WATER QUALITY PROTECTION OF TRUC BACH LAKE IN HANOI

Group Members Le Thi Kim Chi

Nguyen Thanh DuongLuong Loc HaBui Thi Huong

Nguyen Thuy LinhLuu Thi Ha Phuong

Phung Thi Mai PhuongNguyen Thi Thu

K56 Advanced Undergraduate Program in Environmental Science1

Vietnam National University, HanoiUniversity of Science

Faculty of Environmental Sciences

Supervisor: Dr. Do Huu Tuan

CONTENTS

I. Introduction II. Status III. Methodology IV. Investigation & Analysis

A. ParametersB. Biological Composition

V. Sources of Pollution VI. Solutions & Recommendations VII. Conclusion

I. Introduction

RESEARCH LOCATIONTruc Bach Lake is located in thenorthwest of Hanoi’s Old Quarter,immediately adjacent to the easternshore of the city’s largest lake,West Lake, which is a formerbranch of the Red River

Truc Bach LakeFigure 1.Truc Bach Lake

I. Introduction

Coordinates: 21°2′44″N 105°50′17″E

Average depth = 2.0 m

Maximum length =400 m Maximum width = 300 m

Swater = 9,000 m^2

Vinflow and outflow =0 => no changes in the lake’s water level

*

* Dissolved oxygen levels below 12.5 to 25

times

* Ammonium exceed 7.8 to 32 times

* Excess nitrite 48-113 times

2005

II.STATUS

*

Recent years The large amount of bottom mud has accumulated

decades -> too much organic matter Create new toxic species. Feeding fish in polluted water lead to many fishes died

We survey some people who live around the lake .

Mrs. Pham Thi Ngoc Lan told us the main reason is sense of

civic responsibility is low.

II. Status

Figure 5. Our investigation of condition of Truc Bach Lake and residential opinion

September 01,2005 Truc Bach water treatment station was established and operated with a capacity of 2300m3 / day (highest capacity is 3000m3 / day).

In 2007,Ha Noi water company dredge TrucBach lake

Cleaning and pick uprubbishes Planning trees

III. Methodology

1. Field observations: Collect pictures and information fromthe residential areas around the lake2. Refer to the documentation or previous researchs about thewater quality standards in different years, pollution status3. Using the measuring cylinder and seechi dish to estimatethe water level4. Synthesis, statistics and data analysis

IV.1. Parameters

Water Temperature (T) Hydrogen Concentration (pH)

Dissolved oxygen (DO) Biochemical Oxygen Demand (BOD5)

Dissolved Inorganic Nitrogen (NH4

+, NO3-and NO2

- Concentration)Lake

Field Observation + Measurement

Typical summer day and winter day: (2011)

1. April 13th

2. August 23rd

3. November 10th

Period:1. Morning (09:00)

2. Afternoon (15:00)3. Evening (21:00)

Layer:1. Horizontal water layer

Take samples at center of lake2. Vertical water layer

Intervals division of 40 cm, => water samples taken points :

0.4 m, 0.8 m, 1.2 m, 1.6 m

Water TemperatureHorizontal Water Layer

B.Q. Lap et al 2013

Vertical Water Layer

B.Q. Lap et al 2013

Figure 8. Water Temperature Measurement in Horizontal and Vertical Water Layer of Truc Bach Lake

DO change in Horizontal Water Layer13th April 2011

Figure 9. DO Measurement in Horizontal Water Layer of Truc Bach Lake

10th November 2011

B.Q. Lap et al 2013B.Q. Lap et al 2013

DO change in Vertical Water Layer13th April 2011 10th November 2011

Figure 10. DO Measurement in Vertical Water Layer of Truc Bach Lake

B.Q. Lap et al 2013 B.Q. Lap et al 2013

pH change in Horizontal & Vertical Layer

Vertical

13th

April 2011

Horizontal

10th

November 2011

Figure 11. pH Measurement in Horizontal and Vertical Water Layer of Truc Bach Lake

B.Q. Lap et al 2013

BOD5 Seasonal Change

High = between the end of spring and the beginning of

summer (13/4) and in winter (10/11)

Low= summer and autumnMinimum = 15 mg /L(

does not meet QCVN 08: 2008)

Maximum = 38 mg/L (>2.5 times QCVN 08:

2008 for Water Quality class B1)

B.Q. Lap et al 2013

Figure 12. BOD5 Seasonal Change in TrucBach Lake

Dissolved inorganic nitrogen in dry season

NH4+

• = 0.5 mg/L ( limiting value for water quality class B1 for irrigation).

