BIOTREATMENT OF A POINT-SOURCE INDUSTRIAL WASTE-WATER ARISING IN 3,4-DICHLOROANILINE MANUFACTURE USING AN EXTRACTIVE MEMBRANE BIOREACTOR

A novel membrane bioreactor has been used to detoxify an industrial ''point-source'' wastewater containing aniline, 4-chloroaniline (4CA), 2,3-dichloroaniline (23DCA), and 3,4-dichloroaniline (34DCA). This wastewater arises during the process of manufacturing 34DCA. Direct biological-treatment of this wastewater is difficult without some form of pretreatment or dilution due to its inorganic composition. The reactor system described overcomes this problem;by selectively extracting the anilines from the wastewater by means of a membrane separation step and transferring them into a biological growth compartment (biomedium) where they are biodegraded by specifically enriched microorganisms. This article reports the use of a membrane bioreactor configuration that uses shell and tube membrane modules linked to a CSTR bioreactor via a recirculating biomedium flow. The reactor system has successfully extracted and biodegraded the targeted pollutants from industrial wastewater samples over an operating period of 5 months with removal efficiencies of over 99 % at wastewater residence times of less than 2 h.