, 2 trade villages in Cam Khe district In addition, Cam Khe is also famous for its craft of silk weaving, embroidery, rattan, giant knitting, mushroom cultivation, wood ear, etc., contributing to increase income and attract idle labor force in the district With the goal of taking small handicrafts as core, to preserving and promoting the old craft villages, the district will focus on expanding a number of new jobs

According to Cam Khe Portal Gate, Cam Khe has many advantages of ponds, lakes, large lagoons and low-lying fields with a water surface with 3,370 ha and rice-growing area

of 1,900 ha It is convenient for aquaculture to develop Aquaculture in Cam Khe appeared very early With an annual output of 2,200 tons of fish, Cam Khe fish not only meets the needs of the province but also is present in Ha Tay, Hanoi, Yen Bai,

Agriculture and forestry account for 43.8%; Industry - Handicraft: 20%; Commercial services: 36.2%

With a total population of 128,879 people, Cam Khe is one of the districts with the most population in Phu Tho province Looking back on the process of population formation in Cam Khe also has its own historical characteristics

Ethnic structure in Cam Khe from ancient times to the present is mainly Kinh By

2011, there were 864 ethnic minorities in Cam Khe district (Muong, Dao, Tay, Nung ) The children of ethnic minorities come to Cam Khe mainly because of family marriage or working conditions Agricultural production is a key sector of economic in Cam Khe During the production process, dealing with the unpredictable impacts of nature, Cam Khe people always uphold the traditions and beautiful qualities

3.1.2 Some characteristics of Red river

Red River basin is an inter-country river basin that flows through Vietnam, China and Laos with a total area about 169,000 km2 and the catchment area in Vietnamese territory is

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about 87,840 km2, accounting for 51% total area The length of Red river in Vietnam is about

328 km, it T is the second largest river (after the Mekong) flowing through Vietnam to the East Sea The Red River is made up of three major tributaries, Da, Lo and Thao Rivers The North borders Truong Giang and Chau Giang river basins of China; The West borders the Mekong River basin; the South borders the Ma river basin; The East borders the Gulf of Tonkin

The topography of the Red River basin has l slope direction from northwest to southeast, the terrain is mostly hilly, strongly divided, about 70% of the area at an altitude of over 500m and about 47% of the basin area at an altitude over 1000m The average height of the basin is about 1090m

The alluvial soils of Red River are mostly in the plain and midland provinces with pH from 6.5 ÷ 7.5, common mechanical components are clay or medium clay, which are the best soil structure is in for growing crops, 2 to 3 crops of rice per year with high yield

Plants in Red- river basin are very rich Due to differences in climate and hydrology, forests are distributed by altitude and are divided into two main categories, above 700m upwards and under 700m From 700m and above, the forest is mainly closed mixed forest with broadleaf leaves, subtropical coniferous coniferous forests and tropical moist evergreen closed evergreen forests At elevations below 700m, the forest is dominated by tropical moist evergreen closed forest In addition, there are other types of planted forests, shrubs on bare hills

The annual average temperature ranges from 23.2oC to 24.6 oC In winter, the average temperature is 20.1 oC The coldest months of the year are January and December The lowest temperatures are up to 6 - 8 oC while in the summer, the average temperature is 28 oC The hottest months of the year are June and July with temperatures are up to 32 - 35oC.; The average of amount of precipitation is about 1,800-2,000 mm

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The rainfall mainly concentrated in July, August and September with nearly 80% of the total rainfall of the year The day with the highest rainfall is up to 200-250 mm Dry seasons start from November until the end of March next year, with a cold climate, little rain The prevailing wind direction is East - North, often causing sudden cold The lowest average temperature is 15 oC, little rainfall, only reaches 15-20% of the annual rainfall

3.2 Determining the potential factors

3.2.1 Methods of collecting, synthesizing and analyzing data

We can collect all types of data, documents, photographs and maps in official form (such as environmental authorities, land administration, state management agencies for the area, in a scientific workshop) or informal

3.2.2 Specialized software

By using geographic information systems, we can process spatial and non-spatial data Using this system in a computer environment can store a large amount of data and access is faster Using ArcGIS, Google Earth, Earth Explorer and paint to simulate land use purposes

on the map in practice, thereby identifying the factors that affect the water quality

3.3 Method for collecting samples and samples preservation

Cam Khe district contains 30 villages in which there are 13 villages located near Red river They are Dong Luong, Dieu Luong, Cat Tru, Hien Da, Tinh Cuong, Yen Tap, Song Thao, Sai Nga, Son Nga, Phung Xa, Phuong Xa, Phu Khe and Tuy Loc Therefore, I conducted to collect sample at 13 communes which directly impact on water quality

1 Dong Luong 105.174 21.35922 Two sides of river are used for

agriculture, and resident

2 Dieu Luong 105.182 21.33487 Two sides of river are mainly agriculture

activities and cattle grazing

3 Cat Tru 105.18 21.34151 High density of resident at left riverside;

agriculture at right riverside

4 Hien Da 105.174 21.35924 High density of resident at left riverside;

bare land and roads at right riverside

High density of resident and agriculture

at left riverside; agriculture at right riverside

Low density of resident, agriculture at left riverside, resident, roads at right riverside

7 Phu Khe 105.145 21.41091 Highway, agriculture and resident at left

riverside; agriculture at right riverside

8 Sông Thao 105.145 21.43028 High density of resident at left riverside;

agriculture at right riverside

9 Sai Nga 105.121 21.44612 Two riverside are roads, agriculture and

resident area

10 Son Nga 105.109 21.44782 Highway, agriculture at left riverside;

agriculture at right riverside

11 Phung Xa 105.096 21.45602 Highway, agriculture at left riverside;

agriculture at right riverside

12 Phuong Xa 105.087 21.47303 Two riverside are agriculture and

resident area

13 Tuy Loc 105.053 21.49409 Two riverside are agriculture and

resident area

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Fig 3.2 Map of survey points at 13 villages in Cam Khe district

I collected samples two times, the first time in 15th, August, 2019; the second time in 15th, September, 2019 Two times I collected samples in the same locations

Time to collect samples: in the morning, from 5a.m -9a.m, weather conditions: no rain, sunshine, and slight wind

The first time I collected samples in sunny days, there is no rain or even little precipitation in few days The second time I collected water samples after heavy rain days, water lever was higher than the first one

Sampling principles: 1- No disturbance to the water layers; 2- The water sample taken should be highly representative; 3- Sampling should be avoided in special areas such as standing water, wild weeds and water intrusion; 4- The sampling tools and containers should

be washed and the necessary measures taken with detergents and acid solutions to avoid variations of samples to a minimum, for Microorganisms analysis, the sampling equipment must be sterile

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Sampling equipment: Using plastic bottles of 500 ml volume, robe, tapes, labeling on each bottle The bottles use to take samples should be careful and clean before and after using

by distilled water and before getting samples, the bottles must be rinsed with river water

Quick measurement equipment: Hanna instrument and Hanna pH

Equipment to measure DO and pH need to adjust before using, after measuring, wash equipment‟s by distilled water for next time measure

Taking samples in the field: The bottles need to be cleaned and rinse out by water at the location that I took samples avoid impurity Dipping bottles into the surface water at a depth of 30-50 cm surface and distance of 1.5 – 2m from riverside., mouth of bottles need to cap immediately under the water after fulfill water to prevent DO in bottles change Labeling and sticking name on each bottles, keep them in shadow and low temperature then transporting samples to laboratory to analyze water quality indicators

Fig 3.3 (a) Quick measuring; (b) taking water samples; (c) laboratory analysis

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After transporting to the laboratory, samples were analyzed for COD, BOD5, TSS, PO4, NH4, TSS, turbidity, Coliform After analyzing the indicators, I preserve the excess water in the refrigerator until the end of the study

3.4 Laboratory analysis

In order to evaluate the water quality of Red river, the parameters pH, TSS, DO, BOD, COD total phosphorus and total nitrogen, coliform were both analyzed on site and in the laboratory Appropriate analyzing is mention in table 3.2

