title: Extraction and solubilization of crude oil and volatile petroleum hydrocarbons by purified humic and fulvic acids and sodium dodecylbenzenesulfonate.
abstract: Solubilization of crude oil (Fula, Sudan) in water demonstrates humic acid (HA), completely dissolves oil with a solubilization efficiency of 1600 g oil /g HA. The order of solubilization increases: HA > HA+ FA (fulvic acid) >> FA >>> SDBS (sodium dodecylbenzene sulfonate). Synthetic surfactant like, SDBS, exhibits the lowest efficiency even with 23 times the concentration of FA or HA. Extraction of diesel contaminated sand and GC-MS analysis show that HA and FA exhibit 50-90% extraction efficiency for C10-C22 at pH 11.9 with just one extraction. SDBS exhibits the least removal efficiency (<1%) for normal hydrocarbons. The effect of pH on extraction with HA by its micelles such as the surface active property was found to be greater than that for FA. On the basis of critical concentration, the extraction efficiencies with FA and HA are 1287 and 11453 times compared to SDBS, respectively, for the least extracted hydrocarbon at pH 10.8. The HSGC experiments showed that the solubilization efficiency of alkylbenzenes in gasoline (Shell 87) increases almost linearly with FA concentration with a slight deviation at 5-6 μM FA. About 35-60% of alkylbenzenes in gasoline were solubilized and partitioned at the highest FA concentration (15 μM) studied. Both studies with gasoline and diesel show similar extraction efficiencies even at 227-fold increased FA with diesel.
authors.affiliation: a Center for Clean Water and Sustainable Technologies, Department of Chemistry and Biochemistry , George Mason University , Fairfax , Virginia , USA.
authors.forename: Mahmoud D
authors.initials: MD
authors.lastname: Eljack
authors.forename: Abul
authors.initials: A
authors.lastname: Hussam
mesh_terms: D001557:Benzenesulfonates / Q000737:chemistry; D001578:Benzopyrans / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D006812:Humic Substances; D010578:Petroleum; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013501:Surface-Active Agents / Q000737:chemistry*; D055549:Volatile Organic Compounds / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D001557:Benzenesulfonates; D001578:Benzopyrans; D006812:Humic Substances; D010578:Petroleum; D013501:Surface-Active Agents; D055549:Volatile Organic Compounds; D014874:Water Pollutants, Chemical; C001114:dodecylbenzenesulfonic acid; C005023:fulvic acid
keywords: Crude oil; extraction; fulvic acid; headspace gas chromatography; humic acid; petroleum hydrocarbons