ABSTRACT
The main target of this work is to characterize the abatements of particulate matter (PM), hydrocarbons (HC) and nitrogen oxides (NO(x)) from an actual diesel exhaust using dielectric barrier discharge technology (DBD). The effects of several parameters, such as peak voltage, frequency and engine load, on the contaminant removals have been investigated intensively. The present study shows that for a given frequency, the removals of PM and HC are enhanced with the increase of peak voltage and level off at higher voltage, while in the range of higher voltages a decline of NO(x) removal efficiency is observed. For a given voltage, the maximums of specific energy density (SED) and removal efficiency are attained at resonance point. The increase of peak voltage will result in a significant decrease of energy utilization efficiency of DBD at most engine loads. Alkanes in soluble organic fraction (SOF) are more readily subjected to removals than polycyclic aromatic hydrocarbons (PAHs).
Subject(s)
Electrochemical Techniques , Hydrocarbons/isolation & purification , Nitrogen Oxides/isolation & purification , Particulate Matter/isolation & purification , Vehicle Emissions , Air Pollution/prevention & control , Alkanes/isolation & purification , Polycyclic Aromatic Hydrocarbons/isolation & purificationABSTRACT
This study was aimed at evaluating the influence of ethanol addition on diesel exhaust emissions and the toxicity of particulate extracts. The experiments were conducted on a heavy-duty diesel engine and five fuels were used, namely: E0 (base diesel fuel), E5 (5%), E10 (10%), E15 (15%) and E20 (20%), respectively. The regulated emissions (THC, CO, NOx, PM) and polycyclic aromatic hydrocarbon (PAH) emissions were measured, and Ames test and Comet assay, respectively, were used to investigate the mutagenicity and genotoxicity of particulate extracts. From the point of exhaust emissions, the introduction of ethanol to diesel fuel could result in higher brake specific THC (BSTHC) and CO (BSCO) emissions and lower smoke emissions, while the effects on the brake specific NOx (BSNOx) and particulate matters (BSPM) were not obvious. The PAH emissions showed an increasing trend with a growth of ethanol content in the ethanol-diesel blends. As to the biotoxicity, E20 always had the highest brake specific revertants (BSR) in both TA98 and TA100 with or without metabolizing enzymes (S9), while the lowest BSR were found in E5 except that of TA98-S9. DNA damage data showed a lower genotoxic potency of E10 and E15 as a whole.
Subject(s)
Ethanol , Gasoline , Mutagens/toxicity , Vehicle Emissions/toxicity , Comet Assay , Polycyclic Aromatic Hydrocarbons/toxicity , Salmonella typhimurium/drug effectsABSTRACT
OBJECTIVE: To study the genotoxicity of components of diesel engine exhausts with ethanol-diesel blending fuel. To provide scientific arguments to find more economical and less polluted fuels. METHODS: Ames test, comet assay and GC-MS technique were used to test the genotoxicity and 16 kinds of PAHs on diesel engine exhausts with different proportions of ethanol (E0, E5, E10, E20). RESULTS: Both Ames test and comet assay were positive. It shows that diesel engine exhausts can lead to mutation and DNA damage, especially in pure diesel oil. But the content of 16 kinds of PAHs and DNA damage level decreased in exhausts of E5. With the increase of ethanol proportion in diesel oil, the content of 16 kinds of PAHs and DNA damage level increased. CONCLUSION: Compared with pure diesel oil and high proportion of ethanol fuel, E5 can reduce the genotoxicity and the brake specific exhausts of PAHs.
