| Author | Thakur, Gajendra Kumar |
| Call Number | AIT Thesis no. EV-97-47 |
| Subject(s) | Water--Purification--Filtration
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-97-47 |
| Abstract | A conventional activated sludge treatment method of nitrification requires more
detention time (in hrs.) and is expensive process. However biological filters which utilize
biological activities, are very effective, and more than 90% of nitrification was achieved during
the course of the research in the laboratory for detention time of less than 4 minutes.
Particularly biological filters using polypropylene pellets as filter media, were found very
effective in nitrification. Both fixed bed and fluidized bed condition biofilters, gave very good
nitrification efficiency, up to flow velocity of as high as 300 m3
/m2
-day. Still, one using fixed
bed condition, was found more efficient, and gave 99% nitrification efficiency. To the places,
where ammonia-nitrogen concentration standards are very strict, fixed bed biofilters using
polypropylene media can be used with a great advantage.
In addition, biological activities in these filters can be used for filtration action also.
During the course of the research study, fixed bed biofilter removed about 40% of the turbidity
of the influent water, and thus can be used as a roughening filter, before sedimentation unit
process, in the existing water utilities. The porosity of media being 68%, it accommodated more
suspended solids, and frequent backwashing was not needed as breakthrough of turbidity
occurred only after about 120 hrs (5 days) of operation. Also, as the biofilters used in the
research work were of upflow type, very less amount of backwash water was needed in the Jab,
which was concluded to be the direct advantage to conventional filters, where 2-5% of filtered
volume of water is needed for backwashing operation. |
| Year | 1997 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. EV-97-47 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Environmental Engineering (EV) |
| Chairperson(s) | Takizawa, Satoshi |
| Examination Committee(s) | Ishibashi, Yoshinobu;Eckhardt, Ing Heinz
|
| Scholarship Donor(s) | WHO;Asain Institute of Technology Fellowship |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1997 |