Concentrations and Distribution Patterns of Perfluoroalkyl Acids in Sewage Sludge and in Biowaste in Hesse, Germany

Abstract

A total of 201 sewage sludge and 45 biowaste samples were examined for 14 different perfluoroalkyl acids (PFAA). For perfluorooctanesulfonic acid, maximum concentrations of 698 μg/kg dry weight were measured in sewage sludge and for perfluorohexanesulfonic acid 29.0 μg/kg dry weight were found in biowaste. Looking at the fingerprints of both these matrixes it can be see that long-chain PFAA make up 85.9% of the total concentration in sewage sludge whereas short-chain PFAA only account for 14.1%. In contrast, the trend in biowaste is just the opposite, with 53.2% long-chain and 46.8% short-chain PFAA. These results lead to the conclusion that sewage sludge functions as a sink for long-chain PFAA, and the plants preferentially take up short-chain PFAA from the sludge/soil, as seen by the concentrations found in biowaste. It can be calculated that the total yearly amount of PFAA spread onto agricultural lands amount to 15.3 kg.