School of Chemical and Environmental Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China.
School of Chemical and Environmental Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China.
J Hazard Mater. 2021 Aug 15;416:125966. doi: 10.1016/j.jhazmat.2021.125966. Epub 2021 Apr 28.
Ammonia nitrogen and phenol are typical inorganic and organic pollutants in the coal chemical wastewater, respectively. In this study, the adsorption characteristics of ammonia nitrogen and phenol on lignite were investigated through experimental and molecular dynamics simulations. The results show that the adsorption of ammonia nitrogen was carried out via ion exchange, which was significantly faster than the adsorption of phenol driven by the π-π interaction. In the binary adsorption, the surface electronegativity of lignite decreased with the adsorption of ammonia nitrogen thereby promoting the adsorption of phenol. However, the extent of ammonia nitrogen adsorption was slightly reduced in the presence of phenol. Molecular dynamics simulation results indicated that the adsorption of phenol molecules on the lignite surface was closer than that of ammonium ion. The addition of ammonium ions could enhance the adsorption of phenol molecules on the lignite surface. The simulation results were well consistent with the experimental findings. This study indicates lignite has a promising potential in coal chemical wastewater adsorption pretreatment.
氨氮和苯酚分别是煤化工废水中典型的无机和有机污染物。本研究通过实验和分子动力学模拟，考察了褐煤对氨氮和苯酚的吸附特性。结果表明，氨氮的吸附是通过离子交换进行的，其吸附速率明显快于π-π相互作用驱动的苯酚吸附。在二元吸附中，随着氨氮的吸附，褐煤表面的电负性降低，从而促进了苯酚的吸附。然而，在苯酚存在的情况下，氨氮的吸附程度略有降低。分子动力学模拟结果表明，苯酚分子在褐煤表面的吸附比铵离子更紧密。添加铵离子可以增强苯酚分子在褐煤表面的吸附。模拟结果与实验结果吻合较好。该研究表明褐煤在煤化工废水吸附预处理方面具有广阔的应用前景。
