机械搅拌/微滤组合工艺处理含锶废水

Treatment of Strontium-containing Wastewater by Mechanical Stir/Microfiltration Combined Process

以Na2CO3为沉淀剂、CaCO3为晶种,采用机械搅拌造粒/微滤组合工艺去除废水中锶元素,同时投加FeCl3以进一步提高去除效果。试验研究了造粒原水、Na2CO3投加量及温度对除锶效果的影响。结果显示:Na2CO3投加量的增加及温度的提高均有利于锶的去除,提高了去污因数(DF)。当Na2CO3投加量为2 g/L、温度为20℃、原水锶浓度为11.53 mg/L时,出水平均锶浓度为15.82μg/L,DF达到728,浓缩倍数(CF)达到1 540。试验产生的污泥体积较小,具有较好的应用前景。但Na2CO3投加量的提高会使出水pH值提高,加大后续处理难度,实际操作中应根据不同的处理要求选择合适的Na2CO3投量。

Mechanical stir granulation/microfihration combined process was used to remove stronti- um in wastewater when Na2CO3 and CaCO3 were used as precipitating agent and crystal seed, respective- ly. At the same time, the treatment effect could be further enhanced by adding FeCI3. The effects of granulation raw water, Na2CO3 dosage and temperature on the removal efficiency of strontium were inves- tigated. The results showed that the increase of Na2CO3 dosage and temperature were all advantageous to remove strontium and improve the decontamination factor （DF）. The strontium concentration in the efflu- ent was 15.82 μg/L, DF was 728, and CF was 1 540 when the NaECO3 dosage was 2 g/L, temperature was 20 ℃, and the average strontium concentration in the influent was 11.53 mg/L. The combined process has a high application prospect due to the small volume of sludge generated by the test. But the increase of NazCO3 dosage could result in increase of the effluent pH, which increased the difficulty of follow-up treatment. So, the appropriate dosage of Na2CO3 should be selected according to different treat- ment requirements in practice.