钛对聚合硫酸铁制备与性能的影响

Effect of titanium on the preparation and coagulation efficiency of polyferric sulphate

研究了由FeSO4制备聚合硫酸铁过程中,钛对聚铁聚合态分布和稳定性的影响,并进一步考察了含钛聚合硫酸铁的絮凝性能.应用络合比色法对聚铁中不同水解形态聚铁的含量进行了分析测定,并通过沉淀实验考察了不同钛含量对聚铁稳定性的影响;随后,通过出水浊度、TOC、金属离子残余量和出水pH等指标测试,研究了钛对聚合硫酸铁混凝性能的影响.结果表明,较低的钛含量(<0.025)在一定程度上有利于中聚态聚铁的形成,提高了聚铁絮凝剂的混凝效率;反之,钛含量超过0.025时不仅聚铁的稳定性显著下降,而且处理后出水的钛残留增加,pH降低.

In this study,a series of polyferric sulphate flocculants（PFS） were prepared with different titanium contents with ferrous sulfate and H2O2.The influence of titanium on the species distribution and stability of PFS were investigated by a complexation absorbance method and a precipitation test.The results showed that titanium favored the formation of Fe（b） species but was unfavorable to the stability of PFS.The coagulation performance of PFS with different titanium contents for the removal of turbidity and TOC,the residue of Fe and Ti ions and pH changes in treated water was compared by batch experiments.The results showed that the titanium less than 0.025 was beneficial to the formation of Fe（b） species,thus improved the coagulation efficiency of PFS.On the other hand,more than 0.025 titanium not only decreased the stability of PFS,but also led to a high titanium residual and acidity in treated water.