Updating vehicle VOCs emissions characteristics under clean air actions in a tropical city of China.

In the context of clean air actions in China, vehicle emission limits have been continuously tightened, which has facilitated the reduction of volatile organic compounds (VOCs) emissions. However, the characteristics of VOC emissions from vehicles with strict emission limits are poorly understood. This study investigated the VOC emission characteristics from vehicles under the latest standards based on tunnel measurements, and identified future control strategies for vehicle emissions.

New solution for predicting the removal efficiency of organic contaminants by UV/ HO: From a case study of 1H-benzotriazole.

Rapid prediction of the removal efficiency and energy consumption of organic contaminants under various operating conditions is crucial for advanced oxidation processes (AOPs) in industrial application. In this study, 1H-Benzotriazole (BTZ, CAS: 95-14-7) is selected as a model micropollutant, a validated incorporated Computational Fluid Dynamics (CFD) model is employed to comprehensively investigate the impacts of initial concentrations of HO, BTZ and dissolved organic carbon (DOC) (i.e.

[Ozone Pollution Characteristics and Formation Mechanism in a Typical Tropical Seaside City].

To investigate the pollution characteristics and formation mechanism of ambient air ozone(O) in a typical tropical seaside city, we conducted an observational experiment on O and its precursors at an urban site in Haikou, Hainan Province, from June to October 2019. The O pollution characteristics were analyzed comprehensively; the O-NO-VOCs sensitivities and key precursors were determined, and the control strategies for O pollution were carried out. The results were as follows:1 O pollution in Haikou mainly occurred in September and October, with daily maximum 8-h O concentrations in the range of 39-190 μg·m, and the daily variation in O was unimodal, peaking at approximately 14:00.

New insight into the removal process of benzotriazole UV stabilizers by UV/HO: Integrating quantum chemical calculation with CFD simulation.

Benzotriazole UV stabilizers (BT-UVs) are important UV absorbers. As high-production chemicals and potential hazards, their ubiquitous presence in aquatic environments is of greatly pressing concern. Herein, the removal of six typical BT-UVs by UV/HO was comprehensively investigated by quantum chemistry calculation integrated with CFD simulation.

Mechanistic insight into the degradation of 1H-benzotriazole and 4-methyl-1H-benzotriazole by •OH-based advanced oxidation process and toxicity assessment.

Benzotriazoles (BTs) are highly produced chemicals that are commonly used in the manufacture of aircraft de-icing/antifreeze fluids (ADAFs), coolants, etc. BTs have been detected in a variety of water environments, causing health hazards to aquatic species and humans. In this study, 1H-benzotriazole (BTri) and 4-methyl-1H-benzotriazole (4-TTri) were selected to investigate their degradation mechanisms in the aqueous phase initiated by ·OH using a theoretical calculation method.

Influence of SO on the MnO/TiO SCR catalyst for elemental mercury removal and the function of Fe modification.

Elemental mercury (Hg) is a highly hazardous pollutant of coal combustion. The low-temperature SCR catalyst of MnO/TiO can efficiently remove Hg in coal-burning flue gas. Considering its sulfur sensitivity, the effect of SO on the catalytic efficiency of MnO/TiO and Fe modified MnO/TiO for Hg removal was investigated comprehensively for the first time.

A Comprehensive Investigation on Potential Risk Factors for NSCL/P in a Rural District of Hebei Province, China.

Non syndromic cleft lip with or without palate (NSCL/P), one of the most common birth defects, is closely related to various risk factors. However, information regarding risk factors for NSCL/P in rural districts in China is very limited thus far. The objective of this study was designed to identify the potential risk factors for NSCL/P in rural districts.

New mechanistic understanding for atmospheric oxidation of isoprene initiated by atomic chlorine.

Isoprene is the most abundant non-methane VOC and a significant SOA contributor. The atmospheric oxidation initiated by atomic chlorine is an important sink for isoprene, especially in certain regions with high Cl concentration, while its detailed oxidation mechanism remains unclear. In this work, we comprehensively investigated the reaction mechanism of isoprene with Cl using quantum chemistry calculation, and first elaborated the specific reaction mechanisms of chloroalkenyl peroxy radicals with HO/NO and the formation of 2-methylbut-3-enal, highlighting their important roles in the SOA formation.

The expression of STAT3 inhibited the NF-ΚB signalling pathway and reduced inflammatory responses in mice with viral myocarditis.

Background: The aim of this study was to investigate the mechanism of STAT3 in reducing the inflammatory responses in mice with viral myocarditis (VMC).

Methods: Induce and generate viral myocarditis by using coxsackievirus B3 (CVB3) infected cardiomyocyte-specific STAT3 conditional knockout (STAT3cKO) mice and BALB/c mice. Use RT-PCR and western blot techniques to detect the expression of related cytokines in the uninfected wild-type mice group (Control group), myocarditis wild-type mice group (Model group) and STAT3cKO group, as well as the differentiation of spleen T cells in each group.

Hazardous volatile organic compounds in ambient air of China.

