106 / 2021-06-30 22:06:21

Adsorption characteristic of Pb(II) using corn stalk biochar and kinetic analysis

Biochar,Pb(II) removal,Adsorption characteristic,Kinetic analysis

The discharge of lead (Pb)-contaminated wastewater is a serious threat to the growth of animals and plants and even human life and health. Biochar is considered a potential adsorbent for removing heavy metals from wastewater because of its abundant surface functional groups and good pore structure, and the molecules on the pore wall with great adsorption force. In this paper, the adsorption and removal ability of Pb(II)-contaminated wastewater by biochar and its kinetic characteristics were studied. It was found that the adsorption of Pb(II) was dominated by heterogeneous adsorption of multi-molecular layers. The influence of solution pH, contact time and biochar concentration on the removal of Pb(II) was investigated by single factor design and response surface analysis. The results showed that the weak acid was more conducive to the ligand exchange between Pb(II) ions and biochar, and the pseudo-first-order model was more suitable to describe the adsorption process of Pb(II) by biochar. The optimal conditions were pH 5, the contact time 255 min and biochar concentration 3 g/L, in which the maximum predicted Pb(II) removal efficiency was 91.52%.