Abstract: The invention relates to a method and a system for purifying process water, particularly for continuously purifying process water in the paper industry. The method comprises at least one process water treatment step, which comprises the following steps: a) an anaerobic purifying step, wherein process water to be purified is brought in contact with anaerobic microorganisms in an anaerobic reactor in order to decompose impurities present in the waste water, b) a first separating step, wherein gases present in the process water obtained in step a) are separated from said process water, and c) a second separating step, wherein solids present in the process water obtained in step b) are separated from the process water.

Abstract: The invention relates to a method and a system for purifying process water, particularly for continuously purifying process water in the paper industry. The method comprises at least one process water treatment step, which comprises the following steps: a) an anaerobic purifying step, wherein process water to be purified is brought in contact with anaerobic microorganisms in an anaerobic reactor in order to decompose impurities present in the waste water, b) a first separating step, wherein gases present in the process water obtained in step a) are separated from said process water, and c) a second separating step, wherein solids present in the process water obtained in step b) are separated from the process water.

Abstract: The invention relates to a device and a method for chemically and physically separating solid materials from a suspension using flotation. A rotationally symmetrical flocculation/flow reactor is provided with outlets in the lower part thereof and is arranged in a separating tank. At least one suspension inlet extends eccentrically into said reactor. The supplied suspension is guided into said reactor. The supplied suspension is guided into the upper area of the flocculation reactor via the suspension inlet. A circular flow is thus created which drains off from the flocculation reactor downwards in a tangential and radial manner over the outer circumference into circularly arranged distribution cells which reinforce the tangential component of the suspension flow when said flow is delivered into the separating tank. In prior art, the flow of the mixture consisting of the suspension and air-sacs extends radially outwards.