Perchlorate degradation using aqueous titanium ions produced by oxidative dissolution of zero-valent titanium

In this work, a new method to rapidly degrade perchlorate using aqueous Ti(II) as the reductant has been developed. To investigate the fundamental chemistry of Ti(II), the basic characteristics of Ti(II) solutions were examined and methods to optimize its production were developed. Then, its ability to reduce perchlorate was evaluated and a kinetic model was proposed to predict the rate of perchlorate reduction. Low pH is needed to produce Ti(II) from Ti(0) and the amounts produced using HCl and H2SO4 increased as the concentration of Ti(0) increased. Kinetic data show that HCl was more effective than H2SO4 in promoting the ability of those solutions to degrade perchlorate, possibly by producing lower pH. Higher concentrations of Ti(0) produced higher concentrations of Ti(II), which resulted in more rapid perchlorate destruction.

► The amounts of Ti(II) produced using HCl and H2SO4 are similar.
► HCl is more effective than H2SO4 in promoting the ability of Ti(II) to degrade perchlorate.
► Reaction rate constants for perchlorate reduction by Ti(II) increased with HCl concentrations.