TANG J T, SONG D Y, LI Y B,et al.Effect of illumination on mercury speciation in PM_2.5 [J].Journal of Henan Polytechnic University(Natural Science) ,2023,42(4):86-91.

doi:10.16186/j.cnki.1673-9787.2021050042

Received:2021/05/11

Revised:2021/08/08

Published:2023/07/25

Effect of illumination on mercury speciation in PM_2.5

TANG Junting1, SONG Dangyu1,2, LI Yunbo1,2, TANG Shunlin1

1.Institute of Resources and Environment， Henan Polytechnic University，Jiaozuo  454000，Henan，China;2.Henan Cooperative Innovation Center of Coalbed Methane （Shale） in Central Plains Economic Zone，Henan Polytechnic University，Jiaozuo  454000，Henan，China

Abstract:In order to reflect the photo-reduction and possible secondary release of particle-bound mercury，the distribution variations of PM_2.5 bound mercury（PBM_2.5）under simulated sunlight were analyzed by using PM_2.5  as the carrier，which provided a reference for the study of PBM_2.5 speciation transformation and regional mercury pollution assessment.Mercury speciation in PM_2.5  was extracted and determined by Bloom and CVAFS respectively.The gaseous mercury produced by PBM_2.5 under different light duration was also collected and determined simultaneously.The results showed that under simulated sunlight，photo-reduction was the mainly chemical reaction of PBM_2.5.More than 90% of the produced gaseous mercury was Hg⁰，and a small amount was Hg²⁺.The transformation of PBM_2.5 to Hg⁰ was mainly affected by illumination，which promoted the transformation.With the increase of illumination time，the volume concentrations of each mercury speciation in PM_2.5 decreased exponentially.F5/ PBM_2.5 increased with the progress of illumination，while other mercury speciation showed the opposite trend，indicating that illumination could promote the existence of particle-bound mercury in a more stable geochemical form and positively affect the deposition of mercury.

Key words:mercury;PM;chemical speciation;photo-reduction

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