Control of Vaporous Naphthalene by Scrubbing with Surfactants

This study investigates the effects of adding anionic and nonionic surfactants to the scrubbing liquid during the absorption of naphthalene (Nap) using a wet scrubber. Both batch and continuous experiments were performed on a laboratory-scale packed tower scrubber by adding surfactants to the scrubbing liquid. An anionic surfactant sodium dodecyl sulfate (SDS) and two nonionic polyoxyethylene surfactants $C_{10}{E}_4$ [tetraethylene glycol mono(decyl ether)] and $C_{14}{E}_8$ [octaethylene glycol mono(tetradecyl ether)] were used. The concentrations of the surfactant solutions all exceeded the critical micelle concentration. The results of continuous experiments indicate that the efficiencies of removal of naphthalene by $C_{10}{E}_4$ and $C_{14}{E}_8$ were 75.0 and 71.9%, respectively, at a concentration of $1.0\times {10}^{-2}M\text{.}$ The removal efficiency of naphthalene by SDS ranged from 6 to 39% at concentrations from $1.0\times {10}^{-2}$ to $1.0\times {10}^{-1}M$ under continuous scrubbing. In the batch experiments, the batch naphthalene absorption capacities were estimated to be $31.8\mu g \mathrm{Nap}/g{C}_{10}{E}_4\text{,}$ $12.9\mu g \mathrm{Nap}/g{C}_{14}{E}_8\text{,}$ and 2.4 μg Nap/g SDS. A comparison was also made among SDS, $C_{10}{E}_4\text{,}$ and $C_{14}{E}_8$ in terms of cost, foaming, impact of wastewater, removal efficiency, and absorption capacity.