Publications by authors named "Jianrong Bi"

5 Publications

  • Page 1 of 1

Water-soluble brown carbon in atmospheric aerosols along the transport pathway of Asian dust: Optical properties, chemical compositions, and potential sources.

Sci Total Environ 2021 Oct 24;789:147971. Epub 2021 May 24.

Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China; Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China. Electronic address:

As an important type of light-absorbing aerosol, brown carbon (BrC) has the potential to affect the atmospheric photochemistry and Earth's energy budget. A comprehensive field campaign was carried out along the transport pathway of Asian dust during the spring of 2016, including a desert site (Erenhot), a rural site (Zhangbei), and an urban site (Jinan), in northern China. Optical properties, bulk chemical compositions, and potential sources of water-soluble brown carbon (WS-BrC) were investigated in atmospheric total suspended particulate (TSP) samples. Samples from Zhangbei had higher mass absorption efficiency at 365 nm (MAE, 1.32 ± 0.34 m g) than those from Jinan (1.00 ± 0.23 m g) and Erenhot (0.84 ± 0.30 m g). Compere to the non-dust samples, elevated water-soluble organic carbon (WSOC) concentrations and MAE values of dust samples from Erenhot are related to the input of high molecular weight organic compounds and biogenic matter from the Gobi Desert, while lower values from Zhangbei and Jinan are attributed to the dilution effect caused by strong northwesterly winds. Based on fluorescence excitation-emission matrix spectra and parallel factor analysis, two humic-like (C1 and C2) and two protein-like (C3 and C4) substances were identified. Together, C1 and C2 accounted for ~64% of total fluorescence intensity at the highly polluted urban Jinan site; C3 represented ~45% at the rural Zhangbei site where local biomass burning affects; and C4 contributed ~24% in the desert region (Erenhot) due to dust-sourced biogenic substances. The relative absorptive forcing of WS-BrC compared to black carbon at 300-400 nm was about 31.3%, 13.9%, and 9.2% during non-dust periods at Erenhot, Zhangbei, and Jinan, respectively, highlighting that WS-BrC may significantly affect the radiative balance of Earth's climate system and should be included in radiative forcing models.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.scitotenv.2021.147971DOI Listing
October 2021

Characteristics and unique sources of polycyclic aromatic hydrocarbons and nitro-polycyclic aromatic hydrocarbons in PM2.5 at a highland background site in northwestern China.

Environ Pollut 2021 Apr 18;274:116527. Epub 2021 Jan 18.

Institute of Nature and Environmental Technology, Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan; Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan. Electronic address:

Polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs (NPAHs) in PM were first observed at a background site (Yuzhong site: YZ site) in the northwestern highlands of China in five seasonal campaigns. Compared with major northwestern cities, PAHs and NPAHs at the YZ site were at a lower level but showed consistent seasonal differences. The PAH and NPAH concentrations peaked in the winter campaigns, which were 36.11 ± 6.54 ng/m and 418.11 ± 123.55 pg/m, respectively, in winter campaign 1 and 28.97 ± 10.07 ng/m and 226.89 ± 133.54 pg/m, respectively, in winter campaign 2. These values were approximately a dozen times larger those in other campaigns. The diagnostic ratios indicate that vehicle emissions were the primary source of the PAHs throughout the five campaigns, and coal and biomass combustion also contributed during the winter, summer, and fall campaigns. Among NPAHs, 2-nitrofluoranthene and 2-nitropyrene were generated through OH radical-initiated reactions during atmospheric transport, while 1-nitropyrene came from combustion sources. There is an observation worth pondering, which is that the ratio between pyrene and fluoranthene increased abnormally in the spring and fall campaigns, which is presumably caused by the burning of Tibetan barley straw in the northwestern highlands. The backward trajectories over Tibetan areas in Qinghai and southwestern Gansu are consistent with this hypothesis. In addition, this study reported for the first time that the burning of Tibetan barley straw has become a seasonal contributor to air pollution in northwestern China and is participating in the atmospheric transport of air pollutants driven by the monsoon in East Asia, which urgently requires further research.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envpol.2021.116527DOI Listing
April 2021

Natural aeolian dust particles have no substantial effect on atmospheric polycyclic aromatic hydrocarbons (PAHs): A laboratory study based on naphthalene.

