Department of Environmental Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 34212, Saudi Arabia.
Center for Environment and Water, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.
Molecules. 2021 Jul 14;26(14):4266. doi: 10.3390/molecules26144266.
A sewage sludge-based activated carbon (SBAC) intercalated MgAlFe ternary layered double hydroxide (SBAC-MgAlFe-LDH) composite was synthesized via the coprecipitation method. The adsorptive performance of the composite for phenol uptake from the aqueous phase was evaluated via the response surface methodology (RSM) modeling technique. The SBAC-MgAlFe-LDH phenol uptake capacity data were well-fitted to reduced RSM cubic model (R = 0.995, R-adjusted = 0.993, R-predicted = 0.959 and -values < 0.05). The optimum phenol adsorption onto the SBAC-MgAlFe-LDH was achieved at 35 °C, 125 mg/L phenol, and pH 6. Under the optimal phenol uptake conditions, pseudo-first-order and Avrami fractional-order models provided a better representation of the phenol uptake kinetic data, while the equilibrium data models' fitting follows the order; Liu > Langmuir > Redlich-Peterson > Freundlich > Temkin. The phenol uptake mechanism was endothermic in nature and predominantly via a physisorption process (ΔG° = -5.33 to -5.77 kJ/mol) with the involvement of π-π interactions between the phenol molecules and the functionalities on the SBAC-LDH surface. The maximum uptake capacity (216.76 mg/g) of SBAC-MgAlFe-LDH was much higher than many other SBAC-based adsorbents. The improved uptake capacity of SBAC-LDH was attributed to the effective synergetic influence of SBAC-MgAlFe-LDH, which yielded abundant functionalized surface groups that favored higher aqueous phase uptake of phenol molecules. This study showcases the potential of SBAC-MgAlFe-LDH as an effective adsorbent material for remediation of phenolic wastewater.
一种基于污水污泥的活性炭 (SBAC) 插层镁铝铁三元层状双氢氧化物 (SBAC-MgAlFe-LDH) 复合材料通过共沉淀法合成。通过响应面法 (RSM) 建模技术评估了该复合材料对水溶液中苯酚的吸附性能。SBAC-MgAlFe-LDH 对苯酚的吸附容量数据很好地符合简化的 RSM 立方模型 (R = 0.995，R-调整 = 0.993，R-预测 = 0.959 和 -值 < 0.05)。在 35°C、125mg/L 苯酚和 pH 6 的最佳条件下，SBAC-MgAlFe-LDH 对苯酚的吸附达到最佳。在最佳苯酚吸附条件下，准一级和 Avrami 分数阶模型更能代表苯酚吸附动力学数据，而平衡数据模型的拟合顺序为：Liu > Langmuir > Redlich-Peterson > Freundlich > Temkin。苯酚的吸附过程是吸热的，主要通过物理吸附过程 (ΔG° = -5.33 至 -5.77 kJ/mol) 进行，其中涉及到苯酚分子与 SBAC-LDH 表面官能团之间的π-π相互作用。SBAC-MgAlFe-LDH 的最大吸附容量 (216.76mg/g) 远高于许多其他基于 SBAC 的吸附剂。SBAC-LDH 吸附容量的提高归因于 SBAC-MgAlFe-LDH 的有效协同影响，它产生了丰富的功能化表面基团，有利于苯酚分子在水溶液中的更高吸附。本研究展示了 SBAC-MgAlFe-LDH 作为修复含酚废水的有效吸附剂材料的潜力。
