Biological treatment of industrial wastewater from post-combustion carbon capture

Amine-based post-combustion capture is a technologically viable process for sequestering carbon emissions from coal-fired power plants. However, the resulting wastewater generally contains high concentrations of organic carbon, sulfates, amines, and amine derivatives. This research set forth to determine the efficacy of a biological treatment approach consisting of nitrification, denitrification, and sulfate reduction to decrease these contaminants. Two systems were considered: the first implemented the aerobic, anoxic, and anaerobic processes into three separate bioreactors; the second implemented each of these processes into a single bioreactor. The average removal efficiencies of chemical oxygen demand, total nitrogen, total Kjeldahl nitrogen, ammonia, and sulfate were 97 %, 79 %, 85 %, >99 %, and 16 % for the three-stage system, and 95 %, 88 %, 88 %, >99 %, and 10 % for the single-stage system. Extending the anaerobic phase by 12 h increased the sulfate removal to 25 % and 39 %, respectively. These results demonstrate the efficacy of biological treatment for carbon capture wastewater.