| 摘要 |
A process for removing organic pollutants from sludge-based materials or wastes having a high concentration of hydrocarbons, comprising the following operations:
a) optional separation and washing with water, optionally added, of fractions having a > 100 m particle size, obtaining a sludge containing the fine fraction having a < 100 m particle size and the pollutants concentrated therein;
b) mixing of the sludge with a lipophilic solvent (preferably ethyl acetate) at a mixing temperature selected in the range of 15-65 deg. C;
c) mechanical separation of the liquid phase, containing the pollutants and the solvent, from a solid phase consisting in the treated sludge;
d) recovery of the solvent from the liquid phase by any one known technique;
e) washing of the solid phase with water, until complete removal of the residual solvent;
f) separation, by decanting, of a solid fraction, consisting of the washed solid, and an aqueous phase saturated with solvent;
g) dewatering of the solid fraction obtained in step f);
h) recovery of the solvent from the aqueous phase by any one known technique. |
