Treatment of acrylic acid production wastewater using an anaerobic membrane bioreactor
University of New Brunswick
The performance of an anaerobic membrane bioreactor (AnMBR) process was evaluated for treating wastewater from the production of acrylic acid. Acrylic acid and formaldehyde are present in the wastewater and these compounds are known to be toxic for anaerobic bacteria. Due to the toxicity of this wastewater, it is presently incinerated. The study aims to evaluate the technical feasibility of treating the wastewater using an AnMBR. This study demonstrates that this high strength toxic wastewater with an influent 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 was not significant; the system experienced only one fouling event after over 400 days of operation at a flux of 0.2 m³ /m² ·d. The system performance was evaluated through time series analysis of performance data and by performing a COD mass balance on the system during a steady state period at each loading. The mass balance calculations suggested that the majority of the influent COD has been converted to methane, indicating that the system was performing well with the biomass successfully converting organic material into methane.