| 生物炭结构性质对氨氮的吸附特性影响 |
| 摘要点击 2370 全文点击 759 投稿时间：2019-05-21 修订日期：2019-07-13 |
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| 中文关键词 生物炭 氨氮 吸附 吸附动力学 等温线吸附 |
| 英文关键词 biochar ammonia nitrogen adsorption adsorption kinetics isothermal adsorption |
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| 中文摘要 |
| 氨抑制现象在富含有机氮底物的沼气工程中普遍存在，采用生物炭吸附法可固定发酵液中氨氮.为探究生物炭理化结构与氨氮吸附特性之间的相关关系，在不同热解温度（350、450和550℃）下制备以玉米秸秆、稻壳为原料的生物炭，通过元素分析、FTIR和BET等分析生物炭结构及其理化性质，并结合批式吸附实验，研究不同理化性质生物炭对氨氮的吸附特性影响.结果表明随着热解温度的升高，生物炭中碳及灰分含量增多；450℃制备的玉米秸秆生物炭（CS450）与550℃制备的稻壳生物炭（RH550）对氨氮的吸附分别遵循准二级和准一级动力学模型.Freundlich吸附模型能更好地描述CS450和RH550生物炭对氨氮的等温吸附过程；玉米秸秆炭吸附量与其表面官能团间具有显著相关性；而与稻壳炭的吸附量相关性最显著的为生物炭的比表面积，其次是表面官能团，最后是灰分.其中，RH550吸附性能最好，最大吸附量为12.16 mg·g-1. |
| 英文摘要 |
| Ammonia inhibition is a common phenomenon in biogas engineering which is rich in organic nitrogen substrate. Ammonia nitrogen in anaerobic digestate slurry can be fixed by biochar adsorption. Biochar is prepared from corn stalks and rice husks as raw materials at different temperatures (350℃, 450℃, and 550℃). The purpose is to explore the correlation between the physical and chemical structure of biochar and the adsorption characteristics of ammonia nitrogen. The structure and physicochemical properties of biochar were analyzed by elemental analysis, FTIR, BET, etc., and batch adsorption experiments were conducted to investigate the effect of biochar with different physicochemical properties on adsorption characteristics of ammonia nitrogen. The results indicated that the carbon and ash content in biochar increases with an increase in pyrolysis temperature; the NH4+-N adsorption of the corn stalk biochar prepared at 450℃ (CS450) and the rice husk biochar prepared at 550℃ (RH550) follows the quasi-secondary-and quasi-first-order kinetic models. The Freundlich adsorption model can better describe the isothermal adsorption process of ammonia nitrogen in CS450 and RH550 biochar. The adsorption capacity of corn straw carbon correlated strongly with its surface functional groups. The most significant correlation with the adsorption capacity of rice husk carbon is the specific surface area of biochar, followed by surface functional groups, and finally ash content. Among them, RH550 had the best adsorption performance, and the maximum adsorption capacity was 12.16 mg·g-1. |
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