ABSTRACT
Acknowledgments ............................................................................................................... 77
References ........................................................................................................................... 78
Iron and manganese are the first and third most abundant transition metals on the Earth’s
crust (5.6 104 ppm and 9.5 102 ppm, respectively) [1]. The redox chemistries of iron II-III and manganese II-IV have important roles and impacts in the environment [2-5]. In contrast,
the second most abundant transition metal, titanium (5.7 103 ppm), occurs only in the IV oxidation state. Abundant crustal aluminosilicates, such as clays and quartz, also lack a
dynamic redox chemistry in natural waters [6].
