A new reusable adsorbent of polyvinyl alcohol/magnesium peroxide (PVA/MgO2) for highly selective adsorption and dye removal

Abstract

New adsorbent polyvinyl alcohol/magnesium peroxide (PVA/MgO2) nano-composite films have been designed for high selective adsorption and dye removal applications. Creation of MgO2 within 40 ± 3 nm has been confirmed by TEM. PVA/MgO2 films have a large surface area of 59.130 m2 g−1, high pore volume 0.191 cm3 g−1 and a high negative surface charge _ 36.4 mV at pH environment ~12, which plays an important role in increasing the uptake capacity, removal efficiency and the selective adsorption performance. PVA/MgO2 nano-composite shows a high selective adsorption for MB dyes from a mixture solution containing both MB and MO dyes. Experiments showed that 30 mg of PVA/MgO2 has the ability to remove 50 mL of 25 mg/L of MB dye with an efficiency (99.9 ± 0.1%) in a fast time ~15 min under the experimental conditions. The Langmuir model is the isotherm model, the pseudo second order is the adsorption kinetics as well as the exothermic is thermodynamic process of the adsorption process. In addition, PVA/MgO2 nano-composite shows a high catalytic activity, in the recycling test, for ten cycles of MB adsorption.