Mesophilic, Anaerobic Digestion in a Full-Scale, Commercial Biogas Reactor Kills Seeds More Efficiently than Lab-Scale Systems

When plant biomass is anaerobically digested, seeds may survive the energy production process and contaminate digestate. Hard-seeded (HS), i.e., physically dormant, species were found to be difficult inactivate. Here, we aimed verify this finding from lab-scale experimental reactors (ERs) in a full-scale commercial reactor (CR). In addition, tested seed survival pH-buffered water bath (WB). Seeds exposed CR, ER WB treatments at 42 °C for maximum of 36 days. The viability was checked by measuring germination response tetrazolium staining modeled as function exposure time using dose–response approach. CR killed more effectively than treatments. non-HS reference species, Chenopodium album, completely inactivated all Responses HS ranged complete inactivation insensitivity. most resistant Malva sylvestris. least mainly temperature, while additional mortality factors effective species. We concluded that mesophilic AD CRs can reduce risk contamination digestate but not Moreover, seem suitable estimate minimum CR.