活性炭的改性及对Pb^(2+)的动力学吸附研究

Study on modification of activated carbon and kinetic adsorption of Pb^(2+)

论文以活性炭为主体吸附剂,进行氯化铁改性,制备出氯化铁改性活性炭吸附剂,并通过FT-IR、SEM、比表面积和孔体积进行表征。实验进一步探究改性活性炭对Pb^(2+)的吸附能力,结果表明,当吸附时间为300min,吸附剂投加量为0.4 g,pH为6时,吸附效果最佳。在此吸附条件下,改性活性炭对Pb^(2+)的去除率达到91.2%。对改性活性炭吸附Pb^(2+)进行动力学吸附研究,结果表明二级速率方程能够更好地描述其动力学吸附过程,吸附的机理可归结为氯化铁改性导致活性炭孔道结构中酸性官能团增加,使得金属阳离子与官能团上的H之间产生离子交换作用,有利于吸附的进行,这一实验结果为后期循环吸附研究提供了新依据。

In this paper,activated carbon is used as the main adsorbent,and ferric chloride is modified to prepare modified activated carbon adsorbent,which was characterized by FT-IR,SEM,specific surface area and pore volume.The experiment further explored the adsorption capacity of modified activated carbon for Pb^(2+).The results show that when the adsorption time is 300 min,the dosage of adsorbent is 0.4 g,and the pH is 6,the adsorption effect is the best.Under this adsorption condition,the removal rate of Pb^(2+)by modified activated carbon reaches 91.2%.The kinetic adsorption of Pb^(2+)on modified activated carbon was studied.The results show that the second-order rate equation can better describe the dynamic adsorption process,and the adsorption mechanism can be attributed to the increase of acidic functional groups in the pore structure of activated carbon caused by the modification of ferric chloride,which makes ion exchange between metal cations and H on functional groups,which is conducive to the adsorption.This experimental result provides a new basis for the later cycle adsorption research.