| Author | Bamroong Kulratanayan |
| Call Number | AIT Thesis no. 317 |
| Subject(s) | Water--Purification--Flocculation
|
| Note | A thesis submitted in partial fulfillment of the requirements
for the degree of Master of Engineering in the Asian Institute
of Technology, Bangkok, Thailand |
| Publisher | Asian Institute of Technology |
| Abstract | The effects of polyelectrolytes used as primary coagulants and as coagulant aids in alum coagulation of the turbid raw water from the Bangkok Waterworks intake were investigated using the jar test. Polyelectrolytes tested included activated silica, sodium alginate, FLOCCOTAN, MAGNIFLOC 990N, PURIFLOC N17, SEPARAN NP10, CALGON CATFLOC, and PRIMAFLOC
C-3, C-5, and C-7. FLOCCOTAN and CATFLOC at low dosages performed better than alum as
primary coagulants but would cost much more if used on the plant scale. Other polyelectrolytes tested were not satisfactory as primary coagulants for the raw water tested. CATFLOC, SEPARAN NP10, MAGNIFLOC 990N,
PURIFLOC N17, FLOCCOTAN, and activated silica, when used as coagulant aids, reduced by approximately 50 percent the alum dosage required to
produce rapidly-settling flocculated particles and the same low residual turbidity. High dosages of polymer in conjunction with alum formed large floc particles but excessive dosages of polymer resulted in a cloudy supernatant. Polyelectrolytes in conjunction with alum could reduce the
settling time of floc and would be more economical than alum alone on the plant scale, giving better clarification and lengthening filter runs. The optimum alum dosages obtained using the colloid titration
technique for this surface water appeared to be independent of the colloid charge in the water but dependent on raw water alkalinity. This seemed
unreasonable and suggested that the empirical equation previously developed was not suitable for application to the raw water tested. |
| Year | 1969 |
| Type | Thesis |
| School | Student Research Before 1980 |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Thesis (Year <=1979) |
| Chairperson(s) | Pescod, M.B. ;Ward, Roscoe F. ;Woodward, R. L. |
| Scholarship Donor(s) | Asian Institute of Technology |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 1969 |
