气隙式膜蒸馏处理模拟放射性废水

对采用自制气隙式膜蒸馏装置净化处理质量浓度为1g/L Sr2+和离子质量浓度均为10g/L的Co2+、Sr2+、Na+、Ca2+四种离子混合模拟放射性废水进行了研究。结果表明:膜蒸馏技术对1g/L Sr2+料液中Sr2+截留率可以达到99.999%以上,去污系数(DF)在105以上;处理离子质量浓度均为10g/L的Co2+、Sr2+、Na+、Ca2+四种离子混合料液时,膜蒸馏对Sr2+、Co2+截留率均接近100%,DF(Sr2+)达1×106,DF(Co2+)达1×107;料液温度和料液流速对膜通量有一定影响,无论是提高料液温度,还是增加料液流速,均可以有效提高膜通量。在保证净化效果的情况下,在料液温度75℃,料液流速7L/min时,处理1g/L Sr2+膜通量可以达到4.15kg/(m2·h)。对离子质量浓度均为10g/L的Co2+、Sr2+、Na+、Ca2+四种离子混合料液进行处理时,膜通量也达到3.88kg/(m2·h)。

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.