THESIS SUMARY
PhD candidate: HUYNH CHUC
Scientific supervisor:
Assoc. Prof. Tang Duc Thang
Thesis: “Study on the scientific backgrounds for assessment and management of
water quality for water supply sources in Saigon river, a tributary of Dongnai
river basin”
Major: Planning and Management of Water Resources;
Course code: 62 62 30 01
Education institution: Southern Institute of Water Resources Research
ABSTRACT
1. Aim and objectives
The thesis aimed at application and modification of theory of aquatic
parameters dispersion in combination with approriate mathematical modeling to assess
and manage the water quality of the water supply sources of Saigon river, a tributary
of Dongnai river system.
The objectives of the study is to identify the pollution mechanism caused
domestic and industrial wastewaters as well as propose the protection measures for
water supply sources of an tide affected downstream of Saigon river, a tributary of
Dongnai river basin.
2. Methodology
- Review of previous studies carried out on the riverine system, which
composed of several tributaries. The study of the dispersion process occured in
tributaries are the bases to canculate environmental factors, which used for proposition
of management measures .
- Investigation, collection and data processing of data related with
environmental quality of previous studies on Dongnai river basin.
- Modelling method using software Mike 11 (Denmark Hydraulic Institute) was
applied as mathematical modelling.
3. Results
3.1 Overview of previous studies related with water’s quantity and quality; the
quality of water supply for domestic purpose are decreased for downstream of
Dongnai river basin, in general and Saigon river, in particular. The documents related
with water sources, pollution sources (location, discharge volume, pollutant load,
receiving water bodies, and maps of pollution sources) have been also collected and
reviewed.
3.2 The impact of tides on pollutant dispersion and water sources distribution in a
complicated riverine system has been also carefully considered. The inverse dispersion
including pollutants in riverine system has been studied. A conclusion on the boundary
conditions for material dispersion (the water sources’ quality) at the low and high
boundaries, which are affected by tides (inverse flow due to certain tidal phases).
BM14-QT751-04/KHTL
3.3 Establish a basis for calculation of the average values for water source’s
distribution during long-term period as well as its components. Thus, following factors
have been defined:
-
The dispersion factor D, which could be apply for all water sources
-
The inverse dispersion velocity vD to estimate the average variation of
pollutant’s concentration.
3.4 Find out the answer for average composition of water quality. In addition, the
result based only hydraulic calculation could be used for assessment and management
of water quality, in general and water supply, in particular.
3.5 The results of study on water’s quality have been showed that the emission
sources, which play an important role in water quality at the water supply sources of
both Saigon river and Dongnai river basin, are domestic sources of sub-aquifer SH1.
The industrial sources, which released into Saigon and Vamco rivers, have effected
only for water supply sources belong to Saigon river. It is necessary to manage these
emission sources to protect the water quality of water supply sources in Saigon and
Dongnai rivers. The other emission sources (domestic sources-SH2, industrial source
of Thivai and Dongnai rivers) have relative insignificant impacts.
3.6 The emision source from Dautieng lake has significant impact on the dilution
as well as the dispersion of pollutants and salinity. Thus, the water quality has been
improved. In contrast, the emision source of Trian lake was insignicant. Both sources
are not directly related with water quality of water supply sources in Dongnai river.
3.7 The measures for water quality protection of Hoaphu station have been
defined as follows:
- It is necessary to install a treatment system of raw water to reduce the increased
BOD5 (6mg/l  8.7mg/l) to meet the certified level;
- Based on the average contributions (%) of emision sources (industrial and
domestic sources, respectively), the appropriate discharge rate of Dautieng aquifer [
pTB(%) = 21.7e-0,045.Qxa ] for ensure p (%) value of 9.1% and the quality of water supply
at Hoaphu station is 19.3 m3/s to 25.0 m3/s, during March and April.
- The present study has shown that in the upstream of Saigon river, the water
pollution could not occur so the water supply stations should be relocated in this area
to ensure safety sources.
Hochiminh City, 15th March 2012
SCIENTIFIC SUPERVISOR
Assoc. Prof. Tang Duc Thang
PhD CANDIDATE
Huynh Chuc
BM14-QT751-04/KHTL