Table 3.2 Measuring methods for each parameter

pH Hana pH measurement directly in the field

TSS TCVN 6625-2000, Water quality, Determination of suspended

solids by filtration through glass-fiber filters

mg/l

BOD5 TCVN 6001-1995, Water quality

Determination of biochemical oxygen demand after 5 days at 20o

Celsius (Dilution and seeding method)

mg/l

COD TCVN 6491-1999, Water quality

Determination of chemical oxygen demand

mg/l

PO43- TCVN 6494-1999, Water quality

Determination of dissolved fluoride, chloride, nitrite,

orthophosphate, bromide, nitrate, and sulfate ions, using liquid

Coliform TCVN 6187-1996, Water quality

Detection and enumeration of coliform organisms, thermotolerant

coliform organisms an presumptive Escherichia coli

MPN/100ml

QCVN contain 35 parameters of water quality which are chemical, physical and biological indicator This method evaluates water quality by comparing index of each parameter to QCVN table In this project, there are 8 indicators which use QCVN containing

pH, TSS, BOD5, COD, NH4+, PO43-, and DO, coliform

After analyzing data in laboratory and in site, these parameters are compared QCVN table (Table 3.3)

Table 3.3 Specific value for surface water quality parameters

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Notes:

The classification of A1, A2, B1, B2 for surface water quality is to assess and control water quality, serving different water use purposes, arranged according to the reduced quality level

A1 - Use for domestic water supply purposes (after applying normal treatment), conservation of aquatic plants and animals and other purposes such as type A2, B1 and B2

A2 – Use for domestic water supply purposes, appropriate treatment technologies or use purposes must be applied as B1 and B2

B1- Use for irrigation or other uses with similar water quality requirements or uses as type B2

B2 – use for transportation and other purposes with low quality water requirements

3.5.2 WQI calculation

The WQI method is employed to evaluate environmental quality of the water surface

in accordance with 9 indicators, including:

1 pH

2 Dissolve Oxygen (DO)

3 Total Suspended Solid (TSS)

4 Biochemical Oxygen Demand (BOD5)

5 Chemical Oxygen Demand (COD)

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Step 1: Calculating WQI index:

The WQI index (WQISI) is calculated based on the results of the indicators: BOD5, COD, N-NH4, P-PO4, total coliform and turbidity, by the following formula:

( ) (1) Whereas:

BPi: the minimum concentration of the parameter value, defined in Table 3.4.2 corresponding to the i

BPi+1: The maximum concentration value of the parameter value, defined in table 3.4.2 corresponding to the i+1

Qi+1: WQI value with i+1 on the table corresponding to BP value

Cp: Parameter values for calculation

Table 3.4 Specifying qi and BPi values

Notes: In case, Cp – the value of parameter coincides with value of Pbi in the table,

we determine the value of WQI as the equal of the value qi

Step 2: Calculating WQI value with regard to DO parameter (WQI DO ), based on percentage of DO saturation value:

Calculating % DOsaturation value:

+ Determine DOsaturation value:

DOsaturation= 14.652 -0.41022T+ 0/0079910T2-0.000077774T3

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Where: T water environment temperature at the time measured (unit: oC)

+ Calculating % DOsaturation:

% DOsaturation= DOdissolve / DOsaturation * 100

DOdissolve: DO value measured (unit: mg/l)

+ Calculate WQIDO value:

( ) (2) Whereas:

Cp: % DOsaturation value

BPi, BPi+1, qi, qi+1 are values corresponding to I, i+1 in the table 3.5

Table 3.5 Specifying BPi and qi values based on % DOsaturation value

Notes:

If % DOsaturation value ≤ 20, WQIDO =1

If 20 < % DOsaturation value < 88, WQIDO is calculated based on formula 2 and table 3.4.3

If 88 ≤ % DOsaturation value ≤ 112, WQIDO =100

If 112 < % DOsaturation value <200, WQIDO is calculated based on formula 1 and table 3.4.3

If % DOsaturation value ≥ 200, WQIDO = 1