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Kinetics of the anaerobic sulfate reduction process | |
Author | Shrestha, Minita |
Call Number | AIT Thesis no. EV-03-13 |
Subject(s) | Sulphates Anaerobic bacteria |
Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science. |
Publisher | Asian Institute of Technology |
Series Statement | Thesis ; no. EV-03-13 |
Abstract | Approaches to mathematical modelling of anaerobic digestion and criteria for reactor design in anaerobic wastewater treatment are based on biological degradation kinetics. Whatever type of kinetics is used, the crucial problem always is reliable parameter estimation. Laboratory scales continuous stirred tank reactors (CSTR) were used to determine the kinetic parameters for methanogens and sulfidogens and to study the simultaneous sulfidogenesis and methanogenesis at different COD: So/- ratios. Kinetic parameters determined for each of these groups were bacterial yield, decay coefficient, maximum specific substrate utilization coefficient, and half-velocity constant and maximum specific growth rate. Results indicated that there are not many differences between estimated kinetic values for SRB and MB. It was found from the experiment that MB has very slightly higher Ks value than SRB which showed that MB outcompeted the SRB under nontoxic conditions in CSTR. In CSTR, sulfate removal of about 65% was achieved at COD: So/- ratio of 5:1. It was found from the study that SRB and MB had intense competition at COD: SO/- ratio of 5:1 for organic substrate. Further reduction in COD: SO/- ratio to 0.7:1, led to 100 % electron flow by SRB in the process. SRB and MB were inhibited by sulfide generation at 188mg L-1 and 80mg L-1 concentration respectively. On studying the effect of BESA on activity of methanogens it was found that lower pH (6.7-6.8) and BESA addition together has great influence on inhibition of methanogens without any effect to sulfidogens. |
Year | 2003 |
Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. EV-03-13 |
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) | Preeda Parkpian ;Satoh, Hiroyasu |
Scholarship Donor(s) | Government of Denmark (DANIDA) |