Leaching of individual PAHs in soil varies with the amounts of sewage sludge applied and total organic carbon content

The aim of the work was the evaluation of the ability of individual PAHs from the US EPA list to migrate in relation to the sludge dose applied. On the basis of statistical analysis, an attempt was undertaken to evaluate the role of organic matter (total content of organic carbon) in the transportation of individual PAHs. Different doses of sewage sludge were introduced into the soil starting with a fertilizing dose (30 t center dot ha(-1)), through melioration doses (75, 150, 300 t center dot ha(-1)) to extreme doses (600 t center dot ha(-1)). A few days after the application of sewage sludge, the increase of PAHs was noted in the 20-40 cm soil horizon. The range of increase depended on the sewage sludge dose applied. The highest increase in PAH content was observed in soil with a sludge dose of 300 t center dot ha(-1), However, after an 18-month period of study, the relationships observed before changed and the highest increase of individual PAHs in the 20-40 cm soil horizon relative to the control was noted in the case of the highest sludge dose.