Biodegradation of waste amines under anaerobic, micro-aerobic and aerobic conditions

Abstract

Monoethanolamines (MEA) are commonly used as adsorbent in CO2 capture plants. MEA are degraded when used and become a waste product. 3 series of BOD test as well as 9 cases of syringe batch experiments under anaerobic, micro-aerobic and aerobic conditions were conduced to examine the biodegradation of waste amines. BOD and syringe batch experiments indicate that waste amines are successfully degraded and degraded with high reaction rates under all anaerobic, micro-aerobic and aerobic conditions, removing more than 90 % of amine COD. Almost all amine COD was removed in the micro-aerobic case. The BOD experiments show that the amine degradation is in first order reaction, and the highest reaction rate 1.08/d was obtained in reactors with 125 mg/l of initial amine. Even high concentration of amines (2000 mg/l) can be degraded if pH is maintained neutral. Small and compact biological treatment plants therefore can be built to treat waste amines at low cost and meanwhile recover energy as CH4.