Fig. 1From: Trace element and temperature effects on microbial communities and links to biogas digester performance at high ammonia levelsMethane production and hydrogen partial pressure after feeding of the continuous laboratory-scale digesters. The kinetics of methane production in the anaerobic digesters was estimated after a 20, b 160 and c 311 days of operation, in order to represent operating period 1, 2 and 3, respectively. The relative hydrogen partial pressure in the digesters was analysed on days b 160 and c 311Back to article page