Correlation Between Aromatic Hydrocarbons And Benzo[a]Pyrene In Coke Plant Emissions

The benzo[a]pyrene (BaP) is the best known for serious carcinogenicity and toxicity. In the coke industry, coke workers are heavily exposed to BaP by inhalation and skin contact. Occupational exposure to BaP has been associated with lung, skin and bladder cancers of humans.Air pollution is a serious problem in Shanxi. The coke industry is considered as a major source of pollution. Statistics suggest that the coke industry that account for40percent of air pollution in the whole province. Shanxi attempted to develop a real-time monitoring system for fugitive emission pollution sources which is effective and could be used to monitor the BaP at any time. The routine methods for PAH quantification have already been used by many labs in the world. But it is much more time-consuming, complex and expensive, it might not be applied in the real-time monitoring system.The main objective was to find a substitution, which has a linear relationship with BaP, can be determined easily. It was considered that the aromatic hydrocarbons might be easier and faster to be determined. Both the particulate-phase and gas-phase aromatic hydrocarbons from5coke plants were analyzed in this study, in order to investigate the correlation between the BaP and aromatic hydrocarbon concentration. A new approximate calculation formula of BaP concentration might be proposed by using linear regression model. And this result was expected to apply to a real-time monitoring system of pollution sources. Major conclusions are as follow:1. On top of coke oven batteries, the particulate-phase aromatic hydrocarbons concentrations were significantly positively correlated to BaP concentrations. The total aromatic hydrocarbons concentrations were significantly positively correlated to total BaP. Pearson correlation coefficients were0.740,0.633, respectively; On the ground of coke plants the particulate-phase aromatic hydrocarbons concentrations were significantly positively correlated to BaP. Pearson correlation coefficient was0.674; The concentration of aromatic hydrocarbons was insignificantly correlated with BaP in charging; In pushing, the particulate-phase aromatic hydrocarbons concentrations were significantly positively correlated to BaP. And the total aromatic hydrocarbons concentrations were significantly positively correlated to total BaP. Pearson correlation coefficients were0.652,0.629, respectively; The concentration of particulate-phase aromatic hydrocarbons was insignificantly correlated with BaP in combustion chamber emission. Pearson correlation coefficient was0.703.If Pearson correlation coefficient was greater than0.6(P<0.1in all cases), BaP concentrations can be predicted based on aromatic hydrocarbons concentrations by applying linear regression models to the obtained data.2. The higher the temperature, the lower the particulate-phase BaP concentrations and the higher the gas-phase BaP concentrations. And high concentrations, the correlation is better.3. The particulate-phase aromatic hydrocarbons and BaP are higher than in gas-phase on top of coke oven batteries; On the ground of coke plants, the particulate-phase aromatic hydrocarbons and BaP are lower than in gas-phase, but particulate-phase BaP is higher than in gas-phase; The gas-phase aromatic hydrocarbons concentrations are higher than in particulate-phase in charging and pushing, meanwhile, the gas-phase BaP concentrations are higher than in particulate-phase except coke plant2; The gas-phase aromatic hydrocarbons and BaP concentrations are higher than in particulate-phase in combustion chamber emissions.4. The results showed that BaP content of pushing emission was the highest in coke plants, here in turn from high to low were charging, coke oven top, combustion chamber, ground.5. Benzo[a]pyrene with high boiling point, low melting point, are easily adsorb on the particulate matters. Ministry of Environmental Protection of China has set a limit on particulate-phase BaP concentration. There are a certain amount of gas-phase aromatic hydrocarbon exist in the fugitive emissions, but it is not limited in the national standard. It should be attached importance and attention.