“…In aquatic ecosystems, the overall oxidation rate of Fe(II) can be accelerated at the presence of DOM, such as humic acids, moreover, the generated organic Fe(III) complexes may slow down the formation of iron colloids and stabilize Fe(III) in dissolved fraction in fresh waters (Pullin and Cabaniss, 2003;Henneberry et al, 2012). The interaction between Fe and DOM also provides a crucial sequence in various geochemical processes including the transportation of trace metals which is remarkably affected by the adsorption to surfaces of in-stream iron particles, affecting the fate of various heavy metals such as Pb, Cr, and As that are bound to the iron (oxy)hydroxides (Neubauer et al, 2013;Blake et al, 2015). The growth and agglomeration of iron (oxy)hydroxides will results in larger particles that deposit in the slow-flowing sections of streams, lakes, or estuaries (Karlsson and Persson, 2012).…”