Efficient removal of naphthalene from aqueous solutions using a nanoporous kaolin/Fe3O4 composite

The presence of naphthalene in environment has carcinogenic properties and threatens human health. Therefore, the removal of naphthalene from wastewater using eco-friendly materials and novel technologies has received tremendous attention. In this study, the performance of a kaolin/Fe 3 O 4 composite toward the uptake of naphthalene from aqueous media was assessed for the first time. The systematic study of the naphthalene adsorption by the kaolin/Fe 3 O 4 composite, using the central composite design, revealed that an increase in solution pH, contact time, or composite dose improves the removal efficiency of naphthalene. Considering the desirability index of 1.00, the optimum conditions for the removal of naphthalene were found at a composite dose of 4.8 g L −1 , contact time of 66 min, and solution pH 6.5 to achieve 97% removal efficiency from a solution containing 10 mg L −1 naphthalene. In comparison with the other clay-based composites, the equilibrium removal efficiency of naphthalene by the kaolin/Fe 3 O 4 composite was significantly high. These results indicated that the kaolin/Fe 3 O 4 composite is one of the most efficient adsorbents for the treatment of naphthalene-contaminated water using the adsorption process.