Environ Pollut 2020 Aug 31;263(Pt A):114454. Epub 2020 Mar 31.

Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan; Institute of Nature and Environmental Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan. Electronic address:

Natural aeolian dust (AD) particles are potential carriers of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere. The heterogeneous interaction between them may lead to worsened air quality and enhanced cytotoxicity and carcinogenicity of ambient particulates in downwind areas, and this topic requires in-depth exploration. In this study, AD samples were collected from four Asian dust sources, and their physical properties and compositions were determined, showing great regional differences. The physical and chemical interactions of different AD particles with naphthalene (Nap; model PAH) were observed in aqueous systems. The results showed that AD particles from the Loess Plateau had weak adsorption to Nap, which was fitted by the Langmuir isotherm. There was no obvious adsorption to Nap found for the other three AD samples. This difference seemed to depend mainly on the specific surface area and/or the total pore volume. In addition, the Nap in the aqueous solution did not undergo chemical reactions under dark conditions and longwave ultraviolet (UV) radiation but degraded under shortwave UV radiation, and 2-formylcinnamaldehyde and 1,4-naphthoquinone were the first-generated products. The degradation of Nap in the aqueous solution was probably initiated by photoionization, and the reaction rate constant (between 1.44 × 10 min and 8.55 × 10 min) was much lower than that of Nap with hydroxyl radicals. Instead of inducing or promoting the chemical change in Nap, the AD particles slowed photodegradation due to the extinction of radiation. Therefore, it is inferred that natural AD particles have no substantial effect on the transportation and transformation of PAHs in the atmosphere.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envpol.2020.114454DOI Listing
August 2020

Investigation of aerosol absorption with dual-polarization lidar observations.

Opt Express 2020 Mar;28(5):7028-7035

Polarization lidar has been widely used in recent decades to observe the vertical structures of aerosols and clouds in the atmosphere. We developed a dual-polarization lidar system that can detect polarization measurements simultaneously at 355 nm and 532 nm. Dust events and haze episodes over northern China in 2014 were observed by the developed lidar. The results showed that the dust-dominated aerosol depolarization ratios at 532 nm were larger than those at 355 nm, but those of the air pollutants were smaller, indicating that this tool could provide a more accurate classification of aerosols. Moreover, we found a good relationship between the absorption coefficient of aerosols and the ratio of depolarization ratios at 532 nm and 355 nm for dust aerosols. Our results imply that aerosol absorption from polarization measurements may be determined by lidar at the ultraviolet and visible wavelengths.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OE.390475DOI Listing
March 2020

Automated detection of cloud and aerosol features with SACOL micro-pulse lidar in northwest China.

Opt Express 2017 Nov;25(24):30732-30753

The detection of cloud and aerosols using a modified retrieval algorithm solely for a ground-based micropulse lidar (MPL) is presented, based on one-year data at the Semi-Arid Climate Observatory and Laboratory (SACOL) site (35.57°N, 104.08°E, 1965.8 m), northwest of China, from March 2011 to February 2012. The work not only identifies atmosphere particle layers by means of the range-dependent thresholds based on elastic scattering ratio and depolarization ratio, but also discriminates the detected layers by combining empirical thresholds of the atmosphere's thermodynamics states and scattering properties and continuous wavelet transform (CWT) analyses. Two cases were first presented in detail that demonstrated that the modified algorithm can capture atmosphere layers well. The cloud macro-physical properties including cloud base height (CBH), cloud geometrical thickness (CGT), and cloud fraction (CF) were then analyzed in terms of their monthly and seasonal variations. It is shown that the maximum/minimum CBHs were found in summer (4.66 ± 1.95km)/autumn (3.34 ± 1.84km). The CGT in winter (1.05 ± 0.43km) is slightly greater than in summer (0.99 ± 0.44km). CF varies significantly throughout year, with the maximum value in autumn (0.68), and a minimum (0.58) in winter, which is dominated by single-layered clouds (81%). The vertical distribution of CF shows a bimodal distribution, with a lower peak between 1 and 4km and a higher one between 6and 9km. The seasonal and vertical variations in CF are important for the local radiative energy budget.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OE.25.030732DOI Listing
November 2017
-->