Impact of nickel and cobalt on biogas production and process stability during semi-continuous anaerobic fermentation of a model substrate for maize silage.

The importance of nickel and cobalt on anaerobic degradation of a defined model substrate for maize was demonstrated. Five semi-continuous reactors were operated for 250 days at 35 °C and a well-defined trace metal solution was added to all reactors. Two reactors each were limited regarding the concentration of Ni(2+) and Co(2+), respectively, for certain time intervals.