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Gehring T.,Ruhr University Bochum | Silva J.D.,Regional University of Blumenau | Kehl O.,TU Munich | Castilhos Jr. A.B.,Federal University of Santa Catarina | And 5 more authors.
Water Science and Technology | Year: 2010

In this paper an extended version of IWA's Activated Sludge Model No 3 (ASM3) was developed to simulate processes in waste stabilisation ponds (WSP). The model modifications included the integration of algae biomass and gas transfer processes for oxygen, carbon dioxide and ammonia depending on wind velocity and a simple ionic equilibrium. The model was applied to a pilot-scale WSP system operated in the city of Florianópolis (Brazil). The system was used to treat leachate from a municipal waste landfill. Mean influent concentrations to the facultative pond of 1,456 gCOD/m3 and 505 gNH4-N/m3 were measured. Experimental results indicated an ammonia nitrogen removal of 89.5% with negligible rates of nitrification but intensive ammonia stripping to the atmosphere. Measured data was used in the simulations to consider the impact of wind velocity on oxygen input of 11.1 to 14.4 gO2/(m2 d) and sun radiation on photosynthesis. Good results for pH and ammonia removal were achieved with mean stripping rates of 18.2 and 4.5 gN/(m2 d) for the facultative and maturation pond respectively. Based on measured chlorophyll a concentrations and depending on light intensity and TSS concentration it was possible to model algae concentrations. © IWA Publishing 2010. Source

Rojas C.,Institute For Umwelttechnik Eutec | Fang S.,Institute For Umwelttechnik Eutec | Uhlenhut F.,Institute For Umwelttechnik Eutec | Borchert A.,Institute For Umwelttechnik Eutec | And 2 more authors.
Engineering in Life Sciences | Year: 2010

Here, we present the results of lab-scale experiments conducted in a batch mode to determine the biogas yield of lipid-rich waste and corn silage under the effect of stirring. Further semi-continuous experiments were carried out for the lipid-rich waste with/without stirring. Additionally, it was analyzed how the starter used for the batch experiment influences the digestion process. The results showed a significant stirring effect on the anaerobic digestion only when seed sludge from a biogas plant was used as a starter. In this case, the experiments without stirring yielded only about 50% of the expected biogas for the investigated substrates. The addition of manure slurry to the batch reactor as part of the starter improved the biogas production. The more diluted media in the reactor allowed a better contact between the bacteria and the substrates making stirring not necessary. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA. Source

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