2 research outputs found
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
Hazy Weather-Induced Variation in Environmental Behavior of PCDD/Fs and PBDEs in Winter Atmosphere of A North China Megacity
Haze is a serious pollution problem
during the wintertime in North
China. In this study, we investigated how the periodic cycle of winter
haze events affect the environmental behaviors of two typical persistent
organic pollutants, namely, polychlorinated dibenzo-<i>p</i>-dioxins and dibenzofurans (PCDD/Fs) and polybrominated diphenyl
ethers (PBDEs), in the atmosphere of a typical megacity, Beijing.
The average atmospheric concentrations of the total di- to octa-CDD/Fs
(∑PCDD/Fs: 378.0 pg/m<sup>3</sup>) and the total mono- to nona-BDEs
(∑<sub>9h</sub>PBDEs: 166.5 pg/m<sup>3</sup>) during haze episodes
increased by 3.6-fold and 1.9-fold compared with those during the
nonhaze periods, respectively; and their concentrations both linearly
increased with PM<sub>2.5</sub> levels and decreased as a power function
of the atmospheric boundary layer height. The elevated concentrations
could be clearly attributed to the vertically sinking motion of airflow
in the midlower troposphere. When a haze event occurred, the partitioning
rate of PCDD/Fs and PBDEs into particles was reduced; the largest
fraction of the particle-bound ∑PCDD/Fs was shifted from ultrafine
particles to accumulation mode particles; and a steady-state model
(Li-Ma-Yang model) satisfactorily described the gas-particle partitioning
of the PCDD/F and PBDE homologues. The inhalation exposure risk evaluation
indicated that special attention should be paid to the increased cancer
risk induced by the elevated inhalation intake of PCDD/Fs during haze
episodes