| Author | Bari, Quazi Hamidul |
| Call Number | AIT Thesis no.EV-93-21 |
| Subject(s) | Water quality--Thailand--Bangkok
|
| Note | A Thesis Submitted in partial fulfillment of the requirement for the degree Master of
Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | Field survey of the klongs (Canals) and laboratory experiments were performed
to find pollution situation and mechanisms in a Klong in Bangkok. In the field survey, a
part of the Klong Saen Saep was selected as a research field, and water samples were
weekly collected from the depth of 50 cm at three stations. The part is one of the most
polluted streams, and is less connected to other klongs. The observation period was from
September 1992 to February 1993. In the batch experiments, water quality change of the
klong water was monitored under the conditions; sedimentation, aerobic stationary,
aerobic shaking and anaerobic conditions.
Although the samples were collected from the depth of 50 cm at three stations,
DO was usually less than 1 mg/I and considerable concentration of H2S was found . The
water color was usually black, and sometimes gray. Accordingly, most of the water in the
klong was considered to be anaerobic. T-COD was fluctuating from 60 to 120 mg/I, and
about half of T-COD was particulate. T-BOD was ranging from 20 to 50 mg/I, and
BOD/COD ratio was about 0.46 for both particulate and soluble fractions on the
average. The survey covered rainy and dry seasons, but the significant difference was not
observed on water quality between two seasons.
The reduction rates of COD in anaerobic condition were very slow compared to
other conditions. The range of reduction rate for T-COD, S-COD and P-COD was
0.0007-0.0015 hr-1 in anaerobic condition. The ratios of overall reduction rates,
Sedimentation:Aerobic stationary:Aerobic shaking:Anaerobic condition at initial were
60:2:3: 1 for P-COD and 0:5: 10: 1 for S-COD.
A material balance of COD for the test field was successfully obtained from the
above field observations, laboratory batch tests and some assumptions. The material
balance of COD shows that the average removal of organic pollutant by biological
activities was only 3.11 % of the sewage inflow into the klong. The main organic pollutants
in the klong were biodegradable, but their high concentration caused the anaerobic
condition, resulting in their low reduction rates. About 17-23 percent removal of T-COD
of klong water can be obtained by aeration and 13-25 percent of that removal can be
obtained by sedimentation. Only the removal of particulate fraction of pollutants can be
achieved by sedimentation whereas both particulate and soluble fraction of pollutant can
be removed by aeration. |
| Year | 1993 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering (EV) |
| Chairperson(s) | Fujii, Shigeo; |
| Examination Committee(s) | Samorn Muttamara;Tanaka, Shuzo; |
| Scholarship Donor(s) | Swedish International Development Authority; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1993 |