Occurrence of Synthetic Phenolic Antioxidants and Major Metabolites in Municipal Sewage Sludge in China

Synthetic phenolic antioxidants (SPAs) are one group of widely used additive chemicals, which have not yet had focused attention except for a few compounds such as 2,6-di-<i>tert</i>-butyl-4-methylphenol (BHT). In this study, the occurrence and composition profiles of 12 frequently used SPAs and three BHT metabolites were investigated in fifty-six sludge samples collected from individual wastewater treatment plants in China. Eleven SPAs were positively found in the sludge samples, in which, to our knowledge, eight SPA compounds were identified for the first time in the environment. BHT, 4-<i>tert</i>-octylphenol (4-<i>t</i>OP), and 2,4,6-tri-<i>tert</i>-bultylphenol (AO 246) were the most dominant SPAs in the sludge at mean concentrations of 4.14 μg/g, 374 ng/g, and 98.1 ng/g d.w. (dry weight). Meanwhile, three BHT metabolites, including 3,5-di-<i>tert</i>-butyl-4-hydroxybenzaldehyde (BHT-CHO), 2,6-di-<i>tert</i>-butyl-1,4-benzoquinone (BHT-Q), and 2,6-di-<i>tert</i>-butyl-4-hydroxy-4-methyl-2,5-cyclohexadienone (BHT-quinol), were also found in most of the samples (>98.2%) with mean concentrations of 141, 562, and 225 ng/g d.w., respectively. The activated sludge system (anaerobic, anoxic, and oxic tanks) of a wastewater treatment plant was further investigated for the removal efficiencies of the SPAs. High removal efficiencies (80.1–89.2%) were found for the six detected SPAs in the aqueous phase, while generation of large proportions of the three BHT metabolites was also observed

Distribution and Preliminary Exposure Assessment of Bisphenol AF (BPAF) in Various Environmental Matrices around a Manufacturing Plant in China

Increasing attention has been paid to bisphenol A and bisphenol (BP) analogues due to high production volumes, wide usage and potential adverse effects. Bisphenol AF (BPAF) is considered a new bisphenol analogue which is used as raw material in plastic industry, but little is known about its occurrence in the environment and the potential associated risk. In this work, BPAF levels and environmental distribution were reported in samples collected around a manufacturing plant and a preliminary exposure risk assessment to local residents was conducted. BPAF was detected in most of the samples, with levels in river ranging between 4 ng/L, sediments (0.520–2.00 × 10³ ng/g dry weight, dw), soils

Identification and Composition of Emerging Quaternary Ammonium Compounds in Municipal Sewage Sludge in China

Quaternary ammonium compounds (QACs) have raised considerable attention due to their wide commercial applications and recent discovery of unknown persistent analogues in aqueous environment. In this work, the occurrence and distribution of alkyltrimethylammonium (ATMAC), benzylakyldimethylethylammonium (BAC) and dialkyldimethylammonium (DADMAC) homologues were investigated in fifty-two municipal sewage sludge samples. ATMAC C10–18, BAC C8–18 and paired DADMAC C8:8-C18:18 as well as emerging homologues such as ATMAC-20, 22 and mixed DADMAC-16:18 and 14:16 were present. Furthermore, paired DADMAC-20:20 and mixed DADMAC-14:18, 18:20 were identified for the first time by nontarget qualitative strategies. A triple quadruple mass spectrometer quantification method was also initially verified with the aid of laboratory synthesized standards for the analysis of the mixed DADMACs with no certificated commercial standards currently available. The total concentrations of ATMACs, BACs and DADMACs were in the range of 0.38–293, 0.09–191 and 0.64–344 μg/g dry weight, respectively, and particularly, mixed DADMACs constituted 39 ± 7% of total DADMAC concentrations. The concentrations and profiles of individual homologues further suggested different QAC applications and fate in China. Significant correlations were also found among the concentrations of various QAC homologues as well as wastewater treatment plant (WWTP) characteristics (total organic carbon contents and daily treatment volumes)

