High-concentration wastewater zero-discharging method

The invention relates to the field of industrial wastewater treatment, in particular to a high-concentration wastewater zero-discharging method. Accoridng to the method, a 'nanofiltration + efficient reverse osmosis + membrane distillation + evaporative crystallization' method is adopted to treat high-concentration wastewater. Firstly, nanofiltration is adopted to remove hardness, multivalent ions and parts of organic matter in the high-concentration wastewater so as to obtain nanofiltration producing water and nanofiltration concentrated water, then an efficient reverse osmosis technology is adopted to conduct deep concentration treatment on the nanofiltration producing water, deep concentration treatment is conducted on the obtained efficient reverse osmosis concentrated water through membrane distillation to obtain membrane-distillation concentrated water, further evaporative crystallization treatment is performed to enable salt solids in the membrane-distillation concentrated water to crystallize out, and centralized drying disposal is performed, wherein salt is added into the nanofiltration concentrated water to perform precipitation treatment so as to obtain calcium residues, supernate obtained after precipitation is subjected to activated carbon adsorption and then is mixed with the high-concentration wastewater, and the mixed liquid is fed into a nanofiltration unit for circular treatment. By means of the high-concentration wastewater zero-discharging method, water resources are recycled to the most degree while the problem of high-concentration wastewater discharging is solved, and zero discharging of high-concentration wastewater is basically achieved.