Effect of pH on the removal of anionic and cationic dyes using zinc curcumin oxide nanoparticles as adsorbent

Abstract

Recently, organic dyes are highly found in wastewater because of the plastic, painting, cosmetics, paper, leather, and food industries. They are dangerous and can affect the environment in addition to the human beings. Many methods were studied in order to get rid of them. Among all the techniques, adsorption was determined to be a successful, economic, ecofriendly, and efficient one. Zinc oxide nanoparticles were complexed with curcumin in order to generate zinc curcumin oxide nanoparticles that will be used as adsorbent. The efficiency of zinc curcumin oxide nanoparticles as adsorbent was investigated for different organic dyes such as congo red (CR), methyl orange (MO), methylene blue (MB), rhodamine 6G (Rh6G), and rhodamine B (RhB). The effect of pH was investigated in this study for the diverse anionic and cationic dyes. The highest adsorption capacities qe of the dyes were determined for CR, MO, MB, Rh6G, and RhB to be 94.54, 44.38, 34.71, 38.184, and 28.34 mg/g respectively. Only congo red had the highest adsorption capacity at an acidic pH while the other dyes had the highest adsorption capacity at a basic pH. In addition, all the adsorption processes that were studied followed a pseudo-second order kinetic model. © 2021 Elsevier B.V.