Evaluation of the occurrence and biodegradation of parabens and halogenated by-products in wastewater by accurate-mass liquid chromatography-quadrupole-time-of-flight-mass spectrometry (LC-QTOF-MS)

Occurrence, fate and risk assessment of parabens and their chlorinated derivatives in an advanced wastewater treatment plant

“…Most commonly used parabens, MeP, PrP, EtP, and BuP, were efficiently removed (97.6-99.8%) during this progress, while PHBA showed moderate removal efficiency of 78.6%. Similar results were also found in other WWTPs from the United Kingdom [41], Spain [11], and Denmark [42], with a very high removal efficiency exceeding 90%. It is reported that the persistence of parabens seems to slightly increase with the length of the alkyl chain [11].…”

“…Similar results were also found in other WWTPs from the United Kingdom [41], Spain [11], and Denmark [42], with a very high removal efficiency exceeding 90%. It is reported that the persistence of parabens seems to slightly increase with the length of the alkyl chain [11]. However, the two parabens with longer alkyl chains, BzP and OcP, which were not detected in effluent (the calculation of removal is limited by the MDLs), were removed more effectively during the conventional treatment in this study, which is consistent with reports that parabens with longer alkyl chains underwent faster degradation than those with short alkyl chains in wastewater [23].…”

“…Several studies have also reported the occurrences of parabens in secondary effluents from WWTPs with activated sludge treatments. The values in this study were slightly lower than or similar to those reported in North-western Spain (MeP: 6.1-50 ng/L; EtP: ND-9.8 ng/L; PrP: ND-21 ng/L; BuP: ND) [11], and North-eastern part of Switzerland (MeP: 4.6-423 ng/L; EtP: <0.3-17 ng/L; PrP: <0.5-28 ng/L; BuP: 0.2-3.9 ng/L) [10], but were much higher than those found in Spain, where all the parabens were below the MDLs [28].…”

“…Similar levels of di-chlorinated MeP were reported to occur in raw sewage water at concentrations ranging from 10 to 100 ng/L [11]. Compared to their respective parent compounds, chlorinated derivatives, especially the di-chlorinated derivatives, are more stable in the environment and more toxic to aquatic organisms [30], so these compounds are worth paying more attention to their environmental fate and toxicological properties.…”

“…Several studies have demonstrated that most of parabens in aqueous-phase were effectively removed during conventional sewage treatments in WWTPs, with the average removal rate over 90% [10,11]. However, it is not clear whether the total input of parabens is really lost during the treatment, accumulates in sludge or ends up dis- charged with the effluent.…”