Per- and polyfluoroalkyl substances fate and transport at a wastewater treatment plant with a collocated sewage sludge incinerator

Fate of perfluoroalkyl and polyfluoroalkyl substances (PFAS) through two full‐scale wastewater sludge incinerators

“…Basically, targeted PFAS that went in with the supply water came out in the drain. Seay et al (2023) observed a similar trend at an FBF WSI where the wet scrubber supply and drain water PFAS content differed by no more than 23% for five compounds; see Table S59. Table S60 contains the results of another study where no differing trend was observed (Weston & Sampson, 2023).…”

“…A mass balance using HF is unrealistic in full‐scale systems given the tendency for this acid to react with the refractory lining of the furnace and ductwork before the wet scrubber (Aleksandrov et al, 2019). Seay et al (2023) observed 44,000 times larger fluoride outflows from the incineration system, largely from the gain across the wet scrubber, compared with the fluorine measured in the targeted PFAS analyses. The fluoride concentrations in the dewatered wastewater sludge may explain the increase in wet scrubber water stream observations.…”

“…This sample volume facilitated a straightforward comparison to stack samples to determine significance of the combustion air contamination on the mass of PFAS moving through an incinerator. For comparison, a recent study that sampled air around a WRRF collected 100 times as much volume and detected several PFAS (Seay et al, 2023). The highest reported value not complicated by qualifications or control contamination exceeding sample values was PFBA at 16 pg/m 3 (25°C and 101.325 Pa).…”

“…Thus, while WSIs are expected to degrade PFAS, the destruction and removal efficiency (DRE) and PIC generation potential have not been documented. Seay et al (2023) attempted to develop a "PFAS" DRE for a WSI, but data used for the calculation suffered from laboratory quality control issues. Beyond that, Loganathan et al (2007) sampled dewatered wastewater sludge and ash from a WSI, observing 26%-97% reduction of six targeted PFAS, while two other compounds increased in concentration.…”

Levels of per- and polyfluoroalkyl substances (PFAS) in various wastewater-derived fertilizers – analytical investigations from different perspectives

“…The lowest PFAS values were detected for the pyrolyzed products which is also in good agreement with previous studies. 55,56 However, it has to be kept in mind that thermal treatment of PFAS containing fertilizers may produce volatile ultrashortchain PFAS 57,58 or organouoride compounds like CF 4 , CHF 3 etc. 59 which have a high global warming potential, and may aerwards enter the atmosphere, depending on the used lter systems in thermal treatment plants.…”