Development of high efficient nitrification process by microfiltration (MF) membrane bioreactor | |
| Author | Kim, Jeong-hun |
| Call Number | AIT Thesis no. EV-91-26 |
| Subject(s) | Sewage--Purification--Activated sludge process Nitrification |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | Three identical small scale membrane bioreactors were operated in parallel to investigate the effect of the ratio of N/COD in the Influent on the nitrification performance. The NH4+-N concentration of the influent was fixed at 400 mg/l varying the COD concentration of that with 0, 1000 mg/l and 2000 mg/l for reactor 1, 2 and 3, respectively. The continuous experiments were conducted for 110 days varying nitrogen loading from 0.6 to 2.4 gNH-i+-N/l.d. The reactors were operated at pH 7.0-7.8 and very long sludge retention time with intermittent feeding mode to examine microfiltration efficiency and maximum allowing nitrogen loading as well as the effect of the activity of heterotrophs on nitrification Clogging did not occur when biological solids were retained in the reactor at a lower concentration. Serious clogging did occur at higher loadings in the reactor retaining a higher solid concentration. The result clearly indicate that the addition of organic matter, which provokes the growth of heterotrophs, inhibits nitrification because of loss of ammonia for assimilation of heterotrophs. Ammonia utilization rate, k, determined in batch experiments was 4. 14d- 1 when no glucose was added. The addition of glucose to the reactor resulted in a low k (2.50d- 1 and 2.30d-1) and 0.097 and 0.036 of the ratio of nitrifies to total biomass when the ratio of N/COD were 2.5 and 5.0, respectively. It is suggested that inhibition takes place by crowded cells of heterotrophs on nitrification. A nitrification rate of 2.51 gNH4+-N/l.d was attained with 88.1% of nitrification efficiency. More than 10% and 25% of the oxidized nitrogen in the reactors were denitrified at the same time when 1000 mg/l and 2000 mg/1 of COD were added, respectively. |
| Year | 1991 |
| 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) | Harada, Hideki; |
| Examination Committee(s) | Kim Sun-Il ;Mino, Takashi |
| Scholarship Donor(s) | DAAD, Federal Republic of Germany; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1991 |