Anaerobic treatment of sugar cane vinasse: treatability and real-scale operation

Autor: Mauricio Passeggi, Liliana Borzacconi, Iván López
Rok vydání: 2017
Předmět:
Zdroj: Journal of Chemical Technology & Biotechnology. 93:1320-1327
ISSN: 0268-2575
DOI: 10.1002/jctb.5493
Popis: BACKGROUND Vinasse is a wastewater from the bioethanol production with a very high concentration of organic matter, usually from 40 to 80 gCOD/L. These features make this wastewater attractive for treatment in an anaerobic system. Anaerobic processes allow the valorisation of this highly polluting wastewater as an energy resource in an environmentally friendly way. RESULTS A multiscale approach was followed, using batch tests, continuous bench scale reactors, and a full-scale UASB reactor. Potential inhibition due to high potassium concentrations was evaluated. From batch tests was determined the IC50 of the potassium concentration around 6 g/L, but continuous reactors could adapt the biomass to this concentration level without removal efficiency decay. A load of 20 gCOD/L.d with chemical oxygen demand (COD) removal efficiencies between 60% and 80% were reached in bench scale UASB and EGSB reactors. Finally, a 100 m3 UASB reactor located in a distillery was tested under industrial conditions. A load of 0.6 kgCOD/kgV SS.d was achieved with a COD removal efficiency of 78%. CONCLUSION Although potassium was inhibitory for the inoculum, the sludge from a continuously operated reactor can be adapted to high potassium concentrations without affecting its performance. The real possibility of working with undiluted vinasse was also verified. For distilleries like the Uruguayan case, which produces 18000 m3 of bioethanol per year, 5x106 m3 of biogas per year, with 68% methane, could be expected, representing an energy potential of about one-third of the main fuel produced.
Databáze: OpenAIRE
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