Characterization of acid tars.
Acid tars from the processing of petroleum and petrochemicals using sulfuric acid were characterized by gas chromatography/mass spectrometry (GC/MS), inductively coupled plasma/optical emission spectrometry (ICP/OES), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectrometry, and scanning electron microscopy/energy dispersive X-ray (SEM/EDX) micro-analysis. Leaching of contaminants from the acid tars in 48 h batch tests with distilled water at a liquid-to-solid ratio 10:1 was also studied. GC/MS results show that the samples contained aliphatic hydrocarbons, cyclic hydrocarbons, up to 12 of the 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs), and numerous other organic groups, including organic acids (sulfonic acids, carboxylic acids and aromatic acids), phenyl, nitrile, amide, furans, thiophenes, pyrroles, and phthalates, many of which are toxic. Metals analysis shows that Pb was present in significant concentration. DSC results show different transition peaks in the studied samples, demonstrating their complexity and variability. FTIR analysis further confirmed the presence of the organic groups detected by GC/MS. The SEM/EDX micro-analysis results provided insight on the surface characteristics of the samples and show that contaminants distribution was heterogeneous. The results provide useful data on the composition, complexity, and variability of acid tars; information which hitherto have been scarce in public domain.
Department of Civil Environmental and Geomatic Engineering, University College London, Chadwick Building, Gower Street, London, WC1E 6BT, United Kingdom. sunday.leonard@ucl.ac.uk
Sunday A
SA
Leonard
Julia A
JA
Stegemann
Amitava
A
Roy
D000143:Acids / Q000737:chemistry; D002152:Calorimetry, Differential Scanning / Q000379:methods; D004577:Electron Probe Microanalysis; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D019015:Geologic Sediments / Q000737:chemistry; D006838:Hydrocarbons / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D019216:Metals, Heavy; D008855:Microscopy, Electron, Scanning / Q000379:methods; D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons / Q000302:isolation & purification; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013696:Temperature; D013997:Time Factors
D000143:Acids; D006838:Hydrocarbons; D007220:Industrial Waste; D019216:Metals, Heavy; D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons