Mobility of Soluble and Non-Soluble Hydrocarbons in Contaminated Aquifer
| Autor: | L. Zilliox, C. Bocard, Olivier Razakarisoa, P. Muntzer, J. Ducreux |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Pollution
geography Environmental Engineering geography.geographical_feature_category Chemistry business.industry media_common.quotation_subject Environmental engineering Residual oil Aquifer Silt Petroleum product Adsorption Environmental chemistry Vadose zone Leaching (metallurgy) business Water Science and Technology media_common |
| Zdroj: | Water Science and Technology. 22:27-36 |
| ISSN: | 1996-9732 0273-1223 |
| DOI: | 10.2166/wst.1990.0048 |
| Popis: | After the contamination of an aquifer by petroleum products, the residual oil trapped is a constant source of pollution by the entrainment of the most soluble hydrocarbons. By studying the exchanges of residual hydrocarbons between oil-water-air and soil, we pointed out that the liquid/gas exchange is the major factor of retention of soluble alkanes masking the adsorbing materials effects. For the soluble aromatic hydrocarbons, the main phenomenon observed is the liquid/solid exchange. The role of residual air is no more preponderant. The residual contamination of the vadose zone thus plays a preponderant role in the long-term pollution of a groundwater table. It is thus imperative to implement methods to prevent such harmful effects. The use of surfactants, by lowering the oil/water interfacial tension seems to be a new and effective method. Their adsorption into a natural matrix was studied with different porous substrates (sand, sand/silt). Their retention on sand is poor, but it increases with silt content. This is mainly due to a cationic exchange (Ca2+/Na+). In order to avoid this phenomenon a salt preflush by a 10 g/l Na Cl solution is effective. That allows a gas-oil recovery enhancement by reducing loss of surfactant in soil. Moreover, a surfactant partition between oil and water is underscored. A better understanding of these parameters would lead to the optimizing of the enhanced drainage technique for recovering residual oil trapped in an aquifer. |
| Databáze: | OpenAIRE |
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