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 optionally 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the gas and solid from the liquid in a three phase separator and thereby generating an anaerobic effluent that is withdrawn from the top of the separator, the improvement comprising separating the solids from the liquid in a separator, wherein, above the separation of the gas from the liquid phase, tilted plates, tubes or other tilted internals are installed in the three phase separator body to increase the effective settling surface, to an upflow reactor suitable for this process as well as to a three phase separator.

Abstract: The invention is directed to a process for the anaerobic purification of waste water in an anaerobic reactor, said process comprising burning the biogas produced in the purification, in a gas-burner, using the hot gases obtained thereby for indirect heating of water in a hot water boiler, which boiler is connected with the reactor by means of a line between the gas head of the boiler and a compartment through which the waste water flows, such as a conditioning tank or the anaerobic reactor, which line ends underneath the water level in the said compartment at such a level that a pressure of between 0.25 and 3 m of water column is maintained in the gas head of the boiler, in which boiler steam is generated which enters the said compartment through the said line and heats the waste water, and wherein the said boiler is further provided with a valve to let off steam in case the amount of biogas is in excess of the amount needed to heat the waste water.

Abstract: The invention is directed to a process for the anaerobic purification of waste water in an anaerobic reactor, said process comprising burning the biogas produced in the purification, in a gas-burner, using the hot gases obtained thereby for indirect heating of water in a hot water boiler, which boiler is connected with the reactor by means of a line between the gas head of the boiler and a compartment through which the waste water flows, such as a conditioning tank or the anaerobic reactor, which line ends underneath the water level in the said compartment at such a level that a pressure of between 0.25 and 3 m of water column is maintained in the gas head of the boiler, in which boiler steam is generated which enters the said compartment through the said line and heats the waste water, and wherein the said boiler is further provided with a valve to let off steam in case the amount of biogas is in excess of the amount needed to heat the waste water.

Abstract: The invention is directed to a process for the aerobic purification of waste water in a reactor containing unsupported granular active sludge. The oxygen necessary for maintaining aerobic conditions within the reactor is provided in the form of an oxygen-containing gas. The oxygen-containing gas is preferably introduced into the reactor at such a place that the oxygen-containing gas provides at least some mixing action in the reactor. The invention also provides a reactor suitable for this process.