Environ Sci Pollut Res Int. 2014 Feb;21(3):2054-63. doi: 10.1007/s11356-013-2112-0.
A comparative study using native garlic peel and mercerized garlic peel as adsorbents for the removal of Pb(2+) has been proposed. Under the optimized pH, contact time, and adsorbent dosage, the adsorption capacity of garlic peel after mercerization was increased 2.1 times and up to 109.05 mg g(-1). The equilibrium sorption data for both garlic peels fitted well with Langmuir adsorption isotherm, and the adsorbent-adsorbate kinetics followed pseudo-second-order model. These both garlic peels were characterized by elemental analysis, Fourier transform infrared spectrometry (FT-IR), and scanning electron microscopy, and the results indicated that mercerized garlic peel offers more little pores acted as adsorption sites than native garlic peel and has lower polymerization and crystalline and more accessible functional hydroxyl groups, which resulted in higher adsorption capacity than native garlic peel. The FT-IR and X-ray photoelectron spectroscopy analyses of both garlic peels before and after loaded with Pb(2+) further illustrated that lead was adsorbed on the through chelation between Pb(2+) and O atom existed on the surface of garlic peels. These results described above showed that garlic peel after mercerization can be a more attractive adsorbent due to its faster sorption uptake and higher capacity.
提出了一种以原生蒜皮和丝光蒜皮为吸附剂去除 Pb(2+)的对比研究。在优化的 pH 值、接触时间和吸附剂用量下，丝光化蒜皮的吸附容量增加了 2.1 倍，达到 109.05mg/g。两种蒜皮的平衡吸附数据均符合 Langmuir 吸附等温线，吸附剂-吸附质动力学遵循拟二级模型。两种蒜皮均通过元素分析、傅里叶变换红外光谱（FT-IR）和扫描电子显微镜进行了表征，结果表明，丝光化蒜皮比原生蒜皮提供了更多的微孔作为吸附位点，其聚合度较低、结晶度较低、更多的功能羟基基团更易接近，从而具有更高的吸附能力。对负载 Pb(2+)前后两种蒜皮的 FT-IR 和 X 射线光电子能谱分析进一步表明，Pb(2+)通过与蒜皮表面存在的 O 原子之间的螯合作用被吸附在蒜皮上。上述结果表明，由于丝光化蒜皮具有更快的吸附速率和更高的容量，因此它可以作为一种更有吸引力的吸附剂。
