| 玉米秸秆生物炭对灰钙土吸附金霉素的影响 |
| 摘要点击 1836 全文点击 570 投稿时间：2021-03-31 修订日期：2021-05-17 |
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| 中文关键词 灰钙土 金霉素 生物炭 吸附动力学 吸附热力学 |
| 英文关键词 sierozem aureomycin biochar kinetic adsorption thermodynamic adsorption |
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| 中文摘要 |
| 为研究生物炭（BC）添加对灰钙土（HGT）吸附金霉素（CTC）的影响，本文以玉米秸秆为原料分别在200、400和600℃下制备BC.采用批平衡法，研究CTC在HGT和HGT+BC上的吸附行为.结果表明，HGT对CTC的吸附平衡时间为240 min，添加BC使平衡时间相对延长，符合准二级动力学模型.CTC的总体吸附速率由表面扩散和颗粒内扩散共同控制，且表面扩散速率更快，疏水分配作用促进吸附进行.3种等温吸附模型拟合对CTC在HGT和HGT+BC中的吸附均呈现较好相关性.添加BC使HGT对CTC的吸附分配系数Kd值增大，亲和力增强.不同温度时分配系数Kd的差异性表明吸附过程为放热反应.吸附满足不同等温线型（L型和S型），是以化学吸附为主的非均质复杂吸附过程，伴随静电引力、氢键相互作用等表面吸附和物理吸附.pH=3时，CTC+与土壤表面的负性位点大量结合，发生阳离子交换与静电吸引作用，吸附量最大.pH增大，CTC存在形态改变，HGT和BC对其吸附能力减弱.BC在不同pH下始终增强HGT对CTC的吸附，且添加量越大，CTC的吸附分配系数Kd值越大.吸附是由HGT和BC的有机质含量、矿物组成、理化性质及CTC存在形态和环境因素共同作用的结果.研究表明适量添加BC对HGT吸附CTC具有积极影响，裂解温度200℃时作用最显著，可以有效促进HGT对CTC的吸附与固定作用. |
| 英文摘要 |
| In order to study the effect of biochar (BC) addition on the adsorption of aureomycin (CTC) fromsierozem (HGT), BC was prepared from corn stalks at 200, 400, and 600℃, respectively. The adsorption behavior of CTC on HGT and HGT+BC was studied using the batch equilibrium method. The results showed that the equilibrium time of CTC adsorption by HGT was 240 min, and the equilibrium time was relatively prolonged by adding BC, which was in line with the pseudo-second-order adsorption kinetic model. The overall adsorption rate of CTC was controlled by both surface diffusion and intra-particle diffusion, the surface diffusion rate was faster, and the hydrophobic distribution promoted the adsorption. The adsorption of CTC in HGT and HGT+BC showed a good correlation among the three isothermal adsorption models. The addition of BC increased the adsorption distribution coefficient Kd value of HGT to CTC, and the affinity was enhanced. The difference of distribution coefficient Kd at different temperatures indicates that the adsorption process is an exothermic reaction. The results revealed different adsorption isothermal lines (L and S type) and the heterogeneity of chemical adsorption in the complex adsorption process, along with the electrostatic force and hydrogen bond interaction in the surface adsorption and physical adsorption. When the pH=3, CTC+ combined with negative sites on the surface of the soil large, cation exchange and electrostatic attraction, the adsorption capacity was the largest. The pH increased, and the CTC existence form changed, weakening the adsorption ability of HGT and BC. BC always enhanced HGT under CTC adsorption at various pHs, and the greater the amount added, the greater the CTC adsorption distribution coefficient Kd values. Adsorption is the result of the joint action of organic matter content, mineral composition, physical and chemical properties, CTC form, and HGT and BC environmental factors. Studies have shown that the appropriate addition of BC has a positive effect on the adsorption of CTC by HGT, and the effect is most significant when the pyrolysis temperature is 200℃, which can effectively promote the adsorption and fixation of CTC by HGT. |
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