Novel Fe₃O₄–ZnO Carbonized Rice Husk Modified Nano Composite Sorbent for Removal of Humic Acid from Aqueous Media

In this study, we used a novel absorbent ZnO/Fe₃O₄/carbonized rice husk (CRH) composite for removal of humic acid (HA) from aqueous solutions. The ZnO/Fe₃O₄/CRH composite was produced via chemical procedure under heating and vigorous stirring conditions. The ZnO/Fe₃O₄/CRH were characterized by SEM, FT-IR, XRD and VSM techniques. The analysis results show that the ZnO/Fe₃O₄/CRH can be used as an appropriate adsorbent. Variables affecting the adsorption of humic acid such as: pH, HA concentration, adsorbent amount and contact time were investigated. The kinetics of adsorption of HA on ZnO/Fe₃O₄/CRH composite could be expressed by the pseudo-second order kinetic model and Langmuir model was found to be more applicable in interpreting between mentioned adsorbent and adsorbent as suitable adsorption isotherms. Furthermore, the ZnO/Fe₃O₄/CRH nanocomposites could be also served as convenient recyclable sorbent because of their magnetic properties.