Degradation of Pyrene Contaminated Soil with Spiked 14C Pyrene by Hemoglobin Catalysis

Abstract

Hemoglobin (Hb) is a member of the hemeprotein family that undergoes non-specific catalytic chain reactions in the presence of hydrogen peroxide (H2O2). The catalytic ability of Hb to degrade the carcinogenic polycyclic aromatic hydrocarbon pyrene was demonstrated using soil contaminated with 14C pyrene. Three bench-scale laboratory tests were performed using 14C pyrene in the presence of a buffer, H2O2, and a combination of Hb and H2O2. The initial pyrene concentration of the contaminated soil was set to 11 mg/kg, with 5,500,000 dpm of 14C pyrene. After a catalytic reaction for 24 h, the results showed that 17% of pyrene was degraded by H2O2, 38% of pyrene was degraded by Hb in combination with H2O2, and 0.13 and 1.2% of 14C pyrene were mineralized by H2O2 and Hb in combination with H2O2, respectively. An analysis of the products from the reaction involving Hb in combination with H2O2 revealed that 15.9% of the 14C intermediates in the acetonitrile fraction were polar products. After the catalytic reaction, 21 intermediate compounds were found via fraction analysis. The results suggested that Hb catalysis could be used to treat pyrene-contaminated soil as a novel catalytic technology for the remediation of hazardous materials in soil.