Fermentative biohydrogen production from a novel combination of vermicompost as inoculum and mild heat-pretreated fruit and vegetable waste

Document Type: Research Paper

Authors

1 Centro de Investigación y Transferencia en Ingeniería Química Ambiental (CIQA), Facultad Regional Córdoba, Universidad Tecnológica Nacional, Maestro López esq. Cruz Roja Argentina, 5016 Córdoba, Argentina.

2 Centro de Investigación en Nanociencia y Nanotecnología (NANOTEC), Facultad Regional Córdoba, Universidad Tecnológica Nacional, Maestro López esq. Cruz Roja Argentina, 5016 Córdoba, Argentina.

3 Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB Buenos Aires, Argentina.

Abstract

This study reports for the first time on biohydrogen production by dark fermentation using a novel combination of mild heat-pretreated fruit and vegetable waste (FVW) as raw material and vermicompost as an economical source of hydrogen-producing bacteria. A suspension rich in reducing sugars obtained from FVW was used at different initial concentrations (5 to 25 g reducing sugars/L) during the bioprocess conducted in batch reactors at mesophilic temperature of 35 °C. The use of a mild heat-pretreated substrate and the consequent elimination of the natural microbiota present in the FVW led to higher hydrogen production than the control. Clostridium species, hydrogen-producing bacteria via butyric acid fermentation pathway, were the dominant microorganisms in the bioprocess. Hydrogen production, volumetric hydrogen production rate, and pretreated substrate degradation efficiency (63.0 mL/g VS, 372.6 mL/L/d, and 50% BOD5, respectively) obtained in the experiments performed with the highest substrate concentration demonstrated that the developed bioprocess was promising simultaneously leading to high hydrogen contents in biogas and high substrate removal efficiencies.

Graphical Abstract

Fermentative biohydrogen production from a novel combination of vermicompost as inoculum and mild heat-pretreated fruit and vegetable waste

Highlights

  • Fruit and vegetable waste can be used as low-cost substrate for biohydrogen production.
  • Vermicompost was used as novel source of hydrogen-producing bacteria.
  • Use of mild heat-pretreated FVW substrate markedly enhanced biohydrogen yield.
  • Clostridium species were the dominant microorganisms in the bioprocess.
  • Biohydrogen production through FVW valorization using the developed process was found promising.

Keywords


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