TY - JOUR
T1 - Enhancement of microbial density and methane production in advanced anaerobic digestion of secondary sewage sludge by continuous removal of ammonia
AU - Tao, Bing
AU - Donnelly, Joanne
AU - Oliveira, Ivo
AU - Anthony, Ruth
AU - Wilson, Victoria
AU - Esteves, Sandra R.
PY - 2017/5/1
Y1 - 2017/5/1
N2 - Ammonia inhibition mitigation in anaerobic digestion of high solids content of thermally hydrolysed secondary sewage sludge by the NH4+ affinitive clinoptilolite and a strong acid type ion-exchange resin S957 was investigated. Continuous NH4+-N removal was achieved through ion-exchanging at both temperatures with average removals of 50 and 70% for the clinoptilolite and resin dosed reactors, respectively. Approximate 0.2–0.5 unit of pH reduction was also observed in the dosed reactors. The synergy of NH4+-N removal and pH reduction exponentially decreased free NH3 concentration, from 600 to 90 mg/L at 43 °C, which mitigated ammonia inhibition and improved methane yields by approximately 54%. Microbial community profiling suggested that facilitated by ammonia removal, the improvement in methane production was mainly achieved through the doubling in bacterial density and a 6-fold increase in population of the Methanosarcinaceae family, which in turn improved the degradation of residual volatile fatty acids, proteins and carbohydrates.
AB - Ammonia inhibition mitigation in anaerobic digestion of high solids content of thermally hydrolysed secondary sewage sludge by the NH4+ affinitive clinoptilolite and a strong acid type ion-exchange resin S957 was investigated. Continuous NH4+-N removal was achieved through ion-exchanging at both temperatures with average removals of 50 and 70% for the clinoptilolite and resin dosed reactors, respectively. Approximate 0.2–0.5 unit of pH reduction was also observed in the dosed reactors. The synergy of NH4+-N removal and pH reduction exponentially decreased free NH3 concentration, from 600 to 90 mg/L at 43 °C, which mitigated ammonia inhibition and improved methane yields by approximately 54%. Microbial community profiling suggested that facilitated by ammonia removal, the improvement in methane production was mainly achieved through the doubling in bacterial density and a 6-fold increase in population of the Methanosarcinaceae family, which in turn improved the degradation of residual volatile fatty acids, proteins and carbohydrates.
KW - Advanced anaerobic digestion
KW - Ammonia inhibition
KW - Ion-exchange resin
KW - Zeolite
KW - Thermal hydrolysed secondary sewage sludge
KW - Bacteria and methanogens gene abundance
U2 - 10.1016/j.biortech.2017.02.066
DO - 10.1016/j.biortech.2017.02.066
M3 - Article
C2 - 28259068
SN - 0960-8524
VL - 232
SP - 380
EP - 388
JO - Bioresource Technology
JF - Bioresource Technology
ER -