摘要
制备负载氧化锆的颗粒活性炭(Zr-GAC),以吸附水溶液中的硫酸根离子。采用扫描电镜(SEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)和比表面积测定等方法对Zr-GAC进行表征。结果表明,Zr-GAC具有多孔的表面积,其上具有许多由氧化锆组成的团聚体。XPS分析证实,吸附剂表面存在大量的锆和羟基,氧化锆改性后的活性炭比表面积减小。采用间歇吸附实验研究了pH值对硫酸盐吸附的影响,在pH值小于10时,吸附效果较好。吸附等温线的模拟分析表明,Dubinin-Radushkevich(D-R)方程比Langmuir模型具有更好的拟合性,由D-R方程确定的在中性水溶液最大吸附量为70.14mg/g,远高于原GAC(8.9mg/g)。需要注意的是,D-R方程在测定溶液吸附的吸附能时可能存在问题,值得进一步研究。动力学研究表明,硫酸根在Zr-GAC上的吸附速度较快,并遵循准二级动力学方程。此外,温度的升高在一定程度上可能利于硫酸盐的吸附。Zr-GAC具有很好的吸附水溶液中硫酸根离子的潜力,特别是其吸附容量约为载锆生物炭吸附剂的两倍,pH值的适用范围更广。
Zirconium oxide-loaded granular activated carbon(Zr-GAC)was prepared for the adsorption of sulfate ions in aqueous solution.The Zr-GAC was characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD),X-ray photoelecton spectroscopy(XPS),and specific surface area measurement.The results showed that the Zr-GAC had a porous surface with many aggregates,composed of zirconium oxides.XPS analysis confirmed the massive presence of zirconium and hydroxyl groups in the adsorbent surface.The specific surface area of the activated carbon decreased after modification with zirconium oxides.Batch adsorption experiments were conducted to determine the effect of pH on sulfate adsorption,and it was found that better adsorption could be achieved at pH lower than 10.Modeling analysis of the adsorption isotherms showed that the Dubinin-Radushkevich(D-R)equation had better fittings than the Langmuir model,and the maximum adsorption capacity of the Zr-GAC determined by the D-R equation was70.14 mg/g in neutral water solution,much higher than that of raw GAC(8.9 mg/g).The D-R equation may have a problem in determining the adsorption energy for a solution adsorption,which deserves more research.Kinetic studies show that the adsorption of sulfate on the Zr-GAC is relatively fast,and it follows the pseudo second-order kinetic equation.In addition,an increase of temperature may facilitate the sulfate adsorption,to some extent.The Zr-GAC showed good potential for the adsorption of sulfate ions in aqueous solution.It exhibited approximately twice the adsorption capacity and a much wider applicable range of pH compared with the zirconium-loaded biochar adsorbent.
作者
洪怡霞
曹威
敖涵婷
邢小蕾
李欣
HONG Yixia;CAO Wei;AO Hanting;XING Xiaolei;LI Xin(College of Civil Engineering,Huaqiao University,Xiamen 361021,Fujian,P.R.China)
出处
《土木与环境工程学报（中英文）》
CSCD
北大核心
2021年第1期203-214,共12页
Journal of Civil and Environmental Engineering
基金
National Natural Science Foundation of China(No.51408239)
Natural Science Foundation of Fujian Province(No.2016J01193)
the Fundamental Research Funds for the Central Universities(No.ZQN-712)
Subsidized Project for Postgraduates Innovative Fund in Scientific Research of Huaqiao University.
