Fig 1.
General view of the LAMACs and of components of one chemostat in the LAMACs module.
(A) 3D view of a LAMACs module, i.e., six chemostats. The electric box containing controlling cards is on the top of the module and above any source of liquids to prevent electric failure in case of leakage. A waterproof stirring plate is underneath the heating block containing the six reactor vessels. Three peristaltic pumps are aligned above each vessel. The upper range of bags is for biogas collection; the lower range serves as substrate reservoirs. The dimensions of one module are 50 cm width × 52 cm length × 100 cm height. (B) Schematic view of a chemostat detailing the use of the three-hose connector. One port is used as inlet for feeding, and two ports as outlet for biomass wasting and degassing. One port for manual sampling is sealed with a rubber stopper. A 0.45 μm pore-size filter is placed in the feedline ahead of the reactor to prevent contamination of the medium.
Table 1.
Detailed prices of major components required for the construction of one LAMACs module containing six reactors.
Detailed references for these items can be found in S1 Table.
Fig 2.
Stable temperature of the LAMACs during operation.
Average temperature and standard deviation over three days of operation at three different positions in the heating block. Data points were recorded every 15 minutes, with 280 total data points.
Fig 3.
Biogas production of four anaerobic digesters measured by the LAMACs.
A) Actual accumulated biogas over time (red curves) and linear regressions (blue lines) B) Biogas production rates derived from linear regressions.
Table 2.
Linear regression of biogas accumulation over time.
Fig 4.
Development of average weekly biogas production rates over time for anaerobic digesters with three different inocula.
Four replicated anaerobic digesters were operated per condition. White boxes stand for the INOC A condition, light gray boxes for INOC B and dark-gray boxes for INOC C. The Kruskal Wallis test was significant in the first eight weeks and the Dunn post hoc test for pairwise multiple comparison displays inocula differences with ‘*’ symbols. In weeks 4 to 6, the simple substrate was used instead of the complex substrate.
Fig 5.
Dynamics of biomass concentration for twelve anaerobic digesters over nine weeks.
Biomass concentration is expressed as volatile solids. A color code was applied by inoculum origin; Light gray stands for INOC A replicates, dark-gray stands for INOC B replicates and black stands for INOC C replicates. During weeks 4 to 6, a simple substrate with halved loading rate in terms of COD was applied to the reactors.