산불로 인한 다환방향족탄화수소 오염특성과 거동

Abstract

Forest fires are the main natural source of polycyclic aromatic hydrocarbons (PAHs). Due to their resistance to the biodegradation, PAHs are well known as persistent organic pollutants (POPs) in the environment. After forest fires, residual ash above a soil layer can be highly contaminated with PAHs. However, little is known about the fate of these contaminants, particularly about their susceptibility to be transferred deeper into underlying soil or downstream during rainfall events. In this study, precipitation, organic carbon (OC) content, and the Σ16PAHs in unburnt control soil, burnt soil, and ash were monitored for 16 months after a forest hillside a semi rural area of Ulsan. Whereas the ash was significantly contaminated with PAHs, the PAH levels of the burnt soil were similar to those of the control soil. Ashes are more exposed to PAH contamination than unburnt control soil and burnt soil. As time passed, the levels of PAHs normalized by OC in the ash bed also decreased. PAH and OC lost from ash bed were likely to have been removed by surface runoff in a considerable amount of PAH rather than the proportion transferred to the soil. The temporal variation of relative disappearance rate (RDR) was due to the gradual evolution of the characteristics of ash bed and the mobility of PAH affected by precipitation. Further studies of various conditions through lab scale experiment may be useful for more understanding the fate of PAHs after forest fires.