NO3-

• =0.7-0.9 mg/L(allowable limits for surface water quality)

NO2-

• =0.05 mg/L (only meet water quality class B2 for navigation)

B.Q. Lap et al 2013

Figure 13. Dissolved inorganic nitrogen concentration in dry season

in Truc Bach Lake

Turbidity

Factory can treat just 1/3 => 1/5 amount of wastewater(>10 drains)

Ngu Xa Village: 15cm Nearby treatment center:

41cm Centre of Truc Bach Lake:

36cm

IV.2. Biological composition Phytoplankton

About 79 species of phytoplankton in Truc Bach lake:

Having high concentration of heavy metals (Cu, Pb, As..)

Euglenophyta

The lake is heavily polluted

Biomass of phytoplankton

increase dramatically, compared to

investigation in the past

Euglenophytais greatest number

4 divisions of algae

IV.2. Biological composition

Rotifer

Zooplankton About 9 zooplankton species belonging to 3

groups:

+ Copepoda (1 species)+ Cladocera (2 species)

+ Rotifer (6 species)

High accumulation in content of

heavy metals as Cd, Cu, Pb, As,

Hg

Biomass of zooplankton is low and lower than in the past

IV.2. Biological Composition

Zoobenthos Almost no single

species of zoobenthos(due primarily to high level of H2S)

Fish in Truc Bach lake

Fish About 11 fish species ( 8 Natural,

3 Introduced

)

1

Fish culture was applied virtually to

control eutrophicat

ion.

2

The level of Pb in fish exceeds

regulatory standard of Ministry of

health.

3

V. Sources of pollution

A drain is discharging wastewater

from a restaurant

From the recent development of restaurants and hotels

Sewage and toilet waste are released directly into the lake, often through drains, sewers..

Pollutants include organic substances, soap and faeces..

V. Sources of pollution

From domestic source

Increasing in residential houses=> more wastes

Waste water, rubbish, poultry dung..are occasionally discharged directly into the lake.

Waste in Ngu Xa trench

V. Sources of pollution From industrial waste

Water in Ngu Xa stench

Wastewater from the facility making copper, aluminum, micro-brewers…in

Ngu Xa village

V. Sources of pollution

Consciousness of people

Having hundreds of tourists visits here each year

People living nearly to the lake

=> Throw rubbish around and even into the lake

VI.1. Solution

VI.1. Solution

A. Treatment TechnologyMRET Activation Technology:

Enhance the activity of micro-

organisms in decomposition of

pollutants

Additional beneficial

microorganisms in the process

creating biodiversity in

water and mud at the bottom

Expected efficient = 60%

VI.1. Solution

B. Management Plan Facilities that

produce Cu, Al inNgu Xa village weresuspendedproduction orrelocated to otherplace (for 10 years)

Control sources ofpollutants.

VI.1. SolutionB. Management Plan

1

• Management of environmental protection

2

• Enhancement of handling violations

Evidences

• June 2014: authorities have discovered and handled 9 violated production facility in Truc Bach lake area (administrative penalty is 150 million)

VI.2. RecommendationA. Treatment Technology Using new treatment water

technology Build more treatment water station

B. Management Plan • Enhance the management of

environment• Increased penalties for

violated production facilities

VI.2.Recommendation- Landscape Plant more tree and flower bed

surrounding lake Restrict restaurant encroach

and unsanitary around the lake Enhance tourism activities

VI.2.Recommendation

Plant more tree and flower bed surrounding lake

Restrict restaurant encroach and unsanitary around the lake

Enhance tourism activities

- Enhance awareness of people- Communication and education

VII. Conclusion

By analyzing the parameters, we can conclude TrucBach Lake is polluted by organic matters and nutrientsby max DO=5 mg/L, minDO=2 mg/L. This indicates byQC:2008 that Truc Bach Lake is meet B2 Water Qualityfor navigation and low quality water

Organisms in Truc Bach lake are threatened seriously.Water pollution in Truc Bach lake is derived from manysources as domestic, industrial and trading activities

In order to preserve this, the most importance isawareness of citizens nearby. On the other hand,treatment technology and management plan should beconcerned comprehensively.

References

Bui Quoc Lap, Masayoshi Harada and Kazuaki Hiramatsu, 2013, “Dynamics of Water Quality in the Truc Bach Lake, Hanoi Capital,

Vietnam”, Faculty of Agriculture, Kyushu University, Japan. Dang Thi Sy, Tran Duc Vien, 2011, “The role of aquaculture in pollution-remediation in West Lake and Truc Bach Lake of Hanoi,

Faculty of Biology, University of Science, Vietnam National University, Hanoi.

Tran Thu Ha, Nguyen Hong Phong, 2010, “2D - MODEL OF CONTAMINANT WATER TRANSMISSION PROCESSES AND

NUMERICAL SIMULATION ON A NATURAL LAKE”, Institute of Mechanics, Vietnam Academy of Science and Technology

Internet sources for images, news and general information

Thank you for listening!

Time for Q & A :D