Morphology and size of the particles emitted from a gasoline-direct-injection-engine vehicle and their ageing in an environmental chamber

Xing, Jiaoping; Shao, Longyi; Zhang, Wenbin; Peng, Jianfei; Wang, Wenhua; Shuai, Shijin; Hu, Min; Zhang, Daizhou

doi:https://doi.org/10.5194/acp-20-2781-2020

Articles | Volume 20, issue 5

https://doi.org/10.5194/acp-20-2781-2020

© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Special issue:

In-depth study of air pollution sources and processes within...

https://doi.org/10.5194/acp-20-2781-2020

© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 20, issue 5

Research article

|

06 Mar 2020

Research article |

| 06 Mar 2020

Morphology and size of the particles emitted from a gasoline-direct-injection-engine vehicle and their ageing in an environmental chamber

Jiaoping Xing, Longyi Shao, Wenbin Zhang, Jianfei Peng, Wenhua Wang, Shijin Shuai, Min Hu, and Daizhou Zhang

Download

Final revised paper (published on 06 Mar 2020)
Supplement to the final revised paper
Preprint (discussion started on 02 Sep 2019)
Supplement to the preprint

Interactive discussion

Status: closed

AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

- Printer-friendly version

- Supplement

RC1: 'Comments for acp-2019-647', Anonymous Referee #1, 28 Sep 2019
- AC1: 'Detailed responses to reviewer comments', Jiaoping Xing, 05 Dec 2019
RC2: 'Review of “Morphology and size of particles emitted from a GDI-engine vehicle and their ageing in an environmental chamber” by Xing et al.', Anonymous Referee #2, 03 Oct 2019
- AC2: 'Detailed responses to reviewer comments', Jiaoping Xing, 05 Dec 2019

Peer-review completion

AR: Author's response | RR: Referee report | ED: Editor decision

AR by Jiaoping Xing on behalf of the Authors (05 Dec 2019) Author's response Manuscript

ED: Referee Nomination & Report Request started (04 Jan 2020) by James Allan

RR by Anonymous Referee #2 (14 Jan 2020)

Suggestions for revision or reasons for rejection

The authors addressed most of my concerns. However, I think there are still a few small issues:
1. Verb tense consistency in the paper is still sometimes an issue.
2. More importantly, though, I am still a bit confused by the statements about the PM emissions being higher for hot start state with respect to cold start state, that's a bit counterintuitive for me. It would be good to comment on some possible explanations for these statements/findings. For example, at line 471 the authors mention: "The PM emission was the highest under the hot stabilized running state, followed by those under the hot start, cold start" (this is mentioned also in other parts of the paper) but looking at figures 3 and 4, it seems to me that during the cold start state the vehicle emitted substantially more particles than during the hot start state. Am I misinterpreting the sentences, or am I misreading the figures, or is there a contradiction? Anyway, it would be good to clarify this and to provide a potential explanation.
3. One of my previous comment was regarding the limitation of the study and the generality of the conclusions having the data being collected from only one vehicle. The authors partially addressed this in their response but did not make any change in the paper that really addresses this issue (if not just mentioning that doing TEM is time-consuming, that is an explanation of why they did what they did, but it does not address the fact that is still a limitation of the study). I think it would be beneficial and honest to clearly point out this caveat in the paper, specifically in the abstract and in the conclusions.
4. A final technical question: At line 393 the authors mention: "... transformation of primary particles emitted by the GDI-engine vehicles could occur within 3.5 hours", however, earlier they mentioned that the equivalent aging time they subjected their particles to in the chamber was ~10 days (line 205), so how do the authors reconcile these two statements? Please clarify.

Hide

RR by Anonymous Referee #1 (25 Jan 2020)

ED: Publish subject to minor revisions (review by editor) (25 Jan 2020) by James Allan

AR by Jiaoping Xing on behalf of the Authors (30 Jan 2020) Author's response Manuscript

ED: Publish subject to technical corrections (31 Jan 2020) by James Allan

AR by Jiaoping Xing on behalf of the Authors (01 Feb 2020) Manuscript

Download

Article (2924 KB)
Full-text XML

Short summary

Our results highlight the contribution of gasoline-direct-injection (GDI) vehicles to aerosols, both primary and secondary. The major particles from GDI vehicles are organic and soot particles; they actively participate in chemical conversions in the atmosphere, leading to morphology and composition changes in hours. Rapid ageing could be attributable to the acid-catalysed mechanism and high concentrations of gaseous pollutants. These results would be beneficial for control of PM_2.5 pollution.