Concentration of potentially carcinogenic PAHs in soils fertilized with sewage sludge

The aim of the study was to determine the effect of urban soil fertilization with different types of sewage sludge on the changes in the concentration of potentially carcinogenic polycyclic aromatic hydrocarbons (PAHs) in soil. The factors in the experiment were: two types of sewage sludge (stabilized dehydrated - S1 and granulated - S2), three sewage sludge doses (0 - control, 14.5 and 29 Mg DM/ha) and 2 years of study. The main objective of this study was the determination of the concentration of the following potentially carcinogenic PAHs: BP - Benzo(g,h,i)perylene, BaA - benzo(a)anthracene, BbF - benzo(b)fluoranthene, Chry - chrysene, BkF - benzo(k)fluoranthene, BaP - benzo(a)pyrene, IP -Indeno(1,2,3cd)pyrene, DBA - dibenzo(a, h)anthracene by using GC/MS. The basic properties of the studied soils were evaluated, that is, dehydrogenase and catalase activity, the total number of bacteria, C: N ratio and organic matter content. Fertilization with sewage sludge had a significant influence on the concentration of individual potentially carcinogenic PAHs in the urban soil samples. Moreover, in the second year, the reduction of the sum of potentially carcinogenic PAHs by approximately 55% after the S1 application and an increase of approximately 6% after the S2 application was observed.