Biological Nitrogen Removal Database
A manually curated data resource for microbial nitrogen removal
Biological Nitrogen Removal Database
A manually curated data resource for microbial nitrogen removal
Influent:Synthetic wastewater
Anammox system:nan
Anammox reactor:Membrane bioreactor (MBR)
Medium:nan
Culture taken from:Full-scale anammox internal circulation reactor of Dokhaven WWTP
Microorganism cultured:Candidatus Brocadia
Respiration:Anaerobic
Electron donor:Ammonium sulfate ((NH4)2SO4)
Electron acceptor:Sodium Nitrite (NaNO2)
PH:7
Maximum sludge concentration:4.47
HRT:2.45–11.83 d
NH4–N Influent conc(mg/L):20–30
NO2–N Influent conc(mg/L):20–30
SO4–S Influent conc(mg/L):nan
NH4–N Removal efficiency (%):nan
NO2–N Removal efficiency (%):nan
SO4-S Removal efficiency (%):nan
NLR kg-N/m3/d:nan
NRR kg-N/m3/d:nan
Major findings:In a MBR a fast-growing highly enriched anammox culture was obtained at 30°C. This culture was exposed to long- and short-term temperature fluctuations. Long-term cultivation at low temperatures resulted in a very strong decrease in growth rate, yield and biomass-specific activity. While short-term experiments showed a regular temperature response (activation energy (Ea) of 64?±?28?kJ?mol?1) the long-term temperature effect was very strong (Ea was 239?kJ?mol?1). To maintain an anammox culture in the membrane reactor, the SRT was increased at decreasing temperatures. This increase in SRT induced an increase in non-active anammox biomass and an increase in the side population, suggesting an indirect temperature effect of long-term cultivation at temperatures lower than 30°C.
Authors:Hoekstra et al., 2018
Title:Deterioration of the anammox process at decreasing temperatures and long SRTs
Pubmed link:Link
Full research link:Link
Abstract:The implementation of autotrophic nitrogen removal in the mainstream of a municipal wastewater treatment plant is currently pursued. Among the crucial unknown factors are the kinetic properties of anaerobic ammonium oxidising (anammox) bacteria at low temperatures. In this study we investigated the adaptation of a fast-growing anammox culture to a lower temperature. In a membrane bioreactor a highly enriched anammox community was obtained at 30°C, 25°C and 20°C. This culture was exposed to long- and short-term temperature changes. In short-term experiments the decrease in biomass-specific activity due to decrease in temperature can be described by an activation energy of 64 ± 28 kJ mol-1. Prolonged cultivation (months) implies that cultivation at low temperatures resulted in deterioration of biomass-specific activity (EaLT 239 kJ mol-1). The growth rate and specific anammox activity in the system decreased from 0.33 d-1 and 4.47 g NO2-N g VSS-1 d-1 at 30°C to 0.0011 d-1 and 0.037 g NO2-N g VSS-1 d-1 at 20°C. The reason for the deterioration of the system was related to the required long SRT in the system. The long SRT leads to an increase of non-active and non-anammox cells in the reactor, thereby decreasing the biomass-specific activity.