| 氢氧化钾改性玉米秸秆生物炭对水中土霉素的吸附特性及机制 |
| 摘要点击 830 全文点击 236 投稿时间：2023-02-15 修订日期：2023-04-14 |
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| 中文关键词 玉米秸秆生物炭 氢氧化钾改性 热解活化 盐酸土霉素（OTC） 吸附 |
| 英文关键词 corn straw biochar potassium hydroxide modification pyrolysis activation oxytetracycline hydrochloride （OTC） adsorption |
| 作者 | 单位 | E-mail | | 刘总堂 | 盐城师范学院化学与环境工程学院, 盐城 224007
盐城师范学院江苏省农业养殖污染治理与资源化工程研究中心, 盐城 224007 | zongtliu@163.com | | 孙玉凤 | 盐城师范学院化学与环境工程学院, 盐城 224007 | | | 费正皓 | 盐城师范学院化学与环境工程学院, 盐城 224007
盐城师范学院江苏省农业养殖污染治理与资源化工程研究中心, 盐城 224007 | | | 沙新龙 | 盐城师范学院化学与环境工程学院, 盐城 224007 | | | 温小菊 | 盐城师范学院化学与环境工程学院, 盐城 224007 | | | 钱彬彬 | 盐城师范学院化学与环境工程学院, 盐城 224007 | | | 陈建 | 盐城师范学院化学与环境工程学院, 盐城 224007 | | | 谷成刚 | 中国科学院南京土壤研究所中国科学院土壤环境与污染修复重点实验室, 南京 210008 | |
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| 中文摘要 |
| 四环素类抗生素污染治理是环境研究热点问题之一,生物炭吸附是高效去除有机污染物的重要方法.以玉米秸秆为原料制备热解生物炭（BC）,通过氢氧化钾改性获得KBC,选择具有最佳吸附性能的KBC在400~600℃二次热解活化,最终制得改性玉米秸秆生物炭AKBC400、AKBC500和AKBC600,并对其结构和表面性质进行表征.通过批处理实验,以BC400为对照,考察了3种AKBC对溶液中盐酸土霉素（OTC）的吸附动力学和吸附热力学特征.与BC400相比,AKBC比表面积增加23.0~37.6倍,孔隙结构显著改善,芳香性增强,吸附性能显著提高.准二级动力学模型可以更好地拟合AKBC对OTC的吸附过程,AKBC500对OTC的吸附速率常数和吸附量均高于AKBC400和AKBC600.颗粒内扩散和膜扩散均是AKBC吸附OTC的控速步骤.Langmuir、Freundlich和Temkin模型均可较好地拟合吸附等温线.AKBC对OTC的吸附均为自发、吸热和熵增加过程,吸附过程同时存在物理吸附和化学吸附作用.AKBC对OTC吸附机制包括孔填充、氢键、π—π共轭、阳离子—π键和强静电作用.AKBC具有良好的孔隙结构和较高的吸附容量,且再生吸附性能稳定,对去除水中土霉素具有较好的潜能. |
| 英文摘要 |
| The pollution control of tetracycline antibiotics in the environment has become a hot topic, and biochar adsorption has become an important technology to remove organic pollutants. Pyrolytic biochars (BC400, BC500, and BC600) were prepared from corn straw and then were modified by KOH to obtain KBC400, KBC500, and KBC600. Among them, KBC400 was selected for secondary pyrolysis activation at 400-600℃ to obtain AKBC400, AKBC500, and AKBC600. The structure characteristics and surface properties of AKBC were also characterized. The adsorption kinetics and thermodynamic characteristics of oxytetracycline hydrochloride (OTC) in the solution by AKBC were investigated using batch experiments. Compared to that of BC400, the specific surface area and pore structure of AKBC were significantly improved, and the aromaticity was also enhanced, resulting in the notable enhancement of the adsorption capacities for OTC. The pseudo-second-order kinetics model could better fit the adsorption process, and AKBC500 had the largest adsorption rate constant and capacity. Both the intraparticle diffusion and film diffusion were the rate-limiting steps. The Langmuir, Freundlich, and Temkin models could fit the adsorption isotherms perfectly. The adsorption of OTC on AKBC was a spontaneous, endothermic, and entropy-increasing process by both physisorption and chemisorption. The pH values in the range of 3.0-7.0 were favorable for the adsorption of OTC by AKBC. The adsorption capacity decreased with the humic acid concentration over 10 mg·L-1. The adsorption mechanism of OTC by AKBC involved pore filling, hydrogen bonding, π-π conjugation, cation-π bond, and strong electrostatic effect. AKBC still had good reusability for OTC removal after five times of regeneration. The obtained AKBC is a potential adsorbent for OTC removal from water due to the good pore structure, high adsorption capacity, and stable adsorption effect. |
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