WARNV3Anolyte buffer capacity 20 mM/pH-unit is below the 25 mM/pH-unit floor for stable pH under load. Expect pH excursions.· Logan-group best practices; Cheng & Logan 2011
WARNV5Coulombic mass-balance is open on 8/10 sweep points (>5% closure error). Check substrate consumption + Q_measured.· Logan-group hygiene check; mass balance fundamentals
WARNV6Mean CE × OLR = 28.2 exceeds empirical Logan-group envelope (≤25). Mass transport limits CE at high loading; prediction may be optimistic.· Cheng & Logan 2011 — empirical envelope
Reproducing
Cusick RD, Bryan B, Parker DS, Merrill MD, Mehanna M, Kiely PD, Liu G, Logan BE (2011) — Applied Microbiology and Biotechnology
Performance of a pilot-scale continuous flow microbial electrolysis cell fed winery wastewater
DOI: 10.1007/s00253-011-3130-9
Metric
Reported
Predicted
Δ
Band
H₂ production rate
1000-L pilot, winery wastewater, 0.9 V applied, 20°C, HRT 24h — Period 2-3 average per Table 2
p. 2059, Table 2
0.19
m³ H₂ / m³ reactor / d
0.01
m³ H₂ / m³ reactor / d
-95.3%
red
Current density
pilot-scale operating current density across all modules at 0.9 V applied
p. 2058, Fig. 3
0.30
A/m²
0.34
A/m²
+13.7%
green
Coulombic efficiency
cathodic H₂ recovery (rCAT) — fraction of current that ended up as H₂ rather than methane or biomass; mapped to the `coulombic` series since the new MEC closure reports rCAT in that slot
p. 2059, Table 2
22.0
%
12.8
%
-41.8%
amber
COD removal
COD removal across the continuous-flow campaign average at 0.9 V applied
p. 2057, §Results
62.0
%
51.7
%
-16.6%
green
Δ-bands per Logan & Regan 2006 lab-to-lab reproducibility envelope: green ≤±25%, amber ±25–50%, red >±50%. Predictions from Butler-Volmer + Ohmic + Tafel closure calibrated against the Logan corpus (regression-tested in butler-volmer-calibration.test.ts).
What we don't know about this paper (6 items)
BV MODEL CALIBRATION IS MFC-ONLY. This preset is the first MEC in the registry and the BV closure was not calibrated against MEC kinetics. Predicted H₂ rate, current density, and CE for MEC configurations are EXTRAPOLATED, not calibrated — Logan & Regan ±25% reproducibility does NOT apply.
The paper's headline negative result (methanogen takeover) is NOT modeled by BV. The V9 `validateMethanogenTakeover` validator surfaces a warning for HRT > 24h × T > 30°C configurations — Cusick 2011 ran at 20°C with HRT 24h, so even the validator does not fire. This is a known gap in the closure for cold-pilot conditions.
CE = 22% is the paper's `rCAT` (cathodic recovery), not the conventional MFC CE. They are NOT the same quantity — `rCAT` is the fraction of current that ended up as H₂; conventional CE is the fraction of substrate-electrons that ended up in current. We map to `coulombic` for the side-by-side, but the comparison is APPROXIMATE.
Winery wastewater is a non-canonical substrate (high in ethanol + sugars + tartaric acid). The BV map's `mixed_anaerobic` culture parameters were fit to domestic wastewater + acetate; winery-specific kinetics are not in the closure.
The pilot ran with stainless-steel cathodes — much higher overpotential than Pt. The BV map treats `stainless_steel` as a known low-activity material; the predicted voltage should track but the current density floor may be optimistic.
The 1000-L reactor is ~10⁴× larger than Liu-Logan 2004 (5 mL). Pilot-scale flow distribution + module connectivity matter more than chemistry at this scale; the BV closure has no flow-distribution term.