Effects of ammonia on hydrolysis of proteins and lipids from fish residues.
This study investigated the influence of ammonia on the hydrolysis rates of proteins and lipids in fish residues under mesophilic anaerobic incubation at a neutral pH. The hydrolysis kinetics of the fish residues, which contained primarily proteins and lipids, were examined at initial ammonia concentrations of 0-16 g N l(-1). Carbon hydrolysis was suppressed more by ammonium in the acidogenesis phase than in the acidogenesis/methanogenesis period of a single-stage anaerobic digestion. Conversely, hydrolysis of compounds containing nitrogen was similarly suppressed by ammonia during acidogenesis and acidogenesis/methanogenesis phases of a single-stage anaerobic digestion. Parameter uncertainty analysis demonstrated that the proteins fraction in the fish residues was entirely biodegradable. Model fitting demonstrated that two fractions of lipid substrates exist, namely, easy and hard to biodegrade with hydrolysis rates that were affected differently by ammonia content.
Lü
Fan
F
State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, 1239 Siping Road, Shanghai, 200092, Peoples Republic of China.
He
Pin-Jing
PJ
Shao
Li-Ming
LM
Lee
Duu-Jong
DJ
D000641:Ammonia / Q000378:metabolism*; D000818:Animals; D005399:Fishes / Q000378:metabolism*; D006868:Hydrolysis; D050356:Lipid Metabolism; D011506:Proteins / Q000378:metabolism*
D011506:Proteins; D000641:Ammonia