| 赵凌宇,王延华,杨浩,王红,徐美娜,王丹.木屑和稻秆基生物质炭对汞的吸附特性比较[J].农业环境科学学报,2015,34(3):556-562. |
| 木屑和稻秆基生物质炭对汞的吸附特性比较 |
| Adsorption of Hg(Ⅱ) by Biochars Produced from Sawdust and Rice Straw |
| 投稿时间：2014-10-30 |
| DOI：10.11654/jaes.2015.03.019 |
| 中文关键词: 生物质炭 吸附 Hg(Ⅱ) 等温线 吸附动力学 |
| 英文关键词: biochar adsorption Hg(Ⅱ) isotherm kinetics |
| 基金项目:国家自然科学基金(41030751,41273102);江苏高校优势学科建设工程资助项目 |
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| 中文摘要: |
| 在600 ℃热解条件下制得木屑和稻秆两种生物质炭,用于比较不同类型的生物质炭对水溶液中重金属Hg(Ⅱ)的吸附特性,通过分析溶液pH值、吸附剂投加量和吸附时间对吸附的影响,探讨了其吸附动力学行为和汞的去除机理。实验结果表明,溶液pH值为5时,两种生物质炭对溶液中Hg(Ⅱ)的去除效果最佳;等温线数据能较好地拟合Langmuir方程,假二阶动力学方程则能较好地描述吸附动力学过程,由粒子内扩散模型分析可知两种生物质炭的吸附过程均受内扩散和膜扩散共同控制。SEM-EDS分析结果表明,生物质炭对Hg(Ⅱ)的吸附机制涉及离子交换作用,同时还可能包括还原作用和生物质炭羟基与羧基与汞的络合作用。 |
| 英文摘要: |
| Biochar can greatly adsorb heavy metals from aqueous solution, thus significantly reducing their concentrations in water environment. In the present study, two biochars obtained from sawdust and rice straw at 600 ℃ were used to study their Hg(Ⅱ) adsorption from aqueous solution under different solution pH, sorbent rates, and contact time. The optimum pH value for Hg(Ⅱ) adsorption by biochars was approximately 5. Langmuir isotherm model fitted the isotherm data of Hg(Ⅱ) adsorption by both biochars, suggesting a functional group-limited sorption process. Kinetics of Hg(Ⅱ) adsorption by two biochars could be well described by the pseudosecond-order model. The intraparticle diffusion model illustrated that the adsorption of Hg(Ⅱ) by two biochars was controlled by internal diffusion and membrane diffusion. The scanning electron microscopy showed that the ion exchange was a major process for the Hg(Ⅱ) removal. Meanwhile, reduction and complexation reaction might also be responsible for the Hg(Ⅱ) adsorption. |
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