Luus-Jaakola Method And Adm1 Based Optimization Of Hydrogen Sulfide In Anaerobic Digestion Of Cow Manure

Anaerobic digestion of cow manure is one of the preferred alternatives for reducing environmental impacts of cattle farming and producing biomethane. Full-scale biodigesters usually incorporate expensive motorized electric generators, whose life cycle is shortened by one of the trace components of biomethane, the corroding hydrogen sulfide, which is a metabolite of strict anaerobic digestion of rich-sulfate substrates. In this work, the extended mathematical model ADM1-S/O and the Luus-Jaakola method were employed to determine in silico the microaeration initiation time of biodigesters treating cow manure as a single substrate that minimizes the hydrogen sulfide production, while methane production remains at competitive levels (0.45 +/- 0.02 g of CH4/g of VS). Optimization results from the mathematical model showed that optimal microaeration initiation time is day 11, whereas oxygen concentration in the biodigester is 1.936 x 10(-4) ppm (equivalent to 0.52 g of O-2/kg of VS). Experimentally validation is evaluated (statistical significance for optimized parameters in the experimental fitting was >= 95 %, and CV-RMSE of 12.56 %) in a non-perfectly mixed batch bioreactor of bench-scale. Microbial consortia evolution is simulated to propose a more mechanistic and deeper explanation of the microaeration effect.