Abstract:

Tween80 solution was employed to flush naphthalene contaminated groundwater. Two factors influencing remediation efficiency including Tween80 mass concentration and flush velocity were evaluated. Before the flushing experiments, a series of solubilization and sorption batch experiments were also carried out. Sorption experiments showed that the isotherm of Tween80 was fitted with Freundlich model; whereas the sorption isotherms of naphthalene were all linear with or without Tween80. Only when Tween80 mass concentration were greater than 2.0 g/L, the sorbed naphthalene can be desorbed into water. The solubilization experiments data indicated that the solubility of naphthalene in 10.0 g/L Tween80 solution increased to 500 mg/L, which equals to 17 times of the naphthalene saturation concentration in water. Column experiments demonstrated that the maximum removal efficiency(≥90%) was achieved at the conditions with the Tween80 concentration of 10.0 g/L and flushing flow rate of 3.0 mL/min.

Key words: Tween80, naphthalene, critical desorption concentration, groundwater, flush velocity, mass concentration