TREATMENT METHOD OF WASTEWATER FORMED DURING NITRATION OF TOLUENE INTO DINITROTOLUENE TO REMOVE NITRATION SECONDARY COMPONENT WITHOUT ADDITIONAL PROCESS AND ADDITION OF FOREIGN MATERIALS

摘要

PURPOSE: Provided is a method for treating an aqueous wastewater formed during the nitration of toluene into dinitrotoluene using nitration acid, comprising the acidic and alkaline wastewater obtained from the washing step of dinitrotoluene and the aqueous distilled product obtained from the concentration step of sulfuric acid, to recollect the nitration product contained in various aqueous waste and to separate and remove the nitration secondary component without additional process and the addition of foreign materials. CONSTITUTION: The method comprises the steps of mixing the acidic and alkaline wastewater obtained from the washing step of the nitration process of toluene into dinitrotoluene with an aqueous distilled product obtained from the concentration step of sulfuric acid to make pH be less than 5; separating an organic phase and an aqueous phase; applying the separated aqueous phase to the extraction process; extracting the organic component present in the aqueous phase with toluene; and introducing the toluene phase rich in an organic component into the toluene nitration process.