Afolabi Felicia Omolara, Musonge Paul
Department of Chemical Engineering, Durban University of Technology, Durban 4001, South Africa.
Institute of Systems Science, Durban University of Technology, Durban 4001, South Africa.
Molecules. 2023 Oct 12;28(20):7050. doi: 10.3390/molecules28207050.
In this study, orange peel (OP) biochar was used as a bio-sorbent for the removal of copper and lead from wastewater in single and binary systems. The equilibrium and kinetic studies were conducted at a pH value of 5, which was the maximum adsorption pH value for both metal ions. The equilibrium studies were investigated at a varying initial concentration (10-200 mg/L) with a constant dosage of 0.1 g, while the kinetic studies were conducted at a fixed initial concentration of 200 mg/L with a constant dosage of 1 g/L for both single and binary systems. The maximum adsorption capacity of the orange peel biochar was 28.06 mg/g, 26.83 mg/g, 30.12 mg/g and 27.71 mg/g for single Cu, binary Cu, single Pb and binary Pb systems, respectively. The Langmuir isotherm model fitted the experimental data, suggesting that adsorption occurred on a monolayer, while the pseudo-second-order model performed well with the kinetic data. The point of zero charge (pH) of the orange peel biochar was found to be 10.03, which revealed that the surface of the bio-sorbent contains basic groups. A Fourier infrared transform (FTIR) spectroscope and scanning electron microscope, coupled with energy dispersive x-ray (SEM-EDX) and x-ray diffraction analyses, were used to determine the functional groups, surface morphology, and inorganic elements present on the surface of the bio-sorbent, respectively. The results obtained have shown that orange peel biochar is efficient for the removal of Cu and Pb ions from an aqueous solution.
在本研究中，橙皮（OP）生物炭被用作生物吸附剂，用于在单一和二元体系中去除废水中的铜和铅。平衡和动力学研究在pH值为5的条件下进行，这是两种金属离子的最大吸附pH值。平衡研究在初始浓度变化（10 - 200 mg/L）且剂量恒定为0.1 g的条件下进行，而动力学研究在单一和二元体系中初始浓度固定为200 mg/L且剂量恒定为1 g/L的条件下进行。橙皮生物炭对单一铜、二元铜、单一铅和二元铅体系的最大吸附容量分别为28.06 mg/g、26.83 mg/g、30.12 mg/g和27.71 mg/g。Langmuir等温线模型拟合了实验数据，表明吸附发生在单分子层上，而伪二级模型与动力学数据拟合良好。发现橙皮生物炭的零电荷点（pH）为10.03，这表明生物吸附剂表面含有碱性基团。分别使用傅里叶红外变换（FTIR）光谱仪、扫描电子显微镜以及能量色散X射线（SEM - EDX）和X射线衍射分析来确定生物吸附剂表面存在的官能团、表面形态和无机元素。所得结果表明，橙皮生物炭对从水溶液中去除铜和铅离子是有效的。
