聚电解质强化超滤技术处理钨(Ⅵ)

Treatment of Tungsten(VI) in Aqueous Solution with Polymer-enhanced Ultrafiltration

以聚季铵盐-6(PQ6)强化超滤技术处理钨(VI),考察了渗滤对PQ6预处理的影响.结果表明,随渗滤体积增加PQ6截留系数逐渐增大到1,PQ6损失率为12.7%,膜通量(J)轻微增大.研究了PQ6与金属质量比r和pH值对钨截留系数(RW)和J的影响,当r从1增大到3,RW线性递增,此后趋于1,PQ6对钨(VI)的络合容量[PQ6/钨(VI)]为3.0mg/mg;当pH值从3增大到9时,RW基本不变;J随r增大略有下降,但不随pH值变化.在r=3和pH=7的条件下,当体积浓缩因子为16时,J下降15.2%,RW接近1,截留液钨浓度从20mg/L增大到317.5mg/L,渗透液钨浓度约为0.04mg/L,钨(VI)被有效浓缩.

Polymer-enhanced ultrafiltration process was investigated for treatment of tungsten（VI） in aqueous solution. Polyquaternium-6 （PQ6） was added as a water soluble polymer to bind selectively tungsten（VI）. The possibility of pre-treating PQ6 was tested by using the diafiltration method. The results showed that PQ6 rejection coefficient increased gradually with increasing of diafiltration volume, and then reached 1. The loss rate of PQ6 was 12.7%, and membrane flux （J） increased slightly in this pre-treatment process. The effects of polyelectrolyte/metal mass ratio （r） and pH value on tungsten（VI） rejection coefficient （RW） and J were studied. When r increased from 1 to 3, RW increased linearly. When r was above 3, RW was close to 1. The binding capacity of PQ6 with tungsten（VI） was 3.0 mg/mg. When pH value increased from 3 to 9, RW values obtained at different pH values were almost equal. J decreased slightly with increasing of r, and did not vary with pH value. The concentration experiment was carried out at r-3 and pH-7. The results showed that when volume concentration factor reached 16, J only declined 15.2%, and RW was about equal to 1. Tungsten（VI） concentration in the retentate increased from 20 to 317.5 mg/L, whereas its concentration in the permeate was always about 0.04 mg/L, i.e., tungsten（VI） was concentrated efficiently.