Modeling and mechanism of the adsorption of proton onto natural bamboo sawdust

► The properties of surface reactivity of Natural bamboo sawdust were analyzed. ► NEM surface complexation models gave a good fitting results. ► Different fitting starting points gave different fitting results. ► Two possibilities were used to explain such difference of titration between acid and alkali side. ► Pznpc, Pzc and Iep of sawdust were characterized.