Electrolyte-aware benchmarking of anaerobic digestion-microbial electrolysis cells treating cattle manure
SUSTAINABLE CHEMISTRY AND PHARMACY, cilt.51, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 51
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.scp.2026.102433
- Dergi Adı: SUSTAINABLE CHEMISTRY AND PHARMACY
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Chemical Abstracts Core, EMBASE
- Orta Doğu Teknik Üniversitesi Adresli: Evet
Özet
Integrating microbial electrolysis cells (MECs) with anaerobic digestion (AD) has been reported to enhance methane production, yet the influence of electrolyte has not been systematically evaluated. In this study, we compared phosphate-buffered saline (PBS; 10-50 mM), carbonate buffer (CB; 30-120 mM), and a no-buffer (NB) baseline in single-chamber batch anaerobic digestion-microbial electrolysis cell (AD-MEC) reactors fed with cattle manure at an applied voltage of 0.7 V, alongside AD-only and open-circuit (OC) controls. NB AD-MECs provided the highest methane yield (310.1 +/- 7.4 mL CH4/g VSadded) and the fastest rate (40.4 +/- 0.6 mL/day). PBS showed a concentration-dependent decrease in methane yield; the lowest occurred in the 50 mM PBS OC control (167.1 +/- 0.9 mL/g VSadded). CB provided more balanced outcomes: at 30 mM, AD-MEC yield was similar to 15% higher than AD-only, while 120 mM CB reduced the methane yield. Within the same electrolytes, AD-MECs increased methane production rates by 5-24% compared to corresponding AD-only controls, but these gains largely diminished when benchmarked against NB controls, indicating that electrolytes can inflate apparent bioelectrochemical gains by shifting the baseline. Endpoint 16S rRNA profiles suggest electrolyte-associated differences, with PBS conditions enriching Geobacteraceae on anodes and hydrogenotrophic methanogens (e.g., Methanoculleus) on cathodes. Overall, these findings raise caution about the routine use of conventional electrolytes in AD-MECs, indicate that electrolyte selection influences methane production, and underline the importance of electrolyte-aware benchmarking (including no-buffer baselines where feasible) to support resource-efficient development of hybrid bioenergy technologies.