Abstract A granular carrier is contacted in a reaction space with a continuous stream of liquid which contains a sufficiently wide flora of microorganisms and sufficient nutrients for the growth and /or preservation of the microorganisms until a sufficiently thick layer of microorganisms is attached to the carrier, while in the liquid 0.1-1.5 kW of mechanical energy per m<3> of reactor liquid, is dissipated at least partly in the form of gas bubbling through the liquid and the residence time of the liquid in the reaction space is kept lower than the reciprocal maximum growth rate of the microorganisms. More preferably an aerobic biomass attached to a carrier is produced, by applying liquids, wherein the growth rate is not limited by the concentration of nutrients and by adjusting a residence time of the liquid in the reactor of below 45 minutes.
<??>The process can be applied for the production of all kinds of biomass attached to a carrier, e.g. biomasses as are applied in the biological purification of waste-water, aerobic biomass, anaerobic biomass, nitrificating biomass and denitrificating biomass, as well as biomasses forming a desired metabolic product which inhibits its own production rate at higher concentrations, e.g. biomass for the production of alcohol.
Process for producing biomass attached to a carrier, wherein in a reaction space a granular carrier is contacted with a continuous stream of liquid which contains a sufficiently wide flora of micro-organisms and sufficient nutrients for the growth and/or preservation of the micro-organisms until a sufficiently thick layer of micro-organisms is attached to the carrier, characterized in that, the carrier is contacted with the liquid stream while in the liquid 0.1-1.5 kW of mechanical energy per m 3 of reactor liquid, is dissipated at least partly in the form of gas bubbling through the liquid, and the residence time of the liquid in the reaction space is kept lover than the reciprocal maximum growth rate of the micro-organisms.
Claim 2
Dependent Claim
118 words
Process for producing biomass attached to a carrier, wherein in a reaction space a granular carrier is contacted with a continuous stream of liquid which contains a sufficiently wide flora of micro-organisms and sufficient nutrients for the growth and/or preservation of the micro-organisms until a sufficiently thick layer of micro-organisms is attached to the carrier, characterized in that, the carrier is contacted with the liquid stream while in the liquid 0.1-1.5 kW of mechanical energy per m 3 of reactor liquid, is dissipated at least partly in the form of gas bubbling through the liquid, and the residence time of the liquid in the reaction space is kept lover than the reciprocal maximum growth rate of the micro-organisms.
Claim 3
Dependent Claim
48 words
Process according to claim 1, characterized in that, in the production of an aerobic biomass attached to a carrier, while applying liquids wherein the growth rate is not limited by the concentration of nutrients, the residence time of the liquid in the reactor is adjusted below 45 minutes.
Claim 4
Dependent Claim
25 words
Process according to claim 2, characterized in that, at a temperature of the reactor contents of 30-50°C the residence time is at most 30 minutes.
Claim 5
Dependent Claim
34 words
Process according to claim 1, characterized in that, in the production of anaerobic biomass attached to a carrier the residence time of the liquid in the reactor is between 1 h and 4 h.
Claim 6
Dependent Claim
23 words
Process according to claim 4, characterized in that, at a temperature of the reactor contents of 30-50°C the residence time is 2-3 h.
Claim 7
Dependent Claim
49 words
Process according to claim 1-5, characterized in that, in the production of an aerobic biomass attached to a carrier at least such an amount of air and/or oxygen is introduced, that per kg COD coming in the reactor space, 0.8-1.6 kg of oxygen is transferred to the reactor liquid.