Application of chemical hot washing method for oily solid waste treatment

In this study, five types of chemical hot cleaning agent were screened to evaluate the oil removal efficiency, which was based on the component analysis of an oily solid waste from an oilfield in western China. The best experimental conditions were determined through single-variable and orthogonal tests. The results indicate that pharmacy AST-01 has the best removal efficiency. The optimum treatment conditions were as follows: AST-01 concentration, 20.0 g/L; temperature, 60 °C; stirring speed, 125 rpm; and stirring time 30 min. The oil content decreased to 1.91% under these conditions. The influence order of different factors decreased in the following order: the dosage of pharmacy, stirring speed, and temperature. The results of a combined experiment show that the removal efficiency was improved. The optimum proportion of pharmacies AST-01 and AST-02 was 10:1. The oil content decreased to 0.82%. The field engineering tests showed that the oil content of the residue was less than 2% when the optimum proportion was used. In general, this method decreases the oil content in an oily solid waste significantly and thus reduces the harmfulness of oily solid wastes.