title: The performance of a combined nitritation-anammox reactor treating anaerobic digestion supernatant under various C/N ratios.
abstract: A combined nitritation-anammox reactor was developed to treat the digestion supernatant under various C/N ratios. Due to the difficulties for heterotroph to utilize the refractory organics, the reactor presented relatively stable performance with increasing supernatant addition. Nevertheless, the adverse effects of supernatant would accumulate during the long-term operation and thus weakened the activity and shock resistance of microbes, which further led to the gradual decrease of reactor performance after 92 days' operation. Under this circumstance, supernatant with volatile fatty acids (VFAs) residuals was further introduced into the reactor to investigate the performance of combined nitritation-anammox process with VFA addition. With the appearance of VFAs, the nitrogen removal performance gradually restored and the reactor finally achieved stable and efficient performance with C/N ratio of 0.35. The VFA residuals within 150 mg/L in the supernatant served as the extra electron donors and stimulated the heterotrophic denitrification process, which was vital for the enhancement of reactor. The nitrogen removal rate and total nitrogen removal efficiency reached 0.49 kg N/(m3·day) and 88.8% after 140 days' operation, respectively. The combined nitritation-anammox reactor was proved suitable to treat digestion supernatant.
authors: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: zhao-j07@mails.tsinghua.edu.cn.
authors: Jian
authors: J
authors: Zhao
authors: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: jiane.zuo@tsinghua.edu.cn.
authors: Jiane
authors: J
authors: Zuo
authors: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors: Jia
authors: J
authors: Lin
authors: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors: Peng
authors: P
authors: Li
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D000693:Anaerobiosis; D052818:Autotrophic Processes; D019149:Bioreactors; D002244:Carbon / Q000378:metabolism; D019069:Cell Respiration; D004305:Dose-Response Relationship, Drug; D005232:Fatty Acids, Volatile / Q000378:metabolism; D058465:Nitrification; D009584:Nitrogen / Q000378:metabolism; D010084:Oxidation-Reduction; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D064751:Ammonium Compounds; D002244:Carbon; D005232:Fatty Acids, Volatile; D009584:Nitrogen; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Anaerobic digestion supernatant; C/N ratios; Combined nitritation–anammox; Volatile fatty acids