[Simultaneous detection of lower aliphatic amines and conventional cations in atmospheric PM2.5 particulates by ion chromatography].

Many amine pollutants exist in the atmosphere. Lower aliphatic amines promote the formation and growth of particles into PM2.5, which damages the heart, lungs, and kidneys of the human body. PM2.5, a common atmospheric particulate pollutant with complex compositions, is the main cause of haze weather. Therefore, measuring the contents of lower aliphatic amines and cations in PM2.5 is of great significance for monitoring environmental air quality and protecting human health. This study established a suppressed ion-chromatographic method with conductivity for the simultaneous detection of four lower aliphatic amines (methylamine, dimethylamine, trimethylamine, and ethylamine) and five cations (Na+, N[Formula: see text], and Ca2+ showed high concentrations. The contents of the four lower aliphatic amines were low; however, the ethylamine content in some samples was high. The results indicate that the proposed method meets the quantification requirements for cations and lower aliphatic amines in PM2.5, with simple processing, high sensitivity, and good accuracy. It can quickly and accurately detect a large number of samples and be used to assess the pollution of small particles in the air as well as trace pollution sources to protect human health.

[O3 Source Characteristics of an Industrial Area in the Yangtze River Delta Based on Boundary Observations].

To study the characteristics of ozone sources in a petrochemical industrial park in Shanghai, O3 and its precursors were synchronously and continuously measured for 3 months(June-August 2020) alongside meteorological parameters using an online monitoring system. The Texas Commission on Environmental Quality(TCEQ) method and principal component analysis(PCA) were used to study the contribution of regional background and local O3 concentrations in the industrial zone, the results of which were compared. The results indicated that:① During the observation period, the dominant wind directions in the park were southeast and east, and the average temperature was 27.12℃. The daily average ρ(VOCs-36), ρ(NOx), and ρ(O3) was 32.05-240.51, 10.15-47.51, and 31.81-144.43µg·m-3, respectively. Alkanes are the most abundant of 36 VOCs; ② The regional background concentrations based on the TCEQ method ranged from 32.63 to 191.13µg·m-3, and the local concentrations ranged from 16.08 to 134.25 µg·m-3. The percentage contribution of the regional background ranged from 32.6% to 87.7%. The PCA analysis showed that the regional background concentrations ranged from 66.3 to 219.83µg·m-3; ③ The variations in local O3 concentrations based on the TCEQ analysis broadly correspond to the variations in ozone formation potential in the park. The two analysis methods were consistent, verifying that the results are reliable; and ④ After eliminating the calculation error caused by the abnormal concentrations recorded at some stations, the proportion of background O3 in the region was generally within the range 75%-95% during the observation period. Overall, regional transport was the main source of O3 in the industrial park, and O3 pollution in the surrounding cities should be the focus of pollution control alongside joint prevention and control measures in the Yangtze River Delta region.

[Non-activated Peroxymonosulfate-Induced Degradation of Sulfasalazine: Kinetics and Mechanism Investigations].

Sulfate-radical-based advanced oxidation technologies by activation of peroxymonosulfate (PMS) have been widely applied for decontamination of wastewater, although our knowledge on the direct oxidation of organic contaminants by PMS is still limited. In this study, the direct interaction between PMS and sulfasalazine (SSZ), a widely used antibiotic, was investigated systematically, including the reaction kinetics and transformation pathways. The results revealed that SSZ degradation obeyed a pseudo-first-order kinetic model and increasing initial PMS concentration or ionic strength could accelerate the degradation rates; alkaline conditions were beneficial to SSZ removal by PMS; and the presence of Cl- markedly promoted SSZ decay. The degradation of SSZ by PMS was inhibited in surface water. By using liquid chromatography-mass spectrometry as well as reaction site identification, two different oxidation pathways were proposed, including hydroxylation and SO2 extrusion. The findings obtained in this study could help to evaluate the feasibility of decontamination of sulfonamide antibiotics by non-activated PMS.

Secondary ion mass spectrometry: The application in the analysis of atmospheric particulate matter.

Currently, considerable attention has been paid to atmospheric particulate matter (PM) investigation due to its importance in human health and global climate change. Surface characterization, single particle analysis and depth profiling of PM is important for a better understanding of its formation processes and predicting its impact on the environment and human being. Secondary ion mass spectrometry (SIMS) is a surface technique with high surface sensitivity, high spatial resolution chemical imaging and unique depth profiling capabilities. Recent research shows that SIMS has great potential in analyzing both surface and bulk chemical information of PM. In this review, we give a brief introduction of SIMS working principle and survey recent applications of SIMS in PM characterization. Particularly, analyses from different types of PM sources by various SIMS techniques were discussed concerning their advantages and limitations. The future development and needs of SIMS in atmospheric aerosol measurement are proposed with a perspective in broader environmental sciences.

The mobile monitoring of black carbon and its association with roadside data in the Chinese megacity of Shanghai.

