Magnetic composites have been widely used in the area of wastewater treatment, which own the properties of simple and quick adsorption and separation functions. This article presented a cost-effective and chemically modified adsorbent (Fe3O4@SiO2@Chitosan) based on a novel facile light-assisted technique for methyl orange (MO) removal. The characterization results of FT-IR, TEM, XRD and the hysteresis loop showed that Fe3O4@SiO2@Chitosan was successfully prepared. The adsorption properties of the magnetic Fe3O4@SiO2@Chitosan composite had been discussed in detail. Results show that the magnetic composite was able to remove more than 99.15% of dyes in water under optimized conditions. The Fe3O4@SiO2@Chitosan composite was stable and easily recovered, which demonstrated that the Fe3O4@SiO2@Chitosan can be successfully used as a reusable absorbent for effective removal of methyl orange from wastewater.
Fe 3 O 4 @SiO 2 -Chitosan/GO (MSCG) nanocomposite was investigated by various techniques (SEM, TEM, XRD, VSM, FT-IR, XPS) for the removal of tetracycline (TC). Effects of pH, zeta potential and initial contaminant concentration were studied in detail. Four background cations (Na + , K + , Ca 2+ and Mg 2+ ) with a concentration of 0.01 M showed little influence on the TC adsorption at the studied pH range while the divalent heavy metal cation Cu(II) could significantly enhance the adsorption. The results indicated that the highest adsorption capacity of TC were 183.47 mmol/kg and 67.57 mmol/kg on MSCG with and without Cu(II), respectively. According to mechanism investigation for the adsorption of TC by pH impact study and XPS analysis, besides electrostatic interaction and π–π interactions, the Cu(II) also acts as a bridge between TC and MSCG, which significantly improve the adsorption of TC. This study provided valuable guidance and effective method for the removal of TC from aquatic environments.
Shi Haowei,Yang Junya,Zhu Lizhong,Yang Yuxiang,Yuan Hongming,Yang Yubing,Liu Xiangnong
In this paper, the chain-like core–shell structure Fe3O4@SiO2@Chitosan composite nanoparticles were synthesized by a two-step coating and following crosslinking glutaraldehyde on chitosan shell. The composite particles showed nearly monodisperse
105 sized particles with a core diameter of 80 nm and chitosan shell thickness of 12 nm. The synthesis conditions of the product were studied, and the morphology and properties of the composite nanoparticles were characterized by IR, XRD, TEM, SEM, EDS and VSM. The adsorption properties of
Hg2+, Pb2+ or Cu2+ ions on Fe3O4, Fe3 O4@SiO2 and the composite particles were in detail studied using the colorimetric method based on forming colored mercuric dithizone, rhodamine-Pb2+ complex and DDTC-Cu(2+)
complex. The results showed, adsorption isotherm, kinetics and separation coefficient of heavy metal ions on these three magnetic nanoparticles were concerned with pH, metal ions’ electronic configuration, silica coating and chitosan shell respectively. In addition, the recycle efficiency
was also studied. The findings demonstrated that Fe3O4@SiO2@Chitosan composite nanoparticles have great application value in the adsorption and separation of heavy metal ions.
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