From Abby Tamkin on her EcoSummit presentation:
“We looked at the effect of loading rate on performance in lab-scale anaerobic digesters that were modeled after a temperate climate (like Ohio’s). We used the temperatures experienced by our pilot-scale digester at (CFAES’s) Waterman dairy farm to create a simplified temperature schedule for the lab-scale study […]
“The digester with the lowest loading rate — longest retention time, the bacteria had a long time to decompose the material — was able to recover from the simulated winter and produce biogas again, while the digesters with the higher organic loading rates ‘soured’ as the temperature decreased — the pH dropped and they stopped producing biogas.”