Study On Inorganic Polymeric Flocculant Titanium-based (Ti-IPF) Synthesis, Structure And Coagulation Performance

In this work, According to a new type of inorganic polymer, poly-silicic titanium sulfate (PTSS), a variety of new inorganic polymeric flocculant titanium-based(Ti-IPF) were prepared by co-polymerization. Poly-silicic titanium-aluminum sulfate(PTAS) and poly-silicic titanium-iron sulfate(PTFS) were selected by industrial applications, The results showed that when the molar ratio of n(Ti+Al):n(Si) or n(Ti +Fe):n(Si) equal to 0.3, the molar ratio of n(Ti):n(Al) or n(Ti):n(Fe) equal to 0.2, the flocculants PTAS and PTFS were optimal.Bonding mechanism of optimal PTSS, PTAS, PTFS was probed by XRD, IR, UV/Vis measurement. The analysis results shows that the framework titanium structure, Ti-O-Si was existed in PTSS, PTAS and PTFS. The flocculant PTSS possessed long-chain branched structure and big molecular weight, which was composed of the framework titanium structure Ti-O-Si and poly silicate bonded. In the strcture of optimal flocculants PTAS and PTFS,the silicon of Si-O-Si was replaced by metal ions, such as titanium ions, iron ions, and aluminum ions, or poly-hydroxy adsorption which was formed by metal ions hydrolysis, the molecular weight was larger than the poly-silicic acid. Then, the particle size in the polymerization process and the Zeta potential of the optimal PTSS, PTAS and PTFS were investigated, thereby conjectures that the coagulation mechanism of PTSS was mainly chain bridging, sweeping and surface poly-hydroxy adsorption. The coagulation mechanism of PTAS and PTFS were mainly adsorption-charge neutralization and the surface poly-hydroxy adsorption, other mechanisms play a supporting roles, such as the chain bridging, sweeping, and so on.The optimal PTSS, PTAS and PTFS were used to treat simulation river water, emulsified oil wastewater and phosphating wastewater, coagulation experiments show that turbidity removal rate reached 99.8%, when the initial pH value of simulation river water was 5.26 to 9.32, the dosage of PTAS and PTFS were respectively 0.3 millimoles percent litre. when the initial pH value of emulsified oil wastewater was 7.15, the dosage of PTAS and PTFS was 0.4 millimoles percent litre, of emulsified oil wastewater turbidity removal rates were respectively 92.5% and 99.8%, the removal rate of CODCr were respectively 99.6% and 99.3%. The pH value of phosphating wastewater increased to 10.18 by neutralization of lime and coagulate of PTFS, the removal rate of phosphorus reached 99.8%.