| 胺硫改性生物炭对水溶液中不同重金属离子的吸附特性及吸附稳定性 |
| 摘要点击 2293 全文点击 816 投稿时间：2020-06-18 修订日期：2020-07-25 |
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| 中文关键词 秸秆生物炭 胺硫改性 重金属 选择吸附 吸附稳定 |
| 英文关键词 straw biochar modified amine sulphur heavy metal selective adsorption adsorption stability |
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| 中文摘要 |
| 以玉米秸秆为原料热裂解制备生物炭，利用二乙烯三胺和二硫化碳，通过酸化氧化，曼妮希反应胺基改性、二硫化碳巯基取代对生物炭进行胺硫双基团改性，研究胺硫改性生物炭（BC-SN）对Pb2+、Ni2+及Cd2+在单一和三元体系下的吸附特性和吸附稳定性.表征分析证实了生物炭表面胺硫双基团改性成功，且具有比表面积大、表面官能团丰富的特点.对吸附过程进行了pH值、吸附剂投加量和吸附平衡时间的研究.结果表明，单一体系下，吸附平衡时间为4 h，最佳投加量为1、0.8和1.2 g·L-1，吸附满足准二级动力学方程；三元体系下，吸附平衡时间缩短到1.5h，最佳投加量为0.4、1.6和0.8 g·L-1，选择吸附顺序为Pb2+ > Cd2+ > Ni2+，吸附总量为0.67 mmol·g-1，均大于单个重金属离子的吸附量，说明BC-SN对3种重金属离子共存下的污染水体处理效果更好.Pb2+和Cd2+的吸附以重金属硫化物和螯合氨基形式稳定结合，Ni2+的为多种官能团的混合吸附；Pb2+和Cd2+竞争吸附时结合能更高，吸附稳定性强. |
| 英文摘要 |
| A novel biochar was prepared by modification with corn straw, ethylene triamine, and carbon disulfide, and its adsorption properties and stability with respect to heavy metal ions in single and mixed systems (Pb2+, Ni2+, and Cd2+) were investigated. Characterization analysis confirmed the successful modification of an amine-sulfur double group on the surface of the biochar, which had abundant functional groups with a large specific surface area. Adsorption experiments under the single system indicated that the adsorption equilibrium time was 4 h and the optimum dosages were 1, 0.8, and 1.2 g·L-1. The adsorption met the conditions of the quasi-second-order kinetic equation. Under the ternary system, the adsorption equilibrium time was reduced to 1.5 h, the optimum dosages were 0.4, 1.6, and 0.8 g·L-1, and the adsorption sequence was Pb2+ > Cd2+ > Ni2+. The total amount of adsorption was 0.67 mmol·g-1, which was higher than that of single heavy metal ions, indicating that amine-sulfur modified straw biochar (BC-SN) has an improved treatment effect on polluted water under the coexistence of three heavy metal ions. The Pb2+ and Cd2+ adsorbed by the biochar was stably bound in the form of heavy metal sulfide and a chelated amino group. In contrast, the adsorption of Ni2+ was via the mixed adsorption of various functional groups. When Pb2+ and Cd2+ compete for adsorption, the binding energy is higher and adsorption stability is more reliable. |
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