Assessment of urban water quality in Nhieu Loc-Thi Nghe Basin, Viet Nam | |
| Author | Ngo Thi Thanh Nhan |
| Call Number | AIT Thesis no.WM-04-01 |
| Subject(s) | Water quality--Vietnam--Nhieu Loc-Thi Nghe Basin--Measurement Municipal water supply--Vietnam--Nhieu Loc-Thi Nghe Basin |
| Note | A thesis submitted in pattial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | Nhieu Loc Thi Nghe (NL TN) Basin is the centre of commerce and culture of Ho Chi Minh City which is located in South of Vietnam. It covers about 33 km2 with more than one million of people. Along with rapid urbanization in Ho Chi Minh City in general and NL TN particularly, surface water quality in NL TN canal system is more and more polluted by mainly domestic wastewater. This impacts on public health and city aesthetics. Therefore, an assessment of water quality in NL TN canal system to help in finding solutions is more important. In this study, MIKE 11 is used as a tool to analyze parameters of water quality as Biochemical Oxygen Demand (BOD) and Dissolved Oxygen (DO). The MIKE 11 model has 3 components: Hydrodynamic (HD) module, Advection dispersion (AD) module and Water quality (WQ) module. The canal network includes main canal, Nhieu Loc Thi Nghe canal (9.4 km of length) and two branches Bong canal (2.1 km) and Van Thanh canal (1.8 km). After calibration of hydrodynamic model is advection-dispersion calibration. The calibrations of models are carried out with observed data in April 2003. The calibrated results show that Manning coefficient is 0.03 of and Dispersion coefficient is 10 m2/s. At present conditions, the BOD level in NL TN canal is very high. The BOD is around 100 mg/l, as 4 times as limit set of Vietnamese Surface Water Quality Standard for Category B (VSWQS-B, type of water not used for domestic use). While DO is mostly depleted, especially at upstream canal when low tide occurs. At downstream canal, polluted water is diluted by water from Sai Gon River, 25 mg/l of BOD and 4 mg/l of DO, so it is better than that at upstream canal. A wastewater collection system and pumping station are being constructed at left canal bank near NL TN canal mouth and it will be completed in 2007. It will improve water quality in basin by collecting wastewater to convert to Sai Gon River. The polluted water in NL TN system and its impact on Sai Gon River are carried out in 2007 before and after operation of pumping station. In 2007, before operation of pumping station, wastewater is discharged to NL TN canal system, the BOD values are not much higher than those in 2003. After having pumping station, the interaction of BOD and DO between NL TN canal system and Sai Gon River has been studied. The discharge of pumps to Sai Gon River is 2.58 m3/s. With this discharge, the BOD level is below the limit set of VSWQS-B. The limitations of wastewater discharge (10m3/s) or BOD load (60 mg/l) to Sai Gon river are defined so that water quality can meet the limit set of VSWQS-B is considered in this study. |
| Year | 2005 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Clemente, Roberto;Sutat Weesakul |
| Examination Committee(s) | Gupta, Ashim Das;Babel, Mukand Singh |
| Scholarship Donor(s) | MARD-DANIDA WaterSPS Vietnam |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2005 |