Operation of lab-scaleanammox process with effluent from A/O process which operated in wastewater treatment plant as substrate

Abstract:

In order to study the feasibility of anaerobic ammonia oxidation(Anammox) process in Waste Water Treatment Plant(WWTP), lab-scale Anammox reactor was employed in municipal WWTP. NaNO₂ was added into the sewage effluent treated by A/O process in WWTP to serve as substance to start up Anammox filter reactor. In order to investigate the performance of Anammox process in engineering application, sewage effluent treated by A/O and nitrification process was served as inflow after the successful start-up of reactor. From the 106th to the 144th day, the maximal ammonia and total nitrogen concentrations in effluent were 4.1 and 13.4 mg/L with water temperature vary from 15 to 20 ℃ and the nitrogen concentration in effluent fitted the national 1A discharge standard of pollutants for municipal wastewater treatment plant. From the 168th to the 204th day, the reactor was running in the winter. When water temperature varied from 12 to 15 ℃, nitrogen concentration in effluent fitted the standard with the strategy of prolonging HRT. From the 222th to the 240th day, when the water temperature reduced to 10-12 ℃, NaHCO₃ was added in inflow at a concentration of 125 mg/L. Nitrogen removal rate increasd 40 percents and the ammonia and total nitrogen in effluent was 1.4 and 13.6 mg/L. Nitrogen concentration in effluent reached the national 1A discharge standard of pollutants for municipal wastewater treatment plant in winter. The thickness of biomembrane increased continuely in the whole process of filter column and finally reached 113 μm. Ammonia anaerobic oxidation loading rate was greater than 5 kg/(kgMLSS·d) and Anammox process operated efficiently and stably.