Revealing the pH-Dependent Adsorption Dynamics of Tetracycline Hydrochloride on Phosphoric Acid-Activated Corncob Biochar.
Saved in:
| Title: | Revealing the pH-Dependent Adsorption Dynamics of Tetracycline Hydrochloride on Phosphoric Acid-Activated Corncob Biochar. |
|---|---|
| Authors: | Zhao, Qiang1,2 (AUTHOR) vv10852026@163.com, Zhao, Gaotian2 (AUTHOR), Zhang, Yalei1,3 (AUTHOR), Yan, Yangyang1 (AUTHOR), Shi, Boyi1,2 (AUTHOR), Yang, Jiawei2,3 (AUTHOR), Sun, Anqi2 (AUTHOR), Chen, Jiabao2 (AUTHOR), Zhang, Zongwei3 (AUTHOR), Wei, Fang1,2 (AUTHOR) f_wei@cauc.edu.cn |
| Source: | Materials (1996-1944). Jun2026, Vol. 19 Issue 11, p2251. 18p. |
| Subjects: | Adsorption kinetics, Biochar, Tetracycline, Wastewater treatment, Physisorption, Functional groups |
| Abstract: | Aquaculture wastewater containing tetracycline hydrochloride (TCH) poses significant environmental problems and health risks. We investigated the adsorption of TCH onto phosphoric acid-activated corncob biochar (PCC) as a sustainable and efficient removal strategy. PCC was synthesized from cob feedstock activated by phosphoric acid under a pyrolysis temperature of 300 °C in a limited-air atmosphere. It was characterized extensively, revealing a high specific surface area (1071.75 m2/g), high porosity with total pore volume of 0.912 cm3/g, and abundant surface functional groups including phosphate, carboxylic, and amine groups. Batch adsorption experiments demonstrated an ultrahigh adsorption capacity for TCH, with a maximum theoretical capacity (Langmuir model) of 953.62 mg/g at 313 K. Its adsorption isotherms transfer from Langmuir type to Freundlich type as temperature rises, indicating a transition from monolayer to multilayer adsorption. The adsorption kinetics were governed by a synergistic mechanism involving surface adsorption and a pore-filling effect (intra-particle diffusion). Critically, the adsorption dynamics exhibit an intra-particle diffusion-controlled process at a low pH (3.0) during the final stage of adsorption. Strong hydrogen bonding led to high initial adsorption rates, and the adsorption converted to diffusion-controlled mode eventually. In contrast, at higher pH (≥7.0), electrostatic repulsion between PCC adsorbents and TCH molecules hindered intra-particle diffusion, causing the final adsorption stage to deviate from diffusion control. This work provides comprehensive insights into the pH-dependent interfacial interactions and kinetics governing TCH removal by corncob-derived, phosphoric acid-activated biochar. [ABSTRACT FROM AUTHOR] |
| Copyright of Materials (1996-1944) is the property of MDPI and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
|
Full text is not displayed to guests.
Login for full access.
|
|
| Abstract: | Aquaculture wastewater containing tetracycline hydrochloride (TCH) poses significant environmental problems and health risks. We investigated the adsorption of TCH onto phosphoric acid-activated corncob biochar (PCC) as a sustainable and efficient removal strategy. PCC was synthesized from cob feedstock activated by phosphoric acid under a pyrolysis temperature of 300 °C in a limited-air atmosphere. It was characterized extensively, revealing a high specific surface area (1071.75 m2/g), high porosity with total pore volume of 0.912 cm3/g, and abundant surface functional groups including phosphate, carboxylic, and amine groups. Batch adsorption experiments demonstrated an ultrahigh adsorption capacity for TCH, with a maximum theoretical capacity (Langmuir model) of 953.62 mg/g at 313 K. Its adsorption isotherms transfer from Langmuir type to Freundlich type as temperature rises, indicating a transition from monolayer to multilayer adsorption. The adsorption kinetics were governed by a synergistic mechanism involving surface adsorption and a pore-filling effect (intra-particle diffusion). Critically, the adsorption dynamics exhibit an intra-particle diffusion-controlled process at a low pH (3.0) during the final stage of adsorption. Strong hydrogen bonding led to high initial adsorption rates, and the adsorption converted to diffusion-controlled mode eventually. In contrast, at higher pH (≥7.0), electrostatic repulsion between PCC adsorbents and TCH molecules hindered intra-particle diffusion, causing the final adsorption stage to deviate from diffusion control. This work provides comprehensive insights into the pH-dependent interfacial interactions and kinetics governing TCH removal by corncob-derived, phosphoric acid-activated biochar. [ABSTRACT FROM AUTHOR] |
|---|---|
| ISSN: | 19961944 |
| DOI: | 10.3390/ma19112251 |
