| 浒苔生物炭的特征及其对Cr(Ⅵ)的吸附特点和吸附机制 |
| 摘要点击 2868 全文点击 1374 投稿时间：2017-01-06 修订日期：2017-04-07 |
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| 中文关键词 浒苔 生物炭 吸附 Cr(Ⅵ) 机制 |
| 英文关键词 Enteromorpha prolifera biochar adsorption Cr(Ⅵ) mechanism |
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| 中文摘要 |
| 为使浒苔得到资源化利用，本研究采用慢速热解技术于不同温度下制备浒苔生物炭，并对其理化性质进行表征.结果表明，400℃时，浒苔裂解已达较高程度.浒苔生物炭产率及灰分含量与热解温度呈负相关，碳含量与热解温度呈正相关，其表面呈蜂窝状多孔结构，比表面积为44.54~317.82 m2·g-1，表面含有丰富的羟基（-OH）和羧基（-COOH）等含氧官能团.吸附实验显示，浒苔生物炭对Cr（Ⅵ）的吸附符合准二级动力学方程和Langmuir等温吸附模型.表明浒苔生物炭对Cr（Ⅵ）的吸附为单分子层化学吸附，主要受快速反应过程控制.浒苔生物炭吸附Cr（Ⅵ）的最适pH为2，吸附容量表现为BC400 > BC700 > BC600 > BC500 > BC300，其中BC400的吸附量为4.79 mg·g-1.浒苔生物炭对Cr（Ⅵ）的吸附机制主要包括生物炭与HCrO4-和Cr2O72-等阴离子之间的静电作用，以及生物炭表面-OH和-COOH等含氧官能团的络合作用. |
| 英文摘要 |
| This study aims to understand the recycling process of Enteromorpha prolifera by using the slow pyrolysis technology to prepare biochars under different temperatures and by characterizing the physicochemical properties of biochars. The results showed that a relatively high level pyrolysis of Enteromorpha prolifera could be reached when the temperature was up to 400℃. The yield rate and the ash content of biochars were negatively correlated with the pyrolysis temperature, while the carbon content was positively correlated. The specific surface area of Enteromorpha prolifera biochars was in the range of 44.54-317.82 m2·g-1. The biochar surface was in the shape of a honeycomb and rich in oxygen-containing functional groups, such as hydroxyl (-OH) and carboxyl (-COOH) groups. The adsorption experiments revealed that the adsorption of Cr(Ⅵ) onto Enteromorpha prolifera biochars followed the pseudo-second-order kinetics equation and Langmuir isotherm, indicating that the adsorption process was controlled by the fast reaction process and governed by monomolecular and chemical adsorption. The optimal pH for Cr(Ⅵ) adsorption onto Enteromorpha prolifera biochars was 2 and their adsorption capabilities were in the order of BC400 > BC700 > BC600 > BC500 > BC300 (the adsorption capacity of BC400 was 4.79 mg·g-1). The adsorption mechanism included the electrostatic interactions between biochar and anions (HCrO4- and Cr2O72-) and the complexation of oxygen-containing functional groups. |
