Preparation of a porous hydroxyapatite-carbon composite with the bio-template of sugarcane top stems and its use for the Pb(II) removal
Preparation of a porous hydroxyapatite-carbon composite with the bio-template of sugarcane top stems and its use for the Pb(II) removal
复制标题
以甘蔗顶茎生物模板制备多孔羟基磷灰石-碳复合材料及其去除Pb(II)的应用
DOI：
10.1016/j.jclepro.2018.03.275
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发表时间：
2018
影响因子：
11.1
通讯作者：
Ju Lin
中科院分区：
文献类型：
--
作者：
Yinian Zhu;Yanhong Jiang;Zongqiang Zhu;Huan Deng;Hui Ding;Yanhong Li;Lihao Zhang;Ju Lin
成熟的甘蔗作物在收获时以顶部的形式产生大量的残留物。本工作的目的是使用废弃的顶部收获的甘蔗作为一个潜在的原材料，从水溶液中去除重金属。以甘蔗茎为原料，经碳化处理后，依次用饱和石灰水溶液和0.02 mol/L（NH 4）2 HPO 4溶液掺杂5次，制备了具有甘蔗茎多级孔结构的羟基磷灰石-炭吸附剂（SS-HAP/C）。SS-HAP/C的形态特征主要表现为贮藏薄壁细胞的大孔（宽30-115 μm）、平行排列的导管（宽20-85 μm）、厚壁厚壁细胞（宽30 μm）、导管和细胞壁上的纹孔（宽4.0 μm）。通过压汞法和Brunauer-Emmett-Teller（BET）比表面积分别估计为5.63 m2/g和8.52-28.44 m2/g。对于在50、100、150和200 mg/L的初始Pb（II）浓度下的测试，未粉碎的SS-HAP/C（>3 mm）的去除能力被确定为分别为52.62、101.85、152.08和210.69 mg/g，这与合成纳米羟基磷灰石的吸附能力相当。SS-HAP/C对Pb（II）离子具有良好的吸附性能。通过离子交换（x = 0.01-0.05）和溶解-沉淀（x = 0.20-0.21）过程形成的（PbxCa 1 + x）5（PO 4）3（OH）固溶体是吸附Pb（II）的主要机制。
A mature crop of sugarcane produces large amount of residue at harvest in the form of tops. The aim of the present work was to use the discarded tops of harvested sugarcane as a potential raw material for the removal of heavy metals from aqueous solution. A hydroxyapatite-carbon adsorbent with the hierarchical porous microstructure of sugarcane stems (SS-HAP/C) was prepared by carbonizing stem internodes of sugarcane tops and subsequent doping with the saturated limewater solution and 0.02 mo1/L (NH4)2HPO4solution in turn for five times. The morphological character of SS-HAP/C was inherited from the bio-precursors of sugarcane top stems, which mainly included the macropores from the storage parenchyma thin-walled cells of 30–115 μm in width, the parallel and densely packed vessels of 20–85 μm in width, the sclerenchyma thick-walled cells of ∼30 μm in width, and the pits in the vessel and cell walls of about ∼4.0 μm in width. The specific surface area through the mercury porosimetry method and the Brunauer–Emmett–Teller (BET) surface area were estimated to be 5.63 m2/g and 8.52–28.44 m2/g, respectively. For the test at the initial Pb(II) concentrations of 50, 100, 150 and 200 mg/L, the removal capacities of the un-pulverized SS-HAP/C (>3 mm) were determined to be 52.62, 101.85, 152.08 and 210.69 mg/g, respectively, which were comparable to the adsorption capacities of the synthetic nano-hydroxyapatites. The SS-HAP/C showed an excellent removal performance as an adsorbent for Pb(II) ions. The formation of the (PbxCa1‒x)5(PO4)3(OH) solid solution through the coexisting ion exchange (x = 0.01–0.05) and dissolution-precipitation (x = 0.20–0.21) processes was the main mechanism for the Pb(II) uptake.