Potential of biohydrogen production from effluents of citrus processing industry using anaerobic bacteria from sewage sludge.
Citrus crops are among the most abundant crops in the world, which processing is mainly based on juice extraction, generating large amounts of effluents with properties that turn them into potential pollution sources if they are improperly discarded. This study evaluated the potential for bioconversion of effluents from citrus-processing industry (wastewater and vinasse) into hydrogen through the dark fermentation process, by applying anaerobic sewage sludge as inoculum. The inoculum was previously heat treated to eliminate H2-consumers microorganisms and improve its activity. Anaerobic batch reactors were operated in triplicate with increasing proportions (50, 80 and 100%) of each effluent as substrate at 37°C, pH 5.5. Citrus effluents had different effects on inoculum growth and H2yields, demonstrated by profiles of acetic acid, butyric acid, propionic acid and ethanol, the main by-products generated. It was verified that there was an increase in the production of biogas with the additions of either wastewater (7.3, 33.4 and 85.3mmolL-1) or vinasse (8.8, 12.7 and 13.4mmolL-1) in substrate. These effluents demonstrated remarkable energetic reuse perspectives: 24.0MJm-3and 4.0MJm-3, respectively. Besides promoting the integrated management and mitigation of anaerobic sludge and effluents from citrus industry, the biohydrogen production may be an alternative for the local energy supply, reducing the operational costs in their own facilities, while enabling a better utilization of the biological potential contained in sewage sludges.
Department of Analytical Chemistry, Institute of Chemistry of Araraquara, São Paulo State University (UNESP), CP 355, 14801-970 Araraquara, São Paulo, Brazil. Electronic address: liliantorquato@yahoo.com.br.
Lilian D M
LDM
Torquato
Center for Monitoring and Research of the Quality of Fuels, Biofuels, Crude Oil and Derivatives (CEMPEQC), Institute of Chemistry of Araraquara, São Paulo State University (UNESP), CP 355, 14801-970 Araraquara, São Paulo, Brazil.
Renan
R
Pachiega
Department of Analytical Chemistry, Institute of Chemistry of Araraquara, São Paulo State University (UNESP), CP 355, 14801-970 Araraquara, São Paulo, Brazil.
Marisa S
MS
Crespi
Center for Monitoring and Research of the Quality of Fuels, Biofuels, Crude Oil and Derivatives (CEMPEQC), Institute of Chemistry of Araraquara, São Paulo State University (UNESP), CP 355, 14801-970 Araraquara, São Paulo, Brazil.
Maurílio Gustavo
MG
Nespeca
Center for Monitoring and Research of the Quality of Fuels, Biofuels, Crude Oil and Derivatives (CEMPEQC), Institute of Chemistry of Araraquara, São Paulo State University (UNESP), CP 355, 14801-970 Araraquara, São Paulo, Brazil.
José Eduardo
JE
de Oliveira
Institute of Research on Bioenergy (IPBEN), São Paulo State University (UNESP), 13500-230 Rio Claro, São Paulo, Brazil. Electronic address: mainting2008@gmail.com.
Sandra I
SI
Maintinguer
D000693:Anaerobiosis; D001421:Bacteria, Anaerobic; D001673:Biodegradation, Environmental; D056804:Biofuels; D019149:Bioreactors; D002957:Citrus; D003362:Cost-Benefit Analysis; D018556:Crops, Agricultural; D005285:Fermentation; D005525:Food-Processing Industry; D005740:Gases; D006859:Hydrogen / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000032:analysis*; D012722:Sewage; D013696:Temperature; D014865:Waste Disposal, Fluid; D018505:Waste Management / Q000191:economics / Q000379:methods*; D062065:Wastewater
D056804:Biofuels; D005740:Gases; D006859:Hydrogen; D007220:Industrial Waste; D012722:Sewage; D062065:Wastewater
Agroenergy; Anaerobic digestion; Biohydrogen production; Citrus waste; Sewage sludge; Waste valorization