Development of an extractive membrane bioreactor for degradation of 3 chloro-4-methylaniline: from lab bench to pilot scale

Abstract

Extractive Membrane Bioreactor (EMB) technology has been applied to an industrial wastewater containing 3-chloro-4-methylaniline, para-toluidine and methanol produced at the Hickson and Welch Ltd. production site in Castleford, UK. Successful treatment was accomplished through a step-wise approach to process development, involving selection of a suitable microbial culture, extractive membrane bioreactor operation under well controlled laboratory conditions, and finally pilot scale-application at the production site. Three experimental steps were undertaken: 1) a microbial culture capable of degrading 3-chloro-4-methylaniline was developed in a continuous enrichment reactor; 2) the selected culture was then inoculated to a lab-scale EMB unit and adapted to the conditions of the industrial waste; and 3) finally the process was scaled-up to assess feasibility and performance at pilot-scale. At the pilot scale, 100% extraction of the target molecules contained in the industrial wastewater was achieved in a 1 m3 extractive membrane bioreactor treating 60 g/d 3-chloro-4-methylaniline and 30 g/d para-toluidine. Stoichiometric amounts of chloride were generated, indicating complete mineralization of 3-chloro-4-methylaniline.