Effect of additives on process stability of mesophilic anaerobic monodigestion of pig slaughterhouse waste

► Anaerobic monodigestion of pig slaughterhouse waste was studied in CSTRs at 35 °C. ► Effect of two additives on process stability was studied as well. ► Additive of trace elements, Fe and HCl improved process stability. ► Additive of trace elements, Fe and HCl allowed higher OLRs to be used. ► Additive of Fe and HCl reduced H2S from biogas, but did not facilate higher OLR.