Effect of organic loading rate on the anaerobic digestion of swine waste with biochar addition

The aim of this study was to investigate the impact biochar addition on mesophilic semi-continuous anaerobic digestion swine waste with a focus effects organic loading rate (OLR) biogas production, methane yield, total volatile fatty acids (TVFA), alkalinity, ammonium, solids (VS) removal efficiency and process stability. Four reactors, two amended (R1 R2) without as controls (R3 R4), were operated at OLRs in range 2–7 g VS/(L d), which corresponded hydraulic retention times (HRTs) 7–2 days, respectively. initially caused an increase generation when compared control reactors 2 3 d). This behaviour could be attributed presence several trace elements (such Fe, Co, Ni Mn) biochar, are involved action acetyl-CoA synthase methyl coenzyme M reductase catalyse key metabolic steps, especially methanogenic stage. pH, TVFA TVFA/Alkalinity ratio values for effluents remained within optimal ranges process. It also found that OLR 2–5 d) determined proportional VS rate. However, increased up 7 drastic decrease reactors. Biochar amendment contributed more balanced state process, preventing biomass washout.