Abuhatab Saqr, El-Qanni Amjad, Marei Nedal N, Hmoudah Maryam, El-Hamouz Amer
Chemical Engineering Department, An-Najah National University Nablus West Bank Palestine
Department of Chemical and Petroleum Engineering, University of Calgary Calgary Alberta Canada.
RSC Adv. 2019 Nov 1;9(61):35483-35498. doi: 10.1039/c9ra07001j. eCollection 2019 Oct 31.
The competitive adsorption of cationic and anionic model molecules; methylene blue (MB) and acid red 88 (AR88), respectively, in aqueous solutions onto NiO and/or MgO SBNs was studied. Adsorption isotherms, kinetics and pH effect were investigated in batch modes. Computational modeling was conducted on Acclerys Material Studio for MB and AR88 adsorption. pH study showed that the adsorption is strongly pH dependent, increases for MB while decreases for AR88 with increasing the pH from 4 to 11. Isotherm studies revealed that the Sips model was the best fit for both molecules in single cases, and thus the Extended-Sips model for the binary systems. The kinetics for the binary systems were well-described by the external mass transfer model; thus, film diffusion is the most dominant in the adsorption of both organic onto the SBNs. The adsorption uptakes in binary systems exceed 130 mg g for AR88 (167.7 MgO-SBNs, 132.93 NiO-SBNs, and 178.5 mg g NiO-MgO-SBN), while it reached an uptake of 76.2 MgO-SBNs, 81.5 NiO-SBNs, and 94.7 mg g NiO-MgO-SBNs for MB within the time needed to reach equilibrium (10 min). The adsorption of these two molecules in binary systems showed a synergistic effect onto the three types of SBNs, that enhanced the adsorption uptakes. Computational modeling confirmed the synergistic effect, the adsorption energy of binary systems was lower than that in single systems. Regeneration study was conducted over four adsorption cycles to confirm the sustainability of SBNs. They were stable under thermal oxidation at 400 °C, without any impact on the adsorption capacity.
研究了阳离子和阴离子模型分子，即亚甲基蓝（MB）和酸性红88（AR88）在水溶液中在NiO和/或MgO SBNs上的竞争吸附。采用分批模式研究了吸附等温线、动力学和pH值影响。利用Accelrys Material Studio对MB和AR88的吸附进行了计算建模。pH值研究表明，吸附强烈依赖于pH值，随着pH值从4增加到11，MB的吸附增加而AR88的吸附减少。等温线研究表明，Sips模型在单组分情况下对两种分子的拟合效果最佳，因此二元体系采用扩展Sips模型。二元体系的动力学可以用外部传质模型很好地描述；因此，膜扩散在两种有机物吸附到SBNs上的过程中起主导作用。二元体系中AR88的吸附量超过130 mg/g（167.7 MgO-SBNs、132.93 NiO-SBNs和178.5 mg/g NiO-MgO-SBN），而在达到平衡所需的时间（10分钟）内，MB在MgO-SBNs、NiO-SBNs和NiO-MgO-SBNs上的吸附量分别达到76.2 mg/g、81.5 mg/g和94.7 mg/g。这两种分子在二元体系中的吸附对三种类型的SBNs表现出协同效应，提高了吸附量。计算建模证实了协同效应，二元体系的吸附能低于单组分体系。进行了四个吸附循环的再生研究，以确认SBNs的可持续性。它们在400℃的热氧化条件下稳定，对吸附容量没有任何影响。
