Influence of inorganic and organic road deicing salts on the mobi 2026 Chemo

Seasonal road salt application is vital for winter road safety, but repeated use of chloride (Cl)-rich salts (e.g., NaCl) releases high Cl loads to nearby soils. Elevated Cl levels can mobilize toxic trace metals from roadside soils, posing environmental risks. Although Cl-free organic salts are recommended as alternatives, their geochemical behavior in soils under varying environmental conditions remains less well understood. This study investigated the effects of pH and temperature on metal release performance from an agricultural roadside soil exposed to different deicing chemicals (NaCl, CaCl2, KCl, calcium magnesium acetate [CMA], sodium acetate [NaOAc], and potassium formate [HCOOK]) under laboratory conditions. The soil was amended with Pb (13 mg/kg) and Cd (3 mg/kg), divided into six portions, incubated separately with each salt (1000 mg/L for Cl-based salts and 1400 mg/L for formate/acetate-based salts) and subjected to alternative freshening and salting cycles under two pHs (5 and 8) and temperatures (5 and 20 °C). Changing the temperature from 5 °C to 20 °C had a minimal influence on the pH of the salt-added soil samples, except for NaOAc-treated soils, which caused the highest alkalinization (pH 6.0 to pH 8.8). This soil also released the greatest concentrations of Zn2+, Cu2+, Pb2+, and Cd2+ in all four pH and temperature conditions during the first freshening stage (cumulative release ~ 2 mg/).