| Autor: |
Griffin A. Burk, Amali Herath, Glenn B. Crisler, David Bridges, Shivani Patel, Charles U. Pittman, Todd Mlsna |
| Jazyk: |
angličtina |
| Rok vydání: |
2020 |
| Předmět: |
|
| Zdroj: |
Frontiers in Environmental Science, Vol 8 (2020) |
| Druh dokumentu: |
article |
| ISSN: |
2296-665X |
| DOI: |
10.3389/fenvs.2020.541203 |
| Popis: |
Gasifier Biochar (GBC) and Chitosan-Coated Gasifier Biochar (CGBC) derived from pine wood was used to remove Cu2+ and Cd2+ from water. Chitosan-Coated Gasifier Biochar was made by mixing GBC with aqueous acetic acid chitosan solution followed by treatment with NaOH. Both CGBC and GBC were characterized using FT-IR, scanning electron microscopy, surface area measurement (BET), elemental analysis, thermogravimetric analysis, and point of zero charge. Chitosan accounts for 25% of the weight of the CGBC. Thermogravimetric analysis showed chitosan decomposes sharply at 225–270°C and then more slowly thereafter. The BET surface areas of GBC and CGBC were 34.1 and 4.61 m2/g, respectively. Batch adsorption studies performed at pH values of 2–5 followed Cu2+ and Cd2+ adsorption quantitatively using atomic absorption spectrophotometry. Sorption was evaluated using the Freundlich, Langmuir, and Sips isotherm models. Cu2+ adsorption on CGBC fit best the Sips model (capacity 111.5 mg/g) and Cd2+ with the Langmuir model (capacity 85.8 mg/g). Langmuir adsorption capacities on GBC were 83.7 and 68.6 mg/g for Cu2+ and Cd2+ respectively. CGBC removed more Cu2+(25.8 mg/g) and Cd2+(17.2 mg/g) than GBC because chitosan modification generates amine coordination sites that enhance metal adsorption. Adsorption on CGBC and GBC of both metal ions followed pseudo-second order kinetics. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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