scholarly journals Formation of Organic Sulfur Compounds through SO<sub>2</sub> Initiated Photochemistry of PAHs and DMSO at the Air-Water Interface

2022 ◽  
Author(s):  
Haoyu Jiang ◽  
Yingyao He ◽  
Yiqun Wang ◽  
Sheng Li ◽  
Bin Jiang ◽  
...  

Abstract. The presence of organic sulfur compounds (OSs) at the water surface, acting as organic surfactants, may influence the air-water interaction and contribute to new particle formation in the atmosphere. However, the impact of ubiquitous anthropogenic pollutant emissions, such as SO2 and polycyclic aromatic hydrocarbons (PAHs) on the formation of OSs at the air-water interface still remains unknown. Here, we observe large amounts of OSs formation in presence of SO2, upon irradiation of aqueous solutions containing typical PAHs such as pyrene (PYR), fluoranthene (FLA), and phenanthrene (PHE), as well as dimethylsulfoxide (DMSO). We observe rapid formation of several gaseous OSs from light-induced heterogeneous reactions of SO2 with either DMSO or a mixture of PAHs/DMSO, and some of these OSs (e.g. methanesulfonic acid) are well established secondary organic aerosol (SOA) precursors. A myriad of OSs and unsaturated compounds are produced and detected in the aqueous phase. The tentative reaction pathways are supported by theoretical calculations of the reaction Gibbs energies. Our findings provide new insights into potential sources and formation pathways of OSs occurring at the water (sea, lake, river) surface, that should be considered in future model studies to better represent the air-water interaction and SOA formation processes.

2002 ◽  
Vol 45 (10) ◽  
pp. 55-60 ◽  
Author(s):  
B.P. Lomans ◽  
A. Pol ◽  
H.J.M. Op den Camp

Microbial cycling of volatile organic sulfur compounds (VOSC) is investigated due to the impact these compounds are thought to have on environmental processes like global temperature control, acid precipitation and the global sulfur cycle. Moreover, in several kinds of industries like composting plants and the paper industry VOSC are released causing odor problems. Waste streams containing these compounds must be treated in order to avoid the release of these compounds to the atmosphere. This paper describes the general mechanisms for the production and degradation of methanethiol (MT) and dimethyl sulfide (DMS), two ubiquitous VOSC in anaerobic environments. Slurry incubations indicated that methylation of sulfide and MT resulting in MT and DMS, respectively, is one of the major mechanisms for VOSC in sulfide-rich anaerobic environments. An anaerobic bacterium that is responsible for the formation of MT and DMS through the anaerobic methylation of H2S and MT was isolated from a freshwater pond after enrichment with syringate as a methyl group donating compound and sole carbon source. In spite of the continuous formation of MT and DMS, steady state concentrations are generally very low. This is due to the microbial degradation of these compounds. Experiments with sulfate-rich and sulfate-amended sediment slurries demonstrated that besides methanogens, sulfate-reducing bacteria can also degrade MT and DMS, provided that sulfate is available. A methanogen was isolated that is able to grow on DMS as the sole carbon source. A large survey of sediments slurries of various origin demonstrated that both isolates are commonly occurring inhabitants of anaerobic environments.


2020 ◽  
Vol 20 (4) ◽  
pp. 1264-1270
Author(s):  
Xiang Tu ◽  
Shaohua Chen ◽  
Siyu Wang ◽  
Haiqing Liao ◽  
Xuejiao Deng

Abstract This study investigated the pollution status of volatile organic sulfur compounds (VOSCs) and the factors influencing their spatial distribution in the Xi River in Shenyang, China. A method for simultaneous determination of 14 VOSCs that cause odor in water samples was developed by using purge and trap coupled with gas chromatography and a flame photometric detector. The results indicated that each target compound could be identified from 15 sampling sites, and the total concentration of 14 VOSCs ranged from 2.575 to 52.981 μg L−1. Dimethyl sulfide (DMS) was the most important contaminant with an average concentration of 4.029 μg L−1, a detection rate of 93.33% and a variation coefficient of 0.72. The VOSCs were primarily distributed in suburban and rural sections, and the suburban section was the worst in regard to pollution by VOSCs. Dimethyl trisulfide was primarily distributed in urban and suburban sections of the Xi River due to industrial emissions. Ethanethiol, DMS, and ethyl methyl sulfide, which are typical by-products of microbial anaerobic decomposition from domestic wastewater, were found in abundance in the suburban section. Diethyl sulfide, diethyl disulfide, methyl propyl disulfide, and 1-propyl disulfide representing agricultural nonpoint source pollution were mostly distributed in the rural section.


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