Ammonia side-stream stripping as a tool to safely manage thermophilic co-digestion of nitrogen-rich wastes
Thermophilic anaerobic digestion is more sensitive than mesophilic digestion to toxicity and changes in operational and environmental conditions.In particular,it is more easily subjected to high concentrations of free ammonia,a strongly inhibitory compound.This fact frustrates the possibility of efficiently treating wastes rich both in carbon and nitrogen.Among the different strategies that can be implemented to control and counteract ammonia inhibition,air side-stream stripping is a remediation technology of particular interest due to its flexibility and easy operation.The present work investigates the feasibility of coupling an air side-stream stripping column (65℃,1 Lair L-1 digestate min-1,3 hours of retention time) to thermophilic (55℃) anaerobic digestion.Firstly,the effects on digester performance of stripping and recirculating 3 or 5 times per week 21% of reactor volume were studied.Ammonium nitrogen diminished in both cases without compromising methane production and digestion stability.Moreover,the efficacy of using side-stream stripping while optimizing methane production by increasing organic (and consequently nitrogen) loading rate was demonstrated.The stripping column-thermophilic digester coupling allowed to double the organic load while maintaining a stable and high methanization and avoiding biomass inhibition.
Ammonia control CO2 stripping food waste pig manure protein
C.Pedizzi J.M.Lema M.Carballa
Department of Chemical Engineering, Institute of Technology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain
国际会议
The 15th IWA World Conference on Anaerobic Digestion( 第15届IWA世界厌氧大会)
北京
英文
523-526
2017-10-17（万方平台首次上网日期，不代表论文的发表时间）