Treating laundry wastewater, comprises releasing the wastewater occurring in laundry as undissolved and biologically biodegradable dissolved substances into biomembrane reactor, and intermediately storing reactor permeate in storage tank

摘要

The method comprises releasing laundry wastewater occurring in the laundry (10) as undissolved and biologically biodegradable dissolved substances into a biomembrane reactor (14), intermediately storing the permeate of the biomembrane reactor in a storage tank (15) as primary water, guiding a first partial stream of the primary water stored in the storage tank through a cleaning device, and feeding the permeate of the cleaning device to a mixing water tank and then mixing with a second partial stream of the primary water stored in the storage tank in a predetermined mixing ratio. The method comprises releasing laundry wastewater occurring in the laundry (10) as undissolved and biologically biodegradable dissolved substances into a biomembrane reactor (14), intermediately storing the permeate of the biomembrane reactor in a storage tank (15) as primary water, guiding a first partial stream of the primary water stored in the storage tank through a cleaning device, feeding the permeate of the cleaning device to a mixing water tank and then mixing with a second partial stream of the primary water stored in the storage tank in a predetermined mixing ratio, and subsequently recirculating the mixing water for laundry. A characteristic value of both secondary water and the primary water is detected and the characteristic value is transmitted to a control unit (20), in which the predetermined mixing ratio is calculated on the basis of the characteristic value, where the predetermined mixing ratio is set in the mixing water tank. The characteristic value is an electrical conductivity of the water. The mixing ratio of the water quantity of the secondary water to the water quantity of the second partial stream of the primary water is 2.0. The percentage portion (A) of the secondary water calculates itself in the mixing water to A[%]=(L(T 2)-L(SOLL))x 100/(L(T 2)-L(T 3)), where L(T 2) is the electrical conductivity of the primary water and the second partial stream present in the storage tank, L(T 3) is the electrical conductivity of the secondary water, L(SOLL) is a predetermined target value of the electrical conductivity of the mixing water and the target value of the L(SOLL) is 550 mu S/cm. The mixing water, primary water and/or the secondary water are disinfected. The secondary water is initially produced and is conveyed into the evacuated mixing water tank. The quantity of the primary water calculated from the control unit is conveyed from the storage tank into the mixing water tank. The mixing eater is mixed in the mixing water tank using a stirring device.