High-level black carbon (BC) pollution is associated with traffic emissions in metropolitan areas with high vehicle density. Mobile monitoring was conducted to assess the in-vehicle BC exposure on three backbone ring roads (inner, middle, and outer ring roads) on October 14 and October 18, 2015 in Shanghai. Ambient BC monitoring was also simultaneously conducted in three fixed roadside stations from October 14 to October 20, 2015. Results of the mobile monitoring showed median BC personal exposure concentrations ranging from 5.0 µg m-3 on the inner ring road to 13.5 µg m-3 on the outer ring road. The ambient BC concentrations during the entire observation period showed an arithmetic mean and a standard deviation of 3.5 ± 2.9 µg m-3. The correlation analysis of urban roadside monitoring (Caoxi Road and South Zhongshan Road) and personal data showed a high and significant correlation. The results of this study highlight the critical level of BC pollution in Shanghai and facilitate the development of evidence-based public health interventions and control strategies to prevent the adverse health effects of BC pollution.

[Correlation of Speciated Mercury with Carbonaceous Components in Atmospheric PM2.5 in Shengsi Region].

PM2.5 samples of four seasons were collected from Nov. 2014 to Aug. 2015 at the site of Shengsi island in Zhoushan islands. Mercury (Hg) and speciated mercury concentrations in PM2.5 samples were measured by Atomic Fluorescence Spectrometry (AFS-9130, China) after digestion with CEM Mars Xpress (PyNN Corporation, USA). The concentrations of organic carbon (OC) and elemental carbon (EC) in PM2.5 samples were determined by thermal/optical carbon analyzer (DRI, USA). The results showed that the daily concentrations of PM2.5-bounded mercury (PBM) ranged from 0.02 to 1.25 ng·m-3. Moreover, the mass content of PBM was (12.46±18.79) µg·g-1, which was higher than those in continental cities. ANOVA analysis result suggested that the highest average mass concentrations of PBM occurred in fall, sequentially followed by spring, winter and summer. Higher concentrations of PBM were in fall and spring, which might be related to biomass burning. In addition, RPM took the highest fraction of 53.1% in PBM, followed by HPM (27.3%) and EPM (19.7%), which might be resulted from the complicated composition of marine aerosols. The strong correlations among OC, EC and PBM indicated that carbonaceous composition may affect the transport of Hg in the atmosphere. The ratio of OC/EC represents atmospheric photo-oxidation capacity, so the positive correlation between OC/EC ratio and HPM indicated that HPM was resulted from atmospheric gas-particle transformation. The negative correlation between Char-EC/soot-EC and mercury species indicated that the atmospheric particle-bounded mercury might come mainly from the input of external mercury sources.

[Characteristics of Reactive VOCs Species During High Haze-Pollution Events in Suburban Area of Shanghai in Winter].

Based on the online measurements of VOCs of high pollution process at the university site in winter, VOCs' characteristics and species at different levels of haze pollution were analyzed. Fifty-five VOCs were detected during sampling. ∑55VOCs concentrations ranged between 25.5×10-9-1320.3×10-9(avg±SD,240×10-9±181×10-9). Toluene and xylene were the major pollutants during high pollution process, the concentrations of which were higher than those of industrial area. The university site shared a similar VOC composition with that of industrial area, which suggested that it might be influenced by the surrounding industries. VOCs species exhibited high concentrations in nighttime while low concentrations in daytime. The ozone concentrations were on the contrary. Aromatic hydrocarbons were predominant with a high percentage of contribution (70.0%) to OFP (ozone formation potential). Alkenes and alkynes were the second highest group (16.7%). The OFP of VOCs was 2078.2×10-9 under the west-south wind direction, about 4 times higher than the value under other wind directions (505.8×10-9). Aromatic hydrocarbons exhibited a predominant contribution to OFP at different levels of haze pollution in this area, among which, Toluene and xylene contributed more than 50% to OFP. The newest version of EPA PMF model was used to identify the major source of VOCs and evaluate their contributions. Gasoline sources and vehicle exhaust, refinery and petroleum products, solvent use and organic synthetic materials were the identified VOC sources in the study area, contributing 33.1%, 31.5%, 30.5%, and 4.9%, respectively to the ∑55VOCs concentrations.

Personal exposure to black carbon during commuting in peak and off-peak hours in Shanghai.

A study on a commuter's exposure to black carbon (BC) in five different traffic modes (taxi, bus, subway, cycling and walking) was conducted in Xuhui District, Shanghai. A commuter's real-time exposure concentrations were recorded by MicroAeth AE51 BC monitors, and the average BC exposure concentration and inhalation dose were analyzed. Data collected by cyclist was applied to characterize the micro-variability in relation to traffic density and street topology. The distance to the traffic and the street topology as well as the volume of heavy diesel trucks were the dominant factors influencing the BC concentrations. In this study, a high variability of BC concentrations between streets and even within streets was observed, and also between days and hour of the day. The average BC exposure concentrations were 5.59±1.02 µg/m(3), 6.58±1.78 µg/m(3), 7.28±1.87 µg/m(3), 8.62±4.13 µg/m(3) and 9.43±2.89 µg/m(3) for walking, cycling, bus, taxi and subway trips, respectively. Exposure levels of in-vehicle microenvironments were 8.66±3.66 µg/m(3), 9.39±6.98 µg/m(3) and 10.96±2.72 µg/m(3) for bus, taxi and subway, respectively. While inhalation doses were 0.68±0.33 µg, 0.95±0.29 µg, 1.36±0.37 µg, 1.50±0.39 µg and 1.58±0.29 µg for taxi, subway, cycling, bus and walking, respectively. BC exposure level of walking was the lowest among all the traffic modes, but its inhalation dose was the highest.