Abstract: Unsymmetrical dimethylhydrazine (UDMH) is the main fuel for missile, satellite and spacecraft launch tests as well as carrier rockets. Its production wastewater contains high concentrations of salt, alkali and UDMH. Direct discharge of the UDMH wastewater can cause water and soil pollution, seriously endangering human health. Therefore, this paper designed a kind of “electrodialysis + reverse osmosis” double membrane processes for recycling treatment of the high salinity UDMH wastewater. Firstly, the electrodialysis (ED) process was used to remove the impunities of salt and base in the wastewater, and then the reverse osmosis (RO) process was carried out to further concentrate the desalinated wastewater for the highly purified recovery of UDMH. Meanwhile, the influences of ion exchange membrane, operating voltage and feed liquid flow rate on desalination process of ED were investigated, and the concentration technique of reverse osmosis process was also optimized. The research results showed that the electrodialysis process can remove 98.6% of NaCl and base (NaOH, ect.), the loss rate of UDMH was less than 13.5%, the current efficiency can reach 53.1%, and the process energy consumption was about 1.02 kW.h.kg-1. The concentration of UDMH was concentrated from 1.12g/L to 6.261g/L, and the concentration ratio of UDMH was about 5.59 times, which met the reuse requirement of UDMH.

Key words: High-salinity unsymmetrical dimethyl wastewater, “Electrodialysis + reverse” double membrane processes, Recycling treatment, Highly purified recovery of UDMH