| 韩珏,李佳欣,崔红艳,吕纬,白淑琴.改性玉米秸秆吸附磷的动力学和热力学特征研究[J].农业环境科学学报,2020,39(9):2008-2014. |
| 改性玉米秸秆吸附磷的动力学和热力学特征研究 |
| Kinetic and thermodynamic characteristics of phosphorus adsorption by modified corn straw |
| 投稿时间：2020-03-20 |
| DOI：10.11654/jaes.2020-0316 |
| 中文关键词: 改性玉米秸秆 磷 等温吸附 吸附机理 |
| 英文关键词: modified corn straw phosphorus isothermal adsorption adsorption mechanism |
| 基金项目:国家自然科学基金项目（21666025）；内蒙古自治区科技计划项目（201802101）；内蒙古自治区自然科学基金项目（2018MS02021） |
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| 中文摘要: |
| 为实现玉米秸秆的资源化，对玉米秸秆进行化学改性，制备成了一种阳离子型吸附剂，并对其吸附水溶液中的磷进行了研究。通过改变初始磷浓度、吸附时间、吸附温度等条件，研究了改性玉米秸秆对磷的吸附行为。结果表明：随着反应时间的延长，吸附量开始急剧上升，后缓慢减小至达到平衡，平衡吸附量随着磷初始浓度的增大而增大。在298 K的条件下，改性玉米秸秆对磷的吸附过程符合Langmuir等温吸附模式，最大吸附量为12.96 mg·g-1；吸附过程符合伪二级反应动力学模式，且受颗粒内扩散模式控制，吸附过程主要为化学吸附；吸附热力学参数ΔH和ΔG均小于0，表示该过程是一个可自发进行的放热反应。研究表明，改性玉米秸秆对水中的磷有很好的去除效果，是一种良好的磷吸附剂。 |
| 英文摘要: |
| In order to realize the resource utilization of corn straw, this study used corn stalks as raw materials after a series of chemical modifications including hydrolysis with NaOH solution, ultrasonic vibration, epichlorohydrin etherification, and Ca(NO3)2 soaking. The corn residues were modified into cationic adsorbents, and the adsorption of phosphorus in water was studied. The influences of the initial concentration of phosphorus solution, adsorption time, and adsorption temperature on the adsorption of phosphorus were observed. The results indicated that the adsorption amount began to increase sharply with the increase in reaction time, and then slowly decreased to reach equilibrium. The equilibrium adsorption capacity of phosphorus increased with the increase in initial concentration. The adsorption process of phosphorus by modified corn straw was well-fitted to a Langmuir adsorption isotherm when the temperature was 298 K, and the maximum adsorption of phosphorus was 12.96 mg·g-1. The study of the adsorption kinetics showed that it was also well-fitted to the pattern of the pseudo second-order model and controlled by the pattern of the particle diffusion model, thereby indicating that the adsorption process was dominated by chemical adsorption. Thermodynamic experiments with varying adsorption temperatures showed that the thermodynamic parameters ΔH and ΔG were less than zero, which revealed that the adsorption process was exothermic and spontaneous. The results showed that the modified corn stalk has a good removal effect on phosphorus in water and is a good adsorbent of phosphorus. |
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