The biosorption behaviour of arsenic(V) and cadmium(II) ions by unmodified and five types of chemically modified Chlorella vulgaris and Spirulina platensis was investigated. The biosorption rates of As(V) and Cd(II) in binary metal solutions were lower than those in sole metal systems, which exhibited a competition between As(V) and Cd(II) ions to occupy the active sites of the adsorbent. Among the five chemical reagents, NaCl and ZnCl₂ were the most suitable modifiers for improving the biosorption performance of C. vulgaris and S. platensis, respectively. The maximum biosorption capacities of As(V) and Cd(II) were: (a) 20.9 and 1.2 mg/g, respectively, for C. vulgaris modified with NaCl; (b) 24.8 and 29.4 mg/g, respectively, for S. platensis modified with ZnCl₂, which were much higher than those using other chemically modifying methods. The pseudo-second-order kinetic model fitted well with all the biosorption processes. The SEM analysis revealed that the modification changed the surface morphologies and enhanced the porosity of the algae biomass. The FTIR analysis established the presence of diverse groups of compounds that were largely hydroxyl, carboxylate, amino, and amide groups on the adsorbents that contributed significantly to the upregulated biosorption. This work showed the potential application of chemically modified C. vulgaris and S. platensis biomasses to effectively remove both from water.

中文翻译：

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砷和镉在化学改性普通小球藻和螺旋藻上的同时生物吸附

研究了未修饰和五种化学修饰的普通小球藻和螺旋藻对砷 (V) 和镉 (II) 离子的吸附行为。二元金属溶液中 As(V) 和 Cd(II) 的生物吸附率低于单一金属体系，这表现出 As(V) 和 Cd(II) 离子之间的竞争以占据吸附剂的活性位点。在五种化学试剂中，NaCl和ZnCl ₂分别是最适合提高C. vulgaris和S. platensis生物吸附性能的改性剂。As(V) 和 Cd(II) 的最大生物吸附能力为： (a) 对于C. vulgaris，分别为 20.9 和 1.2 mg/g用 NaCl 改性；(b)用 ZnCl ₂改性的S. platensis分别为 24.8 和 29.4 mg/g，远高于使用其他化学改性方法的那些。拟二级动力学模型与所有的生物吸附过程非常吻合。SEM 分析表明，改性改变了表面形态并提高了藻类生物质的孔隙率。FTIR 分析确定了吸附剂上存在多种化合物，这些化合物主要是羟基、羧酸盐、氨基和酰胺基团，它们对生物吸附的上调有显着贡献。这项工作显示了化学修饰的C. vulgaris和S. platensis的潜在应用 生物质有效地从水中去除两者。