RESUMEN
The effects of clay dose and mixing energy on the efficiency of vegetable oil sedimentation by clay are investigated. The sedimentation efficiency increased with increasing clay dose to a maximum of about 80% of added oil. The maximum sedimentation efficiency was achieved at a lower clay dose, and the sedimentation efficiency was greater for a given clay dose when the oil was present as a thick oil film rather than as a thinner film. Sedimentation efficiency was relatively constant for mixing energies less than about 0.01 m2 s(-3) (0.01 W kg(-1)) but decreased dramatically at higher energy dissipation rates. Mixing energy may not be an important factor in determining the effectiveness of this response alternative because energy dissipation rates in natural surface water bodies under most typical conditions are less than 0.01 m2 s(-3). The effects of oil film thickness and mixing energy on the efficiency of vegetable oil sedimentation suggests that vegetable oil-mineral aggregates (VOMA) form through a different mechanism to that of petroleum oil-mineral aggregates (OMA). One consequence of the different formation mechanisms is that VOMA are much larger than petroleum OMA.
Asunto(s)
Silicatos de Aluminio/química , Aceites de Plantas/química , Fenómenos Químicos , Arcilla , Relación Dosis-Respuesta a Droga , Restauración y Remediación Ambiental/métodos , Ácidos Grasos Monoinsaturados/química , Ácidos Grasos Monoinsaturados/aislamiento & purificación , Aceites de Plantas/aislamiento & purificación , Aceite de Brassica napus , Propiedades de Superficie , Termodinámica , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/aislamiento & purificaciónRESUMEN
The effects of surfactant composition on the ability of chemical dispersants to disperse crude oil in fresh water were investigated. The objective of this research was to determine whether effective fresh water dispersants can be designed in case this technology is ever considered for use in fresh water environments. Previous studies on the chemical dispersion of crude oil in fresh water neither identified the dispersants that were investigated nor described the chemistry of the surfactants used. This information is necessary for developing a more fundamental understanding of chemical dispersion of crude oil at low salinity. Therefore, we evaluated the relationship between surfactant chemistry and dispersion effectiveness. We found that dispersants can be designed to drive an oil slick into the freshwater column with the same efficiency as in salt water as long as the hydrophilic-lipophilic balance is optimum.