Easily Prepared Titanium Phosphate-Based Composites for the Remediation of Synthetic and Real Wastewaters

Abstract

This study explored the remediation of polluted synthetic and real wastewaters by titanium oxyhydroxide/titanium phosphate (TTP) and TTP/active carbon (TTPC) composites. TTP materials were synthesized in mild conditions by hydrolyzing TiCl4 in a basic medium followed by the reaction with phosphoric acid. Analyses revealed that TTP is a nano-sized low crystalline material (average diameter of TTP ~ 6 nm) composed of 38.38% TiO(OH)2 and 59.89% titanium phosphate. The maximal removal capacities of TTP were achieved in the highly basic waters. They were measured to be 10.60 and 11.55 meq/g TTP with respect to Na and K ions, respectively. The removal capacities of the individual parts of TTP are estimated to be 7.68 and 3.83 meq/g for titanium oxyhydroxide and hydrogen titanium phosphate, respectively, with respect to K ion. At high pH values, all exchangeable protons in the hydrogen titanium phosphate and titanium oxyhydroxide participated in the removal processes. Data also revealed that supporting TTP on activated carbon enhanced its removal efficiency. The exposed surface area of supported TTP sample increased against the targeted cations during the removal experiments. Finally, full analysis of withdrawn real wastewater samples was conducted before and after their treatment using TTP materials. Both TTP and TTPC showed satisfied performance toward the removal of various metal ions and even against organic pollutants.