采用孔径为4nm的陶瓷膜去除水中的Ca2+,考察了不同Ca2+含量、跨膜压差、溶液pH和温度对陶瓷膜渗透通量和Ca2+截留率随时间的变化情况。结果表明,溶液中的Ca2+含量越低,膜渗透通量越高,Ca2+截留率也越高;跨膜压差升高,膜渗透通量增大,Ca2+截留率降低;降低溶液pH及升高温度能够提高膜渗透通量及对Ca2+的截留率。对Ca2+的质量浓度为10mg/L的水溶液,在TMP为0.1MPa、溶液pH为3、温度为50℃时、孔径为4nm陶瓷膜渗透通量稳定在80L/(m2·h),Ca2+截留率为85%左右。研究结果可为金属离子微污染水的净化提供方法。
The ceramic membrane with pore size of 4 nm was used to remove the calcium in the water to reduce the hardness.The filtration flux and rejection rate of calcium ion were studied under the conditions of different calcium ion concentration,trans-membrane pressure,solution pH and temperature.The results showed that,the lower the calcium ion concentration in the solution,the higher the membrane filtration flux and the higher the rejection rate of the calcium ion.With the increase of TMP,the permeate flux decreased and the rejection rate of calcium ion decreased.Increasing temperature and decreasing solution pH could improve the membrane filtration flux and the retention rate of calcium ion.For the calcium ion solution with concentration of 10 mg/L,the TMP with 0.1 MPa,solution pH with 3 and temperature with 50 ℃,the permeate flux of ceramic membrane with pore size of 4 nm could reach 80 L/(m 2.h),the rejection rate of calcium ion could reach 85%.This study provided a method of purification for micro-polluted water by metal ions.