The invention belongs to the technology of
electrodialysis desalination, in particular to a low-cost
water treatment and recycling method for a high-
salinity gas field. The salt in the
wastewater andCOD
wastewater in the water of the high-
salinity gas field are separated through
electrodialysis; the salt easy to form a scale in the
wastewater is subjected to double
decomposition to form a solublesalt; the mixed salt in the wastewater is salted out and concentrated through monovalence and bivalence selective
electrodialysis; the
salt water extracted through the above method is further subjected to membrane distilling, mechanical steam recompression, or multiple-effect
evaporation, concentration and
crystallization to recycle the industrial salt, the COD in the extracted COD wastewater isfurther removed through a
biochemical process, and then the wastewater is recycled and discharged. In the process, that the salt recycled by directly using membrane distilling, mechanical steam recompression, or multiple-effect
evaporation, concentration and
crystallization cannot be sold due to high
organic content, can be avoided, the condition that the recycled salt is the mixed salt and becomes a
solid waste is avoided, and the defect that the
salinity is too high to affect the stable operation of a biochemical
system is also avoided. The method not only solves the problem of wastewater, but also recycles the water and the salt in the wastewater, and the application potential is huge.