Nanoscale Zero-Valent Iron (NZVI) supported on sineguelas waste for Pb(II) removal from aqueous solution: Kinetics, thermodynamic and mechanism
Nanoscale Zero-Valent Iron (NZVI) supported on sineguelas waste for Pb(II) removal from aqueous solution: Kinetics, thermodynamic and mechanism
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DOI：
10.1016/j.jcis.2014.04.014
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发表时间：
2014-07-15
影响因子：
9.9
通讯作者：
SalimiVahid, F.
中科院分区：
文献类型：
--
作者：
Arshadi, M.;Soleymanzadeh, M.;SalimiVahid, F.
本研究以农业生物质为原料，研究了纳米级零价铁颗粒（NZVI）修饰猪粪渣（S-NaOH-NZVI）的新型吸附剂的合成与表征，并对其吸附/还原Pb（II）离子等无机污染物进行了研究。将ZVI颗粒组合在单叶麻废料表面，可以克服超细粉体容易团聚成较大颗粒的缺点，从而对有效表面积和催化剂性能产生不利影响。用FT-IR、BET、XRD、TEM和pH（PZC）等方法对合成的材料进行了表征。观察到NZVI颗粒（约10-70 nm）在单叶藻废料上有良好的分散。考察了接触时间、pH、浓度、吸附剂用量、温度等参数对吸附效果的影响。本文从准一级和准二级动力学的角度研究了Pb（II）离子的吸附，并采用Freundlich、Langmuir和Langmuir-Freundlich等温线模型计算了平衡吸附数据。吸附动力学遵循准二阶方程机理。热力学参数（δ G、δ H和δ S）表明，在25 ~ 80℃下吸附Pb（II）离子是可行的、自发的、吸热的。XRD分析表明，S- naoh - nzvi表面存在Pb(0)。该研究表明，NZVI颗粒改性的黑藻土废物可以低成本制备，并且该材料对环境无害，可以去除水中的Pb（II）离子，以及可能的许多其他重金属离子。(C) 2014爱思唯尔公司版权所有。
In this study, the synthesis and characterization of a new adsorbent containing nanoscale zerovalent iron particles (NZVI) decorated sineguelas waste (S-NaOH-NZVI) from agriculture biomass was investigated for the adsorption/reduction of inorganic pollution such as Pb(II) ions. The combination of ZVI particles on the surface of sineguelas waste can help to overcome the disadvantage of ultra-fine powders which may have strong tendency to agglomerate into larger particles, resulting in an adverse effect on both effective surface area and catalyst performance. The synthesized materials were characterized with different methods such as FT-IR, BET, XRD, TEM and pH(PZC). Good dispersion of NZVI particles (ca. 10-70 nm) on the sineguelas waste was observed. The effects of various parameters, such as contact time, pH, concentration, adsorbent dosage and temperature were studied. The adsorption of Pb(II) ions has been studied in terms of pseudo-first- and second-order kinetics, and the Freundlich, Langmuir and Langmuir-Freundlich isotherms models have also been used to the equilibrium adsorption data. The adsorption kinetics followed the mechanism of the pseudo-second-order equation. The thermodynamic parameters (Delta G, Delta H and Delta S) indicated that the adsorption of Pb(II) ions were feasible, spontaneous and endothermic at 25-80 degrees C. XRD analysis indicated the presence of Pb(0) on the S-NaOH-NZVI surface. This study suggests that the modified sineguelas waste by NZVI particles can be prepared at low cost and the materials are environmentally benign for the removal of Pb(II) ions, and likely many other heavy metal ions, from water. (C) 2014 Elsevier Inc. All rights reserved.