陶瓷膜微滤-聚合物强化超滤处理高浓度含镍废水

Treatment of High Nickel Ion Content Wastewater by Ceramic Membrane Microfiltration and Polymer-enhanced Ultrafiltration

实验研究了0.5?m孔径陶瓷膜对高浓度含镍废水的微滤行为,以聚丙烯酸钠(PAAS)强化超滤技术深度处理陶瓷膜渗透液,考察了PAAS与金属质量比(rp/m)和p H值对恒容超滤膜通量(J)和镍截留系数(RNi)的影响,研究了超滤浓缩、解络合、洗涤及PAAS循环使用过程.结果表明,p H?9时,陶瓷膜浓缩时J先快速降低、缓慢下降后再较快降低,RNi接近1,当体积浓缩因子从1增大到10时,截留液镍浓度(Cr)从5 562.71 mg/L浓缩至55 507.76 mg/L,渗透液镍浓度(Cp)为13.26 mg/L.PAAS强化恒容超滤时,J不随rp/m变化,随p H值增大而增大,RNi随rp/m或p H值增大而增大;超滤浓缩时,控制p H?9和rp/m?9,RNi接近1,Cr呈线性递增,Cp?0.05 mg/L;在p H?3条件下对超滤浓缩液解络合,解离平衡时间为9 min,解络合率为81.9%;以p H?3的盐酸溶液洗涤解络合液,镍洗脱率为98.8%.再生PAAS络合性能良好,可循环使用.

The microfiltration process of wastewater containing high concentration of nickel ion was studied with a ceramic membrane of pore diameter 0.5 μm, and poly（acrylic acid） sodium（PAAS）-enhanced ultrafiltration used for advanced treatment of the permeation fluid of microfiltration process. The effects of mass ratio of PAAS to metal（rp/m） and p H value on membrane flux（J） and nickel rejection coefficient（RNi） were examined. Furthermore, ultrafiltration concentration, decomplexation, washing and reuse of PAAS were also studied. The results showed that in the process of microfiltration concentration, J decreased sharply first, then declined slowly, and finally decreased rapidly at p H 9. RNi was close to 1. When volume concentration factor increased from 1 to 10, nickel ion concentration in the retentate（Cr） increased from 5 562.71 to 55 507.76 mg/L, whereas nickel ion concentration in the permeate（Cp） remained about 13.26 mg/L. In the process of PAAS-enhanced ultrafiltration, J did not change with increasing of rp/m, and increased with p H value. RNiincreased with rp/m or p H value. The ultrafiltration concentration experiment was carried out at pH=9 and rp/m=9. RNi was close to 1. Crincreased linearly, whereas Cp remained about 0.05 mg/L. The decomplexation experiment was done at pH=3 with the previous concentrated solution. It took 9 min to reach the decomplexation equilibrium. The decomplexation rate of nickel（II）-PAAS complex reached 81.9%. The washing experiment was done with the hydrochloric acid solution of pH=3. Nickel ion removal rate of 98.8% was obtained. After the washing process, the regenerated PAAS was recycled, and still had a good complexation capacity.