The inhibition of nitrification in the activated sludge process | |
| Author | Ampon Wiwatcharoenkul |
| Call Number | AIT Thesis no.EV-96-03 |
| Subject(s) | Nitrification Sewage--Purification--Activated sludge process |
| Note | A thesis submitted in partial fulfillment of requirements for the degree of Master of Science |
| Publisher | Asian Institute of Technology |
| Abstract | Nitrification inhibition due to aniline was investigated in completely mixed activated sludge process. Synthetic wastewater with aniline as the carbon source was used as feed. Aniline degradation by heterotrophs and nitrification due to nitrifiers was investigated for the influent aniline concentration of 250-600 mg/L. The activated sludge unit was operated at ambient temperature and an HRT of 8 hours and an SRT of 12 days. The aniline removal by heterotrophs was observed to be nearly 100 % and virtually independent of influent aniline concentration. The influent aniline concentration of 600 mg/L was found to be inhibitory for nitrifying microorganisms since nitrifier activity completely ceased at this concentration. When influent aniline concentration was reduced to 250 mg/L the nitrifier activity again picked up after ASP operation of24 days. Batch tests were conducted to investigate the inhibitory and toxicity effects of aniline on the microorganisms. The initial aniline concentration of 50-400 mg/L were used in the batch tests. The complete aniline degradation was obtained within 4-6 hours and nitrification was initiated only after aniline concentration dropped below 4-5 mg/L. Nitrification beyond 82 % was obtained up to initial aniline concentration of 350 mg/L however this value reduced to 74 % for initial aniline concentration of 400 mg/L. It was found that initial aniline concentration beyond 150 mg/L was inhibitory to Nitrobacter population, while the Nitrosomonas activity was affected by initial aniline concentration beyond 350 mg/L. |
| Year | 1996 |
| 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) | Annachhatre, Ajit P.; |
| Examination Committee(s) | Yang, Byung-Soo;Kamei, Tasuku; |
| Scholarship Donor(s) | Nishihara Co., Japan; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1996 |