Treatment of Acrylic Acid Production Wastewater Using a Submerged Anaerobic Membrane Bioreactor

This paper presents the performance of an anaerobic membrane bioreactor (AnMBR) treating the wastewater from the production of acrylic acid. Acrylic acid and formaldehyde are present in the wastewater, and these are known to be toxic to anaerobic bacteria. Presently due to the toxicity of this wastewater it is typically incinerated. This study aims to evaluate the viability of treating the wastewater using an AnMBR. The system was a 25 L lab scale reactor that was operated for over 1 year. This study demonstrates that this high strength toxic wastewater with a COD concentration of 85 g/L is treatable up to an organic loading of 10 kg·COD/m3·d. The effluent COD was found to be less than 700 mg/L resulting in greater than 99% COD removal irrespective of the variation in loading rates. The effluent contained no detectable acrylic acid and formaldehyde was typically found to be less than 2 mg/L. Membrane fouling observed was not significant; the system experienced only one fouling event during 400 days of operation at a flux of 0.2 m3/m2·d.