Centre of Studies in Surface Science and Technology, School of Chemistry, Sambalpur University, Jyoti Vihar, Burla, Odisha, 768019, India.
CSIR-Institute of Minerals and Materials Technology, Bhubaneswar, Odisha, 751013, India.
Environ Sci Pollut Res Int. 2020 Jul;27(19):24284-24298. doi: 10.1007/s11356-020-08482-0. Epub 2020 Apr 18.
In the present study, a geopolymer from dolochar ash was synthesized and used for the removal of heavy metal ions such as Co(II), Ni(II), Cd(II), and Pb(II) from the aqueous solution through the adsorption process. The geopolymer was characterized by a series of analytical techniques. The XRD pattern revealed the loss of dolochar ash crystallinity on geoploymerization. The peak at 982 cm observed in the FTIR spectrum due to Si-O-Si and Si-O-Al bonds confirmed the formation of geopolymer. BET surface area analyses indicated the mesoporous nature of the sample. The adsorption experiments revealed the higher removal efficiency of the geopolymer in comparison with the feed dolochar ash. The effects of different experimental factors such as pH, temperature, reaction time, and initial concentration of metal ions on metal uptake efficiency were evaluated to optimize the removal efficiency. The maximum removal of 98-99% was achieved when the pH, temperature, and initial metal ion concentration were 7.8, 343 K, and 10 ppm, respectively. The adsorption process followed the pseudo-second-order rate equation and validated the Langmuir adsorption model. Thermodynamic parameters such as ΔH, ΔS, and ΔG confirmed that the process to be spontaneous and endothermic. This geopolymer was found to compete efficiently with many adsorbents reported in the literature for water treatment.
在本研究中，通过吸附过程，从水溶液中去除重金属离子（如 Co(II)、Ni(II)、Cd(II)和 Pb(II)），合成了一种来自多水高岭石灰的地质聚合物。该地质聚合物通过一系列分析技术进行了表征。XRD 图谱显示，在地质聚合过程中多水高岭石灰的结晶度丧失。FTIR 光谱中观察到的 982cm 处的峰归因于 Si-O-Si 和 Si-O-Al 键，证实了地质聚合物的形成。BET 表面积分析表明样品具有中孔性质。吸附实验表明，与原灰相比，地质聚合物的去除效率更高。评估了不同实验因素（如 pH 值、温度、反应时间和金属离子初始浓度）对金属去除效率的影响，以优化去除效率。当 pH 值、温度和初始金属离子浓度分别为 7.8、343K 和 10ppm 时，去除效率达到了 98-99%。吸附过程遵循准二级速率方程，并验证了 Langmuir 吸附模型。热力学参数如ΔH、ΔS 和ΔG 证实该过程是自发和吸热的。该地质聚合物被发现与文献中报道的许多用于水处理的吸附剂相比，具有高效的竞争能力。
