旋转盘剪切辅助络合-超滤处理含Cr3+废水

用旋转盘辅助络合-超滤技术处理含Cr³⁺废水, 研究了最佳操作条件及络合物的剪切稳定性。结果表明, 用聚丙烯酸钠(PAAS)作络合剂, pH=6.0, PAAS与金属质量浓度比为10时, Cr³⁺截留率达到99.5%。pH=6.0时, PAA-Cr络合物会在旋转盘转速超过1 600 r/min时解络, 其临界剪切速率为9.55×104 s^-1。通过剪切诱导解络法可以分离Cr³⁺与PAAS, 实现PAAS回收利用。实验结果可以指导络合-超滤技术的工业化应用。

Treatment of Cr3+-containing Wastewater with a Rotating Disk Assisted Complexation-Ultrafiltration Process

A process of complexation assisted with a rotating disk followed by ultrafiltration was adopted in the treatment of wastewater containing Cr³⁺, and the optimal operation conditions as well as the shear stability of the complex were studied. It is found that, with sodium polyacrylate (PAAS) as a complexing agent, reject rate of Cr³⁺ reached 99.5% at pH=6.0 and the mass concentration ratio of PAAS and metal at 10. Furthermore, the decomplexation of PAA-Cr complex was induced by a rotating disk with the rotating speed exceeding 1 600 r/min at pH=6.0, resulting in the critical shear rate of PAA-Cr complex at 9.55×10⁴s^-1. It is shown that decomplexation induced by shearing can result in Cr³⁺ separated from PAAS, and PAAS can be then recycled for the further utilization. All test results can be of guidance for an industrial application of such complexation-ultrafiltration process.