煤气化细渣制备碳硅复合材料吸附去除水中Pb2+

以煤气化细渣为原料制备了高比表面积碳硅复合材料,并利用过硫酸铵对其进行表面改性,用于吸附100.0 mg/L PbCl₂溶液中Pb²⁺。表征结果显示：碳硅复合材料的比表面积为1 347 m²/g,改性后降为474 m²/g;改性后材料表面的羟基、羰基和羧基等含氧基团的含量显著增加。实验结果表明：溶液pH为5时,改性碳硅复合材料对Pb²⁺的平衡吸附量为124 mg/g,Pb²⁺去除率可达98.2%;吸附过程符合准二级动力学模型,以化学吸附为主,伴有物理吸附;吸附过程分为外扩散和内扩散两个阶段,受内扩散控制。

Adsorption of Pb2+ from water by carbon-silica composite prepared from coal gasification fine slag

The carbon-silica composite with a high surface area was prepared using coal gasification fine slag as raw material and oxidized by ammonium persulfate for surface modification to absorb Pb²⁺from PbCl₂ solution（100.0 mg/L）. The characterization results indicated that：The BET surface area of the carbon-silica composite was 1 347 m²/g and deceased to 474 m²/g after modification;The amounts of oxygen-containing functional groups on the material surface,such as hydroxyl,carbonyl and carboxyl,increased significantly after modification. The experimental results showed that：When the solution pH was 5,the equilibrium adsorption capacity of Pb²⁺ on modified carbon-silica composite reached 124 mg/g and Pb²⁺ removal rate was 98.2%;The adsorption process followed the pseudo-second-order kinetics model and was mainly chemical adsorption,accompanied by physical adsorption;The adsorption process was divided into two adsorption stages of external diffusion and internal diffusion,and was controlled by internal diffusion.