| Author | Subasinghe, Dona Wilani Dynatra |
| Call Number | AIT Thesis no.EV-06-10 |
| Subject(s) | Sewage--Purification--Nitrogen removal
|
| Note | A thesis submitted in partial fulfillment of the requirements fo r the
degree of Master of Science
Inter-University Program on Environmental Toxicology, Technology and Management, School of Environment, Resources and Development
|
| Publisher | Asian Institute of Technology |
| Abstract | The survey of piggery waste management practices in Thailand and France have identified that the situation in both developed and developing countries is such that the main way to dispose of the excess wastes is to treat them biologically. This necessitates major efforts in making N-removal from the piggery wastes a dramatically more efficient process. With this in view, further work was performed to better understand the microbial processes which underlie and enhance the engineering performance of the developed biofiltration-activated sludge hybrid treatment system with a focus on its Aerobic-Anoxic system. Changes in the operational parameters allowed to follow the behavior of the microbial communities reacting to these changes and determining the specific total nitrogen removal rate and specific nitritation/denitritation rates. The use of the Fluorescence In Situ Hybridization (FISH); analysis provided an important vehicle to better our understanding of the phenomena. It appeared that the substantially increased specific total nitrogen removal rate (836 g/m3.day), specific denitritation (229 g/m3.day) and nitritation (450 g/m3.day) rates achieved through engineering modifications has been obtained through the enhanced specific microbial activity rather than through the greater abundance in microbial taxa or their absolute numbers. Conventional Polymerase Chain Reaction (PCR) and PCR-DGGE analysis, undertaken to further corroborate the FISH-generated data, produced community DNA fingerprints which correlated satisfactorily with the nitritaton-denitritation related performance of the bacterial consortia under different organic and nitrogen loads. The experimental results obtained from this study further confirmed that the processes of nitritation and denitritation were the major mechanisms for the nitrogen removal from digested piggery waste in the Aerobic-Anoxic system, while nitrification was observed in some cases. Moreover, it was demonstrated that the molecular microbiological techniques were promising tools to be used in gaining insights into the microbiological phenomena underlying engineering aspects of the N-related treatment of the piggery wastes. The work may serve to promote our fundamental understanding of the process of N-removal as well as pave the way to solving a major environmental problem of swine production in agriculture and environmental management |
| Year | 2006 |
| 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 and Management (EV) |
| Chairperson(s) | Shipin, Olge; |
| Examination Committee(s) | Annachhatre, Ajit P. ;Ranamukhaarachchi, S.L. ;Lee, S.H. ; |
| Scholarship Donor(s) | Asian Institute of Technology and
French Government |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2006 |