Hydrogenotrophic denitrification of aquaculture wastewater using hollow fiber membrane bioreactor | |
| Author | Nguyen Quang Hung |
| Call Number | AIT Thesis no.EV-06-22 |
| Subject(s) | Membrane reactors Bioreactors Aquaculture Water--Purification--Microbial removal |
| 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 | Major problem of aquaculture activities is discharge of wastewater with high concentration of nutrient that causes eutrophication of receiving bodies. A hydrogenotrophic denitrification system, which consists of continuous membrane bioreactors, was evaluated for removal of organic matter and nitrate from synthetic aquaculture wastewater for recycle purpose. Two membrane bioreactors systems namely aeration-denitrification (AD) and denitrification-aeration (DA) systems were studied with inlet concentration of organic matter and nitrate nitrogen of 50 mg/L. AD system was experimented at hydraulic retention time (HRT) of 9, 6, 4, 3 and 2 hours with using buffer (K2HPO4 and KH2PO4) and using CO2 at HRT of 3, 2.5 and 2 hours for controlling pH. DA system was operated at HRT of 3, 2.5 and 2 hours with using CO2 to control pH. The results in AD system with using buffer showed that, removal efficiency reached 100%, 98%, 95%, 86% and 65%; and denitrification rate achieved 104, 191, 280, 332 and 378 g/m3.day at HRT of 9, 6, 4, 3 and 2 hours respectively. COD outlet at denitrification reactor is 20-40mg/L this value is higher than inlet (10-15mg/L) due to soluble microbial products. The results in AD system with using CO2 indicated that, average removal efficiency was 88.3%, 72% and 66%; and denitrification rate was 343, 378 and 379 g/m3.day at HRT of 3, 2.5 and 2 hours respectively. Nitrite accumulation in AD system using CO2 was less than using buffer to control pH. In DA system, not only the sequence of reactors but also function of membrane was changed from diffusion to suction, denitrification rate and efficiency of removal were almost the same with original case but water quality in term of COD removal, turbidity, SS, nitrite and dissolved oxygen were very good. The study has demonstrated that this system can maintain acceptable water quality for aquaculture activity in a closed recirculating system without discharge |
| 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 (EV) |
| Chairperson(s) | Visvanathan, C. |
| Examination Committee(s) | Chongrak Polprasert ;Nguyen Cong Thanh |
| Scholarship Donor(s) | Petro Vietnam |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2006 |