Highly Effective Starch/Graphene Oxide Composites for Ammonium Adsorption from Aqueous Media

In this work, starch/graphene oxide (ST/GO) composites were prepared and investigated as efficient adsorbents for eliminating ammonium () ions from aqueous solution. The physochemical characterization of GO and ST/GO composites confirming the uniform distribution of GO nanosheets within the ST framework. Adsorption experimental results indicated that the adsorption equilibrium was achieved within 90 min, and the ST/0.1GO composite showed the highest removal efficiency. Moreover, the adsorption reduced with increasing temperature which indicates an exothermic process . The adsorption of ions by the ST, GO, ST/0.03GO, and ST/0.1GO composites fitted with the Langmuir model. The estimated maximum adsorption capacity for the ST, GO, ST/0.03GO, and ST/0.1GO composites toward ions are 65.62, 61.73, 64.14, 67.75 mg/g, respectively. The kinetic modeling demonstrated that the pseudo-second-order equation provided the best fit, suggesting chemisorption as the controlling mechanism. Furthermore, the prepared materials displayed high adsorption stability with an average removal efficiency of about 80% after five cycles. Overall, the results highlight ST/GO composites as promising, cost-effective, and environmentally friendly adsorbents for the removal of ions from wastewater.