Data_Sheet_1_Phthalates and phthalate metabolites in urine from Tianjin and implications for platelet mitochondrial DNA methylation.docx

BackgroundPhthalates (PAEs) are important synthetic substances in plastics, attracting much attention due to their potential effects on the cardiovascular system.MethodsIn this study, urine and blood samples from 39 individuals were collected in Tianjin, China. Phthalates and phthalate metabolites (mPAEs) were analyzed using gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography-mass spectrometry (HPLC-MS), respectively. The polymerase chain reaction (PCR) products from bisulfite-treated mitochondrial DNA (mtDNA) samples were analyzed using pyrosequencing technology.ResultsThe detection frequencies for 9 PAEs varied from 2.56 to 92.31%, and those for 10 mPAEs varied from 30.77 to 100%. The estimated daily intakes (EDIs) and cumulative risk of PAEs were calculated based on the experimental statistics of urinary PAEs and mPAEs. For PAEs, the HIRfD (hazard index corresponding to reference doses) values of 10.26% of participants and the HITDI (hazard index corresponding to tolerable daily intake) values of 30.77% of participants were estimated to exceed 1, suggesting a relatively high exposure risk. The mtDNA methylation levels in the MT-ATP8 and MT-ND5 were observed to be lower than in the MT-ATP6. Mono-ethyl phthalate (MEP) and MT-ATP8 were positively correlated with triglyceride levels (p ConclusionThe effects of PAE exposure on cardiovascular diseases (CVDs) should be investigated further.</p

Concentrations and Composition Profiles of Benzotriazole UV Stabilizers in Municipal Sewage Sludge in China

The environmental contamination and fate of benzotriazole UV stabilizers (BZTs) have received increasing attention due to their large production volume and wide usage in various consumer and industrial products. In the present work, 60 municipal sewage sludge samples from wastewater treatment plants (WWTPs) in 33 cities in China were collected to investigate the occurrence and distribution of 9 frequently used BZTs. The most dominant analogue was 2-[3,5-bis­(1-methyl-1-phenylethyl)-2-hydroxyphenyl]­benzotriazole (UV-234) at a median concentration of 116 ng/g (dry weight) and accounted on average for 27.2% of total BZTs. The abundance was successively followed by 2-(2-hydroxy-5-<i>tert</i>-octylphenyl)­benzotriazole (UV-329, average 24.3%), 2-(2-hydroxy-3-<i>tert</i>-butyl-5-methylphenyl)-5-chlorobenzotriazole (UV-326, average 22.2%), 2-(3,5-di-<i>tert</i>-amyl-2-hydroxyphenyl)­benzotriazole (UV-328, average 17.7%), and 2-(2-hydroxy-5-methylphenyl)­benzotriazole (UV-P, average 6.6%), with median concentrations of 66.8, 67.8, 57.3, and 20.6 ng/g, respectively. 5-Chloro-2-(3,5-di-<i>tert</i>-butyl-2-hydroxyphenyl)­benzotriazole (UV-327) and 2-(3-<i>sec</i>-butyl-5-<i>tert</i>-butyl-2-hydroxyphenyl)­benzotriazole (UV-350) had low detection frequency, while 2-(3,5-di-<i>tert</i>-butyl-2-hydroxyphenyl)­benzotriazole (UV-320) and 2-(5-<i>tert</i>-butyl-2-hydroxyphenyl)­benzotriazole (UV-PS) were not detectable in any sample. To our knowledge, this is the first study reporting the occurrence of UV-234, UV-329, and UV-350 in sewage sludge in China. Significant correlations were found among the BZT concentrations and also with a WWTP characteristic (daily treatment volume). Furthermore, results from degradation prediction and multimedia fate simulation based on a quantitative structure–property relationship (QSPR) model at screening level also implied that the commercial BZT chemicals and their plausible transformation products might be persistent in the environment