From illite/smectite clay to mesoporous silicate adsorbent for efficient removal of chlortetracycline from water

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• 作者：Wenbo Wang¹ ; ³ ; Guangyan Tian¹ ; ² ; Li Zong¹ ; ³ ; Yanmin Zhou⁴ ; Yuru Kang¹ ; ³ ; Qin Wang¹ ; ³ ; Aiqin Wang¹ ; ³ ; ^{aqwang@licp.cas.cn}
• 关键词：Illite/smectite clay ; Hybrid silicate adsorbent ; Chlortetracycline ; Removal
• 刊名：Journal of Environmental Sciences
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：51
• 期：Complete
• 页码：31-43
• 全文大小：1855 K
• 卷排序：51

文摘

A series of mesoporous silicate adsorbents with superior adsorption performance for hazardous chlortetracycline (CTC) were sucessfully prepared via a facile one-pot hydrothermal reaction using low-cost illite/smectite (IS) clay, sodium silicate and magnesium sulfate as the starting materials. In this process, IS clay was “teared up” and then “rebuilt” as new porous silicate adsorbent with high specific surface area of 363.52 m2/g (about 8.7 folds higher than that of IS clay) and very negative Zeta potential (− 34.5 mV). The inert SiOSi (Mg, Al) bonds in crystal framework of IS were broken to form Si(Al) O− groups with good adsorption activity, which greatly increased the adsorption sites served for holding much CTC molecules. Systematic evaluation on adsorption properties reveals the optimal silicate adsorbent can adsorb 408.81 mg/g of CTC (only 159.7 mg/g for raw IS clay) and remove 99.3% (only 46.5% for raw IS clay) of CTC from 100 mg/L initial solution (pH 3.51; adsorption temperature 30°C; adsorbent dosage, 3 g/L). The adsorption behaviors of CTC onto the adsorbent follows the Langmuir isotherm model, Temkin equation and pseudo second-order kinetic model. The mesopore adsorption, electrostatic attraction and chemical association mainly contribute to the enhanced adsorption properties. As a whole, the high-efficient silicate adsorbent could be candidates to remove CTC from the wastewater with high amounts of CTC.