2024 Volume 80 Issue 25 Article ID: 24-25006
Recently, sewage sludge has been attracting attention as a stable domestic source of fertilizer raw materials. In Europe and the United States, however, it has been found to contain per/polyfluoroalkyl compounds (PFAS) in sewage sludge, and there is a movement to establish regulations on fertilizer use. However, knowledge of PFAS in sewage sludge in Japan is lacking. In order to clarify the actual status of PFAS contamination, this study analyzed dewatered cake from 34 sewage treatment plants across Japan for 30 types of PFAS. The total concentrations of the 30 PFASs were 4.6-370 ng/g-dry, with PFOS being the most prominent PFAS, and many long- and short-chain PFASs such as PFHxA, PFNA, PFUnDA, etc. were also detected. The concentrations of PFOS tended to be significantly higher in anaerobic digested sludge. PFOA, PFNA, and PFUnDA showed a slight tendency to increase in concentration with inorganic dewatering aids. It is necessary to pay attention to PFOS concentrations and their trends in order to expand the use of fertilizers in the same way as in Europe and the United States.
