Abstract: A method for treating an aqueous fluid containing a biodegradable organic substance in an installation that includes an upflow bioreactor containing a sludge bed, wherein the sludge bed includes biomass, an external separator, and a conditioning tank. The method includes treating the fluid in the conditioning tank; feeding the treated fluid into a lower part of the bioreactor and forming biogas; withdrawing the fluid from an upper part of the bioreactor, which withdrawn fluid includes biomass; feeding the aqueous fluid withdrawn from the upper part of the bioreactor into the external separator, wherein the aqueous fluid that includes the biomass is separated into a liquid phase and a fluid phase enriched in biomass; returning the fluid phase enriched in biomass from the external separator to the bioreactor; and returning a part of the liquid phase to the conditioning tank.

Abstract: A method for treating an aqueous fluid comprising a biodegradable organic substance in an installation comprising an upflow bioreactor containing a sludge bed, said sludge bed comprising biomass, an external separator, and a conditioning tank, the method comprising: treating the fluid in the conditioning tank; feeding the treated fluid into a lower part of the bioreactor and forming biogas; withdrawing the fluid from an upper part of the bioreactor, which withdrawn fluid comprises biomass; feeding the aqueous fluid withdrawn from the upper part of the bioreactor into the external separator wherein the aqueous fluid comprising the biomass is separated into a liquid phase, and a fluid phase enriched in biomass; returning said fluid phase enriched in biomass from the external separator to the bioreactor; and returning a part of said liquid phase to the conditioning tank.

Abstract: The invention relates to a method for treating an aqueous fluid comprising a biodegradable organic substance in an installation comprising an upflow bioreactor containing a sludge bed, said sludge bed comprising biomass, an external separator, and a conditioning tank, comprising treating the fluid in the conditioning tank; feeding the treated fluid into a lower part of the bioreactor and forming biogas; withdrawing the fluid from an upper part of the bioreactor, which withdrawn fluid comprises biomass; feeding the aqueous fluid withdrawn from the upper part of the bioreactor into the external separator wherein the aqueous fluid comprising the biomass is separated into a liquid phase, and a fluid phase enriched in biomass; returning said fluid phase enriched in biomass from the external separator to the bioreactor; and returning a part of said liquid phase to the conditioning tank.

Abstract: The invention is directed to a process for the anaerobic purification of waste water using a sludge bed system, which process comprises feeding waste water and recycle water to the lower part of an upflow reactor containing mainly granular biomass thus producing biogas in the treatment passing the resulting gas/liquid/solid mixture upward and separating the gas and solid from the liquid in a three phase separator and thereby generating an anaerobic effluent that is withdrawn from the top of the separator, the improvement comprising withdrawing the recycle water separately from the effluent, after the separation of the gas from the liquid, either from the three phase separator or from the top of the reactor outside the three phase separator, and to an upflow reactor suitable for this process.

Abstract: The invention is directed to a process for the anaerobic purification of waste water using a sludge bed system, which process comprises feeding waste water and recycle water to the lower part of an upflow reactor containing mainly granular biomass thus producing biogas in the treatment passing the resulting gas/liquid/solid mixture upward and separating the gas and solid from the liquid in a three phase separator and thereby generating an anaerobic effluent that is withdrawn from the top of the separator, the improvement comprising withdrawing the recycle water separately from the effluent, after the separation of the gas from the liquid, either from the three phase separator or from the top of the reactor outside the three phase separator, and to an upflow reactor suitable for this process.