壳聚糖助凝对PAC混凝过程的影响

Influence of chitosan coagulat aid on the coagulation process of polyaluminum chloride

以聚合氯化铝(PAC)为絮凝剂,壳聚糖(CTS)为助凝剂在Taylor-Couette反应器中进行混凝实验.采用粒子成像速度场仪(PIV)研究了不同内筒转速(水力学条件)下CTS助凝对PAC混凝过程中絮体形态和浊度的影响.结果表明,添加CTS后,相应的混凝效果都得到提高,但与单独使用PAC时产生的变化趋势一致,说明适宜的化学条件下,水力条件是制约混凝效果的关键因素;且添加助凝剂有助于降低混凝过程对流体力学条件的依赖性,提高混凝的稳定性.

The coagulating experiment with polyaluminum chloride（PAC） used as coagulant and chitosan（CTS） used as coagulant aid was carried out in Taylor-Couette reactor. The influence of the rotation speed of the inner cylinder（hydraulic condition） on the floc form and removal of turbidity were studied by particle image velocimetry（PIV）. The results indicated that the effect of the coagulation with PAC was improved obviously after CTS was added, and its change tendency was consistent with that of adding PAC only. It was improved that hydraulic conditions is the key restricting factor of the coagulation efficiency; and adding coagulant aid is helpful to reduce the dependence on the hydraulic condition and improve the stability of coagulation process.