| 微纳米粒径生物炭的结构特征及其对Cd2+吸附机制 |
| 摘要点击 1816 全文点击 635 投稿时间：2021-10-13 修订日期：2021-11-28 |
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| 中文关键词 生物炭 微纳米粒径 镉(Cd) 球磨 吸附机制 |
| 英文关键词 biochar micro-nano particle size cadmium (Cd) ball milling adsorption mechanism |
| 作者 | 单位 | E-mail | | 马文艳 | 农业农村部环境保护科研监测所, 农业农村部产地环境污染防控重点实验室, 天津市农业环境与农产品安全重点实验室, 天津 300191 | mawenyan0420@163.com | | 裴鹏刚 | 农业农村部环境保护科研监测所, 农业农村部产地环境污染防控重点实验室, 天津市农业环境与农产品安全重点实验室, 天津 300191 | | | 高歌 | 农业农村部环境保护科研监测所, 农业农村部产地环境污染防控重点实验室, 天津市农业环境与农产品安全重点实验室, 天津 300191 | | | 孙约兵 | 农业农村部环境保护科研监测所, 农业农村部产地环境污染防控重点实验室, 天津市农业环境与农产品安全重点实验室, 天津 300191 | sunyuebing2008@126.com |
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| 中文摘要 |
| 为探究不同微纳米粒径生物炭的结构特性和对Cd2+吸附性能的影响.通过筛分法和球磨法制备不同粒径（180~250、50~75和≤20 μm，分别表示为BC-1、BC-2和BC-3）玉米秸秆生物炭，利用元素分析、激光粒度分析、SEM、BET、FTIR和XPS等手段对生物炭的结构进行了表征，采用静态吸附实验研究了不同初始Cd2+浓度、吸附时间和pH条件下生物炭对Cd2+的吸附行为与机制.结果表明，随粒径减小，生物炭表现为pH值和Zeta电位均下降、芳香性和极性降低、比表面积和孔体积增大.不同粒径生物炭对Cd2+的吸附动力学符合准二级动力学模型，以化学吸附为主，其平衡时间依次为：BC-1（540 min）>BC-2（360 min）>BC-3（80 min）.Langmuir模型能更好拟合Cd2+在不同粒径生物炭上的吸附等温过程（R2>0.97），Cd2+最大吸附量随粒径减小而增大，表现为：BC-3（74.43 mg ·g-1）>BC-2（45.71 mg ·g-1）>BC-1（44.59 mg ·g-1）.生物炭吸附Cd2+主要机制有静电吸引、表面络合和阳离子-π作用. |
| 英文摘要 |
| The aim of this study was to investigate the structural characteristics of biochar with different micro/nano particle sizes and its effect on the adsorption performance of Cd2+. Corn stalk biochar with different particle sizes (180-250 μm, 50-75 μm, and ≤ 20 μm, denoted as BC-1, BC-2, and BC-3, respectively) were prepared using the sieving and ball milling method. The structural properties of different particle sizes of biochar were analyzed via elemental analysis, laser particle size analysis, SEM, BET, FTIR, and XPS. Additionally, the adsorption mechanisms of Cd2+ by three particle sizes of biochar under initial Cd2+ concentrations, adsorption times, and pH conditions were comparatively studied using static adsorption experiments. The results showed that with the decrease in particle size, the pH and zeta potential of biochar were reduced; the aromaticity and polarity decreased; the specific surface area and pore volume increased; and the intensity of the characteristic peaks containing OH, C[FY=,1]C/C[FY=,1]O, and C-O groups increased. The adsorption kinetics of Cd2+ with different particle diameters of biochar were in accordance with the pseudo-secondary kinetic model, with chemisorption dominating. The equilibrium times were in the decreasing order of BC-1 (540 min)>BC-2 (360 min)>BC-3 (80 min). The Langmuir model could better fit the adsorption isotherm process of Cd2+ on biochar of different particle sizes (R2>0.97), and the maximum adsorption capacity of Cd2+ increased with the decrease in particle size, which was expressed as BC-3 (74.43 mg·g-1)>BC-2 (45.71 mg·g-1)>BC-1 (44.59 mg·g-1). The main mechanisms of Cd2+adsorption by biochar were electrostatic attraction, surface complexation, and cation-π interaction. |
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