| Author | Pradhan, Salata |
| Call Number | AIT Thesis no.EV-05-23 |
| Note | A thesis submitted in partial fulfillment of the requirements for the
degree of Master of Science |
| Publisher | Asian Institute of Technology |
| Abstract | The Feasibility of sulfate reduction and sulfide generation in thermophilic biological sulfate reduction process was carried out in lab scale upflow anaerobic packed bed biofilm reactor. Experimental setup consisted of feed tank, anaerobic filter reactor of 4.6 l working volume with media and settling tank. The anaerobic filter was 2.1 m in height and equipped with water jacket for circulation of hot water in order to maintain thermophilic temperature in the range of 55- 65 0C in the reactor. Experimental studies were divided in to two parts. First part was carried out with synthetic wastewater with molasses as a carbon source and Na2SO4 as an electron acceptor. The second set was carried out with real industrial wastewater with sulfate concentration in the range 9000- 10000 mg/l. In the first part effect of COD: SO4 ratio on reactor performance was evaluated with three different COD: SO4 ratio. Influent sulfate concentration was maintained about 500 mg/l and COD concentration was varied from 1500- 500mg/l. Competition between MPB and SRB was influenced by COD: SO4 ratio in the feed. Higher sulfate removal could be achieved at higher COD: SO4 ratio when MPB predominated. Competition between MPB and SRB was intense at low COD: SO4 ratio. Sulfidogenic process operation yielded sulfate removal up to 60% at COD: SO4 ratio of about 3. But the COD removal was only around 40 % at the same ratio. Three experiments with synthetic wastewater yielded maximum sulfide concentration of 108.4 mg/l at sulfate sulfur loading rate of 3.96 kg/m3.d and upflow velocity of 1.6 m/hr when COD: SO4 ratio was maintained at 3:1. In the second part two experimental set was carried out with two different upflow velocities of 2 and 1.8 m/hr and COD: SO4 ratio was tried to maintain at around 1 in both set. Supernatant from the settling tank was partly recirculated back in to the reactor in order to maintain the upflow velocities. Higher removal efficiency and higher sulfide production was observed at low upflow velocity. Experiments with real wastewater yielded maximum sulfide concentration of 480.41 mg/l at sulfate sulfur loading rate of 3.42 kg/m3.d and upflow velocity of 1.8m/hr when COD: SO4 ratio was around 2..The percentage electron flow by MPB was about 1-20 % and by SRB was about 80- 99% during this research. |
| Year | 2005 |
| 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) | Annachhatre, Ajit P. ; |
| Examination Committee(s) | Aramaki, Toshiya;Thammarat Koottatep ; |
| Scholarship Donor(s) | Norwegian Agency for Development
Cooperation (NORAD) ; |
| Degree | Thesis (M. Eng.) -- Asian Institute of Technology, 2005 |