ABSTRACT Seagrass (Cymodocea nodosa) ability to remove cadmium and nickel ions from single metal solutions was investigated in the present study. Metal ions were measured in the solution using an atomic absorption spectrophotometer. Various operational parameters (initial pH, biomass dose, metal ion concentration, and contact time) were tested and found to affect the uptake capacity of Cd (II) and Ni (II). More than 70% of biosorption capacity occurred in the first few minutes for both metal ions. The pseudo-second-order kinetic model and the Langmuir model were found to best fit the experimental data of Cd (II) and Ni (II) biosorption. The maximum uptake capacity (qmax) was 11.6 and 16.7 mg.g−1 for Cd (II) and Ni (II), respectively. The biosorbent was characterised using Fourier transform infrared spectrometry (FTIR), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX). The infrared spectrum demonstrated that hydroxyl, carboxyl, and phenolic functional groups are the major binding sites for Cd (II) and Ni (II) metals. The ion exchange mechanism plays an important role during biosorption process as shown in EDX analysis. Our results conclude that marine macrophyte C. nodosa can be used as a low-cost biosorbent for the removal of Cd (II) and Ni (II) in wastewater.

中文翻译：

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利用海洋大型植物 Cymodocea nodosa 对镉和镍离子的生物吸附

摘要 本研究调查了海草 (Cymodocea nodosa) 从单一金属溶液中去除镉和镍离子的能力。使用原子吸收分光光度计测量溶液中的金属离子。测试了各种操作参数（初始 pH 值、生物质剂量、金属离子浓度和接触时间），发现它们会影响 Cd (II) 和 Ni (II) 的吸收能力。超过 70% 的生物吸附能力发生在最初几分钟内两种金属离子。发现伪二级动力学模型和朗缪尔模型最适合 Cd (II) 和 Ni (II) 生物吸附的实验数据。Cd (II) 和 Ni (II) 的最大吸收容量 (qmax) 分别为 11.6 和 16.7 mg.g-1。使用傅里叶变换红外光谱（FTIR）对生物吸附剂进行表征，扫描电子显微镜 (SEM) 和能量色散 X 射线光谱 (EDX)。红外光谱表明羟基、羧基和酚类官能团是 Cd (II) 和 Ni (II) 金属的主要结合位点。如 EDX 分析所示，离子交换机制在生物吸附过程中起着重要作用。我们的结果得出结论，海洋大型植物 C. nodosa 可用作去除废水中 Cd (II) 和 Ni (II) 的低成本生物吸附剂。