Treatment of Simulated Radioactive Wastewater by Air Gap Membrane Distillation

Air gap membrane distillation was employed for the treatment of simulate radioactive wastewater including the simple ingredient, which contained only 1 g/L Sr²⁺, and the complex ingredient that mixed Co²⁺, Sr²⁺, Na⁺, Ca²⁺ with the mass concentration of 10 g/L, separately. The research results show that the desalination rates of Sr²⁺ in the simple ingredient of simulated radioactive wastewater achieve 99.999%, and the decontamination factor of which is more than 10⁵. The desalination rates of Sr²⁺ and Co²⁺ in the complex ingredient, which mixed Co²⁺, Sr²⁺, Na⁺, Ca²⁺, are all nearly 100%, and the decontamination factors of Sr²⁺ and Co²⁺ reach 1×10⁶ and 1×10⁷, separately. Enhancing the temperature and flow rate of feed can make contribution to an increase in the membrane flux, effectively. In the case that the temperature of feed is 75 ℃ and flow rate of feed is 7 L/min, the membrane fluxes are 4.15 kg/(m²•h) and 3.88 kg/(m²•h) for the simple ingredient and complex ingredient simulated radioactive wastewater, respectively. The results in this work suggest that the membrane distillation as a novel technology will play an important role in the treatment of radioactive wastewater.