Proceedings of The 5th International Conference on Innovation in Science and Technology
INNOVATIVE ANAMMOX ELECTRO–BIOREACTOR TREATING MUNICIPAL WASTEWATER AT LOW TEMPERATURE
Abdelmajeed Adam , Maria Elektorowicz
The anammox (anaerobic ammonium oxidation) process is a promising nitrogen removal technique alternative to conventional nitrification–denitrification, which directly oxidizes ammonium to diatomic nitrogen gas using nitrite as the electron acceptor without oxygen and external carbon supplies, and hence achieving high energy-saving potential. Yet, the implementation of anammox–related process is still limited to side-stream treatment of municipal sewage mainly due to lower operating temperatures and nitrogen concentrations of mainstream conditions. In this work, a novel lab-scale anammox electro–bioreactor was constructed to examine whether the anammox biomass would preserve activity at low temperature, in addition to investigate the potential application of mainstream anammox to treat a synthetic domestic wastewater containing 34 mg/L ammonium. A synthetic solution, consisting mainly of sodium nitrite and ammonium sulfate was used to feed the anammox reactor in the ratio 1:1 at HRT of 1 day. After 4 months of stable operation, temperature was a stepwise decreased by 1°C each 4– 5 days, and afterwards heating device was disconnected maintaining sludge temperature at 14±2 °C. Results showed that the novel reactor achieved simultaneous removal of nitrate and ammonia by over 80% and 83%, respectively. The anammox electro bioreactor successfully preserved adequate activity as a result of biomass adaptation to low temperature and substrate conditions. Furthermore, microbial community analysis by 16S rRNA analysis also proved the presence of the anammox bacteria at low temperature, while the abundance of anammox cells was severely affected by organic carbon inputs in the synthetic influent.
Keywords: anammox electro–assisted bioreactor; low temperature; low-strength ammonium; mainstream anammox process; sustainable technology.