[Characteristics of VOCs Emissions and Ozone Formation Potential for Typical Chemicals Industry Sources in China].

This study selected five typical types of chemical industry volatile organic compounds (VOCs) emission characteristics in China for analysis. The results from 70 source samples showed that alkanes were the dominant VOCs category from synthetic material industry sources, petrochemical industry sources, and coating industry sources (accounting for 43%, 63%, and 68%, respectively); olefins were the main VOCs category from the daily supplies chemical industry (46%); and halogenated hydrocarbons were the dominate VOCs category from specialty chemicals industry account source emissions (43%). Additionally, the machine learning method was applied in this study to analyze the marker components of the above industries. The results showed that decane and tetrahydrofuran were the source markers of the synthetic material industry; n-butanol and toluene were the markers of the daily supplies industry source; 1,2,3-trimethylbenzene and 1,3,5-trimethylbenzene were the markers of the petrochemical industry source; propylene and 3-methyl pentane were the source markers of the coating industry; and P-Xylene and cumene were the markers of the specialty chemicals industry source. The maximum incremental reactivity method (MIR) was used to estimate the ozone formation potential (OFP) of different VOCs-sources. The calculation results showed that when considering per unit TVOCs concentration emissions, the contribution to the ozone generation potential was in the order of the daily supplies chemical industry, specialty chemical industry, petrochemical industry, synthetic material industry, and coating industry. Therefore, we suggest that more attention should be paid to the key active species emitted by various industry sources rather than only the total amount of VOCs emissions in future ozone prevention and control efforts.

Impact assessment of odor nuisance, health risk and variation originating from the landfill surface.

Many researchers are concerned that municipal solid waste (MSW) threatens public health, causing them to increasingly focus on odor pollution. In this study, the odor nuisance and health risk impacts of landfill surface gas on eight sensitive receptors were assessed. The emission rates of odor and 145 volatile organic compounds (VOCs) were acquired by considering various landfilling operations, including high-density polyethylene (HDPE) membrane removal (MR), landfill tipping area (TA), temporary HDPE membrane cover (MC), top of the HDPE membrane (LM) and dumping platform (DP). Furthermore, differences in landfill surface geometry, such as emission height and source area, and variations in residential living floors were considered in odor assessment with the air dispersion model. Based on these uncertain factors, normal-, medial-, and worst-case scenarios were defined to elucidate the odor nuisance effect and health risk impact. Four of the eight sensitive receptors, which were 2.6 km away from the landfill surface, basically experienced odor nuisance and health risk impacts. Dichloromethane exerted an indelible and crucial impact on body health based on a comprehensive investigation of aromatics, halocarbons, and other chemicals. The odor nuisance and health risk impacts were notable near the landfill, and the local environment was remarkably damaged.

[Characterization and Health Risk Assessment of Exposure to Odorous Pollutants Emitted from Industrial Odor Sources].

Odor pollution has a high complaint rate with strong public concern, and industrial production is an important source of this type of pollution in China. To understand odor pollution in industrial parks and to protect the safety of work environments, samples were collected from 14 industrial odor sources and then were analyzed for odorous volatile organic compounds (VOCs) and odor concentration. Based on the field data, the main compounds causing odor were assessed and identified. The cancer and non-cancer risk of odor exposure were correspondingly estimated by the health risk model. These following results were noted. ①The substances discharged from 14 sources were the same, but the content varied greatly. Alkanes and alkenes are the major odorous compounds of fibers and batteries manufacturing and in the synthesis of hydrocarbons, anhydrides, esters, and solvents. Benzene and benzene series in waste gases from refineries, purified terephthalic acid (PTA), and latex sources were the highest. Esters are the main pollutants emitted from activated carbon processing, resin synthesis, and spraying. Carbonyl compounds and sulfides are the main exhaust gases from ceramic manufacturing and additive synthesis. ②Exhaust gases from 14 sources caused strong irritation. The synthesis of lubricating oil additives and latex sources result in severe olfactory stimulation. Ethyl mercaptan, ethyl sulfide, n-butanol, and toluene were the major odorous compounds of lubricating oil additives sources. Styrene, propylbenzene, cumene, butyl acrylate, and 1,3-butadiene were the major odorous compounds of latex sources. ③The carcinogenic risk levels for 14 sources ranged from 3.06×10-7 to 1.06×10-2, expressed as life cancer risk (LCR). Refinery, PTA, ester, and latex sources had the highest carcinogenic risk among the 14 emission sources. The non-carcinogenic risk levels for the 14 sources ranged from 0.02 to 51.66, expressed as hazard index (HI). The total HI of latex synthesis, ester synthesis, petroleum refining, PTA synthesis, and fiber manufacturing has certain non-carcinogenic health risks. Factory boundaries for latex, anhydrides synthesis, and resin synthesis sources have potential carcinogenic risk.