The invention is applicable to the technical field of removal of
sodium sulfate in
saline water, and provides a novel method for efficiently removing
sulfate radicals in a
sodium chloride system, which specifically comprises the following steps: firstly, taking the
saline water with the
sodium chloride concentration of 200-220g / L and the
sodium sulfate concentration of 30-80g / L, then adding pure water, diluting the
saline water until the sodium
chloride concentration is 100-110g / L and the
sodium sulfate concentration is 15-40g / L, and then adding the pure water into the
saline water until the sodium chloride concentration is 100-110g / L and the
sodium sulfate concentration is 15-40g / L; then the diluted
saline water is fed into a
nanofiltration membrane set, penetrating fluid and concentrated liquid are separated out through the
nanofiltration membrane set, the penetrating fluid is fed into the next procedure, the concentration of sodium chloride in the produced concentrated liquid is 100-110 g / L, and the concentration of sodium
sulfate in the produced concentrated liquid is 100-200 g / L. On the basis of an existing technology for removing
sulfate radicals from chlor-alkali through a
saline water membrane
separation method,
secondary treatment of the concentrated solution through the membrane
separation method is achieved through the advanced concept technology, the recycling rate of sodium chloride in light salt brine after
electrolysis is increased, the concentration of the
sulfate radicals in the concentrated solution is increased, the treatment cost of the concentrated solution is reduced, and the purposes of reducing cost and improving efficiency are achieved.