| Author | Le Tuyet Minh |
| Call Number | AIT Thesis no.EV-05-16 |
| Note | A thesis submitted in partial fulfillment of the requirements for the
degree of Master of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | Anaerobic ammonium oxidation (Anammox) a biologically mediated process has been studied and continuously developed in recent 10 years. In the process, nitrite inhibition can be considered as one of the challenges that affect treatment efficiency. In this study, role of intermediates such as hydrazine and hydroxylamine in overcoming anammox inhibitory condition was investigated using sequencing batch reactor (SBR). The study was divided into three steps: operation of anammox process in SBR to reach inhibitory condition (step 1); overcome inhibitory condition by intermediates activity test (step 2) and verify the efficiency of intermediates in sludge activity restoration using SBR (step 3). SBR process was operated in 12hours cycle comprising of fill (25min), react (11hours), settle (25min) and decant (10min) stages. Furthermore, SBR was equipped with pH, level and temperature controller. Initial NH4N and NO2N concentration was gradually increased till anammox biomass was completely inhibited due to NO2N, at 390mg/l. The inhibited biomass then recovered its activity by both chemical and physical method. Half of the inhibited biomass was spent in a number of batch tests in which hydrazine and hydroxylamine was added to ascertain their effects on activity of anammox biomass. The tests were taken at different concentration of either intermediate as 0, 1, 10, 20, 40mg/l in 5 days. The most effective response was recorded at sample with 40mg/l hydroxylamine injected. These batch investigations suggested that hydroxylamine can recover sludge activity better than hydrazine and 0.1mg NH2OH/mgNH4 + or 0.4mg NH2OH/gVSS is satisfactory amount to overcome inhibitory condition. Colorimetric method for analysis of hydrazine and hydroxylamine were also developed. Parallel investigations in SBR with inhibited biomass were combined at lower NH4N and NO2N concentration to overcome inhibition. After sludge activity restoration, Anammox activity of 399g TN/kgVSS*day was recorded. Nitrogen loading rate of 0.93kg TN/m3*day and conversion of 85% total nitrogen was recorded as well. |
| Year | 2005 |
| 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) | Annachhatre, Ajit P. ; |
| Examination Committee(s) | Shipin, Oleg;Preeda Parkpian;Nguyen Thi Kim Oanh ; |
| Scholarship Donor(s) | Her Majesty the Queen of Thailand ; |
| Degree | Thesis (M. Eng.) -- Asian Institute of Technology, 2005 |