Adsorption of Humic Acid from Aqueous Solution Using Composite Magnetic Microspheres of Chitosan and Quaternary Ammonium Chitosan Derivative
Composite magnetic microspheres of chitosan (CTS) and quaternary ammonium chitosan derivative (HTCC) were prepared by inverse suspension method. Tripolyphosphate (TPP) and glutaraldehyde were used successively to co-crosslink the microsphere matrix. The morphology was analyzed using optical microscopy and scanning electron microscopy (SEM), while the chemical composition was characterized using Fourier transform infrared spectroscopy (FTIR). The adsorption of humic acid (HA) by the composite magnetic microspheres (CHMMs) was investigated in terms of adsorption capacity and kinetics in order to optimize preparation conditions. Both CTS/HTCC mass ratio and crosslinker dosage greatly affected the properties of the microspheres. A batch of CHMMs was prepared when the mass ratio of CTS and HTCC was 1:1 and TPP and glutaraldehyde were17% and 30% of total mass of CTS and HTCC, respectively. These CHMMs were between 150 and 800 μm. 85% HA was able to be removed in 60 min using this proposed absorbent. It was fast and efficient for HA removal from aqueous solution.