Abstract：
The presence of phenazopyridine in water is an environmental problem that can cause damage to human health and the environment. However, few studies have reported the adsorption of this emerging contaminant from aqueous matrices. Furthermore, existing research explored only conventional modeling to describe the adsorption phenomenon without understanding the behavior at the molecular level. Herein, the statistical physical modeling of phenazopyridine adsorption into graphene oxide is reported. Steric, energetic, and thermodynamic interpretations were used to describe the phenomenon that controls drug adsorption. The equilibrium data were fitted by mono, double, and multi-layer models, considering factors such as the numbers of phenazopyridine molecules by adsorption sites, density of receptor sites, and half saturation concentration. Furthermore, the statistical physical approach also calculated the thermodynamic parameters (free enthalpy, internal energy, Gibbs free energy, and entropy). The maximum adsorption capacity at the equilibrium was reached at 298 K (510.94 mg g-1). The results showed the physical meaning of adsorption, indicating that the adsorption occurs in multiple layers. The temperature affected the density of receptor sites and half saturation concentration. At the same time, the adsorbed species assumes different positions on the adsorbent surface as a function of the increase in the temperature. Meanwhile, the thermodynamic functions revealed increased entropy with the temperature and the equilibrium concentration.
摘要：
水中非那唑吡啶的存在是一个环境问题，会对人类健康和环境造成损害。然而,很少有研究报道这种新出现的污染物从水性基质中的吸附。此外，现有的研究仅探索常规模型来描述吸附现象，而不了解分子水平的行为。在这里，报道了苯并吡啶在氧化石墨烯中吸附的统计物理模型。Steric,精力充沛，和热力学解释被用来描述控制药物吸附的现象。平衡数据用单声道拟合，双,和多层模型，考虑到吸附位点对苯并吡啶分子数量等因素，受体位点的密度，和半饱和浓度。此外，统计物理方法还计算了热力学参数(自由焓，内部能量，吉布斯自由能,和熵)。在298K（510.94mgg-1）时达到平衡时的最大吸附容量。结果表明吸附的物理意义,表明吸附发生在多层。温度影响受体位点的密度和半饱和浓度。同时,作为温度升高的函数，吸附物种在吸附剂表面上呈现不同的位置。同时,热力学函数显示熵随温度和平衡浓度的增加而增加。
