| 谢童,薛炳松,王珊,吴胜春,梁鹏.巯基改性生物炭对水中甲基汞的吸附[J].农业环境科学学报,2022,41(1):162-170. |
| 巯基改性生物炭对水中甲基汞的吸附 |
| Methylmercury adsorption characteristics of thiol-modified biochar in water |
| 投稿时间：2021-06-11 |
| DOI：10.11654/jaes.2021-0676 |
| 中文关键词: 生物炭 巯基 络合 甲基汞 |
| 英文关键词: biochar sulfhydryl complex methylmercury |
| 基金项目:浙江省自然科学基金项目(LY21D030001); 浙江农林大学大学生科研训练项目(112-2013200146, 112-2013200151) |
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| 中文摘要: |
为探讨巯基改性生物炭对甲基汞的吸附特征及机理，以牛粪、污泥、竹屑为原料制备热解生物炭，并利用3-巯丙基三甲氧基硅烷分别对其改性，采用元素分析、电镜扫描和傅里叶变换红外光谱仪对改性前后的生物炭进行表征，结合等温吸附实验和吸附动力学实验，对比研究不同原料改性生物炭对甲基汞的吸附性能并探讨其吸附机理。结果表明：通过O—Si基团的成功引入证明巯基改性成功，巯基改性后的生物炭对甲基汞的吸附能力增强，主要归因于含硫基团（—SH、C—S）与甲基汞离子有较强的络合能力。改性后，3种生物炭对甲基汞的吸附符合准二级吸附动力学和Langmuir等温吸附方程。巯基改性生物炭对甲基汞的最大拟合吸附量达到526~1 450 ng·g-1，显著高于未改性生物炭（331~533 ng·g-1），改性组生物炭的吸附速率常数k2（1.800~2.640）明显高于未改性组生物炭（0.014~0.156）。研究表明，巯基改性生物炭吸附甲基汞主要是通过其表面引入的—SH和C—S等官能团，与甲基汞形成—SHgCH3和（CH3Hg）2S等络合物，从而有效去除水中甲基汞。 ![]() |
| 英文摘要: |
| Pyrolysis biochar was prepared from cow dung, sludge, and bamboo shavings and modified by 3-mercaptopropyltrimethoxysilane. Elemental analysis, scanning electron microscopy, and Fourier transform infrared spectrometry were used to characterize the biochar before and after thiol modification. Isothermal adsorption and adsorption kinetics experiments were used to conduct a comparative study of the different raw material-modified biochars and to discuss their methylmercurg(MeHg)adsorption mechanisms. The aim was to explore the MeHg adsorption characteristics and mechanisms of thiol-modified biochar. The results showed that O—Si groups were successfully introduced onto the biochar surface, which proved that the introduction of sulfhydryl groups was successful. Thiol-modified biochar has an enhanced ability to complex MeHg, which is mainly due to the stronger complexing ability of sulfur-containing groups(—SH, C—S)to MeHg. After modification, the adsorption of MeHg onto the three types of biochar conformed to the quasi-second-order adsorption kinetics and Langmuir isotherm adsorption equation. The maximum fitting adsorption capacity of thiolmodified biochar to MeHg reached 526~1 450 ng·g-1, which was significantly higher than that of raw biochar(331~533 ng·g-1). The adsorption rate constant(k2)of modified biochar(1.800~2.640)was significantly higher than that of raw biochar(0.014~0.156). All the results showed that compared with the raw biochar, the adsorption capacity of thiol-modified biochar was significantly improved, which effectively removed MeHg in water mainly through the functional groups(—SH and C—S)with MeHg formed —SHgCH3 and(CH3Hg)2S and other complexes. |
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