Solubilization of polycyclic aromatic hydrocarbons in C16E7 nonionic surfactant solutions

•Nonionic surfactant plays an important role in solubilizing PAHs.•The string-like micelles grew with increasing incorporation of PAHs.•The size of micelles depended on the concentration of three kinds of PAHs.•The micelle remained string-like structure even when they were saturated with PAHs.•The naphthalene in the micelles was mainly solubilized in palisade region.