초록
<P><B>Abstract</B></P> <P>Given the limitations of acidogens and methanogens activities under saline environments, this work aims to optimize the main operational parameters affecting hydrogen and methane production from saline-to-hypersaline wastewater containing mono-ethylene glycol (MEG). MEG is the main contaminant in several saline industrial effluents. Anaerobic baffled reactor (ABR), as a multi-stage system, was used at different temperatures (i.e., 19–31 °C [ambient] and 35 °C), organic loading rates (OLRs) of 0.6–2.2 gCOD/L/d, and salinity of 5–35 gNaCl/L. Mesophilic conditions of 35 °C substantially promoted MEG biodegradability (92–98%) and hydrogen/methane productivity, even at elevated salinity. Hydrogen yield (HY) and methane yield (MY) peaked to 258 and 140 mL/gCOD<SUB>add</SUB>, respectively, at OLR 0.64 gCOD/L/d and salinity up to 20–25 gNaCl/L. An immobilized sludge ABR (ISABR), packed with polyurethane media, was further compared with classical ABR, resulting in 1.8-fold higher MY, at 35 gNaCl/L. Microbial analysis showed that introducing attached growth system (ISABR) substantially promoted methanogens abundance, which was dominated by genus <I>Methanosarcina</I>. Among bacterial genera, <I>Acetobacterium</I> was dominant, particularly in 1<SUP>st</SUP> compartment, representing MEG-degrading/salt-tolerant genus. At high salinity up to 35 gNaCl/L, the multi-phase and attached growth configuration can efficiently reduce the induced salt stress, particularly on methanogens, towards balanced and separated acidogenesis/methanogenesis. Overall, producing hydrogen and methane from anaerobic treatment of MEG-based saline wastewater is feasible at optimized parameters and configuration.</P> <P><B>Highlights</B></P> <P> <UL> <LI> H<SUB>2</SUB>/CH<SUB>4</SUB> bio-production from hypersaline effluent (up to 35 gNaCl/L) was assessed. </LI> <LI> Operational temperature and OLR were optimized to adapt different salinity levels. </LI> <LI> H<SUB>2</SUB>/CH<SUB>4</SUB> productivity peaked at low OLR and 35 °C under high salinity (20–25 gNaCl/L). </LI> <LI> Employing attached growth reactor further promoted methane by 80%, at 35 gNaCl/L. </LI> <LI> <I>Acetobacterium</I> and <I>Methanosarcina</I> dominated the bacterial and archaeal genera. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>