摘要
To improve the adsorption effect of biochar on heavy metal Cu(II),we prepared new biochar and explored its modification process influence on original biochar’s physical structure and chemical composition as well as its adsorption mechanism for Cu(II)in an aqueous solution.Through research work,we have reached some significant conclusions:(1)The modified biochar(M2-800)can adsorb Cu(II)at the rate of 98.039 mg g–1,38.8 times higher than that of the original biochar C800(2.525 mg g–1);(2)The biochar modification process boosts its etching and pore expansion,helping Cu(II)enter the inner surface of the adsorbent,but chemical adsorption is still the most essential fixation method for Cu(II);(3)The alkaline modification process promotes the formation of oxygen-containing functional groups,in which–OH/–COOH and iron ions would form C-O-Fe structures such as hydroxyl bridges(Fe-O–)and carboxy bridges(Fe-OOC–);(4)Carboxyl is the primary site of Cu(II)fixation in M2-800,and M2-800 has higher electronegativity(–47.8 mV)and larger pH(11.61),so that Cu(II)can be removed by electrostatic attraction and precipitation.
基金
the National Natural Science Foundation of China(41571283)
the National Key Research and Development Program of China(2018YFD0800703,2016YFD0800702)
the Fundamental Research Funds for the Central Universities(2662018PY078).
