Seasonal characterization of sugarcane vinasse: Assessing environmental impacts from fertirrigation and the bioenergy recovery potential through biodigestion

Author(s)

Fuess, Lucas Tadeu ^[1] ; Garcia, Marcelo Loureiro ^[2] ; Zaiat, Marcelo ^[1]

Affiliation

^[1] Univ Sao Paulo, Sao Carlos Sch Engn EESC, Biol Proc Lab LPB, Av Joao Dagnone 1100, BR-13563120 Sao Carlos, SP - Brazil

^[2] Sao Paulo State Univ UNESP, Inst Geosci & Exact Sci IGCE, Campus Rio Claro, Av 24-A, 1515, BR-13506900 Rio Claro, SP - Brazil

• Document type: Journal article
• Source: Science of The Total Environment; v. 634, p. 29-40, SEP 1 2018.
• Web of Science Citations: 15

Abstract

Sugarcane vinasse has been widely used as a soil fertilizer in the Brazilian sucro-alcohol industry for recycling potassium and water. However, the potential negative effects fromlong-termsoil fertirrigation represent a major drawback regarding this practice, whereas the application of biodigestion represents an efficient method for reducing the polluting organic load and recovering bioenergy from vinasse. Regardless of the predicted use for vinasse, an understanding of the potential of each option is imperative, as the seasonal alterations in the inorganic/organic fractions of vinasse directly affect itsmanagement. In this context, this study presents a detailed compositional characterization of sugarcane vinasse from a large-scale Brazilian biorefinery throughout the 2014/2015 harvest to assess the environmental effects (due to fertirrigation) and to estimate the biogas energetic potential. Calculated inputs of organic matter into soils due to vinasse land application were equivalent to the polluting load of populations (117-257 inhab ha(-1)) at least 2-fold greater than the largest Brazilian capital cities (78-70 inhab ha(-1)). Two-phase biodigestion could efficiently reduce the polluting load of vinasse (23-52 inhab ha(-1)) and eliminate the negative effects from direct sulfide emissions in the environment. However, a high risk of soil sodification could result from using high doses of Na-based alkalizing compounds in biodigestion plants. Finally, the optimized recovery of bioenergy through biogas (13.3-26.7 MW as electricity) could supply populations as large as 305 thousand inhabitants, so that over 30% of the surplus electricity produced by the studied biorefinery could be obtained from biogas. Overall, applying biodigestion in the treatment of vinasse provides important environmental and energetic gains. However, the benefits of reducing the polluting organic load of vinasse through bioenergy recovery may lose their effect depending on the alkalizing strategy, indicating that the proper use of chemicals in full-scale biodigestion plants is imperative to attain process sustainability. (C) 2018 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 09/15984-0 - Bioenergy production from wastewaters and environmental fitting of liquid and solid wastes generated
• Grantee: Marcelo Zaiat
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 12/15606-9 - Thermophilic anaerobic biodigestion of vinasse in combined acidogenic-methanogenic systems to enhance bioenergy recovery in first generation sugarcane biorefineries
• Grantee: Lucas Tadeu Fuess
• Support Opportunities: Scholarships in Brazil - Doctorate