Degradation of alkyllead compounds to inorganic lead in contaminated soil

In glass columns with sandy soil from a former antiknocking agents factory hydrophobic tetraalkyllead was transformed in oxygen-saturated water to inorganic lead. Up to 324 mg l−1 trialkyllead, but only very little dialkyllead accumulated. After 740 days 49.1±6.7% of the organic lead was converted to inorganic lead. Conversion of hydrocarbons was 39.6±5.1%. To reduce toxicity of high trialkyllead concentrations the water of soil columns was replaced by tap water after 450 d. Trialkyllead in the new water increased again to more than 150 mg l−1. If the alkyllead-containing water from these columns was diluted to concentrations of alkyllead compounds that were found in the groundwater after air injection (total alkyllead<10 mg l−1) and used as a source of alkyllead compounds in columns with non-contaminated sandy soil, elimination of tetra-, tri- and dialkyllead compounds followed first-order kinetics. In the soil 85.8–93.6% of the alkyllead dissappeared in only 170 days with 51% being converted to inorganic lead. This makes in situ remediation reasonable.