Characterisation of dissolved organic matter in fermentation industry effluents and comparison with model compounds

Jeraz Cooper; Alice Antony; Audrey Luiz; John Kavanagh; Amir Razmjou; Vicki Chen; Greg Leslie

doi:10.1016/j.chemosphere.2019.05.272

Characterisation of dissolved organic matter in fermentation industry effluents and comparison with model compounds

Chemosphere. 2019 Nov:234:630-639. doi: 10.1016/j.chemosphere.2019.05.272. Epub 2019 May 30.

Authors

Jeraz Cooper¹, Alice Antony¹, Audrey Luiz², John Kavanagh², Amir Razmjou¹, Vicki Chen³, Greg Leslie¹

Affiliations

¹ UNESCO Centre for Membrane Science and Technology, School of Chemical Engineering, The University of New South Wales, Sydney, 2052, Australia.
² School of Chemical and Biomolecular Engineering, Chemical Engineering Building J01, The University of Sydney, NSW, 2006, Australia.
³ UNESCO Centre for Membrane Science and Technology, School of Chemical Engineering, The University of New South Wales, Sydney, 2052, Australia; School of Chemical Engineering, University of Queensland, Queensland, 4072, Australia. Electronic address: amirr@unsw.edu.au.

PMID: 31229724
DOI: 10.1016/j.chemosphere.2019.05.272

Abstract

Advanced organic characterisation methods were used to investigate the suitability of lab-based model compounds as surrogates to mimic the dissolved organic matter (DOM) of both first and second generation fermentation industry effluents. Comparisons to both humic acid and synthetic melanoidin revealed the limitations of using these model organic compounds in treatment studies of biorefinery effluent. Rapid resin fractionation (RRF) of effluent from yeast cultivated on molasses suggests that 64% of the dissolved organic matter is present in the form of very hydrophobic acid (VHPhoA) compounds. Molecular weight distribution by size exclusion chromatography (LC-OCND) and fluorophore specific intensity by fluorescence excitation and emission matrix (FEEM) of the yeast effluent was comparable to signatures from humic acid. This indicates that humic acid would be a suitable model compound for oxidation, adsorption and filtration studies. Differences among the fermentation industry effluents were found to be inherently dependent on both the biochemistry of yeast and processes used. RRF and FEEM spectra of effluent from bioethanol production on cellulosic feed highlighted a preponderance of neutral compounds with fluorophore specific intensity characteristic of non-humic compounds with a higher fraction of neutral compounds (41%) relative to VHPhoA (38%), SHPhoA (16%) and HPhi (5%) moieties. Findings were not consistent with commercial humics, synthetic melanoidins or other cellulosic and lignocellulosic based effluents from Kraft and Thermomechanical pulp mills since the actual pollutants are heavily dependent on the pre-treatment process. This suggests further work is required to develop a model compound for treatment studies of effluent from second generation bio-refineries.

Keywords: Bioethanol; Dunder; Fluorescence excitation emission matrix (FEEM); Lignocellulose; Liquid Chromatography–Organic carbon detection (LC–OCND); Synthetic melanoidin.

MeSH terms

Adsorption
Environmental Pollutants / analysis
Fermentation*
Filtration
Humic Substances* / analysis
Models, Theoretical*
Organic Chemicals*
Waste Disposal, Fluid / methods*

Substances

Environmental Pollutants
Humic Substances
Organic Chemicals