Application of Tween 80 in the Remediation of Diesel-Contaminated Podzolic Soils Under Boreal Conditions

Surfactant-enhanced remediation is a promising approach for treating petroleum-contaminated soils, particularly in areas where conventional methods are limited by environmental constraints. This study investigates the application of Tween 80, a non-ionic surfactant, for remediating diesel-contaminated Albic Podzolic soils typical of boreal regions. Laboratory experiments were conducted over 90 days, using two surfactant concentrations (3.0 × 10−4 and 1.5 × 10−4 mol L−1) and two temperature regimes (22–24 °C and 2–3 °C), simulating seasonal variability in cold-climate contaminated sites. The lower Tween 80 concentration—below the critical micelle concentration—proved more effective, achieving up to 21% total petroleum hydrocarbon (TPH) reduction at ambient temperature and 17% under refrigerated conditions. Treated soils also exhibited pH neutralization, indicating improved chemical stability. Acute toxicity bioassays (Vibrio fischeri and Ceriodaphnia affinis) confirmed the environmental safety of the applied concentrations (≤0.3 mol L−1). These results support the practical use of Tween 80 in the remediation of petroleum-contaminated soils under boreal constraints, providing transferable data for designing safe and efficient field-scale treatment strategies. This work also offers insights that are relevant to remediation policies in cold climates and to the adaptation of surfactant-assisted technologies for diverse field conditions.