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- Title
基于超磁分离磁性4A分子筛/壳聚糖吸附氨氮.
- Authors
马加加; 柯博瀚; 钟锦堂; 刘曦; 李绍秀
- Abstract
A novel magnetic composite (M-CS-MS) consisting of ferroferric oxide, 4A-molecular-sieve and chitosan was developed by means of the hydrothermal synthesis method. It was characterized by X-ray diffraction, Fourier transform infrared spectroscopy and vibrating-sample magnetometer, respectively. When applied to treat some simulated wastewater, M-CS-MS was investigated for the adsorption of ammonia nitrogen onto it in terms of the influencing factors, and the adsorption kinetics, thermodynamics and adsorption mechanism were discussed. As for the super-magnetic separation system for treating wastewater, in which M-CS-MS was used as magnetic seeding materials, the experimental results showed that the removal rate of ammonia nitrogen was more than 80% by adsorption with 5 g/L M-CS-MS. The removal rate of ammonia nitrogen increased with the increase of M-CS-MS dosage while decreased with the increase of initial concentration of ammonia nitrogen, but the adsorption amount increased. When pH value equaled six the removal effect of ammonia nitrogen was maximized. In addition, M-CS-MS had a good magnetic property and could be recovered by magnetic separation from water and M-CS-MS could be regenerated with sodium chloride solution, the regeneration efficacy being the best in weak alkaline solution; besides, after three adsorption-regeneration cycles, the removal rate of ammonia nitrogen could still maintain more than 70%. The study of adsorption process proved that the adsorption fit the pseudo-second-order kinetic model and Freundlich adsorption isotherm, it was a kind of exothermic reaction in which physical adsorption and chemical adsorption existed simultaneously. When M-CS-MS as magnetic seeds adopted (with the dosage of 6 g/L) in the supermagnetic separation system for treating the simulated wastewater, ammonia nitrogen, turbidity and CODMn was simultaneously removed from the wastewater, with the removal rate being above 80%, 96% and 58%, respectively. The magnetic seeds can be regenerated by cheap sodium chloride solution, and reused. In conclusion, the super-magnetic separation system in which M-CS-MS was used as magnetic seeds is of fine prospect for the application in wastewater treatment.
- Subjects
FREUNDLICH isotherm equation; FOURIER transform infrared spectroscopy; PHYSISORPTION; ADSORPTION kinetics; EXOTHERMIC reactions; ALKALINE solutions; COAGULANTS
- Publication
Environmental Science & Technology (10036504), 2022, Vol 45, Issue 3, p204
- ISSN
1003-6504
- Publication type
Article
- DOI
10.19672/j.cnki.1003-6504.2446.21.338