wastewater management (wwm) and its impacts to water environments in vietnam. wwm concepts and...
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WASTEWATER MANAGEMENT (WWM) AND ITS IMPACTS TO WATER ENVIRONMENTS IN VIETNAM.
WWM CONCEPTS AND TECHNOLOGIES
Hanoi University of Civil Engineering,
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Cities in Vietnam, classes I - V
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0
20
40
60
80
100
120
Po
pu
lati
on
, m
ln.
2000 2010 2020 Years
Urban population ratio in Vietnam
Total population,mln.
urbanpopulation, mln.
YearsTotal population,
mln.Urban population,
mln.%
2000 76 15 202010 93 30.4 332020 103 46 45
Rapid urbanization and industrialization
Hanoi city: Population 1945: 280,000 1954: 380,000 1960: 1,050,000 2001: 1,700,000 among 2,750,000 total urban zone population 2020: 2.5 million among 4.5 millions total urban zone population The area of Hanoi urban in 1994 was 4,600 ha, in 2000: 9,000
ha, and it will be up to 25,000 ha in 2020
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Hanoi inner-city population (4 districts), 1918 - 1994
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
1918
1928
1939
1954
1969
1978
1980
1982
1984
1986
1988
1990
1992
1994
Years
Popu
latio
n, in
h.
Agricultural ratio from GDP, %
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
1990 1995 1999 2000 Years
% G
DP
Agricultural ratiofrom GDP, %
Industrial ratio from GDP, %
32.0
34.0
36.0
38.0
40.0
1996 1997 1998 1999 2000Years
% G
DP Industrial ratio
from GDP, %
Rapid urbanization and industrialization
Urbanization and industrialization processes create pressures on the environment and natural resources; destroy the ecological balance, impact on environmental quality and natural resources
These pressures could exceed the “enduring ability” of the environment and natural resources as well as the “response ability”
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Pressure-Status-Response (PSR) Model (Adopted from EPA)
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PressuresProduction, Commerce,
Consumption
Energy, Transport, Industries, Agriculture,
Forestry, etc.
Environmental status
Air, Water, Soil,Natural resources,
Ecosystems,Urban and rural areas
ResponseLegislations, Strategies,
Policies, New technologies,
Pollution control,Consumption change
Conventions, etc.
ResponsesDecisions,
Actions
Pressures
Environment, natural resources
Information
Information
ResponsesDecisions,
Actions
Water resources
Surface water resources: 2360 rivers with lengths over 10 km accounting for a total
flow of 835 Billion m3
Year 2000: 4700 m3 person yr-1 (global average: 7400 m3 person yr-1)
Not equally distributed by locality or season:
- 5 months wet season: 75 - 80% of total flow
- 7 months dry season: 20 - 25% of total flow
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Ground water:
50 - 60 Billion m3 of total potential Maximum available for exploitation: 10 - 12 Billion m3
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8
Hanoi water supply
9
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
Wat
er d
eman
d, c
mpd
2001 2005 2020 Year
Water supply in Hanoi city
Ground water Surface water (Red river)
Groundwater over-exploitation has caused depression and subsidence phenomenon in some areas of Hanoi city• The highest rate of subsidence (30 mm yr-1) has been
found in a 2-km2 radius surrounding Phap Van water treatment plant
Groundwater in Pleistocene (QII) aquifer has been slightly polluted by nitrogen compounds, especially by ammonia, which has being found at Ha Dinh, Tuong Mai and Phap Van water treatment plants (up to 20 mg NH4-N l-1)
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Domestic water use
640 cities and towns with a population of 18 Million (23%) 200 urban water supply projects, provide 2.7 Million m3 d-1 for
60% of the urban population this is equivalent to 60-80 l d-1
40% of the urban population does not have access to an adequate water supply
90% urban areas are not equipped with adequate sewerage systems
1995: 28% population in rural areas served by clean water 1999: 36% 2002: 50% receiving 50 l d-1
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Water use for agriculture
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1990: 47 Billion m3 (90% of total water consumption) 1999: 60 Billion m3 (85% of total)
Water use for industrial activities
1990: 5.33 Billion m3 (9.8% of total water consumption) 1999: 14 Billion m3 (15% of total)
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Industrial wastewaters
90% of industrial enterprises do not meet National effluent standards
73% of industrial enterprises do not have WW treatment systems
60% of WW treatment systems are not operated properly
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Water quality of river basins
Red river delta: Organics pollution Domestic wastewater is a major pollution source, among
domestic, industrial and agricultural activities
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Rivers in Central Vietnam: Affordable quality Lightly affected by salt intrusion due to tidal regime
Rivers in the Southern Vietnam: Increasing levels of organic and inorganic pollutants Sai Gon, Dong Nai, Thi Vai rivers, etc.
