Marine macroalga Sargassum horneri as biosorbent for heavy metal removal: roles of calcium in ion exchange mechanism.
Marine macroalga Sargassum horneri as biosorbent for heavy metal removal: roles of calcium in ion exchange mechanism.
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DOI：
10.2166/wst.2008.696
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发表时间：
2008-08
期刊：
影响因子：
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通讯作者：
B. Southichak;K. Nakano;M. Nomura;N. Chiba;Osamu Nishimura
中科院分区：
文献类型：
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作者：
B. Southichak;K. Nakano;M. Nomura;N. Chiba;Osamu Nishimura
褐海藻马尾藻是一种散布在海岸上的麻烦生物质，被用作从水溶液中去除 Pb(II) 的生物吸附剂。 CaCl(2)预处理增强了褐海藻对Pb(II)的吸附，Langmuir吸附等温方程显示最大容量Q(max)为0.696 mmol/g，b值为94.33 L/mmol。由Langmuir吸附等温线模拟模型推导出的质量平衡方程得出的结果表明，褐藻生物吸附剂的吸附性能足以降低Pb(II)的浓度，使其符合WHO指南的范围。使用 pH 监测、吸附速率和离子交换模型阐明的机制涉及金属溶液 pH 值的快速变化，从而导致生物吸附过程的前 30 分钟内反应速率高和 Pb(II) 吸收。能量X射线分析结果证实了生物吸附剂吸附Pb(II)后钙含量急剧降低。从生物吸附剂中释放的钙离子量约为Pb(II)吸附量的1.5倍，证明了钙在离子交换机制中的作用。这些吸附平衡和机理研究为生物吸附过程的系统设计和性能预测提供了有用的信息。
Brown seaweed Sargassum horneri, a troublesome biomass scattered along the seashore, was utilized as a biosorbent for Pb(II) removal from aqueous solutions. The Pb(II) adsorption by brown seaweed was enhanced by pretreatment with CaCl(2), and the Langmuir adsorption isotherm equation showed a maximum capacity of a Q(max) of 0.696 mmol/g and a b value of 94.33 L/mmol. Results obtained from the mass-balance equation derived from the simulation model of the Langmuir adsorption isotherm suggested that the adsorption performance of brown seaweed biosorbent was sufficient to reduce the concentration of Pb(II) to meet the range of WHO guideline. The mechanism, as elucidated using pH monitoring, adsorption rate and ion exchange model, involved the rapid pH change of metal solutions that led to high reaction rate and Pb(II) uptake in the first 30 min of the biosorption process. The energy X-ray analysis's result confirmed the sharp reduction of calcium content in the biosorbent after Pb(II) adsorption. The amount of calcium ions released from the biosorbent was about 1.5 times the amount of Pb(II) adsorbed and proved the role of calcium in the ion exchange mechanism. These adsorption equilibrium and mechanistic studies provide useful information for system design and performance prediction of biosorption processes.