the hydrophile–lipophile balance (HLB; calculated as HLB=% wt. EO/5) was 9.7 for Brij 30, 13.4 for Tween 80, and 13.6 for Triton X-100. The critical micelle concentrations (CMC) for the surfactants were determined by measuring the surface tension at each surfactant concentration. The characteristics of the selected PAHs and surfactants are given in Table 1. Purified water was used for all tests (Ultrapure System, Barnsterd, USA).