Ammonia removal with different deammonification technologies from thermal hydrolysis anaerobic digestion dewatering liquors: PRESENTATION ONLY
Ochs, P.1,2, Martin, B2, Germain-Cripps, E.2, van Loosdrecht, M.3, Stephenson, T.1, Soares, A.1, 1Cranfield University, UK, 2Thames Water, UK, 3Delft University of Technology, The Netherlands
(free)
The benefits of biological nitrogen from conventional anaerobic digestion dewatering liquors in sidestream via deammonification are well recognized. However, the increasing need for greater biogas production and a final cake product of higher dry solids resulted in a surge of advanced digestion process such as the thermal hydrolysis process coupled with mesophilic anaerobic digestion (THP/AD). In THP/AD the sludge is treated with steam to 180°C breaking down lipids and complex proteins. This increases the biosolid dewaterability and the digester throughput and subsequently the biogas production. By accelerating the hydrolysis step, the ammonia concentration in the dewatering liquors increases from 800 mgN/L to >1,000 mgN/L. Additionally, it is thought that pure THP/AD dewatering liquors are causing inhibition to biological processes such as deammonification. Different deammonification technologies, using different biomass types and control philosophies were used to treat THP/AD dewatering liquors in different configurations. The different biomass types were suspended, granular and plastic media biofilm. The deammonification reactors achieved average nitrogen removal rates between 0.4 – 0.7 kgN/(m3.d) and inhibition of pure THP/AD dewatering liquors was not observed.
