Effect and mechanism of changes in physical structure and chemical composition of new biochar on Cu(II) adsorption in an aqueous solution

To improve the adsorption effect of biochar on heavy metal Cu(II), we prepared new and explored its modification process influence original biochar’s physical structure chemical composition as well mechanism for Cu(II) in an aqueous solution. Through research work, have reached some significant conclusions: (1) The modified (M2–800) can adsorb at rate 98.039 mg g?1, 38.8 times higher than that C800 (2.525 g?1); (2) boosts etching pore expansion, helping enter inner surface adsorbent, but is still most essential fixation method Cu(II); (3) alkaline promotes formation oxygen-containing functional groups, which ?OH/?COOH iron ions would form C-O-Fe structures such hydroxyl bridges (Fe-O?) carboxy (Fe-OOC?); (4) Carboxyl primary site M2–800, M2–800 has electronegativity (?47.8 mV) larger pH (11.61), so be removed by electrostatic attraction precipitation.