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Water environment problems
Flooding Salt intrusion Pollution
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Monitoring data: 1995 - 2001
BOD5 , COD, NH+4, NO-
3 are generally 2 – 4 times higher than the permissible value
Total coli-form is 100 times higher than the permissible value
In some places Pb and Hg concentrations were several times higher than permissible value
Some rivers are effectively drainage channels
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Variables Measured: Temp, pH, BOD5, COD, SS, TDS, EC, DO,NH4
+, NO3-, PO4
3-, Cl-, Fe, Pb, Cd, (Cr, Hg, As), Coliform.
Pollution of surface water has increasd
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0.00
50.00
100.00
150.00
1995 1996 1997 1998 1999 2000 2001
Years
BOD5
, mg/l
To Lich River, at New BridgeKim Nguu River, at Yen So Gate
0.00
5.00
10.00
15.00
20.00
25.00
1995 1996 1997 1998 1999 2000 2001
Years
NH4,
mg/l
To Lich River, at New BridgeKim Nguu River, at Yen So Gate
Wastewater re-use in agriculture
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Untreated faecal sludge use in aquaculture
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Pesticides
Before 1985: 0.3 kg ha-1
1986 – 1990: 0.4 – 0.5 kg ha-1
1995: 0.85 kg ha-1
1999 - 2000: 1.12 kg ha-1
Concentrated in Red and Mekong River deltas Improper use
Fertilizer
5 Million t yr-1 inorganic fertilizers including 3 Million t yr-1 of imported fertilizers
Vietnam: 80-90 kg inorganic fertilizer ha (Rice = 100 - 110 kg ha-1)
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Mitigation measures
Legislative base, economical tools Environmental standards Urban planning and management Pollution control technologies Education and public awareness
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Standards
Water qualityTCVN 5942:1995 TCVN 5943:1995 TCVN 5944:1995
DischargesTCVN 5945:1995 TCVN 6772:2000 TCVN 6773:2000 TCVN 6774:2000 TCVN 6980:2001 TCVN 6981:2001 TCVN 6982:2001 TCVN 6983:2001 TCVN 6984:2001 TCVN 6985:2001 TCVN 6986:2001 TCVN 6987:2001
Reuse: (WHO)Stepwise approach!
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“Critical Control Points” as barriersagainst disease transmission
Pathogens in faeces
Person-to-person
Flies
Soil
Dom. animals, rodents
Water
Dishes
Food
Fish
Barriers:improved excreta disposal, hygiene and waste management
Containment, treatment
Planning
DEWATS concepts vs centralized WW systems
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IC’s: “Flush-and-Discharge”(all mixed)
Facets
RURBIFARM Project
Sustainable Farming at the rural-urban interface. Introduction to the NISF research
sites in Hanoi, Vietnam
by NISF team
What is peri-urban agriculture?
1. Geographically close to cities.2. Agricultural production mainly for city use.3. City activities have a direct impact on rural
activities.
Two proposed NISF study sites: Tien Phong & Minh Khai Commune
Two proposed NISF study sites: Tien Phong & Minh Khai Commune
0
50
100
150
200
250
300
1 2 3 4 5 6 7 8 9 10 11 12
month
mm
0
5
10
15
20
25
30
35
oC
Rainfall
Evaporation
Temperature
Year 1996 1997 1998 1999 2000N 109.4 103.2 107.9 106.3 113.6P2O5 51.8 43.4 49.5 59.9 54.7K2O 9.1 22.7 24.7 43.9 22.6Total 184.6 169.3 182.0 210.1 190.8Agricultural land(1000 ha)
7681.2 7843.1 8080.2 8712.8 9345.3
Inorganic fertilizers pressure in a ha of agricultural land in Vietnam from 1996 - 2000
Organic fertilizers pressure in a ha of agricultural land in Vietnam from 1996 - 2000
Year 1996 1997 1998 1999 2000N 43.2 43.4 42.9 40.8 39.2P2O5 48.9 49.5 49.2 47.1 46.1K2O 105.3 105.4 104.2 98.7 94.0Total 197.4 198.3 196.2 186.6 197.4Agricultural land(1000 ha)
7681.2 7843.1 8080.2 8712.8 9345.3
Hanoi meteorological 2000 (Lang station)
Overview of Hanoi city and the study area
Minh Khai site
Tien Phong site
Minh Khai commune
Tien Phong commune/ACIAR
Degraded land
(Acrisols)
Fertile soil (Fluvisols)
Minh Khai site(vegetable-FS)
ACIAR/Tien Phong site(mixed FS)
Land preparation for vegetable planting
Irrigation work