硫酸チタン (IV) による廃液中のリン酸の沈殿除去

The conditions of removal of phosphates from the different wastewater containing phosphate by addition of titanium (IV) sulfate with precipitation method were examined experimentally. As a result of experiment, it was found that about 100% phosphate was precipitated as an useful titanium phosphate from the wastewater by addition of two moles of titanium to one mole of phosphate and by adjustment of pH between 1.0 and 5.5. In the case of the wastewater containing heavy metals besides phosphate, it is desirable to set pH 1.0 as possible for removal of about 100% phosphate and for keeping the heavy metallic ions in the liquid phase successively. In the case of the wastewater containing fluoride and phosphate, it is necessary to adjust pH above 1.5 but the partial coprecipitation of fluoride is not avoidable. In the case of condenced phosphate, the phosphor was perfectly precipitated by addition of two moles of titanium to one mole of phosphor just as orthophosphates but pH must be adjusted between 1.5 and 3.0.