A study of titanium sulfate flocculation for water treatment

There are limited studies available on titanium salt flocculation. In this research, coagulation experiments of titanium sulfate were conducted using both distilled water and kaolin clay suspension. Results showed that titanium sulfate flocculation was most effective in the pH range 4–6, and negligible concentrations of titanium were found in the well-flocculated water. The floc isoelectric point (IEP) was found to be near pH 5. Measurements showed that the titanium flocs possessed greater density, diameter and settling velocity than the aluminum flocs. The titanium flocs were composed of TiO(OH)2, which would change from the amorphous phase into anatase titanium dioxide under elevated temperatures. Floc images showed the structural similarity of titanium and aluminum flocs. Laboratory results and a pilot experiment showed that titanium sulfate could be an alternative coagulant for water and wastewater treatment.

► The pH range of titanium sulfate flocculation was defined.
► Residual titanium concentration was measured.
► Isoelectric point, size, density and settling speed of titanium flocs were measured.
► Titanium flocs were characterized with SEM, TEM, TG, DSC, XRF and XRD.
► Pilot experiment of titanium sulfate flocculation was conducted.