Iron/carbon conductive materials for enhancing anaerobic treatment of synthetic acrylamide wastewater

Abstract

BACKGROUND: Most studies have focused on the degradation of acrylamide (AM) by a single strain. There are relatively few studies on the treatment of AM by anaerobic activated sludge. Previous studies have shown that conductive particles can change the mode of electron transport between anaerobic microorganisms. Therefore, this study compared the enhancement effect of three different particles (Fe 3 O 4 , granular activated carbon (GAC), graphite) on the treatment of synthetic AM wastewater by anaerobic activated sludge under different temperature conditions (30, 25, 20 °C) and particle dose (2, 6 g L −1 ). RESULTS:The results showed that 6 g L −1 GAC improved the removal rate of chemical oxygen demand (COD) and AM by 22.95% and 19% compared with the control group at 30 °C, respectively, indicating that the addition of GAC contributes to the degradation of AM and improves COD removal rate. Results of high-performance liquid chromatography (HPLC) showed that the activated sludge with GAC obviously promoted the degradation of AM. Besides, a large amount of propionic acid was detected in all experimental groups during the reaction, and the activated sludge with GAC promoted degradation of propionic acid.CONCLUSION: Anaerobic activated sludge supplemented with sufficient GAC can not only absorb and degrade AM synchronously but also accelerate the conversion of intermediates, such as acrylic and propionic acids. Based on the results of HPLC and liquid chromatography-mass spectrometry, a possible method of degradation of AM by anaerobic activated sludge was proposed.