A novel adsorbent of core-shell construction of chitosan-cellulose magnetic carbon foam: Synthesis, characterization and application to remove copper in wastewater

Developing a environmental and cost-effective adsorbents for removal of Cu(II) from industrial wastewater is a quite serious problem. This study prepared a novel adsorbent of chitosan-cellulose enwrapped magnetic carbon foam (CCMF) to remove Cu(II) from industrial sewage. Magnetic core-shell construction facilitated the solid-liquid separation after adsorption. Groups of adsorption experiments for the adsorbability of CCMF were systematically studied at various conditions, such as pH (3.0-6.0), adsorbent dosage (1.0-4.0 g/L), initial concentration of Cu(II) (25-600 mg/L), temperature (20-30 degrees C) and adsorption time (10-1800 min). Fourier-transform infrared (FTIR) spectroscopy indicated that the amino and hydroxyl groups of chitosan were involved in the adsorption reaction and that N and O atoms were the adsorption sites. X-ray photoelectron spectroscopy (XPS) further confirmed that the N atom was the main adsorption site. The adsorption isotherm of Cu(II) on the CCMF was well correlated with the Langmuir isotherm model, the adsorption processes were a monolayer reaction and controlled by homogeneous adsorption sites on the surface, and the maximum adsorption capacity was 115.65 mg/g at pH 6.0 and 30 degrees C. The adsorption process of Cu(II) on the CCMF followed the pseudo-first-order kinetic equation within the initial 120 min. Meanwhile, the entire process fitted well with the pseudo-second-order kinetic model. Results have demonstrated that CCMF is a potential environmental adsorbent for the removal of Cu(II) in industry wastewater.