The invention relates to a method for treating
refined sugar ion-exchange waste liquid and belongs to the technical field of light
chemistry. The method comprises the steps that
refined sugar ion-exchange waste liquid is filtered with a sheet frame filtering
machine to remove suspended impurities, filter liquid enters a
nanofiltration device to be treated, and
permeation liquid and concentrated liquid are obtained, wherein the pH of the
refined sugar ion-exchange waste liquid is larger than 11, a
nanofiltration membrane in the
nanofiltration device is hydrophilic and is made of
polyamide, a 1812 roll type membrane
assembly is adopted for the nanofiltration membrane, the molecular weight
cut-off of the nanofiltration membrane is larger than 300 Da and smaller than 800 Da, and the maximum operation pressure of the nanofiltration device ranges from 2.0 MPa to 3.0 MPa. By means of the method, the purification recycling rate reaches 80% or above, and the
pigment interception reaches 98% or above;
permeation liquid passing through the membrane can be directly returned to the main process to be reused without treatment; as eluent obtained after regeneration mainly contains
sugar and salt, the eluent can be recycled into the main process without
contamination; meanwhile, the using amounts of a regeneration
reagent and washing water are greatly reduced, and
wastewater treatment pressure is relieved.