| 摘要 |
<p>The invention concerns a method for treating alkaline waste water derived from washing waste oil with water and containing organic substances, comprising a predetermined sequence of steps consisting in: a) contacting the alkaline waste water, at a temperature between 60 and 105 °C approximately, for a time interval between 5 and 60 minutes approximately, with a mineral acid in amount greater than 1 to 20 % than that corresponding to the reaction stoichiometry transforming into mineral salt all the atoms present in the alkaline waste water to be treated; b) allowing the resulting organic and aqueous phases to decant, at a temperature between 60 and 105 °C approximately, to recuperate the aqueous acid phase; c) contacting the aqueous acid phase, at a temperature between 40 and 95 °C approximately, with an alkaline solution in effective amount to obtain a pH of the reaction medium between 7.5 and 9 approximately, then leaving the reaction medium to rest, at a temperature between 40 and 95 °C approximately, to obtain the formation then the decantation of a floc, and filtering to recuperate the aqueous phase. This method enables to obtain water that can be discharged into known circuits treating industrial waste water or that can be upgraded for preparing fertilisers or an agent for eliminating glazed frost on road surfaces. The organic substances are recuperated in the form of an organic phase that can be upgraded as a substitute for organic acids, in particular naphthenic acids for acidifying bitumen.</p> |
