A novel approach for removing 2-naphthol from wastewater using immobilized organo-bentonite.

The major concern limiting the industrial application of organo-bentonite in powder form (P-Bent) for wastewater treatment is that it is difficult to separate it from treated water by settlement. To address this problem, a novel approach for synthesizing immobilized organo-bentonite in globular form (G-Bent) is proposed. The G-Bent is modified using the cationic surfactant cetylpyridinium chloride (CPC) and immobilized by polyvinyl alcohol (PVA). The removal of 2-naphthol by G-Bent was compared with removal by P-Bent for solid/liquid separation, removal efficiency and desorption of the modifier used in its preparation. Results indicated that G-Bent was easy to recover from treated wastewater, and was effective and reusable in removing 2-naphthol. The percentage of 2-naphthol removed by G-Bent exceeded 90% with the cationic exchange capacity (CEC) loadings ranging from 100% to 150%. This was almost equivalent to the results obtained using P-Bent. In the five rounds of reuse examined, the percentage of 2-naphthol removed was maintained above 50% for 150%-G-Bent. The percentage of CPC desorption was less than 0.75% after five rounds of reuse and no PVA was detected. The results of this work provide novel information for using G-Bent in the treatment of wastewater containing organic contaminants.