Continuous Enzymatic Prehydrolysis Treatment of High-Fat Wastewater
Rodrigo Augusto Franco de Oliveira Zawadzki1, Marcelo Real Prado2, David Alexander Mitchell3 and Nadia Krieger1*
1Department of Chemistry, Federal University of Paraná, Centro Politécnico, P.O. Box 19081, Curitiba 81531-980, Paraná, Brazil
2Department of Chemistry and Biology, Federal Technological University of Paraná, Av. Sete de Setembro, 3165, Curitiba 80230-901, Paraná, Brazil
3Department of Biochemistry and Molecular Biology, Federal University of Paraná, Centro Politécnico, P.O. Box 19046, Curitiba 81531-980, Paraná, Brazil
Article history:
Received May 13, 2012
Accepted March 8, 2013
Key words:
enzymatic hydrolysis, lipases, Rhizopus microsporus, high-fat wastewater, packed- -bed bioreactor
Summary:
A lipolytic fermented solid was produced by solid-state fermentation of Rhizopus microsporus CPQBA 312-07 DRM on a mixture of sugarcane bagasse and sunflower seed meal and used, in a packed-bed bioreactor, to pretreat a high-fat wastewater from a meat and sausage processing factory located in São José dos Pinhais, State of Paraná, Brazil. With a hydraulic residence time of 24 h, this pretreatment not only reduced the wastewater’s oil and grease content by up to 96 %, but also increased its 5-day biochemical oxygen demand to chemical oxygen demand (BOD5/COD) ratio. This ratio was only 0.19 in the raw wastewater, indicating poor biodegradability, but increased to 0.55 in the pretreated wastewater, indicating that it had a sufficiently high biodegradability to be sent to a traditional anaerobic digestion or activated sludge process. After 96 days of operation of the packed bed, a microbiological analysis showed that R. microsporus was still present and viable in the fermented solid. Our work shows that a continuous packed-bed bioreactor containing fermented solid produced by R. microsporus has good potential for the treatment of high-fat wastewater.
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