| Anaerobic digestion is one of the most efficient ways to metabolize organic waste. The development of mathematical model of anaerobic digestion is always the research focus and hot spot. In2002, the International Water Association released the Anaerobic Digestion Model No.1(ADM1)on the basis of predecessors’research results. These years has sawn ADM1’s application in simulating the bench scale, pilot scale and full scale reactors. Besides, it has also been adjusted to model the mesophilic and thermophilic processes, hydrogen and methan productions as well as the digestion of microalgae and biomass which gives a strong back support for ADMl’s universality. However, ADM1also lies its defection in including only continuous stirred tank reactor (CSTR) and easily degradable material like carbonhydrates, lipids and proteins and its defection in not including sulfate and nitrate reduction, etc. This research introduced the hydrodynamics of the upflow anaerobic sludge blanket (UASB) and also the refractory phenolic substrates into the original ADM1to extend its application, arriving the conclusions as follows.1. UASB reactor was regarded as several CSTRs in series. This multi-CSTRs model were able to model the tracer trajectory at the effluent port only with tracer early flushing out.When inserted with the biochemical kinetics, this ADM1-based multi-CSTRs model could give a good depiction of the shock loading experiments only with an extra sludge retention time between the tanks or the biomass would be discharged with the fluid leading the failure of the model.2. The convection-diffusion model was perfect in decribing differnet heights’ tracer concentration. When it’s combined with bio-dynamics, two loading shocks were used to calibrate and validate the ADM1-based dispersive model. The modeling result showed good agreement between the experimental and simulated data. In the shocks, propionate has accumulated much heavier than acetate. This model not only showed this trend well but also clearly presented the higher and quicker accumulation of the bottom ports. The simulation result proved that ADM1-based dispersive model is much more proper in simulating UASB reactors although a much longer time was required to aquire the calculation results.3. Phenol, as a refractory substrate, was introduced in ADM1. Its anaerobic fermentation process was simplified to its directly reduced to acetate and hydrogen. The degradation kinetics was revised to the Monod kinetics with a introduced self-inhibition parameter. The facilitation function of easily degradable glucose done to phenol was achieved by the introduction of parameter K. Two instances, namely the the co-metabolism of glucose and phenol and the sole phenol was used to validate the resonability of the developed model. The result showed this model’s feasibility.4. When m-crsol and phenol were both inserted to ADM1, m-cresol digestion process was reduced to via4-hydrogen-2-methyl benzoic acid to acetate and hydrogen. The degradation kinetics of m-cresol was also revised to the Monod kinetics with a introduced self-inhibition parameter. Meanwhile, as the mutual inhibition existing between the phenolic substrates, mutual inhibition parameters were also introduced. The promotion effect of gulcose was also achieved by the parameter K. The developed model was validated by two instances, the co-metabolism of glucose and phenolic substrates and the sole phenol and m-cresol digstion experiments. Simulating result showed good agreement between the experimental and calculated data which proved the resonability of the developed model. |
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