Volatile organic compounds (VOCs) are ubiquitous in the atmosphere and the majority of them have been proved to be detrimental to human health. The hazardous VOCs were studied very insufficiently in China, despite the enormous emissions of VOCs. In this study, the concentrations and sources of 17 hazardous VOCs reported in literature were reviewed, based on which the health effects were assessed.

Correction to: Gas-phase reaction of benzo[a]anthracene with hydroxyl radical in the atmosphere: products, oxidation mechanism, and kinetics.

The original version of this article unfortunately contained a mistake. The sequence of the author affiliations was incorrect. The correct information is given below.

Mechanism and kinetics studies of the atmospheric oxidation of p,p'-Dicofol by OH and NO radicals.

As an effective organochlorine pesticide, Dicofol has been extensively applied in more than 30 countries for protecting over 60 different crops. Considering its large consumption and potential adverse effect on human health (endocrine disrupting and carcinogenicity), the fate of Dicofol sprayed into the air is of public concern. In this study, we conducted a comprehensive study on the reaction mechanisms of p,p'-Dicofol with OH and NO radicals using DFT method.

Gas-phase reaction of benzo[a]anthracene with hydroxyl radical in the atmosphere: products, oxidation mechanism, and kinetics.

Polycyclic aromatic hydrocarbons (PAHs) have induced large-scale and long-term environmental contamination due to heavy emissions, toxicity, and persistence. The investigation of the ultimate sink of PAHs in the atmosphere is very important. In this work, using quantum chemistry methods, the reaction mechanism of hydroxyl radical-initiated oxidation of benzo[a]anthracene (BaA) in the atmosphere was studied.

Relationship of polycyclic aromatic hydrocarbons with oxy(quinone) and nitro derivatives during air mass transport.

Airborne concentrations of Polycyclic Aromatic Hydrocarbons (PAH), quinone and nitro derivatives have been measured at three sites on the coast of Saudi Arabia to the north of the city of Jeddah. The PAH show a general reduction in concentrations from northwest to southeast, consistent with a source from a petrochemical works to the northwest of the sampling sites. In comparison, the concentrations of quinones show little variation between the sampling sites consistent with these being predominantly longer lived secondary pollutants formed from PAH oxidation.

Theoretical perspectives on the mechanism and kinetics of the OH radical-initiated gas-phase oxidation of PCB126 in the atmosphere.

Polychlorinated biphenyls (PCBs) primarily exist in the gas phase in air and may undergo atmospheric oxidation degradations, particularly the oxidation reaction initiated by OH radicals. In this work, the mechanism of the OH radical-initiated atmospheric oxidation of the most toxic PCB congener 3,3',4,4',5-pentachlorobiphenyl (PCB126) was investigated by using quantum chemistry methods. The rate constants of the crucial elementary reactions were estimated by the Rice-Ramsperger-Kassel-Marcus (RRKM) theory.

Mechanism and thermal rate constant for the gas-phase ozonolysis of acenaphthylene in the atmosphere.

Due to its prevalent presence, it is critical to clarify the atmospheric fate of acenaphthylene (Ary). In this paper, the reaction mechanism of the gas-phase ozonolysis of Ary was investigated by using quantum chemistry methods. Possible reaction pathways were discussed, and the theoretical results were compared with the available experimental data.

Mechanism and kinetic properties for the OH-initiated atmospheric oxidation degradation of 9,10-Dichlorophenanthrene.

Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) have become a serious environmental concern due to their widespread occurrence and dioxin-like toxicities. In this work, the mechanism of the OH-initiated atmospheric oxidation degradation of 9,10-dichlorophenanthrene (9,10-Cl₂Phe) was investigated by using high-accuracy quantum chemistry calculations. The rate constants of the crucial elementary reactions were determined by the Rice-Ramsperger-Kassel-Marcus (RRKM) theory.

Mechanism and kinetic properties of NO3-initiated atmospheric degradation of DDT.

In this article, the NO3 radical-initiated atmospheric oxidation degradation of DDT was theoretically investigated using molecular orbital theory calculations. All the calculations of intermediates, transition states and products were performed at the MPWB1K/6-311+G(3df,2p)//MPWB1K/6-31+G(d,p) level of theory. Several energetically favorable reaction pathways were revealed.

Mechanistic and kinetic studies on OH-initiated atmospheric oxidation degradation of benzo[α]pyrene in the presence of O2 and NO(x).

The degradation of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere can lead to toxic derivatives which contribute to the carcinogenic potential of particulate organic matter. This paper aimed to investigate the mechanism of the OH-initiated oxidation degradation of benzo[α]pyrene (BaP), a cancer risk indicator. High-accuracy molecular orbital calculations were carried out, and all of the possible degradation pathways were discussed.

Mechanistic and kinetic studies on the OH-initiated atmospheric oxidation of fluoranthene.

The atmospheric oxidation of polycyclic aromatic hydrocarbons (PAHs) can generate toxic derivatives which contribute to the carcinogenic potential of particulate organic matter. In this work, the mechanism of the OH-initiated atmospheric oxidation of fluoranthene (Flu) was investigated by using high-accuracy molecular orbital calculations. All of the possible oxidation pathways were discussed, and the theoretical results were compared with the available experimental observation.