Biochar obtained from cinnamon and cannabis as effective adsorbents for removal of lead ions from water.

The feedstock from cinnamon (CI) and cannabis (CA) were used for providing biochar at different temperatures using the pyrolysis method (300, 400, and 600 °C) as appropriate adsorbents for removing Pb(II) ions. The properties of materials were examined with varied techniques. The BET surface area of CI600 and CA600 was higher compared with others. The adsorption efficiency of Pb(II) ions relies on initial Pb(II) concentration, pH, adsorbent dose, equilibrium time, and temperature. The adsorption isotherms of Pb(II) ions were assessed via Langmuir adsorption isotherm and the pseudo-second-order model and electrostatic interaction became visible to play the main role in the adsorption process.