Toxic effects of cadmium (Cd2+) on anaerobic biomass: Kinetic and metabolic implications

► The increase of cadmium concentration affected the organic matter removal efficiency. ► The operation of the bioreactor was stable up to a critical concentration of cadmium (29.8 mg Cd2+ L−1). ► Metabolic pathways can be altered by the presence of cadmium with formation of longer chain organic acids. ► A kinetic model of competitive inhibition adjusted well to the toxic effect of cadmium.