Changes in the content of polycyclic aromatic hydrocarbons (PAHs) in light soil fertilized with sewage sludge

In the present work the influence of soil fertilization with sewage sludge on the changes in the content of polycyclic aromatic hydrocarbons (PAH) in this soil was studied during a one-year field experiment. The experiment consisted of six plots to which sewage sludge was introduced at doses of 30 (1%), 75 (2.5%), 150 (5%), 300 (10%) and 600 ton/ha (20%) as calculated for dry mass. The PAH content at a depth of 0-20 and 20-40 cm was determined. With time, an increase in the PAH content in the lower soil layer (20-40 cm) and a gradual decrease of the PAH content in the 0-20 cm layer was observed. In most cases, a decrease by half in the PAH content in the soil fertilised with sewage sludge was observed.